1 /* Exception (throw catch) mechanism, for GDB, the GNU debugger.
3 Copyright (C) 1986-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #ifndef COMMON_COMMON_EXCEPTIONS_H
21 #define COMMON_COMMON_EXCEPTIONS_H
27 /* Reasons for calling throw_exceptions(). NOTE: all reason values
28 must be different from zero. enum value 0 is reserved for internal
29 use as the return value from an initial setjmp(). */
35 /* Any other error. */
39 #define RETURN_MASK(reason) (1 << (int)(-reason))
43 RETURN_MASK_QUIT
= RETURN_MASK (RETURN_QUIT
),
44 RETURN_MASK_ERROR
= RETURN_MASK (RETURN_ERROR
),
45 RETURN_MASK_ALL
= (RETURN_MASK_QUIT
| RETURN_MASK_ERROR
)
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 /* Value not available. E.g., a register was not collected in a
85 /* Value was optimized out. Note: if the value was a register, this
86 means the register was not saved in the frame. */
89 /* DW_OP_entry_value resolving failed. */
92 /* Target throwing an error has been closed. Current command should be
93 aborted as the inferior state is no longer valid. */
96 /* An undefined command was executed. */
97 UNDEFINED_COMMAND_ERROR
,
99 /* Requested feature, method, mechanism, etc. is not supported. */
102 /* The number of candidates generated during line completion has
103 reached the user's specified limit. This isn't an error, this exception
104 is used to halt searching for more completions, but for consistency
105 "_ERROR" is appended to the name. */
106 MAX_COMPLETIONS_REACHED_ERROR
,
108 /* Add more errors here. */
115 : reason ((enum return_reason
) 0),
120 gdb_exception (enum return_reason r
, enum errors e
)
126 /* The copy constructor exists so that we can mark it "noexcept",
127 which is a good practice for any sort of exception object. */
128 gdb_exception (const gdb_exception
&other
) noexcept
129 : reason (other
.reason
),
131 message (other
.message
)
135 /* The assignment operator exists so that we can mark it "noexcept",
136 which is a good practice for any sort of exception object. */
137 gdb_exception
&operator= (const gdb_exception
&other
) noexcept
139 reason
= other
.reason
;
141 message
= other
.message
;
145 /* Return the contents of the exception message, as a C string. The
146 string remains owned by the exception object. */
147 const char *what () const noexcept
149 return message
->c_str ();
152 enum return_reason reason
;
154 std::shared_ptr
<std::string
> message
;
157 /* Functions to drive the sjlj-based exceptions state machine. Though
158 declared here by necessity, these functions should be considered
159 internal to the exceptions subsystem and not used other than via
160 the TRY/CATCH (or TRY_SJLJ/CATCH_SJLJ) macros defined below. */
162 extern jmp_buf *exceptions_state_mc_init (void);
163 extern int exceptions_state_mc_action_iter (void);
164 extern int exceptions_state_mc_action_iter_1 (void);
165 extern int exceptions_state_mc_catch (struct gdb_exception
*, int);
167 /* Macro to wrap up standard try/catch behavior.
169 The double loop lets us correctly handle code "break"ing out of the
170 try catch block. (It works as the "break" only exits the inner
171 "while" loop, the outer for loop detects this handling it
172 correctly.) Of course "return" and "goto" are not so lucky.
181 CATCH_SJLJ (e, RETURN_MASK_ERROR)
185 case RETURN_ERROR: ...
190 The SJLJ variants are needed in some cases where gdb exceptions
191 need to cross third-party library code compiled without exceptions
192 support (e.g., readline). */
197 exceptions_state_mc_init (); \
200 while (exceptions_state_mc_action_iter ()) \
201 while (exceptions_state_mc_action_iter_1 ())
203 #define CATCH_SJLJ(EXCEPTION, MASK) \
205 struct gdb_exception EXCEPTION; \
206 if (exceptions_state_mc_catch (&(EXCEPTION), MASK))
208 #define END_CATCH_SJLJ \
211 /* The exception types client code may catch. They're just shims
212 around gdb_exception that add nothing but type info. Which is used
213 is selected depending on the MASK argument passed to CATCH. */
215 struct gdb_exception_error
: public gdb_exception
217 gdb_exception_error (enum return_reason r
, enum errors e
)
218 : gdb_exception (r
, e
)
222 explicit gdb_exception_error (const gdb_exception
&ex
) noexcept
228 struct gdb_exception_quit
: public gdb_exception
230 gdb_exception_quit (enum return_reason r
, enum errors e
)
231 : gdb_exception (r
, e
)
235 explicit gdb_exception_quit (const gdb_exception
&ex
) noexcept
241 /* An exception type that inherits from both std::bad_alloc and a gdb
242 exception. This is necessary because operator new can only throw
243 std::bad_alloc, and OTOH, we want exceptions thrown due to memory
244 allocation error to be caught by all the CATCH/RETURN_MASK_ALL
245 spread around the codebase. */
247 struct gdb_quit_bad_alloc
248 : public gdb_exception_quit
,
249 public std::bad_alloc
251 explicit gdb_quit_bad_alloc (const gdb_exception
&ex
) noexcept
252 : gdb_exception_quit (ex
),
260 /* Throw an exception (as described by "struct gdb_exception"),
261 landing in the inner most containing exception handler established
263 extern void throw_exception (const gdb_exception
&exception
)
266 /* Throw an exception by executing a LONG JUMP to the inner most
267 containing exception handler established using TRY_SJLJ. Necessary
268 in some cases where we need to throw GDB exceptions across
269 third-party library code (e.g., readline). */
270 extern void throw_exception_sjlj (struct gdb_exception exception
)
273 /* Convenience wrappers around throw_exception that throw GDB
275 extern void throw_verror (enum errors
, const char *fmt
, va_list ap
)
276 ATTRIBUTE_NORETURN
ATTRIBUTE_PRINTF (2, 0);
277 extern void throw_vquit (const char *fmt
, va_list ap
)
278 ATTRIBUTE_NORETURN
ATTRIBUTE_PRINTF (1, 0);
279 extern void throw_error (enum errors error
, const char *fmt
, ...)
280 ATTRIBUTE_NORETURN
ATTRIBUTE_PRINTF (2, 3);
281 extern void throw_quit (const char *fmt
, ...)
282 ATTRIBUTE_NORETURN
ATTRIBUTE_PRINTF (1, 2);
284 /* A pre-defined non-exception. */
285 extern const struct gdb_exception exception_none
;
287 #endif /* COMMON_COMMON_EXCEPTIONS_H */