[GWP-ASan] Split options_parser and backtrace_sanitizer_common.
optional/options_parser and optional/backtrace_sanitizer_common are logically
separate components. They both use sanitizer-common to power their
functionality, but there was an unstated implicit dependency that in order for
backtrace_sanitizer_common to function correctly, one had to also use
This was because options_parser called __sanitizer::InitialiseCommonFlags. This
is a requirement for backtrace_sanitizer_common to work, as the sanitizer
unwinder uses the sanitizer_common flags and will SEGV on a null page if
they're not initialised correctly.
This patch removes this hidden dependency. You can now use
backtrace_sanitizer_common without the requirements of options_parser.
This patch also makes the GWP-ASan unit tests only have a soft dependency on
sanitizer-common. The unit tests previously explicitly used
__sanitizer::Printf, which is now provided under
tests/optional/printf_sanitizer_common. This allows Android to build the unit
tests using their own signal-safe printf().
Reviewed By: eugenis
Subscribers: srhines, mgorny, #sanitizers, llvm-commits, vlad.tsyrklevich, morehouse
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D66684