Michael Spencer
2014-Aug-25 19:13 UTC
[LLVMdev] [RFC] Raising minimum required Visual Studio version to 2013 for trunk
On Mon, Aug 25, 2014 at 12:04 PM, Gao, Yunzhong <yunzhong_gao at playstation.sony.com> wrote:> Hi, > Sorry for the delay in responding, we have been discussing this internally > and have not had time to do a proper investigation. > >> We absolutely have to ship a set of DLLs that run hosted in VS2012. Is >> there any sort of runtime incompatibility that would happen if we >> built with 2013, needed the 2013 CRT, but tried to run inside the >> VS2012 process? That would be a complete show stopper for us since we >> have a committed schedule for support of versions of VS that we host in. > >> Has any size/performance testing been done to compare LLVM built with >> the two versions of MSVC? Perf regressions are bad, m'kay? > > I do not know the answer to either of Alex's questions, so I am a bit > concerned. Two weeks is not going to be enough to test the updates; two > months might be more realistic... > > What is the impact on the static libraries (such as LLVMCore.lib or > ClangLex.lib)? Can libraries built with Visual Studio 2013 link with other > objects built with Visual Studio 2012 or earlier? > > - GaoNo, you cannot link C++ code compiled with one version of VS to C++ code compiled with a different version of VS. The C++ ABI and standard library change between versions. - Michael Spencer> > > -----Original Message----- > From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Aaron Ballman > Sent: Friday, August 22, 2014 6:01 AM > To: Renato Golin > Cc: LLVM Developers Mailing List > Subject: Re: [LLVMdev] [RFC] Raising minimum required Visual Studio version to 2013 for trunk > > On Fri, Aug 22, 2014 at 8:58 AM, Renato Golin <renato.golin at linaro.org> wrote: >> On 22 August 2014 13:43, Aaron Ballman <aaron at aaronballman.com> wrote: >>> My opposition to this switch was the timing. When we researched "what >>> minimum can we live with for C++11" nine months ago, we determined >>> what versions would make sense, which included MSVC 2012, and told >>> people what the plan was. My concern was pulling the rug out from >>> under people who were relying on that determination without putting >>> in the proper research and giving them enough time to react. >> >> The fact that you spoke, and others echoed your views, is proof that >> what you fear will not happen. >> >> Chandler's plan is simply showing the failures before we switch, which >> is exactly what we've done last time, what you're asking now, and what >> we'll do next. >> >> Progress is made by breaking small things, one at a time. :) > > We're in violent agreement. :-) > > ~Aaron > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
Zachary Turner
2014-Aug-26 03:38 UTC
[LLVMdev] [RFC] Raising minimum required Visual Studio version to 2013 for trunk
If it's a DLL that only exposes a C api you can. That's how, for example, your code can link against KERNEL32.DLL and others. If there is a C++ api though things change. On Mon, Aug 25, 2014 at 12:13 PM, Michael Spencer <bigcheesegs at gmail.com> wrote:> On Mon, Aug 25, 2014 at 12:04 PM, Gao, Yunzhong > <yunzhong_gao at playstation.sony.com> wrote: > > Hi, > > Sorry for the delay in responding, we have been discussing this > internally > > and have not had time to do a proper investigation. > > > >> We absolutely have to ship a set of DLLs that run hosted in VS2012. Is > >> there any sort of runtime incompatibility that would happen if we > >> built with 2013, needed the 2013 CRT, but tried to run inside the > >> VS2012 process? That would be a complete show stopper for us since we > >> have a committed schedule for support of versions of VS that we host in. > > > >> Has any size/performance testing been done to compare LLVM built with > >> the two versions of MSVC? Perf regressions are bad, m'kay? > > > > I do not know the answer to either of Alex's questions, so I am a bit > > concerned. Two weeks is not going to be enough to test the updates; two > > months might be more realistic... > > > > What is the impact on the static libraries (such as LLVMCore.lib or > > ClangLex.lib)? Can libraries built with Visual Studio 2013 link with > other > > objects built with Visual Studio 2012 or earlier? > > > > - Gao > > No, you cannot link C++ code compiled with one version of VS to C++ > code compiled with a different version of VS. The C++ ABI and standard > library change between versions. > > - Michael Spencer > > > > > > > -----Original Message----- > > From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] > On Behalf Of Aaron Ballman > > Sent: Friday, August 22, 2014 6:01 AM > > To: Renato Golin > > Cc: LLVM Developers Mailing List > > Subject: Re: [LLVMdev] [RFC] Raising minimum required Visual Studio > version to 2013 for trunk > > > > On Fri, Aug 22, 2014 at 8:58 AM, Renato Golin <renato.golin at linaro.org> > wrote: > >> On 22 August 2014 13:43, Aaron Ballman <aaron at aaronballman.com> wrote: > >>> My opposition to this switch was the timing. When we researched "what > >>> minimum can we live with for C++11" nine months ago, we determined > >>> what versions would make sense, which included MSVC 2012, and told > >>> people what the plan was. My concern was pulling the rug out from > >>> under people who were relying on that determination without putting > >>> in the proper research and giving them enough time to react. > >> > >> The fact that you spoke, and others echoed your views, is proof that > >> what you fear will not happen. > >> > >> Chandler's plan is simply showing the failures before we switch, which > >> is exactly what we've done last time, what you're asking now, and what > >> we'll do next. > >> > >> Progress is made by breaking small things, one at a time. :) > > > > We're in violent agreement. :-) > > > > ~Aaron > > _______________________________________________ > > LLVM Developers mailing list > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > > _______________________________________________ > > LLVM Developers mailing list > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140825/d82c2c6e/attachment.html>
Alex Rosenberg
2014-Aug-26 16:47 UTC
[LLVMdev] [RFC] Raising minimum required Visual Studio version to 2013 for trunk
While that is correct, it does not hold for any of us because LLVM exposes a C++ API amongst it's own components. Alex On Aug 25, 2014, at 8:38 PM, Zachary Turner <zturner at google.com> wrote:> If it's a DLL that only exposes a C api you can. That's how, for example, your code can link against KERNEL32.DLL and others. If there is a C++ api though things change. > > > On Mon, Aug 25, 2014 at 12:13 PM, Michael Spencer <bigcheesegs at gmail.com> wrote: > On Mon, Aug 25, 2014 at 12:04 PM, Gao, Yunzhong > <yunzhong_gao at playstation.sony.com> wrote: > > Hi, > > Sorry for the delay in responding, we have been discussing this internally > > and have not had time to do a proper investigation. > > > >> We absolutely have to ship a set of DLLs that run hosted in VS2012. Is > >> there any sort of runtime incompatibility that would happen if we > >> built with 2013, needed the 2013 CRT, but tried to run inside the > >> VS2012 process? That would be a complete show stopper for us since we > >> have a committed schedule for support of versions of VS that we host in. > > > >> Has any size/performance testing been done to compare LLVM built with > >> the two versions of MSVC? Perf regressions are bad, m'kay? > > > > I do not know the answer to either of Alex's questions, so I am a bit > > concerned. Two weeks is not going to be enough to test the updates; two > > months might be more realistic... > > > > What is the impact on the static libraries (such as LLVMCore.lib or > > ClangLex.lib)? Can libraries built with Visual Studio 2013 link with other > > objects built with Visual Studio 2012 or earlier? > > > > - Gao > > No, you cannot link C++ code compiled with one version of VS to C++ > code compiled with a different version of VS. The C++ ABI and standard > library change between versions. > > - Michael Spencer > > > > > > > -----Original Message----- > > From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Aaron Ballman > > Sent: Friday, August 22, 2014 6:01 AM > > To: Renato Golin > > Cc: LLVM Developers Mailing List > > Subject: Re: [LLVMdev] [RFC] Raising minimum required Visual Studio version to 2013 for trunk > > > > On Fri, Aug 22, 2014 at 8:58 AM, Renato Golin <renato.golin at linaro.org> wrote: > >> On 22 August 2014 13:43, Aaron Ballman <aaron at aaronballman.com> wrote: > >>> My opposition to this switch was the timing. When we researched "what > >>> minimum can we live with for C++11" nine months ago, we determined > >>> what versions would make sense, which included MSVC 2012, and told > >>> people what the plan was. My concern was pulling the rug out from > >>> under people who were relying on that determination without putting > >>> in the proper research and giving them enough time to react. > >> > >> The fact that you spoke, and others echoed your views, is proof that > >> what you fear will not happen. > >> > >> Chandler's plan is simply showing the failures before we switch, which > >> is exactly what we've done last time, what you're asking now, and what > >> we'll do next. > >> > >> Progress is made by breaking small things, one at a time. :) > > > > We're in violent agreement. :-) > > > > ~Aaron > > _______________________________________________ > > LLVM Developers mailing list > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > > > _______________________________________________ > > LLVM Developers mailing list > > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev > > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140826/f0eef7fc/attachment.html>