fix: unmarshal into defined ptr type (#392)

decoder/compiler.go

@@ -679,12 +679,38 @@ func (self *_Compiler) compilePtr(p *_Program, sp int, et reflect.Type) {
 
     /* dereference all the way down */
     for et.Kind() == reflect.Ptr {
+        if et.Implements(jsonUnmarshalerType) {
+            p.rtt(_OP_unmarshal_p, et)
+            return
+        }
+
+        if et.Implements(encodingTextUnmarshalerType) {
+            p.add(_OP_lspace)
+            self.compileUnmarshalTextPtr(p, et)
+            return
+        }
+
         et = et.Elem()
         p.rtt(_OP_deref, et)
     }
 
-    /* compile the element type */
-    self.compileOne(p, sp + 1, et)
+    /* check for recursive nesting */
+    ok := self.tab[et]
+    if ok {
+        p.rtt(_OP_recurse, et)
+        return
+    }
+
+    /* enter the recursion */
+    p.add(_OP_lspace)
+    self.tab[et] = true
+    
+    /* not inline the pointer type
+     * recursing the defined pointer type's elem will casue issue379.
+     */
+    self.compileOps(p, sp, et)
+    delete(self.tab, et)
+
     j := p.pc()
     p.add(_OP_goto)
     p.pin(i)

decoder/decoder.go

@@ -17,6 +17,7 @@
 package decoder
 
 import (
+    `unsafe`
     `encoding/json`
     `reflect`
     `runtime`
@@ -127,8 +128,17 @@ func (self *Decoder) Decode(val interface{}) error {
         return &json.InvalidUnmarshalError{Type: vv.Type.Pack()}
     }
 
+    etp := rt.PtrElem(vv.Type)
+
+    /* check the defined pointer type for issue 379 */
+    if vv.Type.IsNamed() {
+        newp := vp
+        etp  = vv.Type
+        vp   = unsafe.Pointer(&newp)
+    }
+
     /* create a new stack, and call the decoder */
-    sb, etp := newStack(), rt.PtrElem(vv.Type)
+    sb := newStack()
     nb, err := decodeTypedPointer(self.s, self.i, etp, vp, sb, self.f)
     /* return the stack back */
     self.i = nb

internal/rt/fastvalue.go

@@ -22,14 +22,23 @@ import (
 )
 
 var (
-	reflectRtypeItab = findReflectRtypeItab()
+    reflectRtypeItab = findReflectRtypeItab()
 )
 
+// GoType.KindFlags const
 const (
     F_direct    = 1 << 5
     F_kind_mask = (1 << 5) - 1
 )
 
+// GoType.Flags const
+const (
+    tflagUncommon      uint8 = 1 << 0
+    tflagExtraStar     uint8 = 1 << 1
+    tflagNamed         uint8 = 1 << 2
+    tflagRegularMemory uint8 = 1 << 3
+)
+
 type GoType struct {
     Size       uintptr
     PtrData    uintptr
@@ -44,6 +53,10 @@ type GoType struct {
     PtrToSelf  int32
 }
 
+func (self *GoType) IsNamed() bool {
+    return (self.Flags & tflagNamed) != 0
+}
+
 func (self *GoType) Kind() reflect.Kind {
     return reflect.Kind(self.KindFlags & F_kind_mask)
 }

issue_test/issue379_test.go

@@ -0,0 +1,99 @@
+/*
+ * Copyright 2023 ByteDance Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package issue_test
+
+import (
+    `testing`
+    `encoding/json`
+    `github.com/bytedance/sonic`
+    `github.com/stretchr/testify/require`
+)
+
+type Foo struct {
+    Name string
+}
+
+func (f *Foo) UnmarshalJSON(data []byte) error {
+    f.Name = "Unmarshaler"
+    return nil
+}
+
+type MyPtr *Foo
+
+func TestIssue379(t *testing.T) {
+    tests := []struct{
+        data  string
+        newf  func() interface{} 
+    } {
+        {
+            data: `{"Name":"MyPtr"}`,
+            newf:  func() interface{} { return &Foo{} },
+        },
+        {
+            data: `{"Name":"MyPtr"}`,
+            newf:  func() interface{} { return MyPtr(&Foo{}) },
+        },
+        {
+            data: `{"Name":"MyPtr"}`,
+            newf:  func() interface{} { ptr := MyPtr(&Foo{}); return &ptr },
+        },
+        {
+            data: `null`,
+            newf:  func() interface{} { return MyPtr(&Foo{}) },
+        },
+        {
+            data: `null`,
+            newf:  func() interface{} { return &Foo{} },
+        },
+        {
+            data: `null`,
+            newf:  func() interface{} { ptr := MyPtr(&Foo{}); return &ptr },
+        },
+        {
+            data: `{"map":{"Name":"MyPtr"}}`,
+            newf:  func() interface{} { return new(map[string]MyPtr) },
+        },
+        {
+            data: `{"map":{"Name":"MyPtr"}}`,
+            newf:  func() interface{} { return new(map[string]*Foo) },
+        },
+        {
+            data: `{"map":{"Name":"MyPtr"}}`,
+            newf:  func() interface{} { return new(map[string]*MyPtr) },
+        },
+        {
+            data: `[{"Name":"MyPtr"}]`,
+            newf:  func() interface{} { return new([]MyPtr) },
+        },
+        {
+            data: `[{"Name":"MyPtr"}]`,
+            newf:  func() interface{} { return new([]*MyPtr) },
+        },
+        {
+            data: `[{"Name":"MyPtr"}]`,
+            newf:  func() interface{} { return new([]*Foo) },
+        },
+    }
+
+    for _, tt := range tests {
+        jv, sv := tt.newf(), tt.newf()
+        jerr := json.Unmarshal([]byte(tt.data), jv)
+        serr := sonic.Unmarshal([]byte(tt.data), sv)
+        require.Equal(t, jv, sv)
+        require.Equal(t, jerr, serr)
+    }
+}