https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68213
Bug ID: 68213
Summary: Exception handling corrupts a VLA in MinGW
Product: gcc
Version: 5.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: hedayat.fwd at gmail dot com
Target Milestone: ---
Code:
-----------------------------------------------------------------
#include <iostream>
#include <cstring>
#include <sstream>
#include <stdexcept>
using namespace std;
int main(int argc, char **argv)
{
int n;
stringstream ss(argv[1]);
ss >> n;
cout << "N: " << n << endl;
char tbuff[n];
try
{
memset(tbuff, 0, n);
throw runtime_error("ERR");
}
catch (exception &e)
{
cout << "Writing to VLA" << endl;
memset(tbuff, 0, n);
cout << "Wrote" << endl;
}
}
-----------------------------------------------------------------
Compiled with:
/usr/bin/i686-w64-mingw32-g++ -O2 test.cpp -o t
Run with wine (similar results under Windows) results in crash:
[]% ./t 100
fixme:winediag:start_process Wine Staging is a testing version containing
experimental patches.
fixme:winediag:start_process Please report bugs at http://bugs.wine-staging.com
(instead of winehq.org).
N: 100
Writing to VLA
wine: Unhandled page fault on read access to 0x00000000 at address (nil)
(thread 0009), starting debugger...
Unhandled exception: page fault on read access to 0x00000000 in 32-bit code
(0x00000000).
....
