From cc666af7d40826e6863b9baea2e90c0b46f68b1a Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 10 Aug 2007 17:02:28 +0000
Subject: [PATCH] implement initial codegen for aggregate return functions. 
 This implements codegen for:

_Complex double bar(int);
void test(_Complex double*);

void test2(int c) {
  _Complex double X;
  X = bar(1);
  test(&X);
}



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40993 91177308-0d34-0410-b5e6-96231b3b80d8
---
 CodeGen/CGExpr.cpp          | 15 ++++++++++++---
 CodeGen/CodeGenFunction.cpp |  2 +-
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/CodeGen/CGExpr.cpp b/CodeGen/CGExpr.cpp
index 65d03c2d1e..08bd93f22d 100644
--- a/CodeGen/CGExpr.cpp
+++ b/CodeGen/CGExpr.cpp
@@ -721,7 +721,14 @@ RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
   
   llvm::SmallVector<llvm::Value*, 16> Args;
   
-  // FIXME: Handle struct return.
+  // Handle struct-return functions by passing a pointer to the location that
+  // we would like to return into.
+  if (hasAggregateLLVMType(E->getType())) {
+    // Create a temporary alloca to hold the result of the call. :(
+    Args.push_back(CreateTempAlloca(ConvertType(E->getType())));
+    // FIXME: set the stret attribute on the argument.
+  }
+  
   for (unsigned i = 0, e = E->getNumArgs(); i != e; ++i) {
     QualType ArgTy = E->getArg(i)->getType();
     RValue ArgVal = EmitExpr(E->getArg(i));
@@ -752,8 +759,10 @@ RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
   llvm::Value *V = Builder.CreateCall(Callee, &Args[0], &Args[0]+Args.size());
   if (V->getType() != llvm::Type::VoidTy)
     V->setName("call");
-  
-  // FIXME: Struct return;
+  else if (hasAggregateLLVMType(E->getType()))
+    // Struct return.
+    return RValue::getAggregate(Args[0]);
+      
   return RValue::get(V);
 }
 
diff --git a/CodeGen/CodeGenFunction.cpp b/CodeGen/CodeGenFunction.cpp
index 8cea3e7aaf..389bd05a70 100644
--- a/CodeGen/CodeGenFunction.cpp
+++ b/CodeGen/CodeGenFunction.cpp
@@ -45,7 +45,7 @@ const llvm::Type *CodeGenFunction::ConvertType(QualType T) {
 
 bool CodeGenFunction::hasAggregateLLVMType(QualType T) {
   return !T->isRealType() && !T->isPointerType() && !T->isVoidType() &&
-         !T->isVectorType();
+         !T->isVectorType() && !T->isFunctionType();
 }
 
 
-- 
2.40.0