[clang] [clang][analyzer] Fix crash caused by overload operator member function with explicit this (PR #132581)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-static-analyzer-1

Author: None (flovent)

<details>
<summary>Changes</summary>

This PR fixs #<!-- -->116372.

>From this PR #<!-- -->83585, CSA starts to model overload operator member function with explicit this as `SimpleFunctionCall` rather than `CXXMemberOperatorCall` (derived from `CXXInstanceCall`), so `CXXInstanceCall` only represents a non-static C++ member function call `with implicit this`.

For this checker, it models `operator=` for STL containers, which always uses implicit this, so the situation using explicit this can be skipped directly.

---
Full diff: https://github.com/llvm/llvm-project/pull/132581.diff


2 Files Affected:

- (modified) clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp (+5-2) 
- (added) clang/test/Analysis/issue-116372.cpp (+21) 


``````````diff
diff --git a/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
index 55ed809bfed6c..d850344db6591 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
@@ -157,8 +157,11 @@ void ContainerModeling::checkPostCall(const CallEvent &Call,
   if (Func->isOverloadedOperator()) {
     const auto Op = Func->getOverloadedOperator();
     if (Op == OO_Equal) {
-      // Overloaded 'operator=' must be a non-static member function.
-      const auto *InstCall = cast<CXXInstanceCall>(&Call);
+      // Only handle the assignment operator with implicit this
+      const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call);
+      if (!InstCall)
+        return;
+
       if (cast<CXXMethodDecl>(Func)->isMoveAssignmentOperator()) {
         handleAssignment(C, InstCall->getCXXThisVal(), Call.getOriginExpr(),
                      Call.getArgSVal(0));
diff --git a/clang/test/Analysis/issue-116372.cpp b/clang/test/Analysis/issue-116372.cpp
new file mode 100644
index 0000000000000..0843cd614d87c
--- /dev/null
+++ b/clang/test/Analysis/issue-116372.cpp
@@ -0,0 +1,21 @@
+// RUN: %clang_analyze_cc1 -std=c++23 %s -verify -analyzer-checker=alpha.cplusplus.InvalidatedIterator -analyzer-config aggressive-binary-operation-simplification=true
+
+// expected-no-diagnostics
+
+class ExplicitThis {
+  int f = 0;
+public:
+  ExplicitThis();
+  ExplicitThis(ExplicitThis& other);
+
+  ExplicitThis& operator=(this ExplicitThis& self, ExplicitThis const& other) { // no crash
+    self.f = other.f;
+    return self;
+  }
+
+  ~ExplicitThis();
+};
+
+void func(ExplicitThis& obj1) {
+    obj1 = obj1;
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/132581