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#include <sys/types.h>
/* brk is handled entirely within the C library. This limits METAL programs that
* use the C library to be disallowed from dynamically allocating memory
* without talking to the C library, but that sounds like a sane way to go
* about it. Note that there is no error checking anywhere in this file, users
* will simply get the relevant error when actually trying to use the memory
* that's been allocated. */
extern char __heap_start;
extern char __heap_end;
static char *brk = &__heap_start;
int
_brk(void *addr)
{
brk = addr;
return 0;
}
char *
_sbrk(ptrdiff_t incr)
{
char *old = brk;
/* If __heap_size == 0, we can't allocate memory on the heap */
if(&__heap_start == &__heap_end) {
return (void *)-1;
}
/* Don't move the break past the end of the heap */
if ((brk + incr) <= &__heap_end) {
brk += incr;
} else {
return (void *)-1;
}
return old;
}
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