1 /*
2  * Copyright (C) 2019 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 #include "linkerconfig/librarylistloader.h"
18 
19 #include <android-base/result.h>
20 #include <android-base/strings.h>
21 #include <algorithm>
22 #include <fstream>
23 #include <iterator>
24 #include <set>
25 #include <sstream>
26 #include <unordered_map>
27 
28 #include "linkerconfig/environment.h"
29 #include "linkerconfig/log.h"
30 
31 using LibraryList = std::set<std::string>;
32 
33 using android::base::Result;
34 
35 namespace {
36 std::unordered_map<std::string, LibraryList> library_file_cache;
37 Result<LibraryList> GetLibrariesFromFile(std::string file_path) {
38   auto cached_data = library_file_cache.find(file_path);
39   if (cached_data != library_file_cache.end()) {
40     return cached_data->second;
41   }
42 
43   std::string library_name;
44   LibraryList library_list;
45   std::ifstream library_file(file_path.c_str(), std::ifstream::in);
46 
47   if (!library_file) {
48     return ErrnoErrorf("Failed to open file {}", file_path);
49   }
50 
51   while (std::getline(library_file, library_name)) {
52     library_name = android::base::Trim(library_name);
53     if (!library_name.empty()) {
54       library_list.insert(library_name);
55     }
56   }
57 
58   library_file_cache.insert({file_path, library_list});
59 
60   return library_list;
61 }
62 }  // namespace
63 
64 namespace android {
65 namespace linkerconfig {
66 namespace generator {
67 std::string GetLibrariesString(const std::string& library_file_path) {
68   auto library_list_result = GetLibrariesFromFile(library_file_path);
69   if (library_list_result.ok()) {
70     return android::base::Join(*library_list_result, ':');
71   } else {
72     // Consider unavailable library file as empty
73     LOG(WARNING) << library_list_result.error();
74     return "";
75   }
76 }
77 
78 std::string GetPublicLibrariesString(
79     const std::string& library_file_path,
80     const std::string& private_library_file_path) {
81   auto library_list = GetLibrariesFromFile(library_file_path);
82   auto private_library_list = GetLibrariesFromFile(private_library_file_path);
83 
84   if (!library_list.ok()) {
85     // Consider unavailable library file as empty
86     LOG(WARNING) << library_list.error();
87     return "";
88   }
89 
90   if (!private_library_list.ok()) {
91     // No private library found. All libraries are public
92     LOG(WARNING) << private_library_list.error();
93     return android::base::Join(*library_list, ':');
94   }
95 
96   LibraryList public_library_list;
97 
98   std::set_difference(
99       library_list->begin(),
100       library_list->end(),
101       private_library_list->begin(),
102       private_library_list->end(),
103       std::inserter(public_library_list, public_library_list.begin()));
104 
105   return android::base::Join(public_library_list, ':');
106 }
107 
108 std::string GetPrivateLibrariesString(
109     const std::string& library_file_path,
110     const std::string& private_library_file_path) {
111   auto library_list = GetLibrariesFromFile(library_file_path);
112   auto private_library_list = GetLibrariesFromFile(private_library_file_path);
113 
114   if (!library_list.ok()) {
115     // Consider unavailable library file as empty
116     LOG(WARNING) << library_list.error();
117     return "";
118   }
119 
120   if (!private_library_list.ok()) {
121     // No private library found. All libraries are public
122     LOG(WARNING) << private_library_list.error();
123     return "";
124   }
125 
126   LibraryList private_only_library_list;
127 
128   std::set_intersection(library_list->begin(),
129                         library_list->end(),
130                         private_library_list->begin(),
131                         private_library_list->end(),
132                         std::inserter(private_only_library_list,
133                                       private_only_library_list.begin()));
134 
135   return android::base::Join(private_only_library_list, ':');
136 }
137 }  // namespace generator
138 }  // namespace linkerconfig
139 }  // namespace android
140