Make `_` an expression, to discard values in destructuring assignments
This is the third and final step towards implementing destructuring assignment (RFC: rust-lang/rfcs#2909, tracking issue: #71126). This PR is the third and final part of #71156, which was split up to allow for easier review.
With this PR, an underscore `_` is parsed as an expression but is allowed *only* on the left-hand side of a destructuring assignment. There it simply discards a value, similarly to the wildcard `_` in patterns. For instance,
```rust
(a, _) = (1, 2)
```
will simply assign 1 to `a` and discard the 2. Note that for consistency,
```
_ = foo
```
is also allowed and equivalent to just `foo`.
Thanks to ````@varkor```` who helped with the implementation, particularly around pre-expansion gating.
r? ````@petrochenkov````
Fix rustc_ast_pretty print_qpath resulting in invalid macro input
related https://github.com/rust-lang/rust/issues/76874 (third case)
### Issue:
The input for a procedural macro is incorrect, for the rust code:
```rust
mod m {
pub trait Tr {
type Ts: super::Tu;
}
}
trait Tu {
fn dummy() { }
}
#[may_proc_macro]
fn foo() {
<T as m::Tr>::Ts::dummy();
}
```
the macro will get the input:
```rust
fn foo() {
<T as m::Tr>::dummy();
}
```
Thus `Ts` has disappeared.
### Fix:
This is due to invalid pretty print of qpath. This PR fix it.
Normalize function type during validation
During inlining, the callee body is normalized and has types revealed,
but some of locals corresponding to the arguments might come from the
caller body which is not. As a result the caller body does not pass
validation without additional normalization.
Closes#78442.
Add a test for r# identifiers
I'm not entirely sure I properly ran the test locally (I think so though), waiting for CI to confirm. :)
```````@rustbot``````` modify labels: T-rustdoc
r? ```````@jyn514```````
refactor: removing alloc::collections::vec_deque ignore-tidy-filelength
This PR removes the need for ignore-tidy-filelength for alloc::collections::vec_deque which is part of the issue https://github.com/rust-lang/rust/issues/60302
It is probably easiest to review this PR by looking at it commit by commit rather than looking at the overall diff.
Lower intrinsics calls: forget, size_of, unreachable, wrapping_*
This allows constant propagation to evaluate `size_of` and `wrapping_*`,
and unreachable propagation to propagate a call to `unreachable`.
The lowering is performed as a MIR optimization, rather than during MIR
building to preserve the special status of intrinsics with respect to
unsafety checks and promotion.
Currently enabled by default to determine the performance impact (no
significant impact expected). In practice only useful when combined with
inlining since intrinsics are rarely used directly (with exception of
`unreachable` and `discriminant_value` used by built-in derive macros).
Closes#32716.
Previously, cap-lints was ignored when checking the previous forbid level, which
meant that it was a hard error to do so. This is different from the normal
behavior of lints, which are silenced by cap-lints; if the forbid would not take
effect regardless, there is not much point in complaining about the fact that we
are reducing its level.
It might be considered a bug that even `--cap-lints deny` would suffice to
silence the error on overriding forbid, depending on if one cares about failing
the build or precisely forbid being set. But setting cap-lints to deny is quite
odd and not really done in practice, so we don't try to handle it specially.
This also unifies the code paths for nested and same-level scopes. However, the
special case for CLI lint flags is left in place (introduced by #70918) to fix
the regression noted in #70819. That means that CLI flags do not lint on forbid
being overridden by a non-forbid level. It is unclear whether this is a bug or a
desirable feature, but it is certainly inconsistent. CLI flags are a
sufficiently different "type" of place though that this is deemed out of scope
for this commit.
add error_occured field to ConstQualifs,
fix#76064
I wasn't sure what `in_return_place` actually did and not sure why it returns `ConstQualifs` while it's sibling functions return `bool`. So I tried to make as minimal changes to the structure as possible. Please point out whether I have to refactor it or not.
r? `@oli-obk`
cc `@RalfJung`
This allows constant propagation to evaluate `size_of` and `wrapping_*`,
and unreachable propagation to propagate a call to `unreachable`.
The lowering is performed as a MIR optimization, rather than during MIR
building to preserve the special status of intrinsics with respect to
unsafety checks and promotion.
Fix and re-enable two coverage tests on MacOS
Note, in the coverage-reports test, the comment about MacOS was wrong.
The setting is based on config.toml llvm `optimize` setting. There
doesn't appear to be any environment variable I can check, and I
don't think we should add one. Testing the binary itself is a more
reliable way to check anyway.
For the coverage-spanview test, I removed the dependency on sed
altogether, which is much less ugly than trying to work around the
MacOS sed differences.
I tested these changes on Linux, Windows, and Mac.
r? `@tmandry`
FYI `@wesleywiser`
commit c547d5fabcd756515afa7263ee5304965bb4c497
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 11:22:23 2020 +0000
test: updating ui/hygiene/panic-location.rs expected
commit 2af03769c4ffdbbbad75197a1ad0df8c599186be
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 10:43:30 2020 +0000
fix: documentation unresolved link
commit c4b0df361ce27d7392d8016229f2e0265af32086
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 02:58:31 2020 +0000
style: compiling with Rust's style guidelines
commit bdd2de5f3c09b49a18e3293f2457fcab25557c96
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 02:56:31 2020 +0000
refactor: removing ignore-tidy-filelength
commit fcc4b3bc41f57244c65ebb8e4efe4cbc9460b5a9
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 02:51:35 2020 +0000
refactor: moving trait RingSlices to ring_slices.rs
commit 2f0cc539c06d8841baf7f675168f68ca7c21e68e
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 02:46:09 2020 +0000
refactor: moving struct PairSlices to pair_slices.rs
commit a55d3ef1dab4c3d85962b3a601ff8d1f7497faf2
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 02:31:45 2020 +0000
refactor: moving struct Iter to iter.rs
commit 76ab33a12442a03726f36f606b4e0fe70f8f246b
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 02:24:32 2020 +0000
refactor: moving struct IntoIter into into_iter.rs
commit abe0d9eea2933881858c3b1bc09df67cedc5ada5
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 02:19:07 2020 +0000
refactor: moving struct IterMut into iter_mut.rs
commit 70ebd6420335e1895e2afa2763a0148897963e24
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 01:49:15 2020 +0000
refactor: moved macros into macros.rs
commit b08dd2add994b04ae851aa065800bd8bd6326134
Author: C <DeveloperC@protonmail.com>
Date: Sat Oct 31 01:05:36 2020 +0000
refactor: moving vec_deque.rs to vec_deque/mod.rs
Rustdoc check option
The ultimate goal behind this option would be to have `rustdoc --check` being run when you use `cargo check` as a second step.
r? `@jyn514`
During inlining, the callee body is normalized and has types revealed,
but some of locals corresponding to the arguments might come from the
caller body which is not. As a result the caller body does not pass
validation without additional normalization.
The inliner looks if a sanitizer is enabled before considering
`no_sanitize` attribute as possible source of incompatibility.
The MIR inlining could happen in a crate with sanitizer disabled, but
code generation in a crate with sanitizer enabled, thus the attribute
would be incorrectly ignored.
To avoid the issue never inline functions with different `no_sanitize`
attributes.
extend min_const_generics param ty tests
Apparently we never tested for `u128` and `i128` before this, so I added a test for all types which are allowed.
r? ``@varkor``
Implement destructuring assignment for structs and slices
This is the second step towards implementing destructuring assignment (RFC: rust-lang/rfcs#2909, tracking issue: #71126). This PR is the second part of #71156, which was split up to allow for easier review.
Note that the first PR (#78748) is not merged yet, so it is included as the first commit in this one. I thought this would allow the review to start earlier because I have some time this weekend to respond to reviews. If ``@petrochenkov`` prefers to wait until the first PR is merged, I totally understand, of course.
This PR implements destructuring assignment for (tuple) structs and slices. In order to do this, the following *parser change* was necessary: struct expressions are not required to have a base expression, i.e. `Struct { a: 1, .. }` becomes legal (in order to act like a struct pattern).
Unfortunately, this PR slightly regresses the diagnostics implemented in #77283. However, it is only a missing help message in `src/test/ui/issues/issue-77218.rs`. Other instances of this diagnostic are not affected. Since I don't exactly understand how this help message works and how to fix it yet, I was hoping it's OK to regress this temporarily and fix it in a follow-up PR.
Thanks to ``@varkor`` who helped with the implementation, particularly around the struct rest changes.
r? ``@petrochenkov``
Reusing bindings causes errors later in lowering:
```
error[E0596]: cannot borrow `vec` as mutable, as it is not declared as mutable
--> /checkout/src/test/ui/async-await/argument-patterns.rs:12:20
|
LL | async fn b(n: u32, ref mut vec: A) {
| ^^^^^^^^^^^
| |
| cannot borrow as mutable
| help: consider changing this to be mutable: `mut vec`
```
