commit d5e0be8f432ae2dc70f678475d6b958b10c1356e
author Tom Sepez <tsepez@chromium.org> Sat Jun 05 00:05:51 2021 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> Sat Jun 05 00:05:51 2021 +0000
tree 56d1c2c52ce01adc2f9beb5ad50f30b2793f7afb
parent a7df4cb631906cb4b839eec7a0734b830cabbe55

Pass span<> to CPDF_StreamContentParser::Parse()

Then use subspan() operation in place of size arithmethic.

Change-Id: Ib2cc230e922ec35245b296db69a2370df5a4002a
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/81413
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

core/fpdfapi/page/cpdf_contentparser.cpp

diff --git a/core/fpdfapi/page/cpdf_contentparser.cpp b/core/fpdfapi/page/cpdf_contentparser.cpp
index 6ffce1d..823a0fc 100644
--- a/core/fpdfapi/page/cpdf_contentparser.cpp
+++ b/core/fpdfapi/page/cpdf_contentparser.cpp
@@ -200,7 +200,7 @@
     m_StreamSegmentOffsets.push_back(0);
 
   static constexpr uint32_t kParseStepLimit = 100;
-  m_CurrentOffset += m_pParser->Parse(m_pData.Get(), m_Size, m_CurrentOffset,
+  m_CurrentOffset += m_pParser->Parse({m_pData.Get(), m_Size}, m_CurrentOffset,
                                       kParseStepLimit, m_StreamSegmentOffsets);
   return Stage::kParse;
 }

core/fpdfapi/page/cpdf_streamcontentparser.cpp

diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index a28a922..4cb27e6 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -1492,34 +1492,29 @@
 }
 
 uint32_t CPDF_StreamContentParser::Parse(
-    const uint8_t* pData,
-    uint32_t dwSize,
+    pdfium::span<const uint8_t> pData,
     uint32_t start_offset,
     uint32_t max_cost,
     const std::vector<uint32_t>& stream_start_offsets) {
-  DCHECK(start_offset < dwSize);
+  DCHECK(start_offset < pData.size());
 
-  // Parsing will be done from |pDataStart|, for at most |size_left| bytes.
-  const uint8_t* pDataStart = pData + start_offset;
-  uint32_t size_left = dwSize - start_offset;
-
+  // Parsing will be done from within |pDataStart|.
+  pdfium::span<const uint8_t> pDataStart = pData.subspan(start_offset);
   m_StartParseOffset = start_offset;
-
   if (m_ParsedSet->size() > kMaxFormLevel ||
-      pdfium::Contains(*m_ParsedSet, pDataStart)) {
-    return size_left;
+      pdfium::Contains(*m_ParsedSet, pDataStart.data())) {
+    return pDataStart.size();
   }
 
   m_StreamStartOffsets = stream_start_offsets;
 
   ScopedSetInsertion<const uint8_t*> scopedInsert(m_ParsedSet.Get(),
-                                                  pDataStart);
+                                                  pDataStart.data());
 
   uint32_t init_obj_count = m_pObjectHolder->GetPageObjectCount();
   AutoNuller<std::unique_ptr<CPDF_StreamParser>> auto_clearer(&m_pSyntax);
   m_pSyntax = std::make_unique<CPDF_StreamParser>(
-      pdfium::make_span(pDataStart, size_left),
-      m_pDocument->GetByteStringPool());
+      pDataStart, m_pDocument->GetByteStringPool());
 
   while (1) {
     uint32_t cost = m_pObjectHolder->GetPageObjectCount() - init_obj_count;

core/fpdfapi/page/cpdf_streamcontentparser.h

diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.h b/core/fpdfapi/page/cpdf_streamcontentparser.h
index 343faf5..008c12a 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.h
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.h
@@ -20,6 +20,7 @@
 #include "core/fxcrt/unowned_ptr.h"
 #include "core/fxge/cfx_fillrenderoptions.h"
 #include "core/fxge/cfx_pathdata.h"
+#include "third_party/base/span.h"
 
 class CPDF_AllStates;
 class CPDF_ColorSpace;
@@ -50,8 +51,7 @@
                            std::set<const uint8_t*>* pParsedSet);
   ~CPDF_StreamContentParser();
 
-  uint32_t Parse(const uint8_t* pData,
-                 uint32_t dwSize,
+  uint32_t Parse(pdfium::span<const uint8_t> pData,
                  uint32_t start_offset,
                  uint32_t max_cost,
                  const std::vector<uint32_t>& stream_start_offsets);