A computer readable medium including executable instructions that when executed perform a method for validating an optimization in generated code using an executable constraints document is provided. The medium can include instructions for relating an assumption to the optimization during code generation. The medium can include instructions for generating the executable constraints document during the code generation, the executable constraints document including information about the relating; and the medium can include instructions for executing the constraints document when the validating is performed, the validating including performing an operation based on a validation result produced by the validating, where the operation includes displaying the validation result to a user, storing the validation result, sending the validation result to a destination, or modifying the generated code.