[PATCH] D95573: [ASTMatchers] Avoid pathological traversal over nested lambdas

[Stephen Kelly via Phabricator via cfe-commits]

steveire created this revision.
steveire added a reviewer: aaron.ballman.
steveire requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D95573

Files:
  clang/include/clang/AST/RecursiveASTVisitor.h
  clang/lib/ASTMatchers/ASTMatchFinder.cpp


Index: clang/lib/ASTMatchers/ASTMatchFinder.cpp
===================================================================
--- clang/lib/ASTMatchers/ASTMatchFinder.cpp
+++ clang/lib/ASTMatchers/ASTMatchFinder.cpp
@@ -561,9 +561,9 @@
         if (LE->hasExplicitResultType())
           TraverseTypeLoc(Proto.getReturnLoc());
         TraverseStmt(LE->getTrailingRequiresClause());
-
-        TraverseStmt(LE->getBody());
       }
+
+      TraverseStmt(LE->getBody());
       return true;
     }
     return RecursiveASTVisitor<MatchASTVisitor>::dataTraverseNode(S, Queue);
@@ -702,6 +702,10 @@
   bool shouldVisitTemplateInstantiations() const { return true; }
   bool shouldVisitImplicitCode() const { return true; }
 
+  // We visit the lambda body explicitly, so instruct the RAV
+  // to not visit it on our behalf too.
+  bool shouldVisitLambdaBody() const { return false; }
+
   bool IsMatchingInASTNodeNotSpelledInSource() const override {
     return TraversingASTNodeNotSpelledInSource;
   }
Index: clang/include/clang/AST/RecursiveASTVisitor.h
===================================================================
--- clang/include/clang/AST/RecursiveASTVisitor.h
+++ clang/include/clang/AST/RecursiveASTVisitor.h
@@ -186,6 +186,9 @@
   /// code, e.g., implicit constructors and destructors.
   bool shouldVisitImplicitCode() const { return false; }
 
+  /// Return whether this visitor should recurse into lambda body
+  bool shouldVisitLambdaBody() const { return true; }
+
   /// Return whether this visitor should traverse post-order.
   bool shouldTraversePostOrder() const { return false; }
 
@@ -2057,6 +2060,14 @@
       // by clang.
       (!D->isDefaulted() || getDerived().shouldVisitImplicitCode());
 
+  if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
+    if (const auto *RD = MD->getParent()) {
+      if (RD->isLambda()) {
+        VisitBody = VisitBody && getDerived().shouldVisitLambdaBody();
+      }
+    }
+  }
+
   if (VisitBody) {
     TRY_TO(TraverseStmt(D->getBody())); // Function body.
   }


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