jiebi/CodeConvo huggingface dataset:
Code change:
use std::mem; use crate::errors::{ <del> ChangeFieldsToBeOfUnitType, IgnoredDerivedImpls, MultipleDeadCodes, ParentInfo, UselessAssignment, </del> <ins> ChangeFields, IgnoredDerivedImpls, MultipleDeadCodes, ParentInfo, UselessAssignment, </ins> }; // Any local node that may call something in its body block should be

Related discussion:
text: The idea of changing a field to unit type to preserve field numbering makes sense for fields in the middle of a tuple. However, if the unused field is at the end, or it's the only field, then deleting it won't affect field numbering of any other field. No response No response <!-- TRIAGEBOTSTART --<!-- TRIAGEBOTASSIGNSTART --<!-- TRIAGEBOTASSIGNDATASTARTTRIAGEBOTASSIGNDATAEND --<!-- TRIAGEBOTASSIGNEND --<!-- TRIAGEBOTEND --
claim
Code change:
// A rest pattern `..`. self.bump(); // `..` PatKind::Rest <ins> } else if self.check(&token::DotDotDot) && !self.is_pat_range_end_start(1) { self.recover_dotdotdot_rest_pat(lo) </ins> } else if let Some(form) = self.parse_range_end() { self.parse_pat_range_to(form)? // `..=X`, `...X`, or `..X`. } else if self.eat_keyword(kw::Underscore) {

Related discussion:
text: ` The problem here is that we have instead of The compiler however points towards in the error message instead of the superfluous : Fun fact: when using four dots , it correctly points at the last dot :) <!-- TRIAGEBOTSTART --<!-- TRIAGEBOTASSIGNSTART --This issue has been assigned to via . <!-- TRIAGEBOTASSIGNDATASTARTTRIAGEBOTASSIGNDATAEND --<!-- TRIAGEBOTASSIGNEND --<!-- TRIAGEBOTEND --
seems like a simple issue to fix. If I were to take a shot at fixing this, where would I start?
Mentoring instructions: Add a branch after this one... instead of , check that . This should be interpreted as a as in the previous branch, but an error should also be emitted. (Add the code for error emission in a separate method, with an appropriate , where the span of the is replaced with . See for an example on emitting an error with a suggestion.)
Sure thing! Will get to it right after work. Thanks for the pointers.
assign
Code change:
unsafe { let mut fds = [0, 0]; <del> // Like above, see if we can set cloexec atomically #[cfg(target_os = "linux")] { match cvt(libc::socketpair(fam, ty | libc::SOCK_CLOEXEC, 0, fds.as_mut_ptr())) { Ok(_) => { return Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1])))); } Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {} Err(e) => return Err(e), </del> <ins> cfg_if::cfg_if! { if #[cfg(target_os = "linux")] { // Like above, set cloexec atomically cvt(libc::socketpair(fam, ty | libc::SOCK_CLOEXEC, 0, fds.as_mut_ptr()))?; Ok((Socket(FileDesc::new(fds[0])), Socket(FileDesc::new(fds[1])))) } else { cvt(libc::socketpair(fam, ty, 0, fds.as_mut_ptr()))?; let a = FileDesc::new(fds[0]); let b = FileDesc::new(fds[1]); a.set_cloexec()?; b.set_cloexec()?; Ok((Socket(a), Socket(b))) </ins> } } <del> cvt(libc::socketpair(fam, ty, 0, fds.as_mut_ptr()))?; let a = FileDesc::new(fds[0]); let b = FileDesc::new(fds[1]); a.set_cloexec()?; b.set_cloexec()?; Ok((Socket(a), Socket(b))) </del> } }

Related discussion:
text: Good question! There are 6 workarounds in for older Linux versions (that I could find). Increasing the minimum version to 2.6.32 (aka 3rd Kernel LTS, aka RHEL 6) would fix 5 of them. Code links are inline: uses the flag with  (mentioned above, in 2.6.23) uses with  ( in 2.6.24, there is also the mention of a bug occuring on "some linux kernel at some point") uses  to atomically set the flag on the pipe fds ( in 2.6.27) uses with  ( in 2.6.27) uses  to permit use of ( in 2.6.28) ~ ( in 4.5, not fixed by this proposal)~ As you can see, the workarounds fixed by this proposal all have a similar flavor. Originally posted by in
Kernel updated in .
As noted, needs a much newer kernel 4.5, so we'll still need that fallback. But all the stuff should be ok to assume available now.
The new minimal version is 2.6.27 from what I can see, so "Socket::accept uses accept4(2) to permit use of SOCK_CLOEXEC" still needs a fallback, right?
The builder is using 2.6.32 headers, so I would call that our new minimum.
Ah right; I am actually not sure where I got the 27 from...
The title of suggested 2.6.27, but we went a little higher to match the actual distros in use.
I know this is ancient history, but do you recall the problem with ? You introduced that comment about "some kernel" in , and you were the last to update it in . If the problem kernels were before 2.6.32, then I'd like to clean that up now.
Just digging in kernel history, I did find one hiccup in , but that bug was introduced and resolved during the 3.7 development cycle, not in a release.
IIRC we just mirrored what musl did at the time, which looks like it : Looks like the original mailing list thread is gone and there's no comments in the musl source, and I don't recall what happened here. I suspect it would be safe to remove those workarounds and just assume works one the first try until someone says differently.
Code change:
<ins> error[E0309]: the parameter type `T` may not live long enough --> $DIR/min-choice-reject-ambiguous.rs:17:5 | LL |     type_test::<'_, T>() // This should pass if we pick 'b. |     ^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds | help: consider adding an explicit lifetime bound... | LL |     T: 'b + 'a, |           ++++ error[E0309]: the parameter type `T` may not live long enough --> $DIR/min-choice-reject-ambiguous.rs:28:5 | LL |     type_test::<'_, T>() // This should pass if we pick 'c. |     ^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds | help: consider adding an explicit lifetime bound... | LL |     T: 'c + 'a, |           ++++ error[E0700]: hidden type for `impl Cap<'b> + Cap<'c>` captures lifetime that does not appear in bounds --> $DIR/min-choice-reject-ambiguous.rs:39:5 | LL | fn test_ambiguous<'a, 'b, 'c>(s: &'a u8) -> impl Cap<'b> + Cap<'c> |                   -- hidden type `&'a u8` captures the lifetime `'a` as defined here ... LL |     s |     ^ | help: to declare that `impl Cap<'b> + Cap<'c>` captures `'a`, you can add an explicit `'a` lifetime bound | LL | fn test_ambiguous<'a, 'b, 'c>(s: &'a u8) -> impl Cap<'b> + Cap<'c> + 'a |                                                                    ++++ error: aborting due to 3 previous errors Some errors have detailed explanations: E0309, E0700. For more information about an error, try `rustc --explain E0309`. </ins>

Related discussion:
text: The following code should pass regardless of the declaration order of lifetimes: This is related to but it's different in that we do have a lower bound region, , but we fail to recognize that because , which is responsible for calculating from , assumes that the outlive relation is a total order, which is not true. Here is the graph of : ! So we need an efficient algorithm that works for partial order relations, but the one that comes to mind is . The perf may not be really important here but I'm curious to see the alternatives. label C-bug T-compiler A-borrow-checker E-mentor E-help-wanted <!-- TRIAGEBOTSTART --<!-- TRIAGEBOTASSIGNSTART --<!-- TRIAGEBOTASSIGNDATASTARTTRIAGEBOTASSIGNDATAEND --<!-- TRIAGEBOTASSIGNEND --<!-- TRIAGEBOTEND --
claim
Here is the code of concern The code should calculate the from a set of universal regions (). The relations are encoded in and are guaranteed to be transitive and reflexive. The relation graph may have cycles and can be sparse. The goal here is to find a unique minimum choice that is known to be outlived by all other regions. If none can be found, the function returns . Regions that have cycles between them are considered equivalent so we can pick either one of them as a unique choice. e.g. , we can pick either one of as a minimum choice.
Code change:
<ins> // This is a non-regression test for issue #117146, where NLL and `-Zpolonius=next` computed // different loan scopes when a region flowed into an SCC whose representative was an existential // region. // revisions: nll polonius // [polonius] compile-flags: -Zpolonius=next fn main() { let a = (); let b = |_| &a; //[nll]~^ ERROR `a` does not live long enough //[polonius]~^^ ERROR `a` does not live long enough bad(&b); //[nll]~^ ERROR implementation of `Fn` //[nll]~| ERROR implementation of `FnOnce` //[polonius]~^^^ ERROR implementation of `Fn` //[polonius]~| ERROR implementation of `FnOnce` } fn bad<F: Fn(&()) -> &()>(_: F) {} </ins>

Related discussion:
text: File: snippet: Version information Command: <!-- Include a backtrace in the code block by setting in your environment. E.g. . --<details<summary<strongProgram output</strong</summary<p</p</details
cc removing the println macro from around the match avoids the ice :thinking:
Fun :)
A more minimal version would be:
Code change:
Some((ident.name, ns)), ) } <ins> /// Construct the list of in-scope lifetime parameters for async lowering. /// We include all lifetime parameters, either named or "Fresh". /// The order of those parameters does not matter, as long as it is /// deterministic. fn record_lifetime_params_for_async( &mut self, fn_id: NodeId, async_node_id: Option<(NodeId, Span)>, ) { if let Some((async_node_id, _)) = async_node_id { let mut extra_lifetime_params = self.r.extra_lifetime_params_map.get(&fn_id).cloned().unwrap_or_default(); for rib in self.lifetime_ribs.iter().rev() { extra_lifetime_params.extend( rib.bindings.iter().map(|(&ident, &(node_id, res))| (ident, node_id, res)), ); match rib.kind { LifetimeRibKind::Item => break, LifetimeRibKind::AnonymousCreateParameter { binder, .. } => { if let Some(earlier_fresh) = self.r.extra_lifetime_params_map.get(&binder) { extra_lifetime_params.extend(earlier_fresh); } } _ => {} } } self.r.extra_lifetime_params_map.insert(async_node_id, extra_lifetime_params); } } </ins> } struct LifetimeCountVisitor<'a, 'b> {

Related discussion:
text: Example: yields <details<summaryBacktrace</summary</details
cc and
This has to do with late-bound regions and RPITITs. I have a fix, but it's probably not right nor is it cleaned up much. I'll put it up for scrutiny soon though.
Actually nvm, it was a silly little resolver bug.
label +I-ICE +C-bug
Code change:
Some((ident.name, ns)), ) } <ins> /// Construct the list of in-scope lifetime parameters for async lowering. /// We include all lifetime parameters, either named or "Fresh". /// The order of those parameters does not matter, as long as it is /// deterministic. fn record_lifetime_params_for_async( &mut self, fn_id: NodeId, async_node_id: Option<(NodeId, Span)>, ) { if let Some((async_node_id, _)) = async_node_id { let mut extra_lifetime_params = self.r.extra_lifetime_params_map.get(&fn_id).cloned().unwrap_or_default(); for rib in self.lifetime_ribs.iter().rev() { extra_lifetime_params.extend( rib.bindings.iter().map(|(&ident, &(node_id, res))| (ident, node_id, res)), ); match rib.kind { LifetimeRibKind::Item => break, LifetimeRibKind::AnonymousCreateParameter { binder, .. } => { if let Some(earlier_fresh) = self.r.extra_lifetime_params_map.get(&binder) { extra_lifetime_params.extend(earlier_fresh); } } _ => {} } } self.r.extra_lifetime_params_map.insert(async_node_id, extra_lifetime_params); } } </ins> } struct LifetimeCountVisitor<'a, 'b> {

Related discussion:
text: I'm seeing an internal compiler error on the following input (found by ):
Report from : regressed nightly: nightly-2020-02-07
It looks like caused the regression. (The error happens at but not at .) cc
The specific commit where the error starts happening is .
triage: P-high. Removing nomination. Added regression stable-to-nightly tag.
Fixed by
Code change:
fn make_items(mut self: Box<ExpandResult<'a>>) -> Option<SmallVector<P<ast::Item>>> { let mut ret = SmallVector::zero(); <del> loop { </del> <ins> while self.p.token != token::Eof { </ins> match self.p.parse_item_with_outer_attributes() { Some(item) => ret.push(item), <del> None => break </del> <ins> None => self.p.span_fatal( self.p.span, &format!("expected item, found `{}`", self.p.this_token_to_string())[] ) </ins> } } Some(ret)

Related discussion:
text: Testcase: : : Output: Should output, instead, the parse errors from . Probably misplacing the diagnostic emitter somehow, when creating the nested parser for the included source, and doesn't have an .
(I suspect this is an easy fix, but am not quite sure)
Code change:
self.tcx().mk_region(ReScope(lub)) } <del> (&ReEarlyBound(_), &ReEarlyBound(_) | &ReFree(_)) | (&ReFree(_), &ReEarlyBound(_) | &ReFree(_)) => { </del> <ins> (&ReEarlyBound(_) | &ReFree(_), &ReEarlyBound(_) | &ReFree(_)) => { </ins> self.region_rels.lub_free_regions(a, b) }

Related discussion:
text: () Errors: Backtrace: modify labels: +I-hang +T-compiler +C-bug +A-lifetimes
somewhat minimized: To replicate this I needed: async two other arguments by ref at least one arg must not be bound to , compiles quickly the problematic argument must be contain an indirection: compiles fine. and also freeze. and a trait object containing at least one non marker trait explicitly bound to . and are both ok
repro is a regression in 1.43. It compiles immediately with 1.39 through 1.42.
I am currently bisecting this using
regression in modify labels: -E-needs-bisection
FYI who had context on .
Code change:
<ins> error[E0277]: the trait bound `K: Hash` is not satisfied --> $DIR/bad-index-due-to-nested.rs:20:5 | LL |     map[k] |     ^^^ the trait `Hash` is not implemented for `K` | note: required by a bound in `<HashMap<K, V> as Index<&K>>` --> $DIR/bad-index-due-to-nested.rs:9:8 | LL |     K: Hash, |        ^^^^ required by this bound in `<HashMap<K, V> as Index<&K>>` help: consider restricting type parameter `K` | LL | fn index<'a, K: std::hash::Hash, V>(map: &'a HashMap<K, V>, k: K) -> &'a V { |               +++++++++++++++++ error[E0277]: the trait bound `V: Copy` is not satisfied --> $DIR/bad-index-due-to-nested.rs:20:5 | LL |     map[k] |     ^^^ the trait `Copy` is not implemented for `V` | note: required by a bound in `<HashMap<K, V> as Index<&K>>` --> $DIR/bad-index-due-to-nested.rs:10:8 | LL |     V: Copy, |        ^^^^ required by this bound in `<HashMap<K, V> as Index<&K>>` help: consider restricting type parameter `V` | LL | fn index<'a, K, V: std::marker::Copy>(map: &'a HashMap<K, V>, k: K) -> &'a V { |                  +++++++++++++++++++ error[E0308]: mismatched types --> $DIR/bad-index-due-to-nested.rs:20:9 | LL | fn index<'a, K, V>(map: &'a HashMap<K, V>, k: K) -> &'a V { |              - this type parameter LL |     map[k] |         ^ |         | |         expected `&K`, found type parameter `K` |         help: consider borrowing here: `&k` | = note:   expected reference `&K` found type parameter `K` error[E0308]: mismatched types --> $DIR/bad-index-due-to-nested.rs:20:5 | LL | fn index<'a, K, V>(map: &'a HashMap<K, V>, k: K) -> &'a V { |                 - this type parameter               ----- expected `&'a V` because of return type LL |     map[k] |     ^^^^^^ |     | |     expected `&V`, found type parameter `V` |     help: consider borrowing here: `&map[k]` | = note:   expected reference `&'a V` found type parameter `V` error: aborting due to 4 previous errors Some errors have detailed explanations: E0277, E0308. For more information about an error, try `rustc --explain E0277`. </ins>

Related discussion:
text: I tried this code (): I expected to see this happen: rustc outputs an error saying that I need to add the and traits on . Instead, this happened: which is jarring to see, and unhelpful, because HashMap does support Index, but only with particular trait bounds on . <!-- TRIAGEBOTSTART --<!-- TRIAGEBOTASSIGNSTART --<!-- TRIAGEBOTASSIGNDATASTARTTRIAGEBOTASSIGNDATAEND --<!-- TRIAGEBOTASSIGNEND --<!-- TRIAGEBOT_END --
The reduced case: works as expected, perhaps it is caused when the implementer is not from the local crate?
claim
Code change:
<ins> // #124563 use std::marker::PhantomData; pub trait Trait {} pub trait Foo { type Trait: Trait; type Bar: Bar; fn foo(&mut self); } pub struct FooImpl<'a, 'b, A: Trait>(PhantomData<&'a &'b A>); impl<'a, 'b, T> Foo for FooImpl<'a, 'b, T> where T: Trait, { type Trait = T; type Bar = BarImpl<'a, 'b, T>; //~ ERROR lifetime bound not satisfied fn foo(&mut self) { self.enter_scope(|ctx| { //~ ERROR lifetime may not live long enough BarImpl(ctx); //~ ERROR lifetime may not live long enough }); } } impl<'a, 'b, T> FooImpl<'a, 'b, T> where T: Trait, { fn enter_scope(&mut self, _scope: impl FnOnce(&mut Self)) {} } pub trait Bar { type Foo: Foo; } pub struct BarImpl<'a, 'b, T: Trait>(&'b mut FooImpl<'a, 'b, T>); impl<'a, 'b, T> Bar for BarImpl<'a, 'b, T> where T: Trait, { type Foo = FooImpl<'a, 'b, T>; } fn main() {} </ins>

Related discussion:
text: <!-- [31mICE[0m: Rustc '' 'thread 'rustc' panicked at 'expected region for ('a//0) but found Type(&'{erased} mut FooImpl<'{erased}, '{erased}, T/) when instantiating args=[&'{erased} mut FooImpl<'{erased}, '{erased}, T/, '?27, ?2t, Closure(DefId(0:22 ~ a[a197]::{impl}::foo::{closure}), ['{erased}, '{erased}, T/, i32, Binder(fn((&ReLateParam(DefId(0:22 ~ a[a197]::{impl}::foo::{closure}), BrAnon) mut FooImpl<'{erased}, '{erased}, T/,)), []), ()])]'', 'thread 'rustc' panicked at 'expected region for ('a//0) but found Type(&'{erased} mut FooImpl<'{erased}, '{erased}, T/) when instantiating args=[&'{erased} mut FooImpl<'{erased}, '{erased}, T/, '?27, ?2t, Closure(DefId(0:22 ~ a[a197]::{impl}::foo::{closure}), ['{erased}, '{erased}, T/, i32, Binder(fn((&ReLateParam(DefId(0:22 ~ a[a197]::{impl}::foo::{closure}), BrAnon) mut FooImpl<'{erased}, '{erased}, T/,)), []), ()])]'' File: --auto-reduced (treereduce-rust): original: Version information ` Command: <!-- Include a backtrace in the code block by setting in your environment. E.g. . --<details<summary<strongProgram output</strong</summary<p</p</details<!-- query stack: [mirborrowck] borrow-checking [mirborrowck] borrow-checking --
ICEs on nightly and beta, but not on stable. Minimized further: <details<summaryProgram output</summary</details
The ICE is another one from , cc
Still reproduces on 1.81.0-nightly (2024-06-13 ) -E-needs-test
I'll look into it later today.
Code change:
<ins> // #124563 use std::marker::PhantomData; pub trait Trait {} pub trait Foo { type Trait: Trait; type Bar: Bar; fn foo(&mut self); } pub struct FooImpl<'a, 'b, A: Trait>(PhantomData<&'a &'b A>); impl<'a, 'b, T> Foo for FooImpl<'a, 'b, T> where T: Trait, { type Trait = T; type Bar = BarImpl<'a, 'b, T>; //~ ERROR lifetime bound not satisfied fn foo(&mut self) { self.enter_scope(|ctx| { //~ ERROR lifetime may not live long enough BarImpl(ctx); //~ ERROR lifetime may not live long enough }); } } impl<'a, 'b, T> FooImpl<'a, 'b, T> where T: Trait, { fn enter_scope(&mut self, _scope: impl FnOnce(&mut Self)) {} } pub trait Bar { type Foo: Foo; } pub struct BarImpl<'a, 'b, T: Trait>(&'b mut FooImpl<'a, 'b, T>); impl<'a, 'b, T> Bar for BarImpl<'a, 'b, T> where T: Trait, { type Foo = FooImpl<'a, 'b, T>; } fn main() {} </ins>

Related discussion:
text: : <details<summary<strongBacktrace</strong</summary<p</p</details
This looks to be a recent regression from cc and is on beta 1.79, but is just in diagnostics.
Code change:
<ins> // This test is a regression test for #34792 // check-pass pub struct A; pub struct B; pub trait Foo { type T: PartialEq<A> + PartialEq<B>; } pub fn generic<F: Foo>(t: F::T, a: A, b: B) -> bool { t == a && t == b } pub fn main() {} </ins>

Related discussion:
text: rustc 1.12.0-nightly ( 2016-07-10) Changing the order of bounds in the associated type declaration changes which causes a spurious "mismatched types" error. Using UFCS works around the issue: The same issue exists with bounds like to compare with itself as well as another type. <!-- TRIAGEBOTSTART --<!-- TRIAGEBOTASSIGNSTART --<!-- TRIAGEBOTASSIGNDATASTARTTRIAGEBOTASSIGNDATAEND --<!-- TRIAGEBOTASSIGNEND --<!-- TRIAGEBOTEND --
cf.
Looks like this is caused by on the set of bounds from the trait, but that is just find the first one (in the order they are internally stored), this needs to filter and produce a vector of bounds or something similar. cc
Update: using filter and then calling on all matching bounds does not fix this issue.
I believe your problem is . Right now it works fine because the above would trigger for vs or vs . However, it's incorrect with your changes as is dropped in favor of even if and are not equal. The correct form would be more like this:
I guess that you didn't just call , but are also packaging up the specific bound that was matched? Anyway, not having seen the full diff, the general direction of these changes make sense to me.
Related:
triage: P-medium
Triage: :
This is fixed on current master. Should be closed.
I would like to work on this issue if its still relevant?
As mentioned the original code now compiles: Closing as there doesn’t seem to be anything left to do here.
do we have any regression test? I couldn't see any.
Oh good point. Sorry I missed the label. Yes, feel free to work on adding a regression test!
claim
Code change:
return; } <ins> // #90113: Do not count an inaccessible reexported item as a candidate. if let NameBindingKind::Import { binding, .. } = name_binding.kind { if this.is_accessible_from(binding.vis, parent_scope.module) && !this.is_accessible_from(name_binding.vis, parent_scope.module) { return; } } </ins> // collect results based on the filter function // avoid suggesting anything from the same module in which we are resolving if ident.name == lookup_ident.name

Related discussion:
text: Bisected to a rollup, but I think it's very likely to be . cc searched nightlies: from nightly-2021-10-01 to nightly-2021-10-19 regressed nightly: nightly-2021-10-02 searched commits: from to regressed commit: <details<summarybisected with <a href=''cargo-bisect-rustc</av0.6.0</summaryHost triple: x86_64-apple-darwin Reproduce with: </details
The old suggestion was actually incorrect because it suggested , which is a private import. However, the new error is "more incorrect" IMO since it says something confusing (and incorrect).
Assigning priority as discussed in the of the Prioritization Working Group. label -I-prioritize +P-medium
Code change:
hir_typeck_convert_to_str = try converting the passed type into a `&str` <ins> hir_typeck_ctor_is_private = tuple struct constructor `{$def}` is private </ins> hir_typeck_expected_default_return_type = expected `()` because of default return type hir_typeck_expected_return_type = expected `{$expected}` because of return type

Related discussion:
text: I tried this code: I expected to see this happen: compilation should fail because the trait impl is defined outside of the module for the type but refers to its private field. Instead, this happened: this compiled successfully This reproduces on the playground for stable Rust, version 1.69.0:
Adding a main function and attempting to call the (playground link: ) raises the compilation error: !
This can be reproduced with cross-crate (e.i., any other crate can access the private field). This means that all encapsulations that take advantage of the field being private can be bypassed. (For example, if we change Vec to a tuple struct, the same thing as setlen could be done in safe code by abusing this bug.) label +I-unsound Also, this can be reproduced in all versions where is stable (e.i., 1.32+). It's a matter of how you initialize Foo. If you provide a constructor for Foo, you won't get a compile error:
Just for completeness, turning this into a segfault without external crates/just std:
label A-visibility
this has been unsound ever since in version 1.32
WG-prioritization assigning priority (). label -I-prioritize +P-high