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43e67019 | 1 | ;;; cconv.el --- Closure conversion for statically scoped Emacs lisp. -*- lexical-binding: nil -*- |
94d11cb5 | 2 | |
d779e73c SM |
3 | ;; Copyright (C) 2011 Free Software Foundation, Inc. |
4 | ||
5 | ;; Author: Igor Kuzmin <kzuminig@iro.umontreal.ca> | |
6 | ;; Maintainer: FSF | |
7 | ;; Keywords: lisp | |
8 | ;; Package: emacs | |
9 | ||
10 | ;; This file is part of GNU Emacs. | |
11 | ||
12 | ;; GNU Emacs is free software: you can redistribute it and/or modify | |
13 | ;; it under the terms of the GNU General Public License as published by | |
14 | ;; the Free Software Foundation, either version 3 of the License, or | |
15 | ;; (at your option) any later version. | |
16 | ||
17 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;; GNU General Public License for more details. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. | |
94d11cb5 IK |
24 | |
25 | ;;; Commentary: | |
26 | ||
27 | ;; This takes a piece of Elisp code, and eliminates all free variables from | |
28 | ;; lambda expressions. The user entry points are cconv-closure-convert and | |
29 | ;; cconv-closure-convert-toplevel(for toplevel forms). | |
d779e73c SM |
30 | ;; All macros should be expanded beforehand. |
31 | ;; | |
32 | ;; Here is a brief explanation how this code works. | |
33 | ;; Firstly, we analyse the tree by calling cconv-analyse-form. | |
34 | ;; This function finds all mutated variables, all functions that are suitable | |
94d11cb5 IK |
35 | ;; for lambda lifting and all variables captured by closure. It passes the tree |
36 | ;; once, returning a list of three lists. | |
d779e73c SM |
37 | ;; |
38 | ;; Then we calculate the intersection of first and third lists returned by | |
39 | ;; cconv-analyse form to find all mutated variables that are captured by | |
40 | ;; closure. | |
94d11cb5 | 41 | |
d779e73c SM |
42 | ;; Armed with this data, we call cconv-closure-convert-rec, that rewrites the |
43 | ;; tree recursivly, lifting lambdas where possible, building closures where it | |
94d11cb5 IK |
44 | ;; is needed and eliminating mutable variables used in closure. |
45 | ;; | |
46 | ;; We do following replacements : | |
47 | ;; (lambda (v1 ...) ... fv1 fv2 ...) => (lambda (v1 ... fv1 fv2 ) ... fv1 fv2 .) | |
48 | ;; if the function is suitable for lambda lifting (if all calls are known) | |
49 | ;; | |
d779e73c | 50 | ;; (lambda (v1 ...) ... fv ...) => |
94d11cb5 IK |
51 | ;; (curry (lambda (env v1 ...) ... env ...) env) |
52 | ;; if the function has only 1 free variable | |
53 | ;; | |
d779e73c SM |
54 | ;; and finally |
55 | ;; (lambda (v1 ...) ... fv1 fv2 ...) => | |
94d11cb5 | 56 | ;; (curry (lambda (env v1 ..) .. (aref env 0) (aref env 1) ..) (vector fv1 fv2)) |
d779e73c | 57 | ;; if the function has 2 or more free variables. |
94d11cb5 IK |
58 | ;; |
59 | ;; If the function has no free variables, we don't do anything. | |
94d11cb5 | 60 | ;; |
d779e73c SM |
61 | ;; If a variable is mutated (updated by setq), and it is used in a closure |
62 | ;; we wrap it's definition with list: (list val) and we also replace | |
63 | ;; var => (car var) wherever this variable is used, and also | |
64 | ;; (setq var value) => (setcar var value) where it is updated. | |
94d11cb5 | 65 | ;; |
d779e73c SM |
66 | ;; If defun argument is closure mutable, we letbind it and wrap it's |
67 | ;; definition with list. | |
68 | ;; (defun foo (... mutable-arg ...) ...) => | |
69 | ;; (defun foo (... m-arg ...) (let ((m-arg (list m-arg))) ...)) | |
94d11cb5 IK |
70 | ;; |
71 | ;;; Code: | |
72 | ||
94d11cb5 IK |
73 | (eval-when-compile (require 'cl)) |
74 | ||
75 | (defconst cconv-liftwhen 3 | |
d779e73c | 76 | "Try to do lambda lifting if the number of arguments + free variables |
94d11cb5 | 77 | is less than this number.") |
d779e73c | 78 | (defvar cconv-mutated nil |
94d11cb5 | 79 | "List of mutated variables in current form") |
d779e73c | 80 | (defvar cconv-captured nil |
94d11cb5 | 81 | "List of closure captured variables in current form") |
d779e73c | 82 | (defvar cconv-captured+mutated nil |
94d11cb5 | 83 | "An intersection between cconv-mutated and cconv-captured lists.") |
d779e73c | 84 | (defvar cconv-lambda-candidates nil |
43e67019 SM |
85 | "List of candidates for lambda lifting. |
86 | Each candidate has the form (VAR INCLOSURE BINDER PARENTFORM).") | |
87 | ||
88 | (defun cconv-not-lexical-var-p (var) | |
89 | (or (not (symbolp var)) ; form is not a list | |
295fb2ac SM |
90 | (if (eval-when-compile (fboundp 'special-variable-p)) |
91 | (special-variable-p var) | |
92 | (boundp var)) | |
43e67019 SM |
93 | ;; byte-compile-bound-variables normally holds both the |
94 | ;; dynamic and lexical vars, but the bytecomp.el should | |
95 | ;; only call us at the top-level so there shouldn't be | |
96 | ;; any lexical vars in it here. | |
97 | (memq var byte-compile-bound-variables) | |
98 | (memq var '(nil t)) | |
99 | (keywordp var))) | |
94d11cb5 | 100 | |
94d11cb5 IK |
101 | (defun cconv-freevars (form &optional fvrs) |
102 | "Find all free variables of given form. | |
103 | Arguments: | |
104 | -- FORM is a piece of Elisp code after macroexpansion. | |
105 | -- FVRS(optional) is a list of variables already found. Used for recursive tree | |
106 | traversal | |
107 | ||
108 | Returns a list of free variables." | |
109 | ;; If a leaf in the tree is a symbol, but it is not a global variable, not a | |
110 | ;; keyword, not 'nil or 't we consider this leaf as a variable. | |
111 | ;; Free variables are the variables that are not declared above in this tree. | |
d779e73c | 112 | ;; For example free variables of (lambda (a1 a2 ..) body-forms) are |
94d11cb5 | 113 | ;; free variables of body-forms excluding a1, a2 .. |
d779e73c | 114 | ;; Free variables of (let ((v1 ..) (v2) ..)) body-forms) are |
94d11cb5 | 115 | ;; free variables of body-forms excluding v1, v2 ... |
d779e73c | 116 | ;; and so on. |
94d11cb5 | 117 | |
d779e73c | 118 | ;; A list of free variables already found(FVRS) is passed in parameter |
94d11cb5 | 119 | ;; to try to use cons or push where possible, and to minimize the usage |
d779e73c | 120 | ;; of append. |
94d11cb5 | 121 | |
d779e73c | 122 | ;; This function can return duplicates (because we use 'append instead |
94d11cb5 IK |
123 | ;; of union of two sets - for performance reasons). |
124 | (pcase form | |
d779e73c SM |
125 | (`(let ,varsvalues . ,body-forms) ; let special form |
126 | (let ((fvrs-1 '())) | |
127 | (dolist (exp body-forms) | |
128 | (setq fvrs-1 (cconv-freevars exp fvrs-1))) | |
129 | (dolist (elm varsvalues) | |
130 | (setq fvrs-1 (delq (if (consp elm) (car elm) elm) fvrs-1))) | |
131 | (setq fvrs (nconc fvrs-1 fvrs)) | |
132 | (dolist (exp varsvalues) | |
133 | (when (consp exp) (setq fvrs (cconv-freevars (cadr exp) fvrs)))) | |
134 | fvrs)) | |
135 | ||
136 | (`(let* ,varsvalues . ,body-forms) ; let* special form | |
137 | (let ((vrs '()) | |
138 | (fvrs-1 '())) | |
139 | (dolist (exp varsvalues) | |
140 | (if (consp exp) | |
141 | (progn | |
142 | (setq fvrs-1 (cconv-freevars (cadr exp) fvrs-1)) | |
143 | (dolist (elm vrs) (setq fvrs-1 (delq elm fvrs-1))) | |
144 | (push (car exp) vrs)) | |
145 | (progn | |
146 | (dolist (elm vrs) (setq fvrs-1 (delq elm fvrs-1))) | |
147 | (push exp vrs)))) | |
148 | (dolist (exp body-forms) | |
149 | (setq fvrs-1 (cconv-freevars exp fvrs-1))) | |
150 | (dolist (elm vrs) (setq fvrs-1 (delq elm fvrs-1))) | |
151 | (append fvrs fvrs-1))) | |
152 | ||
153 | (`((lambda . ,_) . ,_) ; first element is lambda expression | |
154 | (dolist (exp `((function ,(car form)) . ,(cdr form))) | |
155 | (setq fvrs (cconv-freevars exp fvrs))) fvrs) | |
156 | ||
157 | (`(cond . ,cond-forms) ; cond special form | |
158 | (dolist (exp1 cond-forms) | |
159 | (dolist (exp2 exp1) | |
160 | (setq fvrs (cconv-freevars exp2 fvrs)))) fvrs) | |
161 | ||
162 | (`(quote . ,_) fvrs) ; quote form | |
163 | ||
164 | (`(function . ((lambda ,vars . ,body-forms))) | |
165 | (let ((functionform (cadr form)) (fvrs-1 '())) | |
166 | (dolist (exp body-forms) | |
167 | (setq fvrs-1 (cconv-freevars exp fvrs-1))) | |
168 | (dolist (elm vars) (setq fvrs-1 (delq elm fvrs-1))) | |
169 | (append fvrs fvrs-1))) ; function form | |
170 | ||
171 | (`(function . ,_) fvrs) ; same as quote | |
94d11cb5 | 172 | ;condition-case |
d779e73c SM |
173 | (`(condition-case ,var ,protected-form . ,conditions-bodies) |
174 | (let ((fvrs-1 '())) | |
175 | (dolist (exp conditions-bodies) | |
176 | (setq fvrs-1 (cconv-freevars (cadr exp) fvrs-1))) | |
177 | (setq fvrs-1 (delq var fvrs-1)) | |
178 | (setq fvrs-1 (cconv-freevars protected-form fvrs-1)) | |
179 | (append fvrs fvrs-1))) | |
180 | ||
181 | (`(,(and sym (or `defun `defconst `defvar)) . ,_) | |
43e67019 | 182 | ;; We call cconv-freevars only for functions(lambdas) |
d779e73c | 183 | ;; defun, defconst, defvar are not allowed to be inside |
43e67019 SM |
184 | ;; a function (lambda). |
185 | ;; FIXME: should be a byte-compile-report-error! | |
d779e73c SM |
186 | (error "Invalid form: %s inside a function" sym)) |
187 | ||
43e67019 | 188 | (`(,_ . ,body-forms) ; First element is (like) a function. |
d779e73c SM |
189 | (dolist (exp body-forms) |
190 | (setq fvrs (cconv-freevars exp fvrs))) fvrs) | |
191 | ||
43e67019 | 192 | (_ (if (cconv-not-lexical-var-p form) |
d779e73c SM |
193 | fvrs |
194 | (cons form fvrs))))) | |
94d11cb5 IK |
195 | |
196 | ;;;###autoload | |
295fb2ac SM |
197 | (defun cconv-closure-convert (form) |
198 | "Main entry point for closure conversion. | |
94d11cb5 IK |
199 | -- FORM is a piece of Elisp code after macroexpansion. |
200 | -- TOPLEVEL(optional) is a boolean variable, true if we are at the root of AST | |
201 | ||
202 | Returns a form where all lambdas don't have any free variables." | |
43e67019 | 203 | (message "Entering cconv-closure-convert...") |
94d11cb5 IK |
204 | (let ((cconv-mutated '()) |
205 | (cconv-lambda-candidates '()) | |
206 | (cconv-captured '()) | |
d779e73c SM |
207 | (cconv-captured+mutated '())) |
208 | ;; Analyse form - fill these variables with new information | |
43e67019 | 209 | (cconv-analyse-form form '() 0) |
d779e73c SM |
210 | ;; Calculate an intersection of cconv-mutated and cconv-captured |
211 | (dolist (mvr cconv-mutated) | |
212 | (when (memq mvr cconv-captured) ; | |
213 | (push mvr cconv-captured+mutated))) | |
214 | (cconv-closure-convert-rec | |
215 | form ; the tree | |
216 | '() ; | |
217 | '() ; fvrs initially empty | |
218 | '() ; envs initially empty | |
94d11cb5 | 219 | '() |
295fb2ac | 220 | ))) |
94d11cb5 | 221 | |
295fb2ac SM |
222 | (defun cconv-lookup-let (table var binder form) |
223 | (let ((res nil)) | |
224 | (dolist (elem table) | |
225 | (when (and (eq (nth 2 elem) binder) | |
226 | (eq (nth 3 elem) form)) | |
227 | (assert (eq (car elem) var)) | |
228 | (setq res elem))) | |
229 | res)) | |
94d11cb5 | 230 | |
295fb2ac | 231 | (defconst cconv--dummy-var (make-symbol "ignored")) |
94d11cb5 | 232 | |
d779e73c | 233 | (defun cconv-closure-convert-rec |
295fb2ac | 234 | (form emvrs fvrs envs lmenvs) |
d779e73c | 235 | ;; This function actually rewrites the tree. |
94d11cb5 IK |
236 | "Eliminates all free variables of all lambdas in given forms. |
237 | Arguments: | |
238 | -- FORM is a piece of Elisp code after macroexpansion. | |
239 | -- LMENVS is a list of environments used for lambda-lifting. Initially empty. | |
240 | -- EMVRS is a list that contains mutated variables that are visible | |
241 | within current environment. | |
d779e73c SM |
242 | -- ENVS is an environment(list of free variables) of current closure. |
243 | Initially empty. | |
244 | -- FVRS is a list of variables to substitute in each context. | |
245 | Initially empty. | |
94d11cb5 IK |
246 | |
247 | Returns a form where all lambdas don't have any free variables." | |
d779e73c | 248 | ;; What's the difference between fvrs and envs? |
94d11cb5 IK |
249 | ;; Suppose that we have the code |
250 | ;; (lambda (..) fvr (let ((fvr 1)) (+ fvr 1))) | |
d779e73c SM |
251 | ;; only the first occurrence of fvr should be replaced by |
252 | ;; (aref env ...). | |
94d11cb5 IK |
253 | ;; So initially envs and fvrs are the same thing, but when we descend to |
254 | ;; the 'let, we delete fvr from fvrs. Why we don't delete fvr from envs? | |
255 | ;; Because in envs the order of variables is important. We use this list | |
d779e73c SM |
256 | ;; to find the number of a specific variable in the environment vector, |
257 | ;; so we never touch it(unless we enter to the other closure). | |
258 | ;;(if (listp form) (print (car form)) form) | |
259 | (pcase form | |
295fb2ac | 260 | (`(,(and letsym (or `let* `let)) ,binders . ,body-forms) |
94d11cb5 IK |
261 | |
262 | ; let and let* special forms | |
d779e73c | 263 | (let ((body-forms-new '()) |
295fb2ac | 264 | (binders-new '()) |
d779e73c SM |
265 | ;; next for variables needed for delayed push |
266 | ;; because we should process <value(s)> | |
267 | ;; before we change any arguments | |
268 | (lmenvs-new '()) ;needed only in case of let | |
269 | (emvrs-new '()) ;needed only in case of let | |
270 | (emvr-push) ;needed only in case of let* | |
271 | (lmenv-push)) ;needed only in case of let* | |
272 | ||
295fb2ac SM |
273 | (dolist (binder binders) |
274 | (let* ((value nil) | |
275 | (var (if (not (consp binder)) | |
276 | binder | |
277 | (setq value (cadr binder)) | |
278 | (car binder))) | |
279 | (new-val | |
280 | (cond | |
281 | ;; Check if var is a candidate for lambda lifting. | |
282 | ((cconv-lookup-let cconv-lambda-candidates var binder form) | |
283 | ||
284 | (let* ((fv (delete-dups (cconv-freevars value '()))) | |
285 | (funargs (cadr (cadr value))) | |
286 | (funcvars (append fv funargs)) | |
287 | (funcbodies (cddadr value)) ; function bodies | |
288 | (funcbodies-new '())) | |
94d11cb5 | 289 | ; lambda lifting condition |
295fb2ac | 290 | (if (or (not fv) (< cconv-liftwhen (length funcvars))) |
94d11cb5 | 291 | ; do not lift |
295fb2ac SM |
292 | (cconv-closure-convert-rec |
293 | value emvrs fvrs envs lmenvs) | |
94d11cb5 | 294 | ; lift |
295fb2ac SM |
295 | (progn |
296 | (dolist (elm2 funcbodies) | |
297 | (push ; convert function bodies | |
298 | (cconv-closure-convert-rec | |
299 | elm2 emvrs nil envs lmenvs) | |
300 | funcbodies-new)) | |
301 | (if (eq letsym 'let*) | |
302 | (setq lmenv-push (cons var fv)) | |
303 | (push (cons var fv) lmenvs-new)) | |
94d11cb5 IK |
304 | ; push lifted function |
305 | ||
295fb2ac SM |
306 | `(function . |
307 | ((lambda ,funcvars . | |
308 | ,(reverse funcbodies-new)))))))) | |
309 | ||
310 | ;; Check if it needs to be turned into a "ref-cell". | |
311 | ((cconv-lookup-let cconv-captured+mutated var binder form) | |
312 | ;; Declared variable is mutated and captured. | |
313 | (prog1 | |
314 | `(list ,(cconv-closure-convert-rec | |
315 | value emvrs | |
316 | fvrs envs lmenvs)) | |
d779e73c SM |
317 | (if (eq letsym 'let*) |
318 | (setq emvr-push var) | |
295fb2ac SM |
319 | (push var emvrs-new)))) |
320 | ||
321 | ;; Normal default case. | |
322 | (t | |
323 | (cconv-closure-convert-rec | |
324 | value emvrs fvrs envs lmenvs))))) | |
d779e73c SM |
325 | |
326 | ;; this piece of code below letbinds free | |
327 | ;; variables of a lambda lifted function | |
328 | ;; if they are redefined in this let | |
329 | ;; example: | |
330 | ;; (let* ((fun (lambda (x) (+ x y))) (y 1)) (funcall fun 1)) | |
331 | ;; Here we can not pass y as parameter because it is | |
332 | ;; redefined. We add a (closed-y y) declaration. | |
333 | ;; We do that even if the function is not used inside | |
334 | ;; this let(*). The reason why we ignore this case is | |
335 | ;; that we can't "look forward" to see if the function | |
336 | ;; is called there or not. To treat well this case we | |
337 | ;; need to traverse the tree one more time to collect this | |
338 | ;; data, and I think that it's not worth it. | |
339 | ||
340 | (when (eq letsym 'let*) | |
341 | (let ((closedsym '()) | |
342 | (new-lmenv '()) | |
343 | (old-lmenv '())) | |
344 | (dolist (lmenv lmenvs) | |
345 | (when (memq var (cdr lmenv)) | |
346 | (setq closedsym | |
347 | (make-symbol | |
348 | (concat "closed-" (symbol-name var)))) | |
349 | (setq new-lmenv (list (car lmenv))) | |
350 | (dolist (frv (cdr lmenv)) (if (eq frv var) | |
351 | (push closedsym new-lmenv) | |
352 | (push frv new-lmenv))) | |
353 | (setq new-lmenv (reverse new-lmenv)) | |
354 | (setq old-lmenv lmenv))) | |
355 | (when new-lmenv | |
356 | (setq lmenvs (remq old-lmenv lmenvs)) | |
357 | (push new-lmenv lmenvs) | |
295fb2ac | 358 | (push `(,closedsym ,var) binders-new)))) |
d779e73c SM |
359 | ;; we push the element after redefined free variables |
360 | ;; are processes. this is important to avoid the bug | |
361 | ;; when free variable and the function have the same | |
362 | ;; name | |
295fb2ac | 363 | (push (list var new-val) binders-new) |
d779e73c SM |
364 | |
365 | (when (eq letsym 'let*) ; update fvrs | |
366 | (setq fvrs (remq var fvrs)) | |
367 | (setq emvrs (remq var emvrs)) ; remove if redefined | |
368 | (when emvr-push | |
369 | (push emvr-push emvrs) | |
370 | (setq emvr-push nil)) | |
371 | (let (lmenvs-1) ; remove var from lmenvs if redefined | |
372 | (dolist (iter lmenvs) | |
373 | (when (not (assq var lmenvs)) | |
374 | (push iter lmenvs-1))) | |
375 | (setq lmenvs lmenvs-1)) | |
376 | (when lmenv-push | |
377 | (push lmenv-push lmenvs) | |
378 | (setq lmenv-push nil))) | |
295fb2ac | 379 | )) ; end of dolist over binders |
d779e73c SM |
380 | (when (eq letsym 'let) |
381 | ||
382 | (let (var fvrs-1 emvrs-1 lmenvs-1) | |
383 | ;; Here we update emvrs, fvrs and lmenvs lists | |
384 | (dolist (vr fvrs) | |
94d11cb5 | 385 | ; safely remove |
295fb2ac | 386 | (when (not (assq vr binders-new)) (push vr fvrs-1))) |
d779e73c SM |
387 | (setq fvrs fvrs-1) |
388 | (dolist (vr emvrs) | |
94d11cb5 | 389 | ; safely remove |
295fb2ac | 390 | (when (not (assq vr binders-new)) (push vr emvrs-1))) |
d779e73c | 391 | (setq emvrs emvrs-1) |
94d11cb5 | 392 | ; push new |
d779e73c SM |
393 | (setq emvrs (append emvrs emvrs-new)) |
394 | (dolist (vr lmenvs) | |
295fb2ac | 395 | (when (not (assq (car vr) binders-new)) |
d779e73c SM |
396 | (push vr lmenvs-1))) |
397 | (setq lmenvs (append lmenvs lmenvs-new))) | |
398 | ||
399 | ;; Here we do the same letbinding as for let* above | |
400 | ;; to avoid situation when a free variable of a lambda lifted | |
401 | ;; function got redefined. | |
402 | ||
403 | (let ((new-lmenv) | |
404 | (var nil) | |
405 | (closedsym nil) | |
295fb2ac SM |
406 | (letbinds '())) |
407 | (dolist (binder binders) | |
408 | (setq var (if (consp binder) (car binder) binder)) | |
d779e73c SM |
409 | |
410 | (let ((lmenvs-1 lmenvs)) ; just to avoid manipulating | |
411 | (dolist (lmenv lmenvs-1) ; the counter inside the loop | |
412 | (when (memq var (cdr lmenv)) | |
413 | (setq closedsym (make-symbol | |
414 | (concat "closed-" | |
415 | (symbol-name var)))) | |
416 | ||
417 | (setq new-lmenv (list (car lmenv))) | |
418 | (dolist (frv (cdr lmenv)) (if (eq frv var) | |
419 | (push closedsym new-lmenv) | |
420 | (push frv new-lmenv))) | |
421 | (setq new-lmenv (reverse new-lmenv)) | |
422 | (setq lmenvs (remq lmenv lmenvs)) | |
423 | (push new-lmenv lmenvs) | |
424 | (push `(,closedsym ,var) letbinds) | |
425 | )))) | |
295fb2ac | 426 | (setq binders-new (append binders-new letbinds)))) |
d779e73c SM |
427 | |
428 | (dolist (elm body-forms) ; convert body forms | |
429 | (push (cconv-closure-convert-rec | |
295fb2ac | 430 | elm emvrs fvrs envs lmenvs) |
d779e73c | 431 | body-forms-new)) |
295fb2ac | 432 | `(,letsym ,(reverse binders-new) . ,(reverse body-forms-new)))) |
94d11cb5 IK |
433 | ;end of let let* forms |
434 | ||
d779e73c SM |
435 | ; first element is lambda expression |
436 | (`(,(and `(lambda . ,_) fun) . ,other-body-forms) | |
437 | ||
438 | (let ((other-body-forms-new '())) | |
439 | (dolist (elm other-body-forms) | |
440 | (push (cconv-closure-convert-rec | |
295fb2ac | 441 | elm emvrs fvrs envs lmenvs) |
d779e73c | 442 | other-body-forms-new)) |
295fb2ac SM |
443 | `(funcall |
444 | ,(cconv-closure-convert-rec | |
445 | (list 'function fun) emvrs fvrs envs lmenvs) | |
446 | ,@(nreverse other-body-forms-new)))) | |
d779e73c SM |
447 | |
448 | (`(cond . ,cond-forms) ; cond special form | |
449 | (let ((cond-forms-new '())) | |
450 | (dolist (elm cond-forms) | |
451 | (push (let ((elm-new '())) | |
452 | (dolist (elm-2 elm) | |
453 | (push | |
454 | (cconv-closure-convert-rec | |
295fb2ac | 455 | elm-2 emvrs fvrs envs lmenvs) |
d779e73c SM |
456 | elm-new)) |
457 | (reverse elm-new)) | |
458 | cond-forms-new)) | |
459 | (cons 'cond | |
460 | (reverse cond-forms-new)))) | |
461 | ||
462 | (`(quote . ,_) form) ; quote form | |
463 | ||
464 | (`(function . ((lambda ,vars . ,body-forms))) ; function form | |
43e67019 | 465 | (let (fvrs-new) ; we remove vars from fvrs |
d779e73c SM |
466 | (dolist (elm fvrs) ;i use such a tricky way to avoid side effects |
467 | (when (not (memq elm vars)) | |
468 | (push elm fvrs-new))) | |
469 | (setq fvrs fvrs-new)) | |
470 | (let* ((fv (delete-dups (cconv-freevars form '()))) | |
471 | (leave fvrs) ; leave = non nil if we should leave env unchanged | |
472 | (body-forms-new '()) | |
473 | (letbind '()) | |
474 | (mv nil) | |
475 | (envector nil)) | |
476 | (when fv | |
477 | ;; Here we form our environment vector. | |
478 | ;; If outer closure contains all | |
479 | ;; free variables of this function(and nothing else) | |
480 | ;; then we use the same environment vector as for outer closure, | |
481 | ;; i.e. we leave the environment vector unchanged | |
482 | ;; otherwise we build a new environmet vector | |
483 | (if (eq (length envs) (length fv)) | |
484 | (let ((fv-temp fv)) | |
485 | (while (and fv-temp leave) | |
486 | (when (not (memq (car fv-temp) fvrs)) (setq leave nil)) | |
487 | (setq fv-temp (cdr fv-temp)))) | |
488 | (setq leave nil)) | |
489 | ||
490 | (if (not leave) | |
491 | (progn | |
492 | (dolist (elm fv) | |
493 | (push | |
494 | (cconv-closure-convert-rec | |
295fb2ac | 495 | elm (remq elm emvrs) fvrs envs lmenvs) |
d779e73c SM |
496 | envector)) ; process vars for closure vector |
497 | (setq envector (reverse envector)) | |
498 | (setq envs fv)) | |
499 | (setq envector `(env))) ; leave unchanged | |
500 | (setq fvrs fv)) ; update substitution list | |
501 | ||
502 | ;; the difference between envs and fvrs is explained | |
503 | ;; in comment in the beginning of the function | |
504 | (dolist (elm cconv-captured+mutated) ; find mutated arguments | |
505 | (setq mv (car elm)) ; used in inner closures | |
506 | (when (and (memq mv vars) (eq form (caddr elm))) | |
507 | (progn (push mv emvrs) | |
508 | (push `(,mv (list ,mv)) letbind)))) | |
509 | (dolist (elm body-forms) ; convert function body | |
510 | (push (cconv-closure-convert-rec | |
295fb2ac | 511 | elm emvrs fvrs envs lmenvs) |
d779e73c SM |
512 | body-forms-new)) |
513 | ||
514 | (setq body-forms-new | |
515 | (if letbind `((let ,letbind . ,(reverse body-forms-new))) | |
516 | (reverse body-forms-new))) | |
517 | ||
518 | (cond | |
94d11cb5 | 519 | ;if no freevars - do nothing |
d779e73c SM |
520 | ((null envector) |
521 | `(function (lambda ,vars . ,body-forms-new))) | |
522 | ; 1 free variable - do not build vector | |
523 | ((null (cdr envector)) | |
524 | `(curry | |
525 | (function (lambda (env . ,vars) . ,body-forms-new)) | |
526 | ,(car envector))) | |
527 | ; >=2 free variables - build vector | |
528 | (t | |
529 | `(curry | |
530 | (function (lambda (env . ,vars) . ,body-forms-new)) | |
531 | (vector . ,envector)))))) | |
532 | ||
533 | (`(function . ,_) form) ; same as quote | |
94d11cb5 IK |
534 | |
535 | ;defconst, defvar | |
d779e73c SM |
536 | (`(,(and sym (or `defconst `defvar)) ,definedsymbol . ,body-forms) |
537 | ||
295fb2ac SM |
538 | (let ((body-forms-new '())) |
539 | (dolist (elm body-forms) | |
540 | (push (cconv-closure-convert-rec | |
541 | elm emvrs fvrs envs lmenvs) | |
542 | body-forms-new)) | |
543 | (setq body-forms-new (reverse body-forms-new)) | |
544 | `(,sym ,definedsymbol . ,body-forms-new))) | |
d779e73c SM |
545 | |
546 | ;defun, defmacro | |
547 | (`(,(and sym (or `defun `defmacro)) | |
548 | ,func ,vars . ,body-forms) | |
295fb2ac SM |
549 | (let ((body-new '()) ; the whole body |
550 | (body-forms-new '()) ; body w\o docstring and interactive | |
551 | (letbind '())) | |
94d11cb5 | 552 | ; find mutable arguments |
295fb2ac SM |
553 | (let ((lmutated cconv-captured+mutated) ismutated) |
554 | (dolist (elm vars) | |
555 | (setq ismutated nil) | |
556 | (while (and lmutated (not ismutated)) | |
557 | (when (and (eq (caar lmutated) elm) | |
558 | (eq (cadar lmutated) form)) | |
559 | (setq ismutated t)) | |
560 | (setq lmutated (cdr lmutated))) | |
561 | (when ismutated | |
562 | (push elm letbind) | |
563 | (push elm emvrs)))) | |
43e67019 | 564 | ;transform body-forms |
295fb2ac SM |
565 | (when (stringp (car body-forms)) ; treat docstring well |
566 | (push (car body-forms) body-new) | |
567 | (setq body-forms (cdr body-forms))) | |
568 | (when (eq (car-safe (car body-forms)) 'interactive) | |
569 | (push (cconv-closure-convert-rec | |
570 | (car body-forms) | |
571 | emvrs fvrs envs lmenvs) | |
572 | body-new) | |
573 | (setq body-forms (cdr body-forms))) | |
574 | ||
575 | (dolist (elm body-forms) | |
576 | (push (cconv-closure-convert-rec | |
577 | elm emvrs fvrs envs lmenvs) | |
578 | body-forms-new)) | |
579 | (setq body-forms-new (reverse body-forms-new)) | |
d779e73c | 580 | |
295fb2ac | 581 | (if letbind |
94d11cb5 | 582 | ; letbind mutable arguments |
295fb2ac SM |
583 | (let ((binders-new '())) |
584 | (dolist (elm letbind) (push `(,elm (list ,elm)) | |
585 | binders-new)) | |
586 | (push `(let ,(reverse binders-new) . | |
587 | ,body-forms-new) body-new) | |
588 | (setq body-new (reverse body-new))) | |
589 | (setq body-new (append (reverse body-new) body-forms-new))) | |
94d11cb5 | 590 | |
295fb2ac | 591 | `(,sym ,func ,vars . ,body-new))) |
94d11cb5 | 592 | |
94d11cb5 | 593 | ;condition-case |
295fb2ac SM |
594 | (`(condition-case ,var ,protected-form . ,handlers) |
595 | (let ((handlers-new '()) | |
596 | (newform (cconv-closure-convert-rec | |
597 | `(function (lambda () ,protected-form)) | |
598 | emvrs fvrs envs lmenvs))) | |
d779e73c | 599 | (setq fvrs (remq var fvrs)) |
295fb2ac SM |
600 | (dolist (handler handlers) |
601 | (push (list (car handler) | |
602 | (cconv-closure-convert-rec | |
603 | `(function (lambda (,(or var cconv--dummy-var)) | |
604 | ,@(cdr handler))) | |
605 | emvrs fvrs envs lmenvs)) | |
606 | handlers-new)) | |
607 | `(condition-case :fun-body ,newform | |
608 | ,@(nreverse handlers-new)))) | |
609 | ||
610 | (`(,(and head (or `catch `unwind-protect)) ,form . ,body) | |
611 | `(,head ,(cconv-closure-convert-rec form emvrs fvrs envs lmenvs) | |
612 | :fun-body | |
613 | ,(cconv-closure-convert-rec `(function (lambda () ,@body)) | |
614 | emvrs fvrs envs lmenvs))) | |
615 | ||
616 | (`(,(and head (or `save-window-excursion `track-mouse)) . ,body) | |
617 | `(,head | |
618 | :fun-body | |
619 | ,(cconv-closure-convert-rec `(function (lambda () ,@body)) | |
620 | emvrs fvrs envs lmenvs))) | |
d779e73c SM |
621 | |
622 | (`(setq . ,forms) ; setq special form | |
623 | (let (prognlist sym sym-new value) | |
624 | (while forms | |
625 | (setq sym (car forms)) | |
626 | (setq sym-new (cconv-closure-convert-rec | |
627 | sym | |
295fb2ac | 628 | (remq sym emvrs) fvrs envs lmenvs)) |
d779e73c SM |
629 | (setq value |
630 | (cconv-closure-convert-rec | |
295fb2ac | 631 | (cadr forms) emvrs fvrs envs lmenvs)) |
d779e73c SM |
632 | (if (memq sym emvrs) |
633 | (push `(setcar ,sym-new ,value) prognlist) | |
634 | (if (symbolp sym-new) | |
635 | (push `(setq ,sym-new ,value) prognlist) | |
636 | (push `(set ,sym-new ,value) prognlist))) | |
637 | (setq forms (cddr forms))) | |
638 | (if (cdr prognlist) | |
639 | `(progn . ,(reverse prognlist)) | |
640 | (car prognlist)))) | |
641 | ||
642 | (`(,(and (or `funcall `apply) callsym) ,fun . ,args) | |
643 | ; funcall is not a special form | |
644 | ; but we treat it separately | |
645 | ; for the needs of lambda lifting | |
646 | (let ((fv (cdr (assq fun lmenvs)))) | |
647 | (if fv | |
648 | (let ((args-new '()) | |
649 | (processed-fv '())) | |
650 | ;; All args (free variables and actual arguments) | |
651 | ;; should be processed, because they can be fvrs | |
652 | ;; (free variables of another closure) | |
653 | (dolist (fvr fv) | |
654 | (push (cconv-closure-convert-rec | |
655 | fvr (remq fvr emvrs) | |
295fb2ac | 656 | fvrs envs lmenvs) |
d779e73c SM |
657 | processed-fv)) |
658 | (setq processed-fv (reverse processed-fv)) | |
659 | (dolist (elm args) | |
660 | (push (cconv-closure-convert-rec | |
295fb2ac | 661 | elm emvrs fvrs envs lmenvs) |
d779e73c SM |
662 | args-new)) |
663 | (setq args-new (append processed-fv (reverse args-new))) | |
664 | (setq fun (cconv-closure-convert-rec | |
295fb2ac | 665 | fun emvrs fvrs envs lmenvs)) |
d779e73c SM |
666 | `(,callsym ,fun . ,args-new)) |
667 | (let ((cdr-new '())) | |
668 | (dolist (elm (cdr form)) | |
669 | (push (cconv-closure-convert-rec | |
295fb2ac | 670 | elm emvrs fvrs envs lmenvs) |
d779e73c SM |
671 | cdr-new)) |
672 | `(,callsym . ,(reverse cdr-new)))))) | |
673 | ||
674 | (`(,func . ,body-forms) ; first element is function or whatever | |
675 | ; function-like forms are: | |
676 | ; or, and, if, progn, prog1, prog2, | |
677 | ; while, until | |
678 | (let ((body-forms-new '())) | |
679 | (dolist (elm body-forms) | |
680 | (push (cconv-closure-convert-rec | |
295fb2ac | 681 | elm emvrs fvrs envs lmenvs) |
d779e73c SM |
682 | body-forms-new)) |
683 | (setq body-forms-new (reverse body-forms-new)) | |
684 | `(,func . ,body-forms-new))) | |
685 | ||
686 | (_ | |
43e67019 SM |
687 | (let ((free (memq form fvrs))) |
688 | (if free ;form is a free variable | |
689 | (let* ((numero (- (length fvrs) (length free))) | |
690 | (var '())) | |
691 | (assert numero) | |
692 | (if (null (cdr envs)) | |
693 | (setq var 'env) | |
d779e73c | 694 | ;replace form => |
94d11cb5 | 695 | ;(aref env #) |
43e67019 SM |
696 | (setq var `(aref env ,numero))) |
697 | (if (memq form emvrs) ; form => (car (aref env #)) if mutable | |
698 | `(car ,var) | |
699 | var)) | |
700 | (if (memq form emvrs) ; if form is a mutable variable | |
701 | `(car ,form) ; replace form => (car form) | |
702 | form)))))) | |
703 | ||
704 | (defun cconv-analyse-function (args body env parentform inclosure) | |
705 | (dolist (arg args) | |
706 | (cond | |
707 | ((cconv-not-lexical-var-p arg) | |
708 | (byte-compile-report-error | |
709 | (format "Argument %S is not a lexical variable" arg))) | |
710 | ((eq ?& (aref (symbol-name arg) 0)) nil) ;Ignore &rest, &optional, ... | |
711 | (t (push (list arg inclosure parentform) env)))) ;Push vrs to vars. | |
712 | (dolist (form body) ;Analyse body forms. | |
713 | (cconv-analyse-form form env inclosure))) | |
714 | ||
715 | (defun cconv-analyse-form (form env inclosure) | |
d779e73c SM |
716 | "Find mutated variables and variables captured by closure. Analyse |
717 | lambdas if they are suitable for lambda lifting. | |
94d11cb5 | 718 | -- FORM is a piece of Elisp code after macroexpansion. |
43e67019 SM |
719 | -- ENV is a list of variables visible in current lexical environment. |
720 | Each entry has the form (VAR INCLOSURE BINDER PARENTFORM) | |
721 | for let-bound vars and (VAR INCLOSURE PARENTFORM) for function arguments. | |
722 | -- INCLOSURE is the nesting level within lambdas." | |
94d11cb5 IK |
723 | (pcase form |
724 | ; let special form | |
43e67019 | 725 | (`(,(and (or `let* `let) letsym) ,binders . ,body-forms) |
d779e73c | 726 | |
43e67019 | 727 | (let ((orig-env env) |
d779e73c | 728 | (var nil) |
43e67019 SM |
729 | (value nil)) |
730 | (dolist (binder binders) | |
731 | (if (not (consp binder)) | |
d779e73c | 732 | (progn |
43e67019 SM |
733 | (setq var binder) ; treat the form (let (x) ...) well |
734 | (setq value nil)) | |
735 | (setq var (car binder)) | |
736 | (setq value (cadr binder)) | |
737 | ||
738 | (cconv-analyse-form value (if (eq letsym 'let*) env orig-env) | |
739 | inclosure)) | |
740 | ||
741 | (unless (cconv-not-lexical-var-p var) | |
742 | (let ((varstruct (list var inclosure binder form))) | |
743 | (push varstruct env) ; Push a new one. | |
744 | ||
745 | (pcase value | |
746 | (`(function (lambda . ,_)) | |
747 | ;; If var is a function push it to lambda list. | |
748 | (push varstruct cconv-lambda-candidates))))))) | |
749 | ||
750 | (dolist (form body-forms) ; Analyse body forms. | |
751 | (cconv-analyse-form form env inclosure))) | |
752 | ||
94d11cb5 | 753 | ; defun special form |
d779e73c | 754 | (`(,(or `defun `defmacro) ,func ,vrs . ,body-forms) |
43e67019 SM |
755 | (when env |
756 | (byte-compile-log-warning | |
757 | (format "Function %S will ignore its context %S" | |
758 | func (mapcar #'car env)) | |
759 | t :warning)) | |
760 | (cconv-analyse-function vrs body-forms nil form 0)) | |
761 | ||
762 | (`(function (lambda ,vrs . ,body-forms)) | |
763 | (cconv-analyse-function vrs body-forms env form (1+ inclosure))) | |
764 | ||
765 | (`(setq . ,forms) | |
766 | ;; If a local variable (member of env) is modified by setq then | |
767 | ;; it is a mutated variable. | |
d779e73c | 768 | (while forms |
43e67019 | 769 | (let ((v (assq (car forms) env))) ; v = non nil if visible |
d779e73c SM |
770 | (when v |
771 | (push v cconv-mutated) | |
43e67019 | 772 | ;; Delete from candidate list for lambda lifting. |
d779e73c | 773 | (setq cconv-lambda-candidates (delq v cconv-lambda-candidates)) |
43e67019 SM |
774 | (unless (eq inclosure (cadr v)) ;Bound in a different closure level. |
775 | (push v cconv-captured)))) | |
776 | (cconv-analyse-form (cadr forms) env inclosure) | |
777 | (setq forms (cddr forms)))) | |
778 | ||
779 | (`((lambda . ,_) . ,_) ; first element is lambda expression | |
d779e73c | 780 | (dolist (exp `((function ,(car form)) . ,(cdr form))) |
43e67019 | 781 | (cconv-analyse-form exp env inclosure))) |
d779e73c SM |
782 | |
783 | (`(cond . ,cond-forms) ; cond special form | |
43e67019 SM |
784 | (dolist (forms cond-forms) |
785 | (dolist (form forms) | |
786 | (cconv-analyse-form form env inclosure)))) | |
d779e73c SM |
787 | |
788 | (`(quote . ,_) nil) ; quote form | |
d779e73c SM |
789 | (`(function . ,_) nil) ; same as quote |
790 | ||
43e67019 SM |
791 | (`(condition-case ,var ,protected-form . ,handlers) |
792 | ;; FIXME: The bytecode for condition-case forces us to wrap the | |
793 | ;; form and handlers in closures (for handlers, it's probably | |
794 | ;; unavoidable, but not for the protected form). | |
795 | (setq inclosure (1+ inclosure)) | |
796 | (cconv-analyse-form protected-form env inclosure) | |
797 | (push (list var inclosure form) env) | |
798 | (dolist (handler handlers) | |
799 | (dolist (form (cdr handler)) | |
800 | (cconv-analyse-form form env inclosure)))) | |
801 | ||
802 | ;; FIXME: The bytecode for catch forces us to wrap the body. | |
803 | (`(,(or `catch `unwind-protect) ,form . ,body) | |
804 | (cconv-analyse-form form env inclosure) | |
805 | (setq inclosure (1+ inclosure)) | |
806 | (dolist (form body) | |
807 | (cconv-analyse-form form env inclosure))) | |
808 | ||
809 | ;; FIXME: The bytecode for save-window-excursion and the lack of | |
810 | ;; bytecode for track-mouse forces us to wrap the body. | |
811 | (`(,(or `save-window-excursion `track-mouse) . ,body) | |
812 | (setq inclosure (1+ inclosure)) | |
813 | (dolist (form body) | |
814 | (cconv-analyse-form form env inclosure))) | |
815 | ||
816 | (`(,(or `defconst `defvar) ,var ,value . ,_) | |
817 | (push var byte-compile-bound-variables) | |
818 | (cconv-analyse-form value env inclosure)) | |
d779e73c SM |
819 | |
820 | (`(,(or `funcall `apply) ,fun . ,args) | |
43e67019 SM |
821 | ;; Here we ignore fun because funcall and apply are the only two |
822 | ;; functions where we can pass a candidate for lambda lifting as | |
823 | ;; argument. So, if we see fun elsewhere, we'll delete it from | |
824 | ;; lambda candidate list. | |
825 | (if (symbolp fun) | |
826 | (let ((lv (assq fun cconv-lambda-candidates))) | |
827 | (when lv | |
828 | (unless (eq (cadr lv) inclosure) | |
829 | (push lv cconv-captured) | |
830 | ;; If this funcall and the definition of fun are in | |
831 | ;; different closures - we delete fun from candidate | |
832 | ;; list, because it is too complicated to manage free | |
833 | ;; variables in this case. | |
834 | (setq cconv-lambda-candidates | |
835 | (delq lv cconv-lambda-candidates))))) | |
836 | (cconv-analyse-form fun env inclosure)) | |
837 | (dolist (form args) | |
838 | (cconv-analyse-form form env inclosure))) | |
839 | ||
840 | (`(,_ . ,body-forms) ; First element is a function or whatever. | |
841 | (dolist (form body-forms) | |
842 | (cconv-analyse-form form env inclosure))) | |
843 | ||
844 | ((pred symbolp) | |
845 | (let ((dv (assq form env))) ; dv = declared and visible | |
846 | (when dv | |
847 | (unless (eq inclosure (cadr dv)) ; capturing condition | |
848 | (push dv cconv-captured)) | |
849 | ;; Delete lambda if it is found here, since it escapes. | |
850 | (setq cconv-lambda-candidates | |
851 | (delq dv cconv-lambda-candidates))))))) | |
94d11cb5 IK |
852 | |
853 | (provide 'cconv) | |
854 | ;;; cconv.el ends here |