[gentoo-dev] Depending on clang as a compiler
Hi! First of all, I'm not a Gentoo dev but a proud Gentoo user and also a developer of a piece of software that's present in portage tree under app-lc/ category, and Gentoo is kind of tier-1 distro for me. I'm currently considering using C++14 in my project, particularly features that aren't supported by gcc 4.8 and are barely supported by 4.9 [1], but the standard is already fully supported by clang 3.4 [2]. Thus I wonder how bad is actually depending on recent clang in ebuilds? I ask because depending on the outcome of the discussion I'll either start playing around with C++14 in, say, only new modules that aren't present in the tree yet (most likely I guess) but are good candidates for inclusion, or postpone that until gcc like 4.10 is released (less likely but most safe I guess), or happily start using all new nifty C++14 features in the existing codebase as well (extremely unlikely :)). [1] http://gcc.gnu.org/projects/cxx1y.html [2] http://clang.llvm.org/cxx_status.html under C++1y section -- Georg Rudoy
Re: [gentoo-dev] Depending on clang as a compiler
On Wed, Feb 26, 2014 at 9:26 AM, Georg Rudoy 0xd34df...@gmail.com wrote: I'm currently considering using C++14 in my project, particularly features that aren't supported by gcc 4.8 and are barely supported by 4.9 [1], but the standard is already fully supported by clang 3.4 [2]. Thus I wonder how bad is actually depending on recent clang in ebuilds? If you want to do that, it's not a problem with me. That said, I probably wouldn't install packages that wanted to pull in a whole different toolchain unless I wanted them really badly (but on machines where I already have clang installed, I might not even notice). I'd say there's value in staying close to where the community's at, if you actually want your software to be used. If you don't care that much about your software being used by other people, nobody can stop you. Cheers, Dirkjan
Re: [gentoo-dev] Depending on clang as a compiler
Dnia 2014-02-26, o godz. 12:26:06 Georg Rudoy 0xd34df...@gmail.com napisał(a): I'm currently considering using C++14 in my project, particularly features that aren't supported by gcc 4.8 and are barely supported by 4.9 [1], but the standard is already fully supported by clang 3.4 [2]. Thus I wonder how bad is actually depending on recent clang in ebuilds? Well, you should note that DEPENDing on sys-devel/clang is currently implemented as USE=clang in sys-devel/llvm (please don't depend on that directly, we will split it back ASAP). So if someone doesn't have clang enabled, he'd hit portage telling him to enable the flag. Good news is that you won't take people by surprise, i.e. they will notice that you're forcing them to use clang. Bad news is that it won't be as transparent as you wished it was. -- Best regards, Michał Górny signature.asc Description: PGP signature
Re: [gentoo-dev] Depending on clang as a compiler
2014-02-26 12:35 GMT+04:00 Dirkjan Ochtman d...@gentoo.org: On Wed, Feb 26, 2014 at 9:26 AM, Georg Rudoy 0xd34df...@gmail.com wrote: I'm currently considering using C++14 in my project, particularly features that aren't supported by gcc 4.8 and are barely supported by 4.9 [1], but the standard is already fully supported by clang 3.4 [2]. Thus I wonder how bad is actually depending on recent clang in ebuilds? If you want to do that, it's not a problem with me. That said, I probably wouldn't install packages that wanted to pull in a whole different toolchain unless I wanted them really badly (but on machines where I already have clang installed, I might not even notice). I'd say there's value in staying close to where the community's at, if you actually want your software to be used. If you don't care that much about your software being used by other people, nobody can stop you. I thought about some policy-related problems. Good if there aren't any. Thanks for the opinion. Depending strictly on clang is more like a temporary measure until gcc catches up, which I hope will happen fast enough. In this case I'll also probably stick with just introducing the dependency in newer, probably even unpackaged modules so everyone will be able to use what's already considered to be somewhat stable and solid part of the app with standard gcc. -- Georg Rudoy
Re: [gentoo-dev] Depending on clang as a compiler
2014-02-26 12:52 GMT+04:00 Michał Górny mgo...@gentoo.org: Dnia 2014-02-26, o godz. 12:26:06 Georg Rudoy 0xd34df...@gmail.com napisał(a): I'm currently considering using C++14 in my project, particularly features that aren't supported by gcc 4.8 and are barely supported by 4.9 [1], but the standard is already fully supported by clang 3.4 [2]. Thus I wonder how bad is actually depending on recent clang in ebuilds? Well, you should note that DEPENDing on sys-devel/clang is currently implemented as USE=clang in sys-devel/llvm (please don't depend on that directly, we will split it back ASAP). So if someone doesn't have clang enabled, he'd hit portage telling him to enable the flag. And what about setting CMAKE_CXX_COMPILER in src_configure() (or where it should be overriden)? I don't think it's a good idea to forcefully set the compiler binary in CMakeLists.txt itself, is it better done in ebuild? -- Georg Rudoy
Re: [gentoo-dev] Depending on clang as a compiler
Dnia 2014-02-26, o godz. 12:56:30 Georg Rudoy 0xd34df...@gmail.com napisał(a): 2014-02-26 12:52 GMT+04:00 Michał Górny mgo...@gentoo.org: Dnia 2014-02-26, o godz. 12:26:06 Georg Rudoy 0xd34df...@gmail.com napisał(a): I'm currently considering using C++14 in my project, particularly features that aren't supported by gcc 4.8 and are barely supported by 4.9 [1], but the standard is already fully supported by clang 3.4 [2]. Thus I wonder how bad is actually depending on recent clang in ebuilds? Well, you should note that DEPENDing on sys-devel/clang is currently implemented as USE=clang in sys-devel/llvm (please don't depend on that directly, we will split it back ASAP). So if someone doesn't have clang enabled, he'd hit portage telling him to enable the flag. And what about setting CMAKE_CXX_COMPILER in src_configure() (or where it should be overriden)? I don't think it's a good idea to forcefully set the compiler binary in CMakeLists.txt itself, is it better done in ebuild? I don't know CMake well but I think it's enough to set CXX before calling cmake-utils_src_configure(). You gotta know the details better. And yes, it's better done in ebuild, it will also make it easier to support new enough gcc. You may add some checks for necessary features in CMake though, and fail explicitly when the compiler doesn't provide them. -- Best regards, Michał Górny signature.asc Description: PGP signature
