On Tue, Nov 12, 2013 at 10:25 PM, Jeff Law <l...@redhat.com> wrote: > On 11/12/13 13:35, Jakub Jelinek wrote: >> >> On Tue, Nov 12, 2013 at 12:59:47PM -0700, Jeff Law wrote: >>> >>> So I lost something like 3 hrs last night due to writing a hunk of >>> code like this >>> >>> if (INTEGRAL_TYPE_P (gimple_assign_lhs (stmt))) >> >> >> INTEGRAL_TYPE_P is a macro, which accepts everything, just adding >> a TYPE_CHECK to that macro would be sufficient to catch that > > Yes, I know full well that I could hack up INTEGRAL_TYPE_P to detect this > case and my brain damage would have been caught via the check sometime > during building the runtime libraries or the stage2 build. > > My point is the mere need to hack up INTEGRAL_TYPE_P in that way is a result > of a fundamental misdesign of the tree structures. If the structures were > properly designed what I did would have been flagged as a compile error. > > It's that fundamental mis-design that we're trying to correct now with the > work from Andrew, David & others.
You know - 'tree's were a design decision (well, just my guess - I wasn't around 25 years ago ...). They are a perfect match to represent an AST. So I'd say whoever introduced that middle-end between the FEs AST and RTL was at fault :P (luckily I wasn't around either ... ;)) Still splitting 'tree's into a few separate classes is not hard. It's just work - and in the end even the frontends will benefit. Oh, and I believe it is a project that has a much higher success rate than trying to replace trees with "something else" in the GIMPLE and RTL middle-end only and have that cooperate sanely with the rest of the compiler. Something along 1 man year for the first with a 75% success chance against 6 man years for the second with a 20% success chance. And the nice thing is that the first can be done incrementally (we _are_ already in the process of that transition - see the changes done to 'tree' during the last 6 years). And the other nice thing is that even non-100% success will end up in something better than we have now. With the second project it's a all-or-nothing (or rather all-or-just-uglification). Richard. > Jeff >
