Annotation of gforth/libcc.fs, revision 1.24

1.1       anton       1: \ libcc.fs     foreign function interface implemented using a C compiler
                      2: 
                      3: \ Copyright (C) 2006 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 2
                     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, write to the Free Software
                     19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
                     20: 
                     21: 
                     22: \ What this implementation does is this: if it sees a declaration like
                     23: 
1.2       anton      24: \ \ something that tells it that the current library is libc
1.6       anton      25: \ \c #include <unistd.h>
1.2       anton      26: \ c-function dlseek lseek n d n -- d
1.1       anton      27: 
                     28: \ it genererates C code similar to the following:
                     29: 
                     30: \ #include <gforth.h>
1.2       anton      31: \ #include <unistd.h>
1.1       anton      32: \ 
1.2       anton      33: \ void gforth_c_lseek_ndn_d(void)
1.1       anton      34: \ {
                     35: \   Cell *sp = gforth_SP;
                     36: \   Float *fp = gforth_FP;
1.2       anton      37: \   long long result;  /* longest type in C */
                     38: \   gforth_ll2d(lseek(sp[3],gforth_d2ll(sp[2],sp[1]),sp[0]),sp[3],sp[2]);
                     39: \   gforth_SP = sp+2;
1.1       anton      40: \ }
                     41: 
                     42: \ Then it compiles this code and dynamically links it into the Gforth
                     43: \ system (batching and caching are future work).  It also dynamically
                     44: \ links lseek.  Performing DLSEEK then puts the function pointer of
1.2       anton      45: \ the function pointer of gforth_c_lseek_ndn_d on the stack and
                     46: \ calls CALL-C.
                     47: 
1.7       anton      48: \ ToDo:
                     49: 
                     50: \ Batching, caching and lazy evaluation:
                     51: 
                     52: \ Batching:
                     53: 
                     54: \ New words are deferred, and the corresponding C functions are
                     55: \ collected in one file, until the first word is EXECUTEd; then the
                     56: \ file is compiled and linked into the system, and the word is
                     57: \ resolved.
                     58: 
                     59: \ Caching:
                     60: 
                     61: \ Instead of compiling all this stuff anew for every execution, we
                     62: \ keep the files around and have an index file containing the function
                     63: \ names and their corresponding .so files.  If the needed wrapper name
                     64: \ is already present, it is just linked instead of generating the
                     65: \ wrapper again.  This is all done by loading the index file(s?),
                     66: \ which define words for the wrappers in a separate wordlist.
                     67: 
                     68: \ The files are built in .../lib/gforth/$VERSION/libcc/ or
                     69: \ ~/.gforth/libcc/$HOST/.
                     70: 
1.2       anton      71: \ other things to do:
                     72: 
                     73: \ c-variable forth-name c-name
                     74: \ c-constant forth-name c-name
                     75: 
1.20      anton      76: \ Todo: conversion between function pointers and xts (both directions)
                     77: 
                     78: \ taking an xt and turning it into a function pointer:
                     79: 
                     80: \ e.g., assume we have the xt of + and want to create a C function int
                     81: \ gforth_callback_plus(int, int), and then pass the pointer to that
                     82: \ function:
                     83: 
                     84: \ There should be Forth code like this:
                     85: \   ] + 0 (bye)
                     86: \ Assume that the start of this code is START
                     87:         
                     88: \ Now, there should be a C function:
                     89: 
                     90: \ int gforth_callback_plus(int p1, int p2)
                     91: \ {
                     92: \   Cell   *sp = gforth_SP;
                     93: \   Float  *fp = gforth_FP;
                     94: \   Float  *fp = gforth_FP;
                     95: \   Address lp = gforth_LP;
                     96: \   sp -= 2;
                     97: \   sp[0] = p1;
                     98: \   sp[1] = p2;
                     99: \   gforth_engine(START, sp, rp, fp, lp);
                    100: \   sp += 1;
                    101: \   gforth_RP = rp;
                    102: \   gforth_SP = sp;
                    103: \   gforth_FP = fp;
                    104: \   gforth_LP = lp;
                    105: \   return sp[0];
                    106: \ }
                    107: 
                    108: \ and the pointer to that function is the C function pointer for the XT of +.
                    109: 
                    110: \ Future problems:
                    111: \   how to combine the Forth code generation with inlining
                    112: \   START is not a constant across executions (when caching the C files)
                    113: \      Solution: make START a variable, and store into it on startup with dlsym
                    114: 
                    115: \ Syntax:
                    116: \  callback <rettype> <params> <paramtypes> -- <rettype>
                    117: 
1.2       anton     118: 
                    119: \ data structures
                    120: 
1.10      anton     121: \ For every c-function, we have three words: two anonymous words
                    122: \ created by c-function-ft (first time) and c-function-rt (run-time),
                    123: \ and a named deferred word.  The deferred word first points to the
                    124: \ first-time word, then to the run-time word; the run-time word calls
                    125: \ the c function.
                    126: 
1.22      anton     127: : delete-file 2drop 0 ;
1.12      anton     128: 
                    129: require struct.fs
                    130: 
                    131:     \ counted-string
                    132:     
1.10      anton     133: \ c-function-ft word body:
1.12      anton     134: struct
                    135:     cell% field cff-cfr \ xt of c-function-rt word
                    136:     cell% field cff-deferred \ xt of c-function deferred word
                    137:     cell% field cff-lha \ address of the lib-handle for the lib that
                    138:                         \ contains the wrapper function of the word
                    139:     char% field cff-rtype  \ return type
                    140:     char% field cff-np     \ number of parameters
                    141:     1 0   field cff-ptypes \ #npar parameter types
                    142:     \  counted string: c-name
                    143: end-struct cff%
                    144: 
1.14      anton     145: variable c-source-file-id \ contains the source file id of the current batch
                    146: 0 c-source-file-id !
                    147: variable lib-handle-addr \ points to the library handle of the current batch.
                    148:                          \ the library handle is 0 if the current
                    149:                          \ batch is not yet compiled.
1.23      anton     150: 2variable lib-filename   \ filename without extension
                    151: 2variable lib-modulename \ basename of the file without extension
1.2       anton     152: 
1.3       anton     153: : .nb ( n -- )
1.2       anton     154:     0 .r ;
                    155: 
                    156: : const+ ( n1 "name" -- n2 )
                    157:     dup constant 1+ ;
                    158: 
1.10      anton     159: : front-string { c-addr1 u1 c-addr2 u2 -- c-addr3 u3 }
                    160:     \ insert string c-addr2 u2 in buffer c-addr1 u1; c-addr3 u3 is the
                    161:     \ remainder of the buffer.
                    162:     assert( u1 u2 u>= )
                    163:     c-addr2 c-addr1 u2 move
                    164:     c-addr1 u1 u2 /string ;
                    165: 
                    166: : front-char { c-addr1 u1 c -- c-addr3 u2 }
                    167:     \ insert c in buffer c-addr1 u1; c-addr3 u3 is the remainder of
                    168:     \ the buffer.
                    169:     assert( u1 0 u> )
                    170:     c c-addr1 c!
                    171:     c-addr1 u1 1 /string ;
                    172: 
1.15      anton     173: : s+ { addr1 u1 addr2 u2 -- addr u }
                    174:     u1 u2 + allocate throw { addr }
                    175:     addr1 addr u1 move
                    176:     addr2 addr u1 + u2 move
                    177:     addr u1 u2 +
                    178: ;
                    179: 
                    180: : append { addr1 u1 addr2 u2 -- addr u }
                    181:     addr1 u1 u2 + dup { u } resize throw { addr }
                    182:     addr2 addr u1 + u2 move
                    183:     addr u ;
                    184: 
1.6       anton     185: \ linked list stuff (should go elsewhere)
                    186: 
                    187: struct
                    188:     cell% field list-next
                    189:     1 0   field list-payload
                    190: end-struct list%
                    191: 
                    192: : list-insert { node list -- }
                    193:     list list-next @ node list-next !
                    194:     node list list-next ! ;
                    195: 
                    196: : list-append { node endlistp -- }
                    197:     \ insert node at place pointed to by endlistp
                    198:     node endlistp @ list-insert
                    199:     node list-next endlistp ! ;
                    200: 
                    201: : list-map ( ... list xt -- ... )
                    202:     \ xt ( ... node -- ... )
                    203:     { xt } begin { node }
                    204:        node while
                    205:            node xt execute
                    206:            node list-next @
                    207:     repeat ;
                    208: 
                    209: \ C prefix lines
                    210: 
                    211: \ linked list of longcstrings: [ link | count-cell | characters ]
                    212: 
                    213: list%
                    214:     cell% field c-prefix-count
                    215:     1 0   field c-prefix-chars
                    216: end-struct c-prefix%
                    217: 
                    218: variable c-prefix-lines 0 c-prefix-lines !
                    219: variable c-prefix-lines-end c-prefix-lines c-prefix-lines-end !
                    220: 
1.14      anton     221: : print-c-prefix-line ( node -- )
                    222:     dup c-prefix-chars swap c-prefix-count @ type cr ;
                    223: 
                    224: : print-c-prefix-lines ( -- )
                    225:     c-prefix-lines @ ['] print-c-prefix-line list-map ;
                    226: 
1.6       anton     227: : save-c-prefix-line ( c-addr u -- )
1.14      anton     228:     c-source-file-id @ ?dup-if
                    229:        >r 2dup r> write-line throw
                    230:     then
1.6       anton     231:     align here 0 , c-prefix-lines-end list-append ( c-addr u )
                    232:     longstring, ;
                    233: 
1.18      anton     234: : \c ( "rest-of-line" -- ) \ gforth backslash-c
1.17      anton     235:     \G One line of C declarations for the C interface
1.6       anton     236:     -1 parse save-c-prefix-line ;
                    237: 
1.19      anton     238: s" #include <gforth/" version-string s+ s" /libcc.h>" append ( c-addr u )
                    239:   2dup save-c-prefix-line drop free throw
1.5       anton     240: 
1.6       anton     241: \ Types (for parsing)
1.5       anton     242: 
1.2       anton     243: wordlist constant libcc-types
                    244: 
                    245: get-current libcc-types set-current
                    246: 
                    247: \ index values
                    248: -1
                    249: const+ -- \ end of arguments
                    250: const+ n \ integer cell
1.5       anton     251: const+ a \ address cell
1.2       anton     252: const+ d \ double
                    253: const+ r \ float
                    254: const+ func \ C function pointer
                    255: const+ void
                    256: drop
                    257: 
                    258: set-current
                    259: 
                    260: : parse-libcc-type ( "libcc-type" -- u )
                    261:     parse-name libcc-types search-wordlist 0= -13 and throw execute ;
                    262: 
                    263: : parse-function-types ( "{libcc-type}" "--" "libcc-type" -- )
                    264:     here 2 chars allot here begin
                    265:        parse-libcc-type dup 0>= while
                    266:            c,
                    267:     repeat
1.3       anton     268:     drop here swap - over char+ c!
                    269:     parse-libcc-type dup 0< -32 and throw swap c! ;
1.2       anton     270: 
                    271: : type-letter ( n -- c )
1.5       anton     272:     chars s" nadrfv" drop + c@ ;
1.2       anton     273: 
                    274: \ count-stacks
                    275: 
                    276: : count-stacks-n ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    277:     1+ ;
                    278: 
1.5       anton     279: : count-stacks-a ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
1.2       anton     280:     1+ ;
                    281: 
                    282: : count-stacks-d ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    283:     2 + ;
                    284: 
                    285: : count-stacks-r ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    286:     swap 1+ swap ;
                    287: 
                    288: : count-stacks-func ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    289:     1+ ;
                    290: 
                    291: : count-stacks-void ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    292: ;
                    293: 
                    294: create count-stacks-types
                    295: ' count-stacks-n ,
1.5       anton     296: ' count-stacks-a ,
1.2       anton     297: ' count-stacks-d ,
                    298: ' count-stacks-r ,
                    299: ' count-stacks-func ,
                    300: ' count-stacks-void ,
                    301: 
                    302: : count-stacks ( pars -- fp-change sp-change )
                    303:     \ pars is an addr u pair
                    304:     0 0 2swap over + swap u+do
1.3       anton     305:        i c@ cells count-stacks-types + @ execute
1.2       anton     306:     loop ;
                    307: 
                    308: \ gen-pars
                    309: 
                    310: : gen-par-n ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.5       anton     311:     ." sp[" 1- dup .nb ." ]" ;
1.2       anton     312: 
1.5       anton     313: : gen-par-a ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.2       anton     314:     ." (void *)(" gen-par-n ." )" ;
                    315: 
                    316: : gen-par-d ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.4       anton     317:     ." gforth_d2ll(" gen-par-n ." ," gen-par-n ." )" ;
1.2       anton     318: 
                    319: : gen-par-r ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.3       anton     320:     swap 1- tuck ." fp[" .nb ." ]" ;
1.2       anton     321: 
                    322: : gen-par-func ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.5       anton     323:     gen-par-a ;
1.2       anton     324: 
                    325: : gen-par-void ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
                    326:     -32 throw ;
                    327: 
                    328: create gen-par-types
                    329: ' gen-par-n ,
1.5       anton     330: ' gen-par-a ,
1.2       anton     331: ' gen-par-d ,
                    332: ' gen-par-r ,
                    333: ' gen-par-func ,
                    334: ' gen-par-void ,
                    335: 
                    336: : gen-par ( fp-depth1 sp-depth1 partype -- fp-depth2 sp-depth2 )
1.3       anton     337:     cells gen-par-types + @ execute ;
1.2       anton     338: 
                    339: \ the call itself
                    340: 
                    341: : gen-wrapped-call { d: pars d: c-name fp-change1 sp-change1 -- }
                    342:     c-name type ." ("
1.3       anton     343:     fp-change1 sp-change1 pars over + swap u+do 
1.2       anton     344:        i c@ gen-par
                    345:        i 1+ i' < if
                    346:            ." ,"
                    347:        endif
                    348:     loop
                    349:     2drop ." )" ;
                    350: 
                    351: \ calls for various kinds of return values
                    352: 
                    353: : gen-wrapped-void ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
                    354:     2dup 2>r gen-wrapped-call 2r> ;
                    355: 
1.3       anton     356: : gen-wrapped-n ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
1.5       anton     357:     2dup gen-par-n 2>r ." =" gen-wrapped-call 2r> ;
1.3       anton     358: 
1.5       anton     359: : gen-wrapped-a ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
                    360:     2dup gen-par-n 2>r ." =(Cell)" gen-wrapped-call 2r> ;
1.3       anton     361: 
                    362: : gen-wrapped-d ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
                    363:     ." gforth_ll2d(" gen-wrapped-void
1.5       anton     364:     ." ," gen-par-n ." ," gen-par-n ." )" ;
1.3       anton     365: 
                    366: : gen-wrapped-r ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
1.5       anton     367:     2dup gen-par-r 2>r ." =" gen-wrapped-void 2r> ;
1.3       anton     368: 
                    369: : gen-wrapped-func ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
1.5       anton     370:     gen-wrapped-a ;
1.3       anton     371: 
1.2       anton     372: create gen-wrapped-types
                    373: ' gen-wrapped-n ,
1.5       anton     374: ' gen-wrapped-a ,
1.2       anton     375: ' gen-wrapped-d ,
                    376: ' gen-wrapped-r ,
                    377: ' gen-wrapped-func ,
                    378: ' gen-wrapped-void ,
                    379: 
                    380: : gen-wrapped-stmt ( pars c-name fp-change1 sp-change1 ret -- fp-change sp-change )
1.3       anton     381:     cells gen-wrapped-types + @ execute ;
1.2       anton     382: 
1.10      anton     383: : wrapper-function-name ( addr -- c-addr u )
                    384:     \ addr points to the return type index of a c-function descriptor
                    385:     count { r-type } count { d: pars }
                    386:     pars + count { d: c-name }
                    387:     s" gforth_c_" { d: prefix }
                    388:     prefix nip c-name nip + pars nip + 3 + { u }
                    389:     u allocate throw { c-addr }
                    390:     c-addr u
                    391:     prefix front-string c-name front-string '_ front-char
                    392:     pars bounds u+do
                    393:        i c@ type-letter front-char
                    394:     loop
                    395:     '_ front-char r-type type-letter front-char assert( dup 0= )
                    396:     2drop c-addr u ;
                    397: 
1.2       anton     398: : gen-wrapper-function ( addr -- )
                    399:     \ addr points to the return type index of a c-function descriptor
1.10      anton     400:     dup { descriptor }
1.13      anton     401:     count { ret } count 2dup { d: pars } chars + count { d: c-name }
1.23      anton     402:     ." void " lib-modulename 2@ type ." _LTX_" descriptor wrapper-function-name 2dup type drop free throw
1.10      anton     403:     .\" (void)\n"
1.4       anton     404:     .\" {\n  Cell MAYBE_UNUSED *sp = gforth_SP;\n  Float MAYBE_UNUSED *fp = gforth_FP;\n  "
1.2       anton     405:     pars c-name 2over count-stacks ret gen-wrapped-stmt .\" ;\n"
                    406:     ?dup-if
1.3       anton     407:        ."   gforth_SP = sp+" .nb .\" ;\n"
1.2       anton     408:     endif
                    409:     ?dup-if
1.3       anton     410:        ."   gforth_FP = fp+" .nb .\" ;\n"
1.2       anton     411:     endif
1.3       anton     412:     .\" }\n" ;
1.2       anton     413: 
1.16      anton     414: : tempdir ( -- c-addr u )
                    415:     s" TMPDIR" getenv dup 0= if
                    416:         2drop s" /tmp"
                    417:     then ;
                    418: 
1.15      anton     419: : gen-filename ( x -- c-addr u )
                    420:     \ generates a filename without extension for lib-handle-addr X
1.16      anton     421:     0 <<# ['] #s $10 base-execute #> 
1.23      anton     422:     tempdir s" /gforth_c_" s+ 2swap append #>> ;
1.15      anton     423: 
1.12      anton     424: : init-c-source-file ( -- )
                    425:     c-source-file-id @ 0= if
1.23      anton     426:         here 0 , dup lib-handle-addr ! gen-filename 2dup lib-filename 2!
                    427:         2dup tempdir nip 1+ /string lib-modulename 2!
1.15      anton     428:        s" .c" s+ 2dup w/o create-file throw dup c-source-file-id !
                    429:         ['] print-c-prefix-lines swap outfile-execute
                    430:         drop free throw
1.12      anton     431:     endif ;
1.11      anton     432: 
                    433: : c-source-file ( -- file-id )
1.12      anton     434:     c-source-file-id @ assert( dup ) ;
1.11      anton     435: 
1.24    ! anton     436: : .lib-error ( -- )
        !           437:     [ifdef] lib-error
        !           438:         ['] cr stderr outfile-execute
        !           439:         lib-error ['] type outfile-execute
        !           440:     [then] ;
1.23      anton     441: 
1.21      anton     442: DEFER compile-wrapper-function
                    443: :NONAME ( -- )
1.12      anton     444:     c-source-file close-file throw
                    445:     0 c-source-file-id !
1.23      anton     446:     [ s" libtool --silent --mode=compile gcc -I "
                    447:       s" includedir" getenv append ] sliteral
                    448:     s"  -O -c " s+ lib-filename 2@ append s" .c -o " append
                    449:     lib-filename 2@ append s" .lo" append ( c-addr u )
                    450:     2dup system drop free throw $? abort" libtool compile failed"
                    451:     s" libtool --silent --mode=link gcc -module -rpath " tempdir s+ s"  " append
                    452:     lib-filename 2@ append s" .lo -o " append
1.22      anton     453:     lib-filename 2@ append s" .la" append ( c-addr u )
1.23      anton     454:     2dup system drop free throw $? abort" libtool link failed"
                    455:     lib-filename 2@ s" .la" s+
                    456:     2dup open-lib dup 0= if
1.24    ! anton     457:         .lib-error true abort" open-lib failed"
1.23      anton     458:     endif
1.15      anton     459:     ( lib-handle ) lib-handle-addr @ !
                    460:     2dup delete-file throw drop free throw
                    461:     lib-filename 2@ s" .c" s+ 2dup delete-file throw drop free throw
1.21      anton     462:     lib-filename 2@ drop free throw 0 0 lib-filename 2! ; IS compile-wrapper-function
1.5       anton     463: \    s" ar rcs xxx.a xxx.o" system
                    464: \    $? abort" ar generated error" ;
                    465: 
1.12      anton     466: : link-wrapper-function { cff -- sym }
                    467:     cff cff-rtype wrapper-function-name { d: wrapper-name }
1.23      anton     468:     wrapper-name cff cff-lha @ @ assert( dup ) lib-sym dup 0= if
1.24    ! anton     469:         .lib-error -&32 throw
1.23      anton     470:     endif
1.10      anton     471:     wrapper-name drop free throw ;
1.8       anton     472: 
1.12      anton     473: : c-function-ft ( xt-defr xt-cfr "c-name" "{libcc-type}" "--" "libcc-type" -- )
1.8       anton     474:     \ build time/first time action for c-function
1.12      anton     475:     init-c-source-file
                    476:     noname create 2, lib-handle-addr @ ,
1.2       anton     477:     parse-name { d: c-name }
1.8       anton     478:     here parse-function-types c-name string,
1.11      anton     479:     ['] gen-wrapper-function c-source-file outfile-execute
1.8       anton     480:   does> ( ... -- ... )
1.10      anton     481:     dup 2@ { xt-defer xt-cfr }
1.12      anton     482:     dup cff-lha @ @ 0= if
                    483:        compile-wrapper-function
                    484:     endif
                    485:     link-wrapper-function xt-cfr >body !
1.8       anton     486:     xt-cfr xt-defer defer!
                    487:     xt-cfr execute ;
                    488: 
                    489: : c-function-rt ( -- )
                    490:     \ run-time definition for c function; addr is the address where
                    491:     \ the sym should be stored
                    492:     noname create 0 ,
1.2       anton     493:   does> ( ... -- ... )
                    494:     @ call-c ;
                    495: 
1.18      anton     496: : c-function ( "forth-name" "c-name" "@{type@}" "--" "type" -- ) \ gforth
1.17      anton     497:     \G Define a Forth word @i{forth-name}.  @i{Forth-name} has the
                    498:     \G specified stack effect and calls the C function @code{c-name}.
1.8       anton     499:     defer lastxt dup c-function-rt lastxt c-function-ft
                    500:     lastxt swap defer! ;

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