// Copyright 2017 The Bazel Authors. 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.google.devtools.build.lib.packages;
import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
import com.google.devtools.build.lib.events.Location;
import com.google.devtools.build.lib.syntax.EvalException;
import com.google.devtools.build.lib.syntax.FunctionSignature;
import com.google.devtools.build.lib.syntax.SkylarkType;
import com.google.devtools.build.lib.util.Pair;
import java.util.Map;
import javax.annotation.Nullable;
/**
* Base class for declared providers {@see ClassObjectConstructor} defined
* in native code.
*
* Every non-abstract derived class of {@link NativeClassObjectConstructor}
* corresponds to a single declared provider. This is enforced by final
* {@link #equals(Object)} and {@link #hashCode()}.
*
* Typical implementation of a non-constructable from Skylark declared provider is as follows:
*
* public static final ClassObjectConstructor CC_LINK_PARAMS =
* new NativeClassObjectConstructor("link_params") { };
*
*
* To allow construction from Skylark and custom construction logic, override
* {@link #createInstanceFromSkylark(Object[], Location)} (see {@link #STRUCT} for an example.
*/
@Immutable
public abstract class NativeClassObjectConstructor extends ClassObjectConstructor {
private final NativeKey key;
private final String errorMessageForInstances;
/**
* "struct" function.
*/
public static final StructConstructor STRUCT = new StructConstructor();
/**
* A constructor for default {@code struct}s.
*
* Singleton, instance is {@link #STRUCT}.
*/
public static final class StructConstructor extends NativeClassObjectConstructor {
private StructConstructor() {
super("struct");
}
@Override
protected SkylarkClassObject createInstanceFromSkylark(Object[] args, Location loc) {
@SuppressWarnings("unchecked")
Map kwargs = (Map) args[0];
return new SkylarkClassObject(this, kwargs, loc);
}
public SkylarkClassObject create(Map values, String message) {
return new SkylarkClassObject(this, values, message);
}
}
private static final FunctionSignature.WithValues