1 // -*- C++ -*-
2 //===----------------------- support/win32/support.h ----------------------===//
3 //
4 // The LLVM Compiler Infrastructure
5 //
6 // This file is dual licensed under the MIT and the University of Illinois Open
7 // Source Licenses. See LICENSE.TXT for details.
8 //
9 //===----------------------------------------------------------------------===//
10
11 #include <cstdarg> // va_start, va_end
12 #include <cstddef> // size_t
13 #include <cstdlib> // malloc
14 #include <cstdio> // vsprintf, vsnprintf
15 #include <cstring> // strcpy, wcsncpy
16 #include <cwchar> // mbstate_t
17
18
19 // Like sprintf, but when return value >= 0 it returns
20 // a pointer to a malloc'd string in *sptr.
21 // If return >= 0, use free to delete *sptr.
__libcpp_vasprintf(char ** sptr,const char * __restrict format,va_list ap)22 int __libcpp_vasprintf( char **sptr, const char *__restrict format, va_list ap )
23 {
24 *sptr = NULL;
25 // Query the count required.
26 int count = _vsnprintf( NULL, 0, format, ap );
27 if (count < 0)
28 return count;
29 size_t buffer_size = static_cast<size_t>(count) + 1;
30 char* p = static_cast<char*>(malloc(buffer_size));
31 if ( ! p )
32 return -1;
33 // If we haven't used exactly what was required, something is wrong.
34 // Maybe bug in vsnprintf. Report the error and return.
35 if (_vsnprintf(p, buffer_size, format, ap) != count) {
36 free(p);
37 return -1;
38 }
39 // All good. This is returning memory to the caller not freeing it.
40 *sptr = p;
41 return count;
42 }
43
44 // Returns >= 0: the number of wide characters found in the
45 // multi byte sequence src (of src_size_bytes), that fit in the buffer dst
46 // (of max_dest_chars elements size). The count returned excludes the
47 // null terminator. When dst is NULL, no characters are copied
48 // and no "out" parameters are updated.
49 // Returns (size_t) -1: an incomplete sequence encountered.
50 // Leaves *src pointing the next character to convert or NULL
51 // 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)52 size_t mbsnrtowcs( wchar_t *__restrict dst, const char **__restrict src,
53 size_t src_size_bytes, size_t max_dest_chars, mbstate_t *__restrict ps )
54 {
55 const size_t terminated_sequence = static_cast<size_t>(0);
56 //const size_t invalid_sequence = static_cast<size_t>(-1);
57 const size_t incomplete_sequence = static_cast< size_t>(-2);
58
59 size_t dest_converted = 0;
60 size_t source_converted = 0;
61 size_t source_remaining = src_size_bytes;
62 size_t result = 0;
63 bool have_result = false;
64
65 while ( source_remaining ) {
66 if ( dst && dest_converted >= max_dest_chars )
67 break;
68 // Converts one multi byte character.
69 // if result > 0, it's the size in bytes of that character.
70 // othewise if result is zero it indicates the null character has been found.
71 // otherwise it's an error and errno may be set.
72 size_t char_size = mbrtowc( dst ? dst + dest_converted : NULL, *src + source_converted, source_remaining, ps );
73 // Don't do anything to change errno from here on.
74 if ( char_size > 0 ) {
75 source_remaining -= char_size;
76 source_converted += char_size;
77 ++dest_converted;
78 continue;
79 }
80 result = char_size;
81 have_result = true;
82 break;
83 }
84 if ( dst ) {
85 if ( have_result && result == terminated_sequence )
86 *src = NULL;
87 else
88 *src += source_converted;
89 }
90 if ( have_result && result != terminated_sequence && result != incomplete_sequence )
91 return static_cast<size_t>(-1);
92
93 return dest_converted;
94 }
95
96 // Converts max_source_chars from the wide character buffer pointer to by *src,
97 // into the multi byte character sequence buffer stored at dst which must be
98 // dst_size_bytes bytes in size.
99 // Returns >= 0: the number of bytes in the sequence
100 // converted from *src, excluding the null terminator.
101 // Returns size_t(-1) if an error occurs, also sets errno.
102 // If dst is NULL dst_size_bytes is ignored and no bytes are copied to dst
103 // 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)104 size_t wcsnrtombs( char *__restrict dst, const wchar_t **__restrict src,
105 size_t max_source_chars, size_t dst_size_bytes, mbstate_t *__restrict ps )
106 {
107 //const size_t invalid_sequence = static_cast<size_t>(-1);
108
109 size_t source_converted = 0;
110 size_t dest_converted = 0;
111 size_t dest_remaining = dst_size_bytes;
112 size_t char_size = 0;
113 const errno_t no_error = ( errno_t) 0;
114 errno_t result = ( errno_t ) 0;
115 bool have_result = false;
116 bool terminator_found = false;
117
118 while ( source_converted != max_source_chars ) {
119 if ( ! dest_remaining )
120 break;
121 wchar_t c = (*src)[source_converted];
122 if ( dst )
123 result = wcrtomb_s( &char_size, dst + dest_converted, dest_remaining, c, ps);
124 else
125 result = wcrtomb_s( &char_size, NULL, 0, c, ps);
126 // If result is zero there is no error and char_size contains the
127 // size of the multi-byte-sequence converted.
128 // Otherwise result indicates an errno type error.
129 if ( result == no_error ) {
130 if ( c == L'\0' ) {
131 terminator_found = true;
132 break;
133 }
134 ++source_converted;
135 if ( dst )
136 dest_remaining -= char_size;
137 dest_converted += char_size;
138 continue;
139 }
140 have_result = true;
141 break;
142 }
143 if ( dst ) {
144 if ( terminator_found )
145 *src = NULL;
146 else
147 *src = *src + source_converted;
148 }
149 if ( have_result && result != no_error ) {
150 errno = result;
151 return static_cast<size_t>(-1);
152 }
153
154 return dest_converted;
155 }
156