[libcxx-commits] [libcxx] [ASan][libc++] std::basic_string annotations (PR #72677)

[Louis Dionne via libcxx-commits]

ldionne wrote:

If we encode the fact that libc++ was built with instrumentation in `__config_site`, a user should be able to pass `-fsanitize=address` while building against a library that isn't built with annotations, and the container annotations would be disabled. And if a user uses a dylib that is built with instrumentation and doesn't pass `-fsanitize=address`, I'm not sure what would happen but we should make it work.

Basically the idea would be to make these container annotations distinct from whether the user is compiling with `-fsanitize=address`, and in the future we should ensure that we ship an instrumented version of libc++ at all times, and then make `-fsanitize=address` select that instrumented version.

https://github.com/llvm/llvm-project/pull/72677