1*bb722a7dSDimitry Andric //===-- Implementation for mbrtowc function ---------------------*- C++ -*-===// 2*bb722a7dSDimitry Andric // 3*bb722a7dSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*bb722a7dSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*bb722a7dSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*bb722a7dSDimitry Andric // 7*bb722a7dSDimitry Andric //===----------------------------------------------------------------------===// 8*bb722a7dSDimitry Andric 9*bb722a7dSDimitry Andric #include "src/__support/wchar/mbrtowc.h" 10*bb722a7dSDimitry Andric #include "hdr/errno_macros.h" 11*bb722a7dSDimitry Andric #include "hdr/types/mbstate_t.h" 12*bb722a7dSDimitry Andric #include "hdr/types/size_t.h" 13*bb722a7dSDimitry Andric #include "hdr/types/wchar_t.h" 14*bb722a7dSDimitry Andric #include "src/__support/common.h" 15*bb722a7dSDimitry Andric #include "src/__support/error_or.h" 16*bb722a7dSDimitry Andric #include "src/__support/macros/config.h" 17*bb722a7dSDimitry Andric #include "src/__support/wchar/character_converter.h" 18*bb722a7dSDimitry Andric #include "src/__support/wchar/mbstate.h" 19*bb722a7dSDimitry Andric 20*bb722a7dSDimitry Andric namespace LIBC_NAMESPACE_DECL { 21*bb722a7dSDimitry Andric namespace internal { 22*bb722a7dSDimitry Andric mbrtowc(wchar_t * __restrict pwc,const char * __restrict s,size_t n,mbstate * __restrict ps)23*bb722a7dSDimitry AndricErrorOr<size_t> mbrtowc(wchar_t *__restrict pwc, const char *__restrict s, 24*bb722a7dSDimitry Andric size_t n, mbstate *__restrict ps) { 25*bb722a7dSDimitry Andric CharacterConverter char_conv(ps); 26*bb722a7dSDimitry Andric if (!char_conv.isValidState()) 27*bb722a7dSDimitry Andric return Error(EINVAL); 28*bb722a7dSDimitry Andric if (s == nullptr) 29*bb722a7dSDimitry Andric return 0; 30*bb722a7dSDimitry Andric size_t i = 0; 31*bb722a7dSDimitry Andric // Reading in bytes until we have a complete wc or error 32*bb722a7dSDimitry Andric for (; i < n && !char_conv.isFull(); ++i) { 33*bb722a7dSDimitry Andric int err = char_conv.push(static_cast<char8_t>(s[i])); 34*bb722a7dSDimitry Andric // Encoding error 35*bb722a7dSDimitry Andric if (err == EILSEQ) 36*bb722a7dSDimitry Andric return Error(err); 37*bb722a7dSDimitry Andric } 38*bb722a7dSDimitry Andric auto wc = char_conv.pop_utf32(); 39*bb722a7dSDimitry Andric if (wc.has_value()) { 40*bb722a7dSDimitry Andric *pwc = wc.value(); 41*bb722a7dSDimitry Andric // null terminator -> return 0 42*bb722a7dSDimitry Andric if (wc.value() == L'\0') 43*bb722a7dSDimitry Andric return 0; 44*bb722a7dSDimitry Andric return i; 45*bb722a7dSDimitry Andric } 46*bb722a7dSDimitry Andric // Incomplete but potentially valid 47*bb722a7dSDimitry Andric return -2; 48*bb722a7dSDimitry Andric } 49*bb722a7dSDimitry Andric 50*bb722a7dSDimitry Andric } // namespace internal 51*bb722a7dSDimitry Andric 52*bb722a7dSDimitry Andric } // namespace LIBC_NAMESPACE_DECL 53