jiebi/CodeConvo huggingface dataset:
Code change:
For this snippet (): rustc gives: Since , for const-able values, rustc suggests the creation of a constant binding. Here this is not possible because is not const fn. However, we can suggest instead.
Personally, I prefer over a separate binding. Even in the case, the generated code will call the initialization function many times. Maybe in the case where bindings are possible, we can suggest both? Where they are not possible, we don't suggest anything right now, so at the least we should suggest there. what do you think?
Once is stable we can suggest that :3. But until then sounds reasonable.
Agreed, good point about . It seems to have a stabilization PR open with an FCP, which is blocked: . Maybe there might be progress on it this month: . Even if we stabilize inline const, it might make sense to wait with suggesting it for a while so that we don't make code depend on the latest MSRV immediately. So therefore, I think that it might still make sense to implement this in the meantime.
I think this should (in the future) suggest  instead, since the function would only be called once if were , whereas calls it for every element.

Related discussion:
text: |               ^ the trait `Copy` is not implemented for `Foo` | = note: the `Copy` trait is required because this value will be copied for each element of the array <ins> = help: consider using `core::array::from_fn` to initialize the array = help: see https://doc.rust-lang.org/stable/std/array/fn.from_fn.html# for more information </ins> help: consider annotating `Foo` with `#[derive(Copy)]` | LL + #[derive(Copy)]
Code change:
For this snippet (): rustc gives: Since , for const-able values, rustc suggests the creation of a constant binding. Here this is not possible because is not const fn. However, we can suggest instead.
Personally, I prefer over a separate binding. Even in the case, the generated code will call the initialization function many times. Maybe in the case where bindings are possible, we can suggest both? Where they are not possible, we don't suggest anything right now, so at the least we should suggest there. what do you think?
Once is stable we can suggest that :3. But until then sounds reasonable.
Agreed, good point about . It seems to have a stabilization PR open with an FCP, which is blocked: . Maybe there might be progress on it this month: . Even if we stabilize inline const, it might make sense to wait with suggesting it for a while so that we don't make code depend on the latest MSRV immediately. So therefore, I think that it might still make sense to implement this in the meantime.
I think this should (in the future) suggest  instead, since the function would only be called once if were , whereas calls it for every element.

Related discussion:
text: <ins> fn foo() -> String { String::new() } fn main() { let string_arr = [foo(); 64]; //~ ERROR the trait bound `String: Copy` is not satisfied } </ins>
Code change:
For this snippet (): rustc gives: Since , for const-able values, rustc suggests the creation of a constant binding. Here this is not possible because is not const fn. However, we can suggest instead.
Personally, I prefer over a separate binding. Even in the case, the generated code will call the initialization function many times. Maybe in the case where bindings are possible, we can suggest both? Where they are not possible, we don't suggest anything right now, so at the least we should suggest there. what do you think?
Once is stable we can suggest that :3. But until then sounds reasonable.
Agreed, good point about . It seems to have a stabilization PR open with an FCP, which is blocked: . Maybe there might be progress on it this month: . Even if we stabilize inline const, it might make sense to wait with suggesting it for a while so that we don't make code depend on the latest MSRV immediately. So therefore, I think that it might still make sense to implement this in the meantime.
I think this should (in the future) suggest  instead, since the function would only be called once if were , whereas calls it for every element.

Related discussion:
text: <ins> error[E0277]: the trait bound `String: Copy` is not satisfied --> $DIR/issue-119530-sugg-from-fn.rs:4:23 | LL |     let string_arr = [foo(); 64]; |                       ^^^^^ the trait `Copy` is not implemented for `String` | = note: the `Copy` trait is required because this value will be copied for each element of the array = help: consider using `core::array::from_fn` to initialize the array = help: see https://doc.rust-lang.org/stable/std/array/fn.from_fn.html# for more information error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`. </ins>
Code change:
run Output: Miri: The underlying issue was found when reviewing the implementation of . The code is a reproduction to trigger the unsoundness. The implementation in question features: Where is turned into and dropped. Yes, that’s , not . The code for seems to be doing the same thing. For comparison: The code for (and the same thing for ) seems to properly use a … no actually, that’s a with zero lengths… notably the allocator is correct though. So the buggy code for should just switch to create a presumably. label I-unsound requires-nightly T-libs

Related discussion:
text: // Free the allocation without dropping its contents let (bptr, alloc) = Box::into_raw_with_allocator(src); <del> let src = Box::from_raw(bptr as *mut mem::ManuallyDrop<T>); </del> <ins> let src = Box::from_raw_in(bptr as *mut mem::ManuallyDrop<T>, alloc.by_ref()); </ins> drop(src); Self::from_ptr_in(ptr, alloc)
Code change:
creates an error string dynamically, then passes it as an unsafe pointer to , which then casts the string to , then to , then throws it to another task. Nominating.

Related discussion:
text: //! Runtime calls emitted by the compiler. <del> use c_str::ToCStr; </del> <ins> use c_str::CString; use libc::c_char; use cast; use option::Some; </ins> #[cold] #[lang="fail_"]
Code change:
creates an error string dynamically, then passes it as an unsafe pointer to , which then casts the string to , then to , then throws it to another task. Nominating.

Related discussion:
text: pub fn fail_bounds_check(file: *u8, line: uint, index: uint, len: uint) -> ! { let msg = format!("index out of bounds: the len is {} but the index is {}", len as uint, index as uint); <del> msg.with_c_str(|buf| fail_(buf as *u8, file, line)) </del> <ins> let file_str = match unsafe { CString::new(file as *c_char, false) }.as_str() { // This transmute is safe because `file` is always stored in rodata. Some(s) => unsafe { cast::transmute::<&str, &'static str>(s) }, None    => "file wasn't UTF-8 safe" }; ::rt::begin_unwind(msg, file_str, line) </ins> } #[lang="malloc"]
Code change:
<!-- [31mICE[0m: Rustc '' 'error: internal compiler error: is not fully resolved', 'error: internal compiler error: is not fully resolved' File: --Another regression of 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<!-- query stack: [checkmodimpl_wf] checking that impls are well-formed in top-level module [analysis] running analysis passes on this crate --
This is caused by the fact that  does not check for const effect vars when visiting . It should be relatively simple to match on in the folder.
Working on this one.

Related discussion:
text: UnresolvedFloatTy(FloatVid), UnresolvedTy(TyVid), UnresolvedConst(ConstVid), <ins> UnresolvedEffect(EffectVid), </ins> } /// See the `region_obligations` field for more information.
Code change:
<!-- [31mICE[0m: Rustc '' 'error: internal compiler error: is not fully resolved', 'error: internal compiler error: is not fully resolved' File: --Another regression of 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<!-- query stack: [checkmodimpl_wf] checking that impls are well-formed in top-level module [analysis] running analysis passes on this crate --
This is caused by the fact that  does not check for const effect vars when visiting . It should be relatively simple to match on in the folder.
Working on this one.

Related discussion:
text: ), UnresolvedTy(_) => write!(f, "unconstrained type"), UnresolvedConst(_) => write!(f, "unconstrained const value"), <ins> UnresolvedEffect(_) => write!(f, "unconstrained effect value"), </ins> } } }
Code change:
<!-- [31mICE[0m: Rustc '' 'error: internal compiler error: is not fully resolved', 'error: internal compiler error: is not fully resolved' File: --Another regression of 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<!-- query stack: [checkmodimpl_wf] checking that impls are well-formed in top-level module [analysis] running analysis passes on this crate --
This is caused by the fact that  does not check for const effect vars when visiting . It should be relatively simple to match on in the folder.
Working on this one.

Related discussion:
text: ty::ConstKind::Infer(InferConst::Fresh(_)) => { bug!("Unexpected const in full const resolver: {:?}", c); } <ins> ty::ConstKind::Infer(InferConst::EffectVar(evid)) => { return Err(FixupError::UnresolvedEffect(evid)); } </ins> _ => {} } c.try_super_fold_with(self)
Code change:
<!-- [31mICE[0m: Rustc '' 'error: internal compiler error: is not fully resolved', 'error: internal compiler error: is not fully resolved' File: --Another regression of 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<!-- query stack: [checkmodimpl_wf] checking that impls are well-formed in top-level module [analysis] running analysis passes on this crate --
This is caused by the fact that  does not check for const effect vars when visiting . It should be relatively simple to match on in the folder.
Working on this one.

Related discussion:
text: <del> //@ known-bug: #119830 #![feature(effects)] #![feature(min_specialization)] trait Specialize {} trait Foo {} impl<T> const Foo for T {} impl<T> const Foo for T where T: const Specialize {} </del>
Code change:
<!-- [31mICE[0m: Rustc '' 'error: internal compiler error: is not fully resolved', 'error: internal compiler error: is not fully resolved' File: --Another regression of 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<!-- query stack: [checkmodimpl_wf] checking that impls are well-formed in top-level module [analysis] running analysis passes on this crate --
This is caused by the fact that  does not check for const effect vars when visiting . It should be relatively simple to match on in the folder.
Working on this one.

Related discussion:
text: <ins> //@ check-fail // Fixes #119830 #![feature(effects)] #![feature(min_specialization)] #![feature(const_trait_impl)] trait Specialize {} trait Foo {} impl<T> const Foo for T {} //~^ error: const `impl` for trait `Foo` which is not marked with `#[const_trait]` //~| error: the const parameter `host` is not constrained by the impl trait, self type, or predicates [E0207] impl<T> const Foo for T where T: const Specialize {} //~^ error: const `impl` for trait `Foo` which is not marked with `#[const_trait]` //~| error: `const` can only be applied to `#[const_trait]` traits //~| error: the const parameter `host` is not constrained by the impl trait, self type, or predicates [E0207] //~| error: specialization impl does not specialize any associated items //~| error: could not resolve generic parameters on overridden impl fn main() { } </ins>
Code change:
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fyi
not caused by that, only exposed by it. The issue is a typo using instead of in diagnostic code, getting the wrong and then attempting to treat as an associated item

Related discussion:
text: .extend( // Group the return ty with its def id, if we had one. entry.return_ty.map(|ty| { <del> (tcx.require_lang_item(LangItem::FnOnce, None), ty) </del> <ins> (tcx.require_lang_item(LangItem::FnOnceOutput, None), ty) </ins> }), ); }
Code change:
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fyi
not caused by that, only exposed by it. The issue is a typo using instead of in diagnostic code, getting the wrong and then attempting to treat as an associated item

Related discussion:
text: <ins> //! This is a regression test to avoid an ICE in diagnostics code. //! A typo in the compiler used to get the DefId of FnOnce, and //! use it where an associated item was expected. fn frob() -> impl Fn<P, Output = T> + '_ {} //~^ ERROR missing lifetime specifier //~| ERROR cannot find type `P` //~| ERROR cannot find type `T` //~| ERROR `Fn`-family traits' type parameters is subject to change fn open_parent<'path>() { todo!() } fn main() { let old_path = frob("hello"); //~^ ERROR function takes 0 arguments open_parent(&old_path) //~^ ERROR function takes 0 arguments } </ins>
Code change:
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text: <ins> #![feature(associated_type_bounds)] // Test for <https://github.com/rust-lang/rust/issues/119857>. pub trait Iter { type Item<'a>: 'a where Self: 'a; fn next<'a>(&'a mut self) -> Option<Self::Item<'a, As1: Copy>>; //~^ ERROR associated type bindings are not allowed here } impl Iter for () { type Item<'a> = &'a mut [()]; fn next<'a>(&'a mut self) -> Option<Self::Item<'a>> { None } } fn main() {} </ins>
Code change:
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Related discussion:
text: <ins> error[E0229]: associated type bindings are not allowed here --> $DIR/no-gat-position.rs:8:56 | LL |     fn next<'a>(&'a mut self) -> Option<Self::Item<'a, As1: Copy>>; |                                                        ^^^^^^^^^ associated type not allowed here error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0229`. </ins>
Code change:
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text: <ins> #![feature(generic_const_exprs)] //~^ WARN the feature `generic_const_exprs` is incomplete #![feature(non_lifetime_binders)] //~^ WARN the feature `non_lifetime_binders` is incomplete // Test for <https://github.com/rust-lang/rust/issues/115497>, // which originally relied on associated_type_bounds, but was // minimized away from that. trait TraitA { type AsA; } trait TraitB { type AsB; } trait TraitC {} fn foo<T>() where for<const N: u8 = { T::A }> T: TraitA<AsA = impl TraitB<AsB = impl TraitC>>, //~^ ERROR defaults for generic parameters are not allowed in `for<...>` binders //~| ERROR `impl Trait` is not allowed in bounds { } fn main() {} </ins>
Code change:
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Related discussion:
text: <ins> warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes --> $DIR/bad-suggestion-on-missing-assoc.rs:1:12 | LL | #![feature(generic_const_exprs)] |            ^^^^^^^^^^^^^^^^^^^ | = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information = note: `#[warn(incomplete_features)]` on by default warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes --> $DIR/bad-suggestion-on-missing-assoc.rs:3:12 | LL | #![feature(non_lifetime_binders)] |            ^^^^^^^^^^^^^^^^^^^^ | = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information error: defaults for generic parameters are not allowed in `for<...>` binders --> $DIR/bad-suggestion-on-missing-assoc.rs:20:9 | LL |     for<const N: u8 = { T::A }> T: TraitA<AsA = impl TraitB<AsB = impl TraitC>>, |         ^^^^^^^^^^^^^^^^^^^^^^ error[E0562]: `impl Trait` is not allowed in bounds --> $DIR/bad-suggestion-on-missing-assoc.rs:20:49 | LL |     for<const N: u8 = { T::A }> T: TraitA<AsA = impl TraitB<AsB = impl TraitC>>, |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: `impl Trait` is only allowed in arguments and return types of functions and methods error: aborting due to 2 previous errors; 2 warnings emitted For more information about this error, try `rustc --explain E0562`. </ins>
Code change:
No response No response No response
I thought the intent with was to use it in a passthrough style, so you can insert it into existing expressions ie. becomes . In which case, maybe the lint should be for not using the value resulting from evaluating .
Not sure about the majority of users but for me is a convenience over . I use it without using the return value almost all of the time.
Probably a common thing to do, sure, but if we're talking about adding a lint, why not nudge the user in the direction of the intended and documented usage? You could at least do both: "insert into an existing expression or pass it a borrow" etc.
The fix in will only report a hint when there is already a happened. For example this code: before this fix the error is: with the fix, since there is already a error, the lint will try to find out the original macro, and suggest a borrow: The suggestion is not 100% right, since if we change it to , we need one more extra fix now(the return type is not expecting a reference), but there is a different issue, at least we have already moved one step on. If the original code is: Then suggest a borrow is a great and correct hint.
Similar in the scenario of function argument: original error is: new errors from the fix:
Would not also be a good hint? The suggestion wouldn't compile anyway right? Because would need to change to take ? Without involved, the compiler does indeed suggest that: Once that's addressed (whichever way it's done), once again becomes transparent, and eg. or works. does not, however, and I see why a "consider borrowing" hint would be good there. However, if you make the change first and leave as-is, the resulting error does not include the suggestion to change , which is unhelpful. (I agree that the message is even less helpful though, I'm not disputing that.)
Yes, it's a good hint, but from the implementation view of a hint, it's much harder to analyze the following code from the error point and then construct a new expression. Even it seems an easy thing for humans. You are right, the suggestion is not 100% right, we may need an extra follow-up fix after applying the hint, which is also a common thing in rustc diagnostics.

Related discussion:
text: #![allow(rustc::untranslatable_diagnostic)] use either::Either; <del> use hir::ClosureKind; </del> <ins> use hir::{ClosureKind, Path}; </ins> use rustc_data_structures::captures::Captures; use rustc_data_structures::fx::FxIndexSet; use rustc_errors::{codes::*, struct_span_code_err, Applicability, Diag, MultiSpan};