17. Changing Automake's Behavior

Various features of Automake can be controlled by options in the ‘Makefile.am’. Such options are applied on a per-‘Makefile’ basis when listed in a special ‘Makefile’ variable named AUTOMAKE_OPTIONS. They are applied globally to all processed ‘Makefiles’ when listed in the first argument of AM_INIT_AUTOMAKE in ‘configure.ac’. Currently understood options are:

‘gnits’

‘gnu’

‘foreign’

‘cygnus’

Set the strictness as appropriate. The ‘gnits’ option also implies options ‘readme-alpha’ and ‘check-news’.

‘ansi2knr’

‘path/ansi2knr’

Turn on the obsolete de-ANSI-fication feature. See section Automatic de-ANSI-fication. If preceded by a path, the generated ‘Makefile.in’ will look in the specified directory to find the ‘ansi2knr’ program. The path should be a relative path to another directory in the same distribution (Automake currently does not check this).

‘check-news’

Cause ‘make dist’ to fail unless the current version number appears in the first few lines of the ‘NEWS’ file.

‘dejagnu’

Cause dejagnu-specific rules to be generated. See section Support for test suites.

‘dist-bzip2’

Hook dist-bzip2 to dist.

‘dist-shar’

Hook dist-shar to dist.

‘dist-zip’

Hook dist-zip to dist.

‘dist-tarZ’

Hook dist-tarZ to dist.

‘filename-length-max=99’

Abort if file names longer than 99 characters are found during ‘make dist’. Such long file names are generally considered not to be portable in tarballs. See the ‘tar-v7’ and ‘tar-ustar’ options below. This option should be used in the top-level ‘Makefile.am’ or as an argument of AM_INIT_AUTOMAKE in ‘configure.ac’, it will be ignored otherwise. It will also be ignored in sub-packages of nested packages (see section Nesting Packages).

‘no-define’

This options is meaningful only when passed as an argument to AM_INIT_AUTOMAKE. It will prevent the PACKAGE and VERSION variables to be AC_DEFINEd.

‘no-dependencies’

This is similar to using ‘--ignore-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 (see section Automatic dependency tracking). In this case the effect is to effectively disable automatic dependency tracking.

‘no-dist’

Don't emit any code related to dist target. This is useful when a package has its own method for making distributions.

‘no-dist-gzip’

Do not hook dist-gzip to dist.

‘no-exeext’

If your ‘Makefile.am’ defines a rule for target foo, it will override a rule for a target named ‘foo$(EXEEXT)’. This is necessary when EXEEXT is found to be empty. However, by default automake will generate an error for this use. The ‘no-exeext’ option will disable this error. This is intended for use only where it is known in advance that the package will not be ported to Windows, or any other operating system using extensions on executables.

‘no-installinfo’

The generated ‘Makefile.in’ will not cause info pages to be built or installed by default. However, info and install-info targets will still be available. This option is disallowed at ‘gnu’ strictness and above.

‘no-installman’

The generated ‘Makefile.in’ will not cause man pages to be installed by default. However, an install-man target will still be available for optional installation. This option is disallowed at ‘gnu’ strictness and above.

‘nostdinc’

This option can be used to disable the standard ‘-I’ options that are ordinarily automatically provided by Automake.

‘no-texinfo.tex’

Don't require ‘texinfo.tex’, even if there are texinfo files in this directory.

‘readme-alpha’

If this release is an alpha release, and the file ‘README-alpha’ exists, then it will be added to the distribution. If this option is given, version numbers are expected to follow one of two forms. The first form is ‘MAJOR.MINOR.ALPHA’, where each element is a number; the final period and number should be left off for non-alpha releases. The second form is ‘MAJOR.MINORALPHA’, where ALPHA is a letter; it should be omitted for non-alpha releases.

‘std-options’

Make the installcheck rule check that installed scripts and programs support the ‘--help’ and ‘--version’ options. This also provides a basic check that the program's run-time dependencies are satisfied after installation.

In a few situations, programs (or scripts) have to be exempted from this test. For instance, false (from GNU sh-utils) is never successful, even for ‘--help’ or ‘--version’. You can list such programs in the variable AM_INSTALLCHECK_STD_OPTIONS_EXEMPT. Programs (not scripts) listed in this variable should be suffixed by ‘$(EXEEXT)’ for the sake of Win32 or OS/2. For instance, suppose we build ‘false’ as a program but ‘true.sh’ as a script, and that neither of them support ‘--help’ or ‘--version’:

AUTOMAKE_OPTIONS = std-options bin_PROGRAMS = false ... bin_SCRIPTS = true.sh ... AM_INSTALLCHECK_STD_OPTIONS_EXEMPT = false$(EXEEXT) true.sh

‘subdir-objects’

If this option is specified, then objects are placed into the subdirectory of the build directory corresponding to the subdirectory of the source file. For instance, if the source file is ‘subdir/file.cxx’, then the output file would be ‘subdir/file.o’.

In order to use this option with C sources, you should add AM_PROG_CC_C_O to ‘configure.ac’.

‘tar-v7’

‘tar-ustar’

‘tar-pax’

These three mutually exclusive options select the tar format to use when generating tarballs with ‘make dist’. (The tar file created is then compressed according to the set of ‘no-dist-gzip’, ‘dist-bzip2’ and ‘dist-tarZ’ options in use.)

These options must be passed as argument to AM_INIT_AUTOMAKE (see section Autoconf macros supplied with Automake) because they can require additional configure checks. Automake will complain if it sees such options in an AUTOMAKE_OPTIONS variable.

‘tar-v7’ selects the old V7 tar format. This is the historical default. This antiquated format is understood by all tar implementations and supports file names with up to 99 characters. When given longer file names some tar implementations will diagnose the problem while other will generate broken tarballs or use non-portable extensions. Furthermore, the V7 format cannot store empty directories. When using this format, consider using the ‘filename-length-max=99’ option to catch file names too long.

‘tar-ustar’ selects the ustar format defined by POSIX 1003.1-1988. This format is believed to be old enough to be portable. It fully supports empty directories. It can store file names with up to 256 characters, provided that the file name can be split at directory separator in two parts, first of them being at most 155 bytes long. So, in most cases the maximum file name length will be shorter than 256 characters. However you may run against broken tar implementations that incorrectly handle file names longer than 99 characters (please report them to bug-automake@gnu.org so we can document this accurately).

‘tar-pax’ selects the new pax interchange format defined by POSIX 1003.1-2001. It does not limit the length of file names. However, this format is very young and should probably be restricted to packages that target only very modern platforms. There are moves to change the pax format in an upward-compatible way, so this option may refer to a more recent version in the future.

See (tar)Formats section `Controlling the Archive Format' in GNU Tar, for further discussion about tar formats.

configure knows several ways to construct these formats. It will not abort if it cannot find a tool up to the task (so that the package can still be built), but ‘make dist’ will fail.

version

A version number (e.g., ‘0.30’) can be specified. If Automake is not newer than the version specified, creation of the ‘Makefile.in’ will be suppressed.

‘-Wcategory’ or ‘--warnings=category’

These options behave exactly like their command-line counterpart (see section Creating a ‘Makefile.in’). This allows you to enable or disable some warning categories on a per-file basis. You can also setup some warnings for your entire project; for instance, try ‘AM_INIT_AUTOMAKE([-Wall])’ in your ‘configure.ac’.

Unrecognized options are diagnosed by automake.

If you want an option to apply to all the files in the tree, you can use the AM_INIT_AUTOMAKE macro in ‘configure.ac’. See section Autoconf macros supplied with Automake.