From 9a8ab1c39970a4938a72d94e6fd13be88a797590 Mon Sep 17 00:00:00 2001 From: Daniel Santos Date: Thu, 21 Feb 2013 16:41:55 -0800 Subject: [PATCH] bug.h, compiler.h: introduce compiletime_assert & BUILD_BUG_ON_MSG Introduce compiletime_assert to compiler.h, which moves the details of how to break a build and emit an error message for a specific compiler to the headers where these details should be. Following in the tradition of the POSIX assert macro, compiletime_assert creates a build-time error when the supplied condition is *false*. Next, we add BUILD_BUG_ON_MSG to bug.h which simply wraps compiletime_assert, inverting the logic, so that it fails when the condition is *true*, consistent with the language "build bug on." This macro allows you to specify the error message you want emitted when the supplied condition is true. Finally, we remove all other code from bug.h that mucks with these details (BUILD_BUG & BUILD_BUG_ON), and have them all call BUILD_BUG_ON_MSG. This not only reduces source code bloat, but also prevents the possibility of code being changed for one macro and not for the other (which was previously the case for BUILD_BUG and BUILD_BUG_ON). Since __compiletime_error_fallback is now only used in compiler.h, I'm considering it a private macro and removing the double negation that's now extraneous. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Daniel Santos Cc: Andi Kleen Cc: Borislav Petkov Cc: David Rientjes Cc: Joe Perches Cc: Josh Triplett Cc: Paul Gortmaker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed