;
; seh.sh
;
; Structured Exception Handling, the Sapphire way
;
; © 1995-1998 Straylight
;

;----- Licensing note -------------------------------------------------------
;
; This file is part of Straylight's Sapphire library.
;
; Sapphire 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, or (at your option)
; any later version.
;
; Sapphire 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 Sapphire.  If not, write to the Free Software Foundation,
; 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

;----- Overview -------------------------------------------------------------
;
; Functions provided:
;
;  seh_try
;  seh_unTry
;  seh_throw
;  seh_throwErrors
;  seh_setListBase
;  seh_init

		[	:LNOT::DEF:seh__dfn
		GBLL	seh__dfn

; --- seh_try ---
;
; On entry:	R0 == pointer to catch definition block
;
; On exit:	R13 dropped by a (small) amount
;
; Use:		Inserts an exception handler at the current position.
;		Exceptions are matched against those described in the catch
;		block.  If there is a handler for the exception, the
;		corresponding handler is called, and expected to resume
;		normally.  Otherwise the tidy-up routine is called and we
;		unwind the stack further to find an appropriate handler.
;
;		The catch block has the following format:
;
;		word	B to tidy-up routine
;		word	1st exception mask
;		word	1st B to catch routine
;		word	2nd exception mask
;		word	2nd B to catch routine
;		...
;		word	0
;
;		An exception mask contains two halfwords.  Bits 16-31 are the
;		class to match, or -1 for all classes.  Bits 0-15 are the
;		subtype to match, or -1 for all subtypes.  You can do really
;		odd things if you set bits 16-31 to -1 and leave 0-15
;		matching specific subtypes -- do this at your own risk.

		IMPORT	seh_try

; --- seh_unTry ---
;
; On entry:	--
;
; On exit:	R13 moved to position before corresponding seh_try
;
; Use:		Removes the try block marker in the stack at the current
;		position.  Note that the stack will be unwound to where it
;		was when seh_try was called.

		IMPORT	seh_unTry

; --- seh_throw ---
;
; On entry:	R0 == exception to match
;		R1-R3 == useful bits of information
;
; On exit:	Doesn't return, unless you've done something /really/ odd
;
; Use:		Throws an exception.  The stack is unwound until we find
;		a handler which can cope.  If there is no handler, we abort
;		the program.

		IMPORT	seh_throw

; --- seh_throwErrors ---
;
; On entry:	--
;
; On exit:	--
;
; Use:		Sets up an except-style error handler to throw errors
;		as SEH exceptions.

		IMPORT	seh_throwErrors

; --- seh_setListBase ---
;
; On entry:	R0 == pointer to try block list base, or 0 to use global
;
; On exit:	--
;
; Use:		Sets the try block list base.  This should only be used by
;		coroutine providers, like coRoutine and thread.

		IMPORT	seh_setListBase

; --- seh_init ---
;
; On entry:	--
;
; On exit:	--
;
; Use:		Initialises SEH's facilities.

		IMPORT	seh_init

		]

;----- That's all, folks ----------------------------------------------------

		END