Extend ExternalASTSource with the ability to lazily complete the

definition of an Objective-C class. Unlike with C/C++ classes, we
don't have a well-defined point in Sema where Objective-C classes are
checked for completeness, nor do we need to involve Sema when
completing a class. Therefore, we take the appropriate of having the
external AST source mark a particular Objective-C class as having an
external declaration; when using one of the accessors of an
Objective-C class that has an external declaration, we request that
the external AST source fill in the Objective-C class definition.

llvm-svn: 120627

1 files changed, 31 insertions, 1 deletions

diff --git a/clang/lib/AST/DeclObjC.cpp b/clang/lib/AST/DeclObjC.cpp
index 5e57cf87b9e..ea8fd4ae89d 100644
--- a/clang/lib/AST/DeclObjC.cpp
+++ b/clang/lib/AST/DeclObjC.cpp
@@ -153,6 +153,9 @@ ObjCContainerDecl::FindPropertyDeclaration(IdentifierInfo *PropertyId) const {
 ObjCPropertyDecl *
 ObjCInterfaceDecl::FindPropertyVisibleInPrimaryClass(
                                             IdentifierInfo *PropertyId) const {
+  if (ExternallyCompleted)
+    LoadExternalDefinition();
+
   if (ObjCPropertyDecl *PD =
       ObjCPropertyDecl::findPropertyDecl(cast<DeclContext>(this), PropertyId))
     return PD;
@@ -171,6 +174,9 @@ void ObjCInterfaceDecl::mergeClassExtensionProtocolList(
                               ObjCProtocolDecl *const* ExtList, unsigned ExtNum,
                               ASTContext &C)
 {
+  if (ExternallyCompleted)
+    LoadExternalDefinition();
+
   if (AllReferencedProtocols.empty() && ReferencedProtocols.empty()) {
     AllReferencedProtocols.set(ExtList, ExtNum, C);
     return;
@@ -270,6 +276,9 @@ ObjCMethodDecl *ObjCInterfaceDecl::lookupMethod(Selector Sel,
   const ObjCInterfaceDecl* ClassDecl = this;
   ObjCMethodDecl *MethodDecl = 0;
 
+  if (ExternallyCompleted)
+    LoadExternalDefinition();
+
   while (ClassDecl != NULL) {
     if ((MethodDecl = ClassDecl->getMethod(Sel, isInstance)))
       return MethodDecl;
@@ -443,11 +452,29 @@ ObjCInterfaceDecl(DeclContext *DC, SourceLocation atLoc, IdentifierInfo *Id,
   : ObjCContainerDecl(ObjCInterface, DC, atLoc, Id),
     TypeForDecl(0), SuperClass(0),
     CategoryList(0), IvarList(0), 
-    ForwardDecl(FD), InternalInterface(isInternal),
+    ForwardDecl(FD), InternalInterface(isInternal), ExternallyCompleted(false),
     ClassLoc(CLoc) {
 }
 
+void ObjCInterfaceDecl::LoadExternalDefinition() const {
+  assert(ExternallyCompleted && "Class is not externally completed");
+  ExternallyCompleted = false;
+  getASTContext().getExternalSource()->CompleteType(
+                                        const_cast<ObjCInterfaceDecl *>(this));
+}
+
+void ObjCInterfaceDecl::setExternallyCompleted() {
+  assert(getASTContext().getExternalSource() && 
+         "Class can't be externally completed without an external source");
+  assert(!ForwardDecl && 
+         "Forward declarations can't be externally completed");
+  ExternallyCompleted = true;
+}
+
 ObjCImplementationDecl *ObjCInterfaceDecl::getImplementation() const {
+  if (ExternallyCompleted)
+    LoadExternalDefinition();
+
   return getASTContext().getObjCImplementation(
                                           const_cast<ObjCInterfaceDecl*>(this));
 }
@@ -506,6 +533,9 @@ ObjCIvarDecl *ObjCInterfaceDecl::all_declared_ivar_begin() {
 ///
 ObjCCategoryDecl *
 ObjCInterfaceDecl::FindCategoryDeclaration(IdentifierInfo *CategoryId) const {
+  if (ExternallyCompleted)
+    LoadExternalDefinition();
+
   for (ObjCCategoryDecl *Category = getCategoryList();
        Category; Category = Category->getNextClassCategory())
     if (Category->getIdentifier() == CategoryId)