\ 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 that the current library is libc
\ \c #include <unistd.h>
\ c-function dlseek lseek n d n -- d
\ it genererates C code similar to the following:
\ #include <gforth.h>
\ #include <unistd.h>
\
\ 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.
\ ToDo:
\ Batching, caching and lazy evaluation:
\ Batching:
\ New words are deferred, and the corresponding C functions are
\ collected in one file, until the first word is EXECUTEd; then the
\ file is compiled and linked into the system, and the word is
\ resolved.
\ Caching:
\ Instead of compiling all this stuff anew for every execution, we
\ keep the files around and have an index file containing the function
\ names and their corresponding .so files. If the needed wrapper name
\ is already present, it is just linked instead of generating the
\ wrapper again. This is all done by loading the index file(s?),
\ which define words for the wrappers in a separate wordlist.
\ The files are built in .../lib/gforth/$VERSION/libcc/ or
\ ~/.gforth/libcc/$HOST/.
\ other things to do:
\ c-variable forth-name c-name
\ c-constant forth-name c-name
\ data structures
\ For every c-function, we have three words: two anonymous words
\ created by c-function-ft (first time) and c-function-rt (run-time),
\ and a named deferred word. The deferred word first points to the
\ first-time word, then to the run-time word; the run-time word calls
\ the c function.
require struct.fs
\ counted-string
\ c-function-ft word body:
struct
cell% field cff-cfr \ xt of c-function-rt word
cell% field cff-deferred \ xt of c-function deferred word
cell% field cff-lha \ address of the lib-handle for the lib that
\ contains the wrapper function of the word
char% field cff-rtype \ return type
char% field cff-np \ number of parameters
1 0 field cff-ptypes \ #npar parameter types
\ counted string: c-name
end-struct cff%
variable c-source-file-id \ contains the source file id of the current batch
0 c-source-file-id !
variable lib-handle-addr \ points to the library handle of the current batch.
\ the library handle is 0 if the current
\ batch is not yet compiled.
: .nb ( n -- )
0 .r ;
: const+ ( n1 "name" -- n2 )
dup constant 1+ ;
: front-string { c-addr1 u1 c-addr2 u2 -- c-addr3 u3 }
\ insert string c-addr2 u2 in buffer c-addr1 u1; c-addr3 u3 is the
\ remainder of the buffer.
assert( u1 u2 u>= )
c-addr2 c-addr1 u2 move
c-addr1 u1 u2 /string ;
: front-char { c-addr1 u1 c -- c-addr3 u2 }
\ insert c in buffer c-addr1 u1; c-addr3 u3 is the remainder of
\ the buffer.
assert( u1 0 u> )
c c-addr1 c!
c-addr1 u1 1 /string ;
\ linked list stuff (should go elsewhere)
hex
struct
cell% field list-next
1 0 field list-payload
end-struct list%
: list-insert { node list -- }
list list-next @ node list-next !
node list list-next ! ;
: list-append { node endlistp -- }
\ insert node at place pointed to by endlistp
node endlistp @ list-insert
node list-next endlistp ! ;
: list-map ( ... list xt -- ... )
\ xt ( ... node -- ... )
{ xt } begin { node }
node while
node xt execute
node list-next @
repeat ;
\ C prefix lines
\ linked list of longcstrings: [ link | count-cell | characters ]
list%
cell% field c-prefix-count
1 0 field c-prefix-chars
end-struct c-prefix%
variable c-prefix-lines 0 c-prefix-lines !
variable c-prefix-lines-end c-prefix-lines c-prefix-lines-end !
: print-c-prefix-line ( node -- )
dup c-prefix-chars swap c-prefix-count @ type cr ;
: print-c-prefix-lines ( -- )
c-prefix-lines @ ['] print-c-prefix-line list-map ;
: save-c-prefix-line ( c-addr u -- )
c-source-file-id @ ?dup-if
>r 2dup r> write-line throw
then
align here 0 , c-prefix-lines-end list-append ( c-addr u )
longstring, ;
: \c ( "rest-of-line" -- )
-1 parse save-c-prefix-line ;
\c #include "engine/libcc.h"
\ Types (for parsing)
wordlist constant libcc-types
get-current libcc-types set-current
\ index values
-1
const+ -- \ end of arguments
const+ n \ integer cell
const+ a \ address 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 here swap - over char+ c!
parse-libcc-type dup 0< -32 and throw swap c! ;
: type-letter ( n -- c )
chars s" nadrfv" drop + c@ ;
\ count-stacks
: count-stacks-n ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
1+ ;
: count-stacks-a ( 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-a ,
' 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-types + @ execute
loop ;
\ gen-pars
: gen-par-n ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
." sp[" 1- dup .nb ." ]" ;
: gen-par-a ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
." (void *)(" gen-par-n ." )" ;
: gen-par-d ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
." gforth_d2ll(" gen-par-n ." ," gen-par-n ." )" ;
: gen-par-r ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
swap 1- tuck ." fp[" .nb ." ]" ;
: gen-par-func ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
gen-par-a ;
: gen-par-void ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
-32 throw ;
create gen-par-types
' gen-par-n ,
' gen-par-a ,
' 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> ;
: gen-wrapped-n ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
2dup gen-par-n 2>r ." =" gen-wrapped-call 2r> ;
: gen-wrapped-a ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
2dup gen-par-n 2>r ." =(Cell)" gen-wrapped-call 2r> ;
: gen-wrapped-d ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
." gforth_ll2d(" gen-wrapped-void
." ," gen-par-n ." ," gen-par-n ." )" ;
: gen-wrapped-r ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
2dup gen-par-r 2>r ." =" gen-wrapped-void 2r> ;
: gen-wrapped-func ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
gen-wrapped-a ;
create gen-wrapped-types
' gen-wrapped-n ,
' gen-wrapped-a ,
' 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 ;
: wrapper-function-name ( addr -- c-addr u )
\ addr points to the return type index of a c-function descriptor
count { r-type } count { d: pars }
pars + count { d: c-name }
s" gforth_c_" { d: prefix }
prefix nip c-name nip + pars nip + 3 + { u }
u allocate throw { c-addr }
c-addr u
prefix front-string c-name front-string '_ front-char
pars bounds u+do
i c@ type-letter front-char
loop
'_ front-char r-type type-letter front-char assert( dup 0= )
2drop c-addr u ;
: gen-wrapper-function ( addr -- )
\ addr points to the return type index of a c-function descriptor
dup { descriptor }
count { ret } count 2dup { d: pars } chars + count { d: c-name }
." void " descriptor wrapper-function-name 2dup type drop free throw
.\" (void)\n"
.\" {\n Cell MAYBE_UNUSED *sp = gforth_SP;\n Float MAYBE_UNUSED *fp = gforth_FP;\n "
pars c-name 2over count-stacks ret gen-wrapped-stmt .\" ;\n"
?dup-if
." gforth_SP = sp+" .nb .\" ;\n"
endif
?dup-if
." gforth_FP = fp+" .nb .\" ;\n"
endif
.\" }\n" ;
: init-c-source-file ( -- )
c-source-file-id @ 0= if
s" xxx.c" w/o create-file throw dup c-source-file-id !
['] print-c-prefix-lines swap outfile-execute
here 0 , lib-handle-addr !
endif ;
: c-source-file ( -- file-id )
c-source-file-id @ assert( dup ) ;
: compile-wrapper-function ( -- )
c-source-file close-file throw
0 c-source-file-id !
s" gcc -fPIC -shared -Wl,-soname,xxx.so.1 -Wl,-export_dynamic -o xxx.so.1 -O xxx.c" system
$? abort" compiler generated error"
s" /home/anton/gforth/xxx.so.1" open-lib dup 0= abort" open-lib failed"
( lib-handle ) lib-handle-addr @ ! ;
\ s" ar rcs xxx.a xxx.o" system
\ $? abort" ar generated error" ;
: link-wrapper-function { cff -- sym }
cff cff-rtype wrapper-function-name { d: wrapper-name }
wrapper-name cff cff-lha @ @ assert( dup ) lib-sym dup 0= -&32 and throw
wrapper-name drop free throw ;
: c-function-ft ( xt-defr xt-cfr "c-name" "{libcc-type}" "--" "libcc-type" -- )
\ build time/first time action for c-function
init-c-source-file
noname create 2, lib-handle-addr @ ,
parse-name { d: c-name }
here parse-function-types c-name string,
['] gen-wrapper-function c-source-file outfile-execute
does> ( ... -- ... )
dup 2@ { xt-defer xt-cfr }
dup cff-lha @ @ 0= if
compile-wrapper-function
endif
link-wrapper-function xt-cfr >body !
xt-cfr xt-defer defer!
xt-cfr execute ;
: c-function-rt ( -- )
\ run-time definition for c function; addr is the address where
\ the sym should be stored
noname create 0 ,
does> ( ... -- ... )
@ call-c ;
: c-function ( "forth-name" "c-name" "{libcc-type}" "--" "libcc-type" -- )
defer lastxt dup c-function-rt lastxt c-function-ft
lastxt swap defer! ;
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 )
@ ;
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>