Go version
go version go1.26.5 darwin/arm64
Also reproduced with golang.org/x/tools master at a5c4651b8e4951086fc536519d0eb869feefa7cb and with x/tools v0.38.0.
Output of go env
GOOS=darwin GOARCH=arm64
What did you do?
Built and interpreted this program with go/ssa:
package main
import "fmt"
func seq(yield func(int) bool) {
for i := 1; i <= 4; i++ {
if !yield(i) {
return
}
}
}
func main() {
var got []int
restarts := 0
again:
for i := range seq {
got = append(got, i)
if i == 1 && restarts < 2 {
restarts++
goto again
}
}
fmt.Println(got)
}The standard Go compiler prints the expected result. An equivalent go/ssa/interp test on current x/tools master prints the incorrect result.
What did you expect to see?
[1 1 1 2 3 4]
A goto to the label on a range-over-func statement must stop the current iterator call and restart the labeled range statement.
What did you see instead?
[1 2 3 4]
buildYieldFunc currently maps both _goto and _continue for the range label to yield-continue. Thus the goto is lowered like continue: the current iterator keeps yielding instead of returning false and resuming at the range label in the parent function.
Go version
go version go1.26.5 darwin/arm64Also reproduced with
golang.org/x/toolsmaster at a5c4651b8e4951086fc536519d0eb869feefa7cb and with x/tools v0.38.0.Output of
go envGOOS=darwin GOARCH=arm64What did you do?
Built and interpreted this program with
go/ssa:The standard Go compiler prints the expected result. An equivalent
go/ssa/interptest on current x/tools master prints the incorrect result.What did you expect to see?
[1 1 1 2 3 4]A
gototo the label on a range-over-func statement must stop the current iterator call and restart the labeled range statement.What did you see instead?
[1 2 3 4]buildYieldFunccurrently maps both_gotoand_continuefor the range label toyield-continue. Thus thegotois lowered likecontinue: the current iterator keeps yielding instead of returning false and resuming at the range label in the parent function.