[compiler-rt] [compiler-rt][asan][test] Make wchar tests more robust (PR #163715)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Maosu Zhao (zhaomaosu)

<details>
<summary>Changes</summary>

The stack buffer which is used to trigger out of bounds issue doesn't have obervable side effects, so it can easily be optimized by compiler as dead code.

---
Full diff: https://github.com/llvm/llvm-project/pull/163715.diff


4 Files Affected:

- (modified) compiler-rt/test/asan/TestCases/wcscat.cpp (+4-2) 
- (modified) compiler-rt/test/asan/TestCases/wcscpy.cpp (+4-2) 
- (modified) compiler-rt/test/asan/TestCases/wcsncat.cpp (+4-2) 
- (modified) compiler-rt/test/asan/TestCases/wcsncpy.cpp (+4-2) 


``````````diff
diff --git a/compiler-rt/test/asan/TestCases/wcscat.cpp b/compiler-rt/test/asan/TestCases/wcscat.cpp
index fd0b5a4310351..beab1dc52e437 100644
--- a/compiler-rt/test/asan/TestCases/wcscat.cpp
+++ b/compiler-rt/test/asan/TestCases/wcscat.cpp
@@ -9,11 +9,13 @@
 int main() {
   const wchar_t *start = L"X means ";
   const wchar_t *append = L"dog";
-  wchar_t goodDst[12];
+  wchar_t goodArray[12];
+  wchar_t *volatile goodDst = goodArray;
   wcscpy(goodDst, start);
   wcscat(goodDst, append);
 
-  wchar_t badDst[9];
+  wchar_t badArray[9];
+  wchar_t *volatile badDst = badArray;
   wcscpy(badDst, start);
   fprintf(stderr, "Good so far.\n");
   // CHECK-DAG: Good so far.
diff --git a/compiler-rt/test/asan/TestCases/wcscpy.cpp b/compiler-rt/test/asan/TestCases/wcscpy.cpp
index 8133a588cb071..2b828035cb498 100644
--- a/compiler-rt/test/asan/TestCases/wcscpy.cpp
+++ b/compiler-rt/test/asan/TestCases/wcscpy.cpp
@@ -8,10 +8,12 @@
 
 int main() {
   const wchar_t *src = L"X means dog";
-  wchar_t goodDst[12];
+  wchar_t goodArray[12];
+  wchar_t *volatile goodDst = goodArray;
   wcscpy(goodDst, src);
 
-  wchar_t badDst[7];
+  wchar_t badArray[7];
+  wchar_t *volatile badDst = badArray;
   fprintf(stderr, "Good so far.\n");
   // CHECK-DAG: Good so far.
   fflush(stderr);
diff --git a/compiler-rt/test/asan/TestCases/wcsncat.cpp b/compiler-rt/test/asan/TestCases/wcsncat.cpp
index 365e732e2d051..04cdcf290ffed 100644
--- a/compiler-rt/test/asan/TestCases/wcsncat.cpp
+++ b/compiler-rt/test/asan/TestCases/wcsncat.cpp
@@ -9,11 +9,13 @@
 int main() {
   const wchar_t *start = L"X means ";
   const wchar_t *append = L"dog";
-  wchar_t goodDst[15];
+  wchar_t goodArray[15];
+  wchar_t *volatile goodDst = goodArray;
   wcscpy(goodDst, start);
   wcsncat(goodDst, append, 5);
 
-  wchar_t badDst[11];
+  wchar_t badArray[11];
+  wchar_t *volatile badDst = badArray;
   wcscpy(badDst, start);
   wcsncat(badDst, append, 1);
   fprintf(stderr, "Good so far.\n");
diff --git a/compiler-rt/test/asan/TestCases/wcsncpy.cpp b/compiler-rt/test/asan/TestCases/wcsncpy.cpp
index 485ddc4804dcd..9e11b55fe4ec9 100644
--- a/compiler-rt/test/asan/TestCases/wcsncpy.cpp
+++ b/compiler-rt/test/asan/TestCases/wcsncpy.cpp
@@ -8,10 +8,12 @@
 
 int main() {
   const wchar_t *src = L"X means dog";
-  wchar_t goodDst[12];
+  wchar_t goodArray[12];
+  wchar_t *volatile goodDst = goodArray;
   wcsncpy(goodDst, src, 12);
 
-  wchar_t badDst[7];
+  wchar_t badArray[7];
+  wchar_t *volatile badDst = badArray;
   wcsncpy(badDst, src, 7); // This should still work.
   fprintf(stderr, "Good so far.\n");
   // CHECK-DAG: Good so far.

``````````

</details>


https://github.com/llvm/llvm-project/pull/163715