VAR_EXTERNAL blocks have no effect

Variables declared in a VAR_EXTERNAL block are currently ignored and the referenced globals will be used instead.

Example:

VAR_GLOBAL
    myArray : ARRAY [0..10] OF INT;
    myString: STRING;
END_VAR

FUNCTION main
VAR_EXTERNAL CONSTANT
    myArray : ARRAY [0..10] OF INT;
END_VAR
    myArray[5] := 42;
    myString := 'Hello, world!';
END_FUNCTION

In this example, even though arr is declared as VAR_EXTERNAL CONSTANT, the CONSTANT constraint will be ignored and the global myArray will be mutated. The global myString can be read from and written to from within main even though it is not declared in a VAR_EXTERNAL block.