[PATCH] D103304: Update and improve compiler-rt tests for -mllvm -asan_use_after_return=(never|[runtime]|always).

[Kevin Athey via Phabricator via llvm-commits]

kda added inline comments.


================
Comment at: compiler-rt/lib/asan/asan_rtl.cpp:402
+  if (&__asan_detect_use_after_return_always &&
+      __asan_detect_use_after_return_always) {
+    __asan_option_detect_stack_use_after_return = 1;
----------------
morehouse wrote:
> According to the comment above, we should not override the runtime flag when this is 1.
Check the code in AddressSanitizer, this global (__asan_detect_use_after_return_always) is only created when ClUseAfterReturn is set to 2.


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Comment at: llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp:2654
+          M, IntTy, /*isConstant=*/true, GlobalValue::WeakODRLinkage,
+          ConstantInt::get(IntTy, 1), "__asan_detect_use_after_return_always");
+    });
----------------
morehouse wrote:
> The constant value 1 is also inconsistent with the comment in the runtime (should be 2).
I could change it if you felt it made the code clearer.  __asan_detect_use_after_return_always is functionally a boolean.  It is only created if ClUseAfterReturn is equal to Always (2).


Repository:
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  https://reviews.llvm.org/D103304/new/

https://reviews.llvm.org/D103304