Mercurial > octave
diff libinterp/corefcn/regexp.cc @ 23816:d396866fa7d8 stable
Add documentation about PCRE library regexp stack overflow (bug #51589).
* regexp.cc: Place detailed note at end of help about stack overflow for high
match count recursion in regexp() searches, an upstream issue for which no
good solution was found.
| author | Daniel J Sebald <daniel.sebald@ieee.org> |
|---|---|
| date | Fri, 28 Jul 2017 13:47:45 -0500 |
| parents | fdce2b73f5ce |
| children | d9ca3f15f739 4a4a8b2a5bf2 |
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--- a/libinterp/corefcn/regexp.cc Wed Jul 19 11:41:25 2017 -0700 +++ b/libinterp/corefcn/regexp.cc Fri Jul 28 13:47:45 2017 -0500 @@ -850,6 +850,18 @@ are zero or more @qcode{'b'} characters at positions 1 and end-of-string. @end table +Stack Limitation Note: Pattern searches are done with a recursive function +which can overflow the program stack when there are a high number of matches. +For example, + +@example +@code{regexp (repmat ('a', 1, 1e5), '(a)+')} +@end example + +may lead to a segfault. As an alternative, consider constructing pattern +searches that reduce the number of matches (e.g., by creatively using set +complement), and then further processing the return variables (now reduced in +size) with successive @code{regexp} searches. @seealso{regexpi, strfind, regexprep} @end deftypefn */) {