1 files changed, 10 insertions, 13 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java b/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java
index 2036401394..3ea0849634 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/python/PyCommon.java
@@ -30,7 +30,6 @@ import com.google.devtools.build.lib.analysis.PseudoAction;
 import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
 import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
 import com.google.devtools.build.lib.analysis.RuleContext;
-import com.google.devtools.build.lib.analysis.SkylarkProviders;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.analysis.Util;
 import com.google.devtools.build.lib.cmdline.Label;
@@ -294,12 +293,13 @@ public final class PyCommon {
   private NestedSet<Artifact> getTransitivePythonSourcesFromSkylarkProvider(
       TransitiveInfoCollection dep) {
     SkylarkClassObject pythonSkylarkProvider = null;
-    SkylarkProviders skylarkProviders = dep.getProvider(SkylarkProviders.class);
     try {
-      if (skylarkProviders != null) {
-        pythonSkylarkProvider = skylarkProviders.getValue(PYTHON_SKYLARK_PROVIDER_NAME,
-            SkylarkClassObject.class);
-      }
+      pythonSkylarkProvider = SkylarkType.cast(
+              dep.get(PYTHON_SKYLARK_PROVIDER_NAME),
+              SkylarkClassObject.class,
+              null,
+              "%s should be a struct", PYTHON_SKYLARK_PROVIDER_NAME
+      );
 
       if (pythonSkylarkProvider != null) {
         Object sourceFiles = pythonSkylarkProvider.getValue(TRANSITIVE_PYTHON_SRCS);
@@ -472,13 +472,10 @@ public final class PyCommon {
   public static boolean checkForSharedLibraries(Iterable<TransitiveInfoCollection> deps)
           throws EvalException{
     for (TransitiveInfoCollection dep : deps) {
-      SkylarkProviders providers = dep.getProvider(SkylarkProviders.class);
-      SkylarkClassObject provider = null;
-      if (providers != null) {
-        provider = providers.getValue(PYTHON_SKYLARK_PROVIDER_NAME,
-                SkylarkClassObject.class);
-      }
-      if (provider != null) {
+      Object providerObject = dep.get(PYTHON_SKYLARK_PROVIDER_NAME);
+      if (providerObject != null) {
+        SkylarkType.checkType(providerObject, SkylarkClassObject.class, null);
+        SkylarkClassObject provider = (SkylarkClassObject) providerObject;
         Boolean isUsingSharedLibrary = provider.getValue(IS_USING_SHARED_LIBRARY, Boolean.class);
         if (Boolean.TRUE.equals(isUsingSharedLibrary)) {
           return true;