[PATCH] include: add BUG_WARN_MSG for custom error message on bug condition

[Peter Hutterer]

__BUG_WARN_MSG is a simple helper to enable call with and without varargs. I
couldn't find a way to otherwise do this without getting gcc warnings.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 include/misc.h |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/include/misc.h b/include/misc.h
index 0584f08..2b8ea2e 100644
--- a/include/misc.h
+++ b/include/misc.h
@@ -359,11 +359,18 @@ typedef struct _CharInfo *CharInfoPtr; /* also in fonts/include/font.h */
 extern _X_EXPORT unsigned long globalSerialNumber;
 extern _X_EXPORT unsigned long serverGeneration;
 
-#define BUG_WARN(cond)                                                    \
+/* Don't use this directly, use BUG_WARN or BUG_WARN_MSG instead */
+#define __BUG_WARN_MSG(cond, with_msg, ...)                                \
           do { if (cond) {                                                \
               ErrorF("BUG: triggered 'if (" #cond ")'\nBUG: %s:%d in %s()\n",     \
                       __FILE__, __LINE__, __func__);                      \
+              if (with_msg) ErrorF(__VA_ARGS__);                          \
               xorg_backtrace();                                           \
           } } while(0)
 
+#define BUG_WARN_MSG(cond, msg, ...)                                      \
+          __BUG_WARN_MSG(cond, 1, msg, __VA_ARGS__)
+
+#define BUG_WARN(cond)  __BUG_WARN_MSG(cond, 0, NULL)
+
 #endif /* MISC_H */
-- 
1.7.7.1