Supported Features

• Simple assignment
• list and unset construction
• Work with superglobal variables
• Variables initialization inside the foreach loop
• Function and method parameters
• Classes and their methods including inheritance
• Included files
• Internal function parameters passed by reference
• Access to global variables through global (except functions called from functions)
• static properties
• Abstract methods, interfaces, exceptions, __halt_compiler
• Alternative syntax for control structures
• Variables initialization inside the short-circuit operators
• Access to constant global variables through $GLOBALS
• Usage of undefined constants like $row[id]

Unsupported Features

• The visibility scope is a block and not a function (good practice but many false positives)
• The code is not executed thus variable variables, variable functions, inclusion of inconstant files, eval neither ${"a"} construction is not supported
• Function has to be defined before usage
• Only variables are checked, not object properties or array keys
• do { $j = 1; } while ($j) and for (; ; $j) { $j = 1; } are false positives