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;;;; (ice-9 debugger breakpoints) -- general breakpoints interface
;;; Copyright (C) 2002 Free Software Foundation, Inc.
;;;
;; This library is free software; you can redistribute it and/or
;; modify it under the terms of the GNU Lesser General Public
;; License as published by the Free Software Foundation; either
;; version 2.1 of the License, or (at your option) any later version.
;;
;; This library 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
;; Lesser General Public License for more details.
;;
;; You should have received a copy of the GNU Lesser General Public
;; License along with this library; if not, write to the Free Software
;; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
(define-module (ice-9 debugger breakpoints)
#:use-module (ice-9 debugger behaviour)
#:use-module (ice-9 format)
#:use-module (oop goops)
#:export (;; For <breakpoint> subclass implementations.
<breakpoint>
register-breakpoint-subclass
;; For application use and subclass implementations.
bp-number
bp-enabled?
bp-behaviour
bp-run
bp-message
bp-delete!
bp-describe
break!
trace!
trace-subtree!
set-breakpoint!
get-breakpoint
describe-breakpoint
disable-breakpoint!
enable-breakpoint!
delete-breakpoint!
all-breakpoints
describe-all-breakpoints))
;;; {Breakpoints -- General Properties and Behaviour}
;;; Generics with names beginning `bp-' all take a single breakpoint
;;; argument (i.e. an instance of a subclass of <breakpoint>).
(define-generic bp-number) ; implemented
(define-generic bp-enabled?) ; implemented
(define-generic bp-behaviour) ; implemented
(define-generic bp-run) ; implemented
(define-generic bp-message) ; virtual
(define-generic bp-delete!) ; virtual
(define-generic bp-describe) ; implemented
;;; The following all take arguments that describe (in whatever way
;;; the various subclasses support) a breakpoint location. The
;;; <breakpoint> implementations of `break!' and `trace!' just call
;;; `set-breakpoint!' specifying the `debug-here' and `trace-here'
;;; behaviours respectively.
(define-generic set-breakpoint!) ; semi-virtual
(define-generic get-breakpoint) ; semi-virtual
;;; Common base class for breakpoints.
(define-class <breakpoint> ()
;; Breakpoint number.
(number #:accessor bp-number
#:init-thunk (let ((count 0))
(lambda ()
(set! count (+ count 1))
count)))
;; Whether this breakpoint is currently enabled.
(enabled? #:accessor bp-enabled?
#:init-value #t)
;; Breakpoint behaviour, either a list of behaviour indicators, or a
;; thunk that, when called, returns such a list.
(behaviour #:accessor bp-behaviour
#:init-value '()))
;;; Registration of <breakpoint> subclasses. The only current reason
;;; for this is so that we can provide `all-breakpoints'.
(define subclass-registrations '())
(define (register-breakpoint-subclass class list-thunk)
;; LIST-THUNK should be a thunk that returns a list containing all
;; current breakpoints of the corresponding class.
(set! subclass-registrations
(assq-set! subclass-registrations class list-thunk)))
(define (all-breakpoints)
(sort (apply append
(map (lambda (list-thunk) (list-thunk))
(map cdr subclass-registrations)))
(lambda (bp1 bp2)
(< (bp-number bp1) (bp-number bp2)))))
(define (describe-all-breakpoints)
(for-each (lambda (bp)
(bp-describe bp #t))
(all-breakpoints)))
(define-method (get-breakpoint (number <integer>))
(let loop ((bps (all-breakpoints)))
(if (null? bps)
#f
(let* ((bp (car bps))
(bp-num (bp-number bp)))
(cond ((= bp-num number) bp)
((> bp-num number) #f)
(else (loop (cdr bps))))))))
(define (make-breakpoint-command proc)
(lambda args
(let ((bp (apply get-breakpoint args)))
(if bp
(proc bp)
(display "Breakpoint not found\n")))))
(define describe-breakpoint
(make-breakpoint-command (lambda (bp)
(bp-describe bp #t))))
(define disable-breakpoint!
(make-breakpoint-command (lambda (bp)
(set! (bp-enabled? bp) #f)
(bp-describe bp #t))))
(define enable-breakpoint!
(make-breakpoint-command (lambda (bp)
(set! (bp-enabled? bp) #t)
(bp-describe bp #t))))
(define delete-breakpoint!
(make-breakpoint-command bp-delete!))
(define-method (set-breakpoint! behaviour (number <integer>))
(let ((bp (get-breakpoint number)))
(if bp
(begin
(set! (bp-behaviour bp) behaviour)
(bp-describe bp #t))
(display "No such breakpoint\n"))))
;;; `bp-run' is what trap hook functions should call when they
;;; establish that the program is at a breakpoint location.
(define-method (bp-run (bp <breakpoint>))
;; Only do anything if the breakpoint is enabled.
(add-debug-entry-message (bp-message bp "Hit breakpoint" #f))
(if (bp-enabled? bp)
;; Get behaviour for this breakpoint.
(let ((behaviour (bp-behaviour bp)))
;; Behaviour should be a thunk or a list of thunks.
(cond ((thunk? behaviour)
(behaviour))
((list? behaviour)
(for-each (lambda (thunk) (thunk)) behaviour))
(else
(bp-message bp "Bad behaviour for breakpoint" #t)))
; (if (thunk? behaviour)
; (set! behaviour (behaviour)))
; ;; If not a list, wrap as a list.
; (or (list? behaviour)
; (set! behaviour (list behaviour)))
; ;; If behaviour indicates tracing, do so.
; (if (memq #:trace behaviour)
; (trace-here))
; ;; If behaviour indicates a thunk to be run when we exit the
; ;; current frame, register it.
; (let ((at-exit (memq #:at-exit behaviour)))
; (if (and at-exit (not (null? (cdr at-exit))))
; (set-at-exit (cadr at-exit))))
; ;; If behaviour indicates interactive debugging, set flag that
; ;; will cause us to enter the debugger.
; (if (memq #:debug behaviour)
; (begin
; (bp-message "Hit breakpoint" bp)
; (debug-here)))
)))
;;; `break! ...' is just shorthand for `set-breakpoint! debug-here ...'.
(define (break! . args)
(apply set-breakpoint! debug-here args))
;;; Similarly `trace! ...' and `set-breakpoint! trace-here ...'.
(define (trace! . args)
(apply set-breakpoint! trace-here args))
;;; And so on.
(define (trace-subtree! . args)
(apply set-breakpoint! trace-subtree args))
;;; `bp-describe' is expected to be overridden/extended by subclasses,
;;; but subclass implementations may want to leverage this
;;; implementation by beginning with `(next-method)'.
(define-method (bp-describe (bp <breakpoint>) port)
(bp-message bp "Breakpoint" port)
(format port "\tenabled? = ~S\n" (bp-enabled? bp))
(format port "\tbehaviour = ~S\n" (bp-behaviour bp))
*unspecified*)
;;; (ice-9 debugger breakpoints) ends here.
|
