Various minor target feature cleanups around backchain, crt-static, reserve-x18 #142500
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
| r? @SparrowLii rustbot has assigned @SparrowLii. Use |
rustbot added A-attributes | Some changes occurred in compiler/rustc_codegen_ssa Some changes occurred in compiler/rustc_codegen_ssa/src/codegen_attrs.rs Some changes occurred in compiler/rustc_codegen_gcc |
This comment has been minimized.
This comment has been minimized.
RalfJung force-pushed the target-feature-cleanup branch from 92baddb to 3a6d0c2 Compare 
| r? codegen |
| ☔ The latest upstream changes (presumably #138165) made this pull request unmergeable. Please resolve the merge conflicts. |
WaffleLapkin approved these changes Jun 18, 2025
WaffleLapkin added S-blocked 
This does change the logic a bit: previously, we didn't forward reverse implications of negated features to the backend, instead relying on the backend to handle the implication itself.
RalfJung force-pushed the target-feature-cleanup branch from 3a6d0c2 to a50a3b8 Compare 
| Folded into #140920 |
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
7 participants
Add this suggestion to a batch that can be applied as a single commit. This suggestion is invalid because no changes were made to the code. Suggestions cannot be applied while the pull request is closed. Suggestions cannot be applied while viewing a subset of changes. Only one suggestion per line can be applied in a batch. Add this suggestion to a batch that can be applied as a single commit. Applying suggestions on deleted lines is not supported. You must change the existing code in this line in order to create a valid suggestion. Outdated suggestions cannot be applied. This suggestion has been applied or marked resolved. Suggestions cannot be applied from pending reviews. Suggestions cannot be applied on multi-line comments. Suggestions cannot be applied while the pull request is queued to merge. Suggestion cannot be applied right now. Please check back later.
Based on top of #140920, only the last commit is new.
cfg(target_feature = "backchain")(s390x target feature) be enabled? #142412.-Ctarget-featurethat only care about actual target features (and not "crt-static") have it. Previously, we actually setcfg(target_feature = "crt-static")twice: once in the backend target feature logic, and once specifically for that one feature. IIUC, some targets are meant to ignore-Ctarget-feature=+crt-static, it seems like before this PR that flag still incorrectly enabledcfg(target_feature = "crt-static")(but I didn't test this).-Zflag.