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kc3-lang/automake/automake.in

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  • Author : Alexandre Duret-Lutz
    Date : 2002-09-22 14:35:19
    Hash : 749fdb7f
    Message : * automake.in (macro_define): Update a variable's location each time its owner is updated. * tests/gnuwarn.test: Append to CFLAGS to check for this. Reported by Harlan Stenn.

  • automake.in
  • #!@PERL@ -w
    # -*- perl -*-
    # @configure_input@
    
    eval 'case $# in 0) exec @PERL@ -S "$0";; *) exec @PERL@ -S "$0" "$@";; esac'
        if 0;
    
    # automake - create Makefile.in from Makefile.am
    # Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002
    # Free Software Foundation, Inc.
    
    # This program is free software; you can redistribute it and/or modify
    # it under the terms of the GNU General Public License as published by
    # the Free Software Foundation; either version 2, or (at your option)
    # any later version.
    
    # This program is distributed in the hope that it will be useful,
    # but WITHOUT ANY WARRANTY; without even the implied warranty of
    # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    # GNU General Public License for more details.
    
    # You should have received a copy of the GNU General Public License
    # along with this program; if not, write to the Free Software
    # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
    # 02111-1307, USA.
    
    # Originally written by David Mackenzie <djm@gnu.ai.mit.edu>.
    # Perl reimplementation by Tom Tromey <tromey@redhat.com>.
    
    package Language;
    
    BEGIN
    {
      my $perllibdir = $ENV{'perllibdir'} || '@datadir@/@PACKAGE@-@APIVERSION@';
      unshift @INC, $perllibdir;
    }
    
    use Automake::Struct;
    struct (# Short name of the language (c, f77...).
            'name' => "\$",
            # Nice name of the language (C, Fortran 77...).
            'Name' => "\$",
    
    	# List of configure variables which must be defined.
    	'config_vars' => '@',
    
            'ansi'    => "\$",
    	# `pure' is `1' or `'.  A `pure' language is one where, if
    	# all the files in a directory are of that language, then we
    	# do not require the C compiler or any code to call it.
    	'pure'   => "\$",
    
    	'autodep' => "\$",
    
    	# Name of the compiling variable (COMPILE).
            'compiler'  => "\$",
            # Content of the compiling variable.
            'compile'  => "\$",
            # Flag to require compilation without linking (-c).
            'compile_flag' => "\$",
            'extensions' => '@',
    	# A subroutine to compute a list of possible extensions of
    	# the product given the input extensions.
    	# (defaults to a subroutine which returns ('.$(OBJEXT)', '.lo'))
    	'output_extensions' => "\$",
    	# A list of flag variables used in 'compile'.
    	# (defaults to [])
            'flags' => "@",
    
    	# The file to use when generating rules for this language.
    	# The default is 'depend2'.
    	'rule_file' => "\$",
    
            # Name of the linking variable (LINK).
            'linker' => "\$",
            # Content of the linking variable.
            'link' => "\$",
    
            # Name of the linker variable (LD).
            'lder' => "\$",
            # Content of the linker variable ($(CC)).
            'ld' => "\$",
    
            # Flag to specify the output file (-o).
            'output_flag' => "\$",
            '_finish' => "\$",
    
    	# This is a subroutine which is called whenever we finally
    	# determine the context in which a source file will be
    	# compiled.
    	'_target_hook' => "\$");
    
    
    sub finish ($)
    {
      my ($self) = @_;
      if (defined $self->_finish)
        {
          &{$self->_finish} ();
        }
    }
    
    sub target_hook ($$$$)
    {
        my ($self) = @_;
        if (defined $self->_target_hook)
        {
    	&{$self->_target_hook} (@_);
        }
    }
    
    package Automake;
    
    use strict 'vars', 'subs';
    use Automake::General;
    use Automake::XFile;
    use Automake::Channels;
    use File::Basename;
    use Carp;
    
    ## ----------- ##
    ## Constants.  ##
    ## ----------- ##
    
    # Parameters set by configure.  Not to be changed.  NOTE: assign
    # VERSION as string so that eg version 0.30 will print correctly.
    my $VERSION = '@VERSION@';
    my $PACKAGE = '@PACKAGE@';
    my $libdir = '@datadir@/@PACKAGE@-@APIVERSION@';
    
    # Some regular expressions.  One reason to put them here is that it
    # makes indentation work better in Emacs.
    
    # Writting singled-quoted-$-terminated regexes is a pain because
    # perl-mode thinks of $' as the ${'} variable (intead of a $ followed
    # by a closing quote.  Letting perl-mode think the quote is not closed
    # leads to all sort of misindentations.  On the other hand, defining
    # regexes as double-quoted strings is far less readable.  So usually
    # we will write:
    #
    #  $REGEX = '^regex_value' . "\$";
    
    my $IGNORE_PATTERN = '^\s*##([^#\n].*)?\n';
    my $WHITE_PATTERN = '^\s*' . "\$";
    my $COMMENT_PATTERN = '^#';
    my $TARGET_PATTERN='[$a-zA-Z_.@%][-.a-zA-Z0-9_(){}/$+@%]*';
    # A rule has three parts: a list of targets, a list of dependencies,
    # and optionally actions.
    my $RULE_PATTERN =
      "^($TARGET_PATTERN(?:(?:\\\\\n|\\s)+$TARGET_PATTERN)*) *:([^=].*|)\$";
    
    my $SUFFIX_RULE_PATTERN =
        '^(\.[a-zA-Z0-9_(){}$+@]+)(\.[a-zA-Z0-9_(){}$+@]+)' . "\$";
    # Only recognize leading spaces, not leading tabs.  If we recognize
    # leading tabs here then we need to make the reader smarter, because
    # otherwise it will think rules like `foo=bar; \' are errors.
    my $MACRO_PATTERN = '^[.A-Za-z0-9_@]+' . "\$";
    my $ASSIGNMENT_PATTERN = '^ *([^ \t=:+]*)\s*([:+]?)=\s*(.*)' . "\$";
    # This pattern recognizes a Gnits version id and sets $1 if the
    # release is an alpha release.  We also allow a suffix which can be
    # used to extend the version number with a "fork" identifier.
    my $GNITS_VERSION_PATTERN = '\d+\.\d+([a-z]|\.\d+)?(-[A-Za-z0-9]+)?';
    
    my $IF_PATTERN = '^if\s+(!?)\s*([A-Za-z][A-Za-z0-9_]*)\s*(?:#.*)?' . "\$";
    my $ELSE_PATTERN =
      '^else(?:\s+(!?)\s*([A-Za-z][A-Za-z0-9_]*))?\s*(?:#.*)?' . "\$";
    my $ENDIF_PATTERN =
      '^endif(?:\s+(!?)\s*([A-Za-z][A-Za-z0-9_]*))?\s*(?:#.*)?' . "\$";
    my $PATH_PATTERN = '(\w|[/.-])+';
    # This will pass through anything not of the prescribed form.
    my $INCLUDE_PATTERN = ('^include\s+'
    		       . '((\$\(top_srcdir\)/' . $PATH_PATTERN . ')'
    		       . '|(\$\(srcdir\)/' . $PATH_PATTERN . ')'
    		       . '|([^/\$]' . $PATH_PATTERN . '))\s*(#.*)?' . "\$");
    
    # This handles substitution references like ${foo:.a=.b}.
    my $SUBST_REF_PATTERN = "^([^:]*):([^=]*)=(.*)\$";
    
    # Match `-d' as a command-line argument in a string.
    my $DASH_D_PATTERN = "(^|\\s)-d(\\s|\$)";
    # Directories installed during 'install-exec' phase.
    my $EXEC_DIR_PATTERN =
      '^(?:bin|sbin|libexec|sysconf|localstate|lib|pkglib|.*exec.*)' . "\$";
    
    # Constants to define the "strictness" level.
    use constant FOREIGN => 0;
    use constant GNU     => 1;
    use constant GNITS   => 2;
    
    # Values for AC_CANONICAL_*
    use constant AC_CANONICAL_HOST   => 1;
    use constant AC_CANONICAL_SYSTEM => 2;
    
    # Values indicating when something should be cleaned.
    use constant MOSTLY_CLEAN     => 0;
    use constant CLEAN            => 1;
    use constant DIST_CLEAN       => 2;
    use constant MAINTAINER_CLEAN => 3;
    
    # Libtool files.
    my @libtool_files = qw(ltmain.sh config.guess config.sub);
    # ltconfig appears here for compatibility with old versions of libtool.
    my @libtool_sometimes = qw(ltconfig ltcf-c.sh ltcf-cxx.sh ltcf-gcj.sh);
    
    # Commonly found files we look for and automatically include in
    # DISTFILES.
    my @common_files =
        (qw(ABOUT-GNU ABOUT-NLS AUTHORS BACKLOG COPYING COPYING.DOC COPYING.LIB
    	COPYING.LESSER ChangeLog INSTALL NEWS README THANKS TODO acinclude.m4
    	ansi2knr.1 ansi2knr.c compile config.guess config.rpath config.sub
    	configure configure.ac configure.in depcomp elisp-comp
    	install-sh libversion.in mdate-sh missing mkinstalldirs
    	py-compile texinfo.tex ylwrap),
         @libtool_files, @libtool_sometimes);
    
    # Commonly used files we auto-include, but only sometimes.
    my @common_sometimes =
        qw(aclocal.m4 acconfig.h config.h.top config.h.bot stamp-vti);
    
    # Standard directories from the GNU Coding Standards, and additional
    # pkg* directories from Automake.  Stored in a hash for fast member check.
    my %standard_prefix =
        map { $_ => 1 } (qw(bin data exec include info lib libexec lisp
    			localstate man man1 man2 man3 man4 man5 man6
    			man7 man8 man9 oldinclude pkgdatadir
    			pkgincludedir pkglibdir sbin sharedstate
    			sysconf));
    
    # Declare the macros that define known variables, so we can
    # hint the user if she try to use one of these variables.
    
    # Macros accessible via aclocal.
    my %am_macro_for_var =
      (
       ANSI2KNR => 'AM_C_PROTOTYPES',
       CCAS => 'AM_PROG_AS',
       CCASFLAGS => 'AM_PROG_AS',
       EMACS => 'AM_PATH_LISPDIR',
       GCJ => 'AM_PROG_GCJ',
       LEX => 'AM_PROG_LEX',
       LIBTOOL => 'AC_PROG_LIBTOOL',
       lispdir => 'AM_PATH_LISPDIR',
       pkgpyexecdir => 'AM_PATH_PYTHON',
       pkgpythondir => 'AM_PATH_PYTHON',
       pyexecdir => 'AM_PATH_PYTHON',
       PYTHON => 'AM_PATH_PYTHON',
       pythondir => 'AM_PATH_PYTHON',
       U => 'AM_C_PROTOTYPES',
       );
    
    # Macros shipped with Autoconf.
    my %ac_macro_for_var =
      (
       CC => 'AC_PROG_CC',
       CFLAGS => 'AC_PROG_CC',
       CXX => 'AC_PROG_CXX',
       CXXFLAGS => 'AC_PROG_CXX',
       F77 => 'AC_PROG_F77',
       F77FLAGS => 'AC_PROG_F77',
       RANLIB => 'AC_PROG_RANLIB',
       YACC => 'AC_PROG_YACC',
       );
    
    # Copyright on generated Makefile.ins.
    my $gen_copyright = "\
    # Copyright 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002
    # Free Software Foundation, Inc.
    # This Makefile.in is free software; the Free Software Foundation
    # gives unlimited permission to copy and/or distribute it,
    # with or without modifications, as long as this notice is preserved.
    
    # This program is distributed in the hope that it will be useful,
    # but WITHOUT ANY WARRANTY, to the extent permitted by law; without
    # even the implied warranty of MERCHANTABILITY or FITNESS FOR A
    # PARTICULAR PURPOSE.
    ";
    
    # These constants are returned by lang_*_rewrite functions.
    # LANG_SUBDIR means that the resulting object file should be in a
    # subdir if the source file is.  In this case the file name cannot
    # have `..' components.
    use constant LANG_IGNORE  => 0;
    use constant LANG_PROCESS => 1;
    use constant LANG_SUBDIR  => 2;
    
    # These are used when keeping track of whether an object can be built
    # by two different paths.
    use constant COMPILE_LIBTOOL  => 1;
    use constant COMPILE_ORDINARY => 2;
    
    
    
    ## ---------------------------------- ##
    ## Variables related to the options.  ##
    ## ---------------------------------- ##
    
    # TRUE if we should always generate Makefile.in.
    my $force_generation = 1;
    
    # Strictness level as set on command line.
    my $default_strictness = GNU;
    
    # Name of strictness level, as set on command line.
    my $default_strictness_name = 'gnu';
    
    # This is TRUE if automatic dependency generation code should be
    # included in generated Makefile.in.
    my $cmdline_use_dependencies = 1;
    
    # From the Perl manual.
    my $symlink_exists = (eval 'symlink ("", "");', $@ eq '');
    
    # TRUE if missing standard files should be installed.
    my $add_missing = 0;
    
    # TRUE if we should copy missing files; otherwise symlink if possible.
    my $copy_missing = 0;
    
    # TRUE if we should always update files that we know about.
    my $force_missing = 0;
    
    
    ## ---------------------------------------- ##
    ## Variables filled during files scanning.  ##
    ## ---------------------------------------- ##
    
    # Name of the top autoconf input: `configure.ac' or `configure.in'.
    my $configure_ac = '';
    
    # Files found by scanning configure.ac for LIBOBJS.
    my %libsources = ();
    
    # Names used in AC_CONFIG_HEADER call.
    my @config_headers = ();
    # Where AC_CONFIG_HEADER appears.
    my $config_header_location;
    
    # Directory where output files go.  Actually, output files are
    # relative to this directory.
    my $output_directory;
    
    # List of Makefile.am's to process, and their corresponding outputs.
    my @input_files = ();
    my %output_files = ();
    
    # Complete list of Makefile.am's that exist.
    my @configure_input_files = ();
    
    # List of files in AC_CONFIG_FILES/AC_OUTPUT without Makefile.am's,
    # and their outputs.
    my @other_input_files = ();
    # Where the last AC_CONFIG_FILES/AC_OUTPUT appears.
    my $ac_config_files_location;
    
    # List of directories to search for configure-required files.  This
    # can be set by AC_CONFIG_AUX_DIR.
    my @config_aux_path = qw(. .. ../..);
    my $config_aux_dir = '';
    my $config_aux_dir_set_in_configure_in = 0;
    
    # Whether AM_GNU_GETTEXT has been seen in configure.ac.
    my $seen_gettext = 0;
    # Whether AM_GNU_GETTEXT([external]) is used.
    my $seen_gettext_external = 0;
    # Where AM_GNU_GETTEXT appears.
    my $ac_gettext_location;
    
    # TRUE if we've seen AC_CANONICAL_(HOST|SYSTEM).
    my $seen_canonical = 0;
    my $canonical_location;
    
    # Where AM_MAINTAINER_MODE appears.
    my $seen_maint_mode;
    
    # Actual version we've seen.
    my $package_version = '';
    
    # Where version is defined.
    my $package_version_location;
    
    # TRUE if we've seen AC_ENABLE_MULTILIB.
    my $seen_multilib = 0;
    
    # TRUE if we've seen AM_PROG_CC_C_O
    my $seen_cc_c_o = 0;
    
    # Where AM_INIT_AUTOMAKE is called;
    my $seen_init_automake = 0;
    
    # TRUE if we've seen AM_AUTOMAKE_VERSION.
    my $seen_automake_version = 0;
    
    # Hash table of discovered configure substitutions.  Keys are names,
    # values are `FILE:LINE' strings which are used by error message
    # generation.
    my %configure_vars = ();
    
    # This is used to keep track of which variable definitions we are
    # scanning.  It is only used in certain limited ways, but it has to be
    # global.  It is declared just for documentation purposes.
    my %vars_scanned = ();
    
    # TRUE if --cygnus seen.
    my $cygnus_mode = 0;
    
    # Hash table of AM_CONDITIONAL variables seen in configure.
    my %configure_cond = ();
    
    # This maps extensions onto language names.
    my %extension_map = ();
    
    # List of the DIST_COMMON files we discovered while reading
    # configure.in
    my $configure_dist_common = '';
    
    # This maps languages names onto objects.
    my %languages = ();
    
    # List of targets we must always output.
    # FIXME: Complete, and remove falsely required targets.
    my %required_targets =
      (
       'all'          => 1,
       'dvi'	  => 1,
       'pdf'	  => 1,
       'ps'		  => 1,
       'info'	  => 1,
       'install-info' => 1,
       'install'      => 1,
       'install-data' => 1,
       'install-exec' => 1,
       'uninstall'    => 1,
    
       # FIXME: Not required, temporary hacks.
       # Well, actually they are sort of required: the -recursive
       # targets will run them anyway...
       'dvi-am'          => 1,
       'pdf-am'          => 1,
       'ps-am'           => 1,
       'info-am'         => 1,
       'install-data-am' => 1,
       'install-exec-am' => 1,
       'installcheck-am' => 1,
       'uninstall-am' => 1,
    
       'install-man' => 1,
      );
    
    # This is set to 1 when Automake needs to be run again.
    # (For instance, this happens when an auxiliary file such as
    # depcomp is added after the toplevel Makefile.in -- which
    # should distribute depcomp -- has been generated.)
    my $automake_needs_to_reprocess_all_files = 0;
    
    # Options set via AM_INIT_AUTOMAKE.
    my $global_options = '';
    
    # Same as $suffix_rules (declared below), but records only the
    # default rules supplied by the languages Automake supports.
    my $suffix_rules_default;
    
    # If a file name appears as a key in this hash, then it has already
    # been checked for.  This variable is local to the "require file"
    # functions.
    my %require_file_found = ();
    
    
    ################################################################
    
    ## ------------------------------------------ ##
    ## Variables reset by &initialize_per_input.  ##
    ## ------------------------------------------ ##
    
    # Basename and relative dir of the input file.
    my $am_file_name;
    my $am_relative_dir;
    
    # Same but wrt Makefile.in.
    my $in_file_name;
    my $relative_dir;
    
    # These two variables are used when generating each Makefile.in.
    # They hold the Makefile.in until it is ready to be printed.
    my $output_rules;
    my $output_vars;
    my $output_trailer;
    my $output_all;
    my $output_header;
    
    # Suffixes found during a run.
    my @suffixes;
    
    # Handling the variables.
    #
    # For a $VAR:
    # - $var_value{$VAR}{$COND} is its value associated to $COND,
    # - $var_location{$VAR}{$COND} is where it was defined,
    # - $var_comment{$VAR}{$COND} are the comments associated to it.
    # - $var_type{$VAR}{$COND} is how it has been defined (`', `+', or `:'),
    # - $var_owner{$VAR}{$COND} tells who owns the variable (VAR_AUTOMAKE,
    #     VAR_CONFIGURE, or VAR_MAKEFILE).
    my %var_value;
    my %var_location;
    my %var_comment;
    my %var_type;
    my %var_owner;
    # Possible values for var_owner.  Defined so that the owner of
    # a variable can only be increased (e.g Automake should not
    # override a configure or Makefile variable).
    use constant VAR_AUTOMAKE => 0; # Variable defined by Automake.
    use constant VAR_CONFIGURE => 1;# Variable defined in configure.ac.
    use constant VAR_MAKEFILE => 2; # Variable defined in Makefile.am.
    
    # This holds a 1 if a particular variable was examined.
    my %content_seen;
    
    # This holds the names which are targets.  These also appear in
    # %contents.  $targets{TARGET}{COND} is the location of the definition
    # of TARGET for condition COND.
    my %targets;
    
    # $target_source{TARGET}{COND} is the filename where TARGET
    # were defined for condition COND.  Note this must be a
    # filename, *without* any line number.
    my %target_source;
    
    # $target_owner{TARGET}{COND} the owner of TARGET in condition COND.
    my %target_owner;
    use constant TARGET_AUTOMAKE => 0; # Target defined by Automake.
    use constant TARGET_USER => 1;	# Target defined in the user's Makefile.am.
    
    # This is the conditional stack.
    my @cond_stack;
    
    # This holds the set of included files.
    my @include_stack;
    
    # This holds a list of directories which we must create at `dist'
    # time.  This is used in some strange scenarios involving weird
    # AC_OUTPUT commands.
    my %dist_dirs;
    
    # List of dependencies for the obvious targets.
    my @all;
    my @check;
    my @check_tests;
    
    # Holds the dependencies of targets which dependencies are factored.
    # Typically, `.PHONY' will appear in plenty of *.am files, but must
    # be output once.  Arguably all pure dependencies could be subject
    # to this factorization, but it is not unpleasant to have paragraphs
    # in Makefile: keeping related stuff altogether.
    my %dependencies;
    
    # Holds the factored actions.  Tied to %DEPENDENCIES, i.e., filled
    # only when keys exists in %DEPENDENCIES.
    my %actions;
    
    # Keys in this hash table are files to delete.  The associated
    # value tells when this should happen (MOSTLY_CLEAN, DIST_CLEAN, etc.)
    my %clean_files;
    
    # Keys in this hash table are object files or other files in
    # subdirectories which need to be removed.  This only holds files
    # which are created by compilations.  The value in the hash indicates
    # when the file should be removed.
    my %compile_clean_files;
    
    # Keys in this hash table are directories where we expect to build a
    # libtool object.  We use this information to decide what directories
    # to delete.
    my %libtool_clean_directories;
    
    # Value of `$(SOURCES)', used by tags.am.
    my @sources;
    # Sources which go in the distribution.
    my @dist_sources;
    
    # This hash maps object file names onto their corresponding source
    # file names.  This is used to ensure that each object is created
    # by a single source file.
    my %object_map;
    
    # This hash maps object file names onto an integer value representing
    # whether this object has been built via ordinary compilation or
    # libtool compilation (the COMPILE_* constants).
    my %object_compilation_map;
    
    
    # This keeps track of the directories for which we've already
    # created `.dirstamp' code.
    my %directory_map;
    
    # All .P files.
    my %dep_files;
    
    # Strictness levels.
    my $strictness;
    my $strictness_name;
    
    # Options from AUTOMAKE_OPTIONS.
    my %options;
    
    # Whether or not dependencies are handled.  Can be further changed
    # in handle_options.
    my $use_dependencies;
    
    # This is a list of all targets to run during "make dist".
    my @dist_targets;
    
    # Keys in this hash are the basenames of files which must depend on
    # ansi2knr.  Values are either the empty string, or the directory in
    # which the ANSI source file appears; the directory must have a
    # trailing `/'.
    my %de_ansi_files;
    
    # This maps the source extension for all suffix rule seen to
    # a \hash whose keys are the possible output extensions.
    #
    # Note that this is transitively closed by construction:
    # if we have
    #       exists $suffix_rules{$ext1}{$ext2}
    #    && exists $suffix_rules{$ext2}{$ext3}
    # then we also have
    #       exists $suffix_rules{$ext1}{$ext3}
    #
    # So it's easy to check whether '.foo' can be transformed to '.$(OBJEXT)'
    # by checking whether $suffix_rules{'.foo'}{'.$(OBJEXT)'} exist.  This
    # will work even if transforming '.foo' to '.$(OBJEXT)' involves a chain
    # of several suffix rules.
    #
    # The value of `$suffix_rules{$ext1}{$ext2}' is the a pair
    # `[ $next_sfx, $dist ]' where `$next_sfx' is target suffix
    # for the next rule to use to reach '$ext2', and `$dist' the
    # distance to `$ext2'.
    my $suffix_rules;
    
    # This is the name of the redirect `all' target to use.
    my $all_target;
    
    # This keeps track of which extensions we've seen (that we care
    # about).
    my %extension_seen;
    
    # This is random scratch space for the language finish functions.
    # Don't randomly overwrite it; examine other uses of keys first.
    my %language_scratch;
    
    # We keep track of which objects need special (per-executable)
    # handling on a per-language basis.
    my %lang_specific_files;
    
    # This is set when `handle_dist' has finished.  Once this happens,
    # we should no longer push on dist_common.
    my $handle_dist_run;
    
    # Used to store a set of linkers needed to generate the sources currently
    # under consideration.
    my %linkers_used;
    
    # True if we need `LINK' defined.  This is a hack.
    my $need_link;
    
    # This is the list of such variables to output.
    # FIXME: Might be useless actually.
    my @var_list;
    
    # Was get_object_extension run?
    # FIXME: This is a hack. a better switch should be found.
    my $get_object_extension_was_run;
    
    # Contains a stack of `from' parts of variable substitutions currently in
    # force.
    my @substfroms;
    
    # Contains a stack of `to' parts of variable substitutions currently in
    # force.
    my @substtos;
    
    # This keeps track of all variables defined by subobjname.
    # The value stored is the variable names.
    # The key has the form "(COND1)VAL1(COND2)VAL2..." where VAL1 and VAL2
    # are the values of the variable for condition COND1 and COND2.
    my %subobjvar = ();
    
    # This hash records helper variables used to implement '+=' in conditionals.
    # Keys have the form "VAR:CONDITIONS".  The value associated to a key is
    # the named of the helper variable used to append to VAR in CONDITIONS.
    my %appendvar = ();
    
    
    ## --------------------------------- ##
    ## Forward subroutine declarations.  ##
    ## --------------------------------- ##
    sub register_language (%);
    sub file_contents_internal ($$%);
    sub define_objects_from_sources ($$$$$$$);
    
    
    # &initialize_per_input ()
    # ------------------------
    # (Re)-Initialize per-Makefile.am variables.
    sub initialize_per_input ()
    {
        reset_local_duplicates ();
    
        $am_file_name = '';
        $am_relative_dir = '';
    
        $in_file_name = '';
        $relative_dir = '';
    
        $output_rules = '';
        $output_vars = '';
        $output_trailer = '';
        $output_all = '';
        $output_header = '';
    
        @suffixes = ();
    
        %var_value = ();
        %var_location = ();
        %var_comment = ();
        %var_type = ();
        %var_owner = ();
    
        %content_seen = ();
    
        %targets = ();
        %target_source = ();
        %target_owner = ();
    
        @cond_stack = ();
    
        @include_stack = ();
    
        %dist_dirs = ();
    
        @all = ();
        @check = ();
        @check_tests = ();
    
        %dependencies =
          (
           # Texinfoing.
           'dvi'      => [],
           'dvi-am'   => [],
           'pdf'      => [],
           'pdf-am'   => [],
           'ps'       => [],
           'ps-am'    => [],
           'info'     => [],
           'info-am'  => [],
    
           # Installing/uninstalling.
           'install-data-am'      => [],
           'install-exec-am'      => [],
           'uninstall-am'         => [],
    
           'install-man'	      => [],
           'uninstall-man'	      => [],
    
           'install-info'         => [],
           'install-info-am'      => [],
           'uninstall-info'       => [],
    
           'installcheck-am'      => [],
    
           # Cleaning.
           'clean-am'             => [],
           'mostlyclean-am'       => [],
           'maintainer-clean-am'  => [],
           'distclean-am'         => [],
           'clean'                => [],
           'mostlyclean'          => [],
           'maintainer-clean'     => [],
           'distclean'            => [],
    
           # Tarballing.
           'dist-all'             => [],
    
           # Phoning.
           '.PHONY'               => []
          );
        %actions = ();
    
        %clean_files = ();
    
        @sources = ();
        @dist_sources = ();
    
        %object_map = ();
        %object_compilation_map = ();
    
        %directory_map = ();
    
        %dep_files = ();
    
        $strictness = $default_strictness;
        $strictness_name = $default_strictness_name;
    
        %options = ();
    
        $use_dependencies = $cmdline_use_dependencies;
    
        @dist_targets = ();
    
        %de_ansi_files = ();
    
    
        # The first time we initialize the variables,
        # we save the value of $suffix_rules.
        if (defined $suffix_rules_default)
          {
    	$suffix_rules = $suffix_rules_default;
          }
        else
          {
    	$suffix_rules_default = $suffix_rules;
          }
    
        $all_target = '';
    
        %extension_seen = ();
    
        %language_scratch = ();
    
        %lang_specific_files = ();
    
        $handle_dist_run = 0;
    
        $need_link = 0;
    
        @var_list = ();
    
        $get_object_extension_was_run = 0;
    
        %compile_clean_files = ();
    
        # We always include `.'.  This isn't strictly correct.
        %libtool_clean_directories = ('.' => 1);
    
        %subobjvar = ();
    
        %appendvar = ();
    }
    
    
    ################################################################
    
    # Initialize our list of error/warning channels.
    # Do not forget to update &usage and the manual
    # if you add or change a warning channel.
    
    # Fatal errors.
    register_channel 'fatal', type => 'fatal';
    # Common errors.
    register_channel 'error', type => 'error';
    # Errors related to GNU Standards.
    register_channel 'error-gnu', type => 'error';
    # Errors related to GNU Standards that should be warnings in `foreign' mode.
    register_channel 'error-gnu/warn', type => 'error';
    # Errors related to GNITS Standards (silent by default).
    register_channel 'error-gnits', type => 'error', silent => 1;
    # Internal errors.
    register_channel 'automake', type => 'fatal', backtrace => 1,
      header => ("####################\n" .
    	     "## Internal Error ##\n" .
    	     "####################\n"),
      footer => "\nPlease contact <bug-automake\@gnu.org>.";
    
    # Warnings related to GNU Coding Standards.
    register_channel 'gnu', type => 'warning';
    # Warnings about obsolete features (silent by default).
    register_channel 'obsolete', type => 'warning', silent => 1;
    # Warnings about non-portable constructs.
    register_channel 'portability', type => 'warning', silent => 1;
    # Weird syntax, unused variables, typos...
    register_channel 'syntax', type => 'warning';
    # Warnings about unsupported (or mis-supported) features.
    register_channel 'unsupported', type => 'warning';
    
    # For &verb.
    register_channel 'verb', type => 'debug', silent => 1;
    # Informative messages.
    register_channel 'note', type => 'debug', silent => 0;
    
    
    # Initialize our list of languages that are internally supported.
    
    # C.
    register_language ('name' => 'c',
    		   'Name' => 'C',
    		   'config_vars' => ['CC'],
    		   'ansi' => 1,
    		   'autodep' => '',
    		   'flags' => ['CFLAGS', 'CPPFLAGS'],
    		   'compiler' => 'COMPILE',
    		   'compile' => '$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)',
    		   'lder' => 'CCLD',
    		   'ld' => '$(CC)',
    		   'linker' => 'LINK',
    		   'link' => '$(CCLD) $(AM_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@',
    		   'compile_flag' => '-c',
    		   'extensions' => ['.c'],
    		   '_finish' => \&lang_c_finish);
    
    # C++.
    register_language ('name' => 'cxx',
    		   'Name' => 'C++',
    		   'config_vars' => ['CXX'],
    		   'linker' => 'CXXLINK',
    		   'link' => '$(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@',
    		   'autodep' => 'CXX',
    		   'flags' => ['CXXFLAGS', 'CPPFLAGS'],
    		   'compile' => '$(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS)',
    		   'compiler' => 'CXXCOMPILE',
    		   'compile_flag' => '-c',
    		   'output_flag' => '-o',
    		   'lder' => 'CXXLD',
    		   'ld' => '$(CXX)',
    		   'pure' => 1,
    		   'extensions' => ['.c++', '.cc', '.cpp', '.cxx', '.C']);
    
    # Objective C.
    register_language ('name' => 'objc',
    		   'Name' => 'Objective C',
    		   'config_vars' => ['OBJC'],
    		   'linker' => 'OBJCLINK',,
     		   'link' => '$(OBJCLD) $(AM_OBJCFLAGS) $(OBJCFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@',
    		   'autodep' => 'OBJC',
    		   'flags' => ['OBJCFLAGS', 'CPPFLAGS'],
    		   'compile' => '$(OBJC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_OBJCFLAGS) $(OBJCFLAGS)',
    		   'compiler' => 'OBJCCOMPILE',
    		   'compile_flag' => '-c',
    		   'output_flag' => '-o',
    		   'lder' => 'OBJCLD',
    		   'ld' => '$(OBJC)',
    		   'pure' => 1,
    		   'extensions' => ['.m']);
    
    # Headers.
    register_language ('name' => 'header',
    		   'Name' => 'Header',
    		   'extensions' => ['.h', '.H', '.hxx', '.h++', '.hh',
    				    '.hpp', '.inc'],
    		   # No output.
    		   'output_extensions' => sub { return () },
    		   # Nothing to do.
    		   '_finish' => sub { });
    
    # Yacc (C & C++).
    register_language ('name' => 'yacc',
    		   'Name' => 'Yacc',
    		   'config_vars' => ['YACC'],
    		   'flags' => ['YFLAGS'],
    		   'compile' => '$(YACC) $(YFLAGS) $(AM_YFLAGS)',
    		   'compiler' => 'YACCCOMPILE',
    		   'extensions' => ['.y'],
    		   'output_extensions' => sub { (my $ext = $_[0]) =~ tr/y/c/;
    						return ($ext,) },
    		   'rule_file' => 'yacc',
    		   '_finish' => \&lang_yacc_finish,
    		   '_target_hook' => \&lang_yacc_target_hook);
    register_language ('name' => 'yaccxx',
    		   'Name' => 'Yacc (C++)',
    		   'config_vars' => ['YACC'],
    		   'rule_file' => 'yacc',
    		   'flags' => ['YFLAGS'],
    		   'compiler' => 'YACCCOMPILE',
    		   'compile' => '$(YACC) $(YFLAGS) $(AM_YFLAGS)',
    		   'extensions' => ['.y++', '.yy', '.yxx', '.ypp'],
    		   'output_extensions' => sub { (my $ext = $_[0]) =~ tr/y/c/;
    						return ($ext,) },
    		   '_finish' => \&lang_yacc_finish,
    		   '_target_hook' => \&lang_yacc_target_hook);
    
    # Lex (C & C++).
    register_language ('name' => 'lex',
    		   'Name' => 'Lex',
    		   'config_vars' => ['LEX'],
    		   'rule_file' => 'lex',
    		   'flags' => ['LFLAGS'],
    		   'compile' => '$(LEX) $(LFLAGS) $(AM_LFLAGS)',
    		   'compiler' => 'LEXCOMPILE',
    		   'extensions' => ['.l'],
    		   'output_extensions' => sub { (my $ext = $_[0]) =~ tr/l/c/;
    						return ($ext,) },
    		   '_finish' => \&lang_lex_finish,
    		   '_target_hook' => \&lang_lex_target_hook);
    register_language ('name' => 'lexxx',
    		   'Name' => 'Lex (C++)',
    		   'config_vars' => ['LEX'],
    		   'rule_file' => 'lex',
    		   'flags' => ['LFLAGS'],
    		   'compile' => '$(LEX) $(LFLAGS) $(AM_LFLAGS)',
    		   'compiler' => 'LEXCOMPILE',
    		   'extensions' => ['.l++', '.ll', '.lxx', '.lpp'],
    		   'output_extensions' => sub { (my $ext = $_[0]) =~ tr/l/c/;
    						return ($ext,) },
    		   '_finish' => \&lang_lex_finish,
    		   '_target_hook' => \&lang_lex_target_hook);
    
    # Assembler.
    register_language ('name' => 'asm',
    		   'Name' => 'Assembler',
    		   'config_vars' => ['CCAS', 'CCASFLAGS'],
    
    		   'flags' => ['CCASFLAGS'],
    		   # Users can set AM_ASFLAGS to includes DEFS, INCLUDES,
    		   # or anything else required.  They can also set AS.
    		   'compile' => '$(CCAS) $(AM_CCASFLAGS) $(CCASFLAGS)',
    		   'compiler' => 'CCASCOMPILE',
    		   'compile_flag' => '-c',
    		   'extensions' => ['.s', '.S'],
    
    		   # With assembly we still use the C linker.
    		   '_finish' => \&lang_c_finish);
    
    # Fortran 77
    register_language ('name' => 'f77',
    		   'Name' => 'Fortran 77',
    		   'linker' => 'F77LINK',
    		   'link' => '$(F77LD) $(AM_FFLAGS) $(FFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@',
    		   'flags' => ['FFLAGS'],
    		   'compile' => '$(F77) $(AM_FFLAGS) $(FFLAGS)',
    		   'compiler' => 'F77COMPILE',
    		   'compile_flag' => '-c',
    		   'output_flag' => '-o',
    		   'lder' => 'F77LD',
    		   'ld' => '$(F77)',
    		   'pure' => 1,
    		   'extensions' => ['.f', '.for', '.f90']);
    
    # Preprocessed Fortran 77
    #
    # The current support for preprocessing Fortran 77 just involves
    # passing `$(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS)
    # $(CPPFLAGS)' as additional flags to the Fortran 77 compiler, since
    # this is how GNU Make does it; see the `GNU Make Manual, Edition 0.51
    # for `make' Version 3.76 Beta' (specifically, from info file
    # `(make)Catalogue of Rules').
    #
    # A better approach would be to write an Autoconf test
    # (i.e. AC_PROG_FPP) for a Fortran 77 preprocessor, because not all
    # Fortran 77 compilers know how to do preprocessing.  The Autoconf
    # macro AC_PROG_FPP should test the Fortran 77 compiler first for
    # preprocessing capabilities, and then fall back on cpp (if cpp were
    # available).
    register_language ('name' => 'ppf77',
    		   'Name' => 'Preprocessed Fortran 77',
    		   'config_vars' => ['F77'],
    		   'linker' => 'F77LINK',
    		   'link' => '$(F77LD) $(AM_FFLAGS) $(FFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@',
    		   'lder' => 'F77LD',
    		   'ld' => '$(F77)',
    		   'flags' => ['FFLAGS', 'CPPFLAGS'],
    		   'compiler' => 'PPF77COMPILE',
    		   'compile' => '$(F77) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_FFLAGS) $(FFLAGS)',
    		   'compile_flag' => '-c',
    		   'output_flag' => '-o',
    		   'pure' => 1,
    		   'extensions' => ['.F']);
    
    # Ratfor.
    register_language ('name' => 'ratfor',
    		   'Name' => 'Ratfor',
    		   'config_vars' => ['F77'],
    		   'linker' => 'F77LINK',
    		   'link' => '$(F77LD) $(AM_FFLAGS) $(FFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@',
    		   'lder' => 'F77LD',
    		   'ld' => '$(F77)',
    		   'flags' => ['RFLAGS', 'FFLAGS'],
    		   # FIXME also FFLAGS.
    		   'compile' => '$(F77) $(AM_FFLAGS) $(FFLAGS) $(AM_RFLAGS) $(RFLAGS)',
    		   'compiler' => 'RCOMPILE',
    		   'compile_flag' => '-c',
    		   'output_flag' => '-o',
    		   'pure' => 1,
    		   'extensions' => ['.r']);
    
    # Java via gcj.
    register_language ('name' => 'java',
    		   'Name' => 'Java',
    		   'config_vars' => ['GCJ'],
    		   'linker' => 'GCJLINK',
    		   'link' => '$(GCJLD) $(AM_GCJFLAGS) $(GCJFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@',
    		   'autodep' => 'GCJ',
    		   'flags' => ['GCJFLAGS'],
    		   'compile' => '$(GCJ) $(AM_GCJFLAGS) $(GCJFLAGS)',
    		   'compiler' => 'GCJCOMPILE',
    		   'compile_flag' => '-c',
    		   'output_flag' => '-o',
    		   'lder' => 'GCJLD',
    		   'ld' => '$(GCJ)',
    		   'pure' => 1,
    		   'extensions' => ['.java', '.class', '.zip', '.jar']);
    
    ################################################################
    
    # Parse the WARNINGS environnent variable.
    &parse_WARNINGS;
    
    # Parse command line.
    &parse_arguments;
    
    # Do configure.ac scan only once.
    &scan_autoconf_files;
    
    &fatal ("no `Makefile.am' found or specified\n")
      if ! @input_files;
    
    my $automake_has_run = 0;
    
    do
    {
      if ($automake_has_run)
        {
          &verb ('processing Makefiles another time to fix them up.');
          &prog_error ('running more than two times should never be needed.')
    	if $automake_has_run >= 2;
        }
      $automake_needs_to_reprocess_all_files = 0;
    
      # Now do all the work on each file.
      # This guy must be local otherwise it's private to the loop.
      use vars '$am_file';
      local $am_file;
      foreach $am_file (@input_files)
        {
          if (! -f ($am_file . '.am'))
    	{
    	  &err ("`$am_file.am' does not exist");
    	}
          else
    	{
    	  &generate_makefile ($output_files{$am_file}, $am_file);
    	}
        }
      ++$automake_has_run;
    }
    while ($automake_needs_to_reprocess_all_files);
    
    exit $exit_code;
    
    ################################################################
    
    # Error reporting functions.
    
    # prog_error ($MESSAGE, [%OPTIONS])
    # -------------------------------
    # Signal a programming error, display $MESSAGE, and exit 1.
    sub prog_error ($;%)
    {
      my ($msg, %opts) = @_;
      msg 'automake', '', $msg, %opts;
    }
    
    # err ($WHERE, $MESSAGE, [%OPTIONS])
    # err ($MESSAGE)
    # ----------------------------------
    # Uncategorized errors.
    sub err ($;$%)
    {
      my ($where, $msg, %opts) = @_;
      msg ('error', $where, $msg, %opts);
    }
    
    # fatal ($WHERE, $MESSAGE, [%OPTIONS])
    # fatal ($MESSAGE)
    # ----------------------------------
    # Fatal errors.
    sub fatal ($;$%)
    {
      my ($where, $msg, %opts) = @_;
      msg ('fatal', $where, $msg, %opts);
    }
    
    # err_var ($VARNAME, $MESSAGE, [%OPTIONS])
    # ----------------------------------------
    # Uncategorized errors about variables.
    sub err_var ($$;%)
    {
      msg_var ('error', @_);
    }
    
    # err_target ($TARGETNAME, $MESSAGE, [%OPTIONS])
    # ----------------------------------------------
    # Uncategorized errors about targets.
    sub err_target ($$;%)
    {
      msg_target ('error', @_);
    }
    
    # err_cond_target ($COND, $TARGETNAME, $MESSAGE, [%OPTIONS])
    # ----------------------------------------------------------
    # Uncategorized errors about conditional targets.
    sub err_cond_target ($$$;%)
    {
      msg_cond_target ('error', @_);
    }
    
    # err_am ($MESSAGE, [%OPTIONS])
    # -----------------------------
    # Uncategorized errors about the current Makefile.am.
    sub err_am ($;%)
    {
      msg_am ('error', @_);
    }
    
    # err_ac ($MESSAGE, [%OPTIONS])
    # -----------------------------
    # Uncategorized errors about configure.ac.
    sub err_ac ($;%)
    {
      msg_ac ('error', @_);
    }
    
    # msg_cond_var ($CHANNEL, $COND, $VARNAME, $MESSAGE, [%OPTIONS])
    # --------------------------------------------------------------
    # Messages about conditional variable.
    sub msg_cond_var ($$$$;%)
    {
      my ($channel, $cond, $var, $msg, %opts) = @_;
      msg $channel, $var_location{$var}{$cond}, $msg, %opts;
    }
    
    # msg_var ($CHANNEL, $VARNAME, $MESSAGE, [%OPTIONS])
    # --------------------------------------------------
    # Messages about variables.
    sub msg_var ($$$;%)
    {
      my ($channel, $var, $msg, %opts) = @_;
      # Don't know which condition is concerned.  Pick any.
      my $cond = (keys %{$var_value{$var}})[0];
      msg_cond_var $channel, $cond, $var, $msg, %opts;
    }
    
    # msg_cond_target ($CHANNEL, $COND, $TARGETNAME, $MESSAGE, [%OPTIONS])
    # --------------------------------------------------------------------
    # Messages about conditional targets.
    sub msg_cond_target ($$$$;%)
    {
      my ($channel, $cond, $target, $msg, %opts) = @_;
      msg $channel, $targets{$target}{$cond}, $msg, %opts;
    }
    
    # msg_target ($CHANNEL, $TARGETNAME, $MESSAGE, [%OPTIONS])
    # --------------------------------------------------------
    # Messages about targets.
    sub msg_target ($$$;%)
    {
      my ($channel, $target, $msg, %opts) = @_;
      # Don't know which condition is concerned.  Pick any.
      my $cond = (keys %{$targets{$target}})[0];
      msg_cond_target ($channel, $cond, $target, $msg, %opts);
    }
    
    # msg_am ($CHANNEL, $MESSAGE, [%OPTIONS])
    # ---------------------------------------
    # Messages about about the current Makefile.am.
    sub msg_am ($$;%)
    {
      my ($channel, $msg, %opts) = @_;
      msg $channel, "${am_file}.am", $msg, %opts;
    }
    
    # msg_ac ($CHANNEL, $MESSAGE, [%OPTIONS])
    # ---------------------------------------
    # Messages about about configure.ac.
    sub msg_ac ($$;%)
    {
      my ($channel, $msg, %opts) = @_;
      msg $channel, $configure_ac, $msg, %opts;
    }
    
    # $BOOL
    # reject_var ($VAR, $ERROR_MSG)
    # -----------------------------
    sub reject_var ($$)
    {
      my ($var, $msg) = @_;
      if (variable_defined ($var))
        {
          err_var $var, $msg;
          return 1;
        }
      return 0;
    }
    
    # $BOOL
    # reject_target ($VAR, $ERROR_MSG)
    # --------------------------------
    sub reject_target ($$)
    {
      my ($target, $msg) = @_;
      if (target_defined ($target))
        {
          err_target $target, $msg;
          return 1;
        }
      return 0;
    }
    
    # verb ($MESSAGE, [%OPTIONS])
    # ---------------------------
    sub verb ($;%)
    {
      my ($msg, %opts) = @_;
      msg 'verb', '', $msg, %opts;
    }
    
    ################################################################
    
    # subst ($TEXT)
    # -------------
    # Return a configure-style substitution using the indicated text.
    # We do this to avoid having the substitutions directly in automake.in;
    # when we do that they are sometimes removed and this causes confusion
    # and bugs.
    sub subst ($)
    {
        my ($text) = @_;
        return '@' . $text . '@';
    }
    
    ################################################################
    
    
    # $BACKPATH
    # &backname ($REL-DIR)
    # --------------------
    # If I `cd $REL-DIR', then to come back, I should `cd $BACKPATH'.
    # For instance `src/foo' => `../..'.
    # Works with non strictly increasing paths, i.e., `src/../lib' => `..'.
    sub backname ($)
    {
        my ($file) = @_;
        my @res;
        foreach (split (/\//, $file))
        {
    	next if $_ eq '.' || $_ eq '';
    	if ($_ eq '..')
    	{
    	    pop @res;
    	}
    	else
    	{
    	    push (@res, '..');
    	}
        }
        return join ('/', @res) || '.';
    }
    
    ################################################################
    
    # Pattern that matches all know input extensions (i.e. extensions used
    # by the languages supported by Automake).  Using this pattern
    # (instead of `\..*$') to match extensions allows Automake to support
    # dot-less extensions.
    my $KNOWN_EXTENSIONS_PATTERN = "";
    my @known_extensions_list = ();
    
    # accept_extensions (@EXTS)
    # -------------------------
    # Update $KNOWN_EXTENSIONS_PATTERN to recognize the extensions
    # listed @EXTS.  Extensions should contain a dot if needed.
    sub accept_extensions (@)
    {
        push @known_extensions_list, @_;
        $KNOWN_EXTENSIONS_PATTERN =
    	'(?:' . join ('|', map (quotemeta, @known_extensions_list)) . ')';
    }
    
    # var_SUFFIXES_trigger ($TYPE, $VALUE)
    # ------------------------------------
    # This is called automagically by macro_define() when SUFFIXES
    # is defined ($TYPE eq '') or appended ($TYPE eq '+').
    # The work here needs to be performed as a side-effect of the
    # macro_define() call because SUFFIXES definitions impact
    # on $KNOWN_EXTENSIONS_PATTERN, and $KNOWN_EXTENSIONS_PATTERN
    # are used when parsing the input am file.
    sub var_SUFFIXES_trigger ($$)
    {
        my ($type, $value) = @_;
        accept_extensions (split (' ', $value));
    }
    
    ################################################################
    
    
    # switch_warning ($CATEGORY)
    # --------------------------
    # If $CATEGORY is mumble, turn on the mumble channel.
    # If it's no-mumble, turn mumble off.
    # Alse handle `all' and `none' for completeness.
    sub switch_warning ($)
    {
      my ($cat) = @_;
      my $has_no = 0;
    
      if ($cat =~ /^no-(.*)$/)
        {
          $cat = $1;
          $has_no = 1;
        }
    
      if ($cat eq 'all')
        {
          setup_channel_type 'warning', silent => $has_no;
        }
      elsif ($cat eq 'none')
        {
          setup_channel_type 'warning', silent => 1 - $has_no;
        }
      elsif ($cat eq 'error')
        {
          $warnings_are_errors = 1 - $has_no;
        }
      elsif (channel_type ($cat) eq 'warning')
        {
          setup_channel $cat, silent => $has_no;
        }
      else
        {
          return 1;
        }
      return 0;
    }
    
    # parse_WARNINGS
    # --------------
    # Honor the WARNINGS environment variable.
    sub parse_WARNINGS ($$)
    {
      if (exists $ENV{'WARNINGS'})
        {
          # Ignore unknown categories.  This is required because WARNINGS
          # should be honored by many tools.
          switch_warning $_ foreach (split (',', $ENV{'WARNINGS'}));
        }
    }
    
    # parse_warning ($OPTION, $ARGUMENT)
    # ----------------------------------
    # Parse the argument of --warning=CATEGORY or -WCATEGORY.
    sub parse_warnings ($$)
    {
      my ($opt, $categories) = @_;
    
      foreach my $cat (split (',', $categories))
        {
          msg 'unsupported', "unknown warning category `$cat'"
    	if switch_warning $cat;
        }
    }
    
    # Parse command line.
    sub parse_arguments ()
    {
      # Start off as gnu.
      &set_strictness ('gnu');
    
      my %options =
        (
         'libdir:s' 	=> \$libdir,
         'gnu' 		=> sub { &set_strictness ('gnu'); },
         'gnits' 		=> sub { &set_strictness ('gnits'); },
         'cygnus' 	        => \$cygnus_mode,
         'foreign' 	        => sub { &set_strictness ('foreign'); },
         'include-deps' 	=> sub { $cmdline_use_dependencies = 1; },
         'i|ignore-deps' 	=> sub { $cmdline_use_dependencies = 0; },
         'no-force' 	=> sub { $force_generation = 0; },
         'f|force-missing'  => \$force_missing,
         'o|output-dir:s'	=> \$output_directory,
         'a|add-missing' 	=> \$add_missing,
         'c|copy' 	        => \$copy_missing,
         'v|verbose' 	=> sub { setup_channel 'verb', silent => 0; },
         'W|warnings:s'     => \&parse_warnings,
         # These long options (--Werror and --Wno-error) for backward
         # compatibility.  Use -Werror and -Wno-error today.
         'Werror'           => sub { parse_warnings 'W', 'error'; },
         'Wno-error'        => sub { parse_warnings 'W', 'no-error'; },
         );
    
      use Getopt::Long;
      Getopt::Long::config ("bundling", "pass_through");
    
      # See if --version or --help is used.  We want to process these before
      # anything else because the GNU Coding Standards require us to
      # `exit 0' after processing these options, and we can't garanty this
      # if we treat other options first.  (Handling other options first
      # could produce error diagnostics, and in this condition it is
      # confusing if Automake `exit 0'.)
      my %options_1st_pass =
        (
         'version' => \&version,
         'help'    => \&usage,
         # Recognize all other options (and their arguments) but do nothing.
         map { $_ => sub {} } (keys %options)
         );
      my @ARGV_backup = @ARGV;
      Getopt::Long::GetOptions %options_1st_pass
        or exit 1;
      @ARGV = @ARGV_backup;
    
      # Now *really* process the options.  This time we know
      # that --help and --version are not present.
      Getopt::Long::GetOptions %options
        or exit 1;
    
      if (defined $output_directory)
        {
          msg 'obsolete', "`--output-dir' is deprecated\n";
        }
      else
        {
          # In the next release we'll remove this entirely.
          $output_directory = '.';
        }
    
      foreach my $arg (@ARGV)
        {
          if ($arg =~ /^-./)
    	{
    	  fatal ("unrecognized option `$arg'\n"
    		 . "Try `$0 --help' for more information.");
    	}
    
          # Handle $local:$input syntax.  Note that we only examine the
          # first ":" file to see if it is automake input; the rest are
          # just taken verbatim.  We still keep all the files around for
          # dependency checking, however.
          my ($local, $input, @rest) = split (/:/, $arg);
          if (! $input)
    	{
    	  $input = $local;
    	}
          else
    	{
    	  # Strip .in; later on .am is tacked on.  That is how the
    	  # automake input file is found.  Maybe not the best way, but
    	  # it is easy to explain.
    	  $input =~ s/\.in$//
    	    or fatal "invalid input file name `$arg'\n.";
    	}
          push (@input_files, $input);
          $output_files{$input} = join (':', ($local, @rest));
        }
    
      # Take global strictness from whatever we currently have set.
      $default_strictness = $strictness;
      $default_strictness_name = $strictness_name;
    }
    
    ################################################################
    
    # Generate a Makefile.in given the name of the corresponding Makefile and
    # the name of the file output by config.status.
    sub generate_makefile
    {
        my ($output, $makefile) = @_;
    
        # Reset all the Makefile.am related variables.
        &initialize_per_input;
    
        # Any warning setting now local to this Makefile.am.
        &dup_channel_setup;
        # AUTOMAKE_OPTIONS can contains -W flags to disable or enable
        # warnings for this file.  So hold any warning issued before
        # we have processed AUTOMAKE_OPTIONS.
        &buffer_messages ('warning');
    
        # Name of input file ("Makefile.am") and output file
        # ("Makefile.in").  These have no directory components.
        $am_file_name = basename ($makefile) . '.am';
        $in_file_name = basename ($makefile) . '.in';
    
        # $OUTPUT is encoded.  If it contains a ":" then the first element
        # is the real output file, and all remaining elements are input
        # files.  We don't scan or otherwise deal with these input file,
        # other than to mark them as dependencies.  See
        # &scan_autoconf_files for details.
        my (@secondary_inputs);
        ($output, @secondary_inputs) = split (/:/, $output);
    
        $relative_dir = dirname ($output);
        $am_relative_dir = dirname ($makefile);
    
        &read_main_am_file ($makefile . '.am');
        if (&handle_options)
        {
          # Process buffered warnings.
          &flush_messages;
          # Fatal error.  Just return, so we can continue with next file.
          return;
        }
        # Process buffered warnings.
        &flush_messages;
    
        # There are a few install-related variables that you should not define.
        foreach my $var ('PRE_INSTALL', 'POST_INSTALL', 'NORMAL_INSTALL')
          {
    	if (exists $var_owner{$var})
    	  {
    	    prog_error "\$var_owner{$var}{TRUE} doesn't exist"
    	      unless exists $var_owner{$var}{'TRUE'};
    	    reject_var $var, "`$var' should not be defined"
    	      if $var_owner{$var}{'TRUE'} != VAR_AUTOMAKE;
    	  }
          }
    
        # Catch some obsolete variables.
        msg_var ('obsolete', 'INCLUDES',
    	     "`INCLUDES' is the old name for `AM_CPPFLAGS'")
          if variable_defined ('INCLUDES');
    
        # At the toplevel directory, we might need config.guess, config.sub
        # or libtool scripts (ltconfig and ltmain.sh).
        if ($relative_dir eq '.')
        {
            # AC_CANONICAL_HOST and AC_CANONICAL_SYSTEM need config.guess and
            # config.sub.
            require_conf_file ($canonical_location, FOREIGN,
    			   'config.guess', 'config.sub')
    	  if $seen_canonical;
        }
    
        # We still need Makefile.in here, because sometimes the `dist'
        # target doesn't re-run automake.
        if ($am_relative_dir eq $relative_dir)
        {
    	# Only distribute the files if they are in the same subdir as
    	# the generated makefile.
    	&push_dist_common ($in_file_name, $am_file_name);
        }
    
        push (@sources, '$(SOURCES)')
    	if variable_defined ('SOURCES');
    
        # Must do this after reading .am file.  See read_main_am_file to
        # understand weird tricks we play there with variables.
        &define_variable ('subdir', $relative_dir);
    
        # Check first, because we might modify some state.
        &check_cygnus;
        &check_gnu_standards;
        &check_gnits_standards;
    
        &handle_configure ($output, $makefile, @secondary_inputs);
        &handle_gettext;
        &handle_libraries;
        &handle_ltlibraries;
        &handle_programs;
        &handle_scripts;
    
        # This must run first so that the ANSI2KNR definition is generated
        # before it is used by the _.c rules.  We have to do this because
        # a variable which is used in a dependency must be defined before
        # the target, or else make won't properly see it.
        &handle_compile;
        # This must be run after all the sources are scanned.
        &handle_languages;
    
        # We have to run this after dealing with all the programs.
        &handle_libtool;
    
        # Re-init SOURCES.  FIXME: other code shouldn't depend on this
        # (but currently does).
        macro_define ('SOURCES', VAR_AUTOMAKE, '', 'TRUE', "@sources", 'internal');
        define_pretty_variable ('DIST_SOURCES', '', @dist_sources);
    
        &handle_multilib;
        &handle_texinfo;
        &handle_emacs_lisp;
        &handle_python;
        &handle_java;
        &handle_man_pages;
        &handle_data;
        &handle_headers;
        &handle_subdirs;
        &handle_tags;
        &handle_minor_options;
        &handle_tests;
    
        # This must come after most other rules.
        &handle_dist ($makefile);
    
        &handle_footer;
        &do_check_merge_target;
        &handle_all ($output);
    
        # FIXME: Gross!
        if (variable_defined ('lib_LTLIBRARIES') &&
    	variable_defined ('bin_PROGRAMS'))
        {
    	$output_rules .= "install-binPROGRAMS: install-libLTLIBRARIES\n\n";
        }
    
        &handle_installdirs;
        &handle_clean;
        &handle_factored_dependencies;
    
        check_typos ();
    
        if (! -d ($output_directory . '/' . $am_relative_dir))
        {
    	mkdir ($output_directory . '/' . $am_relative_dir, 0755);
        }
    
        my ($out_file) = $output_directory . '/' . $makefile . ".in";
        if (! $force_generation && -e $out_file)
        {
    	my ($am_time) = (stat ($makefile . '.am'))[9];
    	my ($in_time) = (stat ($out_file))[9];
    	# FIXME: should cache these times.
    	my ($conf_time) = (stat ($configure_ac))[9];
    	# FIXME: how to do unsigned comparison?
    	if ($am_time < $in_time || $am_time < $conf_time)
    	{
    	    # No need to update.
    	    return;
    	}
    	if (-f 'aclocal.m4')
    	{
    	    my ($acl_time) = (stat _)[9];
    	    return if ($am_time < $acl_time);
    	}
        }
    
        if (-e "$out_file")
        {
    	unlink ($out_file)
    	    or fatal "cannot remove $out_file: $!\n";
        }
        my $gm_file = new Automake::XFile "> $out_file";
        verb "creating $makefile.in";
    
        print $gm_file $output_vars;
        # We make sure that `all:' is the first target.
        print $gm_file $output_all;
        print $gm_file $output_header;
        print $gm_file $output_rules;
        print $gm_file $output_trailer;
    
        # Back out any warning setting.
        &drop_channel_setup;
    }
    
    ################################################################
    
    # A version is a string that looks like
    #   MAJOR.MINOR[.MICRO][ALPHA][-FORK]
    # where
    #   MAJOR, MINOR, and MICRO are digits, ALPHA is a character, and
    # FORK any alphanumeric word.
    # Usually, ALPHA is used to label alpha releases or intermediate snapshots,
    # FORK is used for CVS branches or patched releases, and MICRO is used
    # for bug fixes releases on the MAJOR.MINOR branch.
    #
    # For the purpose of ordering, 1.4 is the same as 1.4.0, but 1.4g is
    # the same as 1.4.99g.  The FORK identifier is ignored in the
    # ordering, except when it looks like -pMINOR[ALPHA]: some versions
    # were labelled like 1.4-p3a, this is the same as an alpha release
    # labelled 1.4.3a.  Yes it's horrible, but Automake did not support
    # two-dot versions in the past.
    
    # version_split (VERSION)
    # -----------------------
    # Split a version string into the corresponding (MAJOR, MINOR, MICRO,
    # ALPHA, FORK) tuple.  For instance "1.4g" would be split into
    # (1, 4, 99, 'g', '').
    # Return () on error.
    sub version_split ($)
    {
        my ($ver) = @_;
    
        # Special case for versions like 1.4-p2a.
        if ($ver =~ /^(\d+)\.(\d+)(?:-p(\d+)([a-z]+)?)$/)
        {
    	return ($1, $2, $3, $4 || '', '');
        }
        # Common case.
        elsif ($ver =~ /^(\d+)\.(\d+)(?:\.(\d+))?([a-z])?(?:-([A-Za-z0-9]+))?$/)
        {
    	return ($1, $2, $3 || (defined $4 ? 99 : 0), $4 || '', $5 || '');
        }
        return ();
    }
    
    # version_compare (\@LVERSION, \@RVERSION)
    # ----------------------------------------
    # Return 1 if LVERSION > RVERSION,
    #       -1 if LVERSION < RVERSION,
    #        0 if LVERSION = RVERSION.
    sub version_compare (\@\@)
    {
        my @l = @{$_[0]};
        my @r = @{$_[1]};
    
        for my $i (0, 1, 2)
        {
    	return 1  if ($l[$i] > $r[$i]);
    	return -1 if ($l[$i] < $r[$i]);
        }
        for my $i (3, 4)
        {
    	return 1  if ($l[$i] gt $r[$i]);
    	return -1 if ($l[$i] lt $r[$i]);
        }
        return 0;
    }
    
    # Handles the logic of requiring a version number in AUTOMAKE_OPTIONS.
    # Return 0 if the required version is satisfied, 1 otherwise.
    sub version_check ($)
    {
      my ($required) = @_;
      my @version = version_split $VERSION;
      my @required = version_split $required;
    
      prog_error "version is incorrect: $VERSION"
        if $#version == -1;
    
      # This should not happen, because process_option_list and split_version
      # use similar regexes.
      prog_error "required version is incorrect: $required"
        if $#required == -1;
    
      # If we require 3.4n-foo then we require something
      # >= 3.4n, with the `foo' fork identifier.
      return 1
        if ($required[4] ne '' && $required[4] ne $version[4]);
    
      return 0 > version_compare @version, @required;
    }
    
    # $BOOL
    # process_option_list ($CONFIG, @OPTIONS)
    # ------------------------------
    # Process a list of options.  Return 1 on error, 0 otherwise.
    # This is a helper for handle_options.  CONFIG is true if we're
    # handling global options.
    sub process_option_list
    {
      my ($config, @list) = @_;
    
      # FIXME: We should disallow conditional deffinitions of AUTOMAKE_OPTIONS.
      my $where = ($config ?
    	       $seen_init_automake :
    	       $var_location{'AUTOMAKE_OPTIONS'}{'TRUE'});
    
      foreach (@list)
        {
          $options{$_} = 1;
          if ($_ eq 'gnits' || $_ eq 'gnu' || $_ eq 'foreign')
    	{
    	  &set_strictness ($_);
    	}
          elsif ($_ eq 'cygnus')
    	{
    	  $cygnus_mode = 1;
    	}
          elsif (/^(.*\/)?ansi2knr$/)
    	{
    	  # An option like "../lib/ansi2knr" is allowed.  With no
    	  # path prefix, we assume the required programs are in this
    	  # directory.  We save the actual option for later.
    	  $options{'ansi2knr'} = $_;
    	}
          elsif ($_ eq 'no-installman' || $_ eq 'no-installinfo'
    	     || $_ eq 'dist-shar' || $_ eq 'dist-zip'
    	     || $_ eq 'dist-tarZ' || $_ eq 'dist-bzip2'
    	     || $_ eq 'dejagnu' || $_ eq 'no-texinfo.tex'
    	     || $_ eq 'readme-alpha' || $_ eq 'check-news'
    	     || $_ eq 'subdir-objects' || $_ eq 'nostdinc'
    	     || $_ eq 'no-exeext' || $_ eq 'no-define'
    	     || $_ eq 'std-options')
    	{
    	  # Explicitly recognize these.
    	}
          elsif ($_ eq 'no-dependencies')
    	{
    	  $use_dependencies = 0;
    	}
          elsif (/^\d+\.\d+(?:\.\d+)?[a-z]?(?:-[A-Za-z0-9]+)?$/)
    	{
    	  # Got a version number.
    	  if (version_check $&)
    	    {
    	      err ($where, "require Automake $_, but have $VERSION",
    		   uniq_scope => US_GLOBAL);
    		return 1;
    	    }
    	}
          elsif (/^(?:--warnings=|-W)(.*)$/)
    	{
    	  foreach my $cat (split (',', $1))
    	    {
    	      msg 'unsupported', $where, "unknown warning category `$cat'"
    		if switch_warning $cat;
    	    }
    	}
          else
    	{
    	  err ($where, "option `$_' not recognized",
    	       uniq_scope => US_GLOBAL);
    	  return 1;
    	}
        }
    }
    
    # Handle AUTOMAKE_OPTIONS variable.  Return 1 on error, 0 otherwise.
    sub handle_options
    {
        # Process global options first so that more specific options can
        # override.
        if (&process_option_list (1, split (' ', $global_options)))
        {
    	return 1;
        }
    
        if (variable_defined ('AUTOMAKE_OPTIONS'))
        {
    	if (&process_option_list (0, &variable_value_as_list_recursive ('AUTOMAKE_OPTIONS', '')))
    	{
    	    return 1;
    	}
        }
    
        if ($strictness == GNITS)
        {
    	$options{'readme-alpha'} = 1;
    	$options{'std-options'} = 1;
    	$options{'check-news'} = 1;
        }
    
        return 0;
    }
    
    
    # get_object_extension ($OUT)
    # ---------------------------
    # Return object extension.  Just once, put some code into the output.
    # OUT is the name of the output file
    sub get_object_extension
    {
        my ($out) = @_;
    
        # Maybe require libtool library object files.
        my $extension = '.$(OBJEXT)';
        $extension = '.lo' if ($out =~ /\.la$/);
    
        # Check for automatic de-ANSI-fication.
        $extension = '$U' . $extension
          if defined $options{'ansi2knr'};
    
        $get_object_extension_was_run = 1;
    
        return $extension;
    }
    
    
    # Call finish function for each language that was used.
    sub handle_languages
    {
        if ($use_dependencies)
        {
    	# Include auto-dep code.  Don't include it if DEP_FILES would
    	# be empty.
    	if (&saw_sources_p (0) && keys %dep_files)
    	{
    	    # Set location of depcomp.
    	    &define_variable ('depcomp', "\$(SHELL) $config_aux_dir/depcomp");
    	    &define_variable ('am__depfiles_maybe', 'depfiles');
    
    	    require_conf_file ("$am_file.am", FOREIGN, 'depcomp');
    
    	    my @deplist = sort keys %dep_files;
    
    	    # We define this as a conditional variable because BSD
    	    # make can't handle backslashes for continuing comments on
    	    # the following line.
    	    define_pretty_variable ('DEP_FILES', 'AMDEP_TRUE', @deplist);
    
    	    # Generate each `include' individually.  Irix 6 make will
    	    # not properly include several files resulting from a
    	    # variable expansion; generating many separate includes
    	    # seems safest.
    	    $output_rules .= "\n";
    	    foreach my $iter (@deplist)
     	    {
    		$output_rules .= (subst ('AMDEP_TRUE')
    				  . subst ('am__include')
    				  . ' '
    				  . subst ('am__quote')
    				  . $iter
    				  . subst ('am__quote')
    				  . "\n");
    	    }
    
    	    # Compute the set of directories to remove in distclean-depend.
    	    my @depdirs = uniq (map { dirname ($_) } @deplist);
    	    $output_rules .= &file_contents ('depend',
    					     DEPDIRS => "@depdirs");
    	}
        }
        else
        {
    	&define_variable ('depcomp', '');
    	&define_variable ('am__depfiles_maybe', '');
        }
    
        my %done;
    
        # Is the c linker needed?
        my $needs_c = 0;
        foreach my $ext (sort keys %extension_seen)
        {
    	next unless $extension_map{$ext};
    
    	my $lang = $languages{$extension_map{$ext}};
    
    	my $rule_file = $lang->rule_file || 'depend2';
    
    	# Get information on $LANG.
    	my $pfx = $lang->autodep;
    	my $fpfx = ($pfx eq '') ? 'CC' : $pfx;
    
    	my $AMDEP = (($use_dependencies && $lang->autodep ne 'no')
    		     ? 'AMDEP' : 'FALSE');
    	my $FASTDEP = (($use_dependencies && $lang->autodep ne 'no')
    		       ? ('am__fastdep' . $fpfx) : 'FALSE');
    
    	my %transform = ('EXT'     => $ext,
    			 'PFX'     => $pfx,
    			 'FPFX'    => $fpfx,
    			 'AMDEP'   => $AMDEP,
    			 'FASTDEP' => $FASTDEP,
    			 '-c'      => $lang->compile_flag || '',
    			 'MORE-THAN-ONE'
    			           => (count_files_for_language ($lang->name) > 1));
    
    	# Generate the appropriate rules for this extension.
    	if (($use_dependencies && $lang->autodep ne 'no')
    	    || defined $lang->compile)
    	{
    	    # Some C compilers don't support -c -o.  Use it only if really
    	    # needed.
    	    my $output_flag = $lang->output_flag || '';
    	    $output_flag = '-o'
    	      if (! $output_flag
    		  && $lang->name eq 'c'
    		  && defined $options{'subdir-objects'});
    
    	    # Compute a possible derived extension.
    	    # This is not used by depend2.am.
    	    my $der_ext = (&{$lang->output_extensions} ($ext))[0];
    
    	    $output_rules .=
    	      file_contents ($rule_file,
    			     %transform,
    			     'GENERIC'   => 1,
    
    			     'DERIVED-EXT' => $der_ext,
    
    			     # In this situation we know that the
    			     # object is in this directory, so
    			     # $(DEPDIR) is the correct location for
    			     # dependencies.
    			     'DEPBASE'   => '$(DEPDIR)/$*',
    			     'BASE'      => '$*',
    			     'SOURCE'    => '$<',
    			     'OBJ'       => '$@',
    			     'OBJOBJ'    => '$@',
    			     'LTOBJ'     => '$@',
    
    			     'COMPILE'   => '$(' . $lang->compiler . ')',
    			     'LTCOMPILE' => '$(LT' . $lang->compiler . ')',
    			     '-o'        => $output_flag);
    	}
    
    	# Now include code for each specially handled object with this
    	# language.
    	my %seen_files = ();
    	foreach my $file (@{$lang_specific_files{$lang->name}})
    	{
    	    my ($derived, $source, $obj, $myext) = split (' ', $file);
    
    	    # For any specially-generated object, we must respect the
    	    # ansi2knr setting so that we don't inadvertently try to
    	    # use the default rule.
    	    if ($lang->ansi && defined $options{'ansi2knr'})
    	    {
    		$myext = '$U' . $myext;
    	    }
    
    	    # We might see a given object twice, for instance if it is
    	    # used under different conditions.
    	    next if defined $seen_files{$obj};
    	    $seen_files{$obj} = 1;
    
    	    prog_error ("found " . $lang->name .
    			" in handle_languages, but compiler not defined")
    	      unless defined $lang->compile;
    
    	    my $obj_compile = $lang->compile;
    
    	    # Rewrite each occurence of `AM_$flag' in the compile
    	    # rule into `${derived}_$flag' if it exists.
    	    for my $flag (@{$lang->flags})
    	      {
    		my $val = "${derived}_$flag";
    		$obj_compile =~ s/\(AM_$flag\)/\($val\)/
    		  if variable_defined ($val);
    	      }
    
    	    my $obj_ltcompile = '$(LIBTOOL) --mode=compile ' . $obj_compile;
    
    	    # We _need_ `-o' for per object rules.
    	    my $output_flag = $lang->output_flag || '-o';
    
    	    my $depbase = dirname ($obj);
    	    $depbase = ''
    		if $depbase eq '.';
    	    $depbase .= '/'
    		unless $depbase eq '';
    	    $depbase .= '$(DEPDIR)/' . basename ($obj);
    
    	    # Generate a transform which will turn suffix targets in
    	    # depend2.am into real targets for the particular objects we
    	    # are building.
    	    $output_rules .=
    	      file_contents ($rule_file,
    			     (%transform,
    			      'GENERIC'   => 0,
    
    			      'DEPBASE'   => $depbase,
    			      'BASE'      => $obj,
    			      'SOURCE'    => $source,
    			      # Use $myext and not `.o' here, in case
    			      # we are actually building a new source
    			      # file -- e.g. via yacc.
    			      'OBJ'       => "$obj$myext",
    			      'OBJOBJ'    => "$obj.obj",
    			      'LTOBJ'     => "$obj.lo",
    
    			      'COMPILE'   => $obj_compile,
    			      'LTCOMPILE' => $obj_ltcompile,
    			      '-o'        => $output_flag));
    	}
    
    	# The rest of the loop is done once per language.
    	next if defined $done{$lang};
    	$done{$lang} = 1;
    
    	# Load the language dependent Makefile chunks.
    	my %lang = map { uc ($_) => 0 } keys %languages;
    	$lang{uc ($lang->name)} = 1;
    	$output_rules .= file_contents ('lang-compile', %transform, %lang);
    
    	# If the source to a program consists entirely of code from a
    	# `pure' language, for instance C++ for Fortran 77, then we
    	# don't need the C compiler code.  However if we run into
    	# something unusual then we do generate the C code.  There are
    	# probably corner cases here that do not work properly.
    	# People linking Java code to Fortran code deserve pain.
    	$needs_c ||= ! $lang->pure;
    
    	define_compiler_variable ($lang)
    	  if ($lang->compile);
    
    	define_linker_variable ($lang)
    	  if ($lang->link);
    
    	require_variables ("$am_file.am", $lang->Name . " source seen",
    			   'TRUE', @{$lang->config_vars});
    
    	# Call the finisher.
    	$lang->finish;
    
    	# Flags listed in `->flags' are user variables (per GNU Standards),
    	# they should not be overriden in the Makefile...
    	my @dont_override = @{$lang->flags};
    	# ... and so is LDFLAGS.
    	push @dont_override, 'LDFLAGS' if $lang->link;
    
    	foreach my $flag (@dont_override)
    	  {
    	    if (exists $var_owner{$flag})
    	      {
    		for my $cond (keys %{$var_owner{$flag}})
    		  {
    		    if ($var_owner{$flag}{$cond} == VAR_MAKEFILE)
    		      {
    			msg_cond_var ('gnu', $cond, $flag,
    				      "`$flag' is a user variable, "
    				      . "you should not override it;\n"
    				      . "use `AM_$flag' instead.");
    		      }
    		  }
    	      }
    	  }
        }
    
        # If the project is entirely C++ or entirely Fortran 77 (i.e., 1
        # suffix rule was learned), don't bother with the C stuff.  But if
        # anything else creeps in, then use it.
        $needs_c = 1
          if $need_link || ((scalar keys %$suffix_rules)
    			- (scalar keys %$suffix_rules_default)) > 1;
    
        if ($needs_c)
          {
    	&define_compiler_variable ($languages{'c'})
    	  unless defined $done{$languages{'c'}};
    	define_linker_variable ($languages{'c'});
          }
    }
    
    # Check to make sure a source defined in LIBOBJS is not explicitly
    # mentioned.  This is a separate function (as opposed to being inlined
    # in handle_source_transform) because it isn't always appropriate to
    # do this check.
    sub check_libobjs_sources
    {
      my ($one_file, $unxformed) = @_;
    
      foreach my $prefix ('', 'EXTRA_', 'dist_', 'nodist_',
    		      'dist_EXTRA_', 'nodist_EXTRA_')
        {
            my @files;
    	if (variable_defined ($prefix . $one_file . '_SOURCES'))
    	{
    	    @files = &variable_value_as_list_recursive (
    				($prefix . $one_file . '_SOURCES'),
    				'all');
    	}
    	elsif ($prefix eq '')
    	{
    	    @files = ($unxformed . '.c');
    	}
    	else
    	{
    	    next;
    	}
    
    	foreach my $file (@files)
    	{
    	  err_var ($prefix . $one_file . '_SOURCES',
    		   "automatically discovered file `$file' should not" .
    		   " be explicitly mentioned")
    	    if defined $libsources{$file};
    	}
        }
    }
    
    
    # @OBJECTS
    # handle_single_transform_list ($VAR, $TOPPARENT, $DERIVED, $OBJ, @FILES)
    # -----------------------------------------------------------------------
    # Does much of the actual work for handle_source_transform.
    # Arguments are:
    #   $VAR is the name of the variable that the source filenames come from
    #   $TOPPARENT is the name of the _SOURCES variable which is being processed
    #   $DERIVED is the name of resulting executable or library
    #   $OBJ is the object extension (e.g., `$U.lo')
    #   @FILES is the list of source files to transform
    # Result is a list of the names of objects
    # %linkers_used will be updated with any linkers needed
    sub handle_single_transform_list ($$$$@)
    {
        my ($var, $topparent, $derived, $obj, @files) = @_;
        my @result = ();
        my $nonansi_obj = $obj;
        $nonansi_obj =~ s/\$U//g;
    
        # Turn sources into objects.  We use a while loop like this
        # because we might add to @files in the loop.
        while (scalar @files > 0)
        {
    	$_ = shift @files;
    
            # Configure substitutions in _SOURCES variables are errors.
            if (/^\@.*\@$/)
            {
                err_var ($var,
    		     "`$var' includes configure substitution `$_', and is " .
    		     "referred to\nfrom `$topparent': configure " .
    		     "substitutions are not allowed\nin _SOURCES variables");
                next;
            }
    
            # If the source file is in a subdirectory then the `.o' is put
            # into the current directory, unless the subdir-objects option
            # is in effect.
    
            # Split file name into base and extension.
            next if ! /^(?:(.*)\/)?([^\/]*)($KNOWN_EXTENSIONS_PATTERN)$/;
            my $full = $_;
            my $directory = $1 || '';
            my $base = $2;
            my $extension = $3;
    
            # We must generate a rule for the object if it requires its own flags.
            my $renamed = 0;
            my ($linker, $object);
    
    	# This records whether we've seen a derived source file (eg,
    	# yacc output).
    	my $derived_source = 0;
    
    	# This holds the `aggregate context' of the file we are
    	# currently examining.  If the file is compiled with
    	# per-object flags, then it will be the name of the object.
    	# Otherwise it will be `AM'.  This is used by the target hook
    	# language function.
    	my $aggregate = 'AM';
    
            $extension = &derive_suffix ($extension, $nonansi_obj);
            my $lang;
            if ($extension_map{$extension} &&
                ($lang = $languages{$extension_map{$extension}}))
    	{
                # Found the language, so see what it says.
                &saw_extension ($extension);
    
                # Note: computed subr call.  The language rewrite function
                # should return one of the LANG_* constants.  It could
                # also return a list whose first value is such a constant
                # and whose second value is a new source extension which
                # should be applied.  This means this particular language
                # generates another source file which we must then process
                # further.
                my $subr = 'lang_' . $lang->name . '_rewrite';
                my ($r, $source_extension)
    		= & $subr ($directory, $base, $extension);
                # Skip this entry if we were asked not to process it.
                next if $r == LANG_IGNORE;
    
                # Now extract linker and other info.
                $linker = $lang->linker;
    
                my $this_obj_ext;
    	    if (defined $source_extension)
    	    {
    		$this_obj_ext = $source_extension;
    		$derived_source = 1;
    	    }
    	    elsif ($lang->ansi)
    	    {
    		$this_obj_ext = $obj;
    	    }
    	    else
    	    {
    		$this_obj_ext = $nonansi_obj;
    	    }
    	    $object = $base . $this_obj_ext;
    
    	    # Do we have per-executable flags for this executable?
    	    my $have_per_exec_flags = 0;
    	    foreach my $flag (@{$lang->flags})
    	      {
    		if (variable_defined ("${derived}_$flag"))
    		  {
    		    $have_per_exec_flags = 1;
    		    last;
    		  }
    	      }
    
                if ($have_per_exec_flags)
                {
                    # We have a per-executable flag in effect for this
                    # object.  In this case we rewrite the object's
                    # name to ensure it is unique.  We also require
                    # the `compile' program to deal with compilers
                    # where `-c -o' does not work.
    
                    # We choose the name `DERIVED_OBJECT' to ensure
                    # (1) uniqueness, and (2) continuity between
                    # invocations.  However, this will result in a
                    # name that is too long for losing systems, in
                    # some situations.  So we provide _SHORTNAME to
                    # override.
    
                    my $dname = $derived;
                    if (variable_defined ($derived . '_SHORTNAME'))
                    {
                        # FIXME: should use the same conditional as
                        # the _SOURCES variable.  But this is really
                        # silly overkill -- nobody should have
                        # conditional shortnames.
                        $dname = &variable_value ($derived . '_SHORTNAME');
                    }
                    $object = $dname . '-' . $object;
    
                    require_conf_file ("$am_file.am", FOREIGN, 'compile')
                        if $lang->name eq 'c';
    
    		prog_error ($lang->name . " flags defined without compiler")
    		  if ! defined $lang->compile;
    
                    $renamed = 1;
                }
    
                # If rewrite said it was ok, put the object into a
                # subdir.
                if ($r == LANG_SUBDIR && $directory ne '')
                {
                    $object = $directory . '/' . $object;
                }
    
                # If doing dependency tracking, then we can't print
                # the rule.  If we have a subdir object, we need to
                # generate an explicit rule.  Actually, in any case
                # where the object is not in `.' we need a special
                # rule.  The per-object rules in this case are
                # generated later, by handle_languages.
                if ($renamed || $directory ne '')
                {
                    my $obj_sans_ext = substr ($object, 0,
    					   - length ($this_obj_ext));
    		my $val = ("$full $obj_sans_ext "
    			   # Only use $this_obj_ext in the derived
    			   # source case because in the other case we
    			   # *don't* want $(OBJEXT) to appear here.
    			   . ($derived_source ? $this_obj_ext : '.o'));
    
    		# If we renamed the object then we want to use the
    		# per-executable flag name.  But if this is simply a
    		# subdir build then we still want to use the AM_ flag
    		# name.
    		if ($renamed)
    		{
    		    $val = "$derived $val";
    		    $aggregate = $derived;
    		}
    		else
    		{
    		    $val = "AM $val";
    		}
    
    		# Each item on this list is a string consisting of
    		# four space-separated values: the derived flag prefix
    		# (eg, for `foo_CFLAGS', it is `foo'), the name of the
    		# source file, the base name of the output file, and
    		# the extension for the object file.
                    push (@{$lang_specific_files{$lang->name}}, $val);
                }
            }
            elsif ($extension eq $nonansi_obj)
            {
                # This is probably the result of a direct suffix rule.
                # In this case we just accept the rewrite.
                $object = "$base$extension";
                $linker = '';
            }
            else
            {
                # No error message here.  Used to have one, but it was
                # very unpopular.
    	    # FIXME: we could potentially do more processing here,
    	    # perhaps treating the new extension as though it were a
    	    # new source extension (as above).  This would require
    	    # more restructuring than is appropriate right now.
                next;
            }
    
    	err_am "object `$object' created by `$full' and `$object_map{$object}'"
    	  if (defined $object_map{$object}
    	      && $object_map{$object} ne $full);
    
    	my $comp_val = (($object =~ /\.lo$/)
    			? COMPILE_LIBTOOL : COMPILE_ORDINARY);
    	(my $comp_obj = $object) =~ s/\.lo$/.\$(OBJEXT)/;
    	if (defined $object_compilation_map{$comp_obj}
    	    && $object_compilation_map{$comp_obj} != 0
    	    # Only see the error once.
    	    && ($object_compilation_map{$comp_obj}
    		!= (COMPILE_LIBTOOL | COMPILE_ORDINARY))
    	    && $object_compilation_map{$comp_obj} != $comp_val)
    	  {
    	    err_am "object `$object' created both with libtool and without";
    	  }
    	$object_compilation_map{$comp_obj} |= $comp_val;
    
    	if (defined $lang)
    	{
    	    # Let the language do some special magic if required.
    	    $lang->target_hook ($aggregate, $object, $full);
    	}
    
    	if ($derived_source)
    	  {
    	    prog_error ($lang->name . " has automatic dependency tracking")
    	      if $lang->autodep ne 'no';
    	    # Make sure this new source file is handled next.  That will
    	    # make it appear to be at the right place in the list.
    	    unshift (@files, $object);
    	    # Distribute derived sources unless the source they are
    	    # derived from is not.
    	    &push_dist_common ($object)
    	      unless ($topparent =~ /^(?:nobase_)?nodist_/);
    	    next;
    	  }
    
            $linkers_used{$linker} = 1;
    
            push (@result, $object);
    
            if (! defined $object_map{$object})
            {
                my @dep_list = ();
                $object_map{$object} = $full;
    
                # If file is in subdirectory, we need explicit
                # dependency.
                if ($directory ne '' || $renamed)
                {
                    push (@dep_list, $full);
                }
    
                # If resulting object is in subdir, we need to make
                # sure the subdir exists at build time.
                if ($object =~ /\//)
                {
                    # FIXME: check that $DIRECTORY is somewhere in the
                    # project
    
    		# For Java, the way we're handling it right now, a
    		# `..' component doesn't make sense.
                    if ($lang->name eq 'java' && $object =~ /(\/|^)\.\.\//)
    		  {
    		    err_am "`$full' should not contain a `..' component";
    		  }
    
    		# Make sure object is removed by `make mostlyclean'.
    		$compile_clean_files{$object} = MOSTLY_CLEAN;
    		# If we have a libtool object then we also must remove
    		# the ordinary .o.
    		if ($object =~ /\.lo$/)
    		{
    		    (my $xobj = $object) =~ s,lo$,\$(OBJEXT),;
    		    $compile_clean_files{$xobj} = MOSTLY_CLEAN;
    
    		    $libtool_clean_directories{$directory} = 1;
    		}
    
                    push (@dep_list, require_build_directory ($directory));
    
                    # If we're generating dependencies, we also want
                    # to make sure that the appropriate subdir of the
                    # .deps directory is created.
    		push (@dep_list,
    		      require_build_directory ($directory . '/$(DEPDIR)'))
    		    if $use_dependencies;
                }
    
                &pretty_print_rule ($object . ':', "\t", @dep_list)
                    if scalar @dep_list > 0;
            }
    
            # Transform .o or $o file into .P file (for automatic
            # dependency code).
            if ($lang && $lang->autodep ne 'no')
            {
                my $depfile = $object;
                $depfile =~ s/\.([^.]*)$/.P$1/;
                $depfile =~ s/\$\(OBJEXT\)$/o/;
                $dep_files{dirname ($depfile) . '/$(DEPDIR)/'
    			   . basename ($depfile)} = 1;
            }
        }
    
        return @result;
    }
    
    # ($LINKER, $OBJVAR)
    # define_objects_from_sources ($VAR, $OBJVAR, $NODEFINE, $ONE_FILE,
    #                              $OBJ, $PARENT, $TOPPARENT)
    # ---------------------------------------------------------------------
    # Define an _OBJECTS variable for a _SOURCES variable (or subvariable)
    #
    # Arguments are:
    #   $VAR is the name of the _SOURCES variable
    #   $OBJVAR is the name of the _OBJECTS variable if known (otherwise
    #     it will be generated and returned).
    #   $NODEFINE is a boolean: if true, $OBJVAR will not be defined (but
    #     work done to determine the linker will be).
    #   $ONE_FILE is the canonical (transformed) name of object to build
    #   $OBJ is the object extension (ie either `.o' or `.lo').
    #   $PARENT is the variable in which $VAR is used, or $VAR if not applicable.
    #   $TOPPARENT is the _SOURCES variable being processed.
    #
    # Result is a pair ($LINKER, $OBJVAR):
    #    $LINKER is a boolean, true if a linker is needed to deal with the objects,
    #    $OBJVAR is the name of the variable defined to hold the objects.
    #
    # %linkers_used, %vars_scanned, @substfroms and @substtos should be cleared
    # before use:
    #   %linkers_used variable will be set to contain the linkers desired.
    #   %vars_scanned will be used to check for recursive definitions.
    #   @substfroms and @substtos will be used to keep a stack of variable
    #   substitutions to be applied.
    #
    sub define_objects_from_sources ($$$$$$$)
    {
        my ($var, $objvar, $nodefine, $one_file, $obj, $parent, $topparent) = @_;
    
        if (defined $vars_scanned{$var})
        {
    	err_var $var, "variable `$var' recursively defined";
    	return "";
        }
        $vars_scanned{$var} = 1;
    
        my $needlinker = "";
        my @allresults = ();
        foreach my $cond (variable_conditions ($var))
        {
    	my @result;
    	foreach my $val (&variable_value_as_list ($var, $cond, $parent))
    	{
    	    # If $val is a variable (i.e. ${foo} or $(bar), not a filename),
    	    # handle the sub variable recursively.
    	    if ($val =~ /^\$\{([^}]*)\}$/ || $val =~ /^\$\(([^)]*)\)$/)
    	    {
    		my $subvar = $1;
    
    		# If the user uses a losing variable name, just ignore it.
    		# This isn't ideal, but people have requested it.
    		next if ($subvar =~ /\@.*\@/);
    
    		# See if the variable is actually a substitution reference
    		my ($from, $to);
    		my @temp_list;
    		if ($subvar =~ /$SUBST_REF_PATTERN/o)
    		{
    		    $subvar = $1;
    		    $to = $3;
    		    $from = quotemeta $2;
    		}
    		push @substfroms, $from;
    		push @substtos, $to;
    
    		my ($temp, $varname)
    		    = define_objects_from_sources ($subvar, undef,
    						   $nodefine, $one_file,
    						   $obj, $var, $topparent);
    
    		push (@result, '$('. $varname . ')');
    		$needlinker ||= $temp;
    
    		pop @substfroms;
    		pop @substtos;
    	    }
    	    else # $var is a filename
    	    {
    	        my $substnum=$#substfroms;
    	        while ($substnum >= 0)
    		{
    		    $val =~ s/$substfroms[$substnum]$/$substtos[$substnum]/
    			if defined $substfroms[$substnum];
    		    $substnum -= 1;
    		}
    
    		my (@transformed) =
    		      &handle_single_transform_list ($var, $topparent, $one_file, $obj, $val);
    		push (@result, @transformed);
    		$needlinker = "true" if @transformed;
    	    }
    	}
    	push (@allresults, [$cond, @result]);
        }
        # Find a name for the variable, unless imposed.
        $objvar = subobjname (@allresults) unless defined $objvar;
        # Define _OBJECTS conditionally
        unless ($nodefine)
        {
    	foreach my $pair (@allresults)
    	{
    	    my ($cond, @result) = @$pair;
    	    define_pretty_variable ($objvar, $cond, @result);
    	}
        }
    
        delete $vars_scanned{$var};
        return ($needlinker, $objvar);
    }
    
    
    # $VARNAME
    # subobjname (@DEFINITIONS)
    # -------------------------
    # Return a name for an object variable that with definitions @DEFINITIONS.
    # @DEFINITIONS is a list of pair [$COND, @OBJECTS].
    #
    # If we already have an object variable containing @DEFINITIONS, reuse it.
    # This way, we avoid combinatorial explosion of the generated
    # variables.  Especially, in a Makefile such as:
    #
    # | if FOO1
    # | A1=1
    # | endif
    # |
    # | if FOO2
    # | A2=2
    # | endif
    # |
    # | ...
    # |
    # | if FOON
    # | AN=N
    # | endif
    # |
    # | B=$(A1) $(A2) ... $(AN)
    # |
    # | c_SOURCES=$(B)
    # | d_SOURCES=$(B)
    #
    # The generated c_OBJECTS and d_OBJECTS will share the same variable
    # definitions.
    #
    # This setup can be the case of a testsuite containing lots (>100) of
    # small C programs, all testing the same set of source files.
    sub subobjname (@)
    {
        my $key = '';
        foreach my $pair (@_)
        {
    	my ($cond, @values) = @$pair;
    	$key .= "($cond)@values";
        }
    
        return $subobjvar{$key} if exists $subobjvar{$key};
    
        my $num = 1 + keys (%subobjvar);
        my $name = "am__objects_${num}";
        $subobjvar{$key} = $name;
        return $name;
    }
    
    
    # Handle SOURCE->OBJECT transform for one program or library.
    # Arguments are:
    #   canonical (transformed) name of object to build
    #   actual name of object to build
    #   object extension (ie either `.o' or `$o'.
    # Return result is name of linker variable that must be used.
    # Empty return means just use `LINK'.
    sub handle_source_transform
    {
        # one_file is canonical name.  unxformed is given name.  obj is
        # object extension.
        my ($one_file, $unxformed, $obj) = @_;
    
        my ($linker) = '';
    
        # No point in continuing if _OBJECTS is defined.
        return if reject_var ($one_file . '_OBJECTS',
    			  $one_file . '_OBJECTS should not be defined');
    
        my %used_pfx = ();
        my $needlinker;
        %linkers_used = ();
        foreach my $prefix ('', 'EXTRA_', 'dist_', 'nodist_',
    			'dist_EXTRA_', 'nodist_EXTRA_')
        {
    	my $var = $prefix . $one_file . "_SOURCES";
    	next
    	  if !variable_defined ($var);
    
    	# We are going to define _OBJECTS variables using the prefix.
    	# Then we glom them all together.  So we can't use the null
    	# prefix here as we need it later.
    	my $xpfx = ($prefix eq '') ? 'am_' : $prefix;
    
    	# Keep track of which prefixes we saw.
    	$used_pfx{$xpfx} = 1
    	  unless $prefix =~ /EXTRA_/;
    
    	push @sources, "\$($var)";
    	push @dist_sources, "\$($var)"
    	  unless $prefix =~ /^nodist_/;
    
    	@substfroms = ();
    	@substtos = ();
    	%vars_scanned = ();
    	my ($temp, $objvar) =
    	    define_objects_from_sources ($var,
    					 $xpfx . $one_file . '_OBJECTS',
    					 $prefix =~ /EXTRA_/,
    					 $one_file, $obj, $var, $var);
    	$needlinker ||= $temp;
        }
        if ($needlinker)
        {
    	$linker ||= &resolve_linker (%linkers_used);
        }
    
        my @keys = sort keys %used_pfx;
        if (scalar @keys == 0)
        {
    	&define_variable ($one_file . "_SOURCES", $unxformed . ".c");
    	push (@sources, $unxformed . '.c');
    	push (@dist_sources, $unxformed . '.c');
    
    	%linkers_used = ();
    	my (@result) =
    	  &handle_single_transform_list ($one_file . '_SOURCES',
    					 $one_file . '_SOURCES',
    					 $one_file, $obj,
    					 "$unxformed.c");
    	$linker ||= &resolve_linker (%linkers_used);
    	define_pretty_variable ($one_file . "_OBJECTS", '', @result)
        }
        else
        {
    	grep ($_ = '$(' . $_ . $one_file . '_OBJECTS)', @keys);
    	define_pretty_variable ($one_file . '_OBJECTS', '', @keys);
        }
    
        # If we want to use `LINK' we must make sure it is defined.
        if ($linker eq '')
        {
    	$need_link = 1;
        }
    
        return $linker;
    }
    
    
    # handle_lib_objects ($XNAME, $VAR)
    # ---------------------------------
    # Special-case ALLOCA and LIBOBJS substitutions in _LDADD or _LIBADD variables.
    # Also, generate _DEPENDENCIES variable if appropriate.
    # Arguments are:
    #   transformed name of object being built, or empty string if no object
    #   name of _LDADD/_LIBADD-type variable to examine
    # Returns 1 if LIBOBJS seen, 0 otherwise.
    sub handle_lib_objects
    {
        my ($xname, $var) = @_;
    
        prog_error "handle_lib_objects: $var undefined"
          if ! variable_defined ($var);
    
        my $ret = 0;
        foreach my $cond (variable_conditions_recursive ($var))
          {
    	if (&handle_lib_objects_cond ($xname, $var, $cond))
    	  {
    	    $ret = 1;
    	  }
          }
        return $ret;
    }
    
    # Subroutine of handle_lib_objects: handle a particular condition.
    sub handle_lib_objects_cond
    {
        my ($xname, $var, $cond) = @_;
    
        # We recognize certain things that are commonly put in LIBADD or
        # LDADD.
        my @dep_list = ();
    
        my $seen_libobjs = 0;
        my $flagvar = 0;
    
        foreach my $lsearch (&variable_value_as_list_recursive ($var, $cond))
        {
    	# Skip -lfoo and -Ldir; these are explicitly allowed.
    	next if $lsearch =~ /^-[lL]/;
    	if (! $flagvar && $lsearch =~ /^-/)
    	{
    	    if ($var =~ /^(.*)LDADD$/)
    	    {
    		# Skip -dlopen and -dlpreopen; these are explicitly allowed.
    		next if $lsearch =~ /^-dl(pre)?open$/;
    		my $prefix = $1 || 'AM_';
    		err_var ($var, "linker flags such as `$lsearch' belong in "
    			 . "`${prefix}LDFLAGS");
    	    }
    	    else
    	    {
    		$var =~ /^(.*)LIBADD$/;
    		# Only get this error once.
    		$flagvar = 1;
    		err_var ($var, "linker flags such as `$lsearch' belong in "
    			 . "`${1}LDFLAGS");
    	    }
    	}
    
    	# Assume we have a file of some sort, and push it onto the
    	# dependency list.  Autoconf substitutions are not pushed;
    	# rarely is a new dependency substituted into (eg) foo_LDADD
    	# -- but "bad things (eg -lX11) are routinely substituted.
    	# Note that LIBOBJS and ALLOCA are exceptions to this rule,
    	# and handled specially below.
    	push (@dep_list, $lsearch)
    	    unless $lsearch =~ /^\@.*\@$/;
    
    	# Automatically handle LIBOBJS and ALLOCA substitutions.
    	# Basically this means adding entries to dep_files.
    	if ($lsearch =~ /^\@(LT)?LIBOBJS\@$/)
    	{
    	    my $lt = $1 ? $1 : '';
    	    my $myobjext = ($1 ? 'l' : '') . 'o';
    
    	    push (@dep_list, $lsearch);
    	    $seen_libobjs = 1;
    	    if (! keys %libsources
    		&& ! variable_defined ($lt . 'LIBOBJS'))
    	    {
    	        err_var ($var, "\@${lt}LIBOBJS\@ seen but never set in "
    			 . "`$configure_ac'");
    	    }
    
    	    foreach my $iter (keys %libsources)
    	    {
    		if ($iter =~ /\.[cly]$/)
    		{
    		    &saw_extension ($&);
    		    &saw_extension ('.c');
    		}
    
    		if ($iter =~ /\.h$/)
    		{
    		    require_file_with_macro ($cond, $var, FOREIGN, $iter);
    		}
    		elsif ($iter ne 'alloca.c')
    		{
    		    my $rewrite = $iter;
    		    $rewrite =~ s/\.c$/.P$myobjext/;
    		    $dep_files{'$(DEPDIR)/' . $rewrite} = 1;
    		    $rewrite = "^" . quotemeta ($iter) . "\$";
    		    # Only require the file if it is not a built source.
    		    if (! variable_defined ('BUILT_SOURCES')
    			|| ! grep (/$rewrite/,
    				   &variable_value_as_list_recursive (
    				   	'BUILT_SOURCES', 'all')))
    		    {
    			require_file_with_macro ($cond, $var, FOREIGN, $iter);
    		    }
    		}
    	    }
    	}
    	elsif ($lsearch =~ /^\@(LT)?ALLOCA\@$/)
    	{
    	    my $lt = $1 ? $1 : '';
    	    my $myobjext = ($1 ? 'l' : '') . 'o';
    
    	    push (@dep_list, $lsearch);
    	    err_var ($var, "\@${lt}ALLOCA\@ seen but `AC_FUNC_ALLOCA' not in "
    		     . "`$configure_ac'")
    	      if ! defined $libsources{'alloca.c'};
    	    $dep_files{'$(DEPDIR)/alloca.P' . $myobjext} = 1;
    	    require_file_with_macro ($cond, $var, FOREIGN, 'alloca.c');
    	    &saw_extension ('c');
    	}
        }
    
      if ($xname ne '')
        {
          my $depvar = $xname . '_DEPENDENCIES';
          if ((conditional_ambiguous_p ($depvar, $cond,
    				    keys %{$var_value{$depvar}}))[0] ne '')
    	{
    	  # Note that we've examined this.
    	  &examine_variable ($depvar);
    	}
          else
    	{
    	  define_pretty_variable ($depvar, $cond, @dep_list);
    	}
        }
    
      return $seen_libobjs;
    }
    
    # Canonicalize the input parameter
    sub canonicalize
    {
        my ($string) = @_;
        $string =~ tr/A-Za-z0-9_\@/_/c;
        return $string;
    }
    
    # Canonicalize a name, and check to make sure the non-canonical name
    # is never used.  Returns canonical name.  Arguments are name and a
    # list of suffixes to check for.
    sub check_canonical_spelling
    {
      my ($name, @suffixes) = @_;
    
      my $xname = &canonicalize ($name);
      if ($xname ne $name)
        {
          foreach my $xt (@suffixes)
    	{
    	  reject_var ("$name$xt", "use `$xname$xt', not `$name$xt'");
    	}
        }
    
      return $xname;
    }
    
    
    # handle_compile ()
    # -----------------
    # Set up the compile suite.
    sub handle_compile ()
    {
        return
          unless $get_object_extension_was_run;
    
        # Boilerplate.
        my $default_includes = '';
        if (! defined $options{'nostdinc'})
          {
    	$default_includes = ' -I. -I$(srcdir)';
    
    	if (variable_defined ('CONFIG_HEADER'))
    	  {
    	    foreach my $hdr (split (' ', &variable_value ('CONFIG_HEADER')))
    	      {
    		$default_includes .= ' -I' . dirname ($hdr);
    	      }
    	  }
          }
    
        my (@mostly_rms, @dist_rms);
        foreach my $item (sort keys %compile_clean_files)
        {
    	if ($compile_clean_files{$item} == MOSTLY_CLEAN)
    	{
    	    push (@mostly_rms, "\t-rm -f $item");
    	}
    	elsif ($compile_clean_files{$item} == DIST_CLEAN)
    	{
    	    push (@dist_rms, "\t-rm -f $item");
    	}
    	else
    	{
    	  prog_error 'invalid entry in %compile_clean_files';
    	}
        }
    
        my ($coms, $vars, $rules) =
          &file_contents_internal (1, "$libdir/am/compile.am",
    			       ('DEFAULT_INCLUDES' => $default_includes,
    				'MOSTLYRMS' => join ("\n", @mostly_rms),
    				'DISTRMS' => join ("\n", @dist_rms)));
        $output_vars .= $vars;
        $output_rules .= "$coms$rules";
    
        # Check for automatic de-ANSI-fication.
        if (defined $options{'ansi2knr'})
          {
    	require_variables_for_macro ('AUTOMAKE_OPTIONS',
    				     "option `ansi2knr' is used",
    				     "ANSI2KNR", "U");
    
    	# topdir is where ansi2knr should be.
    	if ($options{'ansi2knr'} eq 'ansi2knr')
    	  {
    	    # Only require ansi2knr files if they should appear in
    	    # this directory.
    	    require_file_with_macro ('TRUE', 'AUTOMAKE_OPTIONS', FOREIGN,
    				     'ansi2knr.c', 'ansi2knr.1');
    
    	    # ansi2knr needs to be built before subdirs, so unshift it.
    	    unshift (@all, '$(ANSI2KNR)');
    	  }
    
    	my $ansi2knr_dir = '';
    	$ansi2knr_dir = dirname ($options{'ansi2knr'})
    	  if $options{'ansi2knr'} ne 'ansi2knr';
    
    	$output_rules .= &file_contents ('ansi2knr',
    					 ('ANSI2KNR-DIR' => $ansi2knr_dir));
    
        }
    }
    
    # handle_libtool ()
    # -----------------
    # Handle libtool rules.
    sub handle_libtool
    {
      return unless variable_defined ('LIBTOOL');
    
      # Libtool requires some files, but only at top level.
      require_conf_file_with_macro ('TRUE', 'LIBTOOL', FOREIGN, @libtool_files)
        if $relative_dir eq '.';
    
      my @libtool_rms;
      foreach my $item (sort keys %libtool_clean_directories)
        {
          my $dir = ($item eq '.') ? '' : "$item/";
          # .libs is for Unix, _libs for DOS.
          push (@libtool_rms, "\t-rm -rf ${dir}.libs ${dir}_libs");
        }
    
      # Output the libtool compilation rules.
      $output_rules .= &file_contents ('libtool',
    				   ('LTRMS' => join ("\n", @libtool_rms)));
    }
    
    # handle_programs ()
    # ------------------
    # Handle C programs.
    sub handle_programs
    {
      my @proglist = &am_install_var ('progs', 'PROGRAMS',
    				  'bin', 'sbin', 'libexec', 'pkglib',
    				  'noinst', 'check');
      return if ! @proglist;
    
      my $seen_global_libobjs =
        variable_defined ('LDADD') && &handle_lib_objects ('', 'LDADD');
    
      foreach my $one_file (@proglist)
        {
          my $seen_libobjs = 0;
          my $obj = &get_object_extension ($one_file);
    
          # Canonicalize names and check for misspellings.
          my $xname = &check_canonical_spelling ($one_file, '_LDADD', '_LDFLAGS',
    					     '_SOURCES', '_OBJECTS',
    					     '_DEPENDENCIES');
    
          my $linker = &handle_source_transform ($xname, $one_file, $obj);
    
          my $xt = '';
          if (variable_defined ($xname . "_LDADD"))
    	{
    	  $seen_libobjs = &handle_lib_objects ($xname, $xname . '_LDADD');
    	  $xt = '_LDADD';
    	}
          else
    	{
    	  # User didn't define prog_LDADD override.  So do it.
    	  &define_variable ($xname . '_LDADD', '$(LDADD)');
    
    	  # This does a bit too much work.  But we need it to
    	  # generate _DEPENDENCIES when appropriate.
    	  if (variable_defined ('LDADD'))
    	    {
    	      $seen_libobjs = &handle_lib_objects ($xname, 'LDADD');
    	    }
    	  elsif (! variable_defined ($xname . '_DEPENDENCIES'))
    	    {
    	      &define_variable ($xname . '_DEPENDENCIES', '');
    	    }
    	  $xt = '_SOURCES';
    	}
    
          reject_var ($xname . '_LIBADD',
    		  "use `${xname}_LDADD', not `${xname}_LIBADD'");
    
          if (! variable_defined ($xname . '_LDFLAGS'))
    	{
    	  # Define the prog_LDFLAGS variable.
    	  &define_variable ($xname . '_LDFLAGS', '');
    	}
    
          # Determine program to use for link.
          my $xlink;
          if (variable_defined ($xname . '_LINK'))
    	{
    	  $xlink = $xname . '_LINK';
    	}
          else
    	{
    	  $xlink = $linker ? $linker : 'LINK';
    	}
    
          # If the resulting program lies into a subdirectory,
          # make sure this directory will exist.
          my $dirstamp = require_build_directory_maybe ($one_file);
    
          # Don't add $(EXEEXT) if user already did.
          my $extension = ($one_file !~ /\$\(EXEEXT\)$/
    		       ? "\$(EXEEXT)"
    		       : '');
    
          $output_rules .= &file_contents ('program',
    				       ('PROGRAM'  => $one_file,
    					'XPROGRAM' => $xname,
    					'XLINK'    => $xlink,
    					'DIRSTAMP' => $dirstamp,
    					'EXEEXT'   => $extension));
    
          if ($seen_libobjs || $seen_global_libobjs)
    	{
    	  if (variable_defined ($xname . '_LDADD'))
    	    {
    	      &check_libobjs_sources ($xname, $xname . '_LDADD');
    	    }
    	  elsif (variable_defined ('LDADD'))
    	    {
    	      &check_libobjs_sources ($xname, 'LDADD');
    	    }
    	}
        }
    }
    
    
    # handle_libraries ()
    # -------------------
    # Handle libraries.
    sub handle_libraries
    {
      my @liblist = &am_install_var ('libs', 'LIBRARIES',
    				 'lib', 'pkglib', 'noinst', 'check');
      return if ! @liblist;
    
      my @prefix = am_primary_prefixes ('LIBRARIES', 0, 'lib', 'pkglib',
    				    'noinst', 'check');
    
      require_variables_for_macro ($prefix[0] . '_LIBRARIES',
    			       'library used', 'RANLIB')
        if (@prefix);
    
      foreach my $onelib (@liblist)
        {
          my $seen_libobjs = 0;
          # Check that the library fits the standard naming convention.
          if (basename ($onelib) !~ /^lib.*\.a/)
    	{
    	  # FIXME should put line number here.  That means mapping
    	  # from library name back to variable name.
    	  err_am "`$onelib' is not a standard library name";
    	}
    
          my $obj = &get_object_extension ($onelib);
    
          # Canonicalize names and check for misspellings.
          my $xlib = &check_canonical_spelling ($onelib, '_LIBADD', '_SOURCES',
    					    '_OBJECTS', '_DEPENDENCIES',
    					    '_AR');
    
          if (! variable_defined ($xlib . '_AR'))
    	{
    	  &define_variable ($xlib . '_AR', '$(AR) cru');
    	}
    
          if (variable_defined ($xlib . '_LIBADD'))
    	{
    	  if (&handle_lib_objects ($xlib, $xlib . '_LIBADD'))
    	    {
    	      $seen_libobjs = 1;
    	    }
    	}
          else
    	{
    	  # Generate support for conditional object inclusion in
    	  # libraries.
    	  &define_variable ($xlib . "_LIBADD", '');
    	}
    
          reject_var ($xlib . '_LDADD',
    		  "use `${xlib}_LIBADD', not `${xlib}_LDADD'");
    
          # Make sure we at look at this.
          &examine_variable ($xlib . '_DEPENDENCIES');
    
          &handle_source_transform ($xlib, $onelib, $obj);
    
          # If the resulting library lies into a subdirectory,
          # make sure this directory will exist.
          my $dirstamp = require_build_directory_maybe ($onelib);
    
          $output_rules .= &file_contents ('library',
    				       ('LIBRARY'  => $onelib,
    					'XLIBRARY' => $xlib,
    					'DIRSTAMP' => $dirstamp));
    
          if ($seen_libobjs)
    	{
    	  if (variable_defined ($xlib . '_LIBADD'))
    	    {
    	      &check_libobjs_sources ($xlib, $xlib . '_LIBADD');
    	    }
    	}
        }
    }
    
    
    # handle_ltlibraries ()
    # ---------------------
    # Handle shared libraries.
    sub handle_ltlibraries
    {
      my @liblist = &am_install_var ('ltlib', 'LTLIBRARIES',
    				 'noinst', 'lib', 'pkglib', 'check');
      return if ! @liblist;
    
      my %instdirs;
      my @prefix = am_primary_prefixes ('LTLIBRARIES', 0, 'lib', 'pkglib',
    				    'noinst', 'check');
    
      require_variables_for_macro ($prefix[0] . '_LTLIBRARIES',
    			       'Libtool library used', 'LIBTOOL')
        if (@prefix);
    
      foreach my $key (@prefix)
        {
          # Get the installation directory of each library.
          (my $dir = $key) =~ s/^nobase_//;
          for (variable_value_as_list_recursive ($key . '_LTLIBRARIES', 'all'))
    	{
    	  if ($instdirs{$_})
    	    {
    	      err_am ("`$_' is already going to be installed in "
    		      . "`$instdirs{$_}'");
    	    }
    	  else
    	    {
    	      $instdirs{$_} = $dir;
    	    }
    	}
        }
    
      foreach my $onelib (@liblist)
        {
          my $seen_libobjs = 0;
          my $obj = &get_object_extension ($onelib);
    
          # Canonicalize names and check for misspellings.
          my $xlib = &check_canonical_spelling ($onelib, '_LIBADD', '_LDFLAGS',
    					    '_SOURCES', '_OBJECTS',
    					    '_DEPENDENCIES');
    
          if (! variable_defined ($xlib . '_LDFLAGS'))
    	{
    	  # Define the lib_LDFLAGS variable.
    	  &define_variable ($xlib . '_LDFLAGS', '');
    	}
    
          # Check that the library fits the standard naming convention.
          my $libname_rx = "^lib.*\.la";
          if ((variable_defined ($xlib . '_LDFLAGS')
    	   && grep (/-module/,
    		    &variable_value_as_list_recursive ($xlib . '_LDFLAGS',
    						       'all')))
    	  || (variable_defined ('LDFLAGS')
    	      && grep (/-module/,
    		       &variable_value_as_list_recursive ('LDFLAGS', 'all'))))
    	{
    	  # Relax name checking for libtool modules.
    	  $libname_rx = "\.la";
    	}
          if (basename ($onelib) !~ /$libname_rx$/)
    	{
    	  # FIXME should put line number here.  That means mapping
    	  # from library name back to variable name.
    	  msg_am ('error-gnu/warn',
    		  "`$onelib' is not a standard libtool library name");
    	}
    
          if (variable_defined ($xlib . '_LIBADD'))
    	{
    	  if (&handle_lib_objects ($xlib, $xlib . '_LIBADD'))
    	    {
    	      $seen_libobjs = 1;
    	    }
    	}
          else
    	{
    	  # Generate support for conditional object inclusion in
    	  # libraries.
    	  &define_variable ($xlib . "_LIBADD", '');
    	}
    
          reject_var ("${xlib}_LDADD",
    		  "use `${xlib}_LIBADD', not `${xlib}_LDADD'");
    
          # Make sure we at look at this.
          &examine_variable ($xlib . '_DEPENDENCIES');
    
          my $linker = &handle_source_transform ($xlib, $onelib, $obj);
    
          # Determine program to use for link.
          my $xlink;
          if (variable_defined ($xlib . '_LINK'))
    	{
    	  $xlink = $xlib . '_LINK';
    	}
          else
    	{
    	  $xlink = $linker ? $linker : 'LINK';
    	}
    
          my $rpath;
          if ($instdirs{$onelib} eq 'EXTRA'
    	  || $instdirs{$onelib} eq 'noinst'
    	  || $instdirs{$onelib} eq 'check')
    	{
    	  # It's an EXTRA_ library, so we can't specify -rpath,
    	  # because we don't know where the library will end up.
    	  # The user probably knows, but generally speaking automake
    	  # doesn't -- and in fact configure could decide
    	  # dynamically between two different locations.
    	  $rpath = '';
    	}
          else
    	{
    	  $rpath = ('-rpath $(' . $instdirs{$onelib} . 'dir)');
    	}
    
          # If the resulting library lies into a subdirectory,
          # make sure this directory will exist.
          my $dirstamp = require_build_directory_maybe ($onelib);
    
          $output_rules .= &file_contents ('ltlibrary',
    				       ('LTLIBRARY'  => $onelib,
    					'XLTLIBRARY' => $xlib,
    					'RPATH'      => $rpath,
    					'XLINK'      => $xlink,
    					'DIRSTAMP'   => $dirstamp));
          if ($seen_libobjs)
    	{
    	  if (variable_defined ($xlib . '_LIBADD'))
    	    {
    	      &check_libobjs_sources ($xlib, $xlib . '_LIBADD');
    	    }
    	}
        }
    }
    
    # See if any _SOURCES variable were misspelled.
    sub check_typos ()
    {
      # It is ok if the user sets this particular variable.
      &examine_variable ('AM_LDFLAGS');
    
      foreach my $varname (keys %var_value)
        {
          foreach my $primary ('_SOURCES', '_LIBADD', '_LDADD', '_LDFLAGS',
    			   '_DEPENDENCIES')
    	{
    	  msg_var 'syntax', $varname, "unused variable: `$varname'"
    	    # Note that a configure variable is always legitimate.
    	    if ($varname =~ /$primary$/ && ! $content_seen{$varname}
    		&& ! exists $configure_vars{$varname});
    	}
        }
    }
    
    
    # Handle scripts.
    sub handle_scripts
    {
        # NOTE we no longer automatically clean SCRIPTS, because it is
        # useful to sometimes distribute scripts verbatim.  This happens
        # eg in Automake itself.
        &am_install_var ('-candist', 'scripts', 'SCRIPTS',
    		     'bin', 'sbin', 'libexec', 'pkgdata',
    		     'noinst', 'check');
    }
    
    
    # ($OUTFILE, $VFILE, @CLEAN_FILES)
    # &scan_texinfo_file ($FILENAME)
    # ------------------------------
    # $OUTFILE is the name of the info file produced by $FILENAME.
    # $VFILE is the name of the version.texi file used (empty if none).
    # @CLEAN_FILES is the list of by products (indexes etc.)
    sub scan_texinfo_file
    {
        my ($filename) = @_;
    
        # These are always created, no matter whether indexes are used or not.
        # (Actually tmp is only created if an @macro is used and a certain e-TeX
        # feature is not available.)
        my @clean_suffixes = qw(aux log toc tmp
    			    cp fn ky vr tp pg); # grep new.*index texinfo.tex
    
        # There are predefined indexes which don't follow the regular rules.
        my %predefined_index = qw(c cps
    			      f fns
    			      k kys
    			      v vrs
    			      t tps
    			      p pgs);
    
        # There are commands which include a hidden index command.
        my %hidden_index = (tp => 'tps');
        $hidden_index{$_} = 'fns' foreach qw(fn un typefn typefun max spec
    					 op typeop method typemethod);
        $hidden_index{$_} = 'vrs' foreach qw(vr var typevr typevar opt cv
    					 ivar typeivar);
    
        # Indexes stored into another one.  In this case, the *.??s file
        # is not created.
        my @syncodeindexes = ();
    
        my $texi = new Automake::XFile "< $filename";
        verb "reading $filename";
    
        my ($outfile, $vfile);
        while ($_ = $texi->getline)
        {
          if (/^\@setfilename +(\S+)/)
          {
            $outfile = $1;
            if ($outfile =~ /\.(.+)$/ && $1 ne 'info')
              {
    	    err "$filename:$.", "output `$outfile' has unrecognized extension";
                return;
              }
          }
          # A "version.texi" file is actually any file whose name
          # matches "vers*.texi".
          elsif (/^\@include\s+(vers[^.]*\.texi)\s*$/)
          {
            $vfile = $1;
          }
    
          # Try to find what are the indexes which are used.
    
          # Creating a new category of index.
          elsif (/^\@def(code)?index (\w+)/)
          {
            push @clean_suffixes, $2;
          }
    
          # Storing in a predefined index.
          elsif (/^\@([cfkvtp])index /)
          {
            push @clean_suffixes, $predefined_index{$1};
          }
          elsif (/^\@def(\w+) /)
          {
    	push @clean_suffixes, $hidden_index{$1}
    	  if defined $hidden_index{$1};
          }
    
          # Merging an index into an another.
          elsif (/^\@syn(code)?index (\w+) (\w+)/)
          {
    	push @syncodeindexes, "$2s";
    	push @clean_suffixes, "$3s";
          }
    
        }
    
        if ($outfile eq '')
          {
    	err_am "`$filename' missing \@setfilename";
    	return;
          }
    
        my $infobase = basename ($filename);
        $infobase =~ s/\.te?xi(nfo)?$//;
        my %clean_files = map { +"$infobase.$_" => 1 } @clean_suffixes;
        grep { delete $clean_files{"$infobase.$_"} } @syncodeindexes;
        return ($outfile, $vfile, (sort keys %clean_files));
    }
    
    # ($DIRSTAMP, @CLEAN_FILES)
    # output_texinfo_build_rules ($SOURCE, $DEST, @DEPENDENCIES)
    # ----------------------------------------------------------
    # SOURCE - the source Texinfo file
    # DEST - the destination Info file
    # DEPENDENCIES - known dependencies
    sub output_texinfo_build_rules ($$@)
    {
      my ($source, $dest, @deps) = @_;
    
      # Split `a.texi' into `a' and `.texi'.
      my ($spfx, $ssfx) = ($source =~ /^(.*?)(\.[^.]*)?$/);
      my ($dpfx, $dsfx) = ($dest =~ /^(.*?)(\.[^.]*)?$/);
    
      $ssfx ||= "";
      $dsfx ||= "";
    
      # We can output two kinds of rules: the "generic" rules
      # use Make suffix rules and are appropritate when
      # $source and $dest lie in the current directory; the "specifix"
      # rules is needed in the other case.
      #
      # The former are output only once (this is not really apparent
      # here, but just remember that some logic deeper in Automake will
      # not output the same rule twice); while the later need to be output
      # for each Texinfo source.
      my $generic;
      my $makeinfoflags;
      my $sdir = dirname $source;
      if ($sdir eq '.' && dirname ($dest) eq '.')
        {
          $generic = 1;
          $makeinfoflags = '-I $(srcdir)';
        }
      else
        {
          $generic = 0;
          $makeinfoflags = "-I $sdir -I \$(srcdir)/$sdir";
        }
    
      # If the resulting file lie into a subdirectory,
      # make sure this directory will exist.
      my $dirstamp = require_build_directory_maybe ($dest);
    
      $output_rules .= &file_contents ('texibuild',
                                       GENERIC       => $generic,
                                       SOURCE_SUFFIX => $ssfx,
                                       SOURCE => ($generic ? '$<' : $source),
                                       DEST_PREFIX   => $dpfx,
                                       DEST_SUFFIX   => $dsfx,
                                       MAKEINFOFLAGS => $makeinfoflags,
                                       DEPS          => "@deps",
    				   DIRSTAMP      => $dirstamp);
      return ($dirstamp, "$dpfx.dvi", "$dpfx.pdf", "$dpfx.ps");
    }
    
    
    # ($DO-SOMETHING, $TEXICLEANS)
    # handle_texinfo_helper ()
    # ------------------------
    # Handle all Texinfo source; helper for handle_texinfo
    sub handle_texinfo_helper
    {
        reject_var 'TEXINFOS', "`TEXINFOS' is an anachronism; use `info_TEXINFOS'";
        reject_var 'html_TEXINFOS', "HTML generation not yet supported";
    
        return (0, '') if ! variable_defined ('info_TEXINFOS');
    
        my @texis = &variable_value_as_list_recursive ('info_TEXINFOS', 'all');
    
        my (@info_deps_list, @dvis_list, @pdfs_list, @pss_list, @texi_deps);
        my %versions;
        my $done = 0;
        my @texi_cleans;
        my $canonical;
    
        foreach my $info_cursor (@texis)
        {
            my $infobase = $info_cursor;
            $infobase =~ s/\.(txi|texinfo|texi)$//;
    
    	if ($infobase eq $info_cursor)
    	  {
    	    # FIXME: report line number.
    	    err_am "texinfo file `$info_cursor' has unrecognized extension";
    	    next;
    	  }
    
    	# If 'version.texi' is referenced by input file, then include
    	# automatic versioning capability.
    	my ($out_file, $vtexi, @clean_files) =
    	  &scan_texinfo_file ("$relative_dir/$info_cursor")
    	    or next;
    	push (@texi_cleans, @clean_files);
    
    	# If the Texinfo source is in a subdirectory, create the
    	# resulting info in this subdirectory.  If it is in the
    	# current directory, try hard to not prefix "./" because
    	# it breaks the generic rules.
    	my $outdir = dirname ($info_cursor) . '/';
    	$outdir = "" if $outdir eq './';
    	$out_file =  $outdir . $out_file;
    
    	# If user specified file_TEXINFOS, then use that as explicit
    	# dependency list.
    	@texi_deps = ();
    	push (@texi_deps, "$outdir$vtexi") if $vtexi;
    
    	my $canonical = &canonicalize ($infobase);
    	if (variable_defined ($canonical . "_TEXINFOS"))
    	{
    	    push (@texi_deps, '$(' . $canonical . '_TEXINFOS)');
    	    &push_dist_common ('$(' . $canonical . '_TEXINFOS)');
    	}
    
    	my ($dirstamp, @cfiles) =
    	  output_texinfo_build_rules ($info_cursor, $out_file, @texi_deps);
    	push (@texi_cleans, @cfiles);
    
    	push (@info_deps_list, $out_file);
    	push (@dvis_list, $infobase . '.dvi');
    	push (@pdfs_list, $infobase . '.pdf');
    	push (@pss_list, $infobase . '.ps');
    
    	# If a vers*.texi file is needed, emit the rule.
    	if ($vtexi)
    	{
    	    err_am ("`$vtexi', included in `$info_cursor', "
    		    . "also included in `$versions{$vtexi}'")
    	      if defined $versions{$vtexi};
    	    $versions{$vtexi} = $info_cursor;
    
    	    # We number the stamp-vti files.  This is doable since the
    	    # actual names don't matter much.  We only number starting
    	    # with the second one, so that the common case looks nice.
    	    my $vti = ($done ? $done : 'vti');
    	    ++$done;
    
    	    # This is ugly, but it is our historical practice.
    	    if ($config_aux_dir_set_in_configure_in)
    	    {
    		require_conf_file_with_macro ('TRUE', 'info_TEXINFOS', FOREIGN,
    					      'mdate-sh');
    	    }
    	    else
    	    {
    		require_file_with_macro ('TRUE', 'info_TEXINFOS',
    					 FOREIGN, 'mdate-sh');
    	    }
    
    	    my $conf_dir;
    	    if ($config_aux_dir_set_in_configure_in)
    	    {
    		$conf_dir = $config_aux_dir;
    		$conf_dir .= '/' unless $conf_dir =~ /\/$/;
    	    }
    	    else
    	    {
    		$conf_dir = '$(srcdir)/';
    	    }
    	    $output_rules .= &file_contents ('texi-vers',
    					     TEXI     => $info_cursor,
    					     VTI      => $vti,
    					     STAMPVTI => "${outdir}stamp-$vti",
    					     VTEXI    => "$outdir$vtexi",
    					     MDDIR    => $conf_dir,
    					     DIRSTAMP => $dirstamp);
    	}
        }
    
        # Handle location of texinfo.tex.
        my $need_texi_file = 0;
        my $texinfodir;
        if ($cygnus_mode)
        {
            $texinfodir = '$(top_srcdir)/../texinfo';
    	&define_variable ('TEXINFO_TEX', "$texinfodir/texinfo.tex");
        }
        elsif ($config_aux_dir_set_in_configure_in)
        {
            $texinfodir = $config_aux_dir;
    	&define_variable ('TEXINFO_TEX', "$texinfodir/texinfo.tex");
    	$need_texi_file = 2; # so that we require_conf_file later
        }
        elsif (variable_defined ('TEXINFO_TEX'))
        {
    	# The user defined TEXINFO_TEX so assume he knows what he is
    	# doing.
            $texinfodir = ('$(srcdir)/'
    		       . dirname (&variable_value ('TEXINFO_TEX')));
        }
        else
        {
            $texinfodir = '$(srcdir)';
    	$need_texi_file = 1;
        }
        &define_variable ('am__TEXINFO_TEX_DIR', $texinfodir);
    
        # The return value.
        my $texiclean = &pretty_print_internal ("", "\t  ", @texi_cleans);
    
        push (@dist_targets, 'dist-info');
    
        if (! defined $options{'no-installinfo'})
        {
    	# Make sure documentation is made and installed first.  Use
    	# $(INFO_DEPS), not 'info', because otherwise recursive makes
    	# get run twice during "make all".
    	unshift (@all, '$(INFO_DEPS)');
        }
    
        &define_variable ("INFO_DEPS", "@info_deps_list");
        &define_variable ("DVIS", "@dvis_list");
        &define_variable ("PDFS", "@pdfs_list");
        &define_variable ("PSS", "@pss_list");
        # This next isn't strictly needed now -- the places that look here
        # could easily be changed to look in info_TEXINFOS.  But this is
        # probably better, in case noinst_TEXINFOS is ever supported.
        &define_variable ("TEXINFOS", &variable_value ('info_TEXINFOS'));
    
        # Do some error checking.  Note that this file is not required
        # when in Cygnus mode; instead we defined TEXINFO_TEX explicitly
        # up above.
        if ($need_texi_file && ! defined $options{'no-texinfo.tex'})
        {
    	if ($need_texi_file > 1)
    	{
    	    require_conf_file_with_macro ('TRUE', 'info_TEXINFOS', FOREIGN,
    					  'texinfo.tex');
    	}
    	else
    	{
    	    require_file_with_macro ('TRUE', 'info_TEXINFOS', FOREIGN,
    				     'texinfo.tex');
    	}
        }
    
        return (1, $texiclean);
    }
    
    # handle_texinfo ()
    # -----------------
    # Handle all Texinfo source.
    sub handle_texinfo
    {
        my ($do_something, $texiclean) = handle_texinfo_helper ();
        $output_rules .=  &file_contents ('texinfos',
    				      ('TEXICLEAN' => $texiclean,
    				       'LOCAL-TEXIS' => $do_something));
    }
    
    # Handle any man pages.
    sub handle_man_pages
    {
        reject_var 'MANS', "`MANS' is an anachronism; use `man_MANS'";
    
        # Find all the sections in use.  We do this by first looking for
        # "standard" sections, and then looking for any additional
        # sections used in man_MANS.
        my (%sections, %vlist);
        # We handle nodist_ for uniformity.  man pages aren't distributed
        # by default so it isn't actually very important.
        foreach my $pfx ('', 'dist_', 'nodist_')
        {
    	# Add more sections as needed.
    	foreach my $section ('0'..'9', 'n', 'l')
    	{
    	    if (variable_defined ($pfx . 'man' . $section . '_MANS'))
    	    {
    		$sections{$section} = 1;
    		$vlist{'$(' . $pfx . 'man' . $section . '_MANS)'} = 1;
    
    		&push_dist_common ('$(' . $pfx . 'man' . $section . '_MANS)')
    		    if $pfx eq 'dist_';
    	    }
    	}
    
    	if (variable_defined ($pfx . 'man_MANS'))
    	{
    	    $vlist{'$(' . $pfx . 'man_MANS)'} = 1;
    	    foreach (&variable_value_as_list_recursive ($pfx . 'man_MANS', 'all'))
    	    {
    		# A page like `foo.1c' goes into man1dir.
    		if (/\.([0-9a-z])([a-z]*)$/)
    		{
    		    $sections{$1} = 1;
    		}
    	    }
    
    	    &push_dist_common ('$(' . $pfx . 'man_MANS)')
    		if $pfx eq 'dist_';
    	}
        }
    
        return unless %sections;
    
        # Now for each section, generate an install and unintall rule.
        # Sort sections so output is deterministic.
        foreach my $section (sort keys %sections)
        {
    	$output_rules .= &file_contents ('mans', ('SECTION' => $section));
        }
    
        my @mans = sort keys %vlist;
        $output_vars .= file_contents ('mans-vars',
    				   ('MANS' => "@mans"));
    
        if (! defined $options{'no-installman'})
        {
    	push (@all, '$(MANS)');
        }
    }
    
    # Handle DATA variables.
    sub handle_data
    {
        &am_install_var ('-noextra', '-candist', 'data', 'DATA',
    		     'data', 'sysconf', 'sharedstate', 'localstate',
    		     'pkgdata', 'noinst', 'check');
    }
    
    # Handle TAGS.
    sub handle_tags
    {
        my @tag_deps = ();
        my @ctag_deps = ();
        if (variable_defined ('SUBDIRS'))
        {
    	$output_rules .= ("tags-recursive:\n"
    			  . "\tlist=\'\$(SUBDIRS)\'; for subdir in \$\$list; do \\\n"
    			  # Never fail here if a subdir fails; it
    			  # isn't important.
    			  . "\t  test \"\$\$subdir\" = . || (cd \$\$subdir"
    			  . " && \$(MAKE) \$(AM_MAKEFLAGS) tags); \\\n"
    			  . "\tdone\n");
    	push (@tag_deps, 'tags-recursive');
    	&depend ('.PHONY', 'tags-recursive');
    
    	$output_rules .= ("ctags-recursive:\n"
    			  . "\tlist=\'\$(SUBDIRS)\'; for subdir in \$\$list; do \\\n"
    			  # Never fail here if a subdir fails; it
    			  # isn't important.
    			  . "\t  test \"\$\$subdir\" = . || (cd \$\$subdir"
    			  . " && \$(MAKE) \$(AM_MAKEFLAGS) ctags); \\\n"
    			  . "\tdone\n");
    	push (@ctag_deps, 'ctags-recursive');
    	&depend ('.PHONY', 'ctags-recursive');
        }
    
        if (&saw_sources_p (1)
    	|| variable_defined ('ETAGS_ARGS')
    	|| @tag_deps)
        {
    	my @config;
    	foreach my $spec (@config_headers)
    	{
    	    my ($out, @ins) = split_config_file_spec ($spec);
    	    foreach my $in (@ins)
    	      {
    		# If the config header source is in this directory,
    		# require it.
    		push @config, basename ($in)
    		  if $relative_dir eq dirname ($in);
    	      }
    	}
    	$output_rules .= &file_contents ('tags',
    					 ('CONFIG' => "@config",
    					  'TAGSDIRS'   => "@tag_deps",
    					  'CTAGSDIRS'  => "@ctag_deps"));
    	&examine_variable ('TAGS_DEPENDENCIES');
        }
        elsif (reject_var ('TAGS_DEPENDENCIES',
    		       "doesn't make sense to define `TAGS_DEPENDENCIES'"
    		       . "without\nsources or `ETAGS_ARGS'"))
        {
        }
        else
        {
    	# Every Makefile must define some sort of TAGS rule.
    	# Otherwise, it would be possible for a top-level "make TAGS"
    	# to fail because some subdirectory failed.
    	$output_rules .= "tags: TAGS\nTAGS:\n\n";
    	# Ditto ctags.
    	$output_rules .= "ctags: CTAGS\nCTAGS:\n\n";
        }
    }
    
    # Handle multilib support.
    sub handle_multilib
    {
        if ($seen_multilib && $relative_dir eq '.')
        {
    	$output_rules .= &file_contents ('multilib');
        }
    }
    
    
    # $BOOLEAN
    # &for_dist_common ($A, $B)
    # -------------------------
    # Subroutine for &handle_dist: sort files to dist.
    #
    # We put README first because it then becomes easier to make a
    # Usenet-compliant shar file (in these, README must be first).
    #
    # FIXME: do more ordering of files here.
    sub for_dist_common
    {
        return 0
            if $a eq $b;
        return -1
            if $a eq 'README';
        return 1
            if $b eq 'README';
        return $a cmp $b;
    }
    
    
    # handle_dist ($MAKEFILE)
    # -----------------------
    # Handle 'dist' target.
    sub handle_dist
    {
        my ($makefile) = @_;
    
        # `make dist' isn't used in a Cygnus-style tree.
        # Omit the rules so that people don't try to use them.
        return if $cygnus_mode;
    
        # Look for common files that should be included in distribution.
        # If the aux dir is set, and it does not have a Makefile.am, then
        # we check for these files there as well.
        my $check_aux = 0;
        my $auxdir = '';
        if ($relative_dir eq '.'
    	&& $config_aux_dir_set_in_configure_in)
        {
    	($auxdir = $config_aux_dir) =~ s,^\$\(top_srcdir\)/,,;
    	if (! &is_make_dir ($auxdir))
    	{
    	    $check_aux = 1;
    	}
        }
        foreach my $cfile (@common_files)
        {
    	if (-f ($relative_dir . "/" . $cfile)
    	    # The file might be absent, but if it can be built it's ok.
    	    || exists $targets{$cfile})
    	{
    	    &push_dist_common ($cfile);
    	}
    
    	# Don't use `elsif' here because a file might meaningfully
    	# appear in both directories.
    	if ($check_aux && -f ($auxdir . '/' . $cfile))
    	{
    	    &push_dist_common ($auxdir . '/' . $cfile);
    	}
        }
    
        # We might copy elements from $configure_dist_common to
        # %dist_common if we think we need to.  If the file appears in our
        # directory, we would have discovered it already, so we don't
        # check that.  But if the file is in a subdir without a Makefile,
        # we want to distribute it here if we are doing `.'.  Ugly!
        if ($relative_dir eq '.')
        {
           foreach my $file (split (' ' , $configure_dist_common))
           {
    	   push_dist_common ($file)
    	     unless is_make_dir (dirname ($file));
           }
        }
    
    
    
        # Files to distributed.  Don't use &variable_value_as_list_recursive
        # as it recursively expands `$(dist_pkgdata_DATA)' etc.
        check_variable_defined_unconditionally ('DIST_COMMON');
        my @dist_common = split (' ', variable_value ('DIST_COMMON', 'TRUE'));
        @dist_common = uniq (sort for_dist_common (@dist_common));
        pretty_print ('DIST_COMMON = ', "\t", @dist_common);
    
        # Now that we've processed DIST_COMMON, disallow further attempts
        # to set it.
        $handle_dist_run = 1;
    
        # Scan EXTRA_DIST to see if we need to distribute anything from a
        # subdir.  If so, add it to the list.  I didn't want to do this
        # originally, but there were so many requests that I finally
        # relented.
        if (variable_defined ('EXTRA_DIST'))
        {
    	# FIXME: This should be fixed to work with conditionals.  That
    	# will require only making the entries in %dist_dirs under the
    	# appropriate condition.  This is meaningful if the nature of
    	# the distribution should depend upon the configure options
    	# used.
    	foreach (&variable_value_as_list_recursive ('EXTRA_DIST', ''))
    	{
    	    next if /^\@.*\@$/;
    	    next unless s,/+[^/]+$,,;
    	    $dist_dirs{$_} = 1
    		unless $_ eq '.';
    	}
        }
    
        # We have to check DIST_COMMON for extra directories in case the
        # user put a source used in AC_OUTPUT into a subdir.
        foreach (&variable_value_as_list_recursive ('DIST_COMMON', 'all'))
        {
    	next if /^\@.*\@$/;
    	next unless s,/+[^/]+$,,;
    	$dist_dirs{$_} = 1
    	    unless $_ eq '.';
        }
    
        # Rule to check whether a distribution is viable.
        my %transform = ('DISTCHECK-HOOK' => &target_defined ('distcheck-hook'),
    		     'GETTEXT'        => $seen_gettext);
    
        # Prepend $(distdir) to each directory given.
        my %rewritten = map { '$(distdir)/' . "$_" => 1 } keys %dist_dirs;
        $transform{'DISTDIRS'} = join (' ', sort keys %rewritten);
    
        # If we have SUBDIRS, create all dist subdirectories and do
        # recursive build.
        if (variable_defined ('SUBDIRS'))
        {
    	# If SUBDIRS is conditionally defined, then set DIST_SUBDIRS
    	# to all possible directories, and use it.  If DIST_SUBDIRS is
    	# defined, just use it.
    	my $dist_subdir_name;
    	# Note that we check DIST_SUBDIRS first on purpose.  At least
    	# one project uses so many conditional subdirectories that
    	# calling variable_conditionally_defined on SUBDIRS will cause
    	# automake to grow to 150Mb.  Sigh.
    	if (variable_defined ('DIST_SUBDIRS')
    	    || variable_conditionally_defined ('SUBDIRS'))
    	{
    	    $dist_subdir_name = 'DIST_SUBDIRS';
    	    if (! variable_defined ('DIST_SUBDIRS'))
    	    {
    		define_pretty_variable
    		  ('DIST_SUBDIRS', '',
    		   uniq (&variable_value_as_list_recursive ('SUBDIRS', 'all')));
    	    }
    	}
    	else
    	{
    	    $dist_subdir_name = 'SUBDIRS';
    	    # We always define this because that is what `distclean'
    	    # wants.
    	    define_pretty_variable ('DIST_SUBDIRS', '', '$(SUBDIRS)');
    	}
    
    	$transform{'DIST_SUBDIR_NAME'} = $dist_subdir_name;
        }
    
        # If the target `dist-hook' exists, make sure it is run.  This
        # allows users to do random weird things to the distribution
        # before it is packaged up.
        push (@dist_targets, 'dist-hook')
          if &target_defined ('dist-hook');
        $transform{'DIST-TARGETS'} = join(' ', @dist_targets);
    
        # Defining $(DISTDIR).
        $transform{'DISTDIR'} = !variable_defined('distdir');
        $transform{'TOP_DISTDIR'} = backname ($relative_dir);
    
        $output_rules .= &file_contents ('distdir', %transform);
    }
    
    
    # Handle subdirectories.
    sub handle_subdirs
    {
        return
          unless variable_defined ('SUBDIRS');
    
        my @subdirs = &variable_value_as_list_recursive ('SUBDIRS', 'all');
        my @dsubdirs = ();
        @dsubdirs = &variable_value_as_list_recursive ('DIST_SUBDIRS', 'all')
          if variable_defined ('DIST_SUBDIRS');
    
        # If an `obj/' directory exists, BSD make will enter it before
        # reading `Makefile'.  Hence the `Makefile' in the current directory
        # will not be read.
        #
        #  % cat Makefile
        #  all:
        #          echo Hello
        #  % cat obj/Makefile
        #  all:
        #          echo World
        #  % make      # GNU make
        #  echo Hello
        #  Hello
        #  % pmake     # BSD make
        #  echo World
        #  World
        msg_var ('portability', 'SUBDIRS',
    	     "naming a subdirectory `obj' causes troubles with BSD make")
          if grep ($_ eq 'obj', @subdirs);
        msg_var ('portability', 'DIST_SUBDIRS',
    	     "naming a subdirectory `obj' causes troubles with BSD make")
          if grep ($_ eq 'obj', @dsubdirs);
    
        # Make sure each directory mentioned in SUBDIRS actually exists.
        foreach my $dir (@subdirs)
        {
    	# Skip directories substituted by configure.
    	next if $dir =~ /^\@.*\@$/;
    
    	if (! -d $am_relative_dir . '/' . $dir)
    	{
    	    err_var ('SUBDIRS', "required directory $am_relative_dir/$dir "
    		     . "does not exist");
    	    next;
    	}
    
    	err_var 'SUBDIRS', "directory should not contain `/'"
    	  if $dir =~ /\//;
        }
    
        $output_rules .= &file_contents ('subdirs');
        variable_pretty_output ('RECURSIVE_TARGETS', 'TRUE');
    }
    
    
    # ($REGEN, @DEPENDENCIES)
    # &scan_aclocal_m4
    # ----------------
    # If aclocal.m4 creation is automated, return the list of its dependencies.
    sub scan_aclocal_m4
    {
        my $regen_aclocal = 0;
    
        return (0, ())
          unless $relative_dir eq '.';
    
        &examine_variable ('CONFIG_STATUS_DEPENDENCIES');
        &examine_variable ('CONFIGURE_DEPENDENCIES');
    
        if (-f 'aclocal.m4')
        {
    	&define_variable ("ACLOCAL_M4", '$(top_srcdir)/aclocal.m4');
    	&push_dist_common ('aclocal.m4');
    
    	my $aclocal = new Automake::XFile "< aclocal.m4";
    	my $line = $aclocal->getline;
    	$regen_aclocal = $line =~ 'generated automatically by aclocal';
        }
    
        my @ac_deps = ();
    
        if (-f 'acinclude.m4')
        {
    	$regen_aclocal = 1;
    	push @ac_deps, 'acinclude.m4';
        }
    
        if (variable_defined ('ACLOCAL_M4_SOURCES'))
        {
    	push (@ac_deps, '$(ACLOCAL_M4_SOURCES)');
        }
        elsif (variable_defined ('ACLOCAL_AMFLAGS'))
        {
    	# Scan all -I directories for m4 files.  These are our
    	# dependencies.
    	my $examine_next = 0;
    	foreach my $amdir (&variable_value_as_list_recursive ('ACLOCAL_AMFLAGS', ''))
    	{
    	    if ($examine_next)
    	    {
    		$examine_next = 0;
    		if ($amdir !~ /^\// && -d $amdir)
    		{
    		    foreach my $ac_dep (&my_glob ($amdir . '/*.m4'))
    		    {
    			$ac_dep =~ s/^\.\/+//;
    			push (@ac_deps, $ac_dep)
    			  unless $ac_dep eq "aclocal.m4"
    			    || $ac_dep eq "acinclude.m4";
    		    }
    		}
    	    }
    	    elsif ($amdir eq '-I')
    	    {
    		$examine_next = 1;
    	    }
    	}
        }
    
        # Note that it might be possible that aclocal.m4 doesn't exist but
        # should be auto-generated.  This case probably isn't very
        # important.
    
        return ($regen_aclocal, @ac_deps);
    }
    
    
    # @DEPENDENCY
    # &rewrite_inputs_into_dependencies ($ADD_SRCDIR, @INPUTS)
    # --------------------------------------------------------
    # Rewrite a list of input files into a form suitable to put on a
    # dependency list.  The idea is that if an input file has a directory
    # part the same as the current directory, then the directory part is
    # simply removed.  But if the directory part is different, then
    # $(top_srcdir) is prepended.  Among other things, this is used to
    # generate the dependency list for the output files generated by
    # AC_OUTPUT.  Consider what the dependencies should look like in this
    # case:
    #   AC_OUTPUT(src/out:src/in1:lib/in2)
    # The first argument, ADD_SRCDIR, is 1 if $(top_srcdir) should be added.
    # If 0 then files that require this addition will simply be ignored.
    sub rewrite_inputs_into_dependencies ($@)
    {
        my ($add_srcdir, @inputs) = @_;
        my @newinputs;
    
        foreach my $single (@inputs)
        {
    	if (dirname ($single) eq $relative_dir)
    	{
    	    push (@newinputs, basename ($single));
    	}
    	elsif ($add_srcdir)
    	{
    	    push (@newinputs, '$(top_srcdir)/' . $single);
    	}
        }
    
        return @newinputs;
    }
    
    # Handle remaking and configure stuff.
    # We need the name of the input file, to do proper remaking rules.
    sub handle_configure
    {
        my ($local, $input, @secondary_inputs) = @_;
    
        my $input_base = basename ($input);
        my $local_base = basename ($local);
    
        my $amfile = $input_base . '.am';
        # We know we can always add '.in' because it really should be an
        # error if the .in was missing originally.
        my $infile = '$(srcdir)/' . $input_base . '.in';
        my $colon_infile = '';
        if ($local ne $input || @secondary_inputs)
        {
    	$colon_infile = ':' . $input . '.in';
        }
        $colon_infile .= ':' . join (':', @secondary_inputs)
    	if @secondary_inputs;
    
        my @rewritten = rewrite_inputs_into_dependencies (1, @secondary_inputs);
    
        my ($regen_aclocal_m4, @aclocal_m4_deps) = scan_aclocal_m4 ();
    
        $output_rules .=
          &file_contents ('configure',
    		      ('MAKEFILE'
    		       => $local_base,
    		       'MAKEFILE-DEPS'
    		       => "@rewritten",
    		       'CONFIG-MAKEFILE'
    		       => ((($relative_dir eq '.') ? '$@' : '$(subdir)/$@')
    			   . $colon_infile),
    		       'MAKEFILE-IN'
    		       => $infile,
    		       'MAKEFILE-IN-DEPS'
    		       => "@include_stack",
    		       'MAKEFILE-AM'
    		       => $amfile,
    		       'STRICTNESS'
    		       => $cygnus_mode ? 'cygnus' : $strictness_name,
    		       'USE-DEPS'
    		       => $cmdline_use_dependencies ? '' : ' --ignore-deps',
    		       'MAKEFILE-AM-SOURCES'
    		       =>  "$input$colon_infile",
    		       'REGEN-ACLOCAL-M4'
    		       => $regen_aclocal_m4,
    		       'ACLOCAL_M4_DEPS'
    		       => "@aclocal_m4_deps"));
    
        if ($relative_dir eq '.')
        {
    	&push_dist_common ('acconfig.h')
    	    if -f 'acconfig.h';
        }
    
        # If we have a configure header, require it.
        my $hdr_index = 0;
        my @distclean_config;
        foreach my $spec (@config_headers)
          {
    	$hdr_index += 1;
    	# $CONFIG_H_PATH: config.h from top level.
    	my ($config_h_path, @ins) = split_config_file_spec ($spec);
    	my $config_h_dir = dirname ($config_h_path);
    
    	# If the header is in the current directory we want to build
    	# the header here.  Otherwise, if we're at the topmost
    	# directory and the header's directory doesn't have a
    	# Makefile, then we also want to build the header.
    	if ($relative_dir eq $config_h_dir
    	    || ($relative_dir eq '.' && ! &is_make_dir ($config_h_dir)))
    	{
    	    my ($cn_sans_dir, $stamp_dir);
    	    if ($relative_dir eq $config_h_dir)
    	    {
    		$cn_sans_dir = basename ($config_h_path);
    		$stamp_dir = '';
    	    }
    	    else
    	    {
    		$cn_sans_dir = $config_h_path;
    		if ($config_h_dir eq '.')
    		{
    		    $stamp_dir = '';
    		}
    		else
    		{
    		    $stamp_dir = $config_h_dir . '/';
    		}
    	    }
    
    	    # Compute relative path from directory holding output
    	    # header to directory holding input header.  FIXME:
    	    # doesn't handle case where we have multiple inputs.
    	    my $in0_sans_dir;
    	    if (dirname ($ins[0]) eq $relative_dir)
    	    {
    		$in0_sans_dir = basename ($ins[0]);
    	    }
    	    else
    	    {
    	        $in0_sans_dir = backname ($relative_dir) . '/' . $ins[0];
    	    }
    
    	    require_file ($config_header_location, FOREIGN, $in0_sans_dir);
    
    	    # Header defined and in this directory.
    	    my @files;
    	    if (-f $config_h_path . '.top')
    	    {
    		push (@files, "$cn_sans_dir.top");
    	    }
    	    if (-f $config_h_path . '.bot')
    	    {
    		push (@files, "$cn_sans_dir.bot");
    	    }
    
    	    push_dist_common (@files);
    
    	    # For now, acconfig.h can only appear in the top srcdir.
    	    if (-f 'acconfig.h')
    	    {
    	        push (@files, '$(top_srcdir)/acconfig.h');
    	    }
    
    	    my $stamp = "${stamp_dir}stamp-h${hdr_index}";
                $output_rules .=
    	      file_contents ('remake-hdr',
    			     ('FILES'         => "@files",
    			      'CONFIG_H'      => $cn_sans_dir,
    			      'CONFIG_HIN'    => $in0_sans_dir,
    			      'CONFIG_H_PATH' => $config_h_path,
    			      'STAMP'         => "$stamp"));
    
    	    push @distclean_config, $cn_sans_dir, $stamp;
    	}
        }
    
        $output_rules .= file_contents ('clean-hdr',
    				    ('FILES' => "@distclean_config"))
          if @distclean_config;
    
        # Set location of mkinstalldirs.
        define_variable ('mkinstalldirs',
    		     ('$(SHELL) ' . $config_aux_dir . '/mkinstalldirs'));
    
        reject_var ('CONFIG_HEADER',
    		"`CONFIG_HEADER' is an anachronism; now determined "
    		. "automatically\nfrom `$configure_ac'");
    
        my @config_h;
        foreach my $spec (@config_headers)
          {
    	my ($out, @ins) = split_config_file_spec ($spec);
    	# Generate CONFIG_HEADER define.
    	if ($relative_dir eq dirname ($out))
    	{
    	    push @config_h, basename ($out);
    	}
    	else
    	{
    	    push @config_h, "\$(top_builddir)/$out";
    	}
        }
        define_variable ("CONFIG_HEADER", "@config_h")
          if @config_h;
    
        # Now look for other files in this directory which must be remade
        # by config.status, and generate rules for them.
        my @actual_other_files = ();
        foreach my $lfile (@other_input_files)
        {
            my $file;
    	my @inputs;
    	if ($lfile =~ /^([^:]*):(.*)$/)
    	{
    	    # This is the ":" syntax of AC_OUTPUT.
    	    $file = $1;
    	    @inputs = split (':', $2);
    	}
    	else
    	{
    	    # Normal usage.
    	    $file = $lfile;
    	    @inputs = $file . '.in';
    	}
    
    	# Automake files should not be stored in here, but in %MAKE_LIST.
            prog_error "$lfile in \@other_input_files"
    	  if -f $file . '.am';
    
    	my $local = basename ($file);
    
    	# Make sure the dist directory for each input file is created.
    	# We only have to do this at the topmost level though.  This
    	# is a bit ugly but it easier than spreading out the logic,
    	# especially in cases like AC_OUTPUT(foo/out:bar/in), where
    	# there is no Makefile in bar/.
    	if ($relative_dir eq '.')
    	{
    	    foreach (@inputs)
    	    {
    		$dist_dirs{dirname ($_)} = 1;
    	    }
    	}
    
    	# We skip files that aren't in this directory.  However, if
    	# the file's directory does not have a Makefile, and we are
    	# currently doing `.', then we create a rule to rebuild the
    	# file in the subdir.
    	my $fd = dirname ($file);
    	if ($fd ne $relative_dir)
    	{
    	    if ($relative_dir eq '.' && ! &is_make_dir ($fd))
    	    {
    		$local = $file;
    	    }
    	    else
    	    {
    		next;
    	    }
    	}
    
    	my @rewritten_inputs = rewrite_inputs_into_dependencies (1, @inputs);
    	$output_rules .= ($local . ': '
    			  . '$(top_builddir)/config.status '
    			  . "@rewritten_inputs\n"
    			  . "\t"
    			  . 'cd $(top_builddir) && '
    			  . '$(SHELL) ./config.status '
    			  . ($relative_dir eq '.' ? '' : '$(subdir)/')
       			  . '$@'
    			  . "\n");
    	push (@actual_other_files, $local);
    
    	# Require all input files.
    	require_file ($ac_config_files_location, FOREIGN,
    		      rewrite_inputs_into_dependencies (0, @inputs));
        }
    
        # These files get removed by "make clean".
        define_pretty_variable ('CONFIG_CLEAN_FILES', '', @actual_other_files);
    }
    
    # Handle C headers.
    sub handle_headers
    {
        my @r = &am_install_var ('-defaultdist', 'header', 'HEADERS', 'include',
    			     'oldinclude', 'pkginclude',
    			     'noinst', 'check');
        foreach (@r)
        {
    	next unless /\..*$/;
    	&saw_extension ($&);
        }
    }
    
    sub handle_gettext
    {
      return if ! $seen_gettext || $relative_dir ne '.';
    
      if (! variable_defined ('SUBDIRS'))
        {
          err_ac "AM_GNU_GETTEXT used but SUBDIRS not defined";
          return;
        }
    
      my @subdirs = &variable_value_as_list_recursive ('SUBDIRS', 'all');
      err_var 'SUBDIRS', "AM_GNU_GETTEXT used but `po' not in SUBDIRS"
        if ! grep ($_ eq 'po', @subdirs);
      # intl/ is not required when AM_GNU_GETTEXT is called with
      # the `external' option.
      err_var 'SUBDIRS', "AM_GNU_GETTEXT used but `intl' not in SUBDIRS"
        if (! $seen_gettext_external
    	&& ! grep ($_ eq 'intl', @subdirs));
    
      require_file ($ac_gettext_location, GNU, 'ABOUT-NLS');
    }
    
    # Handle footer elements.
    sub handle_footer
    {
        # NOTE don't use define_pretty_variable here, because
        # $contents{...} is already defined.
        $output_vars .= 'SOURCES = ' . variable_value ('SOURCES') . "\n\n"
          if variable_value ('SOURCES');
    
        reject_target ('.SUFFIXES',
    		   "use variable `SUFFIXES', not target `.SUFFIXES'");
    
        # Note: AIX 4.1 /bin/make will fail if any suffix rule appears
        # before .SUFFIXES.  So we make sure that .SUFFIXES appears before
        # anything else, by sticking it right after the default: target.
        $output_header .= ".SUFFIXES:\n";
        if (@suffixes || variable_defined ('SUFFIXES'))
        {
    	# Make sure suffixes has unique elements.  Sort them to ensure
    	# the output remains consistent.  However, $(SUFFIXES) is
    	# always at the start of the list, unsorted.  This is done
    	# because make will choose rules depending on the ordering of
    	# suffixes, and this lets the user have some control.  Push
    	# actual suffixes, and not $(SUFFIXES).  Some versions of make
    	# do not like variable substitutions on the .SUFFIXES line.
    	my @user_suffixes = (variable_defined ('SUFFIXES')
    			     ? &variable_value_as_list_recursive ('SUFFIXES', '')
    			     : ());
    
    	my %suffixes = map { $_ => 1 } @suffixes;
    	delete @suffixes{@user_suffixes};
    
    	$output_header .= (".SUFFIXES: "
    			   . join (' ', @user_suffixes, sort keys %suffixes)
    			   . "\n");
        }
    
        $output_trailer .= file_contents ('footer');
    }
    
    # Deal with installdirs target.
    sub handle_installdirs ()
    {
        $output_rules .=
          &file_contents ('install',
    		      ('am__installdirs'
    		       => variable_value ('am__installdirs') || '',
    		       'installdirs-local'
    		       => (target_defined ('installdirs-local')
    			   ? ' installdirs-local' : '')));
    }
    
    
    # Deal with all and all-am.
    sub handle_all ($)
    {
        my ($makefile) = @_;
    
        # Output `all-am'.
    
        # Put this at the beginning for the sake of non-GNU makes.  This
        # is still wrong if these makes can run parallel jobs.  But it is
        # right enough.
        unshift (@all, basename ($makefile));
    
        foreach my $spec (@config_headers)
          {
            my ($out, @ins) = split_config_file_spec ($spec);
    	push (@all, basename ($out))
    	  if dirname ($out) eq $relative_dir;
          }
    
        # Install `all' hooks.
        if (&target_defined ("all-local"))
        {
          push (@all, "all-local");
          &depend ('.PHONY', "all-local");
        }
    
        &pretty_print_rule ("all-am:", "\t\t", @all);
        &depend ('.PHONY', 'all-am', 'all');
    
    
        # Output `all'.
    
        my @local_headers = ();
        push @local_headers, '$(BUILT_SOURCES)'
          if variable_defined ('BUILT_SOURCES');
        foreach my $spec (@config_headers)
          {
            my ($out, @ins) = split_config_file_spec ($spec);
    	push @local_headers, basename ($out)
    	  if dirname ($out) eq $relative_dir;
          }
    
        if (@local_headers)
          {
    	# We need to make sure config.h is built before we recurse.
    	# We also want to make sure that built sources are built
    	# before any ordinary `all' targets are run.  We can't do this
    	# by changing the order of dependencies to the "all" because
    	# that breaks when using parallel makes.  Instead we handle
    	# things explicitly.
    	$output_all .= ("all: @local_headers"
    			. "\n\t"
    			. '$(MAKE) $(AM_MAKEFLAGS) '
    			. (variable_defined ('SUBDIRS')
    			   ? 'all-recursive' : 'all-am')
    			. "\n\n");
          }
        else
          {
    	$output_all .= "all: " . (variable_defined ('SUBDIRS')
    				  ? 'all-recursive' : 'all-am') . "\n\n";
          }
    }
    
    
    # Handle check merge target specially.
    sub do_check_merge_target
    {
        if (&target_defined ('check-local'))
        {
    	# User defined local form of target.  So include it.
    	push (@check_tests, 'check-local');
    	&depend ('.PHONY', 'check-local');
        }
    
        # In --cygnus mode, check doesn't depend on all.
        if ($cygnus_mode)
        {
    	# Just run the local check rules.
    	&pretty_print_rule ('check-am:', "\t\t", @check);
        }
        else
        {
    	# The check target must depend on the local equivalent of
    	# `all', to ensure all the primary targets are built.  Then it
    	# must build the local check rules.
    	$output_rules .= "check-am: all-am\n";
    	&pretty_print_rule ("\t\$(MAKE) \$(AM_MAKEFLAGS)", "\t  ",
    			    @check)
    	    if @check;
        }
        &pretty_print_rule ("\t\$(MAKE) \$(AM_MAKEFLAGS)", "\t  ",
    			@check_tests)
    	if @check_tests;
    
        &depend ('.PHONY', 'check', 'check-am');
        $output_rules .= ("check: "
    		      . (variable_defined ('SUBDIRS')
    			 ? 'check-recursive' : 'check-am')
    		      . "\n");
    }
    
    # Handle all 'clean' targets.
    sub handle_clean
    {
      # Clean the files listed in user variables if they exist.
      $clean_files{'$(MOSTLYCLEANFILES)'} = MOSTLY_CLEAN
        if variable_defined ('MOSTLYCLEANFILES');
      $clean_files{'$(CLEANFILES)'} = CLEAN
        if variable_defined ('CLEANFILES');
      $clean_files{'$(DISTCLEANFILES)'} = DIST_CLEAN
        if variable_defined ('DISTCLEANFILES');
      $clean_files{'$(MAINTAINERCLEANFILES)'} = MAINTAINER_CLEAN
        if variable_defined ('MAINTAINERCLEANFILES');
    
      # Built sources are automatically removed by maintainer-clean.
      $clean_files{'$(BUILT_SOURCES)'} = MAINTAINER_CLEAN
        if variable_defined ('BUILT_SOURCES');
    
      # Compute a list of "rm"s to run for each target.
      my %rms = (MOSTLY_CLEAN, [],
    	     CLEAN, [],
    	     DIST_CLEAN, [],
    	     MAINTAINER_CLEAN, []);
    
      foreach my $file (keys %clean_files)
        {
          my $when = $clean_files{$file};
          prog_error 'invalid entry in %clean_files'
    	unless exists $rms{$when};
    
          my $rm = "rm -f $file";
          # If file is a variable, make sure when don't call `rm -f' without args.
          $rm ="test -z \"$file\" || $rm"
    	if ($file =~ /^\s*\$(\(.*\)|\{.*\})\s*$/);
    
          push @{$rms{$when}}, "\t-$rm\n";
        }
    
      $output_rules .= &file_contents
        ('clean',
         MOSTLYCLEAN_RMS      => join ('', @{$rms{&MOSTLY_CLEAN}}),
         CLEAN_RMS            => join ('', @{$rms{&CLEAN}}),
         DISTCLEAN_RMS        => join ('', @{$rms{&DIST_CLEAN}}),
         MAINTAINER_CLEAN_RMS => join ('', @{$rms{&MAINTAINER_CLEAN}}));
    }
    
    
    # &depend ($CATEGORY, @DEPENDENDEES)
    # ----------------------------------
    # The target $CATEGORY depends on @DEPENDENDEES.
    sub depend
    {
        my ($category, @dependendees) = @_;
        {
          push (@{$dependencies{$category}}, @dependendees);
        }
    }
    
    
    # &target_cmp ($A, $B)
    # --------------------
    # Subroutine for &handle_factored_dependencies to let `.PHONY' be last.
    sub target_cmp
    {
        return 0
            if $a eq $b;
        return -1
            if $b eq '.PHONY';
        return 1
            if $a eq '.PHONY';
        return $a cmp $b;
    }
    
    
    # &handle_factored_dependencies ()
    # --------------------------------
    # Handle everything related to gathered targets.
    sub handle_factored_dependencies
    {
      # Reject bad hooks.
      foreach my $utarg ('uninstall-data-local', 'uninstall-data-hook',
    		     'uninstall-exec-local', 'uninstall-exec-hook')
        {
          my $x = $utarg;
          $x =~ s/(data|exec)-//;
          reject_target ($utarg, "use `$x', not `$utarg'");
        }
    
      reject_target ('install-local',
    		 "use `install-data-local' or `install-exec-local', "
    		 . "not `install-local'");
    
      reject_target ('install-info-local',
    		 "`install-info-local' target defined but "
    		 . "`no-installinfo' option not in use")
        unless defined $options{'no-installinfo'};
    
      # Install the -local hooks.
      foreach (keys %dependencies)
        {
          # Hooks are installed on the -am targets.
          s/-am$// or next;
          if (&target_defined ("$_-local"))
    	{
    	  depend ("$_-am", "$_-local");
    	  &depend ('.PHONY', "$_-local");
    	}
        }
    
      # Install the -hook hooks.
      # FIXME: Why not be as liberal as we are with -local hooks?
      foreach ('install-exec', 'install-data', 'uninstall')
        {
          if (&target_defined ("$_-hook"))
    	{
    	  $actions{"$_-am"} .=
    	    ("\t\@\$(NORMAL_INSTALL)\n"
    	     . "\t" . '$(MAKE) $(AM_MAKEFLAGS) ' . "$_-hook\n");
    	}
        }
    
      # All the required targets are phony.
      depend ('.PHONY', keys %required_targets);
    
      # Actually output gathered targets.
      foreach (sort target_cmp keys %dependencies)
        {
          # If there is nothing about this guy, skip it.
          next
    	unless (@{$dependencies{$_}}
    		|| $actions{$_}
    		|| $required_targets{$_});
          &pretty_print_rule ("$_:", "\t",
    			  uniq (sort @{$dependencies{$_}}));
          $output_rules .= $actions{$_}
          if defined $actions{$_};
          $output_rules .= "\n";
        }
    }
    
    
    # &handle_tests_dejagnu ()
    # ------------------------
    sub handle_tests_dejagnu
    {
        push (@check_tests, 'check-DEJAGNU');
        $output_rules .= file_contents ('dejagnu');
    }
    
    
    # Handle TESTS variable and other checks.
    sub handle_tests
    {
      if (defined $options{'dejagnu'})
        {
          &handle_tests_dejagnu;
        }
      else
        {
          foreach my $c ('DEJATOOL', 'RUNTEST', 'RUNTESTFLAGS')
    	{
    	  reject_var ($c, "`$c' defined but `dejagnu' not in "
    		      . "`AUTOMAKE_OPTIONS'");
    	}
        }
    
      if (variable_defined ('TESTS'))
        {
          push (@check_tests, 'check-TESTS');
          $output_rules .= &file_contents ('check');
        }
    }
    
    # Handle Emacs Lisp.
    sub handle_emacs_lisp
    {
      my @elfiles = &am_install_var ('-candist', 'lisp', 'LISP',
    				 'lisp', 'noinst');
    
      return if ! @elfiles;
    
      # Generate .elc files.
      my @elcfiles = map { $_ . 'c' } @elfiles;
      define_pretty_variable ('ELCFILES', '', @elcfiles);
    
      push (@all, '$(ELCFILES)');
    
      require_variables ("$am_file.am", "Emacs Lisp sources seen", 'TRUE',
    		     'EMACS', 'lispdir');
      require_conf_file ("$am_file.am", FOREIGN, 'elisp-comp');
      &define_variable ('elisp_comp', $config_aux_dir . '/elisp-comp');
    }
    
    # Handle Python
    sub handle_python
    {
      my @pyfiles = &am_install_var ('-defaultdist', 'python', 'PYTHON',
    				 'noinst');
      return if ! @pyfiles;
    
      require_variables ("$am_file.am", "Python sources seen", 'TRUE',
    		     'PYTHON');
      require_conf_file ("$am_file.am", FOREIGN, 'py-compile');
      &define_variable ('py_compile', $config_aux_dir . '/py-compile');
    }
    
    # Handle Java.
    sub handle_java
    {
        my @sourcelist = &am_install_var ('-candist',
    				      'java', 'JAVA',
    				      'java', 'noinst', 'check');
        return if ! @sourcelist;
    
        my @prefix = am_primary_prefixes ('JAVA', 1,
    				      'java', 'noinst', 'check');
    
        my $dir;
        foreach my $curs (@prefix)
          {
    	next
    	  if $curs eq 'EXTRA';
    
    	err_var "${curs}_JAVA", "multiple _JAVA primaries in use"
    	  if defined $dir;
    	$dir = $curs;
          }
    
    
        push (@all, 'class' . $dir . '.stamp');
    }
    
    
    # Handle some of the minor options.
    sub handle_minor_options
    {
      if (defined $options{'readme-alpha'})
        {
          if ($relative_dir eq '.')
    	{
    	  if ($package_version !~ /^$GNITS_VERSION_PATTERN$/)
    	    {
    	      msg ('error-gnits', $package_version_location,
    		   "version `$package_version' doesn't follow " .
    		   "Gnits standards");
    	    }
    	  if (defined $1 && -f 'README-alpha')
    	    {
    	      # This means we have an alpha release.  See
    	      # GNITS_VERSION_PATTERN for details.
    	      require_file_with_macro ('TRUE', 'AUTOMAKE_OPTIONS',
    				       FOREIGN, 'README-alpha');
    	    }
    	}
        }
    }
    
    ################################################################
    
    # ($OUTPUT, @INPUTS)
    # &split_config_file_spec ($SPEC)
    # -------------------------------
    # Decode the Autoconf syntax for config files (files, headers, links
    # etc.).
    sub split_config_file_spec ($)
    {
      my ($spec) = @_;
      my ($output, @inputs) = split (/:/, $spec);
    
      push @inputs, "$output.in"
        unless @inputs;
    
      return ($output, @inputs);
    }
    
    
    my %make_list;
    
    # &scan_autoconf_config_files ($CONFIG-FILES)
    # -------------------------------------------
    # Study $CONFIG-FILES which is the first argument to AC_CONFIG_FILES
    # (or AC_OUTPUT).
    sub scan_autoconf_config_files
    {
        my ($config_files) = @_;
        # Look at potential Makefile.am's.
        foreach (split ' ', $config_files)
        {
            # Must skip empty string for Perl 4.
            next if $_ eq "\\" || $_ eq '';
    
            # Handle $local:$input syntax.  Note that we ignore
            # every input file past the first, though we keep
            # those around for later.
            my ($local, $input, @rest) = split (/:/);
            if (! $input)
            {
                $input = $local;
            }
            else
            {
                # FIXME: should be error if .in is missing.
                $input =~ s/\.in$//;
            }
    
            if (-f $input . '.am')
            {
                # We have a file that automake should generate.
                $make_list{$input} = join (':', ($local, @rest));
            }
            else
            {
                # We have a file that automake should cause to be
                # rebuilt, but shouldn't generate itself.
                push (@other_input_files, $_);
            }
        }
    }
    
    
    # &scan_autoconf_traces ($FILENAME)
    # ---------------------------------
    sub scan_autoconf_traces ($)
    {
      my ($filename) = @_;
    
      my @traced = qw(AC_CANONICAL_HOST
    		  AC_CANONICAL_SYSTEM
    		  AC_CONFIG_AUX_DIR
    		  AC_CONFIG_FILES
    		  AC_CONFIG_HEADERS
    		  AC_INIT
    		  AC_LIBSOURCE
    		  AC_SUBST
    		  AM_AUTOMAKE_VERSION
    		  AM_CONDITIONAL
    		  AM_GNU_GETTEXT
    		  AM_INIT_AUTOMAKE
    		  AM_MAINTAINER_MODE
    		  AM_PROG_CC_C_O);
    
      my $traces = ($ENV{AUTOCONF} || 'autoconf') . " ";
    
      # Use a separator unlikely to be used, not `:', the default, which
      # has a precise meaning for AC_CONFIG_FILES and so on.
      $traces .= join (' ',
    		   map { "--trace=$_" . ':\$f:\$l::\$n::\${::}%' } @traced);
    
      my $tracefh = new Automake::XFile ("$traces $filename |");
      verb "reading $traces";
    
      while ($_ = $tracefh->getline)
        {
          chomp;
          my ($here, @args) = split /::/;
          my $macro = $args[0];
    
          # Alphabetical ordering please.
          if ($macro eq 'AC_CANONICAL_HOST')
    	{
    	  if (! $seen_canonical)
    	    {
    	      $seen_canonical = AC_CANONICAL_HOST;
    	      $canonical_location = $here;
    	    };
    	}
          elsif ($macro eq 'AC_CANONICAL_SYSTEM')
    	{
    	  $seen_canonical = AC_CANONICAL_SYSTEM;
    	  $canonical_location = $here;
    	}
          elsif ($macro eq 'AC_CONFIG_AUX_DIR')
    	{
    	  @config_aux_path = $args[1];
    	  $config_aux_dir_set_in_configure_in = 1;
    	}
          elsif ($macro eq 'AC_CONFIG_FILES')
    	{
    	  # Look at potential Makefile.am's.
    	  $ac_config_files_location = $here;
    	  &scan_autoconf_config_files ($args[1]);
    	}
          elsif ($macro eq 'AC_CONFIG_HEADERS')
    	{
    	  $config_header_location = $here;
    	  push @config_headers, split (' ', $args[1]);
    	}
          elsif ($macro eq 'AC_INIT')
            {
    	  if (defined $args[2])
    	    {
    	      $package_version = $args[2];
    	      $package_version_location = $here;
    	    }
    	}
          elsif ($macro eq 'AC_LIBSOURCE')
    	{
    	  $libsources{$args[1]} = $here;
    	}
          elsif ($macro eq 'AC_SUBST')
    	{
    	  # Just check for alphanumeric in AC_SUBST.  If you do
    	  # AC_SUBST(5), then too bad.
    	  $configure_vars{$args[1]} = $here
    	    if $args[1] =~ /^\w+$/;
    	}
          elsif ($macro eq 'AM_AUTOMAKE_VERSION')
            {
    	  err ($here,
    	       "version mismatch.  This is Automake $VERSION,\n" .
    	       "but the definition used by this AM_INIT_AUTOMAKE\n" .
    	       "comes from Automake $args[1].  You should recreate\n" .
    	       "aclocal.m4 with aclocal and run automake again.\n")
    	    if ($VERSION ne $args[1]);
    
    	  $seen_automake_version = 1;
            }
          elsif ($macro eq 'AM_CONDITIONAL')
    	{
    	  $configure_cond{$args[1]} = $here;
    	}
          elsif ($macro eq 'AM_GNU_GETTEXT')
    	{
    	  $seen_gettext = $here;
    	  $ac_gettext_location = $here;
    	  $seen_gettext_external = grep ($_ eq 'external', @args);
    	}
          elsif ($macro eq 'AM_INIT_AUTOMAKE')
    	{
    	  $seen_init_automake = $here;
    	  if (defined $args[2])
    	    {
    	      $package_version = $args[2];
    	      $package_version_location = $here;
    	    }
    	  elsif (defined $args[1])
    	    {
    	      $global_options = $args[1];
    	    }
    	}
          elsif ($macro eq 'AM_MAINTAINER_MODE')
    	{
    	  $seen_maint_mode = $here;
    	}
          elsif ($macro eq 'AM_PROG_CC_C_O')
    	{
    	  $seen_cc_c_o = $here;
    	}
       }
    }
    
    
    # &scan_autoconf_files ()
    # -----------------------
    # Check whether we use `configure.ac' or `configure.in'.
    # Scan it (and possibly `aclocal.m4') for interesting things.
    # We must scan aclocal.m4 because there might be AC_SUBSTs and such there.
    sub scan_autoconf_files
    {
        # Reinitialize libsources here.  This isn't really necessary,
        # since we currently assume there is only one configure.ac.  But
        # that won't always be the case.
        %libsources = ();
    
        $configure_ac = find_configure_ac;
        fatal "`configure.ac' or `configure.in' is required\n"
            if !$configure_ac;
    
        scan_autoconf_traces ($configure_ac);
    
        # Set input and output files if not specified by user.
        if (! @input_files)
        {
    	@input_files = sort keys %make_list;
    	%output_files = %make_list;
        }
    
        @configure_input_files = sort keys %make_list;
    
        err_ac "`AM_INIT_AUTOMAKE' must be used"
          if ! $seen_init_automake;
    
        if (! $seen_automake_version)
          {
    	if (-f 'aclocal.m4')
    	  {
    	    err ($seen_init_automake || $me,
    		 "your implementation of AM_INIT_AUTOMAKE comes from " .
    		 "an\nold Automake version.  You should recreate " .
    		 "aclocal.m4\nwith aclocal and run automake again.\n");
    	  }
    	else
    	  {
    	    err ($seen_init_automake || $me,
    		 "no proper implementation of AM_INIT_AUTOMAKE was " .
    		 "found,\nprobably because aclocal.m4 is missing...\n" .
    		 "You should run aclocal to create this file, then\n" .
    		 "run automake again.\n");
    	  }
          }
    
        # Look for some files we need.  Always check for these.  This
        # check must be done for every run, even those where we are only
        # looking at a subdir Makefile.  We must set relative_dir so that
        # the file-finding machinery works.
        # FIXME: Is this broken because it needs dynamic scopes.
        # My tests seems to show it's not the case.
        $relative_dir = '.';
        require_conf_file ($configure_ac, FOREIGN,
    		       'install-sh', 'mkinstalldirs', 'missing');
        err_am "`install.sh' is an anachronism; use `install-sh' instead"
          if -f $config_aux_path[0] . '/install.sh';
    
        # Preserve dist_common for later.
        $configure_dist_common = variable_value ('DIST_COMMON', 'TRUE') || '';
    }
    
    ################################################################
    
    # Set up for Cygnus mode.
    sub check_cygnus
    {
      return unless $cygnus_mode;
    
      &set_strictness ('foreign');
      $options{'no-installinfo'} = 1;
      $options{'no-dependencies'} = 1;
      $use_dependencies = 0;
    
      err_ac "`AM_MAINTAINER_MODE' required when --cygnus specified"
        if !$seen_maint_mode;
    }
    
    # Do any extra checking for GNU standards.
    sub check_gnu_standards
    {
      if ($relative_dir eq '.')
        {
          # In top level (or only) directory.
    
          # Accept one of these three licenses; default to COPYING.
          my $license = 'COPYING';
          foreach (qw /COPYING.LIB COPYING.LESSER/)
    	{
    	  $license = $_ if -f $_;
    	}
          require_file ("$am_file.am", GNU, $license,
    		    qw/INSTALL NEWS README AUTHORS ChangeLog/);
        }
    
      for my $opt ('no-installman', 'no-installinfo')
        {
          msg_var ('error-gnu', 'AUTOMAKE_OPTIONS',
    	       "option `$opt' disallowed by GNU standards")
    	if (defined $options{$opt});
        }
    }
    
    # Do any extra checking for GNITS standards.
    sub check_gnits_standards
    {
      if ($relative_dir eq '.')
        {
          # In top level (or only) directory.
          require_file ("$am_file.am", GNITS, 'THANKS');
        }
    }
    
    ################################################################
    #
    # Functions to handle files of each language.
    
    # Each `lang_X_rewrite($DIRECTORY, $BASE, $EXT)' function follows a
    # simple formula: Return value is LANG_SUBDIR if the resulting object
    # file should be in a subdir if the source file is, LANG_PROCESS if
    # file is to be dealt with, LANG_IGNORE otherwise.
    
    # Much of the actual processing is handled in
    # handle_single_transform_list.  These functions exist so that
    # auxiliary information can be recorded for a later cleanup pass.
    # Note that the calls to these functions are computed, so don't bother
    # searching for their precise names in the source.
    
    # This is just a convenience function that can be used to determine
    # when a subdir object should be used.
    sub lang_sub_obj
    {
        return defined $options{'subdir-objects'} ? LANG_SUBDIR : LANG_PROCESS;
    }
    
    # Rewrite a single C source file.
    sub lang_c_rewrite
    {
      my ($directory, $base, $ext) = @_;
    
      if (defined $options{'ansi2knr'} && $base =~ /_$/)
        {
          # FIXME: include line number in error.
          err_am "C source file `$base.c' would be deleted by ansi2knr rules";
        }
    
      my $r = LANG_PROCESS;
      if (defined $options{'subdir-objects'})
        {
          $r = LANG_SUBDIR;
          $base = $directory . '/' . $base
    	unless $directory eq '.' || $directory eq '';
    
          err_am ("C objects in subdir but `AM_PROG_CC_C_O' "
    	      . "not in `$configure_ac'",
    	      uniq_scope => US_GLOBAL)
    	unless $seen_cc_c_o;
    
          require_conf_file ("$am_file.am", FOREIGN, 'compile');
    
          # In this case we already have the directory information, so
          # don't add it again.
          $de_ansi_files{$base} = '';
        }
      else
        {
          $de_ansi_files{$base} = (($directory eq '.' || $directory eq '')
    			       ? ''
    			       : "$directory/");
        }
    
        return $r;
    }
    
    # Rewrite a single C++ source file.
    sub lang_cxx_rewrite
    {
        return &lang_sub_obj;
    }
    
    # Rewrite a single header file.
    sub lang_header_rewrite
    {
        # Header files are simply ignored.
        return LANG_IGNORE;
    }
    
    # Rewrite a single yacc file.
    sub lang_yacc_rewrite
    {
        my ($directory, $base, $ext) = @_;
    
        my $r = &lang_sub_obj;
        (my $newext = $ext) =~ tr/y/c/;
        return ($r, $newext);
    }
    
    # Rewrite a single yacc++ file.
    sub lang_yaccxx_rewrite
    {
        my ($directory, $base, $ext) = @_;
    
        my $r = &lang_sub_obj;
        (my $newext = $ext) =~ tr/y/c/;
        return ($r, $newext);
    }
    
    # Rewrite a single lex file.
    sub lang_lex_rewrite
    {
        my ($directory, $base, $ext) = @_;
    
        my $r = &lang_sub_obj;
        (my $newext = $ext) =~ tr/l/c/;
        return ($r, $newext);
    }
    
    # Rewrite a single lex++ file.
    sub lang_lexxx_rewrite
    {
        my ($directory, $base, $ext) = @_;
    
        my $r = &lang_sub_obj;
        (my $newext = $ext) =~ tr/l/c/;
        return ($r, $newext);
    }
    
    # Rewrite a single assembly file.
    sub lang_asm_rewrite
    {
        return &lang_sub_obj;
    }
    
    # Rewrite a single Fortran 77 file.
    sub lang_f77_rewrite
    {
        return LANG_PROCESS;
    }
    
    # Rewrite a single preprocessed Fortran 77 file.
    sub lang_ppf77_rewrite
    {
        return LANG_PROCESS;
    }
    
    # Rewrite a single ratfor file.
    sub lang_ratfor_rewrite
    {
        return LANG_PROCESS;
    }
    
    # Rewrite a single Objective C file.
    sub lang_objc_rewrite
    {
        return &lang_sub_obj;
    }
    
    # Rewrite a single Java file.
    sub lang_java_rewrite
    {
        return LANG_SUBDIR;
    }
    
    # The lang_X_finish functions are called after all source file
    # processing is done.  Each should handle defining rules for the
    # language, etc.  A finish function is only called if a source file of
    # the appropriate type has been seen.
    
    sub lang_c_finish
    {
        # Push all libobjs files onto de_ansi_files.  We actually only
        # push files which exist in the current directory, and which are
        # genuine source files.
        foreach my $file (keys %libsources)
        {
    	if ($file =~ /^(.*)\.[cly]$/ && -f "$relative_dir/$file")
    	{
    	    $de_ansi_files{$1} = (($relative_dir eq '.' || $relative_dir eq '')
    				  ? ''
    				  : "$relative_dir/");
    	}
        }
    
        if (defined $options{'ansi2knr'} && keys %de_ansi_files)
        {
     	# Make all _.c files depend on their corresponding .c files.
     	my @objects;
     	foreach my $base (sort keys %de_ansi_files)
     	{
    	    # Each _.c file must depend on ansi2knr; otherwise it
    	    # might be used in a parallel build before it is built.
    	    # We need to support files in the srcdir and in the build
    	    # dir (because these files might be auto-generated.  But
    	    # we can't use $< -- some makes only define $< during a
    	    # suffix rule.
    	    my $ansfile = $de_ansi_files{$base} . $base . '.c';
     	    $output_rules .= ($base . "_.c: $ansfile \$(ANSI2KNR)\n\t"
    			      . '$(CPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) '
    			      . '`if test -f $(srcdir)/' . $ansfile
    			      . '; then echo $(srcdir)/' . $ansfile
    			      . '; else echo ' . $ansfile . '; fi` '
    			      . "| sed 's/^# \\([0-9]\\)/#line \\1/' "
    			      . '| $(ANSI2KNR) > ' . $base . "_.c"
    			      # If ansi2knr fails then we shouldn't
    			      # create the _.c file
    			      . " || rm -f ${base}_.c\n");
     	    push (@objects, $base . '_.$(OBJEXT)');
     	    push (@objects, $base . '_.lo')
    	      if variable_defined ('LIBTOOL');
     	}
    
     	# Make all _.o (and _.lo) files depend on ansi2knr.
     	# Use a sneaky little hack to make it print nicely.
     	&pretty_print_rule ('', '', @objects, ':', '$(ANSI2KNR)');
        }
    }
    
    # This is a yacc helper which is called whenever we have decided to
    # compile a yacc file.
    sub lang_yacc_target_hook
    {
        my ($self, $aggregate, $output, $input) = @_;
    
        my $flag = $aggregate . "_YFLAGS";
        if ((variable_defined ($flag)
    	 && &variable_value ($flag) =~ /$DASH_D_PATTERN/o)
    	|| (variable_defined ('YFLAGS')
    	    && &variable_value ('YFLAGS') =~ /$DASH_D_PATTERN/o))
        {
    	(my $output_base = $output) =~ s/$KNOWN_EXTENSIONS_PATTERN$//;
    	my $header = $output_base . '.h';
    
    	# Found a `-d' that applies to the compilation of this file.
    	# Add a dependency for the generated header file, and arrange
    	# for that file to be included in the distribution.
    	# FIXME: this fails for `nodist_*_SOURCES'.
    	$output_rules .= ("${header}: $output\n"
    			  # Recover from removal of $header
    			  . "\t\@if test ! -f \$@; then \\\n"
    			  . "\t  rm -f $output; \\\n"
    			  . "\t  \$(MAKE) $output; \\\n"
    			  . "\telse :; fi\n");
    	&push_dist_common ($header);
    	# If the files are built in the build directory, then we want
    	# to remove them with `make clean'.  If they are in srcdir
    	# they shouldn't be touched.  However, we can't determine this
    	# statically, and the GNU rules say that yacc/lex output files
    	# should be removed by maintainer-clean.  So that's what we
    	# do.
    	$clean_files{$header} = MAINTAINER_CLEAN;
        }
        # Erase $OUTPUT on `make maintainer-clean' (by GNU standards).
        # See the comment above for $HEADER.
        $clean_files{$output} = MAINTAINER_CLEAN;
    }
    
    # This is a lex helper which is called whenever we have decided to
    # compile a lex file.
    sub lang_lex_target_hook
    {
        my ($self, $aggregate, $output, $input) = @_;
        # If the files are built in the build directory, then we want to
        # remove them with `make clean'.  If they are in srcdir they
        # shouldn't be touched.  However, we can't determine this
        # statically, and the GNU rules say that yacc/lex output files
        # should be removed by maintainer-clean.  So that's what we do.
        $clean_files{$output} = MAINTAINER_CLEAN;
    }
    
    # This is a helper for both lex and yacc.
    sub yacc_lex_finish_helper
    {
        return if defined $language_scratch{'lex-yacc-done'};
        $language_scratch{'lex-yacc-done'} = 1;
    
        # If there is more than one distinct yacc (resp lex) source file
        # in a given directory, then the `ylwrap' program is required to
        # allow parallel builds to work correctly.  FIXME: for now, no
        # line number.
        require_conf_file ($configure_ac, FOREIGN, 'ylwrap');
        if ($config_aux_dir_set_in_configure_in)
        {
    	&define_variable ('YLWRAP', $config_aux_dir . "/ylwrap");
        }
        else
        {
    	&define_variable ('YLWRAP', '$(top_srcdir)/ylwrap');
        }
    }
    
    sub lang_yacc_finish
    {
      return if defined $language_scratch{'yacc-done'};
      $language_scratch{'yacc-done'} = 1;
    
      reject_var 'YACCFLAGS', "`YACCFLAGS' obsolete; use `YFLAGS' instead";
    
      &yacc_lex_finish_helper
        if count_files_for_language ('yacc') > 1;
    }
    
    
    sub lang_lex_finish
    {
      return if defined $language_scratch{'lex-done'};
      $language_scratch{'lex-done'} = 1;
    
      &yacc_lex_finish_helper
        if count_files_for_language ('lex') > 1;
    }
    
    
    # Given a hash table of linker names, pick the name that has the most
    # precedence.  This is lame, but something has to have global
    # knowledge in order to eliminate the conflict.  Add more linkers as
    # required.
    sub resolve_linker
    {
        my (%linkers) = @_;
    
        foreach my $l (qw(GCJLINK CXXLINK F77LINK OBJCLINK))
        {
    	return $l if defined $linkers{$l};
        }
        return 'LINK';
    }
    
    # Called to indicate that an extension was used.
    sub saw_extension
    {
        my ($ext) = @_;
        if (! defined $extension_seen{$ext})
        {
    	$extension_seen{$ext} = 1;
        }
        else
        {
    	++$extension_seen{$ext};
        }
    }
    
    # Return the number of files seen for a given language.  Knows about
    # special cases we care about.  FIXME: this is hideous.  We need
    # something that involves real language objects.  For instance yacc
    # and yaccxx could both derive from a common yacc class which would
    # know about the strange ylwrap requirement.  (Or better yet we could
    # just not support legacy yacc!)
    sub count_files_for_language
    {
        my ($name) = @_;
    
        my @names;
        if ($name eq 'yacc' || $name eq 'yaccxx')
        {
    	@names = ('yacc', 'yaccxx');
        }
        elsif ($name eq 'lex' || $name eq 'lexxx')
        {
    	@names = ('lex', 'lexxx');
        }
        else
        {
    	@names = ($name);
        }
    
        my $r = 0;
        foreach $name (@names)
        {
    	my $lang = $languages{$name};
    	foreach my $ext (@{$lang->extensions})
    	{
    	    $r += $extension_seen{$ext}
    	        if defined $extension_seen{$ext};
    	}
        }
    
        return $r
    }
    
    # Called to ask whether source files have been seen . If HEADERS is 1,
    # headers can be included.
    sub saw_sources_p
    {
        my ($headers) = @_;
    
        # count all the sources
        my $count = 0;
        foreach my $val (values %extension_seen)
        {
    	$count += $val;
        }
    
        if (!$headers)
        {
    	$count -= count_files_for_language ('header');
        }
    
        return $count > 0;
    }
    
    
    # register_language (%ATTRIBUTE)
    # ------------------------------
    # Register a single language.
    # Each %ATTRIBUTE is of the form ATTRIBUTE => VALUE.
    sub register_language (%)
    {
      my (%option) = @_;
    
      # Set the defaults.
      $option{'ansi'} = 0
        unless defined $option{'ansi'};
      $option{'autodep'} = 'no'
        unless defined $option{'autodep'};
      $option{'linker'} = ''
        unless defined $option{'linker'};
      $option{'flags'} = []
        unless defined $option{'flags'};
      $option{'output_extensions'} = sub { return ( '.$(OBJEXT)', '.lo' ) }
        unless defined $option{'output_extensions'};
    
      my $lang = new Language (%option);
    
      # Fill indexes.
      grep ($extension_map{$_} = $lang->name, @{$lang->extensions});
      $languages{$lang->name} = $lang;
    
      # Update the pattern of known extensions.
      accept_extensions (@{$lang->extensions});
    
      # Upate the $suffix_rule map.
      foreach my $suffix (@{$lang->extensions})
        {
          foreach my $dest (&{$lang->output_extensions} ($suffix))
    	{
    	  &register_suffix_rule ('internal', $suffix, $dest);
    	}
        }
    }
    
    # derive_suffix ($EXT, $OBJ)
    # --------------------------
    # This function is used to find a path from a user-specified suffix $EXT
    # to $OBJ or to some other suffix we recognize internally, eg `cc'.
    sub derive_suffix ($$)
    {
      my ($source_ext, $obj) = @_;
    
      while (! $extension_map{$source_ext}
    	 && $source_ext ne $obj
    	 && exists $suffix_rules->{$source_ext}
    	 && exists $suffix_rules->{$source_ext}{$obj})
        {
          $source_ext = $suffix_rules->{$source_ext}{$obj}[0];
        }
    
      return $source_ext;
    }
    
    
    ################################################################
    
    # Pretty-print something.  HEAD is what should be printed at the
    # beginning of the first line, FILL is what should be printed at the
    # beginning of every subsequent line.
    sub pretty_print_internal
    {
        my ($head, $fill, @values) = @_;
    
        my $column = length ($head);
        my $result = $head;
    
        # Fill length is number of characters.  However, each Tab
        # character counts for eight.  So we count the number of Tabs and
        # multiply by 7.
        my $fill_length = length ($fill);
        $fill_length += 7 * ($fill =~ tr/\t/\t/d);
    
        foreach (@values)
        {
    	# "71" because we also print a space.
    	if ($column + length ($_) > 71)
    	{
    	    $result .= " \\\n" . $fill;
    	    $column = $fill_length;
    	}
    	$result .= ' ' if $result =~ /\S\z/;
    	$result .= $_;
    	$column += length ($_) + 1;
        }
    
        $result .= "\n";
        return $result;
    }
    
    # Pretty-print something and append to output_vars.
    sub pretty_print
    {
        $output_vars .= &pretty_print_internal (@_);
    }
    
    # Pretty-print something and append to output_rules.
    sub pretty_print_rule
    {
        $output_rules .= &pretty_print_internal (@_);
    }
    
    
    ################################################################
    
    
    # $STRING
    # &conditional_string(@COND-STACK)
    # --------------------------------
    # Build a string which denotes the conditional in @COND-STACK.  Some
    # simplifications are done: `TRUE' entries are elided, and any `FALSE'
    # entry results in a return of `FALSE'.
    sub conditional_string
    {
      my (@stack) = @_;
    
      if (grep (/^FALSE$/, @stack))
        {
          return 'FALSE';
        }
      else
        {
          return join (' ', uniq sort grep (!/^TRUE$/, @stack));
        }
    }
    
    
    # $BOOLEAN
    # &conditional_true_when ($COND, $WHEN)
    # -------------------------------------
    # See if a conditional is true.  Both arguments are conditional
    # strings.  This returns true if the first conditional is true when
    # the second conditional is true.
    # For instance with $COND = `BAR FOO', and $WHEN = `BAR BAZ FOO',
    # obviously return 1, and 0 when, for instance, $WHEN = `FOO'.
    sub conditional_true_when ($$)
    {
        my ($cond, $when) = @_;
    
        # Make a hash holding all the values from $WHEN.
        my %cond_vals = map { $_ => 1 } split (' ', $when);
    
        # Nothing is true when FALSE (not even FALSE itself, but it
        # shouldn't hurt if you decide to change that).
        return 0 if exists $cond_vals{'FALSE'};
    
        # Check each component of $cond, which looks `COND1 COND2'.
        foreach my $comp (split (' ', $cond))
        {
    	# TRUE is always true.
    	next if $comp eq 'TRUE';
    	return 0 if ! defined $cond_vals{$comp};
        }
    
        return 1;
    }
    
    
    # $BOOLEAN
    # &conditional_is_redundant ($COND, @WHENS)
    # ----------------------------------------
    # Determine whether $COND is redundant with respect to @WHENS.
    #
    # Returns true if $COND is true for any of the conditions in @WHENS.
    #
    # If there are no @WHENS, then behave as if @WHENS contained a single empty
    # condition.
    sub conditional_is_redundant ($@)
    {
        my ($cond, @whens) = @_;
    
        @whens = ("") if @whens == 0;
    
        foreach my $when (@whens)
        {
    	return 1 if conditional_true_when ($cond, $when);
        }
        return 0;
    }
    
    
    # $BOOLEAN
    # &conditional_implies_any ($COND, @CONDS)
    # ----------------------------------------
    # Returns true iff $COND implies any of the conditions in @CONDS.
    sub conditional_implies_any ($@)
    {
        my ($cond, @conds) = @_;
    
        @conds = ("") if @conds == 0;
    
        foreach my $c (@conds)
        {
    	return 1 if conditional_true_when ($c, $cond);
        }
        return 0;
    }
    
    
    # $NEGATION
    # condition_negate ($COND)
    # ------------------------
    sub condition_negate ($)
    {
        my ($cond) = @_;
    
        $cond =~ s/TRUE$/TRUEO/;
        $cond =~ s/FALSE$/TRUE/;
        $cond =~ s/TRUEO$/FALSE/;
    
        return $cond;
    }
    
    
    # Compare condition names.
    # Issue them in alphabetical order, foo_TRUE before foo_FALSE.
    sub by_condition
    {
        # Be careful we might be comparing `' or `#'.
        $a =~ /^(.*)_(TRUE|FALSE)$/;
        my ($aname, $abool) = ($1 || '', $2 || '');
        $b =~ /^(.*)_(TRUE|FALSE)$/;
        my ($bname, $bbool) = ($1 || '', $2 || '');
        return ($aname cmp $bname
    	    # Don't bother with IFs, given that TRUE is after FALSE
    	    # just cmp in the reverse order.
    	    || $bbool cmp $abool
    	    # Just in case...
    	    || $a cmp $b);
    }
    
    
    # &make_condition (@CONDITIONS)
    # -----------------------------
    # Transform a list of conditions (themselves can be an internal list
    # of conditions, e.g., @CONDITIONS = ('cond1 cond2', 'cond3')) into a
    # Make conditional (a pattern for AC_SUBST).
    # Correctly returns the empty string when there are no conditions.
    sub make_condition
    {
        my $res = conditional_string (@_);
    
        # There are no conditions.
        if ($res eq '')
          {
    	# Nothing to do.
          }
        # It's impossible.
        elsif ($res eq 'FALSE')
          {
    	$res = '#';
          }
        # Build it.
        else
          {
    	$res = '@' . $res . '@';
    	$res =~ s/ /@@/g;
          }
    
        return $res;
    }
    
    
    
    ## ------------------------------ ##
    ## Handling the condition stack.  ##
    ## ------------------------------ ##
    
    
    # $COND_STRING
    # cond_stack_if ($NEGATE, $COND, $WHERE)
    # --------------------------------------
    sub cond_stack_if ($$$)
    {
      my ($negate, $cond, $where) = @_;
    
      err $where, "$cond does not appear in AM_CONDITIONAL"
        if ! $configure_cond{$cond} && $cond !~ /^TRUE|FALSE$/;
    
      $cond = "${cond}_TRUE"
        unless $cond =~ /^TRUE|FALSE$/;
      $cond = condition_negate ($cond)
        if $negate;
    
      push (@cond_stack, $cond);
    
      return conditional_string (@cond_stack);
    }
    
    
    # $COND_STRING
    # cond_stack_else ($NEGATE, $COND, $WHERE)
    # ----------------------------------------
    sub cond_stack_else ($$$)
    {
      my ($negate, $cond, $where) = @_;
    
      if (! @cond_stack)
        {
          err $where, "else without if";
          return;
        }
    
      $cond_stack[$#cond_stack] = condition_negate ($cond_stack[$#cond_stack]);
    
      # If $COND is given, check against it.
      if (defined $cond)
        {
          $cond = "${cond}_TRUE"
    	unless $cond =~ /^TRUE|FALSE$/;
          $cond = condition_negate ($cond)
    	if $negate;
    
          err ($where, "else reminder ($negate$cond) incompatible with "
    	   . "current conditional: $cond_stack[$#cond_stack]")
    	if $cond_stack[$#cond_stack] ne $cond;
        }
    
      return conditional_string (@cond_stack);
    }
    
    
    # $COND_STRING
    # cond_stack_endif ($NEGATE, $COND, $WHERE)
    # -----------------------------------------
    sub cond_stack_endif ($$$)
    {
      my ($negate, $cond, $where) = @_;
      my $old_cond;
    
      if (! @cond_stack)
        {
          err $where, "endif without if: $negate$cond";
          return;
        }
    
    
      # If $COND is given, check against it.
      if (defined $cond)
        {
          $cond = "${cond}_TRUE"
    	unless $cond =~ /^TRUE|FALSE$/;
          $cond = condition_negate ($cond)
    	if $negate;
    
          err ($where, "endif reminder ($negate$cond) incompatible with "
    	   . "current conditional: $cond_stack[$#cond_stack]")
    	if $cond_stack[$#cond_stack] ne $cond;
        }
    
      pop @cond_stack;
    
      return conditional_string (@cond_stack);
    }
    
    
    
    
    
    ## ------------------------ ##
    ## Handling the variables.  ##
    ## ------------------------ ##
    
    
    # check_ambiguous_conditional ($VAR, $COND, $WHERE)
    # -------------------------------------------------
    # Check for an ambiguous conditional.  This is called when a variable
    # is being defined conditionally.  If we already know about a
    # definition that is true under the same conditions, then we have an
    # ambiguity.
    sub check_ambiguous_conditional ($$$)
    {
      my ($var, $cond, $where) = @_;
      my ($message, $ambig_cond) =
        conditional_ambiguous_p ($var, $cond, keys %{$var_value{$var}});
      if ($message)
        {
          msg 'syntax', $where, "$message ...";
          msg_var ('syntax', $var, "... `$var' previously defined here.");
          verb (macro_dump ($var));
        }
    }
    
    # $STRING, $AMBIG_COND
    # conditional_ambiguous_p ($WHAT, $COND, @CONDS)
    # ----------------------------------------------
    # Check for an ambiguous conditional.  Return an error message and
    # the other condition involved if we have one, two empty strings otherwise.
    #   WHAT:  the thing being defined
    #   COND:  the condition under which is is being defined
    #   CONDS: the conditons under which is had already been defined
    sub conditional_ambiguous_p ($$@)
    {
      my ($var, $cond, @conds) = @_;
      foreach my $vcond (@conds)
        {
          # Note that these rules doesn't consider the following
          # example as ambiguous.
          #
          #   if COND1
          #     FOO = foo
          #   endif
          #   if COND2
          #     FOO = bar
          #   endif
          #
          # It's up to the user to not define COND1 and COND2
          # simultaneously.
          my $message;
          if ($vcond eq $cond)
    	{
    	  return ("$var multiply defined in condition $cond", $vcond);
    	}
          elsif (&conditional_true_when ($vcond, $cond))
    	{
    	  return ("$var was already defined in condition $vcond, "
    		  . "which implies condition $cond", $vcond);
    	}
          elsif (&conditional_true_when ($cond, $vcond))
    	{
    	  return ("$var was already defined in condition $vcond, "
    		   . "which is implied by condition $cond", $vcond);
    	}
        }
      return ('', '');
    }
    
    # @MISSING_CONDS
    # variable_not_always_defined_in_cond ($VAR, $COND)
    # ---------------------------------------------
    # Check whether $VAR is always defined for condition $COND.
    # Return a list of conditions where the definition is missing.
    #
    # For instance, given
    #
    #   if COND1
    #     if COND2
    #       A = foo
    #       D = d1
    #     else
    #       A = bar
    #       D = d2
    #     endif
    #   else
    #     D = d3
    #   endif
    #   if COND3
    #     A = baz
    #     B = mumble
    #   endif
    #   C = mumble
    #
    # we should have:
    #   variable_not_always_defined_in_cond ('A', 'COND1_TRUE COND2_TRUE')
    #     => ()
    #   variable_not_always_defined_in_cond ('A', 'COND1_TRUE')
    #     => ()
    #   variable_not_always_defined_in_cond ('A', 'TRUE')
    #     => ("COND1_FALSE COND2_FALSE COND3_FALSE",
    #         "COND1_FALSE COND2_TRUE COND3_FALSE",
    #         "COND1_TRUE COND2_FALSE COND3_FALSE",
    #         "COND1_TRUE COND2_TRUE COND3_FALSE")
    #   variable_not_always_defined_in_cond ('B', 'COND1_TRUE')
    #     => ("COND3_FALSE")
    #   variable_not_always_defined_in_cond ('C', 'COND1_TRUE')
    #     => ()
    #   variable_not_always_defined_in_cond ('D', 'TRUE')
    #     => ()
    #   variable_not_always_defined_in_cond ('Z', 'TRUE')
    #     => ("TRUE")
    #
    sub variable_not_always_defined_in_cond ($$)
    {
      my ($var, $cond) = @_;
    
      # It's easy to answer if the variable is not defined.
      return ("TRUE",) unless exists $var_value{$var};
    
      # How does it work?  Let's take the second example:
      #
      #   variable_not_always_defined_in_cond ('A', 'COND1_TRUE')
      #
      # (1) First, we get the list of conditions where A is defined:
      #
      #   ("COND1_TRUE COND2_TRUE", "COND1_TRUE COND2_FALSE", "COND3_TRUE")
      #
      # (2) Then we generate the set of inverted conditions:
      #
      #   ("COND1_FALSE COND2_TRUE COND3_FALSE",
      #    "COND1_FALSE COND2_FALSE COND3_FALSE")
      #
      # (3) Finally we remove these conditions which are not implied by
      #     COND1_TRUE.  This yields an empty list and we are done.
    
      my @res = ();
      my @cond_defs = keys %{$var_value{$var}}; # (1)
      foreach my $icond (invert_conditions (@cond_defs)) # (2)
        {
          prog_error "invert_conditions returned an input condition"
    	if exists $var_value{$var}{$icond};
    
          push @res, $icond
    	if (conditional_true_when ($cond, $icond)); # (3)
        }
      return @res;
    }
    
    # &macro_define($VAR, $OWNER, $TYPE, $COND, $VALUE, $WHERE)
    # -------------------------------------------------------------
    # The $VAR can go from Automake to user, but not the converse.
    sub macro_define ($$$$$$)
    {
      my ($var, $owner, $type, $cond, $value, $where) = @_;
    
      # We will adjust the owener of this variable unless told otherwise.
      my $adjust_owner = 1;
    
      err $where, "bad characters in variable name `$var'"
        if $var !~ /$MACRO_PATTERN/o;
    
      # NEWS-OS 4.2R complains if a Makefile variable begins with `_'.
      msg ('portability', $where,
           "$var: variable names starting with `_' are not portable")
        if $var =~ /^_/;
    
      # `:='-style assignments are not acknowledged by POSIX.  Moreover it
      # has multiple meanings.  In GNU make or BSD make it means "assign
      # with immediate expansion", while in OSF make it is used for
      # conditional assignments.
      msg ('portability', $where, "`:='-style assignments are not portable")
        if $type eq ':';
    
      check_variable_expansions ($value, $where);
    
      $cond ||= 'TRUE';
    
      # An Automake variable must be consistently defined with the same
      # sign by Automake.  A user variable must be set by either `=' or
      # `:=', and later promoted to `+='.
      if ($owner == VAR_AUTOMAKE)
        {
          if (exists $var_type{$var}
    	  && exists $var_type{$var}{$cond}
    	  && $var_type{$var}{$cond} ne $type)
    	{
    	  err ($where, "$var was set with `$var_type{$var}=' "
    	       . "and is now set with `$type='");
    	}
        }
      else
        {
          if (!exists $var_type{$var} && $type eq '+')
    	{
    	  err $where, "$var must be set with `=' before using `+='";
    	}
        }
      $var_type{$var}{$cond} = $type;
    
      # When adding, since we rewrite, don't try to preserve the
      # Automake continuation backslashes.
      $value =~ s/\\$//mg
        if $type eq '+' && $owner == VAR_AUTOMAKE;
    
      # Differentiate assignment types.
    
      # 1. append (+=) to a variable defined for current condition
      if ($type eq '+' && exists $var_value{$var}{$cond})
        {
          if (chomp $var_value{$var}{$cond})
    	{
    	  # Insert a backslash before a trailing newline.
    	  $var_value{$var}{$cond} .= "\\\n";
    	}
          elsif ($var_value{$var}{$cond})
    	{
    	  # Insert a separator.
    	  $var_value{$var}{$cond} .= ' ';
    	}
           $var_value{$var}{$cond} .= $value;
        }
      # 2. append (+=) to a variable defined for *another* condition
      elsif ($type eq '+' && keys %{$var_value{$var}})
        {
          # * Generally, $cond is not TRUE.  For instance:
          #     FOO = foo
          #     if COND
          #       FOO += bar
          #     endif
          #   In this case, we declare an helper variable conditionally,
          #   and append it to FOO:
          #     FOO = foo $(am__append_1)
          #     @COND_TRUE@am__append_1 = bar
          #   Of course if FOO is defined under several conditions, we add
          #   $(am__append_1) to each definitions.
          #
          # * If $cond is TRUE, we don't need the helper variable.  E.g., in
          #     if COND1
          #       FOO = foo1
          #     else
          #       FOO = foo2
          #     endif
          #     FOO += bar
          #   we can add bar directly to all definition of FOO, and output
          #     @COND_TRUE@FOO = foo1 bar
          #     @COND_FALSE@FOO = foo2 bar
    
          # Do we need an helper variable?
          if ($cond ne 'TRUE')
            {
    	    # Does the helper variable already exists?
    	    my $key = "$var:$cond";
    	    if (exists $appendvar{$key})
    	      {
    		# Yes, let's simply append to it.
    		$var = $appendvar{$key};
    		$owner = VAR_AUTOMAKE;
    	      }
    	    else
    	      {
    		# No, create it.
    		my $num = 1 + keys (%appendvar);
    		my $hvar = "am__append_$num";
    		$appendvar{$key} = $hvar;
    		&macro_define ($hvar, VAR_AUTOMAKE, '+',
    			       $cond, $value, $where);
    		push @var_list, $hvar;
    		# Now HVAR is to be added to VAR.
    		$value = "\$($hvar)";
    	      }
    	}
    
          # Add VALUE to all definitions of VAR.
          foreach my $vcond (keys %{$var_value{$var}})
            {
    	  # We have a bit of error detection to do here.
    	  # This:
    	  #   if COND1
    	  #     X = Y
    	  #   endif
    	  #   X += Z
    	  # should be rejected because X is not defined for all conditions
    	  # where `+=' applies.
    	  my @undef_cond = variable_not_always_defined_in_cond $var, $cond;
    	  if (@undef_cond != 0)
    	    {
    	      err ($where,
    		   "Cannot apply `+=' because `$var' is not defined "
    		   . "in\nthe following conditions:\n  "
    		   . join ("\n  ", @undef_cond)
    		   . "\nEither define `$var' in these conditions,"
    		   . " or use\n`+=' in the same conditions as"
    		   . " the definitions.");
    	    }
    	  else
    	    {
    	      &macro_define ($var, $owner, '+', $vcond, $value, $where);
    	    }
    	}
          # Don't adjust the owner.  The above &macro_define did it in the
          # right conditions.
          $adjust_owner = 0;
        }
      # 3. first assignment (=, :=, or +=)
      else
        {
          # If Automake tries to override a value specified by the user,
          # just don't let it do.
          if (exists $var_value{$var}{$cond}
    	  && $var_owner{$var} != VAR_AUTOMAKE
    	  && $owner == VAR_AUTOMAKE)
    	{
    	  verb ("refusing to override the user definition of:\n"
    		. macro_dump ($var)
    		."with `$cond' => `$value'");
    	}
          else
    	{
    	  # There must be no previous value unless the user is redefining
    	  # an Automake variable or an AC_SUBST variable for an existing
    	  # condition.
    	  check_ambiguous_conditional ($var, $cond, $where)
    	    unless (exists $var_owner{$var}{$cond}
    		    && (($var_owner{$var}{$cond} == VAR_AUTOMAKE
    			 && $owner != VAR_AUTOMAKE)
    			|| $var_owner{$var}{$cond} == VAR_CONFIGURE));
    
    	  $var_value{$var}{$cond} = $value;
    	  # Assignments to a macro set its location.  We don't adjust
    	  # locations for `+='.  Ideally I suppose we would associate
    	  # line numbers with random bits of text.
    	  $var_location{$var}{$cond} = $where;
    	}
        }
    
      # The owner of a variable can only increase, because an Automake
      # variable can be given to the user, but not the converse.
      if ($adjust_owner &&
          (! exists $var_owner{$var}{$cond}
           || $owner > $var_owner{$var}{$cond}))
        {
          $var_owner{$var}{$cond} = $owner;
          # Always adjust the location when the owner changes (even for
          # `+=' statements).  The risk otherwise is to warn about
          # a VAR_MAKEFILE variable and locate it in configure.ac...
          $var_location{$var}{$cond} = $where;
        }
    
      # Call var_VAR_trigger if it's defined.
      # This hook helps to update some internal state *while*
      # parsing the file.  For instance the handling of SUFFIXES
      # requires this (see var_SUFFIXES_trigger).
      my $var_trigger = "var_${var}_trigger";
      &$var_trigger($type, $value) if defined &$var_trigger;
    }
    
    
    # &macro_delete ($VAR, [@CONDS])
    # ------------------------------
    # Forget about $VAR under the conditions @CONDS, or completely if
    # @CONDS is empty.
    sub macro_delete ($@)
    {
      my ($var, @conds) = @_;
    
      if (!@conds)
        {
          delete $var_value{$var};
          delete $var_location{$var};
          delete $var_owner{$var};
          delete $var_comment{$var};
          delete $var_type{$var};
        }
      else
        {
          foreach my $cond (@conds)
    	{
    	  delete $var_value{$var}{$cond};
    	  delete $var_location{$var}{$cond};
    	  delete $var_owner{$var}{$cond};
    	  delete $var_comment{$var}{$cond};
    	  delete $var_type{$var}{$cond};
    	}
        }
    }
    
    
    # &macro_dump ($VAR)
    # ------------------
    sub macro_dump ($)
    {
      my ($var) = @_;
      my $text = '';
    
      if (!exists $var_value{$var})
        {
          $text = "  $var does not exist\n";
        }
      else
        {
          $text .= "  $var $var_type{$var}=\n  {\n";
          foreach my $vcond (sort by_condition keys %{$var_value{$var}})
    	{
    	  prog_error ("`$var' is a key in \$var_value, "
    		      . "but not in \$var_owner\n")
    	    unless exists $var_owner{$var}{$vcond};
    
    	  my $var_owner;
    	  if ($var_owner{$var}{$vcond} == VAR_AUTOMAKE)
    	    {
    	      $var_owner = 'Automake';
    	    }
    	  elsif ($var_owner{$var}{$vcond} == VAR_CONFIGURE)
    	    {
    	      $var_owner = 'Configure';
    	    }
    	  elsif ($var_owner{$var}{$vcond} == VAR_MAKEFILE)
    	    {
    	      $var_owner = 'Makefile';
    	    }
    	  else
    	    {
    	      prog_error ("unexpected value for `\$var_owner{$var}{$vcond}': "
    			  . $var_owner{$var}{$vcond})
    		unless defined $var_owner;
    	    }
    
    	  my $where = (defined $var_location{$var}{$vcond}
    		       ? $var_location{$var}{$vcond} : "undefined");
    	  $text .= "$var_comment{$var}{$vcond}"
    	    if exists $var_comment{$var}{$vcond};
    	  $text .= "    $vcond => $var_value{$var}{$vcond}\n";
    	}
          $text .= "  }\n";
        }
      return $text;
    }
    
    
    # &macros_dump ()
    # ---------------
    sub macros_dump ()
    {
      my ($var) = @_;
    
      my $text = "%var_value =\n{\n";
      foreach my $var (sort (keys %var_value))
        {
          $text .= macro_dump ($var);
        }
      $text .= "}\n";
      return $text;
    }
    
    
    # $BOOLEAN
    # variable_defined ($VAR, [$COND])
    # ---------------------------------
    # See if a variable exists.  $VAR is the variable name, and $COND is
    # the condition which we should check.  If no condition is given, we
    # currently return true if the variable is defined under any
    # condition.
    sub variable_defined ($;$)
    {
        my ($var, $cond) = @_;
    
        if (! exists $var_value{$var}
    	|| (defined $cond && ! exists $var_value{$var}{$cond}))
          {
    	# VAR is not defined.
    
    	# Check there is no target defined with the name of the
    	# variable we check.
    
    	# adl> I'm wondering if this error still makes any sense today. I
    	# adl> guess it was because targets and variables used to share
    	# adl> the same namespace in older versions of Automake?
    	# tom> While what you say is definitely part of it, I think it
    	# tom> might also have been due to someone making a "spelling error"
    	# tom> -- writing "foo:..." instead of "foo = ...".
    	# tom> I'm not sure whether it is really worth diagnosing
    	# tom> this sort of problem.  In the old days I used to add warnings
    	# tom> and errors like this pretty randomly, based on bug reports I
    	# tom> got.  But there's a plausible argument that I was trying
    	# tom> too hard to prevent people from making mistakes.
    	if (exists $targets{$var}
    	    && (! defined $cond || exists $targets{$var}{$cond}))
    	  {
    	    for my $tcond ($cond || keys %{$targets{$var}})
    	      {
    		prog_error ("\$targets{$var}{$tcond} exists but "
    			    . "\$target_owner doesn't")
    		  unless exists $target_owner{$var}{$tcond};
    		# Diagnose the first user target encountered, if any.
    		# Restricting this test to user targets allows Automake
    		# to create rules for things like `bin_PROGRAMS = LDADD'.
    		if ($target_owner{$var}{$tcond} == TARGET_USER)
    		  {
    		    msg_cond_target ('syntax', $tcond, $var,
    				     "`$var' is a target; "
    				     . "expected a variable");
    		    return 0;
    		  }
    	      }
    	  }
    	return 0;
          }
    
        # Even a var_value examination is good enough for us.  FIXME:
        # really should maintain examined status on a per-condition basis.
        $content_seen{$var} = 1;
        return 1;
    }
    
    
    # $BOOLEAN
    # variable_assert ($VAR, $WHERE)
    # ------------------------------
    # Make sure a variable exists.  $VAR is the variable name, and $WHERE
    # is the name of a macro which refers to $VAR.
    sub variable_assert ($$)
    {
      my ($var, $where) = @_;
    
      return 1
        if variable_defined $var;
    
      require_variables ($where, "variable `$var' is used", 'TRUE', $var);
    
      return 0;
    }
    
    # Mark a variable as examined.
    sub examine_variable
    {
      my ($var) = @_;
      variable_defined ($var);
    }
    
    
    # &variable_conditions_recursive ($VAR)
    # -------------------------------------
    # Return the set of conditions for which a variable is defined.
    
    # If the variable is not defined conditionally, and is not defined in
    # terms of any variables which are defined conditionally, then this
    # returns the empty list.
    
    # If the variable is defined conditionally, but is not defined in
    # terms of any variables which are defined conditionally, then this
    # returns the list of conditions for which the variable is defined.
    
    # If the variable is defined in terms of any variables which are
    # defined conditionally, then this returns a full set of permutations
    # of the subvariable conditions.  For example, if the variable is
    # defined in terms of a variable which is defined for COND_TRUE,
    # then this returns both COND_TRUE and COND_FALSE.  This is
    # because we will need to define the variable under both conditions.
    sub variable_conditions_recursive ($)
    {
        my ($var) = @_;
    
        %vars_scanned = ();
    
        my @new_conds = variable_conditions_recursive_sub ($var, '');
    
        # Now we want to return all permutations of the subvariable
        # conditions.
        my %allconds = ();
        foreach my $item (@new_conds)
        {
    	foreach (split (' ', $item))
    	{
    	    s/^(.*)_(TRUE|FALSE)$/$1_TRUE/;
    	    $allconds{$_} = 1;
    	}
        }
        @new_conds = variable_conditions_permutations (sort keys %allconds);
    
        my %uniqify;
        foreach my $cond (@new_conds)
        {
    	my $reduce = variable_conditions_reduce (split (' ', $cond));
            next
    	    if $reduce eq 'FALSE';
    	$uniqify{$cond} = 1;
        }
    
        # Note we cannot just do `return sort keys %uniqify', because this
        # function is sometimes used in a scalar context.
        my @uniq_list = sort by_condition keys %uniqify;
        return @uniq_list;
    }
    
    
    # @CONDS
    # variable_conditions ($VAR)
    # --------------------------
    # Get the list of conditions that a variable is defined with, without
    # recursing through the conditions of any subvariables.
    # Argument is $VAR: the variable to get the conditions of.
    # Returns the list of conditions.
    sub variable_conditions ($)
    {
        my ($var) = @_;
        my @conds = keys %{$var_value{$var}};
        return sort by_condition @conds;
    }
    
    
    # $BOOLEAN
    # &variable_conditionally_defined ($VAR)
    # --------------------------------------
    sub variable_conditionally_defined ($)
    {
        my ($var) = @_;
        foreach my $cond (variable_conditions_recursive ($var))
          {
    	return 1
    	  unless $cond =~ /^TRUE|FALSE$/;
          }
        return 0;
    }
    
    # @LIST
    # &scan_variable_expansions ($TEXT)
    # ---------------------------------
    # Return the list of variable names expanded in $TEXT.
    # Note that unlike some other functions, $TEXT is not split
    # on spaces before we check for subvariables.
    sub scan_variable_expansions ($)
    {
      my ($text) = @_;
      my @result = ();
    
      # Strip comments.
      $text =~ s/#.*$//;
    
      # Record each use of ${stuff} or $(stuff) that do not follow a $.
      while ($text =~ /(?<!\$)\$(?:\{([^\}]*)\}|\(([^\)]*)\))/g)
        {
          my $var = $1 || $2;
          # The occurent may look like $(string1[:subst1=[subst2]]) but
          # we want only `string1'.
          $var =~ s/:[^:=]*=[^=]*$//;
          push @result, $var;
        }
    
      return @result;
    }
    
    # &check_variable_expansions ($TEXT, $WHERE)
    # ------------------------------------------
    # Check variable expansions in $TEXT and warn about any name that
    # does not conform to POSIX.  $WHERE is the location of $TEXT for
    # the error message.
    sub check_variable_expansions ($$)
    {
      my ($text, $where) = @_;
      # Catch expansion of variables whose name does not conform to POSIX.
      foreach my $var (scan_variable_expansions ($text))
        {
          if ($var !~ /$MACRO_PATTERN/)
    	{
    	  # If the variable name contains a space, it's likely
    	  # to be a GNU make extension (such as $(addsuffix ...)).
    	  # Mention this in the diagnostic.
    	  my $gnuext = "";
    	  $gnuext = "\n(probably a GNU make extension)" if $var =~ / /;
    	  msg ('portability', $where,
    	       "$var: non-POSIX variable name$gnuext");
    	}
        }
    }
    
    # &variable_conditions_recursive_sub ($VAR, $PARENT)
    # -------------------------------------------------------
    # A subroutine of variable_conditions_recursive.  This returns all the
    # conditions of $VAR, including those of any sub-variables.
    sub variable_conditions_recursive_sub
    {
        my ($var, $parent) = @_;
        my @new_conds = ();
    
        if (defined $vars_scanned{$var})
        {
            err_var $parent, "variable `$var' recursively defined";
    	return ();
        }
        $vars_scanned{$var} = 1;
    
        my @this_conds = ();
        # Examine every condition under which $VAR is defined.
        foreach my $vcond (keys %{$var_value{$var}})
        {
          push (@this_conds, $vcond);
    
          # If $VAR references some other variable, then compute the
          # conditions for that subvariable.
          my @subvar_conds = ();
          foreach my $varname (scan_variable_expansions $var_value{$var}{$vcond})
    	{
    	  if ($varname =~ /$SUBST_REF_PATTERN/o)
    	    {
    	      $varname = $1;
    	    }
    
    	  # Here we compute all the conditions under which the
    	  # subvariable is defined.  Then we go through and add
    	  # $VCOND to each.
    	  my @svc = variable_conditions_recursive_sub ($varname, $var);
    	  foreach my $item (@svc)
    	    {
    	      my $val = conditional_string ($vcond, split (' ', $item));
    	      $val ||= 'TRUE';
    	      push (@subvar_conds, $val);
    	    }
    	}
    
          # If there are no conditional subvariables, then we want to
          # return this condition.  Otherwise, we want to return the
          # permutations of the subvariables, taking into account the
          # conditions of $VAR.
          if (! @subvar_conds)
    	{
    	  push (@new_conds, $vcond);
    	}
          else
    	{
    	  push (@new_conds, variable_conditions_reduce (@subvar_conds));
    	}
        }
    
        # Unset our entry in vars_scanned.  We only care about recursive
        # definitions.
        delete $vars_scanned{$var};
    
        # If we are being called on behalf of another variable, we need to
        # return all possible permutations of the conditions.  We have
        # already handled everything in @this_conds along with their
        # subvariables.  We now need to add any permutations that are not
        # in @this_conds.
        foreach my $this_cond (@this_conds)
        {
    	my @perms =
    	    variable_conditions_permutations (split (' ', $this_cond));
    	foreach my $perm (@perms)
    	{
    	    my $ok = 1;
    	    foreach my $scan (@this_conds)
    	    {
    		if (&conditional_true_when ($perm, $scan)
    		    || &conditional_true_when ($scan, $perm))
    		{
    		    $ok = 0;
    		    last;
    		}
    	    }
    	    next if ! $ok;
    
    	    # This permutation was not already handled, and is valid
    	    # for the parents.
    	    push (@new_conds, $perm);
    	}
        }
    
        return @new_conds;
    }
    
    
    # Filter a list of conditionals so that only the exclusive ones are
    # retained.  For example, if both `COND1_TRUE COND2_TRUE' and
    # `COND1_TRUE' are in the list, discard the latter.
    # If the list is empty, return TRUE
    sub variable_conditions_reduce
    {
        my (@conds) = @_;
        my @ret = ();
        my $cond;
        while(@conds > 0)
        {
    	$cond = shift(@conds);
    
            # FALSE is absorbent.
    	return 'FALSE'
    	  if $cond eq 'FALSE';
    
    	if (!conditional_is_redundant ($cond, @ret, @conds))
    	  {
    	    push (@ret, $cond);
    	  }
        }
    
        return "TRUE" if @ret == 0;
        return @ret;
    }
    
    # @CONDS
    # invert_conditions (@CONDS)
    # --------------------------
    # Invert a list of conditionals.  Returns a set of conditionals which
    # are never true for any of the input conditionals, and when taken
    # together with the input conditionals cover all possible cases.
    #
    # For example:
    #   invert_conditions("A_TRUE B_TRUE", "A_FALSE B_FALSE")
    #     => ("A_FALSE B_TRUE", "A_TRUE B_FALSE")
    #
    #   invert_conditions("A_TRUE B_TRUE", "A_TRUE B_FALSE", "A_FALSE")
    #     => ()
    sub invert_conditions
    {
        my (@conds) = @_;
    
        my @notconds = ();
    
        # Generate all permutation for all inputs.
        my @perm =
    	map { variable_conditions_permutations (split(' ', $_)); } @conds;
        # Remove redundant conditions.
        @perm = variable_conditions_reduce @perm;
    
        # Now remove all conditions which imply one of the input conditions.
        foreach my $perm (@perm)
        {
    	push @notconds, $perm
    	    if ! conditional_implies_any ($perm, @conds);
        }
        return @notconds;
    }
    
    # Return a list of permutations of a conditional string.
    # (But never output FALSE conditions, they are useless.)
    #
    # Examples:
    #   variable_conditions_permutations ("FOO_FALSE", "BAR_TRUE")
    #     => ("FOO_FALSE BAR_FALSE",
    #         "FOO_FALSE BAR_TRUE",
    #         "FOO_TRUE BAR_FALSE",
    #         "FOO_TRUE BAR_TRUE")
    #   variable_conditions_permutations ("FOO_FALSE", "TRUE")
    #     => ("FOO_FALSE TRUE",
    #         "FOO_TRUE TRUE")
    #   variable_conditions_permutations ("TRUE")
    #     => ("TRUE")
    #   variable_conditions_permutations ("FALSE")
    #     => ("TRUE")
    sub variable_conditions_permutations
    {
        my (@comps) = @_;
        return ()
    	if ! @comps;
        my $comp = shift (@comps);
        return variable_conditions_permutations (@comps)
    	if $comp eq '';
        my $neg = condition_negate ($comp);
    
        my @ret;
        foreach my $sub (variable_conditions_permutations (@comps))
        {
    	push (@ret, "$comp $sub") if $comp ne 'FALSE';
    	push (@ret, "$neg $sub") if $neg ne 'FALSE';
        }
        if (! @ret)
        {
    	push (@ret, $comp) if $comp ne 'FALSE';
    	push (@ret, $neg) if $neg ne 'FALSE';
        }
        return @ret;
    }
    
    
    # $BOOL
    # &check_variable_defined_unconditionally($VAR, $PARENT)
    # ------------------------------------------------------
    # Warn if a variable is conditionally defined.  This is called if we
    # are using the value of a variable.
    sub check_variable_defined_unconditionally ($$)
    {
      my ($var, $parent) = @_;
      foreach my $cond (keys %{$var_value{$var}})
        {
          next
    	if $cond =~ /^TRUE|FALSE$/;
    
          if ($parent)
    	{
    	  msg_var ('unsupported', $parent,
    		   "automake does not support conditional definition of "
    		   . "$var in $parent");
    	}
          else
    	{
    	  msg_var ('unsupported', $var,
    		   "automake does not support $var being defined "
    		   . "conditionally");
    	}
        }
    }
    
    
    # Get the TRUE value of a variable, warn if the variable is
    # conditionally defined.
    sub variable_value
    {
        my ($var) = @_;
        &check_variable_defined_unconditionally ($var);
        return $var_value{$var}{'TRUE'};
    }
    
    
    # @VALUES
    # &value_to_list ($VAR, $VAL, $COND)
    # ----------------------------------
    # Convert a variable value to a list, split as whitespace.  This will
    # recursively follow $(...) and ${...} inclusions.  It preserves @...@
    # substitutions.
    #
    # If COND is 'all', then all values under all conditions should be
    # returned; if COND is a particular condition (all conditions are
    # surrounded by @...@) then only the value for that condition should
    # be returned; otherwise, warn if VAR is conditionally defined.
    # SCANNED is a global hash listing whose keys are all the variables
    # already scanned; it is an error to rescan a variable.
    sub value_to_list ($$$)
    {
        my ($var, $val, $cond) = @_;
        my @result;
    
        # Strip backslashes
        $val =~ s/\\(\n|$)/ /g;
    
        foreach (split (' ', $val))
        {
    	# If a comment seen, just leave.
    	last if /^#/;
    
    	# Handle variable substitutions.
    	if (/^\$\{([^}]*)\}$/ || /^\$\(([^)]*)\)$/)
    	{
    	    my $varname = $1;
    
    	    # If the user uses a losing variable name, just ignore it.
    	    # This isn't ideal, but people have requested it.
    	    next if ($varname =~ /\@.*\@/);
    
    	    my ($from, $to);
    	    my @temp_list;
    	    if ($varname =~ /$SUBST_REF_PATTERN/o)
    	    {
    		$varname = $1;
    		$to = $3;
    		$from = quotemeta $2;
    	    }
    
    	    # Find the value.
    	    @temp_list =
    	      variable_value_as_list_recursive_worker ($1, $cond, $var);
    
    	    # Now rewrite the value if appropriate.
    	    if (defined $from)
    	    {
    		grep (s/$from$/$to/, @temp_list);
    	    }
    
    	    push (@result, @temp_list);
    	}
    	else
    	{
    	    push (@result, $_);
    	}
        }
    
        return @result;
    }
    
    
    # @VALUES
    # variable_value_as_list ($VAR, $COND, $PARENT)
    # ---------------------------------------------
    # Get the value of a variable given a specified condition. without
    # recursing through any subvariables.
    # Arguments are:
    #   $VAR    is the variable
    #   $COND   is the condition.  If this is not given, the value for the
    #           "TRUE" condition will be returned.
    #   $PARENT is the variable in which the variable is used: this is used
    #           only for error messages.
    # Returns the list of conditions.
    # For example, if A is defined as "foo $(B) bar", and B is defined as
    # "baz", this will return ("foo", "$(B)", "bar")
    sub variable_value_as_list
    {
        my ($var, $cond, $parent) = @_;
        my @result;
    
        # Check defined
        return
          unless variable_assert $var, $parent;
    
        # Get value for given condition
        $cond ||= 'TRUE';
        my $onceflag;
        foreach my $vcond (keys %{$var_value{$var}})
        {
    	my $val = $var_value{$var}{$vcond};
    
    	if (&conditional_true_when ($vcond, $cond))
    	{
    	    # Unless variable is not defined conditionally, there should only
    	    # be one value of $vcond true when $cond.
    	    &check_variable_defined_unconditionally ($var, $parent)
    		    if $onceflag;
    	    $onceflag = 1;
    
    	    # Strip backslashes
    	    $val =~ s/\\(\n|$)/ /g;
    
    	    foreach (split (' ', $val))
    	    {
    		# If a comment seen, just leave.
    		last if /^#/;
    
    		push (@result, $_);
    	    }
    	}
        }
    
        return @result;
    }
    
    
    # @VALUE
    # &variable_value_as_list_recursive_worker ($VAR, $COND, $PARENT)
    # ---------------------------------------------------------------
    # Return contents of VAR as a list, split on whitespace.  This will
    # recursively follow $(...) and ${...} inclusions.  It preserves @...@
    # substitutions.  If COND is 'all', then all values under all
    # conditions should be returned; if COND is a particular condition
    # (all conditions are surrounded by @...@) then only the value for
    # that condition should be returned; otherwise, warn if VAR is
    # conditionally defined.  If PARENT is specified, it is the name of
    # the including variable; this is only used for error reports.
    sub variable_value_as_list_recursive_worker ($$$)
    {
        my ($var, $cond, $parent) = @_;
        my @result = ();
    
        return
          unless variable_assert $var, $parent;
    
        if (defined $vars_scanned{$var})
        {
    	# `vars_scanned' is a global we use to keep track of which
    	# variables we've already examined.
    	err_var $parent, "variable `$var' recursively defined";
        }
        elsif ($cond eq 'all')
        {
    	$vars_scanned{$var} = 1;
    	foreach my $vcond (keys %{$var_value{$var}})
    	{
    	    my $val = $var_value{$var}{$vcond};
    	    push (@result, &value_to_list ($var, $val, $cond));
    	}
        }
        else
        {
            $cond ||= 'TRUE';
    	$vars_scanned{$var} = 1;
    	my $onceflag;
    	foreach my $vcond (keys %{$var_value{$var}})
    	{
    	    my $val = $var_value{$var}{$vcond};
    	    if (&conditional_true_when ($vcond, $cond))
    	    {
    		# Warn if we have an ambiguity.  It's hard to know how
    		# to handle this case correctly.
    		&check_variable_defined_unconditionally ($var, $parent)
    		    if $onceflag;
    		$onceflag = 1;
    		push (@result, &value_to_list ($var, $val, $cond));
    	    }
    	}
        }
    
        # Unset our entry in vars_scanned.  We only care about recursive
        # definitions.
        delete $vars_scanned{$var};
    
        return @result;
    }
    
    
    # &variable_output ($VAR, [@CONDS])
    # ---------------------------------
    # Output all the values of $VAR is @COND is not specified, else only
    # that corresponding to @COND.
    sub variable_output ($@)
    {
      my ($var, @conds) = @_;
    
      @conds = keys %{$var_value{$var}}
        unless @conds;
    
      foreach my $cond (sort by_condition @conds)
        {
          prog_error ("unknown condition `$cond' for `$var'")
    	unless exists $var_value{$var}{$cond};
    
          if (exists $var_comment{$var} && exists $var_comment{$var}{$cond})
    	{
    	  $output_vars .= $var_comment{$var}{$cond};
    	}
    
          my $val = $var_value{$var}{$cond};
          my $equals = $var_type{$var}{$cond} eq ':' ? ':=' : '=';
          my $output_var = "$var $equals $val";
          $output_var =~ s/^/make_condition ($cond)/meg;
          $output_vars .= $output_var . "\n";
        }
    }
    
    
    # &variable_pretty_output ($VAR, [@CONDS])
    # ----------------------------------------
    # Likewise, but pretty, i.e., we *split* the values at spaces.   Use only
    # with variables holding filenames.
    sub variable_pretty_output ($@)
    {
      my ($var, @conds) = @_;
    
      @conds = keys %{$var_value{$var}}
        unless @conds;
    
      foreach my $cond (sort by_condition @conds)
        {
          prog_error ("unknown condition `$cond' for `$var'")
    	unless exists $var_value{$var}{$cond};
    
          if (exists $var_comment{$var} && exists $var_comment{$var}{$cond})
    	{
    	  $output_vars .= $var_comment{$var}{$cond};
    	}
    
          my $val = $var_value{$var}{$cond};
          my $equals = $var_type{$var}{$cond} eq ':' ? ':=' : '=';
          my $make_condition = make_condition ($cond);
          $output_vars .= pretty_print_internal ("$make_condition$var $equals",
    					     "$make_condition\t",
    					     split (' ' , $val));
        }
    }
    
    
    # &variable_value_as_list_recursive ($VAR, $COND, $PARENT)
    # --------------------------------------------------------
    # This is just a wrapper for variable_value_as_list_recursive_worker that
    # initializes the global hash `vars_scanned'.  This hash is used to
    # avoid infinite recursion.
    sub variable_value_as_list_recursive ($$@)
    {
        my ($var, $cond, $parent) = @_;
        %vars_scanned = ();
        return &variable_value_as_list_recursive_worker ($var, $cond, $parent);
    }
    
    
    # &define_pretty_variable ($VAR, $COND, @VALUE)
    # ---------------------------------------------
    # Like define_variable, but the value is a list, and the variable may
    # be defined conditionally.  The second argument is the conditional
    # under which the value should be defined; this should be the empty
    # string to define the variable unconditionally.  The third argument
    # is a list holding the values to use for the variable.  The value is
    # pretty printed in the output file.
    sub define_pretty_variable ($$@)
    {
        my ($var, $cond, @value) = @_;
    
        # Beware that an empty $cond has a different semantics for
        # macro_define and variable_pretty_output.
        $cond ||= 'TRUE';
    
        if (! variable_defined ($var, $cond))
        {
            macro_define ($var, VAR_AUTOMAKE, '', $cond, "@value", undef);
    	variable_pretty_output ($var, $cond || 'TRUE');
    	$content_seen{$var} = 1;
        }
    }
    
    
    # define_variable ($VAR, $VALUE)
    # ------------------------------
    # Define a new user variable VAR to VALUE, but only if not already defined.
    sub define_variable ($$)
    {
        my ($var, $value) = @_;
        define_pretty_variable ($var, 'TRUE', $value);
    }
    
    
    # Like define_variable, but define a variable to be the configure
    # substitution by the same name.
    sub define_configure_variable ($)
    {
      my ($var) = @_;
      if (! variable_defined ($var, 'TRUE')
          # Explicitly avoid ANSI2KNR -- we AC_SUBST that in
          # protos.m4, but later define it elsewhere.  This is
          # pretty hacky.  We also explicitly avoid AMDEPBACKSLASH:
          # it might be subst'd by `\', which certainly would not be
          # appreciated by Make.
          && ! grep { $_ eq $var } (qw(ANSI2KNR AMDEPBACKSLASH)))
        {
          macro_define ($var, VAR_CONFIGURE, '', 'TRUE',
    		    subst $var, $configure_vars{$var});
          variable_pretty_output ($var, 'TRUE');
        }
    }
    
    
    # define_compiler_variable ($LANG)
    # --------------------------------
    # Define a compiler variable.  We also handle defining the `LT'
    # version of the command when using libtool.
    sub define_compiler_variable ($)
    {
        my ($lang) = @_;
    
        my ($var, $value) = ($lang->compiler, $lang->compile);
        &define_variable ($var, $value);
        &define_variable ("LT$var", "\$(LIBTOOL) --mode=compile $value")
          if variable_defined ('LIBTOOL');
    }
    
    
    # define_linker_variable ($LANG)
    # ------------------------------
    # Define linker variables.
    sub define_linker_variable ($)
    {
        my ($lang) = @_;
    
        my ($var, $value) = ($lang->lder, $lang->ld);
        # CCLD = $(CC).
        &define_variable ($lang->lder, $lang->ld);
        # CCLINK = $(CCLD) blah blah...
        &define_variable ($lang->linker,
    		      ((variable_defined ('LIBTOOL')
    			? '$(LIBTOOL) --mode=link ' : '')
    		       . $lang->link));
    }
    
    ################################################################
    
    ## ---------------- ##
    ## Handling rules.  ##
    ## ---------------- ##
    
    sub register_suffix_rule ($$$)
    {
      my ($where, $src, $dest) = @_;
    
      verb "Sources ending in $src become $dest";
      push @suffixes, $src, $dest;
    
      # When tranforming sources to objects, Automake uses the
      # %suffix_rules to move from each source extension to
      # `.$(OBJEXT)', not to `.o' or `.obj'.  However some people
      # define suffix rules for `.o' or `.obj', so internally we will
      # consider these extensions equivalent to `.$(OBJEXT)'.  We
      # CANNOT rewrite the target (i.e., automagically replace `.o'
      # and `.obj' by `.$(OBJEXT)' in the output), or warn the user
      # that (s)he'd better use `.$(OBJEXT)', because Automake itself
      # output suffix rules for `.o' or `.obj'...
      $dest = '.$(OBJEXT)' if ($dest eq '.o' || $dest eq '.obj');
    
      # Reading the comments near the declaration of $suffix_rules might
      # help to understand the update of $suffix_rules that follows...
    
      # Register $dest as a possible destination from $src.
      # We might have the create the \hash.
      if (exists $suffix_rules->{$src})
        {
          $suffix_rules->{$src}{$dest} = [ $dest, 1 ];
        }
      else
        {
          $suffix_rules->{$src} = { $dest => [ $dest, 1 ] };
        }
    
      # If we know how to transform $dest in something else, then
      # we know how to transform $src in that "something else".
      if (exists $suffix_rules->{$dest})
        {
          for my $dest2 (keys %{$suffix_rules->{$dest}})
    	{
    	  my $dist = $suffix_rules->{$dest}{$dest2}[1] + 1;
    	  # Overwrite an existing $src->$dest2 path only if
    	  # the path via $dest which is shorter.
    	  if (! exists $suffix_rules->{$src}{$dest2}
    	      || $suffix_rules->{$src}{$dest2}[1] > $dist)
    	    {
    	      $suffix_rules->{$src}{$dest2} = [ $dest, $dist ];
    	    }
    	}
        }
    
      # Similarly, any extension that can be derived into $src
      # can be derived into the same extenstions as $src can.
      my @dest2 = keys %{$suffix_rules->{$src}};
      for my $src2 (keys %$suffix_rules)
        {
          if (exists $suffix_rules->{$src2}{$src})
    	{
    	  for my $dest2 (@dest2)
    	    {
    	      my $dist = $suffix_rules->{$src}{$dest2} + 1;
    	      # Overwrite an existing $src2->$dest2 path only if
    	      # the path via $src is shorter.
    	      if (! exists $suffix_rules->{$src2}{$dest2}
    		  || $suffix_rules->{$src2}{$dest2}[1] > $dist)
    		{
    		  $suffix_rules->{$src2}{$dest2} = [ $src, $dist ];
    		}
    	    }
    	}
        }
    }
    
    # @CONDS
    # rule_define ($TARGET, $SOURCE, $OWNER, $COND, $WHERE)
    # -----------------------------------------------------
    # Define a new rule.  $TARGET is the rule name.  $SOURCE
    # is the filename the rule comes from.  $OWNER is the
    # owener of the rule (TARGET_AUTOMAKE or TARGET_USER).
    # $COND is the condition string under which the rule is defined.
    # $WHERE is where the rule is defined (file name and/or line number).
    # Returns a (possibly empty) list of conditions where the rule
    # should be defined.
    sub rule_define ($$$$$)
    {
      my ($target, $source, $owner, $cond, $where) = @_;
    
      # Don't even think about defining a rule in condition FALSE.
      return () if $cond eq 'FALSE';
    
      # For now `foo:' will override `foo$(EXEEXT):'.  This is temporary,
      # though, so we emit a warning.
      (my $noexe = $target) =~ s,\$\(EXEEXT\)$,,;
      if ($noexe ne $target && exists $targets{$noexe}{$cond})
        {
          # The no-exeext option enables this feature.
          if (! defined $options{'no-exeext'})
    	{
    	  msg ('obsolete', $noexe,
    	       "deprecated feature: `$noexe' overrides `$noexe\$(EXEEXT)'\n"
    	       . "change your target to read `$noexe\$(EXEEXT)'");
    	}
          # Don't define.
          return ();
        }
    
      $target = $noexe;
    
      # A GNU make-style pattern rule has a single "%" in the target name.
      msg ('portability', $where,
           "`%'-style pattern rules are a GNU make extension")
        if $target =~ /^[^%]*%[^%]*$/;
    
      # Diagnose target redefinitions.
      if (exists $target_source{$target}{$cond})
        {
          # Sanity checks.
          prog_error ("\$target_source{$target}{$cond} exists, but \$target_owner"
    		  . " doesn't.")
    	unless exists $target_owner{$target}{$cond};
          prog_error ("\$target_source{$target}{$cond} exists, but \$targets"
    		  . " doesn't.")
    	unless exists $targets{$target}{$cond};
    
          my $oldowner  = $target_owner{$target}{$cond};
    
          # Don't mention true conditions in diagnostics.
          my $condmsg = $cond ne 'TRUE' ? " in condition `$cond'" : '';
    
          if ($owner == TARGET_USER)
    	{
    	  if ($oldowner eq TARGET_USER)
    	    {
    	      # Ignore `%'-style pattern rules.  We'd need the
    	      # dependencies to detect duplicates, and they are
    	      # already diagnosed as unportable by -Wportability.
    	      if ($target !~ /^[^%]*%[^%]*$/)
    		{
    		  ## FIXME: Presently we can't diagnose duplcate user rules
    		  ## because we doesn't distinguish rules with commands
    		  ## from rules that only add dependencies.  E.g.,
    		  ##   .PHONY: foo
    		  ##   .PHONY: bar
    		  ## is legitimate. (This is phony.test.)
    
    		  # msg ('syntax', $where,
    		  #      "redefinition of `$target'$condmsg...");
    		  # msg_cond_target ('syntax', $cond, $target,
    		  # 		   "... `$target' previously defined here.");
    		}
    	      # Return so we don't redefine the rule in our tables,
    	      # don't check for ambiguous conditional, etc.  The rule
    	      # will be output anyway beauce &read_am_file ignore the
    	      # return code.
    	      return ();
    	    }
    	  else
    	    {
    	      # Since we parse the user Makefile.am before reading
    	      # the Automake fragments, this condition should never happen.
    	      prog_error ("user target `$target' seen after Automake's "
    			  . "definition\nfrom `$targets{$target}$condmsg'");
    	    }
    	}
          else # $owner == TARGET_AUTOMAKE
    	{
    	  if ($oldowner == TARGET_USER)
    	    {
    	      # Don't overwrite the user definition of TARGET.
    	      return ();
    	    }
    	  else # $oldowner == TARGET_AUTOMAKE
    	    {
    	      # Automake should ignore redefinitions of its own
    	      # rules if they came from the same file.  This makes
    	      # it easier to process a Makefile fragment several times.
    	      # Hower it's an error if the target is defined in many
    	      # files.  E.g., the user might be using bin_PROGRAMS = ctags
    	      # which clashes with our `ctags' rule.
    	      # (It would be more accurate if we had a way to compare
    	      # the *content* of both rules.  Then $targets_source would
    	      # be useless.)
    	      my $oldsource = $target_source{$target}{$cond};
    	      return () if $source eq $oldsource;
    
    	      msg ('syntax', $where, "redefinition of `$target'$condmsg...");
    	      msg_cond_target ('syntax', $cond, $target,
    			       "... `$target' previously defined here.");
    	      return ();
    	    }
    	}
          # Never reached.
          prog_error ("Unreachable place reached.");
        }
    
      # Conditions for which the rule should be defined.
      my @conds = $cond;
    
      # Check ambiguous conditional definitions.
      my ($message, $ambig_cond) =
        conditional_ambiguous_p ($target, $cond, keys %{$targets{$target}});
      if ($message)			# We have an ambiguty.
        {
          if ($owner == TARGET_USER)
    	{
    	  # For user rules, just diagnose the ambiguity.
    	  msg 'syntax', $where, "$message ...";
    	  msg_cond_target ('syntax', $ambig_cond, $target,
    			   "... `$target' previously defined here.");
    	  return ();
    	}
          else
    	{
    	  # FIXME: for Automake rules, we can't diagnose ambiguities yet.
    	  # The point is that Automake doesn't propagate conditionals
    	  # everywhere.  For instance &handle_PROGRAMS doesn't care if
    	  # bin_PROGRAMS was defined conditionally or not.
    	  # On the following input
    	  #   if COND1
    	  #   foo:
    	  #           ...
    	  #   else
    	  #   bin_PROGRAMS = foo
    	  #   endif
    	  # &handle_PROGRAMS will attempt to define a `foo:' rule
    	  # in condition TRUE (which conflicts with COND1).  Fixing
    	  # this in &handle_PROGRAMS and siblings seems hard: you'd
    	  # have to explain &file_contents what to do with a
    	  # conditional.  So for now we do our best *here*.  If `foo:'
    	  # was already defined in condition COND1 and we want to define
    	  # it in condition TRUE, then define it only in condition !COND1.
    	  # (See cond14.test and cond15.test for some test cases.)
    	  my @defined_conds = keys %{$targets{$target}};
    	  @conds = ();
    	  for my $undefined_cond (invert_conditions(@defined_conds))
    	    {
    	      push @conds, make_condition ($cond, $undefined_cond);
    	    }
    	  # No conditions left to define the rule.
    	  # Warn, because our workaround is meaningless in this case.
    	  if (scalar @conds == 0)
    	    {
    	      msg 'syntax', $where, "$message ...";
    	      msg_cond_target ('syntax', $ambig_cond, $target,
    			       "... `$target' previously defined here.");
    	      return ();
    	    }
    	}
        }
    
      # Finally define this rule.
      for my $c (@conds)
        {
          $targets{$target}{$c} = $where;
          $target_source{$target}{$c} = $source;
          $target_owner{$target}{$c} = $owner;
        }
    
      # Check the rule for being a suffix rule. If so, store in a hash.
      # Either it's a rule for two known extensions...
      if ($target =~ /^($KNOWN_EXTENSIONS_PATTERN)($KNOWN_EXTENSIONS_PATTERN)$/
          # ...or it's a rule with unknown extensions (.i.e, the rule looks like
          # `.foo.bar:' but `.foo' or `.bar' are not declared in SUFFIXES
          # and are not known language extensions).
          # Automake will complete SUFFIXES from @suffixes automatically
          # (see handle_footer).
          || ($target =~ /$SUFFIX_RULE_PATTERN/o && accept_extensions($1)))
        {
          register_suffix_rule ($where, $1, $2);
        }
    
      # Return "" instead of TRUE so it can be used with make_paragraphs
      # directly.
      return "" if 1 == @conds && $conds[0] eq 'TRUE';
      return @conds;
    }
    
    
    # See if a target exists.
    sub target_defined
    {
        my ($target) = @_;
        return exists $targets{$target};
    }
    
    
    ################################################################
    
    # &append_comments ($VARIABLE, $SPACING, $COMMENT)
    # ------------------------------------------------
    # Apped $COMMENT to the other comments for $VARIABLE, using
    # $SPACING as separator.
    sub append_comments ($$$$)
    {
        my ($cond, $var, $spacing, $comment) = @_;
        $var_comment{$var}{$cond} .= $spacing
    	if (!defined $var_comment{$var}{$cond}
    	    || $var_comment{$var}{$cond} !~ /\n$/o);
        $var_comment{$var}{$cond} .= $comment;
    }
    
    
    # &read_am_file ($AMFILE)
    # -----------------------
    # Read Makefile.am and set up %contents.  Simultaneously copy lines
    # from Makefile.am into $output_trailer or $output_vars as
    # appropriate.  NOTE we put rules in the trailer section.  We want
    # user rules to come after our generated stuff.
    sub read_am_file ($)
    {
        my ($amfile) = @_;
    
        my $am_file = new Automake::XFile ("< $amfile");
        verb "reading $amfile";
    
        my $spacing = '';
        my $comment = '';
        my $blank = 0;
        my $saw_bk = 0;
    
        use constant IN_VAR_DEF => 0;
        use constant IN_RULE_DEF => 1;
        use constant IN_COMMENT => 2;
        my $prev_state = IN_RULE_DEF;
    
        while ($_ = $am_file->getline)
        {
    	if (/$IGNORE_PATTERN/o)
    	{
    	    # Merely delete comments beginning with two hashes.
    	}
    	elsif (/$WHITE_PATTERN/o)
    	{
    	    err "$amfile:$.", "blank line following trailing backslash"
    	      if $saw_bk;
    	    # Stick a single white line before the incoming macro or rule.
    	    $spacing = "\n";
    	    $blank = 1;
    	    # Flush all comments seen so far.
    	    if ($comment ne '')
    	    {
    		$output_vars .= $comment;
    		$comment = '';
    	    }
    	}
    	elsif (/$COMMENT_PATTERN/o)
    	{
    	    # Stick comments before the incoming macro or rule.  Make
    	    # sure a blank line preceeds first block of comments.
    	    $spacing = "\n" unless $blank;
    	    $blank = 1;
    	    $comment .= $spacing . $_;
    	    $spacing = '';
    	    $prev_state = IN_COMMENT;
    	}
    	else
    	{
    	    last;
    	}
    	$saw_bk = /\\$/ && ! /$IGNORE_PATTERN/o;
        }
    
        # We save the conditional stack on entry, and then check to make
        # sure it is the same on exit.  This lets us conditonally include
        # other files.
        my @saved_cond_stack = @cond_stack;
        my $cond = conditional_string (@cond_stack);
    
        my $last_var_name = '';
        my $last_var_type = '';
        my $last_var_value = '';
        # FIXME: shouldn't use $_ in this loop; it is too big.
        while ($_)
        {
            my $here = "$amfile:$.";
    
    	# Make sure the line is \n-terminated.
    	chomp;
    	$_ .= "\n";
    
    	# Don't look at MAINTAINER_MODE_TRUE here.  That shouldn't be
    	# used by users.  @MAINT@ is an anachronism now.
    	$_ =~ s/\@MAINT\@//g
    	    unless $seen_maint_mode;
    
    	my $new_saw_bk = /\\$/ && ! /$IGNORE_PATTERN/o;
    
    	if (/$IGNORE_PATTERN/o)
    	{
    	    # Merely delete comments beginning with two hashes.
    	}
    	elsif (/$WHITE_PATTERN/o)
    	{
    	    # Stick a single white line before the incoming macro or rule.
    	    $spacing = "\n";
    	    err $here, "blank line following trailing backslash"
    	      if $saw_bk;
    	}
    	elsif (/$COMMENT_PATTERN/o)
    	{
    	    # Stick comments before the incoming macro or rule.
    	    $comment .= $spacing . $_;
    	    $spacing = '';
    	    err $here, "comment following trailing backslash"
    	      if $saw_bk && $comment eq '';
    	    $prev_state = IN_COMMENT;
    	}
    	elsif ($saw_bk)
    	{
    	    if ($prev_state == IN_RULE_DEF)
    	    {
    	        $output_trailer .= &make_condition (@cond_stack);
    		$output_trailer .= $_;
    	    }
    	    elsif ($prev_state == IN_COMMENT)
    	    {
    		# If the line doesn't start with a `#', add it.
    		# We do this because a continuated comment like
    		#   # A = foo \
    		#         bar \
    		#         baz
    		# is not portable.  BSD make doesn't honor
    		# escaped newlines in comments.
    		s/^#?/#/;
    		$comment .= $spacing . $_;
    	    }
    	    else # $prev_state == IN_VAR_DEF
    	    {
    	      $last_var_value .= ' '
    		unless $last_var_value =~ /\s$/;
    	      $last_var_value .= $_;
    
    	      if (!/\\$/)
    		{
    		  append_comments ($cond || 'TRUE',
    				   $last_var_name, $spacing, $comment);
    		  $comment = $spacing = '';
    		  macro_define ($last_var_name, VAR_MAKEFILE,
    				$last_var_type, $cond,
    				$last_var_value, $here)
    		    if $cond ne 'FALSE';
    		  push (@var_list, $last_var_name);
    		}
    	    }
    	}
    
    	elsif (/$IF_PATTERN/o)
    	  {
    	    $cond = cond_stack_if ($1, $2, $here);
    	  }
    	elsif (/$ELSE_PATTERN/o)
    	  {
    	    $cond = cond_stack_else ($1, $2, $here);
    	  }
    	elsif (/$ENDIF_PATTERN/o)
    	  {
    	    $cond = cond_stack_endif ($1, $2, $here);
    	  }
    
    	elsif (/$RULE_PATTERN/o)
    	{
    	    # Found a rule.
    	    $prev_state = IN_RULE_DEF;
    
    	    # For now we have to output all definitions of user rules
    	    # and can't diagnose duplicates (see the comment in
    	    # rule_define). So we go on and ignore the return value.
    	    rule_define ($1, $amfile, TARGET_USER, $cond || 'TRUE', $here);
    
    	    check_variable_expansions ($_, $here);
    
    	    $output_trailer .= $comment . $spacing;
                $output_trailer .= &make_condition (@cond_stack);
                $output_trailer .= $_;
    	    $comment = $spacing = '';
    	}
    	elsif (/$ASSIGNMENT_PATTERN/o)
    	{
    	    # Found a macro definition.
    	    $prev_state = IN_VAR_DEF;
    	    $last_var_name = $1;
    	    $last_var_type = $2;
    	    $last_var_value = $3;
    	    if ($3 ne '' && substr ($3, -1) eq "\\")
    	    {
    		# We preserve the `\' because otherwise the long lines
    		# that are generated will be truncated by broken
    		# `sed's.
    		$last_var_value = $3 . "\n";
    	    }
    
    	    if (!/\\$/)
    	      {
    		# Accumulating variables must not be output.
    		append_comments ($cond || 'TRUE',
    				 $last_var_name, $spacing, $comment);
    		$comment = $spacing = '';
    
    		macro_define ($last_var_name, VAR_MAKEFILE,
    			      $last_var_type, $cond,
    			      $last_var_value, $here)
    		  if $cond ne 'FALSE';
    		push (@var_list, $last_var_name);
    	      }
    	}
            elsif (/$INCLUDE_PATTERN/o)
            {
                my $path = $1;
    
                if ($path =~ s/^\$\(top_srcdir\)\///)
    	      {
                    push (@include_stack, "\$\(top_srcdir\)/$path");
    		# Distribute any included file.
    		my $distname = backname ($relative_dir) . '/' . $path;
    		push_dist_common ($distname);
    	      }
                else
    	      {
                    $path =~ s/\$\(srcdir\)\///;
                    push (@include_stack, "\$\(srcdir\)/$path");
    		push_dist_common ($path);
    		$path = $relative_dir . "/" . $path;
    	      }
                &read_am_file ($path);
            }
    	else
            {
    	    # This isn't an error; it is probably a continued rule.
    	    # In fact, this is what we assume.
    	    $prev_state = IN_RULE_DEF;
    	    check_variable_expansions ($_, $here);
    	    $output_trailer .= $comment . $spacing;
    	    $output_trailer .= &make_condition  (@cond_stack);
    	    $output_trailer .= $_;
    	    $comment = $spacing = '';
    	    err $here, "`#' comment at start of rule is unportable"
    	      if $_ =~ /^\t\s*\#/;
    	}
    
    	$saw_bk = $new_saw_bk;
            $_ = $am_file->getline;
        }
    
        $output_trailer .= $comment;
    
        err_am (@cond_stack ? "unterminated conditionals: @cond_stack"
    	    : "too many conditionals closed in include file")
          if "@saved_cond_stack" ne "@cond_stack";
    }
    
    
    # define_standard_variables ()
    # ----------------------------
    # A helper for read_main_am_file which initializes configure variables
    # and variables from header-vars.am.
    sub define_standard_variables
    {
        my $saved_output_vars = $output_vars;
        my ($comments, undef, $rules) =
          file_contents_internal (1, "$libdir/am/header-vars.am");
    
        # This will output the definitions in $output_vars, which we don't
        # want...
        foreach my $var (sort keys %configure_vars)
        {
            &define_configure_variable ($var);
            push (@var_list, $var);
        }
    
        # ... hence, we restore $output_vars.
        $output_vars = $saved_output_vars . $comments . $rules;
    }
    
    # Read main am file.
    sub read_main_am_file
    {
        my ($amfile) = @_;
    
        # This supports the strange variable tricks we are about to play.
        prog_error (macros_dump () . "variable defined before read_main_am_file")
          if (scalar keys %var_value > 0);
    
        # Generate copyright header for generated Makefile.in.
        # We do discard the output of predefined variables, handled below.
        $output_vars = ("# $in_file_name generated by automake "
    		   . $VERSION . " from $am_file_name.\n");
        $output_vars .= '# ' . subst ('configure_input') . "\n";
        $output_vars .= $gen_copyright;
    
        # We want to predefine as many variables as possible.  This lets
        # the user set them with `+=' in Makefile.am.  However, we don't
        # want these initial definitions to end up in the output quite
        # yet.  So we just load them, but output them later.
        &define_standard_variables;
    
        # Read user file, which might override some of our values.
        &read_am_file ($amfile);
    
        # Output all the Automake variables.  If the user changed one,
        # then it is now marked as VAR_CONFIGURE or VAR_MAKEFILE.
        foreach my $var (uniq @var_list)
        {
          # Some variables, like AMDEPBACKSLASH are in @var_list
          # but don't have a owner.  This is good, because we don't want
          # to output them.
          foreach my $cond (keys %{$var_owner{$var}})
    	{
    	  variable_output ($var, $cond)
    	    if $var_owner{$var}{$cond} == VAR_AUTOMAKE;
    	}
        }
    
        # Now dump the user variables that were defined.  We do it in the same
        # order in which they were defined (skipping duplicates).
        foreach my $var (uniq @var_list)
        {
          foreach my $cond (keys %{$var_owner{$var}})
    	{
    	  variable_output ($var, $cond)
    	    if $var_owner{$var}{$cond} != VAR_AUTOMAKE;
    	}
        }
    }
    
    ################################################################
    
    # $FLATTENED
    # &flatten ($STRING)
    # ------------------
    # Flatten the $STRING and return the result.
    sub flatten
    {
      $_ = shift;
    
      s/\\\n//somg;
      s/\s+/ /g;
      s/^ //;
      s/ $//;
    
      return $_;
    }
    
    
    # @PARAGRAPHS
    # &make_paragraphs ($MAKEFILE, [%TRANSFORM])
    # ------------------------------------------
    # Load a $MAKEFILE, apply the %TRANSFORM, and return it as a list of
    # paragraphs.
    sub make_paragraphs ($%)
    {
        my ($file, %transform) = @_;
    
        # Complete %transform with global options and make it a Perl
        # $command.
        my $command =
          "s/$IGNORE_PATTERN//gm;"
    	. transform (%transform,
    
    		     'CYGNUS'          => $cygnus_mode,
    		     'MAINTAINER-MODE'
    		     => $seen_maint_mode ? subst ('MAINTAINER_MODE_TRUE') : '',
    
    		     'SHAR'        => $options{'dist-shar'} || 0,
    		     'BZIP2'       => $options{'dist-bzip2'} || 0,
    		     'ZIP'         => $options{'dist-zip'} || 0,
    		     'COMPRESS'    => $options{'dist-tarZ'} || 0,
    
    		     'INSTALL-INFO' => !$options{'no-installinfo'},
    		     'INSTALL-MAN'  => !$options{'no-installman'},
    		     'CK-NEWS'      => $options{'check-news'} || 0,
    
    		     'SUBDIRS'      => variable_defined ('SUBDIRS'),
    		     'TOPDIR'       => backname ($relative_dir),
    		     'TOPDIR_P'     => $relative_dir eq '.',
    		     'CONFIGURE-AC' => $configure_ac,
    
    		     'BUILD'    => $seen_canonical == AC_CANONICAL_SYSTEM,
    		     'HOST'     => $seen_canonical,
    		     'TARGET'   => $seen_canonical == AC_CANONICAL_SYSTEM,
    
    		     'LIBTOOL'      => variable_defined ('LIBTOOL'))
    	  # We don't need more than two consecutive new-lines.
    	  . 's/\n{3,}/\n\n/g';
    
        # Swallow the file and apply the COMMAND.
        my $fc_file = new Automake::XFile "< $file";
        # Looks stupid?
        verb "reading $file";
        my $saved_dollar_slash = $/;
        undef $/;
        $_ = $fc_file->getline;
        $/ = $saved_dollar_slash;
        eval $command;
        $fc_file->close;
        my $content = $_;
    
        # Split at unescaped new lines.
        my @lines = split (/(?<!\\)\n/, $content);
        my @res;
    
        while (defined ($_ = shift @lines))
          {
    	my $paragraph = "$_";
    	# If we are a rule, eat as long as we start with a tab.
    	if (/$RULE_PATTERN/smo)
    	  {
    	    while (defined ($_ = shift @lines) && $_ =~ /^\t/)
    	      {
    		$paragraph .= "\n$_";
    	      }
    	    unshift (@lines, $_);
    	  }
    
    	# If we are a comments, eat as much comments as you can.
    	elsif (/$COMMENT_PATTERN/smo)
    	  {
    	    while (defined ($_ = shift @lines)
    		   && $_ =~ /$COMMENT_PATTERN/smo)
    	      {
    		$paragraph .= "\n$_";
    	      }
    	    unshift (@lines, $_);
    	  }
    
    	push @res, $paragraph;
    	$paragraph = '';
          }
    
        return @res;
    }
    
    
    
    # ($COMMENT, $VARIABLES, $RULES)
    # &file_contents_internal ($IS_AM, $FILE, [%TRANSFORM])
    # -----------------------------------------------------
    # Return contents of a file from $libdir/am, automatically skipping
    # macros or rules which are already known. $IS_AM iff the caller is
    # reading an Automake file (as opposed to the user's Makefile.am).
    sub file_contents_internal ($$%)
    {
        my ($is_am, $file, %transform) = @_;
    
        my $result_vars = '';
        my $result_rules = '';
        my $comment = '';
        my $spacing = '';
    
        # The following flags are used to track rules spanning across
        # multiple paragraphs.
        my $is_rule = 0;		# 1 if we are processing a rule.
        my $discard_rule = 0;	# 1 if the current rule should not be output.
    
        # We save the conditional stack on entry, and then check to make
        # sure it is the same on exit.  This lets us conditonally include
        # other files.
        my @saved_cond_stack = @cond_stack;
        my $cond = conditional_string (@cond_stack);
    
        foreach (make_paragraphs ($file, %transform))
        {
            # Sanity checks.
    	err $file, "blank line following trailing backslash:\n$_"
    	  if /\\$/;
    	err $file, "comment following trailing backslash:\n$_"
    	  if /\\#/;
    
     	if (/^$/)
     	{
    	    $is_rule = 0;
     	    # Stick empty line before the incoming macro or rule.
     	    $spacing = "\n";
     	}
     	elsif (/$COMMENT_PATTERN/mso)
     	{
    	    $is_rule = 0;
     	    # Stick comments before the incoming macro or rule.
     	    $comment = "$_\n";
    	}
    
    	# Handle inclusion of other files.
            elsif (/$INCLUDE_PATTERN/o)
            {
    	    if ($cond ne 'FALSE')
    	      {
    		my $file = ($is_am ? "$libdir/am/" : '') . $1;
    		# N-ary `.=' fails.
    		my ($com, $vars, $rules)
    		  = file_contents_internal ($is_am, $file, %transform);
    		$comment .= $com;
    		$result_vars .= $vars;
    		$result_rules .= $rules;
    	      }
            }
    
            # Handling the conditionals.
            elsif (/$IF_PATTERN/o)
    	  {
    	    $cond = cond_stack_if ($1, $2, $file);
    	  }
    	elsif (/$ELSE_PATTERN/o)
    	  {
    	    $cond = cond_stack_else ($1, $2, $file);
    	  }
    	elsif (/$ENDIF_PATTERN/o)
    	  {
    	    $cond = cond_stack_endif ($1, $2, $file);
    	  }
    
            # Handling rules.
     	elsif (/$RULE_PATTERN/mso)
     	{
    	  $is_rule = 1;
    	  $discard_rule = 0;
    	  # Separate relationship from optional actions: the first
    	  # `new-line tab" not preceded by backslash (continuation
    	  # line).
    	  # I'm quite shoked!  It seems that (\\\n|[^\n]) is not the
    	  # same as `([^\n]|\\\n)!!!  Don't swap it, it breaks.
    	  my $paragraph = $_;
    	  /^((?:\\\n|[^\n])*)(?:\n(\t.*))?$/som;
    	  my ($relationship, $actions) = ($1, $2 || '');
    
    	  # Separate targets from dependencies: the first colon.
    	  $relationship =~ /^([^:]+\S+) *: *(.*)$/som;
    	  my ($targets, $dependencies) = ($1, $2);
    	  # Remove the escaped new lines.
    	  # I don't know why, but I have to use a tmp $flat_deps.
    	  my $flat_deps = &flatten ($dependencies);
    	  my @deps = split (' ', $flat_deps);
    
    	  foreach (split (' ' , $targets))
    	    {
    	      # FIXME: 1. We are not robust to people defining several targets
    	      # at once, only some of them being in %dependencies.  The
    	      # actions from the targets in %dependencies are usually generated
    	      # from the content of %actions, but if some targets in $targets
    	      # are not in %dependencies the ELSE branch will output
    	      # a rule for all $targets (i.e. the targets which are both
    	      # in %dependencies and $targets will have two rules).
    
    	      # FIXME: 2. The logic here is not able to output a
    	      # multi-paragraph rule several time (e.g. for each conditional
    	      # it is defined for) because it only knows the first paragraph.
    
    	      # FIXME: 3. We are not robust to people defining a subset
    	      # of a previously defined "multiple-target" rule.  E.g.
    	      # `foo:' after `foo bar:'.
    
    	      # Output only if not in FALSE.
    	      if (defined $dependencies{$_} && $cond ne 'FALSE')
    		{
    		  &depend ($_, @deps);
    		  $actions{$_} .= $actions;
    		}
    	      else
    		{
    		  # Free-lance dependency.  Output the rule for all the
    		  # targets instead of one by one.
    		  my @undefined_conds =
    		    rule_define ($targets, $file,
    				 $is_am ? TARGET_AUTOMAKE : TARGET_USER,
    				 $cond || 'TRUE', $file);
    		  for my $undefined_cond (@undefined_conds)
    		    {
    		      my $condparagraph = $paragraph;
    		      $condparagraph =~ s/^/$undefined_cond/gm;
    		      $result_rules .= "$spacing$comment$condparagraph\n";
    		    }
    		  if (scalar @undefined_conds == 0)
    		    {
    		      # Remember to discard next paragraphs
    		      # if they belong to this rule.
    		      # (but see also FIXME: #2 above.)
    		      $discard_rule = 1;
    		    }
    		  $comment = $spacing = '';
    		  last;
    		}
    	    }
     	}
    
     	elsif (/$ASSIGNMENT_PATTERN/mso)
     	{
    	    my ($var, $type, $val) = ($1, $2, $3);
     	    err $file, "variable `$var' with trailing backslash"
    	      if /\\$/;
    
    	    $is_rule = 0;
    
    	    # Accumulating variables must not be output.
    	    append_comments ($cond || 'TRUE', $var, $spacing, $comment);
    	    macro_define ($var, $is_am ? VAR_AUTOMAKE : VAR_MAKEFILE,
    			  $type, $cond, $val, $file)
    	      if $cond ne 'FALSE';
    	    push (@var_list, $var);
    
    	    # If the user has set some variables we were in charge
    	    # of (which is detected by the first reading of
    	    # `header-vars.am'), we must not output them.
    	    $result_vars .= "$spacing$comment$_\n"
    	      if ($cond ne 'FALSE' && $type ne '+'
    		  && exists $var_owner{$var}{$cond || 'TRUE'}
    		  && $var_owner{$var}{$cond || 'TRUE'} == VAR_AUTOMAKE);
    
     	    $comment = $spacing = '';
     	}
     	else
     	{
    	    # This isn't an error; it is probably some tokens which
    	    # configure is supposed to replace, such as `@SET-MAKE@',
    	    # or some part of a rule cut by an if/endif.
      	    if ($cond ne 'FALSE' && ! ($is_rule && $discard_rule))
    	      {
    		s/^/make_condition (@cond_stack)/gme;
    		$result_rules .= "$spacing$comment$_\n";
    	      }
     	    $comment = $spacing = '';
     	}
        }
    
        err_am (@cond_stack ?
    	    "unterminated conditionals: @cond_stack" :
    	    "too many conditionals closed in include file")
          if "@saved_cond_stack" ne "@cond_stack";
    
        return ($comment, $result_vars, $result_rules);
    }
    
    
    # $CONTENTS
    # &file_contents ($BASENAME, [%TRANSFORM])
    # ----------------------------------------
    # Return contents of a file from $libdir/am, automatically skipping
    # macros or rules which are already known.
    sub file_contents ($%)
    {
        my ($basename, %transform) = @_;
        my ($comments, $variables, $rules) =
          file_contents_internal (1, "$libdir/am/$basename.am", %transform);
        return "$comments$variables$rules";
    }
    
    
    # $REGEXP
    # &transform (%PAIRS)
    # -------------------
    # Foreach ($TOKEN, $VAL) in %PAIRS produce a replacement expression suitable
    # for file_contents which:
    #   - replaces %$TOKEN% with $VAL,
    #   - enables/disables ?$TOKEN? and ?!$TOKEN?,
    #   - replaces %?$TOKEN% with TRUE or FALSE.
    sub transform (%)
    {
        my (%pairs) = @_;
        my $result = '';
    
        while (my ($token, $val) = each %pairs)
        {
            $result .= "s/\Q%$token%\E/\Q$val\E/gm;";
    	if ($val)
    	{
    	    $result .= "s/\Q?$token?\E//gm;s/^.*\Q?!$token?\E.*\\n//gm;";
    	    $result .= "s/\Q%?$token%\E/TRUE/gm;";
    	}
    	else
    	{
    	    $result .= "s/\Q?!$token?\E//gm;s/^.*\Q?$token?\E.*\\n//gm;";
    	    $result .= "s/\Q%?$token%\E/FALSE/gm;";
    	}
        }
    
        return $result;
    }
    
    
    # &append_exeext ($MACRO)
    # -----------------------
    # Macro is an Automake magic macro which primary is PROGRAMS, e.g.
    # bin_PROGRAMS.  Make sure these programs have $(EXEEXT) appended.
    sub append_exeext ($)
    {
      my ($macro) = @_;
    
      prog_error "append_exeext ($macro)"
        unless $macro =~ /_PROGRAMS$/;
    
      my @conds = variable_conditions_recursive ($macro);
    
      my @condvals;
      foreach my $cond (@conds)
        {
          my @one_binlist = ();
          my @condval = variable_value_as_list_recursive ($macro, $cond);
          foreach my $rcurs (@condval)
    	{
    	  # Skip autoconf substs.  Also skip if the user
    	  # already applied $(EXEEXT).
    	  if ($rcurs =~ /^\@.*\@$/ || $rcurs =~ /\$\(EXEEXT\)$/)
    	    {
    	      push (@one_binlist, $rcurs);
    	    }
    	  else
    	    {
    	      push (@one_binlist, $rcurs . '$(EXEEXT)');
    	    }
    	}
    
          push (@condvals, $cond);
          push (@condvals, "@one_binlist");
        }
    
      macro_delete ($macro);
      while (@condvals)
        {
          my $cond = shift (@condvals);
          my @val = split (' ', shift (@condvals));
          define_pretty_variable ($macro, $cond, @val);
        }
     }
    
    
    # @PREFIX
    # &am_primary_prefixes ($PRIMARY, $CAN_DIST, @PREFIXES)
    # -----------------------------------------------------
    # Find all variable prefixes that are used for install directories.  A
    # prefix `zar' qualifies iff:
    #
    # * `zardir' is a variable.
    # * `zar_PRIMARY' is a variable.
    #
    # As a side effect, it looks for misspellings.  It is an error to have
    # a variable ending in a "reserved" suffix whose prefix is unknown, eg
    # "bni_PROGRAMS".  However, unusual prefixes are allowed if a variable
    # of the same name (with "dir" appended) exists.  For instance, if the
    # variable "zardir" is defined, then "zar_PROGRAMS" becomes valid.
    # This is to provide a little extra flexibility in those cases which
    # need it.
    sub am_primary_prefixes ($$@)
    {
      my ($primary, $can_dist, @prefixes) = @_;
    
      local $_;
      my %valid = map { $_ => 0 } @prefixes;
      $valid{'EXTRA'} = 0;
      foreach my $varname (keys %var_value)
        {
          # Automake is allowed to define variables that look like primaries
          # but which aren't.  E.g. INSTALL_sh_DATA.
          # Autoconf can also define variables like INSTALL_DATA, so
          # ignore all configure variables (at least those which are not
          # redefined in Makefile.am).
          # FIXME: We should make sure that these variables are not
          # conditionally defined (or else adjust the condition below).
          next
    	if (exists $var_owner{$varname}
    	    && exists $var_owner{$varname}{'TRUE'}
    	    && $var_owner{$varname}{'TRUE'} != VAR_MAKEFILE);
    
          if ($varname =~ /^(nobase_)?(dist_|nodist_)?(.*)_$primary$/)
    	{
    	  my ($base, $dist, $X) = ($1 || '', $2 || '', $3 || '');
    	  if ($dist ne '' && ! $can_dist)
                {
    	      err_var ($varname,
    		       "invalid variable `$varname': `dist' is forbidden");
    	    }
    	  # Standard directories must be explicitely allowed.
    	  elsif (! defined $valid{$X} && exists $standard_prefix{$X})
    	    {
    	      err_var ($varname,
    		       "`${X}dir' is not a legitimate directory " .
    		       "for `$primary'");
    	    }
    	  # A not explicitely valid directory is allowed if Xdir is defined.
    	  elsif (! defined $valid{$X} &&
    		 require_variables_for_macro ($varname, "`$varname' is used",
    					      "${X}dir"))
    	    {
    	      # Nothing to do.  Any error message has been output
    	      # by require_variables_for_macro.
    	    }
    	  else
    	    {
    	      # Ensure all extended prefixes are actually used.
    	      $valid{"$base$dist$X"} = 1;
    	    }
    	}
        }
    
      # Return only those which are actually defined.
      return sort grep { variable_defined ($_ . '_' . $primary) } keys %valid;
    }
    
    
    # Handle `where_HOW' variable magic.  Does all lookups, generates
    # install code, and possibly generates code to define the primary
    # variable.  The first argument is the name of the .am file to munge,
    # the second argument is the primary variable (eg HEADERS), and all
    # subsequent arguments are possible installation locations.  Returns
    # list of all values of all _HOW targets.
    #
    # FIXME: this should be rewritten to be cleaner.  It should be broken
    # up into multiple functions.
    #
    # Usage is: am_install_var (OPTION..., file, HOW, where...)
    sub am_install_var
    {
        my (@args) = @_;
    
        my $do_require = 1;
        my $can_dist = 0;
        my $default_dist = 0;
        while (@args)
        {
    	if ($args[0] eq '-noextra')
    	{
    	    $do_require = 0;
    	}
    	elsif ($args[0] eq '-candist')
    	{
    	    $can_dist = 1;
    	}
    	elsif ($args[0] eq '-defaultdist')
    	{
    	    $default_dist = 1;
    	    $can_dist = 1;
    	}
    	elsif ($args[0] !~ /^-/)
    	{
    	    last;
    	}
    	shift (@args);
        }
    
        my ($file, $primary, @prefix) = @args;
    
        # Now that configure substitutions are allowed in where_HOW
        # variables, it is an error to actually define the primary.  We
        # allow `JAVA', as it is customarily used to mean the Java
        # interpreter.  This is but one of several Java hacks.  Similarly,
        # `PYTHON' is customarily used to mean the Python interpreter.
        reject_var $primary, "`$primary' is an anachronism"
          unless $primary eq 'JAVA' || $primary eq 'PYTHON';
    
        # Get the prefixes which are valid and actually used.
        @prefix = am_primary_prefixes ($primary, $can_dist, @prefix);
    
        # If a primary includes a configure substitution, then the EXTRA_
        # form is required.  Otherwise we can't properly do our job.
        my $require_extra;
    
        my @used = ();
        my @result = ();
    
        # True if the iteration is the first one.  Used for instance to
        # output parts of the associated file only once.
        my $first = 1;
        foreach my $X (@prefix)
        {
    	my $nodir_name = $X;
    	my $one_name = $X . '_' . $primary;
    
    	my $strip_subdir = 1;
    	# If subdir prefix should be preserved, do so.
    	if ($nodir_name =~ /^nobase_/)
    	  {
    	    $strip_subdir = 0;
    	    $nodir_name =~ s/^nobase_//;
    	  }
    
    	# If files should be distributed, do so.
    	my $dist_p = 0;
    	if ($can_dist)
    	  {
    	    $dist_p = (($default_dist && $nodir_name !~ /^nodist_/)
    		       || (! $default_dist && $nodir_name =~ /^dist_/));
    	    $nodir_name =~ s/^(dist|nodist)_//;
    	  }
    
    	# Append actual contents of where_PRIMARY variable to
    	# result.
    	foreach my $rcurs (&variable_value_as_list_recursive ($one_name, 'all'))
    	  {
    	    # Skip configure substitutions.  Possibly bogus.
    	    if ($rcurs =~ /^\@.*\@$/)
    	      {
    		if ($nodir_name eq 'EXTRA')
    		  {
    		    err_var ($one_name,
    			     "`$one_name' contains configure substitution, "
    			     . "but shouldn't");
    		  }
    		# Check here to make sure variables defined in
    		# configure.ac do not imply that EXTRA_PRIMARY
    		# must be defined.
    		elsif (! defined $configure_vars{$one_name})
    		  {
    		    $require_extra = $one_name
    		      if $do_require;
    		  }
    
    		next;
    	      }
    
    	    push (@result, $rcurs);
    	  }
    	# A blatant hack: we rewrite each _PROGRAMS primary to include
    	# EXEEXT.
    	append_exeext ($one_name)
    	  if $primary eq 'PROGRAMS';
    	# "EXTRA" shouldn't be used when generating clean targets,
    	# all, or install targets.  We used to warn if EXTRA_FOO was
    	# defined uselessly, but this was annoying.
    	next
    	  if $nodir_name eq 'EXTRA';
    
    	if ($nodir_name eq 'check')
    	  {
    	    push (@check, '$(' . $one_name . ')');
    	  }
    	else
    	  {
    	    push (@used, '$(' . $one_name . ')');
    	  }
    
    	# Is this to be installed?
    	my $install_p = $nodir_name ne 'noinst' && $nodir_name ne 'check';
    
    	# If so, with install-exec? (or install-data?).
    	my $exec_p = ($nodir_name =~ /$EXEC_DIR_PATTERN/o);
    
    	my $check_options_p = $install_p
    			      && defined $options{'std-options'};
    
    	# Singular form of $PRIMARY.
    	(my $one_primary = $primary) =~ s/S$//;
    	$output_rules .= &file_contents ($file,
    					 ('FIRST' => $first,
    
    					  'PRIMARY'     => $primary,
    					  'ONE_PRIMARY' => $one_primary,
    					  'DIR'         => $X,
    					  'NDIR'        => $nodir_name,
    					  'BASE'        => $strip_subdir,
    
    					  'EXEC'    => $exec_p,
    					  'INSTALL' => $install_p,
    					  'DIST'    => $dist_p,
    					  'CK-OPTS' => $check_options_p));
    
    	$first = 0;
        }
    
        # The JAVA variable is used as the name of the Java interpreter.
        # The PYTHON variable is used as the name of the Python interpreter.
        if (@used && $primary ne 'JAVA' && $primary ne 'PYTHON')
        {
    	# Define it.
    	define_pretty_variable ($primary, '', @used);
    	$output_vars .= "\n";
        }
    
        err_var ($require_extra,
    	     "`$require_extra' contains configure substitution,\n"
    	     . "but `EXTRA_$primary' not defined")
          if ($require_extra && ! variable_defined ('EXTRA_' . $primary));
    
        # Push here because PRIMARY might be configure time determined.
        push (@all, '$(' . $primary . ')')
    	if @used && $primary ne 'JAVA' && $primary ne 'PYTHON';
    
        # Make the result unique.  This lets the user use conditionals in
        # a natural way, but still lets us program lazily -- we don't have
        # to worry about handling a particular object more than once.
        return uniq (sort @result);
    }
    
    
    ################################################################
    
    # Each key in this hash is the name of a directory holding a
    # Makefile.in.  These variables are local to `is_make_dir'.
    my %make_dirs = ();
    my $make_dirs_set = 0;
    
    sub is_make_dir
    {
        my ($dir) = @_;
        if (! $make_dirs_set)
        {
    	foreach my $iter (@configure_input_files)
    	{
    	    $make_dirs{dirname ($iter)} = 1;
    	}
    	# We also want to notice Makefile.in's.
    	foreach my $iter (@other_input_files)
    	{
    	    if ($iter =~ /Makefile\.in$/)
    	    {
    		$make_dirs{dirname ($iter)} = 1;
    	    }
    	}
    	$make_dirs_set = 1;
        }
        return defined $make_dirs{$dir};
    }
    
    ################################################################
    
    # This variable is local to the "require file" set of functions.
    my @require_file_paths = ();
    
    
    # &maybe_push_required_file ($DIR, $FILE, $FULLFILE)
    # --------------------------------------------------
    # See if we want to push this file onto dist_common.  This function
    # encodes the rules for deciding when to do so.
    sub maybe_push_required_file
    {
        my ($dir, $file, $fullfile) = @_;
    
        if ($dir eq $relative_dir)
        {
    	push_dist_common ($file);
    	return 1;
        }
        elsif ($relative_dir eq '.' && ! &is_make_dir ($dir))
        {
    	# If we are doing the topmost directory, and the file is in a
    	# subdir which does not have a Makefile, then we distribute it
    	# here.
    	push_dist_common ($fullfile);
    	return 1;
        }
        return 0;
    }
    
    
    # &require_file_internal ($WHERE, $MYSTRICT, @FILES)
    # --------------------------------------------------
    # Verify that the file must exist in the current directory.
    # $MYSTRICT is the strictness level at which this file becomes required.
    #
    # Must set require_file_paths before calling this function.
    # require_file_paths is set to hold a single directory (the one in
    # which the first file was found) before return.
    sub require_file_internal ($$@)
    {
        my ($where, $mystrict, @files) = @_;
    
        foreach my $file (@files)
        {
            my $fullfile;
    	my $errdir;
    	my $errfile;
    	my $save_dir;
    
    	my $found_it = 0;
    	my $dangling_sym = 0;
    	foreach my $dir (@require_file_paths)
    	{
    	    $fullfile = $dir . "/" . $file;
    	    $errdir = $dir unless $errdir;
    
    	    # Use different name for "error filename".  Otherwise on
    	    # an error the bad file will be reported as eg
    	    # `../../install-sh' when using the default
    	    # config_aux_path.
    	    $errfile = $errdir . '/' . $file;
    
    	    if (-l $fullfile && ! -f $fullfile)
    	    {
    		$dangling_sym = 1;
    		last;
    	    }
    	    elsif (-f $fullfile)
    	    {
    		$found_it = 1;
    		maybe_push_required_file ($dir, $file, $fullfile);
    		$save_dir = $dir;
    		last;
    	    }
    	}
    
    	# `--force-missing' only has an effect if `--add-missing' is
    	# specified.
    	if ($found_it && (! $add_missing || ! $force_missing))
    	{
    	    # Prune the path list.
    	    @require_file_paths = $save_dir;
    	}
    	else
    	{
    	    # If we've already looked for it, we're done.  You might
    	    # wonder why we don't do this before searching for the
    	    # file.  If we do that, then something like
    	    # AC_OUTPUT(subdir/foo foo) will fail to put foo.in into
    	    # DIST_COMMON.
    	    if (! $found_it)
    	    {
    		next if defined $require_file_found{$fullfile};
    		$require_file_found{$fullfile} = 1;
    	    }
    
    	    if ($strictness >= $mystrict)
    	    {
    		if ($dangling_sym && $add_missing)
    		{
    		    unlink ($fullfile);
    		}
    
    		my $trailer = '';
    		my $suppress = 0;
    
    		# Only install missing files according to our desired
    		# strictness level.
    		my $message = "required file `$errfile' not found";
    		if ($add_missing)
    		{
    		    $suppress = 1;
    
    		    if (-f ("$libdir/$file"))
    		    {
    			# Install the missing file.  Symlink if we
    			# can, copy if we must.  Note: delete the file
    			# first, in case it is a dangling symlink.
    			$message = "installing `$errfile'";
    			# Windows Perl will hang if we try to delete a
    			# file that doesn't exist.
    			unlink ($errfile) if -f $errfile;
    			if ($symlink_exists && ! $copy_missing)
    			{
    			    if (! symlink ("$libdir/$file", $errfile))
    			    {
    				$suppress = 0;
    				$trailer = "; error while making link: $!";
    			    }
    			}
    			elsif (system ('cp', "$libdir/$file", $errfile))
    			{
    			    $suppress = 0;
    			    $trailer = "\n    error while copying";
    			}
    		    }
    
    		    if (! maybe_push_required_file (dirname ($errfile),
                                                        $file, $errfile))
    		    {
    			if (! $found_it)
    			{
    			    # We have added the file but could not push it
    			    # into DIST_COMMON (probably because this is
    			    # an auxiliary file and we are not processing
    			    # the top level Makefile). This is unfortunate,
    			    # since it means we are using a file which is not
    			    # distributed!
    
    			    # Get Automake to be run again: on the second
    			    # run the file will be found, and pushed into
    			    # the toplevel DIST_COMMON automatically.
    			    $automake_needs_to_reprocess_all_files = 1;
    			}
    		    }
    
    		    # Prune the path list.
    		    @require_file_paths = &dirname ($errfile);
    		}
    
    		# If --force-missing was specified, and we have
    		# actually found the file, then do nothing.
    		next
    		    if $found_it && $force_missing;
    
    		msg ($suppress ? 'note' : 'error', $where, "$message$trailer");
    	    }
    	}
        }
    }
    
    # &require_file ($WHERE, $MYSTRICT, @FILES)
    # -----------------------------------------
    sub require_file ($$@)
    {
        my ($where, $mystrict, @files) = @_;
        @require_file_paths = $relative_dir;
        require_file_internal ($where, $mystrict, @files);
    }
    
    # &require_file_with_macro ($COND, $MACRO, $MYSTRICT, @FILES)
    # -----------------------------------------------------------
    sub require_file_with_macro ($$$@)
    {
        my ($cond, $macro, $mystrict, @files) = @_;
        require_file ($var_location{$macro}{$cond}, $mystrict, @files);
    }
    
    
    # &require_conf_file ($WHERE, $MYSTRICT, @FILES)
    # ----------------------------------------------
    # Looks in configuration path, as specified by AC_CONFIG_AUX_DIR.
    sub require_conf_file ($$@)
    {
        my ($where, $mystrict, @files) = @_;
        @require_file_paths = @config_aux_path;
        require_file_internal ($where, $mystrict, @files);
        my $dir = $require_file_paths[0];
        @config_aux_path = @require_file_paths;
         # Avoid unsightly '/.'s.
        $config_aux_dir = '$(top_srcdir)' . ($dir eq '.' ? "" : "/$dir");
    }
    
    
    # &require_conf_file_with_macro ($COND, $MACRO, $MYSTRICT, @FILES)
    # ----------------------------------------------------------------
    sub require_conf_file_with_macro ($$$@)
    {
        my ($cond, $macro, $mystrict, @files) = @_;
        require_conf_file ($var_location{$macro}{$cond}, $mystrict, @files);
    }
    
    ################################################################
    
    # &require_build_directory ($DIRECTORY)
    # ------------------------------------
    # Emit rules to create $DIRECTORY if needed, and return
    # the file that any target requiring this directory should be made
    # dependent upon.
    sub require_build_directory ($)
    {
        my $directory = shift;
        my $dirstamp = "$directory/.dirstamp";
    
        # Don't emit the rule twice.
        if (! defined $directory_map{$directory})
        {
    	$directory_map{$directory} = 1;
    
    	# Directory must be removed by `make distclean'.
    	$clean_files{$dirstamp} = DIST_CLEAN;
    
    	$output_rules .= ("$dirstamp:\n"
    			  . "\t\@\$(mkinstalldirs) $directory\n"
    			  . "\t\@: > $dirstamp\n");
        }
    
        return $dirstamp;
    }
    
    # &require_build_directory_maybe ($FILE)
    # --------------------------------------
    # If $FILE lies in a subdirectory, emit a rule to create this
    # directory and return the file that $FILE should be made
    # dependent upon.  Otherwise, just return the empty string.
    sub require_build_directory_maybe ($)
    {
        my $file = shift;
        my $directory = dirname ($file);
    
        if ($directory ne '.')
        {
    	return require_build_directory ($directory);
        }
        else
        {
    	return '';
        }
    }
    
    ################################################################
    
    # Push a list of files onto dist_common.
    sub push_dist_common
    {
      prog_error "push_dist_common run after handle_dist"
        if $handle_dist_run;
      macro_define ('DIST_COMMON', VAR_AUTOMAKE, '+', '', "@_", '');
    }
    
    
    # Set strictness.
    sub set_strictness
    {
      $strictness_name = $_[0];
    
      # FIXME: 'portability' warnings are currently disabled by default.
      # Eventually we want to turn them on in GNU and GNITS modes, but
      # we don't do this yet in Automake 1.7 to help the 1.6/1.7 transition.
      #
      # Indeed there would be only two ways to get rid of these new warnings:
      #  1. adjusting Makefile.am
      #     This is not always easy (or wanted).  Consider %-rules or
      #     $(function args) variables.
      #  2. using -Wno-portability
      #     This means there is no way to have the same Makefile.am
      #     working both with Automake 1.6 and 1.7 (since 1.6 does not
      #     understand -Wno-portability).
      #
      # In Automake 1.8 (or whatever it is called) we can turn these
      # warnings on, since -Wno-portability will not be an issue for
      # the 1.7/1.8 transition.
      if ($strictness_name eq 'gnu')
        {
          $strictness = GNU;
          setup_channel 'error-gnu', silent => 0;
          setup_channel 'error-gnu/warn', silent => 0, type => 'error';
          setup_channel 'error-gnits', silent => 1;
          # setup_channel 'portability', silent => 0;
          setup_channel 'gnu', silent => 0;
        }
      elsif ($strictness_name eq 'gnits')
        {
          $strictness = GNITS;
          setup_channel 'error-gnu', silent => 0;
          setup_channel 'error-gnu/warn', silent => 0, type => 'error';
          setup_channel 'error-gnits', silent => 0;
          # setup_channel 'portability', silent => 0;
          setup_channel 'gnu', silent => 0;
        }
      elsif ($strictness_name eq 'foreign')
        {
          $strictness = FOREIGN;
          setup_channel 'error-gnu', silent => 1;
          setup_channel 'error-gnu/warn', silent => 0, type => 'warning';
          setup_channel 'error-gnits', silent => 1;
          # setup_channel 'portability', silent => 1;
          setup_channel 'gnu', silent => 1;
        }
      else
        {
          prog_error "level `$strictness_name' not recognized\n";
        }
    }
    
    
    ################################################################
    
    # Glob something.  Do this to avoid indentation screwups everywhere we
    # want to glob.  Gross!
    sub my_glob
    {
        my ($pat) = @_;
        return <${pat}>;
    }
    
    ################################################################
    
    # INTEGER
    # require_variables ($WHERE, $REASON, $COND, @VARIABLES)
    # ------------------------------------------------------
    # Make sure that each supplied variable is defined in $COND.
    # Otherwise, issue a warning.  If we know which macro can
    # define this variable, hint the user.
    # Return the number of undefined variables.
    sub require_variables ($$$@)
    {
      my ($where, $reason, $cond, @vars) = @_;
      my $res = 0;
      $reason .= ' but ' unless $reason eq '';
    
     VARIABLE:
      foreach my $var (@vars)
        {
          # Nothing to do if the variable exists.  The $configure_vars test
          # needed for strange variables like AMDEPBACKSLASH or ANSI2KNR
          # that are AC_SUBST'ed but never macro_define'd.
          next VARIABLE
    	if ((exists $var_value{$var} && exists $var_value{$var}{$cond})
    	    || exists $configure_vars{$var});
    
          # If the variable exists but was not defined in $cond,
          # look for any definition implied by $cond.
          if (exists $var_value{$var})
    	{
    	  for my $vcond (keys %{$var_value{$var}})
    	    {
    	      next VARIABLE
    		if (conditional_true_when ($vcond, $cond));
    	    }
    	}
    
          ++$res;
    
          my $text = "$reason`$var' is undefined.";
          if (exists $am_macro_for_var{$var})
    	{
    	  $text .= "\nThe usual way to define `$var' is to add "
    	    . "`$am_macro_for_var{$var}'\nto `$configure_ac' and run "
    	    . "`aclocal' and `autoconf' again.";
    	}
          elsif (exists $ac_macro_for_var{$var})
    	{
    	  $text .= "\nThe usual way to define `$var' is to add "
    	    . "`$ac_macro_for_var{$var}'\nto `$configure_ac' and run "
    	    . "`autoconf' again.";
    	}
    
          err $where, $text, uniq_scope => US_GLOBAL;
        }
      return $res;
    }
    
    # INTEGER
    # require_variables_for_macro ($MACRO, $REASON, @VARIABLES)
    # ---------------------------------------------------------
    # Same as require_variables, but take a macro mame as first argument.
    sub require_variables_for_macro ($$@)
    {
      my ($macro, $reason, @args) = @_;
      for my $cond (keys %{$var_value{$macro}})
        {
          return require_variables ($var_location{$macro}{$cond}, $reason,
    				$cond, @args);
        }
    }
    
    # Print usage information.
    sub usage ()
    {
        print "Usage: $0 [OPTION] ... [Makefile]...
    
    Generate Makefile.in for configure from Makefile.am.
    
    Operation modes:
          --help               print this help, then exit
          --version            print version number, then exit
      -v, --verbose            verbosely list files processed
          --no-force           only update Makefile.in's that are out of date
      -W, --warnings=CATEGORY  report the warnings falling in CATEGORY
    
    Dependency tracking:
      -i, --ignore-deps      disable dependency tracking code
          --include-deps     enable dependency tracking code
    
    Flavors:
          --cygnus           assume program is part of Cygnus-style tree
          --foreign          set strictness to foreign
          --gnits            set strictness to gnits
          --gnu              set strictness to gnu
    
    Library files:
      -a, --add-missing      add missing standard files to package
          --libdir=DIR       directory storing library files
      -c, --copy             with -a, copy missing files (default is symlink)
      -f, --force-missing    force update of standard files
    
    Warning categories include:
      `gnu'           GNU coding standards (default in gnu and gnits modes)
      `obsolete'      obsolete features or constructions
      `portability'   portability issues
      `syntax'        dubious syntactic constructs (default)
      `unsupported'   unsupported or incomplete features (default)
      `all'           all the warnings
      `no-CATEGORY'   turn off warnings in CATEGORY
      `none'          turn off all the warnings
      `error'         treat warnings as errors
    ";
    
        my ($last, @lcomm);
        $last = '';
        foreach my $iter (sort ((@common_files, @common_sometimes)))
        {
    	push (@lcomm, $iter) unless $iter eq $last;
    	$last = $iter;
        }
    
        my @four;
        print "\nFiles which are automatically distributed, if found:\n";
        format USAGE_FORMAT =
      @<<<<<<<<<<<<<<<<   @<<<<<<<<<<<<<<<<   @<<<<<<<<<<<<<<<<   @<<<<<<<<<<<<<<<<
      $four[0],           $four[1],           $four[2],           $four[3]
    .
        $~ = "USAGE_FORMAT";
    
        my $cols = 4;
        my $rows = int(@lcomm / $cols);
        my $rest = @lcomm % $cols;
    
        if ($rest)
        {
    	$rows++;
        }
        else
        {
    	$rest = $cols;
        }
    
        for (my $y = 0; $y < $rows; $y++)
        {
    	@four = ("", "", "", "");
    	for (my $x = 0; $x < $cols; $x++)
    	{
    	    last if $y + 1 == $rows && $x == $rest;
    
    	    my $idx = (($x > $rest)
    		       ?  ($rows * $rest + ($rows - 1) * ($x - $rest))
    		       : ($rows * $x));
    
    	    $idx += $y;
    	    $four[$x] = $lcomm[$idx];
    	}
    	write;
        }
    
        print "\nReport bugs to <bug-automake\@gnu.org>.\n";
    
        # --help always returns 0 per GNU standards.
        exit 0;
    }
    
    
    # &version ()
    # -----------
    # Print version information
    sub version ()
    {
      print <<EOF;
    automake (GNU $PACKAGE) $VERSION
    Written by Tom Tromey <tromey\@redhat.com>.
    
    Copyright 2002 Free Software Foundation, Inc.
    This is free software; see the source for copying conditions.  There is NO
    warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    EOF
      # --version always returns 0 per GNU standards.
      exit 0;
    }
    
    ### Setup "GNU" style for perl-mode and cperl-mode.
    ## Local Variables:
    ## perl-indent-level: 2
    ## perl-continued-statement-offset: 2
    ## perl-continued-brace-offset: 0
    ## perl-brace-offset: 0
    ## perl-brace-imaginary-offset: 0
    ## perl-label-offset: -2
    ## cperl-indent-level: 2
    ## cperl-brace-offset: 0
    ## cperl-continued-brace-offset: 0
    ## cperl-label-offset: -2
    ## cperl-extra-newline-before-brace: t
    ## cperl-merge-trailing-else: nil
    ## cperl-continued-statement-offset: 2
    ## End: