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
  11 #include "base/bind.h"
  12 #include "base/command_line.h"
  13 #include "base/file_util.h"
  14 #include "base/files/file_path.h"
  15 #include "base/process/launch.h"
  16 #include "base/strings/string_split.h"
  17 #include "base/strings/string_util.h"
  18 #include "base/strings/utf_string_conversions.h"
  19 #include "build/build_config.h"
  20 #include "tools/gn/filesystem_utils.h"
  21 #include "tools/gn/input_file.h"
  22 #include "tools/gn/parse_tree.h"
  23 #include "tools/gn/parser.h"
  24 #include "tools/gn/source_dir.h"
  25 #include "tools/gn/source_file.h"
  26 #include "tools/gn/standard_out.h"
  27 #include "tools/gn/tokenizer.h"
  28 #include "tools/gn/trace.h"
  29 #include "tools/gn/value.h"
  30
  31 #if defined(OS_WIN)
  32 #include <windows.h>
  33 #endif
  34
  35 extern const char kDotfile_Help[] =
  36     ".gn file\n"
  37     "\n"
  38     "  When gn starts, it will search the current directory and parent\n"
  39     "  directories for a file called \".gn\". This indicates the source root.\n"
  40     "  You can override this detection by using the --root command-line\n"
  41     "  argument\n"
  42     "\n"
  43     "  The .gn file in the source root will be executed. The syntax is the\n"
  44     "  same as a buildfile, but with very limited build setup-specific\n"
  45     "  meaning.\n"
  46     "\n"
  47     "Variables\n"
  48     "\n"
  49     "  buildconfig [required]\n"
  50     "      Label of the build config file. This file will be used to setup\n"
  51     "      the build file execution environment for each toolchain.\n"
  52     "\n"
  53     "  secondary_source [optional]\n"
  54     "      Label of an alternate directory tree to find input files. When\n"
  55     "      searching for a BUILD.gn file (or the build config file discussed\n"
  56     "      above), the file fill first be looked for in the source root.\n"
  57     "      If it's not found, the secondary source root will be checked\n"
  58     "      (which would contain a parallel directory hierarchy).\n"
  59     "\n"
  60     "      This behavior is intended to be used when BUILD.gn files can't be\n"
  61     "      checked in to certain source directories for whatever reason.\n"
  62     "\n"
  63     "      The secondary source root must be inside the main source tree.\n"
  64     "\n"
  65     "Example .gn file contents\n"
  66     "\n"
  67     "  buildconfig = \"//build/config/BUILDCONFIG.gn\"\n"
  68     "\n"
  69     "  secondary_source = \"//build/config/temporary_buildfiles/\"\n";
  70
  71 namespace {
  72
  73 // More logging.
  74 const char kSwitchVerbose[] = "v";
  75
  76 // Set build args.
  77 const char kSwitchArgs[] = "args";
  78
  79 // Set root dir.
  80 const char kSwitchRoot[] = "root";
  81
  82 // Enable timing.
  83 const char kTimeSwitch[] = "time";
  84
  85 const char kTracelogSwitch[] = "tracelog";
  86
  87 const char kSecondarySource[] = "secondary";
  88
  89 const base::FilePath::CharType kGnFile[] = FILE_PATH_LITERAL(".gn");
  90
  91 base::FilePath FindDotFile(const base::FilePath& current_dir) {
  92   base::FilePath try_this_file = current_dir.Append(kGnFile);
  93   if (base::PathExists(try_this_file))
  94     return try_this_file;
  95
  96   base::FilePath with_no_slash = current_dir.StripTrailingSeparators();
  97   base::FilePath up_one_dir = with_no_slash.DirName();
  98   if (up_one_dir == current_dir)
  99     return base::FilePath();  // Got to the top.
 100
 101   return FindDotFile(up_one_dir);
 102 }
 103
 104 // Called on any thread. Post the item to the builder on the main thread.
 105 void ItemDefinedCallback(base::MessageLoop* main_loop,
 106                          scoped_refptr<Builder> builder,
 107                          scoped_ptr<Item> item) {
 108   DCHECK(item);
 109   main_loop->PostTask(FROM_HERE, base::Bind(&Builder::ItemDefined, builder,
 110                                             base::Passed(&item)));
 111 }
 112
 113 void DecrementWorkCount() {
 114   g_scheduler->DecrementWorkCount();
 115 }
 116
 117 }  // namespace
 118
 119 // CommonSetup -----------------------------------------------------------------
 120
 121 CommonSetup::CommonSetup()
 122     : build_settings_(),
 123       loader_(new LoaderImpl(&build_settings_)),
 124       builder_(new Builder(loader_.get())),
 125       check_for_bad_items_(true),
 126       check_for_unused_overrides_(true) {
 127   loader_->set_complete_callback(base::Bind(&DecrementWorkCount));
 128 }
 129
 130 CommonSetup::CommonSetup(const CommonSetup& other)
 131     : build_settings_(other.build_settings_),
 132       loader_(new LoaderImpl(&build_settings_)),
 133       builder_(new Builder(loader_.get())),
 134       check_for_bad_items_(other.check_for_bad_items_),
 135       check_for_unused_overrides_(other.check_for_unused_overrides_) {
 136   loader_->set_complete_callback(base::Bind(&DecrementWorkCount));
 137 }
 138
 139 CommonSetup::~CommonSetup() {
 140 }
 141
 142 void CommonSetup::RunPreMessageLoop() {
 143   // Load the root build file.
 144   loader_->Load(SourceFile("//BUILD.gn"), Label());
 145
 146   // Will be decremented with the loader is drained.
 147   g_scheduler->IncrementWorkCount();
 148 }
 149
 150 bool CommonSetup::RunPostMessageLoop() {
 151   Err err;
 152   if (check_for_bad_items_) {
 153     if (!builder_->CheckForBadItems(&err)) {
 154       err.PrintToStdout();
 155       return false;
 156     }
 157   }
 158
 159   if (check_for_unused_overrides_) {
 160     if (!build_settings_.build_args().VerifyAllOverridesUsed(&err)) {
 161       // TODO(brettw) implement a system of warnings. Until we have a better
 162       // system, print the error but don't return failure.
 163       err.PrintToStdout();
 164       return true;
 165     }
 166   }
 167
 168   // Write out tracing and timing if requested.
 169   const CommandLine* cmdline = CommandLine::ForCurrentProcess();
 170   if (cmdline->HasSwitch(kTimeSwitch))
 171     PrintLongHelp(SummarizeTraces());
 172   if (cmdline->HasSwitch(kTracelogSwitch))
 173     SaveTraces(cmdline->GetSwitchValuePath(kTracelogSwitch));
 174
 175   return true;
 176 }
 177
 178 // Setup -----------------------------------------------------------------------
 179
 180 Setup::Setup()
 181     : CommonSetup(),
 182       empty_settings_(&empty_build_settings_, std::string()),
 183       dotfile_scope_(&empty_settings_) {
 184   empty_settings_.set_toolchain_label(Label());
 185   build_settings_.set_item_defined_callback(
 186       base::Bind(&ItemDefinedCallback, scheduler_.main_loop(), builder_));
 187
 188   // The scheduler's main loop wasn't created when the Loader was created, so
 189   // we need to set it now.
 190   loader_->set_main_loop(scheduler_.main_loop());
 191 }
 192
 193 Setup::~Setup() {
 194 }
 195
 196 bool Setup::DoSetup(const std::string& build_dir) {
 197   CommandLine* cmdline = CommandLine::ForCurrentProcess();
 198
 199   scheduler_.set_verbose_logging(cmdline->HasSwitch(kSwitchVerbose));
 200   if (cmdline->HasSwitch(kTimeSwitch) ||
 201       cmdline->HasSwitch(kTracelogSwitch))
 202     EnableTracing();
 203
 204   if (!FillArguments(*cmdline))
 205     return false;
 206   if (!FillSourceDir(*cmdline))
 207     return false;
 208   if (!RunConfigFile())
 209     return false;
 210   if (!FillOtherConfig(*cmdline))
 211     return false;
 212   if (!FillBuildDir(build_dir))  // Must be after FillSourceDir to resolve.
 213     return false;
 214   FillPythonPath();
 215
 216   return true;
 217 }
 218
 219 bool Setup::Run() {
 220   RunPreMessageLoop();
 221   if (!scheduler_.Run())
 222     return false;
 223   return RunPostMessageLoop();
 224 }
 225
 226 Scheduler* Setup::GetScheduler() {
 227   return &scheduler_;
 228 }
 229
 230 bool Setup::FillArguments(const CommandLine& cmdline) {
 231   std::string args = cmdline.GetSwitchValueASCII(kSwitchArgs);
 232   if (args.empty())
 233     return true;  // Nothing to set.
 234
 235   args_input_file_.reset(new InputFile(SourceFile()));
 236   args_input_file_->SetContents(args);
 237   args_input_file_->set_friendly_name("the command-line \"--args\" settings");
 238
 239   Err err;
 240   args_tokens_ = Tokenizer::Tokenize(args_input_file_.get(), &err);
 241   if (err.has_error()) {
 242     err.PrintToStdout();
 243     return false;
 244   }
 245
 246   args_root_ = Parser::Parse(args_tokens_, &err);
 247   if (err.has_error()) {
 248     err.PrintToStdout();
 249     return false;
 250   }
 251
 252   Scope arg_scope(&empty_settings_);
 253   args_root_->AsBlock()->ExecuteBlockInScope(&arg_scope, &err);
 254   if (err.has_error()) {
 255     err.PrintToStdout();
 256     return false;
 257   }
 258
 259   // Save the result of the command args.
 260   Scope::KeyValueMap overrides;
 261   arg_scope.GetCurrentScopeValues(&overrides);
 262   build_settings_.build_args().AddArgOverrides(overrides);
 263   return true;
 264 }
 265
 266 bool Setup::FillSourceDir(const CommandLine& cmdline) {
 267   // Find the .gn file.
 268   base::FilePath root_path;
 269
 270   // Prefer the command line args to the config file.
 271   base::FilePath relative_root_path = cmdline.GetSwitchValuePath(kSwitchRoot);
 272   if (!relative_root_path.empty()) {
 273     root_path = base::MakeAbsoluteFilePath(relative_root_path);
 274     dotfile_name_ = root_path.Append(kGnFile);
 275   } else {
 276     base::FilePath cur_dir;
 277     base::GetCurrentDirectory(&cur_dir);
 278     dotfile_name_ = FindDotFile(cur_dir);
 279     if (dotfile_name_.empty()) {
 280       Err(Location(), "Can't find source root.",
 281           "I could not find a \".gn\" file in the current directory or any "
 282           "parent,\nand the --root command-line argument was not specified.")
 283           .PrintToStdout();
 284       return false;
 285     }
 286     root_path = dotfile_name_.DirName();
 287   }
 288
 289   if (scheduler_.verbose_logging())
 290     scheduler_.Log("Using source root", FilePathToUTF8(root_path));
 291   build_settings_.SetRootPath(root_path);
 292
 293   return true;
 294 }
 295
 296 bool Setup::FillBuildDir(const std::string& build_dir) {
 297   SourceDir resolved =
 298       SourceDirForCurrentDirectory(build_settings_.root_path()).
 299           ResolveRelativeDir(build_dir);
 300   if (resolved.is_null()) {
 301     Err(Location(), "Couldn't resolve build directory.",
 302         "The build directory supplied (\"" + build_dir + "\") was not valid.").
 303         PrintToStdout();
 304     return false;
 305   }
 306
 307   if (scheduler_.verbose_logging())
 308     scheduler_.Log("Using build dir", resolved.value());
 309   build_settings_.SetBuildDir(resolved);
 310   return true;
 311 }
 312
 313 void Setup::FillPythonPath() {
 314 #if defined(OS_WIN)
 315   // Find Python on the path so we can use the absolute path in the build.
 316   const base::char16 kGetPython[] =
 317       L"cmd.exe /c python -c \"import sys; print sys.executable\"";
 318   std::string python_path;
 319   if (base::GetAppOutput(kGetPython, &python_path)) {
 320     base::TrimWhitespaceASCII(python_path, base::TRIM_ALL, &python_path);
 321     if (scheduler_.verbose_logging())
 322       scheduler_.Log("Found python", python_path);
 323   } else {
 324     scheduler_.Log("WARNING", "Could not find python on path, using "
 325         "just \"python.exe\"");
 326     python_path = "python.exe";
 327   }
 328   build_settings_.set_python_path(base::FilePath(base::UTF8ToUTF16(python_path))
 329                                       .NormalizePathSeparatorsTo('/'));
 330 #else
 331   build_settings_.set_python_path(base::FilePath("python"));
 332 #endif
 333 }
 334
 335 bool Setup::RunConfigFile() {
 336   if (scheduler_.verbose_logging())
 337     scheduler_.Log("Got dotfile", FilePathToUTF8(dotfile_name_));
 338
 339   dotfile_input_file_.reset(new InputFile(SourceFile("//.gn")));
 340   if (!dotfile_input_file_->Load(dotfile_name_)) {
 341     Err(Location(), "Could not load dotfile.",
 342         "The file \"" + FilePathToUTF8(dotfile_name_) + "\" cound't be loaded")
 343         .PrintToStdout();
 344     return false;
 345   }
 346
 347   Err err;
 348   dotfile_tokens_ = Tokenizer::Tokenize(dotfile_input_file_.get(), &err);
 349   if (err.has_error()) {
 350     err.PrintToStdout();
 351     return false;
 352   }
 353
 354   dotfile_root_ = Parser::Parse(dotfile_tokens_, &err);
 355   if (err.has_error()) {
 356     err.PrintToStdout();
 357     return false;
 358   }
 359
 360   dotfile_root_->AsBlock()->ExecuteBlockInScope(&dotfile_scope_, &err);
 361   if (err.has_error()) {
 362     err.PrintToStdout();
 363     return false;
 364   }
 365
 366   return true;
 367 }
 368
 369 bool Setup::FillOtherConfig(const CommandLine& cmdline) {
 370   Err err;
 371
 372   // Secondary source path.
 373   SourceDir secondary_source;
 374   if (cmdline.HasSwitch(kSecondarySource)) {
 375     // Prefer the command line over the config file.
 376     secondary_source =
 377         SourceDir(cmdline.GetSwitchValueASCII(kSecondarySource));
 378   } else {
 379     // Read from the config file if present.
 380     const Value* secondary_value =
 381         dotfile_scope_.GetValue("secondary_source", true);
 382     if (secondary_value) {
 383       if (!secondary_value->VerifyTypeIs(Value::STRING, &err)) {
 384         err.PrintToStdout();
 385         return false;
 386       }
 387       build_settings_.SetSecondarySourcePath(
 388           SourceDir(secondary_value->string_value()));
 389     }
 390   }
 391
 392   // Build config file.
 393   const Value* build_config_value =
 394       dotfile_scope_.GetValue("buildconfig", true);
 395   if (!build_config_value) {
 396     Err(Location(), "No build config file.",
 397         "Your .gn file (\"" + FilePathToUTF8(dotfile_name_) + "\")\n"
 398         "didn't specify a \"buildconfig\" value.").PrintToStdout();
 399     return false;
 400   } else if (!build_config_value->VerifyTypeIs(Value::STRING, &err)) {
 401     err.PrintToStdout();
 402     return false;
 403   }
 404   build_settings_.set_build_config_file(
 405       SourceFile(build_config_value->string_value()));
 406
 407   return true;
 408 }
 409
 410 // DependentSetup --------------------------------------------------------------
 411
 412 DependentSetup::DependentSetup(Setup* derive_from)
 413     : CommonSetup(*derive_from),
 414       scheduler_(derive_from->GetScheduler()) {
 415   build_settings_.set_item_defined_callback(
 416       base::Bind(&ItemDefinedCallback, scheduler_->main_loop(), builder_));
 417 }
 418
 419 DependentSetup::DependentSetup(DependentSetup* derive_from)
 420     : CommonSetup(*derive_from),
 421       scheduler_(derive_from->GetScheduler()) {
 422   build_settings_.set_item_defined_callback(
 423       base::Bind(&ItemDefinedCallback, scheduler_->main_loop(), builder_));
 424 }
 425
 426 DependentSetup::~DependentSetup() {
 427 }
 428
 429 Scheduler* DependentSetup::GetScheduler() {
 430   return scheduler_;
 431 }
 432
 433 void DependentSetup::RunPreMessageLoop() {
 434   CommonSetup::RunPreMessageLoop();
 435 }
 436
 437 bool DependentSetup::RunPostMessageLoop() {
 438   return CommonSetup::RunPostMessageLoop();
 439 }
 440