Suppress MSAN false positives from uninstrumented 3rd-party libraries?

I understand that in order to use MSAN, the entire application (including dependencies) must be compiled with instrumentation, otherwise we get false positives.

Often times, this is not possible, and as such it creates a really high bar to be able to use MSAN in a real-world project. For example, the only reason we can't dump Valgrind just yet is we can't use MSAN.

Would it be possible instead to just be able to suppress those warnings in external libraries? I tried playing a bit with the `-fsanitize-ignorelist` option but I still got warnings even if I suppressed everything (maybe I used that incorrectly).

Thanks!

Start by investigating the MSAN behavior described for uninstrumented third-party libraries and the attempted -fsanitize-ignorelist configuration. The issue does not name files or tests; done would require a decided, documented way to suppress the reported false positives without instrumenting those dependencies.

Written by the indexing model from the issue text.