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 void /* PRIVATE */
 113 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 114    error_message)
 115 {
 116    int iout = 0, iin = 0;
 117
 118    while (iin < 4)
 119    {
 120       int c = png_ptr->chunk_name[iin++];
 121       if (isnonalpha(c))
 122       {
 123          buffer[iout++] = '[';
 124          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
 125          buffer[iout++] = png_digit[c & 0x0f];
 126          buffer[iout++] = ']';
 127       }
 128       else
 129       {
 130          buffer[iout++] = (png_byte)c;
 131       }
 132    }
 133
 134    if (error_message == NULL)
 135       buffer[iout] = 0;
 136    else
 137    {
 138       buffer[iout++] = ':';
 139       buffer[iout++] = ' ';
 140       png_memcpy(buffer+iout, error_message, 64);
 141       buffer[iout+63] = 0;
 142    }
 143 }
 144
 145 void PNGAPI
 146 png_chunk_error(png_structp png_ptr, png_const_charp error_message)
 147 {
 148    char msg[18+64];
 149    png_format_buffer(png_ptr, msg, error_message);
 150    png_error(png_ptr, msg);
 151 }
 152
 153 void PNGAPI
 154 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 155 {
 156    char msg[18+64];
 157    png_format_buffer(png_ptr, msg, warning_message);
 158    png_warning(png_ptr, msg);
 159 }
 160
 161 /* This is the default error handling function.  Note that replacements for
 162  * this function MUST NOT RETURN, or the program will likely crash.  This
 163  * function is used by default, or if the program supplies NULL for the
 164  * error function pointer in png_set_error_fn().
 165  */
 166 static void /* PRIVATE */
 167 png_default_error(png_structp png_ptr, png_const_charp error_message)
 168 {
 169 #ifndef PNG_NO_CONSOLE_IO
 170 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 171    if (*error_message == '#')
 172    {
 173      int offset;
 174      char error_number[16];
 175      for (offset=0; offset<15; offset++)
 176      {
 177          error_number[offset] = *(error_message+offset+1);
 178          if (*(error_message+offset) == ' ')
 179              break;
 180      }
 181      if((offset > 1) && (offset < 15))
 182      {
 183        error_number[offset-1]='\0';
 184        fprintf(stderr, "libpng error no. %s: %s\n", error_number,
 185           error_message+offset);
 186      }
 187      else
 188        fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset);
 189    }
 190    else
 191 #endif
 192    fprintf(stderr, "libpng error: %s\n", error_message);
 193 #else
 194    if (error_message)
 195      /* make compiler happy */ ;
 196 #endif
 197
 198 #ifdef PNG_SETJMP_SUPPORTED
 199 #  ifdef USE_FAR_KEYWORD
 200    {
 201       jmp_buf jmpbuf;
 202       png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
 203       longjmp(jmpbuf, 1);
 204    }
 205 #  else
 206    longjmp(png_ptr->jmpbuf, 1);
 207 # endif
 208 #else
 209    if (png_ptr)
 210      /* make compiler happy */ ;
 211    PNG_ABORT();
 212 #endif
 213 }
 214
 215 /* This function is called when there is a warning, but the library thinks
 216  * it can continue anyway.  Replacement functions don't have to do anything
 217  * here if you don't want them to.  In the default configuration, png_ptr is
 218  * not used, but it is passed in case it may be useful.
 219  */
 220 static void /* PRIVATE */
 221 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 222 {
 223 #ifndef PNG_NO_CONSOLE_IO
 224 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
 225    if (*warning_message == '#')
 226    {
 227      int offset;
 228      char warning_number[16];
 229      for (offset=0; offset<15; offset++)
 230      {
 231         warning_number[offset]=*(warning_message+offset+1);
 232         if (*(warning_message+offset) == ' ')
 233             break;
 234      }
 235      if((offset > 1) && (offset < 15))
 236      {
 237        warning_number[offset-1]='\0';
 238        fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
 239           warning_message+offset);
 240      }
 241      else
 242        fprintf(stderr, "libpng warning: %s\n", warning_message);
 243    }
 244    else
 245 #  endif
 246      fprintf(stderr, "libpng warning: %s\n", warning_message);
 247 #else
 248    if (warning_message)
 249      /* appease compiler */ ;
 250 #endif
 251    if (png_ptr)
 252       return;
 253 }
 254
 255 /* This function is called when the application wants to use another method
 256  * of handling errors and warnings.  Note that the error function MUST NOT
 257  * return to the calling routine or serious problems will occur.  The return
 258  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
 259  */
 260 void PNGAPI
 261 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 262    png_error_ptr error_fn, png_error_ptr warning_fn)
 263 {
 264    png_ptr->error_ptr = error_ptr;
 265    png_ptr->error_fn = error_fn;
 266    png_ptr->warning_fn = warning_fn;
 267 }
 268
 269
 270 /* This function returns a pointer to the error_ptr associated with the user
 271  * functions.  The application should free any memory associated with this
 272  * pointer before png_write_destroy and png_read_destroy are called.
 273  */
 274 png_voidp PNGAPI
 275 png_get_error_ptr(png_structp png_ptr)
 276 {
 277    return ((png_voidp)png_ptr->error_ptr);
 278 }
 279
 280
 281 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 282 void PNGAPI
 283 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 284 {
 285    if(png_ptr != NULL)
 286    {
 287      png_ptr->flags &=
 288        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
 289    }
 290 }
 291 #endif