[compiler-rt] Augment `uncaught-exception.test` fuzzer test to be msvc-compatible (PR #125924)

[David Justo via llvm-commits]

https://github.com/davidmrdavid created https://github.com/llvm/llvm-project/pull/125924

Today, the `uncaught-exception.test` fuzzer test checks for the string "libFuzzer: deadly signal" in the program output as the result of an uncaught exception.

Although this is correct for `clang`, `msvc` reports a different error message: "libFuzzer: uncaught C++ exception". Since `msvc` reuses the `libFuzzer` infrastructure for ASan regression testing, it would help us greatly if the test handled the `msvc` divergence more gracefully.

**This PR:** augments this test so check for a different string (namely "libFuzzer: uncaught C++ exception") if the compiler target matches the `msvc` naming scheme.

I understand if this is outside the scope of support for LLVM as well, and I'm also open for different approaches here. Thanks!

>From 808ce4bc9adc0ac6bcedc3ce2018e99fcfa97088 Mon Sep 17 00:00:00 2001
From: David Justo <david.justo.1996 at gmail.com>
Date: Wed, 5 Feb 2025 12:03:07 -0800
Subject: [PATCH] Augment `uncaught-exception.test` fuzzer test to be
 msvc-compatible

---
 compiler-rt/test/fuzzer/uncaught-exception.test | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/compiler-rt/test/fuzzer/uncaught-exception.test b/compiler-rt/test/fuzzer/uncaught-exception.test
index b055c88f6d90399..d1b98cfb7c74ba8 100644
--- a/compiler-rt/test/fuzzer/uncaught-exception.test
+++ b/compiler-rt/test/fuzzer/uncaught-exception.test
@@ -4,7 +4,10 @@
 REQUIRES: windows
 RUN: %cpp_compiler %S/UncaughtException.cpp -o %t-UncaughtException
 
-RUN: not %run %t-UncaughtException 2>&1 | FileCheck %s
+# Clang will fail the test with 'deadly signal', but other compilers may fail with different error messages.
+# For example, msvc fails with 'uncaught C++ exception'. So the error we check depends on the compiler target.
+RUN: not %run %t-UncaughtException 2>&1 | FileCheck %s --check-prefixes=CHECK-CRASH,%if target={{.*-windows-msvc.*}} %{CHECK-MSVC%} %else %{CHECK-ERROR%}
 
-CHECK: ERROR: libFuzzer: deadly signal
-CHECK: Test unit written to ./crash
+CHECK-ERROR: ERROR: libFuzzer: deadly signal
+CHECK-MSVC: ERROR: libFuzzer: uncaught C++ exception
+CHECK-CRASH: Test unit written to ./crash