Migrate DefaultInfo and its provider to skylarkbuildapi

RELNOTES: None.
PiperOrigin-RevId: 201544076

10 files changed, 358 insertions, 135 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/DefaultInfo.java b/src/main/java/com/google/devtools/build/lib/analysis/DefaultInfo.java
index 642410567d..4da947e0bd 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/DefaultInfo.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/DefaultInfo.java
@@ -13,90 +13,145 @@
 // limitations under the License.
 package com.google.devtools.build.lib.analysis;
 
-import com.google.common.collect.ImmutableCollection;
-import com.google.common.collect.ImmutableList;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.events.Location;
+import com.google.devtools.build.lib.packages.BuiltinProvider;
 import com.google.devtools.build.lib.packages.NativeInfo;
-import com.google.devtools.build.lib.packages.NativeProvider;
-import com.google.devtools.build.lib.syntax.Environment;
+import com.google.devtools.build.lib.skylarkbuildapi.DefaultInfoApi;
+import com.google.devtools.build.lib.skylarkbuildapi.FilesToRunProviderApi;
+import com.google.devtools.build.lib.syntax.EvalException;
+import com.google.devtools.build.lib.syntax.Runtime;
 import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
-import java.util.Map;
-import java.util.concurrent.atomic.AtomicReference;
+import javax.annotation.Nullable;
 
 /** DefaultInfo is provided by all targets implicitly and contains all standard fields. */
 @Immutable
-public final class DefaultInfo extends NativeInfo {
-
-  // Accessors for Skylark
-  private static final String DATA_RUNFILES_FIELD = "data_runfiles";
-  private static final String DEFAULT_RUNFILES_FIELD = "default_runfiles";
-  private static final String FILES_FIELD = "files";
-  private static final ImmutableList<String> KEYS =
-      ImmutableList.of(
-          DATA_RUNFILES_FIELD,
-          DEFAULT_RUNFILES_FIELD,
-          FILES_FIELD,
-          FilesToRunProvider.SKYLARK_NAME);
-
-  private final RunfilesProvider runfilesProvider;
-  private final FileProvider fileProvider;
+public final class DefaultInfo extends NativeInfo implements DefaultInfoApi {
+
+  private final SkylarkNestedSet files;
+  private final Runfiles runfiles;
+  private final Runfiles dataRunfiles;
+  private final Runfiles defaultRunfiles;
+  private final Artifact executable;
   private final FilesToRunProvider filesToRunProvider;
-  private final AtomicReference<SkylarkNestedSet> files = new AtomicReference<>();
-
-  public static final String SKYLARK_NAME = "DefaultInfo";
-
-  // todo(dslomov,vladmos): make this provider return DefaultInfo.
-  public static final NativeProvider<NativeInfo> PROVIDER =
-      new NativeProvider<NativeInfo>(NativeInfo.class, SKYLARK_NAME) {
-        @Override
-        protected NativeInfo createInstanceFromSkylark(
-            Object[] args, Environment env, Location loc) {
-          @SuppressWarnings("unchecked")
-          Map<String, Object> kwargs = (Map<String, Object>) args[0];
-          return new NativeInfo(this, kwargs, loc);
-        }
-      };
+
+  /**
+   * Singleton instance of the provider type for {@link DefaultInfo}.
+   */
+  public static final DefaultInfoProvider PROVIDER = new DefaultInfoProvider();
 
   private DefaultInfo(
-      RunfilesProvider runfilesProvider,
+      @Nullable RunfilesProvider runfilesProvider,
       FileProvider fileProvider,
       FilesToRunProvider filesToRunProvider) {
-    super(PROVIDER);
-    this.runfilesProvider = runfilesProvider;
-    this.fileProvider = fileProvider;
+    this(
+        Location.BUILTIN,
+        SkylarkNestedSet.of(Artifact.class, fileProvider.getFilesToBuild()),
+        Runfiles.EMPTY,
+        (runfilesProvider == null) ? Runfiles.EMPTY : runfilesProvider.getDataRunfiles(),
+        (runfilesProvider == null) ? Runfiles.EMPTY : runfilesProvider.getDefaultRunfiles(),
+        filesToRunProvider.getExecutable(),
+        filesToRunProvider
+    );
+  }
+
+  private DefaultInfo(
+      Location loc,
+      SkylarkNestedSet files, Runfiles runfiles,
+      Runfiles dataRunfiles, Runfiles defaultRunfiles, Artifact executable,
+      @Nullable FilesToRunProvider filesToRunProvider) {
+    super(PROVIDER, loc);
+    this.files = files;
+    this.runfiles = runfiles;
+    this.dataRunfiles = dataRunfiles;
+    this.defaultRunfiles = defaultRunfiles;
+    this.executable = executable;
     this.filesToRunProvider = filesToRunProvider;
   }
 
   public static DefaultInfo build(
-      RunfilesProvider runfilesProvider,
+      @Nullable RunfilesProvider runfilesProvider,
       FileProvider fileProvider,
       FilesToRunProvider filesToRunProvider) {
     return new DefaultInfo(runfilesProvider, fileProvider, filesToRunProvider);
   }
 
   @Override
-  public Object getValue(String name) {
-    switch (name) {
-      case DATA_RUNFILES_FIELD:
-        return (runfilesProvider == null) ? Runfiles.EMPTY : runfilesProvider.getDataRunfiles();
-      case DEFAULT_RUNFILES_FIELD:
-        return (runfilesProvider == null) ? Runfiles.EMPTY : runfilesProvider.getDefaultRunfiles();
-      case FILES_FIELD:
-        if (files.get() == null) {
-          files.compareAndSet(
-              null, SkylarkNestedSet.of(Artifact.class, fileProvider.getFilesToBuild()));
-        }
-        return files.get();
-      case FilesToRunProvider.SKYLARK_NAME:
-        return filesToRunProvider;
-    }
-    return null;
+  public SkylarkNestedSet getFiles() {
+    return files;
+  }
+
+  @Override
+  public FilesToRunProviderApi getFilesToRun() {
+    return filesToRunProvider;
+  }
+
+  /**
+   * Returns a set of runfiles acting as both the data runfiles and the default runfiles.
+   *
+   * This is kept for legacy reasons.
+   */
+  public Runfiles getStatelessRunfiles() {
+    return runfiles;
+  }
+
+  @Override
+  public Runfiles getDataRunfiles() {
+    return dataRunfiles;
   }
 
   @Override
-  public ImmutableCollection<String> getFieldNames() {
-    return KEYS;
+  public Runfiles getDefaultRunfiles() {
+    return defaultRunfiles;
+  }
+
+  /**
+   * If the rule producing this info object is marked 'executable' or 'test', this is an artifact
+   * representing the file that should be executed to run the target. This is null otherwise.
+   */
+  public Artifact getExecutable() {
+    return executable;
+  }
+
+  /**
+   * Provider implementation for {@link DefaultInfoApi}.
+   */
+  public static class DefaultInfoProvider extends BuiltinProvider<DefaultInfo>
+      implements DefaultInfoApi.DefaultInfoApiProvider<Runfiles, Artifact> {
+    private DefaultInfoProvider() {
+      super("DefaultInfo", DefaultInfo.class);
+    }
+
+    @Override
+    public DefaultInfo constructor(Object files, Object runfilesObj,
+        Object dataRunfilesObj, Object defaultRunfilesObj, Object executable, Location loc)
+        throws EvalException {
+
+      Runfiles statelessRunfiles = castNoneToNull(Runfiles.class, runfilesObj);
+      Runfiles dataRunfiles = castNoneToNull(Runfiles.class, dataRunfilesObj);
+      Runfiles defaultRunfiles = castNoneToNull(Runfiles.class, defaultRunfilesObj);
+
+      if ((statelessRunfiles != null) && (dataRunfiles != null || defaultRunfiles != null)) {
+        throw new EvalException(loc, "Cannot specify the provider 'runfiles' "
+            + "together with 'data_runfiles' or 'default_runfiles'");
+      }
+
+      return new DefaultInfo(
+          loc,
+          castNoneToNull(SkylarkNestedSet.class, files),
+          statelessRunfiles,
+          dataRunfiles,
+          defaultRunfiles,
+          castNoneToNull(Artifact.class, executable), null);
+    }
+  }
+
+  private static <T> T castNoneToNull(Class<T> clazz, Object value) {
+    if (value == Runtime.NONE) {
+      return null;
+    } else {
+      return clazz.cast(value);
+    }
   }
 }
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 18aa071b6d..ac626b32ca 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
@@ -209,11 +209,13 @@ public abstract class AbstractConfiguredTarget
     }
     switch (providerKey) {
       case FILES_FIELD:
+        return getDefaultProvider().getFiles();
       case DEFAULT_RUNFILES_FIELD:
+        return getDefaultProvider().getDefaultRunfiles();
       case DATA_RUNFILES_FIELD:
+        return getDefaultProvider().getDataRunfiles();
       case FilesToRunProvider.SKYLARK_NAME:
-        // Standard fields should be proxied to their default provider object
-        return getDefaultProvider().getValue(providerKey);
+        return getDefaultProvider().getFilesToRun();
       case OutputGroupInfo.SKYLARK_NAME:
         return get(OutputGroupInfo.SKYLARK_CONSTRUCTOR);
       default:
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkModules.java b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkModules.java
index 9f50d75077..a71bdab7ad 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkModules.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkModules.java
@@ -16,6 +16,7 @@ package com.google.devtools.build.lib.analysis.skylark;
 
 import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.ActionsProvider;
+import com.google.devtools.build.lib.analysis.DefaultInfo;
 import com.google.devtools.build.lib.analysis.OutputGroupInfo;
 import com.google.devtools.build.lib.packages.SkylarkNativeModule;
 import com.google.devtools.build.lib.packages.StructProvider;
@@ -40,7 +41,8 @@ public final class SkylarkModules {
           SkylarkRuleClassFunctions.class,
           StructProvider.STRUCT,
           OutputGroupInfo.SKYLARK_CONSTRUCTOR,
-          ActionsProvider.INSTANCE);
+          ActionsProvider.INSTANCE,
+          DefaultInfo.PROVIDER);
 
   /**
    * Adds bindings for skylark built-ins and non-rules-specific globals of the build API to
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java
index 410882456c..249c6b6ab2 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java
@@ -34,7 +34,6 @@ import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.analysis.BaseRuleClasses;
-import com.google.devtools.build.lib.analysis.DefaultInfo;
 import com.google.devtools.build.lib.analysis.TemplateVariableInfo;
 import com.google.devtools.build.lib.analysis.config.ConfigAwareRuleClassBuilder;
 import com.google.devtools.build.lib.analysis.config.HostTransition;
@@ -49,7 +48,6 @@ import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.AttributeValueSource;
 import com.google.devtools.build.lib.packages.ImplicitOutputsFunction.SkylarkImplicitOutputsFunctionWithCallback;
 import com.google.devtools.build.lib.packages.ImplicitOutputsFunction.SkylarkImplicitOutputsFunctionWithMap;
-import com.google.devtools.build.lib.packages.NativeProvider;
 import com.google.devtools.build.lib.packages.Package.NameConflictException;
 import com.google.devtools.build.lib.packages.PackageFactory;
 import com.google.devtools.build.lib.packages.PackageFactory.PackageContext;
@@ -72,7 +70,6 @@ import com.google.devtools.build.lib.packages.TestSize;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.skylarkbuildapi.SkylarkRuleFunctionsApi;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkPrinter;
-import com.google.devtools.build.lib.skylarkinterface.SkylarkSignature;
 import com.google.devtools.build.lib.syntax.BaseFunction;
 import com.google.devtools.build.lib.syntax.Environment;
 import com.google.devtools.build.lib.syntax.EvalException;
@@ -219,43 +216,6 @@ public class SkylarkRuleClassFunctions implements SkylarkRuleFunctionsApi<Artifa
         }
       };
 
-  @SkylarkSignature(
-    name = "DefaultInfo",
-    returnType = Provider.class,
-    doc =
-        "A provider that gives general information about a target's direct and transitive files. "
-            + "Every rule type has this provider, even if it is not returned explicitly by the "
-            + "rule's implementation function."
-            + "<p>The <code>DefaultInfo</code> constructor accepts the following parameters:"
-            + "<ul>"
-            + "<li><code>executable</code>: If this rule is marked "
-            + "<a href='globals.html#rule.executable'><code>executable</code></a> or "
-            + "<a href='globals.html#rule.test'><code>test</code></a>, this is a "
-            + "<a href='File.html'><code>File</code></a> object representing the file that should "
-            + "be executed to run the target. By default it is the predeclared output "
-            + "<code>ctx.outputs.executable</code>."
-            + "<li><code>files</code>: A <a href='depset.html'><code>depset</code></a> of "
-            + "<a href='File.html'><code>File</code></a> objects representing the default outputs "
-            + "to build when this target is specified on the blaze command line. By default it is "
-            + "all predeclared outputs."
-            + "<li><code>runfiles</code>: set of files acting as both the "
-            + "<code>data_runfiles</code> and <code>default_runfiles</code>."
-            + "<li><code>data_runfiles</code>: are the files that are added to the runfiles of a "
-            + "target that depends on the rule via the <code>data</code> attribute."
-            + "<li><code>default_runfiles</code>: are the files that are added to the runfiles of "
-            + "a target that depends on the rule via anything but the <code>data</code> attribute."
-            + "</ul>"
-            + "Each <code>DefaultInfo</code> instance has the following fields: "
-            + "<ul>"
-            + "<li><code>files</code>"
-            + "<li><code>files_to_run</code>"
-            + "<li><code>data_runfiles</code>"
-            + "<li><code>default_runfiles</code>"
-            + "</ul>"
-            + "See the <a href='../rules.$DOC_EXT'>rules</a> page for more information."
-  )
-  private static final NativeProvider<?> defaultInfo = DefaultInfo.PROVIDER;
-
   @Override
   public Provider provider(String doc, Object fields, Location location) throws EvalException {
     Iterable<String> fieldNames = null;
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleConfiguredTargetUtil.java b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleConfiguredTargetUtil.java
index e0182e26c9..1f2a184844 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleConfiguredTargetUtil.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleConfiguredTargetUtil.java
@@ -397,34 +397,53 @@ public final class SkylarkRuleConfiguredTargetUtil {
 
     Location loc = provider.getCreationLoc();
 
-    for (String field : provider.getFieldNames()) {
-      if (field.equals("files")) {
-        files = cast("files", provider, SkylarkNestedSet.class, Artifact.class, loc);
-      } else if (field.equals("runfiles")) {
-        statelessRunfiles = cast("runfiles", provider, Runfiles.class, loc);
-      } else if (field.equals("data_runfiles")) {
-        dataRunfiles = cast("data_runfiles", provider, Runfiles.class, loc);
-      } else if (field.equals("default_runfiles")) {
-        defaultRunfiles = cast("default_runfiles", provider, Runfiles.class, loc);
-      } else if (field.equals("executable")) {
-        executable = cast("executable", provider, Artifact.class, loc);
-        if (!executable.getArtifactOwner().equals(context.getRuleContext().getOwner())) {
-          throw new EvalException(
-              loc,
-              String.format(
-                  "'executable' provided by an executable rule '%s' should be created "
-                      + "by the same rule.",
-                  context.getRuleContext().getRule().getRuleClass()));
+    if (provider
+        .getProvider()
+        .getKey()
+        .equals(DefaultInfo.PROVIDER.getKey())) {
+      DefaultInfo defaultInfo = (DefaultInfo) provider;
+
+      files = defaultInfo.getFiles();
+      statelessRunfiles = defaultInfo.getStatelessRunfiles();
+      dataRunfiles = defaultInfo.getDataRunfiles();
+      defaultRunfiles = defaultInfo.getDefaultRunfiles();
+      executable = defaultInfo.getExecutable();
+
+    } else {
+      // Rule implementations aren't reqiured to return default-info fields via a DefaultInfo
+      // provider. They can return them as fields on the returned struct. For example,
+      // 'return struct(executable = foo)' instead of 'return DefaultInfo(executable = foo)'.
+      // TODO(cparsons): Look into deprecating this option.
+      for (String field : provider.getFieldNames()) {
+        if (field.equals("files")) {
+          files = cast("files", provider, SkylarkNestedSet.class, Artifact.class, loc);
+        } else if (field.equals("runfiles")) {
+          statelessRunfiles = cast("runfiles", provider, Runfiles.class, loc);
+        } else if (field.equals("data_runfiles")) {
+          dataRunfiles = cast("data_runfiles", provider, Runfiles.class, loc);
+        } else if (field.equals("default_runfiles")) {
+          defaultRunfiles = cast("default_runfiles", provider, Runfiles.class, loc);
+        } else if (field.equals("executable") && provider.getValue("executable") != null) {
+          executable = cast("executable", provider, Artifact.class, loc);
         }
-      } else if (provider
-          .getProvider()
-          .getKey()
-          .equals(DefaultInfo.PROVIDER.getKey())) {
-        // Custom fields are not allowed for default providers
-        throw new EvalException(loc, "Invalid field for default provider: " + field);
+      }
+
+      if ((statelessRunfiles != null) && (dataRunfiles != null || defaultRunfiles != null)) {
+        throw new EvalException(loc, "Cannot specify the provider 'runfiles' "
+            + "together with 'data_runfiles' or 'default_runfiles'");
       }
     }
 
+    if (executable != null
+        && !executable.getArtifactOwner().equals(context.getRuleContext().getOwner())) {
+      throw new EvalException(
+          loc,
+          String.format(
+              "'executable' provided by an executable rule '%s' should be created "
+                  + "by the same rule.",
+              context.getRuleContext().getRule().getRuleClass()));
+    }
+
     if (executable != null && context.isExecutable() && context.isDefaultExecutableCreated()) {
         Artifact defaultExecutable = context.getRuleContext().createOutputArtifact();
         if (!executable.equals(defaultExecutable)) {
@@ -487,11 +506,6 @@ public final class SkylarkRuleConfiguredTargetUtil {
       builder.setFilesToBuild(files.getSet(Artifact.class));
     }
 
-    if ((statelessRunfiles != null) && (dataRunfiles != null || defaultRunfiles != null)) {
-      throw new EvalException(loc, "Cannot specify the provider 'runfiles' "
-          + "together with 'data_runfiles' or 'default_runfiles'");
-    }
-
     if (statelessRunfiles == null && dataRunfiles == null && defaultRunfiles == null) {
       // No runfiles specified, set default
       statelessRunfiles = Runfiles.EMPTY;
diff --git a/src/main/java/com/google/devtools/build/lib/packages/NativeInfo.java b/src/main/java/com/google/devtools/build/lib/packages/NativeInfo.java
index 186a0d473e..3798b1fc79 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/NativeInfo.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/NativeInfo.java
@@ -75,7 +75,7 @@ public class NativeInfo extends Info {
     this(provider, ImmutableMap.of(), loc);
   }
 
-  // TODO(cparsons): Remove this constructor once DefaultInfo and ToolchainInfo stop using it.
+  // TODO(cparsons): Remove this constructor once ToolchainInfo stops using it.
   @Deprecated
   public NativeInfo(Provider provider, Map<String, Object> values, Location loc) {
     super(provider, loc);
diff --git a/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/DefaultInfoApi.java b/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/DefaultInfoApi.java
new file mode 100644
index 0000000000..b4a3c2596f
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/DefaultInfoApi.java
@@ -0,0 +1,164 @@
+// Copyright 2018 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.skylarkbuildapi;
+
+import com.google.devtools.build.lib.events.Location;
+import com.google.devtools.build.lib.skylarkinterface.Param;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkConstructor;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
+import com.google.devtools.build.lib.syntax.EvalException;
+import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
+
+/** A provider that gives general information about a target's direct and transitive files. */
+@SkylarkModule(
+    name = "DefaultInfo",
+    category = SkylarkModuleCategory.PROVIDER,
+    doc = "A provider that gives general information about a target's direct and transitive files. "
+        + "Every rule type has this provider, even if it is not returned explicitly by the "
+        + "rule's implementation function."
+        + "Each <code>DefaultInfo</code> instance has the following fields: "
+        + "<ul>"
+        + "<li><code>files</code>"
+        + "<li><code>files_to_run</code>"
+        + "<li><code>data_runfiles</code>"
+        + "<li><code>default_runfiles</code>"
+        + "</ul>"
+        + "See the <a href='../rules.$DOC_EXT'>rules</a> page for more information."
+)
+public interface DefaultInfoApi extends StructApi {
+
+  @SkylarkCallable(
+      name = "files",
+      doc =  "A <a href='depset.html'><code>depset</code></a> of "
+          + "<a href='File.html'><code>File</code></a> objects representing the default "
+          + "outputs to build when this target is specified on the blaze command line. By "
+          + "default it is all predeclared outputs.",
+      structField = true,
+      allowReturnNones = true
+  )
+  SkylarkNestedSet getFiles();
+
+  @SkylarkCallable(
+      name = "files_to_run",
+      doc =  "A <a href='FilesToRunProvider.html'><code>FilesToRunProvider</code></a> object "
+          + "containing information about the executable and runfiles of the target.",
+      structField = true,
+      allowReturnNones = true
+  )
+  FilesToRunProviderApi<?> getFilesToRun();
+
+  @SkylarkCallable(
+      name = "data_runfiles",
+      doc = "the files that are added to the runfiles of a "
+          + "target that depend on the rule via the <code>data</code> attribute.",
+      structField = true,
+      allowReturnNones = true
+  )
+  RunfilesApi getDataRunfiles();
+
+  @SkylarkCallable(
+      name = "default_runfiles",
+      doc = "the files that are added to the runfiles of "
+          + "a target that depend on the rule via anything but the <code>data</code> "
+          + "attribute.",
+      structField = true,
+      allowReturnNones = true
+  )
+  RunfilesApi getDefaultRunfiles();
+
+  /**
+   * Provider for {@link DefaultInfoApi}.
+   */
+  @SkylarkModule(name = "Provider", documented = false, doc = "")
+  public static interface DefaultInfoApiProvider<RunfilesT extends RunfilesApi,
+      FileT extends FileApi> extends ProviderApi {
+
+    @SkylarkCallable(
+      name = "DefaultInfo",
+      doc = "<p>The <code>DefaultInfo</code> constructor.",
+      parameters = {
+        @Param(
+          name = "files",
+          type = SkylarkNestedSet.class,
+          named = true,
+          positional = false,
+          defaultValue = "None",
+          noneable = true,
+          doc = "A <a href='depset.html'><code>depset</code></a> of "
+              + "<a href='File.html'><code>File</code></a> objects representing the default "
+              + "outputs to build when this target is specified on the blaze command line. By "
+              + "default it is all predeclared outputs."
+        ),
+        @Param(
+            name = "runfiles",
+            type = RunfilesApi.class,
+            named = true,
+            positional = false,
+            defaultValue = "None",
+            noneable = true,
+            doc = "set of files acting as both the "
+                + "<code>data_runfiles</code> and <code>default_runfiles</code>."
+        ),
+        @Param(
+            name = "data_runfiles",
+            type = RunfilesApi.class,
+            named = true,
+            positional = false,
+            defaultValue = "None",
+            noneable = true,
+            doc = "the files that are added to the runfiles of a "
+                + "target that depend on the rule via the <code>data</code> attribute."
+        ),
+        @Param(
+            name = "default_runfiles",
+            type = RunfilesApi.class,
+            named = true,
+            positional = false,
+            defaultValue = "None",
+            noneable = true,
+            doc = "the files that are added to the runfiles of "
+                + "a target that depend on the rule via anything but the <code>data</code> "
+                + "attribute."
+        ),
+        @Param(
+          name = "executable",
+          type = FileApi.class,
+          named = true,
+          positional = false,
+          defaultValue = "None",
+          noneable = true,
+          doc = "If this rule is marked "
+              + "<a href='globals.html#rule.executable'><code>executable</code></a> or "
+              + "<a href='globals.html#rule.test'><code>test</code></a>, this is a "
+              + "<a href='File.html'><code>File</code></a> object representing the file that "
+              + "should be executed to run the target. By default it is the predeclared output "
+              + "<code>ctx.outputs.executable</code>."
+        )},
+      useLocation = true,
+      selfCall = true)
+    @SkylarkConstructor(objectType = DefaultInfoApi.class,
+        receiverNameForDoc = "DefaultInfo")
+    public DefaultInfoApi constructor(
+        // TODO(cparsons): Use stricter types when Runfiles.NONE is passed as null.
+        Object files,
+        Object runfiles,
+        Object dataRunfiles,
+        Object defaultRunfiles,
+        Object executable,
+        Location loc) throws EvalException;
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/TopLevelBootstrap.java b/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/TopLevelBootstrap.java
index ed0ffec634..002dc41e4c 100644
--- a/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/TopLevelBootstrap.java
+++ b/src/main/java/com/google/devtools/build/lib/skylarkbuildapi/TopLevelBootstrap.java
@@ -15,6 +15,7 @@
 package com.google.devtools.build.lib.skylarkbuildapi;
 
 import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.skylarkbuildapi.DefaultInfoApi.DefaultInfoApiProvider;
 import com.google.devtools.build.lib.skylarkbuildapi.OutputGroupInfoApi.OutputGroupInfoApiProvider;
 import com.google.devtools.build.lib.syntax.Runtime;
 
@@ -30,6 +31,7 @@ public class TopLevelBootstrap implements Bootstrap {
   private final StructApi.StructProviderApi structProvider;
   private final OutputGroupInfoApiProvider outputGroupInfoProvider;
   private final ActionsInfoProviderApi actionsInfoProviderApi;
+  private final DefaultInfoApiProvider<?, ?> defaultInfoProvider;
 
   public TopLevelBootstrap(
       Class<? extends SkylarkBuildApiGlobals> skylarkBuildApiGlobals,
@@ -39,7 +41,8 @@ public class TopLevelBootstrap implements Bootstrap {
       Class<? extends SkylarkRuleFunctionsApi<?>> skylarkRuleFunctionsApi,
       StructApi.StructProviderApi structProvider,
       OutputGroupInfoApiProvider outputGroupInfoProvider,
-      ActionsInfoProviderApi actionsInfoProviderApi) {
+      ActionsInfoProviderApi actionsInfoProviderApi,
+      DefaultInfoApiProvider<?, ?> defaultInfoProvider) {
     this.skylarkAttrApi = skylarkAttrApi;
     this.skylarkBuildApiGlobals = skylarkBuildApiGlobals;
     this.skylarkCommandLineApi = skylarkCommandLineApi;
@@ -48,6 +51,7 @@ public class TopLevelBootstrap implements Bootstrap {
     this.structProvider = structProvider;
     this.outputGroupInfoProvider = outputGroupInfoProvider;
     this.actionsInfoProviderApi = actionsInfoProviderApi;
+    this.defaultInfoProvider = defaultInfoProvider;
   }
 
   @Override
@@ -60,5 +64,6 @@ public class TopLevelBootstrap implements Bootstrap {
     builder.put("struct", structProvider);
     builder.put("OutputGroupInfo", outputGroupInfoProvider);
     builder.put("Actions", actionsInfoProviderApi);
+    builder.put("DefaultInfo", defaultInfoProvider);
   }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
index 877b1a3f24..234899fbf0 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkIntegrationTest.java
@@ -576,7 +576,7 @@ public class SkylarkIntegrationTest extends BuildViewTestCase {
   }
 
   @Test
-  public void testCannotSpecifyRunfilesWithDataOrDefaultRunfiles() throws Exception {
+  public void testCannotSpecifyRunfilesWithDataOrDefaultRunfiles_struct() throws Exception {
     scratch.file(
         "test/skylark/extension.bzl",
         "def custom_rule_impl(ctx):",
@@ -596,6 +596,26 @@ public class SkylarkIntegrationTest extends BuildViewTestCase {
   }
 
   @Test
+  public void testCannotSpecifyRunfilesWithDataOrDefaultRunfiles_defaultInfo() throws Exception {
+    scratch.file(
+        "test/skylark/extension.bzl",
+        "def custom_rule_impl(ctx):",
+        "  rf = ctx.runfiles()",
+        "  return struct(DefaultInfo(runfiles = rf, default_runfiles = rf))",
+        "",
+        "custom_rule = rule(implementation = custom_rule_impl)");
+
+    checkError(
+        "test/skylark",
+        "cr",
+        "Cannot specify the provider 'runfiles' together with "
+            + "'data_runfiles' or 'default_runfiles'",
+        "load('//test/skylark:extension.bzl', 'custom_rule')",
+        "",
+        "custom_rule(name = 'cr')");
+  }
+
+  @Test
   public void testInstrumentedFilesProviderWithCodeCoverageDiabled() throws Exception {
     scratch.file(
         "test/skylark/extension.bzl",
diff --git a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java
index 0312144c85..1de6ab0899 100644
--- a/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skylark/SkylarkRuleImplementationFunctionsTest.java
@@ -1289,7 +1289,8 @@ public class SkylarkRuleImplementationFunctionsTest extends SkylarkTestCase {
       getConfiguredTarget("//test:my_rule");
       fail();
     } catch (AssertionError expected) {
-      assertThat(expected).hasMessageThat().contains("Invalid field for default provider: foo");
+      assertThat(expected).hasMessageThat()
+          .contains("unexpected keyword 'foo' in call to DefaultInfo");
     }
   }