| // Copyright (c) 2018 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/strings/utf_string_conversions.h" |
| |
| #include <stdint.h> |
| |
| #include "base/strings/string_piece.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/utf_string_conversion_utils.h" |
| #include "base/third_party/icu/icu_utf.h" |
| #include "util/build_config.h" |
| |
| namespace base { |
| |
| namespace { |
| |
| constexpr int32_t kErrorCodePoint = 0xFFFD; |
| |
| // Size coefficient ---------------------------------------------------------- |
| // The maximum number of codeunits in the destination encoding corresponding to |
| // one codeunit in the source encoding. |
| |
| template <typename SrcChar, typename DestChar> |
| struct SizeCoefficient { |
| static_assert(sizeof(SrcChar) < sizeof(DestChar), |
| "Default case: from a smaller encoding to the bigger one"); |
| |
| // ASCII symbols are encoded by one codeunit in all encodings. |
| static constexpr int value = 1; |
| }; |
| |
| template <> |
| struct SizeCoefficient<char16, char> { |
| // One UTF-16 codeunit corresponds to at most 3 codeunits in UTF-8. |
| static constexpr int value = 3; |
| }; |
| |
| #if defined(WCHAR_T_IS_UTF32) |
| template <> |
| struct SizeCoefficient<wchar_t, char> { |
| // UTF-8 uses at most 4 codeunits per character. |
| static constexpr int value = 4; |
| }; |
| |
| template <> |
| struct SizeCoefficient<wchar_t, char16> { |
| // UTF-16 uses at most 2 codeunits per character. |
| static constexpr int value = 2; |
| }; |
| #endif // defined(WCHAR_T_IS_UTF32) |
| |
| template <typename SrcChar, typename DestChar> |
| constexpr int size_coefficient_v = |
| SizeCoefficient<std::decay_t<SrcChar>, std::decay_t<DestChar>>::value; |
| |
| // UnicodeAppendUnsafe -------------------------------------------------------- |
| // Function overloads that write code_point to the output string. Output string |
| // has to have enough space for the codepoint. |
| |
| void UnicodeAppendUnsafe(char* out, int32_t* size, uint32_t code_point) { |
| CBU8_APPEND_UNSAFE(out, *size, code_point); |
| } |
| |
| void UnicodeAppendUnsafe(char16* out, int32_t* size, uint32_t code_point) { |
| CBU16_APPEND_UNSAFE(out, *size, code_point); |
| } |
| |
| #if defined(WCHAR_T_IS_UTF32) |
| |
| void UnicodeAppendUnsafe(wchar_t* out, int32_t* size, uint32_t code_point) { |
| out[(*size)++] = code_point; |
| } |
| |
| #endif // defined(WCHAR_T_IS_UTF32) |
| |
| // DoUTFConversion ------------------------------------------------------------ |
| // Main driver of UTFConversion specialized for different Src encodings. |
| // dest has to have enough room for the converted text. |
| |
| template <typename DestChar> |
| bool DoUTFConversion(const char* src, |
| int32_t src_len, |
| DestChar* dest, |
| int32_t* dest_len) { |
| bool success = true; |
| |
| for (int32_t i = 0; i < src_len;) { |
| int32_t code_point; |
| CBU8_NEXT(src, i, src_len, code_point); |
| |
| if (!IsValidCodepoint(code_point)) { |
| success = false; |
| code_point = kErrorCodePoint; |
| } |
| |
| UnicodeAppendUnsafe(dest, dest_len, code_point); |
| } |
| |
| return success; |
| } |
| |
| template <typename DestChar> |
| bool DoUTFConversion(const char16* src, |
| int32_t src_len, |
| DestChar* dest, |
| int32_t* dest_len) { |
| bool success = true; |
| |
| auto ConvertSingleChar = [&success](char16 in) -> int32_t { |
| if (!CBU16_IS_SINGLE(in) || !IsValidCodepoint(in)) { |
| success = false; |
| return kErrorCodePoint; |
| } |
| return in; |
| }; |
| |
| int32_t i = 0; |
| |
| // Always have another symbol in order to avoid checking boundaries in the |
| // middle of the surrogate pair. |
| while (i < src_len - 1) { |
| int32_t code_point; |
| |
| if (CBU16_IS_LEAD(src[i]) && CBU16_IS_TRAIL(src[i + 1])) { |
| code_point = CBU16_GET_SUPPLEMENTARY(src[i], src[i + 1]); |
| if (!IsValidCodepoint(code_point)) { |
| code_point = kErrorCodePoint; |
| success = false; |
| } |
| i += 2; |
| } else { |
| code_point = ConvertSingleChar(src[i]); |
| ++i; |
| } |
| |
| UnicodeAppendUnsafe(dest, dest_len, code_point); |
| } |
| |
| if (i < src_len) |
| UnicodeAppendUnsafe(dest, dest_len, ConvertSingleChar(src[i])); |
| |
| return success; |
| } |
| |
| #if defined(WCHAR_T_IS_UTF32) |
| |
| template <typename DestChar> |
| bool DoUTFConversion(const wchar_t* src, |
| int32_t src_len, |
| DestChar* dest, |
| int32_t* dest_len) { |
| bool success = true; |
| |
| for (int32_t i = 0; i < src_len; ++i) { |
| int32_t code_point = src[i]; |
| |
| if (!IsValidCodepoint(code_point)) { |
| success = false; |
| code_point = kErrorCodePoint; |
| } |
| |
| UnicodeAppendUnsafe(dest, dest_len, code_point); |
| } |
| |
| return success; |
| } |
| |
| #endif // defined(WCHAR_T_IS_UTF32) |
| |
| // UTFConversion -------------------------------------------------------------- |
| // Function template for generating all UTF conversions. |
| |
| template <typename InputString, typename DestString> |
| bool UTFConversion(const InputString& src_str, DestString* dest_str) { |
| if (IsStringASCII(src_str)) { |
| dest_str->assign(src_str.begin(), src_str.end()); |
| return true; |
| } |
| |
| dest_str->resize(src_str.length() * |
| size_coefficient_v<typename InputString::value_type, |
| typename DestString::value_type>); |
| |
| // Empty string is ASCII => it OK to call operator[]. |
| auto* dest = &(*dest_str)[0]; |
| |
| // ICU requires 32 bit numbers. |
| int32_t src_len32 = static_cast<int32_t>(src_str.length()); |
| int32_t dest_len32 = 0; |
| |
| bool res = DoUTFConversion(src_str.data(), src_len32, dest, &dest_len32); |
| |
| dest_str->resize(dest_len32); |
| dest_str->shrink_to_fit(); |
| |
| return res; |
| } |
| |
| } // namespace |
| |
| // UTF16 <-> UTF8 -------------------------------------------------------------- |
| |
| bool UTF8ToUTF16(const char* src, size_t src_len, string16* output) { |
| return UTFConversion(StringPiece(src, src_len), output); |
| } |
| |
| string16 UTF8ToUTF16(StringPiece utf8) { |
| string16 ret; |
| // Ignore the success flag of this call, it will do the best it can for |
| // invalid input, which is what we want here. |
| UTF8ToUTF16(utf8.data(), utf8.size(), &ret); |
| return ret; |
| } |
| |
| bool UTF16ToUTF8(const char16* src, size_t src_len, std::string* output) { |
| return UTFConversion(StringPiece16(src, src_len), output); |
| } |
| |
| std::string UTF16ToUTF8(StringPiece16 utf16) { |
| std::string ret; |
| // Ignore the success flag of this call, it will do the best it can for |
| // invalid input, which is what we want here. |
| UTF16ToUTF8(utf16.data(), utf16.length(), &ret); |
| return ret; |
| } |
| |
| // UTF-16 <-> Wide ------------------------------------------------------------- |
| |
| #if defined(WCHAR_T_IS_UTF16) |
| // When wide == UTF-16 the conversions are a NOP. |
| |
| bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output) { |
| output->assign(src, src_len); |
| return true; |
| } |
| |
| string16 WideToUTF16(WStringPiece wide) { |
| return wide.as_string(); |
| } |
| |
| bool UTF16ToWide(const char16* src, size_t src_len, std::wstring* output) { |
| output->assign(src, src_len); |
| return true; |
| } |
| |
| std::wstring UTF16ToWide(StringPiece16 utf16) { |
| return utf16.as_string(); |
| } |
| |
| #elif defined(WCHAR_T_IS_UTF32) |
| |
| bool WideToUTF16(const wchar_t* src, size_t src_len, string16* output) { |
| return UTFConversion(base::WStringPiece(src, src_len), output); |
| } |
| |
| string16 WideToUTF16(WStringPiece wide) { |
| string16 ret; |
| // Ignore the success flag of this call, it will do the best it can for |
| // invalid input, which is what we want here. |
| WideToUTF16(wide.data(), wide.length(), &ret); |
| return ret; |
| } |
| |
| bool UTF16ToWide(const char16* src, size_t src_len, std::wstring* output) { |
| return UTFConversion(StringPiece16(src, src_len), output); |
| } |
| |
| std::wstring UTF16ToWide(StringPiece16 utf16) { |
| std::wstring ret; |
| // Ignore the success flag of this call, it will do the best it can for |
| // invalid input, which is what we want here. |
| UTF16ToWide(utf16.data(), utf16.length(), &ret); |
| return ret; |
| } |
| |
| #endif // defined(WCHAR_T_IS_UTF32) |
| |
| // UTF-8 <-> Wide -------------------------------------------------------------- |
| |
| // UTF8ToWide is the same code, regardless of whether wide is 16 or 32 bits |
| |
| bool UTF8ToWide(const char* src, size_t src_len, std::wstring* output) { |
| return UTFConversion(StringPiece(src, src_len), output); |
| } |
| |
| std::wstring UTF8ToWide(StringPiece utf8) { |
| std::wstring ret; |
| // Ignore the success flag of this call, it will do the best it can for |
| // invalid input, which is what we want here. |
| UTF8ToWide(utf8.data(), utf8.length(), &ret); |
| return ret; |
| } |
| |
| #if defined(WCHAR_T_IS_UTF16) |
| // Easy case since we can use the "utf" versions we already wrote above. |
| |
| bool WideToUTF8(const wchar_t* src, size_t src_len, std::string* output) { |
| return UTF16ToUTF8(src, src_len, output); |
| } |
| |
| std::string WideToUTF8(WStringPiece wide) { |
| return UTF16ToUTF8(wide); |
| } |
| |
| #elif defined(WCHAR_T_IS_UTF32) |
| |
| bool WideToUTF8(const wchar_t* src, size_t src_len, std::string* output) { |
| return UTFConversion(WStringPiece(src, src_len), output); |
| } |
| |
| std::string WideToUTF8(WStringPiece wide) { |
| std::string ret; |
| // Ignore the success flag of this call, it will do the best it can for |
| // invalid input, which is what we want here. |
| WideToUTF8(wide.data(), wide.length(), &ret); |
| return ret; |
| } |
| |
| #endif // defined(WCHAR_T_IS_UTF32) |
| |
| string16 ASCIIToUTF16(StringPiece ascii) { |
| DCHECK(IsStringASCII(ascii)) << ascii; |
| return string16(ascii.begin(), ascii.end()); |
| } |
| |
| std::string UTF16ToASCII(StringPiece16 utf16) { |
| DCHECK(IsStringASCII(utf16)) << UTF16ToUTF8(utf16); |
| return std::string(utf16.begin(), utf16.end()); |
| } |
| |
| } // namespace base |