Programming Forums - View Single Post - Code Segfaults when compiled with optimizations, doesn't in arbitrary situations

Jessehk · Feb 10th, 2008, 10:33 AM

Just a bit of an update. It turns out that the fact that the code was working before was just a fluke.
It was just a lucky coincidence like before.

The real culprit was Boost.Foreach.
For some reason, something like this:

 c++ Syntax (Toggle Plain Text) 
const char LETTERS[] = { 'A', 'B' };
 
BOOST_FOREACH( char letter, LETTERS ) {
    // ...
}
const char LETTERS[] = { 'A', 'B' };

BOOST_FOREACH( char letter, LETTERS ) {
    // ...
}

was not iterating the correct number of times and that was the result of the segfault. I'm trying to figure out if it was a bug in my code (which ATM seems unlikely) or a bug with Boost.Foreach and arrays.

In any case, your suspicion that the code was falling off the end of an array was correct.

Feb 10th, 2008, 10:33 AM	#4
Jessehk The Oblivious One Join Date: May 2005 Location: Ontario, Canada Posts: 644 Rep Power: 4	Re: Code Segfaults when compiled with optimizations, doesn't in arbitrary situations Just a bit of an update. It turns out that the fact that the code was working before was just a fluke. It was just a lucky coincidence like before. The real culprit was Boost.Foreach. For some reason, something like this: c++ Syntax (Toggle Plain Text) const char LETTERS[] = { 'A', 'B' }; BOOST_FOREACH( char letter, LETTERS ) { // ... } const char LETTERS[] = { 'A', 'B' }; BOOST_FOREACH( char letter, LETTERS ) { // ... } was not iterating the correct number of times and that was the result of the segfault. I'm trying to figure out if it was a bug in my code (which ATM seems unlikely) or a bug with Boost.Foreach and arrays. In any case, your suspicion that the code was falling off the end of an array was correct. __________________ Dr. Zoidberg: [ecstatic] I'm going to a movie... with FRIENDS!