]>
Commit | Line | Data |
---|---|---|
c801d85f KB |
1 | |
2 | /* pngerror.c - stub functions for i/o and memory allocation | |
3 | * | |
4 | * libpng 1.0.1 | |
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 | |
8 | * Copyright (c) 1998, Glenn Randers-Pehrson | |
9 | * March 15, 1998 | |
10 | * | |
11 | * This file provides a location for all error handling. Users which | |
12 | * need special error handling are expected to write replacement functions | |
13 | * and use png_set_error_fn() to use those functions. See the instructions | |
14 | * at each function. | |
15 | */ | |
16 | ||
17 | #define PNG_INTERNAL | |
1f0299c1 | 18 | #include "../png/png.h" |
c801d85f KB |
19 | |
20 | static void png_default_error PNGARG((png_structp png_ptr, | |
21 | png_const_charp message)); | |
22 | static void png_default_warning PNGARG((png_structp png_ptr, | |
23 | png_const_charp message)); | |
24 | ||
25 | /* This function is called whenever there is a fatal error. This function | |
26 | * should not be changed. If there is a need to handle errors differently, | |
27 | * you should supply a replacement error function and use png_set_error_fn() | |
28 | * to replace the error function at run-time. | |
29 | */ | |
30 | void | |
31 | png_error(png_structp png_ptr, png_const_charp message) | |
32 | { | |
33 | if (png_ptr->error_fn != NULL) | |
34 | (*(png_ptr->error_fn))(png_ptr, message); | |
35 | ||
36 | /* if the following returns or doesn't exist, use the default function, | |
37 | which will not return */ | |
38 | png_default_error(png_ptr, message); | |
39 | } | |
40 | ||
41 | /* This function is called whenever there is a non-fatal error. This function | |
42 | * should not be changed. If there is a need to handle warnings differently, | |
43 | * you should supply a replacement warning function and use | |
44 | * png_set_error_fn() to replace the warning function at run-time. | |
45 | */ | |
46 | void | |
47 | png_warning(png_structp png_ptr, png_const_charp message) | |
48 | { | |
49 | if (png_ptr->warning_fn != NULL) | |
50 | (*(png_ptr->warning_fn))(png_ptr, message); | |
51 | else | |
52 | png_default_warning(png_ptr, message); | |
53 | } | |
54 | ||
55 | /* These utilities are used internally to build an error message which relates | |
56 | * to the current chunk. The chunk name comes from png_ptr->chunk_name, | |
57 | * this is used to prefix the message. The message is limited in length | |
58 | * to 63 bytes, the name characters are output as hex digits wrapped in [] | |
59 | * if the character is invalid. | |
60 | */ | |
61 | #define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) | |
62 | static PNG_CONST char png_digit[16] = { | |
63 | '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' | |
64 | }; | |
65 | ||
66 | static void | |
67 | png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp message) | |
68 | { | |
69 | int iout = 0, iin = 0; | |
70 | ||
71 | while (iin < 4) { | |
72 | int c = png_ptr->chunk_name[iin++]; | |
73 | if (isnonalpha(c)) { | |
74 | buffer[iout++] = '['; | |
75 | buffer[iout++] = png_digit[(c & 0xf0) >> 4]; | |
76 | buffer[iout++] = png_digit[c & 0xf]; | |
77 | buffer[iout++] = ']'; | |
78 | } else { | |
79 | buffer[iout++] = c; | |
80 | } | |
81 | } | |
82 | ||
83 | if (message == NULL) | |
84 | buffer[iout] = 0; | |
85 | else { | |
86 | buffer[iout++] = ':'; | |
87 | buffer[iout++] = ' '; | |
88 | png_memcpy(buffer+iout, message, 64); | |
89 | buffer[iout+63] = 0; | |
90 | } | |
91 | } | |
92 | ||
93 | void | |
94 | png_chunk_error(png_structp png_ptr, png_const_charp message) | |
95 | { | |
96 | char msg[16+64]; | |
97 | png_format_buffer(png_ptr, msg, message); | |
98 | png_error(png_ptr, msg); | |
99 | } | |
100 | ||
101 | void | |
102 | png_chunk_warning(png_structp png_ptr, png_const_charp message) | |
103 | { | |
104 | char msg[16+64]; | |
105 | png_format_buffer(png_ptr, msg, message); | |
106 | png_warning(png_ptr, msg); | |
107 | } | |
108 | ||
109 | /* This is the default error handling function. Note that replacements for | |
110 | * this function MUST NOT RETURN, or the program will likely crash. This | |
111 | * function is used by default, or if the program supplies NULL for the | |
112 | * error function pointer in png_set_error_fn(). | |
113 | */ | |
114 | static void | |
115 | png_default_error(png_structp png_ptr, png_const_charp message) | |
116 | { | |
117 | #ifndef PNG_NO_STDIO | |
118 | fprintf(stderr, "libpng error: %s\n", message); | |
119 | #endif | |
120 | ||
121 | #ifdef USE_FAR_KEYWORD | |
122 | { | |
123 | jmp_buf jmpbuf; | |
124 | png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf)); | |
125 | longjmp(jmpbuf, 1); | |
126 | } | |
127 | #else | |
128 | longjmp(png_ptr->jmpbuf, 1); | |
129 | #endif | |
130 | } | |
131 | ||
132 | /* This function is called when there is a warning, but the library thinks | |
133 | * it can continue anyway. Replacement functions don't have to do anything | |
134 | * here if you don't want to. In the default configuration, png_ptr is | |
135 | * not used, but it is passed in case it may be useful. | |
136 | */ | |
137 | static void | |
138 | png_default_warning(png_structp png_ptr, png_const_charp message) | |
139 | { | |
140 | if (png_ptr == NULL) | |
141 | return; | |
142 | ||
143 | #ifndef PNG_NO_STDIO | |
144 | fprintf(stderr, "libpng warning: %s\n", message); | |
145 | #endif | |
146 | } | |
147 | ||
148 | /* This function is called when the application wants to use another method | |
149 | * of handling errors and warnings. Note that the error function MUST NOT | |
150 | * return to the calling routine or serious problems will occur. The return | |
151 | * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) | |
152 | */ | |
153 | void | |
154 | png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, | |
155 | png_error_ptr error_fn, png_error_ptr warning_fn) | |
156 | { | |
157 | png_ptr->error_ptr = error_ptr; | |
158 | png_ptr->error_fn = error_fn; | |
159 | png_ptr->warning_fn = warning_fn; | |
160 | } | |
161 | ||
162 | ||
163 | /* This function returns a pointer to the error_ptr associated with the user | |
164 | * functions. The application should free any memory associated with this | |
165 | * pointer before png_write_destroy and png_read_destroy are called. | |
166 | */ | |
167 | png_voidp | |
168 | png_get_error_ptr(png_structp png_ptr) | |
169 | { | |
170 | return ((png_voidp)png_ptr->error_ptr); | |
171 | } | |
172 | ||
173 | ||
174 |