[ExprMutation] fix false postives on pointer-to-member operator (#166069)

Fixed: #161913

---------

Co-authored-by: Baranov Victor <[email protected]>

Author: HerrCai0907

clang-tools-extra/docs/ReleaseNotes.rst

@@ -379,7 +379,8 @@ Changes in existing checks
   <clang-tidy/checks/misc/const-correctness>` check to avoid false
   positives when pointers is transferred to non-const references
   and avoid false positives of function pointer and fix false
-  positives on return of non-const pointer.
+  positives on return of non-const pointer and fix false positives on
+  pointer-to-member operator.
 
 - Improved :doc:`misc-header-include-cycle
   <clang-tidy/checks/misc/header-include-cycle>` check performance.

clang/lib/Analysis/ExprMutationAnalyzer.cpp

@@ -746,11 +746,14 @@ ExprMutationAnalyzer::Analyzer::findPointeeMemberMutation(const Expr *Exp) {
                     Stm, Context));
   if (MemberCallExpr)
     return MemberCallExpr;
-  const auto Matches =
-      match(stmt(forEachDescendant(
-                memberExpr(hasObjectExpression(canResolveToExprPointee(Exp)))
-                    .bind(NodeID<Expr>::value))),
-            Stm, Context);
+  const auto Matches = match(
+      stmt(forEachDescendant(
+          expr(anyOf(memberExpr(
+                         hasObjectExpression(canResolveToExprPointee(Exp))),
+                     binaryOperator(hasOperatorName("->*"),
+                                    hasLHS(canResolveToExprPointee(Exp)))))
+              .bind(NodeID<Expr>::value))),
+      Stm, Context);
   return findExprMutation(Matches);
 }
 

clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp

@@ -2076,4 +2076,19 @@ TEST(ExprMutationAnalyzerTest, PointeeMutatedByReturn) {
   }
 }
 
+TEST(ExprMutationAnalyzerTest, PointeeMutatedByPointerToMemberOperator) {
+  // GH161913
+  const std::string Code = R"(
+    struct S { int i; };
+    void f(S s) {
+      S *x = &s;
+      (x->*(&S::i))++;
+    }
+  )";
+  auto AST = buildASTFromCodeWithArgs(Code, {"-Wno-everything"});
+  auto Results =
+      match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_TRUE(isPointeeMutated(Results, AST.get()));
+}
+
 } // namespace clang