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/*
* Copyright (C) 2015 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 <windows.h>
#include "android-base/utf8.h"
#include <fcntl.h>
#include <stdio.h>
#include <algorithm>
#include <string>
#include "android-base/logging.h"
namespace android {
namespace base {
// Helper to set errno based on GetLastError() after WideCharToMultiByte()/MultiByteToWideChar().
static void SetErrnoFromLastError() {
switch (GetLastError()) {
case ERROR_NO_UNICODE_TRANSLATION:
errno = EILSEQ;
break;
default:
errno = EINVAL;
break;
}
}
bool WideToUTF8(const wchar_t* utf16, const size_t size, std::string* utf8) {
utf8->clear();
if (size == 0) {
return true;
}
// TODO: Consider using std::wstring_convert once libcxx is supported on
// Windows.
// Only Vista or later has this flag that causes WideCharToMultiByte() to
// return an error on invalid characters.
const DWORD flags =
#if (WINVER >= 0x0600)
WC_ERR_INVALID_CHARS;
#else
0;
#endif
const int chars_required = WideCharToMultiByte(CP_UTF8, flags, utf16, size,
NULL, 0, NULL, NULL);
if (chars_required <= 0) {
SetErrnoFromLastError();
return false;
}
// This could potentially throw a std::bad_alloc exception.
utf8->resize(chars_required);
const int result = WideCharToMultiByte(CP_UTF8, flags, utf16, size,
&(*utf8)[0], chars_required, NULL,
NULL);
if (result != chars_required) {
SetErrnoFromLastError();
CHECK_LE(result, chars_required) << "WideCharToMultiByte wrote " << result
<< " chars to buffer of " << chars_required << " chars";
utf8->clear();
return false;
}
return true;
}
bool WideToUTF8(const wchar_t* utf16, std::string* utf8) {
// Compute string length of NULL-terminated string with wcslen().
return WideToUTF8(utf16, wcslen(utf16), utf8);
}
bool WideToUTF8(const std::wstring& utf16, std::string* utf8) {
// Use the stored length of the string which allows embedded NULL characters
// to be converted.
return WideToUTF8(utf16.c_str(), utf16.length(), utf8);
}
// Internal helper function that takes MultiByteToWideChar() flags.
static bool UTF8ToWideWithFlags(const char* utf8, const size_t size, std::wstring* utf16,
const DWORD flags) {
utf16->clear();
if (size == 0) {
return true;
}
// TODO: Consider using std::wstring_convert once libcxx is supported on
// Windows.
const int chars_required = MultiByteToWideChar(CP_UTF8, flags, utf8, size,
NULL, 0);
if (chars_required <= 0) {
SetErrnoFromLastError();
return false;
}
// This could potentially throw a std::bad_alloc exception.
utf16->resize(chars_required);
const int result = MultiByteToWideChar(CP_UTF8, flags, utf8, size,
&(*utf16)[0], chars_required);
if (result != chars_required) {
SetErrnoFromLastError();
CHECK_LE(result, chars_required) << "MultiByteToWideChar wrote " << result
<< " chars to buffer of " << chars_required << " chars";
utf16->clear();
return false;
}
return true;
}
bool UTF8ToWide(const char* utf8, const size_t size, std::wstring* utf16) {
// If strictly interpreting as UTF-8 succeeds, return success.
if (UTF8ToWideWithFlags(utf8, size, utf16, MB_ERR_INVALID_CHARS)) {
return true;
}
const int saved_errno = errno;
// Fallback to non-strict interpretation, allowing invalid characters and
// converting as best as possible, and return false to signify a problem.
(void)UTF8ToWideWithFlags(utf8, size, utf16, 0);
errno = saved_errno;
return false;
}
bool UTF8ToWide(const char* utf8, std::wstring* utf16) {
// Compute string length of NULL-terminated string with strlen().
return UTF8ToWide(utf8, strlen(utf8), utf16);
}
bool UTF8ToWide(const std::string& utf8, std::wstring* utf16) {
// Use the stored length of the string which allows embedded NULL characters
// to be converted.
return UTF8ToWide(utf8.c_str(), utf8.length(), utf16);
}
static bool isDriveLetter(wchar_t c) {
return (c >= L'a' && c <= L'z') || (c >= L'A' && c <= L'Z');
}
bool UTF8PathToWindowsLongPath(const char* utf8, std::wstring* utf16) {
if (!UTF8ToWide(utf8, utf16)) {
return false;
}
// Note: Although most Win32 File I/O API are limited to MAX_PATH (260
// characters), the CreateDirectory API is limited to 248 characters.
if (utf16->length() >= 248) {
// If path is of the form "x:\" or "x:/"
if (isDriveLetter((*utf16)[0]) && (*utf16)[1] == L':' &&
((*utf16)[2] == L'\\' || (*utf16)[2] == L'/')) {
// Append long path prefix, and make sure there are no unix-style
// separators to ensure a fully compliant Win32 long path string.
utf16->insert(0, LR"(\\?\)");
std::replace(utf16->begin(), utf16->end(), L'/', L'\\');
}
}
return true;
}
// Versions of standard library APIs that support UTF-8 strings.
namespace utf8 {
FILE* fopen(const char* name, const char* mode) {
std::wstring name_utf16;
if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
return nullptr;
}
std::wstring mode_utf16;
if (!UTF8ToWide(mode, &mode_utf16)) {
return nullptr;
}
return _wfopen(name_utf16.c_str(), mode_utf16.c_str());
}
int mkdir(const char* name, mode_t) {
std::wstring name_utf16;
if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
return -1;
}
return _wmkdir(name_utf16.c_str());
}
int open(const char* name, int flags, ...) {
std::wstring name_utf16;
if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
return -1;
}
int mode = 0;
if ((flags & O_CREAT) != 0) {
va_list args;
va_start(args, flags);
mode = va_arg(args, int);
va_end(args);
}
return _wopen(name_utf16.c_str(), flags, mode);
}
int unlink(const char* name) {
std::wstring name_utf16;
if (!UTF8PathToWindowsLongPath(name, &name_utf16)) {
return -1;
}
return _wunlink(name_utf16.c_str());
}
} // namespace utf8
} // namespace base
} // namespace android