[NLL] Fix various unused mut errors
Closes#51801Closes#50897Closes#51830Closes#51904
cc #51918 - keeping this one open in case there are any more issues
This PR contains multiple changes. List of changes with examples of what they fix:
* Change mir generation so that the parameter variable doesn't get a name when a `ref` pattern is used as an argument
```rust
fn f(ref y: i32) {} // doesn't trigger lint
```
* Change mir generation so that by-move closure captures don't get first moved into a temporary.
```rust
let mut x = 0; // doesn't trigger lint
move || {
x = 1;
};
```
* Treat generator upvars the same as closure upvars
```rust
let mut x = 0; // This mut is now necessary and is not linted against.
move || {
x = 1;
yield;
};
```
r? @nikomatsakis
rustc_mir: insert a dummy access to places being matched on, when building MIR.
Fixes#47412 by adding a `_dummy = Discriminant(place)` before each `match place {...}`.
r? @nikomatsakis
Fixes the hash test to recognize that MirValidated can change when changing
around labels, and add a new test that makes sure we're lowering loop statements
correctly.
As opposed to using weirdness involving pretending the body block
is the loop block. This does not pass tests
This commit is [ci skip] because I know it doesn't pass tests yet.
Somehow this commit introduces nondeterminism into the handling of
loops.
Implicit coercions from references to pointers were lowered to slightly
different Mir than explicit casts (e.g. 'foo as *mut T'). This resulted
in certain uses of self-referential structs compiling correctly when an
explicit cast was used, but not when the implicit coercion was used.
To fix this, this commit adds an outer 'Use' expr when applying a
raw-ptr-borrow adjustment. This makes the lowered Mir for coercions
identical to that of explicit coercions, allowing the original code to
compile regardless of how the raw ptr cast occurs.
Fixes#47722
NLL feature complete (adds `feature(nll)`)!
This is the final PR for the nll-master branch; it brings over all remaining content.
The contents of the branch include:
- track causal information and use it to report extended errors
- handle `impl Trait` in NLL code
- improve printing of outlives errors
- add `#![feature(nll)]` and some more sample tests
The commits should for the most part build independently.
r? @pnkfelix (and/or @arielb1)
Fix -Z lower_128bit_ops handling of statics
Avoids ICEs such as the following:
> error: internal compiler error: src\librustc_metadata\cstore_impl.rs:131:
> get_optimized_mir: missing MIR for `DefId(8/0:40 ~
> compiler_builtins[9532]::int[0]::addsub[0]::rust_i128_addo[0])`
r? @nagisa
cc #45676 @est31
Avoids ICEs such as the following:
error: internal compiler error: src\librustc_metadata\cstore_impl.rs:131:
get_optimized_mir: missing MIR for `DefId(8/0:40 ~
compiler_builtins[9532]::int[0]::addsub[0]::rust_i128_addo[0])`
The input/output types found in `UniversalRegions` are not normalized.
The old code used to assign them directly into the MIR, which would
lead to errors when there was a projection in a argument or return
type. This also led to some special cases in the `renumber` code.
We now renumber uniformly but then pass the input/output types into
the MIR type-checker, which equates them with the types found in MIR.
This allows us to normalize at the same time.
