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Diffstat (limited to 'config/override.m4')
| -rw-r--r-- | config/override.m4 | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/config/override.m4 b/config/override.m4 new file mode 100644 index 000000000..52bd1c3d1 --- /dev/null +++ b/config/override.m4 @@ -0,0 +1,104 @@ +dnl Fix Autoconf bugs by overriding broken internal Autoconf +dnl macros with backports of fixes from newer releases. +dnl +dnl The override bits of this file should be a no-op for the newest +dnl Autoconf version, which means they can be removed once the complete +dnl tree has moved to a new enough Autoconf version. +dnl +dnl The _GCC_AUTOCONF_VERSION_TEST ensures that exactly the desired +dnl Autoconf version is used. It should be kept for consistency. + +dnl Use ifdef/ifelse over m4_ifdef/m4_ifelse to be clean for 2.13. +ifdef([m4_PACKAGE_VERSION], [ + +dnl Provide m4_copy_force and m4_rename_force for old Autoconf versions. + +m4_ifndef([m4_copy_force], +[m4_define([m4_copy_force], +[m4_ifdef([$2], [m4_undefine([$2])])m4_copy($@)])]) + +m4_ifndef([m4_rename_force], +[m4_define([m4_rename_force], +[m4_ifdef([$2], [m4_undefine([$2])])m4_rename($@)])]) + +dnl AC_DEFUN a commonly used macro so this file is picked up. +m4_copy([AC_PREREQ], [_AC_PREREQ]) +AC_DEFUN([AC_PREREQ], [frob]) +m4_copy_force([_AC_PREREQ], [AC_PREREQ]) + + +dnl Ensure exactly this Autoconf version is used +m4_ifndef([_GCC_AUTOCONF_VERSION], + [m4_define([_GCC_AUTOCONF_VERSION], [2.64])]) + +dnl Test for the exact version when AC_INIT is expanded. +dnl This allows to update the tree in steps (for testing) +dnl by putting +dnl m4_define([_GCC_AUTOCONF_VERSION], [X.Y]) +dnl in configure.ac before AC_INIT, +dnl without rewriting this file. +dnl Or for updating the whole tree at once with the definition above. +AC_DEFUN([_GCC_AUTOCONF_VERSION_CHECK], +[m4_if(m4_defn([_GCC_AUTOCONF_VERSION]), + m4_defn([m4_PACKAGE_VERSION]), [], + [m4_fatal([Please use exactly Autoconf ]_GCC_AUTOCONF_VERSION[ instead of ]m4_defn([m4_PACKAGE_VERSION])[.])]) +]) +m4_define([AC_INIT], m4_defn([AC_INIT])[ +_GCC_AUTOCONF_VERSION_CHECK +]) + + +dnl Ensure we do not use a buggy M4. +m4_if(m4_index([..wi.d.], [.d.]), [-1], + [m4_fatal(m4_do([m4 with buggy strstr detected. Please install +GNU M4 1.4.16 or newer and set the M4 environment variable]))]) + + +dnl Fix 2.64 cross compile detection for AVR and RTEMS +dnl by not trying to compile fopen. +m4_if(m4_defn([m4_PACKAGE_VERSION]), [2.64], + [m4_foreach([_GCC_LANG], [C, C++, Fortran, Fortran 77], + [m4_define([_AC_LANG_IO_PROGRAM(]_GCC_LANG[)], m4_defn([AC_LANG_PROGRAM(]_GCC_LANG[)]))])]) + +m4_version_prereq([2.66],, [ +dnl We need AC_CHECK_DECL which works for overloaded C++ functions. + +# _AC_CHECK_DECL_BODY +# ------------------- +# Shell function body for AC_CHECK_DECL. +m4_define([_AC_CHECK_DECL_BODY], +[ AS_LINENO_PUSH([$[]1]) + [as_decl_name=`echo $][2|sed 's/ *(.*//'`] + [as_decl_use=`echo $][2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`] + AC_CACHE_CHECK([whether $as_decl_name is declared], [$[]3], + [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$[]4], +[@%:@ifndef $[]as_decl_name +@%:@ifdef __cplusplus + (void) $[]as_decl_use; +@%:@else + (void) $[]as_decl_name; +@%:@endif +@%:@endif +])], + [AS_VAR_SET([$[]3], [yes])], + [AS_VAR_SET([$[]3], [no])])]) + AS_LINENO_POP +])# _AC_CHECK_DECL_BODY + +# _AC_CHECK_DECLS(SYMBOL, ACTION-IF_FOUND, ACTION-IF-NOT-FOUND, +# INCLUDES) +# ------------------------------------------------------------- +# Helper to AC_CHECK_DECLS, which generates the check for a single +# SYMBOL with INCLUDES, performs the AC_DEFINE, then expands +# ACTION-IF-FOUND or ACTION-IF-NOT-FOUND. +m4_define([_AC_CHECK_DECLS], +[AC_CHECK_DECL([$1], [ac_have_decl=1], [ac_have_decl=0], [$4])]dnl +[AC_DEFINE_UNQUOTED(AS_TR_CPP(m4_bpatsubst(HAVE_DECL_[$1],[ *(.*])), + [$ac_have_decl], + [Define to 1 if you have the declaration of `$1', + and to 0 if you don't.])]dnl +[m4_ifvaln([$2$3], [AS_IF([test $ac_have_decl = 1], [$2], [$3])])]) + +]) + +]) |