Revert 214254 "Add initial prototype for the GN meta-buildsystem."

trunk/src/tools/gn/toolchain_manager.cc

Index: trunk/src/tools/gn/toolchain_manager.cc
===================================================================
--- trunk/src/tools/gn/toolchain_manager.cc	(revision 214322)
+++ trunk/src/tools/gn/toolchain_manager.cc	(working copy)
@@ -1,480 +0,0 @@
-// 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/toolchain_manager.h"
-
-#include <set>
-
-#include "base/bind.h"
-#include "tools/gn/err.h"
-#include "tools/gn/item.h"
-#include "tools/gn/item_node.h"
-#include "tools/gn/item_tree.h"
-#include "tools/gn/parse_tree.h"
-#include "tools/gn/scheduler.h"
-#include "tools/gn/scope.h"
-#include "tools/gn/scope_per_file_provider.h"
-
-namespace {
-
-SourceFile DirToBuildFile(const SourceDir& dir) {
-  return SourceFile(dir.value() + "BUILD.gn");
-}
-
-void SetSystemVars(const Settings& settings, Scope* scope) {
-  // FIXME(brettw) port.
-  scope->SetValue("is_win", Value(NULL, 1), NULL);
-  scope->SetValue("is_linux", Value(NULL, 0), NULL);
-  scope->SetValue("is_posix", Value(NULL, 0), NULL);
-  scope->SetValue("is_mac", Value(NULL, 0), NULL);
-  scope->SetValue("is_android", Value(NULL, 0), NULL);
-  scope->SetValue("is_ios", Value(NULL, 0), NULL);
-
-  // Set this value without the terminating slash because the code expects
-  // $root_output_dir/foo to work.
-  scope->SetValue(ScopePerFileProvider::kRootOutputDirName,
-                  ScopePerFileProvider::GetRootOutputDir(&settings),
-                  NULL);
-  scope->SetValue(ScopePerFileProvider::kRootGenDirName,
-                  ScopePerFileProvider::GetRootGenDir(&settings),
-                  NULL);
-}
-
-}  // namespace
-
-struct ToolchainManager::Info {
-  Info(const BuildSettings* build_settings,
-       const Label& toolchain_name,
-       const std::string& output_subdir_name)
-      : state(TOOLCHAIN_SETTINGS_NOT_LOADED),
-        toolchain(toolchain_name),
-        toolchain_set(false),
-        settings(build_settings, &toolchain, output_subdir_name),
-        item_node(NULL) {
-  }
-
-  // MAkes sure that an ItemNode is created for the toolchain, which lets
-  // targets depend on the (potentially future) loading of the toolchain.
-  //
-  // We can't always do this at the beginning since when doing the default
-  // build config, we don't know the toolchain name yet. We also need to go
-  // through some effort to avoid doing this inside the toolchain manager's
-  // lock (to avoid holding two locks at once).
-  void EnsureItemNode() {
-    if (!item_node) {
-      ItemTree& tree = settings.build_settings()->item_tree();
-      item_node = new ItemNode(&toolchain);
-      tree.AddNodeLocked(item_node);
-    }
-  }
-
-  SettingsState state;
-
-  Toolchain toolchain;
-  bool toolchain_set;
-  LocationRange toolchain_definition_location;
-
-  // When the state is TOOLCHAIN_SETTINGS_LOADED, the settings should be
-  // considered read-only and can be read without locking. Otherwise, they
-  // should not be accessed at all except to load them (which can therefore
-  // also be done outside of the lock). This works as long as the state flag
-  // is only ever read or written inside the lock.
-  Settings settings;
-
-  // While state == TOOLCHAIN_SETTINGS_LOADING, this will collect all
-  // scheduled invocations using this toolchain. They'll be issued once the
-  // settings file has been interpreted.
-  //
-  // The map maps the source file to "some" location it was invoked from (so
-  // we can give good error messages. It does NOT map to the root of the
-  // file to be invoked (the file still needs loading). This will be NULL
-  // for internally invoked files.
-  typedef std::map<SourceFile, LocationRange> ScheduledInvocationMap;
-  ScheduledInvocationMap scheduled_invocations;
-
-  // Tracks all scheduled and executed invocations for this toolchain. This
-  // is used to avoid invoking a file more than once for a toolchain.
-  std::set<SourceFile> all_invocations;
-
-  // Filled in by EnsureItemNode, see that for more.
-  ItemNode* item_node;
-};
-
-ToolchainManager::ToolchainManager(const BuildSettings* build_settings)
-    : build_settings_(build_settings) {
-}
-
-ToolchainManager::~ToolchainManager() {
-  for (ToolchainMap::iterator i = toolchains_.begin();
-       i != toolchains_.end(); ++i)
-    delete i->second;
-  toolchains_.clear();
-}
-
-void ToolchainManager::StartLoadingUnlocked(const SourceFile& build_file_name) {
-  // How the default build config works: Initially we don't have a toolchain
-  // name to call the settings for the default build config. So we create one
-  // with an empty toolchain name and execute the default build config file.
-  // When that's done, we'll go and fix up the name to the default build config
-  // that the script set.
-  base::AutoLock lock(GetLock());
-  Err err;
-  Info* info = LoadNewToolchainLocked(LocationRange(), Label(), &err);
-  if (err.has_error())
-    g_scheduler->FailWithError(err);
-  CHECK(info);
-  info->scheduled_invocations[build_file_name] = LocationRange();
-  info->all_invocations.insert(build_file_name);
-
-  g_scheduler->IncrementWorkCount();
-  if (!g_scheduler->input_file_manager()->AsyncLoadFile(
-           LocationRange(), build_settings_,
-           build_settings_->build_config_file(),
-           base::Bind(&ToolchainManager::BackgroundLoadBuildConfig,
-                      base::Unretained(this), info, true),
-           &err)) {
-    g_scheduler->FailWithError(err);
-    g_scheduler->DecrementWorkCount();
-  }
-}
-
-const Settings* ToolchainManager::GetSettingsForToolchainLocked(
-    const LocationRange& from_here,
-    const Label& toolchain_name,
-    Err* err) {
-  GetLock().AssertAcquired();
-  ToolchainMap::iterator found = toolchains_.find(toolchain_name);
-  Info* info = NULL;
-  if (found == toolchains_.end()) {
-    info = LoadNewToolchainLocked(from_here, toolchain_name, err);
-    if (!info)
-      return NULL;
-  } else {
-    info = found->second;
-  }
-  info->EnsureItemNode();
-
-  return &info->settings;
-}
-
-const Toolchain* ToolchainManager::GetToolchainDefinitionUnlocked(
-    const Label& toolchain_name) {
-  base::AutoLock lock(GetLock());
-  ToolchainMap::iterator found = toolchains_.find(toolchain_name);
-  if (found == toolchains_.end() || !found->second->toolchain_set)
-    return NULL;
-
-  // Since we don't allow defining a toolchain more than once, we know that
-  // once it's set it won't be mutated, so we can safely return this pointer
-  // for reading outside the lock.
-  return &found->second->toolchain;
-}
-
-bool ToolchainManager::SetDefaultToolchainUnlocked(
-    const Label& default_toolchain,
-    const LocationRange& defined_here,
-    Err* err) {
-  base::AutoLock lock(GetLock());
-  if (!default_toolchain_.is_null()) {
-    *err = Err(defined_here, "Default toolchain already set.");
-    err->AppendSubErr(Err(default_toolchain_defined_here_,
-                          "Previously defined here.",
-                          "You can only set this once."));
-    return false;
-  }
-
-  if (default_toolchain.is_null()) {
-    *err = Err(defined_here, "Bad default toolchain name.",
-        "You can't set the default toolchain name to nothing.");
-    return false;
-  }
-  if (!default_toolchain.toolchain_dir().is_null() ||
-      !default_toolchain.toolchain_name().empty()) {
-    *err = Err(defined_here, "Toolchain name has toolchain.",
-        "You can't specify a toolchain (inside the parens) for a toolchain "
-        "name. I got:\n" + default_toolchain.GetUserVisibleName(true));
-    return false;
-  }
-
-  default_toolchain_ = default_toolchain;
-  default_toolchain_defined_here_ = defined_here;
-  return true;
-}
-
-Label ToolchainManager::GetDefaultToolchainUnlocked() const {
-  base::AutoLock lock(GetLock());
-  return default_toolchain_;
-}
-
-bool ToolchainManager::SetToolchainDefinitionLocked(
-    const Toolchain& tc,
-    const LocationRange& defined_from,
-    Err* err) {
-  GetLock().AssertAcquired();
-
-  ToolchainMap::iterator found = toolchains_.find(tc.label());
-  Info* info = NULL;
-  if (found == toolchains_.end()) {
-    // New toolchain.
-    info = LoadNewToolchainLocked(defined_from, tc.label(), err);
-    if (!info)
-      return false;
-  } else {
-    // It's important to preserve the exact Toolchain object in our tree since
-    // it will be in the ItemTree and targets may have dependencies on it.
-    info = found->second;
-  }
-
-  // The labels should match or else we're setting the wrong one!
-  CHECK(info->toolchain.label() == tc.label());
-
-  info->toolchain = tc;
-  if (info->toolchain_set) {
-    *err = Err(defined_from, "Duplicate toolchain definition.");
-    err->AppendSubErr(Err(
-        info->toolchain_definition_location,
-        "Previously defined here.",
-        "A toolchain can only be defined once. One tricky way that this could\n"
-        "happen is if your definition is itself in a file that's interpreted\n"
-        "under different toolchains, which would result in multiple\n"
-        "definitions as the file is loaded multiple times. So be sure your\n"
-        "toolchain definitions are in files that either don't define any\n"
-        "targets (probably best) or at least don't contain targets executed\n"
-        "with more than one toolchain."));
-    return false;
-  }
-
-  info->EnsureItemNode();
-
-  info->toolchain_set = true;
-  info->toolchain_definition_location = defined_from;
-  return true;
-}
-
-bool ToolchainManager::ScheduleInvocationLocked(
-    const LocationRange& specified_from,
-    const Label& toolchain_name,
-    const SourceDir& dir,
-    Err* err) {
-  GetLock().AssertAcquired();
-  SourceFile build_file(DirToBuildFile(dir));
-
-  ToolchainMap::iterator found = toolchains_.find(toolchain_name);
-  Info* info = NULL;
-  if (found == toolchains_.end()) {
-    // New toolchain.
-    info = LoadNewToolchainLocked(specified_from, toolchain_name, err);
-    if (!info)
-      return false;
-  } else {
-    // Use existing one.
-    info = found->second;
-    if (info->all_invocations.find(build_file) !=
-        info->all_invocations.end()) {
-      // We've already seen this source file for this toolchain, don't need
-      // to do anything.
-      return true;
-    }
-  }
-
-  info->all_invocations.insert(build_file);
-
-  // True if the settings load needs to be scheduled.
-  bool info_needs_settings_load = false;
-
-  // True if the settings load has completed.
-  bool info_settings_loaded = false;
-
-  switch (info->state) {
-    case TOOLCHAIN_SETTINGS_NOT_LOADED:
-      info_needs_settings_load = true;
-      info->scheduled_invocations[build_file] = specified_from;
-      break;
-
-    case TOOLCHAIN_SETTINGS_LOADING:
-      info->scheduled_invocations[build_file] = specified_from;
-      break;
-
-    case TOOLCHAIN_SETTINGS_LOADED:
-      info_settings_loaded = true;
-      break;
-  }
-
-  if (info_needs_settings_load) {
-    // Load the settings file.
-    g_scheduler->IncrementWorkCount();
-    if (!g_scheduler->input_file_manager()->AsyncLoadFile(
-             specified_from, build_settings_,
-             build_settings_->build_config_file(),
-             base::Bind(&ToolchainManager::BackgroundLoadBuildConfig,
-                        base::Unretained(this), info, false),
-             err)) {
-      g_scheduler->DecrementWorkCount();
-      return false;
-    }
-  } else if (info_settings_loaded) {
-    // Settings are ready to go, load the target file.
-    g_scheduler->IncrementWorkCount();
-    if (!g_scheduler->input_file_manager()->AsyncLoadFile(
-             specified_from, build_settings_, build_file,
-             base::Bind(&ToolchainManager::BackgroundInvoke,
-                        base::Unretained(this), info, build_file),
-             err)) {
-      g_scheduler->DecrementWorkCount();
-      return false;
-    }
-  }
-  // Else we should have added the infocations to the scheduled_invocations
-  // from within the lock above.
-  return true;
-}
-
-// static
-std::string ToolchainManager::ToolchainToOutputSubdir(
-    const Label& toolchain_name) {
-  // For now just assume the toolchain name is always a valid dir name. We may
-  // want to clean up the in the future.
-  return toolchain_name.name();
-}
-
-ToolchainManager::Info* ToolchainManager::LoadNewToolchainLocked(
-    const LocationRange& specified_from,
-    const Label& toolchain_name,
-    Err* err) {
-  GetLock().AssertAcquired();
-  Info* info = new Info(build_settings_,
-                        toolchain_name,
-                        ToolchainToOutputSubdir(toolchain_name));
-
-  toolchains_[toolchain_name] = info;
-
-  // Invoke the file containing the toolchain definition so that it gets
-  // defined. The default one (label is empty) will be done spearately.
-  if (!toolchain_name.is_null()) {
-    // The default toolchain should be specified whenever we're requesting
-    // another one. This is how we know under what context we should execute
-    // the invoke for the toolchain file.
-    CHECK(!default_toolchain_.is_null());
-    ScheduleInvocationLocked(specified_from, default_toolchain_,
-                             toolchain_name.dir(), err);
-  }
-  return info;
-}
-
-void ToolchainManager::FixupDefaultToolchainLocked() {
-  // Now that we've run the default build config, we should know the
-  // default toolchain name. Fix up our reference.
-  // See Start() for more.
-  GetLock().AssertAcquired();
-  if (default_toolchain_.is_null()) {
-    g_scheduler->FailWithError(Err(Location(),
-        "Default toolchain not set.",
-        "Your build config file \"" +
-        build_settings_->build_config_file().value() +
-        "\"\ndid not call set_default_toolchain(). This is needed so "
-        "I know how to actually\ncompile your code."));
-    return;
-  }
-
-  ToolchainMap::iterator old_default = toolchains_.find(Label());
-  CHECK(old_default != toolchains_.end());
-  Info* info = old_default->second;
-  toolchains_[default_toolchain_] = info;
-  toolchains_.erase(old_default);
-
-  // Toolchain should not have been loaded in the build config file.
-  CHECK(!info->toolchain_set);
-
-  // We need to set the toolchain label now that we know it. There's no way
-  // to set the label, but we can assign the toolchain to a new one. Loading
-  // the build config can not change the toolchain, so we won't be overwriting
-  // anything useful.
-  info->toolchain = Toolchain(default_toolchain_);
-  info->EnsureItemNode();
-
-  // Schedule a load of the toolchain build file.
-  Err err;
-  ScheduleInvocationLocked(LocationRange(), default_toolchain_,
-                           default_toolchain_.dir(), &err);
-  if (err.has_error())
-    g_scheduler->FailWithError(err);
-}
-
-void ToolchainManager::BackgroundLoadBuildConfig(Info* info,
-                                                 bool is_default,
-                                                 const ParseNode* root) {
-  // Danger: No early returns without decrementing the work count.
-  if (root && !g_scheduler->is_failed()) {
-    // Nobody should be accessing settings at this point other than us since we
-    // haven't marked it loaded, so we can do it outside the lock.
-    Scope* base_config = info->settings.base_config();
-    SetSystemVars(info->settings, base_config);
-    base_config->SetProcessingBuildConfig();
-    if (is_default)
-      base_config->SetProcessingDefaultBuildConfig();
-
-    const BlockNode* root_block = root->AsBlock();
-    Err err;
-    root_block->ExecuteBlockInScope(base_config, &err);
-
-    base_config->ClearProcessingBuildConfig();
-    if (is_default)
-      base_config->ClearProcessingDefaultBuildConfig();
-
-    if (err.has_error()) {
-      g_scheduler->FailWithError(err);
-    } else {
-      // Base config processing succeeded.
-      Info::ScheduledInvocationMap schedule_these;
-      {
-        base::AutoLock lock(GetLock());
-        schedule_these.swap(info->scheduled_invocations);
-        info->state = TOOLCHAIN_SETTINGS_LOADED;
-        if (is_default)
-          FixupDefaultToolchainLocked();
-      }
-
-      // Schedule build files waiting on this settings. There can be many so we
-      // want to load them in parallel on the pool.
-      for (Info::ScheduledInvocationMap::iterator i = schedule_these.begin();
-           i != schedule_these.end() && !g_scheduler->is_failed(); ++i) {
-        // Note i->second may be NULL, so don't dereference.
-        g_scheduler->IncrementWorkCount();
-        if (!g_scheduler->input_file_manager()->AsyncLoadFile(
-                 i->second, build_settings_, i->first,
-                 base::Bind(&ToolchainManager::BackgroundInvoke,
-                            base::Unretained(this), info, i->first),
-                 &err)) {
-          g_scheduler->FailWithError(err);
-          g_scheduler->DecrementWorkCount();
-          break;
-        }
-      }
-    }
-  }
-  g_scheduler->DecrementWorkCount();
-}
-
-void ToolchainManager::BackgroundInvoke(const Info* info,
-                                        const SourceFile& file_name,
-                                        const ParseNode* root) {
-  if (root && !g_scheduler->is_failed()) {
-    if (g_scheduler->verbose_logging())
-      g_scheduler->Log("Running", file_name.value());
-
-    Scope our_scope(info->settings.base_config());
-    ScopePerFileProvider per_file_provider(&our_scope, file_name);
-
-    Err err;
-    root->Execute(&our_scope, &err);
-    if (err.has_error())
-      g_scheduler->FailWithError(err);
-  }
-
-  g_scheduler->DecrementWorkCount();
-}
-
-base::Lock& ToolchainManager::GetLock() const {
-  return build_settings_->item_tree().lock();
-}