src/Utils/CreateProcessHelper.h

   1 // TortoiseGit - a Windows shell extension for easy version control
   2
   3 // Copyright (C) 2016 - TortoiseGit
   4 // Copyright (C) 2009-2010 - TortoiseSVN
   5
   6 // This program is free software; you can redistribute it and/or
   7 // modify it under the terms of the GNU General Public License
   8 // as published by the Free Software Foundation; either version 2
   9 // of the License, or (at your option) any later version.
  10
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software Foundation,
  18 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 //
  20 #pragma once
  21 #include "scope_exit_noexcept.h"
  22
  23 /**
  24  * A helper class for invoking CreateProcess(). The lpProcessInformation
  25  * can point to an uninitialized struct - it's memset to all zeroes inside.
  26  */
  27
  28 class CCreateProcessHelper
  29 {
  30 public:
  31         static bool CreateProcess(LPCWSTR lpApplicationName, LPWSTR lpCommandLine, LPCWSTR lpCurrentDirectory, LPPROCESS_INFORMATION lpProcessInformation);
  32         static bool CreateProcess(LPCWSTR lpApplicationName, LPWSTR lpCommandLine, LPPROCESS_INFORMATION lpProcessInformation);
  33
  34         static bool CreateProcessDetached(LPCWSTR lpApplicationName, LPWSTR lpCommandLine, LPCWSTR lpCurrentDirectory);
  35         static bool CreateProcessDetached(LPCWSTR lpApplicationName, LPWSTR lpCommandLine);
  36         static bool CreateProcessDetached(LPCWSTR lpApplicationName, LPCWSTR lpCommandLine);
  37 };
  38
  39 inline bool CCreateProcessHelper::CreateProcess(LPCWSTR applicationName,
  40         LPWSTR commandLine, LPCWSTR currentDirectory,
  41         LPPROCESS_INFORMATION processInfo)
  42 {
  43         STARTUPINFO startupInfo = { 0 };
  44         startupInfo.cb = sizeof(STARTUPINFO);
  45
  46         memset(processInfo, 0, sizeof(PROCESS_INFORMATION));
  47         const BOOL result = ::CreateProcess(applicationName, commandLine, nullptr, nullptr, FALSE, CREATE_UNICODE_ENVIRONMENT, nullptr, currentDirectory, &startupInfo, processInfo);
  48         return result != 0;
  49 }
  50
  51 inline bool CCreateProcessHelper::CreateProcess(LPCWSTR applicationName,
  52         LPWSTR commandLine, LPPROCESS_INFORMATION processInformation)
  53 {
  54         return CreateProcess( applicationName, commandLine, nullptr, processInformation );
  55 }
  56
  57 inline bool CCreateProcessHelper::CreateProcessDetached(LPCWSTR lpApplicationName,
  58         LPWSTR lpCommandLine, LPCWSTR lpCurrentDirectory)
  59 {
  60         PROCESS_INFORMATION process;
  61         if (!CreateProcess(lpApplicationName, lpCommandLine, lpCurrentDirectory, &process))
  62                 return false;
  63
  64         CloseHandle(process.hThread);
  65         CloseHandle(process.hProcess);
  66         return true;
  67 }
  68
  69 inline bool CCreateProcessHelper::CreateProcessDetached(LPCWSTR lpApplicationName,
  70         LPWSTR lpCommandLine)
  71 {
  72         return CreateProcessDetached(lpApplicationName, lpCommandLine, nullptr);
  73 }
  74
  75 inline bool CCreateProcessHelper::CreateProcessDetached(LPCWSTR lpApplicationName, LPCWSTR lpCommandLine)
  76 {
  77         // CreateProcess may modify buffer specified by lpCommandLine:
  78         // https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425
  79         // [[
  80         // The Unicode version of this function, CreateProcessW, can modify
  81         // the contents of this string. Therefore, this parameter cannot be a
  82         // pointer to read - only memory(such as a const variable or a literal
  83         // string).If this parameter is a constant string, the function may
  84         // cause an access violation.
  85         // ]]
  86         LPWSTR commandLineBuf = nullptr;
  87         if (lpCommandLine)
  88                 commandLineBuf = _wcsdup(lpCommandLine);
  89         SCOPE_EXIT { free(reinterpret_cast<void*>(commandLineBuf)); };
  90
  91         return CreateProcessDetached(lpApplicationName, commandLineBuf, nullptr);
  92 }