code review 13250047: cmd/go: implement -x correctly for 'go vet', 'go fmt', ...

src/cmd/go/main.go

 // Copyright 2011 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"
         "flag"
         "fmt"
@@ skipping 342 matching lines @@
 var logf = log.Printf
 
 func exitIfErrors() {
         if exitStatus != 0 {
                 exit()
         }
 }
 
 func run(cmdargs ...interface{}) {
         cmdline := stringList(cmdargs...)
-        if buildN || buildV {
+        if buildN || buildX {
                 fmt.Printf("%s\n", strings.Join(cmdline, " "))
                 if buildN {
                         return
                 }
         }
 
         cmd := exec.Command(cmdline[0], cmdline[1:]...)
         cmd.Stdout = os.Stdout
         cmd.Stderr = os.Stderr
         if err := cmd.Run(); err != nil {
@@ skipping 293 matching lines @@
                 if t := clash[fold]; t != "" {
                         if s > t {
                                 s, t = t, s
                         }
                         return s, t
                 }
                 clash[fold] = s
         }
         return "", ""
 }