Fix the population of the `union.impls` field
This pull-request fix the population of the `union.impls` field that was forgot when the `Union` type was introduce as a split from the `Struct` type https://github.com/rust-lang/rust/pull/81500.
``@rustbot`` label +T-rustdoc +A-rustdoc-json
Fix incorrect disambiguation suggestion for associated items
Fixes#88806. I have not added a new test case, because the erroneous behavior is already present in existing test cases.
Previously, the compiler didn't suggest similarly named associated items
unlike we do in many situations. This patch adds such diagnostics for
associated functions, types and constants.
When remapping a resume argument with projections rebase them on top of
the new base.
The case where resume argument has projections is unusual, but might
arise with box syntax where the assignment is performed directly into
the box without an intermediate temporary.
Suggest using the path separator for tuple struct
Fix confusing error message `constructor is not visible here due to private fields` for tuple struct
closes#83450
Use the correct edition for syntax highlighting doctests
Previously it would unconditionally use edition 2015, which was incorrect.
Helps with https://github.com/rust-lang/rust/issues/89135 in that you can now override the doctest to be 2018 edition instead of being forced to fix the error. This doesn't resolve any of the deeper problems that rustdoc disagrees with most rust users on what a code block is.
cc `@Mark-Simulacrum`
Improve cause information for NLL higher-ranked errors
This PR has several interconnected pieces:
1. In some of the NLL region error code, we now pass
around an `ObligationCause`, instead of just a plain `Span`.
This gets forwarded into `fulfill_cx.register_predicate_obligation`
during error reporting.
2. The general InferCtxt error reporting code is extended to
handle `ObligationCauseCode::BindingObligation`
3. A new enum variant `ConstraintCategory::Predicate` is added.
We try to avoid using this as the 'best blame constraint' - instead,
we use it to enhance the `ObligationCause` of the `BlameConstraint`
that we do end up choosing.
As a result, several NLL error messages now contain the same
"the lifetime requirement is introduced here" message as non-NLL
errors.
Having an `ObligationCause` available will likely prove useful
for future improvements to NLL error messages.
Pass real crate-level attributes to `pre_expansion_lint`
The PR concerns the unstable feature `register_tool` (#66079).
The feature's implementation requires the attributes of the crate being compiled, so that when attributes like `allow(foo::bar)` are encountered, it can be verified that `register_tool(foo)` appears in the crate root.
However, the crate's attributes are not readily available during early lint passes. Specifically, on this line, `krate.attrs` appears to be the attributes of the current source file, not the attributes of the whole crate: bf642323d6/compiler/rustc_lint/src/context.rs (L815)
Consequently, "unknown tool" errors were being produced when `allow(foo::bar)` appeared in a submodule, even though `register_tool(foo)` appeared in the crate root.
EDITED: The proposed fix is to obtain the real crate-level attributes in `configure_and_expand` and pass them to `pre_expansion_lint`. (See `@petrochenkov's` [comment](https://github.com/rust-lang/rust/pull/89214#issuecomment-926927072) below.)
The original "prosed fix" text follows.
---
The proposed fix is to add an `error_on_unknown_tool` flag to `LintLevelsBuilder`. The flag controls whether "unknown tool" errors are emitted. The flag is set during late passes, but not earlier.
More specifically, this PR contains two commits:
* The first adds a `known-tool-in-submodule` UI test that does not currently pass.
* The second adds the `error_on_unknown_tool` flag. The new test passes with the addition of this flag.
This change has the added benefit of eliminating some errors that were duplicated in existing tests.
To the reviewer: please check that I implemented the UI test correctly.
This PR has several interconnected pieces:
1. In some of the NLL region error code, we now pass
around an `ObligationCause`, instead of just a plain `Span`.
This gets forwarded into `fulfill_cx.register_predicate_obligation`
during error reporting.
2. The general InferCtxt error reporting code is extended to
handle `ObligationCauseCode::BindingObligation`
3. A new enum variant `ConstraintCategory::Predicate` is added.
We try to avoid using this as the 'best blame constraint' - instead,
we use it to enhance the `ObligationCause` of the `BlameConstraint`
that we do end up choosing.
As a result, several NLL error messages now contain the same
"the lifetime requirement is introduced here" message as non-NLL
errors.
Having an `ObligationCause` available will likely prove useful
for future improvements to NLL error messages.
Remove most box syntax uses from the testsuite except for src/test/ui/issues
Removes most box syntax uses from the testsuite outside of the src/test/ui/issues directory. The goal was to only change tests where box syntax is an implementation detail instead of the actual feature being tested. So some tests were left out, like the regression test for #87935, or tests where the obtained error message changed significantly.
Mostly this replaces box syntax with `Box::new`, but there are some minor drive by improvements, like formatting improvements or `assert_eq` instead of `assert!( == )`.
Prior PR that removed box syntax from the compiler and tools: #87781
Support incremental in compiletest for non-incremental modes.
This adds first-class support for using incremental builds in non-incremental-mode tests. These tests previously manually passed `-C incremental=tmp/foo` which resulted in reusing the same tmp folder between runs. This means that these tests could fail whenever the on-disk incremental format changed (such as when updating one's local source tree). This changes it so that these tests can pass a `// incremental-build` header which instructs compiletest to create a set aside a dedicated incremental directory which will be cleared before the test starts to ensure it has a clean slate.
Validate builtin attributes for macro args.
This adds some validation for `path`, `crate_type`, and `recursion_limit` attributes so that they will now return an error if you attempt to pass a macro into them (such as `#[path = foo!()]`). Previously, the attribute would be completely ignored. These attributes are special because their values need to be known before/during expansion.
cc #87681
Now `Fields` is just a `Vec` of patterns, with some extra info on the
side to reconstruct patterns when needed. This emphasizes that this
extra info is not central to the algorithm.
Once this anonymization has performed, we have no
way of recovering the original names during NLL
borrow checking. Keeping the original names allows
error messages in full NLL mode to contain the original
bound region names.
As a result, the typeck results may contain types that
differ only in the names used for their bound regions. However,
anonimization of bound regions does not guarantee that
all distinct types are unqual (e.g. not subtypes of each other).
For example, `for<'a> fn(&'a u32, &'a u32)` and
`for<'b, 'c> fn(&'b u32, &'c u32)` are subtypes of each other,
as explained here:
63cc2bb3d0/compiler/rustc_infer/src/infer/nll_relate/mod.rs (L682-L690)
Therefore, any code handling types with higher-ranked regions already
needs to handle the case where two distinct `Ty`s are 'actually'
equal.
Currently, we use a relatively 'small' span for THIR
expressions generated by an 'adjustment' (e.g. an autoderef,
autoborrow, unsizing). As a result, if a borrow generated
by an adustment ends up causing a borrowcheck error, for example:
```rust
let mut my_var = String::new();
let my_ref = &my_var
my_var.push('a');
my_ref;
```
then the span for the mutable borrow may end up referring
to only the base expression (e.g. `my_var`), rather than
the method call which triggered the mutable borrow
(e.g. `my_var.push('a')`)
Due to a quirk of the MIR borrowck implementation,
this doesn't always get exposed in migration mode,
but it does in many cases.
This commit makes THIR building consistently use 'larger'
spans for adjustment expressions
The intent of this change it make it clearer to users
when it's the specific way in which a variable is
used (for example, in a method call) that produdes
a borrowcheck error. For example, an error message
claiming that a 'mutable borrow occurs here' might
be confusing if it just points at a usage of a variable
(e.g. `my_var`), when no `&mut` is in sight. Pointing
at the entire expression should help to emphasize
that the method call itself is responsible for
the mutable borrow.
In several cases, this makes the `#![feature(nll)]` diagnostic
output match up exactly with the default (migration mode) output.
As a result, several `.nll.stderr` files end up getting removed
entirely.
