libgo: update to Go1.10beta1

    
    Update the Go library to the 1.10beta1 release.
    
    Requires a few changes to the compiler for modifications to the map
    runtime code, and to handle some nowritebarrier cases in the runtime.
    
    Reviewed-on: https://go-review.googlesource.com/86455

gotools/:
	* Makefile.am (go_cmd_vet_files): New variable.
	(go_cmd_buildid_files, go_cmd_test2json_files): New variables.
	(s-zdefaultcc): Change from constants to functions.
	(noinst_PROGRAMS): Add vet, buildid, and test2json.
	(cgo$(EXEEXT)): Link against $(LIBGOTOOL).
	(vet$(EXEEXT)): New target.
	(buildid$(EXEEXT)): New target.
	(test2json$(EXEEXT)): New target.
	(install-exec-local): Install all $(noinst_PROGRAMS).
	(uninstall-local): Uninstasll all $(noinst_PROGRAMS).
	(check-go-tool): Depend on $(noinst_PROGRAMS).  Copy down
	objabi.go.
	(check-runtime): Depend on $(noinst_PROGRAMS).
	(check-cgo-test, check-carchive-test): Likewise.
	(check-vet): New target.
	(check): Depend on check-vet.  Look at cmd_vet-testlog.
	(.PHONY): Add check-vet.
	* Makefile.in: Rebuild.

From-SVN: r256365

1 files changed, 40 insertions, 12 deletions

diff --git a/libgo/go/encoding/json/decode.go b/libgo/go/encoding/json/decode.go
index 420a07e..536f25d 100644
--- a/libgo/go/encoding/json/decode.go
+++ b/libgo/go/encoding/json/decode.go
@@ -44,8 +44,9 @@ import (
 //
 // To unmarshal JSON into a struct, Unmarshal matches incoming object
 // keys to the keys used by Marshal (either the struct field name or its tag),
-// preferring an exact match but also accepting a case-insensitive match.
-// Unmarshal will only set exported fields of the struct.
+// preferring an exact match but also accepting a case-insensitive match. By
+// default, object keys which don't have a corresponding struct field are
+// ignored (see Decoder.DisallowUnknownFields for an alternative).
 //
 // To unmarshal JSON into an interface value,
 // Unmarshal stores one of these in the interface value:
@@ -138,7 +139,8 @@ func (e *UnmarshalTypeError) Error() string {
 
 // An UnmarshalFieldError describes a JSON object key that
 // led to an unexported (and therefore unwritable) struct field.
-// (No longer used; kept for compatibility.)
+//
+// Deprecated: No longer used; kept for compatibility.
 type UnmarshalFieldError struct {
 	Key   string
 	Type  reflect.Type
@@ -274,8 +276,9 @@ type decodeState struct {
 		Struct string
 		Field  string
 	}
-	savedError error
-	useNumber  bool
+	savedError            error
+	useNumber             bool
+	disallowUnknownFields bool
 }
 
 // errPhase is used for errors that should not happen unless
@@ -508,7 +511,7 @@ func (d *decodeState) array(v reflect.Value) {
 	switch v.Kind() {
 	case reflect.Interface:
 		if v.NumMethod() == 0 {
-			// Decoding into nil interface?  Switch to non-reflect code.
+			// Decoding into nil interface? Switch to non-reflect code.
 			v.Set(reflect.ValueOf(d.arrayInterface()))
 			return
 		}
@@ -612,7 +615,7 @@ func (d *decodeState) object(v reflect.Value) {
 	}
 	v = pv
 
-	// Decoding into nil interface?  Switch to non-reflect code.
+	// Decoding into nil interface? Switch to non-reflect code.
 	if v.Kind() == reflect.Interface && v.NumMethod() == 0 {
 		v.Set(reflect.ValueOf(d.objectInterface()))
 		return
@@ -704,6 +707,19 @@ func (d *decodeState) object(v reflect.Value) {
 				for _, i := range f.index {
 					if subv.Kind() == reflect.Ptr {
 						if subv.IsNil() {
+							// If a struct embeds a pointer to an unexported type,
+							// it is not possible to set a newly allocated value
+							// since the field is unexported.
+							//
+							// See https://golang.org/issue/21357
+							if !subv.CanSet() {
+								d.saveError(fmt.Errorf("json: cannot set embedded pointer to unexported struct: %v", subv.Type().Elem()))
+								// Invalidate subv to ensure d.value(subv) skips over
+								// the JSON value without assigning it to subv.
+								subv = reflect.Value{}
+								destring = false
+								break
+							}
 							subv.Set(reflect.New(subv.Type().Elem()))
 						}
 						subv = subv.Elem()
@@ -712,6 +728,8 @@ func (d *decodeState) object(v reflect.Value) {
 				}
 				d.errorContext.Field = f.name
 				d.errorContext.Struct = v.Type().Name()
+			} else if d.disallowUnknownFields {
+				d.saveError(fmt.Errorf("json: unknown field %q", key))
 			}
 		}
 
@@ -1143,11 +1161,21 @@ func getu4(s []byte) rune {
 	if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
 		return -1
 	}
-	r, err := strconv.ParseUint(string(s[2:6]), 16, 64)
-	if err != nil {
-		return -1
+	var r rune
+	for _, c := range s[2:6] {
+		switch {
+		case '0' <= c && c <= '9':
+			c = c - '0'
+		case 'a' <= c && c <= 'f':
+			c = c - 'a' + 10
+		case 'A' <= c && c <= 'F':
+			c = c - 'A' + 10
+		default:
+			return -1
+		}
+		r = r*16 + rune(c)
 	}
-	return rune(r)
+	return r
 }
 
 // unquote converts a quoted JSON string literal s into an actual string t.
@@ -1190,7 +1218,7 @@ func unquoteBytes(s []byte) (t []byte, ok bool) {
 	b := make([]byte, len(s)+2*utf8.UTFMax)
 	w := copy(b, s[0:r])
 	for r < len(s) {
-		// Out of room?  Can only happen if s is full of
+		// Out of room? Can only happen if s is full of
 		// malformed UTF-8 and we're replacing each
 		// byte with RuneError.
 		if w >= len(b)-2*utf8.UTFMax {