2012/2/10 Vasiliy Korchagin <[email protected]>: > On 10.02.2012 19:45, David Blaikie wrote: >> >> 2012/2/9 Vasiliy Korchagin<[email protected]>: >>> >>> On 08.02.2012 23:47, David Blaikie wrote: >>> >>> On Wed, Feb 8, 2012 at 11:25 AM, Chris Lattner<[email protected]> >>> wrote: >>> >>> On Feb 8, 2012, at 5:31 AM, Vasiliy Korchagin wrote: >>> >>> 07.02.2012 07:27, Eli Friedman пишет: >>> >>> On Mon, Feb 6, 2012 at 6:51 PM, Xin Tong<[email protected]> >>> wrote: >>> >>> Is there any way to stop this ? >>> >>> /home/socrates/llvm/llvm-3.0.src/benchmarks/powerstone/crc/crc.c:67:1: >>> error: 'main' must return 'int' >>> void main() >>> ^ >>> 1 error generated. >>> >>> You mean besides fixing the source of your benchmark so it's valid C? >>> Not at the moment... patches welcome. >>> >>> -Eli >>> >>> We suggest patch for allowing main() function to have non-integer return >>> type. This feature can be enabled with "-allow-non-int-main" option. In >>> this >>> case warning about incorrect main() return type will be printed instead >>> of >>> error. >>> >>> In patch also included test case for this feature. >>> >>> Vasiliy Korchagin, >>> >>> Hi Vasiliy, >>> >>> Please send clang patches to cfe-dev. >>> >>> or even cfe-commits (further instructions are here: >>> http://clang.llvm.org/get_involved.html) >>> >>> [I've dropped llvm-dev and added cfe-commits to this email] >>> >>> My first thought based on your description alone would be that we >>> should support this, if at all, probably in the way that GCC already >>> does - surfacing non-int returning main as a warning in C (under >>> -Wmain) and error in C++ (as it is already) if that's practical. >>> >>> & looking at the patch itself: Your change is even more permissive >>> than GCC (when you use the flag you've added) allowing C++ to have >>> void returning main. I don't see any need to be so accepting. >>> >>> (& the change you've made in Sema::ActOnFinishFunctionBody scares me a >>> bit - what does that do when you have int returning main but you turn >>> this flag on? not allow implicit return 0? that seems problematic) >>> >>> - David >>> >>> David, thanks for your reply. >>> >>> Seems like my response missed mailing list, so I'm sending it again. >>> I changed the patch and now "-allow-non-int-main" option allows to print >>> a warning in C and error in C++ in case of non-integer main. I also >>> fixed implicit returning 0. >> >> Sorry, I just didn't get around to replying - I still think this >> should be under the -Wmain flag, probably - like it is in GCC. But I >> could be wrong - hopefully someone else pipes up with an opinion too. >> >> (it's possible it should be stronger - perhaps a separate warning that >> defaults to error - but I don't think it should be an entirely >> new/separate flag) >> >> - David > > I reduced patch and now it provides GCC-like behavior. In C clang prints a > warning and in C++ prints error. The warning is under control of -Wmain > flag.
This looks better - though do you need the change in codegen? what happens if you remove that (leave it as it was before)? & some test cases would be good. I'm still a bit concerned about relaxing the default behavior too much - hopefully other Clang developers will chime in with a more informed opinion on this, but perhaps we'll want to group this particular warning under its own flag (main-return-type ?) & make that diagnostic an error by default (this is a weird device to use & it turns up in a few other places in Clang, but it might be an appropriate fit here). _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
