cmd: remove bio.BufReader and bio.BufWriter

bio.BufReader was never used.

bio.BufWriter was used to wrap an existing io.Writer, but the
bio.Writer returned would not be seekable, so replace all occurences
with bufio.Reader instead.

Change-Id: I9c6779e35c63178aa4e104c17bb5bb8b52de0359
Reviewed-on: https://go-review.googlesource.com/21722
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/asm/internal/asm/endtoend_test.go

@@ -5,6 +5,7 @@
 package asm
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
 	"io/ioutil"
@@ -17,7 +18,6 @@ import (
 	"testing"
 
 	"cmd/asm/internal/lex"
-	"cmd/internal/bio"
 	"cmd/internal/obj"
 )
 
@@ -34,7 +34,7 @@ func testEndToEnd(t *testing.T, goarch, file string) {
 	pList := obj.Linknewplist(ctxt)
 	var ok bool
 	testOut = new(bytes.Buffer) // The assembler writes test output to this buffer.
-	ctxt.Bso = bio.BufWriter(os.Stdout)
+	ctxt.Bso = bufio.NewWriter(os.Stdout)
 	defer ctxt.Bso.Flush()
 	failed := false
 	ctxt.DiagFunc = func(format string, args ...interface{}) {
@@ -272,7 +272,7 @@ func testErrors(t *testing.T, goarch, file string) {
 	pList := obj.Linknewplist(ctxt)
 	var ok bool
 	testOut = new(bytes.Buffer) // The assembler writes test output to this buffer.
-	ctxt.Bso = bio.BufWriter(os.Stdout)
+	ctxt.Bso = bufio.NewWriter(os.Stdout)
 	defer ctxt.Bso.Flush()
 	failed := false
 	var errBuf bytes.Buffer

src/cmd/asm/main.go

@@ -5,6 +5,7 @@
 package main
 
 import (
+	"bufio"
 	"flag"
 	"fmt"
 	"log"
@@ -32,11 +33,6 @@ func main() {
 
 	flags.Parse()
 
-	// Create object file, write header.
-	fd, err := os.Create(*flags.OutputFile)
-	if err != nil {
-		log.Fatal(err)
-	}
 	ctxt := obj.Linknew(architecture.LinkArch)
 	if *flags.PrintOut {
 		ctxt.Debugasm = 1
@@ -46,9 +42,14 @@ func main() {
 	if *flags.Shared || *flags.Dynlink {
 		ctxt.Flag_shared = 1
 	}
-	ctxt.Bso = bio.BufWriter(os.Stdout)
+	ctxt.Bso = bufio.NewWriter(os.Stdout)
 	defer ctxt.Bso.Flush()
-	output := bio.BufWriter(fd)
+
+	// Create object file, write header.
+	output, err := bio.Create(*flags.OutputFile)
+	if err != nil {
+		log.Fatal(err)
+	}
 	fmt.Fprintf(output, "go object %s %s %s\n", obj.Getgoos(), obj.Getgoarch(), obj.Getgoversion())
 	fmt.Fprintf(output, "!\n")
 

src/cmd/compile/internal/gc/bexport.go

@@ -90,9 +90,9 @@ importer.
 package gc
 
 import (
+	"bufio"
 	"bytes"
 	"cmd/compile/internal/big"
-	"cmd/internal/bio"
 	"encoding/binary"
 	"fmt"
 	"sort"
@@ -124,7 +124,7 @@ const exportVersion = "v0"
 const exportInlined = true // default: true
 
 type exporter struct {
-	out      *bio.Writer
+	out      *bufio.Writer
 	pkgIndex map[*Pkg]int
 	typIndex map[*Type]int
 	inlined  []*Func
@@ -136,7 +136,7 @@ type exporter struct {
 }
 
 // export writes the exportlist for localpkg to out and returns the number of bytes written.
-func export(out *bio.Writer, trace bool) int {
+func export(out *bufio.Writer, trace bool) int {
 	p := exporter{
 		out:      out,
 		pkgIndex: make(map[*Pkg]int),

src/cmd/compile/internal/gc/export.go

@@ -384,7 +384,7 @@ func dumpexport() {
 		if debugFormat {
 			// save a copy of the export data
 			var copy bytes.Buffer
-			bcopy := bio.BufWriter(&copy)
+			bcopy := bufio.NewWriter(&copy)
 			size = export(bcopy, Debug_export != 0)
 			bcopy.Flush() // flushing to bytes.Buffer cannot fail
 			if n, err := bout.Write(copy.Bytes()); n != size || err != nil {
@@ -407,7 +407,7 @@ func dumpexport() {
 			pkgs = savedPkgs
 			pkgMap = savedPkgMap
 		} else {
-			size = export(bout, Debug_export != 0)
+			size = export(bout.Writer(), Debug_export != 0)
 		}
 		exportf("\n$$\n")
 	} else {

src/cmd/compile/internal/gc/go.go

@@ -5,6 +5,7 @@
 package gc
 
 import (
+	"bufio"
 	"cmd/compile/internal/ssa"
 	"cmd/internal/bio"
 	"cmd/internal/obj"
@@ -288,7 +289,7 @@ var Ctxt *obj.Link
 
 var writearchive int
 
-var bstdout *bio.Writer
+var bstdout *bufio.Writer
 
 var Nacl bool
 

src/cmd/compile/internal/gc/main.go

@@ -9,7 +9,6 @@ package gc
 import (
 	"bufio"
 	"cmd/compile/internal/ssa"
-	"cmd/internal/bio"
 	"cmd/internal/obj"
 	"cmd/internal/sys"
 	"flag"
@@ -104,7 +103,7 @@ func Main() {
 
 	Ctxt = obj.Linknew(Thearch.LinkArch)
 	Ctxt.DiagFunc = Yyerror
-	bstdout = bio.BufWriter(os.Stdout)
+	bstdout = bufio.NewWriter(os.Stdout)
 	Ctxt.Bso = bstdout
 
 	localpkg = mkpkg("")

src/cmd/internal/bio/buf.go

@@ -51,18 +51,6 @@ func Open(name string) (*Reader, error) {
 	return &Reader{f: f, r: bufio.NewReader(f)}, nil
 }
 
-// BufWriter returns a Writer on top of w.
-// TODO(dfc) remove this method and replace caller with bufio.Writer.
-func BufWriter(w io.Writer) *Writer {
-	return &Writer{w: bufio.NewWriter(w)}
-}
-
-// BufWriter returns a Reader on top of r.
-// TODO(dfc) remove this method and replace caller with bufio.Reader.
-func BufReader(r io.Reader) *Reader {
-	return &Reader{r: bufio.NewReader(r)}
-}
-
 func (w *Writer) Write(p []byte) (int, error) {
 	return w.w.Write(p)
 }

src/cmd/internal/obj/link.go

@@ -31,7 +31,7 @@
 package obj
 
 import (
-	"cmd/internal/bio"
+	"bufio"
 	"cmd/internal/sys"
 )
 
@@ -629,7 +629,7 @@ type Link struct {
 	Flag_shared   int32
 	Flag_dynlink  bool
 	Flag_optimize bool
-	Bso           *bio.Writer
+	Bso           *bufio.Writer
 	Pathname      string
 	Goroot        string
 	Goroot_final  string

src/cmd/link/internal/ld/lib.go

@@ -241,7 +241,7 @@ const (
 var (
 	headstring string
 	// buffered output
-	Bso *bio.Writer
+	Bso *bufio.Writer
 )
 
 // TODO(dfc) outBuf duplicates bio.Writer

src/cmd/link/internal/ld/link.go

@@ -31,7 +31,7 @@
 package ld
 
 import (
-	"cmd/internal/bio"
+	"bufio"
 	"cmd/internal/sys"
 	"debug/elf"
 	"fmt"
@@ -165,10 +165,9 @@ type Link struct {
 	Headtype  int
 	Arch      *sys.Arch
 	Debugvlog int32
-
-	Bso     *bio.Writer
-	Windows int32
-	Goroot  string
+	Bso       *bufio.Writer
+	Windows   int32
+	Goroot    string
 
 	// Symbol lookup based on name and indexed by version.
 	Hash []map[string]*LSym

src/cmd/link/internal/ld/pobj.go

@@ -31,7 +31,7 @@
 package ld
 
 import (
-	"cmd/internal/bio"
+	"bufio"
 	"cmd/internal/obj"
 	"cmd/internal/sys"
 	"flag"
@@ -46,7 +46,7 @@ var (
 )
 
 func Ldmain() {
-	Bso = bio.BufWriter(os.Stdout)
+	Bso = bufio.NewWriter(os.Stdout)
 
 	Ctxt = linknew(SysArch)
 	Ctxt.Diag = Diag