//===- ObjCMessage.cpp - Wrapper for ObjC messages and dot syntax -*- C++ -*--//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines ObjCMessage which serves as a common wrapper for ObjC
// message expressions or implicit messages for loading/storing ObjC properties.
//
//===----------------------------------------------------------------------===//

#include "clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h"
#include "clang/AST/DeclCXX.h"

using namespace clang;
using namespace ento;

QualType CallOrObjCMessage::getResultType(ASTContext &ctx) const {
  QualType resultTy;
  bool isLVal = false;

  if (isObjCMessage()) {
    resultTy = Msg.getResultType(ctx);
  } else if (const CXXConstructExpr *Ctor =
              CallE.dyn_cast<const CXXConstructExpr *>()) {
    resultTy = Ctor->getType();
  } else {
    const CallExpr *FunctionCall = CallE.get<const CallExpr *>();

    isLVal = FunctionCall->isLValue();
    const Expr *Callee = FunctionCall->getCallee();
    if (const FunctionDecl *FD = State->getSVal(Callee, LCtx).getAsFunctionDecl())
      resultTy = FD->getResultType();
    else
      resultTy = FunctionCall->getType();
  }

  if (isLVal)
    resultTy = ctx.getPointerType(resultTy);

  return resultTy;
}

SVal CallOrObjCMessage::getFunctionCallee() const {
  assert(isFunctionCall());
  assert(!isCXXCall());
  const Expr *Fun = CallE.get<const CallExpr *>()->getCallee()->IgnoreParens();
  return State->getSVal(Fun, LCtx);
}

SVal CallOrObjCMessage::getCXXCallee() const {
  assert(isCXXCall());
  const CallExpr *ActualCall = CallE.get<const CallExpr *>();
  const Expr *callee =
    cast<CXXMemberCallExpr>(ActualCall)->getImplicitObjectArgument();
  
  // FIXME: Will eventually need to cope with member pointers.  This is
  // a limitation in getImplicitObjectArgument().
  if (!callee)
    return UnknownVal();
  
  return State->getSVal(callee, LCtx);
}

SVal
CallOrObjCMessage::getInstanceMessageReceiver(const LocationContext *LC) const {
  assert(isObjCMessage());
  return Msg.getInstanceReceiverSVal(State, LC);
}

const Decl *CallOrObjCMessage::getDecl() const {
  if (isCXXCall()) {
    const CXXMemberCallExpr *CE =
        cast<CXXMemberCallExpr>(CallE.dyn_cast<const CallExpr *>());
    assert(CE);
    return CE->getMethodDecl();
  } else if (isObjCMessage()) {
    return Msg.getMethodDecl();
  } else if (isFunctionCall()) {
    // In case of a C style call, use the path sensitive information to find
    // the function declaration.
    SVal CalleeVal = getFunctionCallee();
    return CalleeVal.getAsFunctionDecl();
  }
  return 0;
}