Show friendlier error message on failure in tf_optimizer.i

Without it we trigger a segmentation fault, but later in a different stack, which is not so helpful.

PiperOrigin-RevId: 183307729

1 files changed, 5 insertions, 0 deletions

diff --git a/tensorflow/python/grappler/tf_optimizer.i b/tensorflow/python/grappler/tf_optimizer.i
index f0dd4483a6..1b657983a4 100644
--- a/tensorflow/python/grappler/tf_optimizer.i
+++ b/tensorflow/python/grappler/tf_optimizer.i
@@ -103,6 +103,11 @@ PyObject* TF_OptimizeGraph(
     std::unique_ptr<tensorflow::grappler::GrapplerItem> grappler_item =
         tensorflow::grappler::GrapplerItemFromMetaGraphDef(graph_id, metagraph, item_config);
 
+    if (!grappler_item) {
+      TF_SetStatus(out_status, TF_INVALID_ARGUMENT, "Failed to import metagraph, check error log for more info.");
+      return nullptr;
+    }
+
     tensorflow::DeviceBase* cpu_device = nullptr;
     tensorflow::GraphDef out_graph;
     tensorflow::grappler::MetaOptimizer optimizer(cpu_device, rewriter_config);