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GCC 10.1 Released

gcc.gnu.org

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Re: GCC 10.1 Released

#71

Post by jcelerier »

rumanator wrote: post #45
jcelerier wrote: post #27

Earlier quoted context omitted.

> One of the core ideas of working with LTS is that you can build your software on an LTS release and ship it to somebody else on the same LTS release, either as a source or as a binary. Yes, and updating compilers don't prevent that at all. You can use GCC 10 to ship code that will build and run on Ubuntu 12.04 without issues. Xcode 11 can ship code that works back to macOS 10.6 and Visual Studio 2019 can still opti…

> Yes, and updating compilers don't prevent that at all. You do understand that ABI backward compabitility is not ensured, don't you? https://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html Some software packages even break between distro releases. The primary value of a distro is to provide a fixed platform that application developers and users can safely target. Risking ABI breakups just because a rare number of u…

Let me quote exactly the page you linked :

> The GNU C++ compiler, g++, has a compiler command line option to switch between various different C++ ABIs. This explicit version switch is the flag -fabi-version.

If you want to target a given distro, you -fabi-version this distro's ABI, just like you set -mmacosx-version-min on mac or set _WIN32_WINNT on windows

Re: GCC 10.1 Released

#72

Post by tele_ski »

CoolGuySteve wrote: post #39
legends2k wrote: post #31

Earlier quoted context omitted.

Tangential: I think many platforms that GCC supports and the kind of optimisation GCC provides might make it a superior choice for projects. For those developers its exciting. Also if an existing project is using it for a long-time and has not intentions of switching to Clang, for them too this would be interesting.

My project uses g++ but I’ve been using a clang static-analysis step in my CI pipeline for a while now. Compiling with clang is much, much slower but it finds interesting errors sometimes. I only had to ifdef out one code section that it couldn’t understand (something about indexing an array with a constexpr function returning an enum class from a template parameter). It depends on the project, but this one and anoth…

Interesting that your build times are slower with clang. I've found on most of my projects clang is roughly 30% faster to compile in debug, but release I haven't seen a huge difference between the two.

Re: GCC 10.1 Released

#73

Post by jcelerier »

klodolph wrote: post #48
jcelerier wrote: post #27

Earlier quoted context omitted.

> One of the core ideas of working with LTS is that you can build your software on an LTS release and ship it to somebody else on the same LTS release, either as a source or as a binary. Yes, and updating compilers don't prevent that at all. You can use GCC 10 to ship code that will build and run on Ubuntu 12.04 without issues. Xcode 11 can ship code that works back to macOS 10.6 and Visual Studio 2019 can still opti…

> [...] and updating compilers don't prevent that at all. This is incorrect. In practice, for larger code bases, upgrading to a newer version of GCC or Clang is something that must be done purposefully, and you must test. Sometimes it turns out that your code relies on some compiler behavior which has changed. Sometimes newer compilers are stricter than older compilers. There are plenty of real-world cases of these p…

> This is incorrect. In practice, for larger code bases, upgrading to a newer version of GCC or Clang is something that must be done purposefully, and you must test. Sometimes it turns out that your code relies on some compiler behavior which has changed. Sometimes newer compilers are stricter than older compilers. There are plenty of real-world cases of these problems!

So if you hit issues, do what you do on every other system which is "installing older Xcode / Visual Studio" ? That would not be an issue at all if the toolchain wasn't vendored as part of the distro, you'd just have something like rustup that allows you to use whatever version of the toolchain your project requires.

> There are a number of features that are specific to the macOS toolchain which make this possible. Take a look at the "-mmacosx-version-min" flag on the macOS compiler. This selectively enables and disables various APIs.

yes ? https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Dialect-Optio...

> We're talking about Linux here. The Windows toolchain is radically different.

what I'm saying is exactly that the Linux desktop world would be in a far better place if Linux followed the Windows / macOS way of vendoring toolchains.

The only thing that is an actual issue on Linux if you want backward compatibility is glibc which does not have an easy way (AFAIK) to say "I want to target this old glibc version". But that's not the issue for what we are talking about which is "getting newer compilers on a given distro" - Red Hat & derivatives manage this without issue with the various devtoolsets for instance.

Re: GCC 10.1 Released

#74

Post by MauranKilom »

q92z8oeif wrote: post #54
MauranKilom wrote: post #47

> Extended characters in identifiers may now be specified directly in the input encoding (UTF-8, by default), in addition to the UCN syntax (\uNNNN or \UNNNNNNNN) that is already supported: static const int π = 3; int get_naïve_pi() { return π; } Lovely!

i don't know if you are being ironic or not, but the non-english speaking world will love it.

Tbh, I mainly shared the example code because I was entertained by the contrast of sophisticated naming and crude approximation. Still, it illustrates that this can come in very handy if used properly.

Of course you can also cause all sorts of mayhem. Even disregarding fun such as GREEK QUESTION MARK looking like a semicolon and zero-width spaces, I probably would not use this feature in enterprise code. Too likely that some tool somewhere (e.g. an alternate compiler?) is KO'd by characters outside of basic ASCII range (which has served us well and will keep doing so).

Re: GCC 10.1 Released

#75

Post by htfy96 »

gpderetta wrote: post #35
peapicker wrote: post #34

Earlier quoted context omitted.

And if you fix it to use delete instead of free, you get "can't delete void *" errors. Perhaps not the best example code.

and if you fix the void->int, the warning goes away.

yeah that's why I changed int* to void* in the example, but I forgot to change new to malloc

Re: GCC 10.1 Released

#76

Post by Florin_Andrei »

klodolph wrote: post #25
jcelerier wrote: post #22

Earlier quoted context omitted.

it does not make sense to pair development toolchain versions with operating system versions.

What do you think LTS entails, exactly? One of the core ideas of working with LTS is that you can build your software on an LTS release and ship it to somebody else on the same LTS release, either as a source or as a binary. If you want the latest GCC, that's fine, you're not forced to use the default compiler distributed with your OS. But it doesn't make sense to update the default compiler used in an LTS release. I…

> it doesn't make sense to update the default compiler used in an LTS release. If you want that, then you don't want LTS

This needs to be emphasized.

Re: GCC 10.1 Released

#80

Post by [deleted] »

fnord123 wrote: post #51
klodolph wrote: post #25

Earlier quoted context omitted.

What do you think LTS entails, exactly? One of the core ideas of working with LTS is that you can build your software on an LTS release and ship it to somebody else on the same LTS release, either as a source or as a binary. If you want the latest GCC, that's fine, you're not forced to use the default compiler distributed with your OS. But it doesn't make sense to update the default compiler used in an LTS release. I…

eh, no. the OS package manager is for sysadmins. LTS is for sysadmins to not have to worry about versions changing under their feet rapidly when they apply security updates. If you want to develop an application, you use your own toolchain. But yes I know most C++ people don't d this because C++ tools don't easily support it. But that's on C++ for not having pyenv, rustup, multiruby, etc equivalent.

[deleted]
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