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

[Matt Morehouse via Phabricator via llvm-commits]

morehouse 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;
----------------
vitalybuka wrote:
> kda wrote:
> > 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.
> I guess @morehouse comment is about comment on the line 39.
> It makes impression that value stored makes a difference, but as we discussed before only presence matters.
> I would put there just:
> if  __asan_detect_use_after_return_always is defined, runtime must not check detect_stack_use_after_return and create FakeStack
> 
> 
> We don't expect 0 there
> ```
> if (&__asan_detect_use_after_return_always) {
>   CHECK_EQ(1, __asan_detect_use_after_return_always);
> ```
Yes my main concern was the inaccurate comment.

But my understanding was that @kda wanted 3 options:  always, never, and decided-by-runtime-flag.  In that case, we *do* expect a zero value to indicate the "never" option.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103304/new/

https://reviews.llvm.org/D103304