Our assembly does not use the GOT to reference symbols, which means
references to visible symbols will often require a TEXTREL. This is
undesirable, so all assembly-referenced symbols should be hidden. CPU
capabilities are the only such symbols defined in C.
These symbols may be hidden by doing at least one of:
1. Build with -fvisibility=hidden
2. __attribute__((visibility("hidden"))) in C.
3. .extern + .hidden in some assembly file referencing the symbol.
We have lots of consumers and can't always rely on (1) happening. We
were doing (3) by way of d216b71f90 and
16e38b2b8f, but missed 32-bit x86 because
it doesn't cause a linker error.
Those two patches are not in upstream. Upstream instead does (3) by way
of x86cpuid.pl and friends, but we have none of these files.
Standardize on doing (2). This avoids accidentally getting TEXTRELs on
some 32-bit x86 build configurations. This also undoes
d216b71f90 and
16e38b2b8f. They are no now longer needed
and reduce the upstream diff.
Change-Id: Ib51c43fce6a7d8292533635e5d85d3c197a93644
Reviewed-on: https://boringssl-review.googlesource.com/22064
Commit-Queue: Matt Braithwaite <mab@google.com>
Reviewed-by: Matt Braithwaite <mab@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
38636aba74