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kc3-lang/automake/lib/Automake/Rule.pm

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  • Author : Alexandre Duret-Lutz
    Date : 2005-05-14 20:28:56
    Hash : 1183efd3
    Message : * COPYING, ChangeLog, ChangeLog.00, ChangeLog.01, ChangeLog.02, ChangeLog.03, ChangeLog.96, ChangeLog.98, HACKING, Makefile.am, NEWS, README, TODO, aclocal.in, automake.in, bootstrap, configure, configure.ac, doc/Makefile.am, doc/fdl.texi, lib/COPYING, lib/Makefile.am, lib/acinstall, lib/compile, lib/config-ml.in, lib/config.guess, lib/config.sub, lib/depcomp, lib/elisp-comp, lib/gnupload, lib/mdate-sh, lib/missing, lib/py-compile, lib/symlink-tree, lib/texinfo.tex, lib/ylwrap, lib/Automake/ChannelDefs.pm, lib/Automake/Channels.pm, lib/Automake/Condition.pm, lib/Automake/Config.in, lib/Automake/Configure_ac.pm, lib/Automake/DisjConditions.pm, lib/Automake/FileUtils.pm, lib/Automake/General.pm, lib/Automake/Item.pm, lib/Automake/ItemDef.pm, lib/Automake/Location.pm, lib/Automake/Makefile.am, lib/Automake/Options.pm, lib/Automake/Rule.pm, lib/Automake/RuleDef.pm, lib/Automake/Struct.pm, lib/Automake/VarDef.pm, lib/Automake/Variable.pm, lib/Automake/Version.pm, lib/Automake/Wrap.pm, lib/Automake/XFile.pm, lib/Automake/tests/Condition.pl, lib/Automake/tests/DisjConditions.pl, lib/Automake/tests/Makefile.am, lib/Automake/tests/Version.pl, lib/Automake/tests/Wrap.pl, lib/am/Makefile.am, lib/am/ansi2knr.am, lib/am/check.am, lib/am/clean-hdr.am, lib/am/clean.am, lib/am/compile.am, lib/am/configure.am, lib/am/data.am, lib/am/dejagnu.am, lib/am/depend.am, lib/am/depend2.am, lib/am/distdir.am, lib/am/footer.am, lib/am/header-vars.am, lib/am/header.am, lib/am/inst-vars.am, lib/am/install.am, lib/am/java.am, lib/am/lang-compile.am, lib/am/lex.am, lib/am/library.am, lib/am/libs.am, lib/am/libtool.am, lib/am/lisp.am, lib/am/ltlib.am, lib/am/ltlibrary.am, lib/am/mans-vars.am, lib/am/mans.am, lib/am/multilib.am, lib/am/program.am, lib/am/progs.am, lib/am/python.am, lib/am/remake-hdr.am, lib/am/scripts.am, lib/am/subdirs.am, lib/am/tags.am, lib/am/texi-vers.am, lib/am/texibuild.am, lib/am/texinfos.am, lib/am/yacc.am, m4/Makefile.am, tests/aclibobj.test, tests/acloca10.test, tests/acloca11.test, tests/acloca12.test, tests/acloca13.test, tests/acloca14.test, tests/acloca15.test, tests/acloca16.test, tests/acloca17.test, tests/acloca18.test, tests/acloca19.test, tests/aclocal.test, tests/aclocal3.test, tests/aclocal4.test, tests/aclocal5.test, tests/aclocal6.test, tests/aclocal7.test, tests/aclocal8.test, tests/aclocal9.test, tests/acoutbs.test, tests/acoutbs2.test, tests/acoutnoq.test, tests/acoutpt.test, tests/acoutpt2.test, tests/acoutqnl.test, tests/acsilent.test, tests/acsubst.test, tests/acsubst2.test, tests/all.test, tests/alloca.test, tests/alloca2.test, tests/alpha.test, tests/alpha2.test, tests/amassign.test, tests/ammissing.test, tests/ansi.test, tests/ansi10.test, tests/ansi2.test, tests/ansi3.test, tests/ansi3b.test, tests/ansi4.test, tests/ansi5.test, tests/ansi6.test, tests/ansi7.test, tests/ansi8.test, tests/ansi9.test, tests/ar.test, tests/ar2.test, tests/asm.test, tests/autohdr.test, tests/autohdr2.test, tests/autohdr3.test, tests/autohdr4.test, tests/automake.test, tests/auxdir.test, tests/auxdir2.test, tests/auxdir3.test, tests/auxdir4.test, tests/backsl.test, tests/backsl2.test, tests/backsl3.test, tests/backsl4.test, tests/badline.test, tests/badopt.test, tests/badprog.test, tests/block.test, tests/bsource.test, tests/canon.test, tests/canon2.test, tests/canon3.test, tests/canon4.test, tests/canon5.test, tests/ccnoco.test, tests/check.test, tests/check2.test, tests/check3.test, tests/check4.test, tests/checkall.test, tests/clean.test, tests/clean2.test, tests/colneq.test, tests/colneq2.test, tests/colon.test, tests/colon2.test, tests/colon3.test, tests/colon4.test, tests/colon5.test, tests/colon6.test, tests/colon7.test, tests/comment.test, tests/comment2.test, tests/comment3.test, tests/comment4.test, tests/comment5.test, tests/comment6.test, tests/comment7.test, tests/comment8.test, tests/comment9.test, tests/compile.test, tests/compile_f90_c_cxx.test, tests/compile_f_c_cxx.test, tests/cond.test, tests/cond10.test, tests/cond11.test, tests/cond13.test, tests/cond14.test, tests/cond15.test, tests/cond16.test, tests/cond17.test, tests/cond18.test, tests/cond19.test, tests/cond2.test, tests/cond20.test, tests/cond21.test, tests/cond22.test, tests/cond23.test, tests/cond24.test, tests/cond25.test, tests/cond26.test, tests/cond27.test, tests/cond28.test, tests/cond29.test, tests/cond3.test, tests/cond30.test, tests/cond31.test, tests/cond32.test, tests/cond33.test, tests/cond34.test, tests/cond35.test, tests/cond36.test, tests/cond37.test, tests/cond4.test, tests/cond5.test, tests/cond6.test, tests/cond7.test, tests/cond8.test, tests/cond9.test, tests/condd.test, tests/condhook.test, tests/condinc.test, tests/condinc2.test, tests/condlib.test, tests/condman.test, tests/condman2.test, tests/conf2.test, tests/confdeps.test, tests/conff.test, tests/conff2.test, tests/confh.test, tests/confh4.test, tests/confh5.test, tests/config.test, tests/confincl.test, tests/conflnk.test, tests/conflnk2.test, tests/conflnk3.test, tests/confsub.test, tests/confvar.test, tests/confvar2.test, tests/copy.test, tests/ctarget1.test, tests/cxx.test, tests/cxx2.test, tests/cxxansi.test, tests/cxxcpp.test, tests/cxxlibobj.test, tests/cxxlink.test, tests/cxxnoc.test, tests/cxxo.test, tests/cygwin32.test, tests/dash.test, tests/defs.in, tests/defun.test, tests/defun2.test, tests/dejagnu.test, tests/dejagnu2.test, tests/dejagnu3.test, tests/dejagnu4.test, tests/dejagnu5.test, tests/dejagnu6.test, tests/dejagnu7.test, tests/depacl2.test, tests/depcomp.test, tests/depcomp2.test, tests/depcomp3.test, tests/depcomp4.test, tests/depcomp5.test, tests/depdist.test, tests/depend.test, tests/depend2.test, tests/depend3.test, tests/depend4.test, tests/destdir.test, tests/dirforbid.test, tests/dirlist.test, tests/discover.test, tests/distcom2.test, tests/distcom3.test, tests/distcom4.test, tests/distcom5.test, tests/distcom6.test, tests/distcom7.test, tests/distdir.test, tests/distname.test, tests/dollar.test, tests/double.test, tests/dup2.test, tests/else.test, tests/empty.test, tests/empty2.test, tests/empty3.test, tests/empty4.test, tests/exdir.test, tests/exdir2.test, tests/exeext.test, tests/exeext2.test, tests/exeext3.test, tests/exeext4.test, tests/exsource.test, tests/ext.test, tests/ext2.test, tests/extra.test, tests/extra2.test, tests/extra3.test, tests/extra4.test, tests/extra5.test, tests/extra6.test, tests/extra7.test, tests/f90only.test, tests/flibs.test, tests/fn99.test, tests/fnoc.test, tests/fo.test, tests/fonly.test, tests/fortdep.test, tests/fpinst2.test, tests/fpinstall.test, tests/gcj.test, tests/gcj2.test, tests/gcj3.test, tests/gcj4.test, tests/gcj5.test, tests/getopt.test, tests/gettext.test, tests/gettext2.test, tests/gnits.test, tests/gnits2.test, tests/gnits3.test, tests/gnumake.test, tests/gnuwarn.test, tests/gnuwarn2.test, tests/header.test, tests/help.test, tests/hfs.test, tests/hosts.test, tests/implicit.test, tests/include.test, tests/include2.test, tests/info.test, tests/insh2.test, tests/install2.test, tests/installdir.test, tests/instdat.test, tests/instdat2.test, tests/instexec.test, tests/insthook.test, tests/instman.test, tests/instman2.test, tests/instsh.test, tests/instsh2.test, tests/instspc.test, tests/interp.test, tests/interp2.test, tests/java.test, tests/java2.test, tests/java3.test, tests/javaprim.test, tests/javasubst.test, tests/ldadd.test, tests/ldflags.test, tests/lex.test, tests/lex2.test, tests/lex3.test, tests/lex4.test, tests/lex5.test, tests/libobj10.test, tests/libobj11.test, tests/libobj12.test, tests/libobj13.test, tests/libobj14.test, tests/libobj2.test, tests/libobj3.test, tests/libobj4.test, tests/libobj5.test, tests/libobj7.test, tests/libobj8.test, tests/library.test, tests/library2.test, tests/library3.test, tests/libtool.test, tests/libtool2.test, tests/libtool3.test, tests/libtool4.test, tests/libtool5.test, tests/libtool6.test, tests/libtool7.test, tests/libtool8.test, tests/libtool9.test, tests/license.test, tests/link_c_cxx.test, tests/link_dist.test, tests/link_f90_only.test, tests/link_f_only.test, tests/link_fc.test, tests/link_fccxx.test, tests/link_fcxx.test, tests/lisp2.test, tests/lisp3.test, tests/lisp4.test, tests/lisp5.test, tests/lisp6.test, tests/lisp7.test, tests/lisp8.test, tests/listval.test, tests/location.test, tests/longlin2.test, tests/longline.test, tests/ltcond.test, tests/ltcond2.test, tests/ltconv.test, tests/ltdeps.test, tests/ltlibobjs.test, tests/ltlibsrc.test, tests/maintclean.test, tests/make.test, tests/makej.test, tests/makevars.test, tests/man.test, tests/man2.test, tests/mclean.test, tests/mdate.test, tests/mdate2.test, tests/mdate3.test, tests/mdate4.test, tests/missing.test, tests/missing2.test, tests/missing3.test, tests/mkinst2.test, tests/mkinstall.test, tests/mmodely.test, tests/multlib.test, tests/nobase.test, tests/nodef.test, tests/nodef2.test, tests/nodep.test, tests/nodepcomp.test, tests/nodist.test, tests/nodist2.test, tests/nodist3.test, tests/nogzip.test, tests/nogzip2.test, tests/noinst.test, tests/noinstdir.test, tests/nolink.test, tests/nostdinc.test, tests/number.test, tests/obsolete.test, tests/order.test, tests/outdir.test, tests/output.test, tests/output10.test, tests/output11.test, tests/output12.test, tests/output2.test, tests/output3.test, tests/output4.test, tests/output5.test, tests/output6.test, tests/output7.test, tests/output8.test, tests/output9.test, tests/overrid.test, tests/parse.test, tests/percent.test, tests/percent2.test, tests/phony.test, tests/pluseq.test, tests/pluseq10.test, tests/pluseq2.test, tests/pluseq3.test, tests/pluseq4.test, tests/pluseq5.test, tests/pluseq6.test, tests/pluseq7.test, tests/pluseq8.test, tests/pluseq9.test, tests/postproc.test, tests/ppf77.test, tests/pr2.test, tests/pr204.test, tests/pr211.test, tests/pr220.test, tests/pr224.test, tests/pr229.test, tests/pr243.test, tests/pr266.test, tests/pr279-2.test, tests/pr279.test, tests/pr287.test, tests/pr300-lib.test, tests/pr300-ltlib.test, tests/pr300-prog.test, tests/pr307.test, tests/pr401.test, tests/pr401b.test, tests/pr401c.test, tests/pr72.test, tests/pr87.test, tests/pr9.test, tests/prefix.test, tests/primary.test, tests/primary2.test, tests/primary3.test, tests/proginst.test, tests/python.test, tests/python10.test, tests/python11.test, tests/python12.test, tests/python2.test, tests/python3.test, tests/python4.test, tests/python5.test, tests/python6.test, tests/python7.test, tests/python8.test, tests/python9.test, tests/recurs.test, tests/recurs2.test, tests/regex.test, tests/remake.test, tests/remake2.test, tests/remake3.test, tests/remake4.test, tests/remake5.test, tests/req.test, tests/reqd.test, tests/reqd2.test, tests/rulepat.test, tests/scripts.test, tests/seenc.test, tests/sinclude.test, tests/space.test, tests/specflg.test, tests/specflg2.test, tests/specflg3.test, tests/specflg6.test, tests/specflg7.test, tests/specflg8.test, tests/specflg9.test, tests/spell.test, tests/spell2.test, tests/spell3.test, tests/spelling.test, tests/spy.test, tests/srcsub.test, tests/srcsub2.test, tests/stamph2.test, tests/stdlib.test, tests/stdlib2.test, tests/strip.test, tests/subcond.test, tests/subcond2.test, tests/subcond3.test, tests/subdir.test, tests/subdir2.test, tests/subdir3.test, tests/subdir4.test, tests/subdir5.test, tests/subdir6.test, tests/subdir7.test, tests/subdir8.test, tests/subdir9.test, tests/subdirbuiltsources.test, tests/subobj.test, tests/subobj2.test, tests/subobj3.test, tests/subobj4.test, tests/subobj5.test, tests/subobj6.test, tests/subobj7.test, tests/subobj8.test, tests/subobj9.test, tests/subobjname.test, tests/subpkg.test, tests/subpkg2.test, tests/subst.test, tests/subst2.test, tests/substre2.test, tests/substref.test, tests/substtarg.test, tests/suffix.test, tests/suffix10.test, tests/suffix11.test, tests/suffix2.test, tests/suffix3.test, tests/suffix4.test, tests/suffix5.test, tests/suffix6.test, tests/suffix7.test, tests/suffix8.test, tests/suffix9.test, tests/symlink.test, tests/symlink2.test, tests/symlink3.test, tests/syntax.test, tests/tags.test, tests/tagsub.test, tests/tar.test, tests/tar2.test, tests/tar3.test, tests/target-cflags.test, tests/targetclash.test, tests/transform.test, tests/txinfo.test, tests/txinfo10.test, tests/txinfo13.test, tests/txinfo16.test, tests/txinfo17.test, tests/txinfo18.test, tests/txinfo19.test, tests/txinfo2.test, tests/txinfo20.test, tests/txinfo21.test, tests/txinfo22.test, tests/txinfo23.test, tests/txinfo24.test, tests/txinfo25.test, tests/txinfo26.test, tests/txinfo27.test, tests/txinfo28.test, tests/txinfo29.test, tests/txinfo3.test, tests/txinfo4.test, tests/txinfo5.test, tests/txinfo6.test, tests/txinfo7.test, tests/txinfo8.test, tests/txinfo9.test, tests/unused.test, tests/vars.test, tests/vars3.test, tests/vartar.test, tests/version.test, tests/version2.test, tests/version3.test, tests/version4.test, tests/version6.test, tests/version7.test, tests/version8.test, tests/vpath.test, tests/vtexi.test, tests/vtexi2.test, tests/warnopts.test, tests/werror.test, tests/werror2.test, tests/whoami.test, tests/xsource.test, tests/yacc.test, tests/yacc2.test, tests/yacc3.test, tests/yacc4.test, tests/yacc5.test, tests/yacc6.test, tests/yacc7.test, tests/yacc8.test, tests/yaccpp.test, tests/yaccvpath.test: Update FSF postal mail address.

  • lib/Automake/Rule.pm
  • # Copyright (C) 2003, 2004  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., 51 Franklin Street, Fifth Floor, Boston, MA
    # 02110-1301, USA.
    
    package Automake::Rule;
    use strict;
    use Carp;
    
    use Automake::Item;
    use Automake::RuleDef;
    use Automake::ChannelDefs;
    use Automake::Channels;
    use Automake::Options;
    use Automake::Condition qw (TRUE FALSE);
    use Automake::DisjConditions;
    require Exporter;
    use vars '@ISA', '@EXPORT', '@EXPORT_OK';
    @ISA = qw/Automake::Item Exporter/;
    @EXPORT = qw (reset register_suffix_rule suffix_rules_count
    	      suffixes rules $suffix_rules $KNOWN_EXTENSIONS_PATTERN
    	      depend %dependencies %actions accept_extensions
    	      reject_rule msg_rule msg_cond_rule err_rule err_cond_rule
    	      rule rrule ruledef rruledef);
    
    =head1 NAME
    
    Automake::Rule - support for rules definitions
    
    =head1 SYNOPSIS
    
      use Automake::Rule;
      use Automake::RuleDef;
    
    
    =head1 DESCRIPTION
    
    This package provides support for Makefile rule definitions.
    
    An C<Automake::Rule> is a rule name associated to possibly
    many conditional definitions.  These definitions are instances
    of C<Automake::RuleDef>.
    
    Therefore obtaining the value of a rule under a given
    condition involves two lookups.  One to look up the rule,
    and one to look up the conditional definition:
    
      my $rule = rule $name;
      if ($rule)
        {
          my $def = $rule->def ($cond);
          if ($def)
            {
              return $def->location;
            }
          ...
        }
      ...
    
    when it is known that the rule and the definition
    being looked up exist, the above can be simplified to
    
      return rule ($name)->def ($cond)->location; # do not write this.
    
    but is better written
    
      return rrule ($name)->rrule ($cond)->location;
    
    or even
    
      return rruledef ($name, $cond)->location;
    
    The I<r> variants of the C<rule>, C<def>, and C<ruledef> methods add
    an extra test to ensure that the lookup succeeded, and will diagnose
    failures as internal errors (with a message which is much more
    informative than Perl's warning about calling a method on a
    non-object).
    
    =head2 Global variables
    
    =over 4
    
    =cut
    
    my $_SUFFIX_RULE_PATTERN =
      '^(\.[a-zA-Z0-9_(){}$+@\-]+)(\.[a-zA-Z0-9_(){}$+@\-]+)' . "\$";
    
    # Suffixes found during a run.
    use vars '@_suffixes';
    
    # Same as $suffix_rules (declared below), but records only the
    # default rules supplied by the languages Automake supports.
    use vars '$_suffix_rules_default';
    
    =item C<%dependencies>
    
    Holds the dependencies of targets which dependencies are factored.
    Typically, C<.PHONY> will appear in plenty of F<*.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.
    
    =cut
    
    use vars '%dependencies';
    
    =item <%actions>
    
    Holds the factored actions.  Tied to C<%dependencies>, i.e., filled
    only when keys exists in C<%dependencies>.
    
    =cut
    
    use vars '%actions';
    
    =item <$suffix_rules>
    
    This maps the source extension for all suffix rule seen to
    a C<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 C<.foo> can be transformed to
    C<.$(OBJEXT)> by checking whether
    C<$suffix_rules{'.foo'}{'.$(OBJEXT)'}> exists.  This will work even if
    transforming C<.foo> to C<.$(OBJEXT)> involves a chain of several
    suffix rules.
    
    The value of C<$suffix_rules{$ext1}{$ext2}> is the a pair
    C<[ $next_sfx, $dist ]> where C<$next_sfx> is target suffix
    for the next rule to use to reach C<$ext2>, and C<$dist> the
    distance to C<$ext2'>.
    
    The content of this variable should be updated via the
    C<register_suffix_rule> function.
    
    =cut
    
    use vars '$suffix_rules';
    
    =item C<$KNOWN_EXTENSIONS_PATTERN>
    
    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.
    
    New extensions should be registered with C<accept_extensions>.
    
    =cut
    
    use vars qw ($KNOWN_EXTENSIONS_PATTERN @_known_extensions_list);
    $KNOWN_EXTENSIONS_PATTERN = "";
    @_known_extensions_list = ();
    
    =back
    
    =head2 Error reporting functions
    
    In these functions, C<$rule> can be either a rule name, or
    an instance of C<Automake::Rule>.
    
    =over 4
    
    =item C<err_rule ($rule, $message, [%options])>
    
    Uncategorized errors about rules.
    
    =cut
    
    sub err_rule ($$;%)
    {
      msg_rule ('error', @_);
    }
    
    =item C<err_cond_rule ($cond, $rule, $message, [%options])>
    
    Uncategorized errors about conditional rules.
    
    =cut
    
    sub err_cond_rule ($$$;%)
    {
      msg_cond_rule ('error', @_);
    }
    
    =item C<msg_cond_rule ($channel, $cond, $rule, $message, [%options])>
    
    Messages about conditional rules.
    
    =cut
    
    sub msg_cond_rule ($$$$;%)
    {
      my ($channel, $cond, $rule, $msg, %opts) = @_;
      my $r = ref ($rule) ? $rule : rrule ($rule);
      msg $channel, $r->rdef ($cond)->location, $msg, %opts;
    }
    
    =item C<msg_rule ($channel, $targetname, $message, [%options])>
    
    Messages about rules.
    
    =cut
    
    sub msg_rule ($$$;%)
    {
      my ($channel, $rule, $msg, %opts) = @_;
      my $r = ref ($rule) ? $rule : rrule ($rule);
      # Don't know which condition is concerned.  Pick any.
      my $cond = $r->conditions->one_cond;
      msg_cond_rule ($channel, $cond, $r, $msg, %opts);
    }
    
    
    =item C<$bool = reject_rule ($rule, $error_msg)>
    
    Bail out with C<$error_msg> if a rule with name C<$rule> has been
    defined.
    
    Return true iff C<$rule> is defined.
    
    =cut
    
    sub reject_rule ($$)
    {
      my ($rule, $msg) = @_;
      if (rule ($rule))
        {
          err_rule $rule, $msg;
          return 1;
        }
      return 0;
    }
    
    =back
    
    =head2 Administrative functions
    
    =over 4
    
    =item C<accept_extensions (@exts)>
    
    Update C<$KNOWN_EXTENSIONS_PATTERN> to recognize the extensions
    listed C<@exts>.  Extensions should contain a dot if needed.
    
    =cut
    
    sub accept_extensions (@)
    {
        push @_known_extensions_list, @_;
        $KNOWN_EXTENSIONS_PATTERN =
    	'(?:' . join ('|', map (quotemeta, @_known_extensions_list)) . ')';
    }
    
    =item C<rules>
    
    Returns the list of all L<Automake::Rule> instances.  (I.e., all
    rules defined so far.)
    
    =cut
    
    use vars '%_rule_dict';
    sub rules ()
    {
      return values %_rule_dict;
    }
    
    
    =item C<Automake::Rule::reset>
    
    The I<forget all> function.  Clears all know rules and reset some
    other internal data.
    
    =cut
    
    sub reset()
    {
      %_rule_dict = ();
      @_suffixes = ();
      # 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;
        }
    
      %dependencies =
        (
         # Texinfoing.
         'dvi'      => [],
         'dvi-am'   => [],
         'pdf'      => [],
         'pdf-am'   => [],
         'ps'       => [],
         'ps-am'    => [],
         'info'     => [],
         'info-am'  => [],
         'html'     => [],
         'html-am'  => [],
    
         # Installing/uninstalling.
         'install-data-am'      => [],
         'install-exec-am'      => [],
         'uninstall-am'         => [],
    
         'install-man'	    => [],
         'uninstall-man'	    => [],
    
         'install-dvi'          => [],
         'install-dvi-am'       => [],
         'install-html'         => [],
         'install-html-am'      => [],
         'install-info'         => [],
         'install-info-am'      => [],
         'install-pdf'          => [],
         'install-pdf-am'       => [],
         'install-ps'           => [],
         'install-ps-am'        => [],
    
         'installcheck-am'      => [],
    
         # Cleaning.
         'clean-am'             => [],
         'mostlyclean-am'       => [],
         'maintainer-clean-am'  => [],
         'distclean-am'         => [],
         'clean'                => [],
         'mostlyclean'          => [],
         'maintainer-clean'     => [],
         'distclean'            => [],
    
         # Tarballing.
         'dist-all'             => [],
    
         # Phoning.
         '.PHONY'               => [],
         # Recursive install targets (so `make -n install' works for BSD Make).
         '.MAKE'		    => [],
         );
      %actions = ();
    }
    
    =item C<register_suffix_rule ($where, $src, $dest)>
    
    Register a suffix rules defined on C<$where> that transform
    files ending in C<$src> into files ending in C<$dest>.
    
    This upgrades the C<$suffix_rules> variables.
    
    =cut
    
    sub register_suffix_rule ($$$)
    {
      my ($where, $src, $dest) = @_;
    
      verb "Sources ending in $src become $dest";
      push @_suffixes, $src, $dest;
    
      # When transforming 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 extensions 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 ];
    		}
    	    }
    	}
        }
    }
    
    =item C<$count = suffix_rules_count>
    
    Return the number of suffix rules added while processing the current
    F<Makefile> (excluding predefined suffix rules).
    
    =cut
    
    sub suffix_rules_count ()
    {
      return (scalar keys %$suffix_rules) - (scalar keys %$_suffix_rules_default);
    }
    
    =item C<@list = suffixes>
    
    Return the list of known suffixes.
    
    =cut
    
    sub suffixes ()
    {
      return @_suffixes;
    }
    
    =item C<rule ($rulename)>
    
    Return the C<Automake::Rule> object for the rule
    named C<$rulename> if defined.   Return 0 otherwise.
    
    =cut
    
    sub rule ($)
    {
      my ($name) = @_;
      # Strip $(EXEEXT) from $name, so we can diagnose
      # a clash if `ctags$(EXEEXT):' is redefined after `ctags:'.
      $name =~ s,\$\(EXEEXT\)$,,;
      return $_rule_dict{$name} if exists $_rule_dict{$name};
      return 0;
    }
    
    =item C<rule ($rulename, $cond>
    
    Return the C<Automake::RuleDef> object for the rule named
    C<$rulename> if defined in condition C<$cond>.  Return false
    if the condition or the rule does not exist.
    
    =cut
    
    sub ruledef ($$)
    {
      my ($name, $cond) = @_;
      my $rule = rule $name;
      return $rule && $rule->def ($cond);
    }
    
    =item C<rrule ($rulename)
    
    Return the C<Automake::Rule> object for the variable named
    C<$rulename>.  Abort with an internal error if the variable was not
    defined.
    
    The I<r> in front of C<var> stands for I<required>.  One
    should call C<rvar> to assert the rule's existence.
    
    =cut
    
    sub rrule ($)
    {
      my ($name) = @_;
      my $r = rule $name;
      prog_error ("undefined rule $name\n" . &rules_dump)
        unless $r;
      return $r;
    }
    
    =item C<rruledef ($varname, $cond)>
    
    Return the C<Automake::RuleDef> object for the rule named
    C<$rulename> if defined in condition C<$cond>.  Abort with an internal
    error if the condition or the rule does not exist.
    
    =cut
    
    sub rruledef ($$)
    {
      my ($name, $cond) = @_;
      return rrule ($name)->rdef ($cond);
    }
    
    # Create the variable if it does not exist.
    # This is used only by other functions in this package.
    sub _crule ($)
    {
      my ($name) = @_;
      my $r = rule $name;
      return $r if $r;
      return _new Automake::Rule $name;
    }
    
    sub _new ($$)
    {
      my ($class, $name) = @_;
    
      # Strip $(EXEEXT) from $name, so we can diagnose
      # a clash if `ctags$(EXEEXT):' is redefined after `ctags:'.
      (my $keyname = $name) =~ s,\$\(EXEEXT\)$,,;
    
      my $self = Automake::Item::new ($class, $name);
      $_rule_dict{$keyname} = $self;
      return $self;
    }
    
    
    =itcem C<@conds = define ($rulename, $source, $owner, $cond, $where)>
    
    Define a new rule.  C<$rulename> is the list of targets.  C<$source>
    is the filename the rule comes from.  C<$owner> is the owner of the
    rule (C<RULE_AUTOMAKE> or C<RULE_USER>).  C<$cond> is the
    C<Automake::Condition> under which the rule is defined.  C<$where> is
    the C<Automake::Location> where the rule is defined.
    
    Returns a (possibly empty) list of C<Automake::Condition>s where the
    rule's definition should be output.
    
    =cut
    
    sub define ($$$$$)
    {
      my ($target, $source, $owner, $cond, $where) = @_;
    
      prog_error "$where is not a reference"
        unless ref $where;
      prog_error "$cond is not a reference"
        unless ref $cond;
    
      # Don't even think about defining a rule in condition FALSE.
      return () if $cond == FALSE;
    
      # For now `foo:' will override `foo$(EXEEXT):'.  This is temporary,
      # though, so we emit a warning.
      (my $noexe = $target) =~ s,\$\(EXEEXT\)$,,;
      my $noexerule = rule $noexe;
      my $tdef = $noexerule ? $noexerule->def ($cond) : undef;
    
      if ($noexe ne $target
          && $tdef
          && $noexerule->name ne $target)
        {
          # The no-exeext option enables this feature.
          if (! option 'no-exeext')
    	{
    	  msg ('obsolete', $tdef->location,
    	       "deprecated feature: target `$noexe' overrides "
    	       . "`$noexe\$(EXEEXT)'\n"
    	       . "change your target to read `$noexe\$(EXEEXT)'");
    	  msg ('obsolete', $where, "target `$target' was defined here");
    	}
          # Don't `return ()' now, as this might hide target clashes
          # detected below.
        }
    
    
      # 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 ($tdef)
        {
          my $oldowner  = $tdef->owner;
          # Ok, it's the name target, but the name maybe different because
          # `foo$(EXEEXT)' and `foo' have the same key in our table.
          my $oldname = $tdef->name;
    
          # Don't mention true conditions in diagnostics.
          my $condmsg =
    	$cond == TRUE ? '' : " in condition `" . $cond->human . "'";
    
          if ($owner == RULE_USER)
    	{
    	  if ($oldowner == RULE_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 duplicate 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...", partial => 1);
    		  # msg_cond_rule ('syntax', $cond, $target,
    		  # 		   "... `$target' previously defined here");
    		}
    	      # Return so we don't redefine the rule in our tables,
    	      # don't check for ambiguous condition, 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 `$target'$condmsg seen after Automake's"
    			  . " definition\nfrom " . $tdef->source);
    	    }
    	}
          else # $owner == RULE_AUTOMAKE
    	{
    	  if ($oldowner == RULE_USER)
    	    {
    	      # -am targets listed in %dependencies support a -local
    	      # variant.  If the user tries to override TARGET or
    	      # TARGET-am for which there exists a -local variant,
    	      # just tell the user to use it.
    	      my $hint = 0;
    	      my $noam = $target;
    	      $noam =~ s/-am$//;
    	      if (exists $dependencies{"$noam-am"})
    		{
    		  $hint = "consider using $noam-local instead of $target";
    		}
    
    	      msg_cond_rule ('override', $cond, $target,
    			     "user target `$target' defined here"
    			     . "$condmsg...", partial => 1);
    	      msg ('override', $where,
    		   "... overrides Automake target `$oldname' defined here",
    		   partial => $hint);
    	      msg_cond_rule ('override', $cond, $target, $hint)
    		if $hint;
    
    	      # Don't overwrite the user definition of TARGET.
    	      return ();
    	    }
    	  else # $oldowner == RULE_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 = $tdef->source;
    	      return () if $source eq $oldsource && $target eq $oldname;
    
    	      msg ('syntax', $where, "redefinition of `$target'$condmsg...",
    		   partial => 1);
    	      msg_cond_rule ('syntax', $cond, $target,
    			     "... `$oldname' 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 $rule = _crule $target;
      my ($message, $ambig_cond) = $rule->conditions->ambiguous_p ($target, $cond);
      if ($message)			# We have an ambiguity.
        {
          if ($owner == RULE_USER)
    	{
    	  # For user rules, just diagnose the ambiguity.
    	  msg 'syntax', $where, "$message ...", partial => 1;
    	  msg_cond_rule ('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 conditions
    	  # 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
    	  # condition.  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.)
    	  @conds = $rule->not_always_defined_in_cond ($cond)->conds;
    
    	  # No conditions left to define the rule.
    	  # Warn, because our workaround is meaningless in this case.
    	  if (scalar @conds == 0)
    	    {
    	      msg 'syntax', $where, "$message ...", partial => 1;
    	      msg_cond_rule ('syntax', $ambig_cond, $target,
    			     "... `$target' previously defined here");
    	      return ();
    	    }
    	}
        }
    
      # Finally define this rule.
      for my $c (@conds)
        {
          my $def = new Automake::RuleDef ($target, '', $where->clone,
    				       $owner, $source);
          $rule->set ($c, $def);
        }
    
      # We honor inference rules with multiple targets because many
      # make support this and people use it.  However this is disallowed
      # by POSIX.  We'll print a warning later.
      my $target_count = 0;
      my $inference_rule_count = 0;
    
      for my $t (split (' ', $target))
        {
          ++$target_count;
          # Check if the rule is a suffix rule: either it's a rule for
          # two known extensions...
          if ($t =~ /^($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).
    
    
    	  || ($t =~ /$_SUFFIX_RULE_PATTERN/o && accept_extensions($1)))
    	{
    	  ++$inference_rule_count;
    	  register_suffix_rule ($where, $1, $2);
    	}
        }
    
      # POSIX allows multiple targets before the colon, but disallows
      # definitions of multiple inference rules.  It's also
      # disallowed to mix plain targets with inference rules.
      msg ('portability', $where,
           "Inference rules can have only one target before the colon (POSIX).")
        if $inference_rule_count > 0 && $target_count > 1;
    
      return @conds;
    }
    
    =item C<depend ($target, @deps)>
    
    Adds C<@deps> to the dependencies of target C<$target>.  This should
    be used only with factored targets (those appearing in
    C<%dependees>).
    
    =cut
    
    sub depend ($@)
    {
      my ($category, @dependees) = @_;
      push (@{$dependencies{$category}}, @dependees);
    }
    
    =back
    
    =head1 SEE ALSO
    
    L<Automake::RuleDef>, L<Automake::Condition>,
    L<Automake::DisjConditions>, L<Automake::Location>.
    
    =cut
    
    1;
    
    ### 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: