Kill last use of CFX_PtrList.

I'd been waiting on this hoping the code would be refactored out
of existence, but it looks to be used.

Use tests against x.end() in place of a "null position".
This is greatly complicated by the use of "tail position", which
now calcluated by std::prev(x.end()) unless the list is empty.

Review-Url: https://codereview.chromium.org/2592163002

5 files changed, 53 insertions, 263 deletions

diff --git a/BUILD.gn b/BUILD.gn
index b9f648fa95..1244bccf99 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -729,7 +729,6 @@ static_library("fxcrt") {
     "core/fxcrt/fx_basic_buffer.cpp",
     "core/fxcrt/fx_basic_coords.cpp",
     "core/fxcrt/fx_basic_gcc.cpp",
-    "core/fxcrt/fx_basic_list.cpp",
     "core/fxcrt/fx_basic_memmgr.cpp",
     "core/fxcrt/fx_basic_plex.cpp",
     "core/fxcrt/fx_basic_utf.cpp",
diff --git a/core/fxcrt/fx_basic.h b/core/fxcrt/fx_basic.h
index 7096e6f8df..3b09489d71 100644
--- a/core/fxcrt/fx_basic.h
+++ b/core/fxcrt/fx_basic.h
@@ -433,79 +433,7 @@ class CFX_MapPtrTemplate : public CFX_MapPtrToPtr {
     rValue = (ValueType)(uintptr_t)pValue;
   }
 };
-#endif  // PDF_ENABLE_XFA
-
-class CFX_PtrList {
- protected:
-  struct CNode {
-    CNode* pNext;
-    CNode* pPrev;
-    void* data;
-  };
-
- public:
-  explicit CFX_PtrList(int nBlockSize = 10);
-
-  FX_POSITION GetHeadPosition() const { return (FX_POSITION)m_pNodeHead; }
-  FX_POSITION GetTailPosition() const { return (FX_POSITION)m_pNodeTail; }
-
-  void* GetNext(FX_POSITION& rPosition) const {
-    CNode* pNode = (CNode*)rPosition;
-    rPosition = (FX_POSITION)pNode->pNext;
-    return pNode->data;
-  }
-
-  void* GetPrev(FX_POSITION& rPosition) const {
-    CNode* pNode = (CNode*)rPosition;
-    rPosition = (FX_POSITION)pNode->pPrev;
-    return pNode->data;
-  }
-
-  FX_POSITION GetNextPosition(FX_POSITION pos) const {
-    return ((CNode*)pos)->pNext;
-  }
-
-  FX_POSITION GetPrevPosition(FX_POSITION pos) const {
-    return ((CNode*)pos)->pPrev;
-  }
-
-  void* GetAt(FX_POSITION rPosition) const {
-    CNode* pNode = (CNode*)rPosition;
-    return pNode->data;
-  }
 
-  int GetCount() const { return m_nCount; }
-  FX_POSITION AddTail(void* newElement);
-  FX_POSITION AddHead(void* newElement);
-
-  void SetAt(FX_POSITION pos, void* newElement) {
-    CNode* pNode = (CNode*)pos;
-    pNode->data = newElement;
-  }
-  FX_POSITION InsertAfter(FX_POSITION pos, void* newElement);
-
-  FX_POSITION Find(void* searchValue, FX_POSITION startAfter = nullptr) const;
-  FX_POSITION FindIndex(int index) const;
-
-  void RemoveAt(FX_POSITION pos);
-  void RemoveAll();
-
- protected:
-  CNode* m_pNodeHead;
-  CNode* m_pNodeTail;
-  int m_nCount;
-  CNode* m_pNodeFree;
-  struct CFX_Plex* m_pBlocks;
-  int m_nBlockSize;
-
-  CNode* NewNode(CNode* pPrev, CNode* pNext);
-  void FreeNode(CNode* pNode);
-
- public:
-  ~CFX_PtrList();
-};
-
-#ifdef PDF_ENABLE_XFA
 typedef void (*PD_CALLBACK_FREEDATA)(void* pData);
 #endif  // PDF_ENABLE_XFA
 
diff --git a/core/fxcrt/fx_basic_list.cpp b/core/fxcrt/fx_basic_list.cpp
deleted file mode 100644
index 09ad08b281..0000000000
--- a/core/fxcrt/fx_basic_list.cpp
+++ /dev/null
@@ -1,131 +0,0 @@
-// Copyright 2014 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/fxcrt/fx_basic.h"
-#include "core/fxcrt/plex.h"
-
-CFX_PtrList::CFX_PtrList(int nBlockSize)
-    : m_pNodeHead(nullptr),
-      m_pNodeTail(nullptr),
-      m_nCount(0),
-      m_pNodeFree(nullptr),
-      m_pBlocks(nullptr),
-      m_nBlockSize(nBlockSize) {}
-FX_POSITION CFX_PtrList::AddTail(void* newElement) {
-  CNode* pNewNode = NewNode(m_pNodeTail, nullptr);
-  pNewNode->data = newElement;
-  if (m_pNodeTail) {
-    m_pNodeTail->pNext = pNewNode;
-  } else {
-    m_pNodeHead = pNewNode;
-  }
-  m_pNodeTail = pNewNode;
-  return (FX_POSITION)pNewNode;
-}
-FX_POSITION CFX_PtrList::AddHead(void* newElement) {
-  CNode* pNewNode = NewNode(nullptr, m_pNodeHead);
-  pNewNode->data = newElement;
-  if (m_pNodeHead) {
-    m_pNodeHead->pPrev = pNewNode;
-  } else {
-    m_pNodeTail = pNewNode;
-  }
-  m_pNodeHead = pNewNode;
-  return (FX_POSITION)pNewNode;
-}
-FX_POSITION CFX_PtrList::InsertAfter(FX_POSITION position, void* newElement) {
-  if (!position) {
-    return AddTail(newElement);
-  }
-  CNode* pOldNode = (CNode*)position;
-  CNode* pNewNode = NewNode(pOldNode, pOldNode->pNext);
-  pNewNode->data = newElement;
-  if (pOldNode->pNext) {
-    pOldNode->pNext->pPrev = pNewNode;
-  } else {
-    m_pNodeTail = pNewNode;
-  }
-  pOldNode->pNext = pNewNode;
-  return (FX_POSITION)pNewNode;
-}
-void CFX_PtrList::RemoveAt(FX_POSITION position) {
-  CNode* pOldNode = (CNode*)position;
-  if (pOldNode == m_pNodeHead) {
-    m_pNodeHead = pOldNode->pNext;
-  } else {
-    pOldNode->pPrev->pNext = pOldNode->pNext;
-  }
-  if (pOldNode == m_pNodeTail) {
-    m_pNodeTail = pOldNode->pPrev;
-  } else {
-    pOldNode->pNext->pPrev = pOldNode->pPrev;
-  }
-  FreeNode(pOldNode);
-}
-void CFX_PtrList::FreeNode(CFX_PtrList::CNode* pNode) {
-  pNode->pNext = m_pNodeFree;
-  m_pNodeFree = pNode;
-  m_nCount--;
-  if (m_nCount == 0) {
-    RemoveAll();
-  }
-}
-
-void CFX_PtrList::RemoveAll() {
-  m_nCount = 0;
-  m_pNodeHead = nullptr;
-  m_pNodeTail = nullptr;
-  m_pNodeFree = nullptr;
-  if (m_pBlocks) {
-    m_pBlocks->FreeDataChain();
-    m_pBlocks = nullptr;
-  }
-}
-
-CFX_PtrList::CNode* CFX_PtrList::NewNode(CFX_PtrList::CNode* pPrev,
-                                         CFX_PtrList::CNode* pNext) {
-  if (!m_pNodeFree) {
-    CFX_Plex* pNewBlock =
-        CFX_Plex::Create(m_pBlocks, m_nBlockSize, sizeof(CNode));
-    CNode* pNode = (CNode*)pNewBlock->data();
-    pNode += m_nBlockSize - 1;
-    for (int i = m_nBlockSize - 1; i >= 0; i--, pNode--) {
-      pNode->pNext = m_pNodeFree;
-      m_pNodeFree = pNode;
-    }
-  }
-  CFX_PtrList::CNode* pNode = m_pNodeFree;
-  m_pNodeFree = m_pNodeFree->pNext;
-  pNode->pPrev = pPrev;
-  pNode->pNext = pNext;
-  m_nCount++;
-  ASSERT(m_nCount > 0);
-  pNode->data = 0;
-  return pNode;
-}
-CFX_PtrList::~CFX_PtrList() {
-  RemoveAll();
-  ASSERT(m_nCount == 0);
-}
-FX_POSITION CFX_PtrList::FindIndex(int nIndex) const {
-  if (nIndex >= m_nCount || nIndex < 0) {
-    return nullptr;
-  }
-  CNode* pNode = m_pNodeHead;
-  while (nIndex--) {
-    pNode = pNode->pNext;
-  }
-  return (FX_POSITION)pNode;
-}
-FX_POSITION CFX_PtrList::Find(void* searchValue, FX_POSITION startAfter) const {
-  CNode* pNode = (CNode*)startAfter;
-  pNode = pNode ? pNode->pNext : m_pNodeHead;
-  for (; pNode; pNode = pNode->pNext) {
-    if (pNode->data == searchValue)
-      return (FX_POSITION)pNode;
-  }
-  return nullptr;
-}
diff --git a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
index 1be6d27129..1a3da9ecb3 100644
--- a/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
+++ b/xfa/fxfa/parser/cxfa_layoutpagemgr.cpp
@@ -243,7 +243,7 @@ CXFA_LayoutPageMgr::CXFA_LayoutPageMgr(CXFA_LayoutProcessor* pLayoutProcessor)
       m_pTemplatePageSetRoot(nullptr),
       m_pPageSetLayoutItemRoot(nullptr),
       m_pPageSetCurRoot(nullptr),
-      m_pCurrentContainerRecord(nullptr),
+      m_CurrentContainerRecordIter(m_ProposedContainerRecords.end()),
       m_pCurPageArea(nullptr),
       m_nAvailPages(0),
       m_nCurPageCount(0),
@@ -378,23 +378,26 @@ bool CXFA_LayoutPageMgr::PrepareFirstPage(CXFA_Node* pRootSubform) {
   CXFA_Node *pLeader, *pTrailer;
   if (pBreakBeforeNode &&
       ExecuteBreakBeforeOrAfter(pBreakBeforeNode, true, pLeader, pTrailer)) {
-    m_pCurrentContainerRecord = m_rgProposedContainerRecord.GetHeadPosition();
+    m_CurrentContainerRecordIter = m_ProposedContainerRecords.begin();
     return true;
   }
   return AppendNewPage(true);
 }
 
 bool CXFA_LayoutPageMgr::AppendNewPage(bool bFirstTemPage) {
-  if (m_pCurrentContainerRecord !=
-      m_rgProposedContainerRecord.GetTailPosition()) {
+  if (m_CurrentContainerRecordIter != GetTailPosition())
     return true;
-  }
+
   CXFA_Node* pPageNode = GetNextAvailPageArea(nullptr);
   if (!pPageNode)
     return false;
-  if (bFirstTemPage && !m_pCurrentContainerRecord)
-    m_pCurrentContainerRecord = m_rgProposedContainerRecord.GetHeadPosition();
-  return !bFirstTemPage || m_pCurrentContainerRecord;
+
+  if (bFirstTemPage &&
+      m_CurrentContainerRecordIter == m_ProposedContainerRecords.end()) {
+    m_CurrentContainerRecordIter = m_ProposedContainerRecords.begin();
+  }
+  return !bFirstTemPage ||
+         m_CurrentContainerRecordIter != m_ProposedContainerRecords.end();
 }
 
 void CXFA_LayoutPageMgr::RemoveLayoutRecord(CXFA_ContainerRecord* pNewRecord,
@@ -444,11 +447,10 @@ void CXFA_LayoutPageMgr::SubmitContentItem(
 
   if (eStatus != XFA_ItemLayoutProcessorResult_Done) {
     if (eStatus == XFA_ItemLayoutProcessorResult_PageFullBreak &&
-        m_pCurrentContainerRecord ==
-            m_rgProposedContainerRecord.GetTailPosition()) {
+        m_CurrentContainerRecordIter == GetTailPosition()) {
       AppendNewPage();
     }
-    m_pCurrentContainerRecord = m_rgProposedContainerRecord.GetTailPosition();
+    m_CurrentContainerRecordIter = GetTailPosition();
     m_pCurPageArea = GetCurrentContainerRecord()->pCurPageArea->m_pFormNode;
   }
 }
@@ -463,10 +465,8 @@ FX_FLOAT CXFA_LayoutPageMgr::GetAvailHeight() {
       pLayoutItem->m_pFormNode->GetMeasure(XFA_ATTRIBUTE_H).ToUnit(XFA_UNIT_Pt);
   if (fAvailHeight >= XFA_LAYOUT_FLOAT_PERCISION)
     return fAvailHeight;
-  if (m_pCurrentContainerRecord ==
-      m_rgProposedContainerRecord.GetHeadPosition()) {
+  if (m_CurrentContainerRecordIter == m_ProposedContainerRecords.begin())
     return 0.0f;
-  }
   return XFA_LAYOUT_FLOAT_MAX;
 }
 
@@ -484,10 +484,10 @@ CXFA_ContainerRecord* CXFA_LayoutPageMgr::CreateContainerRecord(
     CXFA_Node* pPageNode,
     bool bCreateNew) {
   CXFA_ContainerRecord* pNewRecord = new CXFA_ContainerRecord();
-  if (m_pCurrentContainerRecord) {
+  if (m_CurrentContainerRecordIter != m_ProposedContainerRecords.end()) {
     if (!IsPageSetRootOrderedOccurrence() || !pPageNode) {
       *pNewRecord = *GetCurrentContainerRecord();
-      m_rgProposedContainerRecord.AddTail(pNewRecord);
+      m_ProposedContainerRecords.push_back(pNewRecord);
       return pNewRecord;
     }
     CXFA_Node* pPageSet = pPageNode->GetNodeItem(XFA_NODEITEM_Parent);
@@ -546,7 +546,7 @@ CXFA_ContainerRecord* CXFA_LayoutPageMgr::CreateContainerRecord(
       pNewRecord->pCurPageSet = m_pPageSetLayoutItemRoot;
     }
   }
-  m_rgProposedContainerRecord.AddTail(pNewRecord);
+  m_ProposedContainerRecords.push_back(pNewRecord);
   return pNewRecord;
 }
 
@@ -748,7 +748,8 @@ bool CXFA_LayoutPageMgr::RunBreak(XFA_Element eBreakType,
     case XFA_ATTRIBUTEENUM_ContentArea:
       if (pTarget && pTarget->GetElementType() != XFA_Element::ContentArea)
         pTarget = nullptr;
-      if (!pTarget || !m_pCurrentContainerRecord ||
+      if (!pTarget ||
+          m_CurrentContainerRecordIter == m_ProposedContainerRecords.end() ||
           pTarget !=
               GetCurrentContainerRecord()->pCurContentArea->m_pFormNode ||
           bStartNew) {
@@ -763,7 +764,8 @@ bool CXFA_LayoutPageMgr::RunBreak(XFA_Element eBreakType,
     case XFA_ATTRIBUTEENUM_PageArea:
       if (pTarget && pTarget->GetElementType() != XFA_Element::PageArea)
         pTarget = nullptr;
-      if (!pTarget || !m_pCurrentContainerRecord ||
+      if (!pTarget ||
+          m_CurrentContainerRecordIter == m_ProposedContainerRecords.end() ||
           pTarget != GetCurrentContainerRecord()->pCurPageArea->m_pFormNode ||
           bStartNew) {
         CXFA_Node* pPageArea = GetNextAvailPageArea(pTarget, nullptr, true);
@@ -816,9 +818,8 @@ bool CXFA_LayoutPageMgr::ExecuteBreakBeforeOrAfter(
                    bStartNew)) {
         return true;
       }
-      if (m_rgProposedContainerRecord.GetCount() > 0 &&
-          m_pCurrentContainerRecord ==
-              m_rgProposedContainerRecord.GetHeadPosition() &&
+      if (!m_ProposedContainerRecords.empty() &&
+          m_CurrentContainerRecordIter == m_ProposedContainerRecords.begin() &&
           eType == XFA_Element::BreakBefore) {
         CXFA_Node* pParentNode = pFormNode->GetNodeItem(
             XFA_NODEITEM_Parent, XFA_ObjectType::ContainerNode);
@@ -1101,9 +1102,10 @@ bool CXFA_LayoutPageMgr::FindPageAreaFromPageSet(CXFA_Node* pPageSet,
                                            pTargetPageArea, pTargetContentArea,
                                            bNewPage, bQuery);
   }
-  XFA_ATTRIBUTEENUM ePreferredPosition = m_pCurrentContainerRecord
-                                             ? XFA_ATTRIBUTEENUM_Rest
-                                             : XFA_ATTRIBUTEENUM_First;
+  XFA_ATTRIBUTEENUM ePreferredPosition =
+      m_CurrentContainerRecordIter != m_ProposedContainerRecords.end()
+          ? XFA_ATTRIBUTEENUM_Rest
+          : XFA_ATTRIBUTEENUM_First;
   return FindPageAreaFromPageSet_SimplexDuplex(
       pPageSet, pStartChild, pTargetPageArea, pTargetContentArea, bNewPage,
       bQuery, ePreferredPosition);
@@ -1528,21 +1530,18 @@ bool CXFA_LayoutPageMgr::GetNextAvailContentHeight(FX_FLOAT fChildHeight) {
     if (m_nCurPageCount == iMax) {
       CXFA_Node* pSrcPage = m_pCurPageArea;
       int32_t nSrcPageCount = m_nCurPageCount;
-      FX_POSITION psSrcRecord = m_rgProposedContainerRecord.GetTailPosition();
+      auto psSrcIter = GetTailPosition();
       CXFA_Node* pNextPage =
           GetNextAvailPageArea(nullptr, nullptr, false, true);
       m_pCurPageArea = pSrcPage;
       m_nCurPageCount = nSrcPageCount;
-      CXFA_ContainerRecord* pPrevRecord = static_cast<CXFA_ContainerRecord*>(
-          m_rgProposedContainerRecord.GetNext(psSrcRecord));
-      while (psSrcRecord) {
-        FX_POSITION psSaveRecord = psSrcRecord;
-        CXFA_ContainerRecord* pInsertRecord =
-            static_cast<CXFA_ContainerRecord*>(
-                m_rgProposedContainerRecord.GetNext(psSrcRecord));
+      CXFA_ContainerRecord* pPrevRecord = *psSrcIter++;
+      while (psSrcIter != m_ProposedContainerRecords.end()) {
+        auto psSaveIter = psSrcIter;
+        CXFA_ContainerRecord* pInsertRecord = *psSrcIter++;
         RemoveLayoutRecord(pInsertRecord, pPrevRecord);
         delete pInsertRecord;
-        m_rgProposedContainerRecord.RemoveAt(psSaveRecord);
+        m_ProposedContainerRecords.erase(psSaveIter);
       }
       if (pNextPage) {
         CXFA_Node* pContentArea =
@@ -1570,23 +1569,16 @@ bool CXFA_LayoutPageMgr::GetNextAvailContentHeight(FX_FLOAT fChildHeight) {
 }
 
 void CXFA_LayoutPageMgr::ClearData() {
-  ClearRecordList();
-}
-
-void CXFA_LayoutPageMgr::ClearRecordList() {
   if (!m_pTemplatePageSetRoot)
     return;
-  if (m_rgProposedContainerRecord.GetCount() > 0) {
-    FX_POSITION sPos;
-    sPos = m_rgProposedContainerRecord.GetHeadPosition();
-    while (sPos) {
-      CXFA_ContainerRecord* pRecord = static_cast<CXFA_ContainerRecord*>(
-          m_rgProposedContainerRecord.GetNext(sPos));
-      delete pRecord;
-    }
-    m_rgProposedContainerRecord.RemoveAll();
+
+  auto sPos = m_ProposedContainerRecords.begin();
+  while (sPos != m_ProposedContainerRecords.end()) {
+    CXFA_ContainerRecord* pRecord = *sPos++;
+    delete pRecord;
   }
-  m_pCurrentContainerRecord = nullptr;
+  m_ProposedContainerRecords.clear();
+  m_CurrentContainerRecordIter = m_ProposedContainerRecords.end();
   m_pCurPageArea = nullptr;
   m_nCurPageCount = 0;
   m_bCreateOverFlowPage = false;
@@ -1942,7 +1934,7 @@ void CXFA_LayoutPageMgr::SyncLayoutData() {
     pNotify->OnPageEvent(pPage, XFA_PAGEVIEWEVENT_PostRemoved);
     delete pPage;
   }
-  ClearRecordList();
+  ClearData();
 }
 
 void XFA_ReleaseLayoutItem_NoPageArea(CXFA_LayoutItem* pLayoutItem) {
@@ -1961,7 +1953,7 @@ void CXFA_LayoutPageMgr::PrepareLayout() {
   m_pPageSetCurRoot = nullptr;
   m_ePageSetMode = XFA_ATTRIBUTEENUM_OrderedOccurrence;
   m_nAvailPages = 0;
-  ClearRecordList();
+  ClearData();
   if (!m_pPageSetLayoutItemRoot)
     return;
 
diff --git a/xfa/fxfa/parser/cxfa_layoutpagemgr.h b/xfa/fxfa/parser/cxfa_layoutpagemgr.h
index 3f0410f74c..b466f3ad1f 100644
--- a/xfa/fxfa/parser/cxfa_layoutpagemgr.h
+++ b/xfa/fxfa/parser/cxfa_layoutpagemgr.h
@@ -7,6 +7,9 @@
 #ifndef XFA_FXFA_PARSER_CXFA_LAYOUTPAGEMGR_H_
 #define XFA_FXFA_PARSER_CXFA_LAYOUTPAGEMGR_H_
 
+#include <iterator>
+#include <list>
+
 #include "xfa/fxfa/parser/xfa_layout_itemlayout.h"
 
 class CXFA_ContainerRecord;
@@ -54,12 +57,12 @@ class CXFA_LayoutPageMgr {
                                         CXFA_ContainerRecord* pPrevRecord);
   void RemoveLayoutRecord(CXFA_ContainerRecord* pNewRecord,
                           CXFA_ContainerRecord* pPrevRecord);
-  inline CXFA_ContainerRecord* GetCurrentContainerRecord() {
-    CXFA_ContainerRecord* result =
-        ((CXFA_ContainerRecord*)m_rgProposedContainerRecord.GetAt(
-            m_pCurrentContainerRecord));
-    ASSERT(result);
-    return result;
+  CXFA_ContainerRecord* GetCurrentContainerRecord() {
+    return *m_CurrentContainerRecordIter;
+  }
+  std::list<CXFA_ContainerRecord*>::iterator GetTailPosition() {
+    auto iter = m_ProposedContainerRecords.end();
+    return !m_ProposedContainerRecords.empty() ? std::prev(iter) : iter;
   }
   CXFA_ContainerRecord* CreateContainerRecord(CXFA_Node* pPageNode = nullptr,
                                               bool bCreateNew = false);
@@ -120,7 +123,6 @@ class CXFA_LayoutPageMgr {
     return m_ePageSetMode == XFA_ATTRIBUTEENUM_OrderedOccurrence;
   }
   void ClearData();
-  void ClearRecordList();
   void MergePageSetContents();
   void LayoutPageSetContents();
   void PrepareLayout();
@@ -129,8 +131,8 @@ class CXFA_LayoutPageMgr {
   CXFA_Node* m_pTemplatePageSetRoot;
   CXFA_ContainerLayoutItem* m_pPageSetLayoutItemRoot;
   CXFA_ContainerLayoutItem* m_pPageSetCurRoot;
-  FX_POSITION m_pCurrentContainerRecord;
-  CFX_PtrList m_rgProposedContainerRecord;
+  std::list<CXFA_ContainerRecord*> m_ProposedContainerRecords;
+  std::list<CXFA_ContainerRecord*>::iterator m_CurrentContainerRecordIter;
   CXFA_Node* m_pCurPageArea;
   int32_t m_nAvailPages;
   int32_t m_nCurPageCount;