Why is Visual C++ 2010 complaining about 'Using uninitialized memory'?
c++, memory-management
Solution
This has to be a bug in Visual Studio 2010. Wrapping `malloc` removes the warning, as in the following tested code:
char * mymalloc(int i)
{
return (char *) malloc(i);
}
// ...
void *r = mymalloc(cb);
char *p;
p = (char *) malloc(cb);
Problem
I've got a function that takes a pointer to a buffer, and the size of that buffer (via a pointer). If the buffer's not big enough, it returns an error value and sets the required length in the out-param: ``` // FillBuffer is defined in another compilation unit (OBJ file). // Whole program optimization is off. int FillBuffer(__int_bcount_opt(*pcb) char *buffer, size_t *pcb); ``` I call it like this: ``` size_t cb = 12; char *p = (char *)malloc(cb); if (!p) return ENOMEM; int result; for (;;) { result = FillBuffer(p, &cb); if (result == ENOBUFS) { char *q = (char *)realloc(p, cb); if (!q) { free(p); return ENOMEM; } p = q; } else break; } ``` Visual C++ 2010 (with code analysis cranked to the max) complains with `'warning C6001: Using uninitialized memory 'p': Lines: ...'`. It reports line numbers covering pretty much the entire function. Visual C++ 2008 doesn't. As far as I can tell, this code's OK. What am I missing? Or what is VC2010 missing?