1. A computing device-implemented method comprising: generating a program code from a graphical model, the graphical model including textual items; creating, with a computing device, an abstract syntax tree based on the generated program code, the creating: tokenizing the generated program code into tokens; identifying executable tokens among the tokens, and parsing the executable tokens into the abstract syntax tree; analyzing the abstract syntax tree to identify at least one of the textual items that refers to at least one of a non-volatile data symbol, a volatile data symbol, data defined in a data dictionary, global data access and a symbol distinguishing between input and output data; determining at least one location, based on the analyzing, at which to provide a visual indicator in the graphical model, the at least one visual indicator corresponding to the at least one identified textual item in the program code; and displaying, with a display element, the at least one visual indicator in the graphical model at the at least one location.