base: add SystemErrorCodeToString() function.
Pulls the Windows error string generation out of adb into libbase so
that it can be used by fastboot as well. Also makes a Unix equivalent
that just wraps strerror() so that upcoming fastboot error reporting
code can be platform-independent.
The intent here is just to provide a portable way to report an error to
the user. More general cross-platform error handling is out of scope.
Bug: http://b/26236380
Change-Id: I5a784a844775949562d069bb41dcb0ebd13a32bc
diff --git a/base/errors_windows.cpp b/base/errors_windows.cpp
new file mode 100644
index 0000000..a5ff511
--- /dev/null
+++ b/base/errors_windows.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#include "android-base/errors.h"
+
+#include <windows.h>
+
+#include "android-base/stringprintf.h"
+#include "android-base/strings.h"
+#include "android-base/utf8.h"
+
+// A Windows error code is a DWORD. It's simpler to use an int error code for
+// both Unix and Windows if possible, but if this fails we'll need a different
+// function signature for each.
+static_assert(sizeof(int) >= sizeof(DWORD),
+ "Windows system error codes are too large to fit in an int.");
+
+namespace android {
+namespace base {
+
+static constexpr DWORD kErrorMessageBufferSize = 256;
+
+std::string SystemErrorCodeToString(int int_error_code) {
+ WCHAR msgbuf[kErrorMessageBufferSize];
+ DWORD error_code = int_error_code;
+ DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
+ DWORD len = FormatMessageW(flags, nullptr, error_code, 0, msgbuf,
+ kErrorMessageBufferSize, nullptr);
+ if (len == 0) {
+ return android::base::StringPrintf(
+ "Error %lu while retrieving message for error %lu", GetLastError(),
+ error_code);
+ }
+
+ // Convert UTF-16 to UTF-8.
+ std::string msg;
+ if (!android::base::WideToUTF8(msgbuf, &msg)) {
+ return android::base::StringPrintf(
+ "Error %lu while converting message for error %lu from UTF-16 to UTF-8",
+ GetLastError(), error_code);
+ }
+
+ // Messages returned by the system end with line breaks.
+ msg = android::base::Trim(msg);
+
+ // There are many Windows error messages compared to POSIX, so include the
+ // numeric error code for easier, quicker, accurate identification. Use
+ // decimal instead of hex because there are decimal ranges like 10000-11999
+ // for Winsock.
+ android::base::StringAppendF(&msg, " (%lu)", error_code);
+ return msg;
+}
+
+} // namespace base
+} // namespace android