tree 58a15fbdf9f04d70534a4ab068ca41e97fd86ee7
parent 47c3ca02be7551945603db46ebe3eecaa2f4aea9
author Nicolas Capens <capn@google.com> 1625117008 -0400
committer Nicolas Capens <nicolascapens@google.com> 1625152913 +0000

Work around MemorySanitizer false-positive

The initialization of static thread-local data is not observed by
MemorySanitizer when inside a shared library, leading to false-positive
use-of-uninitialized-data errors:
https://github.com/google/sanitizers/issues/1409

We work around this by assigning an initial value to it ourselves on
first use. Note that since the flag to check whether this
initialization has already been done is itself a static thread-local,
we must suppress the MemorySanitizer check with a function attribute.

Bug: b/191050320
Change-Id: I356a89f90ff099e08a12f5562e0545ed14d93ee3
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/55328
Tested-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Corentin Wallez <cwallez@google.com>