1 //===----------------------------------------------------------------------===//
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 <cstdarg> // va_start, va_end
10 #include <cstddef> // size_t
11 #include <cstdlib> // malloc
12 #include <cstdio> // vsprintf, vsnprintf
13 #include <cstring> // strcpy, wcsncpy
14 #include <cwchar> // mbstate_t
15
16
17 // Like sprintf, but when return value >= 0 it returns
18 // a pointer to a malloc'd string in *sptr.
19 // If return >= 0, use free to delete *sptr.
__libcpp_vasprintf(char ** sptr,const char * __restrict format,va_list ap)20 int __libcpp_vasprintf( char **sptr, const char *__restrict format, va_list ap )
21 {
22 *sptr = NULL;
23 // Query the count required.
24 va_list ap_copy;
25 va_copy(ap_copy, ap);
26 _LIBCPP_DIAGNOSTIC_PUSH
27 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral")
28 int count = vsnprintf( NULL, 0, format, ap_copy );
29 _LIBCPP_DIAGNOSTIC_POP
30 va_end(ap_copy);
31 if (count < 0)
32 return count;
33 size_t buffer_size = static_cast<size_t>(count) + 1;
34 char* p = static_cast<char*>(malloc(buffer_size));
35 if ( ! p )
36 return -1;
37 // If we haven't used exactly what was required, something is wrong.
38 // Maybe bug in vsnprintf. Report the error and return.
39 _LIBCPP_DIAGNOSTIC_PUSH
40 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral")
41 if (vsnprintf(p, buffer_size, format, ap) != count) {
42 _LIBCPP_DIAGNOSTIC_POP
43 free(p);
44 return -1;
45 }
46 // All good. This is returning memory to the caller not freeing it.
47 *sptr = p;
48 return count;
49 }
50
51 // Returns >= 0: the number of wide characters found in the
52 // multi byte sequence src (of src_size_bytes), that fit in the buffer dst
53 // (of max_dest_chars elements size). The count returned excludes the
54 // null terminator. When dst is NULL, no characters are copied
55 // and no "out" parameters are updated.
56 // Returns (size_t) -1: an incomplete sequence encountered.
57 // Leaves *src pointing the next character to convert or NULL
58 // if a null character was converted from *src.
mbsnrtowcs(wchar_t * __restrict dst,const char ** __restrict src,size_t src_size_bytes,size_t max_dest_chars,mbstate_t * __restrict ps)59 size_t mbsnrtowcs( wchar_t *__restrict dst, const char **__restrict src,
60 size_t src_size_bytes, size_t max_dest_chars, mbstate_t *__restrict ps )
61 {
62 const size_t terminated_sequence = static_cast<size_t>(0);
63 //const size_t invalid_sequence = static_cast<size_t>(-1);
64 const size_t incomplete_sequence = static_cast< size_t>(-2);
65
66 size_t dest_converted = 0;
67 size_t source_converted = 0;
68 size_t source_remaining = src_size_bytes;
69 size_t result = 0;
70 bool have_result = false;
71
72 // If dst is null then max_dest_chars should be ignored according to the
73 // standard. Setting max_dest_chars to a large value has this effect.
74 if (!dst)
75 max_dest_chars = static_cast<size_t>(-1);
76
77 while ( source_remaining ) {
78 if ( dst && dest_converted >= max_dest_chars )
79 break;
80 // Converts one multi byte character.
81 // if result > 0, it's the size in bytes of that character.
82 // othewise if result is zero it indicates the null character has been found.
83 // otherwise it's an error and errno may be set.
84 size_t char_size = mbrtowc( dst ? dst + dest_converted : NULL, *src + source_converted, source_remaining, ps );
85 // Don't do anything to change errno from here on.
86 if ( char_size > 0 ) {
87 source_remaining -= char_size;
88 source_converted += char_size;
89 ++dest_converted;
90 continue;
91 }
92 result = char_size;
93 have_result = true;
94 break;
95 }
96 if ( dst ) {
97 if ( have_result && result == terminated_sequence )
98 *src = NULL;
99 else
100 *src += source_converted;
101 }
102 if ( have_result && result != terminated_sequence && result != incomplete_sequence )
103 return static_cast<size_t>(-1);
104
105 return dest_converted;
106 }
107
108 // Converts max_source_chars from the wide character buffer pointer to by *src,
109 // into the multi byte character sequence buffer stored at dst which must be
110 // dst_size_bytes bytes in size.
111 // Returns >= 0: the number of bytes in the sequence
112 // converted from *src, excluding the null terminator.
113 // Returns size_t(-1) if an error occurs, also sets errno.
114 // If dst is NULL dst_size_bytes is ignored and no bytes are copied to dst
115 // and no "out" parameters are updated.
wcsnrtombs(char * __restrict dst,const wchar_t ** __restrict src,size_t max_source_chars,size_t dst_size_bytes,mbstate_t * __restrict ps)116 size_t wcsnrtombs( char *__restrict dst, const wchar_t **__restrict src,
117 size_t max_source_chars, size_t dst_size_bytes, mbstate_t *__restrict ps )
118 {
119 //const size_t invalid_sequence = static_cast<size_t>(-1);
120
121 size_t source_converted = 0;
122 size_t dest_converted = 0;
123 size_t dest_remaining = dst_size_bytes;
124 size_t char_size = 0;
125 const errno_t no_error = ( errno_t) 0;
126 errno_t result = ( errno_t ) 0;
127 bool have_result = false;
128 bool terminator_found = false;
129
130 // If dst is null then dst_size_bytes should be ignored according to the
131 // standard. Setting dest_remaining to a large value has this effect.
132 if (!dst)
133 dest_remaining = static_cast<size_t>(-1);
134
135 while ( source_converted != max_source_chars ) {
136 if ( ! dest_remaining )
137 break;
138 wchar_t c = (*src)[source_converted];
139 if ( dst )
140 result = wcrtomb_s( &char_size, dst + dest_converted, dest_remaining, c, ps);
141 else
142 result = wcrtomb_s( &char_size, NULL, 0, c, ps);
143 // If result is zero there is no error and char_size contains the
144 // size of the multi-byte-sequence converted.
145 // Otherwise result indicates an errno type error.
146 if ( result == no_error ) {
147 if ( c == L'\0' ) {
148 terminator_found = true;
149 break;
150 }
151 ++source_converted;
152 if ( dst )
153 dest_remaining -= char_size;
154 dest_converted += char_size;
155 continue;
156 }
157 have_result = true;
158 break;
159 }
160 if ( dst ) {
161 if ( terminator_found )
162 *src = NULL;
163 else
164 *src = *src + source_converted;
165 }
166 if ( have_result && result != no_error ) {
167 errno = result;
168 return static_cast<size_t>(-1);
169 }
170
171 return dest_converted;
172 }
173