1 files changed, 94 insertions, 0 deletions
diff --git a/macros/mm-warnings.m4 b/macros/mm-warnings.m4
new file mode 100644
index 0000000..10ea951
--- /dev/null
+++ b/macros/mm-warnings.m4
@@ -0,0 +1,94 @@
+## Copyright (c) 2009  Daniel Elstner <daniel.kitta@gmail.com>
+##
+## This file is part of mm-common.
+##
+## mm-common is free software: you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published
+## by the Free Software Foundation, either version 2 of the License,
+## or (at your option) any later version.
+##
+## mm-common is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with mm-common.  If not, see <http://www.gnu.org/licenses/>.
+
+#serial 20090804
+
+## MM_ARG_ENABLE_WARNINGS(variable, min-flags, max-flags, [deprecation-prefixes])
+##
+## Provide the --enable-warnings configure argument, set to "min" by default.
+## <min-flags> and <max-flags> should be space-separated lists of compiler
+## warning flags to use with --enable-warnings=min or --enable-warnings=max,
+## respectively.  Warning level "fatal" is the same as "max" but in addition
+## enables -Werror mode.
+##
+## If not empty, <deprecation-prefixes> should be a list of module prefixes
+## which is expanded to -D<module>_DISABLE_DEPRECATED flags if fatal warnings
+## are enabled, too.
+##
+AC_DEFUN([MM_ARG_ENABLE_WARNINGS],
+[dnl
+m4_assert([$# >= 3])[]dnl
+dnl
+AC_ARG_ENABLE([warnings],
+              [AS_HELP_STRING([[--enable-warnings[=min|max|fatal|no]]],
+                              [set compiler pedantry level [default=min]])],
+              [mm_enable_warnings=$enableval],
+              [mm_enable_warnings=min])[]dnl
+
+AS_CASE([$ac_compile],
+        [*'$CXXFLAGS '*], [mm_lang='C++' mm_cc=$CXX mm_conftest=conftest.${ac_ext-cc}],
+        [*'$CFLAGS '*],   [mm_lang=C mm_cc=$CC mm_conftest=conftest.${ac_ext-c}],
+        [mm_lang=])[]dnl
+
+AS_IF([test "x$mm_lang" != x],
+[
+  AC_MSG_CHECKING([which $mm_lang compiler warning flags to use])
+  mm_deprecation_flags=
+  mm_tested_flags=
+
+  AS_CASE([$mm_enable_warnings],
+          [no],    [mm_warning_flags=],
+          [max],   [mm_warning_flags="$3"],
+          [fatal], [mm_warning_flags="$3 -Werror"][m4_ifval([$4], [
+           for mm_prefix in $4
+           do
+             mm_deprecation_flags="${mm_deprecation_flags}-D${mm_prefix}_DISABLE_DEPRECATED "
+           done])],
+          [mm_warning_flags="$2"])[]dnl
+
+  AS_IF([test "x$mm_warning_flags" != x],
+  [
+    # Keep in mind that the dummy source must be devoid of any
+    # problems that might cause diagnostics.
+    AC_LANG_CONFTEST([AC_LANG_SOURCE([[
+int main(int argc, char** argv) { return (argv != 0) ? argc : 0; }
+]])])
+    for mm_flag in $mm_warning_flags
+    do
+      # Test whether the compiler accepts the flag.  GCC doesn't bail
+      # out when given an unsupported flag but prints a warning, so
+      # check the compiler output instead.
+      mm_cc_out=`$mm_cc $mm_tested_flags $mm_flag -c "$mm_conftest" 2>&1 || echo failed`
+      rm -f "conftest.${OBJEXT-o}"
+
+      AS_IF([test "x$mm_cc_out" = x],
+            [AS_IF([test "x$mm_tested_flags" = x],
+                   [mm_tested_flags=$mm_flag],
+                   [mm_tested_flags="$mm_tested_flags $mm_flag"])],
+            [cat <<_MMEOF >&AS_MESSAGE_LOG_FD
+$mm_cc: $mm_cc_out
+_MMEOF])
+    done
+    rm -f "$mm_conftest"
+  ])
+  mm_all_flags=$mm_deprecation_flags$mm_tested_flags
+  AC_SUBST([$1], [$mm_all_flags])[]dnl
+
+  test "x$mm_all_flags" != x || mm_all_flags=none
+  AC_MSG_RESULT([$mm_all_flags])[]dnl
+])[]dnl
+])