all: delete dead non-test code

This change removes a lot of dead code. Some of the code has never been
used, not even when it was first commited. The rest shouldn't have
survived refactors.

This change doesn't remove unused routines helpful for debugging, nor
does it remove code that's used in commented out blocks of code that are
only unused temporarily. Furthermore, unused constants weren't removed
when they were part of a set of constants from specifications.

One noteworthy omission from this CL are about 1000 lines of unused code
in cmd/fix, 700 lines of which are the typechecker, which hasn't been
used ever since the pre-Go 1 fixes have been removed. I wasn't sure if
this code should stick around for future uses of cmd/fix or be culled as
well.

Change-Id: Ib714bc7e487edc11ad23ba1c3222d1fd02e4a549
Reviewed-on: https://go-review.googlesource.com/20926Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/api/goapi.go

@@ -368,15 +368,6 @@ func (w *Walker) parseFile(dir, file string) (*ast.File, error) {
 	return f, nil
 }
 
-func contains(list []string, s string) bool {
-	for _, t := range list {
-		if t == s {
-			return true
-		}
-	}
-	return false
-}
-
 // The package cache doesn't operate correctly in rare (so far artificial)
 // circumstances (issue 8425). Disable before debugging non-obvious errors
 // from the type-checker.

src/cmd/cgo/gcc.go

@@ -1283,7 +1283,6 @@ func runGcc(stdin []byte, args []string) (string, string) {
 type typeConv struct {
 	// Cache of already-translated or in-progress types.
 	m map[dwarf.Type]*Type
-	typedef map[string]ast.Expr
 
 	// Map from types to incomplete pointers to those types.
 	ptrs map[dwarf.Type][]*Type

src/cmd/dist/util.go

@@ -131,7 +131,6 @@ var maxbg = 4 /* maximum number of jobs to run at once */
 
 var (
 	bgwork = make(chan func(), 1e5)
-	bgdone = make(chan struct{}, 1e5)
 
 	bghelpers sync.WaitGroup
 

src/cmd/doc/pkg.go

@@ -32,8 +32,6 @@ type Package struct {
 	writer   io.Writer    // Destination for output.
 	name     string       // Package name, json for encoding/json.
 	userPath string       // String the user used to find this package.
-	unexported bool
-	matchCase  bool
 	pkg      *ast.Package // Parsed package.
 	file     *ast.File    // Merged from all files in the package
 	doc      *doc.Package

src/cmd/go/build.go

@@ -1312,16 +1312,6 @@ func (b *builder) do(root *action) {
 	wg.Wait()
 }
 
-// hasString reports whether s appears in the list of strings.
-func hasString(strings []string, s string) bool {
-	for _, t := range strings {
-		if s == t {
-			return true
-		}
-	}
-	return false
-}
-
 // build is the action for building a single package or command.
 func (b *builder) build(a *action) (err error) {
 	// Return an error if the package has CXX files but it's not using

src/cmd/go/generate.go

@@ -17,7 +17,6 @@ import (
 	"runtime"
 	"strconv"
 	"strings"
-	"unicode"
 )
 
 var cmdGenerate = &Command{
@@ -371,17 +370,6 @@ func (g *Generator) expandVar(word string) string {
 	return os.Getenv(word)
 }
 
-// identLength returns the length of the identifier beginning the string.
-func (g *Generator) identLength(word string) int {
-	for i, r := range word {
-		if r == '_' || unicode.IsLetter(r) || unicode.IsDigit(r) {
-			continue
-		}
-		return i
-	}
-	return len(word)
-}
-
 // setShorthand installs a new shorthand as defined by a -command directive.
 func (g *Generator) setShorthand(words []string) {
 	// Create command shorthand.

src/cmd/go/main.go

@@ -403,8 +403,6 @@ func errorf(format string, args ...interface{}) {
 	setExitStatus(1)
 }
 
-var logf = log.Printf
-
 func exitIfErrors() {
 	if exitStatus != 0 {
 		exit()
@@ -428,19 +426,6 @@ func run(cmdargs ...interface{}) {
 	}
 }
 
-func runOut(dir string, cmdargs ...interface{}) []byte {
-	cmdline := stringList(cmdargs...)
-	cmd := exec.Command(cmdline[0], cmdline[1:]...)
-	cmd.Dir = dir
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		os.Stderr.Write(out)
-		errorf("%v", err)
-		out = nil
-	}
-	return out
-}
-
 // envForDir returns a copy of the environment
 // suitable for running in the given directory.
 // The environment is the current process's environment

src/cmd/go/pkg.go

@@ -90,7 +90,6 @@ type Package struct {
 	target       string               // installed file for this package (may be executable)
 	fake         bool                 // synthesized package
 	external     bool                 // synthesized external test package
-	forceBuild   bool                 // this package must be rebuilt
 	forceLibrary bool                 // this package is a library (even if named "main")
 	cmdline      bool                 // defined by files listed on command line
 	local        bool                 // imported via local path (./ or ../)

src/cmd/pprof/internal/report/report.go

@@ -10,7 +10,6 @@ import (
 	"fmt"
 	"io"
 	"math"
-	"os"
 	"path/filepath"
 	"regexp"
 	"sort"
@@ -248,14 +247,6 @@ func valueOrDot(value int64, rpt *Report) string {
 	return rpt.formatValue(value)
 }
 
-// canAccessFile determines if the filename can be opened for reading.
-func canAccessFile(path string) bool {
-	if fi, err := os.Stat(path); err == nil {
-		return fi.Mode().Perm()&0400 != 0
-	}
-	return false
-}
-
 // printTags collects all tags referenced in the profile and prints
 // them in a sorted table.
 func printTags(w io.Writer, rpt *Report) error {
@@ -764,14 +755,6 @@ type node struct {
 	tags tagMap
 }
 
-func (ts tags) string() string {
-	var ret string
-	for _, s := range ts {
-		ret = ret + fmt.Sprintf("%s %s %d %d\n", s.name, s.unit, s.value, s.weight)
-	}
-	return ret
-}
-
 type nodeInfo struct {
 	name              string
 	origName          string
@@ -1697,22 +1680,3 @@ type Report struct {
 	sampleValue func(*profile.Sample) int64
 	formatValue func(int64) string
 }
-
-func (rpt *Report) formatTags(s *profile.Sample) (string, bool) {
-	var labels []string
-	for key, vals := range s.Label {
-		for _, v := range vals {
-			labels = append(labels, key+":"+v)
-		}
-	}
-	for key, nvals := range s.NumLabel {
-		for _, v := range nvals {
-			labels = append(labels, scaledValueLabel(v, key, "auto"))
-		}
-	}
-	if len(labels) == 0 {
-		return "", false
-	}
-	sort.Strings(labels)
-	return strings.Join(labels, `\n`), true
-}

src/cmd/yacc/yacc.go

@@ -237,7 +237,6 @@ var defact = make([]int, NSTATES)  // default actions of states
 
 // lookahead set information
 
-var lkst []Lkset
 var nolook = 0  // flag to turn off lookahead computations
 var tbitset = 0 // size of lookahead sets
 var clset Lkset // temporary storage for lookahead computations
@@ -3185,8 +3184,6 @@ func isword(c rune) bool {
 	return c >= 0xa0 || c == '_' || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
 }
 
-func mktemp(t string) string { return t }
-
 //
 // return 1 if 2 arrays are equal
 // return 0 if not equal
@@ -3204,13 +3201,6 @@ func aryeq(a []int, b []int) int {
 	return 1
 }
 
-func putrune(f *bufio.Writer, c int) {
-	s := string(c)
-	for i := 0; i < len(s); i++ {
-		f.WriteByte(s[i])
-	}
-}
-
 func getrune(f *bufio.Reader) rune {
 	var r rune
 

src/compress/bzip2/bzip2.go

@@ -29,7 +29,6 @@ type reader struct {
 	setupDone    bool // true if we have parsed the bzip2 header.
 	blockSize    int  // blockSize in bytes, i.e. 900 * 1000.
 	eof          bool
-	buf          []byte    // stores Burrows-Wheeler transformed data.
 	c            [256]uint // the `C' array for the inverse BWT.
 	tt           []uint32  // mirrors the `tt' array in the bzip2 source and contains the P array in the upper 24 bits.
 	tPos         uint32    // Index of the next output byte in tt.

src/compress/flate/token.go

@@ -75,9 +75,6 @@ func matchToken(xlength uint32, xoffset uint32) token {
 	return token(matchType + xlength<<lengthShift + xoffset)
 }
 
-// Returns the type of a token
-func (t token) typ() uint32 { return uint32(t) & typeMask }
-
 // Returns the literal of a literal token
 func (t token) literal() uint32 { return uint32(t - literalType) }
 

src/crypto/tls/common.go

@@ -590,13 +590,6 @@ type Certificate struct {
 	Leaf *x509.Certificate
 }
 
-// A TLS record.
-type record struct {
-	contentType  recordType
-	major, minor uint8
-	payload      []byte
-}
-
 type handshakeMessage interface {
 	marshal() []byte
 	unmarshal([]byte) bool

src/crypto/tls/conn.go

@@ -174,13 +174,6 @@ func (hc *halfConn) incSeq() {
 	panic("TLS: sequence number wraparound")
 }
 
-// resetSeq resets the sequence number to zero.
-func (hc *halfConn) resetSeq() {
-	for i := range hc.seq {
-		hc.seq[i] = 0
-	}
-}
-
 // removePadding returns an unpadded slice, in constant time, which is a prefix
 // of the input. It also returns a byte which is equal to 255 if the padding
 // was valid and 0 otherwise. See RFC 2246, section 6.2.3.2

src/database/sql/sql.go

@@ -838,11 +838,6 @@ func (db *DB) conn(strategy connReuseStrategy) (*driverConn, error) {
 	return dc, nil
 }
 
-var (
-	errConnClosed = errors.New("database/sql: internal sentinel error: conn is closed")
-	errConnBusy   = errors.New("database/sql: internal sentinel error: conn is busy")
-)
-
 // putConnHook is a hook for testing.
 var putConnHook func(*DB, *driverConn)
 

src/debug/macho/macho.go

@@ -291,26 +291,3 @@ func stringName(i uint32, names []intName, goSyntax bool) string {
 	}
 	return strconv.FormatUint(uint64(i), 10)
 }
-
-func flagName(i uint32, names []intName, goSyntax bool) string {
-	s := ""
-	for _, n := range names {
-		if n.i&i == n.i {
-			if len(s) > 0 {
-				s += "+"
-			}
-			if goSyntax {
-				s += "macho."
-			}
-			s += n.s
-			i -= n.i
-		}
-	}
-	if len(s) == 0 {
-		return "0x" + strconv.FormatUint(uint64(i), 16)
-	}
-	if i != 0 {
-		s += "+0x" + strconv.FormatUint(uint64(i), 16)
-	}
-	return s
-}

src/encoding/xml/marshal.go

@@ -178,7 +178,6 @@ var (
 	begComment  = []byte("<!--")
 	endComment  = []byte("-->")
 	endProcInst = []byte("?>")
-	endDirective = []byte(">")
 )
 
 // EncodeToken writes the given XML token to the stream.

src/html/escape.go

@@ -10,10 +10,6 @@ import (
 	"unicode/utf8"
 )
 
-type writer interface {
-	WriteString(string) (int, error)
-}
-
 // These replacements permit compatibility with old numeric entities that
 // assumed Windows-1252 encoding.
 // http://www.whatwg.org/specs/web-apps/current-work/multipage/tokenization.html#consume-a-character-reference

src/io/pipe.go

@@ -15,11 +15,6 @@ import (
 // ErrClosedPipe is the error used for read or write operations on a closed pipe.
 var ErrClosedPipe = errors.New("io: read/write on closed pipe")
 
-type pipeResult struct {
-	n   int
-	err error
-}
-
 // A pipe is the shared pipe structure underlying PipeReader and PipeWriter.
 type pipe struct {
 	rl    sync.Mutex // gates readers one at a time

src/net/http/fcgi/fcgi.go

@@ -58,8 +58,6 @@ const (
 	statusUnknownRole
 )
 
-const headerLen = 8
-
 type header struct {
 	Version       uint8
 	Type          recType
@@ -158,11 +156,6 @@ func (c *conn) writeRecord(recType recType, reqId uint16, b []byte) error {
 	return err
 }
 
-func (c *conn) writeBeginRequest(reqId uint16, role uint16, flags uint8) error {
-	b := [8]byte{byte(role >> 8), byte(role), flags}
-	return c.writeRecord(typeBeginRequest, reqId, b[:])
-}
-
 func (c *conn) writeEndRequest(reqId uint16, appStatus int, protocolStatus uint8) error {
 	b := make([]byte, 8)
 	binary.BigEndian.PutUint32(b, uint32(appStatus))

src/net/http/httputil/dump.go

@@ -168,13 +168,6 @@ var reqWriteExcludeHeaderDump = map[string]bool{
 	"Trailer":           true,
 }
 
-// dumpAsReceived writes req to w in the form as it was received, or
-// at least as accurately as possible from the information retained in
-// the request.
-func dumpAsReceived(req *http.Request, w io.Writer) error {
-	return nil
-}
-
 // DumpRequest returns the given request in its HTTP/1.x wire
 // representation. It should only be used by servers to debug client
 // requests. The returned representation is an approximation only;

src/net/http/transport.go

@@ -1371,7 +1371,6 @@ func (e *httpError) Timeout() bool   { return e.timeout }
 func (e *httpError) Temporary() bool { return true }
 
 var errTimeout error = &httpError{err: "net/http: timeout awaiting response headers", timeout: true}
-var errClosed error = &httpError{err: "net/http: server closed connection before response was received"}
 var errRequestCanceled = errors.New("net/http: request canceled")
 var errRequestCanceledConn = errors.New("net/http: request canceled while waiting for connection") // TODO: unify?
 
@@ -1697,17 +1696,6 @@ type fakeLocker struct{}
 func (fakeLocker) Lock()   {}
 func (fakeLocker) Unlock() {}
 
-func isNetWriteError(err error) bool {
-	switch e := err.(type) {
-	case *url.Error:
-		return isNetWriteError(e.Err)
-	case *net.OpError:
-		return e.Op == "write"
-	default:
-		return false
-	}
-}
-
 // cloneTLSConfig returns a shallow clone of the exported
 // fields of cfg, ignoring the unexported sync.Once, which
 // contains a mutex and must not be copied.

src/reflect/value.go

@@ -11,7 +11,6 @@ import (
 )
 
 const ptrSize = 4 << (^uintptr(0) >> 63) // unsafe.Sizeof(uintptr(0)) but an ideal const
-const cannotSet = "cannot set value obtained from unexported struct field"
 
 // Value is the reflection interface to a Go value.
 //

src/regexp/backtrack.go

@@ -36,7 +36,6 @@ type bitState struct {
 
 	end     int
 	cap     []int
-	input   input
 	jobs    []job
 	visited []uint32
 }

src/regexp/exec.go

@@ -107,14 +107,6 @@ func (m *machine) alloc(i *syntax.Inst) *thread {
 	return t
 }
 
-// free returns t to the free pool.
-func (m *machine) free(t *thread) {
-	m.inputBytes.str = nil
-	m.inputString.str = ""
-	m.inputReader.r = nil
-	m.pool = append(m.pool, t)
-}
-
 // match runs the machine over the input starting at pos.
 // It reports whether a match was found.
 // If so, m.matchcap holds the submatch information.
@@ -192,7 +184,6 @@ func (m *machine) match(i input, pos int) bool {
 func (m *machine) clear(q *queue) {
 	for _, d := range q.dense {
 		if d.t != nil {
-			// m.free(d.t)
 			m.pool = append(m.pool, d.t)
 		}
 	}
@@ -213,7 +204,6 @@ func (m *machine) step(runq, nextq *queue, pos, nextPos int, c rune, nextCond sy
 			continue
 		}
 		if longest && m.matched && len(t.cap) > 0 && m.matchcap[0] < t.cap[0] {
-			// m.free(t)
 			m.pool = append(m.pool, t)
 			continue
 		}
@@ -232,7 +222,6 @@ func (m *machine) step(runq, nextq *queue, pos, nextPos int, c rune, nextCond sy
 				// First-match mode: cut off all lower-priority threads.
 				for _, d := range runq.dense[j+1:] {
 					if d.t != nil {
-						// m.free(d.t)
 						m.pool = append(m.pool, d.t)
 					}
 				}
@@ -253,7 +242,6 @@ func (m *machine) step(runq, nextq *queue, pos, nextPos int, c rune, nextCond sy
 			t = m.add(nextq, i.Out, nextPos, t.cap, nextCond, t)
 		}
 		if t != nil {
-			// m.free(t)
 			m.pool = append(m.pool, t)
 		}
 	}

src/regexp/regexp.go

@@ -75,8 +75,6 @@ import (
 	"unicode/utf8"
 )
 
-var debug = false
-
 // Regexp is the representation of a compiled regular expression.
 // A Regexp is safe for concurrent use by multiple goroutines.
 type Regexp struct {

src/sort/sort.go

@@ -19,13 +19,6 @@ type Interface interface {
 	Swap(i, j int)
 }
 
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 // Insertion sort
 func insertionSort(data Interface, a, b int) {
 	for i := a + 1; i < b; i++ {

src/text/template/funcs.go

@@ -322,7 +322,6 @@ const (
 	complexKind
 	intKind
 	floatKind
-	integerKind
 	stringKind
 	uintKind
 )

src/time/time.go

@@ -225,9 +225,6 @@ const (
 	// Assumed by the unixToInternal computation below.
 	internalYear = 1
 
-	// The year of the zero Unix time.
-	unixYear = 1970
-
 	// Offsets to convert between internal and absolute or Unix times.
 	absoluteToInternal int64 = (absoluteZeroYear - internalYear) * 365.2425 * secondsPerDay
 	internalToAbsolute       = -absoluteToInternal