scalar decoders

R=rsc
DELTA=897  (728 added, 14 deleted, 155 changed)
OCL=30955
CL=30955

src/pkg/gob/codec_test.go

@@ -11,6 +11,7 @@ import (
 	"testing";
 	"unsafe";
 )
+import "fmt" // TODO DELETE
 
 // Guarantee encoding format by comparing some encodings to hand-written values
 type EncodeT struct {
@@ -117,7 +118,7 @@ var floatResult = []byte{0x80, 0x40, 0xe2, 0x81, 0x40, 0xe2, 0x82, 0x40, 0xe2}
 // Do not run the machine yet; instead do individual instructions crafted by hand.
 func TestScalarEncInstructions(t *testing.T) {
 	var b = new(bytes.Buffer);
-	var state EncState;
+	state := new(EncState);
 
 	// bool
 	{
@@ -129,15 +130,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encBool, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(boolResult, b.Data()) {
 			t.Errorf("bool enc instructions: expected % x got % x", boolResult, b.Data())
 		}
@@ -153,15 +154,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encInt, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(signedResult, b.Data()) {
 			t.Errorf("int enc instructions: expected % x got % x", signedResult, b.Data())
 		}
@@ -177,15 +178,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encUint, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(unsignedResult, b.Data()) {
 			t.Errorf("uint enc instructions: expected % x got % x", unsignedResult, b.Data())
 		}
@@ -201,15 +202,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encInt, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(signedResult, b.Data()) {
 			t.Errorf("int8 enc instructions: expected % x got % x", signedResult, b.Data())
 		}
@@ -225,15 +226,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encUint, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(unsignedResult, b.Data()) {
 			t.Errorf("uint8 enc instructions: expected % x got % x", unsignedResult, b.Data())
 		}
@@ -249,15 +250,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encInt16, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(signedResult, b.Data()) {
 			t.Errorf("int16 enc instructions: expected % x got % x", signedResult, b.Data())
 		}
@@ -273,15 +274,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encUint16, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(unsignedResult, b.Data()) {
 			t.Errorf("uint16 enc instructions: expected % x got % x", unsignedResult, b.Data())
 		}
@@ -297,15 +298,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encInt32, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(signedResult, b.Data()) {
 			t.Errorf("int32 enc instructions: expected % x got % x", signedResult, b.Data())
 		}
@@ -321,15 +322,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encUint32, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(unsignedResult, b.Data()) {
 			t.Errorf("uint32 enc instructions: expected % x got % x", unsignedResult, b.Data())
 		}
@@ -345,15 +346,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encInt64, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(signedResult, b.Data()) {
 			t.Errorf("int64 enc instructions: expected % x got % x", signedResult, b.Data())
 		}
@@ -369,15 +370,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encUint, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(unsignedResult, b.Data()) {
 			t.Errorf("uint64 enc instructions: expected % x got % x", unsignedResult, b.Data())
 		}
@@ -393,15 +394,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encFloat, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(floatResult, b.Data()) {
 			t.Errorf("float enc instructions: expected % x got % x", floatResult, b.Data())
 		}
@@ -417,15 +418,15 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encFloat32, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(floatResult, b.Data()) {
 			t.Errorf("float32 enc instructions: expected % x got % x", floatResult, b.Data())
 		}
@@ -441,17 +442,453 @@ func TestScalarEncInstructions(t *testing.T) {
 		instr := &encInstr{ encFloat64, 0, 0, 0 };
 		state.w = b;
 		state.base = uintptr(unsafe.Pointer(&data));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 1;
 		instr.indir = 1;
 		instr.offset = uintptr(unsafe.Offsetof(data.b));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		instr.field = 2;
 		instr.indir = 2;
 		instr.offset = uintptr(unsafe.Offsetof(data.c));
-		instr.op(instr, &state);
+		instr.op(instr, state);
 		if !bytes.Equal(floatResult, b.Data()) {
 			t.Errorf("float64 enc instructions: expected % x got % x", floatResult, b.Data())
 		}
 	}
 }
+
+func expectField(n int, state *DecState, t *testing.T) {
+	v := int(DecodeUint(state));
+	if state.err != nil {
+		t.Fatalf("decoding field number %d: %v", n, state.err);
+	}
+	if v != n {
+		t.Fatalf("decoding field number %d, got %d", n, v);
+	}
+}
+
+// Test instruction execution for decoding.
+// Do not run the machine yet; instead do individual instructions crafted by hand.
+func TestScalarDecInstructions(t *testing.T) {
+	state := new(DecState);
+
+	// bool
+	{
+		b := bytes.NewBuffer(boolResult);
+		var data struct { a bool; b *bool; c **bool };
+		instr := &decInstr{ decBool, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != true {
+			t.Errorf("int a = %v not true", data.a)
+		}
+		if *data.b != true {
+			t.Errorf("int b = %v not true", *data.b)
+		}
+		if **data.c != true {
+			t.Errorf("int c = %v not true", **data.c)
+		}
+	}
+
+	// int
+	{
+		b := bytes.NewBuffer(signedResult);
+		var data struct { a int; b *int; c **int };
+		instr := &decInstr{ decInt, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// uint
+	{
+		b := bytes.NewBuffer(unsignedResult);
+		var data struct { a uint; b *uint; c **uint };
+		instr := &decInstr{ decUint, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// int8
+	{
+		b := bytes.NewBuffer(signedResult);
+		var data struct { a int8; b *int8; c **int8 };
+		instr := &decInstr{ decInt8, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// uint8
+	{
+		b := bytes.NewBuffer(unsignedResult);
+		var data struct { a uint8; b *uint8; c **uint8 };
+		instr := &decInstr{ decUint8, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// int16
+	{
+		b := bytes.NewBuffer(signedResult);
+		var data struct { a int16; b *int16; c **int16 };
+		instr := &decInstr{ decInt16, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// uint16
+	{
+		b := bytes.NewBuffer(unsignedResult);
+		var data struct { a uint16; b *uint16; c **uint16 };
+		instr := &decInstr{ decUint16, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// int32
+	{
+		b := bytes.NewBuffer(signedResult);
+		var data struct { a int32; b *int32; c **int32 };
+		instr := &decInstr{ decInt32, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// uint32
+	{
+		b := bytes.NewBuffer(unsignedResult);
+		var data struct { a uint32; b *uint32; c **uint32 };
+		instr := &decInstr{ decUint32, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// int64
+	{
+		b := bytes.NewBuffer(signedResult);
+		var data struct { a int64; b *int64; c **int64 };
+		instr := &decInstr{ decInt64, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// uint64
+	{
+		b := bytes.NewBuffer(unsignedResult);
+		var data struct { a uint64; b *uint64; c **uint64 };
+		instr := &decInstr{ decUint64, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// float
+	{
+		b := bytes.NewBuffer(floatResult);
+		var data struct { a float; b *float; c **float };
+		instr := &decInstr{ decFloat, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// float32
+	{
+		b := bytes.NewBuffer(floatResult);
+		var data struct { a float32; b *float32; c **float32 };
+		instr := &decInstr{ decFloat32, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+
+	// float64
+	{
+		b := bytes.NewBuffer(floatResult);
+		var data struct { a float64; b *float64; c **float64 };
+		instr := &decInstr{ decFloat64, 0, 0, 0 };
+		state.r = b;
+		state.base = uintptr(unsafe.Pointer(&data));
+		expectField(0, state, t);
+		instr.op(instr, state);
+		instr.field = 1;
+		instr.indir = 1;
+		instr.offset = uintptr(unsafe.Offsetof(data.b));
+		expectField(1, state, t);
+		instr.op(instr, state);
+		instr.field = 2;
+		instr.indir = 2;
+		instr.offset = uintptr(unsafe.Offsetof(data.c));
+		expectField(2, state, t);
+		instr.op(instr, state);
+		if data.a != 17 {
+			t.Errorf("int a = %v not 17", data.a)
+		}
+		if *data.b != 17 {
+			t.Errorf("int b = %v not 17", *data.b)
+		}
+		if **data.c != 17 {
+			t.Errorf("int c = %v not 17", **data.c)
+		}
+	}
+}

src/pkg/gob/decode.go

@@ -6,6 +6,7 @@ package gob
 
 import (
 	"io";
+	"math";
 	"os";
 	"unsafe";
 )
@@ -52,3 +53,283 @@ func DecodeInt(state *DecState) int64 {
 	}
 	return int64(x >> 1)
 }
+
+// The 'instructions' of the decoding machine
+type decInstr struct {
+	op	func(i *decInstr, state *DecState);
+	field		int;	// field number
+	indir	int;	// how many pointer indirections to reach the value in the struct
+	offset	uintptr;	// offset in the structure of the field to encode
+}
+
+// Since the encoder writes no zeros, if we arrive at a decoder we have
+// a value to extract and store.  The field number has already been read
+// (it's how we knew to call this decoder).
+// Each decoder is responsible for handling any indirections associated
+// with the data structure.  If any pointer so reached is nil, allocation must
+// be done.
+
+// Walk the pointer hierarchy, allocating if we find a nil.  Stop one before the end.
+func decIndirect(p unsafe.Pointer, indir int) unsafe.Pointer {
+	for ; indir > 1; indir-- {
+		if *(*unsafe.Pointer)(p) == nil {
+			// Allocation required
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(unsafe.Pointer));
+		}
+		p = *(*unsafe.Pointer)(p);
+	}
+	return p
+}
+
+func decBool(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := int(DecodeInt(state));
+	if state.err == nil {
+		*(*bool)(p) = v != 0;
+	}
+}
+
+func decInt(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := int(DecodeInt(state));
+	if state.err == nil {
+		*(*int)(p) = v;
+	}
+}
+
+func decUint(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := uint(DecodeUint(state));
+	if state.err == nil {
+		*(*uint)(p) = v;
+	}
+}
+
+func decInt8(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := int8(DecodeInt(state));
+	if state.err == nil {
+		*(*int8)(p) = v;
+	}
+}
+
+func decUint8(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := uint8(DecodeUint(state));
+	if state.err == nil {
+		*(*uint8)(p) = v;
+	}
+}
+
+func decInt16(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := int16(DecodeInt(state));
+	if state.err == nil {
+		*(*int16)(p) = v;
+	}
+}
+
+func decUint16(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := uint16(DecodeUint(state));
+	if state.err == nil {
+		*(*uint16)(p) = v;
+	}
+}
+
+func decInt32(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := int32(DecodeInt(state));
+	if state.err == nil {
+		*(*int32)(p) = v;
+	}
+}
+
+func decUint32(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := uint32(DecodeUint(state));
+	if state.err == nil {
+		*(*uint32)(p) = v;
+	}
+}
+
+func decInt64(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := int64(DecodeInt(state));
+	if state.err == nil {
+		*(*int64)(p) = v;
+	}
+}
+
+func decUint64(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := uint64(DecodeUint(state));
+	if state.err == nil {
+		*(*uint64)(p) = v;
+	}
+}
+
+// Floating-point numbers are transmitted as uint64s holding the bits
+// of the underlying representation.  They are sent byte-reversed, with
+// the exponent end coming out first, so integer floating point numbers
+// (for example) transmit more compactly.  This routine does the
+// unswizzling.
+func floatFromBits(u uint64) float64 {
+	var v uint64;
+	for i := 0; i < 8; i++ {
+		v <<= 8;
+		v |= u & 0xFF;
+		u >>= 8;
+	}
+	return math.Float64frombits(v);
+}
+
+func decFloat(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := float(floatFromBits(uint64(DecodeUint(state))));
+	if state.err == nil {
+		*(*float)(p) = v;
+	}
+}
+
+func decFloat32(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := float32(floatFromBits(uint64(DecodeUint(state))));
+	if state.err == nil {
+		*(*float32)(p) = v;
+	}
+}
+
+func decFloat64(i *decInstr, state *DecState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if i.indir > 1 {
+			p = decIndirect(p, i.indir);
+		}
+		if *(*unsafe.Pointer)(p) == nil {
+			*(*unsafe.Pointer)(p) = unsafe.Pointer(new(int));
+			p = *(*unsafe.Pointer)(p);
+		}
+	}
+	v := floatFromBits(uint64(DecodeUint(state)));
+	if state.err == nil {
+		*(*float64)(p) = v;
+	}
+}

src/pkg/gob/encode.go

@@ -67,11 +67,20 @@ type encInstr struct {
 // Otherwise, the output (for a scalar) is the field number, as an encoded integer,
 // followed by the field data in its appropriate format.
 
-func encBool(i *encInstr, state *EncState) {
+func encIndirect(p unsafe.Pointer, indir int) unsafe.Pointer {
-	p := unsafe.Pointer(state.base+i.offset);
+	for ; indir > 0; indir-- {
-	for indir := i.indir; indir > 0; indir-- {
 		p = *(*unsafe.Pointer)(p);
 		if p == nil {
+			return unsafe.Pointer(nil)
+		}
+	}
+	return p
+}
+
+func encBool(i *encInstr, state *EncState) {
+	p := unsafe.Pointer(state.base+i.offset);
+	if i.indir > 0 {
+		if p = encIndirect(p, i.indir); p == nil {
 			return
 		}
 	}
@@ -84,9 +93,8 @@ func encBool(i *encInstr, state *EncState) {
 
 func encInt(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -99,9 +107,8 @@ func encInt(i *encInstr, state *EncState) {
 
 func encUint(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -114,9 +121,8 @@ func encUint(i *encInstr, state *EncState) {
 
 func encInt8(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -129,9 +135,8 @@ func encInt8(i *encInstr, state *EncState) {
 
 func encUint8(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -144,9 +149,8 @@ func encUint8(i *encInstr, state *EncState) {
 
 func encInt16(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -159,9 +163,8 @@ func encInt16(i *encInstr, state *EncState) {
 
 func encUint16(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -174,9 +177,8 @@ func encUint16(i *encInstr, state *EncState) {
 
 func encInt32(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -189,9 +191,8 @@ func encInt32(i *encInstr, state *EncState) {
 
 func encUint32(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -204,9 +205,8 @@ func encUint32(i *encInstr, state *EncState) {
 
 func encInt64(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -219,9 +219,8 @@ func encInt64(i *encInstr, state *EncState) {
 
 func encUint64(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -250,9 +249,8 @@ func floatBits(f float64) uint64 {
 
 func encFloat(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -266,9 +264,8 @@ func encFloat(i *encInstr, state *EncState) {
 
 func encFloat32(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}
@@ -282,9 +279,8 @@ func encFloat32(i *encInstr, state *EncState) {
 
 func encFloat64(i *encInstr, state *EncState) {
 	p := unsafe.Pointer(state.base+i.offset);
-	for indir := i.indir; indir > 0; indir-- {
+	if i.indir > 0 {
-		p = *(*unsafe.Pointer)(p);
+		if p = encIndirect(p, i.indir); p == nil {
-		if p == nil {
 			return
 		}
 	}