Function compile_pattern_atom

grep.c:605–632

static struct grep_expr *compile_pattern_or(struct grep_pat **);
static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
{
	struct grep_pat *p;
	struct grep_expr *x;

	p = *list;
	if (!p)
		return NULL;
	switch (p->token) {
	case GREP_PATTERN: /* atom */
	case GREP_PATTERN_HEAD:
	case GREP_PATTERN_BODY:
		CALLOC_ARRAY(x, 1);
		x->node = GREP_NODE_ATOM;
		x->u.atom = p;
		*list = p->next;
		return x;
	case GREP_OPEN_PAREN:
		*list = p->next;
		x = compile_pattern_or(list);
		if (!*list || (*list)->token != GREP_CLOSE_PAREN)
			die("unmatched ( for expression group");
		*list = (*list)->next;
		return x;
	default:
		return NULL;
	}
}

static struct grep_expr *compile_pattern_not(struct grep_pat **list)
{