src/tint/utils/command/command_windows.cc - dawn - Git at Google

 // Copyright 2021 The Tint Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #include "src/tint/utils/command/command.h"

 #define WIN32_LEAN_AND_MEAN 1
 #include <Windows.h>
 #include <dbghelp.h>
 #include <string>

 #include "src/tint/utils/macros/defer.h"
 #include "src/tint/utils/text/string_stream.h"

 namespace tint::utils {

 namespace {

 /// Handle is a simple wrapper around the Win32 HANDLE
 class Handle {
   public:
     /// Constructor
     Handle() : handle_(nullptr) {}

     /// Constructor
     explicit Handle(HANDLE handle) : handle_(handle) {}

     /// Destructor
     ~Handle() { Close(); }

     /// Move assignment operator
     Handle& operator=(Handle&& rhs) {
         Close();
         handle_ = rhs.handle_;
         rhs.handle_ = nullptr;
         return *this;
     }

     /// Closes the handle (if it wasn't already closed)
     void Close() {
         if (handle_) {
             CloseHandle(handle_);
         }
         handle_ = nullptr;
     }

     /// @returns the handle
     operator HANDLE() { return handle_; }

     /// @returns true if the handle is not invalid
     operator bool() { return handle_ != nullptr; }

   private:
     Handle(const Handle&) = delete;
     Handle& operator=(const Handle&) = delete;

     HANDLE handle_ = nullptr;
 };

 /// Pipe is a simple wrapper around a Win32 CreatePipe() function
 class Pipe {
   public:
     /// Constructs the pipe
     explicit Pipe(bool for_read) {
         SECURITY_ATTRIBUTES sa;
         sa.nLength = sizeof(SECURITY_ATTRIBUTES);
         sa.bInheritHandle = TRUE;
         sa.lpSecurityDescriptor = nullptr;

         HANDLE hread;
         HANDLE hwrite;
         if (CreatePipe(&hread, &hwrite, &sa, 0)) {
             read = Handle(hread);
             write = Handle(hwrite);
             // Ensure the read handle to the pipe is not inherited
             if (!SetHandleInformation(for_read ? read : write, HANDLE_FLAG_INHERIT, 0)) {
                 read.Close();
                 write.Close();
             }
         }
     }

     /// @returns true if the pipe has an open read or write file
     operator bool() { return read || write; }

     /// The reader end of the pipe
     Handle read;

     /// The writer end of the pipe
     Handle write;
 };

 /// Queries whether the file at the given path is an executable or DLL.
 bool ExecutableExists(const std::string& path) {
     auto file = Handle(CreateFileA(path.c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr,
                                    OPEN_EXISTING, FILE_ATTRIBUTE_READONLY, nullptr));
     if (!file) {
         return false;
     }

     auto map = Handle(CreateFileMappingA(file, nullptr, PAGE_READONLY, 0, 0, nullptr));
     if (map == INVALID_HANDLE_VALUE) {
         return false;
     }

     void* addr_header = MapViewOfFileEx(map, FILE_MAP_READ, 0, 0, 0, nullptr);

     // Dynamically obtain the address of, and call ImageNtHeader. This is done to avoid tint.exe
     // needing to statically link Dbghelp.lib.
     static auto* dbg_help = LoadLibraryA("Dbghelp.dll");  // Leaks, but who cares?
     if (dbg_help) {
         if (FARPROC proc = GetProcAddress(dbg_help, "ImageNtHeader")) {
             using ImageNtHeaderPtr = decltype(&ImageNtHeader);
             auto* image_nt_header = reinterpret_cast<ImageNtHeaderPtr>(proc)(addr_header);
             return image_nt_header != nullptr;
         }
     }

     // Couldn't call ImageNtHeader, assume it is executable
     return false;
 }

 std::string FindExecutable(const std::string& name) {
     if (ExecutableExists(name)) {
         return name;
     }
     if (ExecutableExists(name + ".exe")) {
         return name + ".exe";
     }
     if (name.find("/") == std::string::npos && name.find("\\") == std::string::npos) {
         char* path_env = nullptr;
         size_t path_env_len = 0;
         if (_dupenv_s(&path_env, &path_env_len, "PATH")) {
             return "";
         }
         std::istringstream path{path_env};
         free(path_env);
         std::string dir;
         while (getline(path, dir, ';')) {
             auto test = dir + "\\" + name;
             if (ExecutableExists(test)) {
                 return test;
             }
             if (ExecutableExists(test + ".exe")) {
                 return test + ".exe";
             }
         }
     }
     return "";
 }

 }  // namespace

 Command::Command(const std::string& path) : path_(path) {}

 Command Command::LookPath(const std::string& executable) {
     return Command(FindExecutable(executable));
 }

 bool Command::Found() const {
     return ExecutableExists(path_);
 }

 Command::Output Command::Exec(std::initializer_list<std::string> arguments) const {
     Pipe stdout_pipe(true);
     Pipe stderr_pipe(true);
     Pipe stdin_pipe(false);
     if (!stdin_pipe || !stdout_pipe || !stderr_pipe) {
         Output output;
         output.err = "Command::Exec(): Failed to create pipes";
         return output;
     }

     if (!input_.empty()) {
         if (!WriteFile(stdin_pipe.write, input_.data(), input_.size(), nullptr, nullptr)) {
             Output output;
             output.err = "Command::Exec() Failed to write stdin";
             return output;
         }
     }
     stdin_pipe.write.Close();

     STARTUPINFOA si{};
     si.cb = sizeof(si);
     si.dwFlags |= STARTF_USESTDHANDLES;
     si.hStdOutput = stdout_pipe.write;
     si.hStdError = stderr_pipe.write;
     si.hStdInput = stdin_pipe.read;

     utils::StringStream args;
     args << path_;
     for (auto& arg : arguments) {
         if (!arg.empty()) {
             args << " " << arg;
         }
     }

     PROCESS_INFORMATION pi{};
     if (!CreateProcessA(nullptr,                                // No module name (use command line)
                         const_cast<LPSTR>(args.str().c_str()),  // Command line
                         nullptr,                                // Process handle not inheritable
                         nullptr,                                // Thread handle not inheritable
                         TRUE,                                   // Handles are inherited
                         0,                                      // No creation flags
                         nullptr,                                // Use parent's environment block
                         nullptr,                                // Use parent's starting directory
                         &si,                                    // Pointer to STARTUPINFO structure
                         &pi)) {  // Pointer to PROCESS_INFORMATION structure
         Output out;
         out.err = "Command::Exec() CreateProcess('" + args.str() + "') failed";
         out.error_code = 1;
         return out;
     }

     stdin_pipe.read.Close();
     stdout_pipe.write.Close();
     stderr_pipe.write.Close();

     struct StreamReadThreadArgs {
         HANDLE stream;
         std::string output;
     };

     auto stream_read_thread = [](LPVOID user) -> DWORD {
         auto* thread_args = reinterpret_cast<StreamReadThreadArgs*>(user);
         DWORD n = 0;
         char buf[256];
         while (ReadFile(thread_args->stream, buf, sizeof(buf), &n, NULL)) {
             auto s = std::string(buf, buf + n);
             thread_args->output += std::string(buf, buf + n);
         }
         return 0;
     };

     StreamReadThreadArgs stdout_read_args{stdout_pipe.read, {}};
     auto* stdout_read_thread =
         ::CreateThread(nullptr, 0, stream_read_thread, &stdout_read_args, 0, nullptr);

     StreamReadThreadArgs stderr_read_args{stderr_pipe.read, {}};
     auto* stderr_read_thread =
         ::CreateThread(nullptr, 0, stream_read_thread, &stderr_read_args, 0, nullptr);

     HANDLE handles[] = {pi.hProcess, stdout_read_thread, stderr_read_thread};
     constexpr DWORD num_handles = sizeof(handles) / sizeof(handles[0]);

     Output output;

     auto res = WaitForMultipleObjects(num_handles, handles, /* wait_all = */ TRUE, INFINITE);
     if (res >= WAIT_OBJECT_0 && res < WAIT_OBJECT_0 + num_handles) {
         output.out = stdout_read_args.output;
         output.err = stderr_read_args.output;
         DWORD exit_code = 0;
         GetExitCodeProcess(pi.hProcess, &exit_code);
         output.error_code = static_cast<int>(exit_code);
     } else {
         output.err = "Command::Exec() WaitForMultipleObjects() returned " + std::to_string(res);
     }

     return output;
 }

 }  // namespace tint::utils
	// Copyright 2021 The Tint Authors.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#include "src/tint/utils/command/command.h"

	#define WIN32_LEAN_AND_MEAN 1
	#include <Windows.h>
	#include <dbghelp.h>
	#include <string>

	#include "src/tint/utils/macros/defer.h"
	#include "src/tint/utils/text/string_stream.h"

	namespace tint::utils {

	namespace {

	/// Handle is a simple wrapper around the Win32 HANDLE
	class Handle {
	public:
	/// Constructor
	Handle() : handle_(nullptr) {}

	/// Constructor
	explicit Handle(HANDLE handle) : handle_(handle) {}

	/// Destructor
	~Handle() { Close(); }

	/// Move assignment operator
	Handle& operator=(Handle&& rhs) {
	Close();
	handle_ = rhs.handle_;
	rhs.handle_ = nullptr;
	return *this;
	}

	/// Closes the handle (if it wasn't already closed)
	void Close() {
	if (handle_) {
	CloseHandle(handle_);
	}
	handle_ = nullptr;
	}

	/// @returns the handle
	operator HANDLE() { return handle_; }

	/// @returns true if the handle is not invalid
	operator bool() { return handle_ != nullptr; }

	private:
	Handle(const Handle&) = delete;
	Handle& operator=(const Handle&) = delete;

	HANDLE handle_ = nullptr;
	};

	/// Pipe is a simple wrapper around a Win32 CreatePipe() function
	class Pipe {
	public:
	/// Constructs the pipe
	explicit Pipe(bool for_read) {
	SECURITY_ATTRIBUTES sa;
	sa.nLength = sizeof(SECURITY_ATTRIBUTES);
	sa.bInheritHandle = TRUE;
	sa.lpSecurityDescriptor = nullptr;

	HANDLE hread;
	HANDLE hwrite;
	if (CreatePipe(&hread, &hwrite, &sa, 0)) {
	read = Handle(hread);
	write = Handle(hwrite);
	// Ensure the read handle to the pipe is not inherited
	if (!SetHandleInformation(for_read ? read : write, HANDLE_FLAG_INHERIT, 0)) {
	read.Close();
	write.Close();
	}
	}
	}

	/// @returns true if the pipe has an open read or write file
	operator bool() { return read \|\| write; }

	/// The reader end of the pipe
	Handle read;

	/// The writer end of the pipe
	Handle write;
	};

	/// Queries whether the file at the given path is an executable or DLL.
	bool ExecutableExists(const std::string& path) {
	auto file = Handle(CreateFileA(path.c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr,
	OPEN_EXISTING, FILE_ATTRIBUTE_READONLY, nullptr));
	if (!file) {
	return false;
	}

	auto map = Handle(CreateFileMappingA(file, nullptr, PAGE_READONLY, 0, 0, nullptr));
	if (map == INVALID_HANDLE_VALUE) {
	return false;
	}

	void* addr_header = MapViewOfFileEx(map, FILE_MAP_READ, 0, 0, 0, nullptr);

	// Dynamically obtain the address of, and call ImageNtHeader. This is done to avoid tint.exe
	// needing to statically link Dbghelp.lib.
	static auto* dbg_help = LoadLibraryA("Dbghelp.dll"); // Leaks, but who cares?
	if (dbg_help) {
	if (FARPROC proc = GetProcAddress(dbg_help, "ImageNtHeader")) {
	using ImageNtHeaderPtr = decltype(&ImageNtHeader);
	auto* image_nt_header = reinterpret_cast<ImageNtHeaderPtr>(proc)(addr_header);
	return image_nt_header != nullptr;
	}
	}

	// Couldn't call ImageNtHeader, assume it is executable
	return false;
	}

	std::string FindExecutable(const std::string& name) {
	if (ExecutableExists(name)) {
	return name;
	}
	if (ExecutableExists(name + ".exe")) {
	return name + ".exe";
	}
	if (name.find("/") == std::string::npos && name.find("\\") == std::string::npos) {
	char* path_env = nullptr;
	size_t path_env_len = 0;
	if (_dupenv_s(&path_env, &path_env_len, "PATH")) {
	return "";
	}
	std::istringstream path{path_env};
	free(path_env);
	std::string dir;
	while (getline(path, dir, ';')) {
	auto test = dir + "\\" + name;
	if (ExecutableExists(test)) {
	return test;
	}
	if (ExecutableExists(test + ".exe")) {
	return test + ".exe";
	}
	}
	}
	return "";
	}

	} // namespace

	Command::Command(const std::string& path) : path_(path) {}

	Command Command::LookPath(const std::string& executable) {
	return Command(FindExecutable(executable));
	}

	bool Command::Found() const {
	return ExecutableExists(path_);
	}

	Command::Output Command::Exec(std::initializer_list<std::string> arguments) const {
	Pipe stdout_pipe(true);
	Pipe stderr_pipe(true);
	Pipe stdin_pipe(false);
	if (!stdin_pipe \|\| !stdout_pipe \|\| !stderr_pipe) {
	Output output;
	output.err = "Command::Exec(): Failed to create pipes";
	return output;
	}

	if (!input_.empty()) {
	if (!WriteFile(stdin_pipe.write, input_.data(), input_.size(), nullptr, nullptr)) {
	Output output;
	output.err = "Command::Exec() Failed to write stdin";
	return output;
	}
	}
	stdin_pipe.write.Close();

	STARTUPINFOA si{};
	si.cb = sizeof(si);
	si.dwFlags \|= STARTF_USESTDHANDLES;
	si.hStdOutput = stdout_pipe.write;
	si.hStdError = stderr_pipe.write;
	si.hStdInput = stdin_pipe.read;

	utils::StringStream args;
	args << path_;
	for (auto& arg : arguments) {
	if (!arg.empty()) {
	args << " " << arg;
	}
	}

	PROCESS_INFORMATION pi{};
	if (!CreateProcessA(nullptr, // No module name (use command line)
	const_cast<LPSTR>(args.str().c_str()), // Command line
	nullptr, // Process handle not inheritable
	nullptr, // Thread handle not inheritable
	TRUE, // Handles are inherited
	0, // No creation flags
	nullptr, // Use parent's environment block
	nullptr, // Use parent's starting directory
	&si, // Pointer to STARTUPINFO structure
	&pi)) { // Pointer to PROCESS_INFORMATION structure
	Output out;
	out.err = "Command::Exec() CreateProcess('" + args.str() + "') failed";
	out.error_code = 1;
	return out;
	}

	stdin_pipe.read.Close();
	stdout_pipe.write.Close();
	stderr_pipe.write.Close();

	struct StreamReadThreadArgs {
	HANDLE stream;
	std::string output;
	};

	auto stream_read_thread = [](LPVOID user) -> DWORD {
	auto* thread_args = reinterpret_cast<StreamReadThreadArgs*>(user);
	DWORD n = 0;
	char buf[256];
	while (ReadFile(thread_args->stream, buf, sizeof(buf), &n, NULL)) {
	auto s = std::string(buf, buf + n);
	thread_args->output += std::string(buf, buf + n);
	}
	return 0;
	};

	StreamReadThreadArgs stdout_read_args{stdout_pipe.read, {}};
	auto* stdout_read_thread =
	::CreateThread(nullptr, 0, stream_read_thread, &stdout_read_args, 0, nullptr);

	StreamReadThreadArgs stderr_read_args{stderr_pipe.read, {}};
	auto* stderr_read_thread =
	::CreateThread(nullptr, 0, stream_read_thread, &stderr_read_args, 0, nullptr);

	HANDLE handles[] = {pi.hProcess, stdout_read_thread, stderr_read_thread};
	constexpr DWORD num_handles = sizeof(handles) / sizeof(handles[0]);

	Output output;

	auto res = WaitForMultipleObjects(num_handles, handles, /* wait_all = */ TRUE, INFINITE);
	if (res >= WAIT_OBJECT_0 && res < WAIT_OBJECT_0 + num_handles) {
	output.out = stdout_read_args.output;
	output.err = stderr_read_args.output;
	DWORD exit_code = 0;
	GetExitCodeProcess(pi.hProcess, &exit_code);
	output.error_code = static_cast<int>(exit_code);
	} else {
	output.err = "Command::Exec() WaitForMultipleObjects() returned " + std::to_string(res);
	}

	return output;
	}

	} // namespace tint::utils