Summary:
Change the way we use ASan and UBSan together. Instead of keeping two
separate runtimes (libclang_rt.asan and libclang_rt.ubsan), embed UBSan
into ASan and get rid of libclang_rt.ubsan. If UBSan is not supported on
a platform, all UBSan sources are just compiled into dummy empty object
files. UBSan initialization code (e.g. flag parsing) is directly called
from ASan initialization, so we are able to enforce correct
initialization order.
This mirrors the approach we already use for ASan+LSan. This change
doesn't modify the way we use standalone UBSan.
Test Plan: regression test suite
Reviewers: kubabrecka, zaks.anna, rsmith, kcc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8646
llvm-svn: 233861
Specifically, use .preinit_array initialization on Linux and dynamic global
initializer on another platforms. Historically UBSan didn't have any
initialization code and its runtime was stateless. This is no longer the
case - UBSan relies on some non-trivial functionality from sanitizer_common
(e.g. online symbolization) and is now configurable by runtime flags.
Additionally, we've dropped support for enabling UBSan only for a few shared
objects, so UBSan is now always linked into the main executable, so now
we can use similar initialization as all the rest sanitizers.
llvm-svn: 213983
Alexey Samsonov