Parsing, semantic analysis, and AST for Objective-C type parameters.

Produce type parameter declarations for Objective-C type parameters,
and attach lists of type parameters to Objective-C classes,
categories, forward declarations, and extensions as
appropriate. Perform semantic analysis of type bounds for type
parameters, both in isolation and across classes/categories/extensions
to ensure consistency.

Also handle (de-)serialization of Objective-C type parameter lists,
along with sundry other things one must do to add a new declaration to
Clang.

Note that Objective-C type parameters are typedef name declarations,
like typedefs and C++11 type aliases, in support of type erasure.

Part of rdar://problem/6294649.

llvm-svn: 241541

3 files changed, 63 insertions, 1 deletions

diff --git a/clang/lib/Serialization/ASTCommon.cpp b/clang/lib/Serialization/ASTCommon.cpp
index 85c574c2021..b1bf4a6bff8 100644
--- a/clang/lib/Serialization/ASTCommon.cpp
+++ b/clang/lib/Serialization/ASTCommon.cpp
@@ -221,6 +221,7 @@ bool serialization::isRedeclarableDeclKind(unsigned Kind) {
   // redeclarable.
   case Decl::ImplicitParam:
   case Decl::ParmVar:
+  case Decl::ObjCTypeParam:
     return false;
   }
 
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index b23c33c5518..e01ea2b8a59 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -350,8 +350,11 @@ namespace clang {
                               RedeclarableTemplateDecl *Existing,
                               DeclID DsID);
 
+    ObjCTypeParamList *ReadObjCTypeParamList();
+
     // FIXME: Reorder according to DeclNodes.td?
     void VisitObjCMethodDecl(ObjCMethodDecl *D);
+    void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
     void VisitObjCContainerDecl(ObjCContainerDecl *D);
     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
     void VisitObjCIvarDecl(ObjCIvarDecl *D);
@@ -899,18 +902,46 @@ void ASTDeclReader::VisitObjCMethodDecl(ObjCMethodDecl *MD) {
   MD->setParamsAndSelLocs(Reader.getContext(), Params, SelLocs);
 }
 
+void ASTDeclReader::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
+  VisitTypedefNameDecl(D);
+  D->ColonLoc = ReadSourceLocation(Record, Idx);
+}
+
 void ASTDeclReader::VisitObjCContainerDecl(ObjCContainerDecl *CD) {
   VisitNamedDecl(CD);
   CD->setAtStartLoc(ReadSourceLocation(Record, Idx));
   CD->setAtEndRange(ReadSourceRange(Record, Idx));
 }
 
+ObjCTypeParamList *ASTDeclReader::ReadObjCTypeParamList() {
+  unsigned numParams = Record[Idx++];
+  if (numParams == 0)
+    return nullptr;
+
+  SmallVector<ObjCTypeParamDecl *, 4> typeParams;
+  typeParams.reserve(numParams);
+  for (unsigned i = 0; i != numParams; ++i) {
+    auto typeParam = ReadDeclAs<ObjCTypeParamDecl>(Record, Idx);
+    if (!typeParam)
+      return nullptr;
+
+    typeParams.push_back(typeParam);
+  }
+
+  SourceLocation lAngleLoc = ReadSourceLocation(Record, Idx);
+  SourceLocation rAngleLoc = ReadSourceLocation(Record, Idx);
+
+  return ObjCTypeParamList::create(Reader.getContext(), lAngleLoc,
+                                   typeParams, rAngleLoc);
+}
+
 void ASTDeclReader::VisitObjCInterfaceDecl(ObjCInterfaceDecl *ID) {
   RedeclarableResult Redecl = VisitRedeclarable(ID);
   VisitObjCContainerDecl(ID);
   TypeIDForTypeDecl = Reader.getGlobalTypeID(F, Record[Idx++]);
   mergeRedeclarable(ID, Redecl);
-  
+
+  ID->TypeParamList = ReadObjCTypeParamList();
   if (Record[Idx++]) {
     // Read the definition.
     ID->allocateDefinitionData();
@@ -1020,6 +1051,7 @@ void ASTDeclReader::VisitObjCCategoryDecl(ObjCCategoryDecl *CD) {
   Reader.CategoriesDeserialized.insert(CD);
 
   CD->ClassInterface = ReadDeclAs<ObjCInterfaceDecl>(Record, Idx);
+  CD->TypeParamList = ReadObjCTypeParamList();
   unsigned NumProtoRefs = Record[Idx++];
   SmallVector<ObjCProtocolDecl *, 16> ProtoRefs;
   ProtoRefs.reserve(NumProtoRefs);
@@ -3259,6 +3291,9 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
   case DECL_EMPTY:
     D = EmptyDecl::CreateDeserialized(Context, ID);
     break;
+  case DECL_OBJC_TYPE_PARAM:
+    D = ObjCTypeParamDecl::CreateDeserialized(Context, ID);
+    break;
   }
 
   assert(D && "Unknown declaration reading AST file");
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 6c5bc5bbd48..5e9151eed5e 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -117,6 +117,7 @@ namespace clang {
 
     // FIXME: Put in the same order is DeclNodes.td?
     void VisitObjCMethodDecl(ObjCMethodDecl *D);
+    void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
     void VisitObjCContainerDecl(ObjCContainerDecl *D);
     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
     void VisitObjCIvarDecl(ObjCIvarDecl *D);
@@ -131,6 +132,22 @@ namespace clang {
     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
 
+    /// Add an Objective-C type parameter list to the given record.
+    void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
+      // Empty type parameter list.
+      if (!typeParams) {
+        Record.push_back(0);
+        return;
+      }
+
+      Record.push_back(typeParams->size());
+      for (auto typeParam : *typeParams) {
+        Writer.AddDeclRef(typeParam, Record);
+      }
+      Writer.AddSourceLocation(typeParams->getLAngleLoc(), Record);
+      Writer.AddSourceLocation(typeParams->getRAngleLoc(), Record);
+    }
+
     void AddFunctionDefinition(const FunctionDecl *FD) {
       assert(FD->doesThisDeclarationHaveABody());
       if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
@@ -562,6 +579,13 @@ void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
   Code = serialization::DECL_OBJC_METHOD;
 }
 
+void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
+  VisitTypedefNameDecl(D);
+  Writer.AddSourceLocation(D->ColonLoc, Record);
+
+  Code = serialization::DECL_OBJC_TYPE_PARAM;
+}
+
 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
   VisitNamedDecl(D);
   Writer.AddSourceLocation(D->getAtStartLoc(), Record);
@@ -573,6 +597,7 @@ void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
   VisitRedeclarable(D);
   VisitObjCContainerDecl(D);
   Writer.AddTypeRef(QualType(D->getTypeForDecl(), 0), Record);
+  AddObjCTypeParamList(D->TypeParamList);
 
   Record.push_back(D->isThisDeclarationADefinition());
   if (D->isThisDeclarationADefinition()) {
@@ -660,6 +685,7 @@ void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
   Writer.AddSourceLocation(D->getIvarLBraceLoc(), Record);
   Writer.AddSourceLocation(D->getIvarRBraceLoc(), Record);
   Writer.AddDeclRef(D->getClassInterface(), Record);
+  AddObjCTypeParamList(D->TypeParamList);
   Record.push_back(D->protocol_size());
   for (const auto *I : D->protocols())
     Writer.AddDeclRef(I, Record);