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

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Congcong Cai (HerrCai0907)

<details>
<summary>Changes</summary>

Fixed: #<!-- -->161913

---
Full diff: https://github.com/llvm/llvm-project/pull/166069.diff


3 Files Affected:

- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+2-1) 
- (modified) clang/lib/Analysis/ExprMutationAnalyzer.cpp (+8-5) 
- (modified) clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp (+16) 


``````````diff
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index ab7dc87d9d5f3..7fa096a9495f2 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -369,7 +369,8 @@ 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 positive on
+  pointer-to-member operator.
 
 - Improved :doc:`misc-header-include-cycle
   <clang-tidy/checks/misc/header-include-cycle>` check performance.
diff --git a/clang/lib/Analysis/ExprMutationAnalyzer.cpp b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
index 75b17c545bb78..54c30c05c3e19 100644
--- a/clang/lib/Analysis/ExprMutationAnalyzer.cpp
+++ b/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);
 }
 
diff --git a/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp b/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
index ef229606de0f0..f7b799ab58719 100644
--- a/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
+++ b/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
@@ -2076,4 +2076,20 @@ 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

``````````

</details>


https://github.com/llvm/llvm-project/pull/166069