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+/* 2019, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+/*
+ Replacement of the buggy implementations of popen in Windows CRT
+*/
+#include <windows.h>
+#include <fcntl.h>
+#include <io.h>
+#include <mutex>
+#include <stdlib.h>
+#include <unordered_map>
+
+enum
+{
+ REDIRECT_STDIN= 'w',
+ REDIRECT_STDOUT= 'r'
+};
+
+/** Map from FILE* returned by popen() to corresponding process handle.*/
+static std::unordered_map<FILE *, HANDLE> popen_map;
+/* Mutex to protect the map.*/
+static std::mutex popen_mtx;
+
+/**
+Creates a FILE* from HANDLE.
+*/
+static FILE *make_fp(HANDLE *handle, const char *mode)
+{
+ int flags = 0;
+
+ if (mode[0] == REDIRECT_STDOUT)
+ flags |= O_RDONLY;
+ switch (mode[1])
+ {
+ case 't':
+ flags |= _O_TEXT;
+ break;
+ case 'b':
+ flags |= _O_BINARY;
+ break;
+ }
+
+ int fd= _open_osfhandle((intptr_t) *handle, flags);
+ if (fd < 0)
+ return NULL;
+ FILE *fp= fdopen(fd, mode);
+ if (!fp)
+ {
+ /* Closing file descriptor also closes underlying handle.*/
+ close(fd);
+ *handle= 0;
+ }
+ return fp;
+}
+
+/** A home-backed version of popen(). */
+extern "C" FILE *my_win_popen(const char *cmd, const char *mode)
+{
+ FILE *fp(0);
+ char type= mode[0];
+ HANDLE parent_pipe_end(0);
+ HANDLE child_pipe_end(0);
+ PROCESS_INFORMATION pi{};
+ STARTUPINFO si{};
+ std::string command_line;
+
+ /* Create a pipe between this and child process.*/
+ SECURITY_ATTRIBUTES sa_attr{};
+ sa_attr.nLength= sizeof(SECURITY_ATTRIBUTES);
+ sa_attr.bInheritHandle= TRUE;
+ switch (type)
+ {
+ case REDIRECT_STDIN:
+ if (!CreatePipe(&child_pipe_end, &parent_pipe_end, &sa_attr, 0))
+ goto error;
+ break;
+ case REDIRECT_STDOUT:
+ if (!CreatePipe(&parent_pipe_end, &child_pipe_end, &sa_attr, 0))
+ goto error;
+ break;
+ default:
+ /* Unknown mode, expected "r", "rt", "w", "wt" */
+ abort();
+ }
+ if (!SetHandleInformation(parent_pipe_end, HANDLE_FLAG_INHERIT, 0))
+ goto error;
+
+ /* Start child process with redirected output.*/
+
+ si.cb= sizeof(STARTUPINFO);
+ si.hStdError= GetStdHandle(STD_ERROR_HANDLE);
+ si.hStdOutput= (type == REDIRECT_STDOUT) ? child_pipe_end
+ : GetStdHandle(STD_OUTPUT_HANDLE);
+ si.hStdInput= (type == REDIRECT_STDIN) ? child_pipe_end
+ : GetStdHandle(STD_INPUT_HANDLE);
+
+ si.dwFlags|= STARTF_USESTDHANDLES;
+ command_line.append("cmd.exe /c ").append(cmd);
+
+ if (!CreateProcess(0, (LPSTR) command_line.c_str(), 0, 0, TRUE, 0, 0, 0, &si,
+ &pi))
+ goto error;
+
+ CloseHandle(pi.hThread);
+ CloseHandle(child_pipe_end);
+ child_pipe_end= 0;
+
+ fp= make_fp(&parent_pipe_end, mode);
+ if (fp)
+ {
+ std::unique_lock<std::mutex> lk(popen_mtx);
+ popen_map[fp]= pi.hProcess;
+ return fp;
+ }
+
+error:
+ for (auto handle : { parent_pipe_end, child_pipe_end })
+ {
+ if (handle)
+ CloseHandle(handle);
+ }
+
+ if (pi.hProcess)
+ {
+ TerminateProcess(pi.hProcess, 1);
+ CloseHandle(pi.hProcess);
+ }
+ return NULL;
+}
+
+/** A home-backed version of pclose(). */
+
+extern "C" int my_win_pclose(FILE *fp)
+{
+ /* Find process entry for given file pointer.*/
+ std::unique_lock<std::mutex> lk(popen_mtx);
+ HANDLE proc= popen_map[fp];
+ if (!proc)
+ {
+ errno= EINVAL;
+ return -1;
+ }
+ popen_map.erase(fp);
+ lk.unlock();
+
+ fclose(fp);
+
+ /* Wait for process to complete, return its exit code.*/
+ DWORD ret;
+ if (WaitForSingleObject(proc, INFINITE) || !GetExitCodeProcess(proc, &ret))
+ {
+ ret= -1;
+ errno= EINVAL;
+ }
+ CloseHandle(proc);
+ return ret;
+}