2 * Portable Exception Handling for ANSI C.
3 * Copyright (C) 1999 Kaz Kylheku <kaz@ashi.footprints.net>
7 * Free Software License:
9 * All rights are reserved by the author, with the following exceptions:
10 * Permission is granted to freely reproduce and distribute this software,
11 * possibly in exchange for a fee, provided that this copyright notice appears
12 * intact. Permission is also granted to adapt this software to produce
13 * derivative works, as long as the modified versions carry this copyright
14 * notice and additional notices stating that the work has been modified.
15 * This source code may be translated into executable form and incorporated
16 * into proprietary software; there is no requirement for such software to
17 * contain a copyright notice related to this source.
21 * Modified to support throwing an exception with a null message pointer,
22 * and to have the message not be const (as we generate messages with
23 * "g_strdup_sprintf()", which means they need to be freed; using
24 * a null message means that we don't have to use a special string
25 * for exceptions with no message, and don't have to worry about
45 #include "exceptions.h"
48 #define XCEPT_BUFFER_SIZE 1024
50 #ifdef KAZLIB_POSIX_THREADS
54 static pthread_mutex_t init_mtx = PTHREAD_MUTEX_INITIALIZER;
55 static int init_counter;
56 static pthread_key_t top_key;
57 static pthread_key_t uh_key;
58 static pthread_key_t alloc_key;
59 static pthread_key_t dealloc_key;
60 static void unhandled_catcher(except_t *);
62 #define get_top() ((struct except_stacknode *) pthread_getspecific(top_key))
63 #define set_top(T) (pthread_setspecific(top_key, (T)), (void)((T) == (struct except_stacknode *) 0))
64 #define set_catcher(C) (pthread_setspecific(uh_key, (void *) (C)), (void)((C) == (void (*)(except_t *)) 0))
65 #define set_alloc(A) (pthread_setspecific(alloc_key, (void *) (A)), (void)((A) == (void *(*)(size_t)) 0))
66 #define set_dealloc(D) (pthread_setspecific(dealloc_key, (void *) (D)), (void)((D) == (void (*)(void *)) 0))
68 static void (*get_catcher(void))(except_t *)
70 void (*catcher)(except_t *) = (void (*)(except_t *)) pthread_getspecific(uh_key);
71 return (catcher == 0) ? unhandled_catcher : catcher;
74 static void *(*get_alloc(void))(size_t)
76 void *(*alloc)(size_t) = (void *(*)(size_t)) pthread_getspecific(alloc_key);
77 return (alloc == 0) ? malloc : alloc;
80 static void (*get_dealloc(void))(void *)
82 void (*dealloc)(void *) = (void (*)(void *)) pthread_getspecific(dealloc_key);
83 return (dealloc == 0) ? free : dealloc;
90 pthread_mutex_lock(&init_mtx);
92 assert (init_counter < INT_MAX);
94 if (init_counter++ == 0) {
95 int top_ok = (pthread_key_create(&top_key, 0) == 0);
96 int uh_ok = (pthread_key_create(&uh_key, 0) == 0);
97 int alloc_ok = (pthread_key_create(&alloc_key, 0) == 0);
98 int dealloc_ok = (pthread_key_create(&dealloc_key, 0) == 0);
100 if (!top_ok || !uh_ok || !alloc_ok || !dealloc_ok) {
104 pthread_key_delete(top_key);
106 pthread_key_delete(uh_key);
108 pthread_key_delete(alloc_key);
110 pthread_key_delete(dealloc_key);
114 pthread_mutex_unlock(&init_mtx);
119 void except_deinit(void)
121 pthread_mutex_lock(&init_mtx);
123 assert (init_counter > 0);
125 if (--init_counter == 0) {
126 pthread_key_delete(top_key);
127 pthread_key_delete(uh_key);
128 pthread_key_delete(alloc_key);
129 pthread_key_delete(dealloc_key);
132 pthread_mutex_unlock(&init_mtx);
135 #else /* no thread support */
137 static int init_counter;
138 static void unhandled_catcher(except_t *);
139 static void (*uh_catcher_ptr)(except_t *) = unhandled_catcher;
140 /* We need this 'size_t' cast due to a glitch in GLib where g_malloc was prototyped
141 * as 'gpointer g_malloc (gulong n_bytes)'. This was later fixed to the correct prototype
142 * 'gpointer g_malloc (gsize n_bytes)'. In Wireshark we use the latter prototype
143 * throughout the code. We can get away with this even with older versions of GLib by
144 * adding a '(void *(*)(size_t))' cast whenever we refer to g_malloc. The only platform
145 * supported by Wireshark where this isn't safe (sizeof size_t != sizeof gulong) is Win64.
146 * However, we _always_ bundle the newest version of GLib on this platform so
147 * the size_t issue doesn't exists here. Pheew.. */
148 static void *(*allocator)(size_t) = (void *(*)(size_t)) g_malloc;
149 static void (*deallocator)(void *) = g_free;
150 static struct except_stacknode *stack_top;
152 #define get_top() (stack_top)
153 #define set_top(T) (stack_top = (T))
154 #define get_catcher() (uh_catcher_ptr)
155 #define set_catcher(C) (uh_catcher_ptr = (C))
156 #define get_alloc() (allocator)
157 #define set_alloc(A) (allocator = (A))
158 #define get_dealloc() (deallocator)
159 #define set_dealloc(D) (deallocator = (D))
161 int except_init(void)
163 assert (init_counter < INT_MAX);
168 void except_deinit(void)
170 assert (init_counter > 0);
177 static int match(const volatile except_id_t *thrown, const except_id_t *caught)
179 int group_match = (caught->except_group == XCEPT_GROUP_ANY ||
180 caught->except_group == thrown->except_group);
181 int code_match = (caught->except_code == XCEPT_CODE_ANY ||
182 caught->except_code == thrown->except_code);
184 return group_match && code_match;
187 G_GNUC_NORETURN WS_MSVC_NORETURN static void do_throw(except_t *except)
189 struct except_stacknode *top;
191 assert (except->except_id.except_group != 0 &&
192 except->except_id.except_code != 0);
194 for (top = get_top(); top != 0; top = top->except_down) {
195 if (top->except_type == XCEPT_CLEANUP) {
196 top->except_info.except_cleanup->except_func(top->except_info.except_cleanup->except_context);
198 struct except_catch *catcher = top->except_info.except_catcher;
199 const except_id_t *pi = catcher->except_id;
202 assert (top->except_type == XCEPT_CATCHER);
203 except_free(catcher->except_obj.except_dyndata);
205 for (i = 0; i < catcher->except_size; pi++, i++) {
206 if (match(&except->except_id, pi)) {
207 catcher->except_obj = *except;
209 longjmp(catcher->except_jmp, 1);
216 get_catcher()(except); /* unhandled exception */
220 static void unhandled_catcher(except_t *except)
222 if (except->except_message == NULL) {
223 fprintf(stderr, "Unhandled exception (group=%ld, code=%ld)\n",
224 except->except_id.except_group,
225 except->except_id.except_code);
227 fprintf(stderr, "Unhandled exception (\"%s\", group=%ld, code=%ld)\n",
228 except->except_message, except->except_id.except_group,
229 except->except_id.except_code);
234 static void stack_push(struct except_stacknode *node)
236 node->except_down = get_top();
240 void except_setup_clean(struct except_stacknode *esn,
241 struct except_cleanup *ecl, void (*cleanf)(void *), void *context)
243 esn->except_type = XCEPT_CLEANUP;
244 ecl->except_func = cleanf;
245 ecl->except_context = context;
246 esn->except_info.except_cleanup = ecl;
250 void except_setup_try(struct except_stacknode *esn,
251 struct except_catch *ech, const except_id_t id[], size_t size)
254 ech->except_size = size;
255 ech->except_obj.except_dyndata = 0;
256 esn->except_type = XCEPT_CATCHER;
257 esn->except_info.except_catcher = ech;
261 struct except_stacknode *except_pop(void)
263 struct except_stacknode *top = get_top();
264 set_top(top->except_down);
268 G_GNUC_NORETURN WS_MSVC_NORETURN void except_rethrow(except_t *except)
270 struct except_stacknode *top = get_top();
272 assert (top->except_type == XCEPT_CATCHER);
273 assert (&top->except_info.except_catcher->except_obj == except);
274 set_top(top->except_down);
278 G_GNUC_NORETURN WS_MSVC_NORETURN void except_throw(long group, long code, const char *msg)
282 except.except_id.except_group = group;
283 except.except_id.except_code = code;
284 except.except_message = msg;
285 except.except_dyndata = 0;
288 if (code == DissectorError && IsDebuggerPresent()) {
296 G_GNUC_NORETURN WS_MSVC_NORETURN void except_throwd(long group, long code, const char *msg, void *data)
300 except.except_id.except_group = group;
301 except.except_id.except_code = code;
302 except.except_message = msg;
303 except.except_dyndata = data;
309 * XXX - should we use g_strdup_sprintf() here, so we're not limited by
310 * XCEPT_BUFFER_SIZE? We could then just use this to generate formatted
313 G_GNUC_NORETURN WS_MSVC_NORETURN void except_throwf(long group, long code, const char *fmt, ...)
315 char *buf = except_alloc(XCEPT_BUFFER_SIZE);
319 g_vsnprintf(buf, XCEPT_BUFFER_SIZE, fmt, vl);
321 except_throwd(group, code, buf, buf);
324 void (*except_unhandled_catcher(void (*new_catcher)(except_t *)))(except_t *)
326 void (*old_catcher)(except_t *) = get_catcher();
327 set_catcher(new_catcher);
333 #undef except_message
336 unsigned long except_code(except_t *ex)
338 return ex->except_id.except_code;
341 unsigned long except_group(except_t *ex)
343 return ex->except_id.except_group;
346 const char *except_message(except_t *ex)
348 return ex->except_message;
351 void *except_data(except_t *ex)
353 return ex->except_dyndata;
356 void *except_take_data(except_t *ex)
358 void *data = ex->except_dyndata;
359 ex->except_dyndata = 0;
363 void except_set_allocator(void *(*alloc)(size_t), void (*dealloc)(void *))
366 set_dealloc(dealloc);
369 void *except_alloc(size_t size)
371 void *ptr = get_alloc()(size);
374 except_throw(XCEPT_BAD_ALLOC, 0, "out of memory");
378 void except_free(void *ptr)
383 #ifdef KAZLIB_TEST_MAIN
388 static void cleanup(void *arg)
390 printf("cleanup(\"%s\") called\n", (char *) arg);
393 static void bottom_level(void)
396 printf("throw exception? "); fflush(stdout);
397 fgets(buf, sizeof buf, stdin);
399 if (buf[0] >= 0 && toupper(buf[0]) == 'Y')
400 except_throw(1, 1, "nasty exception");
403 static void top_level(void)
405 except_cleanup_push(cleanup, "argument");
407 except_cleanup_pop(0);
410 int main(int argc, char **argv)
412 static const except_id_t catch[] = { { 1, 1 }, { 1, 2 } };
417 * Nested exception ``try blocks''
421 except_try_push(catch, 2, &ex);
424 except_try_push(catch, 2, &ex);
429 msg = except_message(ex);
431 printf("caught exception (inner): s=%ld, c=%ld\n",
432 except_group(ex), except_code(ex));
434 printf("caught exception (inner): \"%s\", s=%ld, c=%ld\n",
435 msg, except_group(ex), except_code(ex));
442 msg = except_message(ex);
444 printf("caught exception (outer): s=%ld, c=%ld\n",
445 except_group(ex), except_code(ex));
447 printf("caught exception (outer): \"%s\", s=%ld, c=%ld\n",
448 except_message(ex), except_group(ex), except_code(ex));
452 except_throw(99, 99, "exception in main");