- (- nil)
- (+ nil) (++ nil) (+++ nil)
- (/// nil) (// nil) (/ nil)
- (eof-marker (cons :eof nil)))
- (loop
- (/show0 "at head of outer LOOP in TOPLEVEL-REPL")
- ;; There should only be one TOPLEVEL restart, and it's here, so
- ;; restarting at TOPLEVEL always bounces you all the way out here.
- (with-simple-restart (toplevel
- "Restart at toplevel READ/EVAL/PRINT loop.")
- ;; We add a new ABORT restart for every debugger level, so
- ;; restarting at ABORT in a nested debugger gets you out to the
- ;; innermost enclosing debugger, and only when you're in the
- ;; outermost, unnested debugger level does restarting at ABORT
- ;; get you out to here.
- (with-simple-restart (abort
- "Reduce debugger level (leaving debugger).")
- (catch 'top-level-catcher
- (sb!unix:unix-sigsetmask 0) ; FIXME: What is this for?
- (/show0 "about to enter inner LOOP in TOPLEVEL-REPL")
- (loop ; FIXME: Do we need this inner LOOP?
- ;; FIXME: It seems bad to have GC behavior depend on scrubbing
- ;; the control stack before each interactive command. Isn't
- ;; there some way we can convince the GC to just ignore
- ;; dead areas of the control stack, so that we don't need to
- ;; rely on this half-measure?
- (scrub-control-stack)
- (unless noprint
- (fresh-line)
- (princ (if (functionp *prompt*)
- (funcall *prompt*)
- *prompt*))
- (flush-standard-output-streams))
- (let ((form (read *standard-input* nil eof-marker)))
- (if (eq form eof-marker)
- (quit)
- (let ((results
- (multiple-value-list (interactive-eval form))))
- (unless noprint
- (dolist (result results)
- (fresh-line)
- (prin1 result)))))))))))))
-
-(defun noprogrammer-debugger-hook-fun (condition old-debugger-hook)
- (declare (ignore old-debugger-hook))
- (flet ((failure-quit (&key recklessly-p)
- (quit :unix-status 1 :recklessly-p recklessly-p)))
- ;; This HANDLER-CASE is here mostly to stop output immediately
- ;; (and fall through to QUIT) when there's an I/O error. Thus,
- ;; when we're run under a shell script or something, we can die
- ;; cleanly when the script dies (and our pipes are cut), instead
- ;; of falling into ldb or something messy like that.
- (handler-case
- (progn
- (format *error-output*
- "~@<unhandled condition (of type ~S): ~2I~_~A~:>~2%"
- (type-of condition)
- condition)
- ;; Flush *ERROR-OUTPUT* even before the BACKTRACE, so that
- ;; even if we hit an error within BACKTRACE we'll at least
- ;; have the CONDITION printed out before we die.
- (finish-output *error-output*)
- ;; (Where to truncate the BACKTRACE is of course arbitrary, but
- ;; it seems as though we should at least truncate it somewhere.)
- (sb!debug:backtrace 128 *error-output*)
- (format *error-output*
- "~%unhandled condition in --noprogrammer mode, quitting~%")
- (finish-output *error-output*)
- (failure-quit))
- (condition ()
- ;; We IGNORE-ERRORS here because even %PRIMITIVE PRINT can
- ;; fail when our output streams are blown away, as e.g. when
- ;; we're running under a Unix shell script and it dies somehow
- ;; (e.g. because of a SIGINT). In that case, we might as well
- ;; just give it up for a bad job, and stop trying to notify
- ;; the user of anything.
- ;;
- ;; Actually, the only way I've run across to exercise the
- ;; problem is to have more than one layer of shell script.
- ;; I have a shell script which does
- ;; time nice -10 sh make.sh "$1" 2>&1 | tee make.tmp
- ;; and the problem occurs when I interrupt this with Ctrl-C
- ;; under Linux 2.2.14-5.0 and GNU bash, version 1.14.7(1).
- ;; I haven't figured out whether it's bash, time, tee, Linux, or
- ;; what that is responsible, but that it's possible at all
- ;; means that we should IGNORE-ERRORS here. -- WHN 2001-04-24
- (ignore-errors
- (%primitive print "Argh! error within --noprogrammer error handling"))
- (failure-quit :recklessly-p t)))))
+ (- nil)
+ (+ nil) (++ nil) (+++ nil)
+ (/// nil) (// nil) (/ nil))
+ (/show0 "about to funcall *REPL-FUN-GENERATOR*")
+ (let ((repl-fun (funcall *repl-fun-generator*)))
+ ;; Each REPL in a multithreaded world should have bindings of
+ ;; most CL specials (most critically *PACKAGE*).
+ (with-rebound-io-syntax
+ (handler-bind ((step-condition 'invoke-stepper))
+ (loop
+ (/show0 "about to set up restarts in TOPLEVEL-REPL")
+ ;; CLHS recommends that there should always be an
+ ;; ABORT restart; we have this one here, and one per
+ ;; debugger level.
+ (with-simple-restart
+ (abort "~@<Exit debugger, returning to top level.~@:>")
+ (catch 'toplevel-catcher
+ ;; In the event of a control-stack-exhausted-error, we
+ ;; should have unwound enough stack by the time we get
+ ;; here that this is now possible.
+ #!-win32
+ (sb!kernel::protect-control-stack-guard-page 1)
+ (funcall repl-fun noprint)
+ (critically-unreachable "after REPL")))))))))
+
+;;; Our default REPL prompt is the minimal traditional one.
+(defun repl-prompt-fun (stream)
+ (fresh-line stream)
+ (write-string "* " stream)) ; arbitrary but customary REPL prompt
+
+;;; Our default form reader does relatively little magic, but does
+;;; handle the Unix-style EOF-is-end-of-process convention.
+(defun repl-read-form-fun (in out)
+ (declare (type stream in out) (ignore out))
+ ;; KLUDGE: *READ-SUPPRESS* makes the REPL useless, and cannot be
+ ;; recovered from -- flip it here.
+ (when *read-suppress*
+ (warn "Setting *READ-SUPPRESS* to NIL to restore toplevel usability.")
+ (setf *read-suppress* nil))
+ (let* ((eof-marker (cons nil nil))
+ (form (read in nil eof-marker)))
+ (if (eq form eof-marker)
+ (quit)
+ form)))
+
+(defun repl-fun (noprint)
+ (/show0 "entering REPL")
+ (loop
+ (unwind-protect
+ (progn
+ ;; (See comment preceding the definition of SCRUB-CONTROL-STACK.)
+ (scrub-control-stack)
+ (sb!thread::get-foreground)
+ (unless noprint
+ (flush-standard-output-streams)
+ (funcall *repl-prompt-fun* *standard-output*)
+ ;; (Should *REPL-PROMPT-FUN* be responsible for doing its own
+ ;; FORCE-OUTPUT? I can't imagine a valid reason for it not to
+ ;; be done here, so leaving it up to *REPL-PROMPT-FUN* seems
+ ;; odd. But maybe there *is* a valid reason in some
+ ;; circumstances? perhaps some deadlock issue when being driven
+ ;; by another process or something...)
+ (force-output *standard-output*))
+ (let* ((form (funcall *repl-read-form-fun*
+ *standard-input*
+ *standard-output*))
+ (results (multiple-value-list (interactive-eval form))))
+ (unless noprint
+ (dolist (result results)
+ (fresh-line)
+ (prin1 result)))))
+ ;; If we started stepping in the debugger we want to stop now.
+ (disable-stepping))))