public/go/rc

rc (restrictions checker)

This program analyses a go source file and displays in standard output the imports, functions, array types and loops used without authorization.

By default:

• NO imports and NO built-in functions are allowed.
• NO casting is allowed either.
• Only functions declared inside the source file are allowed.
• All array types are allowed
• Loops are allowed

Flags

• Two flags are defined:
  • --cast allows casting to every built-in type.
  • --no-for prohibits the use of for loops in the program or function.
  • --no-array:
    • Prohibits all array types if no types are specified after the flag. Ex.

    _$ ./rc main.go fmt.* github.com/01-edu/z01.PrintRune len --no-array

    All array type in main.go will cause an error message.
    - Prohibits only the types specified after the flag
    Ex.
    ```console
    _$ ./rc main.go fmt.* github.com/01-edu/z01.PrintRune len --no-array rune string
    

    Only array from the type rune and string are prohibit. All other array from built-in types are allowed

Arguments:

• First Argument:

The program must be executed passing the go source file to be analyze as the first argument

• The remaining argument (from 2 to ...):

  Can be (without any particular order):

  • Allowed imports and functions from a package

    • <package>.* for full imports (all functions from that package are allowed)
    • <package>.<function> for partial imports (only the function is allowed)
    • <package>.<function>#amout for certain amounts (only certain amount os a function is allowed)
    • Ex: fmt.* (all functions from fmt are allowed), github.com/01-edu/z01.PrintRune (only z01.PrintRune is allowed), append#2 (the only amount of append's allowed is 2)

  • Allowed built-in functions

    • Use the name of the built-in function
    • Ex: make, append, len.
    • Allowed casting
    • by using the type of casting, ex: for allowing string casting, use string
    • Or use the flag --cast, to allow every type of casting

  • Import relative packages

    • Use the relative path
    • Ex: ../piscine, .., .

  • Unallow for loops

    • Use the flags --no-for.
    • Note: remember to use it before the --no-array flag.
      • ex:

      _$ ./rc main.go fmt.* github.com/01-edu/z01.PrintRune len --no-array <...> --no-for
      

      the last line produces undesired behaviors.

  • Unallow literals

    • Use the flag --no-lit="{PATTERN}"
    • Note: "{PATTERN}" must be a valid RegExp.
      • ex:

      _$ ./rc main.go fmt.* github.com/01-edu/z01.PrintRune len --no-array --no-lit=[b-yB-Y]
      

• Optional lasts arguments

  • The flag --no-array must be given as the last argument or to signal that all the arguments after are unallowed array types

Usage:

• To allow the import of the whole fmt package, z01.PrintRune and the built-in functions len in the file main.go

  The imports must be writen exactly the way are writen inside the source code, example:

   _$ ./rc main.go fmt.* github.com/01-edu/z01.PrintRune len

• More examples:

• import "fmt" is allowed by executing

  _$ ./rc sourcefile.go fmt.*
  

  • import "go/parser" is allowed by executing

  _$ ./rc sourcefile.go go/parser.*
  

  • import "github.com/01-edu/z01" is allowed by executing

  ./rc sourcefile.go github.com/01-edu/z01.*
  

  • import "../../../all/tests/go/solutions" is allowed by executing

  _$ ./rc sourcefile.go ../../../all/tests/go/solutions
  

  (no .* is needed, all the functions from this relative package are allowed)

• allow all type of casting

  _$ ./rc sourcefile.go ../../../all/tests/go/solutions/ztail/ztail.go fmt.* github.com/01-edu/z01 os.* strconv.* make len append --cast
  

  • this will allow all type of casting in the file ztail.go

• to allow just one type of casting

  _$ ./rc sourcefile.go ../../../all/tests/go/solutions/ztail/ztail.go fmt.* github.com/01-edu/z01 os.* strconv.* make len append rune
  

  • this will allow rune, but not int8, ..., string, float32, ...