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// Copyright 2018 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.
#ifndef TOOLS_GN_METADATA_H_
#define TOOLS_GN_METADATA_H_
#include <memory>
#include "tools/gn/build_settings.h"
#include "tools/gn/scope.h"
#include "tools/gn/source_dir.h"
// Metadata about a particular target.
//
// Metadata is a collection of keys and values relating to a particular target.
// Generally, these keys will include three categories of strings: ordinary
// strings, filenames intended to be rebased according to their particular
// source directory, and target labels intended to be used as barriers to the
// walk. Verfication of these categories occurs at walk time, not creation
// time (since it is not clear until the walk which values are intended for
// which purpose).
//
// Represented as a scope in the expression language, here it is reduced to just
// the KeyValueMap (since it doesn't need the logical overhead of a full scope).
// Values must be lists of strings, as the walking collection logic contatenates
// their values across targets.
class Metadata {
public:
using Contents = Scope::KeyValueMap;
// Members must be set explicitly.
Metadata() = default;
const ParseNode* origin() const { return origin_; }
void set_origin(const ParseNode* origin) { origin_ = origin; }
// The contents of this metadata varaiable.
const Contents& contents() const { return contents_; }
Contents& contents() { return contents_; }
void set_contents(Contents&& contents) { contents_.swap(contents); }
// The relative source directory to use when rebasing.
const SourceDir& source_dir() const { return source_dir_; }
SourceDir& source_dir() { return source_dir_; }
void set_source_dir(const SourceDir& d) { source_dir_ = d; }
// Collect the specified metadata from this instance.
//
// Calling this will populate `next_walk_keys` with the values of targets to
// be walked next (with the empty string "" indicating that the target should
// walk all of its deps and data_deps).
bool WalkStep(const BuildSettings* settings,
const std::vector<std::string>& keys_to_extract,
const std::vector<std::string>& keys_to_walk,
const SourceDir& rebase_dir,
std::vector<Value>* next_walk_keys,
std::vector<Value>* result,
Err* err) const;
private:
const ParseNode* origin_;
Contents contents_;
SourceDir source_dir_;
std::pair<Value, bool> RebaseValue(const BuildSettings* settings,
const SourceDir& rebase_dir,
const Value& value,
Err* err) const;
std::pair<Value, bool> RebaseStringValue(const BuildSettings* settings,
const SourceDir& rebase_dir,
const Value& value,
Err* err) const;
std::pair<Value, bool> RebaseListValue(const BuildSettings* settings,
const SourceDir& rebase_dir,
const Value& value,
Err* err) const;
std::pair<Value, bool> RebaseScopeValue(const BuildSettings* settings,
const SourceDir& rebase_dir,
const Value& value,
Err* err) const;
DISALLOW_COPY_AND_ASSIGN(Metadata);
};
#endif // TOOLS_GN_METADATA_H_