--gnu and --gnits
--cygnus
Automake is a tool for automatically generating `Makefile.in's from
files called `Makefile.am'. Each `Makefile.am' is basically a
series of make macro definitions (with rules being thrown in
occasionally). The generated `Makefile.in's are compliant with the
GNU Makefile standards.
The GNU Makefile Standards Document (see section `Makefile Conventions' in 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 file is simply a series of macro definitions. Each such file is processed to create a `Makefile.in'. There should generally be one `Makefile.am' per directory of a project.
Automake does constrain a project in certain ways; for instance it assumes that the project uses Autoconf (see section `Introduction' in The Autoconf Manual), and enforces certain restrictions on the `configure.in' contents.
Automake requires perl in order to generate the
`Makefile.in's. However, the distributions created by Automake are
fully GNU standards-compliant, and do not require perl in order
to be built.
Mail suggestions and bug reports for Automake to bug-automake@gnu.org.
The following sections cover a few basic ideas that will help you understand how Automake works.
Automake works by reading a `Makefile.am' and generating a `Makefile.in'. Certain macros and targets defined in the `Makefile.am' instruct Automake to generate more specialized code; for instance, a `bin_PROGRAMS' macro definition will cause targets for compiling and linking programs to be generated.
The macro definitions and targets in the `Makefile.am' are copied
verbatim into the generated file. This allows you to add arbitrary code
into the generated `Makefile.in'. For instance the Automake
distribution includes a non-standard 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 `Makefile.am' will lead to errors or confusing behavior.
Automake tries to group comments with adjoining targets and macro definitions in an intelligent way.
A target defined in `Makefile.am' generally overrides any such
target of a similar name that would be automatically generated by
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.
Similarly, a macro defined in `Makefile.am' will override any
definition of the macro that automake would ordinarily create.
This feature is more often useful than the ability to override a target
definition. Be warned that many of the macros generated by
automake are considered to be for internal use only, and their
names might change in future releases.
When examining a macro definition, Automake will recursively examine
macros referenced in the definition. For example, if Automake is
looking at the content of foo_SOURCES in this snippet
xs = a.c b.c foo_SOURCES = c.c $(xs)
it would use the files `a.c', `b.c', and `c.c' as the
contents of foo_SOURCES.
Automake also allows a form of comment which is not copied into the output; all lines beginning with `##' are completely ignored by Automake.
It is customary to make the first line of `Makefile.am' read:
## Process this file with automake to produce Makefile.in
automake supports three kinds of directory hierarchy:
`flat', `shallow', and `deep'.
A flat package is one in which all the files are in a single
directory. The `Makefile.am' for such a package by definition
lacks a SUBDIRS macro. An example of such a package is
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 tar. The top level `Makefile.am' for a deep package
will contain a SUBDIRS macro, but no other macros to define
objects which are built.
A shallow package is one in which the primary source resides in
the top-level directory, while various parts (typically libraries)
reside in subdirectories. Automake is one such package (as is GNU
make, which does not currently use automake).
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 strictness---the strictness indicating how stringently Automake should check standards conformance.
The valid strictness levels are:
For more information on the precise implications of the strictness
level, see section The effect of --gnu and --gnits.
Automake macros (from here on referred to as 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 configure time
determination of what should be built.
At make time, certain variables are used to determine which
objects are to be built. These variables are called primary
variables. For instance, the primary variable PROGRAMS holds a
list of programs which are to be compiled and linked.
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 (see section `Directory Variables' in The GNU Coding Standards). Automake extends this list with
pkglibdir, pkgincludedir, and pkgdatadir; these are
the same as the non-`pkg' versions, but with `@PACKAGE@'
appended. For instance, pkglibdir is defined as
$(datadir)/@PACKAGE@.
For each primary, there is one additional variable named by prepending
`EXTRA_' to the primary name. This variable is used to list
objects which may or may not be built, depending on what
configure decides. This variable is required because Automake
must statically know the entire list of objects that may be built in
order to generate a `Makefile.in' that will work in all cases.
For instance, cpio decides at configure time which programs are
built. Some of the programs are installed in bindir, and some
are installed in sbindir:
EXTRA_PROGRAMS = mt rmt bin_PROGRAMS = cpio pax sbin_PROGRAMS = @PROGRAMS@
Defining a primary variable without a prefix (e.g. PROGRAMS) is
an error.
Note that the common `dir' suffix is left off when constructing the variable names; thus one writes `bin_PROGRAMS' and not `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 (e.g. `zar') is valid if a variable of
the same name with `dir' appended is defined (e.g. zardir).
For instance, until HTML support is part of Automake, you could use this to install raw HTML documentation:
htmldir = $(prefix)/html html_DATA = automake.html
The special prefix `noinst' indicates that the objects in question should not be installed at all.
The special prefix `check' indicates that the objects in question
should not be built until the make check command is run.
Possible primary names are `PROGRAMS', `LIBRARIES', `LISP', `SCRIPTS', `DATA', `HEADERS', `MANS', and `TEXINFOS'.
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 macro naming rules. All characters in the name except
for letters, numbers, and the underscore are turned into underscores
when making macro references. For example, if your program is named
sniff-glue, the derived variable name would be
sniff_glue_SOURCES, not sniff-glue_SOURCES.
Let's suppose you just finished writing zardoz, a program to make
your head float from vortex to vortex. You've been using Autoconf to
provide a portability framework, but your `Makefile.in's have been
ad-hoc. You want to make them bulletproof, so you turn to Automake.
The first step is to update your `configure.in' to include the
commands that automake needs. The simplest way to do this is to
add an AM_INIT_AUTOMAKE call just after AC_INIT:
AM_INIT_AUTOMAKE(zardoz, 1.0)
Since your program doesn't have any complicating factors (e.g., it
doesn't use gettext, it doesn't want to build a shared library),
you're done with this part. That was easy!
Now you must regenerate `configure'. But to do that, you'll need
to tell autoconf how to find the new macro you've used. The
easiest way to do this is to use the aclocal program to generate
your `aclocal.m4' for you. But wait... you already have an
`aclocal.m4', because you had to write some hairy macros for your
program. The aclocal program lets you put your own macros into
`acinclude.m4', so simply rename and then run:
mv aclocal.m4 acinclude.m4 aclocal autoconf
Now it is time to write your `Makefile.am' for zardoz.
Since zardoz is a user program, you want to install it where the
rest of the user programs go. Additionally, zardoz has some
Texinfo documentation. Your `configure.in' script uses
AC_REPLACE_FUNCS, so you need to link against `@LIBOBJS@'.
So here's what you'd write:
bin_PROGRAMS = zardoz zardoz_SOURCES = main.c head.c float.c vortex9.c gun.c zardoz_LDADD = @LIBOBJS@ info_TEXINFOS = zardoz.texi
Now you can run automake --add-missing to generate your
`Makefile.in' and grab any auxiliary files you might need, and
you're done!
GNU hello is renowned for its classic simplicity and versatility. This section shows how Automake could be used with the GNU Hello package. The examples below are from the latest beta version of GNU Hello, but with all of the maintainer-only code stripped out, as well as all copyright comments.
Of course, GNU Hello is somewhat more featureful than your traditional two-liner. GNU Hello is internationalized, does option processing, and has a manual and a test suite. GNU Hello is a deep package.
Here is the `configure.in' from GNU Hello:
dnl Process this file with autoconf to produce a configure script.
AC_INIT(src/hello.c)
AM_INIT_AUTOMAKE(hello, 1.3.11)
AM_CONFIG_HEADER(config.h)
dnl Set of available languages.
ALL_LINGUAS="de fr es ko nl no pl pt sl sv"
dnl Checks for programs.
AC_PROG_CC
AC_ISC_POSIX
dnl Checks for libraries.
dnl Checks for header files.
AC_STDC_HEADERS
AC_HAVE_HEADERS(string.h fcntl.h sys/file.h sys/param.h)
dnl Checks for library functions.
AC_FUNC_ALLOCA
dnl Check for st_blksize in struct stat
AC_ST_BLKSIZE
dnl internationalization macros
AM_GNU_GETTEXT
AC_OUTPUT([Makefile doc/Makefile intl/Makefile po/Makefile.in \
src/Makefile tests/Makefile tests/hello],
[chmod +x tests/hello])
The `AM_' macros are provided by Automake (or the Gettext library); the rest are standard Autoconf macros.
The top-level `Makefile.am':
EXTRA_DIST = BUGS ChangeLog.O SUBDIRS = doc intl po src tests
As you can see, all the work here is really done in subdirectories.
The `po' and `intl' directories are automatically generated
using gettextize; they will not be discussed here.
In `doc/Makefile.am' we see:
info_TEXINFOS = hello.texi hello_TEXINFOS = gpl.texi
This is sufficient to build, install, and distribute the GNU Hello manual.
Here is `tests/Makefile.am':
TESTS = hello EXTRA_DIST = hello.in testdata
The script `hello' is generated by configure, and is the
only test case. make check will run this test.
Last we have `src/Makefile.am', where all the real work is done:
bin_PROGRAMS = hello hello_SOURCES = hello.c version.c getopt.c getopt1.c getopt.h system.h hello_LDADD = @INTLLIBS@ @ALLOCA@ localedir = $(datadir)/locale INCLUDES = -I../intl -DLOCALEDIR=\"$(localedir)\"
Here is another, trickier example. It shows how to generate two
programs (ctags and etags) from the same source file
(`etags.c'). The difficult part is that each compilation of
`etags.c' requires different cpp flags.
bin_PROGRAMS = etags ctags
ctags_SOURCES =
ctags_LDADD = ctags.o
etags.o: etags.c
$(COMPILE) -DETAGS_REGEXPS -c etags.c
ctags.o: etags.c
$(COMPILE) -DCTAGS -o ctags.o -c etags.c
Note that ctags_SOURCES is defined to be empty--that way no
implicit value is substituted. The implicit value, however, is used to
generate etags from `etags.o'.
ctags_LDADD is used to get `ctags.o' into the link line.
ctags_DEPENDENCIES is generated by Automake.
The above rules won't work if your compiler doesn't accept both
`-c' and `-o'. The simplest fix for this is to introduce a
bogus dependency (to avoid problems with a parallel make):
etags.o: etags.c ctags.o
$(COMPILE) -DETAGS_REGEXPS -c etags.c
ctags.o: etags.c
$(COMPILE) -DCTAGS -c etags.c && mv etags.o ctags.o
Also, these explicit rules do not work if the de-ANSI-fication feature is used (see section Automatic de-ANSI-fication). Supporting de-ANSI-fication requires a little more work:
etags._o: etags._c ctags.o
$(COMPILE) -DETAGS_REGEXPS -c etags.c
ctags._o: etags._c
$(COMPILE) -DCTAGS -c etags.c && mv etags._o ctags.o
To create all the `Makefile.in's for a package, run the
automake program in the top level directory, with no arguments.
automake will automatically find each appropriate
`Makefile.am' (by scanning `configure.in'; see section Scanning `configure.in')
and generate the corresponding `Makefile.in'. Note that
automake has a rather simplistic view of what constitutes a
package; it assumes that a package has only one `configure.in', at
the top. If your package has multiple `configure.in's, then you
must run automake in each directory holding a
`configure.in'.
You can optionally give automake an argument; `.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 `Makefile.in'. Note that automake must always
be run from the topmost directory of a project, even if being used to
regenerate the `Makefile.in' in some subdirectory. This is
necessary because automake must scan `configure.in', and
because automake uses the knowledge that a `Makefile.in' is
in a subdirectory to change its behavior in some cases.
automake accepts the following options:
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. By default Automake tries to
make a symbolic link pointing to its own copy of the missing file; this
can be changed with --copy.
make
dist; it should not be used otherwise.
--add-missing, causes installed files to be
copied. The default is to make a symbolic link.
--cygnus.
--gnu and --gnits.
--gnu and --gnits. This is the default strictness.
automake creates all `Makefile.in's mentioned in
`configure.in'. This option causes it to only update those
`Makefile.in's which are out of date with respect to one of their
dependents.
make dist; it should not be used
otherwise.
Automake scans the package's `configure.in' to determine certain
information about the package. Some autoconf macros are required
and some variables must be defined in `configure.in'. Automake
will also use information from `configure.in' to further tailor its
output.
Automake also supplies some Autoconf macros to make the maintenance
easier. These macros can automatically be put into your
`aclocal.m4' using the aclocal program.
The simplest way to meet the basic Automake requirements is to use the
macro AM_INIT_AUTOMAKE (see section Autoconf macros supplied with Automake). But if you prefer, you
can do the required steps by hand:
PACKAGE and VERSION with
AC_SUBST.
PACKAGE should be the name of the package as it appears when
bundled for distribution. For instance, Automake defines PACKAGE
to be `automake'. VERSION should be the version number of
the release that is being developed. We recommend that you make
`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 PACKAGE or
VERSION, except in `Gnits' mode (see section The effect of --gnu and --gnits).
AC_ARG_PROGRAM if a program or script is installed.
See section `Transforming Program Names When Installing' in The Autoconf.
AC_PROG_MAKE_SET if the package is not flat. See section `Creating Output Files' in The Autoconf Manual.
AM_SANITY_CHECK to make sure the build environment is sane.
AC_PROG_INSTALL
(see section `Particular Program Checks' in The Autoconf Manual).
AM_MISSING_PROG to see whether the programs aclocal,
autoconf, automake, autoheader, and makeinfo
are in the build environment. Here is how this is done:
missing_dir=`cd $ac_aux_dir && pwd` AM_MISSING_PROG(ACLOCAL, aclocal, $missing_dir) AM_MISSING_PROG(AUTOCONF, autoconf, $missing_dir) AM_MISSING_PROG(AUTOMAKE, automake, $missing_dir) AM_MISSING_PROG(AUTOHEADER, autoheader, $missing_dir) AM_MISSING_PROG(MAKEINFO, makeinfo, $missing_dir)
Here are the other macros which Automake requires but which are not run
by AM_INIT_AUTOMAKE:
AC_OUTPUT
Makefile are treated as `Makefile's. Other listed
files are treated differently. Currently the only difference is that a
`Makefile' is removed by make distclean, while other files
are removed by make clean.
Automake will also recognize the use of certain macros and tailor the generated `Makefile.in' appropriately. Currently recognized macros and their effects are:
AC_CONFIG_HEADER
AM_CONFIG_HEADER, which is similar
to AC_CONFIG_HEADER (see section `Configuration Header Files' in The Autoconf Manual), but does
some useful Automake-specific work.
AC_CONFIG_AUX_DIR
AC_PATH_XTRA
AC_PATH_XTRA into each `Makefile.in' that builds a C program
or library. See section `System Services' in The Autoconf Manual.
AC_CANONICAL_HOST
AC_CHECK_TOOL
AC_CANONICAL_SYSTEM
AC_CANONICAL_HOST, but also defines the
`Makefile' variables `build_alias' and `target_alias'.
See section `Getting the Canonical System Type' in The Autoconf Manual.
AC_FUNC_ALLOCA
AC_FUNC_GETLOADAVG
AC_FUNC_MEMCMP
AC_STRUCT_ST_BLOCKS
AC_FUNC_FNMATCH
AM_FUNC_STRTOD
AC_REPLACE_FUNCS
AC_REPLACE_GNU_GETOPT
AM_WITH_REGEX
automake -a will not install the sources.
See section Building a library, for more information. Also, see section `Particular Function Checks' in The Autoconf Manual.
LIBOBJS
LIBOBJS, and will treat these additional files as if they were
discovered via AC_REPLACE_FUNCS. See section `Generic Function Checks' in The Autoconf Manual.
AC_PROG_RANLIB
AC_PROG_CXX
AC_PROG_F77
AC_F77_LIBRARY_LDFLAGS
AM_PROG_LIBTOOL
libtool (see section `Introduction' in The Libtool Manual).
AC_PROG_YACC
AC_DECL_YYTEXT
AC_PROG_LEX
ALL_LINGUAS
AM_C_PROTOTYPES
AM_GNU_GETTEXT
AM_MAINTAINER_MODE
configure. If this is used, automake will cause
`maintainer-only' rules to be turned off by default in the
generated `Makefile.in's. This macro is disallowed in `Gnits'
mode (see section The effect of --gnu and --gnits). This macro defines the `MAINTAINER_MODE'
conditional, which you can use in your own `Makefile.am'.
AC_SUBST
AC_CHECK_TOOL
AC_CHECK_PROG
AC_CHECK_PROGS
AC_PATH_PROG
AC_PATH_PROGS
Automake includes a number of Autoconf macros which can be used in your
package; some of them are actually required by Automake in certain
situations. These macros must be defined in your `aclocal.m4';
otherwise they will not be seen by autoconf.
The aclocal program will automatically generate `aclocal.m4'
files based on the contents of `configure.in'. This provides a
convenient way to get Automake-provided macros, without having to
search around. Also, the aclocal mechanism is extensible for use
by other packages.
At startup, aclocal scans all the `.m4' files it can find,
looking for macro definitions. Then it scans `configure.in'. Any
mention of one of the macros found in the first step causes that macro,
and any macros it in turn requires, to be put into `aclocal.m4'.
The contents of `acinclude.m4', if it exists, are also automatically included in `aclocal.m4'. This is useful for incorporating local macros into `configure'.
aclocal accepts the following options:
--acdir=dir
--help
-I dir
--output=file
--print-ac-dir
aclocal will search to
find the `.m4' files. When this option is given, normal processing
is suppressed. This option can be used by a package to determine where
to install a macro file.
--verbose
--version
AM_CONFIG_HEADER
AM_ENABLE_MULTILIB
AM_FUNC_STRTOD
strtod function is not available, or does not work
correctly (like the one on SunOS 5.4), add `strtod.o' to output
variable LIBOBJS.
AM_FUNC_ERROR_AT_LINE
error_at_line is not found, then add
`error.o' to LIBOBJS.
AM_FUNC_MKTIME
mktime function. If not found, add
`mktime.o' to `LIBOBJS'.
AM_FUNC_OBSTACK
AM_C_PROTOTYPES
AM_HEADER_TIOCGWINSZ_NEEDS_SYS_IOCTL
TIOCGWINSZ requires `<sys/ioctl.h>', then
define GWINSZ_IN_SYS_IOCTL. Otherwise TIOCGWINSZ can be
found in `<termios.h>'.
AM_INIT_AUTOMAKE
AC_DEFINE's `PACKAGE' and `VERSION'. This
can be avoided by passing in a non-empty third argument.
AM_PATH_LISPDIR
emacs, and, if found, sets the output
variable lispdir to the full path to Emacs' site-lisp directory.
AM_PROG_CC_STDC
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 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
am_cv_prog_cc_stdc is set to `no'. If you wrote your source
code in ANSI C, you can make an un-ANSIfied copy of it by using the
ansi2knr option (see section Automatic de-ANSI-fication).
AM_PROG_LEX
AC_PROG_LEX with AC_DECL_YYTEXT (see section `Particular Program Checks' in The Autoconf Manual),
but uses the missing script on systems that do not have
lex. `HP-UX 10' is one such system.
AM_SANITY_CHECK
AM_INIT_AUTOMAKE.
AM_SYS_POSIX_TERMIOS
am_cv_sys_posix_termios to
`yes'. If not, set the variable to `no'.
AM_TYPE_PTRDIFF_T
AM_WITH_DMALLOC
WITH_DMALLOC and add `-ldmalloc' to LIBS.
AM_WITH_REGEX
configure command line. If
specified (the default), then the `regex' regular expression
library is used, `regex.o' is put into `LIBOBJS', and
`WITH_REGEX' is defined.. If `--without-regex' is given, then
the `rx' regular expression library is used, and `rx.o' is put
into `LIBOBJS'.
The aclocal program doesn't have any built-in knowledge of any
macros, so it is easy to extend it with your own macros.
This is mostly used for libraries which want to supply their own
Autoconf macros for use by other programs. For instance the
gettext library supplies a macro AM_GNU_GETTEXT which
should be used by any package using gettext. When the library is
installed, it installs this macro so that aclocal will find it.
A file of macros should be a series of AC_DEFUN's. The
aclocal programs also understands AC_REQUIRE, so it is
safe to put each macro in a separate file. See section `Prerequisite Macros' in The Autoconf Manual, and section `Macro Definitions' in The Autoconf Manual.
A macro file's name should end in `.m4'. Such files should be installed in `$(datadir)/aclocal'.
In non-flat packages, the top level `Makefile.am' must tell
Automake which subdirectories are to be built. This is done via the
SUBDIRS variable.
The SUBDIRS macro holds a list of subdirectories in which
building of various sorts can occur. Many targets (e.g. all) in
the generated `Makefile' will run both locally and in all specified
subdirectories. Note that the directories listed in SUBDIRS are
not required to contain `Makefile.am's; only `Makefile's
(after configuration). This allows inclusion of libraries from packages
which do not use Automake (such as gettext). The directories
mentioned in SUBDIRS must be direct children of the current
directory. For instance, you cannot put `src/subdir' into
SUBDIRS.
In a deep package, the top-level `Makefile.am' is often very short. For instance, here is the `Makefile.am' from the GNU Hello distribution:
EXTRA_DIST = BUGS ChangeLog.O README-alpha SUBDIRS = doc intl po src tests
It is possible to override the SUBDIRS variable if, like in the
case of GNU Inetutils, you want to only build a subset of the
entire package. In your `Makefile.am' include:
SUBDIRS = @SUBDIRS@
Then in your `configure.in' you can specify:
SUBDIRS = "src doc lib po" AC_SUBST(SUBDIRS)
The upshot of this is that Automake is tricked into building the package
to take the subdirs, but doesn't actually bind that list until
configure is run.
Although the SUBDIRS macro can contain configure substitutions
(e.g. `@DIRS@'); Automake itself does not actually examine the
contents of this variable.
If SUBDIRS is defined, then your `configure.in' must include
AC_PROG_MAKE_SET.
The use of SUBDIRS is not restricted to just the top-level
`Makefile.am'. Automake can be used to construct packages of
arbitrary depth.
By default, Automake generates `Makefiles' which work depth-first
(`postfix'). However, it is possible to change this ordering. You
can do this by putting `.' into SUBDIRS. For instance,
putting `.' first will cause a `prefix' ordering of
directories.
A large part of Automake's functionality is dedicated to making it easy to build programs and libraries.
In a directory containing source that gets built into a program (as
opposed to a library), the `PROGRAMS' primary is used. Programs
can be installed in bindir, sbindir, libexecdir,
pkglibdir, or not at all (`noinst').
For instance:
bin_PROGRAMS = hello
In this simple case, the resulting `Makefile.in' will contain code
to generate a program named hello. The variable
hello_SOURCES is used to specify which source files get built
into an executable:
hello_SOURCES = hello.c version.c getopt.c getopt1.c getopt.h system.h
This causes each mentioned `.c' file to be compiled into the corresponding `.o'. Then all are linked to produce `hello'.
If `prog_SOURCES' is needed, but not specified, then it defaults to the single file `prog.c'.
Multiple programs can be built in a single directory. Multiple programs can share a single source file, which must be listed in each `_SOURCES' definition.
Header files listed in a `_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 `configure' in an `_SOURCES' variable; this file should not be distributed. Lex (`.l') and Yacc (`.y') files can also be listed; see section Yacc and Lex support.
Automake must know all the source files that could possibly go into a
program, even if not all the files are built in every circumstance.
Any files which are only conditionally built should be listed in the
appropriate `EXTRA_' variable. For instance, if
`hello-linux.c' were conditionally included in hello, the
`Makefile.am' would contain:
EXTRA_hello_SOURCES = hello-linux.c
Similarly, sometimes it is useful to determine the programs that are to
be built at configure time. For instance, GNU cpio only builds
mt and rmt under special circumstances.
In this case, you must notify Automake of all the programs that can
possibly be built, but at the same time cause the generated
`Makefile.in' to use the programs specified by configure.
This is done by having configure substitute values into each
`_PROGRAMS' definition, while listing all optionally built programs
in EXTRA_PROGRAMS.
If you need to link against libraries that are not found by
configure, you can use 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
`prog_LDADD' variable (where prog is the name of the
program as it appears in some `_PROGRAMS' variable, and usually
written in lowercase) to override the global LDADD. If this
variable exists for a given program, then that program is not linked
using LDADD.
For instance, in GNU cpio, pax, cpio and mt are
linked against the library `libcpio.a'. However, rmt is
built in the same directory, and has no such link requirement. Also,
mt and rmt are only built on certain architectures. Here
is what cpio's `src/Makefile.am' looks like (abridged):
bin_PROGRAMS = cpio pax @MT@ libexec_PROGRAMS = @RMT@ EXTRA_PROGRAMS = mt rmt LDADD = ../lib/libcpio.a @INTLLIBS@ rmt_LDADD = cpio_SOURCES = ... pax_SOURCES = ... mt_SOURCES = ... rmt_SOURCES = ...
`prog_LDADD' is inappropriate for passing program-specific linker flags (except for `-l' and `-L'). So, use the `prog_LDFLAGS' variable for this purpose.
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 `prog_DEPENDENCIES' variable. Each program depends on the contents of such a variable, but no further interpretation is done.
If `prog_DEPENDENCIES' is not supplied, it is computed by Automake. The automatically-assigned value is the contents of `prog_LDADD', with most configure substitutions, `-l', and `-L' options removed. The configure substitutions that are left in are only `@LIBOBJS@' and `@ALLOCA@'; these are left because it is known that they will not cause an invalid value for `prog_DEPENDENCIES' to be generated.
Building a library is much like building a program. In this case, the
name of the primary is `LIBRARIES'. Libraries can be installed in
libdir or pkglibdir.
See section Building a Shared Library, for information on how to build shared libraries using Libtool and the `LTLIBRARIES' primary.
Each `_LIBRARIES' variable is a list of the libraries to be built. For instance to create a library named `libcpio.a', but not install it, you would write:
noinst_LIBRARIES = libcpio.a
The sources that go into a library are determined exactly as they are for programs, via the `_SOURCES' variables. Note that the library name is canonicalized (see section How derived variables are named), so the `_SOURCES' variable corresponding to `liblob.a' is `liblob_a_SOURCES', not `liblob.a_SOURCES'.
Extra objects can be added to a library using the
`library_LIBADD' variable. This should be used for objects
determined by configure. Again from cpio:
libcpio_a_LIBADD = @LIBOBJS@ @ALLOCA@
Automake explicitly recognizes the use of @LIBOBJS@ and
@ALLOCA@, and uses this information, plus the list of
LIBOBJS files derived from `configure.in' to automatically
include the appropriate source files in the distribution (see section What Goes in a Distribution).
These source files are also automatically handled in the
dependency-tracking scheme; see See section Automatic dependency tracking.
@LIBOBJS@ and @ALLOCA@ are specially recognized in any
`_LDADD' or `_LIBADD' variable.
Building shared libraries is a relatively complex matter. For this reason, GNU Libtool (see section `Introduction' in The Libtool Manual) was created to help build shared libraries in a platform-independent way.
Automake uses Libtool to build libraries declared with the `LTLIBRARIES' primary. Each `_LTLIBRARIES' variable is a list of shared libraries to build. For instance, to create a library named `libgettext.a' and its corresponding shared libraries, and install them in `libdir', write:
lib_LTLIBRARIES = libgettext.la
Note that shared libraries must be installed, so
check_LTLIBRARIES is not allowed. However,
noinst_LTLIBRARIES is allowed. This feature should be used for
libtool "convenience libraries".
For each library, the `library_LIBADD' variable contains the names of extra libtool objects (`.lo' files) to add to the shared library. The `library_LDFLAGS' variable contains any additional libtool flags, such as `-version-info' or `-static'.
Where an ordinary library might include @LIBOBJS@, a libtool
library must use @LTLIBOBJS@. This is required because the
object files that libtool operates on do not necessarily end in
`.o'. The libtool manual contains more details on this topic.
For libraries installed in some directory, Automake will automatically
supply the appropriate `-rpath' option. However, for libraries
determined at configure time (and thus mentioned in
EXTRA_LTLIBRARIES), Automake does not know the eventual
installation directory; for such libraries you must add the
`-rpath' option to the appropriate `_LDFLAGS' variable by
hand.
See section `The Libtool Manual' in The Libtool Manual, for more information.
Occasionally it is useful to know which `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 CC,
CFLAGS, CPPFLAGS, DEFS, LDFLAGS, and
LIBS.
There are some additional variables which Automake itself defines:
INCLUDES
AC_CONFIG_HEADER or
AM_CONFIG_HEADER).
INCLUDES can actually be used for other cpp options
besides `-I'. For instance, it is sometimes used to pass arbitrary
`-D' options to the compiler.
COMPILE
LINK
Automake has somewhat idiosyncratic support for Yacc and Lex.
Automake assumes that the `.c' file generated by yacc (or
lex) should be named using the basename of the input file. That
is, for a yacc source file `foo.y', Automake will cause the
intermediate file to be named `foo.c' (as opposed to
`y.tab.c', which is more traditional).
The extension of a yacc source file is used to determine the extension of the resulting `C' or `C++' file. Files with the extension `.y' will be turned into `.c' files; likewise, `.yy' will become `.cc'; `.y++', `c++'; and `.yxx', `.cxx'.
Likewise, lex source files can be used to generate `C' or `C++'; the extensions `.l', `.ll', `.l++', and `.lxx' are recognized.
You should never explicitly mention the intermediate (`C' or `C++') file in any `SOURCES' variable; only list the source file.
The intermediate files generated by yacc (or lex) will be
included in any distribution that is made. That way the user doesn't
need to have yacc or lex.
If a yacc source file is seen, then your `configure.in' must
define the variable `YACC'. This is most easily done by invoking
the macro `AC_PROG_YACC' (see section `Particular Program Checks' in The Autoconf Manual).
Similarly, if a lex source file is seen, then your
`configure.in' must define the variable `LEX'. You can use
`AC_PROG_LEX' to do this (see section `Particular Program Checks' in The Autoconf Manual). Automake's lex
support also requires that you use the `AC_DECL_YYTEXT'
macro--automake needs to know the value of `LEX_OUTPUT_ROOT'.
This is all handled for you if you use the AM_PROG_LEX macro
(see section Autoconf macros supplied with Automake).
Automake makes it possible to include multiple yacc (or
lex) source files in a single program. Automake uses a small
program called ylwrap to run yacc (or lex) in a
subdirectory. This is necessary because yacc's output filename is
fixed, and a parallel make could conceivably invoke more than one
instance of yacc simultaneously. The ylwrap program is
distributed with Automake. It should appear in the directory specified
by `AC_CONFIG_AUX_DIR' (see section `Finding `configure' Input' in The Autoconf Manual), or the current directory if that macro
is not used in `configure.in'.
For yacc, simply managing locking is insufficient. The output of
yacc always uses the same symbol names internally, so it isn't
possible to link two yacc parsers into the same executable.
We recommend using the following renaming hack used in gdb:
#define yymaxdepth c_maxdepth #define yyparse c_parse #define yylex c_lex #define yyerror c_error #define yylval c_lval #define yychar c_char #define yydebug c_debug #define yypact c_pact #define yyr1 c_r1 #define yyr2 c_r2 #define yydef c_def #define yychk c_chk #define yypgo c_pgo #define yyact c_act #define yyexca c_exca #define yyerrflag c_errflag #define yynerrs c_nerrs #define yyps c_ps #define yypv c_pv #define yys c_s #define yy_yys c_yys #define yystate c_state #define yytmp c_tmp #define yyv c_v #define yy_yyv c_yyv #define yyval c_val #define yylloc c_lloc #define yyreds c_reds #define yytoks c_toks #define yylhs c_yylhs #define yylen c_yylen #define yydefred c_yydefred #define yydgoto c_yydgoto #define yysindex c_yysindex #define yyrindex c_yyrindex #define yygindex c_yygindex #define yytable c_yytable #define yycheck c_yycheck #define yyname c_yyname #define yyrule c_yyrule
For each define, replace the `c_' prefix with whatever you like.
These defines work for bison, byacc, and traditional
yaccs. If you find a parser generator that uses a symbol not
covered here, please report the new name so it can be added to the list.
Automake includes full support for C++.
Any package including C++ code must define the output variable
`CXX' in `configure.in'; the simplest way to do this is to use
the AC_PROG_CXX macro (see section `Particular Program Checks' in The Autoconf Manual).
A few additional variables are defined when a C++ source file is seen:
CXX
CXXFLAGS
CXXCOMPILE
CXXLINK
Automake includes full support for Fortran 77.
Any package including Fortran 77 code must define the output variable
`F77' in `configure.in'; the simplest way to do this is to use
the AC_PROG_F77 macro (see section `Particular Program Checks' in The Autoconf Manual). See section Fortran 77 and Autoconf.
A few additional variables are defined when a Fortran 77 source file is seen:
F77
FFLAGS
RFLAGS
F77COMPILE
FLINK
Automake can handle preprocessing Fortran 77 and Ratfor source files in addition to compiling them(1). Automake also contains some support for creating programs and shared libraries that are a mixture of Fortran 77 and other languages (see section Mixing Fortran 77 With C and C++).
These issues are covered in the following sections.
`N.f' is made automatically from `N.F' or `N.r'. This rule runs just the preprocessor to convert a preprocessable Fortran 77 or Ratfor source file into a strict Fortran 77 source file. The precise command used is as follows:
$(F77) -F $(DEFS) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_FFLAGS) $(FFLAGS)
$(F77) -F $(AM_FFLAGS) $(FFLAGS) $(AM_RFLAGS) $(RFLAGS)
`N.o' is made automatically from `N.f', `N.F' or `N.r' by running the Fortran 77 compiler. The precise command used is as follows:
$(F77) -c $(AM_FFLAGS) $(FFLAGS)
$(F77) -c $(DEFS) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_FFLAGS) $(FFLAGS)
$(F77) -c $(AM_FFLAGS) $(FFLAGS) $(AM_RFLAGS) $(RFLAGS)
Automake currently provides limited support for creating programs and shared libraries that are a mixture of Fortran 77 and C and/or C++. However, there are many other issues related to mixing Fortran 77 with other languages that are not (currently) handled by Automake, but that are handled by other packages(2).
Automake can help in two ways:
FLIBS by the AC_F77_LIBRARY_LDFLAGS Autoconf macro
supplied with newer versions of Autoconf (Autoconf version 2.13 and
later). See section `Fortran 77 Compiler Characteristics' in The Autoconf.
If Automake detects that a program or shared library (as mentioned in
some _PROGRAMS or _LTLIBRARIES primary) contains source
code that is a mixture of Fortran 77 and C and/or C++, then it requires
that the macro AC_F77_LIBRARY_LDFLAGS be called in
`configure.in', and that either $(FLIBS) or @FLIBS@
appear in the appropriate _LDADD (for programs) or _LIBADD
(for shared libraries) variables. It is the responsibility of the
person writing the `Makefile.am' to make sure that $(FLIBS)
or @FLIBS@ appears in the appropriate _LDADD or
_LIBADD variable.
For example, consider the following `Makefile.am':
bin_PROGRAMS = foo foo_SOURCES = main.cc foo.f foo_LDADD = libfoo.la @FLIBS@ pkglib_LTLIBRARIES = libfoo.la libfoo_la_SOURCES = bar.f baz.c zardoz.cc libfoo_la_LIBADD = $(FLIBS)
In this case, Automake will insist that AC_F77_LIBRARY_LDFLAGS
is mentioned in `configure.in'. Also, if @FLIBS@ hadn't
been mentioned in foo_LDADD and libfoo_la_LIBADD, then
Automake would have issued a warning.
The following diagram demonstrates under what conditions a particular linker is chosen by Automake.
For example, if Fortran 77, C and C++ source code were to be compiled
into a program, then the C++ linker will be used. In this case, if the
C or Fortran 77 linkers required any special libraries that weren't
included by the C++ linker, then they must be manually added to an
_LDADD or _LIBADD variable by the user writing the
`Makefile.am'.
\ Linker
source \
code \ C C++ Fortran
----------------- +---------+---------+---------+
| | | |
C | x | | |
| | | |
+---------+---------+---------+
| | | |
C++ | | x | |
| | | |
+---------+---------+---------+
| | | |
Fortran | | | x |
| | | |
+---------+---------+---------+
| | | |
C + C++ | | x | |
| | | |
+---------+---------+---------+
| | | |
C + Fortran | | | x |
| | | |
+---------+---------+---------+
| | | |
C++ + Fortran | | x | |
| | | |
+---------+---------+---------+
| | | |
C + C++ + Fortran | | x | |
| | | |
+---------+---------+---------+
The current Automake support for Fortran 77 requires a recent enough version Autoconf that also includes support for Fortran 77. Full Fortran 77 support was added to Autoconf 2.13, so you will want to use that version of Autoconf or later.
Automake currently only includes full support for C, C++ (see section C++ Support)and Fortran 77 (see section Fortran 77 Support). There is only rudimentary support for other languages, support for which will be improved based on user demand.
Although the GNU standards allow the use of ANSI C, this can have the effect of limiting portability of a package to some older compilers (notably SunOS).
Automake allows you to work around this problem on such machines by de-ANSI-fying each source file before the actual compilation takes place.
If the `Makefile.am' variable AUTOMAKE_OPTIONS
(see section Changing Automake's Behavior) contains the option ansi2knr then code to
handle de-ANSI-fication is inserted into the generated
`Makefile.in'.
This causes each C source file in the directory to be treated as ANSI C.
If an ANSI C compiler is available, it is used. If no ANSI C compiler
is available, the ansi2knr program is used to convert the source
files into K&R C, which is then compiled.
The ansi2knr program is simple-minded. It assumes the source
code will be formatted in a particular way; see the ansi2knr man
page for details.
Support for de-ANSI-fication requires the source files `ansi2knr.c'
and `ansi2knr.1' to be in the same package as the ANSI C source;
these files are distributed with Automake. Also, the package
`configure.in' must call the macro AM_C_PROTOTYPES
(see section Autoconf macros supplied with Automake).
Automake also handles finding the 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 ansi2knr
option. For instance, suppose the package has ANSI C code in the
`src' and `lib' subdirs. The files `ansi2knr.c' and
`ansi2knr.1' appear in `lib'. Then this could appear in
`src/Makefile.am':
AUTOMAKE_OPTIONS = ../lib/ansi2knr
If no directory prefix is given, the files are assumed to be in the current directory.
Files mentioned in LIBOBJS which need de-ANSI-fication will not
be automatically handled. That's because configure will generate
an object name like `regex.o', while make will be looking
for `regex_.o' (when de-ANSI-fying). Eventually this problem will
be fixed via autoconf magic, but for now you must put this code
into your `configure.in', just before the AC_OUTPUT call:
# This is necessary so that .o files in LIBOBJS are also built via # the ANSI2KNR-filtering rules. LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
As a developer it is often painful to continually update the `Makefile.in' whenever the include-file dependencies change in a project. Automake supplies a way to automatically track dependency changes, and distribute the dependencies in the generated `Makefile.in'.
Currently this support requires the use of GNU make and
gcc. It might become possible in the future to supply a
different dependency generating program, if there is enough demand. In
the meantime, this mode is enabled by default if any C program or
library is defined in the current directory, so you may get a `Must
be a separator' error from non-GNU make.
When you decide to make a distribution, the dist target will
re-run automake with `--include-deps' and other options.
See section Creating a `Makefile.in', and section Changing Automake's Behavior. This will cause the
previously generated dependencies to be inserted into the generated
`Makefile.in', and thus into the distribution. This step also
turns off inclusion of the dependency generation code, so that those who
download your distribution but don't use GNU make and gcc
will not get errors.
When added to the `Makefile.in', the dependencies have all system-specific dependencies automatically removed. This can be done by listing the files in `OMIT_DEPENDENCIES'. For instance all references to system header files are removed by Automake. Sometimes it is useful to specify that a certain header file should be removed. For instance if your `configure.in' uses `AM_WITH_REGEX', then any dependency on `rx.h' or `regex.h' should be removed, because the correct one cannot be known until the user configures the package.
As it turns out, Automake is actually smart enough to handle the particular case of the regular expression header. It will also automatically omit `libintl.h' if `AM_GNU_GETTEXT' is used.
Automatic dependency tracking can be suppressed by putting
no-dependencies in the variable AUTOMAKE_OPTIONS.
If you unpack a distribution made by make dist, and you want to
turn on the dependency-tracking code again, simply re-run
automake.
The actual dependency files are put under the build directory, in a subdirectory named `.deps'. These dependencies are machine specific. It is safe to delete them if you like; they will be automatically recreated during the next build.
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.
It is possible to define and install programs which are scripts. Such programs are listed using the `SCRIPTS' primary name. Automake doesn't define any dependencies for scripts; the `Makefile.am' should include the appropriate rules.
Automake does not assume that scripts are derived objects; such objects must be deleted by hand (see section What Gets Cleaned).
The automake program itself is a Perl script that is generated at
configure time from `automake.in'. Here is how this is handled:
bin_SCRIPTS = automake
Since automake appears in the AC_OUTPUT macro, a target
for it is automatically generated.
Script objects can be installed in bindir, sbindir,
libexecdir, or pkgdatadir.
Header files are specified by the `HEADERS' family of variables.
Generally header files are not installed, so the noinst_HEADERS
variable will be the most used.
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. See section Building a program. Headers listed in a `_SOURCES' variable need not be listed in any `_HEADERS' variable.
Headers can be installed in includedir, oldincludedir, or
pkgincludedir.
Automake supports the installation of miscellaneous data files using the `DATA' family of variables.
Such data can be installed in the directories datadir,
sysconfdir, sharedstatedir, localstatedir, or
pkgdatadir.
By default, data files are not included in a distribution.
Here is how Automake installs its auxiliary data files:
pkgdata_DATA = clean-kr.am clean.am ...
Occasionally a file which would otherwise be called `source'
(e.g. a C `.h' file) is actually derived from some other file.
Such files should be listed in the BUILT_SOURCES variable.
Built sources are also not compiled by default. You must explicitly mention them in some other `_SOURCES' variable for this to happen.
Note that, in some cases, BUILT_SOURCES will work in somewhat
surprising ways. In order to get the built sources to work with
automatic dependency tracking, the `Makefile' must depend on
$(BUILT_SOURCES). This can cause these sources to be rebuilt at
what might seem like funny times.
Since Automake is primarily intended to generate `Makefile.in's for use in GNU programs, it tries hard to interoperate with other GNU tools.
Automake provides some support for Emacs Lisp. The `LISP' primary
is used to hold a list of `.el' files. Possible prefixes for this
primary are `lisp_' and `noinst_'. Note that if
lisp_LISP is defined, then `configure.in' must run
AM_PATH_LISPDIR (see section Autoconf macros supplied with Automake).
By default Automake will byte-compile all Emacs Lisp source files using
the Emacs found by AM_PATH_LISPDIR. If you wish to avoid
byte-compiling, simply define the variable ELCFILES to be empty.
Byte-compiled Emacs Lisp files are not portable among all versions of
Emacs, so it makes sense to turn this off if you expect sites to have
more than one version of Emacs installed. Furthermore, many packages
don't actually benefit from byte-compilation. Still, we recommend that
you leave it enabled by default. It is probably better for sites with
strange setups to cope for themselves than to make the installation less
nice for everybody else.
If AM_GNU_GETTEXT is seen in `configure.in', then Automake
turns on support for GNU gettext, a message catalog system for
internationalization
(see section `GNU Gettext' in GNU gettext utilities).
The gettext support in Automake requires the addition of two
subdirectories to the package, `intl' and `po'. Automake
insures that these directories exist and are mentioned in
SUBDIRS.
Furthermore, Automake checks that the definition of ALL_LINGUAS
in `configure.in' corresponds to all the valid `.po' files,
and nothing more.
Automake provides some automatic support for writing Guile modules.
Automake will turn on Guile support if the AM_INIT_GUILE_MODULE
macro is used in `configure.in'.
Right now Guile support just means that the AM_INIT_GUILE_MODULE
macro is understood to mean:
AM_INIT_AUTOMAKE is run.
AC_CONFIG_AUX_DIR is run, with a path of `..'.
As the Guile module code matures, no doubt the Automake support will grow as well.
Automake provides support for GNU Libtool (see section `Introduction' in The Libtool Manual) with the `LTLIBRARIES' primary. See section Building a Shared Library.
Automake provides some minimal support for Java compilation with the `JAVA' primary.
Any `.java' files listed in a `_JAVA' variable will be
compiled with JAVAC at build time. By default, `.class'
files are not included in the distribution.
Currently Automake enforces the restriction that only one `_JAVA' primary can be used in a given `Makefile.am'. The reason for this restriction is that, in general, it isn't possible to know which `.class' files were generated from which `.java' files -- so it would be impossible to know which files to install where.
Currently Automake provides support for Texinfo and man pages.
If the current directory contains Texinfo source, you must declare it
with the `TEXINFOS' primary. Generally Texinfo files are converted
into info, and thus the info_TEXINFOS macro is most commonly used
here. Note that any Texinfo source file must end in the `.texi' or
`.texinfo' extension.
If the `.texi' file @includes `version.texi', then
that file will be automatically generated. The file `version.texi'
defines three Texinfo macros you can reference: EDITION,
VERSION, and 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 `version.texi'
support requires the mdate-sh program; this program is supplied
with Automake and automatically included when automake is invoked
with the --add-missing option.
Sometimes an info file actually depends on more than one `.texi'
file. For instance, in GNU Hello, `hello.texi' includes the file
`gpl.texi'. You can tell Automake about these dependencies using
the texi_TEXINFOS variable. Here is how GNU Hello does it:
info_TEXINFOS = hello.texi hello_TEXINFOS = gpl.texi
By default, Automake requires the file `texinfo.tex' to appear in
the same directory as the Texinfo source. However, if you used
AC_CONFIG_AUX_DIR in `configure.in' (see section `Finding `configure' Input' in The Autoconf Manual), then
`texinfo.tex' is looked for there. Automake supplies
`texinfo.tex' if `--add-missing' is given.
If your package has Texinfo files in many directories, you can use the
variable TEXINFO_TEX to tell Automake where to find the canonical
`texinfo.tex' for your package. The value of this variable should
be the relative path from the current `Makefile.am' to
`texinfo.tex':
TEXINFO_TEX = ../doc/texinfo.tex
The option `no-texinfo.tex' can be used to eliminate the
requirement for `texinfo.tex'. Use of the variable
TEXINFO_TEX is preferable, however, because that allows the
dvi target to still work.
Automake generates an install-info target; some people apparently
use this. By default, info pages are installed by `make install'.
This can be prevented via the no-installinfo option.
A package can also include man pages (but see the GNU standards on this
matter, section `Man Pages' in The GNU Coding Standards.) Man
pages are declared using the `MANS' primary. Generally the
man_MANS macro is used. Man pages are automatically installed in
the correct subdirectory of mandir, based on the file extension.
They are not automatically included in the distribution.
By default, man pages are installed by `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
no-installman option will prevent the man pages from being
installed by default. The user can still explicitly install them via
`make install-man'.
Here is how the documentation is handled in GNU cpio (which
includes both Texinfo documentation and man pages):
info_TEXINFOS = cpio.texi man_MANS = cpio.1 mt.1 EXTRA_DIST = $(man_MANS)
Texinfo source and info pages are all considered to be source for the purposes of making a distribution.
Man pages are not currently considered to be source, because it is not uncommon for man pages to be automatically generated. For the same reason, they are not automatically included in the distribution.
Naturally, Automake handles the details of actually installing your
program once it has been built. All PROGRAMS, SCRIPTS,
LIBRARIES, LISP, DATA and HEADERS are
automatically installed in the appropriate places.
Automake also handles installing any specified info and man pages.
Automake generates separate install-data and 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 install target depends on
both of these targets.
Automake also generates an uninstall target, an
installdirs target, and an install-strip target.
It is possible to extend this mechanism by defining an
install-exec-local or install-data-local target. If these
targets exist, they will be run at `make install' time.
Variables using the standard directory prefixes `data', `info', `man', `include', `oldinclude', `pkgdata', or `pkginclude' (e.g. `data_DATA') are installed by `install-data'.
Variables using the standard directory prefixes `bin', `sbin', `libexec', `sysconf', `localstate', `lib', or `pkglib' (e.g. `bin_PROGRAMS') are installed by `install-exec'.
Any variable using a user-defined directory prefix with `exec' in the name (e.g. `myexecbin_PROGRAMS' is installed by `install-exec'. All other user-defined prefixes are installed by `install-data'.
Automake generates support for the `DESTDIR' variable in all install rules. `DESTDIR' is used during the `make install' step to relocate install objects into a staging area. Each object and path is prefixed with the value of `DESTDIR' before being copied into the install area. Here is an example of typical DESTDIR usage:
make DESTDIR=/tmp/staging install
This places install objects in a directory tree built under `/tmp/staging'. If `/gnu/bin/foo' and `/gnu/share/aclocal/foo.m4' are to be installed, the above command would install `/tmp/staging/gnu/bin/foo' and `/tmp/staging/gnu/share/aclocal/foo.m4'.
This feature is commonly used to build install images and packages. For more information, see section `Makefile Conventions' in The GNU Coding Standards.
The GNU Makefile Standards specify a number of different clean rules.
Generally the files that can be 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
MOSTLYCLEANFILES, CLEANFILES, DISTCLEANFILES, and
MAINTAINERCLEANFILES.
The dist target in the generated `Makefile.in' can be used
to generate a gzip'd tar file for distribution. The tar file is
named based on the `PACKAGE' and `VERSION' variables; more
precisely it is named `package-version.tar.gz'.
You can use the make variable `GZIP_ENV' to control how gzip
is run. The default setting is `--best'.
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 `Makefile.am's and `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
`automake --help'. Also, files which are read by configure
(i.e. the source files corresponding to the files specified in the
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 EXTRA_DIST variable. You can mention files from
subdirectories in EXTRA_DIST. You can also mention a directory
there; in this case the entire directory will be recursively copied into
the distribution.
If you define SUBDIRS, Automake will recursively include the
subdirectories in the distribution. If SUBDIRS is defined
conditionally (see section Conditionals), Automake will normally include all
directories that could possibly appear in SUBDIRS in the
distribution. If you need to specify the set of directories
conditionally, you can set the variable DIST_SUBDIRS to the exact
list of subdirectories to include in the distribution.
Occasionally it is useful to be able to change the distribution before
it is packaged up. If the 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
files in subdirectories for which a new `Makefile.am' is overkill:
dist-hook:
mkdir $(distdir)/random
cp -p $(srcdir)/random/a1 $(srcdir)/random/a2 $(distdir)/random
Automake also generates a distcheck target which can be help to
ensure that a given distribution will actually work. distcheck
makes a distribution, and then tries to do a VPATH build.
Automake supports two forms of test suites.
If the variable TESTS is defined, its value is taken to be a list
of programs to run in order to do the testing. The programs can either
be derived objects or source objects; the generated rule will look both
in srcdir and `.'. Programs needing data files should look
for them in srcdir (which is both an environment variable and a
make variable) so they work when building in a separate directory
(see section `Build Directories' in The Autoconf Manual), and in particular for the distcheck target
(see section What Goes in a Distribution).
The number of failures will be printed at the end of the run. If a given test program exits with a status of 77, then its result is ignored in the final count. This feature allows non-portable tests to be ignored in environments where they don't make sense.
The variable TESTS_ENVIRONMENT can be used to set environment
variables for the test run; the environment variable srcdir is
set in the rule. If all your test programs are scripts, you can also
set TESTS_ENVIRONMENT to an invocation of the shell (e.g.
`$(SHELL) -x'); this can be useful for debugging the tests.
If `dejagnu' appears in AUTOMAKE_OPTIONS, then a
dejagnu-based test suite is assumed. The value of the variable
DEJATOOL is passed as the --tool argument to
runtest; it defaults to the name of the package.
The variable RUNTESTDEFAULTFLAGS holds the --tool and
--srcdir flags that are passed to dejagnu by default; this can be
overridden if necessary.
The variables EXPECT, RUNTEST and 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.
In either case, the testing is done via `make check'.
Various features of Automake can be controlled by options in the
`Makefile.am'. Such options are listed in a special variable named
AUTOMAKE_OPTIONS. Currently understood options are:
gnits
gnu
foreign
cygnus
gnits option also implies
readme-alpha and check-news.
ansi2knr
path/ansi2knr
check-news
make dist to fail unless the current version number appears
in the first few lines of the `NEWS' file.
dejagnu
dejagnu-specific rules to be generated. See section Support for test suites.
dist-shar
dist-shar target as well as the ordinary dist
target. This new target will create a shar archive of the
distribution.
dist-zip
dist-zip target as well as the ordinary dist
target. This new target will create a zip archive of the distribution.
dist-tarZ
dist-tarZ target as well as the ordinary dist
target. This new target will create a compressed tar archive of the
distribution; a traditional tar and compress will be
assumed. Warning: if you are actually using GNU tar, then the
generated archive might contain nonportable constructs.
no-dependencies
no-installinfo
info and install-info
targets will still be available. This option is disallowed at
`GNU' strictness and above.
no-installman
install-man target will still
be available for optional installation. This option is disallowed at
`GNU' strictness and above.
no-texinfo.tex
readme-alpha
Unrecognized options are diagnosed by automake.
There are a few rules and variables that didn't fit anywhere else.
etagsAutomake will generate rules to generate `TAGS' files for use with GNU Emacs under some circumstances.
If any C, C++ or Fortran 77 source code or headers are present, then
tags and TAGS targets will be generated for the directory.
At the topmost directory of a multi-directory package, a tags
target file will be generated which, when run, will generate a
`TAGS' file that includes by reference all `TAGS' files from
subdirectories.
Also, if the variable ETAGS_ARGS is defined, a tags target
will be generated. This variable is intended for use in directories
which contain taggable source that etags does not understand.
Here is how Automake generates tags for its source, and for nodes in its Texinfo file:
ETAGS_ARGS = automake.in --lang=none \ --regex='/^@node[ \t]+\([^,]+\)/\1/' automake.texi
If you add filenames to `ETAGS_ARGS', you will probably also
want to set `TAGS_DEPENDENCIES'. The contents of this variable
are added directly to the dependencies for the tags target.
Automake will also generate an ID target which will run
mkid on the source. This is only supported on a
directory-by-directory basis.
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 SUFFIXES variable.
For instance, currently Automake does not provide any Java support. If you wrote a macro to generate `.class' files from `.java' source files, you would also need to add these suffixes to the list:
SUFFIXES = .java .class
To include another file (perhaps for common rules), the following syntax is supported:
include ($(srcdir)|$(top_srcdir))/filename
Using files in the current directory:
include $(srcdir)/Makefile.extra
include Makefile.generated
Using a file in the top level directory:
include $(top_srcdir)/filename
Automake supports a simple type of conditionals.
Before using a conditional, you must define it by using
AM_CONDITIONAL in the configure.in file (see section Autoconf macros supplied with Automake).
The AM_CONDITIONAL macro takes two arguments.
The first argument to AM_CONDITIONAL is the name of the
conditional. This should be a simple string starting with a letter and
containing only letters, digits, and underscores.
The second argument to AM_CONDITIONAL is a shell condition,
suitable for use in a shell if statement. The condition is
evaluated when configure is run.
Conditionals typically depend upon options which the user provides to
the configure script. Here is an example of how to write a
conditional which is true if the user uses the `--enable-debug'
option.
AC_ARG_ENABLE(debug,
[ --enable-debug Turn on debugging],
[case "${enableval}" in
yes) debug=true ;;
no) debug=false ;;
*) AC_MSG_ERROR(bad value ${enableval} for --enable-debug) ;;
esac],[debug=false])
AM_CONDITIONAL(DEBUG, test x$debug = xtrue)
Here is an example of how to use that conditional in `Makefile.am':
if DEBUG DBG = debug else DBG = endif noinst_PROGRAMS = $(DBG)
This trivial example could also be handled using EXTRA_PROGRAMS (see section Building a program).
You may only test a single variable in an if statement. The
else statement may be omitted. Conditionals may be nested to any
depth.
Note that conditionals in Automake are not the same as conditionals in
GNU Make. Automake conditionals are checked at configure time by the
`configure' script, and affect the translation from
`Makefile.in' to `Makefile'. They are based on options passed
to `configure' and on results that `configure' has discovered
about the host system. GNU Make conditionals are checked at make
time, and are based on variables passed to the make program or defined
in the `Makefile'.
Automake conditionals will work with any make program.
--gnu and --gnits
The `--gnu' option (or `gnu' in the `AUTOMAKE_OPTIONS'
variable) causes automake to check the following:
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, `--gnu' can require certain
non-standard GNU programs to exist for use by various maintainer-only
targets; for instance in the future pathchk might be required for
`make dist'.
The `--gnits' option does everything that `--gnu' does, and checks the following as well:
--cygnus
Cygnus Solutions has slightly different rules for how a
`Makefile.in' is to be constructed. Passing `--cygnus' to
automake will cause any generated `Makefile.in' to comply
with Cygnus rules.
Here are the precise effects of `--cygnus':
runtest, expect,
makeinfo and texi2dvi.
--foreign is implied.
check target doesn't depend on all.
GNU maintainers are advised to use `gnu' strictness in preference to the special Cygnus mode.
Automake's implicit copying semantics means that many problems can be
worked around by simply adding some make targets and rules to
`Makefile.in'. Automake will ignore these additions.
There are some caveats to doing this. Although you can overload a target already used by Automake, it is often inadvisable, particularly in the topmost directory of a non-flat package. However, various useful targets have a `-local' version you can specify in your `Makefile.in'. Automake will supplement the standard target with these user-supplied targets.
The targets that support a local version are all, info,
dvi, check, install-data, install-exec,
uninstall, and the various clean targets
(mostlyclean, clean, distclean, and
maintainer-clean). Note that there are no
uninstall-exec-local or uninstall-data-local targets; just
use uninstall-local. It doesn't make sense to uninstall just
data or just executables.
For instance, here is one way to install a file in `/etc':
install-data-local:
$(INSTALL_DATA) $(srcdir)/afile /etc/afile
Some targets also have a way to run another target, called a hook,
after their work is done. The hook is named after the principal target,
with `-hook' appended. The targets allowing hooks are
install-data, install-exec, dist, and
distcheck.
For instance, here is how to create a hard link to an installed program:
install-exec-hook:
ln $(bindir)/program $(bindir)/proglink
Automake places no restrictions on the distribution of the resulting `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
--add-missing switch do fall under the GPL; examine each file
to see.
Here are some things that might happen in the future:
Much, if not most, of the information in the following sections pertaining to preprocessing Fortran 77 programs was taken almost verbatim from section `Catalogue of Rules' in The GNU Make Manual.
For example,
the cfortran package
addresses all of these inter-language issues, and runs under nearly all
Fortran 77, C and C++ compilers on nearly all platforms. However,
cfortran is not yet Free Software, but it will be in the next
major release.
This document was generated on 5 July 2000 using the texi2html translator version 1.54.