Annotation of gforth/libcc.fs, revision 1.3

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 to include <unistd.h>
                     25: \ \ something that tells it that the current library is libc
                     26: 
                     27: \ c-function dlseek lseek n d n -- d
1.1       anton      28: 
                     29: \ it genererates C code similar to the following:
                     30: 
                     31: \ #include <gforth.h>
1.2       anton      32: \ #include <unistd.h>
1.1       anton      33: \ 
1.2       anton      34: \ void gforth_c_lseek_ndn_d(void)
1.1       anton      35: \ {
                     36: \   Cell *sp = gforth_SP;
                     37: \   Float *fp = gforth_FP;
1.2       anton      38: \   long long result;  /* longest type in C */
                     39: \   gforth_ll2d(lseek(sp[3],gforth_d2ll(sp[2],sp[1]),sp[0]),sp[3],sp[2]);
                     40: \   gforth_SP = sp+2;
1.1       anton      41: \ }
                     42: 
                     43: \ Then it compiles this code and dynamically links it into the Gforth
                     44: \ system (batching and caching are future work).  It also dynamically
                     45: \ links lseek.  Performing DLSEEK then puts the function pointer of
1.2       anton      46: \ the function pointer of gforth_c_lseek_ndn_d on the stack and
                     47: \ calls CALL-C.
                     48: 
                     49: \ other things to do:
                     50: 
                     51: \ c-variable forth-name c-name
                     52: \ c-constant forth-name c-name
                     53: 
                     54: 
                     55: \ data structures
                     56: 
                     57: \ c-function word body:
                     58: \  cell function pointer
                     59: \  char return type index
                     60: \  char parameter count n
                     61: \  char*n parameters (type indices)
                     62: \  counted string: c-name
                     63: 
1.3     ! anton      64: : .nb ( n -- )
1.2       anton      65:     0 .r ;
                     66: 
                     67: : const+ ( n1 "name" -- n2 )
                     68:     dup constant 1+ ;
                     69: 
                     70: wordlist constant libcc-types
                     71: 
                     72: get-current libcc-types set-current
                     73: 
                     74: \ index values
                     75: -1
                     76: const+ -- \ end of arguments
                     77: const+ n \ integer cell
                     78: const+ p \ pointer cell
                     79: const+ d \ double
                     80: const+ r \ float
                     81: const+ func \ C function pointer
                     82: const+ void
                     83: drop
                     84: 
                     85: set-current
                     86: 
                     87: : parse-libcc-type ( "libcc-type" -- u )
                     88:     parse-name libcc-types search-wordlist 0= -13 and throw execute ;
                     89: 
                     90: : parse-function-types ( "{libcc-type}" "--" "libcc-type" -- )
                     91:     here 2 chars allot here begin
                     92:        parse-libcc-type dup 0>= while
                     93:            c,
                     94:     repeat
1.3     ! anton      95:     drop here swap - over char+ c!
        !            96:     parse-libcc-type dup 0< -32 and throw swap c! ;
1.2       anton      97: 
                     98: : type-letter ( n -- c )
                     99:     chars s" npdrfv" drop + c@ ;
                    100: 
                    101: \ count-stacks
                    102: 
                    103: : count-stacks-n ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    104:     1+ ;
                    105: 
                    106: : count-stacks-p ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    107:     1+ ;
                    108: 
                    109: : count-stacks-d ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    110:     2 + ;
                    111: 
                    112: : count-stacks-r ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    113:     swap 1+ swap ;
                    114: 
                    115: : count-stacks-func ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    116:     1+ ;
                    117: 
                    118: : count-stacks-void ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    119: ;
                    120: 
                    121: create count-stacks-types
                    122: ' count-stacks-n ,
                    123: ' count-stacks-p ,
                    124: ' count-stacks-d ,
                    125: ' count-stacks-r ,
                    126: ' count-stacks-func ,
                    127: ' count-stacks-void ,
                    128: 
                    129: : count-stacks ( pars -- fp-change sp-change )
                    130:     \ pars is an addr u pair
                    131:     0 0 2swap over + swap u+do
1.3     ! anton     132:        i c@ cells count-stacks-types + @ execute
1.2       anton     133:     loop ;
                    134: 
                    135: \ gen-pars
                    136: 
                    137: : gen-par-n ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.3     ! anton     138:     1- dup ." sp[" .nb ." ]" ;
1.2       anton     139: 
                    140: : gen-par-p ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
                    141:     ." (void *)(" gen-par-n ." )" ;
                    142: 
                    143: : gen-par-d ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
                    144:     ." gforthd2ll(" gen-par-n ." ," gen-par-n ." )" ;
                    145: 
                    146: : gen-par-r ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.3     ! anton     147:     swap 1- tuck ." fp[" .nb ." ]" ;
1.2       anton     148: 
                    149: : gen-par-func ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
                    150:     gen-par-p ;
                    151: 
                    152: : gen-par-void ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
                    153:     -32 throw ;
                    154: 
                    155: create gen-par-types
                    156: ' gen-par-n ,
                    157: ' gen-par-p ,
                    158: ' gen-par-d ,
                    159: ' gen-par-r ,
                    160: ' gen-par-func ,
                    161: ' gen-par-void ,
                    162: 
                    163: : gen-par ( fp-depth1 sp-depth1 partype -- fp-depth2 sp-depth2 )
1.3     ! anton     164:     cells gen-par-types + @ execute ;
1.2       anton     165: 
                    166: \ the call itself
                    167: 
                    168: : gen-wrapped-call { d: pars d: c-name fp-change1 sp-change1 -- }
                    169:     c-name type ." ("
1.3     ! anton     170:     fp-change1 sp-change1 pars over + swap u+do 
1.2       anton     171:        i c@ gen-par
                    172:        i 1+ i' < if
                    173:            ." ,"
                    174:        endif
                    175:     loop
                    176:     2drop ." )" ;
                    177: 
                    178: \ calls for various kinds of return values
                    179: 
                    180: : gen-wrapped-void ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
                    181:     2dup 2>r gen-wrapped-call 2r> ;
                    182: 
1.3     ! anton     183: : gen-wrapped-n ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
        !           184:     1- dup ." sp[" .nb ." ]=" gen-wrapped-void ;
        !           185: 
        !           186: : gen-wrapped-p ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
        !           187:     1- dup ." sp[" .nb ." ]=(Cell)" gen-wrapped-void ;
        !           188: 
        !           189: : gen-wrapped-d ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
        !           190:     ." gforth_ll2d(" gen-wrapped-void
        !           191:     ." ,sp[" 1- dup .nb ." ],sp[" 1- dup .nb ." ])" ;
        !           192: 
        !           193: : gen-wrapped-r ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
        !           194:     swap 1- tuck ." fp[" .nb ." ]=" gen-wrapped-void ;
        !           195: 
        !           196: : gen-wrapped-func ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
        !           197:     gen-wrapped-p ;
        !           198: 
1.2       anton     199: create gen-wrapped-types
                    200: ' gen-wrapped-n ,
                    201: ' gen-wrapped-p ,
                    202: ' gen-wrapped-d ,
                    203: ' gen-wrapped-r ,
                    204: ' gen-wrapped-func ,
                    205: ' gen-wrapped-void ,
                    206: 
                    207: : gen-wrapped-stmt ( pars c-name fp-change1 sp-change1 ret -- fp-change sp-change )
1.3     ! anton     208:     cells gen-wrapped-types + @ execute ;
1.2       anton     209: 
                    210: : gen-wrapper-function ( addr -- )
                    211:     \ addr points to the return type index of a c-function descriptor
                    212:     c@+ { ret } count 2dup { d: pars } chars + count { d: c-name }
                    213:     ." void gforth_c_" c-name type ." _"
                    214:     pars 0 +do
                    215:        i chars over + c@ type-letter emit
                    216:     loop
                    217:     ." _" ret type-letter emit .\" (void)\n"
1.3     ! anton     218:     .\" {\n  Cell *sp = gforth_SP;\n  Float *fp = gforth_FP;\n  "
1.2       anton     219:     pars c-name 2over count-stacks ret gen-wrapped-stmt .\" ;\n"
                    220:     ?dup-if
1.3     ! anton     221:        ."   gforth_SP = sp+" .nb .\" ;\n"
1.2       anton     222:     endif
                    223:     ?dup-if
1.3     ! anton     224:        ."   gforth_FP = fp+" .nb .\" ;\n"
1.2       anton     225:     endif
1.3     ! anton     226:     .\" }\n" ;
1.2       anton     227: 
                    228: : c-function ( "forth-name" "c-name" "{libcc-type}" "--" "libcc-type" -- )
                    229:     create here >r 0 , \ place for the wrapper function pointer
                    230:     parse-name { d: c-name }
                    231:     parse-function-types c-name string,
                    232:     r> cell+ gen-wrapper-function
1.3     ! anton     233: \    compile-wrapper-function
        !           234: \    link-wrapper-function
        !           235: \    r> !
1.2       anton     236:   does> ( ... -- ... )
                    237:     @ call-c ;
                    238: 
                    239: 
                    240: 
1.1       anton     241: 
                    242: 
                    243: s" Library not found" exception constant err-nolib
                    244: 
                    245: : library ( "name" "file" -- ) \ gforth
                    246: \G Dynamically links the library specified by @i{file}.  Defines a
                    247: \G word @i{name} ( -- lib ) that starts the declaration of a
                    248: \G function from that library.
                    249:     create parse-name open-lib dup 0= err-nolib and throw ,
                    250:   does> ( -- lib )
                    251:     @ ;
                    252: 
1.3     ! anton     253: \ test
1.1       anton     254: 
1.3     ! anton     255: cr .( #include "engine/forth.h")
        !           256: cr .( #include <unistd.h>)
        !           257: cr ." typedef void (* func)(int);
        !           258: cr ." int test1(int,char*,long,double,void (*)(int));"
        !           259: cr ." Cell *test2(void);"
        !           260: cr ." int test3(void);"
        !           261: cr ." float test4(void);"
        !           262: cr ." func test5(void);"
        !           263: cr ." void test6(void);"
        !           264: cr
        !           265: 
        !           266: c-function dlseek lseek n d n -- d
        !           267: c-function n test1 n p d r func -- n
        !           268: c-function p test2 -- p
        !           269: c-function d test3 -- d
        !           270: c-function r test4 -- r
        !           271: c-function func test5 -- func
        !           272: c-function void test6 -- void

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