Go complains about missing return statement at the end of functions even when those return statements would be unreachable because all code paths appropriately return a value.

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

go version go1.6.3 linux/amd64

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

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/simon/golang"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GO15VENDOREXPERIMENT="1"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0"
CXX="g++"
CGO_ENABLED="1"

What did you do?

This function emits an error message

func foo(x int) int {
     switch x {
     default:
     case 0:
          return 0
     case 1:
          return 1
     }
}

# github.com/graymalkin/unreachable
./unreachable.go:11: missing return at end of function

Despite a return at the end of the function being unreachable in the presence of a default case in the switch statement.

What did you expect to see?

A clean compilation

What did you see instead?

# github.com/graymalkin/unreachable
./unreachable.go:11: missing return at end of function