"Should the debugger display beginner-oriented help messages?")
(defun debug-prompt (stream)
+ (sb!thread::get-foreground)
(format stream
"~%~W~:[~;[~W~]] "
(sb!di:frame-number *current-frame*)
STEP [n] Step to the next location or step n times.
Function and macro commands:
- (SB-DEBUG:DEBUG-RETURN expression)
- Exit the debugger, returning expression's values from the current frame.
(SB-DEBUG:ARG n)
Return the n'th argument in the current frame.
(SB-DEBUG:VAR string-or-symbol [id])
Returns the value of the specified variable in the current frame.
Other commands:
- SLURP Discard all pending input on *STANDARD-INPUT*. (This can be
- useful when the debugger was invoked to handle an error in
- deeply nested input syntax, and now the reader is confused.)")
+ RETURN expr
+ [EXPERIMENTAL] Return the values resulting from evaluation of expr
+ from the current frame, if this frame was compiled with a sufficiently
+ high DEBUG optimization quality.
+ SLURP
+ Discard all pending input on *STANDARD-INPUT*. (This can be
+ useful when the debugger was invoked to handle an error in
+ deeply nested input syntax, and now the reader is confused.)")
\f
;;; This is used to communicate to DEBUG-LOOP that we are at a step breakpoint.
(define-condition step-condition (simple-condition) ())
;;; ANSI specifies that this macro shall exist, even if only as a
;;; trivial placeholder like this.
(defmacro step (form)
- "a trivial placeholder implementation of the CL:STEP macro required by
- the ANSI spec"
- `(progn
+ "This is a trivial placeholder implementation of the CL:STEP macro required
+ by the ANSI spec, simply expanding to `(LET () ,FORM). A more featureful
+ version would be welcome, we just haven't written it."
+ `(let ()
,form))
\f
;;;; BACKTRACE
(defvar *debug-condition*)
(defvar *nested-debug-condition*)
-(defun invoke-debugger (condition)
+;;; the ordinary ANSI case of INVOKE-DEBUGGER, when not suppressed by
+;;; command-line --disable-debugger option
+(defun invoke-debugger/enabled (condition)
#!+sb-doc
"Enter the debugger."
(let ((old-hook *debugger-hook*))
(let ((*debugger-hook* nil))
(funcall old-hook condition old-hook))))
+ ;; If we're a background thread and *background-threads-wait-for-debugger*
+ ;; is NIL, this will invoke a restart
+
;; Note: CMU CL had (SB-UNIX:UNIX-SIGSETMASK 0) here. I deleted it
;; around sbcl-0.7.8.5 (by which time it had mutated to have a
;; #!-SUNOS prefix and a FIXME note observing that it wasn't needed
(*readtable* *debug-readtable*)
(*print-readably* nil)
(*package* original-package)
+ (background-p nil)
(*print-pretty* original-print-pretty))
;; Before we start our own output, finish any pending output.
;; regardless of what the debugger does afterwards.)
(handler-case
(format *error-output*
- "~2&~@<debugger invoked on condition of type ~S: ~
+ "~2&~@<debugger invoked on condition of type ~S in thread ~A: ~
~2I~_~A~:>~%"
(type-of *debug-condition*)
+ (sb!thread:current-thread-id)
*debug-condition*)
(error (condition)
(setf *nested-debug-condition* condition)
;; older debugger code which was written to do i/o on whatever
;; stream was in fashion at the time, and not all of it has
;; been converted to behave this way. -- WHN 2000-11-16)
+
+ (setf background-p
+ (sb!thread::debugger-wait-until-foreground-thread *debug-io*))
+ (unwind-protect
(let (;; FIXME: Rebinding *STANDARD-OUTPUT* here seems wrong,
;; violating the principle of least surprise, and making
;; it impossible for the user to do reasonable things
'*debug-condition*
'*debug-beginner-help-p*))
(show-restarts *debug-restarts* *debug-io*))
- (internal-debug))))))
+ (internal-debug))
+ (when background-p (sb!thread::release-foreground)))))))
+
+;;; the degenerate case of INVOKE-DEBUGGER, when ordinary ANSI behavior
+;;; has been suppressed by command-line --disable-debugger option
+(defun invoke-debugger/disabled (condition)
+ ;; There is no one there to interact with, so report the
+ ;; condition and terminate the program.
+ (flet ((failure-quit (&key recklessly-p)
+ (/show0 "in FAILURE-QUIT (in --disable-debugger debugger hook)")
+ (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. Similarly, we
+ ;; can terminate cleanly even if BACKTRACE dies because of bugs in
+ ;; user PRINT-OBJECT methods.
+ (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 (e.g. a bug in
+ ;; the debugger's own frame-walking code, or a bug in a user
+ ;; PRINT-OBJECT method) 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 --disable-debugger 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 --disable-debugger error handling"))
+ (failure-quit :recklessly-p t)))))
+
+;;; halt-on-failures and prompt-on-failures modes, suitable for
+;;; noninteractive and interactive use respectively
+(defun disable-debugger ()
+ (setf (fdefinition 'invoke-debugger) #'invoke-debugger/disabled
+ *debug-io* *error-output*))
+(defun enable-debugger ()
+ (setf (fdefinition 'invoke-debugger) #'invoke-debugger/enabled
+ *debug-io* *query-io*))
+;;; The enabled mode is the ANSI default.
+(enable-debugger)
(defun show-restarts (restarts s)
(cond ((null restarts)
"~&(no restarts: If you didn't do this on purpose, ~
please report it as a bug.)~%"))
(t
- (format s "~&restarts:~%")
+ (format s "~&restarts (invokable by number or by ~
+ possibly-abbreviated name):~%")
(let ((count 0)
(names-used '(nil))
(max-name-len 0))
(*read-suppress* nil))
(unless (typep *debug-condition* 'step-condition)
(clear-input *debug-io*))
- #!-mp (debug-loop)
- #!+mp (sb!mp:without-scheduling (debug-loop))))
+ (funcall *debug-loop-fun*)))
\f
;;;; DEBUG-LOOP
"When set, avoid calling INVOKE-DEBUGGER recursively when errors occur while
executing in the debugger.")
-(defun debug-loop ()
+(defun debug-loop-fun ()
(let* ((*debug-command-level* (1+ *debug-command-level*))
(*real-stack-top* (sb!di:top-frame))
(*stack-top* (or *stack-top-hint* *real-stack-top*))
level)
(debug-prompt *debug-io*)
(force-output *debug-io*)
- (let ((input (sb!int:get-stream-command *debug-io*)))
- (cond (input
- (let ((cmd-fun (debug-command-p
- (sb!int:stream-command-name input)
- restart-commands)))
- (cond
- ((not cmd-fun)
- (error "unknown stream-command: ~S" input))
- ((consp cmd-fun)
- (error "ambiguous debugger command: ~S" cmd-fun))
- (t
- (apply cmd-fun
- (sb!int:stream-command-args input))))))
+ (let* ((exp (read *debug-io*))
+ (cmd-fun (debug-command-p exp restart-commands)))
+ (cond ((not cmd-fun)
+ (debug-eval-print exp))
+ ((consp cmd-fun)
+ (format t "~&Your command, ~S, is ambiguous:~%"
+ exp)
+ (dolist (ele cmd-fun)
+ (format t " ~A~%" ele)))
(t
- (let* ((exp (read *debug-io*))
- (cmd-fun (debug-command-p exp
- restart-commands)))
- (cond ((not cmd-fun)
- (debug-eval-print exp))
- ((consp cmd-fun)
- (format t
- "~&Your command, ~S, is ambiguous:~%"
- exp)
- (dolist (ele cmd-fun)
- (format t " ~A~%" ele)))
- (t
- (funcall cmd-fun)))))))))))))))
+ (funcall cmd-fun))))))))))))
+
+(defvar *debug-loop-fun* #'debug-loop-fun
+ "a function taking no parameters that starts the low-level debug loop")
;;; FIXME: We could probably use INTERACTIVE-EVAL for much of this logic.
(defun debug-eval-print (expr)
(!def-debug-command "SLURP" ()
(loop while (read-char-no-hang *standard-input*)))
+
+(!def-debug-command "RETURN" (&optional
+ (return (read-prompting-maybe
+ "return: ")))
+ (let ((tag (find-if (lambda (x)
+ (and (typep (car x) 'symbol)
+ (not (symbol-package (car x)))
+ (string= (car x) "SB-DEBUG-CATCH-TAG")))
+ (sb!di::frame-catches *current-frame*))))
+ (if tag
+ (throw (car tag)
+ (funcall (sb!di:preprocess-for-eval
+ return
+ (sb!di:frame-code-location *current-frame*))
+ *current-frame*))
+ (format t "~@<can't find a tag for this frame ~
+ ~2I~_(hint: try increasing the DEBUG optimization quality ~
+ and recompiling)~:@>"))))
\f
;;;; debug loop command utilities