4.4 Finding configure Input

Macro: AC_CONFIG_SRCDIR (unique-file-in-source-dir)

unique-file-in-source-dir is some file that is in the package's source directory; configure checks for this file's existence to make sure that the directory that it is told contains the source code in fact does. Occasionally people accidentally specify the wrong directory with ‘--srcdir’; this is a safety check. See section configure Invocation, for more information.

Packages that do manual configuration or use the install program might need to tell configure where to find some other shell scripts by calling AC_CONFIG_AUX_DIR, though the default places it looks are correct for most cases.

Macro: AC_CONFIG_AUX_DIR (dir)

Use the auxiliary build tools (e.g., ‘install-sh’, ‘config.sub’, ‘config.guess’, Cygnus configure, Automake and Libtool scripts, etc.) that are in directory dir. These are auxiliary files used in configuration. dir can be either absolute or relative to ‘srcdir’. The default is ‘srcdir’ or ‘srcdir/..’ or ‘srcdir/../..’, whichever is the first that contains ‘install-sh’. The other files are not checked for, so that using AC_PROG_INSTALL does not automatically require distributing the other auxiliary files. It checks for ‘install.sh’ also, but that name is obsolete because some make have a rule that creates ‘install’ from it if there is no makefile.

The auxiliary directory is commonly named ‘build-aux’. If you need portability to DOS variants, do not name the auxiliary directory ‘aux’. See section File System Conventions.

Macro: AC_REQUIRE_AUX_FILE (file)

Declares that file is expected in the directory defined above. In Autoconf proper, this macro does nothing: its sole purpose is to be traced by third-party tools to produce a list of expected auxiliary files. For instance it is called by macros like AC_PROG_INSTALL (see section Particular Program Checks) or AC_CANONICAL_BUILD (see section Getting the Canonical System Type) to register the auxiliary files they need.

Similarly, packages that use aclocal should declare where local macros can be found using AC_CONFIG_MACRO_DIR.

Macro: AC_CONFIG_MACRO_DIR (dir)

Specify dir as the location of additional local Autoconf macros. This macro is intended for use by future versions of commands like autoreconf that trace macro calls. It should be called directly from ‘configure.ac’ so that tools that install macros for aclocal can find the macros' declarations.

Note that if you use aclocal from Automake to generate ‘aclocal.m4’, you must also set ACLOCAL_AMFLAGS = -I dir in your top-level ‘Makefile.am’. Due to a limitation in the Autoconf implementation of autoreconf, these include directives currently must be set on a single line in ‘Makefile.am’, without any backslash-newlines.