Make CFX_WideString::FromLocal() take a CFX_ByteStringC arg

It doesn't persist the string beyond the duration of the
call, hence it should take the *StringC variant. Doing so
avoids some allocs by changing to the *StringC ctor in a few
places, at the cost of some explicit .ToByteStringC() calls
(which are cheap).

Review URL: https://codereview.chromium.org/1862953004

8 files changed, 27 insertions, 20 deletions

diff --git a/core/fpdfdoc/doc_action.cpp b/core/fpdfdoc/doc_action.cpp
index c3ab552606..075849482c 100644
--- a/core/fpdfdoc/doc_action.cpp
+++ b/core/fpdfdoc/doc_action.cpp
@@ -73,7 +73,8 @@ CFX_WideString CPDF_Action::GetFilePath() const {
     if (type == "Launch") {
       CPDF_Dictionary* pWinDict = m_pDict->GetDictBy("Win");
       if (pWinDict) {
-        return CFX_WideString::FromLocal(pWinDict->GetStringBy("F"));
+        return CFX_WideString::FromLocal(
+            pWinDict->GetStringBy("F").AsByteStringC());
       }
     }
     return path;
diff --git a/core/fpdfdoc/doc_basic.cpp b/core/fpdfdoc/doc_basic.cpp
index 9318387f7f..308bf04287 100644
--- a/core/fpdfdoc/doc_basic.cpp
+++ b/core/fpdfdoc/doc_basic.cpp
@@ -315,23 +315,27 @@ bool CPDF_FileSpec::GetFileName(CFX_WideString* csFileName) const {
   if (CPDF_Dictionary* pDict = m_pObj->AsDictionary()) {
     *csFileName = pDict->GetUnicodeTextBy("UF");
     if (csFileName->IsEmpty()) {
-      *csFileName = CFX_WideString::FromLocal(pDict->GetStringBy("F"));
+      *csFileName = CFX_WideString::FromLocal(pDict->GetConstStringBy("F"));
     }
     if (pDict->GetStringBy("FS") == "URL")
       return true;
     if (csFileName->IsEmpty()) {
       if (pDict->KeyExist("DOS")) {
-        *csFileName = CFX_WideString::FromLocal(pDict->GetStringBy("DOS"));
+        *csFileName = CFX_WideString::FromLocal(
+            pDict->GetStringBy("DOS").AsByteStringC());
       } else if (pDict->KeyExist("Mac")) {
-        *csFileName = CFX_WideString::FromLocal(pDict->GetStringBy("Mac"));
+        *csFileName = CFX_WideString::FromLocal(
+            pDict->GetStringBy("Mac").AsByteStringC());
       } else if (pDict->KeyExist("Unix")) {
-        *csFileName = CFX_WideString::FromLocal(pDict->GetStringBy("Unix"));
+        *csFileName = CFX_WideString::FromLocal(
+            pDict->GetStringBy("Unix").AsByteStringC());
       } else {
         return false;
       }
     }
   } else if (m_pObj->IsString()) {
-    *csFileName = CFX_WideString::FromLocal(m_pObj->GetString());
+    *csFileName =
+        CFX_WideString::FromLocal(m_pObj->GetString().AsByteStringC());
   } else {
     return false;
   }
diff --git a/core/fpdfdoc/doc_form.cpp b/core/fpdfdoc/doc_form.cpp
index 80c09714a2..384bcaa435 100644
--- a/core/fpdfdoc/doc_form.cpp
+++ b/core/fpdfdoc/doc_form.cpp
@@ -35,12 +35,13 @@ CFX_WideString FPDFDOC_FDF_GetFieldValue(const CPDF_Dictionary& pFieldDict,
   const CFX_ByteString csBValue = pFieldDict.GetStringBy("V");
   for (const auto& encoding : g_fieldEncoding) {
     if (bsEncoding == encoding.m_name)
-      return CFX_WideString::FromCodePage(csBValue, encoding.m_codePage);
+      return CFX_WideString::FromCodePage(csBValue.AsByteStringC(),
+                                          encoding.m_codePage);
   }
   CFX_ByteString csTemp = csBValue.Left(2);
   if (csTemp == "\xFF\xFE" || csTemp == "\xFE\xFF")
     return PDF_DecodeText(csBValue);
-  return CFX_WideString::FromLocal(csBValue);
+  return CFX_WideString::FromLocal(csBValue.AsByteStringC());
 }
 
 }  // namespace
diff --git a/core/fxcrt/fx_basic_bstring.cpp b/core/fxcrt/fx_basic_bstring.cpp
index 2c2264a419..cc0dfe2341 100644
--- a/core/fxcrt/fx_basic_bstring.cpp
+++ b/core/fxcrt/fx_basic_bstring.cpp
@@ -824,7 +824,7 @@ CFX_ByteString CFX_ByteString::FromUnicode(const FX_WCHAR* str,
 
 // static
 CFX_ByteString CFX_ByteString::FromUnicode(const CFX_WideString& str) {
-  return CFX_CharMap::GetByteString(0, str);
+  return CFX_CharMap::GetByteString(0, str.AsWideStringC());
 }
 
 int CFX_ByteString::Compare(const CFX_ByteStringC& str) const {
diff --git a/core/fxcrt/fx_basic_wstring.cpp b/core/fxcrt/fx_basic_wstring.cpp
index e2e122be9a..b5ccaf6da5 100644
--- a/core/fxcrt/fx_basic_wstring.cpp
+++ b/core/fxcrt/fx_basic_wstring.cpp
@@ -747,12 +747,12 @@ void CFX_WideString::SetAt(FX_STRSIZE nIndex, FX_WCHAR ch) {
 }
 
 // static
-CFX_WideString CFX_WideString::FromLocal(const CFX_ByteString& str) {
+CFX_WideString CFX_WideString::FromLocal(const CFX_ByteStringC& str) {
   return FromCodePage(str, 0);
 }
 
 // static
-CFX_WideString CFX_WideString::FromCodePage(const CFX_ByteString& str,
+CFX_WideString CFX_WideString::FromCodePage(const CFX_ByteStringC& str,
                                             uint16_t codepage) {
   return CFX_CharMap::GetWideString(codepage, str);
 }
@@ -943,7 +943,7 @@ FX_FLOAT CFX_WideString::GetFloat() const {
 
 // static
 CFX_ByteString CFX_CharMap::GetByteString(uint16_t codepage,
-                                          const CFX_WideString& wstr) {
+                                          const CFX_WideStringC& wstr) {
   FXSYS_assert(IsValidCodePage(codepage));
   int src_len = wstr.GetLength();
   int dest_len = FXSYS_WideCharToMultiByte(codepage, 0, wstr.c_str(), src_len,
@@ -960,15 +960,16 @@ CFX_ByteString CFX_CharMap::GetByteString(uint16_t codepage,
 
 // static
 CFX_WideString CFX_CharMap::GetWideString(uint16_t codepage,
-                                          const CFX_ByteString& bstr) {
+                                          const CFX_ByteStringC& bstr) {
   FXSYS_assert(IsValidCodePage(codepage));
   int src_len = bstr.GetLength();
   int dest_len =
-      FXSYS_MultiByteToWideChar(codepage, 0, bstr, src_len, nullptr, 0);
+      FXSYS_MultiByteToWideChar(codepage, 0, bstr.c_str(), src_len, nullptr, 0);
   CFX_WideString wstr;
   if (dest_len) {
     FX_WCHAR* dest_buf = wstr.GetBuffer(dest_len);
-    FXSYS_MultiByteToWideChar(codepage, 0, bstr, src_len, dest_buf, dest_len);
+    FXSYS_MultiByteToWideChar(codepage, 0, bstr.c_str(), src_len, dest_buf,
+                              dest_len);
     wstr.ReleaseBuffer(dest_len);
   }
   return wstr;
diff --git a/core/fxcrt/fx_extension.cpp b/core/fxcrt/fx_extension.cpp
index 7e8029baba..f1fd980120 100644
--- a/core/fxcrt/fx_extension.cpp
+++ b/core/fxcrt/fx_extension.cpp
@@ -134,7 +134,7 @@ FX_FLOAT FXSYS_strtof(const FX_CHAR* pcsStr,
     iLength = (int32_t)FXSYS_strlen(pcsStr);
   }
   CFX_WideString ws =
-      CFX_WideString::FromLocal(CFX_ByteString(pcsStr, iLength));
+      CFX_WideString::FromLocal(CFX_ByteStringC(pcsStr, iLength));
   return FXSYS_wcstof(ws.c_str(), iLength, pUsedLen);
 }
 FX_FLOAT FXSYS_wcstof(const FX_WCHAR* pwsStr,
diff --git a/core/fxcrt/include/fx_basic.h b/core/fxcrt/include/fx_basic.h
index 744b2dd10f..1cb5174351 100644
--- a/core/fxcrt/include/fx_basic.h
+++ b/core/fxcrt/include/fx_basic.h
@@ -186,10 +186,10 @@ class CFX_FileBufferArchive {
 class CFX_CharMap {
  public:
   static CFX_ByteString GetByteString(uint16_t codepage,
-                                      const CFX_WideString& wstr);
+                                      const CFX_WideStringC& wstr);
 
   static CFX_WideString GetWideString(uint16_t codepage,
-                                      const CFX_ByteString& bstr);
+                                      const CFX_ByteStringC& bstr);
 
   CFX_CharMap() = delete;
 };
diff --git a/core/fxcrt/include/fx_string.h b/core/fxcrt/include/fx_string.h
index 382e141dc2..8a0b3ff3db 100644
--- a/core/fxcrt/include/fx_string.h
+++ b/core/fxcrt/include/fx_string.h
@@ -497,8 +497,8 @@ class CFX_WideString {
 
   ~CFX_WideString();
 
-  static CFX_WideString FromLocal(const CFX_ByteString& str);
-  static CFX_WideString FromCodePage(const CFX_ByteString& str,
+  static CFX_WideString FromLocal(const CFX_ByteStringC& str);
+  static CFX_WideString FromCodePage(const CFX_ByteStringC& str,
                                      uint16_t codepage);
 
   static CFX_WideString FromUTF8(const CFX_ByteStringC& str);