Add an "alias" rule.
This will be used to replace RedirectChaser so that we don't need to load packages during configuration creation anymore.
--
MOS_MIGRATED_REVID=121935989
diff --git a/src/main/java/com/google/devtools/build/lib/rules/Alias.java b/src/main/java/com/google/devtools/build/lib/rules/Alias.java
new file mode 100644
index 0000000..540bcc9
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/Alias.java
@@ -0,0 +1,120 @@
+// 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;
+
+import static com.google.devtools.build.lib.packages.Attribute.ANY_RULE;
+import static com.google.devtools.build.lib.packages.Attribute.attr;
+import static com.google.devtools.build.lib.packages.BuildType.LABEL;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.analysis.BaseRuleClasses;
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.LicensesProvider;
+import com.google.devtools.build.lib.analysis.LicensesProviderImpl;
+import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.RuleDefinition;
+import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
+import com.google.devtools.build.lib.analysis.VisibilityProvider;
+import com.google.devtools.build.lib.analysis.VisibilityProviderImpl;
+import com.google.devtools.build.lib.packages.RuleClass;
+import com.google.devtools.build.lib.packages.RuleClass.Builder;
+import com.google.devtools.build.lib.util.FileTypeSet;
+
+/**
+ * Implementation of the <code>alias</code> rule.
+ */
+public class Alias implements RuleConfiguredTargetFactory {
+ @Override
+ public ConfiguredTarget create(RuleContext ruleContext) throws InterruptedException {
+ ConfiguredTarget actual = (ConfiguredTarget) ruleContext.getPrerequisite("actual", Mode.TARGET);
+ return new AliasConfiguredTarget(
+ actual,
+ ImmutableMap.of(
+ AliasProvider.class, AliasProvider.fromAliasRule(ruleContext.getLabel(), actual),
+ VisibilityProvider.class, new VisibilityProviderImpl(ruleContext.getVisibility()),
+ LicensesProvider.class, LicensesProviderImpl.of(ruleContext)));
+ }
+
+ /**
+ * Rule definition.
+ */
+ public static class AliasRule implements RuleDefinition {
+ @Override
+ public RuleClass build(Builder builder, RuleDefinitionEnvironment environment) {
+ return builder
+ /*<!-- #BLAZE_RULE(alias).ATTRIBUTE(actual) -->
+ The target this alias refers to. It does not need to be a rule, it can also be an input
+ file.
+ <!-- #END_BLAZE_RULE.ATTRIBUTE -->*/
+ .add(attr("actual", LABEL)
+ .allowedFileTypes(FileTypeSet.ANY_FILE)
+ .allowedRuleClasses(ANY_RULE)
+ .mandatory())
+ .build();
+ }
+
+ @Override
+ public Metadata getMetadata() {
+ return Metadata.builder()
+ .name("alias")
+ .factoryClass(Alias.class)
+ .ancestors(BaseRuleClasses.BaseRule.class)
+ .build();
+ }
+ }
+}
+
+/*<!-- #BLAZE_RULE (NAME = alias, TYPE = OTHER, FAMILY = General)[GENERIC_RULE] -->
+
+<p>
+ The <code>alias</code> rule creates another name a rule can be referred to as.
+</p>
+
+<p>
+ Aliasing only works for "regular" targets. In particular, <code>package_group</code>,
+ <code>config_setting</code> and <code>test_suite</code> rules cannot be aliased.
+</p>
+
+<p>
+ The alias rule has its own visibility and license declaration. In all other respects, it behaves
+ like the rule it references with some minor exceptions:
+
+ <ul>
+ <li>
+ Tests are not run if their alias is mentioned on the command line
+ </li>
+ <li>
+ When defining environment groups, the aliases to <code>environment</code> rules are not
+ supported. They are not supported in the <code>--target_environment</code> command line
+ option, either.
+ </li>
+ </ul>
+</p>
+
+<h4 id="alias_example">Examples</h4>
+
+<pre class="code">
+filegroup(
+ name = "data",
+ srcs = ["data.txt"],
+)
+
+alias(
+ name = 'other',
+ actual = ':data',
+)
+</pre>
+
+<!-- #END_BLAZE_RULE -->*/
diff --git a/src/main/java/com/google/devtools/build/lib/rules/AliasConfiguredTarget.java b/src/main/java/com/google/devtools/build/lib/rules/AliasConfiguredTarget.java
new file mode 100644
index 0000000..c7d2387
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/AliasConfiguredTarget.java
@@ -0,0 +1,111 @@
+// 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;
+
+import com.google.common.collect.ImmutableCollection;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.FileProvider;
+import com.google.devtools.build.lib.analysis.SkylarkProviders;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
+import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
+import com.google.devtools.build.lib.collect.nestedset.Order;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import com.google.devtools.build.lib.packages.Target;
+import com.google.devtools.build.lib.syntax.ClassObject;
+import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
+
+/**
+ * This configured target pretends to be whatever type of target "actual" is, returning its
+ * transitive info providers and target, but returning its own label.
+ *
+ * <p>Transitive info providers can also be overridden.
+ */
+@Immutable
+public final class AliasConfiguredTarget implements ConfiguredTarget, ClassObject {
+ private final ConfiguredTarget configuredTarget;
+ private final ImmutableMap<Class<? extends TransitiveInfoProvider>, TransitiveInfoProvider>
+ overrides;
+
+ public AliasConfiguredTarget(ConfiguredTarget actual,
+ ImmutableMap<Class<? extends TransitiveInfoProvider>, TransitiveInfoProvider> overrides) {
+ configuredTarget = actual;
+ this.overrides = overrides;
+ }
+
+ @Override
+ public <P extends TransitiveInfoProvider> P getProvider(Class<P> provider) {
+ if (overrides.containsKey(provider)) {
+ return provider.cast(overrides.get(provider));
+ }
+
+ return configuredTarget == null ? null : configuredTarget.getProvider(provider);
+ }
+
+ @Override
+ public Label getLabel() {
+ return configuredTarget.getLabel();
+ }
+
+ @Override
+ public Object get(String providerKey) {
+ return configuredTarget == null ? null : configuredTarget.get(providerKey);
+ }
+
+ @Override
+ public Target getTarget() {
+ return configuredTarget == null ? null : configuredTarget.getTarget();
+ }
+
+ @Override
+ public BuildConfiguration getConfiguration() {
+ return configuredTarget.getConfiguration();
+ }
+
+ /* ClassObject methods */
+
+ @Override
+ public Object getValue(String name) {
+ if (name.equals("label")) {
+ return getLabel();
+ } else if (name.equals("files")) {
+ // A shortcut for files to build in Skylark. FileConfiguredTarget and RunleConfiguredTarget
+ // always has FileProvider and Error- and PackageGroupConfiguredTarget-s shouldn't be
+ // accessible in Skylark.
+ return SkylarkNestedSet.of(Artifact.class, configuredTarget == null
+ ? NestedSetBuilder.<Artifact>emptySet(Order.STABLE_ORDER)
+ : getProvider(FileProvider.class).getFilesToBuild());
+ }
+ return configuredTarget == null ? null : configuredTarget.get(name);
+ }
+
+ @Override
+ public ImmutableCollection<String> getKeys() {
+ ImmutableList.Builder<String> result = ImmutableList.<String>builder().add("label", "files");
+ if (configuredTarget != null) {
+ result.addAll(configuredTarget.getProvider(SkylarkProviders.class).getKeys());
+ }
+ return result.build();
+ }
+
+ @Override
+ public String errorMessage(String name) {
+ // Use the default error message.
+ return null;
+ }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/AliasProvider.java b/src/main/java/com/google/devtools/build/lib/rules/AliasProvider.java
new file mode 100644
index 0000000..a6950b2
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/AliasProvider.java
@@ -0,0 +1,79 @@
+// 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;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.analysis.ConfiguredTarget;
+import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import com.google.devtools.build.lib.util.Preconditions;
+
+/**
+ * A provider that gives information about the aliases a rule was resolved through.
+ */
+@Immutable
+public final class AliasProvider implements TransitiveInfoProvider {
+ // We don't expect long alias chains, so it's better to have a list instead of a nested set
+ private final ImmutableList<Label> aliasChain;
+
+ public AliasProvider(ImmutableList<Label> aliasChain) {
+ Preconditions.checkState(!aliasChain.isEmpty());
+ this.aliasChain = aliasChain;
+ }
+
+ public static AliasProvider fromAliasRule(Label label, ConfiguredTarget actual) {
+ ImmutableList.Builder<Label> chain = ImmutableList.builder();
+ chain.add(label);
+ AliasProvider dep = actual.getProvider(AliasProvider.class);
+ if (dep != null) {
+ chain.addAll(dep.getAliasChain());
+ }
+
+ return new AliasProvider(chain.build());
+ }
+
+ /**
+ * Returns the label by which it was referred to in the BUILD file.
+ *
+ * <p>For non-alias rules, it's the label of the rule itself, for alias rules, it's the label of
+ * the alias rule.
+ */
+ public static Label getDependencyLabel(TransitiveInfoCollection dep) {
+ AliasProvider aliasProvider = dep.getProvider(AliasProvider.class);
+ return aliasProvider != null
+ ? aliasProvider.getAliasChain().get(0)
+ : dep.getLabel();
+ }
+
+ /**
+ * Returns the list of aliases from top to bottom (i.e. the last alias depends on the actual
+ * resolved target and the first alias is the one that was in the attribute of the rule currently
+ * being analyzed)
+ */
+ public ImmutableList<Label> getAliasChain() {
+ return aliasChain;
+ }
+
+ public static String printVisibilityChain(ConfiguredTarget target) {
+ AliasProvider aliasProvider = target.getProvider(AliasProvider.class);
+ if (aliasProvider == null) {
+ return "";
+ }
+
+ return " (aliased through '" + Joiner.on("' -> '").join(aliasProvider.getAliasChain()) + "')";
+ }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleImplementationFunctions.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleImplementationFunctions.java
index 44f637f..ffe2fca 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleImplementationFunctions.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleImplementationFunctions.java
@@ -372,7 +372,7 @@
for (AbstractConfiguredTarget current : knownLabels) {
builder.put(
- current.getLabel(),
+ AliasProvider.getDependencyLabel(current),
ImmutableList.copyOf(current.getProvider(FileProvider.class).getFilesToBuild()));
}
diff --git a/src/main/java/com/google/devtools/build/lib/rules/repository/Bind.java b/src/main/java/com/google/devtools/build/lib/rules/repository/Bind.java
index 6ea3ede..a832903 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/repository/Bind.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/repository/Bind.java
@@ -14,107 +14,20 @@
package com.google.devtools.build.lib.rules.repository;
-import com.google.common.collect.ImmutableCollection;
-import com.google.common.collect.ImmutableList;
-import com.google.devtools.build.lib.actions.Artifact;
+import com.google.common.collect.ImmutableMap;
import com.google.devtools.build.lib.analysis.ConfiguredTarget;
-import com.google.devtools.build.lib.analysis.FileProvider;
import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
import com.google.devtools.build.lib.analysis.RuleContext;
-import com.google.devtools.build.lib.analysis.SkylarkProviders;
import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
-import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
-import com.google.devtools.build.lib.cmdline.Label;
-import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
-import com.google.devtools.build.lib.collect.nestedset.Order;
-import com.google.devtools.build.lib.packages.Target;
+import com.google.devtools.build.lib.rules.AliasConfiguredTarget;
+import com.google.devtools.build.lib.rules.AliasProvider;
import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
-import com.google.devtools.build.lib.syntax.ClassObject;
-import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
/**
* Implementation for the bind rule.
*/
public class Bind implements RuleConfiguredTargetFactory {
- /**
- * This configured target pretends to be whatever type of target "actual" is, returning its
- * transitive info providers and target, but returning the label for the //external target.
- */
- private static class BindConfiguredTarget implements ConfiguredTarget, ClassObject {
-
- private Label label;
- private ConfiguredTarget configuredTarget;
- private BuildConfiguration config;
-
- BindConfiguredTarget(RuleContext ruleContext) {
- label = ruleContext.getRule().getLabel();
- config = ruleContext.getConfiguration();
- // TODO(bazel-team): we should special case ConfiguredTargetFactory.createConfiguredTarget,
- // not cast down here.
- configuredTarget = (ConfiguredTarget) ruleContext.getPrerequisite("actual", Mode.TARGET);
- }
-
- @Override
- public <P extends TransitiveInfoProvider> P getProvider(Class<P> provider) {
- return configuredTarget == null ? null : configuredTarget.getProvider(provider);
- }
-
- @Override
- public Label getLabel() {
- return label;
- }
-
- @Override
- public Object get(String providerKey) {
- return configuredTarget == null ? null : configuredTarget.get(providerKey);
- }
-
- @Override
- public Target getTarget() {
- return configuredTarget == null ? null : configuredTarget.getTarget();
- }
-
- @Override
- public BuildConfiguration getConfiguration() {
- return config;
- }
-
- /* ClassObject methods */
-
- @Override
- public Object getValue(String name) {
- if (name.equals("label")) {
- return getLabel();
- } else if (name.equals("files")) {
- // A shortcut for files to build in Skylark. FileConfiguredTarget and RunleConfiguredTarget
- // always has FileProvider and Error- and PackageGroupConfiguredTarget-s shouldn't be
- // accessible in Skylark.
- return SkylarkNestedSet.of(Artifact.class, configuredTarget == null
- ? NestedSetBuilder.<Artifact>emptySet(Order.STABLE_ORDER)
- : getProvider(FileProvider.class).getFilesToBuild());
- }
- return configuredTarget == null ? null : configuredTarget.get(name);
- }
-
- @SuppressWarnings("cast")
- @Override
- public ImmutableCollection<String> getKeys() {
- ImmutableList.Builder<String> result = ImmutableList.<String>builder().add("label", "files");
- if (configuredTarget != null) {
- result.addAll(
- configuredTarget.getProvider(SkylarkProviders.class).getKeys());
- }
- return result.build();
- }
-
- @Override
- public String errorMessage(String name) {
- // Use the default error message.
- return null;
- }
- }
-
@Override
public ConfiguredTarget create(RuleContext ruleContext) throws InterruptedException {
if (ruleContext.getPrerequisite("actual", Mode.TARGET) == null) {
@@ -122,6 +35,10 @@
ruleContext.getLabel()));
return null;
}
- return new BindConfiguredTarget(ruleContext);
+
+ ConfiguredTarget actual = (ConfiguredTarget) ruleContext.getPrerequisite("actual", Mode.TARGET);
+ return new AliasConfiguredTarget(actual,
+ ImmutableMap.<Class<? extends TransitiveInfoProvider>, TransitiveInfoProvider>of(
+ AliasProvider.class, AliasProvider.fromAliasRule(ruleContext.getLabel(), actual)));
}
}
