alistair23-linux/include
David Daney 1399ff86f2 kernel.h: add BUILD_BUG() macro
We can place this in definitions that we expect the compiler to remove by
dead code elimination.  If this assertion fails, we get a nice error
message at build time.

The GCC function attribute error("message") was added in version 4.3, so
we define a new macro __linktime_error(message) to expand to this for
GCC-4.3 and later.  This will give us an error diagnostic from the
compiler on the line that fails.  For other compilers
__linktime_error(message) expands to nothing, and we have to be content
with a link time error, but at least we will still get a build error.

BUILD_BUG() expands to the undefined function __build_bug_failed() and
will fail at link time if the compiler ever emits code for it.  On GCC-4.3
and later, attribute((error())) is used so that the failure will be noted
at compile time instead.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: DM <dm.n9107@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 16:30:42 -08:00
..
acpi
asm-generic Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-01-08 12:19:57 -08:00
crypto
drm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-01-08 13:21:22 -08:00
keys
linux kernel.h: add BUILD_BUG() macro 2012-01-10 16:30:42 -08:00
math-emu
media Merge branch 'depends/rmk/restart' into next/cleanup 2012-01-07 11:51:28 +00:00
misc
mtd
net Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2012-01-09 13:08:28 -08:00
pcmcia
rdma rdma/core: Fix sparse warnings 2012-01-04 09:17:45 -08:00
rxrpc
scsi
sound Driver specific changes 2012-01-09 14:39:22 -08:00
target
trace mm-tracepoint: rename page-free events 2012-01-10 16:30:41 -08:00
video
xen Merge branch 'driver-core-next' into Linux 3.2 2012-01-06 11:42:52 -08:00
Kbuild