linux: build with GCC 13 for loongarch64

[alyssais]

Description of changes

Linux requires either binutils ≤ 2.39 or GCC ≥ 13 to build for loongarch64.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0d8dad7048611e5ba02ae8519539ce4b8b1482d3
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=11cd8a648301af0ad6937ed9493519d1e93fd4c8

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.11 Release Notes (or backporting 23.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[trofi]

Worth adding a comment right into the .nix fiiles as well? Otherwise LGTM.

[wineee]

I prefer to upgrade the stdenv of loongarch64 to GCC 13 instead of specifying the use of gcc13Stdenv when compiling Linux kernels.

As a new architecture, loongarch64 can undoubtedly get new feature support by using the new version of gcc

In a blog of loongson community developer recommends using the 13.0.0 snapshot release for new psABI support. (It should be noted that this blog is updated in 2022-11)

In practice, loongarchlinux as a distribution specifically designed for loongarch, uses GCC 13 and does not provide GCC 12 or any older versions.

The requirement of using GCC >= 13 for Linux kernels indicates that we need to upgrade the gcc in stdenv as well.

[ghost]

I prefer to upgrade the stdenv of loongarch64 to GCC 13 instead of specifying the use of gcc13Stdenv when compiling Linux kernels.

Agree. #245169 creates a designated place for this (and lets you make changes like this via overlays instead of having to edit nixpkgs).

Also, when we bump to gcc14 by default, unless somebody remembers to change (all four of) these, we'll wind up with Loongarch using an older gcc than the default, rather than newer. The gccXStdenvs are meant for holding back to an older version, not for experimenting with newer versions. If you have old code that can't use the latest GCC, an even newer version of GCC isn't going to fix that, which is why it's okay to use a fixed version number in that situation.

If there is a strong reason for wanting gcc13 only for the kernel but not elsewhere, we should put that change on just one line in one place somewhere (like .override { stdenv = gcc13Stdenv; }) guarded by if lib.versionOlder stdenv.cc.cc.version "13.0".

[wegank]

I guess it's not necessary anymore.

[wineee]

gcc 13 is default now