path: root/lib/CodeGen/CGExprAgg.cpp

//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Aggregate Expr nodes as LLVM code.
//
//===----------------------------------------------------------------------===//

#include "CodeGenFunction.h"
#include "CGObjCRuntime.h"
#include "CodeGenModule.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/StmtVisitor.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Intrinsics.h"
using namespace clang;
using namespace CodeGen;

//===----------------------------------------------------------------------===//
//                        Aggregate Expression Emitter
//===----------------------------------------------------------------------===//

namespace  {
class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
  CodeGenFunction &CGF;
  CGBuilderTy &Builder;
  AggValueSlot Dest;

  /// We want to use 'dest' as the return slot except under two
  /// conditions:
  ///   - The destination slot requires garbage collection, so we
  ///     need to use the GC API.
  ///   - The destination slot is potentially aliased.
  bool shouldUseDestForReturnSlot() const {
    return !(Dest.requiresGCollection() || Dest.isPotentiallyAliased());
  }

  ReturnValueSlot getReturnValueSlot() const {
    if (!shouldUseDestForReturnSlot())
      return ReturnValueSlot();

    return ReturnValueSlot(Dest.getAddr(), Dest.isVolatile());
  }

  AggValueSlot EnsureSlot(QualType T) {
    if (!Dest.isIgnored()) return Dest;
    return CGF.CreateAggTemp(T, "agg.tmp.ensured"