tools/gn/function_exec_script.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/command_line.h"
   6 #include "base/file_util.h"
   7 #include "base/logging.h"
   8 #include "base/process/kill.h"
   9 #include "base/process/launch.h"
  10 #include "base/strings/string_number_conversions.h"
  11 #include "base/strings/utf_string_conversions.h"
  12 #include "base/time/time.h"
  13 #include "build/build_config.h"
  14 #include "tools/gn/err.h"
  15 #include "tools/gn/filesystem_utils.h"
  16 #include "tools/gn/functions.h"
  17 #include "tools/gn/input_conversion.h"
  18 #include "tools/gn/input_file.h"
  19 #include "tools/gn/parse_tree.h"
  20 #include "tools/gn/scheduler.h"
  21 #include "tools/gn/trace.h"
  22 #include "tools/gn/value.h"
  23
  24 #if defined(OS_WIN)
  25 #include <windows.h>
  26
  27 #include "base/win/scoped_handle.h"
  28 #include "base/win/scoped_process_information.h"
  29 #endif
  30
  31 #if defined(OS_POSIX)
  32 #include <fcntl.h>
  33 #include <unistd.h>
  34
  35 #include "base/posix/file_descriptor_shuffle.h"
  36 #endif
  37
  38 namespace functions {
  39
  40 namespace {
  41
  42 const char kNoExecSwitch[] = "no-exec";
  43
  44 #if defined(OS_WIN)
  45 bool ExecProcess(const CommandLine& cmdline,
  46                  const base::FilePath& startup_dir,
  47                  std::string* std_out,
  48                  std::string* std_err,
  49                  int* exit_code) {
  50   SECURITY_ATTRIBUTES sa_attr;
  51   // Set the bInheritHandle flag so pipe handles are inherited.
  52   sa_attr.nLength = sizeof(SECURITY_ATTRIBUTES);
  53   sa_attr.bInheritHandle = TRUE;
  54   sa_attr.lpSecurityDescriptor = NULL;
  55
  56   // Create the pipe for the child process's STDOUT.
  57   HANDLE out_read = NULL;
  58   HANDLE out_write = NULL;
  59   if (!CreatePipe(&out_read, &out_write, &sa_attr, 0)) {
  60     NOTREACHED() << "Failed to create pipe";
  61     return false;
  62   }
  63   base::win::ScopedHandle scoped_out_read(out_read);
  64   base::win::ScopedHandle scoped_out_write(out_write);
  65
  66   // Create the pipe for the child process's STDERR.
  67   HANDLE err_read = NULL;
  68   HANDLE err_write = NULL;
  69   if (!CreatePipe(&err_read, &err_write, &sa_attr, 0)) {
  70     NOTREACHED() << "Failed to create pipe";
  71     return false;
  72   }
  73   base::win::ScopedHandle scoped_err_read(err_read);
  74   base::win::ScopedHandle scoped_err_write(err_write);
  75
  76   // Ensure the read handle to the pipe for STDOUT/STDERR is not inherited.
  77   if (!SetHandleInformation(out_read, HANDLE_FLAG_INHERIT, 0)) {
  78     NOTREACHED() << "Failed to disabled pipe inheritance";
  79     return false;
  80   }
  81   if (!SetHandleInformation(err_read, HANDLE_FLAG_INHERIT, 0)) {
  82     NOTREACHED() << "Failed to disabled pipe inheritance";
  83     return false;
  84   }
  85
  86   base::FilePath::StringType cmdline_str(cmdline.GetCommandLineString());
  87
  88   base::win::ScopedProcessInformation proc_info;
  89   STARTUPINFO start_info = { 0 };
  90
  91   start_info.cb = sizeof(STARTUPINFO);
  92   start_info.hStdOutput = out_write;
  93   // Keep the normal stdin.
  94   start_info.hStdInput = GetStdHandle(STD_INPUT_HANDLE);
  95   // FIXME(brettw) set stderr here when we actually read it below.
  96   //start_info.hStdError = err_write;
  97   start_info.hStdError = GetStdHandle(STD_ERROR_HANDLE);
  98   start_info.dwFlags |= STARTF_USESTDHANDLES;
  99
 100   // Create the child process.
 101   if (!CreateProcess(NULL,
 102                      &cmdline_str[0],
 103                      NULL, NULL,
 104                      TRUE,  // Handles are inherited.
 105                      0, NULL,
 106                      startup_dir.value().c_str(),
 107                      &start_info, proc_info.Receive())) {
 108     return false;
 109   }
 110
 111   // Close our writing end of pipes now. Otherwise later read would not be able
 112   // to detect end of child's output.
 113   scoped_out_write.Close();
 114   scoped_err_write.Close();
 115
 116   // Read output from the child process's pipe for STDOUT
 117   const int kBufferSize = 1024;
 118   char buffer[kBufferSize];
 119
 120   // FIXME(brettw) read from stderr here! This is complicated because we want
 121   // to read both of them at the same time, probably need overlapped I/O.
 122   // Also uncomment start_info code above.
 123   for (;;) {
 124     DWORD bytes_read = 0;
 125     BOOL success = ReadFile(out_read, buffer, kBufferSize, &bytes_read, NULL);
 126     if (!success || bytes_read == 0)
 127       break;
 128     std_out->append(buffer, bytes_read);
 129   }
 130
 131   // Let's wait for the process to finish.
 132   WaitForSingleObject(proc_info.process_handle(), INFINITE);
 133
 134   DWORD dw_exit_code;
 135   GetExitCodeProcess(proc_info.process_handle(), &dw_exit_code);
 136   *exit_code = static_cast<int>(dw_exit_code);
 137
 138   return true;
 139 }
 140 #else
 141 bool ExecProcess(const CommandLine& cmdline,
 142                  const base::FilePath& startup_dir,
 143                  std::string* std_out,
 144                  std::string* std_err,
 145                  int* exit_code) {
 146   *exit_code = EXIT_FAILURE;
 147
 148   std::vector<std::string> argv = cmdline.argv();
 149
 150   int pipe_fd[2];
 151   pid_t pid;
 152   base::InjectiveMultimap fd_shuffle1, fd_shuffle2;
 153   scoped_ptr<char*[]> argv_cstr(new char*[argv.size() + 1]);
 154
 155   fd_shuffle1.reserve(3);
 156   fd_shuffle2.reserve(3);
 157
 158   if (pipe(pipe_fd) < 0)
 159     return false;
 160
 161   switch (pid = fork()) {
 162     case -1:  // error
 163       close(pipe_fd[0]);
 164       close(pipe_fd[1]);
 165       return false;
 166     case 0:  // child
 167       {
 168         // DANGER: no calls to malloc are allowed from now on:
 169         // http://crbug.com/36678
 170
 171         // Obscure fork() rule: in the child, if you don't end up doing exec*(),
 172         // you call _exit() instead of exit(). This is because _exit() does not
 173         // call any previously-registered (in the parent) exit handlers, which
 174         // might do things like block waiting for threads that don't even exist
 175         // in the child.
 176         int dev_null = open("/dev/null", O_WRONLY);
 177         if (dev_null < 0)
 178           _exit(127);
 179
 180         fd_shuffle1.push_back(
 181             base::InjectionArc(pipe_fd[1], STDOUT_FILENO, true));
 182         fd_shuffle1.push_back(
 183             base::InjectionArc(dev_null, STDERR_FILENO, true));
 184         fd_shuffle1.push_back(
 185             base::InjectionArc(dev_null, STDIN_FILENO, true));
 186         // Adding another element here? Remeber to increase the argument to
 187         // reserve(), above.
 188
 189         std::copy(fd_shuffle1.begin(), fd_shuffle1.end(),
 190                   std::back_inserter(fd_shuffle2));
 191
 192         if (!ShuffleFileDescriptors(&fd_shuffle1))
 193           _exit(127);
 194
 195         file_util::SetCurrentDirectory(startup_dir);
 196
 197         // TODO(brettw) the base version GetAppOutput does a
 198         // CloseSuperfluousFds call here. Do we need this?
 199
 200         for (size_t i = 0; i < argv.size(); i++)
 201           argv_cstr[i] = const_cast<char*>(argv[i].c_str());
 202         argv_cstr[argv.size()] = NULL;
 203         execvp(argv_cstr[0], argv_cstr.get());
 204         _exit(127);
 205       }
 206     default:  // parent
 207       {
 208         // Close our writing end of pipe now. Otherwise later read would not
 209         // be able to detect end of child's output (in theory we could still
 210         // write to the pipe).
 211         close(pipe_fd[1]);
 212
 213         char buffer[256];
 214         ssize_t bytes_read = 0;
 215
 216         while (true) {
 217           bytes_read = HANDLE_EINTR(read(pipe_fd[0], buffer, sizeof(buffer)));
 218           if (bytes_read <= 0)
 219             break;
 220           std_out->append(buffer, bytes_read);
 221         }
 222         close(pipe_fd[0]);
 223
 224         return base::WaitForExitCode(pid, exit_code);
 225       }
 226   }
 227
 228   return false;
 229 }
 230 #endif
 231
 232 }  // namespace
 233
 234 const char kExecScript[] = "exec_script";
 235 const char kExecScript_Help[] =
 236     "exec_script: Synchronously run a script and return the output.\n"
 237     "\n"
 238     "  exec_script(filename, arguments, input_conversion,\n"
 239     "              [file_dependencies])\n"
 240     "\n"
 241     "  Runs the given script, returning the stdout of the script. The build\n"
 242     "  generation will fail if the script does not exist or returns a nonzero\n"
 243     "  exit code.\n"
 244     "\n"
 245     "  The current directory when executing the script will be the root\n"
 246     "  build directory. If you are passing file names, you will want to use\n"
 247     "  the to_build_dir() function to make file names relative to this\n"
 248     "  path (see \"gn help to_build_dir\").\n"
 249     "\n"
 250     "Arguments:\n"
 251     "\n"
 252     "  filename:\n"
 253     "      File name of python script to execute. Non-absolute names will\n"
 254     "      be treated as relative to the current build file.\n"
 255     "\n"
 256     "  arguments:\n"
 257     "      A list of strings to be passed to the script as arguments.\n"
 258     "\n"
 259     "  input_conversion:\n"
 260     "      Controls how the file is read and parsed.\n"
 261     "      See \"gn help input_conversion\".\n"
 262     "\n"
 263     "  dependencies:\n"
 264     "      (Optional) A list of files that this script reads or otherwise\n"
 265     "      depends on. These dependencies will be added to the build result\n"
 266     "      such that if any of them change, the build will be regenerated and\n"
 267     "      the script will be re-run.\n"
 268     "\n"
 269     "      The script itself will be an implicit dependency so you do not\n"
 270     "      need to list it.\n"
 271     "\n"
 272     "Example:\n"
 273     "\n"
 274     "  all_lines = exec_script(\"myscript.py\", [some_input], \"list lines\",\n"
 275     "                          [ to_build_dir(\"data_file.txt\") ])\n";
 276
 277 Value RunExecScript(Scope* scope,
 278                     const FunctionCallNode* function,
 279                     const std::vector<Value>& args,
 280                     Err* err) {
 281   if (args.size() != 3 && args.size() != 4) {
 282     *err = Err(function->function(), "Wrong number of args to write_file",
 283                "I expected three or four arguments.");
 284     return Value();
 285   }
 286
 287   const Settings* settings = scope->settings();
 288   const BuildSettings* build_settings = settings->build_settings();
 289   const SourceDir& cur_dir = scope->GetSourceDir();
 290
 291   // Find the python script to run.
 292   if (!args[0].VerifyTypeIs(Value::STRING, err))
 293     return Value();
 294   SourceFile script_source =
 295       cur_dir.ResolveRelativeFile(args[0].string_value());
 296   base::FilePath script_path = build_settings->GetFullPath(script_source);
 297   if (!build_settings->secondary_source_path().empty() &&
 298       !base::PathExists(script_path)) {
 299     // Fall back to secondary source root when the file doesn't exist.
 300     script_path = build_settings->GetFullPathSecondary(script_source);
 301   }
 302
 303   ScopedTrace trace(TraceItem::TRACE_SCRIPT_EXECUTE, script_source.value());
 304   trace.SetToolchain(settings->toolchain()->label());
 305
 306   // Add all dependencies of this script, including the script itself, to the
 307   // build deps.
 308   g_scheduler->AddGenDependency(script_path);
 309   if (args.size() == 4) {
 310     const Value& deps_value = args[3];
 311     if (!deps_value.VerifyTypeIs(Value::LIST, err))
 312       return Value();
 313
 314     for (size_t i = 0; i < deps_value.list_value().size(); i++) {
 315       if (!deps_value.list_value()[0].VerifyTypeIs(Value::STRING, err))
 316         return Value();
 317       g_scheduler->AddGenDependency(
 318           build_settings->GetFullPath(cur_dir.ResolveRelativeFile(
 319               deps_value.list_value()[0].string_value())));
 320     }
 321   }
 322
 323   // Make the command line.
 324   const base::FilePath& python_path = build_settings->python_path();
 325   CommandLine cmdline(python_path);
 326   cmdline.AppendArgPath(script_path);
 327
 328   const Value& script_args = args[1];
 329   if (!script_args.VerifyTypeIs(Value::LIST, err))
 330     return Value();
 331   for (size_t i = 0; i < script_args.list_value().size(); i++) {
 332     if (!script_args.list_value()[i].VerifyTypeIs(Value::STRING, err))
 333       return Value();
 334     cmdline.AppendArg(script_args.list_value()[i].string_value());
 335   }
 336
 337   // Log command line for debugging help.
 338   trace.SetCommandLine(cmdline);
 339   base::TimeTicks begin_exec;
 340   if (g_scheduler->verbose_logging()) {
 341 #if defined(OS_WIN)
 342     g_scheduler->Log("Pythoning", UTF16ToUTF8(cmdline.GetCommandLineString()));
 343 #else
 344     g_scheduler->Log("Pythoning", cmdline.GetCommandLineString());
 345 #endif
 346     begin_exec = base::TimeTicks::Now();
 347   }
 348
 349   base::FilePath startup_dir =
 350       build_settings->GetFullPath(build_settings->build_dir());
 351
 352   // Execute the process.
 353   // TODO(brettw) set the environment block.
 354   std::string output;
 355   std::string stderr_output;  // TODO(brettw) not hooked up, see above.
 356   int exit_code = 0;
 357   if (!CommandLine::ForCurrentProcess()->HasSwitch(kNoExecSwitch)) {
 358     if (!ExecProcess(cmdline, startup_dir,
 359                      &output, &stderr_output, &exit_code)) {
 360       *err = Err(function->function(), "Could not execute python.",
 361           "I was trying to execute \"" + FilePathToUTF8(python_path) + "\".");
 362       return Value();
 363     }
 364   }
 365   if (g_scheduler->verbose_logging()) {
 366     g_scheduler->Log("Pythoning", script_source.value() + " took " +
 367         base::Int64ToString(
 368             (base::TimeTicks::Now() - begin_exec).InMilliseconds()) +
 369         "ms");
 370   }
 371
 372   // TODO(brettw) maybe we need stderr also for reasonable stack dumps.
 373   if (exit_code != 0) {
 374     std::string msg = "Current dir: " + FilePathToUTF8(startup_dir) +
 375         "\nCommand: " + FilePathToUTF8(cmdline.GetCommandLineString()) +
 376         "\nReturned " + base::IntToString(exit_code);
 377     if (!output.empty())
 378       msg += " and printed out:\n\n" + output;
 379     else
 380       msg += ".";
 381     *err = Err(function->function(), "Script returned non-zero exit code.",
 382                msg);
 383     return Value();
 384   }
 385
 386   return ConvertInputToValue(output, function, args[2], err);
 387 }
 388
 389 }  // namespace functions