[PATCH] D64762: [AST] Treat semantic form of InitListExpr as implicit code in traversals

[Ilya Biryukov via Phabricator via cfe-commits]

ilya-biryukov created this revision.
ilya-biryukov added a reviewer: gribozavr.
Herald added a subscriber: kadircet.
Herald added a project: clang.

In particular, do not traverse the semantic form shouldVisitImplicitCode()
returns false.

This simplifies the common case of traversals, avoiding the need to
worry about some expressions being traversed twice.

No tests break after the change, the change would allow to simplify at
least one of the usages, i.e. r366070 which had to handle this in
clangd.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D64762

Files:
  clang/include/clang/AST/RecursiveASTVisitor.h


Index: clang/include/clang/AST/RecursiveASTVisitor.h
===================================================================
--- clang/include/clang/AST/RecursiveASTVisitor.h
+++ clang/include/clang/AST/RecursiveASTVisitor.h
@@ -2308,15 +2308,25 @@
   return true;
 }
 
-// This method is called once for each pair of syntactic and semantic
-// InitListExpr, and it traverses the subtrees defined by the two forms. This
-// may cause some of the children to be visited twice, if they appear both in
-// the syntactic and the semantic form.
+// If shouldVisitImplicitCode() returns false, this method traverses only the
+// syntactic form of InitListExpr.
+// If shouldVisitImplicitCode() return true, this method is called once for
+// each pair of syntactic and semantic InitListExpr, and it traverses the
+// subtrees defined by the two forms. This may cause some of the children to be
+// visited twice, if they appear both in the syntactic and the semantic form.
 //
 // There is no guarantee about which form \p S takes when this method is called.
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseInitListExpr(
     InitListExpr *S, DataRecursionQueue *Queue) {
+  if (!getDerived().shouldVisitImplicitCode()) {
+    // Visit only the syntactic form if the clients are not interested in
+    // implicit compiler-generated semantic form.
+    TRY_TO(TraverseSynOrSemInitListExpr(
+        S->isSyntacticForm() ? S : S->getSyntacticForm(), Queue));
+    return true;
+  }
+
   TRY_TO(TraverseSynOrSemInitListExpr(
       S->isSemanticForm() ? S->getSyntacticForm() : S, Queue));
   TRY_TO(TraverseSynOrSemInitListExpr(


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