1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
3 Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
5 2009, 2010, 2011 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
28 /* Reasons for calling throw_exceptions(). NOTE: all reason values
29 must be less than zero. enum value 0 is reserved for internal use
30 as the return value from an initial setjmp(). The function
31 catch_exceptions() reserves values >= 0 as legal results from its
38 /* Any other error. */
42 #define RETURN_MASK(reason) (1 << (int)(-reason))
43 #define RETURN_MASK_QUIT RETURN_MASK (RETURN_QUIT)
44 #define RETURN_MASK_ERROR RETURN_MASK (RETURN_ERROR)
45 #define RETURN_MASK_ALL (RETURN_MASK_QUIT | RETURN_MASK_ERROR)
46 typedef int return_mask;
48 /* Describe all exceptions. */
53 /* Any generic error, the corresponding text is in
57 /* Something requested was not found. */
60 /* Thread library lacks support necessary for finding thread local
62 TLS_NO_LIBRARY_SUPPORT_ERROR,
64 /* Load module not found while attempting to find thread local storage. */
65 TLS_LOAD_MODULE_NOT_FOUND_ERROR,
67 /* Thread local storage has not been allocated yet. */
68 TLS_NOT_ALLOCATED_YET_ERROR,
70 /* Something else went wrong while attempting to find thread local
71 storage. The ``struct gdb_exception'' message field provides
75 /* Problem parsing an XML document. */
78 /* Error accessing memory. */
81 /* Feature is not supported in this copy of GDB. */
84 /* Value not available. E.g., a register was not collected in a
88 /* Add more errors here. */
94 enum return_reason reason;
99 /* A pre-defined non-exception. */
100 extern const struct gdb_exception exception_none;
102 /* Wrap set/long jmp so that it's more portable (internal to
105 #if defined(HAVE_SIGSETJMP)
106 #define EXCEPTIONS_SIGJMP_BUF sigjmp_buf
107 #define EXCEPTIONS_SIGSETJMP(buf) sigsetjmp((buf), 1)
108 #define EXCEPTIONS_SIGLONGJMP(buf,val) siglongjmp((buf), (val))
110 #define EXCEPTIONS_SIGJMP_BUF jmp_buf
111 #define EXCEPTIONS_SIGSETJMP(buf) setjmp(buf)
112 #define EXCEPTIONS_SIGLONGJMP(buf,val) longjmp((buf), (val))
115 /* Functions to drive the exceptions state m/c (internal to
117 EXCEPTIONS_SIGJMP_BUF *exceptions_state_mc_init (volatile struct
118 gdb_exception *exception,
120 int exceptions_state_mc_action_iter (void);
121 int exceptions_state_mc_action_iter_1 (void);
123 /* Macro to wrap up standard try/catch behavior.
125 The double loop lets us correctly handle code "break"ing out of the
126 try catch block. (It works as the "break" only exits the inner
127 "while" loop, the outer for loop detects this handling it
128 correctly.) Of course "return" and "goto" are not so lucky.
134 volatile struct gdb_exception e;
135 TRY_CATCH (e, RETURN_MASK_ERROR)
140 case RETURN_ERROR: ...
145 #define TRY_CATCH(EXCEPTION,MASK) \
147 EXCEPTIONS_SIGJMP_BUF *buf = \
148 exceptions_state_mc_init (&(EXCEPTION), (MASK)); \
149 EXCEPTIONS_SIGSETJMP (*buf); \
151 while (exceptions_state_mc_action_iter ()) \
152 while (exceptions_state_mc_action_iter_1 ())
157 /* If E is an exception, print it's error message on the specified
158 stream. For _fprintf, prefix the message with PREFIX... */
159 extern void exception_print (struct ui_file *file, struct gdb_exception e);
160 extern void exception_fprintf (struct ui_file *file, struct gdb_exception e,
162 ...) ATTRIBUTE_PRINTF (3, 4);
164 /* Throw an exception (as described by "struct gdb_exception"). Will
165 execute a LONG JUMP to the inner most containing exception handler
166 established using catch_exceptions() (or similar).
168 Code normally throws an exception using error() et.al. For various
169 reaons, GDB also contains code that throws an exception directly.
170 For instance, the remote*.c targets contain CNTRL-C signal handlers
171 that propogate the QUIT event up the exception chain. ``This could
172 be a good thing or a dangerous thing.'' -- the Existential
175 extern void throw_exception (struct gdb_exception exception)
177 extern void throw_verror (enum errors, const char *fmt, va_list ap)
178 ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 0);
179 extern void throw_vfatal (const char *fmt, va_list ap)
180 ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 0);
181 extern void throw_error (enum errors error, const char *fmt, ...)
182 ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 3);
184 /* Instead of deprecated_throw_reason, code should use
186 extern void deprecated_throw_reason (enum return_reason reason)
189 /* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
190 handler. If an exception (enum return_reason) is thrown using
191 throw_exception() than all cleanups installed since
192 catch_exceptions() was entered are invoked, the (-ve) exception
193 value is then returned by catch_exceptions. If FUNC() returns
194 normally (with a positive or zero return value) then that value is
195 returned by catch_exceptions(). It is an internal_error() for
196 FUNC() to return a negative value.
198 For the period of the FUNC() call: UIOUT is installed as the output
199 builder; ERRSTRING is installed as the error/quit message; and a
200 new cleanup_chain is established. The old values are restored
201 before catch_exceptions() returns.
203 The variant catch_exceptions_with_msg() is the same as
204 catch_exceptions() but adds the ability to return an allocated
205 copy of the gdb error message. This is used when a silent error is
206 issued and the caller wants to manually issue the error message.
208 MASK specifies what to catch; it is normally set to
209 RETURN_MASK_ALL, if for no other reason than that the code which
210 calls catch_errors might not be set up to deal with a quit which
211 isn't caught. But if the code can deal with it, it generally
212 should be RETURN_MASK_ERROR, unless for some reason it is more
213 useful to abort only the portion of the operation inside the
214 catch_errors. Note that quit should return to the command line
215 fairly quickly, even if some further processing is being done.
217 FIXME; cagney/2001-08-13: The need to override the global UIOUT
218 builder variable should just go away.
220 This function supersedes catch_errors().
222 This function uses SETJMP() and LONGJUMP(). */
225 typedef int (catch_exceptions_ftype) (struct ui_out *ui_out, void *args);
226 extern int catch_exceptions (struct ui_out *uiout,
227 catch_exceptions_ftype *func, void *func_args,
229 typedef void (catch_exception_ftype) (struct ui_out *ui_out, void *args);
230 extern int catch_exceptions_with_msg (struct ui_out *uiout,
231 catch_exceptions_ftype *func,
236 /* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
237 otherwize the result from CATCH_ERRORS_FTYPE is returned. It is
238 probably useful for CATCH_ERRORS_FTYPE to always return a non-zero
239 value. It's unfortunate that, catch_errors() does not return an
240 indication of the exact exception that it caught - quit_flag might
243 This function is superseded by catch_exceptions(). */
245 typedef int (catch_errors_ftype) (void *);
246 extern int catch_errors (catch_errors_ftype *, void *, char *, return_mask);
248 /* Template to catch_errors() that wraps calls to command
251 typedef void (catch_command_errors_ftype) (char *, int);
252 extern int catch_command_errors (catch_command_errors_ftype *func,
253 char *command, int from_tty, return_mask);