Getting Rust for Linux into stable Rust: compiler features

[nikomatsakis]

Metadata
Point of contact	@tomassedovic
Team(s)	compiler
Goal document	2025h2/Rust-for-Linux-compiler

Summary

Continue working towards Rust for Linux on stable. In particular, this goal is focused on the compiler features.

Tasks and status

• Discussion and moral support (compiler )

Finish and stabilize a given -Z... flag

• Discussion and moral support (compiler )
• Finalize remaining work ()
• Author stabilization report ()
• Author stabilization PR ()
• Stabilization decision (compiler )

Flags in use that need to be stabilized:

• -Zbranch-protection (arm64)
• -Zcf-protection (x86_64)
• -Zcrate-attr
• #![register_tool]
• -Zdebuginfo-compression
• -Zdirect-access-external-data (loongarch)
• -Zfixed-x18 (arm64)
• -Zfunction-return (x86)
• -Zfunction-sections
• -Zno-jump-tables (x86_64)
• -Zunpretty=expanded
• -Zsanitizer=kernel-address (arm64, riscv64)
• -Zsanitizer=shadow-call-stack (arm64, riscv64)
• -Zsanitizer=kcfi and -Zsanitizer-cfi-normalize-integers (arm64, riscv64, x86_64)

Flags to be used in the future:

• -Zharden-sls (x86_64)
• -Zindirect-branch-cs-prefix (x86)
• -Zmin-function-alignment
• -Zrandomize-layout
• -Zregparm (x86_32)
• -Zreg-struct-return (x86_32)
• -Zretpoline and -Zretpoline-external-thunk (x86)
• -Zsanitizer=kernel-hwaddress and -Zsanitizer-recover=kernel-hwaddress (arm64)
• -Zsanitize-kcfi-arity (x86_64)

[nikomatsakis]

This issue is intended for status updates only.

For general questions or comments, please contact the owner(s) directly.

[tomassedovic]

I've updated the top-level description to show everything we're tracking here (please let me know if anything's missing or incorrect!).