-
Notifications
You must be signed in to change notification settings - Fork 134
/
BaselineErrorProneScope.java
110 lines (96 loc) · 4.03 KB
/
BaselineErrorProneScope.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
/*
* (c) Copyright 2021 Palantir Technologies Inc. All rights reserved.
*
* 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 com.palantir.baseline.errorprone;
import static com.google.common.base.Preconditions.checkState;
import com.google.errorprone.util.RuntimeVersion;
import com.sun.tools.javac.code.Scope;
import com.sun.tools.javac.code.Scope.LookupKind;
import com.sun.tools.javac.code.Symbol;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
import java.util.function.Predicate;
/**
* A compatibility wrapper around {@link com.sun.tools.javac.util.Filter}.
* Adapted from {@link com.google.errorprone.util.ErrorProneScope} with additional methods.
*
* Original code from (Apache-2.0 License):
* https://github.com/google/error-prone/blob/ce87ca1c7bb005371837b82ffa69041dd8a356e5/check_api/src/main/java/com/google/errorprone/util/ErrorProneScope.java
*
* TODO(fwindheuser): Delete after upstreaming missing methods into "ErrorProneScope".
*/
@SuppressWarnings("ThrowError")
public final class BaselineErrorProneScope {
@SuppressWarnings("unchecked") // reflection
public Iterable<Symbol> getSymbols(Predicate<Symbol> predicate, LookupKind lookupKind) {
return (Iterable<Symbol>) invoke(getSymbols, maybeAsFilter(predicate), lookupKind);
}
private static final Class<?> FILTER_CLASS = getFilterClass();
private static Class<?> getFilterClass() {
if (RuntimeVersion.isAtLeast17()) {
return null;
}
try {
return Class.forName("com.sun.tools.javac.util.Filter");
} catch (ClassNotFoundException e) {
throw new LinkageError(e.getMessage(), e);
}
}
private static final Method getSymbols = getImpl("getSymbols", Predicate.class, LookupKind.class);
private static Method getImpl(String name, Class<?>... parameters) {
return FILTER_CLASS != null
? getMethodOrDie(
Scope.class,
name,
Arrays.stream(parameters)
.map(p -> p.equals(Predicate.class) ? FILTER_CLASS : p)
.toArray(Class<?>[]::new))
: getMethodOrDie(Scope.class, name, parameters);
}
private final Scope scope;
BaselineErrorProneScope(Scope scope) {
this.scope = scope;
}
private Object invoke(Method method, Object... args) {
try {
return method.invoke(scope, args);
} catch (ReflectiveOperationException e) {
throw new LinkageError(e.getMessage(), e);
}
}
@SuppressWarnings("ProxyNonConstantType")
private Object maybeAsFilter(Predicate<Symbol> predicate) {
if (FILTER_CLASS == null) {
return predicate;
}
return Proxy.newProxyInstance(
getClass().getClassLoader(), new Class<?>[] {FILTER_CLASS}, new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) {
checkState(method.getName().equals("accepts"));
return predicate.test((Symbol) args[0]);
}
});
}
private static Method getMethodOrDie(Class<?> clazz, String name, Class<?>... parameters) {
try {
return clazz.getMethod(name, parameters);
} catch (NoSuchMethodException e) {
throw new LinkageError(e.getMessage(), e);
}
}
}