src/SDL_error.c

   1 /*
   2     SDL - Simple DirectMedia Layer
   3     Copyright (C) 1997-2009 Sam Lantinga
   4
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Lesser General Public
   7     License as published by the Free Software Foundation; either
   8     version 2.1 of the License, or (at your option) any later version.
   9
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public
  16     License along with this library; if not, write to the Free Software
  17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18
  19     Sam Lantinga
  20     slouken@libsdl.org
  21 */
  22 #include "SDL_config.h"
  23
  24 /* Simple error handling in SDL */
  25
  26 #include "SDL_error.h"
  27 #include "SDL_error_c.h"
  28
  29 /* Routine to get the thread-specific error variable */
  30 #if SDL_THREADS_DISABLED
  31 /* The  SDL_arraysize(The ),default (non-thread-safe) global error variable */
  32 static SDL_error SDL_global_error;
  33 #define SDL_GetErrBuf() (&SDL_global_error)
  34 #else
  35 extern SDL_error *SDL_GetErrBuf(void);
  36 #endif /* SDL_THREADS_DISABLED */
  37
  38 #define SDL_ERRBUFIZE   1024
  39
  40 /* Private functions */
  41
  42 static const char *SDL_LookupString(const char *key)
  43 {
  44         /* FIXME: Add code to lookup key in language string hash-table */
  45         return key;
  46 }
  47
  48 /* Public functions */
  49
  50 void SDL_SetError (const char *fmt, ...)
  51 {
  52         va_list ap;
  53         SDL_error *error;
  54
  55         /* Copy in the key, mark error as valid */
  56         error = SDL_GetErrBuf();
  57         error->error = 1;
  58         SDL_strlcpy((char *)error->key, fmt, sizeof(error->key));
  59
  60         va_start(ap, fmt);
  61         error->argc = 0;
  62         while ( *fmt ) {
  63                 if ( *fmt++ == '%' ) {
  64                         while ( *fmt == '.' || (*fmt >= '0' && *fmt <= '9') ) {
  65                                 ++fmt;
  66                         }
  67                         switch (*fmt++) {
  68                             case 0:  /* Malformed format string.. */
  69                                 --fmt;
  70                                 break;
  71                             case 'c':
  72                             case 'i':
  73                             case 'd':
  74                             case 'u':
  75                             case 'o':
  76                             case 'x':
  77                             case 'X':
  78                                 error->args[error->argc++].value_i =
  79                                                         va_arg(ap, int);
  80                                 break;
  81                             case 'f':
  82                                 error->args[error->argc++].value_f =
  83                                                         va_arg(ap, double);
  84                                 break;
  85                             case 'p':
  86                                 error->args[error->argc++].value_ptr =
  87                                                         va_arg(ap, void *);
  88                                 break;
  89                             case 's':
  90                                 {
  91                                   int i = error->argc;
  92                                   const char *str = va_arg(ap, const char *);
  93                                   if (str == NULL)
  94                                       str = "(null)";
  95                                   SDL_strlcpy((char *)error->args[i].buf, str, ERR_MAX_STRLEN);
  96                                   error->argc++;
  97                                 }
  98                                 break;
  99                             default:
 100                                 break;
 101                         }
 102                         if ( error->argc >= ERR_MAX_ARGS ) {
 103                                 break;
 104                         }
 105                 }
 106         }
 107         va_end(ap);
 108
 109         /* If we are in debug mode, print out an error message */
 110 #ifdef DEBUG_ERROR
 111         fprintf(stderr, "SDL_SetError: %s\n", SDL_GetError());
 112 #endif
 113 }
 114
 115 /* This function has a bit more overhead than most error functions
 116    so that it supports internationalization and thread-safe errors.
 117 */
 118 char *SDL_GetErrorMsg(char *errstr, unsigned int maxlen)
 119 {
 120         SDL_error *error;
 121
 122         /* Clear the error string */
 123         *errstr = '\0'; --maxlen;
 124
 125         /* Get the thread-safe error, and print it out */
 126         error = SDL_GetErrBuf();
 127         if ( error->error ) {
 128                 const char *fmt;
 129                 char *msg = errstr;
 130                 int len;
 131                 int argi;
 132
 133                 fmt = SDL_LookupString(error->key);
 134                 argi = 0;
 135                 while ( *fmt && (maxlen > 0) ) {
 136                         if ( *fmt == '%' ) {
 137                                 char tmp[32], *spot = tmp;
 138                                 *spot++ = *fmt++;
 139                                 while ( (*fmt == '.' || (*fmt >= '0' && *fmt <= '9')) && spot < (tmp+SDL_arraysize(tmp)-2) ) {
 140                                         *spot++ = *fmt++;
 141                                 }
 142                                 *spot++ = *fmt++;
 143                                 *spot++ = '\0';
 144                                 switch (spot[-2]) {
 145                                     case '%':
 146                                         *msg++ = '%';
 147                                         maxlen -= 1;
 148                                         break;
 149                                     case 'c':
 150                                     case 'i':
 151                                     case 'd':
 152                                     case 'u':
 153                                     case 'o':
 154                                     case 'x':
 155                                     case 'X':
 156                                         len = SDL_snprintf(msg, maxlen, tmp, error->args[argi++].value_i);
 157                                         msg += len;
 158                                         maxlen -= len;
 159                                         break;
 160                                     case 'f':
 161                                         len = SDL_snprintf(msg, maxlen, tmp, error->args[argi++].value_f);
 162                                         msg += len;
 163                                         maxlen -= len;
 164                                         break;
 165                                     case 'p':
 166                                         len = SDL_snprintf(msg, maxlen, tmp, error->args[argi++].value_ptr);
 167                                         msg += len;
 168                                         maxlen -= len;
 169                                         break;
 170                                     case 's':
 171                                         len = SDL_snprintf(msg, maxlen, tmp, SDL_LookupString(error->args[argi++].buf));
 172                                         msg += len;
 173                                         maxlen -= len;
 174                                         break;
 175                                 }
 176                         } else {
 177                                 *msg++ = *fmt++;
 178                                 maxlen -= 1;
 179                         }
 180                 }
 181                 *msg = 0;       /* NULL terminate the string */
 182         }
 183         return(errstr);
 184 }
 185
 186 /* Available for backwards compatibility */
 187 char *SDL_GetError (void)
 188 {
 189         static char errmsg[SDL_ERRBUFIZE];
 190
 191         return((char *)SDL_GetErrorMsg(errmsg, SDL_ERRBUFIZE));
 192 }
 193
 194 void SDL_ClearError(void)
 195 {
 196         SDL_error *error;
 197
 198         error = SDL_GetErrBuf();
 199         error->error = 0;
 200 }
 201
 202 /* Very common errors go here */
 203 void SDL_Error(SDL_errorcode code)
 204 {
 205         switch (code) {
 206                 case SDL_ENOMEM:
 207                         SDL_SetError("Out of memory");
 208                         break;
 209                 case SDL_EFREAD:
 210                         SDL_SetError("Error reading from datastream");
 211                         break;
 212                 case SDL_EFWRITE:
 213                         SDL_SetError("Error writing to datastream");
 214                         break;
 215                 case SDL_EFSEEK:
 216                         SDL_SetError("Error seeking in datastream");
 217                         break;
 218                 default:
 219                         SDL_SetError("Unknown SDL error");
 220                         break;
 221         }
 222 }
 223
 224 #ifdef TEST_ERROR
 225 int main(int argc, char *argv[])
 226 {
 227         char buffer[BUFSIZ+1];
 228
 229         SDL_SetError("Hi there!");
 230         printf("Error 1: %s\n", SDL_GetError());
 231         SDL_ClearError();
 232         SDL_memset(buffer, '1', BUFSIZ);
 233         buffer[BUFSIZ] = 0;
 234         SDL_SetError("This is the error: %s (%f)", buffer, 1.0);
 235         printf("Error 2: %s\n", SDL_GetError());
 236         exit(0);
 237 }
 238 #endif