Am facing the worst bug i've ever encountered. It's in a gcc program which analyzes several grids of binary data read from a file. I can read and analyze each single grid, but when i try to read hundreds or sometimes just dozens of grids in succession, at some point the program crashes with a segmentation fault. Obviously, I'm failing to initialize some variable or array netween grids, but can't see where. to save my soul.

gdb doesn't seem to be available to me, and, anyway, it would be a task beyond my patience to step in a debugger through hundreds of grids, each one of which involves some very heavy looping, only to find that the memory corruption under a debugger may be very different than without it.

My question is: is there a gcc compile option or some other way that i could somehow catch the segmentation fault and dump to standard output or to a file something to indicate where the fault is occurring?

As a start, you could try Electric Fence: it's simply adding option -lefence to linkage

You could also try the -fbounds-check option in gcc to crash (with applicable debugging information) if you step outside of the bounds of an array. It WILL slow down the code significantly, but it can be very helpful for catching that occasional indexing error that ultimately leads to a seg fault.

A brute force method would be to start commenting out chunks of code until the seg fault disappears, and then narrow in on which section of code is causing it. This is painful and time consuming, but it can be used as a last resort when gdb, valgrind, and array bounds checking all fails.

2 members found this post helpful.

I neglected to mention that I'm using a rather old development platform, and do not have Electric Fence. I may try the -fbounds-check option, just to familiarize myself with it for future use.

Meanwhile, after looking at NevemTeve's suggestion and before seeing suicidaleggroll's comment, i was already using the brute force method and have located the offending code, a recently added array for which i was failing to reset the index. A noobie oversight that i was unable to see at first.

Thanks, and i will mark this as solved.

Note: Electric Fence available in source and can compiled in many Unix platform.
http://linux.softpedia.com/get/Progr...nce-3305.shtml