deferが呼ばれるのはreturn前

package main
  
import (
        crand "crypto/rand"
        "fmt"
        "github.com/seehuhn/mt19937"
        "math"
        "math/big"
        "math/rand"
        "os"
)

func main() {
        os.Exit(realMain())
}

func realMain() int {
        seed, _ := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
        rng := rand.New(mt19937.New())
        rng.Seed(seed.Int64())
        r := rng.Intn(2)
        defer fmt.Printf("1\n")
        if r == 0 {
                return 1
        }
        defer fmt.Printf("2\n")

        return 0
}

実行結果

$ go run main.go
2
1
$ go run main.go
1
exit status 1

参考

• os.Exit()とdefer
• defer と log.Fatal について