blob: 9d46103818512a89e820cddd5eba9a1cd493f166 [file] [log] [blame]
// 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 "gn/loader.h"
#include <memory>
#include "gn/build_settings.h"
#include "gn/err.h"
#include "gn/filesystem_utils.h"
#include "gn/input_file_manager.h"
#include "gn/parse_tree.h"
#include "gn/scheduler.h"
#include "gn/scope_per_file_provider.h"
#include "gn/settings.h"
#include "gn/source_dir.h"
#include "gn/source_file.h"
#include "gn/trace.h"
namespace {
struct SourceFileAndOrigin {
SourceFileAndOrigin(const SourceFile& f, const LocationRange& o)
: file(f), origin(o) {}
SourceFile file;
LocationRange origin;
};
} // namespace
// Identifies one time a file is loaded in a given toolchain so we don't load
// it more than once.
struct LoaderImpl::LoadID {
LoadID() = default;
LoadID(const SourceFile& f, const Label& tc_name)
: file(f), toolchain_name(tc_name) {}
bool operator<(const LoadID& other) const {
if (file == other.file)
return toolchain_name < other.toolchain_name;
return file < other.file;
}
SourceFile file;
Label toolchain_name;
};
// Our tracking information for a toolchain.
struct LoaderImpl::ToolchainRecord {
// The default toolchain label can be empty for the first time the default
// toolchain is loaded, since we don't know it yet. This will be fixed up
// later. It should be valid in all other cases.
ToolchainRecord(const BuildSettings* build_settings,
const Label& toolchain_label,
const Label& default_toolchain_label)
: settings(
build_settings,
GetOutputSubdirName(toolchain_label,
toolchain_label == default_toolchain_label)),
is_toolchain_loaded(false),
is_config_loaded(false) {
settings.set_default_toolchain_label(default_toolchain_label);
settings.set_toolchain_label(toolchain_label);
}
Settings settings;
bool is_toolchain_loaded;
bool is_config_loaded;
std::vector<SourceFileAndOrigin> waiting_on_me;
};
// -----------------------------------------------------------------------------
const void* const Loader::kDefaultToolchainKey = &kDefaultToolchainKey;
Loader::Loader() = default;
Loader::~Loader() = default;
void Loader::Load(const Label& label, const LocationRange& origin) {
Load(BuildFileForLabel(label), origin, label.GetToolchainLabel());
}
// -----------------------------------------------------------------------------
LoaderImpl::LoaderImpl(const BuildSettings* build_settings)
: pending_loads_(0), build_settings_(build_settings) {
// There may not be an active TaskRunner at this point. When that's the case,
// the calling code is expected to call set_task_runner().
task_runner_ = MsgLoop::Current();
}
LoaderImpl::~LoaderImpl() = default;
void LoaderImpl::Load(const SourceFile& file,
const LocationRange& origin,
const Label& in_toolchain_name) {
const Label& toolchain_name = in_toolchain_name.is_null()
? default_toolchain_label_
: in_toolchain_name;
LoadID load_id(file, toolchain_name);
if (!invocations_.insert(load_id).second)
return; // Already in set, so this file was already loaded or schedulerd.
if (toolchain_records_.empty()) {
// Nothing loaded, need to load the default build config. The initial load
// should not specify a toolchain.
DCHECK(toolchain_name.is_null());
std::unique_ptr<ToolchainRecord> new_record =
std::make_unique<ToolchainRecord>(build_settings_, Label(), Label());
ToolchainRecord* record = new_record.get();
Label empty_label; // VS issues spurious warning using ...[Label()].
toolchain_records_[empty_label] = std::move(new_record);
// The default build config is no dependent on the toolchain definition,
// since we need to load the build config before we know what the default
// toolchain name is.
record->is_toolchain_loaded = true;
record->waiting_on_me.push_back(SourceFileAndOrigin(file, origin));
ScheduleLoadBuildConfig(&record->settings, Scope::KeyValueMap());
return;
}
ToolchainRecord* record;
if (toolchain_name.is_null())
record = toolchain_records_[default_toolchain_label_].get();
else
record = toolchain_records_[toolchain_name].get();
if (!record) {
DCHECK(!default_toolchain_label_.is_null());
// No reference to this toolchain found yet, make one.
std::unique_ptr<ToolchainRecord> new_record =
std::make_unique<ToolchainRecord>(build_settings_, toolchain_name,
default_toolchain_label_);
record = new_record.get();
toolchain_records_[toolchain_name] = std::move(new_record);
// Schedule a load of the toolchain using the default one.
Load(BuildFileForLabel(toolchain_name), origin, default_toolchain_label_);
}
if (record->is_config_loaded)
ScheduleLoadFile(&record->settings, origin, file);
else
record->waiting_on_me.push_back(SourceFileAndOrigin(file, origin));
}
void LoaderImpl::ToolchainLoaded(const Toolchain* toolchain) {
ToolchainRecord* record = toolchain_records_[toolchain->label()].get();
if (!record) {
DCHECK(!default_toolchain_label_.is_null());
std::unique_ptr<ToolchainRecord> new_record =
std::make_unique<ToolchainRecord>(build_settings_, toolchain->label(),
default_toolchain_label_);
record = new_record.get();
toolchain_records_[toolchain->label()] = std::move(new_record);
}
record->is_toolchain_loaded = true;
// The default build config is loaded first, then its toolchain. Secondary
// ones are loaded in the opposite order so we can pass toolchain parameters
// to the build config. So we may or may not have a config at this point.
if (!record->is_config_loaded) {
ScheduleLoadBuildConfig(&record->settings, toolchain->args());
} else {
// There should be nobody waiting on this if the build config is already
// loaded.
DCHECK(record->waiting_on_me.empty());
}
}
Label LoaderImpl::GetDefaultToolchain() const {
return default_toolchain_label_;
}
const Settings* LoaderImpl::GetToolchainSettings(const Label& label) const {
ToolchainRecordMap::const_iterator found_toolchain;
if (label.is_null()) {
if (default_toolchain_label_.is_null())
return nullptr;
found_toolchain = toolchain_records_.find(default_toolchain_label_);
} else {
found_toolchain = toolchain_records_.find(label);
}
if (found_toolchain == toolchain_records_.end())
return nullptr;
return &found_toolchain->second->settings;
}
SourceFile LoaderImpl::BuildFileForLabel(const Label& label) const {
return SourceFile(
label.dir().value() + "BUILD" + build_file_extension_ + ".gn");
}
void LoaderImpl::ScheduleLoadFile(const Settings* settings,
const LocationRange& origin,
const SourceFile& file) {
Err err;
pending_loads_++;
if (!AsyncLoadFile(
origin, settings->build_settings(), file,
[this, settings, file, origin](const ParseNode* parse_node) {
BackgroundLoadFile(settings, file, origin, parse_node);
},
&err)) {
g_scheduler->FailWithError(err);
DecrementPendingLoads();
}
}
void LoaderImpl::ScheduleLoadBuildConfig(
Settings* settings,
const Scope::KeyValueMap& toolchain_overrides) {
Err err;
pending_loads_++;
if (!AsyncLoadFile(
LocationRange(), settings->build_settings(),
settings->build_settings()->build_config_file(),
[this, settings, toolchain_overrides](const ParseNode* root) {
BackgroundLoadBuildConfig(settings, toolchain_overrides, root);
},
&err)) {
g_scheduler->FailWithError(err);
DecrementPendingLoads();
}
}
void LoaderImpl::BackgroundLoadFile(const Settings* settings,
const SourceFile& file_name,
const LocationRange& origin,
const ParseNode* root) {
if (!root) {
task_runner_->PostTask([this]() { DecrementPendingLoads(); });
return;
}
if (g_scheduler->verbose_logging()) {
g_scheduler->Log("Running",
file_name.value() + " with toolchain " +
settings->toolchain_label().GetUserVisibleName(false));
}
Scope our_scope(settings->base_config());
ScopePerFileProvider per_file_provider(&our_scope, true);
our_scope.set_source_dir(file_name.GetDir());
our_scope.AddBuildDependencyFile(file_name);
// Targets, etc. generated as part of running this file will end up here.
Scope::ItemVector collected_items;
our_scope.set_item_collector(&collected_items);
ScopedTrace trace(TraceItem::TRACE_FILE_EXECUTE, file_name.value());
trace.SetToolchain(settings->toolchain_label());
Err err;
root->Execute(&our_scope, &err);
if (!err.has_error())
our_scope.CheckForUnusedVars(&err);
if (err.has_error()) {
if (!origin.is_null())
err.AppendSubErr(Err(origin, "which caused the file to be included."));
if (!settings->is_default())
err.set_toolchain_label(settings->toolchain_label());
g_scheduler->FailWithError(err);
}
// Pass all of the items that were defined off to the builder.
for (auto& item : collected_items)
settings->build_settings()->ItemDefined(std::move(item));
trace.Done();
task_runner_->PostTask([this]() { DidLoadFile(); });
}
void LoaderImpl::BackgroundLoadBuildConfig(
Settings* settings,
const Scope::KeyValueMap& toolchain_overrides,
const ParseNode* root) {
if (!root) {
task_runner_->PostTask([this]() { DecrementPendingLoads(); });
return;
}
Scope* base_config = settings->base_config();
base_config->set_source_dir(SourceDir("//"));
base_config->AddBuildDependencyFile(
settings->build_settings()->build_config_file());
settings->build_settings()->build_args().SetupRootScope(base_config,
toolchain_overrides);
base_config->SetProcessingBuildConfig();
// See kDefaultToolchainKey in the header.
Label default_toolchain_label;
if (settings->is_default())
base_config->SetProperty(kDefaultToolchainKey, &default_toolchain_label);
ScopedTrace trace(TraceItem::TRACE_FILE_EXECUTE,
settings->build_settings()->build_config_file().value());
trace.SetToolchain(settings->toolchain_label());
// Run the BUILDCONFIG with its directory as the current one. We want
// BUILDCONFIG to modify the base_config so can't make a copy or a nested one.
base_config->set_source_dir(
settings->build_settings()->build_config_file().GetDir());
Err err;
root->Execute(base_config, &err);
// Put back the root as the default source dir. This probably isn't necessary
// as other scopes will set their directories to their own path, but it's a
// better default than the build config's directory.
base_config->set_source_dir(SourceDir("//"));
// Clear all private variables left in the scope. We want the root build
// config to be like a .gni file in that variables beginning with an
// underscore aren't exported.
base_config->RemovePrivateIdentifiers();
trace.Done();
if (err.has_error()) {
if (!settings->is_default())
err.set_toolchain_label(settings->toolchain_label());
g_scheduler->FailWithError(err);
}
base_config->ClearProcessingBuildConfig();
if (settings->is_default()) {
// The default toolchain must have been set in the default build config
// file.
if (default_toolchain_label.is_null()) {
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);
}
}
task_runner_->PostTask(
[this, toolchain_label = settings->toolchain_label()]() {
DidLoadBuildConfig(toolchain_label);
});
}
void LoaderImpl::DidLoadFile() {
DecrementPendingLoads();
}
void LoaderImpl::DidLoadBuildConfig(const Label& label) {
// Do not return early, we must call DecrementPendingLoads() at the bottom.
ToolchainRecordMap::iterator found_toolchain = toolchain_records_.find(label);
ToolchainRecord* record = nullptr;
if (found_toolchain == toolchain_records_.end()) {
// When loading the default build config, we'll insert it into the record
// map with an empty label since we don't yet know what to call it.
//
// In this case, we should have exactly one entry in the map with an empty
// label. We now need to fix up the naming so it refers to the "real" one.
CHECK_EQ(1U, toolchain_records_.size());
ToolchainRecordMap::iterator empty_label = toolchain_records_.find(Label());
CHECK(empty_label != toolchain_records_.end());
// Fix up the toolchain record.
std::unique_ptr<ToolchainRecord> moved_record =
std::move(empty_label->second);
record = moved_record.get();
toolchain_records_[label] = std::move(moved_record);
toolchain_records_.erase(empty_label);
// Save the default toolchain label.
default_toolchain_label_ = label;
DCHECK(record->settings.default_toolchain_label().is_null());
record->settings.set_default_toolchain_label(label);
// The settings object should have the toolchain label already set.
DCHECK(!record->settings.toolchain_label().is_null());
// Update any stored invocations that refer to the empty toolchain label.
// This will normally only be one, for the root build file, so brute-force
// is OK.
LoadIDSet old_loads;
invocations_.swap(old_loads);
for (const auto& load : old_loads) {
if (load.toolchain_name.is_null()) {
// Fix up toolchain label
invocations_.emplace(load.file, label);
} else {
// Can keep the old one.
invocations_.insert(load);
}
}
} else {
record = found_toolchain->second.get();
}
DCHECK(!record->is_config_loaded);
DCHECK(record->is_toolchain_loaded);
record->is_config_loaded = true;
// Schedule all waiting file loads.
for (const auto& waiting : record->waiting_on_me)
ScheduleLoadFile(&record->settings, waiting.origin, waiting.file);
record->waiting_on_me.clear();
DecrementPendingLoads();
}
void LoaderImpl::DecrementPendingLoads() {
DCHECK_GT(pending_loads_, 0);
pending_loads_--;
if (pending_loads_ == 0 && complete_callback_)
complete_callback_();
}
bool LoaderImpl::AsyncLoadFile(const LocationRange& origin,
const BuildSettings* build_settings,
const SourceFile& file_name,
std::function<void(const ParseNode*)> callback,
Err* err) {
if (async_load_file_) {
return async_load_file_(origin, build_settings, file_name,
std::move(callback), err);
}
return g_scheduler->input_file_manager()->AsyncLoadFile(
origin, build_settings, file_name, std::move(callback), err);
}