flag: allow hexadecimal and octal input for integer flags.

R=r
CC=golang-dev
https://golang.org/cl/4182043

src/pkg/flag/flag.go

@@ -96,7 +96,7 @@ func newIntValue(val int, p *int) *intValue {
 }
 
 func (i *intValue) Set(s string) bool {
-	v, err := strconv.Atoi(s)
+	v, err := strconv.Btoi64(s, 0)
 	*i = intValue(v)
 	return err == nil
 }
@@ -112,7 +112,7 @@ func newInt64Value(val int64, p *int64) *int64Value {
 }
 
 func (i *int64Value) Set(s string) bool {
-	v, err := strconv.Atoi64(s)
+	v, err := strconv.Btoi64(s, 0)
 	*i = int64Value(v)
 	return err == nil
 }
@@ -128,7 +128,7 @@ func newUintValue(val uint, p *uint) *uintValue {
 }
 
 func (i *uintValue) Set(s string) bool {
-	v, err := strconv.Atoui(s)
+	v, err := strconv.Btoui64(s, 0)
 	*i = uintValue(v)
 	return err == nil
 }
@@ -144,7 +144,7 @@ func newUint64Value(val uint64, p *uint64) *uint64Value {
 }
 
 func (i *uint64Value) Set(s string) bool {
-	v, err := strconv.Atoui64(s)
+	v, err := strconv.Btoui64(s, 0)
 	*i = uint64Value(v)
 	return err == nil
 }

src/pkg/flag/flag_test.go

@@ -106,7 +106,7 @@ func TestParse(t *testing.T) {
 		"-bool",
 		"-bool2=true",
 		"--int", "22",
-		"--int64", "23",
+		"--int64", "0x23",
 		"-uint", "24",
 		"--uint64", "25",
 		"-string", "hello",
@@ -125,8 +125,8 @@ func TestParse(t *testing.T) {
 	if *intFlag != 22 {
 		t.Error("int flag should be 22, is ", *intFlag)
 	}
-	if *int64Flag != 23 {
-		t.Error("int64 flag should be 23, is ", *int64Flag)
+	if *int64Flag != 0x23 {
+		t.Error("int64 flag should be 0x23, is ", *int64Flag)
 	}
 	if *uintFlag != 24 {
 		t.Error("uint flag should be 24, is ", *uintFlag)