1 ;;;; This file contains miscellaneous utilities used for manipulating
2 ;;;; the IR1 representation.
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.
17 ;;; Return the innermost cleanup enclosing NODE, or NIL if there is
18 ;;; none in its function. If NODE has no cleanup, but is in a LET,
19 ;;; then we must still check the environment that the call is in.
20 (defun node-enclosing-cleanup (node)
21 (declare (type node node))
22 (do ((lexenv (node-lexenv node)
23 (lambda-call-lexenv (lexenv-lambda lexenv))))
25 (let ((cup (lexenv-cleanup lexenv)))
26 (when cup (return cup)))))
28 ;;; Convert the FORM in a block inserted between BLOCK1 and BLOCK2 as
29 ;;; an implicit MV-PROG1. The inserted block is returned. NODE is used
30 ;;; for IR1 context when converting the form. Note that the block is
31 ;;; not assigned a number, and is linked into the DFO at the
32 ;;; beginning. We indicate that we have trashed the DFO by setting
33 ;;; COMPONENT-REANALYZE. If CLEANUP is supplied, then convert with
35 (defun insert-cleanup-code (block1 block2 node form &optional cleanup)
36 (declare (type cblock block1 block2) (type node node)
37 (type (or cleanup null) cleanup))
38 (setf (component-reanalyze (block-component block1)) t)
39 (with-ir1-environment-from-node node
40 (let* ((start (make-continuation))
41 (block (continuation-starts-block start))
42 (cont (make-continuation))
44 (make-lexenv :cleanup cleanup)
46 (change-block-successor block1 block2 block)
47 (link-blocks block block2)
48 (ir1-convert start cont form)
49 (setf (block-last block) (continuation-use cont))
52 ;;;; continuation use hacking
54 ;;; Return a list of all the nodes which use Cont.
55 (declaim (ftype (function (continuation) list) find-uses))
56 (defun find-uses (cont)
57 (ecase (continuation-kind cont)
58 ((:block-start :deleted-block-start)
59 (block-start-uses (continuation-block cont)))
60 (:inside-block (list (continuation-use cont)))
64 ;;; Update continuation use information so that NODE is no longer a
65 ;;; use of its CONT. If the old continuation doesn't start its block,
66 ;;; then we don't update the BLOCK-START-USES, since it will be
67 ;;; deleted when we are done.
69 ;;; Note: if you call this function, you may have to do a
70 ;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something
72 (declaim (ftype (function (node) (values)) delete-continuation-use))
73 (defun delete-continuation-use (node)
74 (let* ((cont (node-cont node))
75 (block (continuation-block cont)))
76 (ecase (continuation-kind cont)
78 ((:block-start :deleted-block-start)
79 (let ((uses (delete node (block-start-uses block))))
80 (setf (block-start-uses block) uses)
81 (setf (continuation-use cont)
82 (if (cdr uses) nil (car uses)))))
84 (setf (continuation-kind cont) :unused)
85 (setf (continuation-block cont) nil)
86 (setf (continuation-use cont) nil)
87 (setf (continuation-next cont) nil)))
88 (setf (node-cont node) nil))
91 ;;; Update continuation use information so that NODE uses CONT. If
92 ;;; CONT is :UNUSED, then we set its block to NODE's NODE-BLOCK (which
95 ;;; Note: if you call this function, you may have to do a
96 ;;; REOPTIMIZE-CONTINUATION to inform IR1 optimization that something
98 (declaim (ftype (function (node continuation) (values)) add-continuation-use))
99 (defun add-continuation-use (node cont)
100 (aver (not (node-cont node)))
101 (let ((block (continuation-block cont)))
102 (ecase (continuation-kind cont)
106 (let ((block (node-block node)))
108 (setf (continuation-block cont) block))
109 (setf (continuation-kind cont) :inside-block)
110 (setf (continuation-use cont) node))
111 ((:block-start :deleted-block-start)
112 (let ((uses (cons node (block-start-uses block))))
113 (setf (block-start-uses block) uses)
114 (setf (continuation-use cont)
115 (if (cdr uses) nil (car uses)))))))
116 (setf (node-cont node) cont)
119 ;;; Return true if CONT is the NODE-CONT for NODE and CONT is
120 ;;; transferred to immediately after the evaluation of NODE.
121 (defun immediately-used-p (cont node)
122 (declare (type continuation cont) (type node node))
123 (and (eq (node-cont node) cont)
124 (not (eq (continuation-kind cont) :deleted))
125 (let ((cblock (continuation-block cont))
126 (nblock (node-block node)))
127 (or (eq cblock nblock)
128 (let ((succ (block-succ nblock)))
129 (and (= (length succ) 1)
130 (eq (first succ) cblock)))))))
132 ;;;; continuation substitution
134 ;;; In OLD's DEST, replace OLD with NEW. NEW's DEST must initially be
135 ;;; NIL. When we are done, we call FLUSH-DEST on OLD to clear its DEST
136 ;;; and to note potential optimization opportunities.
137 (defun substitute-continuation (new old)
138 (declare (type continuation old new))
139 (aver (not (continuation-dest new)))
140 (let ((dest (continuation-dest old)))
143 (cif (setf (if-test dest) new))
144 (cset (setf (set-value dest) new))
145 (creturn (setf (return-result dest) new))
146 (exit (setf (exit-value dest) new))
148 (if (eq old (basic-combination-fun dest))
149 (setf (basic-combination-fun dest) new)
150 (setf (basic-combination-args dest)
151 (nsubst new old (basic-combination-args dest))))))
154 (setf (continuation-dest new) dest))
157 ;;; Replace all uses of OLD with uses of NEW, where NEW has an
158 ;;; arbitary number of uses. If NEW will end up with more than one
159 ;;; use, then we must arrange for it to start a block if it doesn't
161 (defun substitute-continuation-uses (new old)
162 (declare (type continuation old new))
163 (unless (and (eq (continuation-kind new) :unused)
164 (eq (continuation-kind old) :inside-block))
165 (ensure-block-start new))
168 (delete-continuation-use node)
169 (add-continuation-use node new))
170 (dolist (lexenv-use (continuation-lexenv-uses old))
171 (setf (cadr lexenv-use) new))
173 (reoptimize-continuation new)
176 ;;;; block starting/creation
178 ;;; Return the block that CONT is the start of, making a block if
179 ;;; necessary. This function is called by IR1 translators which may
180 ;;; cause a continuation to be used more than once. Every continuation
181 ;;; which may be used more than once must start a block by the time
182 ;;; that anyone does a USE-CONTINUATION on it.
184 ;;; We also throw the block into the next/prev list for the
185 ;;; *CURRENT-COMPONENT* so that we keep track of which blocks we have
187 (defun continuation-starts-block (cont)
188 (declare (type continuation cont))
189 (ecase (continuation-kind cont)
191 (aver (not (continuation-block cont)))
192 (let* ((head (component-head *current-component*))
193 (next (block-next head))
194 (new-block (make-block cont)))
195 (setf (block-next new-block) next)
196 (setf (block-prev new-block) head)
197 (setf (block-prev next) new-block)
198 (setf (block-next head) new-block)
199 (setf (continuation-block cont) new-block)
200 (setf (continuation-use cont) nil)
201 (setf (continuation-kind cont) :block-start)
204 (continuation-block cont))))
206 ;;; Ensure that CONT is the start of a block (or deleted) so that
207 ;;; the use set can be freely manipulated.
208 ;;; -- If the continuation is :UNUSED or is :INSIDE-BLOCK and the
209 ;;; CONT of LAST in its block, then we make it the start of a new
211 ;;; -- If the continuation is :INSIDE-BLOCK inside a block, then we
212 ;;; split the block using Node-Ends-Block, which makes the
213 ;;; continuation be a :BLOCK-START.
214 (defun ensure-block-start (cont)
215 (declare (type continuation cont))
216 (let ((kind (continuation-kind cont)))
218 ((:deleted :block-start :deleted-block-start))
219 ((:unused :inside-block)
220 (let ((block (continuation-block cont)))
221 (cond ((or (eq kind :unused)
222 (eq (node-cont (block-last block)) cont))
223 (setf (continuation-block cont)
224 (make-block-key :start cont
226 :start-uses (find-uses cont)))
227 (setf (continuation-kind cont) :deleted-block-start))
229 (node-ends-block (continuation-use cont))))))))
232 ;;;; miscellaneous shorthand functions
234 ;;; Return the home (i.e. enclosing non-LET) CLAMBDA for NODE. Since
235 ;;; the LEXENV-LAMBDA may be deleted, we must chain up the
236 ;;; LAMBDA-CALL-LEXENV thread until we find a CLAMBDA that isn't
237 ;;; deleted, and then return its home.
238 (defun node-home-lambda (node)
239 (declare (type node node))
240 (do ((fun (lexenv-lambda (node-lexenv node))
241 (lexenv-lambda (lambda-call-lexenv fun))))
242 ((not (eq (functional-kind fun) :deleted))
244 (when (eq (lambda-home fun) fun)
247 (defun node-block (node)
248 (declare (type node node))
249 (the cblock (continuation-block (node-prev node))))
250 (defun node-component (node)
251 (declare (type node node))
252 (block-component (node-block node)))
253 (defun node-physenv (node)
254 (declare (type node node))
255 (the physenv (lambda-physenv (node-home-lambda node))))
257 (defun lambda-block (clambda)
258 (declare (type clambda clambda))
259 (node-block (lambda-bind clambda)))
260 (defun lambda-component (clambda)
261 (block-component (lambda-block clambda)))
263 ;;; Return the enclosing cleanup for environment of the first or last
265 (defun block-start-cleanup (block)
266 (declare (type cblock block))
267 (node-enclosing-cleanup (continuation-next (block-start block))))
268 (defun block-end-cleanup (block)
269 (declare (type cblock block))
270 (node-enclosing-cleanup (block-last block)))
272 ;;; Return the non-LET LAMBDA that holds BLOCK's code, or NIL
273 ;;; if there is none.
275 ;;; There can legitimately be no home lambda in dead code early in the
276 ;;; IR1 conversion process, e.g. when IR1-converting the SETQ form in
277 ;;; (BLOCK B (RETURN-FROM B) (SETQ X 3))
278 ;;; where the block is just a placeholder during parsing and doesn't
279 ;;; actually correspond to code which will be written anywhere.
280 (defun block-home-lambda-or-null (block)
281 (declare (type cblock block))
282 (if (node-p (block-last block))
283 ;; This is the old CMU CL way of doing it.
284 (node-home-lambda (block-last block))
285 ;; Now that SBCL uses this operation more aggressively than CMU
286 ;; CL did, the old CMU CL way of doing it can fail in two ways.
287 ;; 1. It can fail in a few cases even when a meaningful home
288 ;; lambda exists, e.g. in IR1-CONVERT of one of the legs of
290 ;; 2. It can fail when converting a form which is born orphaned
291 ;; so that it never had a meaningful home lambda, e.g. a form
292 ;; which follows a RETURN-FROM or GO form.
293 (let ((pred-list (block-pred block)))
294 ;; To deal with case 1, we reason that
295 ;; previous-in-target-execution-order blocks should be in the
296 ;; same lambda, and that they seem in practice to be
297 ;; previous-in-compilation-order blocks too, so we look back
298 ;; to find one which is sufficiently initialized to tell us
299 ;; what the home lambda is.
301 ;; We could get fancy about this, flooding through the
302 ;; graph of all the previous blocks, but in practice it
303 ;; seems to work just to grab the first previous block and
305 (node-home-lambda (block-last (first pred-list)))
306 ;; In case 2, we end up with an empty PRED-LIST and
307 ;; have to punt: There's no home lambda.
310 ;;; Return the non-LET LAMBDA that holds BLOCK's code.
311 (defun block-home-lambda (block)
313 (block-home-lambda-or-null block)))
315 ;;; Return the IR1 physical environment for BLOCK.
316 (defun block-physenv (block)
317 (declare (type cblock block))
318 (lambda-physenv (block-home-lambda block)))
320 ;;; Return the Top Level Form number of PATH, i.e. the ordinal number
321 ;;; of its original source's top level form in its compilation unit.
322 (defun source-path-tlf-number (path)
323 (declare (list path))
326 ;;; Return the (reversed) list for the PATH in the original source
327 ;;; (with the Top Level Form number last).
328 (defun source-path-original-source (path)
329 (declare (list path) (inline member))
330 (cddr (member 'original-source-start path :test #'eq)))
332 ;;; Return the Form Number of PATH's original source inside the Top
333 ;;; Level Form that contains it. This is determined by the order that
334 ;;; we walk the subforms of the top level source form.
335 (defun source-path-form-number (path)
336 (declare (list path) (inline member))
337 (cadr (member 'original-source-start path :test #'eq)))
339 ;;; Return a list of all the enclosing forms not in the original
340 ;;; source that converted to get to this form, with the immediate
341 ;;; source for node at the start of the list.
342 (defun source-path-forms (path)
343 (subseq path 0 (position 'original-source-start path)))
345 ;;; Return the innermost source form for NODE.
346 (defun node-source-form (node)
347 (declare (type node node))
348 (let* ((path (node-source-path node))
349 (forms (source-path-forms path)))
352 (values (find-original-source path)))))
354 ;;; Return NODE-SOURCE-FORM, T if continuation has a single use,
355 ;;; otherwise NIL, NIL.
356 (defun continuation-source (cont)
357 (let ((use (continuation-use cont)))
359 (values (node-source-form use) t)
362 ;;; Return the LAMBDA that is CONT's home, or NIL if there is none.
363 (defun continuation-home-lambda-or-null (cont)
364 ;; KLUDGE: This function is a post-CMU-CL hack by WHN, and this
365 ;; implementation might not be quite right, or might be uglier than
366 ;; necessary. It appears that the original Python never found a need
367 ;; to do this operation. The obvious things based on
368 ;; NODE-HOME-LAMBDA of CONTINUATION-USE usually work; then if that
369 ;; fails, BLOCK-HOME-LAMBDA of CONTINUATION-BLOCK works, given that
370 ;; we generalize it enough to grovel harder when the simple CMU CL
371 ;; approach fails, and furthermore realize that in some exceptional
372 ;; cases it might return NIL. -- WHN 2001-12-04
373 (cond ((continuation-use cont)
374 (node-home-lambda (continuation-use cont)))
375 ((continuation-block cont)
376 (block-home-lambda-or-null (continuation-block cont)))
378 (bug "confused about home lambda for ~S"))))
380 ;;; Return the LAMBDA that is CONT's home.
381 (defun continuation-home-lambda (cont)
383 (continuation-home-lambda-or-null cont)))
385 ;;; Return a new LEXENV just like DEFAULT except for the specified
386 ;;; slot values. Values for the alist slots are NCONCed to the
387 ;;; beginning of the current value, rather than replacing it entirely.
388 (defun make-lexenv (&key (default *lexenv*)
389 funs vars blocks tags type-restrictions options
390 (lambda (lexenv-lambda default))
391 (cleanup (lexenv-cleanup default))
392 (policy (lexenv-policy default)))
393 (macrolet ((frob (var slot)
394 `(let ((old (,slot default)))
398 (internal-make-lexenv
399 (frob funs lexenv-funs)
400 (frob vars lexenv-vars)
401 (frob blocks lexenv-blocks)
402 (frob tags lexenv-tags)
403 (frob type-restrictions lexenv-type-restrictions)
404 lambda cleanup policy
405 (frob options lexenv-options))))
407 ;;;; flow/DFO/component hackery
409 ;;; Join BLOCK1 and BLOCK2.
410 (defun link-blocks (block1 block2)
411 (declare (type cblock block1 block2))
412 (setf (block-succ block1)
413 (if (block-succ block1)
414 (%link-blocks block1 block2)
416 (push block1 (block-pred block2))
418 (defun %link-blocks (block1 block2)
419 (declare (type cblock block1 block2) (inline member))
420 (let ((succ1 (block-succ block1)))
421 (aver (not (member block2 succ1 :test #'eq)))
422 (cons block2 succ1)))
424 ;;; This is like LINK-BLOCKS, but we separate BLOCK1 and BLOCK2. If
425 ;;; this leaves a successor with a single predecessor that ends in an
426 ;;; IF, then set BLOCK-TEST-MODIFIED so that any test constraint will
427 ;;; now be able to be propagated to the successor.
428 (defun unlink-blocks (block1 block2)
429 (declare (type cblock block1 block2))
430 (let ((succ1 (block-succ block1)))
431 (if (eq block2 (car succ1))
432 (setf (block-succ block1) (cdr succ1))
433 (do ((succ (cdr succ1) (cdr succ))
435 ((eq (car succ) block2)
436 (setf (cdr prev) (cdr succ)))
439 (let ((new-pred (delq block1 (block-pred block2))))
440 (setf (block-pred block2) new-pred)
441 (when (and new-pred (null (rest new-pred)))
442 (let ((pred-block (first new-pred)))
443 (when (if-p (block-last pred-block))
444 (setf (block-test-modified pred-block) t)))))
447 ;;; Swing the succ/pred link between BLOCK and OLD to be between BLOCK
448 ;;; and NEW. If BLOCK ends in an IF, then we have to fix up the
449 ;;; consequent/alternative blocks to point to NEW. We also set
450 ;;; BLOCK-TEST-MODIFIED so that any test constraint will be applied to
451 ;;; the new successor.
452 (defun change-block-successor (block old new)
453 (declare (type cblock new old block) (inline member))
454 (unlink-blocks block old)
455 (let ((last (block-last block))
456 (comp (block-component block)))
457 (setf (component-reanalyze comp) t)
460 (setf (block-test-modified block) t)
461 (let* ((succ-left (block-succ block))
462 (new (if (and (eq new (component-tail comp))
466 (unless (member new succ-left :test #'eq)
467 (link-blocks block new))
468 (macrolet ((frob (slot)
469 `(when (eq (,slot last) old)
470 (setf (,slot last) new))))
472 (frob if-alternative))))
474 (unless (member new (block-succ block) :test #'eq)
475 (link-blocks block new)))))
479 ;;; Unlink a block from the next/prev chain. We also null out the
481 (declaim (ftype (function (cblock) (values)) remove-from-dfo))
482 (defun remove-from-dfo (block)
483 (let ((next (block-next block))
484 (prev (block-prev block)))
485 (setf (block-component block) nil)
486 (setf (block-next prev) next)
487 (setf (block-prev next) prev))
490 ;;; Add BLOCK to the next/prev chain following AFTER. We also set the
491 ;;; Component to be the same as for AFTER.
492 (defun add-to-dfo (block after)
493 (declare (type cblock block after))
494 (let ((next (block-next after))
495 (comp (block-component after)))
496 (aver (not (eq (component-kind comp) :deleted)))
497 (setf (block-component block) comp)
498 (setf (block-next after) block)
499 (setf (block-prev block) after)
500 (setf (block-next block) next)
501 (setf (block-prev next) block))
504 ;;; Set the FLAG for all the blocks in COMPONENT to NIL, except for
505 ;;; the head and tail which are set to T.
506 (declaim (ftype (function (component) (values)) clear-flags))
507 (defun clear-flags (component)
508 (let ((head (component-head component))
509 (tail (component-tail component)))
510 (setf (block-flag head) t)
511 (setf (block-flag tail) t)
512 (do-blocks (block component)
513 (setf (block-flag block) nil)))
516 ;;; Make a component with no blocks in it. The BLOCK-FLAG is initially
517 ;;; true in the head and tail blocks.
518 (declaim (ftype (function nil component) make-empty-component))
519 (defun make-empty-component ()
520 (let* ((head (make-block-key :start nil :component nil))
521 (tail (make-block-key :start nil :component nil))
522 (res (make-component :head head :tail tail)))
523 (setf (block-flag head) t)
524 (setf (block-flag tail) t)
525 (setf (block-component head) res)
526 (setf (block-component tail) res)
527 (setf (block-next head) tail)
528 (setf (block-prev tail) head)
531 ;;; Make NODE the LAST node in its block, splitting the block if necessary.
532 ;;; The new block is added to the DFO immediately following NODE's block.
533 (defun node-ends-block (node)
534 (declare (type node node))
535 (let* ((block (node-block node))
536 (start (node-cont node))
537 (last (block-last block))
538 (last-cont (node-cont last)))
539 (unless (eq last node)
540 (aver (and (eq (continuation-kind start) :inside-block)
541 (not (block-delete-p block))))
542 (let* ((succ (block-succ block))
544 (make-block-key :start start
545 :component (block-component block)
546 :start-uses (list (continuation-use start))
547 :succ succ :last last)))
548 (setf (continuation-kind start) :block-start)
551 (cons new-block (remove block (block-pred b)))))
552 (setf (block-succ block) ())
553 (setf (block-last block) node)
554 (link-blocks block new-block)
555 (add-to-dfo new-block block)
556 (setf (component-reanalyze (block-component block)) t)
558 (do ((cont start (node-cont (continuation-next cont))))
560 (when (eq (continuation-kind last-cont) :inside-block)
561 (setf (continuation-block last-cont) new-block)))
562 (setf (continuation-block cont) new-block))
564 (setf (block-type-asserted block) t)
565 (setf (block-test-modified block) t))))
571 ;;; Deal with deleting the last (read) reference to a LAMBDA-VAR. We
572 ;;; iterate over all local calls flushing the corresponding argument,
573 ;;; allowing the computation of the argument to be deleted. We also
574 ;;; mark the let for reoptimization, since it may be that we have
575 ;;; deleted the last variable.
577 ;;; The LAMBDA-VAR may still have some SETs, but this doesn't cause
578 ;;; too much difficulty, since we can efficiently implement write-only
579 ;;; variables. We iterate over the sets, marking their blocks for dead
580 ;;; code flushing, since we can delete sets whose value is unused.
581 (defun delete-lambda-var (leaf)
582 (declare (type lambda-var leaf))
583 (let* ((fun (lambda-var-home leaf))
584 (n (position leaf (lambda-vars fun))))
585 (dolist (ref (leaf-refs fun))
586 (let* ((cont (node-cont ref))
587 (dest (continuation-dest cont)))
588 (when (and (combination-p dest)
589 (eq (basic-combination-fun dest) cont)
590 (eq (basic-combination-kind dest) :local))
591 (let* ((args (basic-combination-args dest))
593 (reoptimize-continuation arg)
595 (setf (elt args n) nil))))))
597 (dolist (set (lambda-var-sets leaf))
598 (setf (block-flush-p (node-block set)) t))
602 ;;; Note that something interesting has happened to VAR. We only deal
603 ;;; with LET variables, marking the corresponding initial value arg as
604 ;;; needing to be reoptimized.
605 (defun reoptimize-lambda-var (var)
606 (declare (type lambda-var var))
607 (let ((fun (lambda-var-home var)))
608 (when (and (eq (functional-kind fun) :let)
610 (do ((args (basic-combination-args
613 (first (leaf-refs fun)))))
615 (vars (lambda-vars fun) (cdr vars)))
617 (reoptimize-continuation (car args))))))
620 ;;; Delete a function that has no references. This need only be called
621 ;;; on functions that never had any references, since otherwise
622 ;;; DELETE-REF will handle the deletion.
623 (defun delete-functional (fun)
624 (aver (and (null (leaf-refs fun))
625 (not (functional-entry-fun fun))))
627 (optional-dispatch (delete-optional-dispatch fun))
628 (clambda (delete-lambda fun)))
631 ;;; Deal with deleting the last reference to a LAMBDA. Since there is
632 ;;; only one way into a LAMBDA, deleting the last reference to a
633 ;;; LAMBDA ensures that there is no way to reach any of the code in
634 ;;; it. So we just set the FUNCTIONAL-KIND for FUN and its LETs to
635 ;;; :DELETED, causing IR1 optimization to delete blocks in that
638 ;;; If the function isn't a LET, we unlink the function head and tail
639 ;;; from the component head and tail to indicate that the code is
640 ;;; unreachable. We also delete the function from COMPONENT-LAMBDAS
641 ;;; (it won't be there before local call analysis, but no matter.) If
642 ;;; the lambda was never referenced, we give a note.
644 ;;; If the lambda is an XEP, then we null out the ENTRY-FUN in its
645 ;;; ENTRY-FUN so that people will know that it is not an entry point
647 (defun delete-lambda (leaf)
648 (declare (type clambda leaf))
649 (let ((kind (functional-kind leaf))
650 (bind (lambda-bind leaf)))
651 (aver (not (member kind '(:deleted :optional :toplevel))))
652 (aver (not (functional-has-external-references-p leaf)))
653 (setf (functional-kind leaf) :deleted)
654 (setf (lambda-bind leaf) nil)
655 (dolist (let (lambda-lets leaf))
656 (setf (lambda-bind let) nil)
657 (setf (functional-kind let) :deleted))
659 (if (member kind '(:let :mv-let :assignment))
660 (let ((home (lambda-home leaf)))
661 (setf (lambda-lets home) (delete leaf (lambda-lets home))))
662 (let* ((bind-block (node-block bind))
663 (component (block-component bind-block))
664 (return (lambda-return leaf)))
665 (aver (null (leaf-refs leaf)))
666 (unless (leaf-ever-used leaf)
667 (let ((*compiler-error-context* bind))
668 (compiler-note "deleting unused function~:[.~;~:*~% ~S~]"
669 (leaf-debug-name leaf))))
670 (unlink-blocks (component-head component) bind-block)
672 (unlink-blocks (node-block return) (component-tail component)))
673 (setf (component-reanalyze component) t)
674 (let ((tails (lambda-tail-set leaf)))
675 (setf (tail-set-funs tails)
676 (delete leaf (tail-set-funs tails)))
677 (setf (lambda-tail-set leaf) nil))
678 (setf (component-lambdas component)
679 (delete leaf (component-lambdas component)))))
681 (when (eq kind :external)
682 (let ((fun (functional-entry-fun leaf)))
683 (setf (functional-entry-fun fun) nil)
684 (when (optional-dispatch-p fun)
685 (delete-optional-dispatch fun)))))
689 ;;; Deal with deleting the last reference to an OPTIONAL-DISPATCH. We
690 ;;; have to be a bit more careful than with lambdas, since DELETE-REF
691 ;;; is used both before and after local call analysis. Afterward, all
692 ;;; references to still-existing OPTIONAL-DISPATCHes have been moved
693 ;;; to the XEP, leaving it with no references at all. So we look at
694 ;;; the XEP to see whether an optional-dispatch is still really being
695 ;;; used. But before local call analysis, there are no XEPs, and all
696 ;;; references are direct.
698 ;;; When we do delete the OPTIONAL-DISPATCH, we grovel all of its
699 ;;; entry-points, making them be normal lambdas, and then deleting the
700 ;;; ones with no references. This deletes any e-p lambdas that were
701 ;;; either never referenced, or couldn't be deleted when the last
702 ;;; deference was deleted (due to their :OPTIONAL kind.)
704 ;;; Note that the last optional ep may alias the main entry, so when
705 ;;; we process the main entry, its kind may have been changed to NIL
706 ;;; or even converted to a let.
707 (defun delete-optional-dispatch (leaf)
708 (declare (type optional-dispatch leaf))
709 (let ((entry (functional-entry-fun leaf)))
710 (unless (and entry (leaf-refs entry))
711 (aver (or (not entry) (eq (functional-kind entry) :deleted)))
712 (setf (functional-kind leaf) :deleted)
715 (unless (eq (functional-kind fun) :deleted)
716 (aver (eq (functional-kind fun) :optional))
717 (setf (functional-kind fun) nil)
718 (let ((refs (leaf-refs fun)))
722 (or (maybe-let-convert fun)
723 (maybe-convert-to-assignment fun)))
725 (maybe-convert-to-assignment fun)))))))
727 (dolist (ep (optional-dispatch-entry-points leaf))
729 (when (optional-dispatch-more-entry leaf)
730 (frob (optional-dispatch-more-entry leaf)))
731 (let ((main (optional-dispatch-main-entry leaf)))
732 (when (eq (functional-kind main) :optional)
737 ;;; Do stuff to delete the semantic attachments of a REF node. When
738 ;;; this leaves zero or one reference, we do a type dispatch off of
739 ;;; the leaf to determine if a special action is appropriate.
740 (defun delete-ref (ref)
741 (declare (type ref ref))
742 (let* ((leaf (ref-leaf ref))
743 (refs (delete ref (leaf-refs leaf))))
744 (setf (leaf-refs leaf) refs)
749 (delete-lambda-var leaf))
751 (ecase (functional-kind leaf)
752 ((nil :let :mv-let :assignment :escape :cleanup)
753 (aver (not (functional-entry-fun leaf)))
754 (delete-lambda leaf))
756 (delete-lambda leaf))
757 ((:deleted :optional))))
759 (unless (eq (functional-kind leaf) :deleted)
760 (delete-optional-dispatch leaf)))))
763 (clambda (or (maybe-let-convert leaf)
764 (maybe-convert-to-assignment leaf)))
765 (lambda-var (reoptimize-lambda-var leaf))))
768 (clambda (maybe-convert-to-assignment leaf))))))
772 ;;; This function is called by people who delete nodes; it provides a
773 ;;; way to indicate that the value of a continuation is no longer
774 ;;; used. We null out the CONTINUATION-DEST, set FLUSH-P in the blocks
775 ;;; containing uses of CONT and set COMPONENT-REOPTIMIZE. If the PREV
776 ;;; of the use is deleted, then we blow off reoptimization.
778 ;;; If the continuation is :Deleted, then we don't do anything, since
779 ;;; all semantics have already been flushed. :DELETED-BLOCK-START
780 ;;; start continuations are treated just like :BLOCK-START; it is
781 ;;; possible that the continuation may be given a new dest (e.g. by
782 ;;; SUBSTITUTE-CONTINUATION), so we don't want to delete it.
783 (defun flush-dest (cont)
784 (declare (type continuation cont))
786 (unless (eq (continuation-kind cont) :deleted)
787 (aver (continuation-dest cont))
788 (setf (continuation-dest cont) nil)
790 (let ((prev (node-prev use)))
791 (unless (eq (continuation-kind prev) :deleted)
792 (let ((block (continuation-block prev)))
793 (setf (component-reoptimize (block-component block)) t)
794 (setf (block-attributep (block-flags block) flush-p type-asserted)
797 (setf (continuation-%type-check cont) nil)
801 ;;; Do a graph walk backward from BLOCK, marking all predecessor
802 ;;; blocks with the DELETE-P flag.
803 (defun mark-for-deletion (block)
804 (declare (type cblock block))
805 (unless (block-delete-p block)
806 (setf (block-delete-p block) t)
807 (setf (component-reanalyze (block-component block)) t)
808 (dolist (pred (block-pred block))
809 (mark-for-deletion pred)))
812 ;;; Delete CONT, eliminating both control and value semantics. We set
813 ;;; FLUSH-P and COMPONENT-REOPTIMIZE similarly to in FLUSH-DEST. Here
814 ;;; we must get the component from the use block, since the
815 ;;; continuation may be a :DELETED-BLOCK-START.
817 ;;; If CONT has DEST, then it must be the case that the DEST is
818 ;;; unreachable, since we can't compute the value desired. In this
819 ;;; case, we call MARK-FOR-DELETION to cause the DEST block and its
820 ;;; predecessors to tell people to ignore them, and to cause them to
821 ;;; be deleted eventually.
822 (defun delete-continuation (cont)
823 (declare (type continuation cont))
824 (aver (not (eq (continuation-kind cont) :deleted)))
827 (let ((prev (node-prev use)))
828 (unless (eq (continuation-kind prev) :deleted)
829 (let ((block (continuation-block prev)))
830 (setf (block-attributep (block-flags block) flush-p type-asserted) t)
831 (setf (component-reoptimize (block-component block)) t)))))
833 (let ((dest (continuation-dest cont)))
835 (let ((prev (node-prev dest)))
837 (not (eq (continuation-kind prev) :deleted)))
838 (let ((block (continuation-block prev)))
839 (unless (block-delete-p block)
840 (mark-for-deletion block)))))))
842 (setf (continuation-kind cont) :deleted)
843 (setf (continuation-dest cont) nil)
844 (setf (continuation-next cont) nil)
845 (setf (continuation-asserted-type cont) *empty-type*)
846 (setf (continuation-%derived-type cont) *empty-type*)
847 (setf (continuation-use cont) nil)
848 (setf (continuation-block cont) nil)
849 (setf (continuation-reoptimize cont) nil)
850 (setf (continuation-%type-check cont) nil)
851 (setf (continuation-info cont) nil)
855 ;;; This function does what is necessary to eliminate the code in it
856 ;;; from the IR1 representation. This involves unlinking it from its
857 ;;; predecessors and successors and deleting various node-specific
858 ;;; semantic information.
860 ;;; We mark the START as has having no next and remove the last node
861 ;;; from its CONT's uses. We also flush the DEST for all continuations
862 ;;; whose values are received by nodes in the block.
863 (defun delete-block (block)
864 (declare (type cblock block))
865 (aver (block-component block)) ; else block is already deleted!
866 (note-block-deletion block)
867 (setf (block-delete-p block) t)
869 (let* ((last (block-last block))
870 (cont (node-cont last)))
871 (delete-continuation-use last)
872 (if (eq (continuation-kind cont) :unused)
873 (delete-continuation cont)
874 (reoptimize-continuation cont)))
876 (dolist (b (block-pred block))
877 (unlink-blocks b block))
878 (dolist (b (block-succ block))
879 (unlink-blocks block b))
881 (do-nodes (node cont block)
883 (ref (delete-ref node))
885 (flush-dest (if-test node)))
886 ;; The next two cases serve to maintain the invariant that a LET
887 ;; always has a well-formed COMBINATION, REF and BIND. We delete
888 ;; the lambda whenever we delete any of these, but we must be
889 ;; careful that this LET has not already been partially deleted.
891 (when (and (eq (basic-combination-kind node) :local)
892 ;; Guards COMBINATION-LAMBDA agains the REF being deleted.
893 (continuation-use (basic-combination-fun node)))
894 (let ((fun (combination-lambda node)))
895 ;; If our REF was the 2'nd to last ref, and has been deleted, then
896 ;; Fun may be a LET for some other combination.
897 (when (and (member (functional-kind fun) '(:let :mv-let))
898 (eq (let-combination fun) node))
899 (delete-lambda fun))))
900 (flush-dest (basic-combination-fun node))
901 (dolist (arg (basic-combination-args node))
902 (when arg (flush-dest arg))))
904 (let ((lambda (bind-lambda node)))
905 (unless (eq (functional-kind lambda) :deleted)
906 (aver (member (functional-kind lambda) '(:let :mv-let :assignment)))
907 (delete-lambda lambda))))
909 (let ((value (exit-value node))
910 (entry (exit-entry node)))
914 (setf (entry-exits entry)
915 (delete node (entry-exits entry))))))
917 (flush-dest (return-result node))
918 (delete-return node))
920 (flush-dest (set-value node))
921 (let ((var (set-var node)))
922 (setf (basic-var-sets var)
923 (delete node (basic-var-sets var))))))
925 (delete-continuation (node-prev node)))
927 (remove-from-dfo block)
930 ;;; Do stuff to indicate that the return node Node is being deleted.
931 ;;; We set the RETURN to NIL.
932 (defun delete-return (node)
933 (declare (type creturn node))
934 (let ((fun (return-lambda node)))
935 (aver (lambda-return fun))
936 (setf (lambda-return fun) nil))
939 ;;; If any of the VARS in FUN was never referenced and was not
940 ;;; declared IGNORE, then complain.
941 (defun note-unreferenced-vars (fun)
942 (declare (type clambda fun))
943 (dolist (var (lambda-vars fun))
944 (unless (or (leaf-ever-used var)
945 (lambda-var-ignorep var))
946 (let ((*compiler-error-context* (lambda-bind fun)))
947 (unless (policy *compiler-error-context* (= inhibit-warnings 3))
948 ;; ANSI section "3.2.5 Exceptional Situations in the Compiler"
949 ;; requires this to be no more than a STYLE-WARNING.
950 (compiler-style-warn "The variable ~S is defined but never used."
951 (leaf-debug-name var)))
952 (setf (leaf-ever-used var) t)))) ; to avoid repeated warnings? -- WHN
955 (defvar *deletion-ignored-objects* '(t nil))
957 ;;; Return true if we can find OBJ in FORM, NIL otherwise. We bound
958 ;;; our recursion so that we don't get lost in circular structures. We
959 ;;; ignore the car of forms if they are a symbol (to prevent confusing
960 ;;; function referencess with variables), and we also ignore anything
962 (defun present-in-form (obj form depth)
963 (declare (type (integer 0 20) depth))
964 (cond ((= depth 20) nil)
968 (let ((first (car form))
970 (if (member first '(quote function))
972 (or (and (not (symbolp first))
973 (present-in-form obj first depth))
974 (do ((l (cdr form) (cdr l))
976 ((or (atom l) (> n 100))
979 (when (present-in-form obj (car l) depth)
982 ;;; This function is called on a block immediately before we delete
983 ;;; it. We check to see whether any of the code about to die appeared
984 ;;; in the original source, and emit a note if so.
986 ;;; If the block was in a lambda is now deleted, then we ignore the
987 ;;; whole block, since this case is picked off in DELETE-LAMBDA. We
988 ;;; also ignore the deletion of CRETURN nodes, since it is somewhat
989 ;;; reasonable for a function to not return, and there is a different
990 ;;; note for that case anyway.
992 ;;; If the actual source is an atom, then we use a bunch of heuristics
993 ;;; to guess whether this reference really appeared in the original
995 ;;; -- If a symbol, it must be interned and not a keyword.
996 ;;; -- It must not be an easily introduced constant (T or NIL, a fixnum
998 ;;; -- The atom must be "present" in the original source form, and
999 ;;; present in all intervening actual source forms.
1000 (defun note-block-deletion (block)
1001 (let ((home (block-home-lambda block)))
1002 (unless (eq (functional-kind home) :deleted)
1003 (do-nodes (node cont block)
1004 (let* ((path (node-source-path node))
1005 (first (first path)))
1006 (when (or (eq first 'original-source-start)
1008 (or (not (symbolp first))
1009 (let ((pkg (symbol-package first)))
1011 (not (eq pkg (symbol-package :end))))))
1012 (not (member first *deletion-ignored-objects*))
1013 (not (typep first '(or fixnum character)))
1015 (present-in-form first x 0))
1016 (source-path-forms path))
1017 (present-in-form first (find-original-source path)
1019 (unless (return-p node)
1020 (let ((*compiler-error-context* node))
1021 (compiler-note "deleting unreachable code")))
1025 ;;; Delete a node from a block, deleting the block if there are no
1026 ;;; nodes left. We remove the node from the uses of its CONT, but we
1027 ;;; don't deal with cleaning up any type-specific semantic
1028 ;;; attachments. If the CONT is :UNUSED after deleting this use, then
1029 ;;; we delete CONT. (Note :UNUSED is not the same as no uses. A
1030 ;;; continuation will only become :UNUSED if it was :INSIDE-BLOCK
1033 ;;; If the node is the last node, there must be exactly one successor.
1034 ;;; We link all of our precedessors to the successor and unlink the
1035 ;;; block. In this case, we return T, otherwise NIL. If no nodes are
1036 ;;; left, and the block is a successor of itself, then we replace the
1037 ;;; only node with a degenerate exit node. This provides a way to
1038 ;;; represent the bodyless infinite loop, given the prohibition on
1039 ;;; empty blocks in IR1.
1040 (defun unlink-node (node)
1041 (declare (type node node))
1042 (let* ((cont (node-cont node))
1043 (next (continuation-next cont))
1044 (prev (node-prev node))
1045 (block (continuation-block prev))
1046 (prev-kind (continuation-kind prev))
1047 (last (block-last block)))
1049 (unless (eq (continuation-kind cont) :deleted)
1050 (delete-continuation-use node)
1051 (when (eq (continuation-kind cont) :unused)
1052 (aver (not (continuation-dest cont)))
1053 (delete-continuation cont)))
1055 (setf (block-type-asserted block) t)
1056 (setf (block-test-modified block) t)
1058 (cond ((or (eq prev-kind :inside-block)
1059 (and (eq prev-kind :block-start)
1060 (not (eq node last))))
1061 (cond ((eq node last)
1062 (setf (block-last block) (continuation-use prev))
1063 (setf (continuation-next prev) nil))
1065 (setf (continuation-next prev) next)
1066 (setf (node-prev next) prev)))
1067 (setf (node-prev node) nil)
1070 (aver (eq prev-kind :block-start))
1071 (aver (eq node last))
1072 (let* ((succ (block-succ block))
1073 (next (first succ)))
1074 (aver (and succ (null (cdr succ))))
1076 ((member block succ)
1077 (with-ir1-environment-from-node node
1078 (let ((exit (make-exit))
1079 (dummy (make-continuation)))
1080 (setf (continuation-next prev) nil)
1081 (link-node-to-previous-continuation exit prev)
1082 (add-continuation-use exit dummy)
1083 (setf (block-last block) exit)))
1084 (setf (node-prev node) nil)
1087 (aver (eq (block-start-cleanup block)
1088 (block-end-cleanup block)))
1089 (unlink-blocks block next)
1090 (dolist (pred (block-pred block))
1091 (change-block-successor pred block next))
1092 (remove-from-dfo block)
1093 (cond ((continuation-dest prev)
1094 (setf (continuation-next prev) nil)
1095 (setf (continuation-kind prev) :deleted-block-start))
1097 (delete-continuation prev)))
1098 (setf (node-prev node) nil)
1101 ;;; Return true if NODE has been deleted, false if it is still a valid
1103 (defun node-deleted (node)
1104 (declare (type node node))
1105 (let ((prev (node-prev node)))
1107 (not (eq (continuation-kind prev) :deleted))
1108 (let ((block (continuation-block prev)))
1109 (and (block-component block)
1110 (not (block-delete-p block))))))))
1112 ;;; Delete all the blocks and functions in COMPONENT. We scan first
1113 ;;; marking the blocks as DELETE-P to prevent weird stuff from being
1114 ;;; triggered by deletion.
1115 (defun delete-component (component)
1116 (declare (type component component))
1117 (aver (null (component-new-funs component)))
1118 (setf (component-kind component) :deleted)
1119 (do-blocks (block component)
1120 (setf (block-delete-p block) t))
1121 (dolist (fun (component-lambdas component))
1122 (setf (functional-kind fun) nil)
1123 (setf (functional-entry-fun fun) nil)
1124 (setf (leaf-refs fun) nil)
1125 (delete-functional fun))
1126 (do-blocks (block component)
1127 (delete-block block))
1130 ;;; Convert code of the form
1131 ;;; (FOO ... (FUN ...) ...)
1133 ;;; (FOO ... ... ...).
1134 ;;; In other words, replace the function combination FUN by its
1135 ;;; arguments. If there are any problems with doing this, use GIVE-UP
1136 ;;; to blow out of whatever transform called this. Note, as the number
1137 ;;; of arguments changes, the transform must be prepared to return a
1138 ;;; lambda with a new lambda-list with the correct number of
1140 (defun extract-fun-args (cont fun num-args)
1142 "If CONT is a call to FUN with NUM-ARGS args, change those arguments
1143 to feed directly to the continuation-dest of CONT, which must be
1145 (declare (type continuation cont)
1147 (type index num-args))
1148 (let ((outside (continuation-dest cont))
1149 (inside (continuation-use cont)))
1150 (aver (combination-p outside))
1151 (unless (combination-p inside)
1152 (give-up-ir1-transform))
1153 (let ((inside-fun (combination-fun inside)))
1154 (unless (eq (continuation-fun-name inside-fun) fun)
1155 (give-up-ir1-transform))
1156 (let ((inside-args (combination-args inside)))
1157 (unless (= (length inside-args) num-args)
1158 (give-up-ir1-transform))
1159 (let* ((outside-args (combination-args outside))
1160 (arg-position (position cont outside-args))
1161 (before-args (subseq outside-args 0 arg-position))
1162 (after-args (subseq outside-args (1+ arg-position))))
1163 (dolist (arg inside-args)
1164 (setf (continuation-dest arg) outside))
1165 (setf (combination-args inside) nil)
1166 (setf (combination-args outside)
1167 (append before-args inside-args after-args))
1168 (change-ref-leaf (continuation-use inside-fun)
1169 (find-free-fun 'list "???"))
1170 (setf (combination-kind inside) :full)
1171 (setf (node-derived-type inside) *wild-type*)
1173 (setf (continuation-asserted-type cont) *wild-type*)
1178 ;;; Change the LEAF that a REF refers to.
1179 (defun change-ref-leaf (ref leaf)
1180 (declare (type ref ref) (type leaf leaf))
1181 (unless (eq (ref-leaf ref) leaf)
1182 (push ref (leaf-refs leaf))
1184 (setf (ref-leaf ref) leaf)
1185 (let ((ltype (leaf-type leaf)))
1186 (if (fun-type-p ltype)
1187 (setf (node-derived-type ref) ltype)
1188 (derive-node-type ref ltype)))
1189 (reoptimize-continuation (node-cont ref)))
1192 ;;; Change all REFS for OLD-LEAF to NEW-LEAF.
1193 (defun substitute-leaf (new-leaf old-leaf)
1194 (declare (type leaf new-leaf old-leaf))
1195 (dolist (ref (leaf-refs old-leaf))
1196 (change-ref-leaf ref new-leaf))
1199 ;;; like SUBSITUTE-LEAF, only there is a predicate on the REF to tell
1200 ;;; whether to substitute
1201 (defun substitute-leaf-if (test new-leaf old-leaf)
1202 (declare (type leaf new-leaf old-leaf) (type function test))
1203 (dolist (ref (leaf-refs old-leaf))
1204 (when (funcall test ref)
1205 (change-ref-leaf ref new-leaf)))
1208 ;;; Return a LEAF which represents the specified constant object. If
1209 ;;; the object is not in *CONSTANTS*, then we create a new constant
1210 ;;; LEAF and enter it.
1211 (defun find-constant (object)
1213 ;; FIXME: What is the significance of this test? ("things
1214 ;; that are worth uniquifying"?)
1215 '(or symbol number character instance))
1216 (or (gethash object *constants*)
1217 (setf (gethash object *constants*)
1218 (make-constant :value object
1219 :%source-name '.anonymous.
1220 :type (ctype-of object)
1221 :where-from :defined)))
1222 (make-constant :value object
1223 :%source-name '.anonymous.
1224 :type (ctype-of object)
1225 :where-from :defined)))
1227 ;;; If there is a non-local exit noted in ENTRY's environment that
1228 ;;; exits to CONT in that entry, then return it, otherwise return NIL.
1229 (defun find-nlx-info (entry cont)
1230 (declare (type entry entry) (type continuation cont))
1231 (let ((entry-cleanup (entry-cleanup entry)))
1232 (dolist (nlx (physenv-nlx-info (node-physenv entry)) nil)
1233 (when (and (eq (nlx-info-continuation nlx) cont)
1234 (eq (nlx-info-cleanup nlx) entry-cleanup))
1237 ;;;; functional hackery
1239 (declaim (ftype (function (functional) clambda) main-entry))
1240 (defun main-entry (functional)
1241 (etypecase functional
1242 (clambda functional)
1244 (optional-dispatch-main-entry functional))))
1246 ;;; RETURN true if FUNCTIONAL is a thing that can be treated like
1247 ;;; MV-BIND when it appears in an MV-CALL. All fixed arguments must be
1248 ;;; optional with null default and no SUPPLIED-P. There must be a
1249 ;;; &REST arg with no references.
1250 (declaim (ftype (function (functional) boolean) looks-like-an-mv-bind))
1251 (defun looks-like-an-mv-bind (functional)
1252 (and (optional-dispatch-p functional)
1253 (do ((arg (optional-dispatch-arglist functional) (cdr arg)))
1255 (let ((info (lambda-var-arg-info (car arg))))
1256 (unless info (return nil))
1257 (case (arg-info-kind info)
1259 (when (or (arg-info-supplied-p info) (arg-info-default info))
1262 (return (and (null (cdr arg)) (null (leaf-refs (car arg))))))
1266 ;;; Return true if function is an external entry point. This is true
1267 ;;; of normal XEPs (:EXTERNAL kind) and also of top level lambdas
1268 ;;; (:TOPLEVEL kind.)
1270 (declare (type functional fun))
1271 (not (null (member (functional-kind fun) '(:external :toplevel)))))
1273 ;;; If CONT's only use is a non-notinline global function reference,
1274 ;;; then return the referenced symbol, otherwise NIL. If NOTINLINE-OK
1275 ;;; is true, then we don't care if the leaf is NOTINLINE.
1276 (defun continuation-fun-name (cont &optional notinline-ok)
1277 (declare (type continuation cont))
1278 (let ((use (continuation-use cont)))
1280 (let ((leaf (ref-leaf use)))
1281 (if (and (global-var-p leaf)
1282 (eq (global-var-kind leaf) :global-function)
1283 (or (not (defined-fun-p leaf))
1284 (not (eq (defined-fun-inlinep leaf) :notinline))
1286 (leaf-source-name leaf)
1290 ;;; Return the COMBINATION node that is the call to the LET FUN.
1291 (defun let-combination (fun)
1292 (declare (type clambda fun))
1293 (aver (member (functional-kind fun) '(:let :mv-let)))
1294 (continuation-dest (node-cont (first (leaf-refs fun)))))
1296 ;;; Return the initial value continuation for a LET variable, or NIL
1297 ;;; if there is none.
1298 (defun let-var-initial-value (var)
1299 (declare (type lambda-var var))
1300 (let ((fun (lambda-var-home var)))
1301 (elt (combination-args (let-combination fun))
1302 (position-or-lose var (lambda-vars fun)))))
1304 ;;; Return the LAMBDA that is called by the local CALL.
1305 (defun combination-lambda (call)
1306 (declare (type basic-combination call))
1307 (aver (eq (basic-combination-kind call) :local))
1308 (ref-leaf (continuation-use (basic-combination-fun call))))
1310 (defvar *inline-expansion-limit* 200
1312 "an upper limit on the number of inline function calls that will be expanded
1313 in any given code object (single function or block compilation)")
1315 ;;; Check whether NODE's component has exceeded its inline expansion
1316 ;;; limit, and warn if so, returning NIL.
1317 (defun inline-expansion-ok (node)
1318 (let ((expanded (incf (component-inline-expansions
1320 (node-block node))))))
1321 (cond ((> expanded *inline-expansion-limit*) nil)
1322 ((= expanded *inline-expansion-limit*)
1323 ;; FIXME: If the objective is to stop the recursive
1324 ;; expansion of inline functions, wouldn't it be more
1325 ;; correct to look back through surrounding expansions
1326 ;; (which are, I think, stored in the *CURRENT-PATH*, and
1327 ;; possibly stored elsewhere too) and suppress expansion
1328 ;; and print this warning when the function being proposed
1329 ;; for inline expansion is found there? (I don't like the
1330 ;; arbitrary numerical limit in principle, and I think
1331 ;; it'll be a nuisance in practice if we ever want the
1332 ;; compiler to be able to use WITH-COMPILATION-UNIT on
1333 ;; arbitrarily huge blocks of code. -- WHN)
1334 (let ((*compiler-error-context* node))
1335 (compiler-note "*INLINE-EXPANSION-LIMIT* (~W) was exceeded, ~
1336 probably trying to~% ~
1337 inline a recursive function."
1338 *inline-expansion-limit*))
1344 ;;; Apply a function to some arguments, returning a list of the values
1345 ;;; resulting of the evaluation. If an error is signalled during the
1346 ;;; application, then we print a warning message and return NIL as our
1347 ;;; second value to indicate this. Node is used as the error context
1348 ;;; for any error message, and Context is a string that is spliced
1349 ;;; into the warning.
1350 (declaim (ftype (function ((or symbol function) list node string)
1351 (values list boolean))
1353 (defun careful-call (function args node context)
1355 (multiple-value-list
1356 (handler-case (apply function args)
1358 (let ((*compiler-error-context* node))
1359 (compiler-warn "Lisp error during ~A:~%~A" context condition)
1360 (return-from careful-call (values nil nil))))))
1363 ;;;; utilities used at run-time for parsing &KEY args in IR1
1365 ;;; This function is used by the result of PARSE-DEFTRANSFORM to find
1366 ;;; the continuation for the value of the &KEY argument KEY in the
1367 ;;; list of continuations ARGS. It returns the continuation if the
1368 ;;; keyword is present, or NIL otherwise. The legality and
1369 ;;; constantness of the keywords should already have been checked.
1370 (declaim (ftype (function (list keyword) (or continuation null))
1371 find-keyword-continuation))
1372 (defun find-keyword-continuation (args key)
1373 (do ((arg args (cddr arg)))
1375 (when (eq (continuation-value (first arg)) key)
1376 (return (second arg)))))
1378 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1379 ;;; verify that alternating continuations in ARGS are constant and
1380 ;;; that there is an even number of args.
1381 (declaim (ftype (function (list) boolean) check-key-args-constant))
1382 (defun check-key-args-constant (args)
1383 (do ((arg args (cddr arg)))
1385 (unless (and (rest arg)
1386 (constant-continuation-p (first arg)))
1389 ;;; This function is used by the result of PARSE-DEFTRANSFORM to
1390 ;;; verify that the list of continuations ARGS is a well-formed &KEY
1391 ;;; arglist and that only keywords present in the list KEYS are
1393 (declaim (ftype (function (list list) boolean) check-transform-keys))
1394 (defun check-transform-keys (args keys)
1395 (and (check-key-args-constant args)
1396 (do ((arg args (cddr arg)))
1398 (unless (member (continuation-value (first arg)) keys)
1403 ;;; Called by the expansion of the EVENT macro.
1404 (declaim (ftype (function (event-info (or node null)) *) %event))
1405 (defun %event (info node)
1406 (incf (event-info-count info))
1407 (when (and (>= (event-info-level info) *event-note-threshold*)
1408 (policy (or node *lexenv*)
1409 (= inhibit-warnings 0)))
1410 (let ((*compiler-error-context* node))
1411 (compiler-note (event-info-description info))))
1413 (let ((action (event-info-action info)))
1414 (when action (funcall action node))))