\ lib.fs	shared library support package 		16aug03py

\ Copyright (C) 1995,1996,1997,1998,2000,2003 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.

Variable libs 0 libs !
\ links between libraries
Variable thisproc
Variable thislib

Variable revdec  revdec off
\ turn revdec on to compile bigFORTH libraries
Variable revarg  revarg off
\ turn revarg on to compile declarations with reverse arguments
Variable legacy  legacy off
\ turn legacy on to compile bigFORTH legacy libraries

Vocabulary c-decl
Vocabulary cb-decl

: @lib ( lib -- )
    \G obtains library handle
    cell+ dup 2 cells + count open-lib
    dup 0= abort" Library not found" swap ! ;

: @proc ( lib addr -- )
    \G obtains symbol address
    cell+ tuck cell+ @ count rot cell+ @
    lib-sym  dup 0= abort" Proc not found!" swap ! ;

: proc, ( lib -- )
\G allocates and initializes proc stub
\G stub format:
\G    linked list in library
\G    address of proc
\G    ptr to OS name of symbol as counted string
\G    threaded code for invocation
    here dup thisproc !
    swap 2 cells + dup @ A, !
    0 , 0 A, ;

Defer legacy-proc  ' noop IS legacy-proc

: proc:  ( lib "name" -- )
\G Creates a named proc stub
    Create proc, 0 also c-decl
    legacy @ IF  legacy-proc  THEN
DOES> ( x1 .. xn -- r )
    dup cell+ @ swap 3 cells + >r ;

: library ( "name" "file" -- )
\G loads library "file" and creates a proc defining word "name"
\G library format:
\G    linked list of libraries
\G    library handle
\G    linked list of library's procs
\G    OS name of library as counted string
    Create  here libs @ A, dup libs !
    0 , 0 A, parse-name string, @lib
DOES> ( -- )  dup thislib ! proc: ;

: init-shared-libs ( -- )
    defers 'cold  libs
    0  libs  BEGIN  @ dup  WHILE  dup  REPEAT  drop
    BEGIN  dup  WHILE  >r
	r@ @lib
	r@ 2 cells +  BEGIN  @ dup  WHILE  r@ over @proc  REPEAT
	drop rdrop
    REPEAT  drop ;

' init-shared-libs IS 'cold

: argtype ( revxt pushxt fwxt "name" -- )
    Create , , , ;

: arg@ ( arg -- argxt pushxt )
    revarg @ IF  2 cells + @ ['] noop swap  ELSE  2@  THEN ;

: arg, ( xt -- )
    dup ['] noop = IF  drop  EXIT  THEN  compile, ;

: decl, ( 0 arg1 .. argn call start -- )
    2@ compile, >r
    revdec @ IF  0 >r
	BEGIN  dup  WHILE  >r  REPEAT
	BEGIN  r> dup  WHILE  arg@ arg,  REPEAT  drop
	BEGIN  dup  WHILE  arg,  REPEAT drop
    ELSE  0 >r
	BEGIN  dup  WHILE  arg@ arg, >r REPEAT drop
	BEGIN  r> dup  WHILE  arg,  REPEAT  drop
    THEN
    r> compile,  postpone EXIT ;

: symbol, ( "c-symbol" -- )
    here thisproc @ 2 cells + ! parse-name s,
    thislib @ thisproc @ @proc ;

: rettype ( endxt startxt "name" -- )
    Create 2,
  DOES>  decl, symbol, previous revarg off ;

also c-decl definitions

: <rev>  revarg on ;

' av-int      ' av-int-r      ' >r  argtype int
' av-float    ' av-float-r    ' f>l argtype sf
' av-double   ' av-double-r   ' f>l argtype df
' av-longlong ' av-longlong-r ' 2>r argtype llong
' av-ptr      ' av-ptr-r      ' >r  argtype ptr

' av-call-void     ' av-start-void     rettype (void)
' av-call-int      ' av-start-int      rettype (int)
' av-call-float    ' av-start-float    rettype (sf)
' av-call-double   ' av-start-double   rettype (fp)
' av-call-longlong ' av-start-longlong rettype (llong)
' av-call-ptr      ' av-start-ptr      rettype (ptr)

: (addr)  postpone EXIT  symbol, previos revarg off ;

previous definitions

\ legacy support for old library interfaces
\ interface to old vararg stuff not implemented yet

also c-decl

:noname ( n 0 -- 0 int1 .. intn )
    legacy @ 0< revarg !
    swap 0 ?DO  int  LOOP  (int)
; IS legacy-proc

: (int) ( n -- )
    >r ' execute r> 0 ?DO  int  LOOP  (int) ;
: (void) ( n -- )
    >r ' execute r> 0 ?DO  int  LOOP  (void) ;
: (float) ( n -- )
    >r ' execute r> 0 ?DO  df   LOOP  (fp) ;

previous

\ callback stuff

Variable callbacks
\G link between callbacks

: callback ( -- )
    Create  0 ] postpone >r also cb-decl
  DOES>
    Create here >r 0 , callbacks @ A, r@ callbacks !
    swap postpone Literal postpone call , postpone EXIT
    r> dup cell+ cell+ alloc-callback swap !
  DOES> @ ;

: callback; ( 0 xt1 .. xtn -- )
    BEGIN  over  WHILE  compile,  REPEAT
    postpone r> postpone execute compile, drop
    postpone EXIT postpone [ previous ; immediate

: va-ret ( xt xt -- )
    Create A, A, immediate
  DOES> 2@ compile, ;

: init-callbacks ( -- )
    defers 'cold  callbacks 1 cells -
    BEGIN  cell+ @ dup  WHILE  dup cell+ cell+ alloc-callback over !
    REPEAT  drop ;

' init-callbacks IS 'cold

also cb-decl definitions

\ arguments

' va-arg-int      Alias int
' va-arg-float    Alias sf
' va-arg-double   Alias df
' va-arg-longlong Alias llong
' va-arg-ptr      Alias ptr

' va-return-void     ' va-start-void     va-ret (void)
' va-return-int      ' va-start-int      va-ret (int)
' va-return-float    ' va-start-float    va-ret (sf)
' va-return-double   ' va-start-double   va-ret (fp)
' va-return-longlong ' va-start-longlong va-ret (llong)
' va-return-ptr      ' va-start-ptr      va-ret (ptr)

previous definitions