[r6rs-discuss] [Formal] eval needs refining

[Stanislav Ievlev]

Submitter: Stanislav Ievlev
Email address: inger at altlinux.org
Issue type: Defect
Priority: Major
Component: Eval
Report version: 5.91
Summary:  The definition of eval needs refining


The phrase

"Specifically, if the first argument to eval is a definition, it must
raise an exception with condition type &eval-definition".

should be replaced with something like

"Any types of top level definitions are not allowed"

Because, any of the samples below will break the first rule (and security):

(eval '(begin (define a 3) ...) ... )
(eval '(macro-begin '(+ 1 2) (define a 3) ...) ...)
(evel '(my-define-macro a) ...)

With a such security hole "eval" is unusable for sandboxing, because enviroment function can
return the same object for optimization reasons.

(eq? (environment (r6rs)) (environment (r6rs)) ==> #t


The phrase
"The bindings of the environment represented by a specifier are immutable"
are superfluous, because according (6.1) all exported library definitions are
immutable:

"All explicitly exported variables are immutable in both the exporting and importing libraries"