blob: 8162df2df5dfa4e12bfb6eba50ba8349619591c1 [file] [log] [blame]
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
// Author: kenton@google.com (Kenton Varda)
#include "google/protobuf/compiler/subprocess.h"
#include <algorithm>
#include <cstring>
#include <iostream>
#ifndef _WIN32
#include <errno.h>
#include <signal.h>
#include <sys/select.h>
#include <sys/wait.h>
#endif
#include "absl/log/absl_check.h"
#include "absl/log/absl_log.h"
#include "absl/strings/escaping.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/substitute.h"
#include "google/protobuf/io/io_win32.h"
#include "google/protobuf/message.h"
namespace google {
namespace protobuf {
namespace compiler {
#ifdef _WIN32
static void CloseHandleOrDie(HANDLE handle) {
if (!CloseHandle(handle)) {
ABSL_LOG(FATAL) << "CloseHandle: "
<< Subprocess::Win32ErrorMessage(GetLastError());
}
}
Subprocess::Subprocess()
: process_start_error_(ERROR_SUCCESS),
child_handle_(nullptr),
child_stdin_(nullptr),
child_stdout_(nullptr) {}
Subprocess::~Subprocess() {
if (child_stdin_ != nullptr) {
CloseHandleOrDie(child_stdin_);
}
if (child_stdout_ != nullptr) {
CloseHandleOrDie(child_stdout_);
}
}
void Subprocess::Start(const std::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, nullptr, 0)) {
ABSL_LOG(FATAL) << "CreatePipe: " << Win32ErrorMessage(GetLastError());
}
if (!CreatePipe(&stdout_pipe_read, &stdout_pipe_write, nullptr, 0)) {
ABSL_LOG(FATAL) << "CreatePipe: " << Win32ErrorMessage(GetLastError());
}
// Make child side of the pipes inheritable.
if (!SetHandleInformation(stdin_pipe_read, HANDLE_FLAG_INHERIT,
HANDLE_FLAG_INHERIT)) {
ABSL_LOG(FATAL) << "SetHandleInformation: "
<< Win32ErrorMessage(GetLastError());
}
if (!SetHandleInformation(stdout_pipe_write, HANDLE_FLAG_INHERIT,
HANDLE_FLAG_INHERIT)) {
ABSL_LOG(FATAL) << "SetHandleInformation: "
<< Win32ErrorMessage(GetLastError());
}
// Setup STARTUPINFO to redirect handles.
STARTUPINFOW 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) {
ABSL_LOG(FATAL) << "GetStdHandle: " << Win32ErrorMessage(GetLastError());
}
// get wide string version of program as the path may contain non-ascii characters
std::wstring wprogram;
if (!io::win32::strings::utf8_to_wcs(program.c_str(), &wprogram)) {
ABSL_LOG(FATAL) << "utf8_to_wcs: " << Win32ErrorMessage(GetLastError());
}
// Invoking cmd.exe allows for '.bat' files from the path as well as '.exe'.
std::string command_line = absl::StrCat("cmd.exe /c \"", program, "\"");
// get wide string version of command line as the path may contain non-ascii characters
std::wstring wcommand_line;
if (!io::win32::strings::utf8_to_wcs(command_line.c_str(), &wcommand_line)) {
ABSL_LOG(FATAL) << "utf8_to_wcs: " << Win32ErrorMessage(GetLastError());
}
// Using a malloc'ed string because CreateProcess() can mutate its second
// parameter.
wchar_t *wcommand_line_copy = _wcsdup(wcommand_line.c_str());
// Create the process.
PROCESS_INFORMATION process_info;
if (CreateProcessW(
(search_mode == SEARCH_PATH) ? nullptr : wprogram.c_str(),
(search_mode == SEARCH_PATH) ? wcommand_line_copy : nullptr,
nullptr, // process security attributes
nullptr, // thread security attributes
TRUE, // inherit handles?
0, // obscure creation flags
nullptr, // environment (inherit from parent)
nullptr, // 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(wcommand_line_copy);
}
bool Subprocess::Communicate(const Message& input, Message* output,
std::string* error) {
if (process_start_error_ != ERROR_SUCCESS) {
*error = Win32ErrorMessage(process_start_error_);
return false;
}
ABSL_CHECK(child_handle_ != nullptr) << "Must call Start() first.";
std::string input_data;
if (!input.SerializeToString(&input_data)) {
*error = "Failed to serialize request.";
return false;
}
std::string output_data;
int input_pos = 0;
while (child_stdout_ != nullptr) {
HANDLE handles[2];
int handle_count = 0;
if (child_stdin_ != nullptr) {
handles[handle_count++] = child_stdin_;
}
if (child_stdout_ != nullptr) {
handles[handle_count++] = child_stdout_;
}
DWORD wait_result =
WaitForMultipleObjects(handle_count, handles, FALSE, INFINITE);
HANDLE signaled_handle = nullptr;
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) {
ABSL_LOG(FATAL) << "WaitForMultipleObjects: "
<< Win32ErrorMessage(GetLastError());
} else {
ABSL_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, nullptr)) {
// 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_ = nullptr;
}
} else if (signaled_handle == child_stdout_) {
char buffer[4096];
DWORD n;
if (!ReadFile(child_stdout_, buffer, sizeof(buffer), &n, nullptr)) {
// We're done reading. Close.
CloseHandleOrDie(child_stdout_);
child_stdout_ = nullptr;
} else {
output_data.append(buffer, n);
}
}
}
if (child_stdin_ != nullptr) {
// Child did not finish reading input before it closed the output.
// Presumably it exited with an error.
CloseHandleOrDie(child_stdin_);
child_stdin_ = nullptr;
}
DWORD wait_result = WaitForSingleObject(child_handle_, INFINITE);
if (wait_result == WAIT_FAILED) {
ABSL_LOG(FATAL) << "WaitForSingleObject: "
<< Win32ErrorMessage(GetLastError());
} else if (wait_result != WAIT_OBJECT_0) {
ABSL_LOG(FATAL) << "WaitForSingleObject: Unexpected return code: "
<< wait_result;
}
DWORD exit_code;
if (!GetExitCodeProcess(child_handle_, &exit_code)) {
ABSL_LOG(FATAL) << "GetExitCodeProcess: "
<< Win32ErrorMessage(GetLastError());
}
CloseHandleOrDie(child_handle_);
child_handle_ = nullptr;
if (exit_code != 0) {
*error = absl::Substitute("Plugin failed with status code $0.", exit_code);
return false;
}
if (!output->ParseFromString(output_data)) {
*error = absl::StrCat("Plugin output is unparseable: ",
absl::CEscape(output_data));
return false;
}
return true;
}
std::string Subprocess::Win32ErrorMessage(DWORD error_code) {
char* message;
// WTF?
FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
nullptr, error_code,
MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
(LPSTR)&message, // NOT A BUG!
0, nullptr);
std::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_);
}
}
namespace {
char* portable_strdup(const char* s) {
char* ns = (char*)malloc(strlen(s) + 1);
if (ns != nullptr) {
strcpy(ns, s);
}
return ns;
}
} // namespace
void Subprocess::Start(const std::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];
ABSL_CHECK(pipe(stdin_pipe) != -1);
ABSL_CHECK(pipe(stdout_pipe) != -1);
char* argv[2] = {portable_strdup(program.c_str()), nullptr};
child_pid_ = fork();
if (child_pid_ == -1) {
ABSL_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.
int ignored;
ignored = write(STDERR_FILENO, argv[0], strlen(argv[0]));
const char* message =
": program not found or is not executable\n"
"Please specify a program using absolute path or make sure "
"the program is available in your PATH system variable\n";
ignored = write(STDERR_FILENO, message, strlen(message));
(void)ignored;
// 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,
std::string* error) {
ABSL_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);
std::string input_data;
if (!input.SerializeToString(&input_data)) {
*error = "Failed to serialize request.";
return false;
}
std::string output_data;
int input_pos = 0;
int max_fd = std::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, nullptr, nullptr) < 0) {
if (errno == EINTR) {
// Interrupted by signal. Try again.
continue;
} else {
ABSL_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) {
ABSL_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 =
absl::Substitute("Plugin failed with status code $0.", error_code);
return false;
}
} else if (WIFSIGNALED(status)) {
int signal = WTERMSIG(status);
*error = absl::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 = absl::StrCat("Plugin output is unparseable: ",
absl::CEscape(output_data));
return false;
}
return true;
}
#endif // !_WIN32
} // namespace compiler
} // namespace protobuf
} // namespace google