[deliverable/binutils-gdb.git] / gdb / exceptions.h

/* Exception (throw catch) mechanism, for GDB, the GNU debugger.

   Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef EXCEPTIONS_H
#define EXCEPTIONS_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))
#define RETURN_MASK_QUIT	RETURN_MASK (RETURN_QUIT)
#define RETURN_MASK_ERROR	RETURN_MASK (RETURN_ERROR)
#define RETURN_MASK_ALL		(RETURN_MASK_QUIT | RETURN_MASK_ERROR)
typedef int return_mask;

/* Describe all exceptions.  */

enum errors {
  NO_ERROR,
  /* Any generic error, the corresponding text is in
     exception.message.  */
  GENERIC_ERROR,
  NOT_FOUND_ERROR,
  /* Add more errors here.  */
  NR_ERRORS
};

struct exception
{
  enum return_reason reason;
  enum errors error;
  const char *message;
};

/* A pre-defined non-exception.  */
extern const struct exception exception_none;

/* If E is an exception, print it's error message on the specified
   stream. for _fprintf, prefix the message with PREFIX...  */
extern void exception_print (struct ui_file *file, struct exception e);
extern void exception_fprintf (struct ui_file *file, struct exception e,
			       const char *prefix,
			       ...) ATTR_FORMAT (printf, 3, 4);

/* Throw an exception (as described by "struct 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 NORETURN void throw_exception (struct exception exception) ATTR_NORETURN;
extern NORETURN void throw_verror (enum errors, const char *fmt,
				   va_list ap) ATTR_NORETURN;
extern NORETURN void throw_vfatal (const char *fmt, va_list ap) ATTR_NORETURN;
extern NORETURN void throw_error (enum errors error, const char *fmt,
				  ...) ATTR_NORETURN ATTR_FORMAT (printf, 2, 3);

/* Instead of deprecated_throw_reason, code should use catch_exception
   and throw_exception.  */
extern NORETURN void deprecated_throw_reason (enum return_reason reason) ATTR_NORETURN;

/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
   handler.  If an exception (enum return_reason) is thrown using
   throw_exception() than all cleanups installed since
   catch_exceptions() was entered are invoked, the (-ve) exception
   value is then returned by catch_exceptions.  If FUNC() returns
   normally (with a postive or zero return value) then that value is
   returned by catch_exceptions().  It is an internal_error() for
   FUNC() to return a negative value.

   For the period of the FUNC() call: UIOUT is installed as the output
   builder; ERRSTRING is installed as the error/quit message; and a
   new cleanup_chain is established.  The old values are restored
   before catch_exceptions() returns.

   The variant catch_exceptions_with_msg() is the same as
   catch_exceptions() but adds the ability to return an allocated
   copy of the gdb error message.  This is used when a silent error is 
   issued and the caller wants to manually issue the error message.

   FIXME; cagney/2001-08-13: The need to override the global UIOUT
   builder variable should just go away.

   This function superseeds catch_errors().

   This function uses SETJMP() and LONGJUMP().  */

struct ui_out;
typedef int (catch_exceptions_ftype) (struct ui_out *ui_out, void *args);
extern int catch_exceptions (struct ui_out *uiout,
			     catch_exceptions_ftype *func, void *func_args,
			     return_mask mask);
typedef void (catch_exception_ftype) (struct ui_out *ui_out, void *args);
extern int catch_exceptions_with_msg (struct ui_out *uiout,
			     	      catch_exceptions_ftype *func, 
			     	      void *func_args,
			     	      char **gdberrmsg,
				      return_mask mask);

/* This function, in addition, suppresses the printing of the captured
   error message.  It's up to the client to print it.  */

extern struct exception catch_exception (struct ui_out *uiout,
					 catch_exception_ftype *func,
					 void *func_args,
					 return_mask mask);

/* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
   otherwize the result from CATCH_ERRORS_FTYPE is returned. It is
   probably useful for CATCH_ERRORS_FTYPE to always return a non-zero
   value. It's unfortunate that, catch_errors() does not return an
   indication of the exact exception that it caught - quit_flag might
   help.

   This function is superseeded by catch_exceptions().  */

typedef int (catch_errors_ftype) (void *);
extern int catch_errors (catch_errors_ftype *, void *, char *, return_mask);

/* Template to catch_errors() that wraps calls to command
   functions. */

typedef void (catch_command_errors_ftype) (char *, int);
extern int catch_command_errors (catch_command_errors_ftype *func, char *command, int from_tty, return_mask);

#endif
Commit	Line	Data
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
05ff989b AC	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
2a78bfb5	27	/* Reasons for calling throw_exceptions(). NOTE: all reason values
60250e8b AC	28	must be less than zero. enum value 0 is reserved for internal use
	29	as the return value from an initial setjmp(). The function
	30	catch_exceptions() reserves values >= 0 as legal results from its
	31	wrapped function. */
	32
	33	enum return_reason
	34	{
	35	/* User interrupt. */
	36	RETURN_QUIT = -2,
	37	/* Any other error. */
	38	RETURN_ERROR
	39	};
	40
	41	#define RETURN_MASK(reason) (1 << (int)(-reason))
	42	#define RETURN_MASK_QUIT RETURN_MASK (RETURN_QUIT)
	43	#define RETURN_MASK_ERROR RETURN_MASK (RETURN_ERROR)
	44	#define RETURN_MASK_ALL (RETURN_MASK_QUIT \| RETURN_MASK_ERROR)
	45	typedef int return_mask;
	46
2a78bfb5 AC	47	/* Describe all exceptions. */
	48
	49	enum errors {
	50	NO_ERROR,
	51	/* Any generic error, the corresponding text is in
	52	exception.message. */
	53	GENERIC_ERROR,
05ff989b	54	NOT_FOUND_ERROR,
2a78bfb5 AC	55	/* Add more errors here. */
	56	NR_ERRORS
	57	};
	58
	59	struct exception
	60	{
	61	enum return_reason reason;
	62	enum errors error;
b315da38	63	const char *message;
2a78bfb5 AC	64	};
2a78bfb5 AC	65
c1043fc2 AC	66	/* A pre-defined non-exception. */
	67	extern const struct exception exception_none;
	68
8a076db9	69	/* If E is an exception, print it's error message on the specified
9cbc821d AC	70	stream. for _fprintf, prefix the message with PREFIX... */
	71	extern void exception_print (struct ui_file *file, struct exception e);
	72	extern void exception_fprintf (struct ui_file *file, struct exception e,
	73	const char *prefix,
	74	...) ATTR_FORMAT (printf, 3, 4);
8a076db9	75
2a78bfb5 AC	76	/* Throw an exception (as described by "struct exception"). Will
	77	execute a LONG JUMP to the inner most containing exception handler
	78	established using catch_exceptions() (or similar).
60250e8b AC	79
	80	Code normally throws an exception using error() et.al. For various
	81	reaons, GDB also contains code that throws an exception directly.
	82	For instance, the remote*.c targets contain CNTRL-C signal handlers
	83	that propogate the QUIT event up the exception chain. ``This could
2a78bfb5 AC	84	be a good thing or a dangerous thing.'' -- the Existential
	85	Wombat. */
	86
	87	extern NORETURN void throw_exception (struct exception exception) ATTR_NORETURN;
6b1b7650 AC	88	extern NORETURN void throw_verror (enum errors, const char *fmt,
	89	va_list ap) ATTR_NORETURN;
	90	extern NORETURN void throw_vfatal (const char *fmt, va_list ap) ATTR_NORETURN;
05ff989b AC	91	extern NORETURN void throw_error (enum errors error, const char *fmt,
05ff989b AC	92	...) ATTR_NORETURN ATTR_FORMAT (printf, 2, 3);
60250e8b	93
315a522e AC	94	/* Instead of deprecated_throw_reason, code should use catch_exception
	95	and throw_exception. */
	96	extern NORETURN void deprecated_throw_reason (enum return_reason reason) ATTR_NORETURN;
	97
60250e8b AC	98	/* Call FUNC(UIOUT, FUNC_ARGS) but wrapped within an exception
	99	handler. If an exception (enum return_reason) is thrown using
	100	throw_exception() than all cleanups installed since
	101	catch_exceptions() was entered are invoked, the (-ve) exception
	102	value is then returned by catch_exceptions. If FUNC() returns
	103	normally (with a postive or zero return value) then that value is
	104	returned by catch_exceptions(). It is an internal_error() for
	105	FUNC() to return a negative value.
	106
	107	For the period of the FUNC() call: UIOUT is installed as the output
	108	builder; ERRSTRING is installed as the error/quit message; and a
	109	new cleanup_chain is established. The old values are restored
	110	before catch_exceptions() returns.
	111
	112	The variant catch_exceptions_with_msg() is the same as
	113	catch_exceptions() but adds the ability to return an allocated
	114	copy of the gdb error message. This is used when a silent error is
	115	issued and the caller wants to manually issue the error message.
	116
	117	FIXME; cagney/2001-08-13: The need to override the global UIOUT
	118	builder variable should just go away.
	119
	120	This function superseeds catch_errors().
	121
	122	This function uses SETJMP() and LONGJUMP(). */
	123
	124	struct ui_out;
	125	typedef int (catch_exceptions_ftype) (struct ui_out ui_out, void args);
	126	extern int catch_exceptions (struct ui_out *uiout,
	127	catch_exceptions_ftype func, void func_args,
1c3c7ee7	128	return_mask mask);
2a78bfb5	129	typedef void (catch_exception_ftype) (struct ui_out ui_out, void args);
60250e8b AC	130	extern int catch_exceptions_with_msg (struct ui_out *uiout,
	131	catch_exceptions_ftype *func,
	132	void *func_args,
1c3c7ee7	133	char **gdberrmsg,
60250e8b	134	return_mask mask);
8a076db9 AC	135
	136	/* This function, in addition, suppresses the printing of the captured
	137	error message. It's up to the client to print it. */
	138
2a78bfb5 AC	139	extern struct exception catch_exception (struct ui_out *uiout,
	140	catch_exception_ftype *func,
	141	void *func_args,
	142	return_mask mask);
60250e8b AC	143
	144	/* If CATCH_ERRORS_FTYPE throws an error, catch_errors() returns zero
	145	otherwize the result from CATCH_ERRORS_FTYPE is returned. It is
	146	probably useful for CATCH_ERRORS_FTYPE to always return a non-zero
	147	value. It's unfortunate that, catch_errors() does not return an
	148	indication of the exact exception that it caught - quit_flag might
	149	help.
	150
	151	This function is superseeded by catch_exceptions(). */
	152
	153	typedef int (catch_errors_ftype) (void *);
	154	extern int catch_errors (catch_errors_ftype , void , char *, return_mask);
	155
	156	/* Template to catch_errors() that wraps calls to command
	157	functions. */
	158
	159	typedef void (catch_command_errors_ftype) (char *, int);
	160	extern int catch_command_errors (catch_command_errors_ftype func, char command, int from_tty, return_mask);
	161
	162	#endif