| package main |
| |
| import ( |
| "runtime" |
| ) |
| |
| // Large is an object that (since Go 1.22) is allocated in a span that has a |
| // non-nil largeType field. Meaning it must be (>maxSmallSize-mallocHeaderSize). |
| // At the time of writing this is (32768 - 8). |
| type Large struct { |
| ptr *uint8 // Object must contain a pointer to trigger code path. |
| arr [32768 - 8]uint8 |
| } |
| |
| func ping(o *Large) { |
| o.ptr = &o.arr[5] |
| o.arr[5] = 0xCA |
| } |
| |
| func main() { |
| var o Large |
| go ping(&o) // Force an escape of o. |
| o.arr[14] = 0xDE // Prevent a future smart compiler from allocating o directly on pings stack. |
| |
| _ = *(*int)(nil) |
| runtime.KeepAlive(&o) |
| } |
