weakref attribute detection broken with gcc 4.6 and higher
[asterisk/asterisk.git] / autoconf / ast_gcc_attribute.m4
index d47d375..4ade814 100644 (file)
@@ -1,17 +1,35 @@
 # Helper function to check for gcc attributes.
-# AST_GCC_ATTRIBUTE([attribute name])
+# AST_GCC_ATTRIBUTE([attribute name], [attribute syntax], [attribute scope], [makeopts flag])
 
 AC_DEFUN([AST_GCC_ATTRIBUTE],
 [
 AC_MSG_CHECKING(for compiler 'attribute $1' support)
 saved_CFLAGS="$CFLAGS"
-CFLAGS="$CFLAGS -Werror"
+CFLAGS="$CFLAGS -Wall -Wno-unused -Werror"
+m4_ifval([$4],$4=0)
+
+if test "x$2" = "x"
+then
 AC_COMPILE_IFELSE(
-       AC_LANG_PROGRAM([static void __attribute__(($1)) *test(void *muffin, ...) {}],
-                       []),
+       [AC_LANG_PROGRAM([$3 void __attribute__(($1)) *test(void *muffin, ...) {return (void *) 0;}],
+                       [])],
        AC_MSG_RESULT(yes)
+       m4_ifval([$4],$4=1)
        AC_DEFINE_UNQUOTED([HAVE_ATTRIBUTE_$1], 1, [Define to 1 if your GCC C compiler supports the '$1' attribute.]),
-       AC_MSG_RESULT(no))
-]
+       AC_MSG_RESULT(no)
+)
+else
+AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM([$3 void __attribute__(($2)) *test(void *muffin, ...) ;],
+                       [])],
+       AC_MSG_RESULT(yes)
+       m4_ifval([$4],$4=1)
+       AC_DEFINE_UNQUOTED([HAVE_ATTRIBUTE_$1], 1, [Define to 1 if your GCC C compiler supports the '$1' attribute.]),
+       AC_MSG_RESULT(no)
+)
+fi
+
+m4_ifval([$4],[AC_SUBST($4)])
 CFLAGS="$saved_CFLAGS"
+]
 )