Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* Copyright 2022 The Error Prone Authors.
*
* 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.google.errorprone.bugpatterns.checkreturnvalue;
import static com.google.errorprone.bugpatterns.checkreturnvalue.ResultUseRule.RuleScope.ENCLOSING_ELEMENTS;
import static com.google.errorprone.bugpatterns.checkreturnvalue.ResultUseRule.RuleScope.GLOBAL;
import static com.google.errorprone.bugpatterns.checkreturnvalue.ResultUseRule.RuleScope.METHOD;
import static com.google.errorprone.util.ASTHelpers.enclosingElements;
import com.google.auto.value.AutoValue;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.ListMultimap;
import com.google.errorprone.VisitorState;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Symbol.ClassSymbol;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.code.Symbol.PackageSymbol;
import java.util.List;
import java.util.Optional;
import java.util.stream.Stream;
/** A rule for determining {@link ResultUsePolicy} for methods and/or constructors. */
public abstract class ResultUseRule {
// TODO(cgdecker): Switching to a model where scopes can only either be in a "marked" or
// "unmarked" state and only methods can have a specific policy will simplify all of this a lot.
private ResultUseRule() {} // only allow the subclasses below
/** An ID for uniquely identifying this rule. */
public abstract String id();
/** The scopes this rule applies to. */
public abstract ImmutableSet scopes();
/** Evaluates the given {@code symbol} and optionally returns a {@link ResultUsePolicy} for it. */
public abstract Optional evaluate(Symbol symbol, VisitorState state);
/** Evaluates the given symbol and optionally returns an {@link Evaluation} of it. */
public final Optional evaluate(RuleScope scope, Symbol symbol, VisitorState state) {
return evaluate(symbol, state).map(policy -> Evaluation.create(this, scope, symbol, policy));
}
@Override
public final String toString() {
return id();
}
/**
* A rule that evaluates methods and constructors to determine a {@link ResultUsePolicy} for them.
*/
public abstract static class MethodRule extends ResultUseRule {
private static final ImmutableSet SCOPES = ImmutableSet.of(METHOD);
@Override
public final ImmutableSet scopes() {
return SCOPES;
}
/**
* Evaluates the given {@code method} and optionally returns a {@link ResultUsePolicy} for it.
*/
public abstract Optional evaluateMethod(
MethodSymbol method, VisitorState state);
@Override
public final Optional evaluate(Symbol symbol, VisitorState state) {
return symbol instanceof MethodSymbol
? evaluateMethod((MethodSymbol) symbol, state)
: Optional.empty();
}
}
/**
* A rule that evaluates symbols of any kind to determine a {@link ResultUsePolicy} to associate
* with them.
*/
public abstract static class SymbolRule extends ResultUseRule {
private static final ImmutableSet SCOPES =
ImmutableSet.of(METHOD, ENCLOSING_ELEMENTS);
@Override
public final ImmutableSet scopes() {
return SCOPES;
}
}
/**
* A global rule that is evaluated when none of the more specific rules determine a {@link
* ResultUsePolicy} for a method.
*/
public abstract static class GlobalRule extends ResultUseRule {
private static final ImmutableSet SCOPES = ImmutableSet.of(GLOBAL);
@Override
public final ImmutableSet scopes() {
return SCOPES;
}
/** Optionally returns a global policy for methods or constructors. */
public abstract Optional evaluate(boolean constructor, VisitorState state);
@Override
public final Optional evaluate(Symbol symbol, VisitorState state) {
return evaluate(symbol.isConstructor(), state);
}
}
/** Scope to which a rule may apply. */
public enum RuleScope {
/** The specific method or constructor for which a {@link ResultUsePolicy} is being chosen. */
METHOD {
@Override
Stream members(MethodSymbol method) {
return Stream.of(method);
}
},
/**
* Classes and package that enclose a method for which a {@link ResultUsePolicy} is being
* chosen.
*/
ENCLOSING_ELEMENTS {
@Override
Stream members(MethodSymbol method) {
return enclosingElements(method)
.filter(s -> s instanceof ClassSymbol || s instanceof PackageSymbol);
}
},
/** The global scope. */
GLOBAL {
@Override
Stream members(MethodSymbol method) {
return Stream.of(method);
}
};
/** Returns an ordered stream of elements in this scope relative to the given {@code method}. */
abstract Stream members(MethodSymbol method);
/** Returns an ordered stream of policies from rules in this scope. */
final Stream policies(
MethodSymbol method, VisitorState state, ListMultimap rules) {
List scopeRules = rules.get(this);
return members(method)
.flatMap(symbol -> scopeRules.stream().map(rule -> rule.evaluate(symbol, state)))
.flatMap(Optional::stream);
}
/** Returns an ordered stream of evaluations in this scope. */
final Stream evaluations(
MethodSymbol method, VisitorState state, ListMultimap rules) {
List scopeRules = rules.get(this);
return members(method)
.flatMap(symbol -> scopeRules.stream().map(rule -> rule.evaluate(this, symbol, state)))
.flatMap(Optional::stream);
}
}
/** An evaluation that a rule makes. */
@AutoValue
public abstract static class Evaluation {
/** Creates a new {@link Evaluation}. */
public static Evaluation create(
ResultUseRule rule, RuleScope scope, Symbol element, ResultUsePolicy policy) {
return new AutoValue_ResultUseRule_Evaluation(rule, scope, element, policy);
}
/** The rule that made this evaluation. */
public abstract ResultUseRule rule();
/** The scope at which the evaluation was made. */
public abstract RuleScope scope();
/** The specific element in the scope for which the evaluation was made. */
public abstract Symbol element();
/** The policy the rule selected. */
public abstract ResultUsePolicy policy();
}
}
