path: root/lib/Edit/RewriteObjCFoundationAPI.cpp

//===--- RewriteObjCFoundationAPI.cpp - Foundation API Rewriter -----------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Rewrites legacy method calls to modern syntax.
//
//===----------------------------------------------------------------------===//

#include "clang/Edit/Rewriters.h"
#include "clang/Edit/Commit.h"
#include "clang/Lex/Lexer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/NSAPI.h"

using namespace clang;
using namespace edit;

static bool checkForLiteralCreation(const ObjCMessageExpr *Msg,
                                    IdentifierInfo *&ClassId,
                                    const LangOptions &LangOpts) {
  if (!Msg || Msg->isImplicit() || !Msg->getMethodDecl())
    return false;

  const ObjCInterfaceDecl *Receiver = Msg->getReceiverInterface();
  if (!Receiver)
    return false;
  ClassId = Receiver->getIdentifier();

  if (Msg->getReceiverKind() == ObjCMessageExpr::Class)
    return true;

  // When in ARC mode we also convert "[[.. alloc] init]" messages to literals,
  // since the change from +1 to +0 will be handled fine by ARC.
  if (LangOpts.ObjCAutoRefCount) {
    if (Msg->getReceiverKind() == ObjCMessageExpr::Instance) {
      if (const ObjCMessageExpr *Rec = dyn_cast<ObjCMessageExpr>(
                           Msg->getInstanceReceiver()->IgnoreParenImpCasts())) {
        if (Rec->getMethodFamily() == OMF_alloc)
          return true;
      }
    }
  }

  return false;
}

//===----------------------------------------------------------------------===//
// rewriteObjCRedundantCallWithLiteral.
//===----------------------------------------------------------------------===//

bool edit::rewriteObjCRedundantCallWithLiteral(const ObjCMessageExpr *Msg,
                                              const NSAPI &NS, Commit &commit) {
  IdentifierInfo *II = 0;
  if (!checkForLiteralCreation(Msg, II, NS.getASTContext().getLangOpts()))
    return false;
  if (Msg->getNumArgs() != 1)
    return false;

  const Expr *Arg = Msg->getArg(0)->IgnoreParenImpCasts();
  Selector Sel = Msg->getSelector();

  if ((isa<ObjCStringLiteral>(Arg) &&
       NS.getNSClassId(NSAPI::ClassId_NSString) == II &&
       (NS.getNSStringSelector(NSAPI::NSStr_stringWithString) == Sel ||
        NS.getNSStringSelector(NSAPI::NSStr_initWithString) == Sel))   ||

      (isa<ObjCArrayLiteral>(Arg) &&
       NS.getNSClassId(NSAPI::ClassId_NSArray) == II &&
       (NS.getNSArraySelector(NSAPI::NSArr_arrayWithArray) == Sel ||
        NS.getNSArraySelector(NSAPI::NSArr_initWithArray) == Sel))     ||

      (isa<ObjCDictionaryLiteral>(Arg) &&
       NS.getNSClassId(NSAPI::ClassId_NSDictionary) == II &&
       (NS.getNSDictionarySelector(
                              NSAPI::NSDict_dictionaryWithDictionary) == Sel ||
        NS.getNSDictionarySelector(NSAPI::NSDict_initWithDictionary) == Sel))) {
    
    commit.replaceWithInner(Msg->getSourceRange(),
                           Msg->getArg(0)->getSourceRange());
    return true;
  }

  return false;
}

//===----------------------------------------------------------------------===//
// rewriteToObjCSubscriptSyntax.
//===----------------------------------------------------------------------===//

/// \brief Check for classes that accept 'objectForKey:' (or the other selectors
/// that the migrator handles) but return their instances as 'id', resulting
/// in the compiler resolving 'objectForKey:' as the method from NSDictionary.
///
/// When checking if we can convert to subscripting syntax, check whether
/// the receiver is a result of a class method from a hardcoded list of
/// such classes. In such a case return the specific class as the interface
/// of the receiver.
///
/// FIXME: Remove this when these classes start using 'instancetype'.
static const ObjCInterfaceDecl *
maybeAdjustInterfaceForSubscriptingCheck(const ObjCInterfaceDecl *IFace,
                                         const Expr *Receiver,
                                         ASTContext &Ctx) {
  assert(IFace && Receiver);

  // If the receiver has type 'id'...
  if (!Ctx.isObjCIdType(Receiver->getType().getUnqualifiedType()))
    return IFace;

  const ObjCMessageExpr *
    InnerMsg = dyn_cast<ObjCMessageExpr>(Receiver->IgnoreParenCasts());
  if (!InnerMsg)
    return IFace;

  QualType ClassRec;
  switch (InnerMsg->getReceiverKind()) {
  case ObjCMessageExpr::Instance:
  case ObjCMessageExpr::SuperInstance:
    return IFace;

  case ObjCMessageExpr::Class:
    ClassRec = InnerMsg->getClassReceiver();
    break;
  case ObjCMessageExpr::SuperClass:
    ClassRec = InnerMsg->getSuperType();
    break;
  }

  if (