cmd/compile: extraneous quotes in "unexported method or field" error message

[kevinburke]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

tip

What operating system and processor architecture are you using (go env)?

Irrelevant

What did you do?

https://play.golang.org/p/BzZjqEx-Jk

package main

import "net"

func main() {
	d := &net.Dialer{}
	deadline := d.deadline()
}

What did you see instead?

The error message has an extra set of quotes:

d.deadline undefined (cannot refer to unexported field or method net.(*Dialer)."".deadline)

I'd expect it to read:

d.deadline undefined (cannot refer to unexported field or method net.(*Dialer).deadline)

[kevinburke]

Relevant code is here in cmd/compile/internal/gc/typecheck.go:

		if n.Left.Op == OTYPE {
			if !looktypedot(n, t, 0) {
				if looktypedot(n, t, 1) {
					yyerror("%v undefined (cannot refer to unexported method %v)", n, n.Sym)
				} else {
					yyerror("%v undefined (type %v has no method %v)", n, t, n.Sym)
				}
				n.Type = nil
				return n
			}

So maybe the problem is in the representation of n.Sym? Also fine with this being closed as "this is expected behavior."

[gopherbot]

CL https://golang.org/cl/44070 mentions this issue.

[mvdan]

@kevinburke I've taken a stab at this - feel free to review the CL if you're at all familiar with cmd/compile :)

Also, FYI, you were slightly off in where the error actually occurs. The place is:

case lookdot(n, t, 1) != nil:
        // Field or method matches by name, but it is not exported.
        yyerror("%v undefined (cannot refer to unexported field or method %v)", n, n.Sym)

But I believe this doesn't matter, as the problem is that n.Sym.String() is what includes the weird ."" part. My CL above changes the contents of n.Sym.