Implemented declared providers interface #1727

--
MOS_MIGRATED_REVID=133699895

src/main/java/com/google/devtools/build/lib/analysis/AbstractConfiguredTarget.java

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/AbstractConfiguredTarget.java b/src/main/java/com/google/devtools/build/lib/analysis/AbstractConfiguredTarget.java
index ca5aac4..718c67b 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/AbstractConfiguredTarget.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/AbstractConfiguredTarget.java
@@ -22,9 +22,13 @@
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 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.PackageSpecification;
+import com.google.devtools.build.lib.packages.SkylarkClassObjectConstructor;
 import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.syntax.ClassObject;
+import com.google.devtools.build.lib.syntax.EvalException;
+import com.google.devtools.build.lib.syntax.EvalUtils;
 import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
 import javax.annotation.Nullable;
 
@@ -115,6 +119,27 @@
   }
 
   @Override
+  public Object getIndex(Object key, Location loc) throws EvalException {
+    if (!(key instanceof SkylarkClassObjectConstructor)) {
+      throw new EvalException(loc, String.format(
+          "Type Target only supports indexing by object constructors, got %s instead",
+          EvalUtils.getDataTypeName(key)));
+    }
+    SkylarkClassObjectConstructor constructor = (SkylarkClassObjectConstructor) key;
+    SkylarkProviders provider = getProvider(SkylarkProviders.class);
+    if (provider != null) {
+      Object declaredProvider = provider.getDeclaredProvider(constructor.getKey());
+      if (declaredProvider != null) {
+        return declaredProvider;
+      }
+    }
+    // Either provider or declaredProvider is null
+    throw new EvalException(loc, String.format(
+        "Object of type Target doesn't contain declared provider %s",
+        constructor.getKey().getExportedName()));
+  }
+
+  @Override
   public String errorMessage(String name) {
     return null;
   }

src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java b/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
index 6dd8dd7..d1a9ece 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
@@ -18,7 +18,7 @@
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
-
+import com.google.devtools.build.lib.syntax.SkylarkIndexable;
 import javax.annotation.Nullable;
 
 /**
@@ -52,7 +52,7 @@
     + "These extra providers are defined in the <code>struct</code> returned by the rule "
     + "implementation function.</li>"
     + "</ul>")
-public interface TransitiveInfoCollection  {
+public interface TransitiveInfoCollection extends SkylarkIndexable {
 
   /**
    * Returns the transitive information provider requested, or null if the provider is not found.

src/main/java/com/google/devtools/build/lib/rules/AliasConfiguredTarget.java

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
index 596675f..ec184b4 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/AliasConfiguredTarget.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/AliasConfiguredTarget.java
@@ -26,11 +26,12 @@
 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.events.Location;
 import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.syntax.ClassObject;
+import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.syntax.SkylarkNestedSet;
 import com.google.devtools.build.lib.util.Preconditions;
-
 import javax.annotation.Nullable;
 
 /**
@@ -75,6 +76,11 @@
   }
 
   @Override
+  public Object getIndex(Object key, Location loc) throws EvalException {
+    return actual == null ? null : actual.getIndex(key, loc);
+  }
+
+  @Override
   public Target getTarget() {
     return actual == null ? null : actual.getTarget();
   }