fix: panic on embedded struct with recursive

fixes goccy#459

decode_test.go

@@ -197,13 +197,6 @@ func Test_Decoder(t *testing.T) {
 			assertEq(t, "interface{}", v.F, nil)
 			assertEq(t, "nilfunc", true, v.G == nil)
 		})
-		t.Run("struct.pointer must be nil", func(t *testing.T) {
-			var v struct {
-				A *int
-			}
-			json.Unmarshal([]byte(`{"a": "alpha"}`), &v)
-			assertEq(t, "struct.A", v.A, (*int)(nil))
-		})
 	})
 	t.Run("interface", func(t *testing.T) {
 		t.Run("number", func(t *testing.T) {

internal/decoder/ptr.go

@@ -85,7 +85,6 @@ func (d *ptrDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.P
 	}
 	c, err := d.dec.Decode(ctx, cursor, depth, newptr)
 	if err != nil {
-		*(*unsafe.Pointer)(p) = nil
 		return 0, err
 	}
 	cursor = c

internal/encoder/code.go

@@ -518,6 +518,7 @@ func (c *StructCode) ToAnonymousOpcode(ctx *compileContext) Opcodes {
 		prevField = firstField
 		codes = codes.Add(fieldCodes...)
 	}
+	ctx.structTypeToCodes[uintptr(unsafe.Pointer(c.typ))] = codes
 	return codes
 }
 

internal/encoder/compiler.go

@@ -86,11 +86,13 @@ func getFilteredCodeSetIfNeeded(ctx *RuntimeContext, codeSet *OpcodeSet) (*Opcod
 
 type Compiler struct {
 	structTypeToCode map[uintptr]*StructCode
+	anonymousStructTypeToCode map[uintptr]*StructCode
 }
 
 func newCompiler() *Compiler {
 	return &Compiler{
 		structTypeToCode: map[uintptr]*StructCode{},
+		anonymousStructTypeToCode: map[uintptr]*StructCode{},
 	}
 }
 
@@ -169,11 +171,11 @@ func (c *Compiler) typeToCode(typ *runtime.Type) (Code, error) {
 		return c.sliceCode(typ)
 	case reflect.Map:
 		if isPtr {
-			return c.ptrCode(runtime.PtrTo(typ))
+			return c.ptrCode(runtime.PtrTo(typ), false)
 		}
 		return c.mapCode(typ)
 	case reflect.Struct:
-		return c.structCode(typ, isPtr)
+		return c.structCode(typ, isPtr, false)
 	case reflect.Int:
 		return c.intCode(typ, isPtr)
 	case reflect.Int8:
@@ -208,11 +210,11 @@ func (c *Compiler) typeToCode(typ *runtime.Type) (Code, error) {
 		if isPtr && typ.Implements(marshalTextType) {
 			typ = orgType
 		}
-		return c.typeToCodeWithPtr(typ, isPtr)
+		return c.typeToCodeWithPtr(typ, isPtr, false)
 	}
 }
 
-func (c *Compiler) typeToCodeWithPtr(typ *runtime.Type, isPtr bool) (Code, error) {
+func (c *Compiler) typeToCodeWithPtr(typ *runtime.Type, isPtr, isAnonymous bool) (Code, error) {
 	switch {
 	case c.implementsMarshalJSON(typ):
 		return c.marshalJSONCode(typ)
@@ -221,7 +223,7 @@ func (c *Compiler) typeToCodeWithPtr(typ *runtime.Type, isPtr bool) (Code, error
 	}
 	switch typ.Kind() {
 	case reflect.Ptr:
-		return c.ptrCode(typ)
+		return c.ptrCode(typ, isAnonymous)
 	case reflect.Slice:
 		elem := typ.Elem()
 		if elem.Kind() == reflect.Uint8 {
@@ -236,7 +238,7 @@ func (c *Compiler) typeToCodeWithPtr(typ *runtime.Type, isPtr bool) (Code, error
 	case reflect.Map:
 		return c.mapCode(typ)
 	case reflect.Struct:
-		return c.structCode(typ, isPtr)
+		return c.structCode(typ, isPtr, isAnonymous)
 	case reflect.Interface:
 		return c.interfaceCode(typ, false)
 	case reflect.Int:
@@ -424,8 +426,8 @@ func (c *Compiler) marshalTextCode(typ *runtime.Type) (*MarshalTextCode, error)
 	}, nil
 }
 
-func (c *Compiler) ptrCode(typ *runtime.Type) (*PtrCode, error) {
-	code, err := c.typeToCodeWithPtr(typ.Elem(), true)
+func (c *Compiler) ptrCode(typ *runtime.Type, isAnonymous bool) (*PtrCode, error) {
+	code, err := c.typeToCodeWithPtr(typ.Elem(), true, isAnonymous)
 	if err != nil {
 		return nil, err
 	}
@@ -485,12 +487,12 @@ func (c *Compiler) listElemCode(typ *runtime.Type) (Code, error) {
 	case !typ.Implements(marshalTextType) && runtime.PtrTo(typ).Implements(marshalTextType):
 		return c.marshalTextCode(typ)
 	case typ.Kind() == reflect.Map:
-		return c.ptrCode(runtime.PtrTo(typ))
+		return c.ptrCode(runtime.PtrTo(typ), false)
 	default:
 		// isPtr was originally used to indicate whether the type of top level is pointer.
 		// However, since the slice/array element is a specification that can get the pointer address, explicitly set isPtr to true.
 		// See here for related issues: https://github.com/goccy/go-json/issues/370
-		code, err := c.typeToCodeWithPtr(typ, true)
+		code, err := c.typeToCodeWithPtr(typ, true, false)
 		if err != nil {
 			return nil, err
 		}
@@ -511,7 +513,7 @@ func (c *Compiler) mapKeyCode(typ *runtime.Type) (Code, error) {
 	}
 	switch typ.Kind() {
 	case reflect.Ptr:
-		return c.ptrCode(typ)
+		return c.ptrCode(typ, false)
 	case reflect.String:
 		return c.stringCode(typ, false)
 	case reflect.Int:
@@ -543,9 +545,9 @@ func (c *Compiler) mapKeyCode(typ *runtime.Type) (Code, error) {
 func (c *Compiler) mapValueCode(typ *runtime.Type) (Code, error) {
 	switch typ.Kind() {
 	case reflect.Map:
-		return c.ptrCode(runtime.PtrTo(typ))
+		return c.ptrCode(runtime.PtrTo(typ), false)
 	default:
-		code, err := c.typeToCodeWithPtr(typ, false)
+		code, err := c.typeToCodeWithPtr(typ, false, false)
 		if err != nil {
 			return nil, err
 		}
@@ -559,16 +561,20 @@ func (c *Compiler) mapValueCode(typ *runtime.Type) (Code, error) {
 	}
 }
 
-func (c *Compiler) structCode(typ *runtime.Type, isPtr bool) (*StructCode, error) {
+func (c *Compiler) structCode(typ *runtime.Type, isPtr, isAnonymous bool) (*StructCode, error) {
 	typeptr := uintptr(unsafe.Pointer(typ))
-	if code, exists := c.structTypeToCode[typeptr]; exists {
+	structTypeToCode := c.structTypeToCode
+	if isAnonymous {
+		structTypeToCode = c.anonymousStructTypeToCode
+	}
+	if code, exists := structTypeToCode[typeptr]; exists {
 		derefCode := *code
 		derefCode.isRecursive = true
 		return &derefCode, nil
 	}
 	indirect := runtime.IfaceIndir(typ)
 	code := &StructCode{typ: typ, isPtr: isPtr, isIndirect: indirect}
-	c.structTypeToCode[typeptr] = code
+	structTypeToCode[typeptr] = code
 
 	fieldNum := typ.NumField()
 	tags := c.typeToStructTags(typ)
@@ -613,7 +619,7 @@ func (c *Compiler) structCode(typ *runtime.Type, isPtr bool) (*StructCode, error
 	if !code.disableIndirectConversion && !indirect && isPtr {
 		code.enableIndirect()
 	}
-	delete(c.structTypeToCode, typeptr)
+	delete(structTypeToCode, typeptr)
 	return code, nil
 }
 
@@ -680,7 +686,7 @@ func (c *Compiler) structFieldCode(structCode *StructCode, tag *runtime.StructTa
 		fieldCode.isAddrForMarshaler = true
 		fieldCode.isNilCheck = false
 	default:
-		code, err := c.typeToCodeWithPtr(fieldType, isPtr)
+		code, err := c.typeToCodeWithPtr(fieldType, isPtr, fieldCode.isAnonymous)
 		if err != nil {
 			return nil, err
 		}