2015-09-19 Paul Eggert <eggert@cs.ucla.edu>
+ Diagnose ERE '()|\1'
+ Problem reported by Hanno Böck in: http://bugs.gnu.org/21513
+ * lib/regcomp.c (parse_reg_exp): While parsing alternatives, keep
+ track of the set of previously-completed subexpressions available
+ before the first alternative, and restore this set just before
+ parsing each subsequent alternative. This lets us diagnose the
+ invalid back-reference in the ERE '()|\1'.
+
regex: merge patches from libc
2015-09-08 Joseph Myers <joseph@codesourcery.com>
{
re_dfa_t *dfa = preg->buffer;
bin_tree_t *tree, *branch = NULL;
+ bitset_word_t initial_bkref_map = dfa->completed_bkref_map;
tree = parse_branch (regexp, preg, token, syntax, nest, err);
if (BE (*err != REG_NOERROR && tree == NULL, 0))
return NULL;
if (token->type != OP_ALT && token->type != END_OF_RE
&& (nest == 0 || token->type != OP_CLOSE_SUBEXP))
{
+ bitset_word_t accumulated_bkref_map = dfa->completed_bkref_map;
+ dfa->completed_bkref_map = initial_bkref_map;
branch = parse_branch (regexp, preg, token, syntax, nest, err);
if (BE (*err != REG_NOERROR && branch == NULL, 0))
{
postorder (tree, free_tree, NULL);
return NULL;
}
+ dfa->completed_bkref_map |= accumulated_bkref_map;
}
else
branch = NULL;