diff options
author | David Daney <david.daney@cavium.com> | 2012-01-10 15:07:25 -0800 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2015-05-09 23:16:12 +0100 |
commit | 693c24191a7fec64311458b21ce0126d99059606 (patch) | |
tree | 91448786186dc8dd93f3e32bbcdf9af78e7f5f76 /include/misc | |
parent | cbeb30c62f1b5c9ec18840cbda54da4e33ed34b4 (diff) | |
download | kernel_samsung_smdk4412-693c24191a7fec64311458b21ce0126d99059606.zip kernel_samsung_smdk4412-693c24191a7fec64311458b21ce0126d99059606.tar.gz kernel_samsung_smdk4412-693c24191a7fec64311458b21ce0126d99059606.tar.bz2 |
kernel.h: add BUILD_BUG() macro
commit 1399ff86f2a2bbacbbe68fa00c5f8c752b344723 upstream.
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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'include/misc')
0 files changed, 0 insertions, 0 deletions