CMake/Source/cmGeneratedFileStream.cxx

144 lines
4.6 KiB
C++

/*=========================================================================
Program: CMake - Cross-Platform Makefile Generator
Module: $RCSfile$
Language: C++
Date: $Date$
Version: $Revision$
Copyright (c) 2002 Kitware, Inc., Insight Consortium. All rights reserved.
See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#include "cmGeneratedFileStream.h"
#include "cmSystemTools.h"
// Includes needed for implementation of RenameFile. This is not in
// system tools because it is not implemented robustly enough to move
// files across directories.
#ifdef _WIN32
# include <windows.h>
# include <sys/stat.h>
#endif
//----------------------------------------------------------------------------
cmGeneratedFileStream::cmGeneratedFileStream(const char* name, bool quiet):
cmGeneratedFileStreamBase(name),
Stream(m_TempName.c_str())
{
// Check if the file opened.
if(!*this && !quiet)
{
cmSystemTools::Error("Cannot open file for write: ", m_TempName.c_str());
cmSystemTools::ReportLastSystemError("");
}
}
//----------------------------------------------------------------------------
cmGeneratedFileStream::~cmGeneratedFileStream()
{
// This is the first destructor called. Check the status of the
// stream and give the information to the private base. Next the
// stream will be destroyed which will close the temporary file.
// Finally the base destructor will be called to replace the
// destination file.
m_Okay = (*this)?true:false;
}
//----------------------------------------------------------------------------
void cmGeneratedFileStream::SetCopyIfDifferent(bool copy_if_different)
{
m_CopyIfDifferent = copy_if_different;
}
//----------------------------------------------------------------------------
cmGeneratedFileStreamBase::cmGeneratedFileStreamBase(const char* name):
m_Name(name),
m_TempName(name),
m_CopyIfDifferent(false),
m_Okay(false)
{
// Create the name of the temporary file.
m_TempName += ".tmp";
// Make sure the temporary file that will be used is not present.
cmSystemTools::RemoveFile(m_TempName.c_str());
}
//----------------------------------------------------------------------------
cmGeneratedFileStreamBase::~cmGeneratedFileStreamBase()
{
// Only consider replacing the destination file if no error
// occurred.
if(m_Okay &&
(!m_CopyIfDifferent ||
cmSystemTools::FilesDiffer(m_TempName.c_str(), m_Name.c_str())))
{
// The destination is to be replaced. Rename the temporary to the
// destination atomically.
this->RenameFile(m_TempName.c_str(), m_Name.c_str());
}
else
{
// The destination was not replaced. Just delete the temporary
// file.
cmSystemTools::RemoveFile(m_TempName.c_str());
}
}
//----------------------------------------------------------------------------
int cmGeneratedFileStreamBase::RenameFile(const char* oldname,
const char* newname)
{
#ifdef _WIN32
/* On Windows the move functions will not replace existing files.
Check if the destination exists. */
struct stat newFile;
if(stat(newname, &newFile) == 0)
{
/* The destination exists. We have to replace it carefully. The
MoveFileEx function does what we need but is not available on
Win9x. */
OSVERSIONINFO osv;
DWORD attrs;
/* Make sure the destination is not read only. */
attrs = GetFileAttributes(newname);
if(attrs & FILE_ATTRIBUTE_READONLY)
{
SetFileAttributes(newname, attrs & ~FILE_ATTRIBUTE_READONLY);
}
/* Check the windows version number. */
osv.dwOSVersionInfoSize = sizeof(osv);
GetVersionEx(&osv);
if(osv.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS)
{
/* This is Win9x. There is no MoveFileEx implementation. We
cannot quite rename the file atomically. Just delete the
destination and then move the file. */
DeleteFile(newname);
return MoveFile(oldname, newname);
}
else
{
/* This is not Win9x. Use the MoveFileEx implementation. */
return MoveFileEx(oldname, newname, MOVEFILE_REPLACE_EXISTING);
}
}
else
{
/* The destination does not exist. Just move the file. */
return MoveFile(oldname, newname);
}
#else
/* On UNIX we have an OS-provided call to do this atomically. */
return rename(oldname, newname) == 0;
#endif
}