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kc3-lang/automake/automake.texi

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  • Author : Tom Tromey
    Date : 1996-02-12 06:27:59
    Hash : 8da47dfc
    Message : Can put version in AUTOMAKE_OPTIONS. 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
    
    @ifinfo
    @format
    START-INFO-DIR-ENTRY
    * automake: (automake).		Making Makefile.in's
    END-INFO-DIR-ENTRY
    @end format
    @end ifinfo
    
    @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 @*
    675 Massachusetts Avenue, @*
    Cambridge, MA 02139 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
    
    @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
    * Details::                     Creating an Automake template file
    * Invoking automake::           Creating a Makefile.in
    * Distributing::                Distributing generated Makefile.ins
    * Future::                      Some ideas for the future.
    * Some index::                  Index of variables
    @end menu
    
    @end ifinfo
    
    @node Introduction
    @chapter Introduction
    
    The GNU Makefile Standards Document
    (@pxref{Makefile Conventions, , 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 back the individual GNU maintainer (and put it
    on the back of the Automake maintainer).
    
    Typical Automake input files are simply a series of macro definitions.
    Automake processes these files to produce @file{Makefile.in}s which are
    distribution-ready.
    
    Automake does force some structure on the package maintainer.  However,
    it is felt that this (minor) inconvenience is more than offset by
    Automake's convenience.
    
    
    @node Details
    @chapter Making @code{automake} templates
    
    @menu
    * Generalities::                General overview
    * configure::                   Automake and configure
    * Depth::                       Types of package hierarchy
    * Naming::                      The uniform naming scheme
    * Programs::                    Building programs
    * ANSI::                        Automatic de-ANSI-fication
    * Scripts::                     Building scripts
    * Libraries::                   Building libraries
    * Headers::                     Header files
    * Data::                        Data files.
    * Docs::                        Specifying documentation files
    * Install::                     What gets installed
    * Clean::                       What gets cleaned
    * Distribution::                What gets distributed
    * Tags::                        TAGS files
    * Dependencies::                Automatic dependency tracking
    * Options::                     Setting options.
    * Extending::                   If the defaults aren't enough
    @end menu
    
    @node Generalities
    @section General use of Automake
    
    @code{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 the occasional rule thrown in).  The generated
    @file{Makefile.in}s are compliant with the GNU Makefile standards.
    
    There should be one @file{Makefile.am} per directory of a project
    (though it is possible to incorporate directories that don't use
    @code{automake} if necessary).
    
    @code{automake} assumes the package in question uses @code{autoconf}.
    
    
    @node configure
    @section How @code{automake} and @code{configure} interact
    
    Automake enforces a certain amount of structure on the package
    maintainer.  One such item is its requirement that the
    @file{configure.in} for the package define the variables @samp{PACKAGE}
    and @samp{VERSION}.
    
    @var{PACKAGE} should be the name of the package as it appears when
    bundled for distribution.  For instance, Automake defines @samp{PACKAGE}
    to be @samp{automake}.
    
    @var{VERSION} should be the version number of the release being worked
    on.  We recommend that you make @file{configure.in} the only place you
    define the version number for your package; this makes releases simpler.
    
    Here is an example of what to put in @file{configure.in}:
    
    @example
    PACKAGE=cpio
    VERSION=2.3.911
    AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE")
    AC_DEFINE_UNQUOTED(VERSION, "$VERSION")
    AC_SUBST(PACKAGE)
    AC_SUBST(VERSION)
    @end example
    
    @code{automake} also assumes that your @file{configure} script will
    define the variable @samp{INSTALL_SCRIPT}.  Until this is incorporated
    in @code{autoconf}'s @samp{AC_PROG_INSTALL} macro, you can use this
    replacement instead:
    
    @example
    ## --------------------------------------------------------- ##
    ## Use AC_PROG_INSTALL, supplementing it with INSTALL_SCRIPT ##
    ## substitution.                                             ##
    ## --------------------------------------------------------- ##
    
    AC_DEFUN(fp_PROG_INSTALL,
    [AC_PROG_INSTALL
    test -z "$INSTALL_SCRIPT" && INSTALL_SCRIPT='$@{INSTALL@} -m 755'
    AC_SUBST(INSTALL_SCRIPT)dnl
    ])
    @end example
    
    @code{automake} requires this macro if you install any scripts.
    Otherwise only @code{AC_PROG_INSTALL} is required.
    
    @code{automake} also assumes your @file{configure.in} calls
    @samp{AC_ARG_PROGRAM}.
    
    
    @node Depth
    @section Types of directory hierarchy
    
    @code{automake} supports three kinds of directory hierarcy: ``flat'',
    ``shallow'', and ``deep''.
    
    A 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
    @samp{SUBDIRS} macro.  An example of such a package is @code{termutils}.
    
    A 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}, although
    it does not presently use @code{automake}).  The top level
    @file{Makefile.am} for a deep package will contain a @samp{SUBDIRS}
    macro, but no other macros to define objects which are built.
    Typically, @samp{PROGRAMS} is defined in @file{src/Makefile.am}.
    
    A 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}).
    
    
    The @samp{SUBDIRS} macro holds a list of subdirectories in which
    building of various sorts can occur.  Many targets (eg @samp{all}) in
    the generated @file{Makefile} will run both locally and in all specified
    subdirectories.  Note that the directories listed in @samp{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 @code{automake} (such as @code{gettext}).
    
    If @samp{SUBDIRS} is defined, then your @file{configure.in} must include
    @code{AC_PROG_MAKE_SET}.
    
    FIXME supply complete list of recursive targets?
    
    
    @node Naming
    @section The uniform naming scheme
    
    @code{Automake} uses a uniform naming scheme to make it easy to decide
    how programs are built, and how they are installed.  This scheme also
    supports @code{configure}-time determination of what should be built.
    
    There are certain variables which are used at @code{make} time to
    determine which objects are to be built.  For instance, @samp{PROGRAMS}
    holds a list of programs which are to be compiled and linked.  These
    variables are called ``primary'' variables.
    
    A different set of variables are 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 (FIXME xref).  @code{automake} extends this
    list with @samp{pkglibdir}, @samp{pkgincludedir}, and @samp{pkgdatadir};
    these are the same as the non-@samp{pkg} versions, but with
    @code{@@PACKAGE@@} appended.
    
    For instance, @code{cpio} decides at configure time which programs are
    built.  Some of the programs are installed in @samp{bindir}, and some
    are installed in @samp{sbindir}:
    
    @example
    PROGRAMS = @@PROGRAMS@@
    bin_PROGRAMS = cpio pax
    sbin_PROGRAMS = rmt mt
    @end example
    
    Note that the common ``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.
    @code{automake} will flag those attempts it finds in error.
    
    The special prefix @code{noinst} indicates that the objects in question
    should not be installed at all.
    
    Possible primary names are @samp{PROGRAMS}, @samp{LIBRARIES},
    @samp{SCRIPTS}, @samp{DATA}, @samp{HEADERS}, @samp{MANS}, and
    @samp{TEXINFOS}.
    
    
    @node Programs
    @section Which Programs Are Built
    
    In a directory containing source that gets built into a program (as
    opposed to a library), the @samp{PROGRAMS} variable is used:
    
    @example
    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
    @samp{@var{prog}_SOURCES} is used to specify which source files get built
    into an executable:
    
    @example
    hello_SOURCES = hello.c
    @end example
    
    This causes @file{hello.o} to be built from @code{hello.c} at compile
    time, and then linked into @file{hello}.
    
    If @samp{@var{prog}_SOURCES} is not specified, then it defaults to the
    single file @samp{@var{prog}.c}.
    
    Multiple programs can be built in a single directory -- simply list them
    all in the @samp{PROGRAMS} definition.  Multiple programs can share a
    single source file.  The source file must be listed in each ``_SOURCES''
    definition.
    
    Sometimes it is useful to determine the programs that are to be built at
    configure time.  For instance, GNU @code{cpio} only builts @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 trivially by making the @code{PROGRAMS} variable determined
    at configure time, and letting @code{automake} look in the install
    variables for the static list of programs.
    
    If you need to link against libraries that are not found by
    @code{configure}, you can use @samp{LDADD} to do so.  This variable
    actually can be used to add any options to the linker command line.
    
    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 @samp{PROGRAMS}) to override the global
    @samp{LDADD}.  (If this variable exists for a given program, then that
    program is not linked using @samp{LDADD}.)
    
    For instance, in GNU @code{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.  Thus:
    
    @example
    LDADD = ../lib/libcpio.a @@INTLLIBS@@
    rmt_LDADD =
    @end example
    
    @node Scripts
    @section Programs Which are Scripts
    
    It is possible to define and install programs which are scripts.  Such
    programs should be listed in the @samp{SCRIPTS} variable.
    @code{automake} doesn't define any dependencies for scripts; the
    @file{Makefile.am} should include the appropriate rules.
    
    @code{automake} does assume that objects listed in the @samp{SCRIPTS}
    macro are derived objects; such objects are deleted by @code{make clean}.
    
    @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
    
    FIXME xref to rebuilding things listed in AC_OUTPUT
    
    Script objects can be installed in @samp{bindir}, @samp{sbindir}, or
    @samp{libexecdir}.
    
    
    @node Libraries
    @section Building Libraries
    
    The @samp{LIBRARIES} variable holds the names of libraries to be built
    in the current directory.
    
    For a given library @samp{zot}, the sources are taken to be in
    @samp{zot_SOURCES}, just as for programs.  Note that libraries and
    programs share one namespace in @code{automake}: one directory cannot
    contain both a library (``liblob.a'') and a program (``lob'') with the
    same name.
    
    Here is how the @file{libcpio.a} library is built in the GNU @code{cpio}
    distribution's @file{lib} subdirectory:
    
    @example
    noinst_LIBRARIES = cpio
    cpio_SOURCES = dirname.c dstring.c error.c filemode.c \
    getopt.c getopt1.c idcache.c makepath.c octal.c \
    stpcpy.c stripslash.c userspec.c xmalloc.c xstrdup.c
    @end example
    
    Extra objects can be added to a library using the @code{library_LIBADD}
    variable.  This should be used for objects determined by
    @code{configure}.  Again from @code{cpio}:
    
    @example
    cpio_LIBADD = @@LIBOBJS@@ @@ALLOCA@@
    @end example
    
    Library objects can be installed in @samp{libdir} or @samp{pkglibdir}.
    
    
    @node Headers
    @section Header files
    
    Header files are specified by the @samp{HEADERS} family of variables.
    Generally header files are not installed, so the @samp{noinst_HEADERS}
    variable will be the most used.
    
    All header files must be listed somewhere; missing ones will not appear
    in the distribution.
    
    You can also put conditionally compiled source file names into a
    @samp{HEADERS} variable.  (This will probably change in a future
    release).
    
    
    @node Data
    @section Architecture-independent data files
    
    @code{automake} supports the installation of miscellaneous data files
    using the @samp{DATA} family of variables.
    
    Such data can be installed in the directories @code{datadir},
    @code{sysconfdir}, @code{sharedstatedir}, @code{localstatedir}, or
    @code{pkgdatadir}.
    
    All such data files are included in the distribution.  (FIXME, this is
    probably a bug)
    
    Here is how @code{autoconf} 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 Docs
    @section Texinfo and Man Pages
    
    @subsection 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 @samp{info_TEXINFOS} macro is most commonly used
    here.
    Note that any Texinfo source file must end in the @file{.texi} extension
    (@file{.texinfo} won't work).
    
    If the @file{.texi} file ``@@include''s @file{version.texi}, then that
    file will be automatically generated.  @file{version.texi} defines three
    Texinfo macros you can reference: @samp{EDITION}, @samp{VERSION}, and
    @samp{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 a version of @code{date} that
    accepts the @samp{-r} (read time from a file) option.
    
    Sometimes an info file actually depends on more than one @file{.texi}
    file.  For instance, in the @samp{xdvik} distribution,
    @file{kpathsea.texi} includes the files @file{install.texi},
    @file{copying.texi}, and @file{freedom.texi}.  You can tell
    @code{automake} about these dependencies using the @samp{texi_TEXINFOS}
    variable.  Here is how @samp{xdvik} could do it:
    
    @example
    info_TEXINFOS = kpathsea.texi
    kpathsea_TEXINFOS = install.texi copying.texi freedom.texi
    @end example
    
    @code{automake} might be modified to detect these dependencies
    automatically.
    
    Currently @code{automake} can only handle one primary @file{.texi} file.
    This restriction will be lifted if it proves too onerous.
    
    @code{automake} will warn if a directory containing Texinfo source does
    not also contain the file @file{texinfo.tex}.  (I'm not sure if this is
    a good rule or not.  Comments?)
    
    In the future, @code{automake} will probably be modified to support
    generating @samp{HTML} from Texinfo source.
    
    
    @subsection Man pages
    A package can also include man pages.  (Though see the GNU standards on
    this matter.  FIXME xref).
    Man pages are declared using the @samp{MANS} primary.  Generally the
    @samp{man_MANS} macro is used.
    
    By default, man pages are installed by @code{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
    @samp{no-installman} option will prevent the man pages from being
    installed by default.  (The user can still install them via
    @code{make install-man})
    
    
    Here is how the documentation is handled in GNU @code{cpio} (which includes
    both Texinfo documentation and man pages):
    
    @example
    TEXINFOS = cpio.texi
    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 ANSI
    @section Automatic de-ANSI-fication of Source
    
    If the @samp{AUTOMAKE_OPTIONS} variable contains the @samp{ansi2knr}
    option, then code to handle automatic de-ANSI-fication is included in
    the generated @file{Makefile.in}.  This will also happen if
    @file{Makefile.am} includes the text @samp{@@kr@@}, but this use is
    deprecated and will go away eventually.
    
    @c FIXME xref to options here.
    
    This means that each C source file will be treated as ANSI C.  If no
    ANSI C compiler is available on the build system, then the code will be
    turned into K&R C before compilation.
    
    Each directory that uses automatic de-ANSI-fication must include the
    source files @file{ansi2knr.c} and @file{ansi2knr.1}.  Also, your
    @file{configure} script must define the variables @samp{U} and
    @samp{ANSI2KNR}.  Here is a snippet you can add to @file{aclocal.m4} to
    achieve this:
    
    @example
    ## ------------------------------- ##
    ## Check for function prototypes.  ##
    ## ------------------------------- ##
    
    AC_DEFUN(fp_C_PROTOTYPES,
    [AC_REQUIRE([fp_PROG_CC_STDC])
    AC_MSG_CHECKING([for function prototypes])
    if test "$ac_cv_prog_cc_stdc" != no; then
      AC_MSG_RESULT(yes)
      AC_DEFINE(PROTOTYPES)
      U= ANSI2KNR=
    else
      AC_MSG_RESULT(no)
      U=_ ANSI2KNR=./ansi2knr
    fi
    AC_SUBST(U)dnl
    AC_SUBST(ANSI2KNR)dnl
    ])
    
    
    ## ----------------------------------------- ##
    ## ANSIfy the C compiler whenever possible.  ##
    ## ----------------------------------------- ##
    
    # @@defmac AC_PROG_CC_STDC
    # @@maindex PROG_CC_STDC
    # @@ovindex CC
    # If the C compiler in not in ANSI C mode by default, try to add an option
    # to output variable @@code@{CC@} to make it so.  This macro tries various
    # options that select ANSI C on some system or another.  It considers the
    # compiler to be in ANSI C mode if it defines @@code@{__STDC__@} to 1 and
    # handles function prototypes correctly.
    #
    # If you use this macro, you should check after calling it whether the C
    # compiler has been set to accept ANSI C; if not, the shell variable
    # @@code@{ac_cv_prog_cc_stdc@} is set to @@samp@{no@}.  If you wrote your source
    # code in ANSI C, you can make an un-ANSIfied copy of it by using the
    # program @@code@{ansi2knr@}, which comes with Ghostscript.
    # @@end defmac
    
    AC_DEFUN(fp_PROG_CC_STDC,
    [AC_MSG_CHECKING(for $@{CC-cc@} option to accept ANSI C)
    AC_CACHE_VAL(ac_cv_prog_cc_stdc,
    [ac_cv_prog_cc_stdc=no
    ac_save_CFLAGS="$CFLAGS"
    # Don't try gcc -ansi; that turns off useful extensions and
    # breaks some systems' header files.
    # AIX			-qlanglvl=ansi
    # Ultrix and OSF/1	-std1
    # HP-UX			-Aa -D_HPUX_SOURCE
    # SVR4			-Xc
    for ac_arg in "" -qlanglvl=ansi -std1 "-Aa -D_HPUX_SOURCE" -Xc
    do
      CFLAGS="$ac_save_CFLAGS $ac_arg"
      AC_TRY_COMPILE(
    [#if !defined(__STDC__) || __STDC__ != 1
    choke me
    #endif
    ], [int test (int i, double x);
    struct s1 @{int (*f) (int a);@};
    struct s2 @{int (*f) (double a);@};],
    [ac_cv_prog_cc_stdc="$ac_arg"; break])
    done
    CFLAGS="$ac_save_CFLAGS"
    ])
    AC_MSG_RESULT($ac_cv_prog_cc_stdc)
    case "x$ac_cv_prog_cc_stdc" in
      x|xno) ;;
      *) CC="$CC $ac_cv_prog_cc_stdc" ;;
    esac
    ])
    @end example
    
    
    @node Install
    @section What Gets Installed
    
    Naturally, @code{automake} handles the details of actually installing
    your program once it has been built.  All @code{PROGRAMS},
    @code{SCRIPTS}, @code{LIBRARIES}, @code{DATA} and @code{HEADERS} are
    automatically installed in the appropriate places.
    
    @code{automake} also handles installing any specified info and man
    pages.
    
    FIXME xref to Extending node here; sometimes you need to install more.
    
    @code{automake} generates separate @samp{install-data} and
    @samp{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.
    
    @code{automake} also generates an @samp{uninstall} target, and an
    @samp{installdirs} target.
    
    
    @node Clean
    @section Clean targets
    
    The GNU Makefile Standards specify a number of different clean rules.
    Generally the files that can cleaned are determined automatically by
    @code{automake}.  Of course, @code{automake} also recognizes some
    variables that can be defined to specify additional files to clean.
    These variables are @samp{MOSTLYCLEANFILES}, @samp{CLEANFILES},
    @samp{DISTCLEANFILES}, and @samp{MAINTAINERCLEANFILES}.
    
    
    @node Distribution
    @section Building a Release
    
    The @samp{dist} target in the generated @file{Makefile.in} can be used
    to generate a gzip'd tar file for distribution.  The tar file is named
    based on the @var{PACKAGE} and @var{VERSION} variables.
    
    For the most part, the files to distribute are automatically found by
    @code{automake}: all source files are automatically included in a
    distribution, as are all @file{Makefile.am}s and @file{Makefile.in}s.
    @code{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 @code{automake --help}.
    
    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 @samp{DIST_OTHER} variable.
    
    For instance, in the @code{automake} distribution,
    @file{automake.in} (the source to
    @code{automake}) is not found automatically.  So in the
    @file{Makefile.am}, we have:
    
    @example
    DIST_OTHER = automake.in
    @end example
    
    FIXME: describe DIST_SUBDIRS or not?  It is a hack which might go away.
    
    @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 @file{TAGS} file
    will be generated for the directory.
    
    At the topmost directory of a multi-directory package, a @file{TAGS}
    file will be generated that will include by reference all @file{TAGS}
    files from subdirectories.
    
    Also, if the variable @samp{ETAGS_ARGS} is defined, a @file{TAGS} file
    will be generated.  This variable is intended for use in directories
    which contain taggable source that @code{etags} does not understand.
    
    Here is how @code{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
    
    
    @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 @code{GNU 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 @samp{dist} target will
    re-run @code{automake} with the @samp{--include-deps} option.  This
    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 @samp{no-dependencies} in the
    variable @samp{AUTOMAKE_OPTIONS}.
    
    
    @node Options
    @section Setting options
    
    Various features of Automake can be controlled by options in the
    @file{Makefile.am}.  Such options are listed in a special variable named
    @samp{AUTOMAKE_OPTIONS}.  Currently understood options are:
    
    @table @samp
    @item gnits
    @item gnu
    @item normal
    The same as the corresponding @samp{--strictness} option.
    
    @item no-installman
    The generated @file{Makefile.in} will not cause man pages to be
    installed by default.  However, an @samp{install-man} target will still
    be available for optional installation.
    
    @item ansi2knr
    Turn on automatic de-ANSI-fication.
    
    @item dist-shar
    Generate a @samp{dist-shar} target as well as the ordinary @samp{dist}
    target.
    
    @item 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 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
    
    @node Extending
    @section 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.  You can't overload a target
    already used by @code{automake}.  However, various useful targets have a
    ``-local'' version you can specify in your @file{Makefile.in}.
    
    The targets that support a local version are @samp{all}, @samp{info},
    @samp{dvi}, @samp{check}, @samp{install-data}, @samp{install-exec}, and
    @samp{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
    
    
    @node Invoking automake
    @chapter Using @code{automake} to Create @file{Makefile.in}
    
    There are basically two modes in which @code{automake} can be run.
    
    In the first, most common, mode, @code{automake} is simply run without
    any arguments.  It will determine which @file{Makefile.am}s exist by
    looking in the current directory and immediate subdirectories, and will
    automatically build @file{Makefile.in}s in these directories.
    
    In the second mode, @code{automake} is run with the name of one or more
    @file{Makefile}s as arguments.  It then rebuilds the corresponding
    @file{Makefile.in}s from the (also) corresponding @file{Makefile.am}s.
    This second mode is most often used by @code{make} itself, when it
    notices that a @code{Makefile.in} is out of date.
    
    
    @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{--install-missing} switch do fall under the GPL; examine each file
    to see.
    
    
    @node Future
    @chapter Some ideas for the future
    
    Here are some things that might happen in the future:
    
    @itemize @bullet
    @item
    Better error checking would be good.  Automake has been moving in this
    direction for a while.
    
    @item
    The manual could stand updating.
    
    @item
    HTML support.
    
    @item
    The output will be cleaned up.
    @end itemize
    
    @node Some index
    @chapter Nothing yet
    
    @bye
    
    NOTES:
    
    * Need section on operation of automake: it reads Makefile.am and COPIES
    the contents.  This section should include info on SUFFIXES, because
    that is usually only needed when copying in additional targets (?)