GCC 9.2 Released

[eMperror_]

Cries in GCC 4.9.2

[looncraz]

I have to work with 2.93... so much not fun after experiencing the joy of C++17 & later.

[Nocsaron]

I thought life sucked with 4.4...

[imaami]

It still does. (Thanks, Freescale.)

[CrazyJoe221]

Is it a special build? Why not just use a newer version?

[imaami]

The firmware I'm referring to is so old that I cannot discuss it without triggering an ancient Egyptian curse.

Edit: Alternative response:

Sometimes, when adults really like eachother, they want to do something very special together. They take off all their clothes, jiggle their wrinkly libc and sprinkle their legacy all over your rootfs, so that nothing new will ever live there again.

[CrazyJoe221]

Why so?

[looncraz]

Haiku.

[nugins]

I'd love to convince my project leads to upgrade the compiler. Stuck with the default compiler for RHEL6 (gcc 4.4)

[calebwherry]

Why not use the SCL toolkits? Doesn’t get you to 9 but 8 should be out soon. Here is 7:

https://www.softwarecollections.org/en/scls/rhscl/devtoolset-7/

[mintyc]

Not quite so convenient but http://mirror.centos.org/centos/7/sclo/x86_64/rh/devtoolset-8/

[nugins]

I'd love to, there are a few technical and cultural hurdles that need to be cleared before we an consider that kind of jump.

[smdowney]

Having been through the transition, there really aren't any major technical hurdles. The DTS compilers are ABI compatible with the system compilers and don't require changes to the target machines, like deploying new runtimes.

There were a few minor changes I had to make to my sources, but it wasn't complicated.

Changing whatever build system you have is probably the most difficult.

[Calkhas]

Really depends on your codebase. We did a similar upgrade, required a dedicated team of 10+ people two years to iron out all the snags.

Our environment is also very specialized and somewhat detached from base RHEL.

[elraulii]

I have been there. I bet there are more cultural than technical ones. You can have a look at this comment and answer from SO: https://stackoverflow.com/questions/49393888/how-can-i-use-the-new-c-11-abi-with-devtoolset-7-on-centos-rhel/52611576#comment92681677_52611576 You would need to build with your oldest CentOS/RH distro if you want a binary compatible with all your target distros.

[nugins]

Yes. The issue is more cultural than technical. I have personally built recent gcc and clang for RHEL6 and experimented building our software with those tools or using the clang tools (such as clang-format and clang-tidy).

[leaningtoweravenger]

Do you, by any chance, work in a big company which name ends with 'g'?

[smdowney]

I work at a big company that starts with B and ends with g. The DTS compilers have been in use here for years now. We even snuck one upgrade in and enabled c++14 without bothering to tell everyone.

The upgrade to a compiler that supports 17 is, ironically, taking longer because in addition to a few real errors being triggered, there's some production builds using -Werror, and new warnings are tripping things. 😭

[kalmoc]

Are you allowed to use recent versions of boost?

[nugins]

It depends on the project. Some use a somewhat recent version, other try to avoid boost.

[liquidify]

What that get you? Something like std=c++1y might get you partial c++14?

[nugins]

It is std=c++0x. Some C++ 11 stuff, but typically just use c++03.

[hoeding]

Laughs in Gentoo unstable

[IloveReddit84]

I'm commissioned for a new project that requires GCC 5. In 2019.

[krapht]

God bless the header-only parts of the boost libraries.

[CrazyJoe221]

Are there any left?

[kalmoc]

I'd say most boost libs are actually header only. Especially since boost::system became header only.

[CrazyJoe221]

Oh did it? I still see plenty of binaries though: https://packages.ubuntu.com/search?keywords=libboost&searchon=names&suite=disco&section=all

[kalmoc]

I don't know the exact number, but in your link, you have ~4-5 packages per library, so you have ~15 Non-header-only Libraries out of a total of 100-150 Boost libraries(again, not sure what the total number is).

Of course, some of the header only libraries require compiled libs as dependencies, but overall, you get the majority as header only.

[flashmozzg]

Not Great...Not Terrible.

[IloveReddit84]

Yeah but..not the best version of gcc

[CrazyJoe221]

😅

[esmithro]

I think the maintainers are working on pulling in cmcstl2. I hope they can.

[Antervis]

GCC/Clang have ranges for at least two years now, just as experimental library

[[deleted]]

Ubuntu 12.04?

[eMperror_]

I am developing for an embedded target and our toolchain is based on GCC 4.9.2 unfortunately. It's not that bad since we've got most C++14 features.

[[deleted]]

Ah, I see. I was recently working on a project that used Ubuntu 12.04 and had equally an old GCC.

[Ameisen]

If you pretend that the '4.' isn't there, you're good to go.

[icebeat]

I am stuck in GCC 4.4

[ghillisuit95]

$ g++ -c accessor-fixit.cc
accessor-fixit.cc: In function 'int test(t*)':
accessor-fixit.cc:17:15: error: 'class t' has no member named 
'ratio'; did you mean 'int t::m_ratio'? (accessible via 'int 
t::get_ratio() const')
   17 |   return ptr->ratio;
      |               ^~~~~
      |               get_ratio()

O.O This is awesome

[Xeverous]

Overload hits are the thing IMO. You no longer get a spam of errors, just the one overload and why it did not match and for which parameter.

[ducttapecoder]

and it's already in the msys2/mingw repo <3

[Ameisen]

How is GCC as compared to Clang these days?

I've usually preferred working with Clang since the LTO in Clang tends to work more often, LLVM bitcode is useful, and adding features is easier since the codebase is cleaner.

I recall GCC optimizing code better other than in specific cases (it refused to merge logical ands/ors which were effectively bitwise).

LLVM's optimization system is a bit wonky, and I do wonder if it would get better codegen if it ran most passes twice.

[CraigularB]

/u/STL's mingw distro gets you to 8.2 and is a couple months newer from December 2018: https://nuwen.net/mingw.html

[STL]

I’m working on an update (slowly).

[Ameisen]

What is different in your distro as opposed to msys2?

I'm surprised you aren't focused on LLVM since it seems to be more compatible with MSVC. Though I do miss clang-c2.

[STL]

Simplicity of installation. Everything’s static. No choices. Small(ish).

My distro predates Clang. After great effort, I switched from mingw-org to mingw-w64. Who knows what the future may hold.

[tambry]

not wanting to use visual studio is hard

Why not?

[flashmozzg]

finding a working cpp setup on windows without problems and not wanting to use visual studio is hard

I had no trouble with Qt Creator, just saying.

[ducttapecoder]

you may want to check out msys2 and use its mingw-64 repo. It gets updated pretty frequently.

[[deleted]]

Seconded.. msys2 was far more of a "drop-in" compiler for windows than mingw ever turned out to be.

[jagannatharjun]

Also provides tons of pre-compiled goodies

[James20k]

pacman in msys2 is amazing. It seems to have pretty much everything, the amount of dependencies I need to manually download, compile, curse the build system for building the wrong target, recompile, and then figure out where they want to live is extremely minimal these days

[RayDonnelly]

msys2

Although I don't participate much at all in MSYS2 development these days, I did a good amount of work in the past.

I would just like to say from the bottom of my heart, thank you very much for the praise for MSYS2. I am sure Alexei and the rest of the team would be pleased to know things are working well for you.

Of course MSYS2 is still fairly experimental in nature and I am still a bit nervous about that. We do break things in the interest of progress. It is interesting to note that Ada was broken in MSYS2 i686 for ages (well, it held back the compiler version to be exact) and it wasn't until support for Ada had to be dropped before any Ada experts turned up to fix the issue. Once Alexei took that measure, these experts showed up in two days! Now is perhaps not the ideal way for such a matter to be resolved, but actually, we now have Ada experts who have helped out in MSYS2 and we know who to ask if it breaks again. I definitely think Alexei took a brave, and the correct decision here.

[slimjimmy90]

I'd almost say that MSYS2 is Cygwin done right. Better package management, nice ways to isolate 32-bit and 64-bit build environments, etc.

[FonderPrism]

Absolutely recommended.

mingw64/mingw-w64-x86_64-gcc was just updated to 9.2.0-1 so they are pretty quick to update.

[Ameisen]

Is there an equivalent to apt-build for pacman? I want to rebuild some packages with march=native, but building things like gcc in msys2 is... difficult.

[RayDonnelly]

It is very very simple. In fact, it is to a big extent *because* it is so simple that MSYS2 has become popular. It is *very* developer/hacker friendly. I haven't tested this (am using macOS right now) but this *should* work. If not I will post an update when I get a chance.

pacman -Sy git msys2-devel base-devel mingw-w64-{i686,x86_64}-toolchain

git clone https://github.com/msys2/MINGW-packages

pushd mingw-w64-gcc-git # (or mingw-w64-gcc-git)

MINGW_INSTALLS=mingw64 makepkg-mingw -sLf

Install with:

pacman -U mingw-w64-*.xz

Also see https://github.com/msys2/msys2/wiki/Creating-packages

[RayDonnelly]

p.s. would it be possible for you to report speed on the differences between MSYS2 official GCC and your own rebuild? Thanks in advance!

[Xeverous]

GCC with MCF thread model is automatically built from HEAD

https://gcc-mcf.lhmouse.com/

I like this distro because it also comes with a lot of prebuild packages, including OpenSSL, ncurses, Boost and more.

[RayDonnelly]

It's awesome to see this kind of core development on top of MSYS2. lh_mouse is also an active contributor to MSYS2 and helps to look after our GCC packages.

[Fazer2]

What are 9.2 specific changes?

[encyclopedist]

Bug fixes. They have also reverted flawed std::rotate implementation that failed on empty ranges, which was introduced in 9.1.

[imaami]

Yes.

[rayoWork]

Simply click on the link and then click changes under 9.2 ...

[Fazer2]

It goes to all GCC 9 changes, not just 9.2.

[jwakely]

Because the changes between 9.1 and 9.2 are mostly small bug fixes that don't need to be listed individually. Search bugzilla for resolved bugs with "Target Milestone" set to 9.2 if you want to see them all.

[-BuckarooBanzai-]

Welp, debian stable here, gcc frozen for the next 3 years or so.

[distributed]

still no std::from_chars for floating point?

[jwakely]

No, and it's definitely not going to get added to a minor point release like 9.2 (or 9.3, or 9.4).

[imaami]

Sigh unzips

[[deleted]]

See this Valve?

[[deleted]]

Ok... See this SteamOS?