Utf8.cpp (1192B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #define MOZ_PRETEND_NO_JSRUST 1 8 9 #include "mozilla/Maybe.h" 10 #include "mozilla/TextUtils.h" 11 #include "mozilla/Types.h" 12 #include "mozilla/Utf8.h" 13 14 #include <stddef.h> 15 16 MFBT_API bool mozilla::detail::IsValidUtf8(const void* aCodeUnits, 17 size_t aCount) { 18 const auto* s = reinterpret_cast<const unsigned char*>(aCodeUnits); 19 const auto* const limit = s + aCount; 20 21 while (s < limit) { 22 unsigned char c = *s++; 23 24 // If the first byte is ASCII, it's the only one in the code point. Have a 25 // fast path that avoids all the rest of the work and looping in that case. 26 if (IsAscii(c)) { 27 continue; 28 } 29 30 Maybe<char32_t> maybeCodePoint = 31 DecodeOneUtf8CodePoint(Utf8Unit(c), &s, limit); 32 if (maybeCodePoint.isNothing()) { 33 return false; 34 } 35 } 36 37 MOZ_ASSERT(s == limit); 38 return true; 39 }