cmd/internal/doc: merge with cmd/go/internal/doc

Now that cmd/doc has been removed, cmd/go/internal/doc is the only user
of the cmd/internal/doc code. Merge cmd/internal/doc into
cmd/go/internal/doc.

For #74667

Change-Id: I16bbe7b1f418b54ee411c8d6e6609c0973e40b3e
Reviewed-on: https://go-review.googlesource.com/c/go/+/689836
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Matloob <matloob@golang.org>
Reviewed-by: Michael Matloob <matloob@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/cmd/go/internal/doc/dirs.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !cmd_go_bootstrap
+
 package doc
 
 import (

src/cmd/go/internal/doc/doc.go

@@ -8,9 +8,12 @@
 package doc
 
 import (
-	"cmd/go/internal/base"
-	"cmd/internal/doc"
 	"context"
+	"flag"
+	"log"
+	"os"
+
+	"cmd/go/internal/base"
 )
 
 var CmdDoc = &base.Command{
@@ -136,5 +139,12 @@ Flags:
 }
 
 func runDoc(ctx context.Context, cmd *base.Command, args []string) {
-	doc.Main(args)
+	log.SetFlags(0)
+	log.SetPrefix("doc: ")
+	dirsInit()
+	var flagSet flag.FlagSet
+	err := do(os.Stdout, &flagSet, args)
+	if err != nil {
+		log.Fatal(err)
+	}
 }

src/cmd/go/internal/doc/doc_test.go

@@ -29,7 +29,7 @@ func TestMain(m *testing.M) {
 	buildCtx.GOROOT = testenv.GOROOT(nil)
 	build.Default.GOROOT = testenv.GOROOT(nil)
 
-	// Add $GOROOT/src/cmd/doc/testdata explicitly so we can access its contents in the test.
+	// Add $GOROOT/src/cmd/go/internal/doc/testdata explicitly so we can access its contents in the test.
 	// Normally testdata directories are ignored, but sending it to dirs.scan directly is
 	// a hack that works around the check.
 	testdataDir, err := filepath.Abs("testdata")
@@ -90,7 +90,7 @@ type test struct {
 	no   []string // Regular expressions that should not match.
 }
 
-const p = "cmd/internal/doc/testdata"
+const p = "cmd/go/internal/doc/testdata"
 
 var tests = []test{
 	// Sanity check.
@@ -105,7 +105,7 @@ var tests = []test{
 	{
 		"package clause",
 		[]string{p},
-		[]string{`package pkg.*cmd/internal/doc/testdata`},
+		[]string{`package pkg.*cmd/go/internal/doc/testdata`},
 		nil,
 	},
 

src/cmd/go/internal/doc/main.go

@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package doc provides the implementation of the "go doc" subcommand and cmd/doc.
+//go:build !cmd_go_bootstrap
+
 package doc
 
 import (
@@ -53,18 +54,6 @@ func usage(flagSet *flag.FlagSet) {
 	os.Exit(2)
 }
 
-// Main is the entry point, invoked both by go doc and cmd/doc.
-func Main(args []string) {
-	log.SetFlags(0)
-	log.SetPrefix("doc: ")
-	dirsInit()
-	var flagSet flag.FlagSet
-	err := do(os.Stdout, &flagSet, args)
-	if err != nil {
-		log.Fatal(err)
-	}
-}
-
 // do is the workhorse, broken out of main to make testing easier.
 func do(writer io.Writer, flagSet *flag.FlagSet, args []string) (err error) {
 	flagSet.Usage = func() { usage(flagSet) }

src/cmd/go/internal/doc/pkg.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !cmd_go_bootstrap
+
 package doc
 
 import (