copy program and fix op_desc

paddle/fluid/framework/ir/graph.h

@@ -142,8 +142,6 @@ class Graph {
     nodes_.erase(node);
   }
 
-  const ProgramDesc &program() const { return program_; }
-
  private:
   // This method takes ownership of `node`.
   ir::Node *AddNode(ir::Node *node) {
@@ -154,7 +152,7 @@ class Graph {
   }
 
   // NOTE: program_ shouldn't be exposed to user.
-  const ProgramDesc &program_;
+  const ProgramDesc program_;
   std::map<std::string, boost::any> attrs_;
   std::map<std::string, std::function<void(void)>> attr_dels_;
   std::map<ir::Node *, std::unique_ptr<ir::Node>> nodes_;

paddle/fluid/framework/ir/node.h

@@ -41,8 +41,7 @@ class Node {
   explicit Node(OpDesc* op_desc)
       : name_(op_desc->Type()),
         var_desc_(nullptr),
-        op_desc_(new OpDesc(*op_desc)),  // TODO(panyx0718) the pointer in the
-                                         // original OpDesc might go out.
+        op_desc_(new OpDesc(*op_desc, op_desc->Block())),
         type_(Type::kOperation) {}
 
   Type NodeType() const { return type_; }