1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef AAPT_NAME_MANGLER_H
18#define AAPT_NAME_MANGLER_H
19
20#include <set>
21#include <string>
22
23#include "Resource.h"
24#include "util/Maybe.h"
25
26namespace aapt {
27
28struct NameManglerPolicy {
29  /**
30   * Represents the package we are trying to build. References pointing
31   * to this package are not mangled, and mangled references inherit this
32   * package name.
33   */
34  std::string target_package_name;
35
36  /**
37   * We must know which references to mangle, and which to keep (android vs.
38   * com.android.support).
39   */
40  std::set<std::string> packages_to_mangle;
41};
42
43class NameMangler {
44 public:
45  explicit NameMangler(NameManglerPolicy policy) : policy_(policy) {}
46
47  Maybe<ResourceName> MangleName(const ResourceName& name) {
48    if (policy_.target_package_name == name.package ||
49        policy_.packages_to_mangle.count(name.package) == 0) {
50      return {};
51    }
52
53    std::string mangled_entry_name = MangleEntry(name.package, name.entry);
54    return ResourceName(policy_.target_package_name, name.type,
55                        mangled_entry_name);
56  }
57
58  bool ShouldMangle(const std::string& package) const {
59    if (package.empty() || policy_.target_package_name == package) {
60      return false;
61    }
62    return policy_.packages_to_mangle.count(package) != 0;
63  }
64
65  const std::string& GetTargetPackageName() const { return policy_.target_package_name; }
66
67  /**
68   * Returns a mangled name that is a combination of `name` and `package`.
69   * The mangled name should contain symbols that are illegal to define in XML,
70   * so that there will never be name mangling collisions.
71   */
72  static std::string MangleEntry(const std::string& package,
73                                 const std::string& name) {
74    return package + "$" + name;
75  }
76
77  /**
78   * Unmangles the name in `outName`, storing the correct name back in `outName`
79   * and the package in `outPackage`. Returns true if the name was unmangled or
80   * false if the name was never mangled to begin with.
81   */
82  static bool Unmangle(std::string* out_name, std::string* out_package) {
83    size_t pivot = out_name->find('$');
84    if (pivot == std::string::npos) {
85      return false;
86    }
87
88    out_package->assign(out_name->data(), pivot);
89    out_name->assign(out_name->data() + pivot + 1,
90                     out_name->size() - (pivot + 1));
91    return true;
92  }
93
94 private:
95  NameManglerPolicy policy_;
96};
97
98}  // namespace aapt
99
100#endif  // AAPT_NAME_MANGLER_H
101