| // Copyright 2015 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.skyframe; |
| |
| import com.google.devtools.build.lib.causes.LabelCause; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.packages.StarlarkAspect; |
| import com.google.devtools.build.lib.skyframe.AspectValueKey.StarlarkAspectLoadingKey; |
| import com.google.devtools.build.skyframe.SkyFunction; |
| import com.google.devtools.build.skyframe.SkyFunctionException; |
| import com.google.devtools.build.skyframe.SkyKey; |
| import com.google.devtools.build.skyframe.SkyValue; |
| import javax.annotation.Nullable; |
| |
| /** |
| * SkyFunction to load aspects from Starlark extensions and calculate their values. |
| * |
| * <p>Used for loading top-level aspects. At top level, in {@link |
| * com.google.devtools.build.lib.analysis.BuildView}, we cannot invoke two SkyFunctions one after |
| * another, so BuildView calls this function to do the work. |
| */ |
| public class ToplevelStarlarkAspectFunction implements SkyFunction { |
| ToplevelStarlarkAspectFunction() {} |
| |
| @Nullable |
| @Override |
| public SkyValue compute(SkyKey skyKey, Environment env) |
| throws LoadStarlarkAspectFunctionException, InterruptedException { |
| StarlarkAspectLoadingKey aspectLoadingKey = (StarlarkAspectLoadingKey) skyKey.argument(); |
| String starlarkValueName = aspectLoadingKey.getStarlarkValueName(); |
| Label starlarkFileLabel = aspectLoadingKey.getStarlarkFileLabel(); |
| |
| StarlarkAspect starlarkAspect; |
| try { |
| starlarkAspect = AspectFunction.loadStarlarkAspect(env, starlarkFileLabel, starlarkValueName); |
| if (starlarkAspect == null) { |
| return null; |
| } |
| if (!starlarkAspect.getParamAttributes().isEmpty()) { |
| String msg = "Cannot instantiate parameterized aspect " + starlarkAspect.getName() |
| + " at the top level."; |
| throw new AspectCreationException(msg, new LabelCause(starlarkFileLabel, msg)); |
| } |
| } catch (AspectCreationException e) { |
| throw new LoadStarlarkAspectFunctionException(e); |
| } |
| SkyKey aspectKey = aspectLoadingKey.toAspectKey(starlarkAspect.getAspectClass()); |
| |
| return env.getValue(aspectKey); |
| } |
| |
| @Nullable |
| @Override |
| public String extractTag(SkyKey skyKey) { |
| return null; |
| } |
| |
| /** |
| * Exceptions thrown from ToplevelStarlarkAspectFunction. |
| */ |
| public class LoadStarlarkAspectFunctionException extends SkyFunctionException { |
| public LoadStarlarkAspectFunctionException(AspectCreationException cause) { |
| super(cause, Transience.PERSISTENT); |
| } |
| } |
| } |