| // 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.Joiner; |
| import com.google.common.base.Objects; |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableCollection; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.Ordering; |
| import com.google.devtools.build.lib.events.Location; |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkModule; |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory; |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter; |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkValue; |
| import com.google.devtools.build.lib.syntax.ClassObject; |
| import com.google.devtools.build.lib.syntax.EvalException; |
| import com.google.devtools.build.lib.syntax.Printer; |
| import com.google.devtools.build.lib.syntax.SkylarkType; |
| import java.io.Serializable; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import javax.annotation.Nullable; |
| |
| /** Represents information provided by a {@link Provider}. */ |
| @SkylarkModule( |
| name = "struct", |
| category = SkylarkModuleCategory.BUILTIN, |
| doc = |
| "A special language element to support structs (i.e. simple value objects). " |
| + "See the global <a href=\"globals.html#struct\">struct</a> function " |
| + "for more details." |
| ) |
| public abstract class Info implements ClassObject, SkylarkValue, Serializable { |
| private final Provider provider; |
| private final Location creationLoc; |
| private final String errorMessage; |
| |
| /** Creates an empty struct with a given location. */ |
| public Info(Provider provider, Location location) { |
| this.provider = provider; |
| this.creationLoc = location; |
| this.errorMessage = provider.getErrorMessageFormatForInstances(); |
| } |
| |
| /** Creates a built-in struct (i.e. without creation loc). */ |
| public Info(Provider provider) { |
| this.provider = provider; |
| this.creationLoc = null; |
| this.errorMessage = provider.getErrorMessageFormatForInstances(); |
| } |
| |
| /** |
| * Creates a built-in struct (i.e. without creation loc). |
| * |
| * <p>Allows to supply a specific error message. Only used in |
| * {@link com.google.devtools.build.lib.packages.NativeProvider.StructConstructor#create(Map, |
| * String)} If you need to override an error message, preferred way is to create a specific {@link |
| * NativeProvider}. |
| */ |
| Info(Provider provider, Map<String, Object> values, String errorMessage) { |
| this.provider = provider; |
| this.creationLoc = null; |
| this.errorMessage = Preconditions.checkNotNull(errorMessage); |
| } |
| |
| // Ensure that values are all acceptable to Skylark before to stuff them in a ClassObject |
| protected static ImmutableMap<String, Object> copyValues(Map<String, Object> values) { |
| ImmutableMap.Builder<String, Object> builder = ImmutableMap.builder(); |
| for (Map.Entry<String, Object> e : values.entrySet()) { |
| builder.put( |
| Attribute.getSkylarkName(e.getKey()), SkylarkType.convertToSkylark(e.getValue(), null)); |
| } |
| return builder.build(); |
| } |
| |
| public abstract boolean hasKey(String name); |
| |
| /** Returns a value and try to cast it into specified type */ |
| public <TYPE> TYPE getValue(String key, Class<TYPE> type) throws EvalException { |
| Object obj = getValue(key); |
| if (obj == null) { |
| return null; |
| } |
| SkylarkType.checkType(obj, type, key); |
| return type.cast(obj); |
| } |
| |
| public Location getCreationLoc() { |
| return Preconditions.checkNotNull(creationLoc, "This struct was not created in a Skylark code"); |
| } |
| |
| public Provider getProvider() { |
| return provider; |
| } |
| |
| @Nullable |
| public Location getCreationLocOrNull() { |
| return creationLoc; |
| } |
| |
| /** |
| * Returns the fields of this struct. |
| * |
| * Overrides {@link ClassObject#getKeys()}, but does not allow {@link EvalException} to |
| * be thrown. |
| */ |
| @Override |
| public abstract ImmutableCollection<String> getKeys(); |
| |
| /** |
| * Returns the value associated with the name field in this struct, |
| * or null if the field does not exist. |
| * |
| * Overrides {@link ClassObject#getValue(String)}, but does not allow {@link EvalException} to |
| * be thrown. |
| */ |
| @Nullable |
| @Override |
| public abstract Object getValue(String name); |
| |
| @Override |
| public String errorMessage(String name) { |
| String suffix = |
| "Available attributes: " + Joiner.on(", ").join(Ordering.natural().sortedCopy(getKeys())); |
| return String.format(errorMessage, name) + "\n" + suffix; |
| } |
| |
| @Override |
| public boolean equals(Object otherObject) { |
| if (!(otherObject instanceof Info)) { |
| return false; |
| } |
| Info other = (Info) otherObject; |
| if (this == other) { |
| return true; |
| } |
| if (!this.provider.equals(other.provider)) { |
| return false; |
| } |
| // Compare objects' keys and values |
| if (!this.getKeys().equals(other.getKeys())) { |
| return false; |
| } |
| for (String key : getKeys()) { |
| if (!this.getValue(key).equals(other.getValue(key))) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| List<String> keys = new ArrayList<>(getKeys()); |
| Collections.sort(keys); |
| List<Object> objectsToHash = new ArrayList<>(); |
| objectsToHash.add(provider); |
| for (String key : keys) { |
| objectsToHash.add(key); |
| objectsToHash.add(getValue(key)); |
| } |
| return Objects.hashCode(objectsToHash.toArray()); |
| } |
| |
| /** |
| * Convert the object to string using Skylark syntax. The output tries to be reversible (but there |
| * is no guarantee, it depends on the actual values). |
| */ |
| @Override |
| public void repr(SkylarkPrinter printer) { |
| boolean first = true; |
| printer.append("struct("); |
| // Sort by key to ensure deterministic output. |
| for (String key : Ordering.natural().sortedCopy(getKeys())) { |
| if (!first) { |
| printer.append(", "); |
| } |
| first = false; |
| printer.append(key); |
| printer.append(" = "); |
| printer.repr(getValue(key)); |
| } |
| printer.append(")"); |
| } |
| |
| @Override |
| public String toString() { |
| return Printer.repr(this); |
| } |
| } |