[compiler-rt] [compiler-rt][asan] Reland: wcscpy/wcsncpy interceptors and stabilize wchar tests on Darwin/Android (PR #162028)

[Yixuan Cao via llvm-commits]

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@@ -0,0 +1,26 @@
+// RUN: %clangxx_asan -O0 %s -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK
+// RUN: %clangxx_asan -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK
+// RUN: %clangxx_asan -O2 %s -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK
+// RUN: %clangxx_asan -O3 %s -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK
+
+#include <stdio.h>
+#include <wchar.h>
+
+int main() {
+  wchar_t *start = L"X means ";
+  wchar_t *append = L"dog";
+  wchar_t goodDst[12];
+  wcscpy(goodDst, start);
+  wcscat(goodDst, append);
+
+  wchar_t badDst[9];
+  wcscpy(badDst, start);
+  printf("Good so far.\n");
+  // CHECK: Good so far.
+  fflush(stdout);
+  wcscat(badDst, append); // Boom!
+  // CHECK: ERROR: AddressSanitizer: stack-buffer-overflow on address [[ADDR:0x[0-9a-f]+]] at pc {{0x[0-9a-f]+}} bp {{0x[0-9a-f]+}} sp {{0x[0-9a-f]+}}
+  // CHECK: WRITE of size {{[0-9]+}} at [[ADDR:0x[0-9a-f]+]] thread T0
+  // CHECK: #0 [[ADDR:0x[0-9a-f]+]] in wcscat{{.*}}sanitizer_common_interceptors.inc:{{[0-9]+}}
+  printf("Should have failed with ASAN error.\n");
+}
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Cao-Wuhui wrote:

> I think all files you added were missing a newline at last line (Github flags it) .

Thanks for pointing that out! I'll add the missing newline right away.

https://github.com/llvm/llvm-project/pull/162028