diff options
Diffstat (limited to 'tools/gn/import_manager.cc')
-rw-r--r-- | tools/gn/import_manager.cc | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/tools/gn/import_manager.cc b/tools/gn/import_manager.cc new file mode 100644 index 0000000..774f866 --- /dev/null +++ b/tools/gn/import_manager.cc @@ -0,0 +1,83 @@ +// 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/import_manager.h" + +#include "base/memory/scoped_ptr.h" +#include "base/stl_util.h" +#include "tools/gn/parse_tree.h" +#include "tools/gn/scheduler.h" + +namespace { + +// Returns a newly-allocated scope on success, null on failure. +Scope* UncachedImport(const Settings* settings, + const SourceFile& file, + const ParseNode* node_for_err, + Err* err) { + const ParseNode* node = g_scheduler->input_file_manager()->SyncLoadFile( + node_for_err->GetRange(), settings->build_settings(), file, err); + if (!node) + return NULL; + const BlockNode* block = node->AsBlock(); + CHECK(block); + + scoped_ptr<Scope> scope(new Scope(settings->base_config())); + scope->SetProcessingImport(); + block->ExecuteBlockInScope(scope.get(), err); + if (err->has_error()) + return NULL; + scope->ClearProcessingImport(); + + return scope.release(); +} + +} // namesapce + +ImportManager::ImportManager() { +} + +ImportManager::~ImportManager() { + STLDeleteContainerPairSecondPointers(imports_.begin(), imports_.end()); +} + +bool ImportManager::DoImport(const SourceFile& file, + const ParseNode* node_for_err, + Scope* scope, + Err* err) { + // See if we have a cached import, but be careful to actually do the scope + // copying outside of the lock. + const Scope* imported_scope = NULL; + { + base::AutoLock lock(lock_); + ImportMap::const_iterator found = imports_.find(file); + if (found != imports_.end()) + imported_scope = found->second; + } + + if (!imported_scope) { + // Do a new import of the file. + imported_scope = UncachedImport(scope->settings(), file, + node_for_err, err); + if (!imported_scope) + return false; + + // We loaded the file outside the lock. This means that there could be a + // race and the file was already loaded on a background thread. Recover + // from this and use the existing one if that happens. + { + base::AutoLock lock(lock_); + ImportMap::const_iterator found = imports_.find(file); + if (found != imports_.end()) { + delete imported_scope; + imported_scope = found->second; + } else { + imports_[file] = imported_scope; + } + } + } + + return imported_scope->NonRecursiveMergeTo(scope, node_for_err, + "import", err); +} |