* lib/autoconf/c.m4 (AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN(C)): New macro. * lib/autoconf/functions.m4 (_AC_CHECK_FUNC_BODY): Use it when the C compiler is gcc and AC_LANG_WERROR is in effect. * lib/autoconf/lang.m4 (AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN): New macro. (AC_LANG_DEFINE): Copy AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN. * tests/semantics.at (AC_CHECK_FUNCS after AC_LANG_WERROR): New test. --- lib/autoconf/c.m4 | 13 +++++++++++++ lib/autoconf/functions.m4 | 8 +++++++- lib/autoconf/lang.m4 | 8 ++++++++ tests/semantics.at | 13 +++++++++++++ 4 files changed, 41 insertions(+), 1 deletions(-)
diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index 40fdab4..c24204e 100644
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -183,6 +183,19 @@ choke me
], [return $1 ();])])
+# AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN(C)(FUNCTION)
+# ----------------------------------------------
+# Test whether the given function is available as a gcc built-in function.
+#
+m4_define([AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN(C)],
+[AC_LANG_PROGRAM(
+[#undef $1
+/* Declare this function with the same prototype as __builtin_$1.
+ This removes a warning about conflicting types for built-in function $1 */
+__typeof__(__builtin_$1) $1;
+__typeof__(__builtin_$1) *f = $1;
+], [return f != $1;])])
+
# AC_LANG_BOOL_COMPILE_TRY(C)(PROLOGUE, EXPRESSION)
# -------------------------------------------------
# Return a program that is valid if EXPRESSION is nonzero.
diff --git a/lib/autoconf/functions.m4 b/lib/autoconf/functions.m4
index 24dcf86..33e624e 100644
--- a/lib/autoconf/functions.m4
+++ b/lib/autoconf/functions.m4
@@ -47,7 +47,13 @@ m4_define([_AC_CHECK_FUNC_BODY],
AC_CACHE_CHECK([for $[]2], [$[]3],
[AC_LINK_IFELSE([AC_LANG_FUNC_LINK_TRY($[]2)],
[AS_VAR_SET([$[]3], [yes])],
- [AS_VAR_SET([$[]3], [no])])])
+ [if test "$GCC:$ac_[]_AC_LANG_ABBREV[]_werror_flag" =
yes:yes; then
+ AC_LINK_IFELSE([AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN($[]2)],
+ [AS_VAR_SET([$[]3], [yes])],
+ [AS_VAR_SET([$[]3], [no])])
+ else
+ AS_VAR_SET([$[]3], [no])
+ fi])])
AS_LINENO_POP
])# _AC_CHECK_FUNC_BODY
diff --git a/lib/autoconf/lang.m4 b/lib/autoconf/lang.m4
index 98ccf5c..f709633 100644
--- a/lib/autoconf/lang.m4
+++ b/lib/autoconf/lang.m4
@@ -179,6 +179,7 @@ m4_define([AC_LANG_DEFINE],
[m4_copy([AC_LANG_PROGRAM($5)], [AC_LANG_PROGRAM($1)])]
[m4_copy([AC_LANG_CALL($5)], [AC_LANG_CALL($1)])]
[m4_copy([AC_LANG_FUNC_LINK_TRY($5)], [AC_LANG_FUNC_LINK_TRY($1)])]
+[m4_copy([AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN($5)],
[AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN($1)])]
[m4_copy([AC_LANG_BOOL_COMPILE_TRY($5)], [AC_LANG_BOOL_COMPILE_TRY($1)])]
[m4_copy([AC_LANG_INT_SAVE($5)], [AC_LANG_INT_SAVE($1)])]
[m4_copy([_AC_LANG_IO_PROGRAM($5)], [_AC_LANG_IO_PROGRAM($1)])])])
@@ -269,6 +270,13 @@ AC_DEFUN([AC_LANG_FUNC_LINK_TRY],
_AC_LANG_DISPATCH([$0], _AC_LANG, $@)])
+# AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN(FUNCTION, TYPE)
+# -------------------------------------------------
+AC_DEFUN([AC_LANG_FUNC_LINK_TRY_GCC_BUILTIN],
+[m4_ifval([$1], [], [m4_warn([syntax], [$0: no function given])])dnl
+_AC_LANG_DISPATCH([$0], _AC_LANG, $@)])
+
+
# AC_LANG_BOOL_COMPILE_TRY(PROLOGUE, EXPRESSION)
# ----------------------------------------------
# Produce a program that compiles with success iff the boolean EXPRESSION
diff --git a/tests/semantics.at b/tests/semantics.at
index 9aaffc3..213f067 100644
--- a/tests/semantics.at
+++ b/tests/semantics.at
@@ -133,6 +133,19 @@ AT_CHECK_MACRO([AC_CHECK_FUNCS],
])])
+# AC_CHECK_FUNCS after AC_LANG_WERROR
+# -----------------------------------
+# Check that it performs the correct actions:
+# Must define HAVE_PRINTF, but not HAVE_AUTOCONF_FTNIRP
+AT_CHECK_MACRO([AC_CHECK_FUNCS after AC_LANG_WERROR],
+[AC_LANG_WERROR
+AC_CHECK_FUNCS(printf autoconf_ftnirp)],
+[AT_CHECK_DEFINES(
+[/* #undef HAVE_AUTOCONF_FTNIRP */
+#define HAVE_PRINTF 1
+])])
+
+
# AC_REPLACE_FUNCS
# ----------------
# Check that it performs the correct actions: autoconf_ftnirp.c must
--
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