Annotation of gforth/libcc.fs, revision 1.22

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 that the current library is libc
1.6       anton      25: \ \c #include <unistd.h>
1.2       anton      26: \ c-function dlseek lseek n d n -- d
1.1       anton      27: 
                     28: \ it genererates C code similar to the following:
                     29: 
                     30: \ #include <gforth.h>
1.2       anton      31: \ #include <unistd.h>
1.1       anton      32: \ 
1.2       anton      33: \ void gforth_c_lseek_ndn_d(void)
1.1       anton      34: \ {
                     35: \   Cell *sp = gforth_SP;
                     36: \   Float *fp = gforth_FP;
1.2       anton      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;
1.1       anton      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
1.2       anton      45: \ the function pointer of gforth_c_lseek_ndn_d on the stack and
                     46: \ calls CALL-C.
                     47: 
1.7       anton      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: 
1.2       anton      71: \ other things to do:
                     72: 
                     73: \ c-variable forth-name c-name
                     74: \ c-constant forth-name c-name
                     75: 
1.20      anton      76: \ Todo: conversion between function pointers and xts (both directions)
                     77: 
                     78: \ taking an xt and turning it into a function pointer:
                     79: 
                     80: \ e.g., assume we have the xt of + and want to create a C function int
                     81: \ gforth_callback_plus(int, int), and then pass the pointer to that
                     82: \ function:
                     83: 
                     84: \ There should be Forth code like this:
                     85: \   ] + 0 (bye)
                     86: \ Assume that the start of this code is START
                     87:         
                     88: \ Now, there should be a C function:
                     89: 
                     90: \ int gforth_callback_plus(int p1, int p2)
                     91: \ {
                     92: \   Cell   *sp = gforth_SP;
                     93: \   Float  *fp = gforth_FP;
                     94: \   Float  *fp = gforth_FP;
                     95: \   Address lp = gforth_LP;
                     96: \   sp -= 2;
                     97: \   sp[0] = p1;
                     98: \   sp[1] = p2;
                     99: \   gforth_engine(START, sp, rp, fp, lp);
                    100: \   sp += 1;
                    101: \   gforth_RP = rp;
                    102: \   gforth_SP = sp;
                    103: \   gforth_FP = fp;
                    104: \   gforth_LP = lp;
                    105: \   return sp[0];
                    106: \ }
                    107: 
                    108: \ and the pointer to that function is the C function pointer for the XT of +.
                    109: 
                    110: \ Future problems:
                    111: \   how to combine the Forth code generation with inlining
                    112: \   START is not a constant across executions (when caching the C files)
                    113: \      Solution: make START a variable, and store into it on startup with dlsym
                    114: 
                    115: \ Syntax:
                    116: \  callback <rettype> <params> <paramtypes> -- <rettype>
                    117: 
1.2       anton     118: 
                    119: \ data structures
                    120: 
1.10      anton     121: \ For every c-function, we have three words: two anonymous words
                    122: \ created by c-function-ft (first time) and c-function-rt (run-time),
                    123: \ and a named deferred word.  The deferred word first points to the
                    124: \ first-time word, then to the run-time word; the run-time word calls
                    125: \ the c function.
                    126: 
1.22    ! anton     127: : delete-file 2drop 0 ;
1.12      anton     128: 
                    129: require struct.fs
                    130: 
                    131:     \ counted-string
                    132:     
1.10      anton     133: \ c-function-ft word body:
1.12      anton     134: struct
                    135:     cell% field cff-cfr \ xt of c-function-rt word
                    136:     cell% field cff-deferred \ xt of c-function deferred word
                    137:     cell% field cff-lha \ address of the lib-handle for the lib that
                    138:                         \ contains the wrapper function of the word
                    139:     char% field cff-rtype  \ return type
                    140:     char% field cff-np     \ number of parameters
                    141:     1 0   field cff-ptypes \ #npar parameter types
                    142:     \  counted string: c-name
                    143: end-struct cff%
                    144: 
1.14      anton     145: variable c-source-file-id \ contains the source file id of the current batch
                    146: 0 c-source-file-id !
                    147: variable lib-handle-addr \ points to the library handle of the current batch.
                    148:                          \ the library handle is 0 if the current
                    149:                          \ batch is not yet compiled.
1.15      anton     150: 2variable lib-filename \ filename without extension
1.2       anton     151: 
1.3       anton     152: : .nb ( n -- )
1.2       anton     153:     0 .r ;
                    154: 
                    155: : const+ ( n1 "name" -- n2 )
                    156:     dup constant 1+ ;
                    157: 
1.10      anton     158: : front-string { c-addr1 u1 c-addr2 u2 -- c-addr3 u3 }
                    159:     \ insert string c-addr2 u2 in buffer c-addr1 u1; c-addr3 u3 is the
                    160:     \ remainder of the buffer.
                    161:     assert( u1 u2 u>= )
                    162:     c-addr2 c-addr1 u2 move
                    163:     c-addr1 u1 u2 /string ;
                    164: 
                    165: : front-char { c-addr1 u1 c -- c-addr3 u2 }
                    166:     \ insert c in buffer c-addr1 u1; c-addr3 u3 is the remainder of
                    167:     \ the buffer.
                    168:     assert( u1 0 u> )
                    169:     c c-addr1 c!
                    170:     c-addr1 u1 1 /string ;
                    171: 
1.15      anton     172: : s+ { addr1 u1 addr2 u2 -- addr u }
                    173:     u1 u2 + allocate throw { addr }
                    174:     addr1 addr u1 move
                    175:     addr2 addr u1 + u2 move
                    176:     addr u1 u2 +
                    177: ;
                    178: 
                    179: : append { addr1 u1 addr2 u2 -- addr u }
                    180:     addr1 u1 u2 + dup { u } resize throw { addr }
                    181:     addr2 addr u1 + u2 move
                    182:     addr u ;
                    183: 
1.6       anton     184: \ linked list stuff (should go elsewhere)
                    185: 
                    186: struct
                    187:     cell% field list-next
                    188:     1 0   field list-payload
                    189: end-struct list%
                    190: 
                    191: : list-insert { node list -- }
                    192:     list list-next @ node list-next !
                    193:     node list list-next ! ;
                    194: 
                    195: : list-append { node endlistp -- }
                    196:     \ insert node at place pointed to by endlistp
                    197:     node endlistp @ list-insert
                    198:     node list-next endlistp ! ;
                    199: 
                    200: : list-map ( ... list xt -- ... )
                    201:     \ xt ( ... node -- ... )
                    202:     { xt } begin { node }
                    203:        node while
                    204:            node xt execute
                    205:            node list-next @
                    206:     repeat ;
                    207: 
                    208: \ C prefix lines
                    209: 
                    210: \ linked list of longcstrings: [ link | count-cell | characters ]
                    211: 
                    212: list%
                    213:     cell% field c-prefix-count
                    214:     1 0   field c-prefix-chars
                    215: end-struct c-prefix%
                    216: 
                    217: variable c-prefix-lines 0 c-prefix-lines !
                    218: variable c-prefix-lines-end c-prefix-lines c-prefix-lines-end !
                    219: 
1.14      anton     220: : print-c-prefix-line ( node -- )
                    221:     dup c-prefix-chars swap c-prefix-count @ type cr ;
                    222: 
                    223: : print-c-prefix-lines ( -- )
                    224:     c-prefix-lines @ ['] print-c-prefix-line list-map ;
                    225: 
1.6       anton     226: : save-c-prefix-line ( c-addr u -- )
1.14      anton     227:     c-source-file-id @ ?dup-if
                    228:        >r 2dup r> write-line throw
                    229:     then
1.6       anton     230:     align here 0 , c-prefix-lines-end list-append ( c-addr u )
                    231:     longstring, ;
                    232: 
1.18      anton     233: : \c ( "rest-of-line" -- ) \ gforth backslash-c
1.17      anton     234:     \G One line of C declarations for the C interface
1.6       anton     235:     -1 parse save-c-prefix-line ;
                    236: 
1.19      anton     237: s" #include <gforth/" version-string s+ s" /libcc.h>" append ( c-addr u )
                    238:   2dup save-c-prefix-line drop free throw
1.5       anton     239: 
1.6       anton     240: \ Types (for parsing)
1.5       anton     241: 
1.2       anton     242: wordlist constant libcc-types
                    243: 
                    244: get-current libcc-types set-current
                    245: 
                    246: \ index values
                    247: -1
                    248: const+ -- \ end of arguments
                    249: const+ n \ integer cell
1.5       anton     250: const+ a \ address cell
1.2       anton     251: const+ d \ double
                    252: const+ r \ float
                    253: const+ func \ C function pointer
                    254: const+ void
                    255: drop
                    256: 
                    257: set-current
                    258: 
                    259: : parse-libcc-type ( "libcc-type" -- u )
                    260:     parse-name libcc-types search-wordlist 0= -13 and throw execute ;
                    261: 
                    262: : parse-function-types ( "{libcc-type}" "--" "libcc-type" -- )
                    263:     here 2 chars allot here begin
                    264:        parse-libcc-type dup 0>= while
                    265:            c,
                    266:     repeat
1.3       anton     267:     drop here swap - over char+ c!
                    268:     parse-libcc-type dup 0< -32 and throw swap c! ;
1.2       anton     269: 
                    270: : type-letter ( n -- c )
1.5       anton     271:     chars s" nadrfv" drop + c@ ;
1.2       anton     272: 
                    273: \ count-stacks
                    274: 
                    275: : count-stacks-n ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    276:     1+ ;
                    277: 
1.5       anton     278: : count-stacks-a ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
1.2       anton     279:     1+ ;
                    280: 
                    281: : count-stacks-d ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    282:     2 + ;
                    283: 
                    284: : count-stacks-r ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    285:     swap 1+ swap ;
                    286: 
                    287: : count-stacks-func ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    288:     1+ ;
                    289: 
                    290: : count-stacks-void ( fp-change1 sp-change1 -- fp-change2 sp-change2 )
                    291: ;
                    292: 
                    293: create count-stacks-types
                    294: ' count-stacks-n ,
1.5       anton     295: ' count-stacks-a ,
1.2       anton     296: ' count-stacks-d ,
                    297: ' count-stacks-r ,
                    298: ' count-stacks-func ,
                    299: ' count-stacks-void ,
                    300: 
                    301: : count-stacks ( pars -- fp-change sp-change )
                    302:     \ pars is an addr u pair
                    303:     0 0 2swap over + swap u+do
1.3       anton     304:        i c@ cells count-stacks-types + @ execute
1.2       anton     305:     loop ;
                    306: 
                    307: \ gen-pars
                    308: 
                    309: : gen-par-n ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.5       anton     310:     ." sp[" 1- dup .nb ." ]" ;
1.2       anton     311: 
1.5       anton     312: : gen-par-a ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.2       anton     313:     ." (void *)(" gen-par-n ." )" ;
                    314: 
                    315: : gen-par-d ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.4       anton     316:     ." gforth_d2ll(" gen-par-n ." ," gen-par-n ." )" ;
1.2       anton     317: 
                    318: : gen-par-r ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.3       anton     319:     swap 1- tuck ." fp[" .nb ." ]" ;
1.2       anton     320: 
                    321: : gen-par-func ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
1.5       anton     322:     gen-par-a ;
1.2       anton     323: 
                    324: : gen-par-void ( fp-depth1 sp-depth1 -- fp-depth2 sp-depth2 )
                    325:     -32 throw ;
                    326: 
                    327: create gen-par-types
                    328: ' gen-par-n ,
1.5       anton     329: ' gen-par-a ,
1.2       anton     330: ' gen-par-d ,
                    331: ' gen-par-r ,
                    332: ' gen-par-func ,
                    333: ' gen-par-void ,
                    334: 
                    335: : gen-par ( fp-depth1 sp-depth1 partype -- fp-depth2 sp-depth2 )
1.3       anton     336:     cells gen-par-types + @ execute ;
1.2       anton     337: 
                    338: \ the call itself
                    339: 
                    340: : gen-wrapped-call { d: pars d: c-name fp-change1 sp-change1 -- }
                    341:     c-name type ." ("
1.3       anton     342:     fp-change1 sp-change1 pars over + swap u+do 
1.2       anton     343:        i c@ gen-par
                    344:        i 1+ i' < if
                    345:            ." ,"
                    346:        endif
                    347:     loop
                    348:     2drop ." )" ;
                    349: 
                    350: \ calls for various kinds of return values
                    351: 
                    352: : gen-wrapped-void ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
                    353:     2dup 2>r gen-wrapped-call 2r> ;
                    354: 
1.3       anton     355: : gen-wrapped-n ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
1.5       anton     356:     2dup gen-par-n 2>r ." =" gen-wrapped-call 2r> ;
1.3       anton     357: 
1.5       anton     358: : gen-wrapped-a ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
                    359:     2dup gen-par-n 2>r ." =(Cell)" gen-wrapped-call 2r> ;
1.3       anton     360: 
                    361: : gen-wrapped-d ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
                    362:     ." gforth_ll2d(" gen-wrapped-void
1.5       anton     363:     ." ," gen-par-n ." ," gen-par-n ." )" ;
1.3       anton     364: 
                    365: : gen-wrapped-r ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
1.5       anton     366:     2dup gen-par-r 2>r ." =" gen-wrapped-void 2r> ;
1.3       anton     367: 
                    368: : gen-wrapped-func ( pars c-name fp-change1 sp-change1 -- fp-change sp-change )
1.5       anton     369:     gen-wrapped-a ;
1.3       anton     370: 
1.2       anton     371: create gen-wrapped-types
                    372: ' gen-wrapped-n ,
1.5       anton     373: ' gen-wrapped-a ,
1.2       anton     374: ' gen-wrapped-d ,
                    375: ' gen-wrapped-r ,
                    376: ' gen-wrapped-func ,
                    377: ' gen-wrapped-void ,
                    378: 
                    379: : gen-wrapped-stmt ( pars c-name fp-change1 sp-change1 ret -- fp-change sp-change )
1.3       anton     380:     cells gen-wrapped-types + @ execute ;
1.2       anton     381: 
1.10      anton     382: : wrapper-function-name ( addr -- c-addr u )
                    383:     \ addr points to the return type index of a c-function descriptor
                    384:     count { r-type } count { d: pars }
                    385:     pars + count { d: c-name }
                    386:     s" gforth_c_" { d: prefix }
                    387:     prefix nip c-name nip + pars nip + 3 + { u }
                    388:     u allocate throw { c-addr }
                    389:     c-addr u
                    390:     prefix front-string c-name front-string '_ front-char
                    391:     pars bounds u+do
                    392:        i c@ type-letter front-char
                    393:     loop
                    394:     '_ front-char r-type type-letter front-char assert( dup 0= )
                    395:     2drop c-addr u ;
                    396: 
1.2       anton     397: : gen-wrapper-function ( addr -- )
                    398:     \ addr points to the return type index of a c-function descriptor
1.10      anton     399:     dup { descriptor }
1.13      anton     400:     count { ret } count 2dup { d: pars } chars + count { d: c-name }
1.10      anton     401:     ." void " descriptor wrapper-function-name 2dup type drop free throw
                    402:     .\" (void)\n"
1.4       anton     403:     .\" {\n  Cell MAYBE_UNUSED *sp = gforth_SP;\n  Float MAYBE_UNUSED *fp = gforth_FP;\n  "
1.2       anton     404:     pars c-name 2over count-stacks ret gen-wrapped-stmt .\" ;\n"
                    405:     ?dup-if
1.3       anton     406:        ."   gforth_SP = sp+" .nb .\" ;\n"
1.2       anton     407:     endif
                    408:     ?dup-if
1.3       anton     409:        ."   gforth_FP = fp+" .nb .\" ;\n"
1.2       anton     410:     endif
1.3       anton     411:     .\" }\n" ;
1.2       anton     412: 
1.16      anton     413: : tempdir ( -- c-addr u )
                    414:     s" TMPDIR" getenv dup 0= if
                    415:         2drop s" /tmp"
                    416:     then ;
                    417: 
1.15      anton     418: : gen-filename ( x -- c-addr u )
                    419:     \ generates a filename without extension for lib-handle-addr X
1.16      anton     420:     0 <<# ['] #s $10 base-execute #> 
                    421:     tempdir s" /gforth-c-" s+ 2swap append #>> ;
1.15      anton     422: 
1.12      anton     423: : init-c-source-file ( -- )
                    424:     c-source-file-id @ 0= if
1.15      anton     425:        here 0 , dup lib-handle-addr ! gen-filename 2dup lib-filename 2!
                    426:        s" .c" s+ 2dup w/o create-file throw dup c-source-file-id !
                    427:         ['] print-c-prefix-lines swap outfile-execute
                    428:         drop free throw
1.12      anton     429:     endif ;
1.11      anton     430: 
                    431: : c-source-file ( -- file-id )
1.12      anton     432:     c-source-file-id @ assert( dup ) ;
1.11      anton     433: 
1.21      anton     434: DEFER compile-wrapper-function
                    435: :NONAME ( -- )
1.12      anton     436:     c-source-file close-file throw
                    437:     0 c-source-file-id !
1.22    ! anton     438:     [ s" libtool --silent --mode=link gcc -module -I "
        !           439:       s" includedir" getenv append s"  -rpath " append ] sliteral
        !           440:     tempdir s+ s"  -O -c " append lib-filename 2@ append s" .c -o " append
        !           441:     lib-filename 2@ append s" .la" append ( c-addr u )
        !           442: \    s" gcc -fPIC -shared -Wl,-soname," lib-filename 2@ s+
        !           443: \    s" .so.1 -Wl,-export_dynamic -o " append lib-filename 2@ append
        !           444: \    [ s" .so.1 -O -I " s" includedir" getenv append s"  " append ] sliteral
        !           445: \    append lib-filename 2@ append s" .c" append ( c-addr u )
        !           446:     ~~ 2dup type 2dup system drop free throw
1.15      anton     447:     $? abort" compiler generated error" \ !! call dlerror
1.22    ! anton     448:     tempdir s" /.libs/" s+ lib-filename 2@ append s" .so.0" append
        !           449:     2dup type
1.15      anton     450:     2dup open-lib dup 0= abort" open-lib failed" \ !! call dlerror
                    451:     ( lib-handle ) lib-handle-addr @ !
                    452:     2dup delete-file throw drop free throw
                    453:     lib-filename 2@ s" .c" s+ 2dup delete-file throw drop free throw
1.21      anton     454:     lib-filename 2@ drop free throw 0 0 lib-filename 2! ; IS compile-wrapper-function
1.5       anton     455: \    s" ar rcs xxx.a xxx.o" system
                    456: \    $? abort" ar generated error" ;
                    457: 
1.12      anton     458: : link-wrapper-function { cff -- sym }
                    459:     cff cff-rtype wrapper-function-name { d: wrapper-name }
                    460:     wrapper-name cff cff-lha @ @ assert( dup ) lib-sym dup 0= -&32 and throw
1.10      anton     461:     wrapper-name drop free throw ;
1.8       anton     462: 
1.12      anton     463: : c-function-ft ( xt-defr xt-cfr "c-name" "{libcc-type}" "--" "libcc-type" -- )
1.8       anton     464:     \ build time/first time action for c-function
1.12      anton     465:     init-c-source-file
                    466:     noname create 2, lib-handle-addr @ ,
1.2       anton     467:     parse-name { d: c-name }
1.8       anton     468:     here parse-function-types c-name string,
1.11      anton     469:     ['] gen-wrapper-function c-source-file outfile-execute
1.8       anton     470:   does> ( ... -- ... )
1.10      anton     471:     dup 2@ { xt-defer xt-cfr }
1.12      anton     472:     dup cff-lha @ @ 0= if
                    473:        compile-wrapper-function
                    474:     endif
                    475:     link-wrapper-function xt-cfr >body !
1.8       anton     476:     xt-cfr xt-defer defer!
                    477:     xt-cfr execute ;
                    478: 
                    479: : c-function-rt ( -- )
                    480:     \ run-time definition for c function; addr is the address where
                    481:     \ the sym should be stored
                    482:     noname create 0 ,
1.2       anton     483:   does> ( ... -- ... )
                    484:     @ call-c ;
                    485: 
1.18      anton     486: : c-function ( "forth-name" "c-name" "@{type@}" "--" "type" -- ) \ gforth
1.17      anton     487:     \G Define a Forth word @i{forth-name}.  @i{Forth-name} has the
                    488:     \G specified stack effect and calls the C function @code{c-name}.
1.8       anton     489:     defer lastxt dup c-function-rt lastxt c-function-ft
                    490:     lastxt swap defer! ;

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