Add pdfium::Vector2D<>()

Many of the FX_Alloc's that have not been converted to std::vector
are using FX_Alloc2D and the safe math it performs under the covers.
Make an equivalent function for returning a vector to avoid burdening
callers with the safe math equivalents.

Use it in one place.

Change-Id: Ie4a280351b7370b755f2a1928f8b2d84fe007c03
Reviewed-on: https://pdfium-review.googlesource.com/36770
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

2 files changed, 20 insertions, 12 deletions

diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index 0138b81ca1..17b2914900 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -222,7 +222,7 @@ class CPDF_ICCBasedCS : public CPDF_ColorSpace {
 
   MaybeOwned<CPDF_ColorSpace> m_pAlterCS;
   RetainPtr<CPDF_IccProfile> m_pProfile;
-  mutable std::unique_ptr<uint8_t, FxFreeDeleter> m_pCache;
+  mutable std::vector<uint8_t> m_pCache;
   std::vector<float> m_pRanges;
 };
 
@@ -984,24 +984,22 @@ void CPDF_ICCBasedCS::TranslateImageLine(uint8_t* pDestBuf,
     return;
   }
 
-  if (!m_pCache) {
-    m_pCache.reset(FX_Alloc2D(uint8_t, nMaxColors, 3));
-    std::unique_ptr<uint8_t, FxFreeDeleter> temp_src(
-        FX_Alloc2D(uint8_t, nMaxColors, nComponents));
-    uint8_t* pSrc = temp_src.get();
+  if (m_pCache.empty()) {
+    m_pCache = pdfium::Vector2D<uint8_t>(nMaxColors, 3);
+    auto temp_src = pdfium::Vector2D<uint8_t>(nMaxColors, nComponents);
+    size_t src_index = 0;
     for (int i = 0; i < nMaxColors; i++) {
       uint32_t color = i;
       uint32_t order = nMaxColors / 52;
       for (uint32_t c = 0; c < nComponents; c++) {
-        *pSrc++ = static_cast<uint8_t>(color / order * 5);
+        temp_src[src_index++] = static_cast<uint8_t>(color / order * 5);
         color %= order;
         order /= 52;
       }
     }
     CPDF_ModuleMgr::Get()->GetIccModule()->TranslateScanline(
-        m_pProfile->transform(), m_pCache.get(), temp_src.get(), nMaxColors);
+        m_pProfile->transform(), m_pCache.data(), temp_src.data(), nMaxColors);
   }
-  uint8_t* pCachePtr = m_pCache.get();
   for (int i = 0; i < pixels; i++) {
     int index = 0;
     for (uint32_t c = 0; c < nComponents; c++) {
@@ -1009,9 +1007,9 @@ void CPDF_ICCBasedCS::TranslateImageLine(uint8_t* pDestBuf,
       pSrcBuf++;
     }
     index *= 3;
-    *pDestBuf++ = pCachePtr[index];
-    *pDestBuf++ = pCachePtr[index + 1];
-    *pDestBuf++ = pCachePtr[index + 2];
+    *pDestBuf++ = m_pCache[index];
+    *pDestBuf++ = m_pCache[index + 1];
+    *pDestBuf++ = m_pCache[index + 2];
   }
 }
 
diff --git a/third_party/base/stl_util.h b/third_party/base/stl_util.h
index 6c36ddcda1..5d984dc4cc 100644
--- a/third_party/base/stl_util.h
+++ b/third_party/base/stl_util.h
@@ -9,8 +9,10 @@
 #include <iterator>
 #include <memory>
 #include <set>
+#include <vector>
 
 #include "third_party/base/numerics/safe_conversions.h"
+#include "third_party/base/numerics/safe_math.h"
 
 namespace pdfium {
 
@@ -74,6 +76,14 @@ constexpr const T& clamp(const T& v, const T& lo, const T& hi) {
   return std::min(std::max(v, lo), hi);
 }
 
+// Safely allocate a 1-dim vector big enough for |w| by |h| or die.
+template <typename T>
+std::vector<T> Vector2D(size_t w, size_t h) {
+  pdfium::base::CheckedNumeric<size_t> safe_size = w;
+  safe_size *= h;
+  return std::vector<T>(safe_size.ValueOrDie());
+}
+
 }  // namespace pdfium
 
 #endif  // PDFIUM_THIRD_PARTY_BASE_STL_UTIL_H_