Make CPDF_Object containers hold objects via unique pointers.

This tweaks the implementation while leaving the API the
same.  The API change is more disruptive, so break this
part off first.

Review-Url: https://codereview.chromium.org/2385293002

14 files changed, 65 insertions, 89 deletions

diff --git a/core/fpdfapi/edit/fpdf_edit_create.cpp b/core/fpdfapi/edit/fpdf_edit_create.cpp
index e5b1fe1bb0..fae2b14449 100644
--- a/core/fpdfapi/edit/fpdf_edit_create.cpp
+++ b/core/fpdfapi/edit/fpdf_edit_create.cpp
@@ -128,7 +128,7 @@ int32_t PDF_CreatorAppendObject(const CPDF_Object* pObj,
       const CPDF_Dictionary* p = pObj->AsDictionary();
       for (const auto& it : *p) {
         const CFX_ByteString& key = it.first;
-        CPDF_Object* pValue = it.second;
+        CPDF_Object* pValue = it.second.get();
         if (pFile->AppendString("/") < 0) {
           return -1;
         }
@@ -197,7 +197,7 @@ int32_t PDF_CreatorWriteTrailer(CPDF_Document* pDocument,
     CPDF_Dictionary* p = pParser->GetTrailer();
     for (const auto& it : *p) {
       const CFX_ByteString& key = it.first;
-      CPDF_Object* pValue = it.second;
+      CPDF_Object* pValue = it.second.get();
       if (key == "Encrypt" || key == "Size" || key == "Filter" ||
           key == "Index" || key == "Length" || key == "Prev" || key == "W" ||
           key == "XRefStm" || key == "Type" || key == "ID") {
@@ -1192,7 +1192,7 @@ int32_t CPDF_Creator::WriteDirectObj(uint32_t objnum,
       for (const auto& it : *p) {
         FX_BOOL bSignValue = FALSE;
         const CFX_ByteString& key = it.first;
-        CPDF_Object* pValue = it.second;
+        CPDF_Object* pValue = it.second.get();
         if (m_File.AppendString("/") < 0) {
           return -1;
         }
@@ -1714,7 +1714,7 @@ int32_t CPDF_Creator::WriteDoc_Stage4(IFX_Pause* pPause) {
       CPDF_Dictionary* p = m_pParser->GetTrailer();
       for (const auto& it : *p) {
         const CFX_ByteString& key = it.first;
-        CPDF_Object* pValue = it.second;
+        CPDF_Object* pValue = it.second.get();
         // TODO(ochang): Consolidate with similar check in
         // PDF_CreatorWriteTrailer.
         if (key == "Encrypt" || key == "Size" || key == "Filter" ||
diff --git a/core/fpdfapi/page/cpdf_allstates.cpp b/core/fpdfapi/page/cpdf_allstates.cpp
index 70de98e3f0..c00af83aa8 100644
--- a/core/fpdfapi/page/cpdf_allstates.cpp
+++ b/core/fpdfapi/page/cpdf_allstates.cpp
@@ -52,7 +52,7 @@ void CPDF_AllStates::ProcessExtGS(CPDF_Dictionary* pGS,
                                   CPDF_StreamContentParser* pParser) {
   for (const auto& it : *pGS) {
     const CFX_ByteString& key_str = it.first;
-    CPDF_Object* pElement = it.second;
+    CPDF_Object* pElement = it.second.get();
     CPDF_Object* pObject = pElement ? pElement->GetDirect() : nullptr;
     if (!pObject)
       continue;
diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index fe840d10df..12af11e7d4 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -345,7 +345,7 @@ std::unique_ptr<CPDF_ColorSpace> CPDF_ColorSpace::Load(CPDF_Document* pDoc,
 
     for (const auto& it : *pDict) {
       std::unique_ptr<CPDF_ColorSpace> pRet;
-      CPDF_Object* pValue = it.second;
+      CPDF_Object* pValue = it.second.get();
       if (ToName(pValue))
         pRet.reset(ColorspaceFromName(pValue->GetString()));
       if (pRet)
diff --git a/core/fpdfapi/page/fpdf_page_parser.cpp b/core/fpdfapi/page/fpdf_page_parser.cpp
index b6f0bc605c..e27872a538 100644
--- a/core/fpdfapi/page/fpdf_page_parser.cpp
+++ b/core/fpdfapi/page/fpdf_page_parser.cpp
@@ -97,7 +97,7 @@ void PDF_ReplaceAbbr(CPDF_Object* pObj) {
       std::vector<AbbrReplacementOp> replacements;
       for (const auto& it : *pDict) {
         CFX_ByteString key = it.first;
-        CPDF_Object* value = it.second;
+        CPDF_Object* value = it.second.get();
         CFX_ByteStringC fullname =
             PDF_FindFullName(PDF_InlineKeyAbbr, FX_ArraySize(PDF_InlineKeyAbbr),
                              key.AsStringC());
diff --git a/core/fpdfapi/parser/cpdf_array.cpp b/core/fpdfapi/parser/cpdf_array.cpp
index 1aec3e06f3..807f62d7f3 100644
--- a/core/fpdfapi/parser/cpdf_array.cpp
+++ b/core/fpdfapi/parser/cpdf_array.cpp
@@ -20,11 +20,11 @@ CPDF_Array::CPDF_Array() {}
 
 CPDF_Array::~CPDF_Array() {
   // Mark the object as deleted so that it will not be deleted again
-  // in case of cyclic references.
+  // in case of cyclic references, then break cycles.
   m_ObjNum = kInvalidObjNum;
   for (auto& it : m_Objects) {
-    if (it && it->GetObjNum() != kInvalidObjNum)
-      it->Release();
+    if (it && it->GetObjNum() == kInvalidObjNum)
+      it.release();
   }
 }
 
@@ -53,10 +53,11 @@ CPDF_Object* CPDF_Array::CloneNonCyclic(
     std::set<const CPDF_Object*>* pVisited) const {
   pVisited->insert(this);
   CPDF_Array* pCopy = new CPDF_Array();
-  for (size_t i = 0; i < GetCount(); i++) {
-    CPDF_Object* value = m_Objects[i];
-    if (!pdfium::ContainsKey(*pVisited, value))
-      pCopy->m_Objects.push_back(value->CloneNonCyclic(bDirect, pVisited));
+  for (const auto& pObj : m_Objects) {
+    if (!pdfium::ContainsKey(*pVisited, pObj.get())) {
+      pCopy->m_Objects.push_back(
+          UniqueObject(pObj->CloneNonCyclic(bDirect, pVisited)));
+    }
   }
   return pCopy;
 }
@@ -86,7 +87,7 @@ CFX_Matrix CPDF_Array::GetMatrix() {
 CPDF_Object* CPDF_Array::GetObjectAt(size_t i) const {
   if (i >= m_Objects.size())
     return nullptr;
-  return m_Objects[i];
+  return m_Objects[i].get();
 }
 
 CPDF_Object* CPDF_Array::GetDirectObjectAt(size_t i) const {
@@ -139,11 +140,8 @@ void CPDF_Array::RemoveAt(size_t i, size_t nCount) {
   if (nCount <= 0 || nCount > m_Objects.size() - i)
     return;
 
-  for (size_t j = 0; j < nCount; ++j) {
-    if (CPDF_Object* p = m_Objects[i + j])
-      p->Release();
-  }
-  m_Objects.erase(m_Objects.begin() + i, m_Objects.begin() + i + nCount);
+  auto it = m_Objects.begin() + i;
+  m_Objects.erase(it, it + nCount);
 }
 
 void CPDF_Array::ConvertToIndirectObjectAt(size_t i,
@@ -151,12 +149,11 @@ void CPDF_Array::ConvertToIndirectObjectAt(size_t i,
   if (i >= m_Objects.size())
     return;
 
-  CPDF_Object* pObj = m_Objects[i];
-  if (!pObj || pObj->IsReference())
+  if (!m_Objects[i] || m_Objects[i]->IsReference())
     return;
 
-  uint32_t dwObjNum = pHolder->AddIndirectObject(pObj);
-  m_Objects[i] = new CPDF_Reference(pHolder, dwObjNum);
+  uint32_t dwObjNum = pHolder->AddIndirectObject(m_Objects[i].release());
+  m_Objects[i] = UniqueObject(new CPDF_Reference(pHolder, dwObjNum));
 }
 
 void CPDF_Array::SetAt(size_t i, CPDF_Object* pObj) {
@@ -166,10 +163,7 @@ void CPDF_Array::SetAt(size_t i, CPDF_Object* pObj) {
     ASSERT(false);
     return;
   }
-  if (CPDF_Object* pOld = m_Objects[i])
-    pOld->Release();
-
-  m_Objects[i] = pObj;
+  m_Objects[i] = UniqueObject(pObj);
 }
 
 void CPDF_Array::InsertAt(size_t index, CPDF_Object* pObj) {
@@ -177,18 +171,18 @@ void CPDF_Array::InsertAt(size_t index, CPDF_Object* pObj) {
   CHECK(!pObj || pObj->IsInline());
   if (index >= m_Objects.size()) {
     // Allocate space first.
-    m_Objects.resize(index + 1, nullptr);
-    m_Objects[index] = pObj;
+    m_Objects.resize(index + 1);
+    m_Objects[index] = UniqueObject(pObj);
   } else {
     // Directly insert.
-    m_Objects.insert(m_Objects.begin() + index, pObj);
+    m_Objects.insert(m_Objects.begin() + index, UniqueObject(pObj));
   }
 }
 
 void CPDF_Array::Add(CPDF_Object* pObj) {
   ASSERT(IsArray());
   CHECK(!pObj || pObj->IsInline());
-  m_Objects.push_back(pObj);
+  m_Objects.push_back(UniqueObject(pObj));
 }
 
 void CPDF_Array::AddName(const CFX_ByteString& str) {
diff --git a/core/fpdfapi/parser/cpdf_array.h b/core/fpdfapi/parser/cpdf_array.h
index 8cfa0333bb..f473e26800 100644
--- a/core/fpdfapi/parser/cpdf_array.h
+++ b/core/fpdfapi/parser/cpdf_array.h
@@ -17,8 +17,8 @@
 
 class CPDF_Array : public CPDF_Object {
  public:
-  using iterator = std::vector<CPDF_Object*>::iterator;
-  using const_iterator = std::vector<CPDF_Object*>::const_iterator;
+  using iterator = std::vector<UniqueObject>::iterator;
+  using const_iterator = std::vector<UniqueObject>::const_iterator;
 
   CPDF_Array();
 
@@ -67,8 +67,9 @@ class CPDF_Array : public CPDF_Object {
       bool bDirect,
       std::set<const CPDF_Object*>* pVisited) const override;
 
-  std::vector<CPDF_Object*> m_Objects;
+  std::vector<UniqueObject> m_Objects;
 };
+
 using UniqueArray = std::unique_ptr<CPDF_Array, ReleaseDeleter<CPDF_Object>>;
 
 inline CPDF_Array* ToArray(CPDF_Object* obj) {
diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
index e23aa8ecfb..980c94d325 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -155,7 +155,7 @@ FX_BOOL CPDF_DataAvail::AreObjectsAvailable(
 
         for (const auto& it : *pDict) {
           const CFX_ByteString& key = it.first;
-          CPDF_Object* value = it.second;
+          CPDF_Object* value = it.second.get();
           if (key != "Parent")
             new_obj_array.push_back(value);
         }
@@ -493,8 +493,8 @@ FX_BOOL CPDF_DataAvail::CheckPage(DownloadHints* pHints) {
 
     CPDF_Array* pArray = ToArray(pObj);
     if (pArray) {
-      for (CPDF_Object* pArrayObj : *pArray) {
-        if (CPDF_Reference* pRef = ToReference(pArrayObj))
+      for (auto& pArrayObj : *pArray) {
+        if (CPDF_Reference* pRef = ToReference(pArrayObj.get()))
           UnavailObjList.Add(pRef->GetRefObjNum());
       }
     }
@@ -742,7 +742,7 @@ FX_BOOL CPDF_DataAvail::CheckHintTables(DownloadHints* pHints) {
     return FALSE;
   }
 
-  for (const CPDF_Object* pArrayObject : *pHintStreamRange) {
+  for (const auto& pArrayObject : *pHintStreamRange) {
     const CPDF_Number* pNumber = ToNumber(pArrayObject->GetDirect());
     if (!pNumber || !pNumber->IsInteger()) {
       m_docStatus = PDF_DATAAVAIL_ERROR;
diff --git a/core/fpdfapi/parser/cpdf_dictionary.cpp b/core/fpdfapi/parser/cpdf_dictionary.cpp
index aab7422b3c..435eee7248 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.cpp
+++ b/core/fpdfapi/parser/cpdf_dictionary.cpp
@@ -27,11 +27,11 @@ CPDF_Dictionary::CPDF_Dictionary(const CFX_WeakPtr<CFX_ByteStringPool>& pPool)
 
 CPDF_Dictionary::~CPDF_Dictionary() {
   // Mark the object as deleted so that it will not be deleted again
-  // in case of cyclic references.
+  // in case of cyclic references, then break cycles.
   m_ObjNum = kInvalidObjNum;
-  for (const auto& it : m_Map) {
-    if (it.second && it.second->GetObjNum() != kInvalidObjNum)
-      it.second->Release();
+  for (auto& it : m_Map) {
+    if (it.second && it.second->GetObjNum() == kInvalidObjNum)
+      it.second.release();
   }
 }
 
@@ -65,20 +65,19 @@ CPDF_Object* CPDF_Dictionary::CloneNonCyclic(
     bool bDirect,
     std::set<const CPDF_Object*>* pVisited) const {
   pVisited->insert(this);
-  CPDF_Dictionary* pCopy = new CPDF_Dictionary(m_pPool);
+  UniqueDictionary pCopy = UniqueDictionary(new CPDF_Dictionary(m_pPool));
   for (const auto& it : *this) {
-    CPDF_Object* value = it.second;
-    if (!pdfium::ContainsKey(*pVisited, value)) {
-      pCopy->m_Map.insert(
-          std::make_pair(it.first, value->CloneNonCyclic(bDirect, pVisited)));
+    if (!pdfium::ContainsKey(*pVisited, it.second.get())) {
+      pCopy->m_Map[it.first] =
+          UniqueObject(it.second->CloneNonCyclic(bDirect, pVisited));
     }
   }
-  return pCopy;
+  return pCopy.release();
 }
 
 CPDF_Object* CPDF_Dictionary::GetObjectFor(const CFX_ByteString& key) const {
   auto it = m_Map.find(key);
-  return it != m_Map.end() ? it->second : nullptr;
+  return it != m_Map.end() ? it->second.get() : nullptr;
 }
 
 CPDF_Object* CPDF_Dictionary::GetDirectObjectFor(
@@ -174,22 +173,12 @@ bool CPDF_Dictionary::IsSignatureDict() const {
 }
 
 void CPDF_Dictionary::SetFor(const CFX_ByteString& key, CPDF_Object* pObj) {
-  CHECK(!pObj || pObj->IsInline());
-  auto it = m_Map.find(key);
-  if (it == m_Map.end()) {
-    if (pObj)
-      m_Map.insert(std::make_pair(MaybeIntern(key), pObj));
+  if (!pObj) {
+    m_Map.erase(key);
     return;
   }
-
-  if (it->second == pObj)
-    return;
-  it->second->Release();
-
-  if (pObj)
-    it->second = pObj;
-  else
-    m_Map.erase(it);
+  ASSERT(pObj->IsInline());
+  m_Map[key] = UniqueObject(pObj);
 }
 
 void CPDF_Dictionary::ConvertToIndirectObjectFor(
@@ -199,35 +188,24 @@ void CPDF_Dictionary::ConvertToIndirectObjectFor(
   if (it == m_Map.end() || it->second->IsReference())
     return;
 
-  uint32_t objnum = pHolder->AddIndirectObject(it->second);
-  it->second = new CPDF_Reference(pHolder, objnum);
+  uint32_t objnum = pHolder->AddIndirectObject(it->second.release());
+  it->second = UniqueReference(new CPDF_Reference(pHolder, objnum));
 }
 
 void CPDF_Dictionary::RemoveFor(const CFX_ByteString& key) {
-  auto it = m_Map.find(key);
-  if (it == m_Map.end())
-    return;
-
-  it->second->Release();
-  m_Map.erase(it);
+  m_Map.erase(key);
 }
 
 void CPDF_Dictionary::ReplaceKey(const CFX_ByteString& oldkey,
                                  const CFX_ByteString& newkey) {
-  auto old_it = m_Map.find(oldkey);
-  if (old_it == m_Map.end())
+  if (oldkey == newkey)
     return;
 
-  auto new_it = m_Map.find(newkey);
-  if (new_it == old_it)
+  auto old_it = m_Map.find(oldkey);
+  if (old_it == m_Map.end())
     return;
 
-  if (new_it != m_Map.end()) {
-    new_it->second->Release();
-    new_it->second = old_it->second;
-  } else {
-    m_Map.insert(std::make_pair(MaybeIntern(newkey), old_it->second));
-  }
+  m_Map[newkey] = std::move(old_it->second);
   m_Map.erase(old_it);
 }
 
diff --git a/core/fpdfapi/parser/cpdf_dictionary.h b/core/fpdfapi/parser/cpdf_dictionary.h
index fb8200f78c..6265522997 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.h
+++ b/core/fpdfapi/parser/cpdf_dictionary.h
@@ -21,8 +21,8 @@ class CPDF_IndirectObjectHolder;
 
 class CPDF_Dictionary : public CPDF_Object {
  public:
-  using iterator = std::map<CFX_ByteString, CPDF_Object*>::iterator;
-  using const_iterator = std::map<CFX_ByteString, CPDF_Object*>::const_iterator;
+  using iterator = std::map<CFX_ByteString, UniqueObject>::iterator;
+  using const_iterator = std::map<CFX_ByteString, UniqueObject>::const_iterator;
 
   CPDF_Dictionary();
   explicit CPDF_Dictionary(const CFX_WeakPtr<CFX_ByteStringPool>& pPool);
@@ -96,7 +96,7 @@ class CPDF_Dictionary : public CPDF_Object {
       std::set<const CPDF_Object*>* visited) const override;
 
   CFX_WeakPtr<CFX_ByteStringPool> m_pPool;
-  std::map<CFX_ByteString, CPDF_Object*> m_Map;
+  std::map<CFX_ByteString, UniqueObject> m_Map;
 };
 
 using UniqueDictionary =
diff --git a/core/fpdfapi/parser/cpdf_object_unittest.cpp b/core/fpdfapi/parser/cpdf_object_unittest.cpp
index 8215226ef3..e5a5f54915 100644
--- a/core/fpdfapi/parser/cpdf_object_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_object_unittest.cpp
@@ -139,7 +139,7 @@ class PDFObjectsTest : public testing::Test {
           return false;
         for (CPDF_Dictionary::const_iterator it = dict1->begin();
              it != dict1->end(); ++it) {
-          if (!Equal(it->second, dict2->GetObjectFor(it->first)))
+          if (!Equal(it->second.get(), dict2->GetObjectFor(it->first)))
             return false;
         }
         return true;
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index c29ae18da2..40a615fa47 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -826,7 +826,7 @@ FX_BOOL CPDF_Parser::RebuildCrossRef() {
                         auto it = pTrailer->begin();
                         while (it != pTrailer->end()) {
                           const CFX_ByteString& key = it->first;
-                          CPDF_Object* pElement = it->second;
+                          CPDF_Object* pElement = it->second.get();
                           ++it;
                           uint32_t dwObjNum =
                               pElement ? pElement->GetObjNum() : 0;
diff --git a/core/fpdfapi/parser/cpdf_reference.h b/core/fpdfapi/parser/cpdf_reference.h
index 5221832f80..e9416aecad 100644
--- a/core/fpdfapi/parser/cpdf_reference.h
+++ b/core/fpdfapi/parser/cpdf_reference.h
@@ -47,6 +47,9 @@ class CPDF_Reference : public CPDF_Object {
   uint32_t m_RefObjNum;
 };
 
+using UniqueReference =
+    std::unique_ptr<CPDF_Reference, ReleaseDeleter<CPDF_Object>>;
+
 inline CPDF_Reference* ToReference(CPDF_Object* obj) {
   return obj ? obj->AsReference() : nullptr;
 }
diff --git a/core/fpdfapi/parser/cpdf_stream.h b/core/fpdfapi/parser/cpdf_stream.h
index 756eccfba1..b440f94354 100644
--- a/core/fpdfapi/parser/cpdf_stream.h
+++ b/core/fpdfapi/parser/cpdf_stream.h
@@ -51,7 +51,7 @@ class CPDF_Stream : public CPDF_Object {
       bool bDirect,
       std::set<const CPDF_Object*>* pVisited) const override;
 
-  std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> m_pDict;
+  UniqueDictionary m_pDict;
   bool m_bMemoryBased = true;
   uint32_t m_dwSize = 0;
   std::unique_ptr<uint8_t, FxFreeDeleter> m_pDataBuf;
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
index 7b9ead4005..6f1ce14d6e 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -193,7 +193,7 @@ CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj) {
       buf << "<<";
       for (const auto& it : *p) {
         const CFX_ByteString& key = it.first;
-        CPDF_Object* pValue = it.second;
+        CPDF_Object* pValue = it.second.get();
         buf << "/" << PDF_NameEncode(key);
         if (pValue && !pValue->IsInline()) {
           buf << " " << pValue->GetObjNum() << " 0 R ";