;;;; files for more information.
(in-package "SB!IMPL")
-
-(file-comment
- "$Header$")
\f
(defconstant most-positive-fixnum #.sb!vm:*target-most-positive-fixnum*
#!+sb-doc
- "The fixnum closest in value to positive infinity.")
+ "the fixnum closest in value to positive infinity")
(defconstant most-negative-fixnum #.sb!vm:*target-most-negative-fixnum*
#!+sb-doc
- "The fixnum closest in value to negative infinity.")
+ "the fixnum closest in value to negative infinity")
\f
;;;; magic specials initialized by genesis
+;;; FIXME: The DEFVAR here is redundant with the (DECLAIM (SPECIAL ..))
+;;; of all static symbols in early-impl.lisp.
#!-gengc
(progn
(defvar *current-catch-block*)
(declaim
#!-gengc
(special *gc-inhibit* *already-maybe-gcing*
- *need-to-collect-garbage* *gc-verbose*
+ *need-to-collect-garbage*
*gc-notify-stream*
*before-gc-hooks* *after-gc-hooks*
#!+x86 *pseudo-atomic-atomic*
sb!unix::*interrupt-pending*
*type-system-initialized*)
#!+gengc
- (special *gc-verbose* *before-gc-hooks* *after-gc-hooks*
+ (special *before-gc-hooks* *after-gc-hooks*
*gc-notify-stream*
*type-system-initialized*))
(defvar *maximum-error-depth*)
(defvar *current-error-depth*)
\f
+;;;; miscellaneous utilities for working with with TOPLEVEL
+
+;;; Execute BODY in a context where any %END-OF-THE-WORLD (thrown e.g.
+;;; by QUIT) is caught and any final processing and return codes are
+;;; handled appropriately.
+(defmacro handling-end-of-the-world (&body body)
+ (let ((caught (gensym "CAUGHT")))
+ `(let ((,caught (catch '%end-of-the-world
+ (/show0 "inside CATCH '%END-OF-THE-WORLD")
+ ,@body)))
+ (/show0 "back from CATCH '%END-OF-THE-WORLD, flushing output")
+ (flush-standard-output-streams)
+ (/show0 "calling UNIX-EXIT")
+ (sb!unix:unix-exit ,caught))))
+\f
;;;; working with *CURRENT-ERROR-DEPTH* and *MAXIMUM-ERROR-DEPTH*
;;; INFINITE-ERROR-PROTECT is used by ERROR and friends to keep us out of
(* (floor initial-offset sb!vm:word-bytes) sb!vm:word-bytes)
0))))
\f
-;;;; the default TOPLEVEL function
+;;;; the default toplevel function
+
+;;; FIXME: Most stuff below here can probably be byte-compiled.
(defvar / nil
#!+sb-doc
#!+sb-doc
"The top-level prompt string. This also may be a function of no arguments
that returns a simple-string.")
-(defvar *in-top-level-catcher* nil
- #!+sb-doc
- "Are we within the Top-Level-Catcher? This is used by interrupt
- handlers to see whether it is OK to throw.")
(defun interactive-eval (form)
"Evaluate FORM, returning whatever it returns and adjusting ***, **, *,
(values))
;;; the default system top-level function
-(defun toplevel ()
+(defun toplevel-init ()
- (/show0 "entering TOPLEVEL")
+ (/show0 "entering TOPLEVEL-INIT")
- (let ((sysinit nil) ; value of --sysinit option
- (userinit nil) ; value of --userinit option
- (evals nil) ; values of --eval options (in reverse order)
- (noprint nil) ; Has a --noprint option been seen?
- (noprogrammer nil) ; Has a --noprogammer option been seen?
+ (let ((sysinit nil) ; value of --sysinit option
+ (userinit nil) ; value of --userinit option
+ (reversed-evals nil) ; values of --eval options, in reverse order
+ (noprint nil) ; Has a --noprint option been seen?
+ (noprogrammer nil) ; Has a --noprogammer option been seen?
(options (rest *posix-argv*))) ; skipping program name
- (/show0 "done with outer LET in TOPLEVEL")
+ (/show0 "done with outer LET in TOPLEVEL-INIT")
- ;; FIXME: There are lots of ways for errors to happen around here (e.g. bad
- ;; command line syntax, or READ-ERROR while trying to READ an --eval
- ;; string). Make sure that they're handled reasonably.
-
+ ;; FIXME: There are lots of ways for errors to happen around here
+ ;; (e.g. bad command line syntax, or READ-ERROR while trying to
+ ;; READ an --eval string). Make sure that they're handled
+ ;; reasonably. Also, perhaps all errors while parsing the command
+ ;; line should cause the system to QUIT, instead of trying to go
+ ;; into the Lisp debugger.
+
;; Parse command line options.
(loop while options do
- (/show0 "at head of LOOP WHILE OPTIONS DO in TOPLEVEL")
+ (/show0 "at head of LOOP WHILE OPTIONS DO in TOPLEVEL-INIT")
(let ((option (first options)))
(flet ((pop-option ()
(if options
(error "more than one expression in ~S"
eval-as-string))
(t
- (push eval evals)))))))
+ (push eval reversed-evals)))))))
((string= option "--noprint")
(pop-option)
(setf noprint t))
;; because we didn't recognize an option as a
;; toplevel option, then the option we gave up on
;; must have been an error. (E.g. in
- ;; sbcl --eval '(a)' --evl '(b)' --end-toplevel-options
- ;; this test will let us detect that "--evl" is
- ;; an error.)
+ ;; "sbcl --eval '(a)' --eval'(b)' --end-toplevel-options"
+ ;; this test will let us detect that the string
+ ;; "--eval(b)" is an error.)
(if (find "--end-toplevel-options" options
:test #'string=)
(error "bad toplevel option: ~S" (first options))
(return)))))))
- (/show0 "done with LOOP WHILE OPTIONS DO in TOPLEVEL")
+ (/show0 "done with LOOP WHILE OPTIONS DO in TOPLEVEL-INIT")
- ;; Excise all the options that we processed, so that only user-level
- ;; options are left visible to user code.
+ ;; Excise all the options that we processed, so that only
+ ;; user-level options are left visible to user code.
(setf (rest *posix-argv*) options)
+ ;; Handle --noprogrammer option. We intentionally do this
+ ;; early so that it will affect the handling of initialization
+ ;; files and --eval options.
+ (/show0 "handling --noprogrammer option in TOPLEVEL-INIT")
+ (when noprogrammer
+ (setf *debugger-hook* 'noprogrammer-debugger-hook-fun
+ *debug-io* *error-output*))
+
;; FIXME: Verify that errors in init files and/or --eval operations
;; lead to reasonable behavior.
;; Handle initialization files.
- (/show0 "handling initialization files in TOPLEVEL")
+ (/show0 "handling initialization files in TOPLEVEL-INIT")
(flet (;; If any of POSSIBLE-INIT-FILE-NAMES names a real file,
;; return its truename.
(probe-init-files (&rest possible-init-file-names)
possible-init-file-names)
(/show0 "leaving PROBE-INIT-FILES"))))
(let* ((sbcl-home (posix-getenv "SBCL_HOME"))
- #!+sb-show(ignore1 (progn
- (/show0 "SBCL-HOME=..")
- (if sbcl-home
- (%primitive print sbcl-home)
- (%primitive print "NIL"))))
(sysinit-truename (if sbcl-home
(probe-init-files sysinit
(concatenate
(user-home (or (posix-getenv "HOME")
(error "The HOME environment variable is unbound, ~
so user init file can't be found.")))
- #!+sb-show(ignore2 (progn
- (/show0 "USER-HOME=..")
- (%primitive print user-home)))
(userinit-truename (probe-init-files userinit
(concatenate
'string
user-home
"/.sbclrc"))))
(/show0 "assigned SYSINIT-TRUENAME and USERINIT-TRUENAME")
- (when sysinit-truename
- (/show0 "SYSINIT-TRUENAME=..")
- #!+sb-show (%primitive print sysinit-truename)
- (unless (load sysinit-truename)
- (error "~S was not successfully loaded." sysinit-truename))
- (flush-standard-output-streams))
- (/show0 "loaded SYSINIT-TRUENAME")
- (when userinit-truename
- (/show0 "USERINIT-TRUENAME=..")
- #!+sb-show (%primitive print userinit-truename)
- (unless (load userinit-truename)
- (error "~S was not successfully loaded." userinit-truename))
- (flush-standard-output-streams))
- (/show0 "loaded USERINIT-TRUENAME")))
-
- ;; Handle --eval options.
- (/show0 "handling --eval options in TOPLEVEL")
- (dolist (eval (reverse evals))
- (/show0 "handling one --eval option in TOPLEVEL")
- (eval eval)
- (flush-standard-output-streams))
-
- ;; Handle stream binding controlled by --noprogrammer option.
- ;;
- ;; FIXME: When we do actually implement this, shouldn't it go
- ;; earlier in the sequence, so that its stream bindings will
- ;; affect the behavior of init files and --eval options?
- (/show0 "handling --noprogrammer option in TOPLEVEL")
- (when noprogrammer
- (warn "stub: --noprogrammer option unimplemented")) ; FIXME
- (/show0 "falling into TOPLEVEL-REPL from TOPLEVEL")
- (toplevel-repl noprint)))
+
+ ;; We wrap all the pre-REPL user/system customized startup code
+ ;; in a restart.
+ ;;
+ ;; (Why not wrap everything, even the stuff above, in this
+ ;; restart? Errors above here are basically command line or
+ ;; Unix environment errors, e.g. a missing file or a typo on
+ ;; the Unix command line, and you don't need to get into Lisp
+ ;; to debug them, you should just start over and do it right
+ ;; at the Unix level. Errors below here are usually errors in
+ ;; user Lisp code, and it might be helpful to let the user
+ ;; reach the REPL in order to help figure out what's going on.)
+ (restart-case
+ (flet ((process-init-file (truename)
+ (when truename
+ (unless (load truename)
+ (error "~S was not successfully loaded." truename))
+ (flush-standard-output-streams))))
+ (process-init-file sysinit-truename)
+ (process-init-file userinit-truename)
+
+ ;; Process --eval options.
+ (/show0 "handling --eval options in TOPLEVEL-INIT")
+ (dolist (eval (reverse reversed-evals))
+ (/show0 "handling one --eval option in TOPLEVEL-INIT")
+ (eval eval)
+ (flush-standard-output-streams)))
+ (continue ()
+ :report "Continue anyway (skipping to toplevel read/eval/print loop)."
+ (values)) ; (no-op, just fall through)
+ (quit ()
+ :report "Quit SBCL (calling #'QUIT, killing the process)."
+ (quit))))
+
+ ;; one more time for good measure, in case we fell out of the
+ ;; RESTART-CASE above before one of the flushes in the ordinary
+ ;; flow of control had a chance to operate
+ (flush-standard-output-streams)
+
+ (/show0 "falling into TOPLEVEL-REPL from TOPLEVEL-INIT")
+ (toplevel-repl noprint))))
;;; read-eval-print loop for the default system toplevel
(defun toplevel-repl (noprint)
(/// nil) (// nil) (/ nil)
(eof-marker (cons :eof nil)))
(loop
- ;; FIXME: This seems to be the source of one of the basic debugger
- ;; choices in
- ;; Restarts:
- ;; 0: [CONTINUE] Return from BREAK.
- ;; 1: [ABORT ] Return to toplevel.
- ;; (The "Return from BREAK" choice is defined in BREAK.) I'd like to add
- ;; another choice,
- ;; 2: [TERMINATE] Terminate the current Lisp.
- ;; That way, a user hitting ^C could get out of Lisp without knowing
- ;; enough about the system to run (SB-EXT:QUIT).
- ;;
- ;; If I understand the documentation of WITH-SIMPLE-RESTART correctly,
- ;; it shows how to replace this WITH-SIMPLE-RESTART with a RESTART-CASE
- ;; with two choices (ABORT and QUIT). Or perhaps ABORT should be renamed
- ;; TOPLEVEL?
- ;; Restarts:
- ;; 0: [CONTINUE ] Return from BREAK, continuing calculation
- ;; as though nothing happened.
- ;; 1: [TOPLEVEL ] Transfer control to toplevel read/eval/print
- ;; loop, aborting current calculation.
- ;; 2: [TERMINATE] Terminate the current Lisp (equivalent to
- ;; executing (SB-EXT:QUIT)).
(/show0 "at head of outer LOOP in TOPLEVEL-REPL")
- (with-simple-restart (abort "Return to toplevel.")
- (catch 'top-level-catcher
- (sb!unix:unix-sigsetmask 0) ; FIXME: What is this for?
- (let ((*in-top-level-catcher* t))
- (/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)))))))))))))
+ ;; 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)))))
\f
;;; a convenient way to get into the assembly-level debugger
(defun %halt ()