Generally discussed herein are systems, apparatuses, or methods for preprocessor directive symbol definition and preprocessor directive symbol usage analysis. In one or more embodiments a method can include applying a heuristic to a first preprocessor directive symbol from a build file or sub-build file of one or more build files or source code files and a second preprocessor directive symbol from a source code file. The method can include determining a likelihood that the first preprocessor directive symbol is presented erroneously in the source code file as the second preprocessor directive symbol based on a result of applying the heuristic.