[clang] 23fbfb3 - [clang][AST] RecursiveASTVisitor should visit owned TagDecl of friend type.

[Balázs Kéri via cfe-commits]

Author: Balázs Kéri
Date: 2022-08-23T09:15:55+02:00
New Revision: 23fbfb3f725ba3afca65bec04d81826d60cf7fbc

URL: https://github.com/llvm/llvm-project/commit/23fbfb3f725ba3afca65bec04d81826d60cf7fbc
DIFF: https://github.com/llvm/llvm-project/commit/23fbfb3f725ba3afca65bec04d81826d60cf7fbc.diff

LOG: [clang][AST] RecursiveASTVisitor should visit owned TagDecl of friend type.

A FriendDecl node can have a friend record type that owns a RecordDecl
object. This object is different than the one got from TypeSourceInfo
object of the FriendDecl. When building a ParentMapContext this owned
tag decaration has to be encountered to have the parent set for it.

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D131685

Added: 
    

Modified: 
    clang/include/clang/AST/RecursiveASTVisitor.h
    clang/unittests/AST/ASTContextParentMapTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/RecursiveASTVisitor.h b/clang/include/clang/AST/RecursiveASTVisitor.h
index bd7fadb87c5fe..054a7436ff749 100644
--- a/clang/include/clang/AST/RecursiveASTVisitor.h
+++ b/clang/include/clang/AST/RecursiveASTVisitor.h
@@ -1549,10 +1549,15 @@ DEF_TRAVERSE_DECL(ImportDecl, {})
 
 DEF_TRAVERSE_DECL(FriendDecl, {
   // Friend is either decl or a type.
-  if (D->getFriendType())
+  if (D->getFriendType()) {
     TRY_TO(TraverseTypeLoc(D->getFriendType()->getTypeLoc()));
-  else
+    // Traverse any CXXRecordDecl owned by this type, since
+    // it will not be in the parent context:
+    if (auto *ET = D->getFriendType()->getType()->getAs<ElaboratedType>())
+      TRY_TO(TraverseDecl(ET->getOwnedTagDecl()));
+  } else {
     TRY_TO(TraverseDecl(D->getFriendDecl()));
+  }
 })
 
 DEF_TRAVERSE_DECL(FriendTemplateDecl, {

diff  --git a/clang/unittests/AST/ASTContextParentMapTest.cpp b/clang/unittests/AST/ASTContextParentMapTest.cpp
index 4d11ef0b796a5..515dfb99e1126 100644
--- a/clang/unittests/AST/ASTContextParentMapTest.cpp
+++ b/clang/unittests/AST/ASTContextParentMapTest.cpp
@@ -119,5 +119,34 @@ TEST(GetParents, ImplicitLambdaNodes) {
       Lang_CXX11));
 }
 
+TEST(GetParents, FriendTypeLoc) {
+  auto AST = tooling::buildASTFromCode("struct A { friend struct Fr; };"
+                                       "struct B { friend struct Fr; };"
+                                       "struct Fr;");
+  auto &Ctx = AST->getASTContext();
+  auto &TU = *Ctx.getTranslationUnitDecl();
+  auto &A = *TU.lookup(&Ctx.Idents.get("A")).front();
+  auto &B = *TU.lookup(&Ctx.Idents.get("B")).front();
+  auto &FrA = *cast<FriendDecl>(*++(cast<CXXRecordDecl>(A).decls_begin()));
+  auto &FrB = *cast<FriendDecl>(*++(cast<CXXRecordDecl>(B).decls_begin()));
+  TypeLoc FrALoc = FrA.getFriendType()->getTypeLoc();
+  TypeLoc FrBLoc = FrB.getFriendType()->getTypeLoc();
+  TagDecl *FrATagDecl =
+      FrALoc.getTypePtr()->getAs<ElaboratedType>()->getOwnedTagDecl();
+  TagDecl *FrBTagDecl =
+      FrBLoc.getTypePtr()->getAs<ElaboratedType>()->getOwnedTagDecl();
+
+  EXPECT_THAT(Ctx.getParents(A), ElementsAre(DynTypedNode::create(TU)));
+  EXPECT_THAT(Ctx.getParents(B), ElementsAre(DynTypedNode::create(TU)));
+  EXPECT_THAT(Ctx.getParents(FrA), ElementsAre(DynTypedNode::create(A)));
+  EXPECT_THAT(Ctx.getParents(FrB), ElementsAre(DynTypedNode::create(B)));
+  EXPECT_THAT(Ctx.getParents(FrALoc), ElementsAre(DynTypedNode::create(FrA)));
+  EXPECT_THAT(Ctx.getParents(FrBLoc), ElementsAre(DynTypedNode::create(FrB)));
+  EXPECT_TRUE(FrATagDecl);
+  EXPECT_FALSE(FrBTagDecl);
+  EXPECT_THAT(Ctx.getParents(*FrATagDecl),
+              ElementsAre(DynTypedNode::create(FrA)));
+}
+
 } // end namespace ast_matchers
 } // end namespace clang