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/* Exception (throw catch) mechanism, for GDB, the GNU debugger.
Copyright (C) 1986-2015 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef COMMON_EXCEPTIONS_H
#define COMMON_EXCEPTIONS_H
#include "gdb_setjmp.h"
/* Reasons for calling throw_exceptions(). NOTE: all reason values
must be less than zero. enum value 0 is reserved for internal use
as the return value from an initial setjmp(). The function
catch_exceptions() reserves values >= 0 as legal results from its
wrapped function. */
enum return_reason
{
/* User interrupt. */
RETURN_QUIT = -2,
/* Any other error. */
RETURN_ERROR
};
#define RETURN_MASK(reason) (1 << (int)(-reason))
typedef enum
{
RETURN_MASK_QUIT = RETURN_MASK (RETURN_QUIT),
RETURN_MASK_ERROR = RETURN_MASK (RETURN_ERROR),
RETURN_MASK_ALL = (RETURN_MASK_QUIT | RETURN_MASK_ERROR)
} return_mask;
/* Describe all exceptions. */
enum errors {
GDB_NO_ERROR,
/* Any generic error, the corresponding text is in
exception.message. */
GENERIC_ERROR,
/* Something requested was not found. */
NOT_FOUND_ERROR,
/* Thread library lacks support necessary for finding thread local
storage. */
TLS_NO_LIBRARY_SUPPORT_ERROR,
/* Load module not found while attempting to find thread local storage. */
TLS_LOAD_MODULE_NOT_FOUND_ERROR,
/* Thread local storage has not been allocated yet. */
TLS_NOT_ALLOCATED_YET_ERROR,
/* Something else went wrong while attempting to find thread local
storage. The ``struct gdb_exception'' message field provides
more detail. */
TLS_GENERIC_ERROR,
/* Problem parsing an XML document. */
XML_PARSE_ERROR,
/* Error accessing memory. */
MEMORY_ERROR,
/* Value not available. E.g., a register was not collected in a
traceframe. */
NOT_AVAILABLE_ERROR,
/* Value was optimized out. Note: if the value was a register, this
means the register was not saved in the frame. */
OPTIMIZED_OUT_ERROR,
/* DW_OP_GNU_entry_value resolving failed. */
NO_ENTRY_VALUE_ERROR,
/* Target throwing an error has been closed. Current command should be
aborted as the inferior state is no longer valid. */
TARGET_CLOSE_ERROR,
/* An undefined command was executed. */
UNDEFINED_COMMAND_ERROR,
/* Requested feature, method, mechanism, etc. is not supported. */
NOT_SUPPORTED_ERROR,
/* The number of candidates generated during line completion has
reached the user's specified limit. This isn't an error, this exception
is used to halt searching for more completions, but for consistency
"_ERROR" is appended to the name. */
MAX_COMPLETIONS_REACHED_ERROR,
/* Add more errors here. */
NR_ERRORS
};
struct gdb_exception
{
enum return_reason reason;
enum errors error;
const char *message;
};
/* Functions to drive the exceptions state machine. Though declared
here by necessity, these functions should be considered internal to
the exceptions subsystem and not used other than via the TRY_CATCH
macro defined below. */
extern SIGJMP_BUF *exceptions_state_mc_init (volatile struct
gdb_exception *exception,
return_mask mask);
extern int exceptions_state_mc_action_iter (void);
extern int exceptions_state_mc_action_iter_1 (void);
/* Macro to wrap up standard try/catch behavior.
The double loop lets us correctly handle code "break"ing out of the
try catch block. (It works as the "break" only exits the inner
"while" loop, the outer for loop detects this handling it
correctly.) Of course "return" and "goto" are not so lucky.
For instance:
*INDENT-OFF*
volatile struct gdb_exception e;
TRY_CATCH (e, RETURN_MASK_ERROR)
{
}
switch (e.reason)
{
case RETURN_ERROR: ...
}
*/
#define TRY_CATCH(EXCEPTION,MASK) \
{ \
SIGJMP_BUF *buf = \
exceptions_state_mc_init (&(EXCEPTION), (MASK)); \
SIGSETJMP (*buf); \
} \
while (exceptions_state_mc_action_iter ()) \
while (exceptions_state_mc_action_iter_1 ())
/* *INDENT-ON* */
/* Hook to allow client-specific actions to be performed prior to
throwing an exception. This function must be provided by the
client, and will be called before any cleanups are run. */
extern void prepare_to_throw_exception (void);
/* Throw an exception (as described by "struct gdb_exception"). Will
execute a LONG JUMP to the inner most containing exception handler
established using catch_exceptions() (or similar).
Code normally throws an exception using error() et.al. For various
reaons, GDB also contains code that throws an exception directly.
For instance, the remote*.c targets contain CNTRL-C signal handlers
that propogate the QUIT event up the exception chain. ``This could
be a good thing or a dangerous thing.'' -- the Existential
Wombat. */
extern void throw_exception (struct gdb_exception exception)
ATTRIBUTE_NORETURN;
extern void throw_verror (enum errors, const char *fmt, va_list ap)
ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 0);
extern void throw_vquit (const char *fmt, va_list ap)
ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 0);
extern void throw_error (enum errors error, const char *fmt, ...)
ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 3);
extern void throw_quit (const char *fmt, ...)
ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 2);
#endif /* COMMON_EXCEPTIONS_H */
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