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1 | |
2 | /* pngerror.c - stub functions for i/o and memory allocation | |
3 | * | |
a626cc03 | 4 | * libpng 1.0.3 - January 14, 1999 |
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5 | * For conditions of distribution and use, see copyright notice in png.h |
6 | * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. | |
7 | * Copyright (c) 1996, 1997 Andreas Dilger | |
a626cc03 | 8 | * Copyright (c) 1998, 1999 Glenn Randers-Pehrson |
c801d85f | 9 | * |
a626cc03 | 10 | * This file provides a location for all error handling. Users who |
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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 | |
a626cc03 | 17 | #include "png.h" |
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18 | |
19 | static void png_default_error PNGARG((png_structp png_ptr, | |
20 | png_const_charp message)); | |
21 | static void png_default_warning PNGARG((png_structp png_ptr, | |
22 | png_const_charp message)); | |
23 | ||
24 | /* This function is called whenever there is a fatal error. This function | |
25 | * should not be changed. If there is a need to handle errors differently, | |
26 | * you should supply a replacement error function and use png_set_error_fn() | |
27 | * to replace the error function at run-time. | |
28 | */ | |
29 | void | |
30 | png_error(png_structp png_ptr, png_const_charp message) | |
31 | { | |
32 | if (png_ptr->error_fn != NULL) | |
33 | (*(png_ptr->error_fn))(png_ptr, message); | |
34 | ||
35 | /* if the following returns or doesn't exist, use the default function, | |
36 | which will not return */ | |
37 | png_default_error(png_ptr, message); | |
38 | } | |
39 | ||
40 | /* This function is called whenever there is a non-fatal error. This function | |
41 | * should not be changed. If there is a need to handle warnings differently, | |
42 | * you should supply a replacement warning function and use | |
43 | * png_set_error_fn() to replace the warning function at run-time. | |
44 | */ | |
45 | void | |
46 | png_warning(png_structp png_ptr, png_const_charp message) | |
47 | { | |
48 | if (png_ptr->warning_fn != NULL) | |
49 | (*(png_ptr->warning_fn))(png_ptr, message); | |
50 | else | |
51 | png_default_warning(png_ptr, message); | |
52 | } | |
53 | ||
a626cc03 | 54 | /* These utilities are used internally to build an error message that relates |
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55 | * to the current chunk. The chunk name comes from png_ptr->chunk_name, |
56 | * this is used to prefix the message. The message is limited in length | |
57 | * to 63 bytes, the name characters are output as hex digits wrapped in [] | |
58 | * if the character is invalid. | |
59 | */ | |
60 | #define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) | |
61 | static PNG_CONST char png_digit[16] = { | |
62 | '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' | |
63 | }; | |
64 | ||
65 | static void | |
66 | png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp message) | |
67 | { | |
68 | int iout = 0, iin = 0; | |
69 | ||
70 | while (iin < 4) { | |
71 | int c = png_ptr->chunk_name[iin++]; | |
72 | if (isnonalpha(c)) { | |
73 | buffer[iout++] = '['; | |
74 | buffer[iout++] = png_digit[(c & 0xf0) >> 4]; | |
75 | buffer[iout++] = png_digit[c & 0xf]; | |
76 | buffer[iout++] = ']'; | |
77 | } else { | |
78 | buffer[iout++] = c; | |
79 | } | |
80 | } | |
81 | ||
82 | if (message == NULL) | |
83 | buffer[iout] = 0; | |
84 | else { | |
85 | buffer[iout++] = ':'; | |
86 | buffer[iout++] = ' '; | |
87 | png_memcpy(buffer+iout, message, 64); | |
88 | buffer[iout+63] = 0; | |
89 | } | |
90 | } | |
91 | ||
92 | void | |
93 | png_chunk_error(png_structp png_ptr, png_const_charp message) | |
94 | { | |
95 | char msg[16+64]; | |
96 | png_format_buffer(png_ptr, msg, message); | |
97 | png_error(png_ptr, msg); | |
98 | } | |
99 | ||
100 | void | |
101 | png_chunk_warning(png_structp png_ptr, png_const_charp message) | |
102 | { | |
103 | char msg[16+64]; | |
104 | png_format_buffer(png_ptr, msg, message); | |
105 | png_warning(png_ptr, msg); | |
106 | } | |
107 | ||
108 | /* This is the default error handling function. Note that replacements for | |
109 | * this function MUST NOT RETURN, or the program will likely crash. This | |
110 | * function is used by default, or if the program supplies NULL for the | |
111 | * error function pointer in png_set_error_fn(). | |
112 | */ | |
113 | static void | |
114 | png_default_error(png_structp png_ptr, png_const_charp message) | |
115 | { | |
a626cc03 | 116 | #ifndef PNG_NO_CONSOLE_IO |
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117 | fprintf(stderr, "libpng error: %s\n", message); |
118 | #endif | |
119 | ||
120 | #ifdef USE_FAR_KEYWORD | |
121 | { | |
122 | jmp_buf jmpbuf; | |
123 | png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf)); | |
124 | longjmp(jmpbuf, 1); | |
125 | } | |
126 | #else | |
127 | longjmp(png_ptr->jmpbuf, 1); | |
128 | #endif | |
129 | } | |
130 | ||
131 | /* This function is called when there is a warning, but the library thinks | |
132 | * it can continue anyway. Replacement functions don't have to do anything | |
a626cc03 | 133 | * here if you don't want them to. In the default configuration, png_ptr is |
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134 | * not used, but it is passed in case it may be useful. |
135 | */ | |
136 | static void | |
137 | png_default_warning(png_structp png_ptr, png_const_charp message) | |
138 | { | |
a626cc03 | 139 | #ifndef PNG_NO_CONSOLE_IO |
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140 | fprintf(stderr, "libpng warning: %s\n", message); |
141 | #endif | |
a626cc03 RR |
142 | if (png_ptr == NULL) |
143 | return; | |
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144 | } |
145 | ||
146 | /* This function is called when the application wants to use another method | |
147 | * of handling errors and warnings. Note that the error function MUST NOT | |
148 | * return to the calling routine or serious problems will occur. The return | |
149 | * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) | |
150 | */ | |
151 | void | |
152 | png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, | |
153 | png_error_ptr error_fn, png_error_ptr warning_fn) | |
154 | { | |
155 | png_ptr->error_ptr = error_ptr; | |
156 | png_ptr->error_fn = error_fn; | |
157 | png_ptr->warning_fn = warning_fn; | |
158 | } | |
159 | ||
160 | ||
161 | /* This function returns a pointer to the error_ptr associated with the user | |
162 | * functions. The application should free any memory associated with this | |
163 | * pointer before png_write_destroy and png_read_destroy are called. | |
164 | */ | |
165 | png_voidp | |
166 | png_get_error_ptr(png_structp png_ptr) | |
167 | { | |
168 | return ((png_voidp)png_ptr->error_ptr); | |
169 | } | |
170 | ||
171 | ||
172 |