Mark a TagDecl when it is free standing (e.g. "struct foo;")

llvm-svn: 140894

clang/include/clang/AST/Decl.h

@@ -2352,6 +2352,9 @@ private:
   /// in the syntax of a declarator.
   bool IsEmbeddedInDeclarator : 1;
 
+  /// /brief True if this tag is free standing, e.g. "struct foo;".
+  bool IsFreeStanding : 1;
+
 protected:
   // These are used by (and only defined for) EnumDecl.
   unsigned NumPositiveBits : 8;
@@ -2402,6 +2405,7 @@ protected:
     IsDefinition = false;
     IsBeingDefined = false;
     IsEmbeddedInDeclarator = false;
+    IsFreeStanding = false;
     setPreviousDeclaration(PrevDecl);
   }
 
@@ -2462,6 +2466,11 @@ public:
     IsEmbeddedInDeclarator = isInDeclarator;
   }
 
+  bool isFreeStanding() const { return IsFreeStanding; }
+  void setFreeStanding(bool isFreeStanding = true) {
+    IsFreeStanding = isFreeStanding;
+  }
+
   /// \brief Whether this declaration declares a type that is
   /// dependent, i.e., a type that somehow depends on template
   /// parameters.

clang/lib/Sema/SemaDecl.cpp

@@ -2249,6 +2249,9 @@ Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
     Tag = dyn_cast<TagDecl>(TagD);
   }
 
+  if (Tag)
+    Tag->setFreeStanding();
+
   if (unsigned TypeQuals = DS.getTypeQualifiers()) {
     // Enforce C99 6.7.3p2: "Types other than pointer types derived from object
     // or incomplete types shall not be restrict-qualified."

clang/lib/Serialization/ASTReaderDecl.cpp

@@ -284,6 +284,7 @@ void ASTDeclReader::VisitTagDecl(TagDecl *TD) {
   TD->setTagKind((TagDecl::TagKind)Record[Idx++]);
   TD->setDefinition(Record[Idx++]);
   TD->setEmbeddedInDeclarator(Record[Idx++]);
+  TD->setFreeStanding(Record[Idx++]);
   TD->setRBraceLoc(ReadSourceLocation(Record, Idx));
   if (Record[Idx++]) { // hasExtInfo
     TagDecl::ExtInfo *Info = new (Reader.getContext()) TagDecl::ExtInfo();

clang/lib/Serialization/ASTWriterDecl.cpp

@@ -204,6 +204,7 @@ void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
   Record.push_back(D->isDefinition());
   Record.push_back(D->isEmbeddedInDeclarator());
+  Record.push_back(D->isFreeStanding());
   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
   Record.push_back(D->hasExtInfo());
   if (D->hasExtInfo())
@@ -1343,6 +1344,7 @@ void ASTWriter::WriteDeclsBlockAbbrevs() {
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isDefinition
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
   Abv->Add(BitCodeAbbrevOp(0));                         // hasExtInfo
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TypedefNameAnonDecl
@@ -1388,6 +1390,7 @@ void ASTWriter::WriteDeclsBlockAbbrevs() {
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isDefinition
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
   Abv->Add(BitCodeAbbrevOp(0));                         // hasExtInfo
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TypedefNameAnonDecl