It would be nice if the output of the command cgo -godefs with multiple input files resulted in a legal source file. Currently it duplicates the package declaration (and the generated comments) rendering the output useless without post-processing (since all the output goes straight to stdout):

$ cat a.go
package ex

/*
typedef int a;
*/
import "C"

type Atype C.a

$ cat b.go
package ex

/*
typedef int b;
*/
import "C"

type Btype C.b

$ go tool cgo -godefs a.go b.go
// Created by cgo -godefs - DO NOT EDIT
// cgo -godefs a.go b.go

package ex

type Atype int32
// Created by cgo -godefs - DO NOT EDIT
// cgo -godefs a.go b.go

package ex

type Btype int32

It would be nice if the output were instead:

$ go tool cgo -godefs a.go b.go
// Created by cgo -godefs - DO NOT EDIT
// cgo -godefs a.go b.go

package ex

type Atype int32

type Btype int32

This would be useful in situations where cgo -godefs requires extra/different information on different platforms. It is generally fairly easy to workaround though and the lack of this feature in previous versions of go might limit its usefulness.