fix bug in save, select-row save bug. test=release/1.4

paddle/fluid/operators/save_op.cc

@@ -31,8 +31,8 @@ class SaveOp : public framework::OperatorWithKernel {
  protected:
   framework::OpKernelType GetExpectedKernelType(
       const framework::ExecutionContext &ctx) const override {
-    return framework::OpKernelType(ctx.Input<framework::LoDTensor>("X")->type(),
-                                   ctx.GetPlace());
+    auto data_type = framework::GetDataTypeOfVar(ctx.InputVar("X"));
+    return framework::OpKernelType(data_type, ctx.device_context());
   }
 };
 

paddle/fluid/operators/save_op.h

@@ -103,12 +103,21 @@ class SaveOpKernel : public framework::OpKernel<T> {
                         const platform::Place &place,
                         const framework::Variable *var) const {
     framework::Variable *out_put_var = ctx.OutputVar(LOOKUP_TABLE_PATH);
-    PADDLE_ENFORCE(
-        out_put_var != nullptr,
-        "Can not find variable kLookupTablePath for SaveSelectedRows");
-    auto *lt_var = out_put_var->GetMutable<std::string>();
+    auto file_path = ctx.Attr<std::string>("file_path");
+    auto overwrite = ctx.Attr<bool>("overwrite");
+
+    std::string filename = file_path;
+
+    if (out_put_var != nullptr) {
+      auto *lt_var = out_put_var->GetMutable<std::string>();
+      filename = *lt_var;
+    }
+
+    if (FileExists(filename) && !overwrite) {
+      PADDLE_THROW("%s is existed, cannot save to it when overwrite=false",
+                   filename, overwrite);
+    }
 
-    std::string filename = lt_var->data();
     VLOG(4) << "SaveSelectedRows get File name: " << filename;
 
     MkDirRecursively(DirName(filename).c_str());