Add proper const/non-const versions of CPDF_Array methods.

Instead of having const methods that return non-const pointers.

BUG=pdfium:234

Change-Id: I61495543f67229500dfcf2248e93468e9a9b23cf
Reviewed-on: https://pdfium-review.googlesource.com/32183
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

12 files changed, 72 insertions, 32 deletions

diff --git a/core/fpdfapi/edit/cpdf_creator.cpp b/core/fpdfapi/edit/cpdf_creator.cpp
index 872860b0ed..71237f7915 100644
--- a/core/fpdfapi/edit/cpdf_creator.cpp
+++ b/core/fpdfapi/edit/cpdf_creator.cpp
@@ -258,7 +258,7 @@ bool CPDF_Creator::WriteDirectObj(uint32_t objnum,
 
       const CPDF_Array* p = pObj->AsArray();
       for (size_t i = 0; i < p->GetCount(); i++) {
-        CPDF_Object* pElement = p->GetObjectAt(i);
+        const CPDF_Object* pElement = p->GetObjectAt(i);
         if (!pElement->IsInline()) {
           if (!m_Archive->WriteString(" ") ||
               !m_Archive->WriteDWord(pElement->GetObjNum()) ||
@@ -773,7 +773,8 @@ void CPDF_Creator::InitID() {
   bool idArrayPreExisting = !!m_pIDArray;
   if (!idArrayPreExisting) {
     m_pIDArray = pdfium::MakeUnique<CPDF_Array>();
-    CPDF_Object* pID1 = pOldIDArray ? pOldIDArray->GetObjectAt(0) : nullptr;
+    const CPDF_Object* pID1 =
+        pOldIDArray ? pOldIDArray->GetObjectAt(0) : nullptr;
     if (pID1) {
       m_pIDArray->Add(pID1->Clone());
     } else {
@@ -785,7 +786,7 @@ void CPDF_Creator::InitID() {
   }
 
   if (pOldIDArray) {
-    CPDF_Object* pID2 = pOldIDArray->GetObjectAt(1);
+    const CPDF_Object* pID2 = pOldIDArray->GetObjectAt(1);
     if (IsIncremental() && m_pEncryptDict && pID2) {
       m_pIDArray->Add(pID2->Clone());
       return;
diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index 4f68329862..354a342d90 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -854,7 +854,7 @@ CPDF_ICCBasedCS::CPDF_ICCBasedCS(CPDF_Document* pDoc)
 
 CPDF_ICCBasedCS::~CPDF_ICCBasedCS() {
   if (m_pProfile && m_pDocument) {
-    CPDF_Stream* pStream = m_pProfile->GetStream();
+    const CPDF_Stream* pStream = m_pProfile->GetStream();
     m_pProfile.Reset();  // Give up our reference first.
     auto* pPageData = m_pDocument->GetPageData();
     if (pPageData)
@@ -865,7 +865,7 @@ CPDF_ICCBasedCS::~CPDF_ICCBasedCS() {
 uint32_t CPDF_ICCBasedCS::v_Load(CPDF_Document* pDoc,
                                  const CPDF_Array* pArray,
                                  std::set<const CPDF_Object*>* pVisited) {
-  CPDF_Stream* pStream = pArray->GetStreamAt(1);
+  const CPDF_Stream* pStream = pArray->GetStreamAt(1);
   if (!pStream)
     return 0;
 
@@ -1118,13 +1118,13 @@ uint32_t CPDF_IndexedCS::v_Load(CPDF_Document* pDoc,
   }
   m_MaxIndex = pArray->GetIntegerAt(2);
 
-  CPDF_Object* pTableObj = pArray->GetDirectObjectAt(3);
+  const CPDF_Object* pTableObj = pArray->GetDirectObjectAt(3);
   if (!pTableObj)
     return 0;
 
-  if (CPDF_String* pString = pTableObj->AsString()) {
+  if (const CPDF_String* pString = pTableObj->AsString()) {
     m_Table = pString->GetString();
-  } else if (CPDF_Stream* pStream = pTableObj->AsStream()) {
+  } else if (const CPDF_Stream* pStream = pTableObj->AsStream()) {
     auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(pStream);
     pAcc->LoadAllDataFiltered();
     m_Table = ByteStringView(pAcc->GetData(), pAcc->GetSize());
diff --git a/core/fpdfapi/page/cpdf_docpagedata.cpp b/core/fpdfapi/page/cpdf_docpagedata.cpp
index 9ac5c1e304..79e148c72a 100644
--- a/core/fpdfapi/page/cpdf_docpagedata.cpp
+++ b/core/fpdfapi/page/cpdf_docpagedata.cpp
@@ -421,7 +421,7 @@ void CPDF_DocPageData::MaybePurgeImage(uint32_t dwStreamObjNum) {
 }
 
 RetainPtr<CPDF_IccProfile> CPDF_DocPageData::GetIccProfile(
-    CPDF_Stream* pProfileStream) {
+    const CPDF_Stream* pProfileStream) {
   if (!pProfileStream)
     return nullptr;
 
@@ -449,7 +449,7 @@ RetainPtr<CPDF_IccProfile> CPDF_DocPageData::GetIccProfile(
   return pProfile;
 }
 
-void CPDF_DocPageData::MaybePurgeIccProfile(CPDF_Stream* pProfileStream) {
+void CPDF_DocPageData::MaybePurgeIccProfile(const CPDF_Stream* pProfileStream) {
   ASSERT(pProfileStream);
   auto it = m_IccProfileMap.find(pProfileStream);
   if (it != m_IccProfileMap.end() && it->second->HasOneRef())
diff --git a/core/fpdfapi/page/cpdf_docpagedata.h b/core/fpdfapi/page/cpdf_docpagedata.h
index 2d22ee991d..04b77cf3ed 100644
--- a/core/fpdfapi/page/cpdf_docpagedata.h
+++ b/core/fpdfapi/page/cpdf_docpagedata.h
@@ -61,8 +61,8 @@ class CPDF_DocPageData {
   RetainPtr<CPDF_Image> GetImage(uint32_t dwStreamObjNum);
   void MaybePurgeImage(uint32_t dwStreamObjNum);
 
-  RetainPtr<CPDF_IccProfile> GetIccProfile(CPDF_Stream* pProfileStream);
-  void MaybePurgeIccProfile(CPDF_Stream* pProfileStream);
+  RetainPtr<CPDF_IccProfile> GetIccProfile(const CPDF_Stream* pProfileStream);
+  void MaybePurgeIccProfile(const CPDF_Stream* pProfileStream);
 
   RetainPtr<CPDF_StreamAcc> GetFontFileStreamAcc(CPDF_Stream* pFontStream);
   void MaybePurgeFontFileStreamAcc(const CPDF_Stream* pFontStream);
@@ -86,7 +86,7 @@ class CPDF_DocPageData {
 
   bool m_bForceClear;
   UnownedPtr<CPDF_Document> const m_pPDFDoc;
-  std::map<ByteString, CPDF_Stream*> m_HashProfileMap;
+  std::map<ByteString, const CPDF_Stream*> m_HashProfileMap;
   std::map<const CPDF_Object*, CPDF_CountedColorSpace*> m_ColorSpaceMap;
   std::map<const CPDF_Stream*, RetainPtr<CPDF_StreamAcc>> m_FontFileMap;
   std::map<const CPDF_Dictionary*, CPDF_CountedFont*> m_FontMap;
diff --git a/core/fpdfapi/page/cpdf_iccprofile.cpp b/core/fpdfapi/page/cpdf_iccprofile.cpp
index 144f530a2c..c0bf7cd2a2 100644
--- a/core/fpdfapi/page/cpdf_iccprofile.cpp
+++ b/core/fpdfapi/page/cpdf_iccprofile.cpp
@@ -18,7 +18,7 @@ bool DetectSRGB(const uint8_t* pData, uint32_t dwSize) {
 
 }  // namespace
 
-CPDF_IccProfile::CPDF_IccProfile(CPDF_Stream* pStream,
+CPDF_IccProfile::CPDF_IccProfile(const CPDF_Stream* pStream,
                                  const uint8_t* pData,
                                  uint32_t dwSize)
     : m_bsRGB(DetectSRGB(pData, dwSize)), m_pStream(pStream) {
diff --git a/core/fpdfapi/page/cpdf_iccprofile.h b/core/fpdfapi/page/cpdf_iccprofile.h
index 1bc498aa1f..a5c9f6dbfe 100644
--- a/core/fpdfapi/page/cpdf_iccprofile.h
+++ b/core/fpdfapi/page/cpdf_iccprofile.h
@@ -20,7 +20,7 @@ class CPDF_IccProfile : public Retainable {
   template <typename T, typename... Args>
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
 
-  CPDF_Stream* GetStream() const { return m_pStream.Get(); }
+  const CPDF_Stream* GetStream() const { return m_pStream.Get(); }
   bool IsValid() const { return IsSRGB() || IsSupported(); }
   bool IsSRGB() const { return m_bsRGB; }
   bool IsSupported() const { return !!m_Transform; }
@@ -28,11 +28,13 @@ class CPDF_IccProfile : public Retainable {
   uint32_t GetComponents() const { return m_nSrcComponents; }
 
  private:
-  CPDF_IccProfile(CPDF_Stream* pStream, const uint8_t* pData, uint32_t dwSize);
+  CPDF_IccProfile(const CPDF_Stream* pStream,
+                  const uint8_t* pData,
+                  uint32_t dwSize);
   ~CPDF_IccProfile() override;
 
   const bool m_bsRGB;
-  UnownedPtr<CPDF_Stream> const m_pStream;
+  UnownedPtr<const CPDF_Stream> const m_pStream;
   std::unique_ptr<CLcmsCmm> m_Transform;
   uint32_t m_nSrcComponents = 0;
 };
diff --git a/core/fpdfapi/parser/cpdf_array.cpp b/core/fpdfapi/parser/cpdf_array.cpp
index 9293101b32..4f802d9e7f 100644
--- a/core/fpdfapi/parser/cpdf_array.cpp
+++ b/core/fpdfapi/parser/cpdf_array.cpp
@@ -87,13 +87,25 @@ CFX_Matrix CPDF_Array::GetMatrix() const {
                     GetNumberAt(3), GetNumberAt(4), GetNumberAt(5));
 }
 
-CPDF_Object* CPDF_Array::GetObjectAt(size_t i) const {
+CPDF_Object* CPDF_Array::GetObjectAt(size_t i) {
   if (i >= m_Objects.size())
     return nullptr;
   return m_Objects[i].get();
 }
 
-CPDF_Object* CPDF_Array::GetDirectObjectAt(size_t i) const {
+const CPDF_Object* CPDF_Array::GetObjectAt(size_t i) const {
+  if (i >= m_Objects.size())
+    return nullptr;
+  return m_Objects[i].get();
+}
+
+CPDF_Object* CPDF_Array::GetDirectObjectAt(size_t i) {
+  if (i >= m_Objects.size())
+    return nullptr;
+  return m_Objects[i]->GetDirect();
+}
+
+const CPDF_Object* CPDF_Array::GetDirectObjectAt(size_t i) const {
   if (i >= m_Objects.size())
     return nullptr;
   return m_Objects[i]->GetDirect();
@@ -123,7 +135,7 @@ float CPDF_Array::GetNumberAt(size_t i) const {
   return m_Objects[i]->GetNumber();
 }
 
-CPDF_Dictionary* CPDF_Array::GetDictAt(size_t i) const {
+CPDF_Dictionary* CPDF_Array::GetDictAt(size_t i) {
   CPDF_Object* p = GetDirectObjectAt(i);
   if (!p)
     return nullptr;
@@ -134,11 +146,30 @@ CPDF_Dictionary* CPDF_Array::GetDictAt(size_t i) const {
   return nullptr;
 }
 
-CPDF_Stream* CPDF_Array::GetStreamAt(size_t i) const {
+const CPDF_Dictionary* CPDF_Array::GetDictAt(size_t i) const {
+  const CPDF_Object* p = GetDirectObjectAt(i);
+  if (!p)
+    return nullptr;
+  if (const CPDF_Dictionary* pDict = p->AsDictionary())
+    return pDict;
+  if (const CPDF_Stream* pStream = p->AsStream())
+    return pStream->GetDict();
+  return nullptr;
+}
+
+CPDF_Stream* CPDF_Array::GetStreamAt(size_t i) {
   return ToStream(GetDirectObjectAt(i));
 }
 
-CPDF_Array* CPDF_Array::GetArrayAt(size_t i) const {
+const CPDF_Stream* CPDF_Array::GetStreamAt(size_t i) const {
+  return ToStream(GetDirectObjectAt(i));
+}
+
+CPDF_Array* CPDF_Array::GetArrayAt(size_t i) {
+  return ToArray(GetDirectObjectAt(i));
+}
+
+const CPDF_Array* CPDF_Array::GetArrayAt(size_t i) const {
   return ToArray(GetDirectObjectAt(i));
 }
 
@@ -204,7 +235,7 @@ bool CPDF_Array::WriteTo(IFX_ArchiveStream* archive) const {
     return false;
 
   for (size_t i = 0; i < GetCount(); ++i) {
-    CPDF_Object* pElement = GetObjectAt(i);
+    const CPDF_Object* pElement = GetObjectAt(i);
     if (!pElement->IsInline()) {
       if (!archive->WriteString(" ") ||
           !archive->WriteDWord(pElement->GetObjNum()) ||
diff --git a/core/fpdfapi/parser/cpdf_array.h b/core/fpdfapi/parser/cpdf_array.h
index 442b85cc80..d980b14507 100644
--- a/core/fpdfapi/parser/cpdf_array.h
+++ b/core/fpdfapi/parser/cpdf_array.h
@@ -37,15 +37,20 @@ class CPDF_Array : public CPDF_Object {
 
   bool IsEmpty() const { return m_Objects.empty(); }
   size_t GetCount() const { return m_Objects.size(); }
-  CPDF_Object* GetObjectAt(size_t index) const;
-  CPDF_Object* GetDirectObjectAt(size_t index) const;
+  CPDF_Object* GetObjectAt(size_t index);
+  const CPDF_Object* GetObjectAt(size_t index) const;
+  CPDF_Object* GetDirectObjectAt(size_t index);
+  const CPDF_Object* GetDirectObjectAt(size_t index) const;
   ByteString GetStringAt(size_t index) const;
   WideString GetUnicodeTextAt(size_t index) const;
   int GetIntegerAt(size_t index) const;
   float GetNumberAt(size_t index) const;
-  CPDF_Dictionary* GetDictAt(size_t index) const;
-  CPDF_Stream* GetStreamAt(size_t index) const;
-  CPDF_Array* GetArrayAt(size_t index) const;
+  CPDF_Dictionary* GetDictAt(size_t index);
+  const CPDF_Dictionary* GetDictAt(size_t index) const;
+  CPDF_Stream* GetStreamAt(size_t index);
+  const CPDF_Stream* GetStreamAt(size_t index) const;
+  CPDF_Array* GetArrayAt(size_t index);
+  const CPDF_Array* GetArrayAt(size_t index) const;
   float GetFloatAt(size_t index) const { return GetNumberAt(index); }
   CFX_Matrix GetMatrix() const;
   CFX_FloatRect GetRect() const;
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
index fea0bddb33..982539cd72 100644
--- a/core/fpdfapi/parser/cpdf_document.cpp
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -491,7 +491,8 @@ CPDF_Pattern* CPDF_Document::LoadPattern(CPDF_Object* pPatternObj,
   return m_pDocPage->GetPattern(pPatternObj, bShading, matrix);
 }
 
-RetainPtr<CPDF_IccProfile> CPDF_Document::LoadIccProfile(CPDF_Stream* pStream) {
+RetainPtr<CPDF_IccProfile> CPDF_Document::LoadIccProfile(
+    const CPDF_Stream* pStream) {
   return m_pDocPage->GetIccProfile(pStream);
 }
 
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index 6357049777..4bbc6939e2 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -92,7 +92,7 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
 
   RetainPtr<CPDF_Image> LoadImageFromPageData(uint32_t dwStreamObjNum);
   RetainPtr<CPDF_StreamAcc> LoadFontFile(CPDF_Stream* pStream);
-  RetainPtr<CPDF_IccProfile> LoadIccProfile(CPDF_Stream* pStream);
+  RetainPtr<CPDF_IccProfile> LoadIccProfile(const CPDF_Stream* pStream);
 
   void LoadDoc();
   void LoadLinearizedDoc(const CPDF_LinearizedHeader* pLinearizationParams);
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
index 2c0b0818f1..1dad2a8ab3 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -180,7 +180,7 @@ std::ostream& operator<<(std::ostream& buf, const CPDF_Object* pObj) {
       const CPDF_Array* p = pObj->AsArray();
       buf << "[";
       for (size_t i = 0; i < p->GetCount(); i++) {
-        CPDF_Object* pElement = p->GetObjectAt(i);
+        const CPDF_Object* pElement = p->GetObjectAt(i);
         if (pElement && !pElement->IsInline()) {
           buf << " " << pElement->GetObjNum() << " 0 R";
         } else {
diff --git a/fpdfsdk/fpdf_ppo.cpp b/fpdfsdk/fpdf_ppo.cpp
index bf8ed25af0..1790e17fb3 100644
--- a/fpdfsdk/fpdf_ppo.cpp
+++ b/fpdfsdk/fpdf_ppo.cpp
@@ -695,7 +695,7 @@ uint32_t CPDF_NPageToOneExporter::MakeXObject(
   if (const CPDF_Array* pSrcContentArray = ToArray(pSrcContentObj)) {
     ByteString bsSrcContentStream;
     for (size_t i = 0; i < pSrcContentArray->GetCount(); ++i) {
-      CPDF_Stream* pStream = pSrcContentArray->GetStreamAt(i);
+      const CPDF_Stream* pStream = pSrcContentArray->GetStreamAt(i);
       auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(pStream);
       pAcc->LoadAllDataFiltered();
       ByteString bsStream(pAcc->GetData(), pAcc->GetSize());