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5 Creating a Makefile.in

To create all the Makefile.ins 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.ac; see Scanning configure.ac, using aclocal) 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.ac, at the top. If your package has multiple configure.acs, then you must run automake in each directory holding a configure.ac. (Alternatively, you may rely on Autoconf’s autoreconf, which is able to recurse your package tree and run automake where appropriate.)

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 This feature is generally only used to automatically rebuild an out-of-date Makefile.in.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.ac, and because automake uses the knowledge that a Makefile.in is in a subdirectory to change its behavior in some cases.

Automake will run autoconf to scan configure.ac and its dependencies (i.e., aclocal.m4 and any included file), therefore autoconf must be in your PATH. If there is an AUTOCONF variable in your environment it will be used instead of autoconf, this allows you to select a particular version of Autoconf. By the way, don’t misunderstand this paragraph: automake runs autoconf to scan your configure.ac, this won’t build configure and you still have to run autoconf yourself for this purpose.

automake accepts the following options:

-a ¶

--add-missing

Automake requires certain common files to exist in certain situations; for instance, config.guess is required if configure.ac invokes AC_CANONICAL_HOST. Automake is distributed with several of these files (see Programs automake might require); 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.

Many of the potentially-missing files are common scripts whose location may be specified via the AC_CONFIG_AUX_DIR macro. Therefore, AC_CONFIG_AUX_DIR’s setting affects whether a file is considered missing, and where the missing file is added (see Other things Automake recognizes).

In some strictness modes, additional files are installed, see The effect of --gnu and --gnits for more information.

--libdir=dir ¶

Look for Automake data files in directory dir instead of in the installation directory. This is typically used for debugging.

-c ¶

--copy

When used with --add-missing, causes installed files to be copied. The default is to make a symbolic link.

--cygnus ¶

Causes the generated Makefile.ins to follow Cygnus rules, instead of GNU or Gnits rules. For more information, see The effect of --cygnus. Note that this mode of operation is deprecated, and will be removed in a future Automake release.

-f ¶

--force-missing

When used with --add-missing, causes standard files to be reinstalled even if they already exist in the source tree. This involves removing the file from the source tree before creating the new symlink (or, with --copy, copying the new file).

--foreign ¶

Set the global strictness to foreign. For more information, see Strictness.

--gnits ¶

Set the global strictness to gnits. For more information, see The effect of --gnu and --gnits.

--gnu ¶

Set the global strictness to gnu. For more information, see The effect of --gnu and --gnits. This is the default strictness.

--help ¶

Print a summary of the command line options and exit.

-i ¶

--ignore-deps

This disables the dependency tracking feature in generated Makefiles; see Automatic dependency tracking.

--include-deps ¶

This enables the dependency tracking feature. This feature is enabled by default. This option is provided for historical reasons only and probably should not be used.

--no-force ¶

Ordinarily automake creates all Makefile.ins mentioned in configure.ac. This option causes it to only update those Makefile.ins that are out of date with respect to one of their dependents.

-o dir ¶

--output-dir=dir

Put the generated Makefile.in in the directory dir. Ordinarily each Makefile.in is created in the directory of the corresponding Makefile.am. This option is deprecated and will be removed in a future release.

-v ¶

--verbose

Cause Automake to print information about which files are being read or created.

--version ¶

Print the version number of Automake and exit.

-W CATEGORY ¶

--warnings=category

Output warnings falling in category. category can be one of:

gnu

warnings related to the GNU Coding Standards (see The GNU Coding Standards).

obsolete

obsolete features or constructions

override

user redefinitions of Automake rules or variables

portability

portability issues (e.g., use of make features that are known to be not portable)

extra-portability

extra portability issues related to obscure tools. One example of such a tool is the Microsoft lib archiver.

syntax

weird syntax, unused variables, typos

unsupported

unsupported or incomplete features

all

all the warnings

none

turn off all the warnings

error

treat warnings as errors

A category can be turned off by prefixing its name with ‘no-’. For instance, -Wno-syntax will hide the warnings about unused variables.

The categories output by default are ‘syntax’ and ‘unsupported’. Additionally, ‘gnu’ and ‘portability’ are enabled in --gnu and --gnits strictness. On the other hand, the silent-rules options (see Changing Automake’s Behavior) turns off portability warnings about recursive variable expansions.

Turning off ‘portability’ will also turn off ‘extra-portability’, and similarly turning on ‘extra-portability’ will also turn on ‘portability’. However, turning on ‘portability’ or turning off ‘extra-portability’ will not affect the other category.

The environment variable WARNINGS can contain a comma separated list of categories to enable. It will be taken into account before the command-line switches, this way -Wnone will also ignore any warning category enabled by WARNINGS. This variable is also used by other tools like autoconf; unknown categories are ignored for this reason.

If the environment variable AUTOMAKE_JOBS contains a positive number, it is taken as the maximum number of Perl threads to use in automake for generating multiple Makefile.in files concurrently. This is an experimental feature.