[release-branch.go1] cmd/go: invoke godoc with import path when possible

««« backport 5b1e024a5e89
cmd/go: invoke godoc with import path when possible
Also add -n -x flags to doc, fmt, vet.
Also shorten unknown command error.

Fixes #3612.
Fixes #3613.

R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/6211053

»»»

src/cmd/go/build.go

@@ -152,6 +152,11 @@ func addBuildFlags(cmd *Command) {
 	cmd.Flag.Var(buildCompiler{}, "compiler", "")
 }
 
+func addBuildFlagsNX(cmd *Command) {
+	cmd.Flag.BoolVar(&buildN, "n", false, "")
+	cmd.Flag.BoolVar(&buildX, "x", false, "")
+}
+
 type stringsFlag []string
 
 func (v *stringsFlag) Set(s string) error {

src/cmd/go/doc.go

@@ -145,14 +145,17 @@ Run godoc on package sources
 
 Usage:
 
-	go doc [packages]
+	go doc [-n] [-x] [packages]
 
 Doc runs the godoc command on the packages named by the
 import paths.
 
 For more about godoc, see 'godoc godoc'.
 For more about specifying packages, see 'go help packages'.
 
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
 To run godoc with specific options, run godoc itself.
 
 See also: go fix, go fmt, go vet.
@@ -192,14 +195,17 @@ Run gofmt on package sources
 
 Usage:
 
-	go fmt [packages]
+	go fmt [-n] [-x] [packages]
 
 Fmt runs the command 'gofmt -l -w' on the packages named
 by the import paths.  It prints the names of the files that are modified.
 
 For more about gofmt, see 'godoc gofmt'.
 For more about specifying packages, see 'go help packages'.
 
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
 To run gofmt with specific options, run gofmt itself.
 
 See also: go doc, go fix, go vet.
@@ -414,7 +420,7 @@ Run go tool vet on packages
 
 Usage:
 
-	go vet [packages]
+	go vet [-n] [-x] [packages]
 
 Vet runs the Go vet command on the packages named by the import paths.
 
@@ -423,6 +429,9 @@ For more about specifying packages, see 'go help packages'.
 
 To run the vet tool with specific options, run 'go tool vet'.
 
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
 See also: go fmt, go fix.
 
 

src/cmd/go/fmt.go

@@ -4,9 +4,14 @@
 
 package main
 
+func init() {
+	addBuildFlagsNX(cmdFmt)
+	addBuildFlagsNX(cmdDoc)
+}
+
 var cmdFmt = &Command{
 	Run:       runFmt,
-	UsageLine: "fmt [packages]",
+	UsageLine: "fmt [-n] [-x] [packages]",
 	Short:     "run gofmt on package sources",
 	Long: `
 Fmt runs the command 'gofmt -l -w' on the packages named
@@ -15,6 +20,9 @@ by the import paths.  It prints the names of the files that are modified.
 For more about gofmt, see 'godoc gofmt'.
 For more about specifying packages, see 'go help packages'.
 
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
 To run gofmt with specific options, run gofmt itself.
 
 See also: go doc, go fix, go vet.
@@ -32,7 +40,7 @@ func runFmt(cmd *Command, args []string) {
 
 var cmdDoc = &Command{
 	Run:       runDoc,
-	UsageLine: "doc [packages]",
+	UsageLine: "doc [-n] [-x] [packages]",
 	Short:     "run godoc on package sources",
 	Long: `
 Doc runs the godoc command on the packages named by the
@@ -41,6 +49,9 @@ import paths.
 For more about godoc, see 'godoc godoc'.
 For more about specifying packages, see 'go help packages'.
 
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
 To run godoc with specific options, run godoc itself.
 
 See also: go fix, go fmt, go vet.
@@ -53,6 +64,10 @@ func runDoc(cmd *Command, args []string) {
 			errorf("go doc: cannot use package file list")
 			continue
 		}
-		run("godoc", pkg.Dir)
+		if pkg.local {
+			run("godoc", pkg.Dir)
+		} else {
+			run("godoc", pkg.ImportPath)
+		}
 	}
 }

src/cmd/go/main.go

@@ -144,8 +144,9 @@ func main() {
 		}
 	}
 
-	fmt.Fprintf(os.Stderr, "Unknown command %#q\n\n", args[0])
-	usage()
+	fmt.Fprintf(os.Stderr, "go: unknown subcommand %#q\nRun 'go help' for usage.\n", args[0])
+	setExitStatus(2)
+	exit()
 }
 
 var usageTemplate = `Go is a tool for managing Go source code.
@@ -339,6 +340,13 @@ func exitIfErrors() {
 
 func run(cmdargs ...interface{}) {
 	cmdline := stringList(cmdargs...)
+	if buildN || buildV {
+		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

src/cmd/go/vet.go

@@ -4,9 +4,13 @@
 
 package main
 
+func init() {
+	addBuildFlagsNX(cmdVet)
+}
+
 var cmdVet = &Command{
 	Run:       runVet,
-	UsageLine: "vet [packages]",
+	UsageLine: "vet [-n] [-x] [packages]",
 	Short:     "run go tool vet on packages",
 	Long: `
 Vet runs the Go vet command on the packages named by the import paths.
@@ -16,6 +20,9 @@ For more about specifying packages, see 'go help packages'.
 
 To run the vet tool with specific options, run 'go tool vet'.
 
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
 See also: go fmt, go fix.
 	`,
 }