[clang] [NFC][clang][test] Make `instantiation-depth-default.cpp` a valid test case under `asan` and `ubsan` configs (PR #75254)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Duo Wang (wdunicornpro)

<details>
<summary>Changes</summary>

Clang test `instantiation-depth-default.cpp` fails on Windows when built with `ubsan` due to extra warnings printed by the compiler:
```console
File instantiation-depth-default.cpp Line 11: stack nearly exhausted; compilation time may suffer, and crashes due to stack overflow are likely
```
The test case was disabled for `asan` in 571a647 because of the extra stack usage. Since `ubsan` also increases stack usage, seems like the two configs should be treated uniformly.

On the other hand, we might be able to re-enable this test case for `asan`. During some preliminary testing on Windows, Linux, and macOS with the host compiler being as old as clang-10, the test case exited successfully if the `stack-exhausted` warnings are suppressed, though I haven't done exhaustive testing across platforms and clang versions. Any insights into whether this change will introduce any risks to existing buildbots is appreciated.

Enabling this test case for `asan` helps to improve our test coverage, but if it causes problems on any buildbot, marking it as unsupported for `ubsan` is also a viable solution.

---
Full diff: https://github.com/llvm/llvm-project/pull/75254.diff


1 Files Affected:

- (modified) clang/test/SemaTemplate/instantiation-depth-default.cpp (+5-11) 


``````````diff
diff --git a/clang/test/SemaTemplate/instantiation-depth-default.cpp b/clang/test/SemaTemplate/instantiation-depth-default.cpp
index f5835b86b3a385..362cf2b34aef51 100644
--- a/clang/test/SemaTemplate/instantiation-depth-default.cpp
+++ b/clang/test/SemaTemplate/instantiation-depth-default.cpp
@@ -1,18 +1,12 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -ftemplate-backtrace-limit=2 %s
-//
-// FIXME: Disable this test when Clang was built with ASan, because ASan
-// increases our per-frame stack usage enough that this test no longer fits
-// within our normal stack space allocation.
-// UNSUPPORTED: asan
-//
+// RUN: %clang_cc1 -fsyntax-only -verify -ftemplate-backtrace-limit=2 -Wno-stack-exhausted %s
 // The default stack size on NetBSD is too small for this test.
 // UNSUPPORTED: system-netbsd
 
 template<int N, typename T> struct X : X<N+1, T*> {};
-// expected-error-re at 11 {{recursive template instantiation exceeded maximum depth of 1024{{$}}}}
-// expected-note at 11 {{instantiation of template class}}
-// expected-note at 11 {{skipping 1023 contexts in backtrace}}
-// expected-note at 11 {{use -ftemplate-depth=N to increase recursive template instantiation depth}}
+// expected-error-re at 5 {{recursive template instantiation exceeded maximum depth of 1024{{$}}}}
+// expected-note at 5 {{instantiation of template class}}
+// expected-note at 5 {{skipping 1023 contexts in backtrace}}
+// expected-note at 5 {{use -ftemplate-depth=N to increase recursive template instantiation depth}}
 
 X<0, int> x; // expected-note {{in instantiation of}}
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/75254