testing for tail call optimization repression when sanitizing use-after-dtor

[nmusgrave]

Summary

Verify that running in optimized mode while checking for use-after-dtor errors, does not generate tail call invocation of destructor. This avoids possible error where stack frame for the destructor is eliminated, making tracking down the errors more difficult.

[eugenis]

test/msan/dtor-tail-call.cc

35 ↗

(On Diff #30966)

Use @LINE to refer to line numbers in the test case.

37 ↗

(On Diff #30966)

You don't need a 'CHECK-OPT' if it's the same as 'CHECK'

41 ↗

(On Diff #30966)

Don't refer to the line numbers in other files, they will change.
In this case it would be ok to end the line after __sanitizer_dtor_callback}}

[nmusgrave]

• simplified test cases

[nmusgrave]

• updated line numbering on test

[eugenis]

LGTM

Please rename the test to "use-after-dtor.cc". It's not really about tail calls, it's a general test of the use-after-dtor report.

test/msan/dtor-tail-call.cc

4 ↗

(On Diff #30981)

Add a test at -O2

35 ↗

(On Diff #30981)

Maybe remove the space after "main" to make this more robust, in case, on some other platform, the symbolizer would add () after main.

39 ↗

(On Diff #30981)

Remove () for the same reason

[nmusgrave]

• simplified test cases
• updated line numbering on test
• renamed test

test/msan/use-after-dtor.cc

+// RUN: %clangxx_msan %s -fsanitize=memory -fsanitize-memory-use-after-dtor -o %t && MSAN_OPTIONS=poison_in_dtor=1 not %run %t >%t.out 2>&1
+// RUN: FileCheck %s < %t.out
+
+// RUN: %clangxx_msan %s -O1 -fsanitize=memory -fsanitize-memory-use-after-dtor -o %t && MSAN_OPTIONS=poison_in_dtor=1 not %run %t >%t.out 2>&1
+// RUN: FileCheck %s < %t.out
+
+// RUN: %clangxx_msan %s -O2 -fsanitize=memory -fsanitize-memory-use-after-dtor -o %t && MSAN_OPTIONS=poison_in_dtor=1 not %run %t >%t.out 2>&1
+// RUN: FileCheck %s < %t.out
+
+// RUN: %clangxx_msan %s -O1 -fsanitize=memory -fsanitize-memory-use-after-dtor -fsanitize-memory-track-origins -o %t && MSAN_OPTIONS=poison_in_dtor=1 not %run %t >%t.out 2>&1
+// RUN: FileCheck %s --check-prefix=CHECK-ORIGINS < %t.out
+
+#include <sanitizer/msan_interface.h>
+#include <assert.h>
+#include <stdio.h>
+#include <new>
+
+struct Simple {
+  int x_;
+  Simple() {
+    x_ = 5;
+  }
+  ~Simple() {
+    x_ += 1;
+  }
+};
+
+int main() {
+  unsigned long buf[1];
+  assert(sizeof(Simple) <= sizeof(buf));
+
+  Simple *s = new(&buf) Simple();
+  s->~Simple();
+
+  return s->x_;
+
+  // CHECK: WARNING: MemorySanitizer: use-of-uninitialized-value
+  // CHECK: {{#0 0x.* in main.*use-after-dtor.cc:}}[[@LINE-3]]
+
+  // CHECK-ORIGINS: Memory was marked as uninitialized
+  // CHECK-ORIGINS: {{#0 0x.* in __sanitizer_dtor_callback}}
+  // CHECK-ORIGINS: {{#1 0x.* in Simple::~Simple}}
+
+  // CHECK: SUMMARY: MemorySanitizer: use-of-uninitialized-value {{.*main}}
+}