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60250e8b AC |
1 | /* Exception (throw catch) mechanism, for GDB, the GNU debugger. |
2 | ||
3 | Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, | |
05ff989b AC |
4 | 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free |
5 | Software Foundation, Inc. | |
60250e8b AC |
6 | |
7 | This file is part of GDB. | |
8 | ||
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 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
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. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
23 | ||
24 | #ifndef EXCEPTIONS_H | |
25 | #define EXCEPTIONS_H | |
26 | ||
6941d02a AC |
27 | struct ui_out; |
28 | ||
29 | #include <setjmp.h> | |
30 | ||
2a78bfb5 | 31 | /* Reasons for calling throw_exceptions(). NOTE: all reason values |
60250e8b AC |
32 | must be less than zero. enum value 0 is reserved for internal use |
33 | as the return value from an initial setjmp(). The function | |
34 | catch_exceptions() reserves values >= 0 as legal results from its | |
35 | wrapped function. */ | |
36 | ||
37 | enum return_reason | |
38 | { | |
39 | /* User interrupt. */ | |
40 | RETURN_QUIT = -2, | |
41 | /* Any other error. */ | |
42 | RETURN_ERROR | |
43 | }; | |
44 | ||
45 | #define RETURN_MASK(reason) (1 << (int)(-reason)) | |
46 | #define RETURN_MASK_QUIT RETURN_MASK (RETURN_QUIT) | |
47 | #define RETURN_MASK_ERROR RETURN_MASK (RETURN_ERROR) | |
48 | #define RETURN_MASK_ALL (RETURN_MASK_QUIT | RETURN_MASK_ERROR) | |
49 | typedef int return_mask; | |
50 | ||
2a78bfb5 AC |
51 | /* Describe all exceptions. */ |
52 | ||
53 | enum errors { | |
54 | NO_ERROR, | |
55 | /* Any generic error, the corresponding text is in | |
56 | exception.message. */ | |
57 | GENERIC_ERROR, | |
05ff989b | 58 | NOT_FOUND_ERROR, |
93ad78a7 KB |
59 | |
60 | /* Thread library lacks support necessary for finding thread local | |
61 | storage. */ | |
62 | TLS_NO_LIBRARY_SUPPORT_ERROR, | |
63 | ||
64 | /* Load module not found while attempting to find thread local storage. */ | |
65 | TLS_LOAD_MODULE_NOT_FOUND_ERROR, | |
66 | ||
67 | /* Thread local storage has not been allocated yet. */ | |
68 | TLS_NOT_ALLOCATED_YET_ERROR, | |
69 | ||
70 | /* Something else went wrong while attempting to find thread local | |
71 | storage. The ``struct exception'' message field provides more | |
72 | detail. */ | |
73 | TLS_GENERIC_ERROR, | |
74 | ||
2a78bfb5 AC |
75 | /* Add more errors here. */ |
76 | NR_ERRORS | |
77 | }; | |
78 | ||
79 | struct exception | |
80 | { | |
81 | enum return_reason reason; | |
82 | enum errors error; | |
b315da38 | 83 | const char *message; |
2a78bfb5 AC |
84 | }; |
85 | ||
c1043fc2 AC |
86 | /* A pre-defined non-exception. */ |
87 | extern const struct exception exception_none; | |
88 | ||
6941d02a AC |
89 | /* Wrap set/long jmp so that it's more portable (internal to |
90 | exceptions). */ | |
91 | ||
92 | #if defined(HAVE_SIGSETJMP) | |
93 | #define EXCEPTIONS_SIGJMP_BUF sigjmp_buf | |
94 | #define EXCEPTIONS_SIGSETJMP(buf) sigsetjmp((buf), 1) | |
95 | #define EXCEPTIONS_SIGLONGJMP(buf,val) siglongjmp((buf), (val)) | |
96 | #else | |
97 | #define EXCEPTIONS_SIGJMP_BUF jmp_buf | |
98 | #define EXCEPTIONS_SIGSETJMP(buf) setjmp(buf) | |
99 | #define EXCEPTIONS_SIGLONGJMP(buf,val) longjmp((buf), (val)) | |
100 | #endif | |
101 | ||
102 | /* Functions to drive the exceptions state m/c (internal to | |
103 | exceptions). */ | |
104 | EXCEPTIONS_SIGJMP_BUF *exceptions_state_mc_init (struct ui_out *func_uiout, | |
105 | volatile struct exception * | |
106 | exception, | |
107 | return_mask mask); | |
108 | int exceptions_state_mc_action_iter (void); | |
109 | int exceptions_state_mc_action_iter_1 (void); | |
110 | ||
111 | /* Macro to wrap up standard try/catch behavior. | |
112 | ||
113 | The double loop lets us correctly handle code "break"ing out of the | |
114 | try catch block. (It works as the "break" only exits the inner | |
115 | "while" loop, the outer for loop detects this handling it | |
116 | correctly.) Of course "return" and "goto" are not so lucky. | |
117 | ||
118 | For instance: | |
119 | ||
120 | *INDENT-OFF* | |
121 | ||
122 | volatile struct exception e; | |
123 | TRY_CATCH (e, RETURN_MASK_ERROR) | |
124 | { | |
125 | } | |
126 | switch (e.reason) | |
127 | { | |
128 | case RETURN_ERROR: ... | |
129 | } | |
130 | ||
131 | */ | |
132 | ||
133 | #define TRY_CATCH(EXCEPTION,MASK) \ | |
8d19ca47 CV |
134 | { \ |
135 | EXCEPTIONS_SIGJMP_BUF *buf = \ | |
136 | exceptions_state_mc_init (uiout, &(EXCEPTION), (MASK)); \ | |
137 | EXCEPTIONS_SIGSETJMP (*buf); \ | |
138 | } \ | |
139 | while (exceptions_state_mc_action_iter ()) \ | |
140 | while (exceptions_state_mc_action_iter_1 ()) | |
6941d02a AC |
141 | |
142 | /* *INDENT-ON* */ | |
143 | ||
144 | ||
8a076db9 | 145 | /* If E is an exception, print it's error message on the specified |
9cbc821d AC |
146 | stream. for _fprintf, prefix the message with PREFIX... */ |
147 | extern void exception_print (struct ui_file *file, struct exception e); | |
148 | extern void exception_fprintf (struct ui_file *file, struct exception e, | |
149 | const char *prefix, | |
150 | ...) ATTR_FORMAT (printf, 3, 4); | |
8a076db9 | 151 | |
2a78bfb5 AC |
152 | /* Throw an exception (as described by "struct exception"). Will |
153 | execute a LONG JUMP to the inner most containing exception handler | |
154 | established using catch_exceptions() (or similar). | |
60250e8b AC |
155 | |
156 | Code normally throws an exception using error() et.al. For various | |
157 | reaons, GDB also contains code that throws an exception directly. | |
158 | For instance, the remote*.c targets contain CNTRL-C signal handlers | |
159 | that propogate the QUIT event up the exception chain. ``This could | |
2a78bfb5 AC |
160 | be a good thing or a dangerous thing.'' -- the Existential |
161 | Wombat. */ | |
162 | ||
163 | extern NORETURN void throw_exception (struct exception exception) ATTR_NORETURN; | |
6b1b7650 AC |
164 | extern NORETURN void throw_verror (enum errors, const char *fmt, |
165 | va_list ap) ATTR_NORETURN; | |
166 | extern NORETURN void throw_vfatal (const char *fmt, va_list ap) ATTR_NORETURN; | |
05ff989b AC |
167 | extern NORETURN void throw_error (enum errors error, const char *fmt, |
168 | ...) ATTR_NORETURN ATTR_FORMAT (printf, 2, 3); | |
60250e8b | 169 | |
315a522e AC |
170 | /* Instead of deprecated_throw_reason, code should use catch_exception |
171 | and throw_exception. */ | |
172 | extern NORETURN void deprecated_throw_reason (enum return_reason reason) ATTR_NORETURN; | |
173 | ||
60250e8b AC |
174 | /* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception |
175 | handler. If an exception (enum return_reason) is thrown using | |
176 | throw_exception() than all cleanups installed since | |
177 | catch_exceptions() was entered are invoked, the (-ve) exception | |
178 | value is then returned by catch_exceptions. If FUNC() returns | |
179 | normally (with a postive or zero return value) then that value is | |
180 | returned by catch_exceptions(). It is an internal_error() for | |
181 | FUNC() to return a negative value. | |
182 | ||
183 | For the period of the FUNC() call: UIOUT is installed as the output | |
184 | builder; ERRSTRING is installed as the error/quit message; and a | |
185 | new cleanup_chain is established. The old values are restored | |
186 | before catch_exceptions() returns. | |
187 | ||
188 | The variant catch_exceptions_with_msg() is the same as | |
189 | catch_exceptions() but adds the ability to return an allocated | |
190 | copy of the gdb error message. This is used when a silent error is | |
191 | issued and the caller wants to manually issue the error message. | |
192 | ||
193 | FIXME; cagney/2001-08-13: The need to override the global UIOUT | |
194 | builder variable should just go away. | |
195 | ||
196 | This function superseeds catch_errors(). | |
197 | ||
198 | This function uses SETJMP() and LONGJUMP(). */ | |
199 | ||
200 | struct ui_out; | |
201 | typedef int (catch_exceptions_ftype) (struct ui_out *ui_out, void *args); | |
202 | extern int catch_exceptions (struct ui_out *uiout, | |
203 | catch_exceptions_ftype *func, void *func_args, | |
1c3c7ee7 | 204 | return_mask mask); |
2a78bfb5 | 205 | typedef void (catch_exception_ftype) (struct ui_out *ui_out, void *args); |
60250e8b AC |
206 | extern int catch_exceptions_with_msg (struct ui_out *uiout, |
207 | catch_exceptions_ftype *func, | |
208 | void *func_args, | |
1c3c7ee7 | 209 | char **gdberrmsg, |
60250e8b | 210 | return_mask mask); |
8a076db9 AC |
211 | |
212 | /* This function, in addition, suppresses the printing of the captured | |
213 | error message. It's up to the client to print it. */ | |
214 | ||
2a78bfb5 AC |
215 | extern struct exception catch_exception (struct ui_out *uiout, |
216 | catch_exception_ftype *func, | |
217 | void *func_args, | |
218 | return_mask mask); | |
60250e8b AC |
219 | |
220 | /* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero | |
221 | otherwize the result from CATCH_ERRORS_FTYPE is returned. It is | |
222 | probably useful for CATCH_ERRORS_FTYPE to always return a non-zero | |
223 | value. It's unfortunate that, catch_errors() does not return an | |
224 | indication of the exact exception that it caught - quit_flag might | |
225 | help. | |
226 | ||
227 | This function is superseeded by catch_exceptions(). */ | |
228 | ||
229 | typedef int (catch_errors_ftype) (void *); | |
230 | extern int catch_errors (catch_errors_ftype *, void *, char *, return_mask); | |
231 | ||
232 | /* Template to catch_errors() that wraps calls to command | |
233 | functions. */ | |
234 | ||
235 | typedef void (catch_command_errors_ftype) (char *, int); | |
236 | extern int catch_command_errors (catch_command_errors_ftype *func, char *command, int from_tty, return_mask); | |
237 | ||
238 | #endif |