unused: wrong result

[Konstantin8105]

Input data:

package main

import "unsafe"
import "reflect"

type pthread_attr_t [56]byte

func (self *pthread_attr_t) cast(t reflect.Type) reflect.Value {
	return reflect.NewAt(t, unsafe.Pointer(&self[0]))
}

Output of unused program:

exit.go:6:6: type pthread_attr_t is unused (U1000)

[Konstantin8105]

Please clarify - that is happen because that func cast is not used in func main.

[dmitshur]

The program you provided is not valid, it's missing main function.

Given the following program with a main, unused correctly reports that type pthread_attr_t is unused:

package main

import "unsafe"
import "reflect"

type pthread_attr_t [56]byte

func (self *pthread_attr_t) cast(t reflect.Type) reflect.Value {
	return reflect.NewAt(t, unsafe.Pointer(&self[0]))
}

func main() {}

The following program does not produce any output from unused:

package main

import "unsafe"
import "reflect"

type pthread_attr_t [56]byte

func (self *pthread_attr_t) cast(t reflect.Type) reflect.Value {
	return reflect.NewAt(t, unsafe.Pointer(&self[0]))
}

func main() {
	var x pthread_attr_t
	x.cast(reflect.TypeOf(0))
}

Because both pthread_attr_t and its cast method are used.

What's this issue about?

[Konstantin8105]

Thanks