--- gforth/engine/engine.c	1998/12/12 22:32:05	1.8
+++ gforth/engine/engine.c	1999/06/17 15:32:14	1.13
@@ -80,6 +80,7 @@ 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 */
@@ -112,12 +113,6 @@ char *cstr(Char *from, UCell size, int c
   return b->buffer;
 }
 
-#ifdef STANDALONE
-char *tilde_cstr(Char *from, UCell size, int clear)
-{
-  return cstr(from, size, clear);
-}
-#else
 char *tilde_cstr(Char *from, UCell size, int clear)
 /* like cstr(), but perform tilde expansion on the string */
 {
@@ -137,6 +132,8 @@ char *tilde_cstr(Char *from, UCell size,
     UCell i;
     for (i=1; i<size && from[i]!='/'; i++)
       ;
+    if (i==2 && from[1]=='+') /* deal with "~+", i.e., the wd */
+      return cstr(from+3, size<3?0:size-3,clear);
     {
       char user[i];
       memcpy(user,from+1,i-1);
@@ -159,7 +156,7 @@ char *tilde_cstr(Char *from, UCell size,
     return cstr(path,s1_len+s2_len,clear);
   }
 }
-#endif   
+#endif
 
 #define NEWLINE	'\n'
 
@@ -167,6 +164,7 @@ char *tilde_cstr(Char *from, UCell size,
 #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
@@ -180,6 +178,7 @@ 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
@@ -216,25 +215,38 @@ static int ufileattr[6]= {
 
 /* declare and compute cfa for certain threading variants */
 /* warning: this is nonsyntactical; it will not work in place of a statement */
-#ifdef CFA_NEXT
+#ifndef GETCFA
 #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
 */
 {
-  register Xt *ip IPREG = ip0;
+#ifndef GFORTH_DEBUGGING
+  register Xt *ip IPREG;
+  register Cell *rp RPREG;
+#endif
   register Cell *sp SPREG = sp0;
-  register Cell *rp RPREG = rp0;
   register Float *fp FPREG = fp0;
   register Address lp LPREG = lp0;
 #ifdef CFA_NEXT
   register Xt cfa CFAREG;
 #endif
+#ifdef MORE_VARS
+  MORE_VARS
+#endif
   register Address up UPREG = UP;
   IF_TOS(register Cell TOS TOSREG;)
   IF_FTOS(register Float FTOS FTOSREG;)
@@ -261,6 +273,8 @@ Label *engine(Xt *ip0, Cell *sp0, Cell *
   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,
@@ -291,9 +305,10 @@ Label *engine(Xt *ip0, Cell *sp0, Cell *
   IF_TOS(TOS = sp[0]);
   IF_FTOS(FTOS = fp[0]);
 /*  prep_terminal(); */
-  NEXT_P0;
+  SET_IP(ip);
   NEXT;
 
+
 #ifdef CPU_DEP3
   CPU_DEP3
 #endif
@@ -307,22 +322,17 @@ Label *engine(Xt *ip0, Cell *sp0, Cell *
 #ifdef CISC_NEXT
     /* this is the simple version */
     *--rp = (Cell)ip;
-    ip = (Xt *)PFA1(cfa);
-    NEXT_P0;
+    SET_IP((Xt *)PFA1(cfa));
     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
-       */
+    /* this one is important, so we help the compiler optimizing */
     {
       DEF_CA
-      Xt *current_ip = (Xt *)PFA1(cfa);
-      cfa = *current_ip;
-      NEXT1_P1;
-      *--rp = (Cell)ip;
-      ip = current_ip+1;
-      NEXT1_P2;
+      rp[-1] = (Cell)ip;
+      SET_IP((Xt *)PFA1(cfa));
+      NEXT_P1;
+      rp--;
+      NEXT_P2;
     }
 #endif
   }
@@ -390,7 +400,7 @@ Label *engine(Xt *ip0, Cell *sp0, Cell *
 #ifdef DEBUG
     fprintf(stderr,"%08lx: field: %08lx\n",(Cell)ip,(Cell)PFA1(cfa));
 #endif
-    TOS += *(Cell*)PFA1(cfa); 
+    TOS += *(Cell*)PFA1(cfa);
   }
   NEXT_P0;
   NEXT;
@@ -423,16 +433,15 @@ Label *engine(Xt *ip0, Cell *sp0, Cell *
 #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
+    SET_IP(DOES_CODE1(cfa));
     /*    fprintf(stderr,"TOS = %08lx, IP=%08lx\n", TOS, IP);*/
   }
-  NEXT_P0;
   NEXT;
 
 #include "prim.i"