[dataflow] CXXOperatorCallExpr equal operator might not be a glvalue (#80991)

Although in a normal implementation the assumption is reasonable, it
seems that some esoteric implementation are not returning a T&. This
should be handled correctly and the values be propagated.

---------

Co-authored-by: martinboehme <mboehme@google.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
index 55af702..4b3b351 100644
--- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
@@ -2313,6 +2313,42 @@ TEST(TransferTest, AssignmentOperatorWithInitAndInheritance) {
          ASTContext &ASTCtx) {});
 }
 
+TEST(TransferTest, AssignmentOperatorReturnsVoid) {
+  // This is a crash repro.
+  std::string Code = R"(
+    struct S {
+      void operator=(S&& other);
+    };
+    void target() {
+      S s;
+      s = S();
+      // [[p]]
+    }
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {});
+}
+
+TEST(TransferTest, AssignmentOperatorReturnsByValue) {
+  // This is a crash repro.
+  std::string Code = R"(
+    struct S {
+      S operator=(S&& other);
+    };
+    void target() {
+      S s;
+      s = S();
+      // [[p]]
+    }
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {});
+}
+
 TEST(TransferTest, CopyConstructor) {
   std::string Code = R"(
     struct A {