anchor.diff:  (in-package #:cleavir-generate-ast)
   
  +(defmethod convert-special :around (symbol form env)
  +  (declare (ignore env))
  +  (check-special-form-syntax symbol form))
  +
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
   ;;; Converting QUOTE.
   
   (defmethod convert-special
       ((symbol (eql 'quote)) form env)
  -  (cleavir-code-utilities:check-form-proper-list form)
  -  (cleavir-code-utilities:check-argcount form 1 1)
     (cleavir-ast:make-constant-ast (cadr form)))
   
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
positive.code: ;;; Converting RETURN-FROM.
  
  (defmethod convert-special ((symbol (eql 'return-from)) form env)
    (cleavir-code-utilities:check-form-proper-list form)
    (cleavir-code-utilities:check-argcount form 1 2)
    (unless (symbolp (cadr form))
      (error 'block-name-must-be-a-symbol
  	   :expr (cadr form)))
    (let ((info (cleavir-env:block-info (cadr form) env)))
      (if (null info)
  	(error 'block-name-unknown
  
negative.code: ;;; Converting IF.
  
  (defmethod convert-special ((symbol (eql 'if)) form env)
    (cleavir-ast:make-if-ast
     (convert (cadr form) env)
     (convert (caddr form) env)
  