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. aclocal 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.
zardoz is a user program, so you want to install it where the
rest of the user programs go. zardoz also 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!
hello is renowned for its classic simplicity and versatility.
This section shows how Automake could be used with the Hello package.
The examples below are from the latest GNU Hello, but all the
maintainer-only code has been 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 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; supporting that 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
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