third_party/libpng/pngerror.c

   1
   2 /* pngerror.c - stub functions for i/o and memory allocation
   3  *
   4  * Last changed in libpng 1.2.45 [July 7, 2011]
   5  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
   6  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   7  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
   8  *
   9  * This code is released under the libpng license.
  10  * For conditions of distribution and use, see the disclaimer
  11  * and license in png.h
  12  *
  13  * This file provides a location for all error handling.  Users who
  14  * need special error handling are expected to write replacement functions
  15  * and use png_set_error_fn() to use those functions.  See the instructions
  16  * at each function.
  17  */
  18
  19 #define PNG_INTERNAL
  20 #define PNG_NO_PEDANTIC_WARNINGS
  21 #include "png.h"
  22 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
  23
  24 static void /* PRIVATE */
  25 png_default_error PNGARG((png_structp png_ptr,
  26   png_const_charp error_message)) PNG_NORETURN;
  27 #ifdef PNG_WARNINGS_SUPPORTED
  28 static void /* PRIVATE */
  29 png_default_warning PNGARG((png_structp png_ptr,
  30   png_const_charp warning_message));
  31 #endif /* PNG_WARNINGS_SUPPORTED */
  32
  33 /* This function is called whenever there is a fatal error.  This function
  34  * should not be changed.  If there is a need to handle errors differently,
  35  * you should supply a replacement error function and use png_set_error_fn()
  36  * to replace the error function at run-time.
  37  */
  38 #ifdef PNG_ERROR_TEXT_SUPPORTED
  39 void PNGAPI
  40 png_error(png_structp png_ptr, png_const_charp error_message)
  41 {
  42 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
  43    char msg[16];
  44    if (png_ptr != NULL)
  45    {
  46      if (png_ptr->flags&
  47        (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
  48      {
  49        if (*error_message == PNG_LITERAL_SHARP)
  50        {
  51            /* Strip "#nnnn " from beginning of error message. */
  52            int offset;
  53            for (offset = 1; offset<15; offset++)
  54               if (error_message[offset] == ' ')
  55                   break;
  56            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  57            {
  58               int i;
  59               for (i = 0; i < offset - 1; i++)
  60                  msg[i] = error_message[i + 1];
  61               msg[i - 1] = '\0';
  62               error_message = msg;
  63            }
  64            else
  65               error_message += offset;
  66        }
  67        else
  68        {
  69            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
  70            {
  71               msg[0] = '0';
  72               msg[1] = '\0';
  73               error_message = msg;
  74            }
  75        }
  76      }
  77    }
  78 #endif
  79    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  80       (*(png_ptr->error_fn))(png_ptr, error_message);
  81
  82    /* If the custom handler doesn't exist, or if it returns,
  83       use the default handler, which will not return. */
  84    png_default_error(png_ptr, error_message);
  85 }
  86 #else
  87 void PNGAPI
  88 png_err(png_structp png_ptr)
  89 {
  90    /* Prior to 1.2.45 the error_fn received a NULL pointer, expressed
  91     * erroneously as '\0', instead of the empty string "".  This was
  92     * apparently an error, introduced in libpng-1.2.20, and png_default_error
  93     * will crash in this case.
  94     */
  95    if (png_ptr != NULL && png_ptr->error_fn != NULL)
  96       (*(png_ptr->error_fn))(png_ptr, "");
  97
  98    /* If the custom handler doesn't exist, or if it returns,
  99       use the default handler, which will not return. */
 100    png_default_error(png_ptr, "");
 101 }
 102 #endif /* PNG_ERROR_TEXT_SUPPORTED */
 103
 104 #ifdef PNG_WARNINGS_SUPPORTED
 105 /* This function is called whenever there is a non-fatal error.  This function
 106  * should not be changed.  If there is a need to handle warnings differently,
 107  * you should supply a replacement warning function and use
 108  * png_set_error_fn() to replace the warning function at run-time.
 109  */
 110 void PNGAPI
 111 png_warning(png_structp png_ptr, png_const_charp warning_message)
 112 {
 113    int offset = 0;
 114    if (png_ptr != NULL)
 115    {
 116 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 117    if (png_ptr->flags&
 118      (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
 119 #endif
 120      {
 121        if (*warning_message == PNG_LITERAL_SHARP)
 122        {
 123            for (offset = 1; offset < 15; offset++)
 124               if (warning_message[offset] == ' ')
 125                   break;
 126        }
 127      }
 128    }
 129    if (png_ptr != NULL && png_ptr->warning_fn != NULL)
 130       (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
 131    else
 132       png_default_warning(png_ptr, warning_message + offset);
 133 }
 134 #endif /* PNG_WARNINGS_SUPPORTED */
 135
 136 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 137 void PNGAPI
 138 png_benign_error(png_structp png_ptr, png_const_charp error_message)
 139 {
 140   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
 141     png_warning(png_ptr, error_message);
 142   else
 143     png_error(png_ptr, error_message);
 144 }
 145 #endif
 146
 147 /* These utilities are used internally to build an error message that relates
 148  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
 149  * this is used to prefix the message.  The message is limited in length
 150  * to 63 bytes, the name characters are output as hex digits wrapped in []
 151  * if the character is invalid.
 152  */
 153 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
 154 static PNG_CONST char png_digit[16] = {
 155    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 156    'A', 'B', 'C', 'D', 'E', 'F'
 157 };
 158
 159 #define PNG_MAX_ERROR_TEXT 64
 160 #if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
 161 static void /* PRIVATE */
 162 png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 163    error_message)
 164 {
 165    int iout = 0, iin = 0;
 166
 167    while (iin < 4)
 168    {
 169       int c = png_ptr->chunk_name[iin++];
 170       if (isnonalpha(c))
 171       {
 172          buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
 173          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
 174          buffer[iout++] = png_digit[c & 0x0f];
 175          buffer[iout++] = PNG_LITERAL_RIGHT_SQUARE_BRACKET;
 176       }
 177       else
 178       {
 179          buffer[iout++] = (png_byte)c;
 180       }
 181    }
 182
 183    if (error_message == NULL)
 184       buffer[iout] = '\0';
 185    else
 186    {
 187       buffer[iout++] = ':';
 188       buffer[iout++] = ' ';
 189
 190       iin = 0;
 191       while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
 192          buffer[iout++] = error_message[iin++];
 193
 194       /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
 195       buffer[iout] = '\0';
 196    }
 197 }
 198
 199 #ifdef PNG_READ_SUPPORTED
 200 void PNGAPI
 201 png_chunk_error(png_structp png_ptr, png_const_charp error_message)
 202 {
 203    char msg[18+PNG_MAX_ERROR_TEXT];
 204    if (png_ptr == NULL)
 205      png_error(png_ptr, error_message);
 206    else
 207    {
 208      png_format_buffer(png_ptr, msg, error_message);
 209      png_error(png_ptr, msg);
 210    }
 211 }
 212 #endif /* PNG_READ_SUPPORTED */
 213 #endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
 214
 215 #ifdef PNG_WARNINGS_SUPPORTED
 216 void PNGAPI
 217 png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 218 {
 219    char msg[18+PNG_MAX_ERROR_TEXT];
 220    if (png_ptr == NULL)
 221      png_warning(png_ptr, warning_message);
 222    else
 223    {
 224      png_format_buffer(png_ptr, msg, warning_message);
 225      png_warning(png_ptr, msg);
 226    }
 227 }
 228 #endif /* PNG_WARNINGS_SUPPORTED */
 229
 230 #ifdef PNG_READ_SUPPORTED
 231 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 232 void PNGAPI
 233 png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
 234 {
 235   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
 236     png_chunk_warning(png_ptr, error_message);
 237   else
 238     png_chunk_error(png_ptr, error_message);
 239 }
 240 #endif
 241 #endif /* PNG_READ_SUPPORTED */
 242
 243 /* This is the default error handling function.  Note that replacements for
 244  * this function MUST NOT RETURN, or the program will likely crash.  This
 245  * function is used by default, or if the program supplies NULL for the
 246  * error function pointer in png_set_error_fn().
 247  */
 248 static void /* PRIVATE */
 249 png_default_error(png_structp png_ptr, png_const_charp error_message)
 250 {
 251 #ifdef PNG_CONSOLE_IO_SUPPORTED
 252 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 253    if (*error_message == PNG_LITERAL_SHARP)
 254    {
 255      /* Strip "#nnnn " from beginning of error message. */
 256      int offset;
 257      char error_number[16];
 258      for (offset = 0; offset<15; offset++)
 259      {
 260          error_number[offset] = error_message[offset + 1];
 261          if (error_message[offset] == ' ')
 262              break;
 263      }
 264      if ((offset > 1) && (offset < 15))
 265      {
 266        error_number[offset - 1] = '\0';
 267        fprintf(stderr, "libpng error no. %s: %s",
 268           error_number, error_message + offset + 1);
 269        fprintf(stderr, PNG_STRING_NEWLINE);
 270      }
 271      else
 272      {
 273        fprintf(stderr, "libpng error: %s, offset=%d",
 274           error_message, offset);
 275        fprintf(stderr, PNG_STRING_NEWLINE);
 276      }
 277    }
 278    else
 279 #endif
 280    {
 281       fprintf(stderr, "libpng error: %s", error_message);
 282       fprintf(stderr, PNG_STRING_NEWLINE);
 283    }
 284 #endif
 285
 286 #ifdef PNG_SETJMP_SUPPORTED
 287    if (png_ptr)
 288    {
 289 #  ifdef USE_FAR_KEYWORD
 290    {
 291       jmp_buf jmpbuf;
 292       png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 293      longjmp(jmpbuf,1);
 294    }
 295 #  else
 296    longjmp(png_ptr->jmpbuf, 1);
 297 #  endif
 298    }
 299 #endif
 300    /* Here if not setjmp support or if png_ptr is null. */
 301    PNG_ABORT();
 302 #ifndef PNG_CONSOLE_IO_SUPPORTED
 303    error_message = error_message; /* Make compiler happy */
 304 #endif
 305 }
 306
 307 #ifdef PNG_WARNINGS_SUPPORTED
 308 /* This function is called when there is a warning, but the library thinks
 309  * it can continue anyway.  Replacement functions don't have to do anything
 310  * here if you don't want them to.  In the default configuration, png_ptr is
 311  * not used, but it is passed in case it may be useful.
 312  */
 313 static void /* PRIVATE */
 314 png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 315 {
 316 #ifdef PNG_CONSOLE_IO_SUPPORTED
 317 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
 318    if (*warning_message == PNG_LITERAL_SHARP)
 319    {
 320      int offset;
 321      char warning_number[16];
 322      for (offset = 0; offset < 15; offset++)
 323      {
 324         warning_number[offset] = warning_message[offset + 1];
 325         if (warning_message[offset] == ' ')
 326             break;
 327      }
 328      if ((offset > 1) && (offset < 15))
 329      {
 330        warning_number[offset + 1] = '\0';
 331        fprintf(stderr, "libpng warning no. %s: %s",
 332           warning_number, warning_message + offset);
 333        fprintf(stderr, PNG_STRING_NEWLINE);
 334      }
 335      else
 336      {
 337        fprintf(stderr, "libpng warning: %s",
 338           warning_message);
 339        fprintf(stderr, PNG_STRING_NEWLINE);
 340      }
 341    }
 342    else
 343 #  endif
 344    {
 345      fprintf(stderr, "libpng warning: %s", warning_message);
 346      fprintf(stderr, PNG_STRING_NEWLINE);
 347    }
 348 #else
 349    warning_message = warning_message; /* Make compiler happy */
 350 #endif
 351    png_ptr = png_ptr; /* Make compiler happy */
 352 }
 353 #endif /* PNG_WARNINGS_SUPPORTED */
 354
 355 /* This function is called when the application wants to use another method
 356  * of handling errors and warnings.  Note that the error function MUST NOT
 357  * return to the calling routine or serious problems will occur.  The return
 358  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
 359  */
 360 void PNGAPI
 361 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
 362    png_error_ptr error_fn, png_error_ptr warning_fn)
 363 {
 364    if (png_ptr == NULL)
 365       return;
 366    png_ptr->error_ptr = error_ptr;
 367    png_ptr->error_fn = error_fn;
 368    png_ptr->warning_fn = warning_fn;
 369 }
 370
 371
 372 /* This function returns a pointer to the error_ptr associated with the user
 373  * functions.  The application should free any memory associated with this
 374  * pointer before png_write_destroy and png_read_destroy are called.
 375  */
 376 png_voidp PNGAPI
 377 png_get_error_ptr(png_structp png_ptr)
 378 {
 379    if (png_ptr == NULL)
 380       return NULL;
 381    return ((png_voidp)png_ptr->error_ptr);
 382 }
 383
 384
 385 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 386 void PNGAPI
 387 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 388 {
 389    if (png_ptr != NULL)
 390    {
 391      png_ptr->flags &=
 392        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
 393    }
 394 }
 395 #endif
 396 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */