Programming Errors

From dis-Emi-A

Contents 1 Problems 2 Resource Problems 3 Logic Problems 4 Conversion Problems 5 Side-Effect Problems 6 Calculation Problems 7 Maintainence/Meta Problems

Problems

This is a catalog of the problems/defects/issues that appear while writing programs in other languages. The goal of this new lanaguage is of course to make all these problems not possible.

Resource Problems

• not freeing memory (Solved by Memory Management)
• invalid ptr (Solved by Optional Variables)
• out-of-bounds (Solved by Constrained Types)
• buffer overflow (Solved by Constrained Types)
  • overstepping array boundaries
  • too few/too many objects iterated
• pointer vs. value parameter passing (Solved by parameter passing and multiple return values)
• forgetting to declare variables (Solved by Automatic Types)
• uninitialized variables (Solved by Memory Management)
  • incorrect initialization (C/C++ impossible struct syntax)
• pointer loops
• memory bit-ordering/binary file types
  • varying fundamental type sizes
• return of local variables
• incorrect variables/scope problems

Logic Problems

• infinite loop
• unscreened/dirty input to protected function
  • -security errors

• half-completed calculations/procedures
  • -breaks/exceptions in middle
  • -possibly irreversible

• concurrent modifications
• thread [dead]locking
• non-atomic modifications

• wrong if/conditional/while flow (ex. error_bad_return)
  • semicolons on for/while loop (empty loops)
  • contradictory/impossible conditions
• dead/unusued code
• uninitialized variables

• unintended code execution
  • forgetting a "break" statement
  • using = instead of ==
  • misplaced brackets, (added code to single line conditions)

• undeclared functions
  • missing header files
  • multiple declarations / conflicts

• ignored error conditions

Conversion Problems

• multiply encoded text
  • display( encUTF8( str ) );
  • func display( str ) { write( encUTF8( str ) ); }

• incomplete types (also with conversions) (Solutions: Subtypes)
  • speed = 4
  • mass = 5
  • newmass = speed * mass //conversion error (not seen by compiler)
  • =>
  • speed = 4m/s
  • mass = 5kg;
  • newmass = speed * mass //compiler error (will be caught)

• corrupt files / unchecked input

• missing datatypes from serialization

• incorrect comparisions (ptrs, classes, strings, etc.)

Side-Effect Problems

• uninteded modiftion
  • if( a = 0 ) ...
  • if( b.hasSideEffect() ) ...

Calculation Problems

• uncaught/unnoticed overflow (Solution: Constrained Types)
• uncaught/unnoticed underflow
• integer division/loss of precision

Maintainence/Meta Problems

• Code duplication large and small
• odd-flow
• outdated comments
  • -constraints/restrictions/expectations in comments rather than code

• name clashes
  • include files/imports
  • name codependencies
  • multiply defined types

• non-terminating comments (missing code)
• incorrect token use ( a != b vs. b != a, 0 < a < 5 )

• type-unsafe/unchecked macros

• reliance on expresison evaluation ordering (in comparisions, as parameters, etc...)