1 /*
2 * Copyright (C) 2023 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 "FileUtils.h"
18
19 #ifdef BINDER_NO_LIBBASE
20
21 #include <sys/stat.h>
22 #include <filesystem>
23
24 #if defined(__APPLE__)
25 #include <mach-o/dyld.h>
26 #endif
27 #if defined(_WIN32)
28 #include <direct.h>
29 #include <windows.h>
30 #endif
31
32 namespace android::binder {
33
ReadFdToString(borrowed_fd fd,std::string * content)34 bool ReadFdToString(borrowed_fd fd, std::string* content) {
35 content->clear();
36
37 // Although original we had small files in mind, this code gets used for
38 // very large files too, where the std::string growth heuristics might not
39 // be suitable. https://code.google.com/p/android/issues/detail?id=258500.
40 struct stat sb;
41 if (fstat(fd.get(), &sb) != -1 && sb.st_size > 0) {
42 content->reserve(sb.st_size);
43 }
44
45 char buf[4096] __attribute__((__uninitialized__));
46 ssize_t n;
47 while ((n = TEMP_FAILURE_RETRY(read(fd.get(), &buf[0], sizeof(buf)))) > 0) {
48 content->append(buf, n);
49 }
50 return (n == 0) ? true : false;
51 }
52
WriteStringToFd(std::string_view content,borrowed_fd fd)53 bool WriteStringToFd(std::string_view content, borrowed_fd fd) {
54 const char* p = content.data();
55 size_t left = content.size();
56 while (left > 0) {
57 ssize_t n = TEMP_FAILURE_RETRY(write(fd.get(), p, left));
58 if (n == -1) {
59 return false;
60 }
61 p += n;
62 left -= n;
63 }
64 return true;
65 }
66
GetExecutablePath2()67 static std::filesystem::path GetExecutablePath2() {
68 #if defined(__linux__)
69 return std::filesystem::read_symlink("/proc/self/exe");
70 #elif defined(__APPLE__)
71 char path[PATH_MAX + 1];
72 uint32_t path_len = sizeof(path);
73 int rc = _NSGetExecutablePath(path, &path_len);
74 if (rc < 0) {
75 std::unique_ptr<char> path_buf(new char[path_len]);
76 _NSGetExecutablePath(path_buf.get(), &path_len);
77 return path_buf.get();
78 }
79 return path;
80 #elif defined(_WIN32)
81 char path[PATH_MAX + 1];
82 DWORD result = GetModuleFileName(NULL, path, sizeof(path) - 1);
83 if (result == 0 || result == sizeof(path) - 1) return "";
84 path[PATH_MAX - 1] = 0;
85 return path;
86 #elif defined(__EMSCRIPTEN__)
87 abort();
88 #else
89 #error unknown OS
90 #endif
91 }
92
GetExecutableDirectory()93 std::string GetExecutableDirectory() {
94 return GetExecutablePath2().parent_path();
95 }
96
97 } // namespace android::binder
98
99 #endif // BINDER_NO_LIBBASE
100