Report the name of a Python function if we have difficulties calling it.

2 files changed, 20 insertions, 6 deletions

diff --git a/python/pyinterp.cc b/python/pyinterp.cc
index a38def60..582b8e78 100644
--- a/python/pyinterp.cc
+++ b/python/pyinterp.cc
@@ -250,14 +250,22 @@ value_t python_interpreter_t::functor_t::operator()(call_scope_t& args)
 	if (PyObject * val =
 	    PyObject_CallObject(func.ptr(),
 				boost::python::tuple(arglist).ptr())) {
-	  value_t result = extract<value_t>(val)();
-	  Py_DECREF(val);
+	  extract<value_t> xval(val);
+	  value_t result;
+	  if (xval.check()) {
+	    result = xval();
+	    Py_DECREF(val);
+	  } else {
+	    Py_DECREF(val);
+	    throw_(calc_error,
+		   "Could not evaluate Python variable '" << name << "'");
+	  }
 	  return result;
 	}
 	else if (PyObject * err = PyErr_Occurred()) {
 	  PyErr_Print();
 	  throw_(calc_error,
-		 "While calling Python function '" /*<< name() <<*/ "': " << err);
+		 "While calling Python function '" << name << "': " << err);
 	} else {
 	  assert(false);
 	}
@@ -269,7 +277,7 @@ value_t python_interpreter_t::functor_t::operator()(call_scope_t& args)
   catch (const error_already_set&) {
     PyErr_Print();
     throw_(calc_error,
-	   "While calling Python function '" /*<< name() <<*/ "'");
+	   "While calling Python function '" << name << "'");
   }
   return NULL_VALUE;
 }
diff --git a/python/pyinterp.h b/python/pyinterp.h
index a38cd565..cf9ee486 100644
--- a/python/pyinterp.h
+++ b/python/pyinterp.h
@@ -73,13 +73,19 @@ public:
 
   class functor_t {
     functor_t();
+
   protected:
     boost::python::object func;
+
   public:
-    functor_t(const string&, boost::python::object _func) : func(_func) {
+    string name;
+
+    functor_t(const string& _name, boost::python::object _func)
+      : func(_func), name(_name) {
       TRACE_CTOR(functor_t, "const string&, boost::python::object");
     }
-    functor_t(const functor_t& other) : func(other.func) {
+    functor_t(const functor_t& other)
+      : func(other.func), name(other.name) {
       TRACE_CTOR(functor_t, "copy");
     }
     virtual ~functor_t() throw() {