src/SDL_error.c
author Ryan C. Gordon <icculus@icculus.org>
Thu, 17 Nov 2005 03:04:47 +0000
changeset 1172 f69f4d25fb20
parent 769 b8d311d90021
child 1312 c9b51268668f
permissions -rw-r--r--
Don't crash if a NULL is passed for a "%s" parameter to SDL_SetError(),
instead replace it with the string "(null)", like glibc's printf() would do.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2004 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 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     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 #ifdef SAVE_RCSID
    24 static char rcsid =
    25  "@(#) $Id$";
    26 #endif
    27 
    28 /* Simple error handling in SDL */
    29 
    30 #include <stdio.h>
    31 #include <stdlib.h>
    32 #include <stdarg.h>
    33 #include <string.h>
    34 
    35 #include "SDL_types.h"
    36 #include "SDL_getenv.h"
    37 #include "SDL_error.h"
    38 #include "SDL_error_c.h"
    39 #ifndef DISABLE_THREADS
    40 #include "SDL_thread_c.h"
    41 #endif
    42 
    43 #ifdef DISABLE_THREADS
    44 /* The default (non-thread-safe) global error variable */
    45 static SDL_error SDL_global_error;
    46 
    47 #define SDL_GetErrBuf()	(&SDL_global_error)
    48 #endif /* DISABLE_THREADS */
    49 
    50 #ifdef __CYGWIN__
    51 #define DISABLE_STDIO
    52 #endif
    53 
    54 #define SDL_ERRBUFIZE	1024
    55 
    56 /* Private functions */
    57 
    58 static void SDL_LookupString(const Uint8 *key, Uint16 *buf, int buflen)
    59 {
    60 	/* FIXME: Add code to lookup key in language string hash-table */
    61 
    62 	/* Key not found in language string hash-table */
    63 	while ( *key && (--buflen > 0) ) {
    64 		*buf++ = *key++;
    65 	}
    66 	*buf = 0;	/* NULL terminate string */
    67 }
    68 
    69 /* Public functions */
    70 
    71 void SDL_SetError (const char *fmt, ...)
    72 {
    73 	va_list ap;
    74 	SDL_error *error;
    75 
    76 	/* Copy in the key, mark error as valid */
    77 	error = SDL_GetErrBuf();
    78 	error->error = 1;
    79 	strncpy((char *)error->key, fmt, sizeof(error->key));
    80 	error->key[sizeof(error->key)-1] = '\0';
    81 
    82 	va_start(ap, fmt);
    83 	error->argc = 0;
    84 	while ( *fmt ) {
    85 		if ( *fmt++ == '%' ) {
    86 			switch (*fmt++) {
    87 			    case 0:  /* Malformed format string.. */
    88 				--fmt;
    89 				break;
    90 #if 0	/* What is a character anyway?  (UNICODE issues) */
    91 			    case 'c':
    92 				error->args[error->argc++].value_c =
    93 						va_arg(ap, unsigned char);
    94 				break;
    95 #endif
    96 			    case 'd':
    97 				error->args[error->argc++].value_i =
    98 							va_arg(ap, int);
    99 				break;
   100 			    case 'f':
   101 				error->args[error->argc++].value_f =
   102 							va_arg(ap, double);
   103 				break;
   104 			    case 'p':
   105 				error->args[error->argc++].value_ptr =
   106 							va_arg(ap, void *);
   107 				break;
   108 			    case 's':
   109 				{
   110 				  int index = error->argc;
   111 				  char *str = va_arg(ap, char *);
   112 				  if (str == NULL)
   113 				      str = "(null)";
   114 				  strncpy((char *)error->args[index].buf, str, ERR_MAX_STRLEN);
   115 				  error->args[index].buf[ERR_MAX_STRLEN-1] = 0;
   116 				  error->argc++;
   117 				}
   118 				break;
   119 			    default:
   120 				break;
   121 			}
   122 			if ( error->argc >= ERR_MAX_ARGS ) {
   123 				break;
   124 			}
   125 		}
   126 	}
   127 	va_end(ap);
   128 
   129 #ifndef DISABLE_STDIO
   130 	/* If we are in debug mode, print out an error message */
   131 #ifdef DEBUG_ERROR
   132 	fprintf(stderr, "SDL_SetError: %s\n", SDL_GetError());
   133 #else
   134 	if ( getenv("SDL_DEBUG") ) {
   135 		fprintf(stderr, "SDL_SetError: %s\n", SDL_GetError());
   136 	}
   137 #endif
   138 #endif /* !DISABLE_STDIO */
   139 }
   140 
   141 /* Print out an integer value to a UNICODE buffer */
   142 static int PrintInt(Uint16 *str, unsigned int maxlen, int value)
   143 {
   144 	char tmp[128];
   145 	int len, i;
   146 
   147 	sprintf(tmp, "%d", value);
   148 	len = 0;
   149 	if ( strlen(tmp) < maxlen ) {
   150 		for ( i=0; tmp[i]; ++i ) {
   151 			*str++ = tmp[i];
   152 			++len;
   153 		}
   154 	}
   155 	return(len);
   156 }
   157 /* Print out a double value to a UNICODE buffer */
   158 static int PrintDouble(Uint16 *str, unsigned int maxlen, double value)
   159 {
   160 	char tmp[128];
   161 	int len, i;
   162 
   163 	sprintf(tmp, "%f", value);
   164 	len = 0;
   165 	if ( strlen(tmp) < maxlen ) {
   166 		for ( i=0; tmp[i]; ++i ) {
   167 			*str++ = tmp[i];
   168 			++len;
   169 		}
   170 	}
   171 	return(len);
   172 }
   173 /* Print out a pointer value to a UNICODE buffer */
   174 static int PrintPointer(Uint16 *str, unsigned int maxlen, void *value)
   175 {
   176 	char tmp[128];
   177 	int len, i;
   178 
   179 	sprintf(tmp, "%p", value);
   180 	len = 0;
   181 	if ( strlen(tmp) < maxlen ) {
   182 		for ( i=0; tmp[i]; ++i ) {
   183 			*str++ = tmp[i];
   184 			++len;
   185 		}
   186 	}
   187 	return(len);
   188 }
   189 
   190 /* This function has a bit more overhead than most error functions
   191    so that it supports internationalization and thread-safe errors.
   192 */
   193 Uint16 *SDL_GetErrorMsgUNICODE(Uint16 *errstr, unsigned int maxlen)
   194 {
   195 	SDL_error *error;
   196 
   197 	/* Clear the error string */
   198 	*errstr = 0; --maxlen;
   199 
   200 	/* Get the thread-safe error, and print it out */
   201 	error = SDL_GetErrBuf();
   202 	if ( error->error ) {
   203 		Uint16 translated[ERR_MAX_STRLEN], *fmt, *msg;
   204 		int len;
   205 		int argi;
   206 
   207 		/* Print out the UNICODE error message */
   208 		SDL_LookupString(error->key, translated, sizeof(translated));
   209 		msg = errstr;
   210 		argi = 0;
   211 		for ( fmt=translated; *fmt && (maxlen > 0); ) {
   212 			if ( *fmt == '%' ) {
   213 				switch (fmt[1]) {
   214 				    case 'S':	/* Special SKIP operand */
   215 					argi += (fmt[2] - '0');
   216 					++fmt;
   217 					break;
   218 				    case '%':
   219 					*msg++ = '%';
   220 					maxlen -= 1;
   221 					break;
   222 #if 0	/* What is a character anyway?  (UNICODE issues) */
   223 				    case 'c':
   224                                         *msg++ = (unsigned char)
   225 					         error->args[argi++].value_c;
   226 					maxlen -= 1;
   227 					break;
   228 #endif
   229 				    case 'd':
   230 					len = PrintInt(msg, maxlen,
   231 						error->args[argi++].value_i);
   232 					msg += len;
   233 					maxlen -= len;
   234 					break;
   235 				    case 'f':
   236 					len = PrintDouble(msg, maxlen,
   237 						error->args[argi++].value_f);
   238 					msg += len;
   239 					maxlen -= len;
   240 					break;
   241 				    case 'p':
   242 					len = PrintPointer(msg, maxlen,
   243 						error->args[argi++].value_ptr);
   244 					msg += len;
   245 					maxlen -= len;
   246 					break;
   247 				    case 's': /* UNICODE string */
   248 					{ Uint16 buf[ERR_MAX_STRLEN], *str;
   249 					  SDL_LookupString(error->args[argi++].buf, buf, sizeof(buf));
   250 					  str = buf;
   251 					  while ( *str && (maxlen > 0) ) {
   252 						*msg++ = *str++;
   253 						maxlen -= 1;
   254 					  }
   255 					}
   256 					break;
   257 				}
   258 				fmt += 2;
   259 			} else {
   260 				*msg++ = *fmt++;
   261 				maxlen -= 1;
   262 			}
   263 		}
   264 		*msg = 0;	/* NULL terminate the string */
   265 	}
   266 	return(errstr);
   267 }
   268 
   269 Uint8 *SDL_GetErrorMsg(Uint8 *errstr, unsigned int maxlen)
   270 {
   271 	Uint16 *errstr16;
   272 	unsigned int i;
   273 
   274 	/* Allocate the UNICODE buffer */
   275 	errstr16 = (Uint16 *)malloc(maxlen * (sizeof *errstr16));
   276 	if ( ! errstr16 ) {
   277 		strncpy((char *)errstr, "Out of memory", maxlen);
   278 		errstr[maxlen-1] = '\0';
   279 		return(errstr);
   280 	}
   281 
   282 	/* Get the error message */
   283 	SDL_GetErrorMsgUNICODE(errstr16, maxlen);
   284 
   285 	/* Convert from UNICODE to Latin1 encoding */
   286 	for ( i=0; i<maxlen; ++i ) {
   287 		errstr[i] = (Uint8)errstr16[i];
   288 	}
   289 
   290 	/* Free UNICODE buffer (if necessary) */
   291 	free(errstr16);
   292 
   293 	return(errstr);
   294 }
   295 
   296 /* Available for backwards compatibility */
   297 char *SDL_GetError (void)
   298 {
   299 	static char errmsg[SDL_ERRBUFIZE];
   300 
   301 	return((char *)SDL_GetErrorMsg((unsigned char *)errmsg, SDL_ERRBUFIZE));
   302 }
   303 
   304 void SDL_ClearError(void)
   305 {
   306 	SDL_error *error;
   307 
   308 	error = SDL_GetErrBuf();
   309 	error->error = 0;
   310 }
   311 
   312 /* Very common errors go here */
   313 void SDL_Error(SDL_errorcode code)
   314 {
   315 	switch (code) {
   316 		case SDL_ENOMEM:
   317 			SDL_SetError("Out of memory");
   318 			break;
   319 		case SDL_EFREAD:
   320 			SDL_SetError("Error reading from datastream");
   321 			break;
   322 		case SDL_EFWRITE:
   323 			SDL_SetError("Error writing to datastream");
   324 			break;
   325 		case SDL_EFSEEK:
   326 			SDL_SetError("Error seeking in datastream");
   327 			break;
   328 		default:
   329 			SDL_SetError("Unknown SDL error");
   330 			break;
   331 	}
   332 }
   333 
   334 #ifdef TEST_ERROR
   335 int main(int argc, char *argv[])
   336 {
   337 	char buffer[BUFSIZ+1];
   338 
   339 	SDL_SetError("Hi there!");
   340 	printf("Error 1: %s\n", SDL_GetError());
   341 	SDL_ClearError();
   342 	memset(buffer, '1', BUFSIZ);
   343 	buffer[BUFSIZ] = 0;
   344 	SDL_SetError("This is the error: %s (%f)", buffer, 1.0);
   345 	printf("Error 2: %s\n", SDL_GetError());
   346 	exit(0);
   347 }
   348 #endif