Avoid passing pointers by reference in core.

This gets rid of most core/ non-const ref passing, either by passing by
pointer-to-pointer instead, or by returning std::pair.

Change-Id: Id7bdc355a1a725a05f9fa2f1e982ca8c975beef1
Reviewed-on: https://pdfium-review.googlesource.com/19030
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

4 files changed, 20 insertions, 17 deletions

diff --git a/core/fpdfapi/page/cpdf_contentmark.cpp b/core/fpdfapi/page/cpdf_contentmark.cpp
index 7d411b2084..cf8e37ec75 100644
--- a/core/fpdfapi/page/cpdf_contentmark.cpp
+++ b/core/fpdfapi/page/cpdf_contentmark.cpp
@@ -61,7 +61,7 @@ bool CPDF_ContentMark::HasMark(const ByteStringView& mark) const {
 }
 
 bool CPDF_ContentMark::LookupMark(const ByteStringView& mark,
-                                  CPDF_Dictionary*& pDict) const {
+                                  CPDF_Dictionary** pDict) const {
   const MarkData* pData = m_Ref.GetObject();
   if (!pData)
     return false;
@@ -69,7 +69,7 @@ bool CPDF_ContentMark::LookupMark(const ByteStringView& mark,
   for (int i = 0; i < pData->CountItems(); i++) {
     const CPDF_ContentMarkItem& item = pData->GetItem(i);
     if (item.GetName() == mark) {
-      pDict = item.GetParam();
+      *pDict = item.GetParam();
       return true;
     }
   }
diff --git a/core/fpdfapi/page/cpdf_contentmark.h b/core/fpdfapi/page/cpdf_contentmark.h
index f702859065..9619b12b6c 100644
--- a/core/fpdfapi/page/cpdf_contentmark.h
+++ b/core/fpdfapi/page/cpdf_contentmark.h
@@ -28,7 +28,7 @@ class CPDF_ContentMark {
   const CPDF_ContentMarkItem& GetItem(int i) const;
 
   bool HasMark(const ByteStringView& mark) const;
-  bool LookupMark(const ByteStringView& mark, CPDF_Dictionary*& pDict) const;
+  bool LookupMark(const ByteStringView& mark, CPDF_Dictionary** pDict) const;
   void AddMark(const ByteString& name, CPDF_Dictionary* pDict, bool bDirect);
   void DeleteLastMark();
 
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.cpp b/core/fpdfapi/parser/cpdf_simple_parser.cpp
index 5358b183d8..b49f8423c3 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_simple_parser.cpp
@@ -14,17 +14,17 @@ CPDF_SimpleParser::CPDF_SimpleParser(const uint8_t* pData, uint32_t dwSize)
 CPDF_SimpleParser::CPDF_SimpleParser(const ByteStringView& str)
     : m_pData(str.raw_str()), m_dwSize(str.GetLength()), m_dwCurPos(0) {}
 
-void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
-  pStart = nullptr;
-  dwSize = 0;
+std::pair<const uint8_t*, uint32_t> CPDF_SimpleParser::ParseWord() {
+  const uint8_t* pStart = nullptr;
+  uint8_t dwSize = 0;
   uint8_t ch;
   while (1) {
     if (m_dwSize <= m_dwCurPos)
-      return;
+      return std::make_pair(pStart, dwSize);
     ch = m_pData[m_dwCurPos++];
     while (PDFCharIsWhitespace(ch)) {
       if (m_dwSize <= m_dwCurPos)
-        return;
+        return std::make_pair(pStart, dwSize);
       ch = m_pData[m_dwCurPos++];
     }
 
@@ -33,7 +33,7 @@ void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
 
     while (1) {
       if (m_dwSize <= m_dwCurPos)
-        return;
+        return std::make_pair(pStart, dwSize);
       ch = m_pData[m_dwCurPos++];
       if (PDFCharIsLineEnding(ch))
         break;
@@ -46,19 +46,19 @@ void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
     if (ch == '/') {
       while (1) {
         if (m_dwSize <= m_dwCurPos)
-          return;
+          return std::make_pair(pStart, dwSize);
         ch = m_pData[m_dwCurPos++];
         if (!PDFCharIsOther(ch) && !PDFCharIsNumeric(ch)) {
           m_dwCurPos--;
           dwSize = m_dwCurPos - start_pos;
-          return;
+          return std::make_pair(pStart, dwSize);
         }
       }
     } else {
       dwSize = 1;
       if (ch == '<') {
         if (m_dwSize <= m_dwCurPos)
-          return;
+          return std::make_pair(pStart, dwSize);
         ch = m_pData[m_dwCurPos++];
         if (ch == '<')
           dwSize = 2;
@@ -66,7 +66,7 @@ void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
           m_dwCurPos--;
       } else if (ch == '>') {
         if (m_dwSize <= m_dwCurPos)
-          return;
+          return std::make_pair(pStart, dwSize);
         ch = m_pData[m_dwCurPos++];
         if (ch == '>')
           dwSize = 2;
@@ -74,13 +74,13 @@ void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
           m_dwCurPos--;
       }
     }
-    return;
+    return std::make_pair(pStart, dwSize);
   }
 
   dwSize = 1;
   while (1) {
     if (m_dwSize <= m_dwCurPos)
-      return;
+      return std::make_pair(pStart, dwSize);
     ch = m_pData[m_dwCurPos++];
 
     if (PDFCharIsDelimiter(ch) || PDFCharIsWhitespace(ch)) {
@@ -89,12 +89,13 @@ void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
     }
     dwSize++;
   }
+  return std::make_pair(pStart, dwSize);
 }
 
 ByteStringView CPDF_SimpleParser::GetWord() {
   const uint8_t* pStart;
   uint32_t dwSize;
-  ParseWord(pStart, dwSize);
+  std::tie(pStart, dwSize) = ParseWord();
   if (dwSize == 1 && pStart[0] == '<') {
     while (m_dwCurPos < m_dwSize && m_pData[m_dwCurPos] != '>') {
       m_dwCurPos++;
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.h b/core/fpdfapi/parser/cpdf_simple_parser.h
index 72cf700f60..659039e6fa 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser.h
+++ b/core/fpdfapi/parser/cpdf_simple_parser.h
@@ -7,6 +7,8 @@
 #ifndef CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_
 #define CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_
 
+#include <utility>
+
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
 
@@ -25,7 +27,7 @@ class CPDF_SimpleParser {
   uint32_t GetCurPos() const { return m_dwCurPos; }
 
  private:
-  void ParseWord(const uint8_t*& pStart, uint32_t& dwSize);
+  std::pair<const uint8_t*, uint32_t> ParseWord();
 
   const uint8_t* m_pData;
   uint32_t m_dwSize;