zig ld: a drop-in linker replacement

[andrewrk]

Now that there is significant work put into Mach-O linking thanks to @kubkon, Zig is more than just a linker driver for LLD. It is now a linker that competes in the linker space, and some projects may want to use Zig as a drop-in replacement for other linkers.

This issue is to formalize that by adding an "ld" subcommand to Zig's CLI.

This issue does not block 1.0.

[SaptakBhoumik]

Hi @andrewrk , is zig's linker better at link time optimization?

[kubkon]

Hi @andrewrk , is zig's linker better at link time optimization?

I can speak for the MachO linker which is now fully self-hosted (written in Zig): we currently do not offer support for LLVM's LTO (if that's what you mean that is). LLVM forces a client linker to link dynamically to LTO plugin module which I am strongly against given that we already ship statically linked LLVM. I already started a conversation with LLVM maintainers about it a while back, but didn't see it through as other stuff came up. I will need to follow it up although this is not our priority right now.

[SaptakBhoumik]

Hi @andrewrk , is zig's linker better at link time optimization?

I can speak for the MachO linker which is now fully self-hosted (written in Zig): we currently do not offer support for LLVM's LTO (if that's what you mean that is). LLVM forces a client linker to link dynamically to LTO plugin module which I am strongly against given that we already ship statically linked LLVM. I already started a conversation with LLVM maintainers about it a while back, but didn't see it through as other stuff came up. I will need to follow it up although this is not our priority right now.

Hmm I see. Thank for your answer:)

[initdc]

Looking forward to this feature!

And you can try this my rust template to get some unsupported linker flags.

[absolutelynothinghere]

If possible, please also add nm, objdump, strip, and other LLVM commands