Refactor the representation of a collection of package specifications

PiperOrigin-RevId: 175832159

16 files changed, 144 insertions, 90 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
index 768d0ad152..a846022a20 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
@@ -69,6 +69,7 @@ import com.google.devtools.build.lib.packages.NoSuchPackageException;
 import com.google.devtools.build.lib.packages.NoSuchTargetException;
 import com.google.devtools.build.lib.packages.NoSuchThingException;
 import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.packages.RawAttributeMapper;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleTransitionFactory;
@@ -1136,8 +1137,9 @@ public class BuildView {
             ruleClassProvider.getPrerequisiteValidator(),
             ((Rule) target.getTarget()).getRuleClassObject().getConfigurationFragmentPolicy())
         .setVisibility(
-            NestedSetBuilder.<PackageSpecification>create(
-                Order.STABLE_ORDER, PackageSpecification.everything()))
+            NestedSetBuilder.create(
+                Order.STABLE_ORDER,
+                PackageGroupContents.create(ImmutableList.of(PackageSpecification.everything()))))
         .setPrerequisites(
             getPrerequisiteMapForTesting(eventHandler, target, configurations, toolchainContext))
         .setConfigConditions(ImmutableMap.<Label, ConfigMatchingProvider>of())
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java
index 767d220cf3..31c436e9e9 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredTargetFactory.java
@@ -58,6 +58,7 @@ import com.google.devtools.build.lib.packages.OutputFile;
 import com.google.devtools.build.lib.packages.PackageGroup;
 import com.google.devtools.build.lib.packages.PackageGroupsRuleVisibility;
 import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.RuleClass.ConfiguredTargetFactory.RuleErrorException;
@@ -95,21 +96,23 @@ public final class ConfiguredTargetFactory {
    * Returns the visibility of the given target. Errors during package group resolution are reported
    * to the {@code AnalysisEnvironment}.
    */
-  private NestedSet<PackageSpecification> convertVisibility(
-      OrderedSetMultimap<Attribute, ConfiguredTarget> prerequisiteMap, EventHandler reporter,
-      Target target, BuildConfiguration packageGroupConfiguration) {
+  private NestedSet<PackageGroupContents> convertVisibility(
+      OrderedSetMultimap<Attribute, ConfiguredTarget> prerequisiteMap,
+      EventHandler reporter,
+      Target target,
+      BuildConfiguration packageGroupConfiguration) {
     RuleVisibility ruleVisibility = target.getVisibility();
     if (ruleVisibility instanceof ConstantRuleVisibility) {
       return ((ConstantRuleVisibility) ruleVisibility).isPubliclyVisible()
-          ? NestedSetBuilder.<PackageSpecification>create(
-              Order.STABLE_ORDER, PackageSpecification.everything())
-          : NestedSetBuilder.<PackageSpecification>emptySet(Order.STABLE_ORDER);
+          ? NestedSetBuilder.create(
+              Order.STABLE_ORDER,
+              PackageGroupContents.create(ImmutableList.of(PackageSpecification.everything())))
+          : NestedSetBuilder.emptySet(Order.STABLE_ORDER);
     } else if (ruleVisibility instanceof PackageGroupsRuleVisibility) {
       PackageGroupsRuleVisibility packageGroupsVisibility =
           (PackageGroupsRuleVisibility) ruleVisibility;
 
-      NestedSetBuilder<PackageSpecification> packageSpecifications =
-          NestedSetBuilder.stableOrder();
+      NestedSetBuilder<PackageGroupContents> result = NestedSetBuilder.stableOrder();
       for (Label groupLabel : packageGroupsVisibility.getPackageGroups()) {
         // PackageGroupsConfiguredTargets are always in the package-group configuration.
         ConfiguredTarget group =
@@ -127,15 +130,15 @@ public final class ConfiguredTargetFactory {
           provider = group.getProvider(PackageSpecificationProvider.class);
         }
         if (provider != null) {
-          packageSpecifications.addTransitive(provider.getPackageSpecifications());
+          result.addTransitive(provider.getPackageSpecifications());
         } else {
           reporter.handle(Event.error(target.getLocation(),
               String.format("Label '%s' does not refer to a package group", groupLabel)));
         }
       }
 
-      packageSpecifications.addAll(packageGroupsVisibility.getDirectPackages());
-      return packageSpecifications.build();
+      result.add(packageGroupsVisibility.getDirectPackages());
+      return result.build();
     } else {
       throw new IllegalStateException("unknown visibility");
     }
@@ -244,8 +247,8 @@ public final class ConfiguredTargetFactory {
     }
 
     // Visibility, like all package groups, doesn't have a configuration
-    NestedSet<PackageSpecification> visibility = convertVisibility(
-        prerequisiteMap, analysisEnvironment.getEventHandler(), target, null);
+    NestedSet<PackageGroupContents> visibility =
+        convertVisibility(prerequisiteMap, analysisEnvironment.getEventHandler(), target, null);
     TargetContext targetContext = new TargetContext(analysisEnvironment, target, config,
         prerequisiteMap.get(null), visibility);
     if (target instanceof OutputFile) {
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/PackageSpecificationProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/PackageSpecificationProvider.java
index 436a72e3b0..495beae93b 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/PackageSpecificationProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/PackageSpecificationProvider.java
@@ -15,12 +15,12 @@
 package com.google.devtools.build.lib.analysis;
 
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 
 /**
  * A {@link TransitiveInfoProvider} that describes a set of transitive package specifications
  * used in package groups.
  */
 public interface PackageSpecificationProvider extends TransitiveInfoProvider {
-  NestedSet<PackageSpecification> getPackageSpecifications();
+  NestedSet<PackageGroupContents> getPackageSpecifications();
 }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
index 841c47e9ba..3223ae8393 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/RuleContext.java
@@ -74,7 +74,7 @@ import com.google.devtools.build.lib.packages.Info;
 import com.google.devtools.build.lib.packages.InputFile;
 import com.google.devtools.build.lib.packages.NativeProvider;
 import com.google.devtools.build.lib.packages.OutputFile;
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.packages.RawAttributeMapper;
 import com.google.devtools.build.lib.packages.RequiredProviders;
 import com.google.devtools.build.lib.packages.Rule;
@@ -1303,8 +1303,8 @@ public final class RuleContext extends TargetContext
    */
   public static boolean isVisible(Rule rule, TransitiveInfoCollection prerequisite) {
     // Check visibility attribute
-    for (PackageSpecification specification :
-      prerequisite.getProvider(VisibilityProvider.class).getVisibility()) {
+    for (PackageGroupContents specification :
+        prerequisite.getProvider(VisibilityProvider.class).getVisibility()) {
       if (specification.containsPackage(rule.getLabel().getPackageIdentifier())) {
         return true;
       }
@@ -1339,7 +1339,7 @@ public final class RuleContext extends TargetContext
     private final ErrorReporter reporter;
     private OrderedSetMultimap<Attribute, ConfiguredTarget> prerequisiteMap;
     private ImmutableMap<Label, ConfigMatchingProvider> configConditions;
-    private NestedSet<PackageSpecification> visibility;
+    private NestedSet<PackageGroupContents> visibility;
     private ImmutableMap<String, Attribute> aspectAttributes;
     private ImmutableList<AspectDescriptor> aspectDescriptors;
     private ToolchainContext toolchainContext;
@@ -1387,7 +1387,7 @@ public final class RuleContext extends TargetContext
       rule.getRuleClassObject().checkAttributesNonEmpty(rule, reporter, attributes);
     }
 
-    Builder setVisibility(NestedSet<PackageSpecification> visibility) {
+    Builder setVisibility(NestedSet<PackageGroupContents> visibility) {
       this.visibility = visibility;
       return this;
     }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/TargetContext.java b/src/main/java/com/google/devtools/build/lib/analysis/TargetContext.java
index 40eaa8c1e1..e6ea9902b2 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/TargetContext.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/TargetContext.java
@@ -21,7 +21,7 @@ import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTarget;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.packages.Target;
 import java.util.List;
 import javax.annotation.Nullable;
@@ -46,16 +46,20 @@ public class TargetContext {
    * attribute in case of a rule). Rule attributes are handled by the {@link RuleContext} subclass.
    */
   private final List<ConfiguredTarget> directPrerequisites;
-  private final NestedSet<PackageSpecification> visibility;
+
+  private final NestedSet<PackageGroupContents> visibility;
 
   /**
    * The constructor is intentionally package private.
    *
    * <p>directPrerequisites is expected to be ordered.
    */
-  TargetContext(AnalysisEnvironment env, Target target, BuildConfiguration configuration,
+  TargetContext(
+      AnalysisEnvironment env,
+      Target target,
+      BuildConfiguration configuration,
       Iterable<ConfiguredTarget> directPrerequisites,
-      NestedSet<PackageSpecification> visibility) {
+      NestedSet<PackageGroupContents> visibility) {
     this.env = env;
     this.target = target;
     this.configuration = configuration;
@@ -85,7 +89,7 @@ public class TargetContext {
     return configuration;
   }
 
-  public NestedSet<PackageSpecification> getVisibility() {
+  public NestedSet<PackageGroupContents> getVisibility() {
     return visibility;
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProvider.java
index ce6fb03f12..44edd90e74 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProvider.java
@@ -15,15 +15,13 @@
 package com.google.devtools.build.lib.analysis;
 
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 
 /**
  * Provider class for configured targets that have a visibility.
  */
 public interface VisibilityProvider extends TransitiveInfoProvider {
 
-  /**
-   * Returns the visibility specification.
-   */
-  NestedSet<PackageSpecification> getVisibility();
+  /** Returns the visibility specification. */
+  NestedSet<PackageGroupContents> getVisibility();
 }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProviderImpl.java b/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProviderImpl.java
index f84fe36615..239d4edd32 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProviderImpl.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/VisibilityProviderImpl.java
@@ -16,21 +16,21 @@ package com.google.devtools.build.lib.analysis;
 
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 
 /**
  * Visibility provider implementation.
  */
 @Immutable
 public final class VisibilityProviderImpl implements VisibilityProvider {
-  private final NestedSet<PackageSpecification> visibility;
+  private final NestedSet<PackageGroupContents> visibility;
 
-  public VisibilityProviderImpl(NestedSet<PackageSpecification> visibility) {
+  public VisibilityProviderImpl(NestedSet<PackageGroupContents> visibility) {
     this.visibility = visibility;
   }
 
   @Override
-  public NestedSet<PackageSpecification> getVisibility() {
+  public NestedSet<PackageGroupContents> getVisibility() {
     return visibility;
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/AbstractConfiguredTarget.java b/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/AbstractConfiguredTarget.java
index b0e5a2446e..5c9c463e9b 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/AbstractConfiguredTarget.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/AbstractConfiguredTarget.java
@@ -33,7 +33,7 @@ import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.packages.Info;
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.packages.Provider;
 import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
@@ -54,7 +54,7 @@ public abstract class AbstractConfiguredTarget
   private final Target target;
   private final BuildConfiguration configuration;
 
-  private final NestedSet<PackageSpecification> visibility;
+  private final NestedSet<PackageGroupContents> visibility;
 
   // Cached on-demand default provider
   private final AtomicReference<DefaultInfo> defaultProvider = new AtomicReference<>();
@@ -77,7 +77,7 @@ public abstract class AbstractConfiguredTarget
   }
 
   @Override
-  public final NestedSet<PackageSpecification> getVisibility() {
+  public final NestedSet<PackageGroupContents> getVisibility() {
     return visibility;
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/PackageGroupConfiguredTarget.java b/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/PackageGroupConfiguredTarget.java
index 9d6d3c6786..a729e69f0d 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/PackageGroupConfiguredTarget.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/configuredtargets/PackageGroupConfiguredTarget.java
@@ -28,7 +28,7 @@ import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.packages.Info;
 import com.google.devtools.build.lib.packages.PackageGroup;
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.packages.Provider;
 
 /**
@@ -40,14 +40,13 @@ public final class PackageGroupConfiguredTarget extends AbstractConfiguredTarget
   private static final FileProvider NO_FILES = new FileProvider(
       NestedSetBuilder.<Artifact>emptySet(Order.STABLE_ORDER));
 
-  private final NestedSet<PackageSpecification> packageSpecifications;
+  private final NestedSet<PackageGroupContents> packageSpecifications;
 
   public PackageGroupConfiguredTarget(TargetContext targetContext, PackageGroup packageGroup) {
     super(targetContext);
     Preconditions.checkArgument(targetContext.getConfiguration() == null);
 
-    NestedSetBuilder<PackageSpecification> builder =
-        NestedSetBuilder.stableOrder();
+    NestedSetBuilder<PackageGroupContents> builder = NestedSetBuilder.stableOrder();
     for (Label label : packageGroup.getIncludes()) {
       TransitiveInfoCollection include = targetContext.maybeFindDirectPrerequisite(
           label, targetContext.getConfiguration());
@@ -62,7 +61,7 @@ public final class PackageGroupConfiguredTarget extends AbstractConfiguredTarget
       builder.addTransitive(provider.getPackageSpecifications());
     }
 
-    builder.addAll(packageGroup.getPackageSpecifications());
+    builder.add(packageGroup.getPackageSpecifications());
     packageSpecifications = builder.build();
   }
 
@@ -72,7 +71,7 @@ public final class PackageGroupConfiguredTarget extends AbstractConfiguredTarget
   }
 
   @Override
-  public NestedSet<PackageSpecification> getPackageSpecifications() {
+  public NestedSet<PackageGroupContents> getPackageSpecifications() {
     return packageSpecifications;
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageGroup.java b/src/main/java/com/google/devtools/build/lib/packages/PackageGroup.java
index bffd92941d..4e35fc4991 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageGroup.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageGroup.java
@@ -14,13 +14,15 @@
 
 package com.google.devtools.build.lib.packages;
 
+import static com.google.common.collect.ImmutableList.toImmutableList;
+
 import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Lists;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.packages.License.DistributionType;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -36,7 +38,7 @@ public class PackageGroup implements Target {
   private final Label label;
   private final Location location;
   private final Package containingPackage;
-  private final List<PackageSpecification> packageSpecifications;
+  private final PackageGroupContents packageSpecifications;
   private final List<Label> includes;
 
   public PackageGroup(
@@ -67,25 +69,19 @@ public class PackageGroup implements Target {
         packagesBuilder.add(specification);
       }
     }
-    this.packageSpecifications = packagesBuilder.build();
+    this.packageSpecifications = PackageGroupContents.create(packagesBuilder.build());
   }
 
   public boolean containsErrors() {
     return containsErrors;
   }
 
-  public Iterable<PackageSpecification> getPackageSpecifications() {
+  public PackageGroupContents getPackageSpecifications() {
     return packageSpecifications;
   }
 
   public boolean contains(Package pkg) {
-    for (PackageSpecification specification : packageSpecifications) {
-      if (specification.containsPackage(pkg.getPackageIdentifier())) {
-        return true;
-      }
-    }
-
-    return false;
+    return packageSpecifications.containsPackage(pkg.getPackageIdentifier());
   }
 
   public List<Label> getIncludes() {
@@ -93,11 +89,7 @@ public class PackageGroup implements Target {
   }
 
   public List<String> getContainedPackages() {
-    List<String> result = Lists.newArrayListWithCapacity(packageSpecifications.size());
-    for (PackageSpecification specification : packageSpecifications) {
-      result.add(specification.toString());
-    }
-    return result;
+    return packageSpecifications.containedPackages().collect(toImmutableList());
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageGroupsRuleVisibility.java b/src/main/java/com/google/devtools/build/lib/packages/PackageGroupsRuleVisibility.java
index c5eb1db615..14e400daba 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageGroupsRuleVisibility.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageGroupsRuleVisibility.java
@@ -17,7 +17,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
-
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import java.util.Collection;
 import java.util.List;
 
@@ -29,7 +29,7 @@ public class PackageGroupsRuleVisibility implements RuleVisibility {
   public static final String PACKAGE_LABEL = "__pkg__";
   public static final String SUBTREE_LABEL = "__subpackages__";
   private final List<Label> packageGroups;
-  private final List<PackageSpecification> directPackages;
+  private final PackageGroupContents directPackages;
   private final List<Label> declaredLabels;
 
   public PackageGroupsRuleVisibility(Label ruleLabel, List<Label> labels) {
@@ -48,14 +48,14 @@ public class PackageGroupsRuleVisibility implements RuleVisibility {
     }
 
     packageGroups = packageGroupBuilder.build();
-    directPackages = directPackageBuilder.build();
+    directPackages = PackageGroupContents.create(directPackageBuilder.build());
   }
 
   public Collection<Label> getPackageGroups() {
     return packageGroups;
   }
 
-  public Collection<PackageSpecification> getDirectPackages() {
+  public PackageGroupContents getDirectPackages() {
     return directPackages;
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageSpecification.java b/src/main/java/com/google/devtools/build/lib/packages/PackageSpecification.java
index a50a810d1e..63823fbcaa 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageSpecification.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageSpecification.java
@@ -14,11 +14,14 @@
 package com.google.devtools.build.lib.packages;
 
 import com.google.common.base.Verify;
+import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
 import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.cmdline.RepositoryName;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.vfs.PathFragment;
+import java.util.stream.Stream;
 
 /**
  * Represents one of the following:
@@ -42,7 +45,7 @@ public abstract class PackageSpecification {
   private static final String ALL_BENEATH_SUFFIX = "/...";
 
   /** Returns {@code true} if the package spec includes the provided {@code packageName}. */
-  public abstract boolean containsPackage(PackageIdentifier packageName);
+  protected abstract boolean containsPackage(PackageIdentifier packageName);
 
   /**
    * Returns a {@link String} representation of the {@link PackageSpecification} of the same format
@@ -51,7 +54,7 @@ public abstract class PackageSpecification {
    * <p>The returned {@link String} is insensitive to the {@link RepositoryName} associated with the
    * {@link PackageSpecification}.
    */
-  public abstract String toStringWithoutRepository();
+  protected abstract String toStringWithoutRepository();
 
   /**
    * Parses the provided {@link String} into a {@link PackageSpecification}.
@@ -146,12 +149,12 @@ public abstract class PackageSpecification {
     }
 
     @Override
-    public boolean containsPackage(PackageIdentifier packageName) {
+    protected boolean containsPackage(PackageIdentifier packageName) {
       return this.singlePackageName.equals(packageName);
     }
 
     @Override
-    public String toStringWithoutRepository() {
+    protected String toStringWithoutRepository() {
       return "//" + singlePackageName.getPackageFragment().getPathString();
     }
 
@@ -186,13 +189,13 @@ public abstract class PackageSpecification {
     }
 
     @Override
-    public boolean containsPackage(PackageIdentifier packageName) {
+    protected boolean containsPackage(PackageIdentifier packageName) {
       return packageName.getRepository().equals(prefix.getRepository())
           && packageName.getPackageFragment().startsWith(prefix.getPackageFragment());
     }
 
     @Override
-    public String toStringWithoutRepository() {
+    protected String toStringWithoutRepository() {
       return "//" + prefix.getPackageFragment().getPathString() + ALL_BENEATH_SUFFIX;
     }
 
@@ -227,12 +230,12 @@ public abstract class PackageSpecification {
     private static final PackageSpecification EVERYTHING = new AllPackages();
 
     @Override
-    public boolean containsPackage(PackageIdentifier packageName) {
+    protected boolean containsPackage(PackageIdentifier packageName) {
       return true;
     }
 
     @Override
-    public String toStringWithoutRepository() {
+    protected String toStringWithoutRepository() {
       return "//...";
     }
 
@@ -258,4 +261,54 @@ public abstract class PackageSpecification {
       super(message);
     }
   }
+
+  /**
+   * A collection of {@link PackageSpecification}s from a {@code package_group}, which supports
+   * testing a given package for containment (see {@link #containedPackages()}}.
+   */
+  @Immutable
+  public static final class PackageGroupContents {
+
+    private final ImmutableList<PackageSpecification> packageSpecifications;
+
+    private PackageGroupContents(ImmutableList<PackageSpecification> packageSpecifications) {
+      this.packageSpecifications = packageSpecifications;
+    }
+
+    /**
+     * Creates a {@link PackageGroupContents} representing a collection of {@link
+     * PackageSpecification}s.
+     */
+    public static PackageGroupContents create(
+        ImmutableList<PackageSpecification> packageSpecifications) {
+      return new PackageGroupContents(packageSpecifications);
+    }
+
+    /**
+     * Returns {@code true} if the package specifications include the provided {@code packageName}.
+     * That is, at least one positive package specification matches.
+     */
+    public boolean containsPackage(PackageIdentifier packageIdentifier) {
+      return packageSpecifications.stream().anyMatch(p -> p.containsPackage(packageIdentifier));
+    }
+
+    /**
+     * Returns {@link String} representations of the component {@link PackageSpecification}s of the
+     * same format accepted by {@link #fromString}.
+     */
+    public Stream<String> containedPackages() {
+      return packageSpecifications.stream().map(PackageSpecification::toString);
+    }
+
+    /**
+     * Returns {@link String} representations of the component {@link PackageSpecification}s of the
+     * same format accepted by {@link #fromString}.
+     *
+     * <p>The returned {@link String}s are insensitive to the {@link RepositoryName} associated with
+     * the {@link PackageSpecification}.
+     */
+    public Stream<String> containedPackagesWithoutRepository() {
+      return packageSpecifications.stream().map(PackageSpecification::toStringWithoutRepository);
+    }
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryVisibility.java b/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryVisibility.java
index 427ea8483b..a2c5d78c7c 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryVisibility.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/BlazeQueryVisibility.java
@@ -14,26 +14,26 @@
 
 package com.google.devtools.build.lib.query2;
 
-import com.google.devtools.build.lib.packages.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.query2.engine.QueryVisibility;
 
-/** An adapter from a {@link PackageSpecification} to a {@link QueryVisibility}. */
+/** An adapter from {@link PackageGroupContents} to a {@link QueryVisibility}. */
 public class BlazeQueryVisibility extends QueryVisibility<Target> {
 
-  private final PackageSpecification packageSpecification;
+  private final PackageGroupContents packageSpecifications;
 
-  public BlazeQueryVisibility(PackageSpecification packageSpecification) {
-    this.packageSpecification = packageSpecification;
+  public BlazeQueryVisibility(PackageGroupContents packageSpecifications) {
+    this.packageSpecifications = packageSpecifications;
   }
 
   @Override
   public boolean contains(Target target) {
-    return packageSpecification.containsPackage(target.getLabel().getPackageIdentifier());
+    return packageSpecifications.containsPackage(target.getLabel().getPackageIdentifier());
   }
 
   @Override
   public String toString() {
-    return packageSpecification.toString();
+    return packageSpecifications.toString();
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/query2/BlazeTargetAccessor.java b/src/main/java/com/google/devtools/build/lib/query2/BlazeTargetAccessor.java
index e4f4febbc6..62b26f5f0c 100644
--- a/src/main/java/com/google/devtools/build/lib/query2/BlazeTargetAccessor.java
+++ b/src/main/java/com/google/devtools/build/lib/query2/BlazeTargetAccessor.java
@@ -21,7 +21,6 @@ import com.google.devtools.build.lib.packages.AggregatingAttributeMapper;
 import com.google.devtools.build.lib.packages.ConstantRuleVisibility;
 import com.google.devtools.build.lib.packages.PackageGroup;
 import com.google.devtools.build.lib.packages.PackageGroupsRuleVisibility;
-import com.google.devtools.build.lib.packages.PackageSpecification;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleVisibility;
 import com.google.devtools.build.lib.packages.Target;
@@ -150,9 +149,8 @@ final class BlazeTargetAccessor implements TargetAccessor<Target> {
          throw new QueryException(e.getMessage());
        }
      }
-     for (PackageSpecification spec : packageGroupsVisibility.getDirectPackages()) {
-       packageSpecifications.add(new BlazeQueryVisibility(spec));
-     }
+      packageSpecifications.add(
+          new BlazeQueryVisibility(packageGroupsVisibility.getDirectPackages()));
      return;
    } else {
      throw new IllegalStateException("unknown visibility: " + ruleVisibility.getClass());
@@ -166,8 +164,6 @@ final class BlazeTargetAccessor implements TargetAccessor<Target> {
       convertGroupVisibility((PackageGroup) queryEnvironment.getTarget(include),
           packageSpecifications);
     }
-    for (PackageSpecification spec : group.getPackageSpecifications()) {
-      packageSpecifications.add(new BlazeQueryVisibility(spec));
-    }
+    packageSpecifications.add(new BlazeQueryVisibility(group.getPackageSpecifications()));
   }
 }
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 614c78479c..4f9edc3487 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
@@ -14,6 +14,7 @@
 
 package com.google.devtools.build.lib.rules.repository;
 
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.AliasProvider;
 import com.google.devtools.build.lib.analysis.ConfiguredTarget;
@@ -26,6 +27,7 @@ import com.google.devtools.build.lib.analysis.configuredtargets.RuleConfiguredTa
 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.PackageSpecification;
+import com.google.devtools.build.lib.packages.PackageSpecification.PackageGroupContents;
 import com.google.devtools.build.lib.rules.AliasConfiguredTarget;
 
 /**
@@ -51,6 +53,9 @@ public class Bind implements RuleConfiguredTargetFactory {
             AliasProvider.fromAliasRule(ruleContext.getLabel(), actual),
             VisibilityProvider.class,
             new VisibilityProviderImpl(
-                NestedSetBuilder.create(Order.STABLE_ORDER, PackageSpecification.everything()))));
+                NestedSetBuilder.create(
+                    Order.STABLE_ORDER,
+                    PackageGroupContents.create(
+                        ImmutableList.of(PackageSpecification.everything()))))));
   }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/packages/PackageGroupTest.java b/src/test/java/com/google/devtools/build/lib/packages/PackageGroupTest.java
index 7bb8caeb17..4c48f0e62c 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/PackageGroupTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/PackageGroupTest.java
@@ -13,6 +13,7 @@
 // limitations under the License.
 package com.google.devtools.build.lib.packages;
 
+import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.common.truth.Truth.assertThat;
 
 import com.google.devtools.build.lib.events.util.EventCollectionApparatus;
@@ -146,8 +147,9 @@ public class PackageGroupTest {
   public void testEverythingSpecificationWorks() throws Exception {
     scratch.file("fruits/BUILD", "package_group(name = 'mango', packages = ['//...'])");
     PackageGroup packageGroup = getPackageGroup("fruits", "mango");
-    assertThat(packageGroup.getPackageSpecifications())
-        .containsExactly(PackageSpecification.everything());
+    assertThat(
+            packageGroup.getPackageSpecifications().containedPackages().collect(toImmutableList()))
+        .containsExactly(PackageSpecification.everything().toString());
   }
 
   private Package getPackage(String packageName) throws Exception {