handle unsupported types safely.

R=rsc
DELTA=154  (71 added, 6 deleted, 77 changed)
OCL=32483
CL=32492

src/pkg/gob/codec_test.go

@@ -564,7 +564,7 @@ func TestEndToEnd(t *testing.T) {
 	b := new(bytes.Buffer);
 	encode(b, t1);
 	var _t1 T1;
-	decode(b, getTypeInfo(reflect.Typeof(_t1)).id, &_t1);
+	decode(b, getTypeInfoNoError(reflect.Typeof(_t1)).id, &_t1);
 	if !reflect.DeepEqual(t1, &_t1) {
 		t.Errorf("encode expected %v got %v", *t1, _t1);
 	}
@@ -580,7 +580,7 @@ func TestOverflow(t *testing.T) {
 	}
 	var it inputT;
 	var err os.Error;
-	id := getTypeInfo(reflect.Typeof(it)).id;
+	id := getTypeInfoNoError(reflect.Typeof(it)).id;
 	b := new(bytes.Buffer);
 
 	// int8
@@ -733,7 +733,7 @@ func TestNesting(t *testing.T) {
 	b := new(bytes.Buffer);
 	encode(b, rt);
 	var drt RT;
-	decode(b, getTypeInfo(reflect.Typeof(drt)).id, &drt);
+	decode(b, getTypeInfoNoError(reflect.Typeof(drt)).id, &drt);
 	if drt.a != rt.a {
 		t.Errorf("nesting: encode expected %v got %v", *rt, drt);
 	}
@@ -775,7 +775,7 @@ func TestAutoIndirection(t *testing.T) {
 	b := new(bytes.Buffer);
 	encode(b, t1);
 	var t0 T0;
-	t0Id := getTypeInfo(reflect.Typeof(t0)).id;
+	t0Id := getTypeInfoNoError(reflect.Typeof(t0)).id;
 	decode(b, t0Id, &t0);
 	if t0.a != 17 || t0.b != 177 || t0.c != 1777 || t0.d != 17777 {
 		t.Errorf("t1->t0: expected {17 177 1777 17777}; got %v", t0);
@@ -800,7 +800,7 @@ func TestAutoIndirection(t *testing.T) {
 	b.Reset();
 	encode(b, t0);
 	t1 = T1{};
-	t1Id := getTypeInfo(reflect.Typeof(t1)).id;
+	t1Id := getTypeInfoNoError(reflect.Typeof(t1)).id;
 	decode(b, t1Id, &t1);
 	if t1.a != 17 || *t1.b != 177 || **t1.c != 1777 || ***t1.d != 17777 {
 		t.Errorf("t0->t1 expected {17 177 1777 17777}; got {%d %d %d %d}", t1.a, *t1.b, **t1.c, ***t1.d);
@@ -810,7 +810,7 @@ func TestAutoIndirection(t *testing.T) {
 	b.Reset();
 	encode(b, t0);
 	t2 = T2{};
-	t2Id := getTypeInfo(reflect.Typeof(t2)).id;
+	t2Id := getTypeInfoNoError(reflect.Typeof(t2)).id;
 	decode(b, t2Id, &t2);
 	if ***t2.a != 17 || **t2.b != 177 || *t2.c != 1777 || t2.d != 17777 {
 		t.Errorf("t0->t2 expected {17 177 1777 17777}; got {%d %d %d %d}", ***t2.a, **t2.b, *t2.c, t2.d);
@@ -848,7 +848,7 @@ func TestReorderedFields(t *testing.T) {
 	rt0.c = 3.14159;
 	b := new(bytes.Buffer);
 	encode(b, rt0);
-	rt0Id := getTypeInfo(reflect.Typeof(rt0)).id;
+	rt0Id := getTypeInfoNoError(reflect.Typeof(rt0)).id;
 	var rt1 RT1;
 	// Wire type is RT0, local type is RT1.
 	decode(b, rt0Id, &rt1);
@@ -886,7 +886,7 @@ func TestIgnoredFields(t *testing.T) {
 
 	b := new(bytes.Buffer);
 	encode(b, it0);
-	rt0Id := getTypeInfo(reflect.Typeof(it0)).id;
+	rt0Id := getTypeInfoNoError(reflect.Typeof(it0)).id;
 	var rt1 RT1;
 	// Wire type is IT0, local type is RT1.
 	err := decode(b, rt0Id, &rt1);
@@ -897,3 +897,20 @@ func TestIgnoredFields(t *testing.T) {
 		t.Errorf("rt1->rt0: expected %v; got %v", it0, rt1);
 	}
 }
+
+type Bad0 struct {
+	inter interface{};
+	c float;
+}
+
+func TestInvalidField(t *testing.T) {
+	var bad0 Bad0;
+	bad0.inter = 17;
+	b := new(bytes.Buffer);
+	err := encode(b, &bad0);
+	if err == nil {
+		t.Error("expected error; got none")
+	} else if strings.Index(err.String(), "interface") < 0 {
+		t.Error("expected type error; got", err)
+	}
+}

src/pkg/gob/encode.go

@@ -335,11 +335,11 @@ var encOpMap = map[reflect.Type] encOp {
 	valueKind("x"): encString,
 }
 
-func getEncEngine(rt reflect.Type) *encEngine
+func getEncEngine(rt reflect.Type) (*encEngine, os.Error)
 
 // Return the encoding op for the base type under rt and
 // the indirection count to reach it.
-func encOpFor(rt reflect.Type) (encOp, int) {
+func encOpFor(rt reflect.Type) (encOp, int, os.Error) {
 	typ, indir := indirect(rt);
 	op, ok := encOpMap[reflect.Typeof(typ)];
 	if !ok {
@@ -352,7 +352,10 @@ func encOpFor(rt reflect.Type) (encOp, int) {
 				break;
 			}
 			// Slices have a header; we decode it to find the underlying array.
-			elemOp, indir := encOpFor(t.Elem());
+			elemOp, indir, err := encOpFor(t.Elem());
+			if err != nil {
+				return nil, 0, err
+			}
 			op = func(i *encInstr, state *encoderState, p unsafe.Pointer) {
 				slice := (*reflect.SliceHeader)(p);
 				if slice.Len == 0 {
@@ -363,15 +366,21 @@ func encOpFor(rt reflect.Type) (encOp, int) {
 			};
 		case *reflect.ArrayType:
 			// True arrays have size in the type.
-			elemOp, indir := encOpFor(t.Elem());
+			elemOp, indir, err := encOpFor(t.Elem());
+			if err != nil {
+				return nil, 0, err
+			}
 			op = func(i *encInstr, state *encoderState, p unsafe.Pointer) {
 				state.update(i);
 				state.err = encodeArray(state.b, uintptr(p), elemOp, t.Elem().Size(), t.Len(), indir);
 			};
 		case *reflect.StructType:
 			// Generate a closure that calls out to the engine for the nested type.
-			engine := getEncEngine(typ);
-			info := getTypeInfo(typ);
+			engine, err := getEncEngine(typ);
+			if err != nil {
+				return nil, 0, err
+			}
+			info := getTypeInfoNoError(typ);
 			op = func(i *encInstr, state *encoderState, p unsafe.Pointer) {
 				state.update(i);
 				// indirect through info to delay evaluation for recursive structs
@@ -380,13 +389,13 @@ func encOpFor(rt reflect.Type) (encOp, int) {
 		}
 	}
 	if op == nil {
-		panicln("can't happen: encode type", rt.String());
+		return op, indir, os.ErrorString("gob enc: can't happen: encode type" + rt.String());
 	}
-	return op, indir
+	return op, indir, nil
 }
 
 // The local Type was compiled from the actual value, so we know it's compatible.
-func compileEnc(rt reflect.Type) *encEngine {
+func compileEnc(rt reflect.Type) (*encEngine, os.Error) {
 	srt, ok := rt.(*reflect.StructType);
 	if !ok {
 		panicln("can't happen: non-struct");
@@ -395,23 +404,29 @@ func compileEnc(rt reflect.Type) *encEngine {
 	engine.instr = make([]encInstr, srt.NumField()+1);	// +1 for terminator
 	for fieldnum := 0; fieldnum < srt.NumField(); fieldnum++ {
 		f := srt.Field(fieldnum);
-		op, indir := encOpFor(f.Type);
+		op, indir, err := encOpFor(f.Type);
+		if err != nil {
+			return nil, err
+		}
 		engine.instr[fieldnum] = encInstr{op, fieldnum, indir, uintptr(f.Offset)};
 	}
 	engine.instr[srt.NumField()] = encInstr{encStructTerminator, 0, 0, 0};
-	return engine;
+	return engine, nil;
 }
 
 // typeLock must be held (or we're in initialization and guaranteed single-threaded).
 // The reflection type must have all its indirections processed out.
-func getEncEngine(rt reflect.Type) *encEngine {
-	info := getTypeInfo(rt);
+func getEncEngine(rt reflect.Type) (*encEngine, os.Error) {
+	info, err := getTypeInfo(rt);
+	if err != nil {
+		return nil, err
+	}
 	if info.encoder == nil {
 		// mark this engine as underway before compiling to handle recursive types.
 		info.encoder = new(encEngine);
-		info.encoder = compileEnc(rt);
+		info.encoder, err = compileEnc(rt);
 	}
-	return info.encoder;
+	return info.encoder, err;
 }
 
 func encode(b *bytes.Buffer, e interface{}) os.Error {
@@ -425,7 +440,10 @@ func encode(b *bytes.Buffer, e interface{}) os.Error {
 		return os.ErrorString("gob: encode can't handle " + v.Type().String())
 	}
 	typeLock.Lock();
-	engine := getEncEngine(rt);
+	engine, err := getEncEngine(rt);
 	typeLock.Unlock();
+	if err != nil {
+		return err
+	}
 	return encodeStruct(engine, b, v.Addr());
 }

src/pkg/gob/encoder.go

@@ -73,7 +73,7 @@
 
 	Maps are not supported yet, but they will be.  Interfaces, functions, and channels
 	cannot be sent in a gob.  Attempting to encode a value that contains one will
-	fail.  (TODO(r): fix this - it panics now.)
+	fail.
 
 	The rest of this comment documents the encoding, details that are not important
 	for most users.  Details are presented bottom-up.
@@ -267,8 +267,12 @@ func (enc *Encoder) sendType(origt reflect.Type) {
 
 	// Need to send it.
 	typeLock.Lock();
-	info := getTypeInfo(rt);
+	info, err := getTypeInfo(rt);
 	typeLock.Unlock();
+	if err != nil {
+		enc.state.err = err;
+		return;
+	}
 	// Send the pair (-id, type)
 	// Id:
 	encodeInt(enc.state, -int64(info.id));
@@ -285,6 +289,7 @@ func (enc *Encoder) sendType(origt reflect.Type) {
 	for i := 0; i < st.NumField(); i++ {
 		enc.sendType(st.Field(i).Type);
 	}
+	return
 }
 
 // Encode transmits the data item represented by the empty interface value,

src/pkg/gob/encoder_test.go

@@ -69,7 +69,7 @@ func TestBasicEncoder(t *testing.T) {
 	if err != nil {
 		t.Fatal("error decoding ET1 type:", err);
 	}
-	info := getTypeInfo(reflect.Typeof(ET1{}));
+	info := getTypeInfoNoError(reflect.Typeof(ET1{}));
 	trueWire1 := &wireType{s: info.id.gobType().(*structType)};
 	if !reflect.DeepEqual(wire1, trueWire1) {
 		t.Fatalf("invalid wireType for ET1: expected %+v; got %+v\n", *trueWire1, *wire1);
@@ -90,7 +90,7 @@ func TestBasicEncoder(t *testing.T) {
 	if err != nil {
 		t.Fatal("error decoding ET2 type:", err);
 	}
-	info = getTypeInfo(reflect.Typeof(ET2{}));
+	info = getTypeInfoNoError(reflect.Typeof(ET2{}));
 	trueWire2 := &wireType{s: info.id.gobType().(*structType)};
 	if !reflect.DeepEqual(wire2, trueWire2) {
 		t.Fatalf("invalid wireType for ET2: expected %+v; got %+v\n", *trueWire2, *wire2);
@@ -107,7 +107,7 @@ func TestBasicEncoder(t *testing.T) {
 	}
 	// 8) The value of et1
 	newEt1 := new(ET1);
-	et1Id := getTypeInfo(reflect.Typeof(*newEt1)).id;
+	et1Id := getTypeInfoNoError(reflect.Typeof(*newEt1)).id;
 	err = decode(b, et1Id, newEt1);
 	if err != nil {
 		t.Fatal("error decoding ET1 value:", err);

src/pkg/gob/type.go

@@ -202,7 +202,7 @@ func newStructType(name string) *structType {
 }
 
 // Construction
-func newType(name string, rt reflect.Type) gobType
+func getType(name string, rt reflect.Type) (gobType, os.Error)
 
 // Step through the indirections on a type to discover the base type.
 // Return the number of indirections.
@@ -219,55 +219,63 @@ func indirect(t reflect.Type) (rt reflect.Type, count int) {
 	return;
 }
 
-func newTypeObject(name string, rt reflect.Type) gobType {
+func newTypeObject(name string, rt reflect.Type) (gobType, os.Error) {
 	switch t := rt.(type) {
 	// All basic types are easy: they are predefined.
 	case *reflect.BoolType:
-		return tBool.gobType()
+		return tBool.gobType(), nil
 
 	case *reflect.IntType:
-		return tInt.gobType()
+		return tInt.gobType(), nil
 	case *reflect.Int8Type:
-		return tInt.gobType()
+		return tInt.gobType(), nil
 	case *reflect.Int16Type:
-		return tInt.gobType()
+		return tInt.gobType(), nil
 	case *reflect.Int32Type:
-		return tInt.gobType()
+		return tInt.gobType(), nil
 	case *reflect.Int64Type:
-		return tInt.gobType()
+		return tInt.gobType(), nil
 
 	case *reflect.UintType:
-		return tUint.gobType()
+		return tUint.gobType(), nil
 	case *reflect.Uint8Type:
-		return tUint.gobType()
+		return tUint.gobType(), nil
 	case *reflect.Uint16Type:
-		return tUint.gobType()
+		return tUint.gobType(), nil
 	case *reflect.Uint32Type:
-		return tUint.gobType()
+		return tUint.gobType(), nil
 	case *reflect.Uint64Type:
-		return tUint.gobType()
+		return tUint.gobType(), nil
 	case *reflect.UintptrType:
-		return tUint.gobType()
+		return tUint.gobType(), nil
 
 	case *reflect.FloatType:
-		return tFloat.gobType()
+		return tFloat.gobType(), nil
 	case *reflect.Float32Type:
-		return tFloat.gobType()
+		return tFloat.gobType(), nil
 	case *reflect.Float64Type:
-		return tFloat.gobType()
+		return tFloat.gobType(), nil
 
 	case *reflect.StringType:
-		return tString.gobType()
+		return tString.gobType(), nil
 
 	case *reflect.ArrayType:
-		return newArrayType(name, newType("", t.Elem()), t.Len());
+		gt, err := getType("", t.Elem());
+		if err != nil {
+			return nil, err
+		}
+		return newArrayType(name, gt, t.Len()), nil;
 
 	case *reflect.SliceType:
 		// []byte == []uint8 is a special case
 		if _, ok := t.Elem().(*reflect.Uint8Type); ok {
-			return tBytes.gobType()
+			return tBytes.gobType(), nil
+		}
+		gt, err := getType(t.Elem().Name(), t.Elem());
+		if err != nil {
+			return nil, err
 		}
-		return newSliceType(name, newType(t.Elem().Name(), t.Elem()));
+		return newSliceType(name, gt), nil;
 
 	case *reflect.StructType:
 		// Install the struct type itself before the fields so recursive
@@ -283,18 +291,24 @@ func newTypeObject(name string, rt reflect.Type) gobType {
 			if tname == "" {
 				tname = f.Type.String();
 			}
-			field[i] =  &fieldType{ f.Name, newType(tname, f.Type).id() };
+			gt, err := getType(tname, f.Type);
+			if err != nil {
+				return nil, err
+			}
+			field[i] =  &fieldType{ f.Name, gt.id() };
 		}
 		strType.field = field;
-		return strType;
+		return strType, nil;
 
 	default:
-		panicln("gob NewTypeObject can't handle type", rt.String());	// TODO(r): panic?
+		return nil, os.ErrorString("gob NewTypeObject can't handle type: " + rt.String());
 	}
-	return nil
+	return nil, nil
 }
 
-func newType(name string, rt reflect.Type) gobType {
+// getType returns the Gob type describing the given reflect.Type.
+// typeLock must be held.
+func getType(name string, rt reflect.Type) (gobType, os.Error) {
 	// Flatten the data structure by collapsing out pointers
 	for {
 		pt, ok := rt.(*reflect.PtrType);
@@ -305,19 +319,13 @@ func newType(name string, rt reflect.Type) gobType {
 	}
 	typ, present := types[rt];
 	if present {
-		return typ
+		return typ, nil
 	}
-	typ = newTypeObject(name, rt);
-	types[rt] = typ;
-	return typ
-}
-
-// getType returns the Gob type describing the given reflect.Type.
-// typeLock must be held.
-func getType(name string, rt reflect.Type) gobType {
-	// Set lock; all code running under here is synchronized.
-	t := newType(name, rt);
-	return t;
+	typ, err := newTypeObject(name, rt);
+	if err == nil {
+		types[rt] = typ
+	}
+	return typ, err
 }
 
 func checkId(want, got typeId) {
@@ -371,7 +379,7 @@ var typeInfoMap = make(map[reflect.Type] *typeInfo)	// protected by typeLock
 
 // The reflection type must have all its indirections processed out.
 // typeLock must be held.
-func getTypeInfo(rt reflect.Type) *typeInfo {
+func getTypeInfo(rt reflect.Type) (*typeInfo, os.Error) {
 	if pt, ok := rt.(*reflect.PtrType); ok {
 		panicln("pointer type in getTypeInfo:", rt.String())
 	}
@@ -379,12 +387,25 @@ func getTypeInfo(rt reflect.Type) *typeInfo {
 	if !ok {
 		info = new(typeInfo);
 		name := rt.Name();
-		info.id = getType(name, rt).id();
+		gt, err := getType(name, rt);
+		if err != nil {
+			return nil, err
+		}
+		info.id = gt.id();
 		// assume it's a struct type
 		info.wire = &wireType{info.id.gobType().(*structType)};
 		typeInfoMap[rt] = info;
 	}
-	return info;
+	return info, nil;
+}
+
+// Called only when a panic is acceptable and unexpected.
+func getTypeInfoNoError(rt reflect.Type) *typeInfo {
+	t, err := getTypeInfo(rt);
+	if err != nil {
+		panicln("getTypeInfo:", err.String());
+	}
+	return t
 }
 
 func init() {
@@ -396,9 +417,9 @@ func init() {
 	// The string for tBytes is "bytes" not "[]byte" to signify its specialness.
 	tBytes = bootstrapType("bytes", make([]byte, 0), 5);
 	tString= bootstrapType("string", "", 6);
-	tWireType = getTypeInfo(reflect.Typeof(wireType{})).id;
+	tWireType = getTypeInfoNoError(reflect.Typeof(wireType{})).id;
 	checkId(7, tWireType);
-	checkId(8, getTypeInfo(reflect.Typeof(structType{})).id);
-	checkId(9, getTypeInfo(reflect.Typeof(commonType{})).id);
-	checkId(10, getTypeInfo(reflect.Typeof(fieldType{})).id);
+	checkId(8, getTypeInfoNoError(reflect.Typeof(structType{})).id);
+	checkId(9, getTypeInfoNoError(reflect.Typeof(commonType{})).id);
+	checkId(10, getTypeInfoNoError(reflect.Typeof(fieldType{})).id);
 }

src/pkg/gob/type_test.go

@@ -27,7 +27,11 @@ var basicTypes = []typeT {
 func getTypeUnlocked(name string, rt reflect.Type) gobType {
 	typeLock.Lock();
 	defer typeLock.Unlock();
-	return getType(name, rt);
+	t, err := getType(name, rt);
+	if err != nil {
+		panicln("getTypeUnlocked:", err.String())
+	}
+	return t;
 }
 
 // Sanity checks