fix(resolve): Warn on Self-Type Lifetime Elision for Non-Self Types#153692
Open
TKanX wants to merge 4 commits intorust-lang:mainfrom
Open
fix(resolve): Warn on Self-Type Lifetime Elision for Non-Self Types#153692TKanX wants to merge 4 commits intorust-lang:mainfrom
Self Types#153692TKanX wants to merge 4 commits intorust-lang:mainfrom
Conversation
rustbot
added
S-waiting-on-author
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
from
7f7909c to
9922812
Compare
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
from
ea23a3d to
7e85048
Compare
This comment has been minimized.
This comment has been minimized.
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
from
7e85048 to
7a90db6
Compare
rustbot
added
the
S-waiting-on-review
Collaborator
|
Some changes occurred in compiler/rustc_hir/src/attrs |
rustbot
removed
the
S-waiting-on-author
traviscross
added
I-lang-nominated
Contributor
|
before discussing this in a lang meeting, can you extend the PR description a bit to summarize the reasoning and discussion behind this? |
rustbot
added
S-waiting-on-author
Co-authored-by: lcnr <rust@lcnr.de> Co-authored-by: Michael Goulet <michael@errs.io>
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
2 times, most recently
from
f6ec003 to
dfcd644
Compare
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
from
dfcd644 to
805f449
Compare
rustbot
added
the
S-waiting-on-review
This comment has been minimized.
This comment has been minimized.
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
from
5d87eb2 to
347424a
Compare
This comment has been minimized.
This comment has been minimized.
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
from
347424a to
ddda958
Compare
This comment has been minimized.
This comment has been minimized.
…deny for crater run (WILL BE REVERTED) Co-authored-by: Travis Cross <tc@traviscross.com>
TKanX
force-pushed
the
bugfix/140611-self-lifetime-elision-name-match
branch
from
ddda958 to
e46d6c7
Compare
This comment was marked as resolved.
This comment was marked as resolved.
rustbot
added
S-waiting-on-review
This comment was marked as resolved.
This comment was marked as resolved.
Contributor
|
@TKanX: 🔑 Insufficient privileges: not in try users |
Contributor
|
@bors try |
This comment has been minimized.
This comment has been minimized.
rust-bors bot
pushed a commit
that referenced
this pull request
Mar 19, 2026
…e-match, r=<try> fix(resolve): Warn on Self-Type Lifetime Elision for Non-`Self` Types
Contributor
Contributor
|
@craterbot check |
Collaborator
|
👌 Experiment ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more |
craterbot
added
S-waiting-on-crater
Contributor
|
☔ The latest upstream changes (presumably #154123) made this pull request unmergeable. Please resolve the merge conflicts. |
Collaborator
|
🚧 Experiment ℹ️ Crater is a tool to run experiments across parts of the Rust ecosystem. Learn more |
Collaborator
|
🎉 Experiment
Footnotes
|
craterbot
added
S-waiting-on-review
Contributor
Author
GitHub repos: 778 entries (756 unique authors)Crates.io: 312 entriesSome important ones:
|
Contributor
|
my crate |
Contributor
Author
See case f4. Logs |
Contributor
Author
|
@lcnr what should we do next? |
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
10 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.
View all comments
Summary
FCW lint
self_lifetime_elision_not_applicable: fires when aselfparameter contains&but does not syntactically containSelf.Tracking: #140611
Context
Self-type lifetime elision in
rustc_resolverelies on a name-matching hack (is_self_ty) that shallow-comparesResvalues between the self parameter type and the impl self type. As @compiler-errors identified in #140611, this hack cannot see through type aliases (differentRes) and only fires forStruct|Union|Enum|PrimTyimpls (excludesTyAlias). When it misses,find_lifetime_for_selfreturnsEmpty, self-elision silently fails, and a later parameter's lifetime may leak into the return type.@lcnr proposed restricting self-elision to genuine
Selfand FCW'ing everything else. This PR implements that.Behavior
impl Alias { fn f(self: &W) -> &() }'_impl Alias { fn f(self: &Alias) -> &() }'_impl Alias { fn f(&self) -> &() }impl W { fn f(self: &W) -> &() }impl W { fn f(self: &Alias) -> &() }'_impl W { fn f(&self) -> &() }A follow-up PR will remove the hack after a warning period.
r? @lcnr
cc @compiler-errors @traviscross