import (
	"runtime"
	"testing"
	"unsafe"
)

// Test that the error value returned by mmap is positive, as that is
// what the code in mem_bsd.go, mem_darwin.go, and mem_linux.go expects.
// See the uses of ENOMEM in sysMap in those files.
func TestMmapErrorSign(t *testing.T) {
	p, err := runtime.Mmap(nil, ^uintptr(0)&^(runtime.GetPhysPageSize()-1), 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0)

	if p != nil || err != runtime.ENOMEM {

	if err != 0 {
		return nil
	}
	return p
}

func sysMapOS(v unsafe.Pointer, n uintptr) {
	// AIX does not allow mapping a range that is already mapped.
	// So, call mprotect to change permissions.
	// Note that sysMap is always called with a non-nil pointer
	// since it transitions a Reserved memory region to Prepared,
	// so mprotect is always possible.
	_, err := mprotect(v, n, _PROT_READ|_PROT_WRITE)
	if err == _ENOMEM {

func sysReserve(v unsafe.Pointer, n uintptr) unsafe.Pointer {
	return sysReserveOS(v, n)
}

// sysMap transitions a memory region from Reserved to Prepared. It ensures the
// memory region can be efficiently transitioned to Ready.
//
// sysStat must be non-nil.
func sysMap(v unsafe.Pointer, n uintptr, sysStat *sysMemStat) {
	sysStat.add(int64(n))
	sysMapOS(v, n)

	reservation := sysReserve(nil, totalSize)
	if reservation == nil {
		throw("failed to reserve page summary memory")
	}
	// There isn't much. Just map it and mark it as used immediately.
	sysMap(reservation, totalSize, p.sysStat)
	sysUsed(reservation, totalSize, totalSize)
	p.summaryMappedReady += totalSize

	// Iterate over the reservation and cut it up into slices.
	//

		}
		// It's possible that after our pruning above, there's nothing new to map.
		if need.size() == 0 {
			continue
		}

		// Map and commit need.
		sysMap(unsafe.Pointer(need.base.addr()), need.size(), p.sysStat)
		sysUsed(unsafe.Pointer(need.base.addr()), need.size(), need.size())
		p.summaryMappedReady += need.size()
	}

	// Update the scavenge index.

//
// h.lock must be held.
func (h *mheap) grow(npage uintptr) (uintptr, bool) {
	assertLockHeld(&h.lock)

	// We must grow the heap in whole palloc chunks.
	// We call sysMap below but note that because we
	// round up to pallocChunkPages which is on the order
	// of MiB (generally >= to the huge page size) we
	// won't be calling it too much.

	// reusing is set to fault (so, also Reserved), so transition
	// it to Prepared and then Ready.
	//
	// Unlike (*mheap).grow, just map in everything that we
	// asked for. We're likely going to use it all.
	sysMap(unsafe.Pointer(base), userArenaChunkBytes, &gcController.heapReleased)
	sysUsed(unsafe.Pointer(base), userArenaChunkBytes, userArenaChunkBytes)

	// Model the user arena as a heap span for a large object.

		return nil
	}
	l.next = p + size
	if pEnd := alignUp(l.next-1, physPageSize); pEnd > l.mapped {
		if l.mapMemory {
			// Transition from Reserved to Prepared to Ready.
			n := pEnd - l.mapped
			sysMap(unsafe.Pointer(l.mapped), n, sysStat)
			sysUsed(unsafe.Pointer(l.mapped), n, n)
		}
		l.mapped = pEnd
	}
	return unsafe.Pointer(p)
}

		}
		return unsafe.Pointer(ret), 0
	}
	return sysMmap(addr, n, prot, flags, fd, off)
}

func munmap(addr unsafe.Pointer, n uintptr) {
	if _cgo_munmap != nil {
		systemstack(func() { callCgoMunmap(addr, n) })
		return
	}
	sysMunmap(addr, n)
}

// sysMmap calls the mmap system call. It is implemented in assembly.

	}
	width := uint32(32)
	if sf == 1 {
		width = uint32(64)
	}
	if imms >= (width - 15) {
		return (immr % 16) <= (imms - (width - 15))
	}
	return false
}

type sys uint8

const (
	sys_AT sys = iota
	sys_DC
	sys_IC
	sys_TLBI
	sys_SYS
)

func sys_op_4(op1, crn, crm, op2 uint32) sys {
	sysInst := sysInstFields{uint8(op1), uint8(crn), uint8(crm), uint8(op2)}
	return sysInst.getType()
}