Improve check-cfg diagnostics
This PR tries to improve some of the diagnostics of check-cfg.
The main changes is the unexpected name or value being added to the main diagnostic:
```diff
- warning: unexpected `cfg` condition name
+ warning: unexpected `cfg` condition name: `widnows`
```
It also cherry-pick the better sensible logic for when we print the list of expected values when we have a matching value for a very similar name.
Address https://github.com/rust-lang/rust/pull/111072#discussion_r1356818100
r? `@petrochenkov`
Streamline `rustc_driver_impl` pretty-printing.
This PR simplifies a lot of unnecessary structure in
`rustc_driver_impl/src/pretty.rs`. It removes some traits and functions,
simplifies some structs, renames some things for increased consistency, and
eliminates some boilerplate code. Overall it cuts more than 150 lines of code.
r? `@compiler-errors`
`fs::try_exists` currently fails on Windows if encountering a Unix Domain Socket (UDS). Fix this by checking for an error code that's returned when there's a failure to use a reparse point.
A reparse point is a way to invoke a filesystem filter on a file instead of the file being opened normally. This is used to implement symbolic links (by redirecting to a different path) but also to implement other types of special files such as Unix domain sockets. If the reparse point is not a link type then opening it with `CreateFileW` may fail with `ERROR_CANT_ACCESS_FILE` because the filesystem filter does not implement that operation. This differs from resolving links which may fail with errors such as `ERROR_FILE_NOT_FOUND` or `ERROR_CANT_RESOLVE_FILENAME`.
So `ERROR_CANT_ACCESS_FILE` means that the file exists but that we can't open it normally. Still, the file does exist so `try_exists` should report that as `Ok(true)`.
Remove cgu_reuse_tracker from Session
This removes a bit of global mutable state.
It will now miss post-lto cgu reuse when ThinLTO determines that a cgu doesn't get changed, but there weren't any tests for this anyway and a test for it would be fragile to the exact implementation of ThinLTO in LLVM.
When we encounter a type error involving a closure, we try to typeck
prior closure invocations to see if they influenced the current expected
type. When trying to do so, ensure that the closure was defined in our
current scope.
Fix#116658.
exhaustiveness: Rework constructor splitting
`SplitWildcard` was pretty opaque. I replaced it with a more legible abstraction: `ConstructorSet` represents the set of constructors for patterns of a given type. This clarifies responsibilities: `ConstructorSet` handles one clear task, and diagnostic-related shenanigans can be done separately.
I'm quite excited, I had has this in mind for years but could never quite introduce it. This opens up possibilities, including type-specific optimisations (like using a `FxHashSet` to collect enum variants, which had been [hackily attempted some years ago](https://github.com/rust-lang/rust/pull/76918)), my one-pass rewrite (https://github.com/rust-lang/rust/pull/116042), and future librarification.
`NoAnn` and `IdentifiedAnnotation` impl both `pprust_ast::PpAnn` and
`pprust_hir::PpAnn`, which is a bit confusing, because the optional
`tcx` is only needed for the HIR cases. (Currently the `tcx` is
unnecessarily provided in the `expanded` AST cases.)
This commit splits each one into `Ast` and `Hir` versions, which makes
things clear about where the `tcx` is needed. The commit also renames
all the traits so they consistently end with `Ann`.
`call_with_pp_support_ast` and `call_with_pp_support_hir` how each have
a single call site. This commit inlines and removes them, which also
removes the need for all the supporting traits: `Sess`,
`AstPrinterSupport`, and `HirPrinterSupport`. The `sess` member is also
removed from several structs.
The handling of the `PpMode` variants is currently spread across three
functions: `print_after_parsing`, `print_after_hir_lowering`, and
`print_with_analysis`. Each one handles some of the variants. This split
is primarily because `print_after_parsing` has slightly different
arguments to the other two.
This commit changes the structure. It merges the three functions into a
single `print` function, and encapsulates the different arguments in a
new enum `PrintExtra`.
Benefits:
- The code is a little shorter.
- All the `PpMode` variants are handled in a single `match`, with no
need for `unreachable!` arms.
- It enables the trait removal in the subsequent commit by reducing
the number of `call_with_pp_support_ast` call sites from two to one.
First, both `AstPrinterSupport` and `HirPrinterSupport` have a `sess`
method. This commit introduces a `Sess` trait and makes the support
traits be subtraits of `Sess`, to avoid some duplication.
Second, both support traits have a `pp_ann` method that isn't needed if
we enable `trait_upcasting`. This commit removes those methods.
(Both of these traits will be removed in a subsequent commit, as will
the `trait_upcasting` use.)
`phase_3_run_analysis_passes` no longer exists, and AFAICT this code has
been refactored so much since this comment was written that it no longer
has any useful meaning.
Copy 1-element arrays as scalars, not vectors
For `[T; 1]` it's silly to copy as `<1 x T>` when we can just copy as `T`.
Inspired by https://github.com/rust-lang/rust/issues/101210#issuecomment-1732470941, which pointed out that `Option<[u8; 1]>` was codegenning worse than `Option<u8>`.
(I'm not sure *why* LLVM doesn't optimize out `<1 x u8>`, but might as well just not emit it in the first place in this codepath.)
---
I think I bit off too much in #116479; let me try just the scalar case first.
r? `@ghost`
Fix mips platform support entries.
The table entries for these MIPS entries were broken because they had the wrong number of columns (from #116503). Additionally, there was a conflict with #115238, which made the same change (but on different lines, so git didn't complain).
coverage: Clarify loop-edge detection and graph traversal
This is a collection of improvements to two semi-related pieces of code:
- The code in `counters` that detects which graph edges don't exit a loop, and would therefore be good candidates to have their coverage computed as an expression rather than having a physical counter.
- The code in `graph` that traverses the coverage BCB graph in a particular order, and tracks loops and loop edges along the way (which is relevant to the above).
I was originally only planning to make the `graph` changes, but there was going to be a lot of indentation churn in `counters` anyway, and once I started looking I noticed a lot of opportunities for simplification.
---
`@rustbot` label +A-code-coverage
Handle several `#[diagnostic::on_unimplemented]` attributes correctly
This PR fixes an issues where rustc would ignore subsequent `#[diagnostic::on_unimplemented]` attributes. The [corresponding RFC](https://rust-lang.github.io/rfcs/3368-diagnostic-attribute-namespace.html) specifies that the first matching instance of each option is used. Invalid attributes are linted and otherwise ignored.
Having to keep passing in a graph reference was a holdover from when the graph
was partly mutated during traversal. As of #114354 that is no longer necessary,
so we can simplify the traversal code by storing a graph reference as a field
in `TraverseCoverageGraphWithLoops`.
