sandboxing doIts

Avi Bryant avi at
Fri Feb 21 09:49:14 UTC 2003

On Thu, 20 Feb 2003, Tim Rowledge wrote:

> > Has anyone else thought about this?  Would anyone else find this useful?
> Yup, I need this sort of thing for that test-setting website stuff.
> Haven't got to implement any of it yet, but looking at #scopeHas:ifTrue:
> and considering a private version of Undeclared was suggested. It looked
> promising but I still have it on my to-do list...

What I've done for now is implemented the following on CompiledMethod:

	(self hasLiteralSuchThat: [:ea | ea isVariableBinding ] )
		ifTrue: [^ false].
	(self messages includesAnyOf: self unsafeSymbols)
		ifTrue: [^ false].
	(self scanFor: 16r89) ifTrue: [^ false].
	(self primitive = 0 or: [self isQuick]) ifFalse: [^ false].
	^ true

#unsafeSymbols can be whatever you like... #class, #become:, and #perform:
are obvious candidates.

Checking to see if the method is safe before actually installing it is
easy.  And this was a lot simpler than hacking the compiler itself.


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