xref: /aosp_15_r20/build/blueprint/proptools/typeequal.go (revision 1fa6dee971e1612fa5cc0aa5ca2d35a22e2c34a3)
1// Copyright 2015 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package proptools
16
17import "reflect"
18
19// TypeEqual takes two property structs, and returns true if they are of equal type, any embedded
20// pointers to structs or interfaces having matching nilitude, and any interface{} values in any
21// embedded structs, pointers to structs, or interfaces are also of equal type.
22func TypeEqual(s1, s2 interface{}) bool {
23	return typeEqual(reflect.ValueOf(s1), reflect.ValueOf(s2))
24}
25
26func typeEqual(v1, v2 reflect.Value) bool {
27	if v1.Type() != v2.Type() {
28		return false
29	}
30
31	if v1.Kind() == reflect.Interface {
32		if v1.IsNil() != v2.IsNil() {
33			return false
34		}
35		if v1.IsNil() {
36			return true
37		}
38		v1 = v1.Elem()
39		v2 = v2.Elem()
40		if v1.Type() != v2.Type() {
41			return false
42		}
43	}
44
45	if v1.Kind() == reflect.Ptr {
46		if v1.Type().Elem().Kind() != reflect.Struct {
47			return true
48		}
49		if v1.IsNil() && !v2.IsNil() {
50			return concreteType(v2)
51		} else if v2.IsNil() && !v1.IsNil() {
52			return concreteType(v1)
53		} else if v1.IsNil() && v2.IsNil() {
54			return true
55		}
56
57		v1 = v1.Elem()
58		v2 = v2.Elem()
59	}
60
61	if v1.Kind() != reflect.Struct {
62		return true
63	}
64
65	if isConfigurable(v1.Type()) {
66		return true
67	}
68
69	for i := 0; i < v1.NumField(); i++ {
70		v1 := v1.Field(i)
71		v2 := v2.Field(i)
72
73		switch kind := v1.Kind(); kind {
74		case reflect.Interface, reflect.Ptr, reflect.Struct:
75			if !typeEqual(v1, v2) {
76				return false
77			}
78		}
79	}
80
81	return true
82}
83
84// Returns true if v recursively contains no interfaces
85func concreteType(v reflect.Value) bool {
86	if v.Kind() == reflect.Interface {
87		return false
88	}
89
90	if v.Kind() == reflect.Ptr {
91		if v.IsNil() {
92			return true
93		}
94		v = v.Elem()
95	}
96
97	if v.Kind() != reflect.Struct {
98		return true
99	}
100
101	if isConfigurable(v.Type()) {
102		return true
103	}
104
105	for i := 0; i < v.NumField(); i++ {
106		v := v.Field(i)
107
108		switch kind := v.Kind(); kind {
109		case reflect.Interface, reflect.Ptr, reflect.Struct:
110			if !concreteType(v) {
111				return false
112			}
113		}
114	}
115
116	return true
117}
118