> -----Original Message----- > From: cfe-dev-boun...@cs.uiuc.edu [mailto:cfe-dev-boun...@cs.uiuc.edu] On > Behalf Of Aaron Ballman > Sent: Monday, September 29, 2014 4:45 PM > To: Chris Bieneman > Cc: lldb-dev@cs.uiuc.edu; cfe-dev Developers; LLVM Developers Mailing List > Subject: Re: [cfe-dev] [LLVMdev] [RFC] Raising LLVM minimum required MSVC > version to 2013 for trunk > > On Fri, Aug 22, 2014 at 12:42 PM, Chris Bieneman <be...@apple.com> wrote: > > Starting a new thread to loop in cfe-dev and lldb-dev. For those not > > following along there has been a thread on llvm-dev about moving the > minimum > > required Visual Studio version to 2013. The motivating reason is this > will > > allow us to take advantage of a bunch of C++11 features that are not > > supported by MSVC 2012. According to MSDN > > (http://msdn.microsoft.com/en-us/library/hh567368.aspx) the list is: > > > > * Non-static data member initializers > > * Variadic templates > > * Initializer lists > > * Default template arguments for function templates > > * Expression SFINAE > > * Alias templates > > * Delegating constructors > > * Explicit conversion operators > > * Raw string literals > > * Defaulted and deleted functions > > > > From the discussion on LLVM-dev it is also believed that this may ease > some > > development pain as people keep occasionally breaking LLVM trunk by > using > > language features not available in MSVC. > > > > Original thread: > > http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075900.html > > > > Chandler’s proposal for moving forward is as follows: > > 1) Loop in cfe-dev and lldb-dev (Done!) > > 2) Wait until this email fully circulates in digests and LLVM Weekly so > that > > everyone who has an objection can voice it > > 3) If there are no objections, Commit a change to the CMake build which > > errors on old MSVC versions > > 4) Revert and fix buildbots > > 5) Repeat 3 & 4 until no issues > > 6) Once the change is live for a week with no issues, update the > > documentation to reflect the minimum required MSVC version as 2013 > > > > (http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/076090.html) > > > > Feedback is greatly appreciated. > > This thread has sort of stalled without a resolution. Alex, has your > team had the opportunity to weigh in on the subject yet?
I'm expecting to have our internal builds switched over later this week. Our investigations have shown no problems. > > We have run into a hard situation where MSVC 2012 is missing a feature > that we are currently relying on. We made some changes to ASTMatchers > to reduce the number of symbols generated in order to not require > /bigobj support (see http://reviews.llvm.org/D5485). This change > relies on function templates with default arguments, which MSVC does > not support (it generates a C4519 error in MSVC 2012), resulting in > red bots (http://bb.pgr.jp/builders/ninja-clang-i686-msc17- > R/builds/10721). I have a sad bot failing to build in Debug mode, glad to know there's a fix in the works. > > This is a considerably more interesting case (at least to me) than > hypothetical benefits -- if we retain MSVC 2012 support, we will also > require /bigobj support, have slower compile times for ASTMatcher > projects, and slower benchmarks for clang-tidy. This points to > concrete benefits to expediting switching away from MSVC 2012, which > is why I am pinging this thread again. I guess I'm a little surprised that /bigobj is such a compile-time hit, but haven't tried any benchmarking. Anyway, whatever works best for you. --paulr > > Thanks! > > ~Aaron > > _______________________________________________ > cfe-dev mailing list > cfe-...@cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev _______________________________________________ lldb-dev mailing list lldb-dev@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
