1 /*
2 * Copyright (C) 2016 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 "android-base/errors.h"
18
19 #include <windows.h>
20
21 #include "android-base/stringprintf.h"
22 #include "android-base/strings.h"
23 #include "android-base/utf8.h"
24
25 // A Windows error code is a DWORD. It's simpler to use an int error code for
26 // both Unix and Windows if possible, but if this fails we'll need a different
27 // function signature for each.
28 static_assert(sizeof(int) >= sizeof(DWORD),
29 "Windows system error codes are too large to fit in an int.");
30
31 namespace android {
32 namespace base {
33
34 static constexpr DWORD kErrorMessageBufferSize = 256;
35
SystemErrorCodeToString(int int_error_code)36 std::string SystemErrorCodeToString(int int_error_code) {
37 WCHAR msgbuf[kErrorMessageBufferSize];
38 DWORD error_code = int_error_code;
39 DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
40 DWORD len = FormatMessageW(flags, nullptr, error_code, 0, msgbuf,
41 kErrorMessageBufferSize, nullptr);
42 if (len == 0) {
43 return android::base::StringPrintf(
44 "Error %lu while retrieving message for error %lu", GetLastError(),
45 error_code);
46 }
47
48 // Convert UTF-16 to UTF-8.
49 std::string msg;
50 if (!android::base::WideToUTF8(msgbuf, &msg)) {
51 return android::base::StringPrintf(
52 "Error %lu while converting message for error %lu from UTF-16 to UTF-8",
53 GetLastError(), error_code);
54 }
55
56 // Messages returned by the system end with line breaks.
57 msg = android::base::Trim(msg);
58
59 // There are many Windows error messages compared to POSIX, so include the
60 // numeric error code for easier, quicker, accurate identification. Use
61 // decimal instead of hex because there are decimal ranges like 10000-11999
62 // for Winsock.
63 android::base::StringAppendF(&msg, " (%lu)", error_code);
64 return msg;
65 }
66
67 } // namespace base
68 } // namespace android
69