| // 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.rules.repository; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.devtools.build.lib.cmdline.LabelConstants; |
| import com.google.devtools.build.lib.packages.AggregatingAttributeMapper; |
| import com.google.devtools.build.lib.packages.BuildType.SelectorList; |
| import com.google.devtools.build.lib.packages.Rule; |
| import com.google.devtools.build.lib.syntax.EvalException; |
| import com.google.devtools.build.lib.syntax.Type; |
| import javax.annotation.Nullable; |
| |
| /** |
| * An attribute mapper for workspace rules. Similar to NonconfigurableAttributeWrapper, but throws |
| * a wrapped EvalException if select() is used. |
| */ |
| public class WorkspaceAttributeMapper { |
| |
| public static WorkspaceAttributeMapper of(Rule rule) { |
| return new WorkspaceAttributeMapper(rule); |
| } |
| |
| private final Rule rule; |
| |
| private WorkspaceAttributeMapper(Rule rule) { |
| this.rule = rule; |
| } |
| |
| /** |
| * Returns typecasted value for attribute or {@code null} on no match. |
| */ |
| @Nullable |
| public <T> T get(String attributeName, Type<T> type) throws EvalException { |
| Preconditions.checkNotNull(type); |
| Object value = getObject(attributeName); |
| try { |
| return type.cast(value); |
| } catch (ClassCastException e) { |
| throw new EvalException( |
| rule.getAttributeContainer().getAttributeLocation(attributeName), e.getMessage()); |
| } |
| } |
| |
| /** |
| * Returns value for attribute without casting it to any particular type, or null on no match. |
| */ |
| @Nullable |
| public Object getObject(String attributeName) throws EvalException { |
| Object value = rule.getAttributeContainer().getAttr(checkNotNull(attributeName)); |
| if (value instanceof SelectorList) { |
| String message; |
| if (rule.getLocation() |
| .getPath() |
| .getBaseName() |
| .equals(LabelConstants.WORKSPACE_FILE_NAME.getPathString())) { |
| message = "select() cannot be used in WORKSPACE files"; |
| } else { |
| message = "select() cannot be used in macros called from WORKSPACE files"; |
| } |
| throw new EvalException( |
| rule.getAttributeContainer().getAttributeLocation(attributeName), message); |
| } |
| return value; |
| } |
| |
| public boolean isAttributeValueExplicitlySpecified(String attr) { |
| return rule.getAttributeContainer().isAttributeValueExplicitlySpecified(attr); |
| } |
| |
| public Iterable<String> getAttributeNames() { |
| return AggregatingAttributeMapper.of(rule).getAttributeNames(); |
| } |
| } |