Merge branch 'macro-argument-location' of https://github.com/halfspir…

…al/wesnoth into staging/pr-434

src/serialization/preprocessor.cpp

@@ -1075,8 +1075,10 @@ bool preprocessor_data::get_chunk()
 				size_t nb_arg = strings_.size() - token.stack_pos - 1;
 				if (nb_arg != val.arguments.size())
 				{
+					std::vector< std::string > locations = utils::quoted_split(val.location, ' ');
 					std::ostringstream error;
-					error << "Preprocessor symbol '" << symbol << "' expects "
+					error << "Preprocessor symbol '" << symbol << "' defined at "
+					      << get_filename(locations[0]) << ":" << val.linenum << " expects "
 					      << val.arguments.size() << " arguments, but has "
 					      << nb_arg << " arguments";
 					target_.error(error.str(), linenum_);