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Diffstat (limited to 'src/google/protobuf/compiler/subprocess.cc')
| -rw-r--r-- | src/google/protobuf/compiler/subprocess.cc | 458 |
1 files changed, 458 insertions, 0 deletions
diff --git a/src/google/protobuf/compiler/subprocess.cc b/src/google/protobuf/compiler/subprocess.cc new file mode 100644 index 0000000..de46a3e --- /dev/null +++ b/src/google/protobuf/compiler/subprocess.cc @@ -0,0 +1,458 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// http://code.google.com/p/protobuf/ +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// Author: kenton@google.com (Kenton Varda) + +#include <google/protobuf/compiler/subprocess.h> + +#ifndef _WIN32 +#include <errno.h> +#include <sys/wait.h> +#include <signal.h> +#endif + +#include <algorithm> +#include <google/protobuf/stubs/common.h> +#include <google/protobuf/message.h> +#include <google/protobuf/stubs/substitute.h> + +namespace google { +namespace protobuf { +namespace compiler { + +#ifdef _WIN32 + +static void CloseHandleOrDie(HANDLE handle) { + if (!CloseHandle(handle)) { + GOOGLE_LOG(FATAL) << "CloseHandle: " + << Subprocess::Win32ErrorMessage(GetLastError()); + } +} + +Subprocess::Subprocess() + : process_start_error_(ERROR_SUCCESS), + child_handle_(NULL), child_stdin_(NULL), child_stdout_(NULL) {} + +Subprocess::~Subprocess() { + if (child_stdin_ != NULL) { + CloseHandleOrDie(child_stdin_); + } + if (child_stdout_ != NULL) { + CloseHandleOrDie(child_stdout_); + } +} + +void Subprocess::Start(const string& program, SearchMode search_mode) { + // Create the pipes. + HANDLE stdin_pipe_read; + HANDLE stdin_pipe_write; + HANDLE stdout_pipe_read; + HANDLE stdout_pipe_write; + + if (!CreatePipe(&stdin_pipe_read, &stdin_pipe_write, NULL, 0)) { + GOOGLE_LOG(FATAL) << "CreatePipe: " << Win32ErrorMessage(GetLastError()); + } + if (!CreatePipe(&stdout_pipe_read, &stdout_pipe_write, NULL, 0)) { + GOOGLE_LOG(FATAL) << "CreatePipe: " << Win32ErrorMessage(GetLastError()); + } + + // Make child side of the pipes inheritable. + if (!SetHandleInformation(stdin_pipe_read, + HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT)) { + GOOGLE_LOG(FATAL) << "SetHandleInformation: " + << Win32ErrorMessage(GetLastError()); + } + if (!SetHandleInformation(stdout_pipe_write, + HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT)) { + GOOGLE_LOG(FATAL) << "SetHandleInformation: " + << Win32ErrorMessage(GetLastError()); + } + + // Setup STARTUPINFO to redirect handles. + STARTUPINFO startup_info; + ZeroMemory(&startup_info, sizeof(startup_info)); + startup_info.cb = sizeof(startup_info); + startup_info.dwFlags = STARTF_USESTDHANDLES; + startup_info.hStdInput = stdin_pipe_read; + startup_info.hStdOutput = stdout_pipe_write; + startup_info.hStdError = GetStdHandle(STD_ERROR_HANDLE); + + if (startup_info.hStdError == INVALID_HANDLE_VALUE) { + GOOGLE_LOG(FATAL) << "GetStdHandle: " + << Win32ErrorMessage(GetLastError()); + } + + // CreateProcess() mutates its second parameter. WTF? + char* name_copy = strdup(program.c_str()); + + // Create the process. + PROCESS_INFORMATION process_info; + + if (CreateProcess((search_mode == SEARCH_PATH) ? NULL : program.c_str(), + (search_mode == SEARCH_PATH) ? name_copy : NULL, + NULL, // process security attributes + NULL, // thread security attributes + TRUE, // inherit handles? + 0, // obscure creation flags + NULL, // environment (inherit from parent) + NULL, // current directory (inherit from parent) + &startup_info, + &process_info)) { + child_handle_ = process_info.hProcess; + CloseHandleOrDie(process_info.hThread); + child_stdin_ = stdin_pipe_write; + child_stdout_ = stdout_pipe_read; + } else { + process_start_error_ = GetLastError(); + CloseHandleOrDie(stdin_pipe_write); + CloseHandleOrDie(stdout_pipe_read); + } + + CloseHandleOrDie(stdin_pipe_read); + CloseHandleOrDie(stdout_pipe_write); + free(name_copy); +} + +bool Subprocess::Communicate(const Message& input, Message* output, + string* error) { + if (process_start_error_ != ERROR_SUCCESS) { + *error = Win32ErrorMessage(process_start_error_); + return false; + } + + GOOGLE_CHECK(child_handle_ != NULL) << "Must call Start() first."; + + string input_data = input.SerializeAsString(); + string output_data; + + int input_pos = 0; + + while (child_stdout_ != NULL) { + HANDLE handles[2]; + int handle_count = 0; + + if (child_stdin_ != NULL) { + handles[handle_count++] = child_stdin_; + } + if (child_stdout_ != NULL) { + handles[handle_count++] = child_stdout_; + } + + DWORD wait_result = + WaitForMultipleObjects(handle_count, handles, FALSE, INFINITE); + + HANDLE signaled_handle; + if (wait_result >= WAIT_OBJECT_0 && + wait_result < WAIT_OBJECT_0 + handle_count) { + signaled_handle = handles[wait_result - WAIT_OBJECT_0]; + } else if (wait_result == WAIT_FAILED) { + GOOGLE_LOG(FATAL) << "WaitForMultipleObjects: " + << Win32ErrorMessage(GetLastError()); + } else { + GOOGLE_LOG(FATAL) << "WaitForMultipleObjects: Unexpected return code: " + << wait_result; + } + + if (signaled_handle == child_stdin_) { + DWORD n; + if (!WriteFile(child_stdin_, + input_data.data() + input_pos, + input_data.size() - input_pos, + &n, NULL)) { + // Child closed pipe. Presumably it will report an error later. + // Pretend we're done for now. + input_pos = input_data.size(); + } else { + input_pos += n; + } + + if (input_pos == input_data.size()) { + // We're done writing. Close. + CloseHandleOrDie(child_stdin_); + child_stdin_ = NULL; + } + } else if (signaled_handle == child_stdout_) { + char buffer[4096]; + DWORD n; + + if (!ReadFile(child_stdout_, buffer, sizeof(buffer), &n, NULL)) { + // We're done reading. Close. + CloseHandleOrDie(child_stdout_); + child_stdout_ = NULL; + } else { + output_data.append(buffer, n); + } + } + } + + if (child_stdin_ != NULL) { + // Child did not finish reading input before it closed the output. + // Presumably it exited with an error. + CloseHandleOrDie(child_stdin_); + child_stdin_ = NULL; + } + + DWORD wait_result = WaitForSingleObject(child_handle_, INFINITE); + + if (wait_result == WAIT_FAILED) { + GOOGLE_LOG(FATAL) << "WaitForSingleObject: " + << Win32ErrorMessage(GetLastError()); + } else if (wait_result != WAIT_OBJECT_0) { + GOOGLE_LOG(FATAL) << "WaitForSingleObject: Unexpected return code: " + << wait_result; + } + + DWORD exit_code; + if (!GetExitCodeProcess(child_handle_, &exit_code)) { + GOOGLE_LOG(FATAL) << "GetExitCodeProcess: " + << Win32ErrorMessage(GetLastError()); + } + + CloseHandleOrDie(child_handle_); + child_handle_ = NULL; + + if (exit_code != 0) { + *error = strings::Substitute( + "Plugin failed with status code $0.", exit_code); + return false; + } + + if (!output->ParseFromString(output_data)) { + *error = "Plugin output is unparseable: " + CEscape(output_data); + return false; + } + + return true; +} + +string Subprocess::Win32ErrorMessage(DWORD error_code) { + char* message; + + // WTF? + FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | + FORMAT_MESSAGE_FROM_SYSTEM | + FORMAT_MESSAGE_IGNORE_INSERTS, + NULL, error_code, 0, + (LPTSTR)&message, // NOT A BUG! + 0, NULL); + + string result = message; + LocalFree(message); + return result; +} + +// =================================================================== + +#else // _WIN32 + +Subprocess::Subprocess() + : child_pid_(-1), child_stdin_(-1), child_stdout_(-1) {} + +Subprocess::~Subprocess() { + if (child_stdin_ != -1) { + close(child_stdin_); + } + if (child_stdout_ != -1) { + close(child_stdout_); + } +} + +void Subprocess::Start(const string& program, SearchMode search_mode) { + // Note that we assume that there are no other threads, thus we don't have to + // do crazy stuff like using socket pairs or avoiding libc locks. + + // [0] is read end, [1] is write end. + int stdin_pipe[2]; + int stdout_pipe[2]; + + pipe(stdin_pipe); + pipe(stdout_pipe); + + char* argv[2] = { strdup(program.c_str()), NULL }; + + child_pid_ = fork(); + if (child_pid_ == -1) { + GOOGLE_LOG(FATAL) << "fork: " << strerror(errno); + } else if (child_pid_ == 0) { + // We are the child. + dup2(stdin_pipe[0], STDIN_FILENO); + dup2(stdout_pipe[1], STDOUT_FILENO); + + close(stdin_pipe[0]); + close(stdin_pipe[1]); + close(stdout_pipe[0]); + close(stdout_pipe[1]); + + switch (search_mode) { + case SEARCH_PATH: + execvp(argv[0], argv); + break; + case EXACT_NAME: + execv(argv[0], argv); + break; + } + + // Write directly to STDERR_FILENO to avoid stdio code paths that may do + // stuff that is unsafe here. + write(STDERR_FILENO, argv[0], strlen(argv[0])); + const char* message = ": program not found or is not executable\n"; + write(STDERR_FILENO, message, strlen(message)); + + // Must use _exit() rather than exit() to avoid flushing output buffers + // that will also be flushed by the parent. + _exit(1); + } else { + free(argv[0]); + + close(stdin_pipe[0]); + close(stdout_pipe[1]); + + child_stdin_ = stdin_pipe[1]; + child_stdout_ = stdout_pipe[0]; + } +} + +bool Subprocess::Communicate(const Message& input, Message* output, + string* error) { + + GOOGLE_CHECK_NE(child_stdin_, -1) << "Must call Start() first."; + + // The "sighandler_t" typedef is GNU-specific, so define our own. + typedef void SignalHandler(int); + + // Make sure SIGPIPE is disabled so that if the child dies it doesn't kill us. + SignalHandler* old_pipe_handler = signal(SIGPIPE, SIG_IGN); + + string input_data = input.SerializeAsString(); + string output_data; + + int input_pos = 0; + int max_fd = max(child_stdin_, child_stdout_); + + while (child_stdout_ != -1) { + fd_set read_fds; + fd_set write_fds; + FD_ZERO(&read_fds); + FD_ZERO(&write_fds); + if (child_stdout_ != -1) { + FD_SET(child_stdout_, &read_fds); + } + if (child_stdin_ != -1) { + FD_SET(child_stdin_, &write_fds); + } + + if (select(max_fd + 1, &read_fds, &write_fds, NULL, NULL) < 0) { + if (errno == EINTR) { + // Interrupted by signal. Try again. + continue; + } else { + GOOGLE_LOG(FATAL) << "select: " << strerror(errno); + } + } + + if (child_stdin_ != -1 && FD_ISSET(child_stdin_, &write_fds)) { + int n = write(child_stdin_, input_data.data() + input_pos, + input_data.size() - input_pos); + if (n < 0) { + // Child closed pipe. Presumably it will report an error later. + // Pretend we're done for now. + input_pos = input_data.size(); + } else { + input_pos += n; + } + + if (input_pos == input_data.size()) { + // We're done writing. Close. + close(child_stdin_); + child_stdin_ = -1; + } + } + + if (child_stdout_ != -1 && FD_ISSET(child_stdout_, &read_fds)) { + char buffer[4096]; + int n = read(child_stdout_, buffer, sizeof(buffer)); + + if (n > 0) { + output_data.append(buffer, n); + } else { + // We're done reading. Close. + close(child_stdout_); + child_stdout_ = -1; + } + } + } + + if (child_stdin_ != -1) { + // Child did not finish reading input before it closed the output. + // Presumably it exited with an error. + close(child_stdin_); + child_stdin_ = -1; + } + + int status; + while (waitpid(child_pid_, &status, 0) == -1) { + if (errno != EINTR) { + GOOGLE_LOG(FATAL) << "waitpid: " << strerror(errno); + } + } + + // Restore SIGPIPE handling. + signal(SIGPIPE, old_pipe_handler); + + if (WIFEXITED(status)) { + if (WEXITSTATUS(status) != 0) { + int error_code = WEXITSTATUS(status); + *error = strings::Substitute( + "Plugin failed with status code $0.", error_code); + return false; + } + } else if (WIFSIGNALED(status)) { + int signal = WTERMSIG(status); + *error = strings::Substitute( + "Plugin killed by signal $0.", signal); + return false; + } else { + *error = "Neither WEXITSTATUS nor WTERMSIG is true?"; + return false; + } + + if (!output->ParseFromString(output_data)) { + *error = "Plugin output is unparseable."; + return false; + } + + return true; +} + +#endif // !_WIN32 + +} // namespace compiler +} // namespace protobuf +} // namespace google |