tools/aapt2/link/ReferenceLinker.h

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef AAPT_LINKER_REFERENCELINKER_H
#define AAPT_LINKER_REFERENCELINKER_H

#include "android-base/macros.h"

#include "Resource.h"
#include "ResourceValues.h"
#include "ValueVisitor.h"
#include "link/Linkers.h"
#include "process/IResourceTableConsumer.h"
#include "process/SymbolTable.h"
#include "xml/XmlDom.h"

namespace aapt {

/**
 * Resolves all references to resources in the ResourceTable and assigns them
 * IDs.
 * The ResourceTable must already have IDs assigned to each resource.
 * Once the ResourceTable is processed by this linker, it is ready to be
 * flattened.
 */
class ReferenceLinker : public IResourceTableConsumer {
 public:
  ReferenceLinker() = default;

  /**
   * Returns true if the symbol is visible by the reference and from the
   * callsite.
   */
  static bool IsSymbolVisible(const SymbolTable::Symbol& symbol,
                              const Reference& ref, const CallSite& callsite);

  /**
   * Performs name mangling and looks up the resource in the symbol table.
   * Returns nullptr if the symbol was not found.
   */
  static const SymbolTable::Symbol* ResolveSymbol(const Reference& reference, SymbolTable* symbols);

  /**
   * Performs name mangling and looks up the resource in the symbol table. If
   * the symbol is not visible by the reference at the callsite, nullptr is
   * returned. out_error holds the error message.
   */
  static const SymbolTable::Symbol* ResolveSymbolCheckVisibility(const Reference& reference,
                                                                 SymbolTable* symbols,
                                                                 CallSite* callsite,
                                                                 std::string* out_error);

  /**
   * Same as resolveSymbolCheckVisibility(), but also makes sure the symbol is
   * an attribute.
   * That is, the return value will have a non-null value for
   * ISymbolTable::Symbol::attribute.
   */
  static const SymbolTable::Symbol* ResolveAttributeCheckVisibility(const Reference& reference,
                                                                    SymbolTable* symbols,
                                                                    CallSite* callsite,
                                                                    std::string* out_error);

  /**
   * Resolves the attribute reference and returns an xml::AaptAttribute if
   * successful.
   * If resolution fails, outError holds the error message.
   */
  static Maybe<xml::AaptAttribute> CompileXmlAttribute(const Reference& reference,
                                                       SymbolTable* symbols, CallSite* callsite,
                                                       std::string* out_error);

  /**
   * Writes the resource name to the DiagMessage, using the
   * "orig_name (aka <transformed_name>)" syntax.
   */
  static void WriteResourceName(DiagMessage* out_msg, const Reference& orig,
                                const Reference& transformed);

  /**
   * Transforms the package name of the reference to the fully qualified package
   * name using
   * the xml::IPackageDeclStack, then mangles and looks up the symbol. If the
   * symbol is visible
   * to the reference at the callsite, the reference is updated with an ID.
   * Returns false on failure, and an error message is logged to the
   * IDiagnostics in the context.
   */
  static bool LinkReference(Reference* reference, IAaptContext* context,
                            SymbolTable* symbols, xml::IPackageDeclStack* decls,
                            CallSite* callsite);

  /**
   * Links all references in the ResourceTable.
   */
  bool Consume(IAaptContext* context, ResourceTable* table) override;

 private:
  DISALLOW_COPY_AND_ASSIGN(ReferenceLinker);
};

}  // namespace aapt

#endif /* AAPT_LINKER_REFERENCELINKER_H */