| // Copyright 2024 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.errorprone.annotations.CanIgnoreReturnValue; |
| import javax.annotation.Nullable; |
| import net.starlark.java.eval.EvalException; |
| import net.starlark.java.eval.Starlark; |
| import net.starlark.java.eval.StarlarkThread; |
| |
| /** |
| * A context object, usually stored in a {@link StarlarkThread}, upon which rules and symbolic |
| * macros can be instantiated. |
| */ |
| // TODO(#19922): Elevate some Package.Builder methods to this class. |
| public abstract class TargetDefinitionContext extends BazelStarlarkContext { |
| |
| /** |
| * An exception used when the name of a target or symbolic macro clashes with another entity |
| * defined in the package. |
| * |
| * <p>Common examples of conflicts include two targets or symbolic macros sharing the same name, |
| * and one output file being a prefix of another. See {@link Package.Builder#checkForExistingName} |
| * and {@link Package.Builder#checkRuleAndOutputs} for more details. |
| */ |
| public static final class NameConflictException extends Exception { |
| public NameConflictException(String message) { |
| super(message); |
| } |
| } |
| |
| protected TargetDefinitionContext(Phase phase) { |
| super(phase); |
| } |
| |
| /** Retrieves this object from a Starlark thread. Returns null if not present. */ |
| @Nullable |
| public static TargetDefinitionContext fromOrNull(StarlarkThread thread) { |
| BazelStarlarkContext ctx = thread.getThreadLocal(BazelStarlarkContext.class); |
| return (ctx instanceof TargetDefinitionContext) ? (TargetDefinitionContext) ctx : null; |
| } |
| |
| /** |
| * Retrieves this object from a Starlark thread. If not present, throws {@code EvalException} with |
| * an error message indicating that {@code what} can't be used in this Starlark environment. |
| */ |
| @CanIgnoreReturnValue |
| public static TargetDefinitionContext fromOrFail(StarlarkThread thread, String what) |
| throws EvalException { |
| @Nullable BazelStarlarkContext ctx = thread.getThreadLocal(BazelStarlarkContext.class); |
| if (!(ctx instanceof TargetDefinitionContext)) { |
| throw Starlark.errorf("%s can only be used while evaluating a BUILD file or macro", what); |
| } |
| return (TargetDefinitionContext) ctx; |
| } |
| } |