cmd/internal/ld: remove Biobuf unget

The underlying *bufio.Reader does everything that's needed here.

Change-Id: If0712a5b4d3142ae4bceaa2efe287eaf2b91e54e
Reviewed-on: https://go-review.googlesource.com/9365
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/cmd/internal/ld/objfile.go b/src/cmd/internal/ld/objfile.go
index 8eac63497e5d1a97360769d07c726a80d8972d79..0361c50fa8bf58446715522124f28e1dfcfa901a 100644 (file)
--- a/src/cmd/internal/ld/objfile.go
+++ b/src/cmd/internal/ld/objfile.go
@@ -41,9 +41,11 @@ func ldobjfile(ctxt *Link, f *Biobuf, pkg string, length int64, pn string) {
        }
 
        for {
-               c = Bgetc(f)
-               Bungetc(f)
-               if c == 0xff {
+               c, err := f.r.Peek(1)
+               if err != nil {
+                       log.Fatalf("%s: peeking: %v", pn, err)
+               }
+               if c[0] == 0xff {
                        break
                }
                readsym(ctxt, f, pkg, pn)

diff --git a/src/cmd/internal/ld/util.go b/src/cmd/internal/ld/util.go
index ea6ca1589c9f516da2a4a14823f715f71f294e3c..f6a706ca010468c6bce595a5f28946380d1ebf8d 100644 (file)
--- a/src/cmd/internal/ld/util.go
+++ b/src/cmd/internal/ld/util.go
@@ -77,12 +77,10 @@ func cutStringAtNUL(s string) string {
 }
 
 type Biobuf struct {
-       unget    [2]int
-       numUnget int
-       f        *os.File
-       r        *bufio.Reader
-       w        *bufio.Writer
-       linelen  int
+       f       *os.File
+       r       *bufio.Reader
+       w       *bufio.Writer
+       linelen int
 }
 
 func Bopenw(name string) (*Biobuf, error) {
@@ -164,10 +162,6 @@ func Bputc(b *Biobuf, c byte) {
 const Beof = -1
 
 func Bread(b *Biobuf, p []byte) int {
-       if b.numUnget > 0 {
-               Bseek(b, -int64(b.numUnget), 1)
-               b.numUnget = 0
-       }
        n, err := io.ReadFull(b.r, p)
        if n == 0 {
                if err != nil && err != io.EOF {
@@ -178,25 +172,14 @@ func Bread(b *Biobuf, p []byte) int {
 }
 
 func Bgetc(b *Biobuf) int {
-       if b.numUnget > 0 {
-               b.numUnget--
-               return int(b.unget[b.numUnget])
-       }
        c, err := b.r.ReadByte()
-       r := int(c)
        if err != nil {
-               r = -1
+               return -1
        }
-       b.unget[1] = b.unget[0]
-       b.unget[0] = r
-       return r
+       return int(c)
 }
 
 func Bgetrune(b *Biobuf) int {
-       if b.numUnget > 0 {
-               Bseek(b, -int64(b.numUnget), 1)
-               b.numUnget = 0
-       }
        r, _, err := b.r.ReadRune()
        if err != nil {
                return -1
@@ -204,19 +187,11 @@ func Bgetrune(b *Biobuf) int {
        return int(r)
 }
 
-func Bungetrune(b *Biobuf) {
-       b.r.UnreadRune()
-}
-
 func (b *Biobuf) Read(p []byte) (int, error) {
        return b.r.Read(p)
 }
 
 func Brdline(b *Biobuf, delim int) string {
-       if b.numUnget > 0 {
-               Bseek(b, -int64(b.numUnget), 1)
-               b.numUnget = 0
-       }
        s, err := b.r.ReadBytes(byte(delim))
        if err != nil {
                log.Fatalf("reading input: %v", err)
@@ -226,10 +201,6 @@ func Brdline(b *Biobuf, delim int) string {
 }
 
 func Brdstr(b *Biobuf, delim int, cut int) string {
-       if b.numUnget > 0 {
-               Bseek(b, -int64(b.numUnget), 1)
-               b.numUnget = 0
-       }
        s, err := b.r.ReadString(byte(delim))
        if err != nil {
                log.Fatalf("reading input: %v", err)
@@ -255,10 +226,6 @@ func Blinelen(b *Biobuf) int {
        return b.linelen
 }
 
-func Bungetc(b *Biobuf) {
-       b.numUnget++
-}
-
 func Bflush(b *Biobuf) error {
        return b.w.Flush()
 }