| // Copyright 2020 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.events.Location; |
| import com.google.devtools.build.lib.syntax.EvalException; |
| |
| /** Defines an argument to the {@code package()} function. */ |
| public abstract class PackageArgument<T> { |
| private final String name; |
| private final Type<T> type; |
| |
| protected PackageArgument(String name, Type<T> type) { |
| this.name = name; |
| this.type = type; |
| } |
| |
| String getName() { |
| return name; |
| } |
| |
| /** |
| * Converts an untyped argument to a typed one, then calls the user-provided {@link #process}. |
| * |
| * Note that the location is used not just for exceptions (for which null would do), but also for |
| * reporting events. |
| */ |
| final void convertAndProcess( |
| Package.Builder pkgBuilder, Location location, Object value) |
| throws EvalException { |
| T typedValue = type.convert(value, "'package' argument", pkgBuilder.getBuildFileLabel()); |
| process(pkgBuilder, location, typedValue); |
| } |
| |
| /** |
| * Processes an argument. |
| * |
| * @param pkgBuilder the package builder to be mutated |
| * @param location the location of the {@code package} function for error reporting |
| * @param value the value of the argument. Typically passed to {@link Type#convert} |
| */ |
| protected abstract void process( |
| Package.Builder pkgBuilder, Location location, T value) |
| throws EvalException; |
| } |