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Re: Unreviewed C++0x patches
Jason Merrill wrote:
Mark Mitchell wrote:
If we're not going to fix a long-standing bug in non-0x mode because
it's not a regression -- even though it might affect relatively many
people
I would be inclined to change that policy, too, as long as the patch is
deemed safe enough.
I think that's a reasonable point of view, but I think we should decide
that issue first. If we stick with the current policy, then making
changes for C++0x support seems odd. If we change to a more liberal
policy, then it makes sense to include fixes for all features (including
very new ones like C++0x) in that.
then fixing C++0x bugs (which presumably affect fewer, given how new
it is), seems wrong. We're introducing risk for relatively little
upside.
I disagree. Implementation experience is important to the
standardization process; it helps a lot for GCC to be available as a
sample implementation of some of the new features. Though I suppose
interested people could grab a snapshot of the trunk sources, that will
mean a disconnect between 4.3 usage and eventual standardized usage.
Of course, GCC's mission is not to help with standardization. By
actively pushing out pre-standard features we're actually putting our
users in harm's way; they're likely to end up with code that almost, but
not quite, matches the standard, and they may then need to change their
code as we change to match the eventual standard.
I'm all for using GCC to do research on new features and providing input
back to the committee. But, that doesn't necessarily have to happen in
FSF releases; it can happen on branches.
All that said, I'm comfortable with accepting things after they make the
WP, which has been our informal approach up until now.
So, I think the bar ought to be very high. In particular, I think we
ought to consider this only for silent miscompilation, and only if all
changes are isolated with C++0x conditionals. And, if we're going to
consider these patches, then I think we ought to consider fixes for
other silent miscompilations as well, even if not regressions.
I think we should consider those regardless of the C++0x issue. I've
expressed before my disagreement with placing higher priority on
regressions than on wrong-code bugs.
I think that's the core issue here. What do others think?
--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713