1: \ libcc.fs foreign function interface implemented using a C compiler
2:
3: \ Copyright (C) 2006,2007 Free Software Foundation, Inc.
4:
5: \ This file is part of Gforth.
6:
7: \ Gforth is free software; you can redistribute it and/or
8: \ modify it under the terms of the GNU General Public License
9: \ as published by the Free Software Foundation, either version 3
10: \ of the License, or (at your option) any later version.
11:
12: \ This program is distributed in the hope that it will be useful,
13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: \ GNU General Public License for more details.
16:
17: \ You should have received a copy of the GNU General Public License
18: \ along with this program. If not, see http://www.gnu.org/licenses/.
19:
20:
21: \ What this implementation does is this: if it sees a declaration like
22:
23: \ \ something that tells it that the current library is libc
24: \ \c #include <unistd.h>
25: \ c-function dlseek lseek n d n -- d
26:
27: \ it genererates C code similar to the following:
28:
29: \ #include <gforth.h>
30: \ #include <unistd.h>
31: \
32: \ void gforth_c_lseek_ndn_d(void)
33: \ {
34: \ Cell *sp = gforth_SP;
35: \ Float *fp = gforth_FP;
36: \ long long result; /* longest type in C */
37: \ gforth_ll2d(lseek(sp[3],gforth_d2ll(sp[2],sp[1]),sp[0]),sp[3],sp[2]);
38: \ gforth_SP = sp+2;
39: \ }
40:
41: \ Then it compiles this code and dynamically links it into the Gforth
42: \ system (batching and caching are future work). It also dynamically
43: \ links lseek. Performing DLSEEK then puts the function pointer of
44: \ the function pointer of gforth_c_lseek_ndn_d on the stack and
45: \ calls CALL-C.
46:
47: \ ToDo:
48:
49: \ Batching, caching and lazy evaluation:
50:
51: \ Batching:
52:
53: \ New words are deferred, and the corresponding C functions are
54: \ collected in one file, until the first word is EXECUTEd; then the
55: \ file is compiled and linked into the system, and the word is
56: \ resolved.
57:
58: \ Caching:
59:
60: \ Instead of compiling all this stuff anew for every execution, we
61: \ keep the files around and have an index file containing the function
62: \ names and their corresponding .so files. If the needed wrapper name
63: \ is already present, it is just linked instead of generating the
64: \ wrapper again. This is all done by loading the index file(s?),
65: \ which define words for the wrappers in a separate wordlist.
66:
67: \ The files are built in .../lib/gforth/$VERSION/libcc/ or
68: \ ~/.gforth/libcc/$HOST/.
69:
70: \ other things to do:
71:
72: \ c-variable forth-name c-name
73: \ c-constant forth-name c-name
74:
75: \ Todo: conversion between function pointers and xts (both directions)
76:
77: \ taking an xt and turning it into a function pointer:
78:
79: \ e.g., assume we have the xt of + and want to create a C function int
80: \ gforth_callback_plus(int, int), and then pass the pointer to that
81: \ function:
82:
83: \ There should be Forth code like this:
84: \ ] + 0 (bye)
85: \ Assume that the start of this code is START
86:
87: \ Now, there should be a C function:
88:
89: \ int gforth_callback_plus(int p1, int p2)
90: \ {
91: \ Cell *sp = gforth_SP;
92: \ Float *fp = gforth_FP;
93: \ Float *fp = gforth_FP;
94: \ Address lp = gforth_LP;
95: \ sp -= 2;
96: \ sp[0] = p1;
97: \ sp[1] = p2;
98: \ gforth_engine(START, sp, rp, fp, lp);
99: \ sp += 1;
100: \ gforth_RP = rp;
101: \ gforth_SP = sp;
102: \ gforth_FP = fp;
103: \ gforth_LP = lp;
104: \ return sp[0];
105: \ }
106:
107: \ and the pointer to that function is the C function pointer for the XT of +.
108:
109: \ Future problems:
110: \ how to combine the Forth code generation with inlining
111: \ START is not a constant across executions (when caching the C files)
112: \ Solution: make START a variable, and store into it on startup with dlsym
113:
114: \ Syntax:
115: \ callback <rettype> <params> <paramtypes> -- <rettype>
116:
117:
118: \ data structures
119:
120: \ For every c-function, we have three words: two anonymous words
121: \ created by c-function-ft (first time) and c-function-rt (run-time),
122: \ and a named deferred word. The deferred word first points to the
123: \ first-time word, then to the run-time word; the run-time word calls
124: \ the c function.
125:
126: [ifundef] parse-name
127: ' parse-word alias parse-name
128: [then]
129: [ifundef] defer!
130: : defer! ( xt xt-deferred -- ) \ gforth defer-store
131: \G Changes the @code{defer}red word @var{xt-deferred} to execute @var{xt}.
132: >body [ has? rom [IF] ] @ [ [THEN] ] ! ;
133: [then]
134:
135: \ : delete-file 2drop 0 ;
136:
137: require struct.fs
138:
139: \ counted-string
140:
141: \ c-function-ft word body:
142: struct
143: cell% field cff-cfr \ xt of c-function-rt word
144: cell% field cff-deferred \ xt of c-function deferred word
145: cell% field cff-lha \ address of the lib-handle for the lib that
146: \ contains the wrapper function of the word
147: char% field cff-rtype \ return type
148: char% field cff-np \ number of parameters
149: 1 0 field cff-ptypes \ #npar parameter types
150: \ counted string: c-name
151: end-struct cff%
152:
153: variable c-source-file-id \ contains the source file id of the current batch
154: 0 c-source-file-id !
155: variable lib-handle-addr \ points to the library handle of the current batch.
156: \ the library handle is 0 if the current
157: \ batch is not yet compiled.
158: here 0 , lib-handle-addr ! \ just make sure LIB-HANDLE always works
159: 2variable lib-filename \ filename without extension
160: 2variable lib-modulename \ basename of the file without extension
161:
162: : delete-file 2drop 0 ;
163:
164: : .nb ( n -- )
165: 0 .r ;
166:
167: : const+ ( n1 "name" -- n2 )
168: dup constant 1+ ;
169:
170: : front-string { c-addr1 u1 c-addr2 u2 -- c-addr3 u3 }
171: \ insert string c-addr2 u2 in buffer c-addr1 u1; c-addr3 u3 is the
172: \ remainder of the buffer.
173: assert( u1 u2 u>= )
174: c-addr2 c-addr1 u2 move
175: c-addr1 u1 u2 /string ;
176:
177: : front-char { c-addr1 u1 c -- c-addr3 u2 }
178: \ insert c in buffer c-addr1 u1; c-addr3 u3 is the remainder of
179: \ the buffer.
180: assert( u1 0 u> )
181: c c-addr1 c!
182: c-addr1 u1 1 /string ;
183:
184: : s+ { addr1 u1 addr2 u2 -- addr u }
185: u1 u2 + allocate throw { addr }
186: addr1 addr u1 move
187: addr2 addr u1 + u2 move
188: addr u1 u2 +
189: ;
190:
191: : append { addr1 u1 addr2 u2 -- addr u }
192: addr1 u1 u2 + dup { u } resize throw { addr }
193: addr2 addr u1 + u2 move
194: addr u ;
195:
196: \ linked list stuff (should go elsewhere)
197:
198: struct
199: cell% field list-next
200: 1 0 field list-payload
201: end-struct list%
202:
203: : list-insert { node list -- }
204: list list-next @ node list-next !
205: node list list-next ! ;
206:
207: : list-append { node endlistp -- }
208: \ insert node at place pointed to by endlistp
209: node endlistp @ list-insert
210: node list-next endlistp ! ;
211:
212: : list-map ( ... list xt -- ... )
213: \ xt ( ... node -- ... )
214: { xt } begin { node }
215: node while
216: node xt execute
217: node list-next @
218: repeat ;
219:
220: \ linked libraries
221:
222: list%
223: cell% 2* field c-lib-string
224: end-struct c-lib%
225:
226: variable c-libs \ linked list of library names (without "lib")
227:
228: : add-lib ( c-addr u -- )
229: \G Add library lib@i{string} to the list of libraries, where
230: \G @i{string} is represented by @i{c-addr u}.
231: c-lib% %size allocate throw dup >r
232: c-lib-string 2!
233: r> c-libs list-insert ;
234:
235: : append-l ( c-addr1 u1 node -- c-addr2 u2 )
236: \ append " -l<nodelib>" to string1
237: >r s" -l" append r> c-lib-string 2@ append ;
238:
239: \ C prefix lines
240:
241: \ linked list of longcstrings: [ link | count-cell | characters ]
242:
243: list%
244: cell% field c-prefix-count
245: 1 0 field c-prefix-chars
246: end-struct c-prefix%
247:
248: variable c-prefix-lines 0 c-prefix-lines !
249: variable c-prefix-lines-end c-prefix-lines c-prefix-lines-end !
250:
251: : print-c-prefix-line ( node -- )
252: dup c-prefix-chars swap c-prefix-count @ type cr ;
253:
254: : print-c-prefix-lines ( -- )
255: c-prefix-lines @ ['] print-c-prefix-line list-map ;
256:
257: : save-c-prefix-line ( c-addr u -- )
258: c-source-file-id @ ?dup-if
259: >r 2dup r> write-line throw
260: then
261: align here 0 , c-prefix-lines-end list-append ( c-addr u )
262: longstring, ;
263:
264: : \c ( "rest-of-line" -- ) \ gforth backslash-c
265: \G One line of C declarations for the C interface
266: -1 parse save-c-prefix-line ;
267:
268: s" #include <gforth/" version-string s+ s" /libcc.h>" append ( c-addr u )
269: 2dup save-c-prefix-line drop free throw
270:
271: \ Types (for parsing)
272:
273: wordlist constant libcc-types
274:
275: get-current libcc-types set-current
276:
277: \ index values
278: -1
279: const+ -- \ end of arguments
280: const+ n \ integer cell
281: const+ a \ address cell
282: const+ d \ double
283: const+ r \ float
284: const+ func \ C function pointer
285: const+ void
286: drop
287:
288: set-current
289:
290: : parse-libcc-type ( "libcc-type" -- u )
291: parse-name libcc-types search-wordlist 0= -13 and throw execute ;
292:
293: : parse-function-types ( "{libcc-type}" "--" "libcc-type" -- )
294: here 2 chars allot here begin
295: parse-libcc-type dup 0>= while
296: c,
297: repeat
298: drop here swap - over char+ c!
299: parse-libcc-type dup 0< -32 and throw swap c! ;
300:
301: : type-letter ( n -- c )
302: chars s" nadrfv" drop + c@ ;
303:
304: \ count-stacks
305:
306: : count-stacks-n ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
307: 1+ ;
308:
309: : count-stacks-a ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
310: 1+ ;
311:
312: : count-stacks-d ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
313: 2 + ;
314:
315: : count-stacks-r ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
316: swap 1+ swap ;
317:
318: : count-stacks-func ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
319: 1+ ;
320:
321: : count-stacks-void ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
322: ;
323:
324: create count-stacks-types
325: ' count-stacks-n ,
326: ' count-stacks-a ,
327: ' count-stacks-d ,
328: ' count-stacks-r ,
329: ' count-stacks-func ,
330: ' count-stacks-void ,
331:
332: : count-stacks ( pars -- fp-change sp-change )
333: \ pars is an addr u pair
334: 0 0 2swap over + swap u+do
335: i c@ cells count-stacks-types + @ execute
336: loop ;
337:
338: \ gen-pars
339:
340: : gen-par-n ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
341: ." sp[" 1- dup .nb ." ]" ;
342:
343: : gen-par-a ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
344: ." (void *)(" gen-par-n ." )" ;
345:
346: : gen-par-d ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
347: ." gforth_d2ll(" gen-par-n ." ," gen-par-n ." )" ;
348:
349: : gen-par-r ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
350: swap 1- tuck ." fp[" .nb ." ]" ;
351:
352: : gen-par-func ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
353: gen-par-a ;
354:
355: : gen-par-void ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
356: -32 throw ;
357:
358: create gen-par-types
359: ' gen-par-n ,
360: ' gen-par-a ,
361: ' gen-par-d ,
362: ' gen-par-r ,
363: ' gen-par-func ,
364: ' gen-par-void ,
365:
366: : gen-par ( fp-depth1 sp-depth1 partype -- fp-depth2 sp-depth2 )
367: cells gen-par-types + @ execute ;
368:
369: \ the call itself
370:
371: : gen-wrapped-call { d: pars d: c-name fp-change1 sp-change1 -- }
372: c-name type ." ("
373: fp-change1 sp-change1 pars over + swap u+do
374: i c@ gen-par
375: i 1+ i' < if
376: ." ,"
377: endif
378: loop
379: 2drop ." )" ;
380:
381: \ calls for various kinds of return values
382:
383: : gen-wrapped-void ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
384: 2dup 2>r gen-wrapped-call 2r> ;
385:
386: : gen-wrapped-n ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
387: 2dup gen-par-n 2>r ." =" gen-wrapped-call 2r> ;
388:
389: : gen-wrapped-a ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
390: 2dup gen-par-n 2>r ." =(Cell)" gen-wrapped-call 2r> ;
391:
392: : gen-wrapped-d ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
393: ." gforth_ll2d(" gen-wrapped-void
394: ." ," gen-par-n ." ," gen-par-n ." )" ;
395:
396: : gen-wrapped-r ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
397: 2dup gen-par-r 2>r ." =" gen-wrapped-call 2r> ;
398:
399: : gen-wrapped-func ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
400: gen-wrapped-a ;
401:
402: create gen-wrapped-types
403: ' gen-wrapped-n ,
404: ' gen-wrapped-a ,
405: ' gen-wrapped-d ,
406: ' gen-wrapped-r ,
407: ' gen-wrapped-func ,
408: ' gen-wrapped-void ,
409:
410: : gen-wrapped-stmt ( pars c-name fp-change1 sp-change1 ret -- fp-change sp-change )
411: cells gen-wrapped-types + @ execute ;
412:
413: : wrapper-function-name ( addr -- c-addr u )
414: \ addr points to the return type index of a c-function descriptor
415: count { r-type } count { d: pars }
416: pars + count { d: c-name }
417: s" gforth_c_" { d: prefix }
418: prefix nip c-name nip + pars nip + 3 + { u }
419: u allocate throw { c-addr }
420: c-addr u
421: prefix front-string c-name front-string '_ front-char
422: pars bounds u+do
423: i c@ type-letter front-char
424: loop
425: '_ front-char r-type type-letter front-char assert( dup 0= )
426: 2drop c-addr u ;
427:
428: : gen-wrapper-function ( addr -- )
429: \ addr points to the return type index of a c-function descriptor
430: dup { descriptor }
431: count { ret } count 2dup { d: pars } chars + count { d: c-name }
432: ." void " lib-modulename 2@ type ." _LTX_" descriptor wrapper-function-name 2dup type drop free throw
433: .\" (void)\n"
434: .\" {\n Cell MAYBE_UNUSED *sp = gforth_SP;\n Float MAYBE_UNUSED *fp = gforth_FP;\n "
435: pars c-name 2over count-stacks ret gen-wrapped-stmt .\" ;\n"
436: ?dup-if
437: ." gforth_SP = sp+" .nb .\" ;\n"
438: endif
439: ?dup-if
440: ." gforth_FP = fp+" .nb .\" ;\n"
441: endif
442: .\" }\n" ;
443:
444: : scan-back { c-addr u1 c -- c-addr u2 }
445: \ the last occurence of c in c-addr u1 is at u2-1; if it does not
446: \ occur, u2=0.
447: c-addr 1- c-addr u1 + 1- u-do
448: i c@ c = if
449: c-addr i over - 1+ unloop exit endif
450: 1 -loop
451: c-addr 0 ;
452:
453: : dirname ( c-addr1 u1 -- c-addr2 u2 )
454: \ directory name of the file name c-addr1 u1, including the final "/".
455: '/ scan-back ;
456:
457: : basename ( c-addr1 u1 -- c-addr2 u2 )
458: \ file name without directory component
459: 2dup dirname nip /string ;
460:
461: : gen-filename ( x -- c-addr u )
462: \ generates a file basename for lib-handle-addr X
463: 0 <<# ['] #s $10 base-execute #>
464: s" gforth_c_" 2swap s+ #>> ;
465:
466: : libcc-named-dir ( -- c-addr u )
467: s" ~/.gforth/libcc-named/" ;
468:
469: : libcc-tmp-dir ( -- c-addr u )
470: s" ~/.gforth/libcc-tmp/" ;
471:
472: : prepend-dirname ( c-addr1 u1 c-addr2 u2 -- c-addr3 u3 )
473: 2over s+ 2swap drop free throw ;
474:
475: 0 value libcc-path
476: here 1024 dup , 0 , allot to libcc-path \ !! the path words should grow buffers dynamically
477: libcc-path clear-path
478: libcc-named-dir libcc-path also-path
479: \ !! setup path on boot
480:
481: : open-wrappers ( -- addr|0 )
482: lib-filename 2@ s" .la" s+
483: 2dup libcc-named-dir string-prefix? if ( c-addr u )
484: \ see if we can open it in the path
485: libcc-named-dir nip /string
486: libcc-path open-path-file if
487: 0 exit endif
488: ( wfile-id c-addr2 u2 ) rot close-file throw save-mem ( c-addr2 u2 )
489: endif
490: \ 2dup cr type
491: 2dup open-lib >r
492: drop free throw r> ;
493:
494: : c-library-name-setup ( c-addr u -- )
495: assert( c-source-file-id @ 0= )
496: { d: filename }
497: here 0 , lib-handle-addr ! filename lib-filename 2!
498: filename basename lib-modulename 2! ;
499:
500: : c-library-name-create ( -- )
501: lib-filename 2@ s" .c" s+ 2dup w/o create-file throw
502: dup c-source-file-id !
503: ['] print-c-prefix-lines swap outfile-execute
504: drop free throw ;
505:
506: : c-named-library-name ( c-addr u -- )
507: \ set up filenames for a (possibly new) library; c-addr u is the
508: \ basename of the library
509: libcc-named-dir prepend-dirname c-library-name-setup
510: open-wrappers dup if
511: lib-handle-addr @ !
512: else
513: drop c-library-name-create
514: endif ;
515:
516: : c-tmp-library-name ( c-addr u -- )
517: \ set up filenames for a new library; c-addr u is the basename of
518: \ the library
519: libcc-tmp-dir prepend-dirname c-library-name-setup c-library-name-create ;
520:
521: : lib-handle ( -- addr )
522: lib-handle-addr @ @ ;
523:
524: : init-c-source-file ( -- )
525: lib-handle 0= if
526: c-source-file-id @ 0= if
527: here gen-filename c-tmp-library-name
528: endif
529: endif ;
530:
531: : c-source-file ( -- file-id )
532: c-source-file-id @ assert( dup ) ;
533:
534: : notype-execute ( ... xt -- ... )
535: what's type { oldtype } try
536: ['] 2drop is type execute 0
537: restore
538: oldtype is type
539: endtry
540: throw ;
541:
542: : c-source-file-execute ( ... xt -- ... )
543: \ direct the output of xt to c-source-file, or nothing
544: lib-handle if
545: notype-execute
546: else
547: c-source-file outfile-execute
548: endif ;
549:
550: : .lib-error ( -- )
551: [ifdef] lib-error
552: ['] cr stderr outfile-execute
553: lib-error ['] type stderr outfile-execute
554: [then] ;
555:
556: DEFER compile-wrapper-function ( -- )
557: : compile-wrapper-function1 ( -- )
558: lib-handle 0= if
559: c-source-file close-file throw
560: 0 c-source-file-id !
561: [ libtool-command s" --silent --mode=compile gcc -I " s+
562: s" includedir" getenv append ] sliteral
563: s" -O -c " s+ lib-filename 2@ append s" .c -o " append
564: lib-filename 2@ append s" .lo" append ( c-addr u )
565: \ cr 2dup type
566: 2dup system drop free throw $? abort" libtool compile failed"
567: [ libtool-command s" --silent --mode=link gcc -module -rpath " s+ ] sliteral
568: lib-filename 2@ dirname s+ s" " append
569: lib-filename 2@ append s" .lo -o " append
570: lib-filename 2@ append s" .la" append ( c-addr u )
571: c-libs @ ['] append-l list-map
572: \ 2dup type cr
573: 2dup system drop free throw $? abort" libtool link failed"
574: open-wrappers dup 0= if
575: .lib-error true abort" open-lib failed"
576: endif
577: ( lib-handle ) lib-handle-addr @ !
578: endif
579: lib-filename 2@ drop free throw 0 0 lib-filename 2! ;
580: ' compile-wrapper-function1 IS compile-wrapper-function
581: \ s" ar rcs xxx.a xxx.o" system
582: \ $? abort" ar generated error" ;
583:
584: : link-wrapper-function { cff -- sym }
585: cff cff-rtype wrapper-function-name { d: wrapper-name }
586: wrapper-name cff cff-lha @ @ assert( dup ) lib-sym dup 0= if
587: .lib-error -&32 throw
588: endif
589: wrapper-name drop free throw ;
590:
591: : c-function-ft ( xt-defr xt-cfr "c-name" "{libcc-type}" "--" "libcc-type" -- )
592: \ build time/first time action for c-function
593: init-c-source-file
594: noname create 2, lib-handle-addr @ ,
595: parse-name { d: c-name }
596: here parse-function-types c-name string,
597: ['] gen-wrapper-function c-source-file-execute
598: does> ( ... -- ... )
599: dup 2@ { xt-defer xt-cfr }
600: dup cff-lha @ @ 0= if
601: compile-wrapper-function
602: endif
603: link-wrapper-function xt-cfr >body !
604: xt-cfr xt-defer defer!
605: xt-cfr execute ;
606:
607: : c-function-rt ( -- )
608: \ run-time definition for c function; addr is the address where
609: \ the sym should be stored
610: noname create 0 ,
611: does> ( ... -- ... )
612: @ call-c ;
613:
614: : c-function ( "forth-name" "c-name" "@{type@}" "--" "type" -- ) \ gforth
615: \G Define a Forth word @i{forth-name}. @i{Forth-name} has the
616: \G specified stack effect and calls the C function @code{c-name}.
617: defer lastxt dup c-function-rt lastxt c-function-ft
618: lastxt swap defer! ;
619:
620: : clear-libs ( -- )
621: \G Clear the list of libs
622: c-source-file-id @ if
623: compile-wrapper-function
624: endif
625: 0 c-libs ! ;
626: clear-libs
627:
628: : c-library-incomplete ( -- )
629: true abort" Called function of unfinished named C library" ;
630:
631: : c-library-name ( c-addr u -- ) \ gforth
632: \G Start a C library interface with name @i{c-addr u}.
633: clear-libs
634: ['] c-library-incomplete is compile-wrapper-function
635: c-named-library-name ;
636:
637: : c-library ( "name" -- ) \ gforth
638: \G Parsing version of @code{c-library-name}
639: parse-name save-mem c-library-name ;
640:
641: : end-c-library ( -- ) \ gforth
642: \G Finish and (if necessary) build the latest C library interface.
643: ['] compile-wrapper-function1 is compile-wrapper-function
644: compile-wrapper-function1 ;
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