anchor.diff:      |   '++' unaryExpression
       |   '--' unaryExpression
       |   unaryOperator castExpression
  -    |   'sizeof' unaryExpression
  -    |   'sizeof' '(' typeName ')'
  -    |   '_Alignof' '(' typeName ')'
  -    |   '&&' Identifier // GCC extension address of label
       ;
   
   unaryOperator
  
positive.code: 
  selectionStatement
      :   'if' '(' expression ')' statement ('else' statement)?
      |   'switch' '(' expression ')' statement
      ;
  
  iterationStatement
  
negative.code: 
  declaration
      :   declarationSpecifiers initDeclaratorList? ';'
      ;
  
  declarationSpecifiers
      :   declarationSpecifier+
      ;
  
  declarationSpecifier
      :   typeSpecifier
      |   typeQualifier
      ;
  
  initDeclaratorList
  