Convert string Find methods to return an Optional

The Find and ReverseFind methods for WideString, WideStringC,
ByteString, and ByteStringC have been converted from returning a raw
FX_STRSIZE, to returning Optional<FX_STRSIZE>, so that success/failure
can be indicated without using FX_STRNPOS.

This allows for removing FX_STRNPOS and by association makes the
conversion of FX_STRSIZE to size_t easier, since it forces checking
the return value of Find to be explictly done as well as taking the
error value out of the range of FX_STRSIZE.

New Contains methods have been added for cases where the success or
failure is all the call site to Find cared about, and the actual
position was ignored.

BUG=pdfium:828


Change-Id: Id827e508c8660affa68cc08a13d96121369364b7
Reviewed-on: https://pdfium-review.googlesource.com/11350
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

2 files changed, 27 insertions, 31 deletions

diff --git a/xfa/fgas/crt/cfgas_formatstring.cpp b/xfa/fgas/crt/cfgas_formatstring.cpp
index b20fa082c3..9da8bb9583 100644
--- a/xfa/fgas/crt/cfgas_formatstring.cpp
+++ b/xfa/fgas/crt/cfgas_formatstring.cpp
@@ -190,12 +190,9 @@ bool GetNumericDotIndex(const CFX_WideString& wsNum,
     }
     ccf++;
   }
-  *iDotIndex = wsNum.Find('.');
-  if (*iDotIndex != FX_STRNPOS)
-    return true;
-
-  *iDotIndex = iLenf;
-  return false;
+  auto result = wsNum.Find('.');
+  *iDotIndex = result.value_or(iLenf);
+  return result.has_value();
 }
 
 bool ExtractCountDigits(const wchar_t* str,
@@ -249,7 +246,7 @@ bool ParseLocaleDate(const CFX_WideString& wsDate,
       *cc += iLiteralLen;
       ccf++;
       continue;
-    } else if (wsDateSymbols.Find(strf[ccf]) == FX_STRNPOS) {
+    } else if (!wsDateSymbols.Contains(strf[ccf])) {
       if (strf[ccf] != str[*cc])
         return false;
       (*cc)++;
@@ -370,7 +367,7 @@ bool ParseLocaleTime(const CFX_WideString& wsTime,
       ccf++;
       continue;
     }
-    if (wsTimeSymbols.Find(strf[ccf]) == FX_STRNPOS) {
+    if (!wsTimeSymbols.Contains(strf[ccf])) {
       if (strf[ccf] != str[*cc])
         return false;
       (*cc)++;
@@ -577,7 +574,7 @@ CFX_WideString DateFormat(const CFX_WideString& wsDatePattern,
       ccf++;
       continue;
     }
-    if (wsDateSymbols.Find(strf[ccf]) == FX_STRNPOS) {
+    if (!wsDateSymbols.Contains(strf[ccf])) {
       wsResult += strf[ccf++];
       continue;
     }
@@ -635,7 +632,7 @@ CFX_WideString TimeFormat(const CFX_WideString& wsTimePattern,
   int32_t lenf = wsTimePattern.GetLength();
   uint16_t wHour = hour;
   bool bPM = false;
-  if (wsTimePattern.Find('A') != FX_STRNPOS) {
+  if (wsTimePattern.Contains('A')) {
     if (wHour >= 12)
       bPM = true;
   }
@@ -647,7 +644,7 @@ CFX_WideString TimeFormat(const CFX_WideString& wsTimePattern,
       ccf++;
       continue;
     }
-    if (wsTimeSymbols.Find(strf[ccf]) == FX_STRNPOS) {
+    if (!wsTimeSymbols.Contains(strf[ccf])) {
       wsResult += strf[ccf++];
       continue;
     }
@@ -874,7 +871,7 @@ FX_LOCALECATEGORY CFGAS_FormatString::GetCategory(
   while (ccf < iLenf) {
     if (pStr[ccf] == '\'') {
       GetLiteralText(pStr, &ccf, iLenf);
-    } else if (!bBraceOpen && wsConstChars.Find(pStr[ccf]) == FX_STRNPOS) {
+    } else if (!bBraceOpen && !wsConstChars.Contains(pStr[ccf])) {
       CFX_WideString wsCategory(pStr[ccf]);
       ccf++;
       while (true) {
@@ -932,7 +929,7 @@ CFX_WideString CFGAS_FormatString::GetTextFormat(
       int32_t iCurChar = ccf;
       GetLiteralText(pStr, &ccf, iLenf);
       wsPurgePattern += CFX_WideStringC(pStr + iCurChar, ccf - iCurChar + 1);
-    } else if (!bBrackOpen && wsConstChars.Find(pStr[ccf]) == FX_STRNPOS) {
+    } else if (!bBrackOpen && !wsConstChars.Contains(pStr[ccf])) {
       CFX_WideString wsSearchCategory(pStr[ccf]);
       ccf++;
       while (ccf < iLenf && pStr[ccf] != '{' && pStr[ccf] != '.' &&
@@ -984,7 +981,7 @@ IFX_Locale* CFGAS_FormatString::GetNumericFormat(
       int32_t iCurChar = ccf;
       GetLiteralText(pStr, &ccf, iLenf);
       *wsPurgePattern += CFX_WideStringC(pStr + iCurChar, ccf - iCurChar + 1);
-    } else if (!bBrackOpen && wsConstChars.Find(pStr[ccf]) == FX_STRNPOS) {
+    } else if (!bBrackOpen && !wsConstChars.Contains(pStr[ccf])) {
       CFX_WideString wsCategory(pStr[ccf]);
       ccf++;
       while (ccf < iLenf && pStr[ccf] != '{' && pStr[ccf] != '.' &&
@@ -1030,8 +1027,8 @@ IFX_Locale* CFGAS_FormatString::GetNumericFormat(
           ASSERT(pLocale);
 
           wsSubCategory = pLocale->GetNumPattern(eSubCategory);
-          *iDotIndex = wsSubCategory.Find('.');
-          if (*iDotIndex != 0 && *iDotIndex != FX_STRNPOS) {
+          auto result = wsSubCategory.Find('.');
+          if (result.has_value() && result.value() != 0) {
             *iDotIndex += wsPurgePattern->GetLength();
             bFindDot = true;
             *dwStyle |= FX_NUMSTYLE_DotVorv;
@@ -1177,9 +1174,8 @@ bool CFGAS_FormatString::ParseNum(const CFX_WideString& wsSrcNum,
   // If we're looking for a '.', 'V' or 'v' and the input string does not
   // have a dot index for one of those, then we disable parsing the decimal.
   if (!GetNumericDotIndex(wsSrcNum, wsDotSymbol, &dot_index) &&
-      (dwFormatStyle & FX_NUMSTYLE_DotVorv)) {
+      (dwFormatStyle & FX_NUMSTYLE_DotVorv))
     bReverseParse = true;
-  }
 
   // This parse is broken into two parts based on the '.' in the number
   // (or 'V' or 'v'). |dot_index_f| is the location of the dot in the format and
@@ -1570,7 +1566,7 @@ FX_DATETIMETYPE CFGAS_FormatString::GetDateTimeFormat(
       GetLiteralText(pStr, &ccf, iLenf);
       wsTempPattern += CFX_WideStringC(pStr + iCurChar, ccf - iCurChar + 1);
     } else if (!bBraceOpen && iFindCategory != 3 &&
-               wsConstChars.Find(pStr[ccf]) == FX_STRNPOS) {
+               !wsConstChars.Contains(pStr[ccf])) {
       CFX_WideString wsCategory(pStr[ccf]);
       ccf++;
       while (ccf < iLenf && pStr[ccf] != '{' && pStr[ccf] != '.' &&
@@ -1950,12 +1946,12 @@ bool CFGAS_FormatString::FormatStrNum(const CFX_WideStringC& wsInputNum,
   bool bAddNeg = false;
   const wchar_t* str = wsSrcNum.c_str();
   int len = wsSrcNum.GetLength();
-  int dot_index = wsSrcNum.Find('.');
-  if (dot_index == FX_STRNPOS)
+  auto dot_index = wsSrcNum.Find('.');
+  if (!dot_index.has_value())
     dot_index = len;
 
   ccf = dot_index_f - 1;
-  cc = dot_index - 1;
+  cc = dot_index.value() - 1;
   while (ccf >= 0) {
     switch (strf[ccf]) {
       case '9':
@@ -2089,7 +2085,7 @@ bool CFGAS_FormatString::FormatStrNum(const CFX_WideStringC& wsInputNum,
   }
 
   if (cc >= 0) {
-    int nPos = dot_index % 3;
+    int nPos = dot_index.value() % 3;
     wsOutput->clear();
     for (int32_t i = 0; i < dot_index; i++) {
       if (i % 3 == nPos && i != 0)
@@ -2098,7 +2094,7 @@ bool CFGAS_FormatString::FormatStrNum(const CFX_WideStringC& wsInputNum,
     }
     if (dot_index < len) {
       *wsOutput += pLocale->GetNumbericSymbol(FX_LOCALENUMSYMBOL_Decimal);
-      *wsOutput += wsSrcNum.Right(len - dot_index - 1);
+      *wsOutput += wsSrcNum.Right(len - dot_index.value() - 1);
     }
     if (bNeg) {
       *wsOutput =
@@ -2126,7 +2122,7 @@ bool CFGAS_FormatString::FormatStrNum(const CFX_WideStringC& wsInputNum,
   }
 
   ccf = dot_index_f + 1;
-  cc = dot_index + 1;
+  cc = dot_index.value() + 1;
   while (ccf < lenf) {
     switch (strf[ccf]) {
       case '\'':
@@ -2281,8 +2277,8 @@ bool CFGAS_FormatString::FormatDateTime(const CFX_WideString& wsSrcDateTime,
     return false;
 
   CFX_DateTime dt;
-  int32_t iT = wsSrcDateTime.Find(L"T");
-  if (iT == FX_STRNPOS) {
+  auto iT = wsSrcDateTime.Find(L"T");
+  if (!iT.has_value()) {
     if (eCategory == FX_DATETIMETYPE_Date &&
         FX_DateFromCanonical(wsSrcDateTime, &dt)) {
       *wsOutput = FormatDateTimeInternal(dt, wsDatePattern, wsTimePattern, true,
@@ -2296,9 +2292,9 @@ bool CFGAS_FormatString::FormatDateTime(const CFX_WideString& wsSrcDateTime,
       return true;
     }
   } else {
-    CFX_WideString wsSrcDate(wsSrcDateTime.c_str(), iT);
-    CFX_WideStringC wsSrcTime(wsSrcDateTime.c_str() + iT + 1,
-                              wsSrcDateTime.GetLength() - iT - 1);
+    CFX_WideString wsSrcDate(wsSrcDateTime.c_str(), iT.value());
+    CFX_WideStringC wsSrcTime(wsSrcDateTime.c_str() + iT.value() + 1,
+                              wsSrcDateTime.GetLength() - iT.value() - 1);
     if (wsSrcDate.IsEmpty() || wsSrcTime.IsEmpty())
       return false;
     if (FX_DateFromCanonical(wsSrcDate, &dt) &&
diff --git a/xfa/fgas/font/cfgas_fontmgr.cpp b/xfa/fgas/font/cfgas_fontmgr.cpp
index 813a91dc63..36cf10581a 100644
--- a/xfa/fgas/font/cfgas_fontmgr.cpp
+++ b/xfa/fgas/font/cfgas_fontmgr.cpp
@@ -1267,7 +1267,7 @@ void CFGAS_FontMgr::GetUSBCSB(FXFT_Face pFace, uint32_t* USB, uint32_t* CSB) {
 
 int32_t CFGAS_FontMgr::IsPartName(const CFX_WideString& Name1,
                                   const CFX_WideString& Name2) {
-  if (Name1.Find(Name2.c_str()) != FX_STRNPOS)
+  if (Name1.Contains(Name2.c_str()))
     return 1;
   return 0;
 }