256 lines
9.0 KiB
C++
256 lines
9.0 KiB
C++
/* Exception (throw catch) mechanism, for GDB, the GNU debugger.
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Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
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1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
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2009, 2010, 2011 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef EXCEPTIONS_H
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#define EXCEPTIONS_H
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#include "ui-out.h"
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#include <setjmp.h>
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/* Reasons for calling throw_exceptions(). NOTE: all reason values
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must be less than zero. enum value 0 is reserved for internal use
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as the return value from an initial setjmp(). The function
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catch_exceptions() reserves values >= 0 as legal results from its
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wrapped function. */
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enum return_reason
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{
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/* User interrupt. */
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RETURN_QUIT = -2,
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/* Any other error. */
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RETURN_ERROR
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};
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#define RETURN_MASK(reason) (1 << (int)(-reason))
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#define RETURN_MASK_QUIT RETURN_MASK (RETURN_QUIT)
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#define RETURN_MASK_ERROR RETURN_MASK (RETURN_ERROR)
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#define RETURN_MASK_ALL (RETURN_MASK_QUIT | RETURN_MASK_ERROR)
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typedef int return_mask;
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/* Describe all exceptions. */
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enum errors {
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GDB_NO_ERROR,
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/* Any generic error, the corresponding text is in
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exception.message. */
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GENERIC_ERROR,
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NOT_FOUND_ERROR,
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/* Thread library lacks support necessary for finding thread local
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storage. */
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TLS_NO_LIBRARY_SUPPORT_ERROR,
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/* Load module not found while attempting to find thread local storage. */
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TLS_LOAD_MODULE_NOT_FOUND_ERROR,
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/* Thread local storage has not been allocated yet. */
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TLS_NOT_ALLOCATED_YET_ERROR,
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/* Something else went wrong while attempting to find thread local
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storage. The ``struct gdb_exception'' message field provides
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more detail. */
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TLS_GENERIC_ERROR,
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/* Problem parsing an XML document. */
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XML_PARSE_ERROR,
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/* Error accessing memory. */
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MEMORY_ERROR,
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/* Feature is not supported in this copy of GDB. */
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UNSUPPORTED_ERROR,
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/* Add more errors here. */
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NR_ERRORS
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};
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struct gdb_exception
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{
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enum return_reason reason;
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enum errors error;
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const char *message;
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};
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/* A pre-defined non-exception. */
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extern const struct gdb_exception exception_none;
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/* Wrap set/long jmp so that it's more portable (internal to
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exceptions). */
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#if defined(HAVE_SIGSETJMP)
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#define EXCEPTIONS_SIGJMP_BUF sigjmp_buf
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#define EXCEPTIONS_SIGSETJMP(buf) sigsetjmp((buf), 1)
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#define EXCEPTIONS_SIGLONGJMP(buf,val) siglongjmp((buf), (val))
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#else
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#define EXCEPTIONS_SIGJMP_BUF jmp_buf
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#define EXCEPTIONS_SIGSETJMP(buf) setjmp(buf)
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#define EXCEPTIONS_SIGLONGJMP(buf,val) longjmp((buf), (val))
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#endif
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/* Functions to drive the exceptions state m/c (internal to
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exceptions). */
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EXCEPTIONS_SIGJMP_BUF *exceptions_state_mc_init (struct ui_out *func_uiout,
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volatile struct gdb_exception *
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exception,
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return_mask mask);
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int exceptions_state_mc_action_iter (void);
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int exceptions_state_mc_action_iter_1 (void);
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/* Macro to wrap up standard try/catch behavior.
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The double loop lets us correctly handle code "break"ing out of the
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try catch block. (It works as the "break" only exits the inner
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"while" loop, the outer for loop detects this handling it
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correctly.) Of course "return" and "goto" are not so lucky.
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For instance:
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*INDENT-OFF*
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volatile struct gdb_exception e;
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TRY_CATCH (e, RETURN_MASK_ERROR)
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{
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}
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switch (e.reason)
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{
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case RETURN_ERROR: ...
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}
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*/
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#define TRY_CATCH(EXCEPTION,MASK) \
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{ \
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EXCEPTIONS_SIGJMP_BUF *buf = \
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exceptions_state_mc_init (uiout, &(EXCEPTION), (MASK)); \
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EXCEPTIONS_SIGSETJMP (*buf); \
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} \
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while (exceptions_state_mc_action_iter ()) \
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while (exceptions_state_mc_action_iter_1 ())
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/* *INDENT-ON* */
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/* If E is an exception, print it's error message on the specified
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stream. for _fprintf, prefix the message with PREFIX... */
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extern void exception_print (struct ui_file *file, struct gdb_exception e);
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extern void exception_fprintf (struct ui_file *file, struct gdb_exception e,
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const char *prefix,
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...) ATTRIBUTE_PRINTF (3, 4);
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/* Throw an exception (as described by "struct gdb_exception"). Will
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execute a LONG JUMP to the inner most containing exception handler
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established using catch_exceptions() (or similar).
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Code normally throws an exception using error() et.al. For various
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reaons, GDB also contains code that throws an exception directly.
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For instance, the remote*.c targets contain CNTRL-C signal handlers
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that propogate the QUIT event up the exception chain. ``This could
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be a good thing or a dangerous thing.'' -- the Existential
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Wombat. */
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extern void throw_exception (struct gdb_exception exception) ATTRIBUTE_NORETURN;
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extern void throw_verror (enum errors, const char *fmt, va_list ap)
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ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 0);
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extern void throw_vfatal (const char *fmt, va_list ap)
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ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (1, 0);
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extern void throw_error (enum errors error, const char *fmt, ...)
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ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF (2, 3);
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/* Instead of deprecated_throw_reason, code should use catch_exception
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and throw_exception. */
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extern void deprecated_throw_reason (enum return_reason reason)
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ATTRIBUTE_NORETURN;
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/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
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handler. If an exception (enum return_reason) is thrown using
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throw_exception() than all cleanups installed since
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catch_exceptions() was entered are invoked, the (-ve) exception
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value is then returned by catch_exceptions. If FUNC() returns
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normally (with a positive or zero return value) then that value is
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returned by catch_exceptions(). It is an internal_error() for
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FUNC() to return a negative value.
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For the period of the FUNC() call: UIOUT is installed as the output
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builder; ERRSTRING is installed as the error/quit message; and a
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new cleanup_chain is established. The old values are restored
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before catch_exceptions() returns.
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The variant catch_exceptions_with_msg() is the same as
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catch_exceptions() but adds the ability to return an allocated
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copy of the gdb error message. This is used when a silent error is
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issued and the caller wants to manually issue the error message.
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MASK specifies what to catch; it is normally set to
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RETURN_MASK_ALL, if for no other reason than that the code which
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calls catch_errors might not be set up to deal with a quit which
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isn't caught. But if the code can deal with it, it generally
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should be RETURN_MASK_ERROR, unless for some reason it is more
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useful to abort only the portion of the operation inside the
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catch_errors. Note that quit should return to the command line
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fairly quickly, even if some further processing is being done.
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FIXME; cagney/2001-08-13: The need to override the global UIOUT
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builder variable should just go away.
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This function supersedes catch_errors().
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This function uses SETJMP() and LONGJUMP(). */
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struct ui_out;
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typedef int (catch_exceptions_ftype) (struct ui_out *ui_out, void *args);
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extern int catch_exceptions (struct ui_out *uiout,
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catch_exceptions_ftype *func, void *func_args,
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return_mask mask);
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typedef void (catch_exception_ftype) (struct ui_out *ui_out, void *args);
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extern int catch_exceptions_with_msg (struct ui_out *uiout,
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catch_exceptions_ftype *func,
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void *func_args,
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char **gdberrmsg,
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return_mask mask);
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/* This function, in addition, suppresses the printing of the captured
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error message. It's up to the client to print it. */
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extern struct gdb_exception catch_exception (struct ui_out *uiout,
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catch_exception_ftype *func,
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void *func_args,
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return_mask mask);
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/* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
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otherwize the result from CATCH_ERRORS_FTYPE is returned. It is
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probably useful for CATCH_ERRORS_FTYPE to always return a non-zero
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value. It's unfortunate that, catch_errors() does not return an
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indication of the exact exception that it caught - quit_flag might
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help.
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This function is superseded by catch_exceptions(). */
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typedef int (catch_errors_ftype) (void *);
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extern int catch_errors (catch_errors_ftype *, void *, char *, return_mask);
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/* Template to catch_errors() that wraps calls to command
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functions. */
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typedef void (catch_command_errors_ftype) (char *, int);
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extern int catch_command_errors (catch_command_errors_ftype *func, char *command, int from_tty, return_mask);
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#endif
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