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1 | ;;; Continuation-passing style (CPS) intermediate language (IL) |
2 | ||
3 | ;; Copyright (C) 2013 Free Software Foundation, Inc. | |
4 | ||
5 | ;;;; This library is free software; you can redistribute it and/or | |
6 | ;;;; modify it under the terms of the GNU Lesser General Public | |
7 | ;;;; License as published by the Free Software Foundation; either | |
8 | ;;;; version 3 of the License, or (at your option) any later version. | |
9 | ;;;; | |
10 | ;;;; This library is distributed in the hope that it will be useful, | |
11 | ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | ;;;; Lesser General Public License for more details. | |
14 | ;;;; | |
15 | ;;;; You should have received a copy of the GNU Lesser General Public | |
16 | ;;;; License along with this library; if not, write to the Free Software | |
17 | ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | ||
19 | ;;; Commentary: | |
20 | ;;; | |
21 | ;;; This pass converts Tree-IL to the continuation-passing style (CPS) | |
22 | ;;; language. | |
23 | ;;; | |
24 | ;;; CPS is a lower-level representation than Tree-IL. Converting to | |
25 | ;;; CPS, beyond adding names for all control points and all values, | |
26 | ;;; simplifies expressions in the following ways, among others: | |
27 | ;;; | |
28 | ;;; * Fixing the order of evaluation. | |
29 | ;;; | |
30 | ;;; * Converting assigned variables to boxed variables. | |
31 | ;;; | |
32 | ;;; * Requiring that Scheme's <letrec> has already been lowered to | |
33 | ;;; <fix>. | |
34 | ;;; | |
35 | ;;; * Inlining default-value initializers into lambda-case | |
36 | ;;; expressions. | |
37 | ;;; | |
38 | ;;; * Inlining prompt bodies. | |
39 | ;;; | |
40 | ;;; * Turning toplevel and module references into primcalls. This | |
41 | ;;; involves explicitly modelling the "scope" of toplevel lookups | |
42 | ;;; (indicating the module with respect to which toplevel bindings | |
43 | ;;; are resolved). | |
44 | ;;; | |
45 | ;;; The utility of CPS is that it gives a name to everything: every | |
46 | ;;; intermediate value, and every control point (continuation). As such | |
47 | ;;; it is more verbose than Tree-IL, but at the same time more simple as | |
48 | ;;; the number of concepts is reduced. | |
49 | ;;; | |
50 | ;;; Code: | |
51 | ||
52 | (define-module (language tree-il compile-cps) | |
53 | #:use-module (ice-9 match) | |
54 | #:use-module ((srfi srfi-1) #:select (fold fold-right filter-map)) | |
55 | #:use-module (srfi srfi-26) | |
56 | #:use-module ((system foreign) #:select (make-pointer pointer->scm)) | |
57 | #:use-module (language cps) | |
58 | #:use-module (language cps primitives) | |
59 | #:use-module (language tree-il analyze) | |
60 | #:use-module (language tree-il optimize) | |
b7f10def | 61 | #:use-module ((language tree-il) #:hide (let-gensyms)) |
4fefc3a8 AW |
62 | #:export (compile-cps)) |
63 | ||
64 | ;;; Guile's semantics are that a toplevel lambda captures a reference on | |
65 | ;;; the current module, and that all contained lambdas use that module | |
66 | ;;; to resolve toplevel variables. This parameter tracks whether or not | |
67 | ;;; we are in a toplevel lambda. If we are in a lambda, the parameter | |
68 | ;;; is bound to a fresh name identifying the module that was current | |
69 | ;;; when the toplevel lambda is defined. | |
70 | ;;; | |
71 | ;;; This is more complicated than it need be. Ideally we should resolve | |
72 | ;;; all toplevel bindings to bindings from specific modules, unless the | |
73 | ;;; binding is unbound. This is always valid if the compilation unit | |
74 | ;;; sets the module explicitly, as when compiling a module, but it | |
75 | ;;; doesn't work for files auto-compiled for use with `load'. | |
76 | ;;; | |
77 | (define current-topbox-scope (make-parameter #f)) | |
78 | ||
79 | (define (toplevel-box src name bound? val-proc) | |
80 | (let-gensyms (name-sym bound?-sym kbox box) | |
81 | (build-cps-term | |
82 | ($letconst (('name name-sym name) | |
83 | ('bound? bound?-sym bound?)) | |
6e422a35 | 84 | ($letk ((kbox ($kargs ('box) (box) ,(val-proc box)))) |
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85 | ,(match (current-topbox-scope) |
86 | (#f | |
87 | (build-cps-term | |
6e422a35 | 88 | ($continue kbox src |
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89 | ($primcall 'resolve |
90 | (name-sym bound?-sym))))) | |
91 | (scope | |
92 | (let-gensyms (scope-sym) | |
93 | (build-cps-term | |
94 | ($letconst (('scope scope-sym scope)) | |
6e422a35 | 95 | ($continue kbox src |
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96 | ($primcall 'cached-toplevel-box |
97 | (scope-sym name-sym bound?-sym))))))))))))) | |
98 | ||
99 | (define (module-box src module name public? bound? val-proc) | |
100 | (let-gensyms (module-sym name-sym public?-sym bound?-sym kbox box) | |
101 | (build-cps-term | |
102 | ($letconst (('module module-sym module) | |
103 | ('name name-sym name) | |
104 | ('public? public?-sym public?) | |
105 | ('bound? bound?-sym bound?)) | |
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106 | ($letk ((kbox ($kargs ('box) (box) ,(val-proc box)))) |
107 | ($continue kbox src | |
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108 | ($primcall 'cached-module-box |
109 | (module-sym name-sym public?-sym bound?-sym)))))))) | |
110 | ||
111 | (define (capture-toplevel-scope src scope k) | |
112 | (let-gensyms (module scope-sym kmodule) | |
113 | (build-cps-term | |
114 | ($letconst (('scope scope-sym scope)) | |
6e422a35 AW |
115 | ($letk ((kmodule ($kargs ('module) (module) |
116 | ($continue k src | |
117 | ($primcall 'cache-current-module! | |
118 | (module scope-sym)))))) | |
119 | ($continue kmodule src | |
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120 | ($primcall 'current-module ()))))))) |
121 | ||
122 | (define (fold-formals proc seed arity gensyms inits) | |
123 | (match arity | |
124 | (($ $arity req opt rest kw allow-other-keys?) | |
125 | (let () | |
126 | (define (fold-req names gensyms seed) | |
127 | (match names | |
128 | (() (fold-opt opt gensyms inits seed)) | |
129 | ((name . names) | |
130 | (proc name (car gensyms) #f | |
131 | (fold-req names (cdr gensyms) seed))))) | |
132 | (define (fold-opt names gensyms inits seed) | |
133 | (match names | |
134 | (() (fold-rest rest gensyms inits seed)) | |
135 | ((name . names) | |
136 | (proc name (car gensyms) (car inits) | |
137 | (fold-opt names (cdr gensyms) (cdr inits) seed))))) | |
138 | (define (fold-rest rest gensyms inits seed) | |
139 | (match rest | |
140 | (#f (fold-kw kw gensyms inits seed)) | |
141 | (name (proc name (car gensyms) #f | |
142 | (fold-kw kw (cdr gensyms) inits seed))))) | |
143 | (define (fold-kw kw gensyms inits seed) | |
144 | (match kw | |
145 | (() | |
146 | (unless (null? gensyms) | |
147 | (error "too many gensyms")) | |
148 | (unless (null? inits) | |
149 | (error "too many inits")) | |
150 | seed) | |
151 | (((key name var) . kw) | |
152 | (unless (eq? var (car gensyms)) | |
153 | (error "unexpected keyword arg order")) | |
154 | (proc name var (car inits) | |
155 | (fold-kw kw (cdr gensyms) (cdr inits) seed))))) | |
156 | (fold-req req gensyms seed))))) | |
157 | ||
158 | (define (unbound? src sym kt kf) | |
159 | (define tc8-iflag 4) | |
160 | (define unbound-val 9) | |
161 | (define unbound-bits (logior (ash unbound-val 8) tc8-iflag)) | |
162 | (let-gensyms (unbound ktest) | |
163 | (build-cps-term | |
164 | ($letconst (('unbound unbound (pointer->scm (make-pointer unbound-bits)))) | |
6e422a35 AW |
165 | ($letk ((ktest ($kif kt kf))) |
166 | ($continue ktest src | |
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167 | ($primcall 'eq? (sym unbound)))))))) |
168 | ||
169 | (define (init-default-value name sym subst init body) | |
170 | (match (assq-ref subst sym) | |
171 | ((subst-sym box?) | |
172 | (let ((src (tree-il-src init))) | |
173 | (define (maybe-box k make-body) | |
174 | (if box? | |
175 | (let-gensyms (kbox phi) | |
176 | (build-cps-term | |
6e422a35 AW |
177 | ($letk ((kbox ($kargs (name) (phi) |
178 | ($continue k src ($primcall 'box (phi)))))) | |
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179 | ,(make-body kbox)))) |
180 | (make-body k))) | |
181 | (let-gensyms (knext kbound kunbound) | |
182 | (build-cps-term | |
6e422a35 | 183 | ($letk ((knext ($kargs (name) (subst-sym) ,body))) |
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184 | ,(maybe-box |
185 | knext | |
186 | (lambda (k) | |
187 | (build-cps-term | |
6e422a35 AW |
188 | ($letk ((kbound ($kargs () () ($continue k src ($var sym)))) |
189 | (kunbound ($kargs () () ,(convert init k subst)))) | |
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190 | ,(unbound? src sym kunbound kbound)))))))))))) |
191 | ||
192 | ;; exp k-name alist -> term | |
193 | (define (convert exp k subst) | |
194 | ;; exp (v-name -> term) -> term | |
195 | (define (convert-arg exp k) | |
196 | (match exp | |
197 | (($ <lexical-ref> src name sym) | |
198 | (match (assq-ref subst sym) | |
199 | ((box #t) | |
200 | (let-gensyms (kunboxed unboxed) | |
201 | (build-cps-term | |
6e422a35 AW |
202 | ($letk ((kunboxed ($kargs ('unboxed) (unboxed) ,(k unboxed)))) |
203 | ($continue kunboxed src ($primcall 'box-ref (box))))))) | |
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204 | ((subst #f) (k subst)) |
205 | (#f (k sym)))) | |
206 | (else | |
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207 | (let-gensyms (karg arg) |
208 | (build-cps-term | |
209 | ($letk ((karg ($kargs ('arg) (arg) ,(k arg)))) | |
210 | ,(convert exp karg subst))))))) | |
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211 | ;; (exp ...) ((v-name ...) -> term) -> term |
212 | (define (convert-args exps k) | |
213 | (match exps | |
214 | (() (k '())) | |
215 | ((exp . exps) | |
216 | (convert-arg exp | |
217 | (lambda (name) | |
218 | (convert-args exps | |
219 | (lambda (names) | |
220 | (k (cons name names))))))))) | |
221 | (define (box-bound-var name sym body) | |
222 | (match (assq-ref subst sym) | |
223 | ((box #t) | |
224 | (let-gensyms (k) | |
225 | (build-cps-term | |
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226 | ($letk ((k ($kargs (name) (box) ,body))) |
227 | ($continue k #f ($primcall 'box (sym))))))) | |
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228 | (else body))) |
229 | ||
230 | (match exp | |
231 | (($ <lexical-ref> src name sym) | |
232 | (match (assq-ref subst sym) | |
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233 | ((box #t) (build-cps-term ($continue k src ($primcall 'box-ref (box))))) |
234 | ((subst #f) (build-cps-term ($continue k src ($var subst)))) | |
235 | (#f (build-cps-term ($continue k src ($var sym)))))) | |
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236 | |
237 | (($ <void> src) | |
6e422a35 | 238 | (build-cps-term ($continue k src ($void)))) |
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239 | |
240 | (($ <const> src exp) | |
6e422a35 | 241 | (build-cps-term ($continue k src ($const exp)))) |
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242 | |
243 | (($ <primitive-ref> src name) | |
6e422a35 | 244 | (build-cps-term ($continue k src ($prim name)))) |
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245 | |
246 | (($ <lambda> fun-src meta body) | |
247 | (let () | |
248 | (define (convert-clauses body ktail) | |
249 | (match body | |
250 | (#f '()) | |
251 | (($ <lambda-case> src req opt rest kw inits gensyms body alternate) | |
252 | (let* ((arity (make-$arity req (or opt '()) rest | |
253 | (if kw (cdr kw) '()) (and kw (car kw)))) | |
254 | (names (fold-formals (lambda (name sym init names) | |
255 | (cons name names)) | |
256 | '() | |
257 | arity gensyms inits))) | |
258 | (cons | |
259 | (let-gensyms (kclause kargs) | |
260 | (build-cps-cont | |
261 | (kclause | |
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262 | ($kclause ,arity |
263 | (kargs | |
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264 | ($kargs names gensyms |
265 | ,(fold-formals | |
266 | (lambda (name sym init body) | |
267 | (if init | |
268 | (init-default-value name sym subst init body) | |
269 | (box-bound-var name sym body))) | |
270 | (convert body ktail subst) | |
271 | arity gensyms inits))))))) | |
272 | (convert-clauses alternate ktail)))))) | |
273 | (if (current-topbox-scope) | |
274 | (let-gensyms (kentry self ktail) | |
275 | (build-cps-term | |
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276 | ($continue k fun-src |
277 | ($fun fun-src meta '() | |
278 | (kentry ($kentry self (ktail ($ktail)) | |
279 | ,(convert-clauses body ktail))))))) | |
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280 | (let-gensyms (scope kscope) |
281 | (build-cps-term | |
6e422a35 | 282 | ($letk ((kscope ($kargs () () |
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283 | ,(parameterize ((current-topbox-scope scope)) |
284 | (convert exp k subst))))) | |
285 | ,(capture-toplevel-scope fun-src scope kscope))))))) | |
286 | ||
287 | (($ <module-ref> src mod name public?) | |
288 | (module-box | |
289 | src mod name public? #t | |
290 | (lambda (box) | |
6e422a35 | 291 | (build-cps-term ($continue k src ($primcall 'box-ref (box))))))) |
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292 | |
293 | (($ <module-set> src mod name public? exp) | |
294 | (convert-arg exp | |
295 | (lambda (val) | |
296 | (module-box | |
297 | src mod name public? #f | |
298 | (lambda (box) | |
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299 | (build-cps-term |
300 | ($continue k src ($primcall 'box-set! (box val))))))))) | |
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301 | |
302 | (($ <toplevel-ref> src name) | |
303 | (toplevel-box | |
304 | src name #t | |
305 | (lambda (box) | |
6e422a35 | 306 | (build-cps-term ($continue k src ($primcall 'box-ref (box))))))) |
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307 | |
308 | (($ <toplevel-set> src name exp) | |
309 | (convert-arg exp | |
310 | (lambda (val) | |
311 | (toplevel-box | |
312 | src name #f | |
313 | (lambda (box) | |
6e422a35 AW |
314 | (build-cps-term |
315 | ($continue k src ($primcall 'box-set! (box val))))))))) | |
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316 | |
317 | (($ <toplevel-define> src name exp) | |
318 | (convert-arg exp | |
319 | (lambda (val) | |
320 | (let-gensyms (kname name-sym) | |
321 | (build-cps-term | |
322 | ($letconst (('name name-sym name)) | |
6e422a35 | 323 | ($continue k src ($primcall 'define! (name-sym val))))))))) |
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324 | |
325 | (($ <call> src proc args) | |
326 | (convert-args (cons proc args) | |
327 | (match-lambda | |
328 | ((proc . args) | |
6e422a35 | 329 | (build-cps-term ($continue k src ($call proc args))))))) |
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330 | |
331 | (($ <primcall> src name args) | |
58dee5b9 AW |
332 | (cond |
333 | ((branching-primitive? name) | |
334 | (convert (make-conditional src exp (make-const #f #t) | |
335 | (make-const #f #f)) | |
336 | k subst)) | |
92afe25d AW |
337 | ((and (eq? name 'vector) |
338 | (and-map (match-lambda | |
339 | ((or ($ <const>) | |
340 | ($ <void>) | |
341 | ($ <lambda>) | |
342 | ($ <lexical-ref>)) #t) | |
343 | (_ #f)) | |
344 | args)) | |
58dee5b9 AW |
345 | ;; Some macros generate calls to "vector" with like 300 |
346 | ;; arguments. Since we eventually compile to make-vector and | |
347 | ;; vector-set!, it reduces live variable pressure to allocate the | |
92afe25d AW |
348 | ;; vector first, then set values as they are produced, if we can |
349 | ;; prove that no value can capture the continuation. (More on | |
350 | ;; that caveat here: | |
351 | ;; http://wingolog.org/archives/2013/11/02/scheme-quiz-time). | |
352 | ;; | |
353 | ;; Normally we would do this transformation in the compiler, but | |
354 | ;; it's quite tricky there and quite easy here, so hold your nose | |
58dee5b9 AW |
355 | ;; while we drop some smelly code. |
356 | (convert (let ((len (length args))) | |
357 | (let-gensyms (v) | |
358 | (make-let src | |
359 | (list 'v) | |
360 | (list v) | |
361 | (list (make-primcall src 'make-vector | |
362 | (list (make-const #f len) | |
363 | (make-const #f #f)))) | |
364 | (fold (lambda (arg n tail) | |
365 | (make-seq | |
366 | src | |
367 | (make-primcall | |
368 | src 'vector-set! | |
369 | (list (make-lexical-ref src 'v v) | |
370 | (make-const #f n) | |
371 | arg)) | |
372 | tail)) | |
373 | (make-lexical-ref src 'v v) | |
374 | (reverse args) (reverse (iota len)))))) | |
375 | k subst)) | |
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376 | ((and (eq? name 'list) |
377 | (and-map (match-lambda | |
378 | ((or ($ <const>) | |
379 | ($ <void>) | |
380 | ($ <lambda>) | |
381 | ($ <lexical-ref>)) #t) | |
382 | (_ #f)) | |
383 | args)) | |
384 | ;; The same situation occurs with "list". | |
385 | (let lp ((args args) (k k)) | |
386 | (match args | |
387 | (() | |
388 | (build-cps-term | |
6e422a35 | 389 | ($continue k src ($const '())))) |
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390 | ((arg . args) |
391 | (let-gensyms (ktail tail) | |
392 | (build-cps-term | |
6e422a35 | 393 | ($letk ((ktail ($kargs ('tail) (tail) |
0d046513 AW |
394 | ,(convert-arg arg |
395 | (lambda (head) | |
396 | (build-cps-term | |
6e422a35 | 397 | ($continue k src |
0d046513 AW |
398 | ($primcall 'cons (head tail))))))))) |
399 | ,(lp args ktail)))))))) | |
58dee5b9 AW |
400 | (else |
401 | (convert-args args | |
402 | (lambda (args) | |
6e422a35 | 403 | (build-cps-term ($continue k src ($primcall name args)))))))) |
4fefc3a8 AW |
404 | |
405 | ;; Prompts with inline handlers. | |
406 | (($ <prompt> src escape-only? tag body | |
407 | ($ <lambda> hsrc hmeta | |
408 | ($ <lambda-case> _ hreq #f hrest #f () hsyms hbody #f))) | |
409 | ;; Handler: | |
410 | ;; khargs: check args returned to handler, -> khbody | |
411 | ;; khbody: the handler, -> k | |
412 | ;; | |
413 | ;; Post-body: | |
414 | ;; krest: collect return vals from body to list, -> kpop | |
415 | ;; kpop: pop the prompt, -> kprim | |
416 | ;; kprim: load the values primitive, -> kret | |
417 | ;; kret: (apply values rvals), -> k | |
418 | ;; | |
419 | ;; Escape prompts evaluate the body with the continuation of krest. | |
420 | ;; Otherwise we do a no-inline call to body, continuing to krest. | |
421 | (convert-arg tag | |
422 | (lambda (tag) | |
423 | (let ((hnames (append hreq (if hrest (list hrest) '())))) | |
424 | (let-gensyms (khargs khbody kret kprim prim kpop krest vals kbody) | |
425 | (build-cps-term | |
6e422a35 AW |
426 | ;; FIXME: Attach hsrc to $ktrunc. |
427 | ($letk* ((khbody ($kargs hnames hsyms | |
428 | ,(fold box-bound-var | |
429 | (convert hbody k subst) | |
430 | hnames hsyms))) | |
431 | (khargs ($ktrunc hreq hrest khbody)) | |
432 | (kpop ($kargs ('rest) (vals) | |
4fefc3a8 | 433 | ($letk ((kret |
4fefc3a8 AW |
434 | ($kargs () () |
435 | ($letk ((kprim | |
4fefc3a8 | 436 | ($kargs ('prim) (prim) |
6e422a35 | 437 | ($continue k src |
4fefc3a8 AW |
438 | ($primcall 'apply |
439 | (prim vals)))))) | |
6e422a35 | 440 | ($continue kprim src |
4fefc3a8 | 441 | ($prim 'values)))))) |
6e422a35 | 442 | ($continue kret src |
8d59d55e | 443 | ($primcall 'unwind ()))))) |
6e422a35 | 444 | (krest ($ktrunc '() 'rest kpop))) |
4fefc3a8 AW |
445 | ,(if escape-only? |
446 | (build-cps-term | |
6e422a35 | 447 | ($letk ((kbody ($kargs () () |
4fefc3a8 | 448 | ,(convert body krest subst)))) |
6e422a35 | 449 | ($continue kbody src ($prompt #t tag khargs kpop)))) |
4fefc3a8 AW |
450 | (convert-arg body |
451 | (lambda (thunk) | |
452 | (build-cps-term | |
6e422a35 AW |
453 | ($letk ((kbody ($kargs () () |
454 | ($continue krest (tree-il-src body) | |
4fefc3a8 AW |
455 | ($primcall 'call-thunk/no-inline |
456 | (thunk)))))) | |
6e422a35 | 457 | ($continue kbody (tree-il-src body) |
96af4a18 | 458 | ($prompt #f tag khargs kpop)))))))))))))) |
4fefc3a8 AW |
459 | |
460 | ;; Eta-convert prompts without inline handlers. | |
461 | (($ <prompt> src escape-only? tag body handler) | |
b7f10def AW |
462 | (let-gensyms (h args) |
463 | (convert | |
464 | (make-let | |
465 | src (list 'h) (list h) (list handler) | |
466 | (make-seq | |
467 | src | |
468 | (make-conditional | |
469 | src | |
470 | (make-primcall src 'procedure? (list (make-lexical-ref #f 'h h))) | |
471 | (make-void src) | |
472 | (make-primcall | |
473 | src 'scm-error | |
474 | (list | |
475 | (make-const #f 'wrong-type-arg) | |
476 | (make-const #f "call-with-prompt") | |
477 | (make-const #f "Wrong type (expecting procedure): ~S") | |
478 | (make-primcall #f 'list (list (make-lexical-ref #f 'h h))) | |
479 | (make-primcall #f 'list (list (make-lexical-ref #f 'h h)))))) | |
480 | (make-prompt | |
481 | src escape-only? tag body | |
482 | (make-lambda | |
483 | src '() | |
484 | (make-lambda-case | |
485 | src '() #f 'args #f '() (list args) | |
486 | (make-primcall | |
487 | src 'apply | |
488 | (list (make-lexical-ref #f 'h h) | |
489 | (make-lexical-ref #f 'args args))) | |
490 | #f))))) | |
491 | k | |
492 | subst))) | |
4fefc3a8 | 493 | |
486013d6 AW |
494 | (($ <abort> src tag args ($ <const> _ ())) |
495 | (convert-args (cons tag args) | |
496 | (lambda (args*) | |
497 | (build-cps-term | |
6e422a35 AW |
498 | ($continue k src |
499 | ($primcall 'abort-to-prompt args*)))))) | |
486013d6 | 500 | |
4fefc3a8 | 501 | (($ <abort> src tag args tail) |
486013d6 AW |
502 | (convert-args (append (list (make-primitive-ref #f 'abort-to-prompt) |
503 | tag) | |
504 | args | |
505 | (list tail)) | |
4fefc3a8 | 506 | (lambda (args*) |
486013d6 | 507 | (build-cps-term |
6e422a35 | 508 | ($continue k src ($primcall 'apply args*)))))) |
4fefc3a8 AW |
509 | |
510 | (($ <conditional> src test consequent alternate) | |
511 | (let-gensyms (kif kt kf) | |
512 | (build-cps-term | |
6e422a35 AW |
513 | ($letk* ((kt ($kargs () () ,(convert consequent k subst))) |
514 | (kf ($kargs () () ,(convert alternate k subst))) | |
515 | (kif ($kif kt kf))) | |
4fefc3a8 AW |
516 | ,(match test |
517 | (($ <primcall> src (? branching-primitive? name) args) | |
518 | (convert-args args | |
519 | (lambda (args) | |
6e422a35 AW |
520 | (build-cps-term |
521 | ($continue kif src ($primcall name args)))))) | |
4fefc3a8 AW |
522 | (_ (convert-arg test |
523 | (lambda (test) | |
6e422a35 AW |
524 | (build-cps-term |
525 | ($continue kif src ($var test))))))))))) | |
4fefc3a8 AW |
526 | |
527 | (($ <lexical-set> src name gensym exp) | |
528 | (convert-arg exp | |
529 | (lambda (exp) | |
530 | (match (assq-ref subst gensym) | |
531 | ((box #t) | |
532 | (build-cps-term | |
6e422a35 | 533 | ($continue k src ($primcall 'box-set! (box exp))))))))) |
4fefc3a8 AW |
534 | |
535 | (($ <seq> src head tail) | |
536 | (let-gensyms (ktrunc kseq) | |
537 | (build-cps-term | |
6e422a35 AW |
538 | ($letk* ((kseq ($kargs () () |
539 | ,(convert tail k subst))) | |
540 | (ktrunc ($ktrunc '() #f kseq))) | |
4fefc3a8 AW |
541 | ,(convert head ktrunc subst))))) |
542 | ||
543 | (($ <let> src names syms vals body) | |
544 | (let lp ((names names) (syms syms) (vals vals)) | |
545 | (match (list names syms vals) | |
546 | ((() () ()) (convert body k subst)) | |
547 | (((name . names) (sym . syms) (val . vals)) | |
548 | (let-gensyms (klet) | |
549 | (build-cps-term | |
6e422a35 AW |
550 | ($letk ((klet ($kargs (name) (sym) |
551 | ,(box-bound-var name sym | |
552 | (lp names syms vals))))) | |
4fefc3a8 AW |
553 | ,(convert val klet subst)))))))) |
554 | ||
555 | (($ <fix> src names gensyms funs body) | |
556 | ;; Some letrecs can be contified; that happens later. | |
557 | (if (current-topbox-scope) | |
558 | (let-gensyms (self) | |
559 | (build-cps-term | |
560 | ($letrec names | |
561 | gensyms | |
562 | (map (lambda (fun) | |
563 | (match (convert fun k subst) | |
6e422a35 | 564 | (($ $continue _ _ (and fun ($ $fun))) |
4fefc3a8 AW |
565 | fun))) |
566 | funs) | |
567 | ,(convert body k subst)))) | |
568 | (let-gensyms (scope kscope) | |
569 | (build-cps-term | |
6e422a35 AW |
570 | ($letk ((kscope ($kargs () () |
571 | ,(parameterize ((current-topbox-scope scope)) | |
572 | (convert exp k subst))))) | |
4fefc3a8 AW |
573 | ,(capture-toplevel-scope src scope kscope)))))) |
574 | ||
575 | (($ <let-values> src exp | |
576 | ($ <lambda-case> lsrc req #f rest #f () syms body #f)) | |
577 | (let ((names (append req (if rest (list rest) '())))) | |
578 | (let-gensyms (ktrunc kargs) | |
579 | (build-cps-term | |
6e422a35 AW |
580 | ($letk* ((kargs ($kargs names syms |
581 | ,(fold box-bound-var | |
582 | (convert body k subst) | |
583 | names syms))) | |
584 | (ktrunc ($ktrunc req rest kargs))) | |
4fefc3a8 AW |
585 | ,(convert exp ktrunc subst)))))))) |
586 | ||
587 | (define (build-subst exp) | |
588 | "Compute a mapping from lexical gensyms to substituted gensyms. The | |
589 | usual reason to replace one variable by another is assignment | |
590 | conversion. Default argument values is the other reason. | |
591 | ||
592 | Returns a list of (ORIG-SYM SUBST-SYM BOXED?). A true value for BOXED? | |
593 | indicates that the replacement variable is in a box." | |
594 | (define (box-set-vars exp subst) | |
595 | (match exp | |
596 | (($ <lexical-set> src name sym exp) | |
597 | (if (assq sym subst) | |
598 | subst | |
599 | (cons (list sym (gensym "b") #t) subst))) | |
600 | (_ subst))) | |
601 | (define (default-args exp subst) | |
602 | (match exp | |
603 | (($ <lambda-case> src req opt rest kw inits gensyms body alternate) | |
604 | (fold-formals (lambda (name sym init subst) | |
605 | (if init | |
606 | (let ((box? (match (assq-ref subst sym) | |
607 | ((box #t) #t) | |
608 | (#f #f))) | |
609 | (subst-sym (gensym (symbol->string name)))) | |
610 | (cons (list sym subst-sym box?) subst)) | |
611 | subst)) | |
612 | subst | |
613 | (make-$arity req (or opt '()) rest | |
614 | (if kw (cdr kw) '()) (and kw (car kw))) | |
615 | gensyms | |
616 | inits)) | |
617 | (_ subst))) | |
618 | (tree-il-fold box-set-vars default-args '() exp)) | |
619 | ||
620 | (define (cps-convert/thunk exp) | |
621 | (let ((src (tree-il-src exp))) | |
622 | (let-gensyms (kinit init ktail kclause kbody) | |
623 | (build-cps-exp | |
6e422a35 AW |
624 | ($fun src '() '() |
625 | (kinit ($kentry init | |
626 | (ktail ($ktail)) | |
627 | ((kclause | |
628 | ($kclause ('() '() #f '() #f) | |
629 | (kbody ($kargs () () | |
630 | ,(convert exp ktail | |
631 | (build-subst exp)))))))))))))) | |
4fefc3a8 AW |
632 | |
633 | (define *comp-module* (make-fluid)) | |
634 | ||
635 | (define %warning-passes | |
636 | `((unused-variable . ,unused-variable-analysis) | |
637 | (unused-toplevel . ,unused-toplevel-analysis) | |
638 | (unbound-variable . ,unbound-variable-analysis) | |
639 | (arity-mismatch . ,arity-analysis) | |
640 | (format . ,format-analysis))) | |
641 | ||
642 | (define (optimize-tree-il x e opts) | |
643 | (define warnings | |
644 | (or (and=> (memq #:warnings opts) cadr) | |
645 | '())) | |
646 | ||
647 | ;; Go through the warning passes. | |
648 | (let ((analyses (filter-map (lambda (kind) | |
649 | (assoc-ref %warning-passes kind)) | |
650 | warnings))) | |
651 | (analyze-tree analyses x e)) | |
652 | ||
653 | (optimize x e opts)) | |
654 | ||
655 | (define (compile-cps exp env opts) | |
656 | (values (cps-convert/thunk (optimize-tree-il exp env opts)) | |
657 | env | |
658 | env)) | |
659 | ||
660 | ;;; Local Variables: | |
661 | ;;; eval: (put 'convert-arg 'scheme-indent-function 1) | |
662 | ;;; eval: (put 'convert-args 'scheme-indent-function 1) | |
663 | ;;; End: |