[compiler-rt] [ASan][Windows] Honor asan config flags on windows when set through the user function (PR #122990)

[David Justo via llvm-commits]

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@@ -390,17 +390,57 @@ void PrintAddressSpaceLayout() {
           kHighShadowBeg > kMidMemEnd);
 }
 
+// Apply most options specified either through the ASAN_OPTIONS
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davidmrdavid wrote:

I don't think so. It seems to me that `AsanActivate` is about restoring previously 'stashed away' allocator flags, whereas `ApplyFlags` is about applying those flags _for the first time_.

But now that you call this out - I think `ApplyFlags` might not work correctly if ASan starts deactivated, as re-activating it will override the flags. I need to think about that a bit longer. Thanks for calling this out!

https://github.com/llvm/llvm-project/pull/122990