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// Copyright 2016 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.common.base.Preconditions;
import com.google.common.collect.ImmutableSet;
import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
import com.google.devtools.build.lib.util.Fingerprint;
import java.util.ArrayList;
import java.util.Objects;
/**
* Captures the set of providers rules and aspects can advertise. It is either of:
*
* <ul>
* <li>a set of builtin and Starlark providers
* <li>"can have any provider" set that alias rules have.
* </ul>
*
* <p>Built-in providers should in theory only contain subclasses of {@link
* com.google.devtools.build.lib.analysis.TransitiveInfoProvider}, but our current dependency
* structure does not allow a reference to that class here.
*/
@Immutable
public final class AdvertisedProviderSet {
private final boolean canHaveAnyProvider;
private final ImmutableSet<Class<?>> builtinProviders;
private final ImmutableSet<StarlarkProviderIdentifier> starlarkProviders;
private AdvertisedProviderSet(
boolean canHaveAnyProvider,
ImmutableSet<Class<?>> builtinProviders,
ImmutableSet<StarlarkProviderIdentifier> starlarkProviders) {
this.canHaveAnyProvider = canHaveAnyProvider;
this.builtinProviders = builtinProviders;
this.starlarkProviders = starlarkProviders;
}
public static final AdvertisedProviderSet ANY =
new AdvertisedProviderSet(true, ImmutableSet.of(), ImmutableSet.of());
public static final AdvertisedProviderSet EMPTY =
new AdvertisedProviderSet(false, ImmutableSet.of(), ImmutableSet.of());
public static AdvertisedProviderSet create(
ImmutableSet<Class<?>> builtinProviders,
ImmutableSet<StarlarkProviderIdentifier> starlarkProviders) {
if (builtinProviders.isEmpty() && starlarkProviders.isEmpty()) {
return EMPTY;
}
return new AdvertisedProviderSet(false, builtinProviders, starlarkProviders);
}
@Override
public int hashCode() {
return Objects.hash(canHaveAnyProvider, builtinProviders, starlarkProviders);
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof AdvertisedProviderSet)) {
return false;
}
AdvertisedProviderSet that = (AdvertisedProviderSet) obj;
return this.canHaveAnyProvider == that.canHaveAnyProvider
&& Objects.equals(this.builtinProviders, that.builtinProviders)
&& Objects.equals(this.starlarkProviders, that.starlarkProviders);
}
@Override
public String toString() {
if (canHaveAnyProvider()) {
return "Any Provider";
}
return String.format(
"allowed built-in providers=%s, allowed Starlark providers=%s",
builtinProviders, starlarkProviders);
}
/** Checks whether the rule can have any provider.
*
* Used for alias rules.
*/
public boolean canHaveAnyProvider() {
return canHaveAnyProvider;
}
/** Get all advertised built-in providers. */
public ImmutableSet<Class<?>> getBuiltinProviders() {
return builtinProviders;
}
/** Get all advertised Starlark providers. */
public ImmutableSet<StarlarkProviderIdentifier> getStarlarkProviders() {
return starlarkProviders;
}
/**
* Adds the fingerprints of this {@link AdvertisedProviderSet} into {@code fp}.
*
* <p>Fingerprints of {@link AdvertisedProviderSet} must have the following properties:
*
* <ul>
* <li>If {@code aps1.equals(aps2)} then {@code aps1} and {@code aps2} have the same
* fingerprint.
* <li>If {@code !aps1.equals(aps2)} then {@code aps1} and {@code aps2} don't have the same
* fingerprint (except for unintentional digest collisions).
* </ul>
*
* <p>In other words, this method is a proxy for {@link #equals}. These properties *do not* need
* to be maintained across Blaze versions (e.g. there's no need to worry about historical
* serialized fingerprints).
*/
public void fingerprint(Fingerprint fp) {
fp.addBoolean(canHaveAnyProvider);
// #builtinProviders and #starlarkProviders are ordered according to the calls to the builder
// methods, and that order is assumed to be deterministic.
builtinProviders.forEach(clazz -> fp.addString(clazz.getCanonicalName()));
starlarkProviders.forEach(starlarkProvider -> starlarkProvider.fingerprint(fp));
}
public static Builder builder() {
return new Builder();
}
/**
* Returns {@code true} if this provider set can have any provider, or if it advertises the
* specific Starlark provider requested.
*/
public boolean advertises(StarlarkProviderIdentifier starlarkProvider) {
if (canHaveAnyProvider()) {
return true;
}
return starlarkProviders.contains(starlarkProvider);
}
/** Builder for {@link AdvertisedProviderSet} */
public static class Builder {
private boolean canHaveAnyProvider;
private final ArrayList<Class<?>> builtinProviders;
private final ArrayList<StarlarkProviderIdentifier> starlarkProviders;
private Builder() {
builtinProviders = new ArrayList<>();
starlarkProviders = new ArrayList<>();
}
/**
* Advertise all providers inherited from a parent rule.
*/
public Builder addParent(AdvertisedProviderSet parentSet) {
Preconditions.checkState(!canHaveAnyProvider, "Alias rules inherit from no other rules");
Preconditions.checkState(!parentSet.canHaveAnyProvider(),
"Cannot inherit from alias rules");
builtinProviders.addAll(parentSet.getBuiltinProviders());
starlarkProviders.addAll(parentSet.getStarlarkProviders());
return this;
}
public Builder addBuiltin(Class<?> builtinProvider) {
this.builtinProviders.add(builtinProvider);
return this;
}
public void canHaveAnyProvider() {
Preconditions.checkState(builtinProviders.isEmpty() && starlarkProviders.isEmpty());
this.canHaveAnyProvider = true;
}
public AdvertisedProviderSet build() {
if (canHaveAnyProvider) {
Preconditions.checkState(builtinProviders.isEmpty() && starlarkProviders.isEmpty());
return ANY;
}
return AdvertisedProviderSet.create(
ImmutableSet.copyOf(builtinProviders), ImmutableSet.copyOf(starlarkProviders));
}
public Builder addStarlark(String providerName) {
starlarkProviders.add(StarlarkProviderIdentifier.forLegacy(providerName));
return this;
}
public Builder addStarlark(StarlarkProviderIdentifier id) {
starlarkProviders.add(id);
return this;
}
}
}