File:  [gforth] / gforth / engine / engine.c
Revision 1.10: download - view: text, annotated - select for diffs
Fri Jan 8 16:58:31 1999 UTC (21 years, 9 months ago) by anton
Branches: MAIN
CVS tags: HEAD
there is now a debugging version of the engine that maintains ip and
rp in global variables (to allow backtrace on signals). The debugging
engine is called gforth and the original engine is called gforth-fast.

/* Gforth virtual machine (aka inner interpreter)

  Copyright (C) 1995,1996,1997,1998 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "config.h"
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <stdlib.h>
#include <errno.h>
#include "forth.h"
#include "io.h"
#include "threaded.h"
#ifndef STANDALONE
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <time.h>
#include <sys/time.h>
#include <unistd.h>
#include <pwd.h>
#else
#include "systypes.h"
#endif

#if defined(HAVE_LIBDL) || defined(HAVE_DLOPEN) /* what else? */
#include <dlfcn.h>
#endif
#if defined(_WIN32)
#include <windows.h>
#endif
#ifdef hpux
#include <dl.h>
#endif

#ifndef SEEK_SET
/* should be defined in stdio.h, but some systems don't have it */
#define SEEK_SET 0
#endif

#define IOR(flag)	((flag)? -512-errno : 0)

struct F83Name {
  struct F83Name *next;  /* the link field for old hands */
  char		countetc;
  char		name[0];
};

/* are macros for setting necessary? */
#define F83NAME_COUNT(np)	((np)->countetc & 0x1f)
#define F83NAME_SMUDGE(np)	(((np)->countetc & 0x40) != 0)
#define F83NAME_IMMEDIATE(np)	(((np)->countetc & 0x20) != 0)

Cell *SP;
Float *FP;
Address UP=NULL;

#if 0
/* not used currently */
int emitcounter;
#endif
#define NULLC '\0'

#ifdef HAS_FILE
char *cstr(Char *from, UCell size, int clear)
/* return a C-string corresponding to the Forth string ( FROM SIZE ).
   the C-string lives until the next call of cstr with CLEAR being true */
{
  static struct cstr_buffer {
    char *buffer;
    size_t size;
  } *buffers=NULL;
  static int nbuffers=0;
  static int used=0;
  struct cstr_buffer *b;

  if (buffers==NULL)
    buffers=malloc(0);
  if (clear)
    used=0;
  if (used>=nbuffers) {
    buffers=realloc(buffers,sizeof(struct cstr_buffer)*(used+1));
    buffers[used]=(struct cstr_buffer){malloc(0),0};
    nbuffers=used+1;
  }
  b=&buffers[used];
  if (size+1 > b->size) {
    b->buffer = realloc(b->buffer,size+1);
    b->size = size+1;
  }
  memcpy(b->buffer,from,size);
  b->buffer[size]='\0';
  used++;
  return b->buffer;
}

char *tilde_cstr(Char *from, UCell size, int clear)
/* like cstr(), but perform tilde expansion on the string */
{
  char *s1,*s2;
  int s1_len, s2_len;
  struct passwd *getpwnam (), *user_entry;

  if (size<1 || from[0]!='~')
    return cstr(from, size, clear);
  if (size<2 || from[1]=='/') {
    s1 = (char *)getenv ("HOME");
    if(s1 == NULL)
      s1 = "";
    s2 = from+1;
    s2_len = size-1;
  } else {
    UCell i;
    for (i=1; i<size && from[i]!='/'; i++)
      ;
    {
      char user[i];
      memcpy(user,from+1,i-1);
      user[i-1]='\0';
      user_entry=getpwnam(user);
    }
    if (user_entry==NULL)
      return cstr(from, size, clear);
    s1 = user_entry->pw_dir;
    s2 = from+i;
    s2_len = size-i;
  }
  s1_len = strlen(s1);
  if (s1_len>1 && s1[s1_len-1]=='/')
    s1_len--;
  {
    char path[s1_len+s2_len];
    memcpy(path,s1,s1_len);
    memcpy(path+s1_len,s2,s2_len);
    return cstr(path,s1_len+s2_len,clear);
  }
}
#endif

#define NEWLINE	'\n'

#ifndef HAVE_RINT
#define rint(x)	floor((x)+0.5)
#endif

#ifdef HAS_FILE
static char* fileattr[6]={"r","rb","r+","r+b","w","wb"};

#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_TEXT
#define O_TEXT 0
#endif

static int ufileattr[6]= {
  O_RDONLY|O_TEXT, O_RDONLY|O_BINARY,
  O_RDWR  |O_TEXT, O_RDWR  |O_BINARY,
  O_WRONLY|O_TEXT, O_WRONLY|O_BINARY };
#endif

/* if machine.h has not defined explicit registers, define them as implicit */
#ifndef IPREG
#define IPREG
#endif
#ifndef SPREG
#define SPREG
#endif
#ifndef RPREG
#define RPREG
#endif
#ifndef FPREG
#define FPREG
#endif
#ifndef LPREG
#define LPREG
#endif
#ifndef CFAREG
#define CFAREG
#endif
#ifndef UPREG
#define UPREG
#endif
#ifndef TOSREG
#define TOSREG
#endif
#ifndef FTOSREG
#define FTOSREG
#endif

#ifndef CPU_DEP1
# define CPU_DEP1 0
#endif

/* declare and compute cfa for certain threading variants */
/* warning: this is nonsyntactical; it will not work in place of a statement */
#ifdef CFA_NEXT
#define DOCFA
#else
#define DOCFA	Xt cfa; GETCFA(cfa)
#endif

#ifdef GFORTH_DEBUGGING
/* define some VM registers as global variables, so they survive exceptions;
   global register variables are not up to the task (according to the 
   GNU C manual) */
Xt *ip;
Cell *rp;
#endif

Label *engine(Xt *ip0, Cell *sp0, Cell *rp0, Float *fp0, Address lp0)
/* executes code at ip, if ip!=NULL
   returns array of machine code labels (for use in a loader), if ip==NULL
*/
{
#ifndef GFORTH_DEBUGGING
  register Xt *ip IPREG;
  register Cell *rp RPREG;
#endif
  register Cell *sp SPREG = sp0;
  register Float *fp FPREG = fp0;
  register Address lp LPREG = lp0;
#ifdef CFA_NEXT
  register Xt cfa CFAREG;
#endif
  register Address up UPREG = UP;
  IF_TOS(register Cell TOS TOSREG;)
  IF_FTOS(register Float FTOS FTOSREG;)
#if defined(DOUBLY_INDIRECT)
  static Label *symbols;
  static void *routines[]= {
#else /* !defined(DOUBLY_INDIRECT) */
  static Label symbols[]= {
#endif /* !defined(DOUBLY_INDIRECT) */
    (Label)&&docol,
    (Label)&&docon,
    (Label)&&dovar,
    (Label)&&douser,
    (Label)&&dodefer,
    (Label)&&dofield,
    (Label)&&dodoes,
    /* the following entry is normally unused;
       it's there because its index indicates a does-handler */
    CPU_DEP1,
#include "prim_lab.i"
    (Label)0
  };
#ifdef CPU_DEP2
  CPU_DEP2
#endif

  ip = ip0;
  rp = rp0;
#ifdef DEBUG
  fprintf(stderr,"ip=%x, sp=%x, rp=%x, fp=%x, lp=%x, up=%x\n",
          (unsigned)ip,(unsigned)sp,(unsigned)rp,
	  (unsigned)fp,(unsigned)lp,(unsigned)up);
#endif

  if (ip == NULL) {
#if defined(DOUBLY_INDIRECT)
#define MAX_SYMBOLS (sizeof(routines)/sizeof(routines[0]))
#define CODE_OFFSET (22*sizeof(Cell))
    int i;
    Cell code_offset = offset_image? CODE_OFFSET : 0;

    symbols = (Label *)(malloc(MAX_SYMBOLS*sizeof(Cell)+CODE_OFFSET)+code_offset);
    for (i=0; i<DOESJUMP+1; i++)
      symbols[i] = (Label)routines[i];
    for (; routines[i]!=0; i++) {
      if (i>=MAX_SYMBOLS) {
	fprintf(stderr,"gforth-ditc: more than %d primitives\n",MAX_SYMBOLS);
	exit(1);
    }
    symbols[i] = &routines[i];
  }
#endif /* defined(DOUBLY_INDIRECT) */
  return symbols;
}

  IF_TOS(TOS = sp[0]);
  IF_FTOS(FTOS = fp[0]);
/*  prep_terminal(); */
  NEXT_P0;
  NEXT;

#ifdef CPU_DEP3
  CPU_DEP3
#endif
  
 docol:
  {
    DOCFA;
#ifdef DEBUG
    fprintf(stderr,"%08lx: col: %08lx\n",(Cell)ip,(Cell)PFA1(cfa));
#endif
#ifdef CISC_NEXT
    /* this is the simple version */
    *--rp = (Cell)ip;
    ip = (Xt *)PFA1(cfa);
    NEXT_P0;
    NEXT;
#else
    /* this one is important, so we help the compiler optimizing
       The following version may be better (for scheduling), but probably has
       problems with code fields employing calls and delay slots
       */
    {
      DEF_CA
      Xt *current_ip = (Xt *)PFA1(cfa);
      cfa = *current_ip;
      NEXT1_P1;
      *--rp = (Cell)ip;
      ip = current_ip+1;
      NEXT1_P2;
    }
#endif
  }

 docon:
  {
    DOCFA;
#ifdef DEBUG
    fprintf(stderr,"%08lx: con: %08lx\n",(Cell)ip,*(Cell*)PFA1(cfa));
#endif
#ifdef USE_TOS
    *sp-- = TOS;
    TOS = *(Cell *)PFA1(cfa);
#else
    *--sp = *(Cell *)PFA1(cfa);
#endif
  }
  NEXT_P0;
  NEXT;
  
 dovar:
  {
    DOCFA;
#ifdef DEBUG
    fprintf(stderr,"%08lx: var: %08lx\n",(Cell)ip,(Cell)PFA1(cfa));
#endif
#ifdef USE_TOS
    *sp-- = TOS;
    TOS = (Cell)PFA1(cfa);
#else
    *--sp = (Cell)PFA1(cfa);
#endif
  }
  NEXT_P0;
  NEXT;
  
 douser:
  {
    DOCFA;
#ifdef DEBUG
    fprintf(stderr,"%08lx: user: %08lx\n",(Cell)ip,(Cell)PFA1(cfa));
#endif
#ifdef USE_TOS
    *sp-- = TOS;
    TOS = (Cell)(up+*(Cell*)PFA1(cfa));
#else
    *--sp = (Cell)(up+*(Cell*)PFA1(cfa));
#endif
  }
  NEXT_P0;
  NEXT;
  
 dodefer:
  {
    DOCFA;
#ifdef DEBUG
    fprintf(stderr,"%08lx: defer: %08lx\n",(Cell)ip,*(Cell*)PFA1(cfa));
#endif
    EXEC(*(Xt *)PFA1(cfa));
  }

 dofield:
  {
    DOCFA;
#ifdef DEBUG
    fprintf(stderr,"%08lx: field: %08lx\n",(Cell)ip,(Cell)PFA1(cfa));
#endif
    TOS += *(Cell*)PFA1(cfa); 
  }
  NEXT_P0;
  NEXT;

 dodoes:
  /* this assumes the following structure:
     defining-word:
     
     ...
     DOES>
     (possible padding)
     possibly handler: jmp dodoes
     (possible branch delay slot(s))
     Forth code after DOES>
     
     defined word:
     
     cfa: address of or jump to handler OR
          address of or jump to dodoes, address of DOES-code
     pfa:
     
     */
  {
    DOCFA;

    /*    fprintf(stderr, "Got CFA %08lx at doescode %08lx/%08lx: does: %08lx\n",cfa,(Cell)ip,(Cell)PFA(cfa),(Cell)DOES_CODE1(cfa));*/
#ifdef DEBUG
    fprintf(stderr,"%08lx/%08lx: does: %08lx\n",(Cell)ip,(Cell)PFA(cfa),(Cell)DOES_CODE1(cfa));
    fflush(stderr);
#endif
    *--rp = (Cell)ip;
    /* PFA1 might collide with DOES_CODE1 here, so we use PFA */
    ip = DOES_CODE1(cfa);
#ifdef USE_TOS
    *sp-- = TOS;
    TOS = (Cell)PFA(cfa);
#else
    *--sp = (Cell)PFA(cfa);
#endif
    /*    fprintf(stderr,"TOS = %08lx, IP=%08lx\n", TOS, IP);*/
  }
  NEXT_P0;
  NEXT;

#include "prim.i"
}

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