| // +build !nacl,!js,!android,!darwin darwin,!arm | 
 | // run | 
 |  | 
 | // Copyright 2016 The Go Authors. All rights reserved. | 
 | // Use of this source code is governed by a BSD-style | 
 | // license that can be found in the LICENSE file. | 
 |  | 
 | package main | 
 |  | 
 | import ( | 
 | 	"bytes" | 
 | 	"log" | 
 | 	"os/exec" | 
 | 	"strings" | 
 | ) | 
 |  | 
 | func main() { | 
 | 	checkLinkOutput("", "-B argument must start with 0x") | 
 | 	checkLinkOutput("0", "-B argument must start with 0x") | 
 | 	checkLinkOutput("0x", "usage") | 
 | 	checkLinkOutput("0x0", "-B argument must have even number of digits") | 
 | 	checkLinkOutput("0x00", "usage") | 
 | 	checkLinkOutput("0xYZ", "-B argument contains invalid hex digit") | 
 | 	checkLinkOutput("0x"+strings.Repeat("00", 32), "usage") | 
 | 	checkLinkOutput("0x"+strings.Repeat("00", 33), "-B option too long (max 32 digits)") | 
 | } | 
 |  | 
 | func checkLinkOutput(buildid string, message string) { | 
 | 	cmd := exec.Command("go", "tool", "link", "-B", buildid) | 
 | 	out, err := cmd.CombinedOutput() | 
 | 	if err == nil { | 
 | 		log.Fatalf("expected cmd/link to fail") | 
 | 	} | 
 |  | 
 | 	firstLine := string(bytes.SplitN(out, []byte("\n"), 2)[0]) | 
 | 	if strings.HasPrefix(firstLine, "panic") { | 
 | 		log.Fatalf("cmd/link panicked:\n%s", out) | 
 | 	} | 
 |  | 
 | 	if !strings.Contains(firstLine, message) { | 
 | 		log.Fatalf("cmd/link output did not include expected message %q: %s", message, firstLine) | 
 | 	} | 
 | } |