Use pdfium::span<> in CFX_BitStream, CPDF_SimpleParser.

Get bounds checks in parsers automatically when using spans.

Change-Id: I71fbe7b838435d455376db2f89817d807a9cdcfd
Reviewed-on: https://pdfium-review.googlesource.com/29830
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

6 files changed, 36 insertions, 41 deletions

diff --git a/core/fpdfapi/parser/cpdf_hint_tables.cpp b/core/fpdfapi/parser/cpdf_hint_tables.cpp
index 381b160233..123e6594c1 100644
--- a/core/fpdfapi/parser/cpdf_hint_tables.cpp
+++ b/core/fpdfapi/parser/cpdf_hint_tables.cpp
@@ -19,6 +19,7 @@
 #include "core/fxcrt/cfx_bitstream.h"
 #include "core/fxcrt/fx_safe_types.h"
 #include "third_party/base/numerics/safe_conversions.h"
+#include "third_party/base/span.h"
 
 namespace {
 
@@ -488,7 +489,7 @@ bool CPDF_HintTables::LoadHintStream(CPDF_Stream* pHintStream) {
     return false;
   }
 
-  CFX_BitStream bs(pAcc->GetData(), size);
+  CFX_BitStream bs(pdfium::make_span(pAcc->GetData(), size));
   return ReadPageHintTable(&bs) &&
          ReadSharedObjHintTable(&bs, shared_hint_table_offset);
 }
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.cpp b/core/fpdfapi/parser/cpdf_simple_parser.cpp
index 45ea0d4528..ff6e2cf94d 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_simple_parser.cpp
@@ -8,7 +8,8 @@
 
 #include "core/fpdfapi/parser/fpdf_parser_utility.h"
 
-CPDF_SimpleParser::CPDF_SimpleParser(const ByteStringView& str) : data_(str) {}
+CPDF_SimpleParser::CPDF_SimpleParser(pdfium::span<const uint8_t> input)
+    : data_(input) {}
 
 CPDF_SimpleParser::~CPDF_SimpleParser() = default;
 
@@ -17,12 +18,12 @@ ByteStringView CPDF_SimpleParser::GetWord() {
 
   // Skip whitespace and comment lines.
   while (1) {
-    if (data_.GetLength() <= cur_pos_)
+    if (data_.size() <= cur_pos_)
       return ByteStringView();
 
     ch = data_[cur_pos_++];
     while (PDFCharIsWhitespace(ch)) {
-      if (data_.GetLength() <= cur_pos_)
+      if (data_.size() <= cur_pos_)
         return ByteStringView();
       ch = data_[cur_pos_++];
     }
@@ -31,7 +32,7 @@ ByteStringView CPDF_SimpleParser::GetWord() {
       break;
 
     while (1) {
-      if (data_.GetLength() <= cur_pos_)
+      if (data_.size() <= cur_pos_)
         return ByteStringView();
 
       ch = data_[cur_pos_++];
@@ -46,7 +47,7 @@ ByteStringView CPDF_SimpleParser::GetWord() {
     // Find names
     if (ch == '/') {
       while (1) {
-        if (data_.GetLength() <= cur_pos_)
+        if (data_.size() <= cur_pos_)
           break;
 
         ch = data_[cur_pos_++];
@@ -56,29 +57,29 @@ ByteStringView CPDF_SimpleParser::GetWord() {
           break;
         }
       }
-      return data_.Mid(start_pos, dwSize);
+      return data_.subspan(start_pos, dwSize);
     }
 
     dwSize = 1;
     if (ch == '<') {
-      if (data_.GetLength() <= cur_pos_)
-        return data_.Mid(start_pos, dwSize);
+      if (data_.size() <= cur_pos_)
+        return data_.subspan(start_pos, dwSize);
 
       ch = data_[cur_pos_++];
       if (ch == '<') {
         dwSize = 2;
       } else {
-        while (cur_pos_ < data_.GetLength() && data_[cur_pos_] != '>')
+        while (cur_pos_ < data_.size() && data_[cur_pos_] != '>')
           cur_pos_++;
 
-        if (cur_pos_ < data_.GetLength())
+        if (cur_pos_ < data_.size())
           cur_pos_++;
 
         dwSize = cur_pos_ - start_pos;
       }
     } else if (ch == '>') {
-      if (data_.GetLength() <= cur_pos_)
-        return data_.Mid(start_pos, dwSize);
+      if (data_.size() <= cur_pos_)
+        return data_.subspan(start_pos, dwSize);
 
       ch = data_[cur_pos_++];
       if (ch == '>')
@@ -87,7 +88,7 @@ ByteStringView CPDF_SimpleParser::GetWord() {
         cur_pos_--;
     } else if (ch == '(') {
       int level = 1;
-      while (cur_pos_ < data_.GetLength()) {
+      while (cur_pos_ < data_.size()) {
         if (data_[cur_pos_] == ')') {
           level--;
           if (level == 0)
@@ -95,28 +96,28 @@ ByteStringView CPDF_SimpleParser::GetWord() {
         }
 
         if (data_[cur_pos_] == '\\') {
-          if (data_.GetLength() <= cur_pos_)
+          if (data_.size() <= cur_pos_)
             break;
 
           cur_pos_++;
         } else if (data_[cur_pos_] == '(') {
           level++;
         }
-        if (data_.GetLength() <= cur_pos_)
+        if (data_.size() <= cur_pos_)
           break;
 
         cur_pos_++;
       }
-      if (cur_pos_ < data_.GetLength())
+      if (cur_pos_ < data_.size())
         cur_pos_++;
 
       dwSize = cur_pos_ - start_pos;
     }
-    return data_.Mid(start_pos, dwSize);
+    return data_.subspan(start_pos, dwSize);
   }
 
   dwSize = 1;
-  while (cur_pos_ < data_.GetLength()) {
+  while (cur_pos_ < data_.size()) {
     ch = data_[cur_pos_++];
 
     if (PDFCharIsDelimiter(ch) || PDFCharIsWhitespace(ch)) {
@@ -125,5 +126,5 @@ ByteStringView CPDF_SimpleParser::GetWord() {
     }
     dwSize++;
   }
-  return data_.Mid(start_pos, dwSize);
+  return data_.subspan(start_pos, dwSize);
 }
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.h b/core/fpdfapi/parser/cpdf_simple_parser.h
index 8a07323a69..c8dae23ba6 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser.h
+++ b/core/fpdfapi/parser/cpdf_simple_parser.h
@@ -11,10 +11,11 @@
 
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
+#include "third_party/base/span.h"
 
 class CPDF_SimpleParser {
  public:
-  explicit CPDF_SimpleParser(const ByteStringView& str);
+  explicit CPDF_SimpleParser(pdfium::span<const uint8_t> input);
   ~CPDF_SimpleParser();
 
   ByteStringView GetWord();
@@ -23,7 +24,7 @@ class CPDF_SimpleParser {
   uint32_t GetCurPos() const { return cur_pos_; }
 
  private:
-  const ByteStringView data_;
+  const pdfium::span<const uint8_t> data_;
   uint32_t cur_pos_ = 0;
 };
 
diff --git a/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp b/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
index 2fb50f1ff3..254d084bb0 100644
--- a/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
@@ -9,6 +9,7 @@
 #include "core/fpdfapi/parser/fpdf_parser_utility.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/test_support.h"
+#include "third_party/base/span.h"
 
 TEST(SimpleParserTest, GetWord) {
   static const pdfium::StrFuncTestData test_data[] = {
@@ -49,7 +50,7 @@ TEST(SimpleParserTest, GetWord) {
   };
   for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
     const pdfium::StrFuncTestData& data = test_data[i];
-    CPDF_SimpleParser parser(ByteStringView(data.input, data.input_size));
+    CPDF_SimpleParser parser(pdfium::make_span(data.input, data.input_size));
     ByteStringView word = parser.GetWord();
     EXPECT_EQ(data.expected_size, word.GetLength()) << " for case " << i;
     if (data.expected_size != word.GetLength())
diff --git a/core/fpdfapi/parser/cpdf_stream_acc.cpp b/core/fpdfapi/parser/cpdf_stream_acc.cpp
index d115b48226..9cce894fff 100644
--- a/core/fpdfapi/parser/cpdf_stream_acc.cpp
+++ b/core/fpdfapi/parser/cpdf_stream_acc.cpp
@@ -68,12 +68,10 @@ CPDF_Dictionary* CPDF_StreamAcc::GetDict() const {
   return m_pStream ? m_pStream->GetDict() : nullptr;
 }
 
-const uint8_t* CPDF_StreamAcc::GetData() const {
-  return GetDataHelper();
-}
-
-uint8_t* CPDF_StreamAcc::GetData() {
-  return GetDataHelper();
+uint8_t* CPDF_StreamAcc::GetData() const {
+  if (m_bNewBuf)
+    return m_pData;
+  return m_pStream ? m_pStream->GetRawData() : nullptr;
 }
 
 uint32_t CPDF_StreamAcc::GetSize() const {
@@ -93,9 +91,3 @@ std::unique_ptr<uint8_t, FxFreeDeleter> CPDF_StreamAcc::DetachData() {
   memcpy(p.get(), m_pData, m_dwSize);
   return p;
 }
-
-uint8_t* CPDF_StreamAcc::GetDataHelper() const {
-  if (m_bNewBuf)
-    return m_pData;
-  return m_pStream ? m_pStream->GetRawData() : nullptr;
-}
diff --git a/core/fpdfapi/parser/cpdf_stream_acc.h b/core/fpdfapi/parser/cpdf_stream_acc.h
index ac5253a68b..89a454a0f0 100644
--- a/core/fpdfapi/parser/cpdf_stream_acc.h
+++ b/core/fpdfapi/parser/cpdf_stream_acc.h
@@ -14,6 +14,7 @@
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
 #include "core/fxcrt/retain_ptr.h"
+#include "third_party/base/span.h"
 
 class CPDF_StreamAcc : public Retainable {
  public:
@@ -30,11 +31,11 @@ class CPDF_StreamAcc : public Retainable {
   const CPDF_Stream* GetStream() const { return m_pStream.Get(); }
   CPDF_Dictionary* GetDict() const;
 
-  ByteStringView GetDataView() { return ByteStringView(GetData(), GetSize()); }
-
-  const uint8_t* GetData() const;
-  uint8_t* GetData();
+  uint8_t* GetData() const;
   uint32_t GetSize() const;
+  pdfium::span<uint8_t> GetSpan() const {
+    return pdfium::make_span(GetData(), GetSize());
+  }
   const ByteString& GetImageDecoder() const { return m_ImageDecoder; }
   const CPDF_Dictionary* GetImageParam() const { return m_pImageParam; }
   std::unique_ptr<uint8_t, FxFreeDeleter> DetachData();
@@ -44,8 +45,6 @@ class CPDF_StreamAcc : public Retainable {
   ~CPDF_StreamAcc() override;
 
  private:
-  uint8_t* GetDataHelper() const;
-
   uint8_t* m_pData = nullptr;
   uint32_t m_dwSize = 0;
   bool m_bNewBuf = false;