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|
/* $Header: cmd.c,v 2.0 88/06/05 00:08:24 root Exp $
*
* $Log: cmd.c,v $
* Revision 2.0 88/06/05 00:08:24 root
* Baseline version 2.0.
*
*/
#include "EXTERN.h"
#include "perl.h"
static STR str_chop;
/* This is the main command loop. We try to spend as much time in this loop
* as possible, so lots of optimizations do their activities in here. This
* means things get a little sloppy.
*/
STR *
cmd_exec(cmd)
#ifdef cray /* nobody else has complained yet */
CMD *cmd;
#else
register CMD *cmd;
#endif
{
SPAT *oldspat;
int oldsave;
#ifdef DEBUGGING
int olddlevel;
int entdlevel;
#endif
register STR *retstr;
register char *tmps;
register int cmdflags;
register int match;
register char *go_to = goto_targ;
FILE *fp;
ARRAY *ar;
retstr = &str_no;
#ifdef DEBUGGING
entdlevel = dlevel;
#endif
tail_recursion_entry:
#ifdef DEBUGGING
dlevel = entdlevel;
#endif
if (cmd == Nullcmd)
return retstr;
cmdflags = cmd->c_flags; /* hopefully load register */
if (go_to) {
if (cmd->c_label && strEQ(go_to,cmd->c_label))
goto_targ = go_to = Nullch; /* here at last */
else {
switch (cmd->c_type) {
case C_IF:
oldspat = curspat;
oldsave = savestack->ary_fill;
#ifdef DEBUGGING
olddlevel = dlevel;
#endif
retstr = &str_yes;
if (cmd->ucmd.ccmd.cc_true) {
#ifdef DEBUGGING
if (debug) {
debname[dlevel] = 't';
debdelim[dlevel++] = '_';
}
#endif
retstr = cmd_exec(cmd->ucmd.ccmd.cc_true);
}
if (!goto_targ) {
go_to = Nullch;
} else {
retstr = &str_no;
if (cmd->ucmd.ccmd.cc_alt) {
#ifdef DEBUGGING
if (debug) {
debname[dlevel] = 'e';
debdelim[dlevel++] = '_';
}
#endif
retstr = cmd_exec(cmd->ucmd.ccmd.cc_alt);
}
}
if (!goto_targ)
go_to = Nullch;
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)) {
cmdflags |= CF_ONCE;
loop_ptr++;
loop_stack[loop_ptr].loop_label = cmd->c_label;
#ifdef DEBUGGING
if (debug & 4) {
deb("(Pushing label #%d %s)\n",
loop_ptr,cmd->c_label);
}
#endif
}
switch (setjmp(loop_stack[loop_ptr].loop_env)) {
case O_LAST: /* not done unless go_to found */
go_to = Nullch;
retstr = &str_no;
#ifdef DEBUGGING
olddlevel = dlevel;
#endif
curspat = oldspat;
if (savestack->ary_fill > oldsave)
restorelist(oldsave);
goto next_cmd;
case O_NEXT: /* not done unless go_to found */
go_to = Nullch;
goto next_iter;
case O_REDO: /* not done unless go_to found */
go_to = Nullch;
goto doit;
}
oldspat = curspat;
oldsave = savestack->ary_fill;
#ifdef DEBUGGING
olddlevel = dlevel;
#endif
if (cmd->ucmd.ccmd.cc_true) {
#ifdef DEBUGGING
if (debug) {
debname[dlevel] = 't';
debdelim[dlevel++] = '_';
}
#endif
cmd_exec(cmd->ucmd.ccmd.cc_true);
}
if (!goto_targ) {
go_to = Nullch;
goto next_iter;
}
#ifdef DEBUGGING
dlevel = olddlevel;
#endif
if (cmd->ucmd.ccmd.cc_alt) {
#ifdef DEBUGGING
if (debug) {
debname[dlevel] = 'a';
debdelim[dlevel++] = '_';
}
#endif
cmd_exec(cmd->ucmd.ccmd.cc_alt);
}
if (goto_targ)
break;
go_to = Nullch;
goto finish_while;
}
cmd = cmd->c_next;
if (cmd && cmd->c_head == cmd)
/* reached end of while loop */
return retstr; /* targ isn't in this block */
if (cmdflags & CF_ONCE) {
#ifdef DEBUGGING
if (debug & 4) {
deb("(Popping label #%d %s)\n",loop_ptr,
loop_stack[loop_ptr].loop_label);
}
#endif
loop_ptr--;
}
goto tail_recursion_entry;
}
}
until_loop:
/* Set line number so run-time errors can be located */
line = cmd->c_line;
#ifdef DEBUGGING
if (debug) {
if (debug & 2) {
deb("%s (%lx) r%lx t%lx a%lx n%lx cs%lx\n",
cmdname[cmd->c_type],cmd,cmd->c_expr,
cmd->ucmd.ccmd.cc_true,cmd->ucmd.ccmd.cc_alt,cmd->c_next,
curspat);
}
debname[dlevel] = cmdname[cmd->c_type][0];
debdelim[dlevel++] = '!';
}
#endif
while (tmps_max > tmps_base) /* clean up after last eval */
str_free(tmps_list[tmps_max--]);
/* Here is some common optimization */
if (cmdflags & CF_COND) {
switch (cmdflags & CF_OPTIMIZE) {
case CFT_FALSE:
retstr = cmd->c_short;
match = FALSE;
if (cmdflags & CF_NESURE)
goto maybe;
break;
case CFT_TRUE:
retstr = cmd->c_short;
match = TRUE;
if (cmdflags & CF_EQSURE)
goto flipmaybe;
break;
case CFT_REG:
retstr = STAB_STR(cmd->c_stab);
match = str_true(retstr); /* => retstr = retstr, c2 should fix */
if (cmdflags & (match ? CF_EQSURE : CF_NESURE))
goto flipmaybe;
break;
case CFT_ANCHOR: /* /^pat/ optimization */
if (multiline) {
if (*cmd->c_short->str_ptr && !(cmdflags & CF_EQSURE))
goto scanner; /* just unanchor it */
else
break; /* must evaluate */
}
/* FALL THROUGH */
case CFT_STROP: /* string op optimization */
retstr = STAB_STR(cmd->c_stab);
if (*cmd->c_short->str_ptr == *str_get(retstr) &&
strnEQ(cmd->c_short->str_ptr, str_get(retstr),
cmd->c_slen) ) {
if (cmdflags & CF_EQSURE) {
match = !(cmdflags & CF_FIRSTNEG);
retstr = &str_yes;
goto flipmaybe;
}
}
else if (cmdflags & CF_NESURE) {
match = cmdflags & CF_FIRSTNEG;
retstr = &str_no;
goto flipmaybe;
}
break; /* must evaluate */
case CFT_SCAN: /* non-anchored search */
scanner:
retstr = STAB_STR(cmd->c_stab);
if (retstr->str_pok == 5)
if (screamfirst[cmd->c_short->str_rare] >= 0)
tmps = screaminstr(retstr, cmd->c_short);
else
tmps = Nullch;
else {
tmps = str_get(retstr); /* make sure it's pok */
tmps = fbminstr(tmps, tmps + retstr->str_cur, cmd->c_short);
}
if (tmps) {
if (cmdflags & CF_EQSURE) {
++*(long*)&cmd->c_short->str_nval;
match = !(cmdflags & CF_FIRSTNEG);
retstr = &str_yes;
goto flipmaybe;
}
else
hint = tmps;
}
else {
if (cmdflags & CF_NESURE) {
++*(long*)&cmd->c_short->str_nval;
match = cmdflags & CF_FIRSTNEG;
retstr = &str_no;
goto flipmaybe;
}
}
if (--*(long*)&cmd->c_short->str_nval < 0) {
str_free(cmd->c_short);
cmd->c_short = Nullstr;
cmdflags &= ~CF_OPTIMIZE;
cmdflags |= CFT_EVAL; /* never try this optimization again */
cmd->c_flags = cmdflags;
}
break; /* must evaluate */
case CFT_NUMOP: /* numeric op optimization */
retstr = STAB_STR(cmd->c_stab);
switch (cmd->c_slen) {
case O_EQ:
match = (str_gnum(retstr) == cmd->c_short->str_nval);
break;
case O_NE:
match = (str_gnum(retstr) != cmd->c_short->str_nval);
break;
case O_LT:
match = (str_gnum(retstr) < cmd->c_short->str_nval);
break;
case O_LE:
match = (str_gnum(retstr) <= cmd->c_short->str_nval);
break;
case O_GT:
match = (str_gnum(retstr) > cmd->c_short->str_nval);
break;
case O_GE:
match = (str_gnum(retstr) >= cmd->c_short->str_nval);
break;
}
if (match) {
if (cmdflags & CF_EQSURE) {
retstr = &str_yes;
goto flipmaybe;
}
}
else if (cmdflags & CF_NESURE) {
retstr = &str_no;
goto flipmaybe;
}
break; /* must evaluate */
case CFT_INDGETS: /* while (<$foo>) */
last_in_stab = stabent(str_get(STAB_STR(cmd->c_stab)),TRUE);
if (!last_in_stab->stab_io)
last_in_stab->stab_io = stio_new();
goto dogets;
case CFT_GETS: /* really a while (<file>) */
last_in_stab = cmd->c_stab;
dogets:
fp = last_in_stab->stab_io->fp;
retstr = defstab->stab_val;
if (fp && str_gets(retstr, fp)) {
if (*retstr->str_ptr == '0' && !retstr->str_ptr[1])
match = FALSE;
else
match = TRUE;
last_in_stab->stab_io->lines++;
}
else if (last_in_stab->stab_io->flags & IOF_ARGV)
goto doeval; /* doesn't necessarily count as EOF yet */
else {
retstr = &str_no;
match = FALSE;
}
goto flipmaybe;
case CFT_EVAL:
break;
case CFT_UNFLIP:
retstr = eval(cmd->c_expr,Null(STR***),-1);
match = str_true(retstr);
if (cmd->c_expr->arg_type == O_FLIP) /* undid itself? */
cmdflags = copyopt(cmd,cmd->c_expr[3].arg_ptr.arg_cmd);
goto maybe;
case CFT_CHOP:
retstr = cmd->c_stab->stab_val;
match = (retstr->str_cur != 0);
tmps = str_get(retstr);
tmps += retstr->str_cur - match;
str_set(&str_chop,tmps);
*tmps = '\0';
retstr->str_nok = 0;
retstr->str_cur = tmps - retstr->str_ptr;
retstr = &str_chop;
goto flipmaybe;
case CFT_ARRAY:
ar = cmd->c_expr[1].arg_ptr.arg_stab->stab_array;
match = ar->ary_index; /* just to get register */
if (match < 0) /* first time through here? */
cmd->c_short = cmd->c_stab->stab_val;
if (match >= ar->ary_fill) {
ar->ary_index = -1;
/* cmd->c_stab->stab_val = cmd->c_short; - Can't be done in LAST */
match = FALSE;
}
else {
match++;
retstr = cmd->c_stab->stab_val = ar->ary_array[match];
ar->ary_index = match;
match = TRUE;
}
goto maybe;
}
/* we have tried to make this normal case as abnormal as possible */
doeval:
lastretstr = retstr;
retstr = eval(cmd->c_expr,Null(STR***),-1);
match = str_true(retstr);
goto maybe;
/* if flipflop was true, flop it */
flipmaybe:
if (match && cmdflags & CF_FLIP) {
if (cmd->c_expr->arg_type == O_FLOP) { /* currently toggled? */
retstr = eval(cmd->c_expr,Null(STR***),-1);/*let eval undo it*/
cmdflags = copyopt(cmd,cmd->c_expr[3].arg_ptr.arg_cmd);
}
else {
retstr = eval(cmd->c_expr,Null(STR***),-1);/* 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 && cmd->c_type != C_IF)
goto next_cmd;
}
/* 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? */
lastretstr = retstr;
retstr = eval(cmd->ucmd.acmd.ac_expr,Null(STR***),-1);
}
break;
case C_IF:
oldspat = curspat;
oldsave = savestack->ary_fill;
#ifdef DEBUGGING
olddlevel = dlevel;
#endif
if (match) {
retstr = &str_yes;
if (cmd->ucmd.ccmd.cc_true) {
#ifdef DEBUGGING
if (debug) {
debname[dlevel] = 't';
debdelim[dlevel++] = '_';
}
#endif
retstr = cmd_exec(cmd->ucmd.ccmd.cc_true);
}
}
else {
retstr = &str_no;
if (cmd->ucmd.ccmd.cc_alt) {
#ifdef DEBUGGING
if (debug) {
debname[dlevel] = 'e';
debdelim[dlevel++] = '_';
}
#endif
retstr = cmd_exec(cmd->ucmd.ccmd.cc_alt);
}
}
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;
loop_ptr++;
loop_stack[loop_ptr].loop_label = cmd->c_label;
#ifdef DEBUGGING
if (debug & 4) {
deb("(Pushing label #%d %s)\n",
loop_ptr,cmd->c_label);
}
#endif
}
switch (setjmp(loop_stack[loop_ptr].loop_env)) {
case O_LAST:
retstr = lastretstr;
curspat = oldspat;
if (savestack->ary_fill > oldsave)
restorelist(oldsave);
goto next_cmd;
case O_NEXT:
goto next_iter;
case O_REDO:
#ifdef DEBUGGING
dlevel = olddlevel;
#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++] = '_';
}
#endif
cmd_exec(cmd->ucmd.ccmd.cc_true);
}
/* 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++] = '_';
}
#endif
cmd_exec(cmd->ucmd.ccmd.cc_alt);
}
finish_while:
curspat = oldspat;
if (savestack->ary_fill > oldsave)
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) {
deb("(Popping label #%d %s)\n",loop_ptr,
loop_stack[loop_ptr].loop_label);
}
#endif
loop_ptr--;
if ((cmdflags & CF_OPTIMIZE) == CFT_ARRAY) {
cmd->c_stab->stab_val = cmd->c_short;
}
}
cmd = cmd->c_next;
goto tail_recursion_entry;
}
#ifdef DEBUGGING
/*VARARGS1*/
deb(pat,a1,a2,a3,a4,a5,a6,a7,a8)
char *pat;
{
register int i;
fprintf(stderr,"%-4ld",(long)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);
}
#endif
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;
}
void
savelist(sarg,maxsarg)
register STR **sarg;
int maxsarg;
{
register STR *str;
register int i;
for (i = 1; i <= maxsarg; i++) {
apush(savestack,sarg[i]); /* remember the pointer */
str = str_new(0);
str_sset(str,sarg[i]);
apush(savestack,str); /* remember the value */
}
}
void
restorelist(base)
int base;
{
register STR *str;
register STR *value;
while (savestack->ary_fill > base) {
value = apop(savestack);
str = apop(savestack);
str_sset(str,value);
STABSET(str);
str_free(value);
}
}
|