3.5 Using autoreconf to Update configure Scripts

Installing the various components of the GNU Build System can be tedious: running autopoint for Gettext, automake for ‘Makefile.in’ etc. in each directory. It may be needed either because some tools such as automake have been updated on your system, or because some of the sources such as ‘configure.ac’ have been updated, or finally, simply in order to install the GNU Build System in a fresh tree.

autoreconf runs autoconf, autoheader, aclocal, automake, libtoolize, and autopoint (when appropriate) repeatedly to update the GNU Build System in the specified directories and their subdirectories (see section Configuring Other Packages in Subdirectories). By default, it only remakes those files that are older than their sources. The environment variables AUTOCONF, AUTOHEADER, AUTOMAKE, ACLOCAL, AUTOPOINT, LIBTOOLIZE, M4, and MAKE may be used to override the invocation of the respective tools.

If you install a new version of some tool, you can make autoreconf remake all of the files by giving it the ‘--force’ option.

See section Automatic Remaking, for Make rules to automatically rebuild configure scripts when their source files change. That method handles the timestamps of configuration header templates properly, but does not pass ‘--autoconf-dir=dir’ or ‘--localdir=dir’.

Gettext supplies the autopoint command to add translation infrastructure to a source package. If you use autopoint, your ‘configure.ac’ should invoke both AM_GNU_GETTEXT and AM_GNU_GETTEXT_VERSION(gettext-version). See (gettext)autopoint Invocation section `Invoking the autopoint Program' in GNU gettext utilities, for further details.

autoreconf accepts the following options:

‘--help’

‘-h’

Print a summary of the command line options and exit.

‘--version’

‘-V’

Print the version number of Autoconf and exit.

‘--verbose’

‘-V’

Print the name of each directory autoreconf examines and the commands it runs. If given two or more times, pass ‘--verbose’ to subordinate tools that support it.

‘--debug’

‘-d’

Don't remove the temporary files.

‘--force’

‘-f’

Remake even ‘configure’ scripts and configuration headers that are newer than their input files (‘configure.ac’ and, if present, ‘aclocal.m4’).

‘--install’

‘-i’

Install the missing auxiliary files in the package. By default, files are copied; this can be changed with ‘--symlink’.

If deemed appropriate, this option triggers calls to ‘automake --add-missing’, ‘libtoolize’, ‘autopoint’, etc.

‘--no-recursive’

Do not rebuild files in subdirectories to configure (see Configuring Other Packages in Subdirectories, macro AC_CONFIG_SUBDIRS).

‘--symlink’

‘-s’

When used with ‘--install’, install symbolic links to the missing auxiliary files instead of copying them.

‘--make’

‘-m’

When the directories were configured, update the configuration by running ‘./config.status --recheck && ./config.status’, and then run ‘make’.

‘--include=dir’

‘-I dir’

Append dir to the include path. Multiple invocations accumulate. Passed on to aclocal, autoconf and autoheader internally.

‘--prepend-include=dir’

‘-B dir’

Prepend dir to the include path. Multiple invocations accumulate. Passed on to autoconf and autoheader internally.

‘--warnings=category’

‘-W category’

Report the warnings related to category (which can actually be a comma separated list).

‘cross’

related to cross compilation issues.

‘obsolete’

report the uses of obsolete constructs.

‘portability’

portability issues

‘syntax’

dubious syntactic constructs.

‘all’

report all the warnings

‘none’

report none

‘error’

treats warnings as errors

‘no-category’

disable warnings falling into category

Warnings about ‘syntax’ are enabled by default, and the environment variable WARNINGS, a comma separated list of categories, is honored as well. Passing ‘-W category’ actually behaves as if you had passed ‘--warnings syntax,$WARNINGS,category’. To disable the defaults and WARNINGS, and then enable warnings about obsolete constructs, use ‘-W none,obsolete’.

If you want autoreconf to pass flags that are not listed here on to aclocal, set ACLOCAL_AMFLAGS in your ‘Makefile.am’. Due to a limitation in the Autoconf implementation these flags currently must be set on a single line in ‘Makefile.am’, without any backslash-newlines.