X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftoplevel.lisp;h=8c36aad186f8c3aa3880352015ee5c5dce21c851;hb=90ca09b75fbc3b63b2f7d09c67b04b866dd783f6;hp=89b258aa98f7bc9bf31035569a990f64d5c26e9e;hpb=50305b602c3953440af716137a56f50cd204375d;p=sbcl.git diff --git a/src/code/toplevel.lisp b/src/code/toplevel.lisp index 89b258a..8c36aad 100644 --- a/src/code/toplevel.lisp +++ b/src/code/toplevel.lisp @@ -236,20 +236,16 @@ (defvar / nil #!+sb-doc - "a list of all the values returned by the most recent top-level EVAL") + "a list of all the values returned by the most recent top level EVAL") (defvar // nil #!+sb-doc "the previous value of /") (defvar /// nil #!+sb-doc "the previous value of //") -(defvar * nil #!+sb-doc "the value of the most recent top-level EVAL") +(defvar * nil #!+sb-doc "the value of the most recent top level EVAL") (defvar ** nil #!+sb-doc "the previous value of *") (defvar *** nil #!+sb-doc "the previous value of **") -(defvar + nil #!+sb-doc "the value of the most recent top-level READ") +(defvar + nil #!+sb-doc "the value of the most recent top level READ") (defvar ++ nil #!+sb-doc "the previous value of +") (defvar +++ nil #!+sb-doc "the previous value of ++") (defvar - nil #!+sb-doc "the form currently being evaluated") -(defvar *prompt* "* " - #!+sb-doc - "The top-level prompt string. This also may be a function of no arguments - that returns a simple-string.") (defun interactive-eval (form) "Evaluate FORM, returning whatever it returns and adjusting ***, **, *, @@ -285,7 +281,7 @@ (finish-output (symbol-value name))) (values)) -;;; the default system top-level function +;;; the default system top level function (defun toplevel-init () (/show0 "entering TOPLEVEL-INIT") @@ -409,8 +405,6 @@ 'string user-home "/.sbclrc")))) - (/show0 "assigned SYSINIT-TRUENAME and USERINIT-TRUENAME") - ;; We wrap all the pre-REPL user/system customized startup code ;; in a restart. @@ -439,11 +433,14 @@ (eval eval) (flush-standard-output-streams))) (continue () - :report "Continue anyway (skipping to toplevel read/eval/print loop)." - (values)) ; (no-op, just fall through) + :report + "Continue anyway (skipping to toplevel read/eval/print loop)." + (/show0 "CONTINUEing from pre-REPL RESTART-CASE") + (values)) ; (no-op, just fall through) (quit () - :report "Quit SBCL (calling #'QUIT, killing the process)." - (quit)))) + :report "Quit SBCL (calling #'QUIT, killing the process)." + (/show0 "falling through to QUIT from pre-REPL RESTART-CASE") + (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 @@ -451,7 +448,9 @@ (flush-standard-output-streams) (/show0 "falling into TOPLEVEL-REPL from TOPLEVEL-INIT") - (toplevel-repl noprint)))) + (toplevel-repl noprint) + ;; (classic CMU CL error message: "You're certainly a clever child.":-) + (critically-unreachable "after TOPLEVEL-REPL")))) ;;; read-eval-print loop for the default system toplevel (defun toplevel-repl (noprint) @@ -459,50 +458,60 @@ (let ((* nil) (** nil) (*** nil) (- nil) (+ nil) (++ nil) (+++ nil) - (/// nil) (// nil) (/ nil) - (eof-marker (cons :eof nil))) + (/// nil) (// nil) (/ nil)) + ;; WITH-SIMPLE-RESTART doesn't actually restart its body as some + ;; (like WHN for an embarrassingly long time ca. 2001-12-07) might + ;; think, but instead drops control back out at the end. So when a + ;; TOPLEVEL or outermost-ABORT restart happens, we need this outer + ;; LOOP wrapper to grab control and start over again. (And it also + ;; wraps CATCH 'TOPLEVEL-CATCHER for similar reasons.) + (loop + (/show0 "about to set up restarts 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, returning to toplevel).") + (catch 'toplevel-catcher + (sb!unix:unix-sigsetmask 0) ; FIXME: What is this for? + (repl noprint) + (critically-unreachable "after REPL"))))))) + +(defun repl (noprint) + (/show0 "entering REPL") + (let ((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))))))))))))) + ;; 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) + (write-string "* ") ; arbitrary but customary REPL prompt + (flush-standard-output-streams)) + (let ((form (read *standard-input* nil eof-marker))) + (cond ((eq form eof-marker) + (/show0 "doing QUIT for EOF in REPL") + (quit)) + (t + (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) + (/show0 "in FAILURE-QUIT (in noprogrammer 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, @@ -512,12 +521,14 @@ (handler-case (progn (format *error-output* - "~@~2%" + "~&~@~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. + ;; 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.)