[compiler-rt] [compiler-rt] Write ASAN/TSAN reports to a global for crash reporting (PR #200526)

[Dan Blackwell via llvm-commits]

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@@ -1606,6 +1609,50 @@ void InstallPthreadIntrospectionHook(const ThreadEventCallbacks &callbacks) {
       pthread_introspection_hook_install(&sanitizer_pthread_introspection_hook);
 }
 
+void GetDarwinStack(
+    InternalMmapVector<llvm_sanitizer_report_payload_stack_v1>& stacks, int tid,
+    const StackTrace* s, uint16_t type, const char* description,
+    bool includeThreadName) {
+  stacks.resize(stacks.size() + 1);
+  llvm_sanitizer_report_payload_stack_v1& res = stacks.back();
+  res.type = type;
+  res.stack.thread_id = tid;
+  res.stack.time = 0;
+  res.stack.num_frames = Min(
+      (size_t)s->size, sizeof(res.stack.frames) / sizeof(res.stack.frames[0]));
+  for (size_t i = 0; i < res.stack.num_frames; i++) {
+    res.stack.frames[i] = s->trace[res.stack.num_frames - i - 1];
+  }
+  if (includeThreadName) {
+    internal_snprintf(res.description, sizeof(res.description),
+                      "%s by thread %d", description, tid);
+  } else {
+    internal_strncpy(res.description, description, sizeof(res.description));
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DanBlackwell wrote:

Is this guaranteed to fit / is it read back as a string? strncpy won't null-terminate if it fills the buffer

https://github.com/llvm/llvm-project/pull/200526