Re: [Chicken-hackers] [PATCH] Make `define-constant` support singly-quoted symbols

[Peter Bex]

On Tue, May 24, 2016 at 03:41:09PM +1200, Evan Hanson wrote:
> Allows the following program to work correctly:
> 
>   (define-constant a 'frizzle)
>   (print a)
> 
> Previously, the second `a` would be replaced by an *unquoted* `frizzle`,
> resulting in an undefined variable reference (or, if the constant value
> were instead `(quote a)`, causing the compiler to enter an infinite
> loop). This patch makes sure constant values are quoted after evaluation
> so that collapsable literal constants (including symbols) are always
> treated as data when substituted into their usage sites.

I think this fix is not the correct way to do it: it changes "val" from
plain frizzle to (quote frizzle), causing "collapsable-literal?" to
return #f (a list isn't collapsable).  This happens also when val is a
fixnum, for example, so the first case in the cond is _never_ matched,
meaning the constant-table will stay empty.

I think the proper fix is simply to quote the value when it's being
inserted into the constant-table.  This is consistent with all the other
lists into which val is being inserted.

I believe the fix is trivial enough and the bug is nasty enough to
warrant a backport to master.  This is also attached.

Cheers,
Peter

0001-Allows-the-following-program-to-work-correctly.chicken-5.patch
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0001-Allows-the-following-program-to-work-correctly.master.patch
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