/cc @mvdan @alandonovan

Making vet more precise for loop-variable capture is #16520. Marking as duplicate.

Making vet more precise for loop-variable capture is #16520. Marking as duplicate.

can the question be sovled?

This is an interesting special case that we could easily extend the check to handle without the full generality of #16520, which is much harder to solve. Specifically: the go/defer statement is still the last statement within the loop body, if we use a slightly more generalized definition of "last" that traverses down into control constructs (such as if-statements in this example).

Hi @luhexcp, FYI, I tried implementing an older idea from @adonovan and sent https://go.dev/cl/452155. With that CL, go vet now complains about your example that was not flagged before:

func main() {
        done := make(chan bool)

        values := []string{"a", "b", "c"}

        ok := true
        for _, v := range values {
                if ok {
                        go func() {
                                fmt.Println(v) // vet now warns loop variable v captured by func literal
                                done <- true
                        }()
                }
        }

        for _ = range values {
                <-done
        }
}

Change https://go.dev/cl/452155 mentions this issue: go/analysis/passes/loopclosure: recursively check last statements in statements like if, switch, and for