Force erroneous inclusions of compiler-*.h files to be errors

[pandora-kernel.git] / include / linux / compiler-gcc4.h

diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index a03e939..ee7ca5d 100644 (file)
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -1,4 +1,6 @@
-/* Never include this file directly.  Include <linux/compiler.h> instead.  */
+#ifndef __LINUX_COMPILER_H
+#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
+#endif
 
 /* These definitions are for GCC v4.x.  */
 #include <linux/compiler-gcc.h>
@@ -23,3 +25,21 @@
  * code
  */
 #define uninitialized_var(x) x = x
+
+#if !(__GNUC__ == 4 && __GNUC_MINOR__ < 3)
+/* Mark functions as cold. gcc will assume any path leading to a call
+   to them will be unlikely.  This means a lot of manual unlikely()s
+   are unnecessary now for any paths leading to the usual suspects
+   like BUG(), printk(), panic() etc. [but let's keep them for now for
+   older compilers]
+
+   Early snapshots of gcc 4.3 don't support this and we can't detect this
+   in the preprocessor, but we can live with this because they're unreleased.
+   Maketime probing would be overkill here.
+
+   gcc also has a __attribute__((__hot__)) to move hot functions into
+   a special section, but I don't see any sense in this right now in
+   the kernel context */
+#define __cold                 __attribute__((__cold__))
+
+#endif