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kc3-lang/automake/automake.texi

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  • Author : Tom Tromey
    Date : 1996-10-06 03:55:55
    Hash : c19b5620
    Message : Many bug fixes

  • automake.texi
  • \input texinfo   @c -*-texinfo-*-
    @c %**start of header
    @setfilename automake.info
    @settitle automake
    @setchapternewpage off
    @c %**end of header
    
    @include version.texi
    
    @c Yes, this appears in many Texinfo files.  He's just a likeable guy.
    @ifinfo
    @set Francois Franc,ois
    @end ifinfo
    @tex
    @set Francois Fran\noexpand\ptexc cois
    @end tex
    
    @dircategory GNU admin
    @direntry
    * automake: (automake).		Making Makefile.in's
    @end direntry
    
    @dircategory Individual utilities
    @direntry
    * aclocal: (automake)Invoking aclocal           Generating aclocal.m4
    @end direntry
    
    @ifinfo
    This file documents GNU automake @value{VERSION}
    
    Copyright (C) 1995 Free Software Foundation, Inc.
    
    Permission is granted to make and distribute verbatim copies of
    this manual provided the copyright notice and this permission notice
    are preserved on all copies.
    
    @ignore
    Permission is granted to process this file through TeX and print the
    results, provided the printed document carries copying permission
    notice identical to this one except for the removal of this paragraph
    
    
    @end ignore
    Permission is granted to copy and distribute modified versions of this
    manual under the conditions for verbatim copying, provided that the entire
    resulting derived work is distributed under the terms of a permission
    notice identical to this one.
    
    Permission is granted to copy and distribute translations of this manual
    into another language, under the above conditions for modified versions,
    except that this permission notice may be stated in a translation approved
    by the Foundation.
    @end ifinfo
    
    
    @titlepage
    @title GNU Automake
    @subtitle For version @value{VERSION}, @value{UPDATED}
    @c copyright page
    @page
    @vskip 0pt plus 1filll
    Copyright @copyright{} 1995 Free Software Foundation, Inc.
    @sp 2
    This is the first edition of the GNU Automake documentation,@*
    and is consistent with GNU Automake @value{VERSION}.@*
    @sp 2
    Published by the Free Software Foundation @*
    59 Template Place - Suite 330, @*
    Boston, MA 02111-1307 USA @*
    
    Permission is granted to make and distribute verbatim copies of
    this manual provided the copyright notice and this permission notice
    are preserved on all copies.
    
    Permission is granted to copy and distribute modified versions of this
    manual under the conditions for verbatim copying, provided that the entire
    resulting derived work is distributed under the terms of a permission
    notice identical to this one.
    
    Permission is granted to copy and distribute translations of this manual
    into another language, under the above conditions for modified versions,
    except that this permission notice may be stated in a translation
    approved by the Free Software Foundation.
    @end titlepage
    
    @c Define an index of configure variables.
    @defcodeindex cv
    @c Define an index of options.
    @defcodeindex op
    @c Define an index of targets.
    @defcodeindex tr
    
    @ifinfo
    @node Top, Introduction, (dir), (dir)
    @comment  node-name,  next,  previous,  up
    @top GNU Automake
    
    This file documents the GNU Automake package for creating GNU
    Standards-compliant Makefiles from template files.  This edition
    documents version @value{VERSION}.
    
    @menu
    * Introduction::                Automake's purpose
    * Invoking Automake::           Creating a Makefile.in
    * Generalities::                General ideas
    * configure::                   Scanning configure.in
    * Top level::                   The top-level Makefile.am
    * Programs::                    Building programs and libraries
    * Other objects::               Other derived objects
    * Other GNU Tools::             Other GNU Tools
    * Documentation::               Building documentation
    * Install::                     What gets installed
    * Clean::                       What gets cleaned
    * Dist::                        What goes in a distribution
    * Tests::                       Support for test suites
    * Options::                     Changing Automake's behavior
    * Miscellaneous::               Miscellaneous rules
    * Gnits::                       The effect of --gnu and --gnits
    * Extending::                   Extending Automake
    * Distributing::                Distributing the Makefile.in
    * Examples::                    Some example packages
    * Future::                      Some ideas for the future
    * Variables::                   Index of variables
    * Configure variables::         Index of configure variables and macros
    * Targets::                     Index of targets
    @end menu
    
    @end ifinfo
    
    @node Introduction
    @chapter Introduction
    
    Automake is a tool for automatically generating
    @file{Makefile.in}s from files called @file{Makefile.am}.  The
    @file{Makefile.am} is basically a series of @code{make} macro
    definitions (with rules being thrown in occasionally).  The generated
    @file{Makefile.in}s are compliant with the GNU Makefile standards.
    
    The GNU Makefile Standards Document
    (@pxref{Makefile Conventions, , , standards.info, The GNU Coding Standards})
    is long, complicated, and subject to change.  The goal of Automake is to
    remove the burden of Makefile maintenance from the back of the
    individual GNU maintainer (and put it on the back of the Automake
    maintainer).
    
    The typical Automake input files is simply a series of macro
    definitions.  Each such file is processed to create a
    @file{Makefile.in}.  There should generally be one @file{Makefile.am}
    per directory of a project.
    
    Automake does constrain a project in certain ways; for instance it
    assumes that the project uses Autoconf
    (@pxref{Top, , The Autoconf Manual, autoconf.info, The Autoconf Manual}),
    and enforces certain restrictions on the @file{configure.in} contents.
    
    @code{Automake} requires @code{perl} in order to generate the
    @file{Makefile.in}s.  However, the distributions created by Automake are
    fully GNU standards-compliant, and do not require @code{perl} in order
    to be built.
    
    Mail suggestions and bug reports for Automake to
    @email{bug-gnu-utils@@prep.ai.mit.edu}.
    
    
    @node Invoking Automake
    @chapter Creating a @file{Makefile.in}
    
    To create all the @file{Makefile.in}s for a package, run the
    @code{automake} program in the top level directory, with no arguments.
    @code{automake} will automatically find each appropriate
    @file{Makefile.am} (by scanning @file{configure.in}; @pxref{configure})
    and generate the corresponding @file{Makefile.in}.
    
    You can optionally give @code{automake} an argument; @samp{.am} is
    appended to the argument and the result is used as the name of the input
    file.  This feature is generally only used to automatically rebuild an
    out-of-date @file{Makefile.in}.  Note that @code{automake} must always
    be run from the topmost directory of a project, even if being used to
    regenerate the @file{Makefile.in} in some subdirectory.  This is
    necessary because @code{automake} must scan @file{configure.in}, and
    because @code{automake} uses the knowledge that a @file{Makefile.in} is
    in a subdirectory to change its behavior in some cases.
    
    @code{automake} accepts the following options:
    
    @table @code
    @item -a
    @item --add-missing
    Automake requires certain common files to exist in certain situations;
    for instance @file{config.guess} is required if @file{configure.in} runs
    @code{AC_CANONICAL_HOST}.  Automake is distributed with several of these
    files; this option will cause the missing ones to be automatically added
    to the package, whenever possible.  In general if Automake tells you a
    file is missing, try using this option.
    
    @item --amdir=@var{dir}
    Look for Automake data files in directory @var{dir} instead of in the
    installation directory.  This is typically used for debugging.
    
    @item --build-dir=@var{dir}
    Tell Automake where the build directory is.  This option is used when
    including dependencies into a @file{Makefile.in} generated by @code{make
    dist}; it should not be used otherwise.
    
    @item --foreign
    An alias for @samp{--strictness=foreign}.
    
    @item --gnits
    An alias for @samp{--strictness=gnits}.
    
    @item --gnu
    An alias for @samp{--strictness=gnu}.
    
    @item --help
    Print a summary of the command line options and exit.
    
    @item -i
    @item --include-deps
    Include all automatically generated dependency information
    (@pxref{Dependencies}) in the generated
    @file{Makefile.in}.  This is generally done when making a distribution;
    see @ref{Dist}.
    
    @item -o @var{dir}
    @item --output-dir=@var{dir}
    Put the generated @file{Makefile.in} in the directory @var{dir}.
    Ordinarily each @file{Makefile.in} is created in the directory of the
    corresponding @file{Makefile.am}.  This option is used when making
    distributions.
    
    @item --srcdir-name=@var{dir}
    Tell Automake the name of the source directory used in the current
    build.  This option is used when including dependencies into a
    @file{Makefile.in} generated by @code{make dist}; it should not be used
    otherwise.
    
    @item -s @var{level}
    @item --strictness=@var{level}
    Set the global strictness to @var{level}; this can be overridden in each
    @file{Makefile.am} if required.  @xref{Generalities} for more
    information.
    
    @item -v
    @item --verbose
    Cause Automake to print information about which files are being read or
    created.
    
    @item --version
    Print the version number of Automake and exit.
    @end table
    
    
    @node Generalities
    @chapter General ideas
    
    There are a few basic ideas that will help understand how Automake
    works.
    
    @menu
    * General Operation::           General operation of Automake
    * Depth::                       The kinds of packages
    * Strictness::                  Standards conformance checking
    * Uniform::                     The Uniform Naming Scheme
    * Canonicalization::            How derived variables are named
    @end menu
    
    @node General Operation
    @section General Operation
    
    Automake works by reading a @file{Makefile.am} and generating a
    @file{Makefile.in}.  Certain macros and targets defined in the
    @file{Makefile.am} instruct automake to generate more specialized code;
    for instances a @samp{bin_PROGRAMS} macro definition will cause targets
    for compiling and linking to be generated.
    
    The macro definitions and targets in the @file{Makefile.am} are copied
    into the generated file.  This allows you to add arbitrary code into the
    generated @file{Makefile.in}.  For instance the Automake distribution
    includes a non-standard @code{cvs-dist} target, which the Automake
    maintainer uses to make distributions from his source control system.
    
    Note that GNU make extensions are not recognized by Automake.  Using
    such extensions in a @file{Makefile.am} will lead to errors or confusing
    behavior.
    
    Automake tries to group comments with adjoining targets (or variable
    definitions) in an intelligent way.
    
    A target defined in @file{Makefile.am} generally overrides any such
    target of a similar name that would be automatically generated by
    @code{automake}.  Although this is a supported feature, it is generally
    best to avoid making use of it, as sometimes the generated rules are
    very particular.
    
    When examining a variable definition, Automake will recursively examine
    variables referenced in the definition.  Eg if Automake is looking at
    the content of @samp{foo_SOURCES} in this snippet
    
    @example
    xs = a.c b.c
    foo_SOURCES = c.c $(xs)
    @end example
    
    it would use the files @file{a.c}, @file{b.c}, and @file{c.c} as the
    contents of @samp{foo_SOURCES}.
    
    Automake also allows a form of comment which is @emph{not} copied into
    the output; all lines beginning with @samp{##} are completely ignored by
    Automake.
    
    It is customary to make the first line of @file{Makefile.am} read:
    
    @example
    ## Process this file with automake to produce Makefile.in
    @end example
    
    @c FIXME discuss putting a copyright into Makefile.am here?  I would but
    @c I don't know quite what to say.
    
    @c FIXME document customary ordering of Makefile.am here!
    
    
    
    @node Depth
    @section Depth
    @code{automake} supports three kinds of directory hierarchy: ``flat'',
    ``shallow'', and ``deep''.
    
    A @dfn{flat} package is one in which all the files are in a single
    directory.  The @file{Makefile.am} for such a package by definition
    lacks a @code{SUBDIRS} macro.  An example of such a package is
    @code{termutils}.
    @vindex SUBDIRS
    
    A @dfn{deep} package is one in which all the source lies in
    subdirectories; the top level directory contains mainly configuration
    information.  GNU cpio is a good example of such a package, as is GNU
    @code{tar}.  The top level @file{Makefile.am} for a deep package will
    contain a @code{SUBDIRS} macro, but no other macros to define objects
    which are built.
    
    A @dfn{shallow} package is one in which the primary source resides in
    the top-level directory, while various parts (typically libraries)
    reside in subdirectories.  @code{automake} is one such package (as is
    GNU @code{make}, which does not currently use @code{automake}).
    
    
    @node Strictness
    @section Strictness
    While Automake is intended to be used by maintainers of GNU packages, it
    does make some effort to accommodate those who wish to use it, but do
    not want to use all the GNU conventions.
    
    To this end, Automake supports three levels of @dfn{strictness} -- the
    strictness indicating how stringently Automake should check standards
    conformance.
    
    The valid strictness levels are:
    
    @table @samp
    @item foreign
    Automake will check for only those things which are absolutely
    required for proper operations.  For instance, whereas GNU standards
    dictate the existence of a @file{NEWS} file, it will not be required in
    this mode.  The name comes from the fact that Automake is intended to be
    used for GNU programs; these relaxed rules are not the standard mode of
    operation.
    
    @item gnu
    Automake will check -- as much as possible -- for compliance to the GNU
    standards for packages.  This is the default.
    
    @item gnits
    Automake will check for compliance to the as-yet-unwritten GNITS
    standards.  These are based on the GNU standards, but are even more
    detailed.  Unless you are a GNITS standards contributor, it is
    recommended that you avoid this option until such time as the GNITS
    standard is actually published.
    @end table
    
    For more information on the precise implications of the strictness
    level, see @xref{Gnits}.
    
    
    @node Uniform
    @section The Uniform Naming Scheme
    Automake variables generally follow a uniform naming scheme that makes
    it easy to decide how programs (and other derived objects) are built,
    and how they are installed.  This scheme also supports @code{configure}
    time determination of what should be built.
    
    At @code{make} time, certain variables are used to determine which
    objects are to be built.  These variables are called @dfn{primary}
    variables.  For instance, the primary variable @code{PROGRAMS} holds a
    list of programs which are to be compiled and linked.
    @vindex PROGRAMS
    
    A different set of variables is used to decide where the built objects
    should be installed.  These variables are named after the primary
    variables, but have a prefix indicating which standard directory should
    be used as the installation directory.  The standard directory names are
    given in the GNU standards
    (@pxref{Directory Variables, , , standards.info, The GNU Coding
    Standards}).
    @code{automake} extends this list with @code{pkglibdir},
    @code{pkgincludedir}, and @code{pkgdatadir}; these are the same as the
    non-@samp{pkg} versions, but with @samp{@@PACKAGE@@} appended.
    @cvindex PACKAGE
    
    For each primary, there is one additional variable named by prepending
    @samp{EXTRA_} to the primary name.  This variable is used to list
    objects which may or may not be built, depending on what
    @code{configure} decides.  This variable is required because Automake
    must know the entire list of objects to be built in order to generate a
    @file{Makefile.in} that will work in all cases.
    
    For instance, @code{cpio} decides at configure time which programs are
    built.  Some of the programs are installed in @code{bindir}, and some
    are installed in @code{sbindir}:
    
    @example
    EXTRA_PROGRAMS = mt rmt
    bin_PROGRAMS = cpio pax
    sbin_PROGRAMS = @@PROGRAMS@@
    @end example
    
    Defining a primary variable is an error.
    
    Note that the common @samp{dir} suffix is left off when constructing the
    variable names; thus one writes @samp{bin_PROGRAMS} and not
    @samp{bindir_PROGRAMS}.
    
    Not every sort of object can be installed in every directory.  Automake
    will flag those attempts it finds in error.  Automake will also diagnose
    obvious misspellings in directory names.
    
    Sometimes the standard directories -- even as augmented by Automake --
    are not enough.  In particular it is sometimes useful, for clarity, to
    install objects in a subdirectory of some predefined directory.  To this
    end, Automake allows you to extend the list of possible installation
    directories.  A given prefix (eg @samp{zar}) is valid if a variable of
    the same name with @samp{dir} appended is defined (eg @samp{zardir}).
    
    For instance, until HTML support is part of Automake, you could use this
    to install raw HTML documentation:
    
    @example
    htmldir = $(prefix)/html
    html_DATA = automake.html
    @end example
    
    The special prefix @samp{noinst} indicates that the objects in question
    should not be installed at all.
    
    The special prefix @samp{check} indicates that the objects in question
    should not be built until the @code{make check} command is run.
    
    Possible primary names are @samp{PROGRAMS}, @samp{LIBRARIES},
    @samp{LISP}, @samp{SCRIPTS}, @samp{DATA}, @samp{HEADERS}, @samp{MANS},
    and @samp{TEXINFOS}.
    @vindex PROGRAMS
    @vindex LIBRARIES
    @vindex LISP
    @vindex SCRIPTS
    @vindex DATA
    @vindex HEADERS
    @vindex MANS
    @vindex TEXINFOS
    
    
    @node Canonicalization
    @section How derived variables are named
    
    Sometimes a Makefile variable name is derived from some text the user
    supplies.  For instance program names are rewritten into Makefile macro
    names.  Automake canonicalizes this text, so that it does not have to
    follow Makefile variable naming rules.  All characters in the name
    except for letters, numbers, and the underscore are turned into
    underscores when making macro references.  Eg, if your program is named
    @code{sniff-glue}, the derived variable name would be
    @code{sniff_glue_SOURCES}, not @code{sniff-glue_SOURCES}.
    
    
    @node configure
    @chapter Scanning @file{configure.in}
    
    Automake scans the package's @file{configure.in} to determine certain
    information about the package.  Some @code{autoconf} macros are required
    and some variables must be defined in @file{configure.in}.  Automake
    will also use information from @file{configure.in} to further tailor its
    output.
    
    @menu
    * Requirements::                Configuration requirements
    * Optional::                    Other things Automake recognizes
    * Invoking aclocal::            Auto-generating aclocal.m4
    * Macros::                      Autoconf macros supplied with Automake
    * Extending aclocal::           Writing your own aclocal macros
    @end menu
    
    
    @node Requirements
    @section Configuration requirements
    
    The simplest way to meet the basic Automake requirements is to use the
    macro @code{AM_INIT_AUTOMAKE} (FIXME: xref).  But if you prefer, you can
    do the required steps by hand:
    @cvindex AM_INIT_AUTOMAKE
    
    @itemize @bullet
    @item
    Define the variables @code{PACKAGE} and @code{VERSION} with
    @code{AC_SUBST}.
    @cvindex PACKAGE
    @cvindex VERSION
    @code{PACKAGE} should be the name of the package as it appears when
    bundled for distribution.  For instance, Automake defines @code{PACKAGE}
    to be @samp{automake}.  @code{VERSION} should be the version number of
    the release that is being developed.  We recommend that you make
    @file{configure.in} the only place in your package where the version
    number is defined; this makes releases simpler.
    
    Automake doesn't do any interpretation of @code{PACKAGE} or
    @code{VERSION}, except in @samp{Gnits} mode (FIXME xref).
    
    @item
    Use the macro @code{AC_ARG_PROGRAM} if a program or script is installed.
    @cvindex AC_ARG_PROGRAM
    
    @item
    Use @code{AC_PROG_MAKE_SET} if the package is not flat.
    @cvindex AC_PROG_MAKE_SET
    
    @item
    Use @code{AM_PROG_INSTALL} if any scripts (@pxref{Scripts}) are
    installed by the package.  Otherwise, use @code{AC_PROG_INSTALL}.
    @cvindex AC_PROG_INSTALL
    @cvindex AM_PROG_INSTALL
    @end itemize
    
    
    Here are the other macros which Automake requires but which are not run
    by @code{AM_INIT_AUTOMAKE}:
    
    @table @code
    @item AC_OUTPUT
    Automake uses this to determine which files to create.  Listed files
    named @code{Makefile} are treated as @file{Makefile}s.  Other listed
    files are treated differently.  Currently the only difference is that a
    @file{Makefile} is removed by @code{make distclean}, while other files
    are removed by @code{make clean}.
    @c FIXME: this is in violation of standards!
    @cvindex AC_OUTPUT
    @end table
    
    @node Optional
    @section Other things Automake recognizes
    
    Automake will also recognize the use of certain macros and tailor the
    generated @file{Makefile.in} appropriately.  Currently recognized macros
    and their effects are:
    
    @table @code
    @item AC_CONFIG_HEADER
    Automake will generate rules to automatically regenerate the config
    header.  If you do use this macro, you must create the file
    @file{stamp-h.in} in your source directory.  It can be empty.  Also, the
    @code{AC_OUTPUT} command in @file{configure.in} must create
    @file{stamp-h}, eg:
    @example
    AC_OUTPUT(Makefile,
    [test -z "$CONFIG_HEADERS" || echo timestamp > stamp-h])
    @end example
    @cvindex AC_CONFIG_HEADER
    Note that Automake does not currently currently check to make sure the
    @code{AC_OUTPUT} command is correct.  Hopefully a future version of
    @code{autoconf} will let Automake handle this automatically.
    
    @item AC_CONFIG_AUX_DIR
    Automake will look for various helper scripts, such as
    @file{mkinstalldirs}, in the directory named in this macro invocation.
    If not seen, the scripts are looked for in their ``standard'' locations
    (either the top source directory, or in the source directory
    corresponding to the current @file{Makefile.am}, whichever is
    appropriate).
    @cvindex AC_CONFIG_AUX_DIR
    FIXME: give complete list of things looked for in this directory
    
    @item AC_PATH_XTRA
    Automake will insert definitions for the variables defined by
    @code{AC_PATH_XTRA} into each @file{Makefile.in} that builds a C program
    or library.
    @cvindex AC_PATH_XTRA
    
    @item AC_CANONICAL_HOST
    @item AC_CHECK_TOOL
    Automake will ensure that @file{config.guess} and @file{config.sub}
    exist.  Also, the @file{Makefile} variables @samp{host_alias} and
    @samp{host_triplet} are introduced.
    @c fixme xref autoconf docs.
    @cvindex AC_CANONICAL_HOST
    @cvindex AC_CHECK_TOOL
    @vindex host_alias
    @vindex host_triplet
    
    @item AC_CANONICAL_SYSTEM
    This is similar to @code{AC_CANONICAL_HOST}, but also defines the
    @file{Makefile} variables @samp{build_alias} and @samp{target_alias}.
    @cvindex AC_CANONICAL_SYSTEM
    @vindex build_alias
    @vindex target_alias
    
    @item AC_FUNC_ALLOCA
    @item AC_FUNC_GETLOADAVG
    @item AC_FUNC_MEMCMP
    @item AC_STRUCT_ST_BLOCKS
    @item AM_FUNC_FNMATCH
    @item AM_FUNC_STRTOD
    @item AC_REPLACE_FUNCS
    @item AC_REPLACE_GNU_GETOPT
    @item AM_WITH_REGEX
    Automake will ensure that the appropriate source files are part of the
    distribution, and will ensure that the appropriate dependencies are
    generated for these objects.  @xref{A Library} for more
    information.
    @cvindex AC_FUNC_ALLOCA
    @cvindex AC_FUNC_GETLOADAVG
    @cvindex AC_FUNC_MEMCMP
    @cvindex AC_STRUCT_ST_BLOCKS
    @cvindex AM_FUNC_FNMATCH
    @cvindex AC_FUNC_FNMATCH
    @cvindex AC_REPLACE_FUNCS
    @cvindex AC_REPLACE_GNU_GETOPT
    @cvindex AM_FUNC_STRTOD
    @cvindex AM_WITH_REGEX
    
    @item LIBOBJS
    Automake will detect statements which put @samp{.o} files into
    @code{LIBOBJS}, and will treat these additional files as if they were
    discovered via @code{AC_REPLACE_FUNCS}.
    @cvindex LIBOBJS
    
    @item AC_PROG_RANLIB
    This is required if any libraries are built in the package.
    @cvindex AC_PROG_RANLIB
    
    @item AC_PROG_CXX
    This is required if any C++ source is included.
    @cvindex AC_PROG_CXX
    
    @c @item AM_PROG_LIBTOOL
    @c Automake will turn on processing for @code{libtool} (@pxref{Top, , The
    @c Libtool Manual, libtool.info, The Libtool Manual}).  This work is
    @c still preliminary.
    @c @cvindex AM_PROG_LIBTOOL
    
    @item AC_PROG_YACC
    If a Yacc source file is seen, then you must either use this macro or
    declare the variable @samp{YACC} in @file{configure.in}.  The former is
    preferred.
    @cvindex AC_PROG_YACC
    @cvindex YACC
    
    @item AC_DECL_YYTEXT
    This macro is required if there is Yacc source in the package.
    @cvindex AC_DECL_YYTEXT
    
    @item AC_PROG_LEX
    If a Lex source file is seen, then this macro must be used.
    @cvindex AC_PROG_LEX
    
    @item ALL_LINGUAS
    If Automake sees that this variable is set in @file{configure.in}, it
    will check the @file{po} directory to ensure that all the named
    @samp{.po} files exist, and that all the @samp{.po} files that exist are
    named.
    @cvindex ALL_LINGUAS
    
    @item AM_C_PROTOTYPES
    This is required when using automatic de-ANSI-fication, see @ref{ANSI}.
    @cvindex AM_C_PROTOTYPES
    
    @item ud_GNU_GETTEXT
    This macro is required for packages which use GNU gettext
    (@pxref{gettext}).  It is distributed with gettext.  If Automake sees
    this macro it ensures that the package meets some of gettext's
    requirements.
    @cvindex ud_GNU_GETTEXT
    
    @item AM_MAINTAINER_MODE
    This macro adds a @samp{--enable-maintainer-mode} option to
    @code{configure}.  If this is used, @code{automake} will cause
    ``maintainer-only'' rules to be turned off by default in the generated
    @file{Makefile.in}s.  This macro is disallowed in @samp{Gnits} mode.
    FIXME xref.
    @cvindex jm_MAINTAINER_MODE
    @end table
    
    
    @node Invoking aclocal
    @section Auto-generating aclocal.m4
    
    The @code{aclocal} program will automatically generate @file{aclocal.m4}
    files based on the contents of @file{configure.in}.
    
    ... explain why on earth you'd want to do this
    
    @code{aclocal} accepts the following options:
    
    @table @code
    @item --acdir=@var{dir}
    Look for the macro files in @var{dir} instead of the installation
    directory.  This is typically used for debugging.
    
    @item --help
    Print a summary of the command line options and exit.
    
    @item --output=@var{file}
    Cause the output to be put into @var{file} instead of @file{aclocal.m4}.
    
    @item --verbose
    Print the names of the files it examines.
    
    @item --version
    Print the version number of Automake and exit.
    @end table
    
    
    @node Macros
    @section Autoconf macros supplied with Automake
    
    @c consider generating this node automatically from m4 files.
    
    @table @code
    @item AM_FUNC_FNMATCH
    If the @code{fnmatch} function is not available, or does not work
    correctly (like the one on SunOS 5.4), add @samp{fnmatch.o} to output
    variable @code{LIBOBJS}.
    
    @item AM_FUNC_STRTOD
    If the @code{strtod} function is not available, or does not work
    correctly (like the one on SunOS 5.4), add @samp{strtod.o} to output
    variable @code{LIBOBJS}.
    
    @item AM_FUNC_ERROR_AT_LINE
    @item AM_FUNC_MKTIME
    @item AM_FUNC_OBSTACK
    
    @item AM_C_PROTOTYPES
    @item AM_HEADER_TIOCGWINSZ_NEEDS_SYS_IOCTL
    @item AM_INIT_AUTOMAKE
    @item AM_MAINTAINER_MODE
    @item AM_PATH_LISPDIR
    @item AM_PROG_CC_STDC
    @item AM_PROG_INSTALL
    @item AM_SANITY_CHECK_CC
    @item AM_SYS_POSIX_TERMIOS
    @item AM_TYPE_PTRDIFF_T
    @item AM_WITH_DMALLOC
    @item AM_WITH_REGEX
    @end table
    
    
    @node Extending aclocal
    @section Writing your own aclocal macros
    
    ... explain format of macro files
    ... explain how to get your own macros installed (using acinstall)
    ... explain situations where this is actually useful (eg gettext)
    
    
    @node Top level
    @chapter The top-level @file{Makefile.am}
    
    In non-flat packages, the top level @file{Makefile.am} must tell
    Automake which subdirectories are to be built.  This is done via the
    @code{SUBDIRS} variable.
    @vindex SUBDIRS
    
    The @code{SUBDIRS} macro holds a list of subdirectories in which
    building of various sorts can occur.  Many targets (eg @code{all}) in
    the generated @file{Makefile} will run both locally and in all specified
    subdirectories.  Note that the directories listed in @code{SUBDIRS} are
    not required to contain @file{Makefile.am}s; only @file{Makefile}s
    (after configuration).  This allows inclusion of libraries from packages
    which do not use Automake (such as @code{gettext}).
    
    In a deep package, the top-level @file{Makefile.am} is often very short.
    For instance, here is the @file{Makefile.am} from the textutils
    distribution:
    
    @example
    SUBDIRS = lib src doc man
    @end example
    
    @code{SUBDIRS} can contain configure substitutions (eg @samp{@@DIRS@@});
    Automake itself does not actually examine the contents of this variable.
    
    If @code{SUBDIRS} is defined, then your @file{configure.in} must include
    @code{AC_PROG_MAKE_SET}.
    
    The use of @code{SUBDIRS} is not restricted to just the top-level
    @file{Makefile.am}.  Automake can be used to construct packages of
    arbitrary depth.
    
    
    @node Programs
    @chapter Building Programs and Libraries
    
    A large part of Automake's functionality is dedicated to making it easy
    to build C programs and libraries.
    
    @menu
    * A Program::                   Building a program
    * A Library::                   Building a library
    * LIBOBJS::                     Special handling for LIBOBJS and ALLOCA
    * Program variables::           Variables used when building a program
    * Yacc and Lex::                Yacc and Lex support
    * C++::                         C++ and other languages
    * ANSI::                        Automatic de-ANSI-fication
    * Dependencies::                Automatic dependency tracking
    @end menu
    
    
    @node A Program
    @section Building a program
    
    In a directory containing source that gets built into a program (as
    opposed to a library), the @samp{PROGRAMS} primary is used.  Programs
    can be installed in @code{bindir}, @code{sbindir}, @code{libexecdir},
    @code{pkglibdir}, or not at all.
    
    For instance:
    
    @example
    bin_PROGRAMS = hello
    @end example
    
    In this simple case, the resulting @file{Makefile.in} will contain code
    to generate a program named @code{hello}.  The variable
    @code{hello_SOURCES} is used to specify which source files get built
    into an executable:
    
    @example
    hello_SOURCES = hello.c
    @end example
    
    This causes @file{hello.c} to be compiled into @file{hello.o}, and then
    linked to produce @file{hello}.
    
    If @samp{prog_SOURCES} is needed, but not specified, then it defaults to
    the single file @file{prog.c}.  In the example above, the definition of
    @code{hello_SOURCES} is actually redundant.
    @vindex _SOURCES
    @vindex SOURCES
    
    Multiple programs can be built in a single directory.  Multiple programs
    can share a single source file.  The source file must be listed in each
    @samp{_SOURCES} definition.
    
    Header files listed in a @samp{_SOURCES} definition will be included in
    the distribution but otherwise ignored.  In case it isn't obvious, you
    should not include the header file generated by @file{configure} in an
    @samp{_SOURCES} variable; this file should not be distributed.
    Lex (@samp{.l}) and yacc (@samp{.y}) files can also be listed; support
    for these should work but is still preliminary.
    @c lex & yacc should have a separate section
    
    Sometimes it is useful to determine the programs that are to be built at
    configure time.  For instance, GNU @code{cpio} only builds @code{mt} and
    @code{rmt} under special circumstances.
    
    In this case, you must notify @code{Automake} of all the programs that
    can possibly be built, but at the same time cause the generated
    @file{Makefile.in} to use the programs specified by @code{configure}.
    This is done by having @code{configure} substitute values into each
    @samp{_PROGRAMS} definition, while listing all optionally built programs in
    @code{EXTRA_PROGRAMS}.
    @vindex EXTRA_PROGRAMS
    
    If you need to link against libraries that are not found by
    @code{configure}, you can use @code{LDADD} to do so.  This variable
    actually can be used to add any options to the linker command line.
    @vindex LDADD
    
    Sometimes, multiple programs are built in one directory but do not share
    the same link-time requirements.  In this case, you can use the
    @samp{@var{prog}_LDADD} variable (where @var{PROG} is the name of the
    program as it appears in some @samp{_PROGRAMS} variable, and usually
    written in lowercase) to override the global @code{LDADD}.  (If this
    variable exists for a given program, then that program is not linked
    using @code{LDADD}.)
    @vindex _LDADD
    
    For instance, in GNU cpio, @code{pax}, @code{cpio}, and @code{mt} are
    linked against the library @file{libcpio.a}.  However, @code{rmt} is
    built in the same directory, and has no such link requirement.  Also,
    @code{mt} and @code{rmt} are only built on certain architectures.  Here
    is what cpio's @file{src/Makefile.am} looks like (abridged):
    
    @example
    bin_PROGRAMS = cpio pax @@MT@@
    libexec_PROGRAMS = @@RMT@@
    EXTRA_PROGRAMS = mt rmt
    
    LDADD = ../lib/libcpio.a @@INTLLIBS@@
    rmt_LDADD =
    
    cpio_SOURCES = @dots{}
    pax_SOURCES = @dots{}
    mt_SOURCES = @dots{}
    rmt_SOURCES = @dots{}
    @end example
    
    It is also occasionally useful to have a program depend on some other
    target which is not actually part of that program.  This can be done
    using the @samp{prog_DEPENDENCIES} variable.  Each program depends on
    the contents of such a variable, but no further interpretation is done.
    
    If @samp{prog_DEPENDENCIES} is not supplied, it is computed by Automake.
    The automatically-assigned value is the contents of @samp{prog_LDADD}
    with all the @samp{-l} and @samp{-L} options removed.  Be warned that
    @file{configure} substitutions are preserved; this can lead to bad
    dependencies if you are not careful.
    
    
    @node A Library
    @section Building a library
    
    Building a library is much like building a program.  In this case, the
    name of the primary is @samp{LIBRARIES}.  Libraries can be installed in
    @code{libdir} or @code{pkglibdir}.
    
    Each @samp{_LIBRARIES} variable is a list of the base names of
    libraries to be built.  For instance to create a library named
    @file{libcpio.a}, but not install it, you would write:
    
    @example
    noinst_LIBRARIES = cpio
    @end example
    
    The sources that go into a library are determined exactly as they are
    for programs, via the @samp{_SOURCES} variables.  Note that programs and
    libraries share a namespace, so one cannot have a program (@file{lob}) and
    a library (@file{liblob.a}) with the same name in one directory.
    
    Extra objects can be added to a library using the @samp{library_LIBADD}
    variable.  This should be used for objects determined by
    @code{configure}.  Again from cpio:
    @vindex _LIBADD
    @vindex LIBADD
    
    @example
    cpio_LIBADD = @@LIBOBJS@@ @@ALLOCA@@
    @end example
    
    
    @node LIBOBJS
    @section Special handling for LIBOBJS and ALLOCA
    
    Automake explicitly recognizes the use of @code{@@LIBOBJS@@} and
    @code{@@ALLOCA@@}, and uses this information, plus the list of
    @code{LIBOBJS} files derived from @file{configure.in} to automatically
    include the appropriate source files in the distribution (@pxref{Dist}).
    These source files are also automatically handled in the
    dependency-tracking scheme, see @xref{Dependencies}.
    
    @code{@@LIBOBJS@@} and @code{@@ALLOCA@@} are specially recognized in any
    @samp{_LDADD} or @samp{_LIBADD} variable.
    
    
    @node Program variables
    @section Variables used when building a program
    
    Occasionally it is useful to know which @file{Makefile} variables
    Automake uses for compilations; for instance you might need to do your
    own compilation in some special cases.
    
    Some variables are inherited from Autoconf; these are @code{CC},
    @code{CFLAGS}, @code{CPPFLAGS}, @code{DEFS}, @code{LDFLAGS}, and
    @code{LIBS}.
    
    
    There are some additional variables which Automake itself defines:
    
    @table @code
    @item INCLUDES
    A list of @samp{-I} options.  This can be set in your @file{Makefile.am}
    if you have special directories you want to look in.
    
    @item COMPILE
    This is the command used to actually compile a C source file.  The
    filename is appended to form the complete command line.
    
    @item LINK
    This is the command used to actually link a C program.
    @end table
    
    
    @node Yacc and Lex
    @section Yacc and Lex support
    
    Automake has somewhat idiosyncratic support for Yacc and Lex.
    FIXME: describe it here.
    
    
    @node C++
    @section C++ and other languages
    
    Automake includes full support for C++, and rudimentary support for
    other languages.  Support for other languages will be improved based on
    demand.
    
    Any package including C++ code must use @code{AC_PROG_CXX} in its
    @file{configure.in}.
    
    A few additional variables are defined when a C++ source file is seen:
    
    @table @code
    @item CXX
    The name of the C++ compiler.
    
    @item CXXFLAGS
    Any flags to pass to the C++ compiler.
    
    @item CXXCOMPILE
    The command used to actually compile a C++ source file.  The file name
    is appended to form the complete command line.
    
    @item CXXLINK
    The command used to actually link a C++ program.
    @end table
    
    
    @node ANSI
    @section Automatic de-ANSI-fication
    
    Although the GNU standards prohibit it, some GNU programs are written in
    ANSI C; see FIXME.  This is possible because each source file can be
    ``de-ANSI-fied'' before the actual compilation takes place.
    
    If the @file{Makefile.am} variable @code{AUTOMAKE_OPTIONS}
    @vindex AUTOMAKE_OPTIONS
    (@ref{Options}) contains the option @code{ansi2knr}
    @opindex ansi2knr
    then code to handle de-ANSI-fication is inserted into the generated
    @file{Makefile.in}.
    
    This causes each source file to be treated as ANSI C.  If an ANSI C
    compiler is available, it is used.
    
    This support requires the source files @file{ansi2knr.c} and
    @file{ansi2knr.1} to be in the same directory as the ANSI C source;
    these files are distributed with Automake.
    Also, the package @file{configure.in} must call the macro
    @code{AM_C_PROTOTYPES}.
    @cvindex AM_C_PROTOTYPES
    
    Automake also handles finding the @code{ansi2knr} support files in some
    other directory in the current package.  This is done by prepending the
    relative path to the appropriate directory to the @code{ansi2knr}
    option.  For instance, suppose the package has ANSI C code in the
    @file{src} and @file{lib} subdirs.  The files @file{ansi2knr.c} and
    @file{ansi2knr.1} appear in @file{lib}.  Then this could appear in
    @file{src/Makefile.am}:
    
    @example
    AUTOMAKE_OPTIONS = ../lib/ansi2knr
    @end example
    
    Note that the directory holding the @code{ansi2knr} support files must
    be built before all other directories using these files.  Automake does
    not currently check that this is the case.
    
    Note also that @code{ansi2knr} assumes the source code will be formatted
    in a particular way.  See the @code{ansi2knr} man page for details.
    
    
    @node Dependencies
    @section Automatic dependency tracking
    
    As a developer it is often painful to continually update the
    @file{Makefile.in} whenever the include-file dependencies change in a
    project.  @code{automake} supplies a way to automatically track
    dependency changes, and distribute the dependencies in the generated
    @file{Makefile.in}.
    
    Currently this support requires the use of GNU @code{make} and
    @code{gcc}.  It might become possible in the future to supply a
    different dependency generating program, if there is enough demand.
    
    This mode is enabled by default if any C program or library is defined
    in the current directory.
    
    When you decide to make a distribution, the @code{dist} target will
    @trindex dist
    re-run @code{automake} with the @samp{--include-deps} option.  This
    @c FIXME XREF?
    causes the previously generated dependencies to be inserted into the
    generated @file{Makefile.in}, and thus into the distribution.
    @samp{--include-deps} also turns off inclusion of the dependency
    generation code.
    
    This mode can be suppressed by putting @code{no-dependencies} in the
    variable @code{AUTOMAKE_OPTIONS}.
    @vindex AUTOMAKE_OPTIONS
    @opindex no-dependencies
    
    If you unpack a distribution made by @code{make dist}, and you want to
    turn on the dependency-tracking code again, simply run @code{automake}
    with no arguments.
    
    
    @node Other objects
    @chapter Other Derived Objects
    
    Automake can handle derived objects which are not C programs.  Sometimes
    the support for actually building such objects must be explicitly
    supplied, but Automake will still automatically handle installation and
    distribution.
    
    @menu
    * Scripts::                     Executable scripts
    * Headers::                     Header files
    * Data::                        Architecture-independent data files
    * Sources::                     Derived sources
    @end menu
    
    
    @node Scripts
    @section Executable Scripts
    
    It is possible to define and install programs which are scripts.  Such
    programs are listed using the @samp{SCRIPTS} primary name.
    @code{automake} doesn't define any dependencies for scripts; the
    @file{Makefile.am} should include the appropriate rules.
    @vindex SCRIPTS
    
    @code{automake} does not assume that scripts are derived objects; such
    objects must be deleted by hand; see @ref{Clean} for more information.
    
    @code{automake} itself is a script that is generated at configure time
    from @file{automake.in}.  Here is how this is handled:
    
    @example
    bin_SCRIPTS = automake
    @end example
    
    Since @code{automake} appears in the @code{AC_OUTPUT} macro, a target
    for it is automatically generated.
    
    Script objects can be installed in @code{bindir}, @code{sbindir},
    @code{libexecdir}, or @code{pkgdatadir}.
    
    
    @node Headers
    @section Header files
    
    Header files are specified by the @samp{HEADERS} family of variables.
    Generally header files are not installed, so the @code{noinst_HEADERS}
    variable will be the most used.
    @vindex HEADERS
    
    All header files must be listed somewhere; missing ones will not appear
    in the distribution.  Often it is clearest to list uninstalled headers
    with the rest of the sources for a program.  @xref{A Program}.  Headers
    listed in a @samp{_SOURCES} variable need not be listed in any
    @samp{_HEADERS} variable.
    
    Headers can be installed in @code{includedir}, @code{oldincludedir}, or
    @code{pkgincludedir}.
    
    
    @node Data
    @section Architecture-independent data files
    
    Automake supports the installation of miscellaneous data files using the
    @samp{DATA} family of variables.
    @vindex DATA
    
    Such data can be installed in the directories @code{datadir},
    @code{sysconfdir}, @code{sharedstatedir}, @code{localstatedir}, or
    @code{pkgdatadir}.
    
    By default, data files are not included in a distribution.
    
    Here is how @code{automake} installs its auxiliary data files:
    
    @example
    pkgdata_DATA = clean-kr.am clean.am compile-kr.am compile-vars.am \
    compile.am data.am depend.am dist-subd-top.am dist-subd-vars.am \
    dist-subd.am dist-vars.am dist.am footer.am header-vars.am header.am \
    libscripts.am libprograms.am libraries-vars.am libraries.am library.am \
    mans-vars.am mans.am packagedata.am program.am programs.am remake-hdr.am \
    remake-subd.am remake.am scripts.am subdirs.am tags.am tags-subd.am \
    texinfos-vars.am texinfos.am hack-make.sed nl-remove.sed
    @end example
    
    
    @node Sources
    @section Built sources
    
    Occasionally a file which would otherwise be called ``source'' (eg a C
    @samp{.h} file) is actually derived from some other file.  Such files
    should be listed in the @code{BUILT_SOURCES} variable.
    @vindex BUILT_SOURCES
    
    Files listed in @code{BUILT_SOURCES} are built before any automatic
    dependency tracking is done.  By default, built sources are not included
    in a distribution.
    
    
    @node Other GNU Tools
    @chapter Other GNU Tools
    
    Since Automake is primarily intended to generate @file{Makefile.in}s for
    use in GNU programs, it tries hard to interoperatoe with other GNU
    tools.
    
    @menu
    * Emacs Lisp::                  Emacs Lisp
    * gettext::                     Gettext
    @end menu
    
    @node Emacs Lisp
    @section Emacs Lisp
    
    Automake provides some support for Emacs Lisp.  The @samp{LISP} primary
    is used to hold a list of @samp{.el} files.  Possible prefixes for this
    primary are @samp{lisp_} and @samp{noinst_}.  Note that if
    @code{lisp_LISP} is defined, then @file{configure.in} must run
    @code{AM_PATH_LISPDIR} (fixme xref).
    @vindex LISP
    @vindex lisp_LISP
    @vindex noinst_LISP
    
    By default Automake will byte-compile all Emacs Lisp source files using
    the Emacs found by @code{AM_PATH_LISPDIR}.  If you wish to avoid
    byte-compiling, simply define the variable @samp{ELCFILES} to be empty.
    @vindex ELCFILES
    
    @node gettext
    @section Gettext
    
    If @code{ud_GNU_GETTEXT} is seen in @file{configure.in}, then Automake
    turns on support for GNU gettext, a message catalog system for
    internationalization
    (@pxref{GNU Gettext, , , gettext.info, GNU gettext utilities}).
    
    The @code{gettext} support in Automake requires the addition of two
    subdirectories to the package, @file{intl} and @file{po}.  Automake
    ensure that these directories exist and are mentioned in @code{SUBDIRS}.
    
    Furthermore, Automake checks that the definition of @samp{ALL_LINGUAS}
    in @file{configure.in} corresponds to all the valid @samp{.po} files,
    and nothing more.
    
    
    @node Documentation
    @chapter Building documentation
    
    Currently Automake provides support for Texinfo and man pages.
    
    @menu
    * Texinfo::                     Texinfo
    * Man pages::                   Man pages
    @end menu
    
    
    @node Texinfo
    @section Texinfo
    
    If the current directory contains Texinfo source, you must declare it
    with the @samp{TEXINFOS} primary.  Generally Texinfo files are converted
    into info, and thus the @code{info_TEXINFOS} macro is most commonly used
    here.  Note that any Texinfo source file must end in the @samp{.texi} or
    @samp{.texinfo} extension.
    @vindex TEXINFOS
    @vindex info_TEXINFOS
    
    If the @samp{.texi} file @code{@@include}s @file{version.texi}, then that
    file will be automatically generated.  @file{version.texi} defines three
    Texinfo macros you can reference: @code{EDITION}, @code{VERSION}, and
    @code{UPDATED}.  The first two hold the version number of your package
    (but are kept separate for clarity); the last is the date the primary
    file was last modified.  The @file{version.texi} support requires the
    @code{mdate-sh} program; this program is supplied with Automake.
    
    Sometimes an info file actually depends on more than one @samp{.texi}
    file.  For instance, in the @code{xdvik} distribution,
    @file{kpathsea.texi} includes the files @file{install.texi},
    @file{copying.texi}, and @file{freedom.texi}.  You can tell Automake
    about these dependencies using the @samp{texi_TEXINFOS} variable.  Here
    is how @code{xdvik} could do it:
    @vindex TEXINFOS
    @vindex _TEXINFOS
    
    @example
    info_TEXINFOS = kpathsea.texi
    kpathsea_TEXINFOS = install.texi copying.texi freedom.texi
    @end example
    
    By default, Automake requires the file @file{texinfo.tex} to appear in
    the same directory as the Texinfo source.  However, if you used
    @code{AC_CONFIG_AUX_DIR} in @file{configure.in}, then @file{texinfo.tex}
    is looked for there.  Automake supplies @file{texinfo.tex}.
    
    Automake generates an @code{install-info} target; some people apparently
    use this.  By default, info pages are installed by @samp{make install}.
    This can be prevented via the @code{no-installinfo} option.
    
    
    @node Man pages
    @section Man pages
    
    A package can also include man pages.  (Though see the GNU standards on
    this matter, @ref{Man Pages, , , standards.info, The GNU Coding
    Standards}.)  Man pages are declared using the @samp{MANS} primary.
    Generally the @code{man_MANS} macro is used.  Man pages are
    automatically installed in the correct subdirectory of @code{mandir},
    based on the file extension.
    @vindex MANS
    @vindex man_MANS
    
    @c Use @samp{make install} per documentation: (texi.info)code.
    By default, man pages are installed by @samp{make install}.  However,
    since the GNU project does not require man pages, many maintainers do
    not expend effort to keep the man pages up to date.  In these cases, the
    @code{no-installman} option will prevent the man pages from being
    installed by default.  The user can still explicitly install them via
    @samp{make install-man}.
    @opindex no-installman
    @trindex install-man
    
    Here is how the documentation is handled in GNU @code{cpio} (which
    includes both Texinfo documentation and man pages):
    
    @example
    info_TEXINFOS = cpio.texi
    man_MANS = cpio.1 mt.1
    @end example
    
    Texinfo source, info pages and man pages are all considered to be source
    for the purposes of making a distribution.
    
    
    @node Install
    @chapter What Gets Installed
    
    Naturally, Automake handles the details of actually installing your
    program once it has been built.  All @code{PROGRAMS}, @code{SCRIPTS},
    @code{LIBRARIES}, @code{LISP}, @code{DATA} and @code{HEADERS} are
    automatically installed in the appropriate places.
    
    Automake also handles installing any specified info and man pages.
    
    Automake generates separate @code{install-data} and @code{install-exec}
    targets, in case the installer is installing on multiple machines which
    share directory structure -- these targets allow the machine-independent
    parts to be installed only once.  The @code{install} target depends on
    both of these targets.
    @trindex install-data
    @trindex install-exec
    @trindex install
    
    Automake also generates an @code{uninstall} target, and an
    @code{installdirs} target.
    @trindex uninstall
    @trindex installdirs
    
    It is possible to extend this mechanism by defining an
    @code{install-exec-local} or @code{install-data-local} target.  If these
    targets exist, they will be run at @samp{make install} time.
    @trindex install-exec-local
    @trindex install-data-local
    
    
    @node Clean
    @chapter What Gets Cleaned
    
    The GNU Makefile Standards specify a number of different clean rules.
    @c FIXME xref
    Generally the files that can cleaned are determined automatically by
    Automake.  Of course, Automake also recognizes some variables that can
    be defined to specify additional files to clean.  These variables are
    @code{MOSTLYCLEANFILES}, @code{CLEANFILES}, @code{DISTCLEANFILES}, and
    @code{MAINTAINERCLEANFILES}.
    @vindex MOSTLYCLEANFILES
    @vindex CLEANFILES
    @vindex DISTCLEANFILES
    @vindex MAINTAINERCLEANFILES
    
    
    @node Dist
    @chapter What Goes in a Distribution
    
    The @code{dist} target in the generated @file{Makefile.in} can be used
    to generate a gzip'd @code{tar} file for distribution.  The tar file is
    named based on the @var{PACKAGE} and @var{VERSION} variables; more
    precisely it is named @samp{@var{PACKAGE}-@var{VERSION}.tar.gz}.
    @cvindex PACKAGE
    @cvindex VERSION
    @trindex dist
    
    For the most part, the files to distribute are automatically found by
    Automake: all source files are automatically included in a distribution,
    as are all @file{Makefile.am}s and @file{Makefile.in}s.  Automake also
    has a built-in list of commonly used files which, if present in the
    current directory, are automatically included.  This list is printed by
    @samp{automake --help}.  Also, files which are read by @code{configure}
    (ie, the source files corresponding to the files specified in the
    @code{AC_OUTPUT} invocation) are automatically distributed.
    
    Still, sometimes there are files which must be distributed, but which
    are not covered in the automatic rules.  These files should be listed in
    the @code{EXTRA_DIST} variable.  Note that @code{EXTRA_DIST} can only
    handle files in the current directory; files in other directories will
    cause @code{make dist} runtime failures.
    @vindex EXTRA_DIST
    
    Occasionally it is useful to be able to change the distribution before
    it is packaged up.  If the @code{dist-hook} target exists, it is run
    after the distribution directory is filled, but before the actual tar
    (or shar) file is created.  One way to use this is for distributing file
    in subdirectories for which a new @file{Makefile.am} is overkill:
    
    @example
    dist-hook:
            mkdir $(distdir)/random
            cp -p random/a1 random/a2 $(distdir)/random
    @end example
    
    Automake also generates a @code{distcheck} target which can be help to
    ensure that a given distribution will actually work.  @code{distcheck}
    makes a distribution, and then tries to do a @code{VPATH} build.
    @trindex distcheck
    @c FIXME: document distcheck-hook here
    
    @node Tests
    @chapter Support for test suites
    
    Automake supports a two forms of test suite.
    
    If the variable @code{TESTS} is defined, its value is taken to be a list
    of programs to run in order to do the testing.  The programs can either
    be derived objects or source objects; the generated rule will look both
    in @var{srcdir} and @file{.}.  The number of failures will be printed at
    the end of the run.  The variable @code{TESTS_ENVIRONMENT} can be used
    to set environment variables for the test run; the environment variable
    @code{srcdir} is set in the rule.
    @vindex TESTS
    @vindex TESTS_ENVIRONMENT
    
    If @samp{dejagnu} appears in @code{AUTOMAKE_OPTIONS}, then the a
    @code{dejagnu}-based test suite is assumed.  The value of the variable
    @code{DEJATOOL} is passed as the @code{--tool} argument to
    @code{runtest}; it defaults to the name of the package.  The variables
    @code{EXPECT}, @code{RUNTEST} and @code{RUNTESTFLAGS} can also be
    overridden to provide project-specific values.  For instance, you will
    need to do this if you are testing a compiler toolchain, because the
    default values do not take into account host and target names.
    @opindex dejagnu
    @vindex DEJATOOL
    @vindex EXPECT
    @vindex RUNTEST
    @vindex RUNTESTFLAGS
    @c FIXME xref dejagnu
    
    In either case, the testing is done via @samp{make check}.
    
    
    @node Options
    @chapter Changing Automake's Behavior
    
    Various features of Automake can be controlled by options in the
    @file{Makefile.am}.  Such options are listed in a special variable named
    @code{AUTOMAKE_OPTIONS}.  Currently understood options are:
    @vindex AUTOMAKE_OPTIONS
    
    @table @asis
    @item @code{gnits}
    @itemx @code{gnu}
    @itemx @code{foreign}
    The same as the corresponding @samp{--strictness} option.
    
    @item @code{no-installman}
    The generated @file{Makefile.in} will not cause man pages to be
    installed by default.  However, an @code{install-man} target will still
    be available for optional installation.  This option is disallowed at
    @samp{GNU} strictness and above.
    @trindex install-man
    
    @item @code{no-installinfo}
    The generated @file{Makefile.in} will not cause info pages to be built
    or installed by default.  However, @code{info} and @code{install-info}
    targets will still be available.  This option is disallowed at
    @samp{GNU} strictness and above.
    @trindex info
    @trindex install-info
    
    @item @code{ansi2knr}
    @item @code{path/ansi2knr}
    Turn on automatic de-ANSI-fication.  @xref{ANSI}.  If preceeded by a
    path, the generated @file{Makefile.in} will look in the specified
    directory to find the @file{ansi2knr} program.  Generally the path
    should be a relative path to another directory in the same distribution
    (though Automake currently does not check this).  It is up to you to
    make sure that the specified directory is built before the current
    directory; if @file{ansi2knr} does not exist then the build will fail.
    
    @item @code{dejagnu}
    Cause @code{dejagnu}-specific rules to be generated.  @xref{Tests}.
    
    @item @code{dist-shar}
    Generate a @code{dist-shar} target as well as the ordinary @code{dist}
    target.  This new target will create a shar archive of the
    distribution.
    @trindex dist-shar
    
    @item @code{dist-zip}
    Generate a @code{dist-zip} target as well as the ordinary @code{dist}
    target.  This new target will create a zip archive of the distribution.
    @trindex dist-zip
    
    @item @code{dist-tarZ}
    Generate a @code{dist-tarZ} target as well as the ordinary @code{dist}
    target.  This new target will create a compressed tar archive of the
    distribution; a traditional @code{tar} and @code{compress} will be
    assumed.  Warning: if you are actually using @code{GNU tar}, then the
    generated archive might contain nonportable constructs.
    @trindex dist-tarZ
    
    @item @code{no-dependencies}
    This is similar to using @samp{--include-deps} on the command line, but
    is useful for those situations where you don't have the necessary bits
    to make automatic dependency tracking work @xref{Dependencies}.  In this
    case the effect is to effectively disable automatic dependency tracking.
    
    @item @var{version}
    A version number (eg @samp{0.30}) can be specified.  If Automake is not
    newer than the version specified, creation of the @file{Makefile.in}
    will be suppressed.
    @end table
    
    Unrecognized options are diagnosed by @code{automake}.
    
    
    @node Miscellaneous
    @chapter Miscellaneous Rules
    
    There are a few rules and variables that didn't fit anywhere else.
    
    @menu
    * Tags::                        Interfacing to etags and mkid
    * Suffixes::                    Handling new file extensions
    * Built::                       Built sources
    @end menu
    
    
    @node Tags
    @section Interfacing to @code{etags}
    
    @code{automake} will generate rules to generate @file{TAGS} files for
    use with GNU Emacs under some circumstances.
    
    If any C source code or headers are present, then a @code{tags} target
    will be generated for the directory.
    @trindex tags
    
    At the topmost directory of a multi-directory package, a @code{tags}
    target file will be generated which, when run, will generate a
    @file{TAGS} file that includes by reference all @file{TAGS} files from
    subdirectories.
    
    Also, if the variable @code{ETAGS_ARGS} is defined, a @code{tags} target
    will be generated.  This variable is intended for use in directories
    which contain taggable source that @code{etags} does not understand.
    @vindex ETAGS_ARGS
    
    Here is how Automake generates tags for its source, and for nodes in its
    Texinfo file:
    
    @example
    ETAGS_ARGS = automake.in --lang=none \
     --regex='/^@@node[ \t]+\([^,]+\)/\1/' automake.texi
    @end example
    
    If you add filenames to @var{ETAGS_ARGS}, you will probably also
    want to set @var{TAGS_DEPENDENCIES}.  The contents of this variable
    are added directly to the dependencies for the @code{tags} target.
    @vindex TAGS_DEPENDENCIES
    
    Automake will also generate an @code{ID} target which will run
    @code{mkid} on the source.  This is only supported on a
    directory-by-directory basis.
    @trindex id
    
    
    @node Suffixes
    @section Handling new file extensions
    
    It is sometimes useful to introduce a new implicit rule to handle a file
    type that Automake does not know about.  If this is done, you must
    notify GNU Make of the new suffixes.  This can be done by putting a list
    of new suffixes in the @code{SUFFIXES} variable.
    @vindex SUFFIXES
    
    For instance, currently automake does not provide any Java support.  If
    you wrote a macro to generate @samp{.class} files from @samp{.java}
    source files, you would also need to add these suffixes to the list:
    
    @example
    SUFFIXES = .java .class
    @end example
    
    @node Built
    @section Built sources
    
    FIXME write this
    
    
    @node Gnits
    @chapter The effect of --gnu and --gnits
    
    The @samp{--gnu} option (or @samp{gnu} in the @samp{AUTOMAKE_OPTIONS}
    variable) causes @code{automake} to check the following:
    
    @itemize @bullet
    @item
    The files @file{INSTALL}, @file{NEWS}, @file{README}, @file{COPYING},
    @file{AUTHORS}, and @file{ChangeLog} are required at the topmost
    directory of the package.
    
    @item
    The options @samp{no-installman} and @samp{no-installinfo} are
    prohibited.
    @end itemize
    
    Note that this option will be extended in the future to do even more
    checking; it is advisable to be familiar with the precise requirements
    of the GNU standards.  Also, @samp{--gnu} can require certain
    non-standard GNU programs to exist for use by various maintainer-only
    targets; for instance in the future @code{pathchk} might be required for
    @samp{make dist}.
    
    The @samp{--gnits} option does everything that @samp{--gnu} does, and
    checks the following as well:
    
    @itemize @bullet
    @item
    @samp{make dist} will check to make sure the @file{NEWS} file has been
    updated to the current version.
    
    @item
    The file @file{COPYING.LIB} is prohibited.
    
    @item
    @samp{VERSION} is checked to make sure its format complies with Gnits
    standards.
    @c FIXME xref when standards are finished
    
    @item
    If @samp{VERSION} indicates that this is an alpha release, and the file
    @file{README-alpha} appears in the topmost directory of a package, then
    it is included in the distribution.
    
    @item
    The file @file{THANKS} is required.
    @end itemize
    
    
    @node Extending
    @chapter When Automake Isn't Enough
    
    Sometimes @code{automake} isn't enough.  Then you just lose.
    
    Actually, @code{automake}s implicit copying semantics means that many
    problems can be worked around by simply adding some @code{make} targets
    and rules to @file{Makefile.in}.  @code{automake} will ignore these
    additions.
    
    There are some caveats to doing this.  Although you can overload a
    target already used by @code{automake}, it is often inadvisable,
    particularly in the topmost directory of a non-flat package.  However,
    various useful targets have a @samp{-local} version you can specify in your
    @file{Makefile.in}.  Automake will supplement the standard target with
    these user-supplied targets.
    
    The targets that support a local version are @code{all}, @code{info},
    @code{dvi}, @code{check}, @code{install-data}, @code{install-exec}, and
    @code{uninstall}.  Note that there are no @code{uninstall-exec-local} or
    @code{uninstall-data-local} targets; just use @code{uninstall-local}.
    It doesn't make sense to uninstall just data or just executables.
    @trindex all
    @trindex info
    @trindex dvi
    @trindex check
    @trindex install-data
    @trindex install-exec
    @trindex uninstall
    
    For instance, here is how to install a file in @file{/etc}:
    
    @example
    install-data-local:
            $(INSTALL_DATA) $(srcdir)/afile /etc/afile
    @end example
    
    Some targets also have a way to run another target, called a @dfn{hook},
    after their work is done.  The hook is named after the principal target,
    with @samp{-hook} appended.  The targets allowing hooks are
    @code{install-data}, @code{install-exec}, @code{dist}, and
    @code{distcheck}.
    @trindex install-data-hook
    @trindex install-exec-hook
    @trindex dist-hook
    
    For instance, here is how to create a hard link to an installed program:
    
    @example
    install-exec-hook:
            ln $(bindir)/program $(bindir)/proglink
    @end example
    
    @c FIXME should include discussion of variables you can use in these
    @c rules
    
    
    @node Distributing
    @chapter Distributing @file{Makefile.in}s
    
    Automake places no restrictions on the distribution of the resulting
    @file{Makefile.in}s.  We still encourage software authors to distribute
    their work under terms like those of the GPL, but doing so is not
    required to use Automake.
    
    Some of the files that can be automatically installed via the
    @samp{--add-missing} switch do fall under the GPL; examine each file
    to see.
    
    
    @node Examples
    @chapter Some example packages
    
    Here are some examples of how Automake can be used.
    
    @menu
    * Hello::                       The simplest GNU program
    * Tricky::                      A trickier example
    * Automake::                    Automake's own use
    * Textutils::                   A deep hierarchy
    @end menu
    
    @node Hello
    @section The simplest GNU program
    
    @code{hello} is renowned for its classic simplicity and versatility.
    What better place to begin a tour?  The below shows what could be used
    as the Hello distribution's @file{Makefile.am}.
    
    @example
    bin_PROGRAMS = hello
    hello_SOURCES = hello.c version.c getopt.c getopt1.c getopt.h
    hello_LDADD = @@ALLOCA@@
    info_TEXINFOS = hello.texi
    hello_TEXINFOS = gpl.texi
    
    EXTRA_DIST = testdata
    
    check-local: hello
            @@echo expect no output from diff
            ./hello > test.out
            diff -c $(srcdir)/testdata test.out
            rm -f test.out
    @end example
    
    Of course, Automake also requires some minor changes to
    @file{configure.in}.  The new @file{configure.in} would read:
    
    @example
    dnl Process this file with autoconf to produce a configure script.
    AC_INIT(hello.c)
    AM_INIT_AUTOMAKE(hello, 1.3)
    AC_PROG_CC
    AC_PROG_CPP
    AC_PROG_INSTALL
    AC_STDC_HEADERS
    AC_HAVE_HEADERS(string.h fcntl.h sys/file.h)
    AC_ALLOCA
    AC_OUTPUT(Makefile)
    @end example
    
    If Hello were really going to use Automake, the @file{version.c} file
    would probably be deleted, or changed so as to be automatically
    generated.
    
    
    @node Tricky
    @section A tricker example
    
    Here is another, trickier example.  It shows how to generate two
    programs (@code{ctags} and @code{etags}) from the same source file
    (@file{etags.c}).  The difficult part is that each compilation of
    @file{etags.c} requires different @code{cpp} flags.
    
    @example
    bin_PROGRAMS = etags ctags
    ctags_SOURCES =
    ctags_LDADD = ctags.o
    ctags_DEPENDENCIES = ctags.o
    
    etags.o:
            $(COMPILE) -DETAGS_REGEXPS etags.c
    
    ctags.o:
            $(COMPILE) -DCTAGS -o ctags.o etags.c
    @end example
    
    Note that @code{ctags_SOURCES} is defined to be empty -- that way no
    implicit value is substituted.  The implicit value, however, is used to
    generate @code{etags} from @file{etags.o}.
    
    @code{ctags_LDADD} is used to get @file{ctags.o} into the link line,
    while @code{ctags_DEPENDENCIES} exists to make sure that @file{ctags.o}
    gets built in the first place.
    
    This is a somewhat pathological example.
    
    
    @node Automake
    @section Automake uses itself
    
    Automake, of course, uses itself to generate its @file{Makefile.in}.
    Since Automake is a shallow package, it has more than one
    @file{Makefile.am}.  Here is the top-level @file{Makefile.am}:
    
    @example
    ## Process this file with automake to create Makefile.in
    
    AUTOMAKE_OPTIONS = gnits
    MAINT_CHARSET = latin1
    PERL = @@PERL@@
    
    SUBDIRS = tests
    
    bin_SCRIPTS = automake
    info_TEXINFOS = automake.texi
    
    pkgdata_DATA = clean-kr.am clean.am compile-kr.am compile-vars.am \
    compile.am data.am depend.am \
    dist-vars.am footer.am header.am header-vars.am \
    kr-vars.am libraries-vars.am \
    libraries.am library.am mans-vars.am \
    program.am programs.am remake-hdr.am \
    remake-subd.am remake.am scripts.am subdirs.am tags.am tags-subd.am \
    tags-clean.am \
    texi-version.am texinfos-vars.am texinfos.am \
    libraries-clean.am programs-clean.am data-clean.am \
    COPYING INSTALL texinfo.tex \
    ansi2knr.c ansi2knr.1 \
    aclocal.m4
    
    ## These must all be executable when installed.
    pkgdata_SCRIPTS = config.guess config.sub install-sh mdate-sh mkinstalldirs
    
    # The following requires a fixed version of the Emacs 19.30 etags.
    ETAGS_ARGS = automake.in --lang=none \
     --regex='/^@@node[ \t]+\([^,]+\)/\1/' automake.texi
    
    ## `test -x' is not portable.  So we use Perl instead.  If Perl
    ## doesn't exist, then this test is meaningless anyway.
    # Check to make sure some installed files are executable.
    installcheck-local:
    	$(PERL) -e "exit ! -x '$(pkgdatadir)/config.guess';"
    	$(PERL) -e "exit ! -x '$(pkgdatadir)/config.sub';"
    	$(PERL) -e "exit ! -x '$(pkgdatadir)/install-sh';"
    	$(PERL) -e "exit ! -x '$(pkgdatadir)/mdate-sh';"
    	$(PERL) -e "exit ! -x '$(pkgdatadir)/mkinstalldirs';"
    
    # Some simple checks:
    # * syntax check with perl4 and perl5.
    # * make sure the scripts don't use 'true'
    # * expect no instances of '$@{...@}'
    # These are only really guaranteed to work on my machine.
    maintainer-check: automake check
    	$(PERL) -c -w automake
    	@@if grep '^[^#].*true' $(srcdir)/[a-z]*.am; then \
    	  echo "can't use 'true' in GNU Makefile" 1>&2; \
    	  exit 1;				\
    	else :; fi
    	@@if test `fgrep '$$@{' $(srcdir)/[a-z]*.am | wc -l` -ne 0; then \
    	  echo "found too many uses of '\$$@{'" 1>&2; \
    	  exit 1;				\
    	fi
    	if $(SHELL) -c 'perl4.036 -v' >/dev/null 2>&1; then \
    	  perl4.036 -c -w automake; \
    	else :; fi
    
    # Tag before making distribution.  Also, don't make a distribution if
    # checks fail.  Also, make sure the NEWS file is up-to-date.
    cvs-dist: maintainer-check
    	@@if sed 1q NEWS | grep -e "$(VERSION)" > /dev/null; then :; else \
    	  echo "NEWS not updated; not releasing" 1>&2; \
    	  exit 1;				\
    	fi
    	cvs tag `echo "Release-$(VERSION)" | sed 's/\./-/g'`
    	$(MAKE) dist
    @end example
    
    As you can see, Automake defines many of its own rules, to make the
    maintainer's job easier.  For instance the @code{cvs-dist} rule
    automatically tags the current version in the CVS repository, and then
    makes a standard distribution.
    
    Automake consists primarily of one program, @code{automake}, and a
    number of auxiliary scripts.  Automake also installs a number of
    programs which are possibly installed via the @samp{--add-missing}
    option; these scripts are listed in the @code{pkgdata_SCRIPTS} variable.
    
    Automake also has a @file{tests} subdirectory, as indicated in the
    @code{SUBDIRS} variable above.  Here is @file{tests/Makefile.am}:
    
    @example
    ## Process this file with automake to create Makefile.in
    
    AUTOMAKE_OPTIONS = gnits
    
    TESTS = mdate.test vtexi.test acoutput.test instexec.test checkall.test \
    acoutnoq.test acouttbs.test libobj.test proginst.test acoutqnl.test \
    confincl.test spelling.test prefix.test badprog.test depend.test
    
    EXTRA_DIST = defs
    @end example
    
    This is where all the tests are really run.  @file{defs} is an
    initialization file used by each test script; it is explicitly mentioned
    because @code{automake} has no way of automatically finding it.
    
    
    @node Textutils
    @section A deep hierarchy
    
    The GNU textutils are a collection of programs for manipulating text
    files.  They are distributed as a deep package.  The textutils have only
    recently been modified to use Automake; the examples come from a
    prerelease.
    
    Here is the top-level @file{Makefile.am}:
    
    @example
    SUBDIRS = lib src doc man
    @end example
    
    In the @file{lib} directory, a library is built which is used by each
    textutil.  Here is @file{lib/Makefile.am}:
    
    @example
    noinst_LIBRARIES = tu
    
    EXTRA_DIST = rx.c regex.c
    
    tu_SOURCES = error.h getline.h getopt.h linebuffer.h \
    long-options.h md5.h regex.h rx.h xstrtod.h xstrtol.h xstrtoul.h \
    error.c full-write.c getline.c getopt.c getopt1.c \
    linebuffer.c long-options.c md5.c memchr.c safe-read.c \
    xmalloc.c xstrtod.c xstrtol.c xstrtoul.c
    
    tu_LIBADD = @@REGEXOBJ@@ @@LIBOBJS@@ @@ALLOCA@@
    @end example
    
    The @file{src} directory contains the source for all the textutils -- 23
    programs in all.  The @file{Makefile.am} for this directory also
    includes some simple checking code, and constructs a @file{version.c}
    file on the fly:
    
    @example
    bin_PROGRAMS = cat cksum comm csplit cut expand fmt fold head join md5sum \
    nl od paste pr sort split sum tac tail tr unexpand uniq wc
    
    noinst_HEADERS = system.h version.h
    DISTCLEANFILES = stamp-v version.c
    
    INCLUDES = -I$(top_srcdir)/lib
    
    LDADD = version.o ../lib/libtu.a
    
    $(PROGRAMS): version.o ../lib/libtu.a
    
    AUTOMAKE_OPTIONS = ansi2knr
    
    version.c: stamp-v
    stamp-v: Makefile
    	rm -f t-version.c
    	echo '#include <config.h>' > t-version.c
    	echo '#include "version.h"' >> t-version.c
    	echo 'const char *version_string = "'GNU @@PACKAGE@@ @@VERSION@@'";' \
    		>> t-version.c
    	if cmp -s version.c t-version.c; then	\
    	  rm t-version.c;			\
    	else					\
    	  mv t-version.c version.c;		\
    	fi
    	echo timestamp > $@@
    
    check: md5sum
    	./md5sum \
    	 --string="" \
    	 --string="a" \
    	 --string="abc" \
    	 --string="message digest" \
    	 --string="abcdefghijklmnopqrstuvwxyz" \
    	 --string="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" \
    	 --string="12345678901234567890123456789012345678901234567890123456789012345678901234567890" \
           | diff -c $(srcdir)/md5-test.rfc -
    @end example
    
    The @file{doc} directory builds the info documentation for the
    textutils:
    
    @example
    info_TEXINFOS = textutils.texi
    @end example
    
    And, last, the @file{man} directory installs the man pages for all the
    textutils:
    
    @example
    man_MANS = cat.1 cksum.1 comm.1 csplit.1 cut.1 expand.1 fmt.1 fold.1 head.1 \
    join.1 md5sum.1 nl.1 od.1 paste.1 pr.1 sort.1 split.1 sum.1 tac.1 tail.1 \
    tr.1 unexpand.1 uniq.1 wc.1
    @end example
    
    You can now see how easy it is to handle even a largish project using
    Automake.
    
    
    @node Future
    @chapter Some ideas for the future
    
    Here are some things that might happen in the future:
    
    @itemize @bullet
    @item
    HTML support.
    
    @item
    The output will be cleaned up.  For instance, only variables which are
    actually used will appear in the generated @file{Makefile.in}.
    
    @item
    There will be support for automatically recoding a distribution.  The
    intent is to allow a maintainer to use whatever character set is most
    convenient locally, but for all distributions to be Unicode or
    @w{ISO 10646} with the UTF-8 encoding.
    @end itemize
    
    
    @node Variables
    @unnumbered Index of Variables
    
    @printindex vr
    
    
    @node Configure variables
    @unnumbered Index of Configure Variables and Macros
    
    @printindex cv
    
    
    @node Targets
    @unnumbered Index of Targets
    
    @printindex tr
    
    
    @bye