cc @mdempsky @griesemer

The minimum case:

package main

import "unsafe"

type A [1 << 33]byte

type T [1 << 30]A

func main() {
	var t T
	println(unsafe.Sizeof(t))
}

But the following code doesn't cause compiler crashes:

package main

import "unsafe"

type A [1 << 33]byte

type T [1 << 31]A

func main() {
	var t T
	println(unsafe.Sizeof(t))
}

BTW2, the following code also doesn't cause compiler crashes, but the error message looks not good:

type T [1 << 63]byte // error: array length 1 << 63 (untyped int constant 9223372036854775808) must be integer

Thanks for reporting. The case that doesn't produce a crash is a different issue. Filed #59207 for that.

Change https://go.dev/cl/478919 mentions this issue: go/types, types2: don't panic if unsafe.Sizeof/Offsetof is used with oversize types

I filed #59209 for the case that produces a bad error message ((untyped int constant 9223372036854775808) must be integer).

Change https://go.dev/cl/479116 mentions this issue: cmd/compile: don't panic if unsafe.Sizeof/Offsetof is used with oversize types