Diff for /gforth/libcc.fs between versions 1.19 and 1.20

version 1.19, 2007/06/04 18:13:26 version 1.20, 2007/06/09 15:55:44
Line 73 Line 73
 \ c-variable forth-name c-name  \ c-variable forth-name c-name
 \ c-constant 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  \ data structures
   

Removed from v.1.19  
changed lines
  Added in v.1.20


FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>