__heapvalid()

Defined in stdlib.h, this function performs a consistency check on the heap. It outputs full information about every free block if the verbose parameter is nonzero. Otherwise, it only outputs errors.

The function outputs its results by calling the output function dprint(), that must work like fprintf(). The first parameter passed to dprint() is the supplied pointer param. You can pass fprintf() itself, provided you cast it to the right function pointer type. This type is defined as a typedef for convenience. It is called __heapprt. For example:

__heapvalid((__heapprt) fprintf, stderr, 0);

This function is not part of the C library standard, but is supported by the ARM C library as an extension.

int __heapvalid(int (*dprint)(void *param, char const *format,...), void *param, int verbose);