Rework the Parser-Sema interaction for Objective-C message

sends. Major changes include:

  - Expanded the interface from two actions (ActOnInstanceMessage,
    ActOnClassMessage), where ActOnClassMessage also handled sends to
    "super" by checking whether the identifier was "super", to three
    actions (ActOnInstanceMessage, ActOnClassMessage,
    ActOnSuperMessage). Code completion has the same changes.
  - The parser now resolves the type to which we are sending a class
    message, so ActOnClassMessage now accepts a TypeTy* (rather than
    an IdentifierInfo *). This opens the door to more interesting
    types (for Objective-C++ support).
  - Split ActOnInstanceMessage and ActOnClassMessage into parser
    action functions (with their original names) and semantic
    functions (BuildInstanceMessage and BuildClassMessage,
    respectively). At present, this split is onyl used by
    ActOnSuperMessage, which decides which kind of super message it
    has and forwards to the appropriate Build*Message. In the future,
    Build*Message will be used by template instantiation.
  - Use getObjCMessageKind() within the disambiguation of Objective-C
    message sends vs. array designators.

Two notes about substandard bits in this patch:
  - There is some redundancy in the code in ParseObjCMessageExpr and
  ParseInitializerWithPotentialDesignator; this will be addressed
  shortly by centralizing the mapping from identifiers to type names
  for the message receiver.
  - There is some #if 0'd code that won't likely ever be used---it
  handles the use of 'super' in methods whose class does not have a
  superclass---but could be used to model GCC's behavior more
  closely. This code will die in my next check-in, but I want it in
  Subversion.

llvm-svn: 102021

1 files changed, 67 insertions, 47 deletions

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index cb60f0aba11..e71f8c84ebc 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -2947,62 +2947,82 @@ static ObjCInterfaceDecl *GetAssumedMessageSendExprType(Expr *E) {
     .Default(0);
 }
 
-void Sema::CodeCompleteObjCClassMessage(Scope *S, IdentifierInfo *FName,
-                                        SourceLocation FNameLoc,
+void Sema::CodeCompleteObjCSuperMessage(Scope *S, SourceLocation SuperLoc,
                                         IdentifierInfo **SelIdents,
                                         unsigned NumSelIdents) {
-  typedef CodeCompleteConsumer::Result Result;
   ObjCInterfaceDecl *CDecl = 0;
+  if (ObjCMethodDecl *CurMethod = getCurMethodDecl()) {
+    // Figure out which interface we're in.
+    CDecl = CurMethod->getClassInterface();
+    if (!CDecl)
+      return;
+    
+    // Find the superclass of this class.
+    CDecl = CDecl->getSuperClass();
+    if (!CDecl)
+      return;
 
-  if (FName->isStr("super")) {
-    // We're sending a message to "super".
-    if (ObjCMethodDecl *CurMethod = getCurMethodDecl()) {
-      // Figure out which interface we're in.
-      CDecl = CurMethod->getClassInterface();
-      if (!CDecl)
-        return;
-
-      // Find the superclass of this class.
-      CDecl = CDecl->getSuperClass();
-      if (!CDecl)
-        return;
+    if (CurMethod->isInstanceMethod()) {
+      // We are inside an instance method, which means that the message
+      // send [super ...] is actually calling an instance method on the
+      // current object. Build the super expression and handle this like
+      // an instance method.
+      QualType SuperTy = Context.getObjCInterfaceType(CDecl);
+      SuperTy = Context.getObjCObjectPointerType(SuperTy);
+      OwningExprResult Super
+        = Owned(new (Context) ObjCSuperExpr(SuperLoc, SuperTy));
+      return CodeCompleteObjCInstanceMessage(S, (Expr *)Super.get(),
+                                             SelIdents, NumSelIdents);
+    }
 
-      if (CurMethod->isInstanceMethod()) {
-        // We are inside an instance method, which means that the message
-        // send [super ...] is actually calling an instance method on the
-        // current object. Build the super expression and handle this like
-        // an instance method.
-        QualType SuperTy = Context.getObjCInterfaceType(CDecl);
-        SuperTy = Context.getObjCObjectPointerType(SuperTy);
-        OwningExprResult Super
-          = Owned(new (Context) ObjCSuperExpr(FNameLoc, SuperTy));
-        return CodeCompleteObjCInstanceMessage(S, (Expr *)Super.get(),
-                                               SelIdents, NumSelIdents);
-      }
+    // Fall through to send to the superclass in CDecl.
+  } else {
+    // "super" may be the name of a type or variable. Figure out which
+    // it is.
+    IdentifierInfo *Super = &Context.Idents.get("super");
+    NamedDecl *ND = LookupSingleName(S, Super, SuperLoc, 
+                                     LookupOrdinaryName);
+    if ((CDecl = dyn_cast_or_null<ObjCInterfaceDecl>(ND))) {
+      // "super" names an interface. Use it.
+    } else if (TypeDecl *TD = dyn_cast_or_null<TypeDecl>(ND)) {
+      if (const ObjCInterfaceType *Iface
+            = Context.getTypeDeclType(TD)->getAs<ObjCInterfaceType>())
+        CDecl = Iface->getDecl();
+    } else if (ND && isa<UnresolvedUsingTypenameDecl>(ND)) {
+      // "super" names an unresolved type; we can't be more specific.
+    } else {
+      // Assume that "super" names some kind of value and parse that way.
+      CXXScopeSpec SS;
+      UnqualifiedId id;
+      id.setIdentifier(Super, SuperLoc);
+      OwningExprResult SuperExpr = ActOnIdExpression(S, SS, id, false, false);
+      return CodeCompleteObjCInstanceMessage(S, (Expr *)SuperExpr.get(),
+                                             SelIdents, NumSelIdents);
+    }
 
-      // Okay, we're calling a factory method in our superclass.
-    } 
+    // Fall through
   }
 
+  TypeTy *Receiver = 0;
+  if (CDecl)
+    Receiver = Context.getObjCInterfaceType(CDecl).getAsOpaquePtr();
+  return CodeCompleteObjCClassMessage(S, Receiver, SelIdents, 
+                                      NumSelIdents);
+}
+
+void Sema::CodeCompleteObjCClassMessage(Scope *S, TypeTy *Receiver,
+                                        IdentifierInfo **SelIdents,
+                                        unsigned NumSelIdents) {
+  typedef CodeCompleteConsumer::Result Result;
+  ObjCInterfaceDecl *CDecl = 0;
+
   // If the given name refers to an interface type, retrieve the
   // corresponding declaration.
-  if (!CDecl)
-    if (TypeTy *Ty = getTypeName(*FName, FNameLoc, S, 0, false)) {
-      QualType T = GetTypeFromParser(Ty, 0);
-      if (!T.isNull()) 
-        if (const ObjCInterfaceType *Interface = T->getAs<ObjCInterfaceType>())
-          CDecl = Interface->getDecl();
-    }
-
-  if (!CDecl && FName->isStr("super")) {
-    // "super" may be the name of a variable, in which case we are
-    // probably calling an instance method.
-    CXXScopeSpec SS;
-    UnqualifiedId id;
-    id.setIdentifier(FName, FNameLoc);
-    OwningExprResult Super = ActOnIdExpression(S, SS, id, false, false);
-    return CodeCompleteObjCInstanceMessage(S, (Expr *)Super.get(),
-                                           SelIdents, NumSelIdents);
+  if (Receiver) {
+    QualType T = GetTypeFromParser(Receiver, 0);
+    if (!T.isNull()) 
+      if (const ObjCInterfaceType *Interface = T->getAs<ObjCInterfaceType>())
+        CDecl = Interface->getDecl();
   }
 
   // Add all of the factory methods in this Objective-C class, its protocols,
@@ -3013,7 +3033,7 @@ void Sema::CodeCompleteObjCClassMessage(Scope *S, IdentifierInfo *FName,
   if (CDecl) 
     AddObjCMethods(CDecl, false, MK_Any, SelIdents, NumSelIdents, CurContext, 
                    Results);  
-  else if (FName->isStr("id")) {
+  else {
     // We're messaging "id" as a type; provide all class/factory methods.
 
     // If we have an external source, load the entire class method