go/printer: build constraints are moved above block comments

[zyxkad]

Go version

go version go1.22.0 darwin/arm64

Output of go env in your module/workspace:

Not relative

What did you do?

1. https://go.dev/play/p/XfUekq-wb8i
2. Click the format button or run go fmt

/* Ok, the LICENSE is...
 * UNLICENSED
 */

// some test comments here

//go:build !ignore

// some package description
package main

What did you see happen?

//go:build !ignore

/* Ok, the LICENSE is...
 * UNLICENSED
 */

// some test comments here

// some package description
package main

What did you expect to see?

Nothing should happen, so

/* Ok, the LICENSE is...
 * UNLICENSED
 */

// some test comments here

//go:build !ignore

// some package description
package main

[zyxkad]

I am putting my license header in the block comment, so I wish it will stay at the top and not be moved

[zyxkad]

Another example:

// aaa
/* bbb */

//go:build ignore

will become

//go:build ignore

// aaa
/* bbb */

Really weird

[seankhliao]

the old build constraint format // +build could only be preceded by line comments and not block comments so they were moved up

https://github.com/golang/go/blob/master/src/go/printer/gobuild.go#L13

[adonovan]

What is the "ohh" comment if not the copyright header?

[zyxkad]

the ohh just some test comments 💦

I edited the example so it will makes more sense