1 /**************************************************************
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 *
20 *************************************************************/
21
22 #define _SNPRINTF_DLLIMPORT __declspec( dllexport )
23
24 #include <stdarg.h>
25 #include <stdio.h>
26
27 #include <tchar.h>
28 #include <systools/win32/snprintf.h>
29
30 #if defined(_MSC_VER) && (_MSC_VER >= 1400)
31 #pragma warning(disable:4273) // inconsistent dll linkage
32 #endif
33
34 /* uwinapi implements C99 snprintf/vsnprintf because VC9's CRT has neither.
35 A CRT from VS2015 onwards supplies both itself, and defining ours on top of
36 its declarations is a redefinition with different linkage (C2375) -- the
37 same conflict systools/win32/snprintf.h avoids for the DECLARATIONS, here
38 for the DEFINITIONS. On such a runtime this file therefore contributes
39 nothing and the CRT's own implementations are used; on every runtime the
40 XP-era targets build against it is unchanged. Nothing is lost by leaving it
41 out: these symbols are exported only by Uwinapi.def (x86), never by
42 Uwinapi64.def, which exports SHCreateItemFromParsingName alone. */
43 #if !defined(_MSC_VER) || (_MSC_VER < 1900)
44
45 #if (defined(_MSC_VER) && (_MSC_VER < 1300)) || (defined(__MINGW32_VERSION) && ((__MINGW32_MAJOR_VERSION < 3)||((__MINGW32_MAJOR_VERSION == 3)&&(__MINGW32_MINOR_VERSION < 18))))
46
47 /* The non-debug versions of _vscprintf/_scprintf are just calls
48 to _vsprintf/_sprintf with string buffer pointer set to NULL,
49 requires MSVCRT version 7.0 */
50 #ifdef __MINGW32__
_vsctprintf(const TCHAR * format,va_list ap)51 static int __cdecl _vsctprintf( const TCHAR *format, va_list ap )
52 #else
53 static int __cdecl _vsctprintf( const _TXCHAR *format, va_list ap )
54 #endif
55 {
56 FILE *fp = _tfopen( _T("NUL"), _T("wb") );
57
58 if ( fp )
59 {
60 int retval = _vftprintf( fp, format, ap );
61 fclose( fp );
62
63 return retval;
64 }
65
66 return -1;
67 }
68 #endif
69
70 /* This function retrieves the pointer to the last character of a buffer.
71 That is the pointer to the last character of the buffer that fits
72 completely into that buffer or the position of the terminating zero.
73
74 buffer Pointer to a _TXCHAR buffer to be examined
75 count size of the buffer to be examined
76
77 return The pointer to the last character that fits into the buffer or
78 NULL if count is zero or count is one and the first byte was a
79 leading DBCS character
80 */
81
GetLastBufferChar(_TCHAR * buffer,size_t count)82 static _TCHAR *GetLastBufferChar( _TCHAR *buffer, size_t count )
83 {
84 _TCHAR *last = NULL;
85 _TCHAR *cur = buffer;
86
87 while ( (size_t)(cur - buffer) < count )
88 {
89 last = cur;
90
91 if ( !*last )
92 break;
93
94 cur = _tcsinc(last);
95 }
96
97 return last;
98 }
99
100 /* Implementation of snprintf following the ISO/IEC 9899:1999 (ISO C99) standard */
101
vsntprintf(_TCHAR * buffer,size_t count,const _TCHAR * format,va_list list)102 _SNPRINTF_DLLIMPORT int __cdecl vsntprintf( _TCHAR *buffer, size_t count, const _TCHAR *format, va_list list )
103 {
104 int retval;
105
106 /* First of all call the existing non POSIX standard function assuming
107 the buffer size will be large enough */
108
109 retval = _vsntprintf( buffer, count, format, list );
110
111 if ( retval < 0 )
112 {
113 /* If the buffer wasn't large enough ensure that the buffer will be
114 zero terminated */
115
116 _TCHAR *last = GetLastBufferChar( buffer, count );
117 if (last )
118 *last = 0;
119
120 /* Retrieve the count of characters that would have been written
121 if the buffer were large enough */
122
123 retval = _vsctprintf( format, list );
124 }
125 else if ( (size_t)retval == count && count )
126 {
127 /* If the buffer was large enough but not large enough for the trailing
128 zero make the buffer zero terminated */
129
130 _TCHAR *last = GetLastBufferChar( buffer, count );
131 if (last )
132 *last = 0;
133 }
134
135 return retval;
136 }
137
138 /* Implementation of snprintf following the ISO/IEC 9899:1999 (ISO C99) standard */
139
sntprintf(_TCHAR * buffer,size_t count,const _TCHAR * format,...)140 _SNPRINTF_DLLIMPORT int __cdecl sntprintf( _TCHAR *buffer, size_t count, const _TCHAR *format, ... )
141 {
142 va_list list;
143 int retval;
144
145 va_start( list, format );
146 retval = vsntprintf( buffer, count, format, list );
147 va_end( list );
148
149 return retval;
150 }
151
152 #endif /* CRT without a conforming snprintf */
153