tools/gn/command_gen.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/atomicops.h"
   6 #include "base/bind.h"
   7 #include "base/command_line.h"
   8 #include "base/strings/string_number_conversions.h"
   9 #include "base/strings/stringprintf.h"
  10 #include "base/timer/elapsed_timer.h"
  11 #include "tools/gn/build_settings.h"
  12 #include "tools/gn/commands.h"
  13 #include "tools/gn/ninja_target_writer.h"
  14 #include "tools/gn/ninja_writer.h"
  15 #include "tools/gn/runtime_deps.h"
  16 #include "tools/gn/scheduler.h"
  17 #include "tools/gn/setup.h"
  18 #include "tools/gn/standard_out.h"
  19 #include "tools/gn/switches.h"
  20 #include "tools/gn/target.h"
  21
  22 namespace commands {
  23
  24 namespace {
  25
  26 const char kSwitchCheck[] = "check";
  27
  28 // Called on worker thread to write the ninja file.
  29 void BackgroundDoWrite(const Target* target) {
  30   NinjaTargetWriter::RunAndWriteFile(target);
  31   g_scheduler->DecrementWorkCount();
  32 }
  33
  34 // Called on the main thread.
  35 void ItemResolvedCallback(base::subtle::Atomic32* write_counter,
  36                           scoped_refptr<Builder> builder,
  37                           const BuilderRecord* record) {
  38   base::subtle::NoBarrier_AtomicIncrement(write_counter, 1);
  39
  40   const Item* item = record->item();
  41   const Target* target = item->AsTarget();
  42   if (target) {
  43     g_scheduler->IncrementWorkCount();
  44     g_scheduler->ScheduleWork(base::Bind(&BackgroundDoWrite, target));
  45   }
  46 }
  47
  48 // Returns a pointer to the target with the given file as an output, or null
  49 // if no targets generate the file. This is brute force since this is an
  50 // error condition and performance shouldn't matter.
  51 const Target* FindTargetThatGeneratesFile(const Builder* builder,
  52                                           const SourceFile& file) {
  53   std::vector<const Target*> targets = builder->GetAllResolvedTargets();
  54   if (targets.empty())
  55     return nullptr;
  56
  57   OutputFile output_file(targets[0]->settings()->build_settings(), file);
  58   for (const Target* target : targets) {
  59     for (const auto& cur_output : target->computed_outputs()) {
  60       if (cur_output == output_file)
  61         return target;
  62     }
  63   }
  64   return nullptr;
  65 }
  66
  67 // Prints an error that the given file was present as a source or input in
  68 // the given target(s) but was not generated by any of its dependencies.
  69 void PrintInvalidGeneratedInput(const Builder* builder,
  70                                 const SourceFile& file,
  71                                 const std::vector<const Target*>& targets) {
  72   std::string err;
  73
  74   const std::string target_str = targets.size() > 1 ? "targets" : "target";
  75   err += "The file:\n";
  76   err += "  " + file.value() + "\n";
  77   err += "is listed as an input or source for the " + target_str + ":\n";
  78   for (const Target* target : targets)
  79     err += "  " + target->label().GetUserVisibleName(false) + "\n";
  80
  81   const Target* generator = FindTargetThatGeneratesFile(builder, file);
  82   if (generator) {
  83     err += "but this file was not generated by any dependencies of the " +
  84         target_str + ". The target\nthat generates the file is:\n  ";
  85     err += generator->label().GetUserVisibleName(false);
  86   } else {
  87     err += "but no targets in the build generate that file.";
  88   }
  89
  90   Err(Location(), "Input to " + target_str + " not generated by a dependency.",
  91       err).PrintToStdout();
  92 }
  93
  94 bool CheckForInvalidGeneratedInputs(Setup* setup) {
  95   std::multimap<SourceFile, const Target*> unknown_inputs =
  96       g_scheduler->GetUnknownGeneratedInputs();
  97   if (unknown_inputs.empty())
  98     return true;  // No bad files.
  99
 100   int errors_found = 0;
 101   auto cur = unknown_inputs.begin();
 102   while (cur != unknown_inputs.end()) {
 103     errors_found++;
 104     auto end_of_range = unknown_inputs.upper_bound(cur->first);
 105
 106     // Package the values more conveniently for printing.
 107     SourceFile bad_input = cur->first;
 108     std::vector<const Target*> targets;
 109     while (cur != end_of_range)
 110       targets.push_back((cur++)->second);
 111
 112     PrintInvalidGeneratedInput(setup->builder(), bad_input, targets);
 113     OutputString("\n");
 114   }
 115
 116   OutputString(
 117       "If you have generated inputs, there needs to be a dependency path "
 118       "between the\ntwo targets in addition to just listing the files. For "
 119       "indirect dependencies,\nthe intermediate ones must be public_deps. "
 120       "data_deps don't count since they're\nonly runtime dependencies. If "
 121       "you think a dependency chain exists, it might be\nbecause the chain "
 122       "is private. Try \"gn path\" to analyze.\n");
 123
 124   if (errors_found > 1) {
 125     OutputString(base::StringPrintf("\n%d generated input errors found.\n",
 126                                     errors_found), DECORATION_YELLOW);
 127   }
 128   return false;
 129 }
 130
 131 }  // namespace
 132
 133 const char kGen[] = "gen";
 134 const char kGen_HelpShort[] =
 135     "gen: Generate ninja files.";
 136 const char kGen_Help[] =
 137     "gn gen: Generate ninja files.\n"
 138     "\n"
 139     "  gn gen <out_dir>\n"
 140     "\n"
 141     "  Generates ninja files from the current tree and puts them in the given\n"
 142     "  output directory.\n"
 143     "\n"
 144     "  The output directory can be a source-repo-absolute path name such as:\n"
 145     "      //out/foo\n"
 146     "  Or it can be a directory relative to the current directory such as:\n"
 147     "      out/foo\n"
 148     "\n"
 149     "  See \"gn help\" for the common command-line switches.\n";
 150
 151 int RunGen(const std::vector<std::string>& args) {
 152   base::ElapsedTimer timer;
 153
 154   if (args.size() != 1) {
 155     Err(Location(), "Need exactly one build directory to generate.",
 156         "I expected something more like \"gn gen out/foo\"\n"
 157         "You can also see \"gn help gen\".").PrintToStdout();
 158     return 1;
 159   }
 160
 161   // Deliberately leaked to avoid expensive process teardown.
 162   Setup* setup = new Setup();
 163   if (!setup->DoSetup(args[0], true))
 164     return 1;
 165
 166   if (base::CommandLine::ForCurrentProcess()->HasSwitch(kSwitchCheck))
 167     setup->set_check_public_headers(true);
 168
 169   // Cause the load to also generate the ninja files for each target. We wrap
 170   // the writing to maintain a counter.
 171   base::subtle::Atomic32 write_counter = 0;
 172   setup->builder()->set_resolved_callback(
 173       base::Bind(&ItemResolvedCallback, &write_counter,
 174                  scoped_refptr<Builder>(setup->builder())));
 175
 176   // Do the actual load. This will also write out the target ninja files.
 177   if (!setup->Run())
 178     return 1;
 179
 180   Err err;
 181   // Write the root ninja files.
 182   if (!NinjaWriter::RunAndWriteFiles(&setup->build_settings(),
 183                                      setup->builder(),
 184                                      &err)) {
 185     err.PrintToStdout();
 186     return 1;
 187   }
 188
 189   if (!WriteRuntimeDepsFilesIfNecessary(*setup->builder(), &err)) {
 190     err.PrintToStdout();
 191     return 1;
 192   }
 193
 194   if (!CheckForInvalidGeneratedInputs(setup))
 195     return 1;
 196
 197   base::TimeDelta elapsed_time = timer.Elapsed();
 198
 199   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kQuiet)) {
 200     OutputString("Done. ", DECORATION_GREEN);
 201
 202     std::string stats = "Wrote " +
 203         base::IntToString(static_cast<int>(write_counter)) +
 204         " targets from " +
 205         base::IntToString(
 206             setup->scheduler().input_file_manager()->GetInputFileCount()) +
 207         " files in " +
 208         base::Int64ToString(elapsed_time.InMilliseconds()) + "ms\n";
 209     OutputString(stats);
 210   }
 211
 212   return 0;
 213 }
 214
 215 }  // namespace commands