From 492098eb759bba2ff5c86b0a868158afe32e91f8 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Tue, 1 Nov 2011 22:58:09 -0400 Subject: [PATCH] all: rename os.Error to error in various non-code contexts R=adg CC=golang-dev https://golang.org/cl/5328062 --- doc/codelab/wiki/index.html | 16 ++++++------ doc/codelab/wiki/wiki.html | 16 ++++++------ doc/debugging_with_gdb.html | 4 +-- src/cmd/cgo/out.go | 2 +- src/cmd/goinstall/main.go | 2 +- src/cmd/govet/govet.go | 38 ++++++++++++++-------------- src/pkg/compress/bzip2/bit_reader.go | 2 +- src/pkg/crypto/rsa/rsa.go | 3 +-- src/pkg/crypto/tls/conn.go | 2 +- src/pkg/crypto/x509/verify.go | 2 +- src/pkg/exp/ssh/channel.go | 2 +- src/pkg/exp/types/gcimporter.go | 2 +- src/pkg/fmt/print.go | 2 +- src/pkg/go/ast/print.go | 2 +- src/pkg/go/printer/printer.go | 2 +- src/pkg/go/scanner/errors.go | 4 +-- src/pkg/gob/error.go | 10 ++++---- src/pkg/old/netchan/import.go | 2 +- src/pkg/os/dir_plan9.go | 4 +-- src/pkg/os/dir_unix.go | 2 +- src/pkg/os/file_unix.go | 2 +- src/pkg/os/file_windows.go | 2 +- src/pkg/regexp/all_test.go | 2 +- src/pkg/rpc/debug.go | 2 +- src/pkg/rpc/server.go | 25 +++++++++--------- src/pkg/runtime/error.go | 2 +- src/pkg/smtp/auth.go | 4 +-- src/pkg/tabwriter/tabwriter.go | 2 +- src/pkg/template/doc.go | 4 +-- src/pkg/template/exec.go | 2 +- src/pkg/template/exec_test.go | 2 +- src/pkg/template/funcs.go | 4 +-- src/pkg/template/helper.go | 4 +-- src/pkg/utf8/string.go | 20 +++------------ 34 files changed, 91 insertions(+), 105 deletions(-) diff --git a/doc/codelab/wiki/index.html b/doc/codelab/wiki/index.html index 21248c1861..3dafc5cbef 100644 --- a/doc/codelab/wiki/index.html +++ b/doc/codelab/wiki/index.html @@ -107,7 +107,7 @@ func (p *Page) save() error {

This method's signature reads: "This is a method named save that takes as its receiver p, a pointer to Page . It takes -no parameters, and returns a value of type os.Error." +no parameters, and returns a value of type error."

@@ -116,7 +116,7 @@ file. For simplicity, we will use the Title as the file name.

-The save method returns an os.Error value because +The save method returns an error value because that is the return type of WriteFile (a standard library function that writes a byte slice to a file). The save method returns the error value, to let the application handle it should anything go wrong while @@ -152,7 +152,7 @@ The function loadPage constructs the file name from

Functions can return multiple values. The standard library function -io.ReadFile returns []byte and os.Error. +io.ReadFile returns []byte and error. In loadPage, error isn't being handled yet; the "blank identifier" represented by the underscore (_) symbol is used to throw away the error return value (in essence, assigning the value to nothing). @@ -161,7 +161,7 @@ error return value (in essence, assigning the value to nothing).

But what happens if ReadFile encounters an error? For example, the file might not exist. We should not ignore such errors. Let's modify the -function to return *Page and os.Error. +function to return *Page and error. 

@@ -178,7 +178,7 @@ func loadPage(title string) (*Page, error) {
 

 Callers of this function can now check the second parameter; if it is
 nil then it has successfully loaded a Page. If not, it will be an
-os.Error that can be handled by the caller (see the error that can be handled by the caller (see the os package documentation for 
 details).
 

@@ -337,7 +337,7 @@ HTML, and writes it to w, the http.ResponseWriter.
 

 
 

-Again, note the use of _ to ignore the os.Error 
+Again, note the use of _ to ignore the error 
 return value from loadPage. This is done here for simplicity
 and generally considered bad practice. We will attend to this later.
 

@@ -711,7 +711,7 @@ var templates = make(map[string]*template.Template)
 Then we create an init function, which will be called before
 main at program initialization. The function
 template.Must is a convenience wrapper that panics when passed a
-non-nil os.Error value, and otherwise returns the
+non-nil error value, and otherwise returns the
 *Template unaltered. A panic is appropriate here; if the templates
 can't be loaded the only sensible thing to do is exit the program.
 

@@ -768,7 +768,7 @@ The function regexp.MustCompile will parse and compile the
 regular expression, and return a regexp.Regexp. 
 MustCompile is distinct from Compile in that it will
 panic if the expression compilation fails, while Compile returns
-an os.Error as a second parameter. 
+an error as a second parameter. 
 

 
 

diff --git a/doc/codelab/wiki/wiki.html b/doc/codelab/wiki/wiki.html
index 634babd8b8..c3dee3f709 100644
--- a/doc/codelab/wiki/wiki.html
+++ b/doc/codelab/wiki/wiki.html
@@ -101,7 +101,7 @@ But what about persistent storage? We can address that by creating a
 

 This method's signature reads: "This is a method named save that
 takes as its receiver p, a pointer to Page . It takes
-no parameters, and returns a value of type os.Error." 
+no parameters, and returns a value of type error." 
 

 
 

@@ -110,7 +110,7 @@ file. For simplicity, we will use the Title as the file name.
 

 
 

-The save method returns an os.Error value because
+The save method returns an error value because
 that is the return type of WriteFile (a standard library function
 that writes a byte slice to a file).  The save method returns the
 error value, to let the application handle it should anything go wrong while
@@ -142,7 +142,7 @@ The function loadPage constructs the file name from
 
 

 Functions can return multiple values. The standard library function 
-io.ReadFile returns []byte and os.Error. 
+io.ReadFile returns []byte and error. 
 In loadPage, error isn't being handled yet; the "blank identifier"
 represented by the underscore (_) symbol is used to throw away the
 error return value (in essence, assigning the value to nothing). 
@@ -151,7 +151,7 @@ error return value (in essence, assigning the value to nothing).
 

 But what happens if ReadFile encounters an error?  For example,
 the file might not exist. We should not ignore such errors.  Let's modify the
-function to return *Page and os.Error.
+function to return *Page and error.
 

 
 
@@ -161,7 +161,7 @@ function to return *Page and os.Error.
 

 Callers of this function can now check the second parameter; if it is
 nil then it has successfully loaded a Page. If not, it will be an
-os.Error that can be handled by the caller (see the error that can be handled by the caller (see the os package documentation for 
 details).
 

@@ -297,7 +297,7 @@ HTML, and writes it to w, the http.ResponseWriter.
 

 
 

-Again, note the use of _ to ignore the os.Error 
+Again, note the use of _ to ignore the error 
 return value from loadPage. This is done here for simplicity
 and generally considered bad practice. We will attend to this later.
 

@@ -575,7 +575,7 @@ our *Template values, keyed by string
 Then we create an init function, which will be called before
 main at program initialization. The function
 template.Must is a convenience wrapper that panics when passed a
-non-nil os.Error value, and otherwise returns the
+non-nil error value, and otherwise returns the
 *Template unaltered. A panic is appropriate here; if the templates
 can't be loaded the only sensible thing to do is exit the program.
 

@@ -622,7 +622,7 @@ The function regexp.MustCompile will parse and compile the
 regular expression, and return a regexp.Regexp. 
 MustCompile is distinct from Compile in that it will
 panic if the expression compilation fails, while Compile returns
-an os.Error as a second parameter. 
+an error as a second parameter. 
 

 
 

diff --git a/doc/debugging_with_gdb.html b/doc/debugging_with_gdb.html
index 04850c0266..874c468345 100644
--- a/doc/debugging_with_gdb.html
+++ b/doc/debugging_with_gdb.html
@@ -288,8 +288,8 @@ The other goroutine, number 1, is stuck in runtime.gosched, blocked
 #1  0x00000000004031c9 in runtime.chanrecv (c=void, ep=void, selected=void, received=void)
  at  /home/lvd/g/src/pkg/runtime/chan.c:342
 #2  0x0000000000403299 in runtime.chanrecv1 (t=void, c=void) at/home/lvd/g/src/pkg/runtime/chan.c:423
-#3  0x000000000043075b in testing.RunTests (matchString={void (struct string, struct string, bool *, os.Error *)} 0x7ffff7f9ef60, tests=  []testing.InternalTest = {...}) at /home/lvd/g/src/pkg/testing/testing.go:201
-#4  0x00000000004302b1 in testing.Main (matchString={void (struct string, struct string, bool *, os.Error *)} 0x7ffff7f9ef80, tests= []testing.InternalTest = {...}, benchmarks= []testing.InternalBenchmark = {...})
+#3  0x000000000043075b in testing.RunTests (matchString={void (struct string, struct string, bool *, error *)} 0x7ffff7f9ef60, tests=  []testing.InternalTest = {...}) at /home/lvd/g/src/pkg/testing/testing.go:201
+#4  0x00000000004302b1 in testing.Main (matchString={void (struct string, struct string, bool *, error *)} 0x7ffff7f9ef80, tests= []testing.InternalTest = {...}, benchmarks= []testing.InternalBenchmark = {...})
     at /home/lvd/g/src/pkg/testing/testing.go:168
 #5  0x0000000000400dc1 in main.main () at /home/lvd/g/src/pkg/regexp/_testmain.go:98
 #6  0x00000000004022e7 in runtime.mainstart () at /home/lvd/g/src/pkg/runtime/amd64/asm.s:78
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
index 25f4f3e663..86e4d3282d 100644
--- a/src/cmd/cgo/out.go
+++ b/src/cmd/cgo/out.go
@@ -276,7 +276,7 @@ func (p *Package) writeDefsFunc(fc, fgo2 *os.File, n *Name) {
 				v[0] = 0;
 				v[1] = 0;
 			} else {
-				·_Cerrno(v, e);	/* fill in v as os.Error for errno e */
+				·_Cerrno(v, e);	/* fill in v as error for errno e */
 			}
 		}`)
 	}
diff --git a/src/cmd/goinstall/main.go b/src/cmd/goinstall/main.go
index 431a535f9b..7414a25052 100644
--- a/src/cmd/goinstall/main.go
+++ b/src/cmd/goinstall/main.go
@@ -304,7 +304,7 @@ func isStandardPath(s string) bool {
 
 // run runs the command cmd in directory dir with standard input stdin.
 // If the command fails, run prints the command and output on standard error
-// in addition to returning a non-nil os.Error.
+// in addition to returning a non-nil error.
 func run(dir string, stdin []byte, cmd ...string) error {
 	return genRun(dir, stdin, cmd, false)
 }
diff --git a/src/cmd/govet/govet.go b/src/cmd/govet/govet.go
index 08b9845b37..e826f89d71 100644
--- a/src/cmd/govet/govet.go
+++ b/src/cmd/govet/govet.go
@@ -232,23 +232,23 @@ type MethodSig struct {
 // we let it go.  But if it does have a fmt.ScanState, then the
 // rest has to match.
 var canonicalMethods = map[string]MethodSig{
-	// "Flush": {{}, {"os.Error"}}, // http.Flusher and jpeg.writer conflict
-	"Format":        {[]string{"=fmt.State", "rune"}, []string{}},               // fmt.Formatter
-	"GobDecode":     {[]string{"[]byte"}, []string{"os.Error"}},                 // gob.GobDecoder
-	"GobEncode":     {[]string{}, []string{"[]byte", "os.Error"}},               // gob.GobEncoder
-	"MarshalJSON":   {[]string{}, []string{"[]byte", "os.Error"}},               // json.Marshaler
-	"MarshalXML":    {[]string{}, []string{"[]byte", "os.Error"}},               // xml.Marshaler
-	"Peek":          {[]string{"=int"}, []string{"[]byte", "os.Error"}},         // image.reader (matching bufio.Reader)
-	"ReadByte":      {[]string{}, []string{"byte", "os.Error"}},                 // io.ByteReader
-	"ReadFrom":      {[]string{"=io.Reader"}, []string{"int64", "os.Error"}},    // io.ReaderFrom
-	"ReadRune":      {[]string{}, []string{"rune", "int", "os.Error"}},          // io.RuneReader
-	"Scan":          {[]string{"=fmt.ScanState", "rune"}, []string{"os.Error"}}, // fmt.Scanner
-	"Seek":          {[]string{"=int64", "int"}, []string{"int64", "os.Error"}}, // io.Seeker
-	"UnmarshalJSON": {[]string{"[]byte"}, []string{"os.Error"}},                 // json.Unmarshaler
-	"UnreadByte":    {[]string{}, []string{"os.Error"}},
-	"UnreadRune":    {[]string{}, []string{"os.Error"}},
-	"WriteByte":     {[]string{"byte"}, []string{"os.Error"}},                // jpeg.writer (matching bufio.Writer)
-	"WriteTo":       {[]string{"=io.Writer"}, []string{"int64", "os.Error"}}, // io.WriterTo
+	// "Flush": {{}, {"error"}}, // http.Flusher and jpeg.writer conflict
+	"Format":        {[]string{"=fmt.State", "rune"}, []string{}},            // fmt.Formatter
+	"GobDecode":     {[]string{"[]byte"}, []string{"error"}},                 // gob.GobDecoder
+	"GobEncode":     {[]string{}, []string{"[]byte", "error"}},               // gob.GobEncoder
+	"MarshalJSON":   {[]string{}, []string{"[]byte", "error"}},               // json.Marshaler
+	"MarshalXML":    {[]string{}, []string{"[]byte", "error"}},               // xml.Marshaler
+	"Peek":          {[]string{"=int"}, []string{"[]byte", "error"}},         // image.reader (matching bufio.Reader)
+	"ReadByte":      {[]string{}, []string{"byte", "error"}},                 // io.ByteReader
+	"ReadFrom":      {[]string{"=io.Reader"}, []string{"int64", "error"}},    // io.ReaderFrom
+	"ReadRune":      {[]string{}, []string{"rune", "int", "error"}},          // io.RuneReader
+	"Scan":          {[]string{"=fmt.ScanState", "rune"}, []string{"error"}}, // fmt.Scanner
+	"Seek":          {[]string{"=int64", "int"}, []string{"int64", "error"}}, // io.Seeker
+	"UnmarshalJSON": {[]string{"[]byte"}, []string{"error"}},                 // json.Unmarshaler
+	"UnreadByte":    {[]string{}, []string{"error"}},
+	"UnreadRune":    {[]string{}, []string{"error"}},
+	"WriteByte":     {[]string{"byte"}, []string{"error"}},                // jpeg.writer (matching bufio.Writer)
+	"WriteTo":       {[]string{"=io.Writer"}, []string{"int64", "error"}}, // io.WriterTo
 }
 
 func (f *File) checkMethod(id *ast.Ident, t *ast.FuncType) {
@@ -560,11 +560,11 @@ type BadTypeUsedInTests struct {
 	X int "hello" // ERROR "struct field tag"
 }
 
-func (t *BadTypeUsedInTests) Scan(x fmt.ScanState, c byte) { // ERROR "method Scan[(]x fmt.ScanState, c byte[)] should have signature Scan[(]fmt.ScanState, rune[)] os.Error"
+func (t *BadTypeUsedInTests) Scan(x fmt.ScanState, c byte) { // ERROR "method Scan[(]x fmt.ScanState, c byte[)] should have signature Scan[(]fmt.ScanState, rune[)] error"
 }
 
 type BadInterfaceUsedInTests interface {
-	ReadByte() byte // ERROR "method ReadByte[(][)] byte should have signature ReadByte[(][)] [(]byte, os.Error[)]"
+	ReadByte() byte // ERROR "method ReadByte[(][)] byte should have signature ReadByte[(][)] [(]byte, error[)]"
 }
 
 // printf is used by the test.
diff --git a/src/pkg/compress/bzip2/bit_reader.go b/src/pkg/compress/bzip2/bit_reader.go
index 390ee7c926..d058c14833 100644
--- a/src/pkg/compress/bzip2/bit_reader.go
+++ b/src/pkg/compress/bzip2/bit_reader.go
@@ -10,7 +10,7 @@ import (
 )
 
 // bitReader wraps an io.Reader and provides the ability to read values,
-// bit-by-bit, from it. Its Read* methods don't return the usual os.Error
+// bit-by-bit, from it. Its Read* methods don't return the usual error
 // because the error handling was verbose. Instead, any error is kept and can
 // be checked afterwards.
 type bitReader struct {
diff --git a/src/pkg/crypto/rsa/rsa.go b/src/pkg/crypto/rsa/rsa.go
index d1b9577cd3..c9344ffadf 100644
--- a/src/pkg/crypto/rsa/rsa.go
+++ b/src/pkg/crypto/rsa/rsa.go
@@ -55,8 +55,7 @@ type CRTValue struct {
 }
 
 // Validate performs basic sanity checks on the key.
-// It returns nil if the key is valid, or else an os.Error describing a problem.
-
+// It returns nil if the key is valid, or else an error describing a problem.
 func (priv *PrivateKey) Validate() error {
 	// Check that the prime factors are actually prime. Note that this is
 	// just a sanity check. Since the random witnesses chosen by
diff --git a/src/pkg/crypto/tls/conn.go b/src/pkg/crypto/tls/conn.go
index c0523370d6..6312c34d6d 100644
--- a/src/pkg/crypto/tls/conn.go
+++ b/src/pkg/crypto/tls/conn.go
@@ -828,7 +828,7 @@ func (c *Conn) OCSPResponse() []byte {
 }
 
 // VerifyHostname checks that the peer certificate chain is valid for
-// connecting to host.  If so, it returns nil; if not, it returns an os.Error
+// connecting to host.  If so, it returns nil; if not, it returns an error
 // describing the problem.
 func (c *Conn) VerifyHostname(host string) error {
 	c.handshakeMutex.Lock()
diff --git a/src/pkg/crypto/x509/verify.go b/src/pkg/crypto/x509/verify.go
index 49056cfa2d..3021d20a67 100644
--- a/src/pkg/crypto/x509/verify.go
+++ b/src/pkg/crypto/x509/verify.go
@@ -226,7 +226,7 @@ func matchHostnames(pattern, host string) bool {
 }
 
 // VerifyHostname returns nil if c is a valid certificate for the named host.
-// Otherwise it returns an os.Error describing the mismatch.
+// Otherwise it returns an error describing the mismatch.
 func (c *Certificate) VerifyHostname(h string) error {
 	if len(c.DNSNames) > 0 {
 		for _, match := range c.DNSNames {
diff --git a/src/pkg/exp/ssh/channel.go b/src/pkg/exp/ssh/channel.go
index 428e71c806..6ff8203ce2 100644
--- a/src/pkg/exp/ssh/channel.go
+++ b/src/pkg/exp/ssh/channel.go
@@ -20,7 +20,7 @@ type Channel interface {
 	// peer is likely to signal a protocol error and drop the connection.
 	Reject(reason RejectionReason, message string) error
 
-	// Read may return a ChannelRequest as an os.Error.
+	// Read may return a ChannelRequest as an error.
 	Read(data []byte) (int, error)
 	Write(data []byte) (int, error)
 	Close() error
diff --git a/src/pkg/exp/types/gcimporter.go b/src/pkg/exp/types/gcimporter.go
index d88af95031..69dbd5ac5f 100644
--- a/src/pkg/exp/types/gcimporter.go
+++ b/src/pkg/exp/types/gcimporter.go
@@ -188,7 +188,7 @@ func (p *gcParser) error(err interface{}) {
 	if s, ok := err.(string); ok {
 		err = errors.New(s)
 	}
-	// panic with a runtime.Error if err is not an os.Error
+	// panic with a runtime.Error if err is not an error
 	panic(importError{p.scanner.Pos(), err.(error)})
 }
 
diff --git a/src/pkg/fmt/print.go b/src/pkg/fmt/print.go
index 8191ab3b45..1345644544 100644
--- a/src/pkg/fmt/print.go
+++ b/src/pkg/fmt/print.go
@@ -198,7 +198,7 @@ func Sprintf(format string, a ...interface{}) string {
 }
 
 // Errorf formats according to a format specifier and returns the string 
-// as a value that satisfies os.Error.
+// as a value that satisfies error.
 func Errorf(format string, a ...interface{}) error {
 	return errors.New(Sprintf(format, a...))
 }
diff --git a/src/pkg/go/ast/print.go b/src/pkg/go/ast/print.go
index 70c9547e3c..fb3068e1e9 100644
--- a/src/pkg/go/ast/print.go
+++ b/src/pkg/go/ast/print.go
@@ -114,7 +114,7 @@ func (p *printer) Write(data []byte) (n int, err error) {
 	return
 }
 
-// localError wraps locally caught os.Errors so we can distinguish
+// localError wraps locally caught errors so we can distinguish
 // them from genuine panics which we don't want to return as errors.
 type localError struct {
 	err error
diff --git a/src/pkg/go/printer/printer.go b/src/pkg/go/printer/printer.go
index 2a1445dae3..8f1ed1159d 100644
--- a/src/pkg/go/printer/printer.go
+++ b/src/pkg/go/printer/printer.go
@@ -54,7 +54,7 @@ const (
 	noExtraLinebreak
 )
 
-// local error wrapper so we can distinguish os.Errors we want to return
+// local error wrapper so we can distinguish errors we want to return
 // as errors from genuine panics (which we don't want to return as errors)
 type osError struct {
 	err error
diff --git a/src/pkg/go/scanner/errors.go b/src/pkg/go/scanner/errors.go
index 7621cf55c1..cd9620b878 100644
--- a/src/pkg/go/scanner/errors.go
+++ b/src/pkg/go/scanner/errors.go
@@ -135,8 +135,8 @@ func (h *ErrorVector) GetErrorList(mode int) ErrorList {
 	return list
 }
 
-// GetError is like GetErrorList, but it returns an os.Error instead
-// so that a nil result can be assigned to an os.Error variable and
+// GetError is like GetErrorList, but it returns an error instead
+// so that a nil result can be assigned to an error variable and
 // remains nil.
 //
 func (h *ErrorVector) GetError(mode int) error {
diff --git a/src/pkg/gob/error.go b/src/pkg/gob/error.go
index b0c40086d5..fbae8b683d 100644
--- a/src/pkg/gob/error.go
+++ b/src/pkg/gob/error.go
@@ -9,16 +9,16 @@ import "fmt"
 // Errors in decoding and encoding are handled using panic and recover.
 // Panics caused by user error (that is, everything except run-time panics
 // such as "index out of bounds" errors) do not leave the file that caused
-// them, but are instead turned into plain os.Error returns.  Encoding and
-// decoding functions and methods that do not return an os.Error either use
+// them, but are instead turned into plain error returns.  Encoding and
+// decoding functions and methods that do not return an error either use
 // panic to report an error or are guaranteed error-free.
 
-// A gobError wraps an os.Error and is used to distinguish errors (panics) generated in this package.
+// A gobError is used to distinguish errors (panics) generated in this package.
 type gobError struct {
 	err error
 }
 
-// errorf is like error but takes Printf-style arguments to construct an os.Error.
+// errorf is like error_ but takes Printf-style arguments to construct an error.
 // It always prefixes the message with "gob: ".
 func errorf(format string, args ...interface{}) {
 	error_(fmt.Errorf("gob: "+format, args...))
@@ -30,7 +30,7 @@ func error_(err error) {
 }
 
 // catchError is meant to be used as a deferred function to turn a panic(gobError) into a
-// plain os.Error.  It overwrites the error return of the function that deferred its call.
+// plain error.  It overwrites the error return of the function that deferred its call.
 func catchError(err *error) {
 	if e := recover(); e != nil {
 		*err = e.(gobError).err // Will re-panic if not one of our errors, such as a runtime error.
diff --git a/src/pkg/old/netchan/import.go b/src/pkg/old/netchan/import.go
index 0c00e1574e..7243672ecd 100644
--- a/src/pkg/old/netchan/import.go
+++ b/src/pkg/old/netchan/import.go
@@ -186,7 +186,7 @@ func (imp *Importer) Import(name string, chT interface{}, dir Dir, size int) err
 // The channel to be bound to the remote site's channel is provided
 // in the call and may be of arbitrary channel type.
 // Despite the literal signature, the effective signature is
-//	ImportNValues(name string, chT chan T, dir Dir, size, n int) os.Error
+//	ImportNValues(name string, chT chan T, dir Dir, size, n int) error
 // Example usage:
 //	imp, err := NewImporter("tcp", "netchanserver.mydomain.com:1234")
 //	if err != nil { log.Fatal(err) }
diff --git a/src/pkg/os/dir_plan9.go b/src/pkg/os/dir_plan9.go
index abf98768d4..263881e0c1 100644
--- a/src/pkg/os/dir_plan9.go
+++ b/src/pkg/os/dir_plan9.go
@@ -22,7 +22,7 @@ import (
 // If n <= 0, Readdir returns all the FileInfo from the directory in
 // a single slice. In this case, if Readdir succeeds (reads all
 // the way to the end of the directory), it returns the slice and a
-// nil os.Error. If it encounters an error before the end of the
+// nil error. If it encounters an error before the end of the
 // directory, Readdir returns the FileInfo read until that point
 // and a non-nil error.
 func (file *File) Readdir(n int) (fi []FileInfo, err error) {
@@ -87,7 +87,7 @@ func (file *File) Readdir(n int) (fi []FileInfo, err error) {
 // If n <= 0, Readdirnames returns all the names from the directory in
 // a single slice. In this case, if Readdirnames succeeds (reads all
 // the way to the end of the directory), it returns the slice and a
-// nil os.Error. If it encounters an error before the end of the
+// nil error. If it encounters an error before the end of the
 // directory, Readdirnames returns the names read until that point and
 // a non-nil error.
 func (file *File) Readdirnames(n int) (names []string, err error) {
diff --git a/src/pkg/os/dir_unix.go b/src/pkg/os/dir_unix.go
index df89a0e82e..e59c1af2ea 100644
--- a/src/pkg/os/dir_unix.go
+++ b/src/pkg/os/dir_unix.go
@@ -24,7 +24,7 @@ const (
 // If n <= 0, Readdirnames returns all the names from the directory in
 // a single slice. In this case, if Readdirnames succeeds (reads all
 // the way to the end of the directory), it returns the slice and a
-// nil os.Error. If it encounters an error before the end of the
+// nil error. If it encounters an error before the end of the
 // directory, Readdirnames returns the names read until that point and
 // a non-nil error.
 func (f *File) Readdirnames(n int) (names []string, err error) {
diff --git a/src/pkg/os/file_unix.go b/src/pkg/os/file_unix.go
index dc8e6f0034..f4038168fc 100644
--- a/src/pkg/os/file_unix.go
+++ b/src/pkg/os/file_unix.go
@@ -141,7 +141,7 @@ func Lstat(name string) (fi *FileInfo, err error) {
 // If n <= 0, Readdir returns all the FileInfo from the directory in
 // a single slice. In this case, if Readdir succeeds (reads all
 // the way to the end of the directory), it returns the slice and a
-// nil os.Error. If it encounters an error before the end of the
+// nil error. If it encounters an error before the end of the
 // directory, Readdir returns the FileInfo read until that point
 // and a non-nil error.
 func (file *File) Readdir(n int) (fi []FileInfo, err error) {
diff --git a/src/pkg/os/file_windows.go b/src/pkg/os/file_windows.go
index 96cadce4d8..a8c36cb1bc 100644
--- a/src/pkg/os/file_windows.go
+++ b/src/pkg/os/file_windows.go
@@ -131,7 +131,7 @@ func (file *File) Close() error {
 // If n <= 0, Readdir returns all the FileInfo from the directory in
 // a single slice. In this case, if Readdir succeeds (reads all
 // the way to the end of the directory), it returns the slice and a
-// nil os.Error. If it encounters an error before the end of the
+// nil error. If it encounters an error before the end of the
 // directory, Readdir returns the FileInfo read until that point
 // and a non-nil error.
 func (file *File) Readdir(n int) (fi []FileInfo, err error) {
diff --git a/src/pkg/regexp/all_test.go b/src/pkg/regexp/all_test.go
index c707b119bd..8810796daf 100644
--- a/src/pkg/regexp/all_test.go
+++ b/src/pkg/regexp/all_test.go
@@ -32,7 +32,7 @@ var good_re = []string{
 /*
 type stringError struct {
 	re  string
-	err os.Error
+	err error
 }
 
 var bad_re = []stringError{
diff --git a/src/pkg/rpc/debug.go b/src/pkg/rpc/debug.go
index f29ea8dba0..02d577f677 100644
--- a/src/pkg/rpc/debug.go
+++ b/src/pkg/rpc/debug.go
@@ -27,7 +27,7 @@ const debugText = `
 		MethodCalls
 		{{range .Method}}
 			
-			{{.Name}}({{.Type.ArgType}}, {{.Type.ReplyType}}) os.Error
+			{{.Name}}({{.Type.ArgType}}, {{.Type.ReplyType}}) error
 			{{.Type.NumCalls}}
 			
 		{{end}}
diff --git a/src/pkg/rpc/server.go b/src/pkg/rpc/server.go
index 39652b9f41..0f7f0b47a6 100644
--- a/src/pkg/rpc/server.go
+++ b/src/pkg/rpc/server.go
@@ -18,12 +18,12 @@
 		  registering the service).
 		- the method has two arguments, both exported or local types.
 		- the method's second argument is a pointer.
-		- the method has return type os.Error.
+		- the method has return type error.
 
 	The method's first argument represents the arguments provided by the caller; the
 	second argument represents the result parameters to be returned to the caller.
 	The method's return value, if non-nil, is passed back as a string that the client
-	sees as an os.ErrorString.
+	sees as if created by errors.New.
 
 	The server may handle requests on a single connection by calling ServeConn.  More
 	typically it will create a network listener and call Accept or, for an HTTP
@@ -55,14 +55,14 @@
 
 		type Arith int
 
-		func (t *Arith) Multiply(args *Args, reply *int) os.Error {
+		func (t *Arith) Multiply(args *Args, reply *int) error {
 			*reply = args.A * args.B
 			return nil
 		}
 
-		func (t *Arith) Divide(args *Args, quo *Quotient) os.Error {
+		func (t *Arith) Divide(args *Args, quo *Quotient) error {
 			if args.B == 0 {
-				return os.ErrorString("divide by zero")
+				return errors.New("divide by zero")
 			}
 			quo.Quo = args.A / args.B
 			quo.Rem = args.A % args.B
@@ -133,10 +133,9 @@ const (
 	DefaultDebugPath = "/debug/rpc"
 )
 
-// Precompute the reflect type for os.Error.  Can't use os.Error directly
+// Precompute the reflect type for error.  Can't use error directly
 // because Typeof takes an empty interface value.  This is annoying.
-var unusedError *error
-var typeOfOsError = reflect.TypeOf(unusedError).Elem()
+var typeOfError = reflect.TypeOf((*error)(nil)).Elem()
 
 type methodType struct {
 	sync.Mutex // protects counters
@@ -210,7 +209,7 @@ func isExportedOrBuiltinType(t reflect.Type) bool {
 // receiver value that satisfy the following conditions:
 //	- exported method
 //	- two arguments, both pointers to exported structs
-//	- one return value, of type os.Error
+//	- one return value, of type error
 // It returns an error if the receiver is not an exported type or has no
 // suitable methods.
 // The client accesses each method using a string of the form "Type.Method",
@@ -281,13 +280,13 @@ func (server *Server) register(rcvr interface{}, name string, useName bool) erro
 			log.Println("method", mname, "reply type not exported or local:", replyType)
 			continue
 		}
-		// Method needs one out: os.Error.
+		// Method needs one out: error.
 		if mtype.NumOut() != 1 {
 			log.Println("method", mname, "has wrong number of outs:", mtype.NumOut())
 			continue
 		}
-		if returnType := mtype.Out(0); returnType != typeOfOsError {
-			log.Println("method", mname, "returns", returnType.String(), "not os.Error")
+		if returnType := mtype.Out(0); returnType != typeOfError {
+			log.Println("method", mname, "returns", returnType.String(), "not error")
 			continue
 		}
 		s.method[mname] = &methodType{method: method, ArgType: argType, ReplyType: replyType}
@@ -339,7 +338,7 @@ func (s *service) call(server *Server, sending *sync.Mutex, mtype *methodType, r
 	function := mtype.method.Func
 	// Invoke the method, providing a new value for the reply.
 	returnValues := function.Call([]reflect.Value{s.rcvr, argv, replyv})
-	// The return value for the method is an os.Error.
+	// The return value for the method is an error.
 	errInter := returnValues[0].Interface()
 	errmsg := ""
 	if errInter != nil {
diff --git a/src/pkg/runtime/error.go b/src/pkg/runtime/error.go
index 13dc52b32a..4b0ee4931e 100644
--- a/src/pkg/runtime/error.go
+++ b/src/pkg/runtime/error.go
@@ -10,7 +10,7 @@ type Error interface {
 
 	// RuntimeError is a no-op function but
 	// serves to distinguish types that are runtime
-	// errors from ordinary os.Errors: a type is a
+	// errors from ordinary errors: a type is a
 	// runtime error if it has a RuntimeError method.
 	RuntimeError()
 }
diff --git a/src/pkg/smtp/auth.go b/src/pkg/smtp/auth.go
index c4cdcb130d..10a757fc64 100644
--- a/src/pkg/smtp/auth.go
+++ b/src/pkg/smtp/auth.go
@@ -13,7 +13,7 @@ type Auth interface {
 	// and optionally data to include in the initial AUTH message
 	// sent to the server. It can return proto == "" to indicate
 	// that the authentication should be skipped.
-	// If it returns a non-nil os.Error, the SMTP client aborts
+	// If it returns a non-nil error, the SMTP client aborts
 	// the authentication attempt and closes the connection.
 	Start(server *ServerInfo) (proto string, toServer []byte, err error)
 
@@ -21,7 +21,7 @@ type Auth interface {
 	// the fromServer data. If more is true, the server expects a
 	// response, which Next should return as toServer; otherwise
 	// Next should return toServer == nil.
-	// If Next returns a non-nil os.Error, the SMTP client aborts
+	// If Next returns a non-nil error, the SMTP client aborts
 	// the authentication attempt and closes the connection.
 	Next(fromServer []byte, more bool) (toServer []byte, err error)
 }
diff --git a/src/pkg/tabwriter/tabwriter.go b/src/pkg/tabwriter/tabwriter.go
index 670e3c5390..d588b385d2 100644
--- a/src/pkg/tabwriter/tabwriter.go
+++ b/src/pkg/tabwriter/tabwriter.go
@@ -212,7 +212,7 @@ func (b *Writer) dump() {
 	print("\n")
 }
 
-// local error wrapper so we can distinguish os.Errors we want to return
+// local error wrapper so we can distinguish errors we want to return
 // as errors from genuine panics (which we don't want to return as errors)
 type osError struct {
 	err error
diff --git a/src/pkg/template/doc.go b/src/pkg/template/doc.go
index a52f32d91b..42f9e560be 100644
--- a/src/pkg/template/doc.go
+++ b/src/pkg/template/doc.go
@@ -117,7 +117,7 @@ An argument is a simple value, denoted by one of the following.
 		.Method
 	  The result is the value of invoking the method with dot as the
 	  receiver, dot.Method(). Such a method must have one return value (of
-	  any type) or two return values, the second of which is an os.Error.
+	  any type) or two return values, the second of which is an error.
 	  If it has two and the returned error is non-nil, execution terminates
 	  and an error is returned to the caller as the value of Execute.
 	  Method invocations may be chained and combined with fields and keys
@@ -159,7 +159,7 @@ passed as the last argument of the following command. The output of the final
 command in the pipeline is the value of the pipeline.
 
 The output of a command will be either one value or two values, the second of
-which has type os.Error. If that second value is present and evaluates to
+which has type error. If that second value is present and evaluates to
 non-nil, execution terminates and the error is returned to the caller of
 Execute.
 
diff --git a/src/pkg/template/exec.go b/src/pkg/template/exec.go
index 7850f6daf5..228477ce79 100644
--- a/src/pkg/template/exec.go
+++ b/src/pkg/template/exec.go
@@ -492,7 +492,7 @@ func (s *state) evalCall(dot, fun reflect.Value, name string, args []parse.Node,
 		argv[i] = final
 	}
 	result := fun.Call(argv)
-	// If we have an os.Error that is not nil, stop execution and return that error to the caller.
+	// If we have an error that is not nil, stop execution and return that error to the caller.
 	if len(result) == 2 && !result[1].IsNil() {
 		s.errorf("error calling %s: %s", name, result[1].Interface().(error))
 	}
diff --git a/src/pkg/template/exec_test.go b/src/pkg/template/exec_test.go
index 20839c3e34..e32de4d40f 100644
--- a/src/pkg/template/exec_test.go
+++ b/src/pkg/template/exec_test.go
@@ -158,7 +158,7 @@ func (t *T) MSort(m map[string]int) []string {
 	return keys
 }
 
-// EPERM returns a value and an os.Error according to its argument.
+// EPERM returns a value and an error according to its argument.
 func (t *T) EPERM(error bool) (bool, error) {
 	if error {
 		return true, os.EPERM
diff --git a/src/pkg/template/funcs.go b/src/pkg/template/funcs.go
index 59c2ee708c..26c3a6e848 100644
--- a/src/pkg/template/funcs.go
+++ b/src/pkg/template/funcs.go
@@ -17,7 +17,7 @@ import (
 
 // FuncMap is the type of the map defining the mapping from names to functions.
 // Each function must have either a single return value, or two return values of
-// which the second has type os.Error. If the second argument evaluates to non-nil
+// which the second has type error. If the second argument evaluates to non-nil
 // during execution, execution terminates and Execute returns an error.
 type FuncMap map[string]interface{}
 
@@ -68,7 +68,7 @@ func addFuncs(out, in FuncMap) {
 
 // goodFunc checks that the function or method has the right result signature.
 func goodFunc(typ reflect.Type) bool {
-	// We allow functions with 1 result or 2 results where the second is an os.Error.
+	// We allow functions with 1 result or 2 results where the second is an error.
 	switch {
 	case typ.NumOut() == 1:
 		return true
diff --git a/src/pkg/template/helper.go b/src/pkg/template/helper.go
index b7a9deeba9..a743a8326e 100644
--- a/src/pkg/template/helper.go
+++ b/src/pkg/template/helper.go
@@ -14,7 +14,7 @@ import (
 
 // Functions and methods to parse a single template.
 
-// Must is a helper that wraps a call to a function returning (*Template, os.Error)
+// Must is a helper that wraps a call to a function returning (*Template, error)
 // and panics if the error is non-nil. It is intended for use in variable initializations
 // such as
 //	var t = template.Must(template.New("name").Parse("text"))
@@ -66,7 +66,7 @@ func (t *Template) parseFileInSet(filename string, set *Set) (*Template, error)
 
 // Functions and methods to parse a set.
 
-// SetMust is a helper that wraps a call to a function returning (*Set, os.Error)
+// SetMust is a helper that wraps a call to a function returning (*Set, error)
 // and panics if the error is non-nil. It is intended for use in variable initializations
 // such as
 //	var s = template.SetMust(template.ParseSetFiles("file"))
diff --git a/src/pkg/utf8/string.go b/src/pkg/utf8/string.go
index ce430ba4f5..443decf056 100644
--- a/src/pkg/utf8/string.go
+++ b/src/pkg/utf8/string.go
@@ -4,6 +4,8 @@
 
 package utf8
 
+import "errors"
+
 // String wraps a regular string with a small structure that provides more
 // efficient indexing by code point index, as opposed to byte index.
 // Scanning incrementally forwards or backwards is O(1) per index operation
@@ -193,19 +195,5 @@ func (s *String) At(i int) rune {
 	return r
 }
 
-// We want the panic in At(i) to satisfy os.Error, because that's what
-// runtime panics satisfy, but we can't import os.  This is our solution.
-
-// error is the type of the error returned if a user calls String.At(i) with i out of range.
-// It satisfies os.Error and runtime.Error.
-type error_ string
-
-func (err error_) String() string {
-	return string(err)
-}
-
-func (err error_) RunTimeError() {
-}
-
-var outOfRange = error_("utf8.String: index out of range")
-var sliceOutOfRange = error_("utf8.String: slice index out of range")
+var outOfRange = errors.New("utf8.String: index out of range")
+var sliceOutOfRange = errors.New("utf8.String: slice index out of range")
-- 
2.50.0