Make sure string constructors are efficient on literals

core/include/fxcrt/fx_string.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef _FX_STRING_H_
 #define _FX_STRING_H_
 
 #include <stdint.h>  // For intptr_t.
 #include <algorithm>
 
 #include "fx_memory.h"
 
-class CFX_ByteStringC;
+class CFX_BinaryBuf;
 class CFX_ByteString;
-class CFX_WideStringC;
 class CFX_WideString;
 struct CFX_CharMap;
-class CFX_BinaryBuf;
 typedef int FX_STRSIZE;
-class CFX_ByteStringL;
-class CFX_WideStringL;
 
 // An immutable string with caller-provided storage which must outlive the
 // string itself.
 class CFX_ByteStringC
 {
 public:
     typedef FX_CHAR value_type;
 
     CFX_ByteStringC()
     {
@@ skipping 167 matching lines @@
 
     CFX_ByteString()
     {
         m_pData = NULL;
     }
 
     CFX_ByteString(const CFX_ByteString& str);
 
     CFX_ByteString(char ch);
 
-    CFX_ByteString(FX_LPCSTR ptr, FX_STRSIZE len = -1);
+    CFX_ByteString(FX_LPCSTR ptr)

[Lei Zhang, 2015/05/05 21:31:56]

We should mark a whole bunch of these ctors explicit while we are here.

+            : CFX_ByteString(ptr, ptr ? FXSYS_strlen(ptr) : 0) { }
+
+    CFX_ByteString(FX_LPCSTR ptr, FX_STRSIZE len);
 
     CFX_ByteString(FX_LPCBYTE ptr, FX_STRSIZE len);
 
     CFX_ByteString(FX_BSTR bstrc);
-
     CFX_ByteString(FX_BSTR bstrc1, FX_BSTR bstrc2);
 
     ~CFX_ByteString();
 
     static CFX_ByteString       FromUnicode(FX_LPCWSTR ptr, FX_STRSIZE len = -1);
 
     static CFX_ByteString       FromUnicode(const CFX_WideString& str);
 
     // Explicit conversion to raw string
     FX_LPCSTR c_str() const
@@ skipping 397 matching lines @@
 public:
     typedef FX_WCHAR value_type;
 
     CFX_WideString()
     {
         m_pData = NULL;
     }
 
     CFX_WideString(const CFX_WideString& str);
 
-    CFX_WideString(FX_LPCWSTR ptr, FX_STRSIZE len = -1)
-    {
-        InitStr(ptr, len);
-    }
+    CFX_WideString(FX_LPCWSTR ptr)
+            : CFX_WideString(ptr, ptr ? FXSYS_wcslen(ptr) : 0) { }
+
+    CFX_WideString(FX_LPCWSTR ptr, FX_STRSIZE len);
 
     CFX_WideString(FX_WCHAR ch);
 
     CFX_WideString(const CFX_WideStringC& str);
 
     CFX_WideString(const CFX_WideStringC& str1, const CFX_WideStringC& str2);
 
     ~CFX_WideString();
 
     static CFX_WideString       FromLocal(const char* str, FX_STRSIZE len = -1);
@@ skipping 130 matching lines @@
 
     FX_STRSIZE                          Replace(FX_LPCWSTR lpszOld, FX_LPCWSTR lpszNew);
 
     FX_STRSIZE                          Remove(FX_WCHAR ch);
 
     CFX_ByteString                      UTF8Encode() const;
 
     CFX_ByteString                      UTF16LE_Encode() const;
 
     void                                        ConvertFrom(const CFX_ByteString& str, CFX_CharMap* pCharMap = NULL);
+
 protected:
-    void                                        InitStr(FX_LPCWSTR ptr, int len);
-
-    CFX_StringDataW*            m_pData;
     void                                        CopyBeforeWrite();
     void                                        AllocBeforeWrite(FX_STRSIZE nLen);
     void                                        ConcatInPlace(FX_STRSIZE nSrcLen, FX_LPCWSTR lpszSrcData);
     void                                        ConcatCopy(FX_STRSIZE nSrc1Len, FX_LPCWSTR lpszSrc1Data, FX_STRSIZE nSrc2Len, FX_LPCWSTR lpszSrc2Data);
     void                                        AssignCopy(FX_STRSIZE nSrcLen, FX_LPCWSTR lpszSrcData);
     void                                        AllocCopy(CFX_WideString& dest, FX_STRSIZE nCopyLen, FX_STRSIZE nCopyIndex) const;
+
+    CFX_StringDataW*            m_pData;
 };
 inline CFX_WideStringC::CFX_WideStringC(const CFX_WideString& src)
 {
     m_Ptr = src.c_str();
     m_Length = src.GetLength();
 }
 inline CFX_WideStringC& CFX_WideStringC::operator = (const CFX_WideString& src)
 {
     m_Ptr = src.c_str();
     m_Length = src.GetLength();
@@ skipping 66 matching lines @@
 CFX_ByteString  FX_UTF8Encode(FX_LPCWSTR pwsStr, FX_STRSIZE len);
 inline CFX_ByteString   FX_UTF8Encode(FX_WSTR wsStr)
 {
     return FX_UTF8Encode(wsStr.GetPtr(), wsStr.GetLength());
 }
 inline CFX_ByteString   FX_UTF8Encode(const CFX_WideString &wsStr)
 {
     return FX_UTF8Encode(wsStr.c_str(), wsStr.GetLength());
 }
 #endif