compiler-design-eth/TODO.md

Possible code changes

General

• DONE Use more specific messages when throwing a SemanticFailure exception. This has the caveat that the automated testing relies on those tests?

StmtAnalyzer

• DONE Propagate the change of class parameter from ExprAnalyzer.
• DONE Complete checks for MISSING_RETURN, some ideas:
  • DONE Assume no instructions will appear after a return statement and analyze only the last Stmt using other visitor with different class parameters (for example passing the desired type and returning a Optional<TypeSymbol>).
  • DONE Decide the logic behind a return statement in a while loop, maybe treat it as an if with an empty else block.
    • A while as last instruction is not a valid return.
    • A if as last instruction must have a valid return a the end of its then and otherwise blocks.

ExprAnalyzer

• DONE Change the second class parameter to give method AND class information (needed by var and this nodes)
  • DISCARDED Add a ClassSymbol to MethodSymbol and use it as class parameter, the problem arises when visiting a method, should an empty method with the proper class be provided? Could also be solved by using Symbol as class parameter.
  • DONE Create a new class that includes a ClassSymbol and a MethodSymbol and use that. Keep MethodSymbol == null when appropriate.

Tests

This tests have been selected to increase to 100% the code coverage obtained by running the tests designed for the previous HW, which are in folder svn/HW2/javali_tests/HW2_nop90

As they are mostly related to errors that haven't been triggered, each test should be separate, in order to generate all of the errors.

Remaining

Done

• access var from class or superclass
• test ! operator
• type error in unaryOp
• type error in array size
• call method from superclass
• call a method that doesn't exist
• call a method with the wrong type of params
• call a method with the wrong number of params
• assign to all possible syntactically correct options
  • field
  • var
  • array index
  • method (error)
  • this (error)
• indexing both types error
• try to access a field of something that is not a class type
• typing error in cast
• AND and OR operations
• equals operators (a case that is OK and another that's not)
• binary operation with wrong type (any but == and !=)
• search for a type that doesn't exist in a method body
• don't have a Main class
• don't have a main() method in the Main class (all possibilities)
  • wrong name
  • wrong return value
  • wrong parameters
• inherited main method (it should work)
• write something that is not an integer
• declare a variable mutiple times (local variables)
• declare a local variable with the same name as a parameter
• check MISSING_RETURN
  • nested ifElse as end of method
  • while as end of method
  • normal returns at the end of the method
  • return with further statements after it
• while with non-int condition
• use a array type that hasn't been discovered yet
  • class A { B[] name; } class B {}
• name a class Object
• name a class like another class
• name a parameter like another
• override methods and try to break that
  • same return type
  • same number of params
  • same type of params
• name a variable like another (field level)