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1 | ;;; -*-lisp-*- |
2 | ;;; | |
dea4d055 | 3 | ;;; Code generation protocol |
1f1d88f5 MW |
4 | ;;; |
5 | ;;; (c) 2009 Straylight/Edgeware | |
6 | ;;; | |
7 | ||
8 | ;;;----- Licensing notice --------------------------------------------------- | |
9 | ;;; | |
e0808c47 | 10 | ;;; This file is part of the Sensible Object Design, an object system for C. |
1f1d88f5 MW |
11 | ;;; |
12 | ;;; SOD 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 2 of the License, or | |
15 | ;;; (at your option) any later version. | |
16 | ;;; | |
17 | ;;; SOD 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 SOD; if not, write to the Free Software Foundation, | |
24 | ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
25 | ||
26 | (cl:in-package #:sod) | |
27 | ||
28 | ;;;-------------------------------------------------------------------------- | |
29 | ;;; Temporary names. | |
30 | ||
dea4d055 MW |
31 | ;; Protocol. |
32 | ||
33 | (export 'format-temporary-name) | |
34 | (defgeneric format-temporary-name (var stream) | |
1f1d88f5 | 35 | (:documentation |
dea4d055 | 36 | "Write the name of a temporary variable VAR to STREAM.")) |
1f1d88f5 | 37 | |
dea4d055 MW |
38 | (export 'var-in-use-p) |
39 | (defgeneric var-in-use-p (var) | |
40 | (:documentation | |
3109662a | 41 | "Answer whether VAR is currently being used. See `with-temporary-var'.") |
dea4d055 MW |
42 | (:method (var) |
43 | "Non-temporary variables are always in use." | |
1d8cc67a | 44 | (declare (ignore var)) |
dea4d055 MW |
45 | t)) |
46 | (defgeneric (setf var-in-use-p) (value var) | |
47 | (:documentation | |
3109662a | 48 | "Record whether VAR is currently being used. See `with-temporary-var'.")) |
1f1d88f5 | 49 | |
dea4d055 | 50 | ;; Root class. |
1f1d88f5 | 51 | |
1344e1f9 | 52 | (export '(temporary-name temp-tag)) |
dea4d055 MW |
53 | (defclass temporary-name () |
54 | ((tag :initarg :tag :reader temp-tag)) | |
55 | (:documentation | |
56 | "Base class for temporary variable and argument names.")) | |
1f1d88f5 | 57 | |
dea4d055 | 58 | ;; Important temporary names. |
1f1d88f5 | 59 | |
dea4d055 | 60 | (export '(*sod-ap* *sod-master-ap*)) |
1f1d88f5 MW |
61 | (defparameter *sod-ap* |
62 | (make-instance 'temporary-name :tag "sod__ap")) | |
63 | (defparameter *sod-master-ap* | |
64 | (make-instance 'temporary-name :tag "sod__master_ap")) | |
2bbe0f1d MW |
65 | (defparameter *sod-tmp-ap* |
66 | (make-instance 'temporary-name :tag "sod__tmp_ap")) | |
1d8206e9 MW |
67 | (defparameter *sod-tmp-val* |
68 | (make-instance 'temporary-name :tag "sod__t")) | |
1f1d88f5 MW |
69 | |
70 | ;;;-------------------------------------------------------------------------- | |
71 | ;;; Instructions. | |
72 | ||
dea4d055 MW |
73 | ;; Classes. |
74 | ||
75 | (export 'inst) | |
1f1d88f5 MW |
76 | (defclass inst () () |
77 | (:documentation | |
78 | "A base class for instructions. | |
79 | ||
80 | An `instruction' is anything which might be useful to string into a code | |
9ec578d9 MW |
81 | generator. Both statements and expressions can be represented by trees of |
82 | instructions. The `definst' macro is a convenient way of defining new | |
83 | instructions. | |
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84 | |
85 | The only important protocol for instructions is output, which is achieved | |
3109662a | 86 | by calling `print-object' with `*print-escape*' nil. |
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87 | |
88 | This doesn't really do very much, but it acts as a handy marker for | |
89 | instruction subclasses.")) | |
90 | ||
dea4d055 | 91 | (export 'inst-metric) |
1f1d88f5 MW |
92 | (defgeneric inst-metric (inst) |
93 | (:documentation | |
94 | "Returns a `metric' describing how complicated INST is. | |
95 | ||
3109662a MW |
96 | The default metric of an inst node is simply 1; `inst' subclasses |
97 | generated by `definst' (q.v.) have an automatically generated method which | |
98 | returns one plus the sum of the metrics of the node's children. | |
1f1d88f5 MW |
99 | |
100 | This isn't intended to be a particularly rigorous definition. Its purpose | |
101 | is to allow code generators to make decisions about inlining or calling | |
102 | code fairly simply.") | |
9ec578d9 MW |
103 | (:method ((inst t)) |
104 | (declare (ignore inst)) | |
105 | 1) | |
106 | (:method ((inst null)) | |
1d8cc67a | 107 | (declare (ignore inst)) |
9ec578d9 MW |
108 | 1) |
109 | (:method ((inst list)) | |
110 | (reduce #'+ inst :key #'inst-metric))) | |
1f1d88f5 | 111 | |
dea4d055 MW |
112 | ;; Instruction definition. |
113 | ||
114 | (export 'definst) | |
418752c5 | 115 | (defmacro definst (code (streamvar &key export) args &body body) |
1f1d88f5 MW |
116 | "Define an instruction type and describe how to output it. |
117 | ||
3109662a MW |
118 | An `inst' can represent any structured piece of output syntax: a |
119 | statement, expression or declaration, for example. This macro defines the | |
120 | following things: | |
1f1d88f5 | 121 | |
3109662a | 122 | * A class `CODE-inst' to represent the instruction. |
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123 | |
124 | * Instance slots named after the ARGS, with matching keyword initargs, | |
3109662a | 125 | and `inst-ARG' readers. |
1f1d88f5 | 126 | |
3109662a | 127 | * A constructor `make-CODE-inst' which accepts the ARGS (in order, not |
1f1d88f5 MW |
128 | with keywords) as arguments and returns a fresh instance. |
129 | ||
3109662a | 130 | * A print method, which prints a diagnostic dump if `*print-escape*' is |
1f1d88f5 MW |
131 | set, or invokes the BODY (with STREAMVAR bound to the output stream) |
132 | otherwise. The BODY is expected to produce target code at this | |
418752c5 MW |
133 | point. |
134 | ||
135 | If EXPORT is non-nil, then export the `CODE-inst' and `make-CODE-inst' | |
136 | symbols." | |
1f1d88f5 MW |
137 | |
138 | (let ((inst-var (gensym "INST")) | |
139 | (class-name (symbolicate code '-inst)) | |
418752c5 | 140 | (constructor-name (symbolicate 'make- code '-inst)) |
1f1d88f5 MW |
141 | (keys (mapcar (lambda (arg) (intern (symbol-name arg) :keyword)) |
142 | args))) | |
143 | `(progn | |
144 | (defclass ,class-name (inst) | |
145 | ,(mapcar (lambda (arg key) | |
146 | `(,arg :initarg ,key :reader ,(symbolicate 'inst- arg))) | |
147 | args keys)) | |
418752c5 | 148 | (defun ,constructor-name (,@args) |
1f1d88f5 MW |
149 | (make-instance ',class-name ,@(mappend #'list keys args))) |
150 | (defmethod inst-metric ((,inst-var ,class-name)) | |
151 | (with-slots (,@args) ,inst-var | |
152 | (+ 1 ,@(mapcar (lambda (arg) `(inst-metric ,arg)) args)))) | |
153 | (defmethod print-object ((,inst-var ,class-name) ,streamvar) | |
154 | (with-slots (,@args) ,inst-var | |
155 | (if *print-escape* | |
156 | (print-unreadable-object (,inst-var ,streamvar :type t) | |
157 | (format stream "~@<~@{~S ~@_~S~^ ~_~}~:>" | |
158 | ,@(mappend #'list keys args))) | |
fc09e191 | 159 | (block ,code ,@body)))) |
34c51b1c MW |
160 | ,@(and export `((export '(,class-name ,constructor-name |
161 | ,@(mapcar (lambda (arg) | |
162 | (symbolicate 'inst- arg)) | |
163 | args))))) | |
418752c5 | 164 | ',code))) |
1f1d88f5 | 165 | |
dea4d055 MW |
166 | ;; Important instruction classes. |
167 | ||
4b8e5c03 MW |
168 | ;; HACK: use a gensym for the `expr' and `type' slots to avoid leaking the |
169 | ;; slot names, since the symbol `expr' is exported from our package and | |
170 | ;; `type' belongs to the `common-lisp' package. | |
171 | ||
172 | (definst var (stream :export t) (name #1=#:type init) | |
173 | (pprint-c-type #1# stream name) | |
dea4d055 | 174 | (when init |
75dbacfc MW |
175 | (format stream " = ~A" init)) |
176 | (write-char #\; stream)) | |
4b8e5c03 MW |
177 | (definst set (stream :export t) (var #1=#:expr) |
178 | (format stream "~@<~A = ~@_~2I~A;~:>" var #1#)) | |
179 | (definst update (stream :export t) (var op #1=#:expr) | |
180 | (format stream "~@<~A ~A= ~@_~2I~A;~:>" var op #1#)) | |
181 | (definst return (stream :export t) (#1=#:expr) | |
182 | (format stream "return~@[ (~A)~];" #1#)) | |
b559689b MW |
183 | (definst break (stream :export t) () |
184 | (format stream "break;")) | |
185 | (definst continue (stream :export t) () | |
186 | (format stream "continue;")) | |
4b8e5c03 MW |
187 | (definst expr (stream :export t) (#1=#:expr) |
188 | (format stream "~A;" #1#)) | |
418752c5 | 189 | (definst block (stream :export t) (decls body) |
75dbacfc | 190 | (format stream "{~:@_~@< ~2I~@[~{~A~:@_~}~:@_~]~{~A~^~:@_~}~:>~:@_}" |
dea4d055 | 191 | decls body)) |
4b8e5c03 | 192 | (definst function (stream :export t) (name #1=#:type body) |
dea4d055 MW |
193 | (pprint-logical-block (stream nil) |
194 | (princ "static " stream) | |
4b8e5c03 | 195 | (pprint-c-type #1# stream name) |
dea4d055 MW |
196 | (format stream "~:@_~A~:@_~:@_" body))) |
197 | ||
198 | ;; Formatting utilities. | |
199 | ||
1f1d88f5 | 200 | (defun format-compound-statement* (stream child morep thunk) |
3109662a | 201 | "Underlying function for `format-compound-statement'." |
1f1d88f5 MW |
202 | (cond ((typep child 'block-inst) |
203 | (funcall thunk stream) | |
204 | (write-char #\space stream) | |
205 | (princ child stream) | |
206 | (when morep (write-char #\space stream))) | |
207 | (t | |
208 | (pprint-logical-block (stream nil) | |
209 | (funcall thunk stream) | |
210 | (write-char #\space stream) | |
211 | (pprint-indent :block 2 stream) | |
212 | (pprint-newline :linear stream) | |
213 | (princ child stream) | |
214 | (pprint-indent :block 0 stream) | |
215 | (case morep | |
216 | (:space | |
217 | (write-char #\space stream) | |
218 | (pprint-newline :linear stream)) | |
dea4d055 | 219 | ((t) |
1f1d88f5 MW |
220 | (pprint-newline :mandatory stream))))))) |
221 | ||
dea4d055 | 222 | (export 'format-compound-statement) |
1f1d88f5 MW |
223 | (defmacro format-compound-statement |
224 | ((stream child &optional morep) &body body) | |
225 | "Format a compound statement to STREAM. | |
226 | ||
227 | The introductory material is printed by BODY. The CHILD is formatted | |
3109662a | 228 | properly according to whether it's a `block-inst'. If MOREP is true, then |
1f1d88f5 MW |
229 | allow for more stuff following the child." |
230 | `(format-compound-statement* ,stream ,child ,morep | |
231 | (lambda (,stream) ,@body))) | |
232 | ||
233 | ;;;-------------------------------------------------------------------------- | |
dea4d055 | 234 | ;;; Code generation. |
1f1d88f5 | 235 | |
dea4d055 | 236 | ;; Accessors. |
1f1d88f5 | 237 | |
dea4d055 MW |
238 | (export 'codegen-functions) |
239 | (defgeneric codegen-functions (codegen) | |
1f1d88f5 | 240 | (:documentation |
3109662a | 241 | "Return the list of `function-inst's of completed functions.")) |
1f1d88f5 | 242 | |
dea4d055 | 243 | (export 'ensure-var) |
1f1d88f5 MW |
244 | (defgeneric ensure-var (codegen name type &optional init) |
245 | (:documentation | |
246 | "Add a variable to CODEGEN's list. | |
247 | ||
3109662a | 248 | The variable is called NAME (which should be comparable using `equal' and |
1f1d88f5 | 249 | print to an identifier) and has the given TYPE. If INIT is present and |
3109662a | 250 | non-nil it is an expression `inst' used to provide the variable with an |
dea4d055 | 251 | initial value.")) |
1f1d88f5 | 252 | |
dea4d055 MW |
253 | (export '(emit-inst emit-insts)) |
254 | (defgeneric emit-inst (codegen inst) | |
255 | (:documentation | |
256 | "Add INST to the end of CODEGEN's list of instructions.")) | |
257 | (defgeneric emit-insts (codegen insts) | |
258 | (:documentation | |
259 | "Add a list of INSTS to the end of CODEGEN's list of instructions.") | |
260 | (:method (codegen insts) | |
261 | (dolist (inst insts) (emit-inst codegen inst)))) | |
1f1d88f5 | 262 | |
3f4ac959 MW |
263 | (export '(emit-decl emit-decls)) |
264 | (defgeneric emit-decl (codegen inst) | |
265 | (:documentation | |
266 | "Add INST to the end of CODEGEN's list of declarations.")) | |
267 | (defgeneric emit-decls (codegen insts) | |
268 | (:documentation | |
269 | "Add a list of INSTS to the end of CODEGEN's list of declarations.")) | |
270 | ||
dea4d055 | 271 | (export 'codegen-push) |
1f1d88f5 MW |
272 | (defgeneric codegen-push (codegen) |
273 | (:documentation | |
274 | "Pushes the current code generation state onto a stack. | |
275 | ||
dea4d055 | 276 | The state consists of the accumulated variables and instructions.")) |
1f1d88f5 | 277 | |
dea4d055 | 278 | (export 'codegen-pop) |
1f1d88f5 MW |
279 | (defgeneric codegen-pop (codegen) |
280 | (:documentation | |
281 | "Pops a saved state off of the CODEGEN's stack. | |
282 | ||
283 | Returns the newly accumulated variables and instructions as lists, as | |
dea4d055 | 284 | separate values.")) |
1f1d88f5 | 285 | |
dea4d055 | 286 | (export 'codegen-add-function) |
1f1d88f5 MW |
287 | (defgeneric codegen-add-function (codegen function) |
288 | (:documentation | |
289 | "Adds a function to CODEGEN's list. | |
290 | ||
291 | Actually, we're not picky: FUNCTION can be any kind of object that you're | |
3109662a | 292 | willing to find in the list returned by `codegen-functions'.")) |
dea4d055 MW |
293 | |
294 | (export 'temporary-var) | |
295 | (defgeneric temporary-var (codegen type) | |
296 | (:documentation | |
297 | "Return the name of a temporary variable. | |
298 | ||
299 | The temporary variable will have the given TYPE, and will be marked | |
300 | in-use. You should clear the in-use flag explicitly when you've finished | |
3109662a MW |
301 | with the variable -- or, better, use `with-temporary-var' to do the |
302 | cleanup automatically.")) | |
1f1d88f5 | 303 | |
dea4d055 | 304 | (export 'codegen-build-function) |
1f1d88f5 MW |
305 | (defun codegen-build-function (codegen name type vars insts) |
306 | "Build a function and add it to CODEGEN's list. | |
307 | ||
308 | Returns the function's name." | |
309 | (codegen-add-function codegen | |
310 | (make-function-inst name type | |
311 | (make-block-inst vars insts))) | |
312 | name) | |
313 | ||
dea4d055 MW |
314 | (export 'codegen-pop-block) |
315 | (defgeneric codegen-pop-block (codegen) | |
316 | (:documentation | |
3109662a | 317 | "Makes a block (`block-inst') out of the completed code in CODEGEN.") |
dea4d055 MW |
318 | (:method (codegen) |
319 | (multiple-value-bind (vars insts) (codegen-pop codegen) | |
320 | (make-block-inst vars insts)))) | |
321 | ||
322 | (export 'codegen-pop-function) | |
1f1d88f5 MW |
323 | (defgeneric codegen-pop-function (codegen name type) |
324 | (:documentation | |
325 | "Makes a function out of the completed code in CODEGEN. | |
326 | ||
327 | The NAME can be any object you like. The TYPE should be a function type | |
328 | object which includes argument names. The return value is the NAME.") | |
dea4d055 | 329 | (:method (codegen name type) |
1f1d88f5 MW |
330 | (multiple-value-bind (vars insts) (codegen-pop codegen) |
331 | (codegen-build-function codegen name type vars insts)))) | |
332 | ||
dea4d055 | 333 | (export 'with-temporary-var) |
1f1d88f5 MW |
334 | (defmacro with-temporary-var ((codegen var type) &body body) |
335 | "Evaluate BODY with VAR bound to a temporary variable name. | |
336 | ||
337 | During BODY, VAR will be marked in-use; when BODY ends, VAR will be marked | |
9ec578d9 | 338 | available for re-use." |
b8c698ee MW |
339 | (multiple-value-bind (doc decls body) (parse-body body :docp nil) |
340 | (declare (ignore doc)) | |
341 | `(let ((,var (temporary-var ,codegen ,type))) | |
342 | ,@decls | |
343 | (unwind-protect | |
344 | (progn ,@body) | |
345 | (setf (var-in-use-p ,var) nil))))) | |
1f1d88f5 MW |
346 | |
347 | ;;;-------------------------------------------------------------------------- | |
348 | ;;; Code generation idioms. | |
349 | ||
dea4d055 | 350 | (export 'deliver-expr) |
1f1d88f5 MW |
351 | (defun deliver-expr (codegen target expr) |
352 | "Emit code to deliver the value of EXPR to the TARGET. | |
353 | ||
354 | The TARGET may be one of the following. | |
355 | ||
3109662a | 356 | * `:void', indicating that the value is to be discarded. The expression |
1f1d88f5 MW |
357 | will still be evaluated. |
358 | ||
3109662a MW |
359 | * `:void-return', indicating that the value is to be discarded (as for |
360 | `:void') and furthermore a `return' from the current function should | |
361 | be forced after computing the value. | |
1f1d88f5 | 362 | |
3109662a MW |
363 | * `:return', indicating that the value is to be returned from the |
364 | current function. | |
1f1d88f5 MW |
365 | |
366 | * A variable name, indicating that the value is to be stored in the | |
367 | variable. | |
368 | ||
3109662a MW |
369 | In the cases of `:return', `:void' and `:void-return' targets, it is valid |
370 | for EXPR to be nil; this signifies that no computation needs to be | |
371 | performed. Variable-name targets require an expression." | |
1f1d88f5 MW |
372 | |
373 | (case target | |
374 | (:return (emit-inst codegen (make-return-inst expr))) | |
375 | (:void (when expr (emit-inst codegen (make-expr-inst expr)))) | |
376 | (:void-return (when expr (emit-inst codegen (make-expr-inst expr))) | |
377 | (emit-inst codegen (make-return-inst nil))) | |
378 | (t (emit-inst codegen (make-set-inst target expr))))) | |
379 | ||
dea4d055 | 380 | (export 'convert-stmts) |
1f1d88f5 | 381 | (defun convert-stmts (codegen target type func) |
3109662a | 382 | "Invoke FUNC to deliver a value to a non-`:return' target. |
1f1d88f5 | 383 | |
3109662a MW |
384 | FUNC is a function which accepts a single argument, a non-`:return' |
385 | target, and generates statements which deliver a value (see | |
386 | `deliver-expr') of the specified TYPE to this target. In general, the | |
387 | generated code will have the form | |
1f1d88f5 MW |
388 | |
389 | setup instructions... | |
3109662a | 390 | (deliver-expr CODEGEN TARGET (compute value...)) |
1f1d88f5 MW |
391 | cleanup instructions... |
392 | ||
393 | where the cleanup instructions are essential to the proper working of the | |
394 | generated program. | |
395 | ||
3109662a MW |
396 | The `convert-stmts' function will call FUNC to generate code, and arrange |
397 | that its value is correctly delivered to TARGET, regardless of what the | |
398 | TARGET is -- i.e., it lifts the restriction to non-`:return' targets. It | |
399 | does this by inventing a new temporary variable." | |
1f1d88f5 MW |
400 | |
401 | (case target | |
402 | (:return (with-temporary-var (codegen var type) | |
403 | (funcall func var) | |
404 | (deliver-expr codegen target var))) | |
405 | (:void-return (funcall func :void) | |
406 | (emit-inst codegen (make-return-inst nil))) | |
407 | (t (funcall func target)))) | |
408 | ||
409 | ;;;----- That's all, folks -------------------------------------------------- |