cmd: remove bio.Bread

Replace calls to bio.Bread with calls to io.ReadFull.

Change-Id: I2ee8739d01e04a4da9c20b6ce7d1d5b89914b8ad
Reviewed-on: https://go-review.googlesource.com/21750Reviewed-by: Dave Cheney <dave@cheney.net>

src/cmd/internal/bio/buf.go

@@ -7,7 +7,6 @@ package bio
 
 import (
 	"bufio"
-	"io"
 	"log"
 	"os"
 )
@@ -86,16 +85,6 @@ func (w *Writer) Offset() int64 {
 	return off
 }
 
-func Bread(r *Reader, p []byte) int {
-	n, err := io.ReadFull(r, p)
-	if n == 0 {
-		if err != nil && err != io.EOF {
-			n = -1
-		}
-	}
-	return n
-}
-
 func (r *Reader) Close() error {
 	return r.f.Close()
 }

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

@@ -35,6 +35,7 @@ import (
 	"cmd/internal/obj"
 	"encoding/binary"
 	"fmt"
+	"io"
 	"os"
 )
 
@@ -76,8 +77,8 @@ func hostArchive(name string) {
 	}
 	defer f.Close()
 
-	magbuf := make([]byte, len(ARMAG))
-	if bio.Bread(f, magbuf) != len(magbuf) {
+	var magbuf [len(ARMAG)]byte
+	if _, err := io.ReadFull(f, magbuf[:]); err != nil {
 		Exitf("file %s too short", name)
 	}
 
@@ -138,9 +139,8 @@ func readArmap(filename string, f *bio.Reader, arhdr ArHdr) archiveMap {
 		wordSize = 8
 	}
 
-	l := atolwhex(arhdr.size)
-	contents := make([]byte, l)
-	if bio.Bread(f, contents) != int(l) {
+	contents := make([]byte, atolwhex(arhdr.size))
+	if _, err := io.ReadFull(f, contents); err != nil {
 		Exitf("short read from %s", filename)
 	}
 

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

@@ -11,6 +11,7 @@ import (
 	"cmd/internal/bio"
 	"cmd/internal/obj"
 	"fmt"
+	"io"
 	"os"
 	"strings"
 )
@@ -49,7 +50,7 @@ func ldpkg(f *bio.Reader, pkg string, length int64, filename string, whence int)
 	}
 
 	bdata := make([]byte, length)
-	if int64(bio.Bread(f, bdata)) != length {
+	if _, err := io.ReadFull(f, bdata); err != nil {
 		fmt.Fprintf(os.Stderr, "%s: short pkg read %s\n", os.Args[0], filename)
 		if Debug['u'] != 0 {
 			errorexit()

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

@@ -476,7 +476,7 @@ func ldelf(f *bio.Reader, pkg string, length int64, pn string) {
 	var sect *ElfSect
 	var sym ElfSym
 	var symbols []*LSym
-	if bio.Bread(f, hdrbuf[:]) != len(hdrbuf) {
+	if _, err := io.ReadFull(f, hdrbuf[:]); err != nil {
 		goto bad
 	}
 	hdr = new(ElfHdrBytes)
@@ -986,9 +986,11 @@ func elfmap(elfobj *ElfObj, sect *ElfSect) (err error) {
 	}
 
 	sect.base = make([]byte, sect.size)
-	err = fmt.Errorf("short read")
-	if elfobj.f.Seek(int64(uint64(elfobj.base)+sect.off), 0) < 0 || bio.Bread(elfobj.f, sect.base) != len(sect.base) {
-		return err
+	if elfobj.f.Seek(int64(uint64(elfobj.base)+sect.off), 0) < 0 {
+		return fmt.Errorf("short read: seek not successful")
+	}
+	if _, err := io.ReadFull(elfobj.f, sect.base); err != nil {
+		return fmt.Errorf("short read: %v", err)
 	}
 
 	return nil

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

@@ -6,6 +6,7 @@ import (
 	"cmd/internal/sys"
 	"encoding/binary"
 	"fmt"
+	"io"
 	"log"
 	"sort"
 )
@@ -299,7 +300,10 @@ func macholoadrel(m *LdMachoObj, sect *LdMachoSect) int {
 	rel := make([]LdMachoRel, sect.nreloc)
 	n := int(sect.nreloc * 8)
 	buf := make([]byte, n)
-	if m.f.Seek(m.base+int64(sect.reloff), 0) < 0 || bio.Bread(m.f, buf) != n {
+	if m.f.Seek(m.base+int64(sect.reloff), 0) < 0 {
+		return -1
+	}
+	if _, err := io.ReadFull(m.f, buf); err != nil {
 		return -1
 	}
 	var p []byte
@@ -345,7 +349,10 @@ func macholoaddsym(m *LdMachoObj, d *LdMachoDysymtab) int {
 	n := int(d.nindirectsyms)
 
 	p := make([]byte, n*4)
-	if m.f.Seek(m.base+int64(d.indirectsymoff), 0) < 0 || bio.Bread(m.f, p) != len(p) {
+	if m.f.Seek(m.base+int64(d.indirectsymoff), 0) < 0 {
+		return -1
+	}
+	if _, err := io.ReadFull(m.f, p); err != nil {
 		return -1
 	}
 
@@ -362,7 +369,10 @@ func macholoadsym(m *LdMachoObj, symtab *LdMachoSymtab) int {
 	}
 
 	strbuf := make([]byte, symtab.strsize)
-	if m.f.Seek(m.base+int64(symtab.stroff), 0) < 0 || bio.Bread(m.f, strbuf) != len(strbuf) {
+	if m.f.Seek(m.base+int64(symtab.stroff), 0) < 0 {
+		return -1
+	}
+	if _, err := io.ReadFull(m.f, strbuf); err != nil {
 		return -1
 	}
 
@@ -372,7 +382,10 @@ func macholoadsym(m *LdMachoObj, symtab *LdMachoSymtab) int {
 	}
 	n := int(symtab.nsym * uint32(symsize))
 	symbuf := make([]byte, n)
-	if m.f.Seek(m.base+int64(symtab.symoff), 0) < 0 || bio.Bread(m.f, symbuf) != len(symbuf) {
+	if m.f.Seek(m.base+int64(symtab.symoff), 0) < 0 {
+		return -1
+	}
+	if _, err := io.ReadFull(m.f, symbuf); err != nil {
 		return -1
 	}
 	sym := make([]LdMachoSym, symtab.nsym)
@@ -433,7 +446,7 @@ func ldmacho(f *bio.Reader, pkg string, length int64, pn string) {
 
 	Ctxt.IncVersion()
 	base := f.Offset()
-	if bio.Bread(f, hdr[:]) != len(hdr) {
+	if _, err := io.ReadFull(f, hdr[:]); err != nil {
 		goto bad
 	}
 
@@ -455,8 +468,7 @@ func ldmacho(f *bio.Reader, pkg string, length int64, pn string) {
 	}
 
 	if is64 {
-		var tmp [4]uint8
-		bio.Bread(f, tmp[:4]) // skip reserved word in header
+		f.Seek(4, 1) // skip reserved word in header
 	}
 
 	m = new(LdMachoObj)
@@ -494,7 +506,7 @@ func ldmacho(f *bio.Reader, pkg string, length int64, pn string) {
 	m.cmd = make([]LdMachoCmd, ncmd)
 	off = uint32(len(hdr))
 	cmdp = make([]byte, cmdsz)
-	if bio.Bread(f, cmdp) != len(cmdp) {
+	if _, err2 := io.ReadFull(f, cmdp); err2 != nil {
 		err = fmt.Errorf("reading cmds: %v", err)
 		goto bad
 	}
@@ -557,7 +569,11 @@ func ldmacho(f *bio.Reader, pkg string, length int64, pn string) {
 	}
 
 	dat = make([]byte, c.seg.filesz)
-	if f.Seek(m.base+int64(c.seg.fileoff), 0) < 0 || bio.Bread(f, dat) != len(dat) {
+	if f.Seek(m.base+int64(c.seg.fileoff), 0) < 0 {
+		err = fmt.Errorf("cannot load object data: %v", err)
+		goto bad
+	}
+	if _, err2 := io.ReadFull(f, dat); err2 != nil {
 		err = fmt.Errorf("cannot load object data: %v", err)
 		goto bad
 	}

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

@@ -10,6 +10,7 @@ import (
 	"cmd/internal/sys"
 	"encoding/binary"
 	"fmt"
+	"io"
 	"log"
 	"sort"
 	"strconv"
@@ -176,13 +177,13 @@ func ldpe(f *bio.Reader, pkg string, length int64, pn string) {
 	// load string table
 	f.Seek(int64(base)+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(peobj.fh.NumberOfSymbols), 0)
 
-	if bio.Bread(f, symbuf[:4]) != 4 {
+	if _, err := io.ReadFull(f, symbuf[:4]); err != nil {
 		goto bad
 	}
 	l = Le32(symbuf[:])
 	peobj.snames = make([]byte, l)
 	f.Seek(int64(base)+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(peobj.fh.NumberOfSymbols), 0)
-	if bio.Bread(f, peobj.snames) != len(peobj.snames) {
+	if _, err := io.ReadFull(f, peobj.snames); err != nil {
 		goto bad
 	}
 
@@ -205,7 +206,7 @@ func ldpe(f *bio.Reader, pkg string, length int64, pn string) {
 	f.Seek(int64(base)+int64(peobj.fh.PointerToSymbolTable), 0)
 	for i := 0; uint32(i) < peobj.fh.NumberOfSymbols; i += numaux + 1 {
 		f.Seek(int64(base)+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(i), 0)
-		if bio.Bread(f, symbuf[:]) != len(symbuf) {
+		if _, err := io.ReadFull(f, symbuf[:]); err != nil {
 			goto bad
 		}
 
@@ -293,7 +294,7 @@ func ldpe(f *bio.Reader, pkg string, length int64, pn string) {
 		f.Seek(int64(peobj.base)+int64(rsect.sh.PointerToRelocations), 0)
 		for j = 0; j < int(rsect.sh.NumberOfRelocations); j++ {
 			rp = &r[j]
-			if bio.Bread(f, symbuf[:10]) != 10 {
+			if _, err := io.ReadFull(f, symbuf[:10]); err != nil {
 				goto bad
 			}
 			rva := Le32(symbuf[0:])
@@ -466,7 +467,10 @@ func pemap(peobj *PeObj, sect *PeSect) int {
 	if sect.sh.PointerToRawData == 0 { // .bss doesn't have data in object file
 		return 0
 	}
-	if peobj.f.Seek(int64(peobj.base)+int64(sect.sh.PointerToRawData), 0) < 0 || bio.Bread(peobj.f, sect.base) != len(sect.base) {
+	if peobj.f.Seek(int64(peobj.base)+int64(sect.sh.PointerToRawData), 0) < 0 {
+		return -1
+	}
+	if _, err := io.ReadFull(peobj.f, sect.base); err != nil {
 		return -1
 	}
 

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

@@ -745,12 +745,12 @@ func nextar(bp *bio.Reader, off int64, a *ArHdr) int64 {
 		off++
 	}
 	bp.Seek(off, 0)
-	buf := make([]byte, SAR_HDR)
-	if n := bio.Bread(bp, buf); n < len(buf) {
-		if n >= 0 {
-			return 0
+	var buf [SAR_HDR]byte
+	if n, err := io.ReadFull(bp, buf[:]); err != nil {
+		if n == 0 && err != io.EOF {
+			return -1
 		}
-		return -1
+		return 0
 	}
 
 	a.name = artrim(buf[0:16])
@@ -780,8 +780,11 @@ func objfile(lib *Library) {
 		Exitf("cannot open file %s: %v", lib.File, err)
 	}
 
-	magbuf := make([]byte, len(ARMAG))
-	if bio.Bread(f, magbuf) != len(magbuf) || !strings.HasPrefix(string(magbuf), ARMAG) {
+	for i := 0; i < len(ARMAG); i++ {
+		if c, err := f.ReadByte(); err == nil && c == ARMAG[i] {
+			continue
+		}
+
 		/* load it as a regular file */
 		l := f.Seek(0, 2)
 
@@ -811,7 +814,9 @@ func objfile(lib *Library) {
 	if Buildmode == BuildmodeShared {
 		before := f.Offset()
 		pkgdefBytes := make([]byte, atolwhex(arhdr.size))
-		bio.Bread(f, pkgdefBytes)
+		if _, err := io.ReadFull(f, pkgdefBytes); err != nil {
+			Diag("%s: short read on archive file symbol header: %v", lib.File, err)
+		}
 		hash := sha1.Sum(pkgdefBytes)
 		lib.hash = hash[:]
 		f.Seek(before, 0)