--- gforth/libcc.fs	2007/06/01 16:27:37	1.17
+++ gforth/libcc.fs	2007/07/21 18:18:20	1.21
@@ -73,6 +73,48 @@
 \ c-variable forth-name c-name
 \ c-constant forth-name c-name
 
+\ Todo: conversion between function pointers and xts (both directions)
+
+\ taking an xt and turning it into a function pointer:
+
+\ e.g., assume we have the xt of + and want to create a C function int
+\ gforth_callback_plus(int, int), and then pass the pointer to that
+\ function:
+
+\ There should be Forth code like this:
+\   ] + 0 (bye)
+\ Assume that the start of this code is START
+        
+\ Now, there should be a C function:
+
+\ int gforth_callback_plus(int p1, int p2)
+\ {
+\   Cell   *sp = gforth_SP;
+\   Float  *fp = gforth_FP;
+\   Float  *fp = gforth_FP;
+\   Address lp = gforth_LP;
+\   sp -= 2;
+\   sp[0] = p1;
+\   sp[1] = p2;
+\   gforth_engine(START, sp, rp, fp, lp);
+\   sp += 1;
+\   gforth_RP = rp;
+\   gforth_SP = sp;
+\   gforth_FP = fp;
+\   gforth_LP = lp;
+\   return sp[0];
+\ }
+
+\ and the pointer to that function is the C function pointer for the XT of +.
+
+\ Future problems:
+\   how to combine the Forth code generation with inlining
+\   START is not a constant across executions (when caching the C files)
+\      Solution: make START a variable, and store into it on startup with dlsym
+
+\ Syntax:
+\  callback <rettype> <params> <paramtypes> -- <rettype>
+
 
 \ data structures
 
@@ -187,11 +229,12 @@ variable c-prefix-lines-end c-prefix-lin
     align here 0 , c-prefix-lines-end list-append ( c-addr u )
     longstring, ;
 
-: \c ( "rest-of-line" -- )
+: \c ( "rest-of-line" -- ) \ gforth backslash-c
     \G One line of C declarations for the C interface
     -1 parse save-c-prefix-line ;
 
-\c #include "engine/libcc.h"
+s" #include <gforth/" version-string s+ s" /libcc.h>" append ( c-addr u )
+  2dup save-c-prefix-line drop free throw
 
 \ Types (for parsing)
 
@@ -387,12 +430,14 @@ create gen-wrapped-types
 : c-source-file ( -- file-id )
     c-source-file-id @ assert( dup ) ;
 
-: compile-wrapper-function ( -- )
+DEFER compile-wrapper-function
+:NONAME ( -- )
     c-source-file close-file throw
     0 c-source-file-id !
-    s" gcc -I. -fPIC -shared -Wl,-soname," lib-filename 2@ s+
+    s" gcc -fPIC -shared -Wl,-soname," lib-filename 2@ s+
     s" .so.1 -Wl,-export_dynamic -o " append lib-filename 2@ append
-    s" .so.1 -O " append lib-filename 2@ append s" .c" append ( c-addr u )
+    [ s" .so.1 -O -I " s" includedir" getenv append s"  " append ] sliteral
+    append lib-filename 2@ append s" .c" append ( c-addr u )
     2dup system drop free throw
     $? abort" compiler generated error" \ !! call dlerror
     lib-filename 2@ s" .so.1" s+
@@ -400,7 +445,7 @@ create gen-wrapped-types
     ( lib-handle ) lib-handle-addr @ !
     2dup delete-file throw drop free throw
     lib-filename 2@ s" .c" s+ 2dup delete-file throw drop free throw
-    lib-filename 2@ drop free throw 0 0 lib-filename 2! ;
+    lib-filename 2@ drop free throw 0 0 lib-filename 2! ; IS compile-wrapper-function
 \    s" ar rcs xxx.a xxx.o" system
 \    $? abort" ar generated error" ;
 
@@ -432,7 +477,7 @@ create gen-wrapped-types
   does> ( ... -- ... )
     @ call-c ;
 
-: c-function ( "forth-name" "c-name" "{libcc-type}" "--" "libcc-type" -- )
+: c-function ( "forth-name" "c-name" "@{type@}" "--" "type" -- ) \ gforth
     \G Define a Forth word @i{forth-name}.  @i{Forth-name} has the
     \G specified stack effect and calls the C function @code{c-name}.
     defer lastxt dup c-function-rt lastxt c-function-ft