[Lldb-commits] [lldb] [lldb] Fix source line annotations for libsanitizers traces (PR #154247)

[Jonas Devlieghere via lldb-commits]

================
@@ -176,10 +170,24 @@ HistoryThreads MemoryHistoryASan::GetHistoryThreads(lldb::addr_t address) {
   options.SetAutoApplyFixIts(false);
   options.SetLanguage(eLanguageTypeObjC_plus_plus);
 
+  // The ASan compiler-rt runtime already massages the return addresses into
+  // call addresses, so we don't want LLDB's unwinder to try to locate the
+  // previous instruction again as this might lead to us reporting a different
+  // line.
+  auto pc_type = TracePCType::Calls;
+
   if (auto m = GetPreferredAsanModule(process_sp->GetTarget())) {
     SymbolContextList sc_list;
     sc_list.Append(SymbolContext(std::move(m)));
     options.SetPreferredSymbolContexts(std::move(sc_list));
+  } else if (process_sp->GetTarget()
+                 .GetArchitecture()
+                 .GetTriple()
+                 .isOSDarwin()) {
+    // Darwin, but not ASan compiler-rt implies libsanitizers which collects
+    // return addresses.  It also discards a few non-user frames at the top of
+    // the stack.
+    pc_type = TracePCType::ReturnsNoZerothFrame;
   }
----------------
JDevlieghere wrote:

Could we refactor `GetPreferredAsanModule` to abstract over this, instead of having no module + darwin _imply_ libsantizers? This could return a: 
```
struct {
  TracePCType pc_type;
  ModuleSP asan_module;
}
```


https://github.com/llvm/llvm-project/pull/154247