segtree: add pretty-print support for wildcard strings in concatenated sets

For concat ranges, something like 'ppp*' is translated as a range
from 'ppp\0\0\0...' to 'ppp\ff\ff\ff...'.

In order to display this properly, check for presence of string base
type and convert to symbolic expression, with appended '*' character.

Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/src/segtree.c b/src/segtree.c
index 4602becc10e63dc23ade15aa4f83a715e97034d0..f9cac373a5f05c00822b46e564642b47e1249863 100644 (file)
--- a/src/segtree.c
+++ b/src/segtree.c
@@ -345,6 +345,8 @@ void concat_range_aggregate(struct expr *set)
                list_for_each_entry_safe(r1, r1_next,
                                         &expr_value(start)->expressions,
                                         list) {
+                       bool string_type = false;
+
                        mpz_init(range);
                        mpz_init(p);
 
@@ -356,16 +358,48 @@ void concat_range_aggregate(struct expr *set)
                                goto next;
                        }
 
+                       if (expr_basetype(r1)->type == TYPE_STRING &&
+                           expr_basetype(r2)->type == TYPE_STRING) {
+                               string_type = true;
+                               mpz_switch_byteorder(r1->value, r1->len / BITS_PER_BYTE);
+                               mpz_switch_byteorder(r2->value, r2->len / BITS_PER_BYTE);
+                       }
+
                        mpz_sub(range, r2->value, r1->value);
                        mpz_sub_ui(range, range, 1);
                        mpz_and(p, r1->value, range);
 
                        /* Check if we are forced, or if it's anyway preferable,
-                        * to express the range as two points instead of a
-                        * netmask.
+                        * to express the range as a wildcard string, or two points
+                        * instead of a netmask.
                         */
                        prefix_len = range_mask_len(r1->value, r2->value,
                                                    r1->len);
+                       if (string_type) {
+                               mpz_switch_byteorder(r1->value, r1->len / BITS_PER_BYTE);
+                               mpz_switch_byteorder(r2->value, r2->len / BITS_PER_BYTE);
+                       }
+
+                       if (prefix_len >= 0 &&
+                           (prefix_len % BITS_PER_BYTE) == 0 &&
+                           string_type) {
+                               unsigned int str_len = prefix_len / BITS_PER_BYTE;
+                               char data[str_len + 2];
+
+                               mpz_export_data(data, r1->value, BYTEORDER_HOST_ENDIAN, str_len);
+                               data[str_len] = '*';
+
+                               tmp = constant_expr_alloc(&r1->location, r1->dtype,
+                                                         BYTEORDER_HOST_ENDIAN,
+                                                         (str_len + 1) * BITS_PER_BYTE, data);
+                               tmp->len = r2->len;
+                               list_replace(&r2->list, &tmp->list);
+                               r2_next = tmp->list.next;
+                               expr_free(r2);
+                               free_r1 = 1;
+                               goto next;
+                       }
+
                        if (prefix_len < 0 ||
                            !(r1->dtype->flags & DTYPE_F_PREFIX)) {
                                tmp = range_expr_alloc(&r1->location, r1,