Question

I’m writing a program in C++ and for some reason I’m getting a segmentation error at the following line:

char* param= new char[200];

I’ve tried different variations and even tried putting before it

int* param= new int;//for no reason

and the same error occurs. What might I have done to cause this problem?

What could possibly cause a simple memory allocation like this to give problems.

I would include the rest of the program, but it’s over 1000 lines. But feel free to ask for more info.

Answer 1

I’d say Neil’s on the right track – it’s probably something you trampled earlier on that’s only being caught there.

Have you made sure that:

1. All previous allocations succeeded.
2. You’ve not written past the end or beginnings of any arrays (there’s a plethora of information and tools for bounds checking out there).

[Edit] In response to your comment about having 4GB of RAM, suppose you code effectively does the following:

unsigned int amountToAllocate = 0;
amountToAllocate -= 1;

int* someStorage = new int[amountToAllocate];

someStorage[0] = 5;

…because amountToAllocate is an unsigned int, it will wrap round to it’s maximum value (4294967295 if unsigned ints are 32 bit on your hardware). So you’d be trying to allocate 4294967295*4 bytes (again, assuming ints are 32 bit for you)… which is ~4*4GB and will fail and die a nasty death.