Add initial prototype for the GN meta-buildsystem.

tools/gn/target_generator.cc

Index: tools/gn/target_generator.cc
diff --git a/tools/gn/target_generator.cc b/tools/gn/target_generator.cc
new file mode 100644
index 0000000000000000000000000000000000000000..90c8fe65e33cb0b581b02595ed1aafb985b92370
--- /dev/null
+++ b/tools/gn/target_generator.cc
@@ -0,0 +1,334 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tools/gn/target_generator.h"
+
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "tools/gn/build_settings.h"
+#include "tools/gn/config.h"
+#include "tools/gn/config_values_generator.h"
+#include "tools/gn/err.h"
+#include "tools/gn/filesystem_utils.h"
+#include "tools/gn/functions.h"
+#include "tools/gn/input_file.h"
+#include "tools/gn/item_node.h"
+#include "tools/gn/ninja_target_writer.h"
+#include "tools/gn/parse_tree.h"
+#include "tools/gn/scheduler.h"
+#include "tools/gn/scope.h"
+#include "tools/gn/target_manager.h"
+#include "tools/gn/token.h"
+#include "tools/gn/value.h"
+#include "tools/gn/value_extractors.h"
+
+namespace {
+
+bool TypeHasConfigs(Target::OutputType type) {
+  return type == Target::EXECUTABLE ||
+         type == Target::SHARED_LIBRARY ||
+         type == Target::STATIC_LIBRARY ||
+         type == Target::LOADABLE_MODULE;
+}
+
+bool TypeHasConfigValues(Target::OutputType type) {
+  return type == Target::EXECUTABLE ||
+         type == Target::SHARED_LIBRARY ||
+         type == Target::STATIC_LIBRARY ||
+         type == Target::LOADABLE_MODULE;
+}
+
+bool TypeHasSources(Target::OutputType type) {
+  return type != Target::NONE;
+}
+
+bool TypeHasData(Target::OutputType type) {
+  return type != Target::NONE;
+}
+
+bool TypeHasDestDir(Target::OutputType type) {
+  return type == Target::COPY_FILES;
+}
+
+bool TypeHasOutputs(Target::OutputType type) {
+  return type == Target::CUSTOM;
+}
+
+}  // namespace
+
+TargetGenerator::TargetGenerator(Target* target,
+                                 Scope* scope,
+                                 const Token& function_token,
+                                 const std::vector<Value>& args,
+                                 const std::string& output_type,
+                                 Err* err)
+    : target_(target),
+      scope_(scope),
+      function_token_(function_token),
+      args_(args),
+      output_type_(output_type),
+      err_(err),
+      input_directory_(function_token.location().file()->dir()) {
+}
+
+TargetGenerator::~TargetGenerator() {
+}
+
+void TargetGenerator::Run() {
+  // Output type.
+  Target::OutputType output_type = GetOutputType();
+  target_->set_output_type(output_type);
+  if (err_->has_error())
+    return;
+
+  if (TypeHasConfigs(output_type)) {
+    FillConfigs();
+    FillAllDependentConfigs();
+    FillDirectDependentConfigs();
+  }
+  if (TypeHasSources(output_type))
+    FillSources();
+  if (TypeHasData(output_type))
+    FillData();
+  if (output_type == Target::CUSTOM) {
+    FillScript();
+    FillScriptArgs();
+  }
+  if (TypeHasOutputs(output_type))
+    FillOutputs();
+  FillDependencies();  // All types have dependencies.
+
+  if (TypeHasConfigValues(output_type)) {
+    ConfigValuesGenerator gen(&target_->config_values(), scope_,
+                              function_token_, input_directory_, err_);
+    gen.Run();
+    if (err_->has_error())
+      return;
+  }
+
+  if (TypeHasDestDir(output_type))
+    FillDestDir();
+
+  // Set the toolchain as a dependency of the target.
+  // TODO(brettw) currently we lock separately for each config, dep, and
+  // toolchain we add which is bad! Do this in one lock.
+  {
+    ItemTree* tree = &GetBuildSettings()->item_tree();
+    base::AutoLock lock(tree->lock());
+    ItemNode* tc_node =
+        tree->GetExistingNodeLocked(ToolchainLabelForScope(scope_));
+    tree->GetExistingNodeLocked(target_->label())->AddDependency(tc_node);
+  }
+
+  target_->SetGenerated(&function_token_);
+  GetBuildSettings()->target_manager().TargetGenerationComplete(
+      target_->label());
+}
+
+// static
+void TargetGenerator::GenerateTarget(Scope* scope,
+                                     const Token& function_token,
+                                     const std::vector<Value>& args,
+                                     const std::string& output_type,
+                                     Err* err) {
+  // Name is the argument to the function.
+  if (args.size() != 1u || args[0].type() != Value::STRING) {
+    *err = Err(function_token,
+        "Target generator requires one string argument.",
+        "Otherwise I'm not sure what to call this target.");
+    return;
+  }
+
+  // The location of the target is the directory name with no slash at the end.
+  // FIXME(brettw) validate name.
+  const Label& toolchain_label = ToolchainLabelForScope(scope);
+  Label label(function_token.location().file()->dir(),
+              args[0].string_value(),
+              toolchain_label.dir(), toolchain_label.name());
+
+  if (g_scheduler->verbose_logging())
+    g_scheduler->Log("Generating target", label.GetUserVisibleName(true));
+
+  Target* t = scope->settings()->build_settings()->target_manager().GetTarget(
+      label, function_token.range(), NULL, err);
+  if (err->has_error())
+    return;
+
+  TargetGenerator gen(t, scope, function_token, args, output_type, err);
+  gen.Run();
+}
+
+Target::OutputType TargetGenerator::GetOutputType() const {
+  if (output_type_ == functions::kGroup)
+    return Target::NONE;
+  if (output_type_ == functions::kExecutable)
+    return Target::EXECUTABLE;
+  if (output_type_ == functions::kSharedLibrary)
+    return Target::SHARED_LIBRARY;
+  if (output_type_ == functions::kStaticLibrary)
+    return Target::STATIC_LIBRARY;
+  // TODO(brettw) what does loadable module mean?
+  //if (output_type_ == ???)
+  //  return Target::LOADABLE_MODULE;
+  if (output_type_ == functions::kCopy)
+    return Target::COPY_FILES;
+  if (output_type_ == functions::kCustom)
+    return Target::CUSTOM;
+
+  *err_ = Err(function_token_, "Not a known output type",
+              "I am very confused.");
+  return Target::NONE;
+}
+
+void TargetGenerator::FillGenericConfigs(
+    const char* var_name,
+    void (Target::*setter)(std::vector<const Config*>*)) {
+  const Value* value = scope_->GetValue(var_name, true);
+  if (!value)
+    return;
+
+  std::vector<Label> labels;
+  if (!ExtractListOfLabels(*value, input_directory_,
+                           ToolchainLabelForScope(scope_), &labels, err_))
+    return;
+
+  std::vector<const Config*> dest_configs;
+  dest_configs.resize(labels.size());
+  for (size_t i = 0; i < labels.size(); i++) {
+    dest_configs[i] = Config::GetConfig(
+        scope_->settings(),
+        value->list_value()[i].origin()->GetRange(),
+        labels[i], target_, err_);
+    if (err_->has_error())
+      return;
+  }
+  (target_->*setter)(&dest_configs);
+}
+
+void TargetGenerator::FillConfigs() {
+  FillGenericConfigs("configs", &Target::swap_in_configs);
+}
+
+void TargetGenerator::FillAllDependentConfigs() {
+  FillGenericConfigs("all_dependent_configs",
+                     &Target::swap_in_all_dependent_configs);
+}
+
+void TargetGenerator::FillDirectDependentConfigs() {
+  FillGenericConfigs("direct_dependent_configs",
+                     &Target::swap_in_direct_dependent_configs);
+}
+
+void TargetGenerator::FillSources() {
+  const Value* value = scope_->GetValue("sources", true);
+  if (!value)
+    return;
+
+  Target::FileList dest_sources;
+  if (!ExtractListOfRelativeFiles(*value, input_directory_, &dest_sources,
+                                  err_))
+    return;
+  target_->swap_in_sources(&dest_sources);
+}
+
+void TargetGenerator::FillData() {
+  const Value* value = scope_->GetValue("data", true);
+  if (!value)
+    return;
+
+  Target::FileList dest_data;
+  if (!ExtractListOfRelativeFiles(*value, input_directory_, &dest_data,
+                                  err_))
+    return;
+  target_->swap_in_data(&dest_data);
+}
+
+void TargetGenerator::FillDependencies() {
+  const Value* value = scope_->GetValue("deps", true);
+  if (!value)
+    return;
+
+  std::vector<Label> labels;
+  if (!ExtractListOfLabels(*value, input_directory_,
+                           ToolchainLabelForScope(scope_), &labels, err_))
+    return;
+
+  std::vector<const Target*> dest_deps;
+  dest_deps.resize(labels.size());
+  for (size_t i = 0; i < labels.size(); i++) {
+    dest_deps[i] = GetBuildSettings()->target_manager().GetTarget(
+        labels[i], value->list_value()[i].origin()->GetRange(), target_, err_);
+    if (err_->has_error())
+      return;
+  }
+
+  target_->swap_in_deps(&dest_deps);
+}
+
+void TargetGenerator::FillDestDir() {
+  // Destdir is required for all targets that use it.
+  const Value* value = scope_->GetValue("destdir", true);
+  if (!value) {
+    *err_ = Err(function_token_, "This target type requires a \"destdir\".");
+    return;
+  }
+  if (!value->VerifyTypeIs(Value::STRING, err_))
+    return;
+
+  if (!EnsureStringIsInOutputDir(
+          GetBuildSettings()->build_dir(),
+          value->string_value(), *value, err_))
+    return;
+  target_->set_destdir(SourceDir(value->string_value()));
+}
+
+void TargetGenerator::FillScript() {
+  // If this gets called, the target type requires a script, so error out
+  // if it doesn't have one.
+  const Value* value = scope_->GetValue("script", true);
+  if (!value) {
+    *err_ = Err(function_token_, "This target type requires a \"script\".");
+    return;
+  }
+  if (!value->VerifyTypeIs(Value::STRING, err_))
+    return;
+
+  target_->set_script(
+      input_directory_.ResolveRelativeFile(value->string_value()));
+}
+
+void TargetGenerator::FillScriptArgs() {
+  const Value* value = scope_->GetValue("args", true);
+  if (!value)
+    return;
+
+  std::vector<std::string> args;
+  if (!ExtractListOfStringValues(*value, &args, err_))
+    return;
+  target_->swap_in_script_args(&args);
+}
+
+void TargetGenerator::FillOutputs() {
+  const Value* value = scope_->GetValue("outputs", true);
+  if (!value)
+    return;
+
+  Target::FileList outputs;
+  if (!ExtractListOfRelativeFiles(*value, input_directory_, &outputs, err_))
+    return;
+
+  // Validate that outputs are in the output dir.
+  CHECK(outputs.size() == value->list_value().size());
+  for (size_t i = 0; i < outputs.size(); i++) {
+    if (!EnsureStringIsInOutputDir(
+            GetBuildSettings()->build_dir(),
+            outputs[i].value(), value->list_value()[i], err_))
+      return;
+  }
+  target_->swap_in_outputs(&outputs);
+}
+
+const BuildSettings* TargetGenerator::GetBuildSettings() const {
+  return scope_->settings()->build_settings();
+}