gcc: fix missing atomic ops errors on risc-v

[fgaz]

Description of changes

Fixes errors like:

ld: [...]: undefined reference to `__atomic_exchange_1'

• Apply patch from upstream that uses libatomic for missing ops: https://gcc.gnu.org/git?p=gcc.git;a=commit;h=f797260adaf52bee0ec0e16190bbefbe1bfc3692 A few conflicts were resolved, so the patch is included as a file.
• Remove workarounds from
  • aws-sdk-cpp
  • libjxl
  • numactl
  • mariadb
  • zstd

Fixes #258614 (comment)

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
  • riscv64-linux
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• 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
  • cmakeMinimal (was broken by this)
  • aws-sdk-cpp
  • libjxl
  • numactl
  • mariadb
  • zstd
  • llvm and clang 17
• 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.

[ghost]

I'm not excited about carrying a gcc patch simply in order to eliminate LDFLAGS from a few packages.

It looks like this patch didn't make it into gcc 13.2, so if there is a workaround (which there is) we should be using the workaround instead until this patch shows up in a release. Generally we ship merged-but-unreleased patches only when there is no alternative available.

[ghost]

What release is this commit part of? git tag --contains doesn't report any.

[fgaz]

None yet as far as I can see

[fgaz]

Turns out gcc 13 includes the patch

[ghost]

Then why not just use

• default-gcc-version: 12 -> 13 if !isDarwin && !isAarch64 #268097

[fgaz]

Yes that's perfect!

I thought that upgrade was still far off, good to know that's not the case!

[fgaz]

I'm not excited about carrying a gcc patch simply in order to eliminate LDFLAGS from a few packages.

I suspect that there are way more broken packages that we don't know about, since nobody builds the whole nixpkgs on risc-v.

For now I just discovered cmake and llvm 17, so I can certainly apply the workaround to those too.

Up to you.

[fgaz]

...and of course it's a mass rebuild because optionalString false returns an empty string, which is different from an empty LDFLAGS. If we proceed with this I guess I'll have to split the workaround removal (or move everything to staging).

[ghost]

...and of course it's a mass rebuild because optionalString false returns an empty string, which is different from an empty LDFLAGS.

One of the many reasons to move towards env = lib.optionalAttrs { LDFLAGS = ... }...

[fgaz]

Closing due to #268067 (comment).

I'll apply the workaround to cmake in another pr so risc-v is not blocked for another 1-2 staging cycles, then once #145377 is in I'll remove all workarounds.

[NickCao]

Workarounds removed in #274827