xref: /freebsd/contrib/llvm-project/libc/src/__support/wchar/wcrtomb.cpp (revision bb722a7d0f1642bff6487f943ad0427799a6e5bf)
1 //===-- Implementation of wcrtomb -----------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/__support/wchar/wcrtomb.h"
10 #include "src/__support/error_or.h"
11 #include "src/__support/wchar/character_converter.h"
12 #include "src/__support/wchar/mbstate.h"
13 
14 #include "hdr/errno_macros.h"
15 #include "hdr/types/char32_t.h"
16 #include "hdr/types/size_t.h"
17 #include "hdr/types/wchar_t.h"
18 #include "src/__support/common.h"
19 #include "src/__support/libc_assert.h"
20 
21 namespace LIBC_NAMESPACE_DECL {
22 namespace internal {
23 
wcrtomb(char * __restrict s,wchar_t wc,mbstate * __restrict ps)24 ErrorOr<size_t> wcrtomb(char *__restrict s, wchar_t wc,
25                         mbstate *__restrict ps) {
26   static_assert(sizeof(wchar_t) == 4);
27 
28   CharacterConverter cr(ps);
29 
30   if (!cr.isValidState())
31     return Error(EINVAL);
32 
33   int status = cr.push(static_cast<char32_t>(wc));
34   if (status != 0)
35     return Error(status);
36 
37   size_t count = 0;
38   while (!cr.isEmpty()) {
39     auto utf8 = cr.pop_utf8(); // can never fail as long as the push succeeded
40     LIBC_ASSERT(utf8.has_value());
41 
42     *s = utf8.value();
43     s++;
44     count++;
45   }
46   return count;
47 }
48 
49 } // namespace internal
50 } // namespace LIBC_NAMESPACE_DECL
51