summaryrefslogtreecommitdiff
path: root/include/linux/compiler-gcc4.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/compiler-gcc4.h')
-rw-r--r--include/linux/compiler-gcc4.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index 450fa597c94d..ab3af40a53c6 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -36,4 +36,18 @@
the kernel context */
#define __cold __attribute__((__cold__))
+
+#if __GNUC_MINOR__ >= 5
+/*
+ * Mark a position in code as unreachable. This can be used to
+ * suppress control flow warnings after asm blocks that transfer
+ * control elsewhere.
+ *
+ * Early snapshots of gcc 4.5 don't support this and we can't detect
+ * this in the preprocessor, but we can live with this because they're
+ * unreleased. Really, we need to have autoconf for the kernel.
+ */
+#define unreachable() __builtin_unreachable()
+#endif
+
#endif