1 // Functions for Exception Support for -*- C++ -*-
2 // Copyright (C) 1994, 95-97, 1998 Free Software Foundation
4 // This file is part of GNU CC.
6 // GNU CC is free software; you can redistribute it and/or modify
7 // it under the terms of the GNU General Public License as published by
8 // the Free Software Foundation; either version 2, or (at your option)
11 // GNU CC is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License
17 // along with GNU CC; see the file COPYING. If not, write to
18 // the Free Software Foundation, 59 Temple Place - Suite 330,
19 // Boston, MA 02111-1307, USA.
21 // As a special exception, if you link this library with other files,
22 // some of which are compiled with GCC, to produce an executable,
23 // this library does not by itself cause the resulting executable
24 // to be covered by the GNU General Public License.
25 // This exception does not however invalidate any other reasons why
26 // the executable file might be covered by the GNU General Public License.
28 #pragma implementation "exception"
33 #include "gansidecl.h" /* Needed to support macros used in eh-common.h. */
34 #include "eh-common.h"
36 /* Define terminate, unexpected, set_terminate, set_unexpected as
37 well as the default terminate func and default unexpected func. */
39 extern std::terminate_handler __terminate_func __attribute__((__noreturn__));
49 __default_unexpected ()
54 static std::unexpected_handler __unexpected_func __attribute__((__noreturn__))
55 = __default_unexpected;
57 std::terminate_handler
58 std::set_terminate (std::terminate_handler func)
60 std::terminate_handler old = __terminate_func;
62 __terminate_func = func;
66 std::unexpected_handler
67 std::set_unexpected (std::unexpected_handler func)
69 std::unexpected_handler old = __unexpected_func;
71 __unexpected_func = func;
81 /* C++-specific state about the current exception.
82 This must match init_exception_processing().
84 Note that handlers and caught are not redundant; when rethrown, an
85 exception can have multiple active handlers and still be considered
93 void (*cleanup)(void *, int);
100 /* Language-specific EH info pointer, defined in libgcc2. */
102 extern "C" cp_eh_info **__get_eh_info (); // actually void **
104 /* Is P the type_info node for a pointer of some kind? */
106 extern bool __is_pointer (void *);
109 /* OLD Compiler hook to return a pointer to the info for the current exception.
110 Used by get_eh_info (). This fudges the actualy returned value to
111 point to the beginning of what USE to be the cp_eh_info structure.
112 THis is so that old code that dereferences this pointer will find
113 things where it expects it to be.*/
115 __cp_exception_info (void)
117 return &((*__get_eh_info ())->value);
120 #define CP_EH_INFO ((cp_eh_info *) *__get_eh_info ())
122 /* Old Compiler hook to return a pointer to the info for the current exception.
123 Used by get_eh_info (). */
125 extern "C" cp_eh_info *
128 cp_eh_info *p = CP_EH_INFO;
132 /* Compiler hook to return a pointer to the info for the current exception,
133 Set the caught bit, and increment the number of handlers that are
134 looking at this exception. This makes handlers smaller. */
136 extern "C" cp_eh_info *
137 __start_cp_handler (void)
139 cp_eh_info *p = CP_EH_INFO;
145 /* Allocate a buffer for a cp_eh_info and an exception object of size SIZE,
146 and return a pointer to the beginning of the object's space. */
148 extern "C" void * malloc (size_t);
150 __eh_alloc (size_t size)
152 void *p = malloc (size);
158 /* Free the memory for an cp_eh_info and associated exception, given
159 a pointer to the cp_eh_info. */
161 extern "C" void free (void *);
169 typedef void * (* rtimetype) (void);
172 __cplus_type_matcher (cp_eh_info *info, rtimetype match_info,
173 exception_descriptor *exception_table)
177 /* No exception table implies the old style mechanism, so don't check. */
178 if (exception_table != NULL
179 && exception_table->lang.language != EH_LANG_C_plus_plus)
182 if (match_info == CATCH_ALL_TYPE)
185 /* we don't worry about version info yet, there is only one version! */
187 void *match_type = match_info ();
188 ret = __throw_type_match_rtti (match_type, info->type, info->original_value);
189 /* change value of exception */
196 /* Compiler hook to push a new exception onto the stack.
197 Used by expand_throw(). */
200 __cp_push_exception (void *value, void *type, void (*cleanup)(void *, int))
202 cp_eh_info *p = (cp_eh_info *) __eh_alloc (sizeof (cp_eh_info));
206 p->cleanup = cleanup;
209 p->original_value = value;
211 p->eh_info.match_function = __cplus_type_matcher;
212 p->eh_info.language = EH_LANG_C_plus_plus;
213 p->eh_info.version = 1;
215 cp_eh_info **q = __get_eh_info ();
221 /* Compiler hook to pop an exception that has been finalized. Used by
222 push_eh_cleanup(). P is the info for the exception caught by the
223 current catch block. */
226 __cp_pop_exception (cp_eh_info *p)
228 cp_eh_info **q = __get_eh_info ();
232 /* Don't really pop if there are still active handlers for our exception,
233 or if our exception is being rethrown (i.e. if the active exception is
234 our exception and it is uncaught). */
236 || (p == *q && !p->caught))
239 for (; *q; q = &((*q)->next))
249 /* 2 is a magic value for destructors; see build_delete(). */
250 p->cleanup (p->original_value, 2); // value may have been adjusted.
252 if (! __is_pointer (p->type))
253 __eh_free (p->original_value); // value may have been adjusted.
259 __uncatch_exception (void)
261 cp_eh_info *p = CP_EH_INFO;
267 /* As per [except.unexpected]:
268 If an exception is thrown, we check it against the spec. If it doesn't
269 match, we call unexpected (). If unexpected () throws, we check that
270 exception against the spec. If it doesn't match, if the spec allows
271 bad_exception we throw that; otherwise we call terminate ().
273 The compiler treats an exception spec as a try block with a generic
274 handler that just calls this function with a list of the allowed
275 exception types, so we have an active exception that can be rethrown.
277 This function does not return. */
280 __check_eh_spec (int n, const void **spec)
282 cp_eh_info *p = CP_EH_INFO;
284 for (int i = 0; i < n; ++i)
286 if (__throw_type_match_rtti (spec[i], p->type, p->value))
296 // __exception_info is an artificial var pushed into each catch block.
297 if (p != __exception_info)
299 p = __exception_info;
300 for (int i = 0; i < n; ++i)
302 if (__throw_type_match_rtti (spec[i], p->type, p->value))
307 const std::type_info &bad_exc = typeid (std::bad_exception);
308 for (int i = 0; i < n; ++i)
310 if (__throw_type_match_rtti (spec[i], &bad_exc, p->value))
311 throw std::bad_exception ();
319 __throw_bad_cast (void)
321 throw std::bad_cast ();
325 __throw_bad_typeid (void)
327 throw std::bad_typeid ();
330 /* Has the current exception been caught? */
333 std::uncaught_exception ()
335 cp_eh_info *p = CP_EH_INFO;
336 return p && ! p->caught;
339 const char * std::exception::
342 return typeid (*this).name ();