start fobbiden ops checks

Signed-off-by: Ryan Nett <rnett@calpoly.edu>

Author: rnett

tensorflow-core/tensorflow-core-api/src/main/java/org/tensorflow/EagerOperationBuilder.java

@@ -55,6 +55,9 @@
 final class EagerOperationBuilder implements OperationBuilder {
 
   EagerOperationBuilder(EagerSession session, String type, String name) {
+    if(!session.isOpEnabled(type))
+      throw new IllegalArgumentException("Op " + type + " is not valid in eager mode.");
+
     this.session = session;
     this.type = type;
     this.name = name;

tensorflow-core/tensorflow-core-api/src/main/java/org/tensorflow/EagerSession.java

@@ -27,6 +27,9 @@
 import org.tensorflow.internal.c_api.TFE_Context;
 import org.tensorflow.internal.c_api.TFE_ContextOptions;
 import org.tensorflow.internal.c_api.TF_Status;
+import org.tensorflow.op.core.Assign;
+import org.tensorflow.op.core.Placeholder;
+import org.tensorflow.op.core.Variable;
 import org.tensorflow.proto.framework.ConfigProto;
 
 /**
@@ -279,6 +282,18 @@ public Types environmentType() {
     return Types.EAGER;
   }
 
+  @Override
+  public boolean isOpEnabled(String opType) {
+    switch (opType) {
+      case Variable.OP_NAME:
+      case Placeholder.OP_NAME:
+      case Assign.OP_NAME:
+        return false;
+      default:
+        return true;
+    }
+  }
+
   TFE_Context nativeHandle() {
     checkSession();
     return nativeHandle;

tensorflow-core/tensorflow-core-api/src/main/java/org/tensorflow/ExecutionEnvironment.java

@@ -34,6 +34,15 @@ enum Types {
    */
   OperationBuilder opBuilder(String type, String name);
 
+  /**
+   * Returns true if the given operation is valid in this execution environment.
+   * @param opType The op to check.
+   * @return Whether the given operation is valid in this execution environment.
+   */
+  default boolean isOpEnabled(String opType){
+    return true;
+  }
+
   /**
    * Get the type of this environment (from the `Environments` enumeration.
    *

tensorflow-core/tensorflow-core-api/src/main/java/org/tensorflow/GraphOperationBuilder.java

@@ -57,6 +57,9 @@
 public final class GraphOperationBuilder implements OperationBuilder {
 
   GraphOperationBuilder(Graph graph, String type, String name) {
+    if(!graph.isOpEnabled(type))
+      throw new IllegalArgumentException("Op " + type + " is not valid in graph mode.");
+
     this.graph = graph;
     Graph.Reference r = graph.ref();
     try {