cmd.c

早期freebsd实现

		break;
	    if (DBtrace->str_u.str_nval != 0)
		break;
	    goto next_cmd;
	}

    /* we have tried to make this normal case as abnormal as possible */

    doeval:
	if (gimme == G_ARRAY) {
	    lastretstr = Nullstr;
	    lastspbase = sp;
	    lastsize = newsp - sp;
	    if (lastsize < 0)
		lastsize = 0;
	}
	else
	    lastretstr = retstr;
	while (tmps_max > tmps_base) {	/* clean up after last eval */
	    str_free(tmps_list[tmps_max]);
	    tmps_list[tmps_max--] = Nullstr;
	}
	newsp = eval(cmd->c_expr,
	  gimme && (cmdflags & CF_TERM) && cmd->c_type == C_EXPR &&
		!cmd->ucmd.acmd.ac_expr,
	  sp);
	st = stack->ary_array;	/* possibly reallocated */
	retstr = st[newsp];
	if (newsp > sp && retstr)
	    match = str_true(retstr);
	else
	    match = FALSE;
	goto maybe;

    /* if flipflop was true, flop it */

    flipmaybe:
	if (match && cmdflags & CF_FLIP) {
	    while (tmps_max > tmps_base) {	/* clean up after last eval */
		str_free(tmps_list[tmps_max]);
		tmps_list[tmps_max--] = Nullstr;
	    }
	    if (cmd->c_expr->arg_type == O_FLOP) {	/* currently toggled? */
		newsp = eval(cmd->c_expr,G_SCALAR,sp);/*let eval undo it*/
		cmdflags = copyopt(cmd,cmd->c_expr[3].arg_ptr.arg_cmd);
	    }
	    else {
		newsp = eval(cmd->c_expr,G_SCALAR,sp);/* let eval do it */
		if (cmd->c_expr->arg_type == O_FLOP)	/* still toggled? */
		    cmdflags = copyopt(cmd,cmd->c_expr[4].arg_ptr.arg_cmd);
	    }
	}
	else if (cmdflags & CF_FLIP) {
	    if (cmd->c_expr->arg_type == O_FLOP) {	/* currently toggled? */
		match = TRUE;				/* force on */
	    }
	}

    /* at this point, match says whether our expression was true */

    maybe:
	if (cmdflags & CF_INVERT)
	    match = !match;
	if (!match)
	    goto next_cmd;
    }
#ifdef TAINT
    tainted = 0;	/* modifier doesn't affect regular expression */
#endif

    /* now to do the actual command, if any */

    switch (cmd->c_type) {
    case C_NULL:
	fatal("panic: cmd_exec");
    case C_EXPR:			/* evaluated for side effects */
	if (cmd->ucmd.acmd.ac_expr) {	/* more to do? */
	    if (gimme == G_ARRAY) {
		lastretstr = Nullstr;
		lastspbase = sp;
		lastsize = newsp - sp;
		if (lastsize < 0)
		    lastsize = 0;
	    }
	    else
		lastretstr = retstr;
	    while (tmps_max > tmps_base) {	/* clean up after last eval */
		str_free(tmps_list[tmps_max]);
		tmps_list[tmps_max--] = Nullstr;
	    }
	    newsp = eval(cmd->ucmd.acmd.ac_expr,gimme && (cmdflags&CF_TERM),sp);
	    st = stack->ary_array;	/* possibly reallocated */
	    retstr = st[newsp];
	}
	break;
    case C_NSWITCH:
	{
	    double value = str_gnum(STAB_STR(cmd->c_stab));

	    match = (int)value;
	    if (value < 0.0) {
		if (((double)match) > value)
		    --match;		/* was fractional--truncate other way */
	    }
	}
	goto doswitch;
    case C_CSWITCH:
	if (multiline) {
	    cmd = cmd->c_next;			/* can't assume anything */
	    goto tail_recursion_entry;
	}
	match = *(str_get(STAB_STR(cmd->c_stab))) & 255;
      doswitch:
	match -= cmd->ucmd.scmd.sc_offset;
	if (match < 0)
	    match = 0;
	else if (match > cmd->ucmd.scmd.sc_max)
	    match = cmd->ucmd.scmd.sc_max;
	cmd = cmd->ucmd.scmd.sc_next[match];
	goto tail_recursion_entry;
    case C_NEXT:
	cmd = cmd->ucmd.ccmd.cc_alt;
	goto tail_recursion_entry;
    case C_ELSIF:
	fatal("panic: ELSIF");
    case C_IF:
	oldspat = curspat;
	oldsave = savestack->ary_fill;
#ifdef DEBUGGING
	olddlevel = dlevel;
#endif
	retstr = &str_yes;
	newsp = -2;
	if (cmd->ucmd.ccmd.cc_true) {
#ifdef DEBUGGING
	    if (debug) {
		debname[dlevel] = 't';
		debdelim[dlevel] = '_';
		if (++dlevel >= dlmax)
		    grow_dlevel();
	    }
#endif
	    newsp = cmd_exec(cmd->ucmd.ccmd.cc_true,gimme && (cmdflags & CF_TERM),sp);
	    st = stack->ary_array;	/* possibly reallocated */
	    retstr = st[newsp];
	}
	curspat = oldspat;
	if (savestack->ary_fill > oldsave)
	    restorelist(oldsave);
#ifdef DEBUGGING
	dlevel = olddlevel;
#endif
	cmd = cmd->ucmd.ccmd.cc_alt;
	goto tail_recursion_entry;
    case C_ELSE:
	oldspat = curspat;
	oldsave = savestack->ary_fill;
#ifdef DEBUGGING
	olddlevel = dlevel;
#endif
	retstr = &str_undef;
	newsp = -2;
	if (cmd->ucmd.ccmd.cc_true) {
#ifdef DEBUGGING
	    if (debug) {
		debname[dlevel] = 'e';
		debdelim[dlevel] = '_';
		if (++dlevel >= dlmax)
		    grow_dlevel();
	    }
#endif
	    newsp = cmd_exec(cmd->ucmd.ccmd.cc_true,gimme && (cmdflags & CF_TERM),sp);
	    st = stack->ary_array;	/* possibly reallocated */
	    retstr = st[newsp];
	}
	curspat = oldspat;
	if (savestack->ary_fill > oldsave)
	    restorelist(oldsave);
#ifdef DEBUGGING
	dlevel = olddlevel;
#endif
	break;
    case C_BLOCK:
    case C_WHILE:
	if (!(cmdflags & CF_ONCE)) {	/* first time through here? */
	    cmdflags |= CF_ONCE;
	    if (++loop_ptr >= loop_max) {
		loop_max += 128;
		Renew(loop_stack, loop_max, struct loop);
	    }
	    loop_stack[loop_ptr].loop_label = cmd->c_label;
	    loop_stack[loop_ptr].loop_sp = sp;
#ifdef DEBUGGING
	    if (debug & 4) {
		deb("(Pushing label #%d %s)\n",
		  loop_ptr, cmd->c_label ? cmd->c_label : "");
	    }
#endif
	}
#ifdef JMPCLOBBER
	cmdparm = cmd;
#endif
	match = setjmp(loop_stack[loop_ptr].loop_env);
	if (match) {
	    st = stack->ary_array;	/* possibly reallocated */
#ifdef JMPCLOBBER
	    cmd = cmdparm;
	    cmdflags = cmd->c_flags|CF_ONCE;
	    go_to = goto_targ;
#endif
	    if (savestack->ary_fill > oldsave)
		restorelist(oldsave);
	    switch (match) {
	    default:
		fatal("longjmp returned bad value (%d)",match);
	    case O_LAST:
		if (lastretstr) {
		    retstr = lastretstr;
		    newsp = -2;
		}
		else {
		    newsp = sp + lastsize;
		    retstr = st[newsp];
		}
		curspat = oldspat;
		goto next_cmd;
	    case O_NEXT:
#ifdef JMPCLOBBER
		newsp = -2;
		retstr = &str_undef;
#endif
		goto next_iter;
	    case O_REDO:
#ifdef DEBUGGING
		dlevel = olddlevel;
#endif
#ifdef JMPCLOBBER
		newsp = -2;
		retstr = &str_undef;
#endif
		goto doit;
	    }
	}
	oldspat = curspat;
	oldsave = savestack->ary_fill;
#ifdef DEBUGGING
	olddlevel = dlevel;
#endif
    doit:
	if (cmd->ucmd.ccmd.cc_true) {
#ifdef DEBUGGING
	    if (debug) {
		debname[dlevel] = 't';
		debdelim[dlevel] = '_';
		if (++dlevel >= dlmax)
		    grow_dlevel();
	    }
#endif
	    newsp = cmd_exec(cmd->ucmd.ccmd.cc_true,gimme && (cmdflags & CF_TERM),sp);
	    st = stack->ary_array;	/* possibly reallocated */
	    retstr = st[newsp];
	}
	/* actually, this spot is rarely reached anymore since the above
	 * cmd_exec() returns through longjmp().  Hooray for structure.
	 */
      next_iter:
#ifdef DEBUGGING
	dlevel = olddlevel;
#endif
	if (cmd->ucmd.ccmd.cc_alt) {
#ifdef DEBUGGING
	    if (debug) {
		debname[dlevel] = 'a';
		debdelim[dlevel] = '_';
		if (++dlevel >= dlmax)
		    grow_dlevel();
	    }
#endif
	    newsp = cmd_exec(cmd->ucmd.ccmd.cc_alt,gimme && (cmdflags & CF_TERM),sp);
	    st = stack->ary_array;	/* possibly reallocated */
	    retstr = st[newsp];
	}
      finish_while:
	curspat = oldspat;
	if (savestack->ary_fill > oldsave) {
	    if (cmdflags & CF_TERM) {
		for (match = sp + 1; match <= newsp; match++)
		    st[match] = str_mortal(st[match]);
		retstr = st[newsp];
	    }
	    restorelist(oldsave);
	}
#ifdef DEBUGGING
	dlevel = olddlevel - 1;
#endif
	if (cmd->c_type != C_BLOCK)
	    goto until_loop;	/* go back and evaluate conditional again */
    }
    if (cmdflags & CF_LOOP) {
	cmdflags |= CF_COND;		/* now test the condition */
#ifdef DEBUGGING
	dlevel = entdlevel;
#endif
	goto until_loop;
    }
  next_cmd:
    if (cmdflags & CF_ONCE) {
#ifdef DEBUGGING
	if (debug & 4) {
	    tmps = loop_stack[loop_ptr].loop_label;
	    deb("(Popping label #%d %s)\n",loop_ptr, tmps ? tmps : "");
	}
#endif
	loop_ptr--;
	if ((cmdflags & CF_OPTIMIZE) == CFT_ARRAY &&
	  savestack->ary_fill > aryoptsave)
	    restorelist(aryoptsave);
    }
    cmd = cmd->c_next;
    goto tail_recursion_entry;
}

#ifdef DEBUGGING
#  ifndef I_VARARGS
/*VARARGS1*/
void deb(pat,a1,a2,a3,a4,a5,a6,a7,a8)
char *pat;
{
    register int i;

    fprintf(stderr,"%-4ld",(long)curcmd->c_line);
    for (i=0; i<dlevel; i++)
	fprintf(stderr,"%c%c ",debname[i],debdelim[i]);
    fprintf(stderr,pat,a1,a2,a3,a4,a5,a6,a7,a8);
}
#  else
/*VARARGS1*/
void deb(va_alist)
va_dcl
{
    va_list args;
    char *pat;
    register int i;

    va_start(args);
    fprintf(stderr,"%-4ld",(long)curcmd->c_line);
    for (i=0; i<dlevel; i++)
	fprintf(stderr,"%c%c ",debname[i],debdelim[i]);

    pat = va_arg(args, char *);
    (void) vfprintf(stderr,pat,args);
    va_end( args );
}
#  endif
#endif

int
copyopt(cmd,which)
register CMD *cmd;
register CMD *which;
{
    cmd->c_flags &= CF_ONCE|CF_COND|CF_LOOP;
    cmd->c_flags |= which->c_flags;
    cmd->c_short = which->c_short;
    cmd->c_slen = which->c_slen;
    cmd->c_stab = which->c_stab;
    return cmd->c_flags;
}

ARRAY *
saveary(stab)
STAB *stab;
{
    register STR *str;

    str = Str_new(10,0);
    str->str_state = SS_SARY;
    str->str_u.str_stab = stab;
    if (str->str_ptr) {
	Safefree(str->str_ptr);
	str->str_ptr = Nullch;
	str->str_len = 0;
    }
    str->str_ptr = (char*)stab_array(stab);
    (void)apush(savestack,str); /* save array ptr */
    stab_xarray(stab) = Null(ARRAY*);
    return stab_xarray(aadd(stab));
}

HASH *
savehash(stab)
STAB *stab;
{
    register STR *str;

    str = Str_new(11,0);
    str->str_state = SS_SHASH;
    str->str_u.str_stab = stab;
    if (str->str_ptr) {
	Safefree(str->str_ptr);
	str->str_ptr = Nullch;
	str->str_len = 0;
    }
    str->str_ptr = (char*)stab_hash(stab);
    (void)apush(savestack,str); /* save hash ptr */
    stab_xhash(stab) = Null(HASH*);
    return stab_xhash(hadd(stab));
}

void
saveitem(item)
register STR *item;
{
    register STR *str;

    (void)apush(savestack,item);		/* remember the pointer */
    str = Str_new(12,0);
    str_sset(str,item);
    (void)apush(savestack,str);			/* remember the value */
}

void
saveint(intp)
int *intp;
{
    register STR *str;

    str = Str_new(13,0);
    str->str_state = SS_SINT;
    str->str_u.str_useful = (long)*intp;	/* remember value */
    if (str->str_ptr) {
	Safefree(str->str_ptr);
	str->str_len = 0;
    }
    str->str_ptr = (char*)intp;		/* remember pointer */
    (void)apush(savestack,str);
}

void
savelong(longp)
long *longp;
{
    register STR *str;

    str = Str_new(14,0);
    str->str_state = SS_SLONG;
    str->str_u.str_useful = *longp;		/* remember value */
    if (str->str_ptr) {
	Safefree(str->str_ptr);
	str->str_len = 0;
    }
    str->str_ptr = (char*)longp;		/* remember pointer */
    (void)apush(savestack,str);
}

void
savesptr(sptr)
STR **sptr;
{
    register STR *str;

    str = Str_new(15,0);
    str->str_state = SS_SSTRP;
    str->str_magic = *sptr;		/* remember value */
    if (str->str_ptr) {
	Safefree(str->str_ptr);
	str->str_len = 0;
    }
    str->str_ptr = (char*)sptr;		/* remember pointer */
    (void)apush(savestack,str);
}

void
savenostab(stab)
STAB *stab;
{
    register STR *str;

    str = Str_new(16,0);
    str->str_state = SS_SNSTAB;
    str->str_magic = (STR*)stab;	/* remember which stab to free */
    (void)apush(savestack,str);
}

void
savehptr(hptr)
HASH **hptr;
{
    register STR *str;

    str = Str_new(17,0);
    str->str_state = SS_SHPTR;
    str->str_u.str_hash = *hptr;	/* remember value */
    if (str->str_ptr) {
	Safefree(str->str_ptr);
	str->str_len = 0;
    }
    str->str_ptr = (char*)hptr;		/* remember pointer */
    (void)apush(savestack,str);
}

void
saveaptr(aptr)
ARRAY **aptr;
{
    register STR *str;

    str = Str_new(17,0);
    str->str_state = SS_SAPTR;
    str->str_u.str_array = *aptr;	/* remember value */
    if (str->str_ptr) {
	Safefree(str->str_ptr);
	str->str_len = 0;
    }
    str->str_ptr = (char*)aptr;		/* remember pointer */
    (void)apush(savestack,str);
}

void
savelist(sarg,maxsarg)
register STR **sarg;
int maxsarg;
{
    register STR *str;
    register int i;

    for (i = 1; i <= maxsarg; i++) {
	(void)apush(savestack,sarg[i]);		/* remember the pointer */
	str = Str_new(18,0);
	str_sset(str,sarg[i]);
	(void)apush(savestack,str);			/* remember the value */
	sarg[i]->str_u.str_useful = -1;
    }
}

void
restorelist(base)
int base;
{
    register STR *str;
    register STR *value;
    register STAB *stab;

    if (base < -1)
	fatal("panic: corrupt saved stack index");
    while (savestack->ary_fill > base) {
	value = apop(savestack);
	switch (value->str_state) {
	case SS_NORM:				/* normal string */
	case SS_INCR:
	    str = apop(savestack);
	    str_replace(str,value);
	    STABSET(str);
	    break;
	case SS_SARY:				/* array reference */
	    stab = value->str_u.str_stab;
	    afree(stab_xarray(stab));
	    stab_xarray(stab) = (ARRAY*)value->str_ptr;
	    value->str_ptr = Nullch;
	    str_free(value);
	    break;
	case SS_SHASH:				/* hash reference */
	    stab = value->str_u.str_stab;
	    (void)hfree(stab_xhash(stab), FALSE);
	    stab_xhash(stab) = (HASH*)value->str_ptr;
	    value->str_ptr = Nullch;
	    str_free(value);
	    break;
	case SS_SINT:				/* int reference */
	    *((int*)value->str_ptr) = (int)value->str_u.str_useful;
	    value->str_ptr = Nullch;
	    str_free(value);
	    break;
	case SS_SLONG:				/* long reference */
	    *((long*)value->str_ptr) = value->str_u.str_useful;
	    value->str_ptr = Nullch;
	    str_free(value);
	    break;
	case SS_SSTRP:				/* STR* reference */
	    *((STR**)value->str_ptr) = value->str_magic;
	    value->str_magic = Nullstr;
	    value->str_ptr = Nullch;
	    str_free(value);
	    break;
	case SS_SHPTR:				/* HASH* reference */
	    *((HASH**)value->str_ptr) = value->str_u.str_hash;
	    value->str_ptr = Nullch;
	    str_free(value);
	    break;
	case SS_SAPTR:				/* ARRAY* reference */
	    *((ARRAY**)value->str_ptr) = value->str_u.str_array;
	    value->str_ptr = Nullch;
	    str_free(value);
	    break;
	case SS_SNSTAB:
	    stab = (STAB*)value->str_magic;
	    value->str_magic = Nullstr;
	    (void)stab_clear(stab);
	    str_free(value);
	    break;
	case SS_SCSV:				/* callsave structure */
	    {
		CSV *csv = (CSV*) value->str_ptr;

		curcmd = csv->curcmd;
		curcsv = csv->curcsv;
		csv->sub->depth = csv->depth;
		if (csv->hasargs) {		/* put back old @_ */
		    afree(csv->argarray);
		    stab_xarray(defstab) = csv->savearray;
		}
		str_free(value);
	    }
	    break;
	default:
	    fatal("panic: restorelist inconsistency");
	}
    }
}

#ifdef DEBUGGING
void
grow_dlevel()
{
    dlmax += 128;
    Renew(debname, dlmax, char);
    Renew(debdelim, dlmax, char);
}
#endif