1 ;;;; that part of the condition system which can or should come early
2 ;;;; (mostly macro-related)
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
13 (in-package "SB!KERNEL")
15 (defun muffle-warning-p (warning)
16 (declare (special *muffled-warnings
*))
17 (typep warning
*muffled-warnings
*))
19 ;; Host lisp does not need a value for this, so start it out as NIL.
20 (defglobal **initial-handler-clusters
** nil
)
21 (setq **initial-handler-clusters
**
22 `(((,(lambda (condition)
23 (typep condition
'warning
))
26 (when (muffle-warning-p warning
)
27 (muffle-warning warning
)))))))
29 ;;; Each cluster is an alist of the form
31 ;;; ((TYPE-TEST1 . HANDLER1) (TYPE-TEST2 . HANDLER2) ...)
33 ;;; where TYPE-TESTN are functions of one argument which test a given
34 ;;; condition instance for the type required by the corresponding
35 ;;; HANDLERN. HANDLERN are function designators.
37 ;;; Newly established handlers are added at the beginning of the
38 ;;; list. Elements to the left of the alist take precedence over
39 ;;; elements to the right.
41 ;;; Lists to which *HANDLER-CLUSTERS* is bound generally have dynamic
43 (defvar *handler-clusters
* **initial-handler-clusters
**)
45 ;;; a list of lists of currently active RESTART instances. maintained
47 ;;; This variable is proclaimed to be "eventually" always-bound,
48 ;;; meaning in the loaded code. If DEFVAR were used, the compiler knows that
49 ;;; BOUNDP will be T, and therefore a code deletion note should be issused
50 ;;; for the initialization expression (UNLESS (BOUNDP x) <initform>).
51 ;;; Technically it's not even right to use DEFVAR because it works only
52 ;;; if the initializer is really NIL, since that is what %DEFVAR will assign
53 ;;; on account of the fact that an initializer was supplied at all.
54 (defparameter *restart-clusters
* '())
56 (def!method print-object
((restart restart
) stream
)
58 (print-unreadable-object (restart stream
:type t
:identity t
)
59 (prin1 (restart-name restart
) stream
))
60 (restart-report restart stream
)))
63 (setf (fdocumentation 'restart-name
'function
)
64 "Return the name of the given restart object.")
66 (defun restart-report (restart stream
)
67 (if (restart-report-function restart
)
68 (funcall (truly-the function
(restart-report-function restart
))
70 (prin1 (or (restart-name restart
)
74 (defvar *restart-test-stack
* nil
)
76 ;; Call FUNCTION with all restarts in the current dynamic environment,
77 ;; 1) that are associated to CONDITION (when CONDITION is NIL, all
78 ;; restarts are processed)
79 ;; 2) and for which the restart test returns non-NIL for CONDITION.
80 ;; When CALL-TEST-P is non-NIL, all restarts are processed.
81 (defun map-restarts (function &optional condition
(call-test-p t
))
82 (declare (function function
))
83 (let ((stack *restart-test-stack
*))
84 (dolist (restart-cluster *restart-clusters
*)
85 (dolist (restart restart-cluster
)
86 (when (and (or (not condition
)
87 (null (restart-associated-conditions restart
))
88 (memq condition
(restart-associated-conditions restart
)))
89 ;; A call to COMPUTE-RESTARTS -- from an error,
90 ;; from user code, whatever -- inside the test
91 ;; function would cause infinite recursion here, so
92 ;; we disable each restart using
93 ;; *restart-test-stack* for the duration of the
95 (not (memq restart stack
))
97 (let ((*restart-test-stack
* (cons restart stack
)))
98 (declare (truly-dynamic-extent *restart-test-stack
*))
99 (funcall (restart-test-function restart
) condition
))))
100 (funcall function restart
))))))
102 (defun compute-restarts (&optional condition
)
104 "Return a list of all the currently active restarts ordered from most recently
105 established to less recently established. If CONDITION is specified, then only
106 restarts associated with CONDITION (or with no condition) will be returned."
108 (map-restarts (lambda (restart) (result restart
)) condition
)
111 (defun %find-restart
(identifier condition
&optional
(call-test-p t
))
112 (flet ((eq-restart-p (restart)
113 (when (eq identifier restart
)
114 (return-from %find-restart restart
)))
115 (named-restart-p (restart)
116 (when (eq identifier
(restart-name restart
))
117 (return-from %find-restart restart
))))
118 ;; KLUDGE: can the compiler infer this dx automatically?
119 (declare (truly-dynamic-extent #'eq-restart-p
#'named-restart-p
))
120 (if (typep identifier
'restart
)
121 ;; The code under #+previous-... below breaks the abstraction
122 ;; introduced by MAP-RESTARTS, but is about twice as
123 ;; fast as #+equivalent-... . Also, it is a common case due to
125 ;; (INVOKE-RESTART RESTART)
126 ;; -> (FIND-RESTART-OR-CONTROL-ERROR RESTART)
127 ;; -> (FIND-RESTART RESTART)
129 ;; However, both #+previous-... and #+equivalent-... may be
130 ;; wrong altogether because of
131 ;; https://bugs.launchpad.net/sbcl/+bug/774410:
132 ;; The behavior expected in that report can be achieved by the
133 ;; following line (which is, of course, the slowest of all
135 (map-restarts #'eq-restart-p condition call-test-p
)
137 #+equivalent-to-previous-sbcl-behavior--faster-but-see-bug-774410
138 (map-restarts #'eq-restart-p nil nil
)
140 #+previous-behavior--fastest-but-see-bug-774410
141 (and (find-if (lambda (cluster) (find identifier cluster
)) *restart-clusters
*)
144 (map-restarts #'named-restart-p condition call-test-p
))))
146 (defun find-restart (identifier &optional condition
)
148 "Return the first restart identified by IDENTIFIER. If IDENTIFIER is a symbol,
149 then the innermost applicable restart with that name is returned. If IDENTIFIER
150 is a restart, it is returned if it is currently active. Otherwise NIL is
151 returned. If CONDITION is specified and not NIL, then only restarts associated
152 with that condition (or with no condition) will be returned."
153 ;; Calls MAP-RESTARTS such that restart test functions are
155 (%find-restart identifier condition
))
157 ;;; helper for the various functions which are ANSI-spec'ed to do
158 ;;; something with a restart or signal CONTROL-ERROR if there is none
159 (defun find-restart-or-control-error (identifier &optional condition
(call-test-p t
))
160 (or (%find-restart identifier condition call-test-p
)
161 (error 'simple-control-error
162 :format-control
"No restart ~S is active~@[ for ~S~]."
163 :format-arguments
(list identifier condition
))))
165 (defun invoke-restart (restart &rest values
)
167 "Calls the function associated with the given restart, passing any given
168 arguments. If the argument restart is not a restart or a currently active
169 non-nil restart name, then a CONTROL-ERROR is signalled."
170 (/show
"entering INVOKE-RESTART" restart
)
171 ;; The following code calls MAP-RESTARTS (through
172 ;; FIND-RESTART-OR-CONTROL-ERROR -> %FIND-RESTART) such that restart
173 ;; test functions are respected when RESTART is a symbol, but not
174 ;; when RESTART is a RESTART instance.
176 ;; Without disabling test functions for the RESTART instance case,
177 ;; the following problem would arise:
181 ;; ((some-condition (lambda (c)
182 ;; (invoke-restart (find-restart 'foo c)) ; a)
183 ;; (invoke-restart 'foo) ; b)
185 ;; (signal 'some-condition))
187 ;; :test (lambda (c) (typep c 'some-condition))))
189 ;; In case a), INVOKE-RESTART receives the RESTART instance, but
190 ;; cannot supply the condition instance needed by the test. In case
191 ;; b) INVOKE-RESTART calls FIND-RESTART, but again cannot supply the
192 ;; condition instance. As a result, the restart would be impossible
194 (let ((real-restart (find-restart-or-control-error
195 restart nil
(symbolp restart
))))
196 (apply (restart-function real-restart
) values
)))
198 (defun interactive-restart-arguments (real-restart)
199 (let ((interactive-function (restart-interactive-function real-restart
)))
200 (if interactive-function
201 (funcall interactive-function
)
204 (defun invoke-restart-interactively (restart)
206 "Calls the function associated with the given restart, prompting for any
207 necessary arguments. If the argument restart is not a restart or a
208 currently active non-NIL restart name, then a CONTROL-ERROR is signalled."
209 ;; For an explanation of the call to FIND-RESTART-OR-CONTROL-ERROR,
210 ;; see comment in INVOKE-RESTART.
211 (let* ((real-restart (find-restart-or-control-error
212 restart nil
(symbolp restart
)))
213 (args (interactive-restart-arguments real-restart
)))
214 (apply (restart-function real-restart
) args
)))
217 (defun assert-error (assertion args-and-values places datum
&rest arguments
)
218 (let ((cond (if datum
220 datum arguments
'simple-error
'error
)
223 :format-control
"~@<The assertion ~S failed~:[.~:; ~
224 with ~:*~{~{~S = ~S~}~^, ~}.~]~:@>"
225 :format-arguments
(list assertion args-and-values
)))))
229 :report
(lambda (stream)
230 (format stream
"Retry assertion")
232 (format stream
" with new value~P for ~{~S~^, ~}."
233 (length places
) places
)
234 (format stream
".")))
237 ;;; READ-EVALUATED-FORM is used as the interactive method for restart cases
238 ;;; setup by the Common Lisp "casing" (e.g., CCASE and CTYPECASE) macros
239 ;;; and by CHECK-TYPE.
240 (defun read-evaluated-form (&optional
(prompt-control nil promptp
)
242 (apply #'format
*query-io
*
243 (if promptp prompt-control
"~&Type a form to be evaluated: ")
245 (finish-output *query-io
*)
246 (list (eval (read *query-io
*))))
248 (defun check-type-error (place place-value type type-string
)
255 "The value of ~S is ~S, which is not ~:[of type ~S~;~:*~A~]."
256 :format-arguments
(list place place-value type-string type
))))
257 (restart-case (error condition
)
259 :report
(lambda (stream)
260 (format stream
"Supply a new value for ~S." place
))
261 :interactive read-evaluated-form
264 (defun case-failure (name value keys
)
268 :expected-type
(if (eq name
'ecase
)
271 :possibilities keys
))
273 (defun case-body-error (name keyform keyform-value expected-type keys
)
278 :expected-type expected-type
281 :report
(lambda (stream)
282 (format stream
"Supply a new value for ~S." keyform
))
283 :interactive read-evaluated-form