File:  [gforth] / gforth / libcc.fs
Revision 1.17: download - view: text, annotated - select for diffs
Fri Jun 1 16:27:37 2007 UTC (12 years, 2 months ago) by anton
Branches: MAIN
CVS tags: HEAD
more libcc.fs tests
documented C interface (libcc)
lib.fs now aborts if neither libffi nor ffcall are available (oldlib.fs is
  incompatible)

    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: 
   24: \ \ something that tells it that the current library is libc
   25: \ \c #include <unistd.h>
   26: \ c-function dlseek lseek n d n -- d
   27: 
   28: \ it genererates C code similar to the following:
   29: 
   30: \ #include <gforth.h>
   31: \ #include <unistd.h>
   32: \ 
   33: \ void gforth_c_lseek_ndn_d(void)
   34: \ {
   35: \   Cell *sp = gforth_SP;
   36: \   Float *fp = gforth_FP;
   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;
   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
   45: \ the function pointer of gforth_c_lseek_ndn_d on the stack and
   46: \ calls CALL-C.
   47: 
   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: 
   71: \ other things to do:
   72: 
   73: \ c-variable forth-name c-name
   74: \ c-constant forth-name c-name
   75: 
   76: 
   77: \ data structures
   78: 
   79: \ For every c-function, we have three words: two anonymous words
   80: \ created by c-function-ft (first time) and c-function-rt (run-time),
   81: \ and a named deferred word.  The deferred word first points to the
   82: \ first-time word, then to the run-time word; the run-time word calls
   83: \ the c function.
   84: 
   85: 
   86: require struct.fs
   87: 
   88:     \ counted-string
   89:     
   90: \ c-function-ft word body:
   91: struct
   92:     cell% field cff-cfr \ xt of c-function-rt word
   93:     cell% field cff-deferred \ xt of c-function deferred word
   94:     cell% field cff-lha \ address of the lib-handle for the lib that
   95:                         \ contains the wrapper function of the word
   96:     char% field cff-rtype  \ return type
   97:     char% field cff-np     \ number of parameters
   98:     1 0   field cff-ptypes \ #npar parameter types
   99:     \  counted string: c-name
  100: end-struct cff%
  101: 
  102: variable c-source-file-id \ contains the source file id of the current batch
  103: 0 c-source-file-id !
  104: variable lib-handle-addr \ points to the library handle of the current batch.
  105:                          \ the library handle is 0 if the current
  106:                          \ batch is not yet compiled.
  107: 2variable lib-filename \ filename without extension
  108: 
  109: : .nb ( n -- )
  110:     0 .r ;
  111: 
  112: : const+ ( n1 "name" -- n2 )
  113:     dup constant 1+ ;
  114: 
  115: : front-string { c-addr1 u1 c-addr2 u2 -- c-addr3 u3 }
  116:     \ insert string c-addr2 u2 in buffer c-addr1 u1; c-addr3 u3 is the
  117:     \ remainder of the buffer.
  118:     assert( u1 u2 u>= )
  119:     c-addr2 c-addr1 u2 move
  120:     c-addr1 u1 u2 /string ;
  121: 
  122: : front-char { c-addr1 u1 c -- c-addr3 u2 }
  123:     \ insert c in buffer c-addr1 u1; c-addr3 u3 is the remainder of
  124:     \ the buffer.
  125:     assert( u1 0 u> )
  126:     c c-addr1 c!
  127:     c-addr1 u1 1 /string ;
  128: 
  129: : s+ { addr1 u1 addr2 u2 -- addr u }
  130:     u1 u2 + allocate throw { addr }
  131:     addr1 addr u1 move
  132:     addr2 addr u1 + u2 move
  133:     addr u1 u2 +
  134: ;
  135: 
  136: : append { addr1 u1 addr2 u2 -- addr u }
  137:     addr1 u1 u2 + dup { u } resize throw { addr }
  138:     addr2 addr u1 + u2 move
  139:     addr u ;
  140: 
  141: \ linked list stuff (should go elsewhere)
  142: 
  143: struct
  144:     cell% field list-next
  145:     1 0   field list-payload
  146: end-struct list%
  147: 
  148: : list-insert { node list -- }
  149:     list list-next @ node list-next !
  150:     node list list-next ! ;
  151: 
  152: : list-append { node endlistp -- }
  153:     \ insert node at place pointed to by endlistp
  154:     node endlistp @ list-insert
  155:     node list-next endlistp ! ;
  156: 
  157: : list-map ( ... list xt -- ... )
  158:     \ xt ( ... node -- ... )
  159:     { xt } begin { node }
  160: 	node while
  161: 	    node xt execute
  162: 	    node list-next @
  163:     repeat ;
  164: 
  165: \ C prefix lines
  166: 
  167: \ linked list of longcstrings: [ link | count-cell | characters ]
  168: 
  169: list%
  170:     cell% field c-prefix-count
  171:     1 0   field c-prefix-chars
  172: end-struct c-prefix%
  173: 
  174: variable c-prefix-lines 0 c-prefix-lines !
  175: variable c-prefix-lines-end c-prefix-lines c-prefix-lines-end !
  176: 
  177: : print-c-prefix-line ( node -- )
  178:     dup c-prefix-chars swap c-prefix-count @ type cr ;
  179: 
  180: : print-c-prefix-lines ( -- )
  181:     c-prefix-lines @ ['] print-c-prefix-line list-map ;
  182: 
  183: : save-c-prefix-line ( c-addr u -- )
  184:     c-source-file-id @ ?dup-if
  185: 	>r 2dup r> write-line throw
  186:     then
  187:     align here 0 , c-prefix-lines-end list-append ( c-addr u )
  188:     longstring, ;
  189: 
  190: : \c ( "rest-of-line" -- )
  191:     \G One line of C declarations for the C interface
  192:     -1 parse save-c-prefix-line ;
  193: 
  194: \c #include "engine/libcc.h"
  195: 
  196: \ Types (for parsing)
  197: 
  198: wordlist constant libcc-types
  199: 
  200: get-current libcc-types set-current
  201: 
  202: \ index values
  203: -1
  204: const+ -- \ end of arguments
  205: const+ n \ integer cell
  206: const+ a \ address cell
  207: const+ d \ double
  208: const+ r \ float
  209: const+ func \ C function pointer
  210: const+ void
  211: drop
  212: 
  213: set-current
  214: 
  215: : parse-libcc-type ( "libcc-type" -- u )
  216:     parse-name libcc-types search-wordlist 0= -13 and throw execute ;
  217: 
  218: : parse-function-types ( "{libcc-type}" "--" "libcc-type" -- )
  219:     here 2 chars allot here begin
  220: 	parse-libcc-type dup 0>= while
  221: 	    c,
  222:     repeat
  223:     drop here swap - over char+ c!
  224:     parse-libcc-type dup 0< -32 and throw swap c! ;
  225: 
  226: : type-letter ( n -- c )
  227:     chars s" nadrfv" drop + c@ ;
  228: 
  229: \ count-stacks
  230: 
  231: : count-stacks-n ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
  232:     1+ ;
  233: 
  234: : count-stacks-a ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
  235:     1+ ;
  236: 
  237: : count-stacks-d ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
  238:     2 + ;
  239: 
  240: : count-stacks-r ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
  241:     swap 1+ swap ;
  242: 
  243: : count-stacks-func ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
  244:     1+ ;
  245: 
  246: : count-stacks-void ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
  247: ;
  248: 
  249: create count-stacks-types
  250: ' count-stacks-n ,
  251: ' count-stacks-a ,
  252: ' count-stacks-d ,
  253: ' count-stacks-r ,
  254: ' count-stacks-func ,
  255: ' count-stacks-void ,
  256: 
  257: : count-stacks ( pars -- fp-change sp-change )
  258:     \ pars is an addr u pair
  259:     0 0 2swap over + swap u+do
  260: 	i c@ cells count-stacks-types + @ execute
  261:     loop ;
  262: 
  263: \ gen-pars
  264: 
  265: : gen-par-n ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
  266:     ." sp[" 1- dup .nb ." ]" ;
  267: 
  268: : gen-par-a ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
  269:     ." (void *)(" gen-par-n ." )" ;
  270: 
  271: : gen-par-d ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
  272:     ." gforth_d2ll(" gen-par-n ." ," gen-par-n ." )" ;
  273: 
  274: : gen-par-r ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
  275:     swap 1- tuck ." fp[" .nb ." ]" ;
  276: 
  277: : gen-par-func ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
  278:     gen-par-a ;
  279: 
  280: : gen-par-void ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
  281:     -32 throw ;
  282: 
  283: create gen-par-types
  284: ' gen-par-n ,
  285: ' gen-par-a ,
  286: ' gen-par-d ,
  287: ' gen-par-r ,
  288: ' gen-par-func ,
  289: ' gen-par-void ,
  290: 
  291: : gen-par ( fp-depth1 sp-depth1 partype -- fp-depth2 sp-depth2 )
  292:     cells gen-par-types + @ execute ;
  293: 
  294: \ the call itself
  295: 
  296: : gen-wrapped-call { d: pars d: c-name fp-change1 sp-change1 -- }
  297:     c-name type ." ("
  298:     fp-change1 sp-change1 pars over + swap u+do 
  299: 	i c@ gen-par
  300: 	i 1+ i' < if
  301: 	    ." ,"
  302: 	endif
  303:     loop
  304:     2drop ." )" ;
  305: 
  306: \ calls for various kinds of return values
  307: 
  308: : gen-wrapped-void ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
  309:     2dup 2>r gen-wrapped-call 2r> ;
  310: 
  311: : gen-wrapped-n ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
  312:     2dup gen-par-n 2>r ." =" gen-wrapped-call 2r> ;
  313: 
  314: : gen-wrapped-a ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
  315:     2dup gen-par-n 2>r ." =(Cell)" gen-wrapped-call 2r> ;
  316: 
  317: : gen-wrapped-d ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
  318:     ." gforth_ll2d(" gen-wrapped-void
  319:     ." ," gen-par-n ." ," gen-par-n ." )" ;
  320: 
  321: : gen-wrapped-r ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
  322:     2dup gen-par-r 2>r ." =" gen-wrapped-void 2r> ;
  323: 
  324: : gen-wrapped-func ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
  325:     gen-wrapped-a ;
  326: 
  327: create gen-wrapped-types
  328: ' gen-wrapped-n ,
  329: ' gen-wrapped-a ,
  330: ' gen-wrapped-d ,
  331: ' gen-wrapped-r ,
  332: ' gen-wrapped-func ,
  333: ' gen-wrapped-void ,
  334: 
  335: : gen-wrapped-stmt ( pars c-name fp-change1 sp-change1 ret -- fp-change sp-change )
  336:     cells gen-wrapped-types + @ execute ;
  337: 
  338: : wrapper-function-name ( addr -- c-addr u )
  339:     \ addr points to the return type index of a c-function descriptor
  340:     count { r-type } count { d: pars }
  341:     pars + count { d: c-name }
  342:     s" gforth_c_" { d: prefix }
  343:     prefix nip c-name nip + pars nip + 3 + { u }
  344:     u allocate throw { c-addr }
  345:     c-addr u
  346:     prefix front-string c-name front-string '_ front-char
  347:     pars bounds u+do
  348: 	i c@ type-letter front-char
  349:     loop
  350:     '_ front-char r-type type-letter front-char assert( dup 0= )
  351:     2drop c-addr u ;
  352: 
  353: : gen-wrapper-function ( addr -- )
  354:     \ addr points to the return type index of a c-function descriptor
  355:     dup { descriptor }
  356:     count { ret } count 2dup { d: pars } chars + count { d: c-name }
  357:     ." void " descriptor wrapper-function-name 2dup type drop free throw
  358:     .\" (void)\n"
  359:     .\" {\n  Cell MAYBE_UNUSED *sp = gforth_SP;\n  Float MAYBE_UNUSED *fp = gforth_FP;\n  "
  360:     pars c-name 2over count-stacks ret gen-wrapped-stmt .\" ;\n"
  361:     ?dup-if
  362: 	."   gforth_SP = sp+" .nb .\" ;\n"
  363:     endif
  364:     ?dup-if
  365: 	."   gforth_FP = fp+" .nb .\" ;\n"
  366:     endif
  367:     .\" }\n" ;
  368: 
  369: : tempdir ( -- c-addr u )
  370:     s" TMPDIR" getenv dup 0= if
  371:         2drop s" /tmp"
  372:     then ;
  373: 
  374: : gen-filename ( x -- c-addr u )
  375:     \ generates a filename without extension for lib-handle-addr X
  376:     0 <<# ['] #s $10 base-execute #> 
  377:     tempdir s" /gforth-c-" s+ 2swap append #>> ;
  378: 
  379: : init-c-source-file ( -- )
  380:     c-source-file-id @ 0= if
  381: 	here 0 , dup lib-handle-addr ! gen-filename 2dup lib-filename 2!
  382: 	s" .c" s+ 2dup w/o create-file throw dup c-source-file-id !
  383:         ['] print-c-prefix-lines swap outfile-execute
  384:         drop free throw
  385:     endif ;
  386: 
  387: : c-source-file ( -- file-id )
  388:     c-source-file-id @ assert( dup ) ;
  389: 
  390: : compile-wrapper-function ( -- )
  391:     c-source-file close-file throw
  392:     0 c-source-file-id !
  393:     s" gcc -I. -fPIC -shared -Wl,-soname," lib-filename 2@ s+
  394:     s" .so.1 -Wl,-export_dynamic -o " append lib-filename 2@ append
  395:     s" .so.1 -O " append lib-filename 2@ append s" .c" append ( c-addr u )
  396:     2dup system drop free throw
  397:     $? abort" compiler generated error" \ !! call dlerror
  398:     lib-filename 2@ s" .so.1" s+
  399:     2dup open-lib dup 0= abort" open-lib failed" \ !! call dlerror
  400:     ( lib-handle ) lib-handle-addr @ !
  401:     2dup delete-file throw drop free throw
  402:     lib-filename 2@ s" .c" s+ 2dup delete-file throw drop free throw
  403:     lib-filename 2@ drop free throw 0 0 lib-filename 2! ;
  404: \    s" ar rcs xxx.a xxx.o" system
  405: \    $? abort" ar generated error" ;
  406: 
  407: : link-wrapper-function { cff -- sym }
  408:     cff cff-rtype wrapper-function-name { d: wrapper-name }
  409:     wrapper-name cff cff-lha @ @ assert( dup ) lib-sym dup 0= -&32 and throw
  410:     wrapper-name drop free throw ;
  411: 
  412: : c-function-ft ( xt-defr xt-cfr "c-name" "{libcc-type}" "--" "libcc-type" -- )
  413:     \ build time/first time action for c-function
  414:     init-c-source-file
  415:     noname create 2, lib-handle-addr @ ,
  416:     parse-name { d: c-name }
  417:     here parse-function-types c-name string,
  418:     ['] gen-wrapper-function c-source-file outfile-execute
  419:   does> ( ... -- ... )
  420:     dup 2@ { xt-defer xt-cfr }
  421:     dup cff-lha @ @ 0= if
  422: 	compile-wrapper-function
  423:     endif
  424:     link-wrapper-function xt-cfr >body !
  425:     xt-cfr xt-defer defer!
  426:     xt-cfr execute ;
  427: 
  428: : c-function-rt ( -- )
  429:     \ run-time definition for c function; addr is the address where
  430:     \ the sym should be stored
  431:     noname create 0 ,
  432:   does> ( ... -- ... )
  433:     @ call-c ;
  434: 
  435: : c-function ( "forth-name" "c-name" "{libcc-type}" "--" "libcc-type" -- )
  436:     \G Define a Forth word @i{forth-name}.  @i{Forth-name} has the
  437:     \G specified stack effect and calls the C function @code{c-name}.
  438:     defer lastxt dup c-function-rt lastxt c-function-ft
  439:     lastxt swap defer! ;

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