cmd/compile: wrong declaration line in debug_info for variables captured in a closure

[aarzilli]

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

$ go version
go version devel +f376b8510e Fri Jan 3 01:36:26 2020 +0000 linux/amd64

Does this issue reproduce with the latest release?

Yes.

What did you do?

Compile:

package main

import (
	"fmt"
)

func f1(a int) {
	fmt.Printf("a: %d\n", a)
}

func main() {
	a := 1
	f := func() {
		f1(a)
	}
	f()
}

check the DW_AT_decl_line attribute of the variable a in main.main.func1

What did you expect to see?

line 12

What did you see instead?

line 14 (the first use of a inside the closure).

[aarzilli]

Note: this is not a regression.

[gopherbot]

Change https://golang.org/cl/214637 mentions this issue: cmd/compile: assign correct declaration line to DIE of captured vars