Compiler does not recognize the reserve-r9 target feature
Open
Nobody has claimed this yet.
A-LLVM
A-target-feature
O-Arm
T-compiler
- Dominant language
- Rust
- Stars
- 119k
- Forks
- 16.1k
- PR merge metrics
- PR metrics pending
Description
This issue is similar to this issue. On the armv7a-none-eabi target, specifying the reserve-r9 target feature using the flag -Ctarget-feature=+reserve-r9 results in the following warning:
warning: unknown and unstable feature specified for `-Ctarget-feature`: `reserve-r9`
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= note: it is still passed through to the codegen backend, but use of this feature might be unsound and the behavior of this feature can change in the future
= help: consider filing a feature request
The feature is currently working and is used by me and others too.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the warning for armv7a-none-eabi with -Ctarget-feature=+reserve-r9, then inspect the compiler's target-feature handling for this target and the related issue #121970. Done means reserve-r9 is recognized without the unknown-and-unstable warning while remaining passed through correctly to the codegen backend.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers
- Issue type
- Feature
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100