Note specific regions involved in 'borrowed data escapes' error
Fixes#67007
Currently, a 'borrowed data escapes' error does not mention
the specific lifetime involved (except indirectly through a suggestion
about adding a lifetime bound). We now explain the specific lifetime
relationship that failed to hold, which improves otherwise vague
error messages.
Consider unfulfilled obligations in binop errors
When encountering a binop where the types would have been accepted, if
all the predicates had been fulfilled, include information about the
predicates and suggest appropriate `#[derive]`s if possible.
Fix#84515.
When encountering a binop where the types would have been accepted, if
all the predicates had been fulfilled, include information about the
predicates and suggest appropriate `#[derive]`s if possible.
Point at trait(s) that needs to be `impl`emented.
Document behavior of `MaybeLiveLocals` regarding enums and field-senstivity
This arose from a [discussion on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/189540-t-compiler.2Fwg-mir-opt/topic/MaybeLiveLocals.20and.20Discriminants) where a new contributor attempted to implement a dead-store elimination pass using this analysis. They ran into a nasty hack around `SetDiscriminant` the effect of which is to lets handle assignments of literals to enum-typed locals (e.g. `x = Some(4)`) correctly. This took me a while to figure out.
Document this oddity, so the next person will have an easier time, and add a test to enshrine the current behavior.
r? ``@tmiasko``
Make `proc_macro_derive_resolution_fallback` a future-breakage lint
When `cargo report future-incompatibilities` is stabilized
(see #71249), this will cause dependencies that trigger
this lint to be included in the report.
Move generic error message to separate branches
This decomposes an error message in generic constants into more specific branches, for better
readability.
r? ``@lcnr``
Normalize associated type projections when checking return type of main
This fixes#88609.
Previously, the return type of `fn main()` would not have any associated type projections within normalized before checking if it implements the standard library trait `std::process::Termination`. This commit appears to fix it.
This feels vaguely symptomatic of a problem in the underlying trait solving engine, but I am not sure how I would solve that. I am unsure why the example in #88609 with `assert_impl_termination` and `fn foo()` work, but simply `fn main()` doesn't. The way that I solved this is also probably not the best way to do this, so please let me know if there is a better way to do this.
I have added a build-pass regression test for this issue.
Fixes#67007
Currently, a 'borrowed data escapes' error does not mention
the specific lifetime involved (except indirectly through a suggestion
about adding a lifetime bound). We now explain the specific lifetime
relationship that failed to hold, which improves otherwise vague
error messages.
Don't suggest replacing region with 'static in NLL
Fixes#73159
This is similar to #69350 - if the user didn't initially
write out a 'static lifetime, adding 'static in response to
a lifetime error is usually the wrong thing to do.
Fix ICE caused by non_exaustive_omitted_patterns struct lint
fixes#89382
Add check that a list of `Pat`s is non empty to prevent ICE in `FnCtxt::lint_non_exhaustive_omitted_patterns`.
Is related to #89374 and #89105
Fixed numerus of error message
When there are redundant trait requirements and these are hidden, a message is generated by the following code snippet:
`format!("{} redundant requirements hidden", count)`
But if there is only a single hidden requirement, it will still print this message in plural instead of singular.
Fix extra `non_snake_case` warning for shorthand field bindings
Fixes#89469. The problem is the innermost `if` condition here:
d14731cb3c/compiler/rustc_lint/src/nonstandard_style.rs (L435-L452)
This code runs for every `PatKind::Binding`, so if a struct has multiple fields, say A and B, and both are bound in a pattern using shorthands, the call to `self.check_snake_case()` will indeed be skipped in the `check_pat()` call for `A`; but when `check_pat()` is called for `B`, the loop will still iterate over `A`, and `field.ident (= A) != ident (= B)` will be true. I have fixed this by only looking at non-shorthand bindings, and only the binding that `check_pat()` was actually called for.
Correctly handle supertraits for min_specialization
Supertraits of specialization markers could circumvent checks for
min_specialization. Elaborating predicates prevents this.
r? ````@nikomatsakis````
Stabilize `const_panic`
Closes#51999
FCP completed in #89006
```@rustbot``` label +A-const-eval +A-const-fn +T-lang
cc ```@oli-obk``` for review (not `r?`'ing as not on lang team)
Fix ICE with buffered lint referring to AST node deleted by everybody_loops
Fixes#87308. Note the following comment:
08759c691e/compiler/rustc_lint/src/early.rs (L415-L417)
As it turns out, this is not _always_ a bug, because `-Zunpretty=everybody_loops` causes a lot of AST nodes to be deleted, and thus some buffered lints will refer to non-existent node ids. To fix this, my changes simply ignore buffered lints if `-Zunpretty=everybody_loops` is enabled, which, from my understanding, shouldn't be a big issue because it only affects pretty-printing. Of course, a more elegant solution would only ignore buffered lints that actually point at deleted node ids, but I haven't figured out an easy way of achieving this.
For the concrete example in #87308, the buffered lint is created [here](08759c691e/compiler/rustc_expand/src/mbe/macro_rules.rs (L145-L151)) with the `lint_node_id` from [here](08759c691e/compiler/rustc_expand/src/mbe/macro_rules.rs (L319)), i.e. it points at the macro _expansion_, which then gets deleted by `ReplaceBodyWithLoop` [here](08759c691e/compiler/rustc_interface/src/passes.rs (L377)).
Consistently use 'supertrait'.
A subset of places referred to 'super-trait', so this changes them
to all use 'supertrait'. This matches 'supertype' and some other
usages. An exception is 'auto-trait' which is consistently used
in that manner.
Fix an ICE caused by type mismatch errors being ignored
This PR fixes#87771. It turns out that the check on `compiler/rustc_typeck/src/check/demand.rs:148` leads to the ICE. I removed it because the early return in [`check_expr_assign`](dec7fc3ced/compiler/rustc_typeck/src/check/expr.rs (L928)) already prevents unnecessary error messages from the call to `check_expr_coercable_to_type`.
When `cargo report future-incompatibilities` is stabilized
(see #71249), this will cause dependencies that trigger
this lint to be included in the report.
Fixes#73159
This is similar to #69350 - if the user didn't initially
write out a 'static lifetime, adding 'static in response to
a lifetime error is usually the wrong thing to do.
