m4: add Werror when checking for compiler flags

[mesa.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index 156fb15fd3d51ce48703be6cefc5fe305dc1e7be..be9674a0c1db42121b2734cc324f62c786f2347f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -297,6 +297,12 @@ esac
 
 AM_CONDITIONAL(HAVE_ANDROID, test "x$android" = xyes)
 
+# Toggle Werror since at some point clang started treating unknown -W
+# flags as warnings, succeeding with the build, yet issuing an annoying
+# warning.
+save_CFLAGS="$CFLAGS"
+export CFLAGS="$CFLAGS -Werror"
+
 dnl
 dnl Check compiler flags
 dnl
@@ -312,6 +318,11 @@ AX_CHECK_COMPILE_FLAG([-fno-math-errno],                       [CFLAGS="$CFLAGS
 AX_CHECK_COMPILE_FLAG([-fno-trapping-math],                    [CFLAGS="$CFLAGS -fno-trapping-math"])
 AX_CHECK_COMPILE_FLAG([-fvisibility=hidden],                   [VISIBILITY_CFLAGS="-fvisibility=hidden"])
 
+CFLAGS="$save_CFLAGS"
+
+# Toggle Werror since at some point clang started treating unknown -W
+# flags as warnings, succeeding with the build, yet issuing an annoying
+# warning.
 dnl
 dnl Check C++ compiler flags
 dnl