1 ;;;; most of the DESCRIBE mechanism -- that part which isn't derived
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-IMPL") ;(SB-IMPL, not SB!IMPL, since we're built in warm load.)
15 (declaim #.*optimize-byte-compilation*)
18 (defvar *describe-indentation-step* 3
20 "the number of spaces that sets off each line of a recursive description")
22 (declaim (ftype (function (t stream)) describe-object))
23 (defgeneric describe-object ((x t) stream))
25 (defun describe (x &optional (stream-designator *standard-output*))
27 "Print a description of the object X."
28 (declare #.*optimize-external-despite-byte-compilation*)
29 (let ((stream (out-synonym-of stream-designator)))
30 (pprint-logical-block (stream nil)
32 (describe-object x stream)
36 ;;;; miscellaneous DESCRIBE-OBJECT methods
38 (defmethod describe-object ((x t) s)
39 (format s "~@<~S ~_is a ~S.~:>" x (type-of x)))
41 (defmethod describe-object ((x cons) s)
43 (when (and (legal-function-name-p x)
45 (%describe-function (fdefinition x) s :function x)
46 ;;was: (format s "~@:_Its FDEFINITION is ~S.~@:_" (fdefinition x))
47 ;; TO DO: should check for SETF documentation.
48 ;; TO DO: should make it clear whether the definition is a
49 ;; DEFUN (SETF FOO) or DEFSETF FOO or what.
52 (defmethod describe-object ((x array) s)
53 (let ((rank (array-rank x)))
55 (format s "~S ~_is " x)
56 (write-string (if (%array-displaced-p x) "a displaced" "an") s)
57 (format s " array of rank ~S." rank)
58 (format s "~@:_Its dimensions are ~S." (array-dimensions x)))
61 "~@:_~S is a ~:[~;displaced ~]vector of length ~S." x
62 (and (array-header-p x) (%array-displaced-p x)) (length x))
63 (when (array-has-fill-pointer-p x)
64 (format s "~@:_It has a fill pointer, currently ~S."
66 (let ((array-element-type (array-element-type x)))
67 (unless (eq array-element-type t)
69 "~@:_Its element type is specialized to ~S."
70 array-element-type))))
72 (defmethod describe-object ((x hash-table) s)
73 (declare (type stream s))
74 (format s "~@<~S ~_is an ~S hash table.~:>" x (hash-table-test x))
75 (format s "~_Its SIZE is ~S." (hash-table-size x))
77 "~@:_~@<Its REHASH-SIZE is ~S. ~_Its REHASH-THRESHOLD is ~S.~:>"
78 (hash-table-rehash-size x)
79 (hash-table-rehash-threshold x))
80 (let ((count (hash-table-count x)))
81 (format s "~@:_It holds ~S key/value pair~:P~:[: ~2I~_~;.~]"
84 (declare (type index n))
87 (write-char #\space s))
89 (when (and *print-length* (> n *print-length*))
92 (format s "~:_(~@<~S ~:_~S~:>)" k v)))))
94 (defmethod describe-object ((condition condition) s)
95 (sb-kernel:describe-condition condition s))
97 ;;;; DESCRIBE-OBJECT methods for symbols and functions, including all
98 ;;;; sorts of messy stuff about documentation, type information,
99 ;;;; packaging, function implementation, etc..
101 ;;; Print the specified kind of documentation about the given NAME. If
102 ;;; NAME is null, or not a valid name, then don't print anything.
103 (declaim (ftype (function (t stream t t) (values)) %describe-doc))
104 (defun %describe-doc (name s kind kind-doc)
105 (when (and name (typep name '(or symbol cons)))
106 (let ((doc (fdocumentation name kind)))
108 (format s "~_~@(~A documentation:~)~@:_ ~A"
109 (or kind-doc kind) doc))))
112 ;;; Describe various stuff about the functional semantics attached to
113 ;;; the specified NAME, if NAME is the kind of thing you can look
114 ;;; up as a name. (In the case of anonymous closures and other
115 ;;; things, it might not be.) TYPE-SPEC is the function type specifier
116 ;;; extracted from the definition, or NIL if none.
117 (declaim (ftype (function (t stream t)) %describe-function-name))
118 (defun %describe-function-name (name s type-spec)
119 (when (and name (typep name '(or symbol cons)))
120 (multiple-value-bind (type where)
121 (if (or (symbolp name) (and (listp name) (eq (car name) 'setf)))
122 (values (type-specifier (info :function :type name))
123 (info :function :where-from name))
124 (values type-spec :defined))
126 (format s "~@:_Its ~(~A~) argument types are:~@:_ ~S"
128 (format s "~@:_Its result type is:~@:_ ~S" (third type))))
129 (let ((inlinep (info :function :inlinep name)))
132 "~@:_It is currently declared ~(~A~);~
133 ~:[no~;~] expansion is available."
134 inlinep (info :function :inline-expansion name))))))
136 ;;; Print information from the debug-info about where CODE-OBJ was
138 (defun %describe-compiled-from (code-obj s)
139 (declare (type stream s))
140 (let ((info (sb-kernel:%code-debug-info code-obj)))
142 (let ((sources (sb-c::debug-info-source info)))
144 (format s "~@:_On ~A it was compiled from:"
145 ;; FIXME: The FORMAT-UNIVERSAL-TIME calls in the system
146 ;; should become more consistent, probably not using
147 ;; any nondefault options.
148 (format-universal-time nil
149 (sb-c::debug-source-compiled
151 :style :abbreviated))
152 (dolist (source sources)
153 (let ((name (sb-c::debug-source-name source)))
154 (ecase (sb-c::debug-source-from source)
156 (format s "~@:_~A~@:_ Created: " (namestring name))
157 (format-universal-time s (sb-c::debug-source-created
159 (:lisp (format s "~@:_~S" name))))))))))
161 ;;; Describe a compiled function. The closure case calls us to print
163 (defun %describe-function-compiled (x s kind name)
164 (declare (type stream s))
165 ;; FIXME: The lowercaseness of %FUNCTION-ARGLIST results, and the
166 ;; non-sentenceness of the "Arguments" label, makes awkward output.
167 ;; Better would be "Its arguments are: ~S" (with uppercase argument
168 ;; names) when arguments are known, and otherwise "There is no
169 ;; information available about its arguments." or "It has no
170 ;; arguments." (And why is %FUNCTION-ARGLIST a string instead of a
171 ;; list of symbols anyway?)
172 (let ((args (%function-arglist x)))
173 (format s "~@:_~@(~@[~A ~]arguments:~@:_~)" kind)
175 (format s " There is no argument information available."))
177 (write-string " There are no arguments." s))
180 (pprint-logical-block (s nil)
181 (pprint-indent :current 2)
182 (write-string args s)))))
183 (let ((name (or name (%function-name x))))
184 (%describe-doc name s 'function kind)
185 (unless (eq kind :macro)
186 (%describe-function-name name s (%function-type x))))
187 (%describe-compiled-from (sb-kernel:function-code-header x) s))
189 ;;; FIXME: byte compiler to go away completely
191 (defun %describe-function-byte-compiled (x s kind name)
192 (declare (type stream s))
193 (let ((name (or name (sb-c::byte-function-name x))))
194 (%describe-doc name s 'function kind)
195 (unless (eq kind :macro)
196 (%describe-function-name name s 'function)))
197 (%describe-compiled-from (sb-c::byte-function-component x) s))
200 ;;; Describe a function with the specified kind and name. The latter
201 ;;; arguments provide some information about where the function came
202 ;;; from. Kind NIL means not from a name.
203 (defun %describe-function (x s &optional (kind nil) name)
204 (declare (type function x))
205 (declare (type stream s))
206 (declare (type (member :macro :function nil) kind))
209 (:macro (format s "Macro-function: ~S" x))
210 (:function (format s "Function: ~S" x))
211 ((nil) (format s "~S is a function." x)))
213 (#.sb-vm:closure-header-type
214 (%describe-function-compiled (%closure-function x) s kind name)
215 (format s "~@:_Its closure environment is:")
216 (pprint-logical-block (s nil)
217 (pprint-indent :current 8)
218 (dotimes (i (- (get-closure-length x) (1- sb-vm:closure-info-offset)))
219 (format s "~@:_~S: ~S" i (%closure-index-ref x i)))))
220 ((#.sb-vm:function-header-type #.sb-vm:closure-function-header-type)
221 (%describe-function-compiled x s kind name))
222 (#.sb-vm:funcallable-instance-header-type
224 ;; FIXME: byte compiler to go away completely
226 (sb-kernel:byte-function
227 (%describe-function-byte-compiled x s kind name))
228 (sb-kernel:byte-closure
229 (%describe-function-byte-compiled (byte-closure-function x)
231 (format s "~@:_Its closure environment is:")
232 (pprint-logical-block (s nil)
233 (pprint-indent :current 8)
234 (let ((data (byte-closure-data x)))
235 (dotimes (i (length data))
236 (format s "~@:_~S: ~S" i (svref data i))))))
238 (standard-generic-function
239 ;; There should be a special method for this case; we'll
241 (describe-object x s))
243 (format s "~@:_It is an unknown type of funcallable instance."))))
245 (format s "~@:_It is an unknown type of function."))))
247 (defmethod describe-object ((x function) s)
248 (%describe-function x s))
250 (defmethod describe-object ((x symbol) s)
251 (declare (type stream s))
253 ;; Describe the packaging.
254 (let ((package (symbol-package x)))
256 (multiple-value-bind (symbol status)
257 (find-symbol (symbol-name x) package)
258 (declare (ignore symbol))
259 (format s "~S is ~_an ~(~A~) symbol ~_in ~S."
260 x status (symbol-package x)))
261 (format s "~S is ~_an uninterned symbol." x)))
262 ;; TO DO: We could grovel over all packages looking for and
263 ;; reporting other phenomena, e.g. IMPORT and SHADOW, or
264 ;; availability in some package even after (SYMBOL-PACKAGE X) has
267 ;; Describe the value cell.
268 (let* ((kind (info :variable :kind x))
270 (:special "special variable")
271 (:constant "constant")
272 (:global "undefined variable")
276 (let ((info (info :variable :alien-info x)))
277 (format s "~@:_~@<It is an alien at #X~8,'0X of type ~3I~:_~S.~:>~@:_"
278 (sap-int (eval (sb-alien::heap-alien-info-sap-form info)))
279 (sb-alien-internals:unparse-alien-type
280 (sb-alien::heap-alien-info-type info)))
281 (format s "~@<Its current value is ~3I~:_~S.~:>"
284 (format s "~@:_It is a ~A; its ~_value is ~S." wot (symbol-value x)))
285 ((not (eq kind :global))
286 (format s "~@:_It is a ~A; no current value." wot)))
288 (when (eq (info :variable :where-from x) :declared)
289 (format s "~@:_Its declared type ~_is ~S."
290 (type-specifier (info :variable :type x))))
292 (%describe-doc x s 'variable kind))
294 ;; Print out properties.
295 (format s "~@[~@:_Its SYMBOL-PLIST is ~@<~2I~_~S~:>.~]" (symbol-plist x))
297 ;; Describe the function cell.
298 (cond ((macro-function x)
299 (%describe-function (macro-function x) s :macro x))
300 ((special-operator-p x)
301 (%describe-doc x s 'function "Special form"))
303 (%describe-function (fdefinition x) s :function x)))
305 ;; FIXME: Print out other stuff from the INFO database:
306 ;; * Does it name a type?
307 ;; * Is it a structure accessor? (This is important since those are
308 ;; magical in some ways, e.g. blasting the structure if you
311 ;; Print other documentation.
312 (%describe-doc x s 'structure "Structure")
313 (%describe-doc x s 'type "Type")
314 (%describe-doc x s 'setf "Setf macro")
316 (dolist (assoc (info :random-documentation :stuff x))
318 "~@:_Documentation on the ~(~A~):~@:_~A"
322 ;; Describe the associated class, if any.
323 (let ((symbol-named-class (cl:find-class x nil)))
324 (when symbol-named-class
325 (format t "~&It names a class ~A." symbol-named-class)
326 (describe symbol-named-class))))