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
40 /* IsDebuggerPresent() needs this #define! */
41 #define _WIN32_WINNT 0x0400
43 #include "exceptions.h"
46 #define XCEPT_BUFFER_SIZE 1024
48 #ifdef KAZLIB_POSIX_THREADS
52 static pthread_mutex_t init_mtx = PTHREAD_MUTEX_INITIALIZER;
53 static int init_counter;
54 static pthread_key_t top_key;
55 static pthread_key_t uh_key;
56 static pthread_key_t alloc_key;
57 static pthread_key_t dealloc_key;
58 static void unhandled_catcher(except_t *);
60 #define get_top() ((struct except_stacknode *) pthread_getspecific(top_key))
61 #define set_top(T) (pthread_setspecific(top_key, (T)), (void)((T) == (struct except_stacknode *) 0))
62 #define set_catcher(C) (pthread_setspecific(uh_key, (void *) (C)), (void)((C) == (void (*)(except_t *)) 0))
63 #define set_alloc(A) (pthread_setspecific(alloc_key, (void *) (A)), (void)((A) == (void *(*)(size_t)) 0))
64 #define set_dealloc(D) (pthread_setspecific(dealloc_key, (void *) (D)), (void)((D) == (void (*)(void *)) 0))
66 static void (*get_catcher(void))(except_t *)
68 void (*catcher)(except_t *) = (void (*)(except_t *)) pthread_getspecific(uh_key);
69 return (catcher == 0) ? unhandled_catcher : catcher;
72 static void *(*get_alloc(void))(size_t)
74 void *(*alloc)(size_t) = (void *(*)(size_t)) pthread_getspecific(alloc_key);
75 return (alloc == 0) ? malloc : alloc;
78 static void (*get_dealloc(void))(void *)
80 void (*dealloc)(void *) = (void (*)(void *)) pthread_getspecific(dealloc_key);
81 return (dealloc == 0) ? free : dealloc;
88 pthread_mutex_lock(&init_mtx);
90 assert (init_counter < INT_MAX);
92 if (init_counter++ == 0) {
93 int top_ok = (pthread_key_create(&top_key, 0) == 0);
94 int uh_ok = (pthread_key_create(&uh_key, 0) == 0);
95 int alloc_ok = (pthread_key_create(&alloc_key, 0) == 0);
96 int dealloc_ok = (pthread_key_create(&dealloc_key, 0) == 0);
98 if (!top_ok || !uh_ok || !alloc_ok || !dealloc_ok) {
102 pthread_key_delete(top_key);
104 pthread_key_delete(uh_key);
106 pthread_key_delete(alloc_key);
108 pthread_key_delete(dealloc_key);
112 pthread_mutex_unlock(&init_mtx);
117 void except_deinit(void)
119 pthread_mutex_lock(&init_mtx);
121 assert (init_counter > 0);
123 if (--init_counter == 0) {
124 pthread_key_delete(top_key);
125 pthread_key_delete(uh_key);
126 pthread_key_delete(alloc_key);
127 pthread_key_delete(dealloc_key);
130 pthread_mutex_unlock(&init_mtx);
133 #else /* no thread support */
135 static int init_counter;
136 static void unhandled_catcher(except_t *);
137 static void (*uh_catcher_ptr)(except_t *) = unhandled_catcher;
138 /* We need this 'size_t' cast due to a glitch in GLib where g_malloc was prototyped
139 * as 'gpointer g_malloc (gulong n_bytes)'. This was later fixed to the correct prototype
140 * 'gpointer g_malloc (gsize n_bytes)'. In Wireshark we use the latter prototype
141 * throughout the code. We can get away with this even with older versions of GLib by
142 * adding a '(void *(*)(size_t))' cast whenever we refer to g_malloc. The only platform
143 * supported by Wireshark where this isn't safe (sizeof size_t != sizeof gulong) is Win64.
144 * However, we _always_ bundle the newest version of GLib on this platform so
145 * the size_t issue doesn't exists here. Pheew.. */
146 static void *(*allocator)(size_t) = (void *(*)(size_t)) g_malloc;
147 static void (*deallocator)(void *) = g_free;
148 static struct except_stacknode *stack_top;
150 #define get_top() (stack_top)
151 #define set_top(T) (stack_top = (T))
152 #define get_catcher() (uh_catcher_ptr)
153 #define set_catcher(C) (uh_catcher_ptr = (C))
154 #define get_alloc() (allocator)
155 #define set_alloc(A) (allocator = (A))
156 #define get_dealloc() (deallocator)
157 #define set_dealloc(D) (deallocator = (D))
159 int except_init(void)
161 assert (init_counter < INT_MAX);
166 void except_deinit(void)
168 assert (init_counter > 0);
175 static int match(const volatile except_id_t *thrown, const except_id_t *caught)
177 int group_match = (caught->except_group == XCEPT_GROUP_ANY ||
178 caught->except_group == thrown->except_group);
179 int code_match = (caught->except_code == XCEPT_CODE_ANY ||
180 caught->except_code == thrown->except_code);
182 return group_match && code_match;
185 G_GNUC_NORETURN static void do_throw(except_t *except)
187 struct except_stacknode *top;
189 assert (except->except_id.except_group != 0 &&
190 except->except_id.except_code != 0);
192 for (top = get_top(); top != 0; top = top->except_down) {
193 if (top->except_type == XCEPT_CLEANUP) {
194 top->except_info.except_cleanup->except_func(top->except_info.except_cleanup->except_context);
196 struct except_catch *catcher = top->except_info.except_catcher;
197 const except_id_t *pi = catcher->except_id;
200 assert (top->except_type == XCEPT_CATCHER);
201 except_free(catcher->except_obj.except_dyndata);
203 for (i = 0; i < catcher->except_size; pi++, i++) {
204 if (match(&except->except_id, pi)) {
205 catcher->except_obj = *except;
207 longjmp(catcher->except_jmp, 1);
214 get_catcher()(except); /* unhandled exception */
218 static void unhandled_catcher(except_t *except)
220 if (except->except_message == NULL) {
221 fprintf(stderr, "Unhandled exception (group=%ld, code=%ld)\n",
222 except->except_id.except_group,
223 except->except_id.except_code);
225 fprintf(stderr, "Unhandled exception (\"%s\", group=%ld, code=%ld)\n",
226 except->except_message, except->except_id.except_group,
227 except->except_id.except_code);
232 static void stack_push(struct except_stacknode *node)
234 node->except_down = get_top();
238 void except_setup_clean(struct except_stacknode *esn,
239 struct except_cleanup *ecl, void (*cleanf)(void *), void *context)
241 esn->except_type = XCEPT_CLEANUP;
242 ecl->except_func = cleanf;
243 ecl->except_context = context;
244 esn->except_info.except_cleanup = ecl;
248 void except_setup_try(struct except_stacknode *esn,
249 struct except_catch *ech, const except_id_t id[], size_t size)
252 ech->except_size = size;
253 ech->except_obj.except_dyndata = 0;
254 esn->except_type = XCEPT_CATCHER;
255 esn->except_info.except_catcher = ech;
259 struct except_stacknode *except_pop(void)
261 struct except_stacknode *top = get_top();
262 set_top(top->except_down);
266 G_GNUC_NORETURN void except_rethrow(except_t *except)
268 struct except_stacknode *top = get_top();
270 assert (top->except_type == XCEPT_CATCHER);
271 assert (&top->except_info.except_catcher->except_obj == except);
272 set_top(top->except_down);
276 G_GNUC_NORETURN void except_throw(long group, long code, const char *msg)
280 except.except_id.except_group = group;
281 except.except_id.except_code = code;
282 except.except_message = msg;
283 except.except_dyndata = 0;
286 if (code == DissectorError && IsDebuggerPresent()) {
294 G_GNUC_NORETURN void except_throwd(long group, long code, const char *msg, void *data)
298 except.except_id.except_group = group;
299 except.except_id.except_code = code;
300 except.except_message = msg;
301 except.except_dyndata = data;
307 * XXX - should we use g_strdup_sprintf() here, so we're not limited by
308 * XCEPT_BUFFER_SIZE? We could then just use this to generate formatted
311 G_GNUC_NORETURN void except_throwf(long group, long code, const char *fmt, ...)
313 char *buf = except_alloc(XCEPT_BUFFER_SIZE);
317 g_vsnprintf(buf, XCEPT_BUFFER_SIZE, fmt, vl);
319 except_throwd(group, code, buf, buf);
322 void (*except_unhandled_catcher(void (*new_catcher)(except_t *)))(except_t *)
324 void (*old_catcher)(except_t *) = get_catcher();
325 set_catcher(new_catcher);
331 #undef except_message
334 unsigned long except_code(except_t *ex)
336 return ex->except_id.except_code;
339 unsigned long except_group(except_t *ex)
341 return ex->except_id.except_group;
344 const char *except_message(except_t *ex)
346 return ex->except_message;
349 void *except_data(except_t *ex)
351 return ex->except_dyndata;
354 void *except_take_data(except_t *ex)
356 void *data = ex->except_dyndata;
357 ex->except_dyndata = 0;
361 void except_set_allocator(void *(*alloc)(size_t), void (*dealloc)(void *))
364 set_dealloc(dealloc);
367 void *except_alloc(size_t size)
369 void *ptr = get_alloc()(size);
372 except_throw(XCEPT_BAD_ALLOC, 0, "out of memory");
376 void except_free(void *ptr)
381 #ifdef KAZLIB_TEST_MAIN
386 static void cleanup(void *arg)
388 printf("cleanup(\"%s\") called\n", (char *) arg);
391 static void bottom_level(void)
394 printf("throw exception? "); fflush(stdout);
395 fgets(buf, sizeof buf, stdin);
397 if (buf[0] >= 0 && toupper(buf[0]) == 'Y')
398 except_throw(1, 1, "nasty exception");
401 static void top_level(void)
403 except_cleanup_push(cleanup, "argument");
405 except_cleanup_pop(0);
408 int main(int argc, char **argv)
410 static const except_id_t catch[] = { { 1, 1 }, { 1, 2 } };
415 * Nested exception ``try blocks''
419 except_try_push(catch, 2, &ex);
422 except_try_push(catch, 2, &ex);
427 msg = except_message(ex);
429 printf("caught exception (inner): s=%ld, c=%ld\n",
430 except_group(ex), except_code(ex));
432 printf("caught exception (inner): \"%s\", s=%ld, c=%ld\n",
433 msg, except_group(ex), except_code(ex));
440 msg = except_message(ex);
442 printf("caught exception (outer): s=%ld, c=%ld\n",
443 except_group(ex), except_code(ex));
445 printf("caught exception (outer): \"%s\", s=%ld, c=%ld\n",
446 except_message(ex), except_group(ex), except_code(ex));
450 except_throw(99, 99, "exception in main");