/*========================================================================= Program: KWSys - Kitware System Library Module: $RCSfile$ Copyright (c) Kitware, Inc., Insight Consortium. All rights reserved. See Copyright.txt or http://www.kitware.com/Copyright.htm 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. =========================================================================*/ /* On Windows9x platforms, this executable is spawned between a parent process and the child it is invoking to work around a bug. See the Win32 implementation file for details. Future Work: This executable must be linked statically against the C runtime library before being encoded into the library. Building it in this way may be hard because CMake has limited abilities to build different targets with different configurations in the same directory. We may just have to create and encode the executable once instead of generating it during the build. This would be an acceptable solution because the forwarding executable should not change very often and is pretty simple. */ #ifdef _MSC_VER #pragma warning (push, 1) #endif #include <windows.h> #include <stdio.h> void ReportLastError(HANDLE errorPipe); int main() { /* Process startup information for the real child. */ STARTUPINFO si; PROCESS_INFORMATION pi; /* The result of waiting for the child to exit. */ DWORD waitResult; /* The child's process return code. */ DWORD retVal; /* The command line used to invoke this process. */ LPSTR commandLine = GetCommandLine(); /* Pointer that will be advanced to the beginning of the command line of the real child process. */ LPSTR cmdLine = commandLine; /* Handle to the error reporting pipe provided by the parent. This is parsed off the command line. */ HANDLE errorPipe = 0; HANDLE errorPipeOrig = 0; /* Handle to the event the parent uses to tell us to resume the child. This is parsed off the command line. */ HANDLE resumeEvent = 0; /* Handle to the event the parent uses to tell us to kill the child. This is parsed off the command line. */ HANDLE killEvent = 0; /* Flag for whether to hide window of child process. */ int hideWindow = 0; /* An array of the handles on which we wait when the child is running. */ HANDLE waitHandles[2] = {0, 0}; /* Move the pointer past the name of this executable. */ if(*cmdLine == '"') { ++cmdLine; while(*cmdLine && *cmdLine != '"') { ++cmdLine; } if(*cmdLine) { ++cmdLine; } } else { while(*cmdLine && *cmdLine != ' ') { ++cmdLine; } } /* Parse the error pipe handle. */ while(*cmdLine && *cmdLine == ' ') { ++cmdLine; } sscanf(cmdLine, "%p", &errorPipeOrig); /* Parse the resume event handle. */ while(*cmdLine && *cmdLine != ' ') { ++cmdLine; } while(*cmdLine && *cmdLine == ' ') { ++cmdLine; } sscanf(cmdLine, "%p", &resumeEvent); /* Parse the kill event handle. */ while(*cmdLine && *cmdLine != ' ') { ++cmdLine; } while(*cmdLine && *cmdLine == ' ') { ++cmdLine; } sscanf(cmdLine, "%p", &killEvent); /* Parse the hide window flag. */ while(*cmdLine && *cmdLine != ' ') { ++cmdLine; } while(*cmdLine && *cmdLine == ' ') { ++cmdLine; } sscanf(cmdLine, "%d", &hideWindow); /* Skip to the beginning of the command line of the real child. */ while(*cmdLine && *cmdLine != ' ') { ++cmdLine; } while(*cmdLine && *cmdLine == ' ') { ++cmdLine; } /* Create a non-inherited copy of the error pipe. We do not want the child to get it. */ if(DuplicateHandle(GetCurrentProcess(), errorPipeOrig, GetCurrentProcess(), &errorPipe, 0, FALSE, DUPLICATE_SAME_ACCESS)) { /* Have a non-inherited duplicate. Close the inherited one. */ CloseHandle(errorPipeOrig); } else { /* Could not duplicate handle. Report the error. */ ReportLastError(errorPipeOrig); return 1; } /* Create the subprocess. */ ZeroMemory(&si, sizeof(si)); ZeroMemory(&pi, sizeof(pi)); si.cb = sizeof(si); si.dwFlags = STARTF_USESTDHANDLES|STARTF_USESHOWWINDOW; si.wShowWindow = hideWindow?SW_HIDE:SW_SHOWDEFAULT; si.hStdInput = GetStdHandle(STD_INPUT_HANDLE); si.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE); si.hStdError = GetStdHandle(STD_ERROR_HANDLE); if(CreateProcess(0, cmdLine, 0, 0, TRUE, CREATE_SUSPENDED, 0, 0, &si, &pi)) { /* Process created successfully. Close the error reporting pipe to notify the parent of success. */ CloseHandle(errorPipe); } else { /* Error creating the process. Report the error to the parent process through the special error reporting pipe. */ ReportLastError(errorPipe); return 1; } /* Wait for resume or kill event from parent. */ waitHandles[0] = killEvent; waitHandles[1] = resumeEvent; waitResult = WaitForMultipleObjects(2, waitHandles, 0, INFINITE); /* Check what happened. */ if(waitResult == WAIT_OBJECT_0) { /* We were asked to kill the child. */ TerminateProcess(pi.hProcess, 255); WaitForSingleObject(pi.hProcess, INFINITE); CloseHandle(pi.hProcess); CloseHandle(pi.hThread); return 1; } else { /* We were asked to resume the child. */ ResumeThread(pi.hThread); CloseHandle(pi.hThread); } /* Wait for subprocess to exit or for kill event from parent. */ waitHandles[0] = killEvent; waitHandles[1] = pi.hProcess; waitResult = WaitForMultipleObjects(2, waitHandles, 0, INFINITE); /* Check what happened. */ if(waitResult == WAIT_OBJECT_0) { /* We were asked to kill the child. */ TerminateProcess(pi.hProcess, 255); WaitForSingleObject(pi.hProcess, INFINITE); CloseHandle(pi.hProcess); return 1; } else { /* The child exited. Get the return code. */ GetExitCodeProcess(pi.hProcess, &retVal); CloseHandle(pi.hProcess); return retVal; } } void ReportLastError(HANDLE errorPipe) { LPVOID lpMsgBuf; DWORD n; FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language (LPTSTR) &lpMsgBuf, 0, NULL ); WriteFile(errorPipe, lpMsgBuf, strlen(lpMsgBuf)+1, &n, 0); LocalFree( lpMsgBuf ); }