From b37b648b3f2bba4c557a1604ced19b526b25a372 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 12 Feb 2010 17:40:34 +0000
Subject: [PATCH] Improve representation of tag declarations first declared or
 defined within the declarator of another declaration, from Enea Zaffanella!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@95991 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/AST/Decl.h       | 17 +++++++++--------
 lib/Frontend/PCHReaderDecl.cpp |  2 +-
 lib/Frontend/PCHWriterDecl.cpp |  2 +-
 lib/Sema/SemaType.cpp          |  5 ++++-
 4 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index b9c9d9eb2c..07442896dc 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -1511,9 +1511,10 @@ private:
   /// it is a declaration ("struct foo;").
   bool IsDefinition : 1;
 
-  /// IsDefinedInDeclarator - True if this tag declaration is
-  /// syntactically defined in a declarator.
-  bool IsDefinedInDeclarator : 1;
+  /// IsEmbeddedInDeclarator - True if this tag declaration is
+  /// "embedded" (i.e., defined or declared for the very first time)
+  /// in the syntax of a declarator,
+  bool IsEmbeddedInDeclarator : 1;
 
   /// TypedefForAnonDecl - If a TagDecl is anonymous and part of a typedef,
   /// this points to the TypedefDecl. Used for mangling.
@@ -1531,7 +1532,7 @@ protected:
     assert((DK != Enum || TK == TK_enum) &&"EnumDecl not matched with TK_enum");
     TagDeclKind = TK;
     IsDefinition = false;
-    IsDefinedInDeclarator = false;
+    IsEmbeddedInDeclarator = false;
     setPreviousDeclaration(PrevDecl);
   }
 
@@ -1565,11 +1566,11 @@ public:
     return IsDefinition;
   }
 
-  bool isDefinedInDeclarator() const {
-    return IsDefinedInDeclarator;
+  bool isEmbeddedInDeclarator() const {
+    return IsEmbeddedInDeclarator;
   }
-  void setDefinedInDeclarator(bool isInDeclarator) {
-    IsDefinedInDeclarator = isInDeclarator;
+  void setEmbeddedInDeclarator(bool isInDeclarator) {
+    IsEmbeddedInDeclarator = isInDeclarator;
   }
 
   /// \brief Whether this declaration declares a type that is
diff --git a/lib/Frontend/PCHReaderDecl.cpp b/lib/Frontend/PCHReaderDecl.cpp
index 6a93e6c265..625997cac2 100644
--- a/lib/Frontend/PCHReaderDecl.cpp
+++ b/lib/Frontend/PCHReaderDecl.cpp
@@ -117,7 +117,7 @@ void PCHDeclReader::VisitTagDecl(TagDecl *TD) {
                         cast_or_null<TagDecl>(Reader.GetDecl(Record[Idx++])));
   TD->setTagKind((TagDecl::TagKind)Record[Idx++]);
   TD->setDefinition(Record[Idx++]);
-  TD->setDefinedInDeclarator(Record[Idx++]);
+  TD->setEmbeddedInDeclarator(Record[Idx++]);
   TD->setTypedefForAnonDecl(
                     cast_or_null<TypedefDecl>(Reader.GetDecl(Record[Idx++])));
   TD->setRBraceLoc(SourceLocation::getFromRawEncoding(Record[Idx++]));
diff --git a/lib/Frontend/PCHWriterDecl.cpp b/lib/Frontend/PCHWriterDecl.cpp
index 1901b2fad6..d105382b43 100644
--- a/lib/Frontend/PCHWriterDecl.cpp
+++ b/lib/Frontend/PCHWriterDecl.cpp
@@ -115,7 +115,7 @@ void PCHDeclWriter::VisitTagDecl(TagDecl *D) {
   Writer.AddDeclRef(D->getPreviousDeclaration(), Record);
   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
   Record.push_back(D->isDefinition());
-  Record.push_back(D->isDefinedInDeclarator());
+  Record.push_back(D->isEmbeddedInDeclarator());
   Writer.AddDeclRef(D->getTypedefForAnonDecl(), Record);
   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
   Writer.AddSourceLocation(D->getTagKeywordLoc(), Record);
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index ceec5f226f..7911e76d44 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -930,7 +930,10 @@ QualType Sema::GetTypeForDeclarator(Declarator &D, Scope *S,
     
     if (!D.isInvalidType() && D.getDeclSpec().isTypeSpecOwned()) {
       TagDecl* Owned = cast<TagDecl>((Decl *)D.getDeclSpec().getTypeRep());
-      Owned->setDefinedInDeclarator(Owned->isDefinition());
+      // Owned is embedded if it was defined here, or if it is the
+      // very first (i.e., canonical) declaration of this tag type.
+      Owned->setEmbeddedInDeclarator(Owned->isDefinition() ||
+                                     Owned->isCanonicalDecl());
       if (OwnedDecl) *OwnedDecl = Owned;
     }
     break;
-- 
2.40.0