[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

struct ui_out;

#include <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))
#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,

  /* 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 exception'' message field provides more
     detail.  */
  TLS_GENERIC_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;

/* Wrap set/long jmp so that it's more portable (internal to
   exceptions).  */

#if defined(HAVE_SIGSETJMP)
#define EXCEPTIONS_SIGJMP_BUF		sigjmp_buf
#define EXCEPTIONS_SIGSETJMP(buf)	sigsetjmp((buf), 1)
#define EXCEPTIONS_SIGLONGJMP(buf,val)	siglongjmp((buf), (val))
#else
#define EXCEPTIONS_SIGJMP_BUF		jmp_buf
#define EXCEPTIONS_SIGSETJMP(buf)	setjmp(buf)
#define EXCEPTIONS_SIGLONGJMP(buf,val)	longjmp((buf), (val))
#endif

/* Functions to drive the exceptions state m/c (internal to
   exceptions).  */
EXCEPTIONS_SIGJMP_BUF *exceptions_state_mc_init (struct ui_out *func_uiout,
						 volatile struct exception *
						 exception,
						 return_mask mask);
int exceptions_state_mc_action_iter (void);
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 exception e;
   TRY_CATCH (e, RETURN_MASK_ERROR)
     {
     }
   switch (e.reason)
     {
     case RETURN_ERROR: ...
     }

  */

#define TRY_CATCH(EXCEPTION,MASK) \
     { \
       EXCEPTIONS_SIGJMP_BUF *buf = \
	 exceptions_state_mc_init (uiout, &(EXCEPTION), (MASK)); \
       EXCEPTIONS_SIGSETJMP (*buf); \
     } \
     while (exceptions_state_mc_action_iter ()) \
       while (exceptions_state_mc_action_iter_1 ())

/* *INDENT-ON* */


/* 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
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	};
2a78bfb5 AC	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,
05ff989b AC	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