Fix error handling.

theano/sandbox/cuda/cudnn_helper.h

@@ -8,7 +8,7 @@ static inline const char *cudnnGetErrorString(cudnnStatus_t err) {
   case CUDNN_STATUS_SUCCESS:
     return "The operation completed successfully.";
   case CUDNN_STATUS_NOT_INITIALIZED:
-    return "The handle was not initialized.";
+    return "The handle was not initialized(Is your driver recent enought?).";
   case CUDNN_STATUS_ALLOC_FAILED:
     return "Ressource allocation failed inside the library.";
   case CUDNN_STATUS_BAD_PARAM:

theano/sandbox/cuda/dnn.py

@@ -49,6 +49,11 @@ cudnnConvolutionDescriptor_t op%(id)d;
 
     def c_init_code_struct(self, node, struct_id, sub):
         return """
+handle%(id)d = NULL;
+input%(id)d = NULL;
+output%(id)d = NULL;
+kerns%(id)d = NULL;
+op%(id)d = NULL;
 cudnnStatus_t err%(id)d;
 if ((err%(id)d = cudnnCreate(&handle%(id)d)) != CUDNN_STATUS_SUCCESS) {
   PyErr_Format(PyExc_RuntimeError, "could not create cudnn handle: %%s",
@@ -210,7 +215,7 @@ if (err%(name)s != CUDNN_STATUS_SUCCESS) {
            fail=sub['fail'], id=sub['struct_id'], name=name)
 
     def c_code_cache_version(self):
-        return (3,)
+        return (4,)
 
 
 from theano.sandbox.cuda.opt import (local_optimizer, gpu_contiguous,