This patch adds a new static assertion macro that can be used to check the offsets in structures that overlay register sets at compile time. It uses the _Static_assert() declaration from the new ISO C11 standard, which is supported (even without -std=c11) by GCC after version 4.6. (There is supposedly also support in clang, although I haven't tried it... let's deal with compiler issues when/if they turn up.) I've added it to all structures for our current ARM SoCs for now, and I think every new register overlay we add going forward should use them (at least for the last member, but feel free to add more if you think it's useful). Change-Id: If32510e7049739ad05618d363a854dc372d64386 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/179412 Reviewed-by: David Hendricks <dhendrix@chromium.org> Reviewed-by: Stefan Reinauer <reinauer@chromium.org> (cherry picked from commit cef5fa13c31375a316ca4556c0039b17c8ea7900) Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com> Reviewed-on: http://review.coreboot.org/6905 Tested-by: build bot (Jenkins)