[network-manager-applet] build: more flexible build-time warnings and errors options

[Dan Williams <dcbw src gnome org>]

commit 58f3f9a5f5705ba3370312a13e863cc54df79264
Author: Dan Williams <dcbw redhat com>
Date:   Fri Mar 2 13:53:32 2012 -0600

    build: more flexible build-time warnings and errors options

 Makefile.am             |    2 ++
 m4/compiler_warnings.m4 |   13 ++++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 6c48203..96c272b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -26,6 +26,8 @@ schemas_DATA = $(schemas_in_files:.schemas.in=.schemas)
 @INTLTOOL_SCHEMAS_RULE@
 
 
+DISTCHECK_CONFIGURE_FLAGS = --enable-more-warnings=yes
+
 EXTRA_DIST += \
 	$(schemas_in_files) \
 	$(autostart_in_files) \
diff --git a/m4/compiler_warnings.m4 b/m4/compiler_warnings.m4
index 6cea2f7..95ad3fb 100644
--- a/m4/compiler_warnings.m4
+++ b/m4/compiler_warnings.m4
@@ -1,16 +1,16 @@
 AC_DEFUN([NM_COMPILER_WARNINGS],
 [AC_ARG_ENABLE(more-warnings,
-	AS_HELP_STRING([--enable-more-warnings], [Maximum compiler warnings]),
-	set_more_warnings="$enableval",set_more_warnings=yes)
-AC_MSG_CHECKING(for more warnings, including -Werror)
+	AS_HELP_STRING([--enable-more-warnings], [Possible values: no/yes/error]),
+	set_more_warnings="$enableval",set_more_warnings=error)
+AC_MSG_CHECKING(for more warnings)
 if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then
 	AC_MSG_RESULT(yes)
-	CFLAGS="-Wall -Werror -std=gnu89 $CFLAGS"
+	CFLAGS="-Wall -std=gnu89 $CFLAGS"
 
 	for option in -Wshadow -Wmissing-declarations -Wmissing-prototypes \
 		      -Wdeclaration-after-statement -Wstrict-prototypes \
 		      -Wfloat-equal -Wno-unused-parameter -Wno-sign-compare \
-		      -fno-strict-aliasing; do
+		      -fno-strict-aliasing -Wno-unused-but-set-variable; do
 		SAVE_CFLAGS="$CFLAGS"
 		CFLAGS="$CFLAGS $option"
 		AC_MSG_CHECKING([whether gcc understands $option])
@@ -25,6 +25,9 @@ if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then
 		unset SAVE_CFLAGS
 	done
 	unset option
+	if test "x$set_more_warnings" = xerror; then
+		CFLAGS="$CFLAGS -Werror"
+	fi
 else
 	AC_MSG_RESULT(no)
 fi