\ libcc.fs foreign function interface implemented using a C compiler \ Copyright (C) 2006 Free Software Foundation, Inc. \ This file is part of Gforth. \ Gforth is free software; you can redistribute it and/or \ modify it under the terms of the GNU General Public License \ as published by the Free Software Foundation; either version 2 \ of the License, or (at your option) any later version. \ This program is distributed in the hope that it will be useful, \ but WITHOUT ANY WARRANTY; without even the implied warranty of \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the \ GNU General Public License for more details. \ You should have received a copy of the GNU General Public License \ along with this program; if not, write to the Free Software \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. \ What this implementation does is this: if it sees a declaration like \ \ something that tells it to include \ \ something that tells it that the current library is libc \ c-function dlseek lseek n d n -- d \ it genererates C code similar to the following: \ #include \ #include \ \ void gforth_c_lseek_ndn_d(void) \ { \ Cell *sp = gforth_SP; \ Float *fp = gforth_FP; \ long long result; /* longest type in C */ \ gforth_ll2d(lseek(sp[3],gforth_d2ll(sp[2],sp[1]),sp[0]),sp[3],sp[2]); \ gforth_SP = sp+2; \ } \ Then it compiles this code and dynamically links it into the Gforth \ system (batching and caching are future work). It also dynamically \ links lseek. Performing DLSEEK then puts the function pointer of \ the function pointer of gforth_c_lseek_ndn_d on the stack and \ calls CALL-C. \ other things to do: \ c-variable forth-name c-name \ c-constant forth-name c-name \ data structures \ c-function word body: \ cell function pointer \ char return type index \ char parameter count n \ char*n parameters (type indices) \ counted string: c-name : .n ( n -- ) 0 .r ; : const+ ( n1 "name" -- n2 ) dup constant 1+ ; wordlist constant libcc-types get-current libcc-types set-current \ index values -1 const+ -- \ end of arguments const+ n \ integer cell const+ p \ pointer cell const+ d \ double const+ r \ float const+ func \ C function pointer const+ void drop set-current : parse-libcc-type ( "libcc-type" -- u ) parse-name libcc-types search-wordlist 0= -13 and throw execute ; : parse-function-types ( "{libcc-type}" "--" "libcc-type" -- ) here 2 chars allot here begin parse-libcc-type dup 0>= while c, repeat drop swap - over char+ c! parse-libcc-type 0< -32 and throw swap c! ; : type-letter ( n -- c ) chars s" npdrfv" drop + c@ ; \ count-stacks : count-stacks-n ( fp-change1 sp-change1 -- fp-change2 sp-change2 ) 1+ ; : count-stacks-p ( fp-change1 sp-change1 -- fp-change2 sp-change2 ) 1+ ; : count-stacks-d ( fp-change1 sp-change1 -- fp-change2 sp-change2 ) 2 + ; : count-stacks-r ( fp-change1 sp-change1 -- fp-change2 sp-change2 ) swap 1+ swap ; : count-stacks-func ( fp-change1 sp-change1 -- fp-change2 sp-change2 ) 1+ ; : count-stacks-void ( fp-change1 sp-change1 -- fp-change2 sp-change2 ) ; create count-stacks-types ' count-stacks-n , ' count-stacks-p , ' count-stacks-d , ' count-stacks-r , ' count-stacks-func , ' count-stacks-void , : count-stacks ( pars -- fp-change sp-change ) \ pars is an addr u pair 0 0 2swap over + swap u+do i c@ cells count-stacks-type + @ execute loop ; \ gen-pars : gen-par-n ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 ) 1- dup ." sp[" .n ." ]" ; : gen-par-p ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 ) ." (void *)(" gen-par-n ." )" ; : gen-par-d ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 ) ." gforthd2ll(" gen-par-n ." ," gen-par-n ." )" ; : gen-par-r ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 ) swap 1- tuck ." fp[" .n ." ]" ; : gen-par-func ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 ) gen-par-p ; : gen-par-void ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 ) -32 throw ; create gen-par-types ' gen-par-n , ' gen-par-p , ' gen-par-d , ' gen-par-r , ' gen-par-func , ' gen-par-void , : gen-par ( fp-depth1 sp-depth1 partype -- fp-depth2 sp-depth2 ) cells gen-par-types @ execute ; \ the call itself : gen-wrapped-call { d: pars d: c-name fp-change1 sp-change1 -- } c-name type ." (" fp-change1 sp-change1 pars over + swap u+do i c@ gen-par i 1+ i' < if ." ," endif loop 2drop ." )" ; \ calls for various kinds of return values : gen-wrapped-void ( pars c-name fp-change1 sp-change1 -- fp-change sp-change ) 2dup 2>r gen-wrapped-call 2r> ; create gen-wrapped-types ' gen-wrapped-n , ' gen-wrapped-p , ' gen-wrapped-d , ' gen-wrapped-r , ' gen-wrapped-func , ' gen-wrapped-void , : gen-wrapped-stmt ( pars c-name fp-change1 sp-change1 ret -- fp-change sp-change ) cells gen-wrapped-types @ execute ; : gen-wrapper-function ( addr -- ) \ addr points to the return type index of a c-function descriptor c@+ { ret } count 2dup { d: pars } chars + count { d: c-name } ." void gforth_c_" c-name type ." _" pars 0 +do i chars over + c@ type-letter emit loop ." _" ret type-letter emit .\" (void)\n" .\" {\n Cell *sp = gforth_SP;\n Float *fp = gforth_FP;" pars c-name 2over count-stacks ret gen-wrapped-stmt .\" ;\n" ?dup-if ." gforth_SP = sp+" .n .\" ;\n" endif ?dup-if ." gforth_FP = fp+" .n .\" ;\n" endif ." }\n" ; : c-function ( "forth-name" "c-name" "{libcc-type}" "--" "libcc-type" -- ) create here >r 0 , \ place for the wrapper function pointer parse-name { d: c-name } parse-function-types c-name string, r> cell+ gen-wrapper-function compile-wrapper-function link-wrapper-function r> ! does> ( ... -- ... ) @ call-c ; s" Library not found" exception constant err-nolib : library ( "name" "file" -- ) \ gforth \G Dynamically links the library specified by @i{file}. Defines a \G word @i{name} ( -- lib ) that starts the declaration of a \G function from that library. create parse-name open-lib dup 0= err-nolib and throw , does> ( -- lib ) @ ;