Rename as:
(_AC_PROG_CC_GNU, _AC_PROG_CXX_GNU, _AC_PROG_F77_GNU): these.
Compute the value of GCC, GXX and G77 here.
Set to `no' (instead of empty) if not the GNU compiler.
(AC_PROG_CC, AC_PROG_CXX, AC_PROG_F77): Adjust.
* doc/autoconf.texi: Adjust.
Using --host enables cross-compilation.
* acgeneral.m4 (_AC_INIT_PARSE_ARGS): `--host' enables cross
compilation.
(AC_CANONICAL_BUILD): The help string should explicitly mention
cross compilation.
* aclang.m4 (AC_LANG(C), AC_LANG(C++), AC_LANG(Fortran 77)): Don't
set `cross_compiling'.
(AC_PROG_CC, AC_PROG_CXX, AC_PROG_F77): Run your `WORK' partner
only if not cross-compiling.
(AC_PROG_CC_WORKS, AC_PROG_CXX_WORKS, AC_PROG_F77_WORKS):
If does not work, don't assume an implicit cross-compilation:
fail.
* doc/autoconf.texi: Adjust.
* aclang.m4 (_AC_LANG_CURRENT, AC_LANG_STACK): You two are the same
thing, which now we shall name `_AC_LANG'.
All users adjusted.
(AC_LANG_PUSH, AC_LANG_POP): New macros.
(AC_LANG_SAVE, AC_LANG_RESTORE): AU defined.
(AC_PROG_CC_WORKS, AC_PROG_CXXCPP, AC_PROG_CXX_WORKS,
AC_PROG_F77_WORKS, AC_F77_LIBRARY_LDFLAGS, AC_F77_NAME_MANGLING):
Use them.
(AC_F77_LIBRARY_LDFLAGS): Move the requirements at its top.
* doc/autoconf.texi (Language Choice): Document them.
(Old Macros): Welcome AC_LANG_SAVE and AC_LANG_RESTORE.
they don't break the second time you run configure).
* aclang.m4 (AC_F77_NAME_MANGLING): Extract f77_case,
f77_underscore from cache variable.
(AC_F77_WRAPPERS): Get rid of ac_cv_f77_wrappers, it's useless.
Simplify the nested case-esac into a single one.
Simplify the documentation strings of CPP symbols.
* autoheader.m4: Dispatch the prototypes next to there AC_
siblings.
(AH_TEMPLATE, AH_VERBATIM): Move to...
* acgeneral.m4: here.
(AH_OUTPUT): New macro.
* autoheader.sh: Run `autoconf --trace' instead of `m4 autoheader.m4'.
* autoheader.m4: Remove.
* Makefile.am: Adjust.
* tests/tools.m4 (AH_DEFUN): Remove, no longer makes sense.
* tests/actests.m4 (autoheader::AC_TATOOINE): Remove, was used by
the test above.