Use unique_ptr return from CPDF_Parser::ParseIndirectObject()

core/fpdfapi/parser/cpdf_parser.cpp

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/parser/cpdf_parser.h"
 
 #include <vector>
 
@@ skipping 713 matching lines @@
               } else {
                 inside_index++;
               }
               break;
             case 3:
               if (PDFCharIsWhitespace(byte) || PDFCharIsDelimiter(byte)) {
                 FX_FILESIZE obj_pos = start_pos - m_pSyntax->m_HeaderOffset;
                 m_SortedOffset.insert(obj_pos);
                 last_obj = start_pos;
                 FX_FILESIZE obj_end = 0;
-                CPDF_Object* pObject = ParseIndirectObjectAtByStrict(
-                    m_pDocument, obj_pos, objnum, &obj_end);
-                if (CPDF_Stream* pStream = ToStream(pObject)) {
+                std::unique_ptr<CPDF_Object> pObject =
+                    ParseIndirectObjectAtByStrict(m_pDocument, obj_pos, objnum,
+                                                  &obj_end);
+                if (CPDF_Stream* pStream = ToStream(pObject.get())) {
                   if (CPDF_Dictionary* pDict = pStream->GetDict()) {
                     if ((pDict->KeyExist("Type")) &&
                         (pDict->GetStringFor("Type") == "XRef" &&
                          pDict->KeyExist("Size"))) {
                       CPDF_Object* pRoot = pDict->GetObjectFor("Root");
                       if (pRoot && pRoot->GetDict() &&
                           pRoot->GetDict()->GetObjectFor("Pages")) {
                         delete m_pTrailer;
                         m_pTrailer = ToDictionary(pDict->Clone());
                       }
@@ skipping 24 matching lines @@
                     m_ObjectInfo[objnum].pos = obj_pos;
                     m_ObjectInfo[objnum].gennum = gennum;
                     if (oldgen != gennum)
                       m_bVersionUpdated = true;
                   }
                 } else {
                   m_ObjectInfo[objnum].pos = obj_pos;
                   m_ObjectInfo[objnum].type = 1;
                   m_ObjectInfo[objnum].gennum = gennum;
                 }
-
-                delete pObject;
               }
               --i;
               state = ParserState::kDefault;
               break;
           }
           break;
 
         case ParserState::kTrailer:
           if (inside_index == 7) {
             if (PDFCharIsWhitespace(byte) || PDFCharIsDelimiter(byte)) {
               last_trailer = pos + i - 7;
               m_pSyntax->RestorePos(pos + i - m_pSyntax->m_HeaderOffset);
 
-              CPDF_Object* pObj = m_pSyntax->GetObject(m_pDocument, 0, 0, true);
+              std::unique_ptr<CPDF_Object> pObj =
+                  m_pSyntax->GetObject(m_pDocument, 0, 0, true);
               if (pObj) {
-                if (!pObj->IsDictionary() && !pObj->AsStream()) {
-                  delete pObj;
-                } else {
+                if (pObj->IsDictionary() || pObj->AsStream()) {
                   CPDF_Stream* pStream = pObj->AsStream();
                   if (CPDF_Dictionary* pTrailer =
                           pStream ? pStream->GetDict() : pObj->AsDictionary()) {
                     if (m_pTrailer) {
                       CPDF_Object* pRoot = pTrailer->GetObjectFor("Root");
                       CPDF_Reference* pRef = ToReference(pRoot);
                       if (!pRoot ||
                           (pRef && IsValidObjectNumber(pRef->GetRefObjNum()) &&
                            m_ObjectInfo[pRef->GetRefObjNum()].pos != 0)) {
                         auto it = pTrailer->begin();
                         while (it != pTrailer->end()) {
                           const CFX_ByteString& key = it->first;
                           CPDF_Object* pElement = it->second;
                           ++it;
                           uint32_t dwObjNum =
                               pElement ? pElement->GetObjNum() : 0;
                           if (dwObjNum) {
                             m_pTrailer->SetReferenceFor(key, m_pDocument,
                                                         dwObjNum);
                           } else {
                             m_pTrailer->SetFor(key, pElement->Clone());
                           }
                         }
                       }
-                      delete pObj;
                     } else {
                       if (pObj->IsStream()) {
                         m_pTrailer = ToDictionary(pTrailer->Clone());
-                        delete pObj;
                       } else {
+                        pObj.release();

[Lei Zhang, 2016/11/07 21:42:35]

Maybe: m_pTrailer = ToDictionary(pObj.release()));

and fix up |m_pTrailer| later?

[Tom Sepez, 2016/11/07 21:48:37]

I think it becomes a std::move at some point once m_pTrailer changed.

                         m_pTrailer = pTrailer;
                       }
 
                       FX_FILESIZE dwSavePos = m_pSyntax->SavePos();
                       CFX_ByteString strWord = m_pSyntax->GetKeyword();
                       if (!strWord.Compare("startxref")) {
                         bool bNumber;
                         CFX_ByteString bsOffset =
                             m_pSyntax->GetNextWord(&bNumber);
                         if (bNumber)
                           m_LastXRefOffset = FXSYS_atoi(bsOffset.c_str());
                       }
                       m_pSyntax->RestorePos(dwSavePos);
                     }
-                  } else {
-                    delete pObj;
                   }
                 }
               }
             }
             --i;
             state = ParserState::kDefault;
           } else if (byte == "trailer"[inside_index]) {
             inside_index++;
           } else {
             --i;
@@ skipping 223 matching lines @@
   }
   return true;
 }
 
 CPDF_Array* CPDF_Parser::GetIDArray() {
   CPDF_Object* pID = m_pTrailer ? m_pTrailer->GetObjectFor("ID") : nullptr;
   if (!pID)
     return nullptr;
 
   if (CPDF_Reference* pRef = pID->AsReference()) {
-    pID = ParseIndirectObject(nullptr, pRef->GetRefObjNum());
+    pID = ParseIndirectObject(nullptr, pRef->GetRefObjNum()).release();
     m_pTrailer->SetFor("ID", pID);
   }
   return ToArray(pID);
 }
 
 uint32_t CPDF_Parser::GetRootObjNum() {
   CPDF_Reference* pRef =
       ToReference(m_pTrailer ? m_pTrailer->GetObjectFor("Root") : nullptr);
   return pRef ? pRef->GetRefObjNum() : 0;
 }
 
 uint32_t CPDF_Parser::GetInfoObjNum() {
   CPDF_Reference* pRef =
       ToReference(m_pTrailer ? m_pTrailer->GetObjectFor("Info") : nullptr);
   return pRef ? pRef->GetRefObjNum() : 0;
 }
 
-CPDF_Object* CPDF_Parser::ParseIndirectObject(
+std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObject(
     CPDF_IndirectObjectHolder* pObjList,
     uint32_t objnum) {
   if (!IsValidObjectNumber(objnum))
     return nullptr;
 
   // Prevent circular parsing the same object.
   if (pdfium::ContainsKey(m_ParsingObjNums, objnum))
     return nullptr;
 
   pdfium::ScopedSetInsertion<uint32_t> local_insert(&m_ParsingObjNums, objnum);
@@ skipping 182 matching lines @@
     nextoff = m_pSyntax->SavePos();
   }
 
   size = (uint32_t)(nextoff - pos);
   pBuffer = FX_Alloc(uint8_t, size);
   m_pSyntax->RestorePos(pos);
   m_pSyntax->ReadBlock(pBuffer, size);
   m_pSyntax->RestorePos(SavedPos);
 }
 
-CPDF_Object* CPDF_Parser::ParseIndirectObjectAt(
+std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObjectAt(
     CPDF_IndirectObjectHolder* pObjList,
     FX_FILESIZE pos,
     uint32_t objnum) {
   FX_FILESIZE SavedPos = m_pSyntax->SavePos();
   m_pSyntax->RestorePos(pos);
   bool bIsNumber;
   CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
   if (!bIsNumber) {
     m_pSyntax->RestorePos(SavedPos);
     return nullptr;
@@ skipping 12 matching lines @@
     m_pSyntax->RestorePos(SavedPos);
     return nullptr;
   }
 
   uint32_t parser_gennum = FXSYS_atoui(word.c_str());
   if (m_pSyntax->GetKeyword() != "obj") {
     m_pSyntax->RestorePos(SavedPos);
     return nullptr;
   }
 
-  CPDF_Object* pObj =
+  std::unique_ptr<CPDF_Object> pObj =
       m_pSyntax->GetObject(pObjList, objnum, parser_gennum, true);
   m_pSyntax->SavePos();
 
   CFX_ByteString bsWord = m_pSyntax->GetKeyword();
   if (bsWord == "endobj")
     m_pSyntax->SavePos();
 
   m_pSyntax->RestorePos(SavedPos);
   if (pObj) {
     if (!objnum)
       pObj->m_ObjNum = parser_objnum;
     pObj->m_GenNum = parser_gennum;
   }
   return pObj;
 }
 
-CPDF_Object* CPDF_Parser::ParseIndirectObjectAtByStrict(
+std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObjectAtByStrict(
     CPDF_IndirectObjectHolder* pObjList,
     FX_FILESIZE pos,
     uint32_t objnum,
     FX_FILESIZE* pResultPos) {
   FX_FILESIZE SavedPos = m_pSyntax->SavePos();
   m_pSyntax->RestorePos(pos);
 
   bool bIsNumber;
   CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
   if (!bIsNumber) {
@@ skipping 12 matching lines @@
     m_pSyntax->RestorePos(SavedPos);
     return nullptr;
   }
 
   uint32_t gennum = FXSYS_atoui(word.c_str());
   if (m_pSyntax->GetKeyword() != "obj") {
     m_pSyntax->RestorePos(SavedPos);
     return nullptr;
   }
 
-  CPDF_Object* pObj = m_pSyntax->GetObjectForStrict(pObjList, objnum, gennum);
+  std::unique_ptr<CPDF_Object> pObj =
+      m_pSyntax->GetObjectForStrict(pObjList, objnum, gennum);
+
   if (pResultPos)
     *pResultPos = m_pSyntax->m_Pos;
 
   m_pSyntax->RestorePos(SavedPos);
   return pObj;
 }
 
 uint32_t CPDF_Parser::GetFirstPageNo() const {
   return m_pLinearized ? m_pLinearized->GetFirstPageNo() : 0;
 }
@@ skipping 38 matching lines @@
   if (!bIsNumber)
     return false;
 
   uint32_t gennum = FXSYS_atoui(word.c_str());
   if (m_pSyntax->GetKeyword() != "obj") {
     m_pSyntax->RestorePos(SavedPos);
     return false;
   }
 
   m_pLinearized = CPDF_LinearizedHeader::CreateForObject(
-      pdfium::WrapUnique(m_pSyntax->GetObject(nullptr, objnum, gennum, true)));
+      m_pSyntax->GetObject(nullptr, objnum, gennum, true));
   if (!m_pLinearized)
     return false;
+
   m_LastXRefOffset = m_pLinearized->GetLastXRefOffset();
   // Move parser onto first page xref table start.
   m_pSyntax->GetNextWord(nullptr);
   return true;
 }
 
 CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(
     IFX_SeekableReadStream* pFileAccess,
     CPDF_Document* pDocument) {
   ASSERT(!m_bHasParsed);
@@ skipping 120 matching lines @@
   if (!LoadLinearizedAllCrossRefV4(m_LastXRefOffset, m_dwXrefStartObjNum) &&
       !LoadLinearizedAllCrossRefV5(m_LastXRefOffset)) {
     m_LastXRefOffset = 0;
     m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
     return FORMAT_ERROR;
   }
 
   m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
   return SUCCESS;
 }