Hello *,

I currently ran into the issue with xpressive. One of our test suites limits the stack usage to 32K and we have a stack overflow with over 600 function calls within xpressive. I stripped down our test case to the minimally reproducible source:

#include <boost/xpressive/xpressive.hpp>
#include <iostream>
#include <string>

using namespace boost::xpressive;
namespace x=boost::xpressive;
using namespace std;

const sregex allowed_chars = x::set[alnum | (x::set= '_','-','+','.')];

sregex regex(string const& delim)
{
return
bos // begin of sequence followed by
>> !(s1=as_xpr(delim)) // zero or one delimiter (greedy)
>> (s2=*(allowed_chars|as_xpr(delim)))// any number of allowed characters mixed with delim string
;
}

int main()
{
const string s = "Process.DiagBuffer";
string delim;
cout << "enter delim: ";
cin >> delim;

smatch what;
bool matched = regex_match(s, what, regex(delim));
const string suffix=what[s2];
cout << suffix << endl;

return 0;
}

Compilation Platform is Linux 32 bit.

Compiler call:
g++ -g -I"../software/boost_1_47_0" -o test main.cpp

For that source the stack has to be limited to 24K. You can set the stack size and core dump file size like this:
$ ulimit -c 10000 -s 24

Consider using ulimit in the sub-shell, since stack size can't be increased anymore.

If you are interested I can post the compiled executable and the core dump file. When using optimization this works fine (it crashes with stack size being less equal 12K), but the main question is: Is it really normal to have more than 600 function calls in Debug mode?

Many thanks,
Ovanes