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/file_util.h"
  15 #include "base/files/file_path.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/filesystem_utils.h"
  22 #include "tools/gn/header_checker.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 fill 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     std::vector<const Target*> targets = builder_->GetAllResolvedTargets();
 192     scoped_refptr<HeaderChecker> header_checker(
 193         new HeaderChecker(&build_settings_, targets));
 194
 195     std::vector<Err> header_errors;
 196     header_checker->Run(&header_errors);
 197     for (size_t i = 0; i < header_errors.size(); i++) {
 198       if (i > 0)
 199         OutputString("___________________\n", DECORATION_YELLOW);
 200       header_errors[i].PrintToStdout();
 201     }
 202     if (!header_errors.empty())
 203       return false;
 204   }
 205
 206   // Write out tracing and timing if requested.
 207   const CommandLine* cmdline = CommandLine::ForCurrentProcess();
 208   if (cmdline->HasSwitch(kTimeSwitch))
 209     PrintLongHelp(SummarizeTraces());
 210   if (cmdline->HasSwitch(kTracelogSwitch))
 211     SaveTraces(cmdline->GetSwitchValuePath(kTracelogSwitch));
 212
 213   return true;
 214 }
 215
 216 // Setup -----------------------------------------------------------------------
 217
 218 Setup::Setup()
 219     : CommonSetup(),
 220       empty_settings_(&empty_build_settings_, std::string()),
 221       dotfile_scope_(&empty_settings_),
 222       fill_arguments_(true) {
 223   empty_settings_.set_toolchain_label(Label());
 224   build_settings_.set_item_defined_callback(
 225       base::Bind(&ItemDefinedCallback, scheduler_.main_loop(), builder_));
 226
 227   // The scheduler's main loop wasn't created when the Loader was created, so
 228   // we need to set it now.
 229   loader_->set_main_loop(scheduler_.main_loop());
 230 }
 231
 232 Setup::~Setup() {
 233 }
 234
 235 bool Setup::DoSetup(const std::string& build_dir) {
 236   CommandLine* cmdline = CommandLine::ForCurrentProcess();
 237
 238   scheduler_.set_verbose_logging(cmdline->HasSwitch(kSwitchVerbose));
 239   if (cmdline->HasSwitch(kTimeSwitch) ||
 240       cmdline->HasSwitch(kTracelogSwitch))
 241     EnableTracing();
 242
 243   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "DoSetup");
 244
 245   if (!FillSourceDir(*cmdline))
 246     return false;
 247   if (!RunConfigFile())
 248     return false;
 249   if (!FillOtherConfig(*cmdline))
 250     return false;
 251   if (!FillBuildDir(build_dir))  // Must be after FillSourceDir to resolve.
 252     return false;
 253   if (fill_arguments_) {
 254     if (!FillArguments(*cmdline))
 255       return false;
 256   }
 257   FillPythonPath();
 258
 259   return true;
 260 }
 261
 262 bool Setup::Run() {
 263   RunPreMessageLoop();
 264   if (!scheduler_.Run())
 265     return false;
 266   return RunPostMessageLoop();
 267 }
 268
 269 Scheduler* Setup::GetScheduler() {
 270   return &scheduler_;
 271 }
 272
 273 SourceFile Setup::GetBuildArgFile() const {
 274   return SourceFile(build_settings_.build_dir().value() + kBuildArgFileName);
 275 }
 276
 277 bool Setup::FillArguments(const CommandLine& cmdline) {
 278   // Use the args on the command line if specified, and save them. Do this even
 279   // if the list is empty (this means clear any defaults).
 280   if (cmdline.HasSwitch(kSwitchArgs)) {
 281     if (!FillArgsFromCommandLine(cmdline.GetSwitchValueASCII(kSwitchArgs)))
 282       return false;
 283     SaveArgsToFile();
 284     return true;
 285   }
 286
 287   // No command line args given, use the arguments from the build dir (if any).
 288   return FillArgsFromFile();
 289 }
 290
 291 bool Setup::FillArgsFromCommandLine(const std::string& args) {
 292   args_input_file_.reset(new InputFile(SourceFile()));
 293   args_input_file_->SetContents(args);
 294   args_input_file_->set_friendly_name("the command-line \"--args\"");
 295   return FillArgsFromArgsInputFile();
 296 }
 297
 298 bool Setup::FillArgsFromFile() {
 299   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Load args file");
 300
 301   SourceFile build_arg_source_file = GetBuildArgFile();
 302   base::FilePath build_arg_file =
 303       build_settings_.GetFullPath(build_arg_source_file);
 304
 305   std::string contents;
 306   if (!base::ReadFileToString(build_arg_file, &contents))
 307     return true;  // File doesn't exist, continue with default args.
 308
 309   // Add a dependency on the build arguments file. If this changes, we want
 310   // to re-generate the build.
 311   g_scheduler->AddGenDependency(build_arg_file);
 312
 313   if (contents.empty())
 314     return true;  // Empty file, do nothing.
 315
 316   args_input_file_.reset(new InputFile(build_arg_source_file));
 317   args_input_file_->SetContents(contents);
 318   args_input_file_->set_friendly_name(
 319       "build arg file (use \"gn args <out_dir>\" to edit)");
 320
 321   setup_trace.Done();  // Only want to count the load as part of the trace.
 322   return FillArgsFromArgsInputFile();
 323 }
 324
 325 bool Setup::FillArgsFromArgsInputFile() {
 326   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Parse args");
 327
 328   Err err;
 329   args_tokens_ = Tokenizer::Tokenize(args_input_file_.get(), &err);
 330   if (err.has_error()) {
 331     err.PrintToStdout();
 332     return false;
 333   }
 334
 335   args_root_ = Parser::Parse(args_tokens_, &err);
 336   if (err.has_error()) {
 337     err.PrintToStdout();
 338     return false;
 339   }
 340
 341   Scope arg_scope(&empty_settings_);
 342   args_root_->AsBlock()->ExecuteBlockInScope(&arg_scope, &err);
 343   if (err.has_error()) {
 344     err.PrintToStdout();
 345     return false;
 346   }
 347
 348   // Save the result of the command args.
 349   Scope::KeyValueMap overrides;
 350   arg_scope.GetCurrentScopeValues(&overrides);
 351   build_settings_.build_args().AddArgOverrides(overrides);
 352   return true;
 353 }
 354
 355 bool Setup::SaveArgsToFile() {
 356   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Save args file");
 357
 358   Scope::KeyValueMap args = build_settings_.build_args().GetAllOverrides();
 359
 360   std::ostringstream stream;
 361   for (Scope::KeyValueMap::const_iterator i = args.begin();
 362        i != args.end(); ++i) {
 363     stream << i->first.as_string() << " = " << i->second.ToString(true);
 364     stream << std::endl;
 365   }
 366
 367   // For the first run, the build output dir might not be created yet, so do
 368   // that so we can write a file into it. Ignore errors, we'll catch the error
 369   // when we try to write a file to it below.
 370   base::FilePath build_arg_file =
 371       build_settings_.GetFullPath(GetBuildArgFile());
 372   base::CreateDirectory(build_arg_file.DirName());
 373
 374   std::string contents = stream.str();
 375 #if defined(OS_WIN)
 376   // Use Windows lineendings for this file since it will often open in
 377   // Notepad which can't handle Unix ones.
 378   ReplaceSubstringsAfterOffset(&contents, 0, "\n", "\r\n");
 379 #endif
 380   if (base::WriteFile(build_arg_file, contents.c_str(),
 381       static_cast<int>(contents.size())) == -1) {
 382     Err(Location(), "Args file could not be written.",
 383       "The file is \"" + FilePathToUTF8(build_arg_file) +
 384         "\"").PrintToStdout();
 385     return false;
 386   }
 387
 388   // Add a dependency on the build arguments file. If this changes, we want
 389   // to re-generate the build.
 390   g_scheduler->AddGenDependency(build_arg_file);
 391
 392   return true;
 393 }
 394
 395 bool Setup::FillSourceDir(const CommandLine& cmdline) {
 396   // Find the .gn file.
 397   base::FilePath root_path;
 398
 399   // Prefer the command line args to the config file.
 400   base::FilePath relative_root_path = cmdline.GetSwitchValuePath(kSwitchRoot);
 401   if (!relative_root_path.empty()) {
 402     root_path = base::MakeAbsoluteFilePath(relative_root_path);
 403     if (root_path.empty()) {
 404       Err(Location(), "Root source path not found.",
 405           "The path \"" + FilePathToUTF8(relative_root_path) +
 406           "\" doesn't exist.").PrintToStdout();
 407       return false;
 408     }
 409
 410     // When --root is specified, an alternate --dotfile can also be set.
 411     // --dotfile should be a real file path and not a "//foo" source-relative
 412     // path.
 413     base::FilePath dot_file_path = cmdline.GetSwitchValuePath(kSwitchDotfile);
 414     if (dot_file_path.empty()) {
 415       dotfile_name_ = root_path.Append(kGnFile);
 416     } else {
 417       dotfile_name_ = base::MakeAbsoluteFilePath(dot_file_path);
 418       if (dotfile_name_.empty()) {
 419         Err(Location(), "Could not load dotfile.",
 420             "The file \"" + FilePathToUTF8(dot_file_path) +
 421             "\" cound't be loaded.").PrintToStdout();
 422         return false;
 423       }
 424     }
 425   } else {
 426     // In the default case, look for a dotfile and that also tells us where the
 427     // source root is.
 428     base::FilePath cur_dir;
 429     base::GetCurrentDirectory(&cur_dir);
 430     dotfile_name_ = FindDotFile(cur_dir);
 431     if (dotfile_name_.empty()) {
 432       Err(Location(), "Can't find source root.",
 433           "I could not find a \".gn\" file in the current directory or any "
 434           "parent,\nand the --root command-line argument was not specified.")
 435           .PrintToStdout();
 436       return false;
 437     }
 438     root_path = dotfile_name_.DirName();
 439   }
 440
 441   if (scheduler_.verbose_logging())
 442     scheduler_.Log("Using source root", FilePathToUTF8(root_path));
 443   build_settings_.SetRootPath(root_path);
 444
 445   return true;
 446 }
 447
 448 bool Setup::FillBuildDir(const std::string& build_dir) {
 449   SourceDir resolved =
 450       SourceDirForCurrentDirectory(build_settings_.root_path()).
 451           ResolveRelativeDir(build_dir);
 452   if (resolved.is_null()) {
 453     Err(Location(), "Couldn't resolve build directory.",
 454         "The build directory supplied (\"" + build_dir + "\") was not valid.").
 455         PrintToStdout();
 456     return false;
 457   }
 458
 459   if (scheduler_.verbose_logging())
 460     scheduler_.Log("Using build dir", resolved.value());
 461   build_settings_.SetBuildDir(resolved);
 462   return true;
 463 }
 464
 465 void Setup::FillPythonPath() {
 466   // Trace this since it tends to be a bit slow on Windows.
 467   ScopedTrace setup_trace(TraceItem::TRACE_SETUP, "Fill Python Path");
 468 #if defined(OS_WIN)
 469   // Find Python on the path so we can use the absolute path in the build.
 470   const base::char16 kGetPython[] =
 471       L"cmd.exe /c python -c \"import sys; print sys.executable\"";
 472   std::string python_path;
 473   if (base::GetAppOutput(kGetPython, &python_path)) {
 474     base::TrimWhitespaceASCII(python_path, base::TRIM_ALL, &python_path);
 475     if (scheduler_.verbose_logging())
 476       scheduler_.Log("Found python", python_path);
 477   } else {
 478     scheduler_.Log("WARNING", "Could not find python on path, using "
 479         "just \"python.exe\"");
 480     python_path = "python.exe";
 481   }
 482   build_settings_.set_python_path(base::FilePath(base::UTF8ToUTF16(python_path))
 483                                       .NormalizePathSeparatorsTo('/'));
 484 #else
 485   build_settings_.set_python_path(base::FilePath("python"));
 486 #endif
 487 }
 488
 489 bool Setup::RunConfigFile() {
 490   if (scheduler_.verbose_logging())
 491     scheduler_.Log("Got dotfile", FilePathToUTF8(dotfile_name_));
 492
 493   dotfile_input_file_.reset(new InputFile(SourceFile("//.gn")));
 494   if (!dotfile_input_file_->Load(dotfile_name_)) {
 495     Err(Location(), "Could not load dotfile.",
 496         "The file \"" + FilePathToUTF8(dotfile_name_) + "\" cound't be loaded")
 497         .PrintToStdout();
 498     return false;
 499   }
 500
 501   Err err;
 502   dotfile_tokens_ = Tokenizer::Tokenize(dotfile_input_file_.get(), &err);
 503   if (err.has_error()) {
 504     err.PrintToStdout();
 505     return false;
 506   }
 507
 508   dotfile_root_ = Parser::Parse(dotfile_tokens_, &err);
 509   if (err.has_error()) {
 510     err.PrintToStdout();
 511     return false;
 512   }
 513
 514   dotfile_root_->AsBlock()->ExecuteBlockInScope(&dotfile_scope_, &err);
 515   if (err.has_error()) {
 516     err.PrintToStdout();
 517     return false;
 518   }
 519
 520   return true;
 521 }
 522
 523 bool Setup::FillOtherConfig(const CommandLine& cmdline) {
 524   Err err;
 525
 526   // Secondary source path, read from the config file if present.
 527   // Read from the config file if present.
 528   const Value* secondary_value =
 529       dotfile_scope_.GetValue("secondary_source", true);
 530   if (secondary_value) {
 531     if (!secondary_value->VerifyTypeIs(Value::STRING, &err)) {
 532       err.PrintToStdout();
 533       return false;
 534     }
 535     build_settings_.SetSecondarySourcePath(
 536         SourceDir(secondary_value->string_value()));
 537   }
 538
 539   // Root build file.
 540   const Value* root_value = dotfile_scope_.GetValue("root", true);
 541   if (root_value) {
 542     if (!root_value->VerifyTypeIs(Value::STRING, &err)) {
 543       err.PrintToStdout();
 544       return false;
 545     }
 546
 547     Label root_target_label =
 548         Label::Resolve(SourceDir("//"), Label(), *root_value, &err);
 549     if (err.has_error()) {
 550       err.PrintToStdout();
 551       return false;
 552     }
 553
 554     root_build_file_ = Loader::BuildFileForLabel(root_target_label);
 555   }
 556
 557   // Build config file.
 558   const Value* build_config_value =
 559       dotfile_scope_.GetValue("buildconfig", true);
 560   if (!build_config_value) {
 561     Err(Location(), "No build config file.",
 562         "Your .gn file (\"" + FilePathToUTF8(dotfile_name_) + "\")\n"
 563         "didn't specify a \"buildconfig\" value.").PrintToStdout();
 564     return false;
 565   } else if (!build_config_value->VerifyTypeIs(Value::STRING, &err)) {
 566     err.PrintToStdout();
 567     return false;
 568   }
 569   build_settings_.set_build_config_file(
 570       SourceFile(build_config_value->string_value()));
 571
 572   return true;
 573 }
 574
 575 // DependentSetup --------------------------------------------------------------
 576
 577 DependentSetup::DependentSetup(Setup* derive_from)
 578     : CommonSetup(*derive_from),
 579       scheduler_(derive_from->GetScheduler()) {
 580   build_settings_.set_item_defined_callback(
 581       base::Bind(&ItemDefinedCallback, scheduler_->main_loop(), builder_));
 582 }
 583
 584 DependentSetup::DependentSetup(DependentSetup* derive_from)
 585     : CommonSetup(*derive_from),
 586       scheduler_(derive_from->GetScheduler()) {
 587   build_settings_.set_item_defined_callback(
 588       base::Bind(&ItemDefinedCallback, scheduler_->main_loop(), builder_));
 589 }
 590
 591 DependentSetup::~DependentSetup() {
 592 }
 593
 594 Scheduler* DependentSetup::GetScheduler() {
 595   return scheduler_;
 596 }
 597
 598 void DependentSetup::RunPreMessageLoop() {
 599   CommonSetup::RunPreMessageLoop();
 600 }
 601
 602 bool DependentSetup::RunPostMessageLoop() {
 603   return CommonSetup::RunPostMessageLoop();
 604 }
 605