tools/gn/setup.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 "tools/gn/setup.h"
   6
   7 #include <stdlib.h>
   8
   9 #include <algorithm>
  10 #include <sstream>
  11
  12 #include "base/bind.h"
  13 #include "base/command_line.h"
  14 #include "base/files/file_path.h"
  15 #include "base/files/file_util.h"
  16 #include "base/process/launch.h"
  17 #include "base/strings/string_split.h"
  18 #include "base/strings/string_util.h"
  19 #include "base/strings/utf_string_conversions.h"
  20 #include "build/build_config.h"
  21 #include "tools/gn/commands.h"
  22 #include "tools/gn/filesystem_utils.h"
  23 #include "tools/gn/input_file.h"
  24 #include "tools/gn/parse_tree.h"
  25 #include "tools/gn/parser.h"
  26 #include "tools/gn/source_dir.h"
  27 #include "tools/gn/source_file.h"
  28 #include "tools/gn/standard_out.h"
  29 #include "tools/gn/tokenizer.h"
  30 #include "tools/gn/trace.h"
  31 #include "tools/gn/value.h"
  32
  33 #if defined(OS_WIN)
  34 #include <windows.h>
  35 #endif
  36
  37 extern const char kDotfile_Help[] =
  38     ".gn file\n"
  39     "\n"
  40     "  When gn starts, it will search the current directory and parent\n"
  41     "  directories for a file called \".gn\". This indicates the source root.\n"
  42     "  You can override this detection by using the --root command-line\n"
  43     "  argument\n"
  44     "\n"
  45     "  The .gn file in the source root will be executed. The syntax is the\n"
  46     "  same as a buildfile, but with very limited build setup-specific\n"
  47     "  meaning.\n"
  48     "\n"
  49     "  If you specify --root, by default GN will look for the file .gn in\n"
  50     "  that directory. If you want to specify a different file, you can\n"
  51     "  additionally pass --dotfile:\n"
  52     "\n"
  53     "    gn gen out/Debug --root=/home/build --dotfile=/home/my_gn_file.gn\n"
  54     "\n"
  55     "Variables\n"
  56     "\n"
  57     "  buildconfig [required]\n"
  58     "      Label of the build config file. This file will be used to set up\n"
  59     "      the build file execution environment for each toolchain.\n"
  60     "\n"
  61     "  root [optional]\n"
  62     "      Label of the root build target. The GN build will start by loading\n"
  63     "      the build file containing this target name. This defaults to\n"
  64     "      \"//:\" which will cause the file //BUILD.gn to be loaded.\n"
  65     "\n"
  66     "  secondary_source [optional]\n"
  67     "      Label of an alternate directory tree to find input files. When\n"
  68     "      searching for a BUILD.gn file (or the build config file discussed\n"
  69     "      above), the file will first be looked for in the source root.\n"
  70     "      If it's not found, the secondary source root will be checked\n"
  71     "      (which would contain a parallel directory hierarchy).\n"
  72     "\n"
  73     "      This behavior is intended to be used when BUILD.gn files can't be\n"
  74     "      checked in to certain source directories for whatever reason.\n"
  75     "\n"
  76     "      The secondary source root must be inside the main source tree.\n"
  77     "\n"
  78     "Example .gn file contents\n"
  79     "\n"
  80     "  buildconfig = \"//build/config/BUILDCONFIG.gn\"\n"
  81     "\n"
  82     "  root = \"//:root\"\n"
  83     "\n"
  84     "  secondary_source = \"//build/config/temporary_buildfiles/\"\n";
  85
  86 namespace {
  87
  88 // More logging.
  89 const char kSwitchVerbose[] = "v";
  90
  91 // Set build args.
  92 const char kSwitchArgs[] = "args";
  93
  94 // Set root dir.
  95 const char kSwitchRoot[] = "root";
  96
  97 // Set dotfile name.
  98 const char kSwitchDotfile[] = "dotfile";
  99
 100 // Enable timing.
 101 const char kTimeSwitch[] = "time";
 102
 103 const char kTracelogSwitch[] = "tracelog";
 104
 105 const base::FilePath::CharType kGnFile[] = FILE_PATH_LITERAL(".gn");
 106
 107 base::FilePath FindDotFile(const base::FilePath& current_dir) {
 108   base::FilePath try_this_file = current_dir.Append(kGnFile);
 109   if (base::PathExists(try_this_file))
 110     return try_this_file;
 111
 112   base::FilePath with_no_slash = current_dir.StripTrailingSeparators();
 113   base::FilePath up_one_dir = with_no_slash.DirName();
 114   if (up_one_dir == current_dir)
 115     return base::FilePath();  // Got to the top.
 116
 117   return FindDotFile(up_one_dir);
 118 }
 119
 120 // Called on any thread. Post the item to the builder on the main thread.
 121 void ItemDefinedCallback(base::MessageLoop* main_loop,
 122                          scoped_refptr<Builder> builder,
 123                          scoped_ptr<Item> item) {
 124   DCHECK(item);
 125   main_loop->PostTask(FROM_HERE, base::Bind(&Builder::ItemDefined, builder,
 126                                             base::Passed(&item)));
 127 }
 128
 129 void DecrementWorkCount() {
 130   g_scheduler->DecrementWorkCount();
 131 }
 132
 133 }  // namespace
 134
 135 // CommonSetup -----------------------------------------------------------------
 136
 137 const char CommonSetup::kBuildArgFileName[] = "args.gn";
 138
 139 CommonSetup::CommonSetup()
 140     : build_settings_(),
 141       loader_(new LoaderImpl(&build_settings_)),
 142       builder_(new Builder(loader_.get())),
 143       root_build_file_("//BUILD.gn"),
 144       check_for_bad_items_(true),
 145       check_for_unused_overrides_(true),
 146       check_public_headers_(false) {
 147   loader_->set_complete_callback(base::Bind(&DecrementWorkCount));
 148 }
 149
 150 CommonSetup::CommonSetup(const CommonSetup& other)
 151     : build_settings_(other.build_settings_),
 152       loader_(new LoaderImpl(&build_settings_)),
 153       builder_(new Builder(loader_.get())),
 154       root_build_file_(other.root_build_file_),
 155       check_for_bad_items_(other.check_for_bad_items_),
 156       check_for_unused_overrides_(other.check_for_unused_overrides_),
 157       check_public_headers_(other.check_public_headers_) {
 158   loader_->set_complete_callback(base::Bind(&DecrementWorkCount));
 159 }
 160
 161 CommonSetup::~CommonSetup() {
 162 }
 163
 164 void CommonSetup::RunPreMessageLoop() {
 165   // Load the root build file.
 166   loader_->Load(root_build_file_, LocationRange(), Label());
 167
 168   // Will be decremented with the loader is drained.
 169   g_scheduler->IncrementWorkCount();
 170 }
 171
 172 bool CommonSetup::RunPostMessageLoop() {
 173   Err err;
 174   if (check_for_bad_items_) {
 175     if (!builder_->CheckForBadItems(&err)) {
 176       err.PrintToStdout();
 177       return false;
 178     }
 179   }
 180
 181   if (check_for_unused_overrides_) {
 182     if (!build_settings_.build_args().VerifyAllOverridesUsed(&err)) {
 183       // TODO(brettw) implement a system of warnings. Until we have a better
 184       // system, print the error but don't return failure.
 185       err.PrintToStdout();
 186       return true;
 187     }
 188   }
 189
 190   if (check_public_headers_) {
 191     if (!commands::CheckPublicHeaders(&build_settings_,
 192                                       builder_->GetAllResolvedTargets(),
 193                                       std::vector<const Target*>(),
 194                                       false)) {
 195       return false;
 196     }
 197   }
 198
 199   // Write out tracing and timing if requested.
 200   const CommandLine* cmdline = CommandLine::ForCurrentProcess();
 201   if (cmdline->HasSwitch(kTimeSwitch))
 202     PrintLongHelp(SummarizeTraces());
 203   if (cmdline->HasSwitch(kTracelogSwitch))
 204     SaveTraces(cmdline->GetSwitchValuePath(kTracelogSwitch));
 205
 206   return true;
 207 }
 208
 209 // Setup -----------------------------------------------------------------------
 210
 211 Setup::Setup()
 212     : CommonSetup(),
 213       empty_settings_(&empty_build_settings_, std::string()),
 214       dotfile_scope_(&empty_settings_),
 215       fill_arguments_(true) {
 216   empty_settings_.set_toolchain_label(Label());
 217   build_settings_.set_item_defined_callback(
 218       base::Bind(&ItemDefinedCallback, scheduler_.main_loop(), builder_));
 219
 220   // The scheduler's main loop wasn't created when the Loader was created, so
 221   // we need to set it now.
 222   loader_->set_main_loop(scheduler_.main_loop());
 223 }
 224
 225 Setup::~Setup() {
 226 }
 227
 228 bool Setup::DoSetup(const std::string& build_dir, bool force_create) {
 229   CommandLine* cmdline = CommandLine::ForCurrentProcess();
 230
 231   scheduler_.set_verbose_logging(cmdline->HasSwitch(kSwitchVerbose));
 232   if (cmdline->HasSwitch(kTimeSwitch) ||
 233       cmdline->HasSwitch(kTracelogSwitch))
 234     EnableTracing();
 235
 236   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "DoSetup");
 237
 238   if (!FillSourceDir(*cmdline))
 239     return false;
 240   if (!RunConfigFile())
 241     return false;
 242   if (!FillOtherConfig(*cmdline))
 243     return false;
 244
 245   // Must be after FillSourceDir to resolve.
 246   if (!FillBuildDir(build_dir, !force_create))
 247     return false;
 248
 249   if (fill_arguments_) {
 250     if (!FillArguments(*cmdline))
 251       return false;
 252   }
 253   FillPythonPath();
 254
 255   return true;
 256 }
 257
 258 bool Setup::Run() {
 259   RunPreMessageLoop();
 260   if (!scheduler_.Run())
 261     return false;
 262   return RunPostMessageLoop();
 263 }
 264
 265 Scheduler* Setup::GetScheduler() {
 266   return &scheduler_;
 267 }
 268
 269 SourceFile Setup::GetBuildArgFile() const {
 270   return SourceFile(build_settings_.build_dir().value() + kBuildArgFileName);
 271 }
 272
 273 bool Setup::FillArguments(const CommandLine& cmdline) {
 274   // Use the args on the command line if specified, and save them. Do this even
 275   // if the list is empty (this means clear any defaults).
 276   if (cmdline.HasSwitch(kSwitchArgs)) {
 277     if (!FillArgsFromCommandLine(cmdline.GetSwitchValueASCII(kSwitchArgs)))
 278       return false;
 279     SaveArgsToFile();
 280     return true;
 281   }
 282
 283   // No command line args given, use the arguments from the build dir (if any).
 284   return FillArgsFromFile();
 285 }
 286
 287 bool Setup::FillArgsFromCommandLine(const std::string& args) {
 288   args_input_file_.reset(new InputFile(SourceFile()));
 289   args_input_file_->SetContents(args);
 290   args_input_file_->set_friendly_name("the command-line \"--args\"");
 291   return FillArgsFromArgsInputFile();
 292 }
 293
 294 bool Setup::FillArgsFromFile() {
 295   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Load args file");
 296
 297   SourceFile build_arg_source_file = GetBuildArgFile();
 298   base::FilePath build_arg_file =
 299       build_settings_.GetFullPath(build_arg_source_file);
 300
 301   std::string contents;
 302   if (!base::ReadFileToString(build_arg_file, &contents))
 303     return true;  // File doesn't exist, continue with default args.
 304
 305   // Add a dependency on the build arguments file. If this changes, we want
 306   // to re-generate the build.
 307   g_scheduler->AddGenDependency(build_arg_file);
 308
 309   if (contents.empty())
 310     return true;  // Empty file, do nothing.
 311
 312   args_input_file_.reset(new InputFile(build_arg_source_file));
 313   args_input_file_->SetContents(contents);
 314   args_input_file_->set_friendly_name(
 315       "build arg file (use \"gn args <out_dir>\" to edit)");
 316
 317   setup_trace.Done();  // Only want to count the load as part of the trace.
 318   return FillArgsFromArgsInputFile();
 319 }
 320
 321 bool Setup::FillArgsFromArgsInputFile() {
 322   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Parse args");
 323
 324   Err err;
 325   args_tokens_ = Tokenizer::Tokenize(args_input_file_.get(), &err);
 326   if (err.has_error()) {
 327     err.PrintToStdout();
 328     return false;
 329   }
 330
 331   args_root_ = Parser::Parse(args_tokens_, &err);
 332   if (err.has_error()) {
 333     err.PrintToStdout();
 334     return false;
 335   }
 336
 337   Scope arg_scope(&empty_settings_);
 338   args_root_->AsBlock()->ExecuteBlockInScope(&arg_scope, &err);
 339   if (err.has_error()) {
 340     err.PrintToStdout();
 341     return false;
 342   }
 343
 344   // Save the result of the command args.
 345   Scope::KeyValueMap overrides;
 346   arg_scope.GetCurrentScopeValues(&overrides);
 347   build_settings_.build_args().AddArgOverrides(overrides);
 348   return true;
 349 }
 350
 351 bool Setup::SaveArgsToFile() {
 352   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Save args file");
 353
 354   std::ostringstream stream;
 355   for (const auto& pair : build_settings_.build_args().GetAllOverrides()) {
 356     stream << pair.first.as_string() << " = " << pair.second.ToString(true);
 357     stream << std::endl;
 358   }
 359
 360   // For the first run, the build output dir might not be created yet, so do
 361   // that so we can write a file into it. Ignore errors, we'll catch the error
 362   // when we try to write a file to it below.
 363   base::FilePath build_arg_file =
 364       build_settings_.GetFullPath(GetBuildArgFile());
 365   base::CreateDirectory(build_arg_file.DirName());
 366
 367   std::string contents = stream.str();
 368 #if defined(OS_WIN)
 369   // Use Windows lineendings for this file since it will often open in
 370   // Notepad which can't handle Unix ones.
 371   ReplaceSubstringsAfterOffset(&contents, 0, "\n", "\r\n");
 372 #endif
 373   if (base::WriteFile(build_arg_file, contents.c_str(),
 374       static_cast<int>(contents.size())) == -1) {
 375     Err(Location(), "Args file could not be written.",
 376       "The file is \"" + FilePathToUTF8(build_arg_file) +
 377         "\"").PrintToStdout();
 378     return false;
 379   }
 380
 381   // Add a dependency on the build arguments file. If this changes, we want
 382   // to re-generate the build.
 383   g_scheduler->AddGenDependency(build_arg_file);
 384
 385   return true;
 386 }
 387
 388 bool Setup::FillSourceDir(const CommandLine& cmdline) {
 389   // Find the .gn file.
 390   base::FilePath root_path;
 391
 392   // Prefer the command line args to the config file.
 393   base::FilePath relative_root_path = cmdline.GetSwitchValuePath(kSwitchRoot);
 394   if (!relative_root_path.empty()) {
 395     root_path = base::MakeAbsoluteFilePath(relative_root_path);
 396     if (root_path.empty()) {
 397       Err(Location(), "Root source path not found.",
 398           "The path \"" + FilePathToUTF8(relative_root_path) +
 399           "\" doesn't exist.").PrintToStdout();
 400       return false;
 401     }
 402
 403     // When --root is specified, an alternate --dotfile can also be set.
 404     // --dotfile should be a real file path and not a "//foo" source-relative
 405     // path.
 406     base::FilePath dot_file_path = cmdline.GetSwitchValuePath(kSwitchDotfile);
 407     if (dot_file_path.empty()) {
 408       dotfile_name_ = root_path.Append(kGnFile);
 409     } else {
 410       dotfile_name_ = base::MakeAbsoluteFilePath(dot_file_path);
 411       if (dotfile_name_.empty()) {
 412         Err(Location(), "Could not load dotfile.",
 413             "The file \"" + FilePathToUTF8(dot_file_path) +
 414             "\" cound't be loaded.").PrintToStdout();
 415         return false;
 416       }
 417     }
 418   } else {
 419     // In the default case, look for a dotfile and that also tells us where the
 420     // source root is.
 421     base::FilePath cur_dir;
 422     base::GetCurrentDirectory(&cur_dir);
 423     dotfile_name_ = FindDotFile(cur_dir);
 424     if (dotfile_name_.empty()) {
 425       Err(Location(), "Can't find source root.",
 426           "I could not find a \".gn\" file in the current directory or any "
 427           "parent,\nand the --root command-line argument was not specified.")
 428           .PrintToStdout();
 429       return false;
 430     }
 431     root_path = dotfile_name_.DirName();
 432   }
 433
 434   if (scheduler_.verbose_logging())
 435     scheduler_.Log("Using source root", FilePathToUTF8(root_path));
 436   build_settings_.SetRootPath(root_path);
 437
 438   return true;
 439 }
 440
 441 bool Setup::FillBuildDir(const std::string& build_dir, bool require_exists) {
 442   SourceDir resolved =
 443       SourceDirForCurrentDirectory(build_settings_.root_path()).
 444     ResolveRelativeDir(build_dir, build_settings_.root_path_utf8());
 445   if (resolved.is_null()) {
 446     Err(Location(), "Couldn't resolve build directory.",
 447         "The build directory supplied (\"" + build_dir + "\") was not valid.").
 448         PrintToStdout();
 449     return false;
 450   }
 451
 452   if (scheduler_.verbose_logging())
 453     scheduler_.Log("Using build dir", resolved.value());
 454
 455   if (require_exists) {
 456     base::FilePath build_dir_path = build_settings_.GetFullPath(resolved);
 457     if (!base::PathExists(build_dir_path.Append(
 458             FILE_PATH_LITERAL("build.ninja")))) {
 459       Err(Location(), "Not a build directory.",
 460           "This command requires an existing build directory. I interpreted "
 461           "your input\n\"" + build_dir + "\" as:\n  " +
 462           FilePathToUTF8(build_dir_path) +
 463           "\nwhich doesn't seem to contain a previously-generated build.")
 464           .PrintToStdout();
 465       return false;
 466     }
 467   }
 468
 469   build_settings_.SetBuildDir(resolved);
 470   return true;
 471 }
 472
 473 void Setup::FillPythonPath() {
 474   // Trace this since it tends to be a bit slow on Windows.
 475   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Fill Python Path");
 476 #if defined(OS_WIN)
 477   // Find Python on the path so we can use the absolute path in the build.
 478   const base::char16 kGetPython[] =
 479       L"cmd.exe /c python -c \"import sys; print sys.executable\"";
 480   std::string python_path;
 481   if (base::GetAppOutput(kGetPython, &python_path)) {
 482     base::TrimWhitespaceASCII(python_path, base::TRIM_ALL, &python_path);
 483     if (scheduler_.verbose_logging())
 484       scheduler_.Log("Found python", python_path);
 485   } else {
 486     scheduler_.Log("WARNING", "Could not find python on path, using "
 487         "just \"python.exe\"");
 488     python_path = "python.exe";
 489   }
 490   build_settings_.set_python_path(base::FilePath(base::UTF8ToUTF16(python_path))
 491                                       .NormalizePathSeparatorsTo('/'));
 492 #else
 493   build_settings_.set_python_path(base::FilePath("python"));
 494 #endif
 495 }
 496
 497 bool Setup::RunConfigFile() {
 498   if (scheduler_.verbose_logging())
 499     scheduler_.Log("Got dotfile", FilePathToUTF8(dotfile_name_));
 500
 501   dotfile_input_file_.reset(new InputFile(SourceFile("//.gn")));
 502   if (!dotfile_input_file_->Load(dotfile_name_)) {
 503     Err(Location(), "Could not load dotfile.",
 504         "The file \"" + FilePathToUTF8(dotfile_name_) + "\" cound't be loaded")
 505         .PrintToStdout();
 506     return false;
 507   }
 508
 509   Err err;
 510   dotfile_tokens_ = Tokenizer::Tokenize(dotfile_input_file_.get(), &err);
 511   if (err.has_error()) {
 512     err.PrintToStdout();
 513     return false;
 514   }
 515
 516   dotfile_root_ = Parser::Parse(dotfile_tokens_, &err);
 517   if (err.has_error()) {
 518     err.PrintToStdout();
 519     return false;
 520   }
 521
 522   dotfile_root_->AsBlock()->ExecuteBlockInScope(&dotfile_scope_, &err);
 523   if (err.has_error()) {
 524     err.PrintToStdout();
 525     return false;
 526   }
 527
 528   return true;
 529 }
 530
 531 bool Setup::FillOtherConfig(const CommandLine& cmdline) {
 532   Err err;
 533
 534   // Secondary source path, read from the config file if present.
 535   // Read from the config file if present.
 536   const Value* secondary_value =
 537       dotfile_scope_.GetValue("secondary_source", true);
 538   if (secondary_value) {
 539     if (!secondary_value->VerifyTypeIs(Value::STRING, &err)) {
 540       err.PrintToStdout();
 541       return false;
 542     }
 543     build_settings_.SetSecondarySourcePath(
 544         SourceDir(secondary_value->string_value()));
 545   }
 546
 547   // Root build file.
 548   const Value* root_value = dotfile_scope_.GetValue("root", true);
 549   if (root_value) {
 550     if (!root_value->VerifyTypeIs(Value::STRING, &err)) {
 551       err.PrintToStdout();
 552       return false;
 553     }
 554
 555     Label root_target_label =
 556         Label::Resolve(SourceDir("//"), Label(), *root_value, &err);
 557     if (err.has_error()) {
 558       err.PrintToStdout();
 559       return false;
 560     }
 561
 562     root_build_file_ = Loader::BuildFileForLabel(root_target_label);
 563   }
 564
 565   // Build config file.
 566   const Value* build_config_value =
 567       dotfile_scope_.GetValue("buildconfig", true);
 568   if (!build_config_value) {
 569     Err(Location(), "No build config file.",
 570         "Your .gn file (\"" + FilePathToUTF8(dotfile_name_) + "\")\n"
 571         "didn't specify a \"buildconfig\" value.").PrintToStdout();
 572     return false;
 573   } else if (!build_config_value->VerifyTypeIs(Value::STRING, &err)) {
 574     err.PrintToStdout();
 575     return false;
 576   }
 577   build_settings_.set_build_config_file(
 578       SourceFile(build_config_value->string_value()));
 579
 580   return true;
 581 }
 582
 583 // DependentSetup --------------------------------------------------------------
 584
 585 DependentSetup::DependentSetup(Setup* derive_from)
 586     : CommonSetup(*derive_from),
 587       scheduler_(derive_from->GetScheduler()) {
 588   build_settings_.set_item_defined_callback(
 589       base::Bind(&ItemDefinedCallback, scheduler_->main_loop(), builder_));
 590 }
 591
 592 DependentSetup::DependentSetup(DependentSetup* derive_from)
 593     : CommonSetup(*derive_from),
 594       scheduler_(derive_from->GetScheduler()) {
 595   build_settings_.set_item_defined_callback(
 596       base::Bind(&ItemDefinedCallback, scheduler_->main_loop(), builder_));
 597 }
 598
 599 DependentSetup::~DependentSetup() {
 600 }
 601
 602 Scheduler* DependentSetup::GetScheduler() {
 603   return scheduler_;
 604 }
 605
 606 void DependentSetup::RunPreMessageLoop() {
 607   CommonSetup::RunPreMessageLoop();
 608 }
 609
 610 bool DependentSetup::RunPostMessageLoop() {
 611   return CommonSetup::RunPostMessageLoop();
 612 }
 613