Ruby code often lacks annotations to specify variable types, making it difficult to determine the return type of a function like shout(obj). Static analysis tools, such as Sorbet, can help, but annotations may not always reflect runtime behavior accurately due to Ruby’s inheritance system. By implementing an interprocedural type analysis, detailed type information can be obtained for variables and parameters throughout a program, enabling precise compiler optimization. Techniques like Static Single Assignment (SSA) form and Sparse Conditional Constant Propagation (SCCP) can enhance the analysis, especially when applied in an interprocedural context for functions with multiple call sites. Sensitivity strategies, like call-site sensitivity, can further improve precision, albeit at the cost of analysis speed. Tracking object types in Ruby, including instance variables, adds another layer of complexity to static analysis but can yield valuable insights into a program’s behavior.
https://railsatscale.com/2025-02-24-interprocedural-sparse-conditional-type-propagation/