src/png/pngerror.c

   1
   2 /* pngerror.c - stub functions for i/o and memory allocation
   3  *
   4  * libpng 1.2.5rc3 - September 18, 2002
   5  * For conditions of distribution and use, see copyright notice in png.h
   6  * Copyright (c) 1998-2002 Glenn Randers-Pehrson
   7  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   8  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
   9  *
  10  * This file provides a location for all error handling.  Users who
  11  * need special error handling are expected to write replacement functions
  12  * and use png_set_error_fn() to use those functions.  See the instructions
  13  * at each function.
  14  */
  15
  16 #define PNG_INTERNAL
  17 #include "png.h"
  18
  19 static void /* PRIVATE */
  20 png_default_error PNGARG((png_structp png_ptr,
  21   png_const_charp error_message));
  22 static void /* PRIVATE */
  23 png_default_warning PNGARG((png_structp png_ptr,
  24   png_const_charp warning_message));
  25
  26 /* This function is called whenever there is a fatal error.  This function
  27  * should not be changed.  If there is a need to handle errors differently,
  28  * you should supply a replacement error function and use png_set_error_fn()
  29  * to replace the error function at run-time.
  30  */
  31 void PNGAPI
  32 png_error(png_structp png_ptr, png_const_charp error_message)
  33 {
  34 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
  35    char msg[16];
  36    if (png_ptr->flags&(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
  37    {
  38      int offset = 0;
  39      if (*error_message == '#')
  40      {
  41          for (offset=1; offset<15; offset++)
  42             if (*(error_message+offset) == ' ')
  43                 break;
  44          if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  45          {
  46             int i;
  47             for (i=0; i<offset-1; i++)
  48                msg[i]=error_message[i+1];
  49             msg[i]='\0';
  50             error_message=msg;
  51          }
  52          else
  53             error_message+=offset;
  54      }
  55      else
  56      {
  57          if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  58          {
  59             msg[0]='0';
  60             msg[1]='\0';
  61             error_message=msg;
  62          }
  63      }
  64    }
  65 #endif
  66    if (png_ptr->error_fn != NULL)
  67       (*(png_ptr->error_fn))(png_ptr, error_message);
  68
  69    /* if the following returns or doesn't exist, use the default function,
  70       which will not return */
  71    png_default_error(png_ptr, error_message);
  72 }
  73
  74 /* This function is called whenever there is a non-fatal error.  This function
  75  * should not be changed.  If there is a need to handle warnings differently,
  76  * you should supply a replacement warning function and use
  77  * png_set_error_fn() to replace the warning function at run-time.
  78  */
  79 void PNGAPI
  80 png_warning(png_structp png_ptr, png_const_charp warning_message)
  81 {
  82      int offset = 0;
  83 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
  84    if (png_ptr->flags&(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
  85 #endif
  86    {
  87      if (*warning_message == '#')
  88      {
  89          for (offset=1; offset<15; offset++)
  90             if (*(warning_message+offset) == ' ')
  91                 break;
  92      }
  93    }
  94    if (png_ptr->warning_fn != NULL)
  95       (*(png_ptr->warning_fn))(png_ptr,
  96          (png_const_charp)(warning_message+offset));
  97    else
  98       png_default_warning(png_ptr, (png_const_charp)(warning_message+offset));
  99 }
 100
 101 /* These utilities are used internally to build an error message that relates
 102  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
 103  * this is used to prefix the message.  The message is limited in length
 104  * to 63 bytes, the name characters are output as hex digits wrapped in []
 105  * if the character is invalid.
 106  */
 107 #define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97))
 108 static PNG_CONST char png_digit[16] = {
 109    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E',
 110    'F' };
 111
 112 static size_t wxstrnlen( const char *s, size_t maxlen )
 113 {
 114         size_t i ;
 115         for ( i = 0 ; s[i] && i < maxlen ; ++i )
 116                 ;
 117         return i ;
 118 }
 119
 120 static void /* PRIVATE */
 121 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 122    error_message)
 123 {
 124    int iout = 0, iin = 0;
 125
 126    while (iin < 4)
 127    {
 128       int c = png_ptr->chunk_name[iin++];
 129       if (isnonalpha(c))
 130       {
 131          buffer[iout++] = '[';
 132          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
 133          buffer[iout++] = png_digit[c & 0x0f];
 134          buffer[iout++] = ']';
 135       }
 136       else
 137       {
 138          buffer[iout++] = (png_byte)c;
 139       }
 140    }
 141
 142    if (error_message == NULL)
 143       buffer[iout] = 0;
 144    else
 145    {
 146       int len = wxstrnlen(error_message, 64);
 147
 148       buffer[iout++] = ':';
 149       buffer[iout++] = ' ';
 150       png_memcpy(buffer+iout, error_message, len);
 151       buffer[iout+len-1] = 0;
 152    }
 153 }
 154
 155 void PNGAPI
 156 png_chunk_error(png_structp png_ptr, png_const_charp error_message)
 157 {
 158    char msg[18+64];
 159    png_format_buffer(png_ptr, msg, error_message);
 160    png_error(png_ptr, msg);
 161 }
 162
 163 void PNGAPI
 164 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 165 {
 166    char msg[18+64];
 167    png_format_buffer(png_ptr, msg, warning_message);
 168    png_warning(png_ptr, msg);
 169 }
 170
 171 /* This is the default error handling function.  Note that replacements for
 172  * this function MUST NOT RETURN, or the program will likely crash.  This
 173  * function is used by default, or if the program supplies NULL for the
 174  * error function pointer in png_set_error_fn().
 175  */
 176 static void /* PRIVATE */
 177 png_default_error(png_structp png_ptr, png_const_charp error_message)
 178 {
 179 #ifndef PNG_NO_CONSOLE_IO
 180 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 181    if (*error_message == '#')
 182    {
 183      int offset;
 184      char error_number[16];
 185      for (offset=0; offset<15; offset++)
 186      {
 187          error_number[offset] = *(error_message+offset+1);
 188          if (*(error_message+offset) == ' ')
 189              break;
 190      }
 191      if((offset > 1) && (offset < 15))
 192      {
 193        error_number[offset-1]='\0';
 194        fprintf(stderr, "libpng error no. %s: %s\n", error_number,
 195           error_message+offset);
 196      }
 197      else
 198        fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset);
 199    }
 200    else
 201 #endif
 202    fprintf(stderr, "libpng error: %s\n", error_message);
 203 #else
 204    if (error_message)
 205      /* make compiler happy */ ;
 206 #endif
 207
 208 #ifdef PNG_SETJMP_SUPPORTED
 209 #  ifdef USE_FAR_KEYWORD
 210    {
 211       jmp_buf jmpbuf;
 212       png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
 213       longjmp(jmpbuf, 1);
 214    }
 215 #  else
 216    longjmp(png_ptr->jmpbuf, 1);
 217 # endif
 218 #else
 219    if (png_ptr)
 220      /* make compiler happy */ ;
 221    PNG_ABORT();
 222 #endif
 223 }
 224
 225 /* This function is called when there is a warning, but the library thinks
 226  * it can continue anyway.  Replacement functions don't have to do anything
 227  * here if you don't want them to.  In the default configuration, png_ptr is
 228  * not used, but it is passed in case it may be useful.
 229  */
 230 static void /* PRIVATE */
 231 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 232 {
 233 #ifndef PNG_NO_CONSOLE_IO
 234 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
 235    if (*warning_message == '#')
 236    {
 237      int offset;
 238      char warning_number[16];
 239      for (offset=0; offset<15; offset++)
 240      {
 241         warning_number[offset]=*(warning_message+offset+1);
 242         if (*(warning_message+offset) == ' ')
 243             break;
 244      }
 245      if((offset > 1) && (offset < 15))
 246      {
 247        warning_number[offset-1]='\0';
 248        fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
 249           warning_message+offset);
 250      }
 251      else
 252        fprintf(stderr, "libpng warning: %s\n", warning_message);
 253    }
 254    else
 255 #  endif
 256      fprintf(stderr, "libpng warning: %s\n", warning_message);
 257 #else
 258    if (warning_message)
 259      /* appease compiler */ ;
 260 #endif
 261    if (png_ptr)
 262       return;
 263 }
 264
 265 /* This function is called when the application wants to use another method
 266  * of handling errors and warnings.  Note that the error function MUST NOT
 267  * return to the calling routine or serious problems will occur.  The return
 268  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
 269  */
 270 void PNGAPI
 271 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 272    png_error_ptr error_fn, png_error_ptr warning_fn)
 273 {
 274    png_ptr->error_ptr = error_ptr;
 275    png_ptr->error_fn = error_fn;
 276    png_ptr->warning_fn = warning_fn;
 277 }
 278
 279
 280 /* This function returns a pointer to the error_ptr associated with the user
 281  * functions.  The application should free any memory associated with this
 282  * pointer before png_write_destroy and png_read_destroy are called.
 283  */
 284 png_voidp PNGAPI
 285 png_get_error_ptr(png_structp png_ptr)
 286 {
 287    return ((png_voidp)png_ptr->error_ptr);
 288 }
 289
 290
 291 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 292 void PNGAPI
 293 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 294 {
 295    if(png_ptr != NULL)
 296    {
 297      png_ptr->flags &=
 298        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
 299    }
 300 }
 301 #endif