commit 10042915c03ca0b1ff808b9d175946dc70422c2d
author Lei Zhang <thestig@chromium.org> Thu Dec 11 13:27:42 2025 -0800
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Dec 11 13:27:42 2025 -0800
tree 4b1a4c8dc15762c42da63310e1b5994edb7d40b7
parent 79d0cbc2d069ba5fa4a665b0d80cc26235e4a681

Consolidate UNSAFE_BUFFERS usage in CFX_Face

Add GetCharMaps() to make iterating through the charmaps easier. Use it
where appropriate to reduce the number of UNSAFE_BUFFERS() macros.

Change-Id: I99659203af98de595751aa406699a21200f87cbf
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/139133
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fxge/cfx_face.cpp

diff --git a/core/fxge/cfx_face.cpp b/core/fxge/cfx_face.cpp
index ec0c244..c969112 100644
--- a/core/fxge/cfx_face.cpp
+++ b/core/fxge/cfx_face.cpp
@@ -930,21 +930,15 @@
 }
 
 int CFX_Face::GetCharMapPlatformIdByIndex(size_t index) const {
-  CHECK_LT(index, GetCharMapCount());
-  // SAFETY: required from library as enforced by check above.
-  return UNSAFE_BUFFERS(GetRec()->charmaps[index]->platform_id);
+  return GetCharMaps()[index]->platform_id;
 }
 
 int CFX_Face::GetCharMapEncodingIdByIndex(size_t index) const {
-  CHECK_LT(index, GetCharMapCount());
-  // SAFETY: required from library as enforced by check above.
-  return UNSAFE_BUFFERS(GetRec()->charmaps[index]->encoding_id);
+  return GetCharMaps()[index]->encoding_id;
 }
 
 fxge::FontEncoding CFX_Face::GetCharMapEncodingByIndex(size_t index) const {
-  CHECK_LT(index, GetCharMapCount());
-  // SAFETY: required from library as enforced by check above.
-  return ToFontEncoding(UNSAFE_BUFFERS(GetRec()->charmaps[index]->encoding));
+  return ToFontEncoding(GetCharMaps()[index]->encoding);
 }
 
 size_t CFX_Face::GetCharMapCount() const {
@@ -953,6 +947,15 @@
              : 0;
 }
 
+pdfium::span<const FT_CharMap> CFX_Face::GetCharMaps() const {
+  size_t count = GetCharMapCount();
+  if (count == 0) {
+    return {};
+  }
+  // SAFETY: required from library to provide correct count.
+  return UNSAFE_BUFFERS({GetRec()->charmaps, count});
+}
+
 void CFX_Face::SetCharMap(CharMap map) {
   FT_Set_Charmap(GetRec(), static_cast<FT_CharMap>(map));
 }
@@ -997,7 +1000,7 @@
 void CFX_Face::AdjustVariationParams(int glyph_index,
                                      int dest_width,
                                      int weight) {
-  DCHECK(dest_width >= 0);
+  DCHECK_GE(dest_width, 0);
 
   FXFT_FaceRec* rec = GetRec();
   ScopedFXFTMMVar variation_desc(rec);

core/fxge/cfx_face.h

diff --git a/core/fxge/cfx_face.h b/core/fxge/cfx_face.h
index 92b0030..e5957f1 100644
--- a/core/fxge/cfx_face.h
+++ b/core/fxge/cfx_face.h
@@ -168,6 +168,8 @@
 
   void AdjustVariationParams(int glyph_index, int dest_width, int weight);
 
+  pdfium::span<const FT_CharMap> GetCharMaps() const;
+
 #if BUILDFLAG(IS_ANDROID) || defined(PDF_ENABLE_XFA)
   std::optional<std::array<uint8_t, 2>> GetOs2Panose();