Whether an argument is required (in contrast with being an
optional argument passed through the variadic ellipsis)
potentially affects how we need to lower it.  Propagate
this information down to the various getFunctionInfo(...)
overloads on CodeGenTypes.  Furthermore, rename those
overloads to clarify their distinct purposes, and make
sure we're calling the right one in the right place.
This has a nice side-effect of making it easier to construct
a function type, since the 'variadic' bit is no longer
separable.

This shouldn't really change anything for our existing
platforms, with one minor exception --- we should now call
variadic ObjC methods with the ... in the "right place"
(see the test case), which I guess matters for anyone
running GNUStep on MIPS.  Mostly it's just a substantial
clean-up.

llvm-svn: 150788
diff --git a/clang/lib/CodeGen/CGObjCGNU.cpp b/clang/lib/CodeGen/CGObjCGNU.cpp
index 50ab7d2..3e8b528 100644
--- a/clang/lib/CodeGen/CGObjCGNU.cpp
+++ b/clang/lib/CodeGen/CGObjCGNU.cpp
@@ -103,8 +103,6 @@
 /// GNUstep).
 class CGObjCGNU : public CGObjCRuntime {
 protected:
-  /// The module that is using this class
-  CodeGenModule &CGM;
   /// The LLVM module into which output is inserted
   llvm::Module &TheModule;
   /// strut objc_super.  Used for sending messages to super.  This structure
@@ -688,9 +686,9 @@
 
 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
     unsigned protocolClassVersion)
-  : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()),
-  ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion),
-  ProtocolVersion(protocolClassVersion) {
+  : CGObjCRuntime(cgm), TheModule(CGM.getModule()),
+    VMContext(cgm.getLLVMContext()), ClassPtrAlias(0), MetaClassPtrAlias(0),
+    RuntimeVersion(runtimeABIVersion), ProtocolVersion(protocolClassVersion) {
 
   msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
 
@@ -1037,9 +1035,7 @@
   ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
   ActualArgs.addFrom(CallArgs);
 
-  CodeGenTypes &Types = CGM.getTypes();
-  const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs,
-                                                       FunctionType::ExtInfo());
+  MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
 
   llvm::Value *ReceiverClass = 0;
   if (isCategoryImpl) {
@@ -1092,12 +1088,10 @@
   Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1));
 
   ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy);
-  llvm::FunctionType *impType =
-    Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false);
 
   // Get the IMP
   llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd);
-  imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType));
+  imp = EnforceType(Builder, imp, MSI.MessengerType);
 
   llvm::Value *impMD[] = {
       llvm::MDString::get(VMContext, Sel.getAsString()),
@@ -1107,8 +1101,7 @@
   llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
 
   llvm::Instruction *call;
-  RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs,
-      0, &call);
+  RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs, 0, &call);
   call->setMetadata(msgSendMDKind, node);
   return msgRet;
 }
@@ -1181,13 +1174,13 @@
    };
   llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
 
-  CodeGenTypes &Types = CGM.getTypes();
   CallArgList ActualArgs;
   ActualArgs.add(RValue::get(Receiver), ASTIdTy);
   ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
   ActualArgs.addFrom(CallArgs);
-  const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs,
-                                                       FunctionType::ExtInfo());
+
+  MessageSendInfo MSI = getMessageSendInfo(Method, ResultType, ActualArgs);
+
   // Get the IMP to call
   llvm::Value *imp;
 
@@ -1203,7 +1196,7 @@
       if (CGM.ReturnTypeUsesFPRet(ResultType)) {
         imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
                                   "objc_msgSend_fpret");
-      } else if (CGM.ReturnTypeUsesSRet(FnInfo)) {
+      } else if (CGM.ReturnTypeUsesSRet(MSI.CallInfo)) {
         // The actual types here don't matter - we're going to bitcast the
         // function anyway
         imp = CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, IdTy, true),
@@ -1217,12 +1210,10 @@
   // Reset the receiver in case the lookup modified it
   ActualArgs[0] = CallArg(RValue::get(Receiver), ASTIdTy, false);
 
-  llvm::FunctionType *impType =
-    Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false);
-  imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType));
+  imp = EnforceType(Builder, imp, MSI.MessengerType);
 
   llvm::Instruction *call;
-  RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs,
+  RValue msgRet = CGF.EmitCall(MSI.CallInfo, imp, Return, ActualArgs,
       0, &call);
   call->setMetadata(msgSendMDKind, node);
 
@@ -2418,7 +2409,7 @@
 
   CodeGenTypes &Types = CGM.getTypes();
   llvm::FunctionType *MethodTy =
-    Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic());
+    Types.GetFunctionType(Types.arrangeObjCMethodDeclaration(OMD));
   std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName,
       MethodName, isClassMethod);