Re: [PATCH] New predicate covering NOP_EXPR and CONVERT_EXPR

["Giovanni Bajo" <rasky at develer dot com>]

Joseph S. Myers <joseph@codesourcery.com> wrote:

> To my mind, the *essence* of the unification of the tree codes is fixing
> all the places which treat them differently to use a better-defined
> condition, and the *boring mechanical part* is the actual unification.
> The essence should be done separately from the boring mechanical part.
> The essence can readily be split up; fixing
> check_function_arguments_recurse, with a new testcase as above, is
> independent of fixing the rest of the code.

I agree. But I doubt you will find someone with such a spare time. Also it
depends on how much you are able to understand the problems without even
trying to modify the code. Surely you are a C frontend maintainer and you
understand well your frontend, but nobody understands well enough the whole
compiler to do this auditing. For once, I don't have this familiarity being
a spare time contributor.

Your plan is the theoretical perfection, but I think practicity beats purity
in this case. I might have some time to prepare a mechanical patch and fix
all regressions in the testsuite by debugging them, thus making the patch
acceptable by our rules. I don't have time to understand all the uses of
those expressions in the whole compiler to make sure there are no problems.
If other regressions are subsequently submitted in Bugzilla, I'll take a
look and fix. Meanwhile, if you have time to do some auditing in the C
frontend and add testcases for cases that you see that might break, that's
great.
-- 
Giovanni Bajo