Sema/SemaExprObjC.cpp - fp2-dev/platform/external/clang - Gitiles

 //===--- SemaExprObjC.cpp - Semantic Analysis for ObjC Expressions --------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file implements semantic analysis for Objective-C expressions.
 //
 //===----------------------------------------------------------------------===//

 #include "Sema.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/Expr.h"
 using namespace clang;

 Sema::ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
                                               ExprTy **Strings,
                                               unsigned NumStrings) {
   SourceLocation AtLoc = AtLocs[0];
   StringLiteral* S = static_cast<StringLiteral *>(Strings[0]);
   if (NumStrings > 1) {
     // Concatenate objc strings.
     StringLiteral* ES = static_cast<StringLiteral *>(Strings[NumStrings-1]);
     SourceLocation EndLoc = ES->getSourceRange().getEnd();
     unsigned Length = 0;
     for (unsigned i = 0; i < NumStrings; i++)
       Length += static_cast<StringLiteral *>(Strings[i])->getByteLength();
     char *strBuf = new char [Length];
     char *p = strBuf;
     bool isWide = false;
     for (unsigned i = 0; i < NumStrings; i++) {
       S = static_cast<StringLiteral *>(Strings[i]);
       if (S->isWide())
         isWide = true;
       memcpy(p, S->getStrData(), S->getByteLength());
       p += S->getByteLength();
       delete S;
     }
     S = new StringLiteral(strBuf, Length,
                           isWide, Context.getPointerType(Context.CharTy),
                           AtLoc, EndLoc);
   }

   if (CheckBuiltinCFStringArgument(S))
     return true;

   if (Context.getObjcConstantStringInterface().isNull()) {
     // Initialize the constant string interface lazily. This assumes
     // the NSConstantString interface is seen in this translation unit.
     IdentifierInfo *NSIdent = &Context.Idents.get("NSConstantString");
     ScopedDecl *IFace = LookupScopedDecl(NSIdent, Decl::IDNS_Ordinary,
                                          SourceLocation(), TUScope);
     ObjcInterfaceDecl *strIFace = dyn_cast_or_null<ObjcInterfaceDecl>(IFace);
     if (!strIFace)
       return Diag(S->getLocStart(), diag::err_undef_interface,
                   NSIdent->getName());
     Context.setObjcConstantStringInterface(strIFace);
   }
   QualType t = Context.getObjcConstantStringInterface();
   t = Context.getPointerType(t);
   return new ObjCStringLiteral(S, t, AtLoc);
 }

 Sema::ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
                                                  SourceLocation EncodeLoc,
                                                  SourceLocation LParenLoc,
                                                  TypeTy *Ty,
                                                  SourceLocation RParenLoc) {
   QualType EncodedType = QualType::getFromOpaquePtr(Ty);

   QualType t = Context.getPointerType(Context.CharTy);
   return new ObjCEncodeExpr(t, EncodedType, AtLoc, RParenLoc);
 }

 Sema::ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
                                                    SourceLocation AtLoc,
                                                    SourceLocation SelLoc,
                                                    SourceLocation LParenLoc,
                                                    SourceLocation RParenLoc) {
   QualType t = Context.getObjcSelType();
   return new ObjCSelectorExpr(t, Sel, AtLoc, RParenLoc);
 }

 Sema::ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
                                                    SourceLocation AtLoc,
                                                    SourceLocation ProtoLoc,
                                                    SourceLocation LParenLoc,
                                                    SourceLocation RParenLoc) {
   ObjcProtocolDecl* PDecl = ObjcProtocols[ProtocolId];
   if (!PDecl) {
     Diag(ProtoLoc, diag::err_undeclared_protocol, ProtocolId->getName());
     return true;
   }

   QualType t = Context.getObjcProtoType();
   if (t.isNull())
     return true;
   t = Context.getPointerType(t);
   return new ObjCProtocolExpr(t, PDecl, AtLoc, RParenLoc);
 }

 bool Sema::CheckMessageArgumentTypes(Expr **Args, unsigned NumArgs,
                                      ObjcMethodDecl *Method) {
   bool anyIncompatibleArgs = false;

   for (unsigned i = 0; i < NumArgs; i++) {
     Expr *argExpr = Args[i];
     assert(argExpr && "CheckMessageArgumentTypes(): missing expression");

     QualType lhsType = Method->getParamDecl(i)->getType();
     QualType rhsType = argExpr->getType();

     // If necessary, apply function/array conversion. C99 6.7.5.3p[7,8].
     if (const ArrayType *ary = lhsType->getAsArrayType())
       lhsType = Context.getPointerType(ary->getElementType());
     else if (lhsType->isFunctionType())
       lhsType = Context.getPointerType(lhsType);

     AssignConvertType Result = CheckSingleAssignmentConstraints(lhsType,
                                                                 argExpr);
     if (Args[i] != argExpr) // The expression was converted.
       Args[i] = argExpr; // Make sure we store the converted expression.

     anyIncompatibleArgs |=
       DiagnoseAssignmentResult(Result, argExpr->getLocStart(), lhsType, rhsType,
                                argExpr, "sending");
   }
   return anyIncompatibleArgs;
 }

 // ActOnClassMessage - used for both unary and keyword messages.
 // ArgExprs is optional - if it is present, the number of expressions
 // is obtained from Sel.getNumArgs().
 Sema::ExprResult Sema::ActOnClassMessage(
   Scope *S,
   IdentifierInfo *receiverName, Selector Sel,
   SourceLocation lbrac, SourceLocation rbrac, ExprTy **Args, unsigned NumArgs)
 {
   assert(receiverName && "missing receiver class name");

   Expr **ArgExprs = reinterpret_cast<Expr **>(Args);
   ObjcInterfaceDecl* ClassDecl = 0;
   if (!strcmp(receiverName->getName(), "super") && CurMethodDecl) {
     ClassDecl = CurMethodDecl->getClassInterface()->getSuperClass();
     if (ClassDecl && CurMethodDecl->isInstance()) {
       // Synthesize a cast to the super class. This hack allows us to loosely
       // represent super without creating a special expression node.
       IdentifierInfo &II = Context.Idents.get("self");
       ExprResult ReceiverExpr = ActOnIdentifierExpr(S, lbrac, II, false);
       QualType superTy = Context.getObjcInterfaceType(ClassDecl);
       superTy = Context.getPointerType(superTy);
       ReceiverExpr = ActOnCastExpr(SourceLocation(), superTy.getAsOpaquePtr(),
                                    SourceLocation(), ReceiverExpr.Val);
       // We are really in an instance method, redirect.
       return ActOnInstanceMessage(ReceiverExpr.Val, Sel, lbrac, rbrac,
                                   Args, NumArgs);
     }
     // We are sending a message to 'super' within a class method. Do nothing,
     // the receiver will pass through as 'super' (how convenient:-).
   } else
     ClassDecl = getObjCInterfaceDecl(receiverName);

   // FIXME: can ClassDecl ever be null?
   ObjcMethodDecl *Method = ClassDecl->lookupClassMethod(Sel);
   QualType returnType;

   // Before we give up, check if the selector is an instance method.
   if (!Method)
     Method = ClassDecl->lookupInstanceMethod(Sel);
   if (!Method) {
     Diag(lbrac, diag::warn_method_not_found, std::string("+"), Sel.getName(),
          SourceRange(lbrac, rbrac));
     returnType = Context.getObjcIdType();
   } else {
     returnType = Method->getResultType();
     if (Sel.getNumArgs()) {
       if (CheckMessageArgumentTypes(ArgExprs, Sel.getNumArgs(), Method))
         return true;
     }
   }
   return new ObjCMessageExpr(receiverName, Sel, returnType, Method,
                              lbrac, rbrac, ArgExprs, NumArgs);
 }

 // ActOnInstanceMessage - used for both unary and keyword messages.
 // ArgExprs is optional - if it is present, the number of expressions
 // is obtained from Sel.getNumArgs().
 Sema::ExprResult Sema::ActOnInstanceMessage(
   ExprTy *receiver, Selector Sel,
   SourceLocation lbrac, SourceLocation rbrac, ExprTy **Args, unsigned NumArgs)
 {
   assert(receiver && "missing receiver expression");

   Expr **ArgExprs = reinterpret_cast<Expr **>(Args);
   Expr *RExpr = static_cast<Expr *>(receiver);
   QualType receiverType = RExpr->getType();
   QualType returnType;
   ObjcMethodDecl *Method = 0;

   if (receiverType == Context.getObjcIdType() ||
       receiverType == Context.getObjcClassType()) {
     Method = InstanceMethodPool[Sel].Method;
 	if (!Method)
 	  Method = FactoryMethodPool[Sel].Method;
     if (!Method) {
       Diag(lbrac, diag::warn_method_not_found, std::string("-"), Sel.getName(),
            SourceRange(lbrac, rbrac));
       returnType = Context.getObjcIdType();
     } else {
       returnType = Method->getResultType();
       if (Sel.getNumArgs())
         if (CheckMessageArgumentTypes(ArgExprs, Sel.getNumArgs(), Method))
           return true;
     }
   } else {
     bool receiverIsQualId = dyn_cast<ObjcQualifiedIdType>(receiverType) != 0;
     // FIXME (snaroff): checking in this code from Patrick. Needs to be
     // revisited. how do we get the ClassDecl from the receiver expression?
     if (!receiverIsQualId)
       while (receiverType->isPointerType()) {
         PointerType *pointerType =
           static_cast<PointerType*>(receiverType.getTypePtr());
         receiverType = pointerType->getPointeeType();
       }
     ObjcInterfaceDecl* ClassDecl = 0;
     if (ObjcQualifiedInterfaceType *QIT =
         dyn_cast<ObjcQualifiedInterfaceType>(receiverType)) {
       ClassDecl = QIT->getDecl();
       Method = ClassDecl->lookupInstanceMethod(Sel);
       if (!Method) {
         // search protocols
         for (unsigned i = 0; i < QIT->getNumProtocols(); i++) {
           ObjcProtocolDecl *PDecl = QIT->getProtocols(i);
           if (PDecl && (Method = PDecl->lookupInstanceMethod(Sel)))
             break;
         }
       }
       if (!Method)
         Diag(lbrac, diag::warn_method_not_found_in_protocol,
              std::string("-"), Sel.getName(),
              SourceRange(lbrac, rbrac));
     }
     else if (ObjcQualifiedIdType *QIT =
              dyn_cast<ObjcQualifiedIdType>(receiverType)) {
       // search protocols
       for (unsigned i = 0; i < QIT->getNumProtocols(); i++) {
         ObjcProtocolDecl *PDecl = QIT->getProtocols(i);
         if (PDecl && (Method = PDecl->lookupInstanceMethod(Sel)))
           break;
       }
       if (!Method)
         Diag(lbrac, diag::warn_method_not_found_in_protocol,
              std::string("-"), Sel.getName(),
              SourceRange(lbrac, rbrac));
     }
     else {
       assert(ObjcInterfaceType::classof(receiverType.getTypePtr()) &&
              "bad receiver type");
       ClassDecl = static_cast<ObjcInterfaceType*>(
                     receiverType.getTypePtr())->getDecl();
       // FIXME: consider using InstanceMethodPool, since it will be faster
       // than the following method (which can do *many* linear searches). The
       // idea is to add class info to InstanceMethodPool...
       Method = ClassDecl->lookupInstanceMethod(Sel);
     }
     if (!Method) {
       // If we have an implementation in scope, check "private" methods.
       if (ClassDecl)
         if (ObjcImplementationDecl *ImpDecl =
             ObjcImplementations[ClassDecl->getIdentifier()])
           Method = ImpDecl->getInstanceMethod(Sel);
 	  // If we still haven't found a method, look in the global pool. This
 	  // behavior isn't very desirable, however we need it for GCC
           // compatibility.
 	  if (!Method)
 	    Method = InstanceMethodPool[Sel].Method;
     }
     if (!Method) {
       Diag(lbrac, diag::warn_method_not_found, std::string("-"), Sel.getName(),
            SourceRange(lbrac, rbrac));
       returnType = Context.getObjcIdType();
     } else {
       returnType = Method->getResultType();
       if (Sel.getNumArgs())
         if (CheckMessageArgumentTypes(ArgExprs, Sel.getNumArgs(), Method))
           return true;
     }
   }
   return new ObjCMessageExpr(RExpr, Sel, returnType, Method, lbrac, rbrac,
                              ArgExprs, NumArgs);
 }
	//===--- SemaExprObjC.cpp - Semantic Analysis for ObjC Expressions --------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file implements semantic analysis for Objective-C expressions.
	//
	//===----------------------------------------------------------------------===//

	#include "Sema.h"
	#include "clang/AST/ASTContext.h"
	#include "clang/AST/DeclObjC.h"
	#include "clang/AST/Expr.h"
	using namespace clang;

	Sema::ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
	ExprTy **Strings,
	unsigned NumStrings) {
	SourceLocation AtLoc = AtLocs[0];
	StringLiteral* S = static_cast<StringLiteral *>(Strings[0]);
	if (NumStrings > 1) {
	// Concatenate objc strings.
	StringLiteral* ES = static_cast<StringLiteral *>(Strings[NumStrings-1]);
	SourceLocation EndLoc = ES->getSourceRange().getEnd();
	unsigned Length = 0;
	for (unsigned i = 0; i < NumStrings; i++)
	Length += static_cast<StringLiteral *>(Strings[i])->getByteLength();
	char *strBuf = new char [Length];
	char *p = strBuf;
	bool isWide = false;
	for (unsigned i = 0; i < NumStrings; i++) {
	S = static_cast<StringLiteral *>(Strings[i]);
	if (S->isWide())
	isWide = true;
	memcpy(p, S->getStrData(), S->getByteLength());
	p += S->getByteLength();
	delete S;
	}
	S = new StringLiteral(strBuf, Length,
	isWide, Context.getPointerType(Context.CharTy),
	AtLoc, EndLoc);
	}

	if (CheckBuiltinCFStringArgument(S))
	return true;

	if (Context.getObjcConstantStringInterface().isNull()) {
	// Initialize the constant string interface lazily. This assumes
	// the NSConstantString interface is seen in this translation unit.
	IdentifierInfo *NSIdent = &Context.Idents.get("NSConstantString");
	ScopedDecl *IFace = LookupScopedDecl(NSIdent, Decl::IDNS_Ordinary,
	SourceLocation(), TUScope);
	ObjcInterfaceDecl *strIFace = dyn_cast_or_null<ObjcInterfaceDecl>(IFace);
	if (!strIFace)
	return Diag(S->getLocStart(), diag::err_undef_interface,
	NSIdent->getName());
	Context.setObjcConstantStringInterface(strIFace);
	}
	QualType t = Context.getObjcConstantStringInterface();
	t = Context.getPointerType(t);
	return new ObjCStringLiteral(S, t, AtLoc);
	}

	Sema::ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
	SourceLocation EncodeLoc,
	SourceLocation LParenLoc,
	TypeTy *Ty,
	SourceLocation RParenLoc) {
	QualType EncodedType = QualType::getFromOpaquePtr(Ty);

	QualType t = Context.getPointerType(Context.CharTy);
	return new ObjCEncodeExpr(t, EncodedType, AtLoc, RParenLoc);
	}

	Sema::ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
	SourceLocation AtLoc,
	SourceLocation SelLoc,
	SourceLocation LParenLoc,
	SourceLocation RParenLoc) {
	QualType t = Context.getObjcSelType();
	return new ObjCSelectorExpr(t, Sel, AtLoc, RParenLoc);
	}

	Sema::ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
	SourceLocation AtLoc,
	SourceLocation ProtoLoc,
	SourceLocation LParenLoc,
	SourceLocation RParenLoc) {
	ObjcProtocolDecl* PDecl = ObjcProtocols[ProtocolId];
	if (!PDecl) {
	Diag(ProtoLoc, diag::err_undeclared_protocol, ProtocolId->getName());
	return true;
	}

	QualType t = Context.getObjcProtoType();
	if (t.isNull())
	return true;
	t = Context.getPointerType(t);
	return new ObjCProtocolExpr(t, PDecl, AtLoc, RParenLoc);
	}

	bool Sema::CheckMessageArgumentTypes(Expr **Args, unsigned NumArgs,
	ObjcMethodDecl *Method) {
	bool anyIncompatibleArgs = false;

	for (unsigned i = 0; i < NumArgs; i++) {
	Expr *argExpr = Args[i];
	assert(argExpr && "CheckMessageArgumentTypes(): missing expression");

	QualType lhsType = Method->getParamDecl(i)->getType();
	QualType rhsType = argExpr->getType();

	// If necessary, apply function/array conversion. C99 6.7.5.3p[7,8].
	if (const ArrayType *ary = lhsType->getAsArrayType())
	lhsType = Context.getPointerType(ary->getElementType());
	else if (lhsType->isFunctionType())
	lhsType = Context.getPointerType(lhsType);

	AssignConvertType Result = CheckSingleAssignmentConstraints(lhsType,
	argExpr);
	if (Args[i] != argExpr) // The expression was converted.
	Args[i] = argExpr; // Make sure we store the converted expression.

	anyIncompatibleArgs \|=
	DiagnoseAssignmentResult(Result, argExpr->getLocStart(), lhsType, rhsType,
	argExpr, "sending");
	}
	return anyIncompatibleArgs;
	}

	// ActOnClassMessage - used for both unary and keyword messages.
	// ArgExprs is optional - if it is present, the number of expressions
	// is obtained from Sel.getNumArgs().
	Sema::ExprResult Sema::ActOnClassMessage(
	Scope *S,
	IdentifierInfo *receiverName, Selector Sel,
	SourceLocation lbrac, SourceLocation rbrac, ExprTy **Args, unsigned NumArgs)
	{
	assert(receiverName && "missing receiver class name");

	Expr ArgExprs = reinterpret_cast<Expr >(Args);
	ObjcInterfaceDecl* ClassDecl = 0;
	if (!strcmp(receiverName->getName(), "super") && CurMethodDecl) {
	ClassDecl = CurMethodDecl->getClassInterface()->getSuperClass();
	if (ClassDecl && CurMethodDecl->isInstance()) {
	// Synthesize a cast to the super class. This hack allows us to loosely
	// represent super without creating a special expression node.
	IdentifierInfo &II = Context.Idents.get("self");
	ExprResult ReceiverExpr = ActOnIdentifierExpr(S, lbrac, II, false);
	QualType superTy = Context.getObjcInterfaceType(ClassDecl);
	superTy = Context.getPointerType(superTy);
	ReceiverExpr = ActOnCastExpr(SourceLocation(), superTy.getAsOpaquePtr(),
	SourceLocation(), ReceiverExpr.Val);
	// We are really in an instance method, redirect.
	return ActOnInstanceMessage(ReceiverExpr.Val, Sel, lbrac, rbrac,
	Args, NumArgs);
	}
	// We are sending a message to 'super' within a class method. Do nothing,
	// the receiver will pass through as 'super' (how convenient:-).
	} else
	ClassDecl = getObjCInterfaceDecl(receiverName);

	// FIXME: can ClassDecl ever be null?
	ObjcMethodDecl *Method = ClassDecl->lookupClassMethod(Sel);
	QualType returnType;

	// Before we give up, check if the selector is an instance method.
	if (!Method)
	Method = ClassDecl->lookupInstanceMethod(Sel);
	if (!Method) {
	Diag(lbrac, diag::warn_method_not_found, std::string("+"), Sel.getName(),
	SourceRange(lbrac, rbrac));
	returnType = Context.getObjcIdType();
	} else {
	returnType = Method->getResultType();
	if (Sel.getNumArgs()) {
	if (CheckMessageArgumentTypes(ArgExprs, Sel.getNumArgs(), Method))
	return true;
	}
	}
	return new ObjCMessageExpr(receiverName, Sel, returnType, Method,
	lbrac, rbrac, ArgExprs, NumArgs);
	}

	// ActOnInstanceMessage - used for both unary and keyword messages.
	// ArgExprs is optional - if it is present, the number of expressions
	// is obtained from Sel.getNumArgs().
	Sema::ExprResult Sema::ActOnInstanceMessage(
	ExprTy *receiver, Selector Sel,
	SourceLocation lbrac, SourceLocation rbrac, ExprTy **Args, unsigned NumArgs)
	{
	assert(receiver && "missing receiver expression");

	Expr ArgExprs = reinterpret_cast<Expr >(Args);
	Expr RExpr = static_cast<Expr >(receiver);
	QualType receiverType = RExpr->getType();
	QualType returnType;
	ObjcMethodDecl *Method = 0;

	if (receiverType == Context.getObjcIdType() \|\|
	receiverType == Context.getObjcClassType()) {
	Method = InstanceMethodPool[Sel].Method;
	if (!Method)
	Method = FactoryMethodPool[Sel].Method;
	if (!Method) {
	Diag(lbrac, diag::warn_method_not_found, std::string("-"), Sel.getName(),
	SourceRange(lbrac, rbrac));
	returnType = Context.getObjcIdType();
	} else {
	returnType = Method->getResultType();
	if (Sel.getNumArgs())
	if (CheckMessageArgumentTypes(ArgExprs, Sel.getNumArgs(), Method))
	return true;
	}
	} else {
	bool receiverIsQualId = dyn_cast<ObjcQualifiedIdType>(receiverType) != 0;
	// FIXME (snaroff): checking in this code from Patrick. Needs to be
	// revisited. how do we get the ClassDecl from the receiver expression?
	if (!receiverIsQualId)
	while (receiverType->isPointerType()) {
	PointerType *pointerType =
	static_cast<PointerType*>(receiverType.getTypePtr());
	receiverType = pointerType->getPointeeType();
	}
	ObjcInterfaceDecl* ClassDecl = 0;
	if (ObjcQualifiedInterfaceType *QIT =
	dyn_cast<ObjcQualifiedInterfaceType>(receiverType)) {
	ClassDecl = QIT->getDecl();
	Method = ClassDecl->lookupInstanceMethod(Sel);
	if (!Method) {
	// search protocols
	for (unsigned i = 0; i < QIT->getNumProtocols(); i++) {
	ObjcProtocolDecl *PDecl = QIT->getProtocols(i);
	if (PDecl && (Method = PDecl->lookupInstanceMethod(Sel)))
	break;
	}
	}
	if (!Method)
	Diag(lbrac, diag::warn_method_not_found_in_protocol,
	std::string("-"), Sel.getName(),
	SourceRange(lbrac, rbrac));
	}
	else if (ObjcQualifiedIdType *QIT =
	dyn_cast<ObjcQualifiedIdType>(receiverType)) {
	// search protocols
	for (unsigned i = 0; i < QIT->getNumProtocols(); i++) {
	ObjcProtocolDecl *PDecl = QIT->getProtocols(i);
	if (PDecl && (Method = PDecl->lookupInstanceMethod(Sel)))
	break;
	}
	if (!Method)
	Diag(lbrac, diag::warn_method_not_found_in_protocol,
	std::string("-"), Sel.getName(),
	SourceRange(lbrac, rbrac));
	}
	else {
	assert(ObjcInterfaceType::classof(receiverType.getTypePtr()) &&
	"bad receiver type");
	ClassDecl = static_cast<ObjcInterfaceType*>(
	receiverType.getTypePtr())->getDecl();
	// FIXME: consider using InstanceMethodPool, since it will be faster
	// than the following method (which can do many linear searches). The
	// idea is to add class info to InstanceMethodPool...
	Method = ClassDecl->lookupInstanceMethod(Sel);
	}
	if (!Method) {
	// If we have an implementation in scope, check "private" methods.
	if (ClassDecl)
	if (ObjcImplementationDecl *ImpDecl =
	ObjcImplementations[ClassDecl->getIdentifier()])
	Method = ImpDecl->getInstanceMethod(Sel);
	// If we still haven't found a method, look in the global pool. This
	// behavior isn't very desirable, however we need it for GCC
	// compatibility.
	if (!Method)
	Method = InstanceMethodPool[Sel].Method;
	}
	if (!Method) {
	Diag(lbrac, diag::warn_method_not_found, std::string("-"), Sel.getName(),
	SourceRange(lbrac, rbrac));
	returnType = Context.getObjcIdType();
	} else {
	returnType = Method->getResultType();
	if (Sel.getNumArgs())
	if (CheckMessageArgumentTypes(ArgExprs, Sel.getNumArgs(), Method))
	return true;
	}
	}
	return new ObjCMessageExpr(RExpr, Sel, returnType, Method, lbrac, rbrac,
	ArgExprs, NumArgs);
	}