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 #if (defined(_MSC_VER) && (_MSC_VER < 1300)) || (defined(__MINGW32_VERSION) && ((__MINGW32_MAJOR_VERSION < 3)||((__MINGW32_MAJOR_VERSION == 3)&&(__MINGW32_MINOR_VERSION < 18)))) 35 36 /* The non-debug versions of _vscprintf/_scprintf are just calls 37 to _vsprintf/_sprintf with string buffer pointer set to NULL, 38 requires MSVCRT version 7.0 */ 39 #ifdef __MINGW32__ 40 static int __cdecl _vsctprintf( const TCHAR *format, va_list ap ) 41 #else 42 static int __cdecl _vsctprintf( const _TXCHAR *format, va_list ap ) 43 #endif 44 { 45 FILE *fp = _tfopen( _T("NUL"), _T("wb") ); 46 47 if ( fp ) 48 { 49 int retval = _vftprintf( fp, format, ap ); 50 fclose( fp ); 51 52 return retval; 53 } 54 55 return -1; 56 } 57 #endif 58 59 /* This function retrieves the pointer to the last character of a buffer. 60 That is the pointer to the last character of the buffer that fits 61 completly into that buffer or the position of the terminating zero. 62 63 buffer Pointer to a _TXCHAR buffer to be examined 64 count size of the buffer to be examined 65 66 return The pointer to the last character that fits into the buffer or 67 NULL if count is zero or count is one and the first byte was a 68 leading DBCS character 69 */ 70 71 static _TCHAR *GetLastBufferChar( _TCHAR *buffer, size_t count ) 72 { 73 _TCHAR *last = NULL; 74 _TCHAR *cur = buffer; 75 76 while ( (size_t)(cur - buffer) < count ) 77 { 78 last = cur; 79 80 if ( !*last ) 81 break; 82 83 cur = _tcsinc(last); 84 } 85 86 return last; 87 } 88 89 /* Implementation of snprintf following the ISO/IEC 9899:1999 (ISO C99) standard */ 90 91 _SNPRINTF_DLLIMPORT int __cdecl vsntprintf( _TCHAR *buffer, size_t count, const _TCHAR *format, va_list list ) 92 { 93 int retval; 94 95 /* First of all call the existing non POSIX standard function assuming 96 the buffer size will be large enough */ 97 98 retval = _vsntprintf( buffer, count, format, list ); 99 100 if ( retval < 0 ) 101 { 102 /* If the buffer wasn't large enough ensure that the buffer will be 103 zero terminated */ 104 105 _TCHAR *last = GetLastBufferChar( buffer, count ); 106 if (last ) 107 *last = 0; 108 109 /* Retrieve the count of characters that would have been written 110 if the buffer were large enough */ 111 112 retval = _vsctprintf( format, list ); 113 } 114 else if ( (size_t)retval == count && count ) 115 { 116 /* If the buffer was large enough but not large enough for the trailing 117 zero make the buffer zero terminated */ 118 119 _TCHAR *last = GetLastBufferChar( buffer, count ); 120 if (last ) 121 *last = 0; 122 } 123 124 return retval; 125 } 126 127 /* Implementation of snprintf following the ISO/IEC 9899:1999 (ISO C99) standard */ 128 129 _SNPRINTF_DLLIMPORT int __cdecl sntprintf( _TCHAR *buffer, size_t count, const _TCHAR *format, ... ) 130 { 131 va_list list; 132 int retval; 133 134 va_start( list, format ); 135 retval = vsntprintf( buffer, count, format, list ); 136 va_end( list ); 137 138 return retval; 139 } 140