43 lines
961 B
C
43 lines
961 B
C
// Copyright (c) 1993-1999 Microsoft Corporation
|
|
|
|
#include "y3.h"
|
|
|
|
void
|
|
precftn(SSIZE_T r,int t,int s)
|
|
{
|
|
/* decide a shift/reduce conflict by precedence.*/
|
|
/* r is a rule number, t a token number */
|
|
/* the conflict is in state s */
|
|
/* temp1[t] is changed to reflect the action */
|
|
|
|
int lt, action;
|
|
SSIZE_T lp;
|
|
|
|
lp = levprd[r];
|
|
lt = toklev[t];
|
|
if( PLEVEL(lt) == 0 || PLEVEL(lp) == 0 )
|
|
{
|
|
/* conflict */
|
|
if( foutput != NULL ) fprintf( foutput, "\n%d: shift/reduce conflict (shift %d, red'n %d) on %s",
|
|
s, temp1[t], r, symnam(t) );
|
|
++zzsrconf;
|
|
return;
|
|
}
|
|
if( PLEVEL(lt) == PLEVEL(lp) ) action = ASSOC(lt);
|
|
else if( PLEVEL(lt) > PLEVEL(lp) ) action = RASC; /* shift */
|
|
else action = LASC; /* reduce */
|
|
|
|
switch( action )
|
|
{
|
|
|
|
case BASC: /* error action */
|
|
temp1[t] = ERRCODE;
|
|
return;
|
|
|
|
case LASC: /* reduce */
|
|
temp1[t] = -r;
|
|
return;
|
|
|
|
}
|
|
}
|