diff --git a/xfa/fgas/crt/cfgas_stringformatter.cpp b/xfa/fgas/crt/cfgas_stringformatter.cpp
index 325cfc1..62e814c 100644
--- a/xfa/fgas/crt/cfgas_stringformatter.cpp
+++ b/xfa/fgas/crt/cfgas_stringformatter.cpp
@@ -4,11 +4,6 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#if defined(UNSAFE_BUFFERS_BUILD)
-// TODO(crbug.com/pdfium/2154): resolve buffer safety issues.
-#pragma allow_unsafe_buffers
-#endif
-
 #include "xfa/fgas/crt/cfgas_stringformatter.h"
 
 #include <math.h>
@@ -19,10 +14,12 @@
 #include <vector>
 
 #include "core/fxcrt/cfx_datetime.h"
+#include "core/fxcrt/compiler_specific.h"
 #include "core/fxcrt/containers/contains.h"
 #include "core/fxcrt/fx_extension.h"
 #include "core/fxcrt/fx_safe_types.h"
 #include "core/fxcrt/notreached.h"
+#include "core/fxcrt/stl_util.h"
 #include "xfa/fgas/crt/cfgas_decimal.h"
 #include "xfa/fgas/crt/locale_mgr_iface.h"
 
@@ -70,10 +67,17 @@
   int16_t iMinute;
 };
 
-constexpr FX_LOCALETIMEZONEINFO kFXLocaleTimeZoneData[] = {
-    {L"CDT", -5, 0}, {L"CST", -6, 0}, {L"EDT", -4, 0}, {L"EST", -5, 0},
-    {L"MDT", -6, 0}, {L"MST", -7, 0}, {L"PDT", -7, 0}, {L"PST", -8, 0},
-};
+constexpr auto kFXLocaleTimeZoneData =
+    fxcrt::ToArray<const FX_LOCALETIMEZONEINFO>({
+        {L"CDT", -5, 0},
+        {L"CST", -6, 0},
+        {L"EDT", -4, 0},
+        {L"EST", -5, 0},
+        {L"MDT", -6, 0},
+        {L"MST", -7, 0},
+        {L"PDT", -7, 0},
+        {L"PST", -8, 0},
+    });
 
 constexpr wchar_t kTimeSymbols[] = L"hHkKMSFAzZ";
 constexpr wchar_t kDateSymbols[] = L"DJMEeGgYwW";
@@ -257,7 +261,8 @@
       WideString wsLiteral = GetLiteralText(spDatePattern, &ccf);
       size_t iLiteralLen = wsLiteral.GetLength();
       if (*cc + iLiteralLen > spDate.size() ||
-          wcsncmp(spDate.data() + *cc, wsLiteral.c_str(), iLiteralLen) != 0) {
+          UNSAFE_TODO(wcsncmp(spDate.data() + *cc, wsLiteral.c_str(),
+                              iLiteralLen)) != 0) {
         return false;
       }
       *cc += iLiteralLen;
@@ -295,8 +300,8 @@
             pLocale->GetMonthName(i, symbol.EqualsASCII("MMM"));
         if (wsMonthName.IsEmpty())
           continue;
-        if (wcsncmp(wsMonthName.c_str(), spDate.data() + *cc,
-                    wsMonthName.GetLength()) == 0) {
+        if (UNSAFE_TODO(wcsncmp(wsMonthName.c_str(), spDate.data() + *cc,
+                                wsMonthName.GetLength())) == 0) {
           *cc += wsMonthName.GetLength();
           month = i + 1;
           break;
@@ -308,8 +313,8 @@
             pLocale->GetDayName(i, symbol.EqualsASCII("EEE"));
         if (wsDayName.IsEmpty())
           continue;
-        if (wcsncmp(wsDayName.c_str(), spDate.data() + *cc,
-                    wsDayName.GetLength()) == 0) {
+        if (UNSAFE_TODO(wcsncmp(wsDayName.c_str(), spDate.data() + *cc,
+                                wsDayName.GetLength())) == 0) {
           *cc += wsDayName.GetLength();
           break;
         }
@@ -376,7 +381,8 @@
       WideString wsLiteral = GetLiteralText(spTimePattern, &ccf);
       size_t iLiteralLen = wsLiteral.GetLength();
       if (*cc + iLiteralLen > spTime.size() ||
-          wcsncmp(spTime.data() + *cc, wsLiteral.c_str(), iLiteralLen) != 0) {
+          UNSAFE_TODO(wcsncmp(spTime.data() + *cc, wsLiteral.c_str(),
+                              iLiteralLen)) != 0) {
         return false;
       }
       *cc += iLiteralLen;
@@ -434,12 +440,13 @@
       WideString wsAM = pLocale->GetMeridiemName(true);
       WideString wsPM = pLocale->GetMeridiemName(false);
       if (*cc + wsAM.GetLength() <= spTime.size() &&
-          WideStringView(spTime.data() + *cc, wsAM.GetLength()) == wsAM) {
+          UNSAFE_TODO(WideStringView(spTime.data() + *cc, wsAM.GetLength())) ==
+              wsAM) {
         *cc += wsAM.GetLength();
         bHasA = true;
       } else if (*cc + wsPM.GetLength() <= spTime.size() &&
-                 WideStringView(spTime.data() + *cc, wsPM.GetLength()) ==
-                     wsPM) {
+                 UNSAFE_TODO(WideStringView(spTime.data() + *cc,
+                                            wsPM.GetLength())) == wsPM) {
         *cc += wsPM.GetLength();
         bHasA = true;
         bPM = true;
@@ -528,7 +535,8 @@
 }
 
 uint16_t GetWeekDay(uint16_t year, uint16_t month, uint16_t day) {
-  static const uint8_t kMonthDay[] = {0, 3, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5};
+  static constexpr auto kMonthDay =
+      fxcrt::ToArray<const uint8_t>({0, 3, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5});
   uint16_t nDays =
       (year - 1) % 7 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400;
   nDays += kMonthDay[month - 1] + day;
@@ -876,11 +884,13 @@
     if (spFormatString[index] == '\'') {
       bQuote = !bQuote;
     } else if (spFormatString[index] == L'|' && !bQuote) {
-      wsPatterns.emplace_back(spFormatString.data() + token, index - token);
+      UNSAFE_TODO(wsPatterns.emplace_back(spFormatString.data() + token,
+                                          index - token));
       token = index + 1;
     }
   }
-  wsPatterns.emplace_back(spFormatString.data() + token, index - token);
+  UNSAFE_TODO(
+      wsPatterns.emplace_back(spFormatString.data() + token, index - token));
   return wsPatterns;
 }
 
@@ -943,8 +953,8 @@
     if (m_spPattern[ccf] == '\'') {
       size_t iCurChar = ccf;
       GetLiteralText(m_spPattern, &ccf);
-      wsPurgePattern +=
-          WideStringView(m_spPattern.data() + iCurChar, ccf - iCurChar + 1);
+      wsPurgePattern += UNSAFE_TODO(
+          WideStringView(m_spPattern.data() + iCurChar, ccf - iCurChar + 1));
     } else if (!bBrackOpen &&
                !pdfium::Contains(kConstChars, m_spPattern[ccf])) {
       WideString wsSearchCategory(m_spPattern[ccf]);
@@ -994,8 +1004,8 @@
     if (m_spPattern[ccf] == '\'') {
       size_t iCurChar = ccf;
       GetLiteralText(m_spPattern, &ccf);
-      *wsPurgePattern +=
-          WideStringView(m_spPattern.data() + iCurChar, ccf - iCurChar + 1);
+      *wsPurgePattern += UNSAFE_TODO(
+          WideStringView(m_spPattern.data() + iCurChar, ccf - iCurChar + 1));
     } else if (!bBrackOpen &&
                !pdfium::Contains(kConstChars, m_spPattern[ccf])) {
       WideString wsCategory(m_spPattern[ccf]);
@@ -1102,8 +1112,8 @@
         WideString wsLiteral = GetLiteralText(spTextFormat, &iPattern);
         size_t iLiteralLen = wsLiteral.GetLength();
         if (iText + iLiteralLen > spSrcText.size() ||
-            wcsncmp(spSrcText.data() + iText, wsLiteral.c_str(), iLiteralLen) !=
-                0) {
+            UNSAFE_TODO(wcsncmp(spSrcText.data() + iText, wsLiteral.c_str(),
+                                iLiteralLen)) != 0) {
           *wsValue = wsSrcText;
           return false;
         }
@@ -1205,8 +1215,8 @@
         size_t iLiteralLen = wsLiteral.GetLength();
         cc -= iLiteralLen - 1;
         if (cc >= spSrcNum.size() ||
-            wcsncmp(spSrcNum.data() + cc, wsLiteral.c_str(), iLiteralLen) !=
-                0) {
+            UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsLiteral.c_str(),
+                                iLiteralLen)) != 0) {
           return false;
         }
         cc--;
@@ -1241,7 +1251,8 @@
         } else {
           cc -= iMinusLen - 1;
           if (cc >= spSrcNum.size() ||
-              wcsncmp(spSrcNum.data() + cc, wsMinus.c_str(), iMinusLen) != 0) {
+              UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsMinus.c_str(),
+                                  iMinusLen)) != 0) {
             return false;
           }
           cc--;
@@ -1267,8 +1278,8 @@
             continue;
           }
           if (cc - iMinusLen + 1 <= spSrcNum.size() &&
-              wcsncmp(spSrcNum.data() + (cc - iMinusLen + 1), wsMinus.c_str(),
-                      iMinusLen) == 0) {
+              UNSAFE_TODO(wcsncmp(spSrcNum.data() + (cc - iMinusLen + 1),
+                                  wsMinus.c_str(), iMinusLen)) == 0) {
             bExpSign = true;
             cc -= iMinusLen;
             continue;
@@ -1286,7 +1297,8 @@
         size_t iSymbolLen = wsSymbol.GetLength();
         cc -= iSymbolLen - 1;
         if (cc >= spSrcNum.size() ||
-            wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(), iSymbolLen) != 0) {
+            UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(),
+                                iSymbolLen)) != 0) {
           return false;
         }
         cc--;
@@ -1332,7 +1344,8 @@
         size_t iSymbolLen = wsSymbol.GetLength();
         cc -= iSymbolLen - 1;
         if (cc >= spSrcNum.size() ||
-            wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(), iSymbolLen) != 0) {
+            UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(),
+                                iSymbolLen)) != 0) {
           return false;
         }
         cc--;
@@ -1349,8 +1362,8 @@
         if (cc < spSrcNum.size()) {
           cc -= iGroupLen - 1;
           if (cc < spSrcNum.size() &&
-              wcsncmp(spSrcNum.data() + cc, wsGroupSymbol.c_str(), iGroupLen) ==
-                  0) {
+              UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsGroupSymbol.c_str(),
+                                  iGroupLen)) == 0) {
             cc--;
           } else {
             cc += iGroupLen - 1;
@@ -1397,8 +1410,8 @@
           WideString wsLiteral = GetLiteralText(spNumFormat, &ccf);
           size_t iLiteralLen = wsLiteral.GetLength();
           if (cc + iLiteralLen > spSrcNum.size() ||
-              wcsncmp(spSrcNum.data() + cc, wsLiteral.c_str(), iLiteralLen) !=
-                  0) {
+              UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsLiteral.c_str(),
+                                  iLiteralLen)) != 0) {
             return false;
           }
           cc += iLiteralLen;
@@ -1429,8 +1442,8 @@
             cc++;
           } else {
             if (cc + iMinusLen > spSrcNum.size() ||
-                wcsncmp(spSrcNum.data() + cc, wsMinus.c_str(), iMinusLen) !=
-                    0) {
+                UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsMinus.c_str(),
+                                    iMinusLen)) != 0) {
               return false;
             }
             bNeg = true;
@@ -1469,8 +1482,8 @@
           WideString wsSymbol = pLocale->GetCurrencySymbol();
           size_t iSymbolLen = wsSymbol.GetLength();
           if (cc + iSymbolLen > spSrcNum.size() ||
-              wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(), iSymbolLen) !=
-                  0) {
+              UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(),
+                                  iSymbolLen)) != 0) {
             return false;
           }
           cc += iSymbolLen;
@@ -1514,8 +1527,8 @@
           WideString wsSymbol = pLocale->GetPercentSymbol();
           size_t iSymbolLen = wsSymbol.GetLength();
           if (cc + iSymbolLen <= spSrcNum.size() &&
-              wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(), iSymbolLen) ==
-                  0) {
+              UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsSymbol.c_str(),
+                                  iSymbolLen)) == 0) {
             cc += iSymbolLen;
           }
           bHavePercentSymbol = true;
@@ -1531,8 +1544,8 @@
         } break;
         case ',': {
           if (cc + iGroupLen <= spSrcNum.size() &&
-              wcsncmp(spSrcNum.data() + cc, wsGroupSymbol.c_str(), iGroupLen) ==
-                  0) {
+              UNSAFE_TODO(wcsncmp(spSrcNum.data() + cc, wsGroupSymbol.c_str(),
+                                  iGroupLen)) == 0) {
             cc += iGroupLen;
           }
           break;
@@ -1585,8 +1598,8 @@
     if (m_spPattern[ccf] == '\'') {
       size_t iCurChar = ccf;
       GetLiteralText(m_spPattern, &ccf);
-      wsTempPattern +=
-          WideStringView(m_spPattern.data() + iCurChar, ccf - iCurChar + 1);
+      wsTempPattern += UNSAFE_TODO(
+          WideStringView(m_spPattern.data() + iCurChar, ccf - iCurChar + 1));
     } else if (!bBraceOpen && eDateTimeType != DateTimeType::kDateTime &&
                !pdfium::Contains(kConstChars, m_spPattern[ccf])) {
       WideString wsCategory(m_spPattern[ccf]);
@@ -1754,7 +1767,8 @@
       WideString wsLiteral = GetLiteralText(spTextFormat, &iPattern);
       size_t iLiteralLen = wsLiteral.GetLength();
       if (iText + iLiteralLen > spSrcText.size() ||
-          wcsncmp(spSrcText.data() + iText, wsLiteral.c_str(), iLiteralLen)) {
+          UNSAFE_TODO(wcsncmp(spSrcText.data() + iText, wsLiteral.c_str(),
+                              iLiteralLen))) {
         return false;
       }
       iText += iLiteralLen;
@@ -1782,7 +1796,8 @@
       WideString wsLiteral = GetLiteralText(spTextFormat, &iPattern);
       size_t iLiteralLen = wsLiteral.GetLength();
       if (iText + iLiteralLen > spSrcText.size() ||
-          wcsncmp(spSrcText.data() + iText, wsLiteral.c_str(), iLiteralLen)) {
+          UNSAFE_TODO(wcsncmp(spSrcText.data() + iText, wsLiteral.c_str(),
+                              iLiteralLen))) {
         return false;
       }
       iText += iLiteralLen;
diff --git a/xfa/fgas/font/cfgas_defaultfontmanager.cpp b/xfa/fgas/font/cfgas_defaultfontmanager.cpp
index 1410ee1..7ff89d6 100644
--- a/xfa/fgas/font/cfgas_defaultfontmanager.cpp
+++ b/xfa/fgas/font/cfgas_defaultfontmanager.cpp
@@ -4,13 +4,9 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#if defined(UNSAFE_BUFFERS_BUILD)
-// TODO(crbug.com/pdfium/2154): resolve buffer safety issues.
-#pragma allow_unsafe_buffers
-#endif
-
 #include "xfa/fgas/font/cfgas_defaultfontmanager.h"
 
+#include "core/fxcrt/compiler_specific.h"
 #include "core/fxcrt/fx_codepage.h"
 #include "core/fxcrt/numerics/safe_conversions.h"
 #include "core/fxge/fx_font.h"
@@ -46,7 +42,7 @@
   while (iLength > 0) {
     const char* pNameText = pReplace;
     while (*pNameText != ',' && iLength > 0) {
-      pNameText++;
+      UNSAFE_TODO(pNameText++);
       iLength--;
     }
     WideString wsReplace =
@@ -57,7 +53,7 @@
       break;
 
     iLength--;
-    pNameText++;
+    UNSAFE_TODO(pNameText++);
     pReplace = pNameText;
   }
   return pFont;
diff --git a/xfa/fgas/font/cfgas_fontmgr.cpp b/xfa/fgas/font/cfgas_fontmgr.cpp
index 68b08cb..47fdec9 100644
--- a/xfa/fgas/font/cfgas_fontmgr.cpp
+++ b/xfa/fgas/font/cfgas_fontmgr.cpp
@@ -4,11 +4,6 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#if defined(UNSAFE_BUFFERS_BUILD)
-// TODO(crbug.com/pdfium/2154): resolve buffer safety issues.
-#pragma allow_unsafe_buffers
-#endif
-
 #include "xfa/fgas/font/cfgas_fontmgr.h"
 
 #include <stdint.h>
@@ -193,9 +188,11 @@
   font.uCharSet = FX_GetCharsetFromInt(lf.lfCharSet);
   font.dwFontStyles = GetGdiFontStyles(lf);
   FXSYS_wcsncpy(font.wsFontFace, (const wchar_t*)lf.lfFaceName, 31);
-  font.wsFontFace[31] = 0;
-  FXSYS_memcpy(&font.FontSignature, &lpntme->ntmFontSig,
-               sizeof(lpntme->ntmFontSig));
+  UNSAFE_TODO({
+    font.wsFontFace[31] = 0;
+    FXSYS_memcpy(&font.FontSignature, &lpntme->ntmFontSig,
+                 sizeof(lpntme->ntmFontSig));
+  });
   reinterpret_cast<std::deque<FX_FONTDESCRIPTOR>*>(lParam)->push_back(font);
   return 1;
 }
@@ -213,8 +210,10 @@
   static_assert(std::is_aggregate_v<decltype(lfFind)>);
   lfFind.lfCharSet = DEFAULT_CHARSET;
   if (pwsFaceName) {
-    FXSYS_wcsncpy(lfFind.lfFaceName, pwsFaceName, 31);
-    lfFind.lfFaceName[31] = 0;
+    UNSAFE_TODO({
+      FXSYS_wcsncpy(lfFind.lfFaceName, pwsFaceName, 31);
+      lfFind.lfFaceName[31] = 0;
+    });
   }
   HDC hDC = ::GetDC(nullptr);
   EnumFontFamiliesExW(hDC, (LPLOGFONTW)&lfFind, (FONTENUMPROCW)GdiFontEnumProc,
@@ -376,8 +375,9 @@
 
 uint16_t FX_GetCodePageBit(FX_CodePage wCodePage) {
   for (size_t i = 0; i < std::size(kCodePages); ++i) {
-    if (kCodePages[i] == wCodePage)
+    if (UNSAFE_TODO(kCodePages[i]) == wCodePage) {
       return static_cast<uint16_t>(i);
+    }
   }
   return static_cast<uint16_t>(-1);
 }
@@ -520,7 +520,7 @@
   // https://bugs.chromium.org/p/pdfium/issues/detail?id=690
   FXFT_StreamRec* ftStream =
       static_cast<FXFT_StreamRec*>(ft_scalloc(sizeof(FXFT_StreamRec), 1));
-  FXSYS_memset(ftStream, 0, sizeof(FXFT_StreamRec));
+  UNSAFE_TODO(FXSYS_memset(ftStream, 0, sizeof(FXFT_StreamRec)));
   ftStream->base = nullptr;
   ftStream->descriptor.pointer = static_cast<void*>(pFontStream.Get());
   ftStream->pos = 0;
diff --git a/xfa/fgas/font/cfgas_fontmgr.h b/xfa/fgas/font/cfgas_fontmgr.h
index f865501..e91a67a 100644
--- a/xfa/fgas/font/cfgas_fontmgr.h
+++ b/xfa/fgas/font/cfgas_fontmgr.h
@@ -4,11 +4,6 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#if defined(UNSAFE_BUFFERS_BUILD)
-// TODO(crbug.com/pdfium/2154): resolve buffer safety issues.
-#pragma allow_unsafe_buffers
-#endif
-
 #ifndef XFA_FGAS_FONT_CFGAS_FONTMGR_H_
 #define XFA_FGAS_FONT_CFGAS_FONTMGR_H_
 
@@ -20,6 +15,7 @@
 #include <vector>
 
 #include "build/build_config.h"
+#include "core/fxcrt/compiler_specific.h"
 #include "core/fxcrt/fx_codepage_forward.h"
 #include "core/fxcrt/retain_ptr.h"
 #include "core/fxcrt/widestring.h"
@@ -30,8 +26,8 @@
 
 #if BUILDFLAG(IS_WIN)
 struct FX_FONTSIGNATURE {
-  uint32_t fsUsb[4];
-  uint32_t fsCsb[2];
+  std::array<uint32_t, 4> fsUsb;
+  std::array<uint32_t, 2> fsCsb;
 };
 
 inline bool operator==(const FX_FONTSIGNATURE& left,
diff --git a/xfa/fgas/font/cfgas_pdffontmgr.cpp b/xfa/fgas/font/cfgas_pdffontmgr.cpp
index 9c45b31..668591b 100644
--- a/xfa/fgas/font/cfgas_pdffontmgr.cpp
+++ b/xfa/fgas/font/cfgas_pdffontmgr.cpp
@@ -4,11 +4,6 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#if defined(UNSAFE_BUFFERS_BUILD)
-// TODO(crbug.com/pdfium/2154): resolve buffer safety issues.
-#pragma allow_unsafe_buffers
-#endif
-
 #include "xfa/fgas/font/cfgas_pdffontmgr.h"
 
 #include <algorithm>
@@ -21,6 +16,7 @@
 #include "core/fpdfapi/parser/cpdf_document.h"
 #include "core/fpdfapi/parser/fpdf_parser_utility.h"
 #include "core/fxcrt/check.h"
+#include "core/fxcrt/compiler_specific.h"
 #include "core/fxge/fx_font.h"
 #include "xfa/fgas/font/cfgas_fontmgr.h"
 #include "xfa/fgas/font/cfgas_gefont.h"
@@ -107,13 +103,13 @@
                                               bool bBold,
                                               bool bItalic) {
   for (size_t i = 0; i < std::size(kXFAPDFFontName); ++i) {
-    if (strPsName == kXFAPDFFontName[i][0]) {
+    if (strPsName == UNSAFE_TODO(kXFAPDFFontName[i][0])) {
       size_t index = 1;
       if (bBold)
         ++index;
       if (bItalic)
         index += 2;
-      return kXFAPDFFontName[i][index];
+      return UNSAFE_TODO(kXFAPDFFontName[i][index]);
     }
   }
   return strPsName;