GMCheck

A static verification toolset for finding possible bugs in Game Maker Studio 2 projects. On its early stages of development.

Usage

GMCheck is best compiled and run using Haskell Stack:

stack build

stack exec gmcheck-exe -- -o path-to-report.html path-to-gms-project-directory/

Features and Plans

• ✔️ (Mostly) complete parser of pre-2.3 GML. 2.3 additions are in-progress.
• ✔️ Deriving and tracking variable types to detect type errors.
• ✔️ "Extending" the GML type system to distinguish booleans, integers, colors, resource identifiers and so on, which are just ordinary numbers in GML.
• ✔️ Type-annotated signatures of built-in functions and variables, stored in editable external file.
• ✔️ Finding usage of possibly uninitialized variables and missing resources.
• Deriving script type signatures from their arguments and usage.
• Detecting unreachable code, premature breaks and exits, and so on.
• Detecting possible memory leaks from undestroyed data structures.
• Colorful, friendly and readable reports.
• Maybe pretty-pritting.
• ...
• and many more! Send your ideas and use-cases to the author or add them as proposal issues.

Known issues

• Regions, macros and enumerations are not yet supported.
• Due to the highly dynamic nature of GML, it's impossible to 100% detect and analyze variables without actually running the code. Depending on the project, there may be a high percent of false positives.