// instead on the g0 stack.
		throw("cannot trace user goroutine on its own stack")
	}

	if pc0 == ^uintptr(0) && sp0 == ^uintptr(0) { // Signal to fetch saved values from gp.
		if gp.syscallsp != 0 {
			pc0 = gp.syscallpc
			sp0 = gp.syscallsp
			if usesLR {
				lr0 = 0
			}
		} else {
			pc0 = gp.sched.pc
			sp0 = gp.sched.sp
			if usesLR {
				lr0 = gp.sched.lr
			}
		}
	}

	gcController.memoryLimit.Store(maxInt64)
}

// sysAlloc allocates heap arena space for at least n bytes. The
// returned pointer is always heapArenaBytes-aligned and backed by
// h.arenas metadata. The returned size is always a multiple of
// heapArenaBytes. sysAlloc returns nil on failure.
// There is no corresponding free function.
//

	bh := (*buckhashArray)(buckhash.Load())
	if bh == nil {
		lock(&profInsertLock)
		// check again under the lock
		bh = (*buckhashArray)(buckhash.Load())
		if bh == nil {
			bh = (*buckhashArray)(sysAlloc(unsafe.Sizeof(buckhashArray{}), &memstats.buckhash_sys))
			if bh == nil {
				throw("runtime: cannot allocate memory")
			}
			buckhash.StoreNoWB(unsafe.Pointer(bh))
		}
		unlock(&profInsertLock)
	}

// field names when generating the C or Go code. For generated
// C, we leave the names as is (tv_sec, tv_usec), since that's what
// people are used to seeing in C.  For generated Go code, such as
// package syscall's data structures, we drop a common prefix
// (so sec, usec, which will get turned into Sec, Usec for exporting).
func fieldPrefix(fld []*ast.Field) string {
	prefix := ""
	for _, f := range fld {