Fix last `let_chains` blocker
In order to forbid things like `let x = (let y = 1);` or `if let a = 1 && { let x = let y = 1; } {}`, the parser **HAS** to know the context of `let`.
This context thing is not a surprise in the parser because you can see **a lot** of ad hoc fixes mixing parsing logic with validation logic creating code that looks more like spaghetti with tomato sauce.
To make things even greater, a new ad hoc fix was added to only allow `let`s in a valid `let_chains` context by checking the previously processed token. This was the only solution I could think of and believe me, I thought about it for a long time 👍
In the long term, it should be preferable to segregate different responsibilities or create a more robust and cleaner parser framework.
cc https://github.com/rust-lang/rust/pull/94927
cc https://github.com/rust-lang/rust/issues/53667
Moves our projection handling code into a common file, and avoids the use of a
general mplace-based fallback function by have more specialized implementations.
mplace_index (and the other slice-related functions) could be more efficient by
copy-pasting the body of operand_index. Or we could do some trait magic to share
the code between them. But for now this is probably fine.
Do not error during method probe on `Sized` predicates for types that aren't the method receiver
Fixes#61525
This is safe even though we're skipping an error because we end up confirming the method, which means we're still checking the `Sized` predicate in the end. It just means that we don't emit an erroneous message as below:
```
error: the `query` method cannot be invoked on a trait object
--> src/lib.rs:14:11
|
14 | 1.query::<dyn ToString>("")
| ^^^^^
|
= note: another candidate was found in the following trait, perhaps add a `use` for it:
`use crate::Example;`
```
Also fixes erroneously suggesting the same trait over again, as seen in the `issue-35976.rs` UI test.
Don't rerun the build script for the compiler each time on non-windows platforms
In practice, this doesn't matter very much because the script takes ~no time to run.
But this makes `CARGO_LOG=info` easier to read, and theoretically saves a few milliseconds.
Fix sized check ICE in asm check
Fixes (beta nominated, so doesn't close) #99122
1. Moves a check for unresolved inference variables to _before_ other checks that could possibly ICE. We're not changing behavior here, just doing the same thing earlier in the function.
2. Erases region variables in sized check (which are not resolved at this point) because rustc will also ICE when region vars are passed to a query which does not canonicalize them.
Fix duplicated type annotation suggestion
Before, there was more or less duplicated suggestions to add type hints.
Fix by clearing more generic suggestions when a more specific suggestion
is possible.
This fixes#93506 .
Create fresh lifetime parameters for bare fn trait too
The current code fails to account for the equivalence between `dyn FnMut(&mut u8)` and bare `FnMut(&mut u8)`, and treated them differently.
This PR introduces a special case for `Fn` traits, which are always fully resolved.
Fixes#98616Fixes#98726
This will require a beta-backport, as beta contains that bug.
r? `@petrochenkov`
Inline assembly uses the target features to determine which registers
are available on the current target. However it needs to be able to
access unstable target features for this.
Fixes#99071
Mention similarly named associated type even if it's not clearly in supertrait
Due to query cycle avoidance, we sometimes restrict the candidates in `complain_about_assoc_type_not_found` too much so that we can't detect typo replacements from just supertraits.
This creates a more general note of the existence of a similarly named associated type from _all_ visible traits when possible.
Fixes#55673
Implement `SourceMap::is_span_accessible`
This patch adds `SourceMap::is_span_accessible` and replaces `span_to_snippet(span).is_ok()` and `span_to_snippet(span).is_err()` with it. This removes a `&str` to `String` conversion.
explain doc comments in macros a bit
Open to suggestions on improving this... macro parsing is very foreign to me.
Should we have a structured suggestion to turn them into their regular non-doc comments?
Fixes#92846Fixes#97850
Currently, for the enums and comparison traits we always check the tag
for equality before doing anything else. This is a bit clumsy. This
commit changes things so that the tags are handled very much like a
zeroth field in the enum.
For `eq`/ne` this makes the code slightly cleaner.
For `partial_cmp` and `cmp` it's a more notable change: in the case
where the tags aren't equal, instead of having a tag equality check
followed by a tag comparison, it just does a single tag comparison.
The commit also improves how `Hash` works for enums: instead of having
duplicated code to hash the tag for every arm within the match, we do
it just once before the match.
All this required replacing the `EnumNonMatchingCollapsed` value with a
new `EnumTag` value.
For fieldless enums the new code is particularly improved. All the code
now produced is close to optimal, being very similar to what you'd write
by hand.
In practice, this doesn't matter very much because the script takes ~no time to run.
But this makes `CARGO_LOG=info` easier to read, and theoretically saves a few milliseconds.
