[compiler-rt] [compiler-rt] Relax CHECK line in reaches_function.c (PR #83089)

[Alexander Richardson via llvm-commits]

https://github.com/arichardson created https://github.com/llvm/llvm-project/pull/83089

In my build environment, the output is a relative path:
```
test/dfsan/reaches_function.c:34 add.dfsan
test/dfsan/reaches_function.c:56 main
```

This fixes check-dfsan in my configuration:
```
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -G Ninja
-DCMAKE_C_COMPILER=$HOME/output/upstream-llvm/bin/clang
-DCMAKE_CXX_COMPILER=$HOME/output/upstream-llvm/bin/clang++
-DCOMPILER_RT_INCLUDE_TESTS=ON
-DLLVM_EXTERNAL_LIT=$HOME/build/upstream-llvm-project-build/bin/llvm-lit
-DLLVM_CMAKE_DIR=$HOME/output/upstream-llvm
-DCOMPILER_RT_DEBUG=OFF
-S $HOME/src/upstream-llvm-project/compiler-rt
-B $HOME/src/upstream-llvm-project/compiler-rt/cmake-build-all-sanitizers
```


>From 0daa7885dd9c70481f6fd33232f64c021c387cd5 Mon Sep 17 00:00:00 2001
From: Alex Richardson <alexrichardson at google.com>
Date: Mon, 26 Feb 2024 17:01:50 -0800
Subject: [PATCH] =?UTF-8?q?[=F0=9D=98=80=F0=9D=97=BD=F0=9D=97=BF]=20initia?=
 =?UTF-8?q?l=20version?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Created using spr 1.3.4
---
 compiler-rt/test/dfsan/reaches_function.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler-rt/test/dfsan/reaches_function.c b/compiler-rt/test/dfsan/reaches_function.c
index 9e2bcee935b2ac..afcd08cee76a0e 100644
--- a/compiler-rt/test/dfsan/reaches_function.c
+++ b/compiler-rt/test/dfsan/reaches_function.c
@@ -32,7 +32,7 @@ void my_dfsan_reaches_function_callback(dfsan_label label, dfsan_origin origin,
 __attribute__((noinline)) uint64_t add(uint64_t *a, uint64_t *b) {
 
   return *a + *b;
-  // CHECK: {{.*}}compiler-rt/test/dfsan/reaches_function.c:[[# @LINE - 1]] add.dfsan
+  // CHECK: test/dfsan/reaches_function.c:[[# @LINE - 1]] add.dfsan
   // CHECK-ORIGIN-TRACKING: Origin value: 0x10000002, Taint value was stored to memory at
   // CHECK-ORIGIN-TRACKING: #0 {{.*}} in add.dfsan {{.*}}compiler-rt/test/dfsan/reaches_function.c:[[# @LINE - 3]]:{{.*}}
   // CHECK-ORIGIN-TRACKING: Origin value: 0x1, Taint value was created at
@@ -54,7 +54,7 @@ int main(int argc, char *argv[]) {
 
   dfsan_set_label(8, &a, sizeof(a));
   uint64_t c = add(&a, &b);
-  // CHECK: {{.*}}compiler-rt/test/dfsan/reaches_function.c:[[# @LINE - 1]] main
+  // CHECK: test/dfsan/reaches_function.c:[[# @LINE - 1]] main
   // CHECK-ORIGIN-TRACKING: Origin value: 0x10000002, Taint value was stored to memory at
   // CHECK-ORIGIN-TRACKING: #0 {{.*}} in add.dfsan {{.*}}compiler-rt/test/dfsan/reaches_function.c:{{.*}}
   // CHECK-ORIGIN-TRACKING: Origin value: 0x1, Taint value was created at