[clang] Thread Safety Analysis: Basic capability alias-analysis (PR #142955)

[Marco Elver via cfe-commits]

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@@ -1012,6 +1030,107 @@ void SExprBuilder::exitCFG(const CFGBlock *Last) {
   IncompleteArgs.clear();
 }
 
+bool SExprBuilder::isVariableReassigned(const VarDecl *VD) {
+  // Note: The search is performed lazily per-variable and result is cached. An
+  // alternative would have been to eagerly create a set of all reassigned
+  // variables, but that would consume significantly more memory. The number of
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melver wrote:

This test still fails:
```
--- a/clang/test/SemaCXX/warn-thread-safety-analysis.cpp
+++ b/clang/test/SemaCXX/warn-thread-safety-analysis.cpp
@@ -7361,6 +7361,17 @@ void testIndirectAccess(ContainerOfPtr *fc) {
   ptr->mu.Unlock();
 }

+void testControlFlowDoWhile0(Foo *f, int x) {
+  Foo *ptr = f;
+
+  f->mu.Lock();
+  if (x) {
+    do { } while (0);
+  }
+  ptr->data = 42;
+  ptr->mu.Unlock();
+}
+
```
Hmm...

https://github.com/llvm/llvm-project/pull/142955