static struct grep_expr *compile_pattern_not(struct grep_pat **list)
{
struct grep_pat *p;
struct grep_expr *x;
p = *list;
switch (p->token) {
case GREP_NOT:
if (!p->next)
die("--not not followed by pattern expression");
*list = p->next;
x = xcalloc(1, sizeof (struct grep_expr));
x->node = GREP_NODE_NOT;
x->u.unary = compile_pattern_not(list);
if (!x->u.unary)
die("--not followed by non pattern expression");
return x;
default:
return compile_pattern_atom(list);
}
}
static struct grep_expr *compile_pattern_and(struct grep_pat **list)
{
struct grep_pat *p;
struct grep_expr *x, *y, *z;
x = compile_pattern_not(list);
p = *list;
if (p && p->token == GREP_AND) {
if (!p->next)
die("--and not followed by pattern expression");
*list = p->next;
y = compile_pattern_and(list);
if (!y)
die("--and not followed by pattern expression");
z = xcalloc(1, sizeof (struct grep_expr));
z->node = GREP_NODE_AND;
z->u.binary.left = x;
z->u.binary.right = y;
return z;
}
return x;
}
