Update m4
[m6w6/libmemcached] / m4 / ax_harden_compiler_flags.m4
index af3ee7ff13fe54ffb12722b54ff8537253c4cfe0..247665caf8f5de88fea94133a343c50c7d23fa60 100644 (file)
 # AX_APPEND_COMPILE_FLAGS([-fstack-protector-all]) -- Issues on 32bit compile
 # AX_APPEND_COMPILE_FLAGS([-Wlong-long]) -- Don't turn on for compatibility issues memcached_stat_st
 
-#serial 4
-
-  AC_DEFUN([AX_HARDEN_LINKER_FLAGS], [
-      AC_REQUIRE([AX_CHECK_LINK_FLAG])
-      AC_REQUIRE([AX_VCS_CHECKOUT])
-      AC_REQUIRE([AX_DEBUG])
-      AC_REQUIRE([AX_CXX_COMPILER_VERSION])
-
-      dnl If we are inside of VCS we append -Werror, otherwise we just use it to test other flags
-      AX_HARDEN_LIB=
-      ax_append_compile_link_flags_extra=
-      AS_IF([test "x$ac_cv_vcs_checkout" = "xyes"],[
-        AX_CHECK_LINK_FLAG([-Werror],[
-          AX_HARDEN_LIB="-Werror $AX_HARDEN_LIB"
-          ])
-        ],[
-        AX_CHECK_LINK_FLAG([-Werror],[
-          ax_append_compile_link_flags_extra='-Werror'
-          ])
+#serial 5
+
+AC_DEFUN([AX_HARDEN_LINKER_FLAGS],
+    [AC_PREREQ([2.63])dnl
+    AC_REQUIRE([AX_CHECK_LINK_FLAG])
+    AC_REQUIRE([AX_VCS_CHECKOUT])
+    AC_REQUIRE([AX_DEBUG])
+    AC_REQUIRE([AX_CXX_COMPILER_VERSION])
+
+    dnl If we are inside of VCS we append -Werror, otherwise we just use it to test other flags
+    AX_HARDEN_LIB=
+    ax_append_compile_link_flags_extra=
+    AS_IF([test "x$ac_cv_vcs_checkout" = "xyes"],
+      [AX_CHECK_LINK_FLAG([-Werror],
+        [AX_HARDEN_LIB="-Werror $AX_HARDEN_LIB"])
+      ],
+      [AX_CHECK_LINK_FLAG([-Werror],[
+        ax_append_compile_link_flags_extra='-Werror'
         ])
+      ])
 
-      AX_CHECK_LINK_FLAG([-z relro -z now],[
-        AX_HARDEN_LIB="-z relro -z now $AX_HARDEN_LIB"
-      ],,[$ax_append_compile_link_flags_extra])
+    AX_CHECK_LINK_FLAG([-z relro -z now],
+      [AX_HARDEN_LIB="-z relro -z now $AX_HARDEN_LIB"],,
+      [$ax_append_compile_link_flags_extra])
 
-      AX_CHECK_LINK_FLAG([-pie],[
-          AX_HARDEN_LIB="-pie $AX_HARDEN_LIB"
-          ],,[$ax_append_compile_link_flags_extra])
+    AX_CHECK_LINK_FLAG([-pie],
+        [AX_HARDEN_LIB="-pie $AX_HARDEN_LIB"],,
+        [$ax_append_compile_link_flags_extra])
 
-      LIB="$LIB $AX_HARDEN_LIB"
-      ])
+    LIB="$LIB $AX_HARDEN_LIB"
+    ])
 
-  AC_DEFUN([AX_HARDEN_CC_COMPILER_FLAGS], [
-      AC_REQUIRE([AX_APPEND_COMPILE_FLAGS])
-      AC_REQUIRE([AX_HARDEN_LINKER_FLAGS])
+      AC_DEFUN([AX_HARDEN_CC_COMPILER_FLAGS],
+          [AC_PREREQ([2.63])dnl
+          AC_REQUIRE([AX_APPEND_COMPILE_FLAGS])
+          AC_REQUIRE([AX_HARDEN_LINKER_FLAGS])
 
-      AC_LANG_PUSH([C])
+          AC_LANG_PUSH([C])
 
-      ac_cv_warnings_as_errors=no
-      ax_append_compile_cflags_extra=
-      AS_IF([test "$ac_cv_vcs_checkout" = "yes"],[
-        AX_APPEND_COMPILE_FLAGS([-Werror])
-        ac_cv_warnings_as_errors=yes
-        ],[
-        AX_APPEND_COMPILE_FLAGS([-Werror],[ax_append_compile_cflags_extra])
-        ])
+          ac_cv_warnings_as_errors=no
+          ax_append_compile_cflags_extra=
+          AS_IF([test "$ac_cv_vcs_checkout" = "yes"],[
+            AX_APPEND_COMPILE_FLAGS([-Werror])
+            ac_cv_warnings_as_errors=yes
+            ],[
+            AX_APPEND_COMPILE_FLAGS([-Werror],[ax_append_compile_cflags_extra])
+            ])
 
-      AX_APPEND_COMPILE_FLAGS([-g])
-      AS_IF([test "$ax_enable_debug" = "yes"], [
-        AX_APPEND_COMPILE_FLAGS([-ggdb],,[$ax_append_compile_cflags_extra])
-        AX_APPEND_COMPILE_FLAGS([-O0],,[$ax_append_compile_cflags_extra])
-        ],[
-        AX_APPEND_COMPILE_FLAGS([-O2],,[$ax_append_compile_cflags_extra])
-        ])
+          AX_APPEND_COMPILE_FLAGS([-g])
+          AS_IF([test "$ax_enable_debug" = "yes"], [
+            AX_APPEND_COMPILE_FLAGS([-ggdb],,[$ax_append_compile_cflags_extra])
+            AX_APPEND_COMPILE_FLAGS([-O0],,[$ax_append_compile_cflags_extra])
+            ],[
+            AX_APPEND_COMPILE_FLAGS([-O2],,[$ax_append_compile_cflags_extra])
+            ])
+
+  AX_APPEND_COMPILE_FLAGS([-fstack-check],,[$ax_append_compile_cflags_extra])
+AX_APPEND_COMPILE_FLAGS([-Wno-pragmas],,[$ax_append_compile_cflags_extra])
 
-      AX_APPEND_COMPILE_FLAGS([-fstack-check],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wno-pragmas],,[$ax_append_compile_cflags_extra])
-
-      AX_APPEND_COMPILE_FLAGS([-Wall],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wextra],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wunknown-pragmas],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wthis-test-should-fail],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-std=c99],,[$ax_append_compile_cflags_extra])
-      dnl Anything below this comment please keep sorted.
-      AX_APPEND_COMPILE_FLAGS([--param=ssp-buffer-size=1],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Waddress],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Warray-bounds],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wbad-function-cast],,[$ax_append_compile_cflags_extra])
-      dnl Not in use -Wc++-compat
-      AX_APPEND_COMPILE_FLAGS([-Wchar-subscripts],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wcomment],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wfloat-equal],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wformat-security],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wformat=2],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wlogical-op],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wmaybe-uninitialized],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wmissing-field-initializers],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wall],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wextra],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunknown-pragmas],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wthis-test-should-fail],,[$ax_append_compile_cflags_extra])
+AX_APPEND_COMPILE_FLAGS([-std=c99],,[$ax_append_compile_cflags_extra])
+  dnl Anything below this comment please keep sorted.
+AX_APPEND_COMPILE_FLAGS([--param=ssp-buffer-size=1],,[$ax_append_compile_cflags_extra])
+  dnl -Wmissing-format-attribute
+  AX_APPEND_COMPILE_FLAGS([-Wno-attributes],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Waddress],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Warray-bounds],,[$ax_append_compile_cflags_extra])
+AX_APPEND_COMPILE_FLAGS([-Wbad-function-cast],,[$ax_append_compile_cflags_extra])
+  dnl Not in use -Wc++-compat
+  AX_APPEND_COMPILE_FLAGS([-Wchar-subscripts],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wcomment],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wfloat-equal],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wformat-security],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wformat=2],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wlogical-op],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wmaybe-uninitialized],,[$ax_append_compile_cflags_extra])
+AX_APPEND_COMPILE_FLAGS([-Wmissing-field-initializers],,[$ax_append_compile_cflags_extra])
+  AS_IF([test "$MINGW" = "yes"],[
+      AX_APPEND_COMPILE_FLAGS([-Wno-missing-noreturn],,[$ax_append_compile_cflags_extra])
+      ],[
       AX_APPEND_COMPILE_FLAGS([-Wmissing-noreturn],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wmissing-prototypes],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wnested-externs],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wnormalized=id],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wold-style-definition],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Woverride-init],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wpointer-sign],,[$ax_append_compile_cflags_extra])
+      ])
+  AX_APPEND_COMPILE_FLAGS([-Wmissing-prototypes],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wnested-externs],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wnormalized=id],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wold-style-definition],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Woverride-init],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cflags_extra])
+AX_APPEND_COMPILE_FLAGS([-Wpointer-sign],,[$ax_append_compile_cflags_extra])
+  AS_IF([test "$MINGW" = "yes"],[
+      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=const],,[$ax_append_compile_cflags_extra])
+      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=noreturn],,[$ax_append_compile_cflags_extra])
+      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=pure],,[$ax_append_compile_cflags_extra])
+      AX_APPEND_COMPILE_FLAGS([-Wno-redundant-decls],,[$ax_append_compile_cflags_extra])
+      ],[
       AX_APPEND_COMPILE_FLAGS([-Wredundant-decls],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wstrict-prototypes],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wswitch-enum],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wundef],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wunused-result],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wunused-variable],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wwrite-strings],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-floop-parallelize-all],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-fwrapv],,[$ax_append_compile_cflags_extra])
-      AC_LANG_POP
       ])
+  AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wstrict-prototypes],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wswitch-enum],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wundef],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunused],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunused-result],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunused-variable],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wwrite-strings],,[$ax_append_compile_cflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-floop-parallelize-all],,[$ax_append_compile_cflags_extra])
+AX_APPEND_COMPILE_FLAGS([-fwrapv],,[$ax_append_compile_cflags_extra])
+  AC_LANG_POP
+  ])
 
-  AC_DEFUN([AX_HARDEN_CXX_COMPILER_FLAGS], [
+  AC_DEFUN([AX_HARDEN_CXX_COMPILER_FLAGS],
+      [AC_PREREQ([2.63])dnl
       AC_REQUIRE([AX_HARDEN_CC_COMPILER_FLAGS])
       AC_LANG_PUSH([C++])
 
         ])
 
       AX_APPEND_COMPILE_FLAGS([-g],,[$ax_append_compile_cxxflags_extra])
-      AS_IF([test "$ax_enable_debug" = "yes" ], [
+      AS_IF([test "$ax_enable_debug" = "yes"], [
         AX_APPEND_COMPILE_FLAGS([-O0],,[$ax_append_compile_cxxflags_extra])
         AX_APPEND_COMPILE_FLAGS([-ggdb],,[$ax_append_compile_cxxflags_extra])
         ],[
         AX_APPEND_COMPILE_FLAGS([-D_FORTIFY_SOURCE=2],,[$ax_append_compile_cxxflags_extra])
         ])
 
-      AS_IF([test "$ac_cv_vcs_checkout" = "yes" ], [
-        AX_APPEND_COMPILE_FLAGS([-Werror],,[$ax_append_compile_cxxflags_extra])
-        AX_APPEND_COMPILE_FLAGS([-fstack-check],,[$ax_append_compile_cxxflags_extra])
-        ],[
-        AX_APPEND_COMPILE_FLAGS([-Wno-pragmas],,[$ax_append_compile_cxxflags_extra])
-        ])
+  AS_IF([test "$ac_cv_vcs_checkout" = "yes"], [
+      AX_APPEND_COMPILE_FLAGS([-Werror],,[$ax_append_compile_cxxflags_extra])
+      AX_APPEND_COMPILE_FLAGS([-fstack-check],,[$ax_append_compile_cxxflags_extra])
+      ],[
+      AX_APPEND_COMPILE_FLAGS([-Wno-pragmas],,[$ax_append_compile_cxxflags_extra])
+      ])
 
-      AX_APPEND_COMPILE_FLAGS([-Wall],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wextra],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wunknown-pragmas],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wthis-test-should-fail],,[$ax_append_compile_cxxflags_extra])
-      dnl Anything below this comment please keep sorted.
-      AX_APPEND_COMPILE_FLAGS([--param=ssp-buffer-size=1],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Waddress],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Warray-bounds],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wchar-subscripts],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wcomment],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wctor-dtor-privacy],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wfloat-equal],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wformat=2],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wmaybe-uninitialized],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wmissing-field-initializers],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wall],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wextra],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunknown-pragmas],,[$ax_append_compile_cxxflags_extra])
+AX_APPEND_COMPILE_FLAGS([-Wthis-test-should-fail],,[$ax_append_compile_cxxflags_extra])
+  dnl Anything below this comment please keep sorted.
+AX_APPEND_COMPILE_FLAGS([--param=ssp-buffer-size=1],,[$ax_append_compile_cxxflags_extra])
+  dnl -Wmissing-format-attribute
+  AX_APPEND_COMPILE_FLAGS([-Wno-attributes],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Waddress],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Warray-bounds],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wchar-subscripts],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wcomment],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wctor-dtor-privacy],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wfloat-equal],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wformat=2],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wmaybe-uninitialized],,[$ax_append_compile_cxxflags_extra])
+AX_APPEND_COMPILE_FLAGS([-Wmissing-field-initializers],,[$ax_append_compile_cxxflags_extra])
+  AS_IF([test "$MINGW" = "yes"],[
+      AX_APPEND_COMPILE_FLAGS([-Wno-missing-noreturn],,[$ax_append_compile_cxxflags_extra])
+      ],[
       AX_APPEND_COMPILE_FLAGS([-Wmissing-noreturn],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wlogical-op],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wnon-virtual-dtor],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wnormalized=id],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Woverloaded-virtual],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cxxflags_extra])
+      ])
+  AX_APPEND_COMPILE_FLAGS([-Wlogical-op],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wnon-virtual-dtor],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wnormalized=id],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Woverloaded-virtual],,[$ax_append_compile_cxxflags_extra])
+AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cxxflags_extra])
+  AS_IF([test "$MINGW" = "yes"],[
+      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=const],,[$ax_append_compile_cxxflags_extra])
+      AX_APPEND_COMPILE_FLAGS([-Wno-suggest-attribute=noreturn],,[$ax_append_compile_cxxflags_extra])
+      AX_APPEND_COMPILE_FLAGS([-Wno-error=suggest-attribute=noreturn],,[$ax_append_compile_cxxflags_extra])
+      AX_APPEND_COMPILE_FLAGS([-Wno-redundant-decls],,[$ax_append_compile_cxxflags_extra])
+      ],[
       AX_APPEND_COMPILE_FLAGS([-Wredundant-decls],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wswitch-enum],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wundef],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wc++11-compat],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wunused-result],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wunused-variable],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wwrite-strings],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wformat-security],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-floop-parallelize-all],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-fwrapv],,[$ax_append_compile_cxxflags_extra])
-      AC_LANG_POP
+      ])
+  AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wswitch-enum],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wundef],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wc++11-compat],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunused],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunused-result],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wunused-variable],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wwrite-strings],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-Wformat-security],,[$ax_append_compile_cxxflags_extra])
+  AX_APPEND_COMPILE_FLAGS([-floop-parallelize-all],,[$ax_append_compile_cxxflags_extra])
+AX_APPEND_COMPILE_FLAGS([-fwrapv],,[$ax_append_compile_cxxflags_extra])
+  AC_LANG_POP
   ])
 
-  AC_DEFUN([AX_HARDEN_COMPILER_FLAGS], [
+  AC_DEFUN([AX_HARDEN_COMPILER_FLAGS],
+      [AC_PREREQ([2.63])dnl
       AC_REQUIRE([AX_HARDEN_CXX_COMPILER_FLAGS])
       AC_REQUIRE([AX_CC_OTHER_FLAGS])
       gl_VISIBILITY
-      AS_IF([ test -n "$CFLAG_VISIBILITY" ], [ CPPFLAGS="$CPPFLAGS $CFLAG_VISIBILITY" ])
+      AS_IF([test -n "$CFLAG_VISIBILITY"], [ CPPFLAGS="$CPPFLAGS $CFLAG_VISIBILITY" ])
       ])
 
-  AC_DEFUN([AX_CC_OTHER_FLAGS], [
+  AC_DEFUN([AX_CC_OTHER_FLAGS],
+      [AC_PREREQ([2.63])dnl
       AC_REQUIRE([AX_APPEND_COMPILE_FLAGS])
       AC_REQUIRE([AX_HARDEN_CC_COMPILER_FLAGS])