Support explicit pools in actions

tools/gn/loader.cc

 // 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/loader.h"
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/err.h"
 #include "tools/gn/filesystem_utils.h"
+#include "tools/gn/functions.h"
 #include "tools/gn/input_file_manager.h"
 #include "tools/gn/parse_tree.h"
+#include "tools/gn/pool.h"
 #include "tools/gn/scheduler.h"
 #include "tools/gn/scope_per_file_provider.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/source_dir.h"
 #include "tools/gn/source_file.h"
 #include "tools/gn/trace.h"
+#include "tools/gn/variables.h"
 
 namespace {
 
 struct SourceFileAndOrigin {
   SourceFileAndOrigin(const SourceFile& f, const LocationRange& o)
       : file(f),
         origin(o) {
   }
 
   SourceFile file;
@@ skipping 301 matching lines @@
       g_scheduler->FailWithError(Err(Location(),
           "The default build config file did not call set_default_toolchain()",
           "If you don't call this, I can't figure out what toolchain to use\n"
           "for all of this code."));
     } else {
       DCHECK(settings->toolchain_label().is_null());
       settings->set_toolchain_label(default_toolchain_label);
     }
   }
 
+  // Create the predefined console pool object.

[brettw, 2017/06/28 21:23:27]

This seems weird to me. It looks like this will be creating a pool in Chrome
named "//build/config:console". I don't know how one is supposed to know about
this.

From what Opera said we don't need this. Let's just delete the console support.
If we need console pools, I'd rather add a "console" variable to the pool
definition and map anything with this flag to the builtin one.

[Petr Hosek, 2017/06/28 23:42:32]

It has "//:console" label but it's accessible through a prebuilt console
variable, similarly to e.g. current_os or current_cpu, so you can do pool =
console. I agree that it's probably easier to remove this altogether if it's no
longer needed.

+  Label label(MakeLabelForScope(base_config, nullptr, "console"));
+  std::unique_ptr<Pool> pool(new Pool(base_config->settings(), label));
+  pool->set_console(true);
+  Value console_val(nullptr, label.GetUserVisibleName(true));
+  base_config->SetValue(variables::kConsole, console_val, nullptr);
+  settings->build_settings()->ItemDefined(std::move(pool));
+
   task_runner_->PostTask(FROM_HERE,
                          base::Bind(&LoaderImpl::DidLoadBuildConfig, this,
                                     settings->toolchain_label()));
 }
 
 void LoaderImpl::DidLoadFile() {
   DecrementPendingLoads();
 }
 
 void LoaderImpl::DidLoadBuildConfig(const Label& label) {
@@ skipping 69 matching lines @@
     const SourceFile& file_name,
     const base::Callback<void(const ParseNode*)>& callback,
     Err* err) {
   if (async_load_file_.is_null()) {
     return g_scheduler->input_file_manager()->AsyncLoadFile(
         origin, build_settings, file_name, callback, err);
   }
   return async_load_file_.Run(
       origin, build_settings, file_name, callback, err);
 }