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
43 /* IsDebuggerPresent() needs this #define! */
44 #define _WIN32_WINNT 0x0400
47 #include "exceptions.h"
50 #define XCEPT_BUFFER_SIZE 1024
52 #ifdef KAZLIB_POSIX_THREADS
56 static pthread_mutex_t init_mtx = PTHREAD_MUTEX_INITIALIZER;
57 static int init_counter;
58 static pthread_key_t top_key;
59 static pthread_key_t uh_key;
60 static pthread_key_t alloc_key;
61 static pthread_key_t dealloc_key;
62 static void unhandled_catcher(except_t *);
64 #define get_top() ((struct except_stacknode *) pthread_getspecific(top_key))
65 #define set_top(T) (pthread_setspecific(top_key, (T)), (void)((T) == (struct except_stacknode *) 0))
66 #define set_catcher(C) (pthread_setspecific(uh_key, (void *) (C)), (void)((C) == (void (*)(except_t *)) 0))
67 #define set_alloc(A) (pthread_setspecific(alloc_key, (void *) (A)), (void)((A) == (void *(*)(size_t)) 0))
68 #define set_dealloc(D) (pthread_setspecific(dealloc_key, (void *) (D)), (void)((D) == (void (*)(void *)) 0))
70 static void (*get_catcher(void))(except_t *)
72 void (*catcher)(except_t *) = (void (*)(except_t *)) pthread_getspecific(uh_key);
73 return (catcher == 0) ? unhandled_catcher : catcher;
76 static void *(*get_alloc(void))(size_t)
78 void *(*alloc)(size_t) = (void *(*)(size_t)) pthread_getspecific(alloc_key);
79 return (alloc == 0) ? malloc : alloc;
82 static void (*get_dealloc(void))(void *)
84 void (*dealloc)(void *) = (void (*)(void *)) pthread_getspecific(dealloc_key);
85 return (dealloc == 0) ? free : dealloc;
92 pthread_mutex_lock(&init_mtx);
94 assert (init_counter < INT_MAX);
96 if (init_counter++ == 0) {
97 int top_ok = (pthread_key_create(&top_key, 0) == 0);
98 int uh_ok = (pthread_key_create(&uh_key, 0) == 0);
99 int alloc_ok = (pthread_key_create(&alloc_key, 0) == 0);
100 int dealloc_ok = (pthread_key_create(&dealloc_key, 0) == 0);
102 if (!top_ok || !uh_ok || !alloc_ok || !dealloc_ok) {
106 pthread_key_delete(top_key);
108 pthread_key_delete(uh_key);
110 pthread_key_delete(alloc_key);
112 pthread_key_delete(dealloc_key);
116 pthread_mutex_unlock(&init_mtx);
121 void except_deinit(void)
123 pthread_mutex_lock(&init_mtx);
125 assert (init_counter > 0);
127 if (--init_counter == 0) {
128 pthread_key_delete(top_key);
129 pthread_key_delete(uh_key);
130 pthread_key_delete(alloc_key);
131 pthread_key_delete(dealloc_key);
134 pthread_mutex_unlock(&init_mtx);
137 #else /* no thread support */
139 static int init_counter;
140 static void unhandled_catcher(except_t *);
141 static void (*uh_catcher_ptr)(except_t *) = unhandled_catcher;
142 /* We need this 'size_t' cast due to a glitch in GLib where g_malloc was prototyped
143 * as 'gpointer g_malloc (gulong n_bytes)'. This was later fixed to the correct prototype
144 * 'gpointer g_malloc (gsize n_bytes)'. In Wireshark we use the latter prototype
145 * throughout the code. We can get away with this even with older versions of GLib by
146 * adding a '(void *(*)(size_t))' cast whenever we refer to g_malloc. The only platform
147 * supported by Wireshark where this isn't safe (sizeof size_t != sizeof gulong) is Win64.
148 * However, we _always_ bundle the newest version of GLib on this platform so
149 * the size_t issue doesn't exists here. Pheew.. */
150 static void *(*allocator)(size_t) = (void *(*)(size_t)) g_malloc;
151 static void (*deallocator)(void *) = g_free;
152 static struct except_stacknode *stack_top;
154 #define get_top() (stack_top)
155 #define set_top(T) (stack_top = (T))
156 #define get_catcher() (uh_catcher_ptr)
157 #define set_catcher(C) (uh_catcher_ptr = (C))
158 #define get_alloc() (allocator)
159 #define set_alloc(A) (allocator = (A))
160 #define get_dealloc() (deallocator)
161 #define set_dealloc(D) (deallocator = (D))
163 int except_init(void)
165 assert (init_counter < INT_MAX);
170 void except_deinit(void)
172 assert (init_counter > 0);
179 static int match(const volatile except_id_t *thrown, const except_id_t *caught)
181 int group_match = (caught->except_group == XCEPT_GROUP_ANY ||
182 caught->except_group == thrown->except_group);
183 int code_match = (caught->except_code == XCEPT_CODE_ANY ||
184 caught->except_code == thrown->except_code);
186 return group_match && code_match;
189 G_GNUC_NORETURN WS_MSVC_NORETURN static void do_throw(except_t *except)
191 struct except_stacknode *top;
193 assert (except->except_id.except_group != 0 &&
194 except->except_id.except_code != 0);
196 for (top = get_top(); top != 0; top = top->except_down) {
197 if (top->except_type == XCEPT_CLEANUP) {
198 top->except_info.except_cleanup->except_func(top->except_info.except_cleanup->except_context);
200 struct except_catch *catcher = top->except_info.except_catcher;
201 const except_id_t *pi = catcher->except_id;
204 assert (top->except_type == XCEPT_CATCHER);
205 except_free(catcher->except_obj.except_dyndata);
207 for (i = 0; i < catcher->except_size; pi++, i++) {
208 if (match(&except->except_id, pi)) {
209 catcher->except_obj = *except;
211 longjmp(catcher->except_jmp, 1);
218 get_catcher()(except); /* unhandled exception */
222 static void unhandled_catcher(except_t *except)
224 if (except->except_message == NULL) {
225 fprintf(stderr, "Unhandled exception (group=%ld, code=%ld)\n",
226 except->except_id.except_group,
227 except->except_id.except_code);
229 fprintf(stderr, "Unhandled exception (\"%s\", group=%ld, code=%ld)\n",
230 except->except_message, except->except_id.except_group,
231 except->except_id.except_code);
236 static void stack_push(struct except_stacknode *node)
238 node->except_down = get_top();
242 void except_setup_clean(struct except_stacknode *esn,
243 struct except_cleanup *ecl, void (*cleanf)(void *), void *context)
245 esn->except_type = XCEPT_CLEANUP;
246 ecl->except_func = cleanf;
247 ecl->except_context = context;
248 esn->except_info.except_cleanup = ecl;
252 void except_setup_try(struct except_stacknode *esn,
253 struct except_catch *ech, const except_id_t id[], size_t size)
256 ech->except_size = size;
257 ech->except_obj.except_dyndata = 0;
258 esn->except_type = XCEPT_CATCHER;
259 esn->except_info.except_catcher = ech;
263 struct except_stacknode *except_pop(void)
265 struct except_stacknode *top = get_top();
266 set_top(top->except_down);
270 G_GNUC_NORETURN WS_MSVC_NORETURN void except_rethrow(except_t *except)
272 struct except_stacknode *top = get_top();
274 assert (top->except_type == XCEPT_CATCHER);
275 assert (&top->except_info.except_catcher->except_obj == except);
276 set_top(top->except_down);
280 G_GNUC_NORETURN WS_MSVC_NORETURN void except_throw(long group, long code, const char *msg)
284 except.except_id.except_group = group;
285 except.except_id.except_code = code;
286 except.except_message = msg;
287 except.except_dyndata = 0;
290 if (code == DissectorError && IsDebuggerPresent()) {
298 G_GNUC_NORETURN WS_MSVC_NORETURN void except_throwd(long group, long code, const char *msg, void *data)
302 except.except_id.except_group = group;
303 except.except_id.except_code = code;
304 except.except_message = msg;
305 except.except_dyndata = data;
311 * XXX - should we use g_strdup_sprintf() here, so we're not limited by
312 * XCEPT_BUFFER_SIZE? We could then just use this to generate formatted
315 G_GNUC_NORETURN WS_MSVC_NORETURN void except_throwf(long group, long code, const char *fmt, ...)
317 char *buf = except_alloc(XCEPT_BUFFER_SIZE);
321 g_vsnprintf(buf, XCEPT_BUFFER_SIZE, fmt, vl);
323 except_throwd(group, code, buf, buf);
326 void (*except_unhandled_catcher(void (*new_catcher)(except_t *)))(except_t *)
328 void (*old_catcher)(except_t *) = get_catcher();
329 set_catcher(new_catcher);
335 #undef except_message
338 unsigned long except_code(except_t *ex)
340 return ex->except_id.except_code;
343 unsigned long except_group(except_t *ex)
345 return ex->except_id.except_group;
348 const char *except_message(except_t *ex)
350 return ex->except_message;
353 void *except_data(except_t *ex)
355 return ex->except_dyndata;
358 void *except_take_data(except_t *ex)
360 void *data = ex->except_dyndata;
361 ex->except_dyndata = 0;
365 void except_set_allocator(void *(*alloc)(size_t), void (*dealloc)(void *))
368 set_dealloc(dealloc);
371 void *except_alloc(size_t size)
373 void *ptr = get_alloc()(size);
376 except_throw(XCEPT_BAD_ALLOC, 0, "out of memory");
380 void except_free(void *ptr)
385 #ifdef KAZLIB_TEST_MAIN
390 static void cleanup(void *arg)
392 printf("cleanup(\"%s\") called\n", (char *) arg);
395 static void bottom_level(void)
398 printf("throw exception? "); fflush(stdout);
399 fgets(buf, sizeof buf, stdin);
401 if (buf[0] >= 0 && toupper(buf[0]) == 'Y')
402 except_throw(1, 1, "nasty exception");
405 static void top_level(void)
407 except_cleanup_push(cleanup, "argument");
409 except_cleanup_pop(0);
412 int main(int argc, char **argv)
414 static const except_id_t catch[] = { { 1, 1 }, { 1, 2 } };
419 * Nested exception ``try blocks''
423 except_try_push(catch, 2, &ex);
426 except_try_push(catch, 2, &ex);
431 msg = except_message(ex);
433 printf("caught exception (inner): s=%ld, c=%ld\n",
434 except_group(ex), except_code(ex));
436 printf("caught exception (inner): \"%s\", s=%ld, c=%ld\n",
437 msg, except_group(ex), except_code(ex));
444 msg = except_message(ex);
446 printf("caught exception (outer): s=%ld, c=%ld\n",
447 except_group(ex), except_code(ex));
449 printf("caught exception (outer): \"%s\", s=%ld, c=%ld\n",
450 except_message(ex), except_group(ex), except_code(ex));
454 except_throw(99, 99, "exception in main");