Every time Automake is run it calls Autoconf to trace
configure.in. This way it can recognize the use of certain
macros and tailor the generated Makefile.in appropriately.
Currently recognized macros and their effects are:
AC_CONFIG_HEADERS
AM_CONFIG_HEADER
(see Macros); this is no longer the case today.
AC_CONFIG_AUX_DIR
mkinstalldirs, in the directory named in this macro invocation.
(The full list of scripts is: config.guess, config.sub,
depcomp, elisp-comp, compile, install-sh,
ltmain.sh, mdate-sh, missing, mkinstalldirs,
py-compile, texinfo.tex, and ylwrap.) Not all
scripts are always searched for; some scripts will only be sought if the
generated Makefile.in requires them.
If AC_CONFIG_AUX_DIR is not given, the scripts are looked for in
their standard locations. For mdate-sh,
texinfo.tex, and ylwrap, the standard location is the
source directory corresponding to the current Makefile.am. For
the rest, the standard location is the first one of ., ..,
or ../.. (relative to the top source directory) that provides any
one of the helper scripts. See Finding `configure' Input.
Required files from AC_CONFIG_AUX_DIR are automatically
distributed, even if there is no Makefile.am in this directory.
AC_CANONICAL_HOST
config.guess and config.sub
exist. Also, the Makefile variables host_alias and
host_triplet are introduced. See Getting the Canonical System Type.
AC_CANONICAL_SYSTEM
AC_CANONICAL_HOST, but also defines the
Makefile variables build_alias and target_alias.
See Getting the Canonical System Type.
AC_LIBSOURCE
AC_LIBSOURCES
AC_LIBOBJ
AC_LIBSOURCE or AC_LIBSOURCES.
Note that the AC_LIBOBJ macro calls AC_LIBSOURCE. So if
an Autoconf macro is documented to call AC_LIBOBJ([file]), then
file.c will be distributed automatically by Automake. This
encompasses many macros like AC_FUNC_ALLOCA,
AC_FUNC_MEMCMP, AC_REPLACE_FUNCS, and others.
By the way, direct assignments to LIBOBJS are no longer
supported. You should always use AC_LIBOBJ for this purpose.
See AC_LIBOBJ vs. LIBOBJS.
AC_PROG_RANLIB
AC_PROG_CXX
AC_PROG_F77
AC_F77_LIBRARY_LDFLAGS
AC_PROG_LIBTOOL
libtool (see Introduction).
AC_PROG_YACC
YACC in configure.in. The former is
preferred (see Particular Program Checks).
AC_PROG_LEX
AC_SUBST
Makefile.in. See Setting Output Variables.
If the Autoconf manual says that a macro calls AC_SUBST for
var, or defined the output variable var then var will
be defined in each generated Makefile.in.
E.g. AC_PATH_XTRA defines X_CFLAGS and X_LIBS, so
you can use the variable in any Makefile.am if
AC_PATH_XTRA is called.
AM_C_PROTOTYPES
AM_GNU_GETTEXT
AM_MAINTAINER_MODE
--enable-maintainer-mode option to
configure. If this is used, automake will cause
maintainer-only rules to be turned off by default in the
generated Makefile.ins. This macro defines the
MAINTAINER_MODE conditional, which you can use in your own
Makefile.am.