diff --git a/Source/cmSystemTools.cxx b/Source/cmSystemTools.cxx index c2521d99f..525efb4a5 100644 --- a/Source/cmSystemTools.cxx +++ b/Source/cmSystemTools.cxx @@ -1180,46 +1180,35 @@ bool cmSystemTools::CopyFileIfDifferent(const char* source, bool cmSystemTools::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) +# ifndef INVALID_FILE_ATTRIBUTES +# define INVALID_FILE_ATTRIBUTES ((DWORD)-1) +# endif + /* Windows MoveFileEx may not replace read-only or in-use files. If it + fails then remove the read-only attribute from any existing destination. + Try multiple times since we may be racing against another process + creating/opening the destination file just before our MoveFileEx. */ + int tries = 5; + while(!MoveFileEx(oldname, newname, MOVEFILE_REPLACE_EXISTING) && --tries) { - /* 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) + // Try again only if failure was due to access permissions. + if(GetLastError() != ERROR_ACCESS_DENIED) { - SetFileAttributes(newname, attrs & ~FILE_ATTRIBUTE_READONLY); + return false; } - - /* Check the windows version number. */ - osv.dwOSVersionInfoSize = sizeof(osv); - GetVersionEx(&osv); - if(osv.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS) + DWORD attrs = GetFileAttributes(newname); + if((attrs != INVALID_FILE_ATTRIBUTES) && + (attrs & FILE_ATTRIBUTE_READONLY)) { - /* 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) != 0; + // Remove the read-only attribute from the destination file. + SetFileAttributes(newname, attrs & ~FILE_ATTRIBUTE_READONLY); } else { - /* This is not Win9x. Use the MoveFileEx implementation. */ - return MoveFileEx(oldname, newname, MOVEFILE_REPLACE_EXISTING) != 0; + // The file may be temporarily in use so wait a bit. + cmSystemTools::Delay(100); } } - else - { - /* The destination does not exist. Just move the file. */ - return MoveFile(oldname, newname) != 0; - } + return tries > 0; #else /* On UNIX we have an OS-provided call to do this atomically. */ return rename(oldname, newname) == 0;