notnull
{ --inloop; $$ = stat4(FOR, $3, notnull($6), $9, $12); }
IF '(' pattern rparen { $$ = notnull($3); }
pattern { $$ = notnull($1); }
{ $$ = op3(CONDEXPR, notnull($1), $3, $5); }
{ $$ = op2(BOR, notnull($1), notnull($3)); }
{ $$ = op2(AND, notnull($1), notnull($3)); }
{ $$ = op3(CONDEXPR, notnull($1), $3, $5); }
{ $$ = op2(BOR, notnull($1), notnull($3)); }
{ $$ = op2(AND, notnull($1), notnull($3)); }
| NOT re { $$ = op1(NOT, notnull($2)); }
{ $$ = stat2(DO, $3, notnull($7)); }
| NOT term %prec UMINUS { $$ = op1(NOT, notnull($2)); }
WHILE '(' pattern rparen { $$ = notnull($3); }
extern Node *notnull(Node *);