Since array and slice constants are now lowered to array and slice
patterns, `non_scalar_compare` was only called for string comparisons.
This specializes it to strings, renames it, and removes the unused
array-unsizing logic.
This also updates some outdated doc comments.
Rollup of 8 pull requests
Successful merges:
- #138435 (Add support for postfix yield expressions)
- #138685 (Use `Option<Ident>` for lowered param names.)
- #138700 (Suggest `-Whelp` when pass `--print lints` to rustc)
- #138727 (Do not rely on `type_var_origin` in `OrphanCheckErr::NonLocalInputType`)
- #138729 (Clean up `FnCtxt::resolve_coroutine_interiors`)
- #138731 (coverage: Add LLVM plumbing for expansion regions)
- #138732 (Use `def_path_str` for def id arg in `UnsupportedOpInfo`)
- #138735 (Remove `llvm` and `llvms` triagebot ping aliases for `icebreakers-llvm` ping group)
r? `@ghost`
`@rustbot` modify labels: rollup
Use `Option<Ident>` for lowered param names.
Parameter patterns are lowered to an `Ident` by `lower_fn_params_to_names`, which is used when lowering bare function types, trait methods, and foreign functions. Currently, there are two exceptional cases where the lowered param can become an empty `Ident`.
- If the incoming pattern is an empty `Ident`. This occurs if the parameter is anonymous, e.g. in a bare function type.
- If the incoming pattern is neither an ident nor an underscore. Any such parameter will have triggered a compile error (hence the `span_delayed_bug`), but lowering still occurs.
This commit replaces these empty `Ident` results with `None`, which eliminates a number of `kw::Empty` uses, and makes it impossible to fail to check for these exceptional cases.
Note: the `FIXME` comment in `is_unwrap_or_empty_symbol` is removed. It actually should have been removed in #138482, the precursor to this PR. That PR changed the lowering of wild patterns to `_` symbols instead of empty symbols, which made the mentioned underscore check load-bearing.
r? ``@compiler-errors``
Consider fields to be inhabited if they are unstable
Fixes#133885 with a simple heuristic
r? Nadrieril
Not totally certain if this needs T-lang approval or a crater run.
Rollup of 7 pull requests
Successful merges:
- #135394 (`MaybeUninit` inherent slice methods part 2)
- #137051 (Implement default methods for `io::Empty` and `io::Sink`)
- #138001 (mir_build: consider privacy when checking for irrefutable patterns)
- #138540 (core/slice: Mark some `split_off` variants unstably const)
- #138589 (If a label is placed on the block of a loop instead of the header, suggest moving it to the header.)
- #138594 (Fix next solver handling of shallow trait impl check)
- #138613 (Remove E0773 "A builtin-macro was defined more than once.")
Failed merges:
- #138602 (Slim `rustc_parse_format` dependencies down)
r? `@ghost`
`@rustbot` modify labels: rollup
mir_build: consider privacy when checking for irrefutable patterns
This PR fixes#137999.
Note that, since this makes the compiler reject code that was previously accepted, it will probably need a crater run.
I include a commit that factors out a common code pattern into a helper function, purely because the fact that this was repeated all over the place was bothering me. Let me know if I should split that into a separate PR instead.
Represent diagnostic side effects as dep nodes
This changes diagnostic to be tracked as a special dep node (`SideEffect`) instead of having a list of side effects associated with each dep node. `SideEffect` is always red and when forced, it emits the diagnostic and marks itself green. Each emitted diagnostic generates a new `SideEffect` with an unique dep node index.
Some implications of this:
- Diagnostic may now be emitted more than once as they can be emitted once when the `SideEffect` gets marked green and again if the task it depends on needs to be re-executed due to another node being red. It relies on deduplicating of diagnostics to avoid that.
- Anon tasks which emits diagnostics will no longer *incorrectly* be merged with other anon tasks.
- Reusing a CGU will now emit diagnostics from the task generating it.
Parameter patterns are lowered to an `Ident` by
`lower_fn_params_to_names`, which is used when lowering bare function
types, trait methods, and foreign functions. Currently, there are two
exceptional cases where the lowered param can become an empty `Ident`.
- If the incoming pattern is an empty `Ident`. This occurs if the
parameter is anonymous, e.g. in a bare function type.
- If the incoming pattern is neither an ident nor an underscore. Any
such parameter will have triggered a compile error (hence the
`span_delayed_bug`), but lowering still occurs.
This commit replaces these empty `Ident` results with `None`, which
eliminates a number of `kw::Empty` uses, and makes it impossible to fail
to check for these exceptional cases.
Note: the `FIXME` comment in `is_unwrap_or_empty_symbol` is removed. It
actually should have been removed in #138482, the precursor to this PR.
That PR changed the lowering of wild patterns to `_` symbols instead of
empty symbols, which made the mentioned underscore check load-bearing.
Remove existing AFIDT implementation
This experiment will need to be reworked differently; I don't think we'll be going with the `dyn* Future` approach that is currently implemented.
r? oli-obk
Fixes#136286Fixes#137706Fixes#137895
Tracking:
* #133119
Extract `for_each_immediate_subpat` from THIR pattern visitors
This is extracted from some larger changes I've been working on, trying to introduce a “THIR pattern id” to refer to THIR pattern nodes without a direct reference.
The future of those changes is somewhat uncertain, due to some [proposed changes involving upvar inference](https://rust-lang.zulipchat.com/#narrow/channel/131828-t-compiler/topic/upvar.20inference.20on.20THIR.3F). So I'm taking my preparatory changes that make sense on their own, and extracting them into one or more independent PRs.
---
This particular patch takes two different functions that were both matching on `PatKind` to traverse subpatterns, and extracts the core match into a single helper function.
Rollup of 7 pull requests
Successful merges:
- #138384 (Move `hir::Item::ident` into `hir::ItemKind`.)
- #138508 (Clarify "owned data" in E0515.md)
- #138531 (Store test diffs in job summaries and improve analysis formatting)
- #138533 (Only use `DIST_TRY_BUILD` for try jobs that were not selected explicitly)
- #138556 (Fix ICE: attempted to remap an already remapped filename)
- #138608 (rustc_target: Add target feature constraints for LoongArch)
- #138619 (Flatten `if`s in `rustc_codegen_ssa`)
r? `@ghost`
`@rustbot` modify labels: rollup
Mangle rustc_std_internal_symbols functions
This reduces the risk of issues when using a staticlib or rust dylib compiled with a different rustc version in a rust program. Currently this will either (in the case of staticlib) cause a linker error due to duplicate symbol definitions, or (in the case of rust dylibs) cause rustc_std_internal_symbols functions to be silently overridden. As rust gets more commonly used inside the implementation of libraries consumed with a C interface (like Spidermonkey, Ruby YJIT (curently has to do partial linking of all rust code to hide all symbols not part of the C api), the Rusticl OpenCL implementation in mesa) this is becoming much more of an issue. With this PR the only symbols remaining with an unmangled name are rust_eh_personality (LLVM doesn't allow renaming it) and `__rust_no_alloc_shim_is_unstable`.
Helps mitigate https://github.com/rust-lang/rust/issues/104707
try-job: aarch64-gnu-debug
try-job: aarch64-apple
try-job: x86_64-apple-1
try-job: x86_64-mingw-1
try-job: i686-mingw-1
try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: test-various
try-job: armhf-gnu
Move `hir::Item::ident` into `hir::ItemKind`.
`hir::Item` has an `ident` field.
- It's always non-empty for these item kinds: `ExternCrate`, `Static`, `Const`, `Fn`, `Macro`, `Mod`, `TyAlias`, `Enum`, `Struct`, `Union`, Trait`, TraitAalis`.
- It's always empty for these item kinds: `ForeignMod`, `GlobalAsm`, `Impl`.
- For `Use`, it is non-empty for `UseKind::Single` and empty for `UseKind::{Glob,ListStem}`.
All of this is quite non-obvious; the only documentation is a single comment saying "The name might be a dummy name in case of anonymous items". Some sites that handle items check for an empty ident, some don't. This is a very C-like way of doing things, but this is Rust, we have sum types, we can do this properly and never forget to check for the exceptional case and never YOLO possibly empty identifiers (or possibly dummy spans) around and hope that things will work out.
This is step towards `kw::Empty` elimination (#137978).
r? `@fmease`
`hir::Item` has an `ident` field.
- It's always non-empty for these item kinds: `ExternCrate`, `Static`,
`Const`, `Fn`, `Macro`, `Mod`, `TyAlias`, `Enum`, `Struct`, `Union`,
Trait`, TraitAalis`.
- It's always empty for these item kinds: `ForeignMod`, `GlobalAsm`,
`Impl`.
- For `Use`, it is non-empty for `UseKind::Single` and empty for
`UseKind::{Glob,ListStem}`.
All of this is quite non-obvious; the only documentation is a single
comment saying "The name might be a dummy name in case of anonymous
items". Some sites that handle items check for an empty ident, some
don't. This is a very C-like way of doing things, but this is Rust, we
have sum types, we can do this properly and never forget to check for
the exceptional case and never YOLO possibly empty identifiers (or
possibly dummy spans) around and hope that things will work out.
The commit is large but it's mostly obvious plumbing work. Some notable
things.
- A similar transformation makes sense for `ast::Item`, but this is
already a big change. That can be done later.
- Lots of assertions are added to item lowering to ensure that
identifiers are empty/non-empty as expected. These will be removable
when `ast::Item` is done later.
- `ItemKind::Use` doesn't get an `Ident`, but `UseKind::Single` does.
- `lower_use_tree` is significantly simpler. No more confusing `&mut
Ident` to deal with.
- `ItemKind::ident` is a new method, it returns an `Option<Ident>`. It's
used with `unwrap` in a few places; sometimes it's hard to tell
exactly which item kinds might occur. None of these unwraps fail on
the test suite. It's conceivable that some might fail on alternative
input. We can deal with those if/when they happen.
- In `trait_path` the `find_map`/`if let` is replaced with a loop, and
things end up much clearer that way.
- `named_span` no longer checks for an empty name; instead the call site
now checks for a missing identifier if necessary.
- `maybe_inline_local` doesn't need the `glob` argument, it can be
computed in-function from the `renamed` argument.
- `arbitrary_source_item_ordering::check_mod` had a big `if` statement
that was just getting the ident from the item kinds that had one. It
could be mostly replaced by a single call to the new `ItemKind::ident`
method.
- `ItemKind` grows from 56 to 64 bytes, but `Item` stays the same size,
and that's what matters, because `ItemKind` only occurs within `Item`.
mir_build: Avoid some useless work when visiting "primary" bindings
While looking over `visit_primary_bindings`, I noticed that it does a bunch of extra work to build up a collection of “user-type projections”, even though 2/3 of its call sites don't even use them. Those callers can get the same result via `thir::Pat::walk_always`.
(And it turns out that doing so also avoids creating some redundant user-type entries in MIR for some binding constructs.)
I also noticed that even when the user-type projections *are* used, the process of building them ends up eagerly cloning some nested vectors at every recursion step, even in cases where they won't be used because the current subpattern has no bindings. To avoid this, the visit method now assembles a linked list on the stack containing the information that *would* be needed to create projections, and only creates the concrete projections as needed when a primary binding is encountered.
Some relevant prior PRs:
- #55274
- 0bfe184b1a in #55937
---
There should be no user-visible change in compiler output.
The existing method does some non-obvious extra work to collect user types and
build user-type projections, which is specifically needed by `declare_bindings`
and not by the other two callers.
Rollup of 5 pull requests
Successful merges:
- #138283 (Enforce type of const param correctly in MIR typeck)
- #138439 (feat: check ARG_MAX on Unix platforms)
- #138502 (resolve: Avoid some unstable iteration)
- #138514 (Remove fake borrows of refs that are converted into non-refs in `MakeByMoveBody`)
- #138524 (Mark myself as unavailable for reviews temporarily)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix HIR printing of parameters
HIR pretty printing does the wrong thing for anonymous parameters, and there is no test coverage for it. This PR remedies both of those things.
r? ``@lcnr``
Currently (PatKind::Wild` (i.e. `_`) gets turned by
`lower_fn_params_to_names` into an empty identifier, which means it is
printed incorrectly by HIR pretty printing.
And likewise for `lower_fn_params_to_names`, which affects some error
messages.
This commit fixes them. This requires a slight tweak in a couple of
places to continue using parameter numbers in some error messages. And
it improves the output of `tests/ui/typeck/cyclic_type_ice.rs`:
`/* _ */` is a better suggestion than `/* */`.
Add an opt-out in pretty printing for RTN rendering
Today, we render RPITIT types like `impl Sized { T::method(..) }` when RTN is enabled. This is very useful for diagnostics, since it's often not clear what the `impl Sized` type means by itself, and it makes it clear that that's an RPITIT that can be bounded using RTN syntax. See #115624.
However, since we don't distinguish types that are rendered for the purposes of printing messages vs suggestions, this representation leaks into suggestions and turns into code that can't be parsed. This PR adds a new `with_types_for_suggestion! {}` and `with_types_for_signature! {}` options to the pretty printing architecture to make it clear that we're rendering a type for code suggestions.
This can be applied later as we find that we need it.
Add a .bss-like scheme for encoded const allocs
This check if all bytes are zero feel like it should be too slow, and instead we should have a flag that we track, but that seems hard. Let's see how this perfs first.
Also we can probably stash the "it's all zero actually" flag inside one of the other struct members that's already not using an entire byte. This optimization doesn't fire all that often, so it's possible that by sticking it in the varint length field, this PR actually makes rmeta size worse.
make precise capturing args in rustdoc Json typed
close#137616
This PR includes below changes.
- Add `rustc_hir::PreciseCapturingArgKind` which allows the query system to return a arg's data.
- Add `rustdoc::clean::types::PreciseCapturingArg` and change to use it.
- Add `rustdoc-json-types::PreciseCapturingArg` and change to use it.
- Update `tests/rustdoc-json/impl-trait-precise-capturing.rs`.
- Bump `rustdoc_json_types::FORMAT_VERSION`.
Convert `ShardedHashMap` to use `hashbrown::HashTable`
The `hash_raw_entry` feature (#56167) has finished fcp-close, so the compiler
should stop using it to allow its removal. Several `Sharded` maps were
using raw entries to avoid re-hashing between shard and map lookup, and
we can do that with `hashbrown::HashTable` instead.
Continuing the work from #137350.
Removes the unused methods: `expect_variant`, `expect_field`,
`expect_foreign_item`.
Every method gains a `hir_` prefix.
To make room for the moving of `Map::attrs` to `TyCtxt::hir_attrs` in
the next commit. (It makes sense to rename the query, because it has
many fewer uses than the method.)
Rollup of 10 pull requests
Successful merges:
- #137715 (Allow int literals for pattern types with int base types)
- #138002 (Disable CFI for weakly linked syscalls)
- #138051 (Add support for downloading GCC from CI)
- #138231 (Prevent ICE in autodiff validation by emitting user-friendly errors)
- #138245 (stabilize `ci_rustc_if_unchanged_logic` test for local environments)
- #138256 (Do not feed anon const a type that references generics that it does not have)
- #138284 (Do not write user type annotation for const param value path)
- #138296 (Remove `AdtFlags::IS_ANONYMOUS` and `Copy`/`Clone` condition for anonymous ADT)
- #138352 (miri native_calls: ensure we actually expose *mutable* provenance to the memory FFI can access)
- #138354 (remove redundant `body` arguments)
r? `@ghost`
`@rustbot` modify labels: rollup
miri native_calls: ensure we actually expose *mutable* provenance to the memory FFI can access
In native call mode, the interpreter memory itself is accessed directly by external code via pointers created from integers and passed via libffi, so we have to ensure the provenance in Miri itself (on the meta level) is sufficiently exposed. So far we only exposed the provenance for read-only accesses. This may we enough as that may actually be the same provenance as for mutable accesses, but it's hard to be sure, and anyway there's no reason to do such a gambit -- we have this function, `prepare_for_native_call`, which iterates all memory the call can access. let's just also (re-)expose Miri's own allocations there. We expose the read-only provenance for all of them and the mutable provenance for the mutable allocations.
r? ``@oli-obk``
Remove `AdtFlags::IS_ANONYMOUS` and `Copy`/`Clone` condition for anonymous ADT
cc #131045, which removed anonymous ADTs from the compiler
I forgot more stuff I guess.
Add `#[define_opaques]` attribute and require it for all type-alias-impl-trait sites that register a hidden type
Instead of relying on the signature of items to decide whether they are constraining an opaque type, the opaque types that the item constrains must be explicitly listed.
A previous version of this PR used an actual attribute, but had to keep the resolved `DefId`s in a side table.
Now we just lower to fields in the AST that have no surface syntax, instead a builtin attribute macro fills in those fields where applicable.
Note that for convenience referencing opaque types in associated types from associated methods on the same impl will not require an attribute. If that causes problems `#[defines()]` can be used to overwrite the default of searching for opaques in the signature.
One wart of this design is that closures and static items do not have generics. So since I stored the opaques in the generics of functions, consts and methods, I would need to add a custom field to closures and statics to track this information. During a T-types discussion we decided to just not do this for now.
fixes#131298
The `hash_raw_entry` feature has finished fcp-close, so the compiler
should stop using it to allow its removal. Several `Sharded` maps were
using raw entries to avoid re-hashing between shard and map lookup, and
we can do that with `hashbrown::HashTable` instead.
Revert <https://github.com/rust-lang/rust/pull/138084> to buy time to
consider options that avoids breaking downstream usages of cargo on
distributed `rustc-src` artifacts, where such cargo invocations fail due
to inability to inherit `lints` from workspace root manifest's
`workspace.lints` (this is only valid for the source rust-lang/rust
workspace, but not really the distributed `rustc-src` artifacts).
This breakage was reported in
<https://github.com/rust-lang/rust/issues/138304>.
This reverts commit 48caf81484, reversing
changes made to c6662879b2.
depend more on attr_data_structures and move find_attr! there
r? ``@oli-obk``
This should be an easy one. It just moves some imports around. This is necessary for other changes that I'm working on not to have import cycles. However, it's an easy one to just merge on its own.
Move more layouting logic to `rustc_abi`
Move all `LayoutData`-constructing code to `rustc_abi`:
- Infaillible operations get a new `LayoutData` constructor method;
- Faillible ones get a new method on `LayoutCalculator`.
compiler: Use `size_of` from the prelude instead of imported
Use `std::mem::{size_of, size_of_val, align_of, align_of_val}` from the prelude instead of importing or qualifying them. Apply this change across the compiler.
These functions were added to all preludes in Rust 1.80.
r? ``@compiler-errors``
By naming them in `[workspace.lints.rust]` in the top-level
`Cargo.toml`, and then making all `compiler/` crates inherit them with
`[lints] workspace = true`. (I omitted `rustc_codegen_{cranelift,gcc}`,
because they're a bit different.)
The advantages of this over the current approach:
- It uses a standard Cargo feature, rather than special handling in
bootstrap. So, easier to understand, and less likely to get
accidentally broken in the future.
- It works for proc macro crates.
It's a shame it doesn't work for rustc-specific lints, as the comments
explain.
Use `std::mem::{size_of, size_of_val, align_of, align_of_val}` from the
prelude instead of importing or qualifying them.
These functions were added to all preludes in Rust 1.80.
A check for `#[non_exhaustive]` is often done in combination with
checking whether the type is local to the crate, in a variety of ways.
Create a helper method and standardize on it as the way to check for
this.
Currently it relies on special treatment of `kw::Empty`, which is really
easy to get wrong. This commit makes the special case clearer in the
type system by using `Option`. It's a bit clumsy, but the synthetic name
handling itself is a bit clumsy; better to make it explicit than sneak
it in.
Fixes#133426.
In `walk_item`, we call `visit_id` on every item kind. For most of them
we do it directly in `walk_item`. But for `ItemKind::Mod`,
`ItemKind::Enum`, and `ItemKind::Use` we instead do it in the `walk_*`
function called (via the `visit_*` function) from `walk_item`.
I can see no reason for this inconsistency, so this commit makes those
three cases like all the other cases, moving the `visit_id` calls into
`walk_item`. This also avoids the need for a few `HirId` arguments.
Rollup of 17 pull requests
Successful merges:
- #137827 (Add timestamp to unstable feature usage metrics)
- #138041 (bootstrap and compiletest: Use `size_of_val` from the prelude instead of imported)
- #138046 (trim channel value in `get_closest_merge_commit`)
- #138053 (Increase the max. custom try jobs requested to `20`)
- #138061 (triagebot: add a `compiler_leads` ad-hoc group)
- #138064 (Remove - from xtensa targets cpu names)
- #138075 (Use final path segment for diagnostic)
- #138078 (Reduce the noise of bootstrap changelog warnings in --dry-run mode)
- #138081 (Move `yield` expressions behind their own feature gate)
- #138090 (`librustdoc`: flatten nested ifs)
- #138092 (Re-add `DynSend` and `DynSync` impls for `TyCtxt`)
- #138094 (a small borrowck cleanup)
- #138098 (Stabilize feature `const_copy_from_slice`)
- #138103 (Git ignore citool's target directory)
- #138105 (Fix broken link to Miri intrinsics in documentation)
- #138108 (Mention me (WaffleLapkin) when changes to `rustc_codegen_ssa` occur)
- #138117 ([llvm/PassWrapper] use `size_t` when building arg strings)
r? `@ghost`
`@rustbot` modify labels: rollup
interpret/provenance_map: consistently use range_is_empty
https://github.com/rust-lang/rust/pull/137704 started using this for per-ptr provenance; let's be consistent and use it also for the per-byte provenance check. Also rename the methods to avoid having both "get" and "is_empty" in the name.
r? ````@oli-obk````
Clarify why InhabitedPredicate::instantiate_opt exists
At first glance, the extra casework seems pointless and needlessly error-prone. Clarify that there is a reason for it being there.
Re-add `Clone`-derive on `Thir`
This PR adds back `Clone` for `Thir`.
If a tool wants to access a `thir_body` query result in the `Callbacks::after_analysis` hook, it can't do so (I think) without a `Clone` impl on `Thir`, because `check_unsafety` steals the value. With `Clone`, the `thir_body` query provider can be overriden to cache a clone of the `Thir`, circumventing that issue.
Specifically, we need it for https://github.com/rust-corpus/qrates, [here](ca7a230196/extractor/src/lib.rs (L205)).
Please let me know if there are issues with this PR/if there's another way to solve the problem at hand
Only use implied bounds hack if bevy, and use deeply normalize in implied bounds hack
Consolidates the implied bounds computation mode into a single function, which deeply normalizes, and if it's in **compat** mode (for bevy), it extracts outlives bounds from the infcx.
Previously, we were using the implied bounds compat mode in two cases:
1. During WF, if it detects `ParamSet`
2. EVERYWHERE ELSE (lol) -- e.g. borrowck, predicate entailment, etc.
While I think this is fine, and the net effect was just that we emitted fewer diagnostics, it makes me uncomfortable that all crates were using the supposed "compat" code.
Fixes#137767
Simplify `<Postorder as Iterator>::size_hint`
The current version is sometimes malformed (cc #137919); let's see if we can get away with a loose but trivially-correct one.
mgca: Lower all const paths as `ConstArgKind::Path`
When `#![feature(min_generic_const_args)]` is enabled, we now lower all
const paths in generic arg position to `hir::ConstArgKind::Path`. We
then lower assoc const paths to `ty::ConstKind::Unevaluated` since we
can no longer use the anon const expression lowering machinery. In the
process of implementing this, I factored out `hir_ty_lowering` code that
is now shared between lowering assoc types and assoc consts.
This PR also introduces a `#[type_const]` attribute for trait assoc
consts that are allowed as const args. However, we still need to
implement code to check that assoc const definitions satisfy
`#[type_const]` if present (basically is it a const path or a
monomorphic anon const).
r? `@BoxyUwU`
When `#![feature(min_generic_const_args)]` is enabled, we now lower all
const paths in generic arg position to `hir::ConstArgKind::Path`. We
then lower assoc const paths to `ty::ConstKind::Unevaluated` since we
can no longer use the anon const expression lowering machinery. In the
process of implementing this, I factored out `hir_ty_lowering` code that
is now shared between lowering assoc types and assoc consts.
This PR also introduces a `#[type_const]` attribute for trait assoc
consts that are allowed as const args. However, we still need to
implement code to check that assoc const definitions satisfy
`#[type_const]` if present (basically is it a const path or a
monomorphic anon const).
This is error-prone. Explicitly write down which cases don't need
anything substituted. Turn the `OpaqueType` case, which currently
seems to be unreachable, into a `bug!`.
A few cleanups after the removal of `cfg(not(parallel))`
I noticed a few small things that are no longer needed after the removal of `cfg(not(parallel))` in #132282.
One of the later changes adjusts several imports, so viewing the changes individually is recommended.
r? SparrowLii (or reroll)
Fix pretty printing of unsafe binders
We used to render `unsafe<> i32` as `i32`, and `unsafe<'a> &'a i32` as `for<'a> &'a i32`.
r? oli-obk
Review with whitespace b/c adding a new argument changes some the wrapping of some function calls.
Optimize empty provenance range checks.
Currently it gets the pointers in the range and checks if the result is empty, but it can be done faster if you combine those two steps.
r? `@oli-obk`
Update `const_conditions` and `explicit_implied_const_bounds` docs
Move documentation to query definitions, and add docs to `explicit_implied_const_bounds`.
r? project-const-traits
Remove `ParamEnv::without_caller_bounds`
This doesn't really do anything that `ParamEnv::empty` doesn't do nowadays as `ParamEnv` *only* stores caller bounds since other information has been moved out into `TypingMode`
r? ```@compiler-errors``` ```@lcnr```
Use `mk_ty_from_kind` a bit less, clean up lifetime handling in borrowck
r? ``@BoxyUwU``
Pulled out of my attempt to turn that `*const dyn Tr + '_` casting into a lint (which failed lmao)
Introduce `feature(generic_const_parameter_types)`
Allows to define const generic parameters whose type depends on other generic parameters, e.g. `Foo<const N: usize, const ARR: [u8; N]>;`
Wasn't going to implement for this for a while until we could implement it with `bad_inference.rs` resolved but apparently the project simd folks would like to be able to use this for some intrinsics and the inference issue isn't really a huge problem there aiui. (cc ``@workingjubilee`` )
Use `Binder<Vec<Ty>>` instead of `Vec<Binder<Ty>>` in both solvers for sized/auto traits/etc.
It's more conceptually justified IMO, especially when binders get implications.
r? lcnr
Clean up TypeckResults::extract_binding_mode
- Remove the `Option` from the result type, as `None` is never returned.
- Document the difference from the `BindingMode` in `PatKind::Binding`.
A cycle was previously coinductive if all steps were coinductive.
Change this to instead considerm cycles to be coinductive if they
step through at least one where-bound of an impl of a coinductive
trait goal.
Rollup of 8 pull requests
Successful merges:
- #136542 ([`compiletest`-related cleanups 4/7] Make the distinction between root build directory vs test suite specific build directory in compiletest less confusing)
- #136579 (Fix UB in ThinVec::flat_map_in_place)
- #136688 (require trait impls to have matching const stabilities as the traits)
- #136846 (Make `AssocOp` more like `ExprKind`)
- #137304 (add `IntoBounds::intersect` and `RangeBounds::is_empty`)
- #137455 (Reuse machinery from `tail_expr_drop_order` for `if_let_rescope`)
- #137480 (Return unexpected termination error instead of panicing in `Thread::join`)
- #137694 (Spruce up `AttributeKind` docs)
r? `@ghost`
`@rustbot` modify labels: rollup
Don't infer attributes of virtual calls based on the function body
Fixes (after backport) #137646.
Since we don't know the exact implementation of the virtual call, it might write to parameters, we can't infer the readonly attribute.
Reuse machinery from `tail_expr_drop_order` for `if_let_rescope`
Namely, it defines its own `extract_component_with_significant_dtor` which is a bit more accurate than `Ty::has_significant_drop`, since it has a hard-coded list of types from the ecosystem which are opted out of the lint.[^a]
Also, since we extract the dtors themselves, adopt the same *label* we use in `tail_expr_drop_order` to point out the destructor impl. This makes it much clear what's actually being dropped, so it should be clearer to know when it's a false positive.
This conflicts with #137444, but I will rebase whichever lands first.
[^a]: Side-note, it's kinda a shame that now there are two functions that presumably do the same thing. But this isn't my circus, nor are these my monkeys.
It mirrors `ExprKind::Binary`, and contains a `BinOpKind`. This makes
`AssocOp` more like `ExprKind`. Note that the variants removed from
`AssocOp` are all named differently to `BinOpToken`, e.g. `Multiply`
instead of `Mul`, so that's an inconsistency removed.
The commit adds `precedence` and `fixity` methods to `BinOpKind`, and
calls them from the corresponding methods in `AssocOp`. This avoids the
need to create an `AssocOp` from a `BinOpKind` in a bunch of places, and
`AssocOp::from_ast_binop` is removed.
`AssocOp::to_ast_binop` is also no longer needed.
Overall things are shorter and nicer.
Make -Z unpretty=mir suggest -Z dump-mir as well for discoverability
While debugging something else, I got quite annoyed with `-Z unpretty=mir` showing me post-processed MIR instead of the one just after it is built. I ended up asking on Zulip and got pointed to `-Z dump-mir`. While this feature is documented in the rustc dev guide, I think it'd be good if the possibility of making use of it was staring you in the face while you need it.
Teach structured errors to display short `Ty<'_>`
Make it so that in every structured error annotated with `#[derive(Diagnostic)]` that has a field of type `Ty<'_>`, the printing of that value into a `String` will look at the thread-local storage `TyCtxt` in order to shorten to a length appropriate with the terminal width. When this happen, the resulting error will have a note with the file where the full type name was written to.
```
error[E0618]: expected function, found `((..., ..., ..., ...), ..., ..., ...)``
--> long.rs:7:5
|
6 | fn foo(x: D) { //~ `x` has type `(...
| - `x` has type `((..., ..., ..., ...), ..., ..., ...)`
7 | x(); //~ ERROR expected function, found `(...
| ^--
| |
| call expression requires function
|
= note: the full name for the type has been written to 'long.long-type-14182675702747116984.txt'
= note: consider using `--verbose` to print the full type name to the console
```
Follow up to and response to the comments on #136898.
r? ``@oli-obk``
Change interners to start preallocated with an increased capacity
Inspired by https://github.com/rust-lang/rust/issues/137005.
Added a `with_capacity` function to `InternedSet`. Changed the `CtxtInterners` to start with `InternedSets` preallocated with a capacity.
This *does* increase memory usage at very slightly(by ~1 MB at the start), altough that increase quickly disaperars for larger crates(since they require such capacity anyway).
A local perf run indicates this improves compiletimes for small crates(like `ripgrep`), without a negative effect on larger ones.
ssa/mono: deduplicate `type_has_metadata`
The implementation of the `type_has_metadata` function is duplicated in `rustc_codegen_ssa` and `rustc_monomorphize`, so move this to `rustc_middle`.
Make it so that every structured error annotated with `#[derive(Diagnostic)]` that has a field of type `Ty<'_>`, the printing of that value into a `String` will look at the thread-local storage `TyCtxt` in order to shorten to a length appropriate with the terminal width. When this happen, the resulting error will have a note with the file where the full type name was written to.
```
error[E0618]: expected function, found `((..., ..., ..., ...), ..., ..., ...)``
--> long.rs:7:5
|
6 | fn foo(x: D) { //~ `x` has type `(...
| - `x` has type `((..., ..., ..., ...), ..., ..., ...)`
7 | x(); //~ ERROR expected function, found `(...
| ^--
| |
| call expression requires function
|
= note: the full name for the type has been written to 'long.long-type-14182675702747116984.txt'
= note: consider using `--verbose` to print the full type name to the console
```
remove `#[rustc_intrinsic_must_be_overridde]`
In https://github.com/rust-lang/rust/pull/135031, we gained support for just leaving away the body. Now that the bootstrap compiler got bumped, stop using the old style and remove support for it.
r? `@oli-obk`
There are a few more mentions of this attribute in RA code that I didn't touch; Cc `@rust-lang/rust-analyzer`
New attribute parsing infrastructure
Another step in the plan outlined in https://github.com/rust-lang/rust/issues/131229
introduces infrastructure for structured parsers for attributes, as well as converting a couple of complex attributes to have such structured parsers.
This PR may prove too large to review. I left some of my own comments to guide it a little. Some general notes:
- The first commit is basically standalone. It just preps some mostly unrelated sources for the rest of the PR to work. It might not have enormous merit on its own, but not negative merit either. Could be merged alone, but also doesn't make the review a whole lot easier. (but it's only +274 -209)
- The second commit is the one that introduces new infrastructure. It's the important one to review.
- The 3rd commit uses the new infrastructure showing how some of the more complex attributes can be parsed using it. Theoretically can be split up, though the parsers in this commit are the ones that really test the new infrastructure and show that it all works.
- The 4th commit fixes up rustdoc and clippy. In the previous 2 they didn't compile yet while the compiler does. Separated them out to separate concerns and make the rest more palatable.
- The 5th commit blesses some test outputs. Sometimes that's just because a diagnostic happens slightly earlier than before, which I'd say is acceptable. Sometimes a diagnostic is now only emitted once where it would've been twice before (yay! fixed some bugs). One test I actually moved from crashes to fixed, because it simply doesn't crash anymore. That's why this PR Closes#132391. I think most choices I made here are generally reasonable, but let me know if you disagree anywhere.
- The 6th commit adds a derive to pretty print attributes
- The 7th removes smir apis for attributes, for the time being. The api will at some point be replaced by one based on `rustc_ast_data_structures::AttributeKind`
In general, a lot of the additions here are comments. I've found it very important to document new things in the 2nd commit well so other people can start using it.
Closes#132391Closes#136717
Greatly simplify lifetime captures in edition 2024
Remove most of the `+ Captures` and `+ '_` from the compiler, since they are now unnecessary with the new edition 2021 lifetime capture rules. Use some `+ 'tcx` and `+ 'static` rather than being overly verbose with precise capturing syntax.
Give `global_asm` a fake body to store typeck results, represent `sym fn` as a hir expr to fix `sym fn` operands with lifetimes
There are a few intertwined problems with `sym fn` operands in both inline and global asm macros.
Specifically, unlike other anon consts, they may evaluate to a type with free regions in them without actually having an item-level type annotation to give them a "proper" type. This is in contrast to named constants, which always have an item-level type annotation, or unnamed constants which are constrained by their position (e.g. a const arg in a turbofish, or a const array length).
Today, we infer the type of the operand by looking at the HIR typeck results; however, those results are region-erased, so during borrowck we ICE since we don't expect to encounter erased regions. We can't just fill this type with something like `'static`, since we may want to use real (free) regions:
```rust
fn foo<'a>() {
asm!("/* ... */", sym bar::<&'a ()>);
}
```
The first idea may be to represent `sym fn` operands using *inline* consts instead of anon consts. This makes sense, since inline consts can reference regions from the parent body (like the `'a` in the example above). However, this introduces a problem with `global_asm!`, which doesn't *have* a parent body; inline consts *must* be associated with a parent body since they are not a body owner of their own. In #116087, I attempted to fix this by using two separate `sym` operands for global and inline asm. However, this led to a lot of confusion and also some unattractive code duplication.
In this PR, I adjust the lowering of `global_asm!` so that it's lowered in a "fake" HIR body. This body contains a single expression which is `ExprKind::InlineAsm`; we don't *use* this HIR body, but it's used in typeck and borrowck so that we can properly infer and validate the the lifetimes of `sym fn` operands.
I then adjust the lowering of `sym fn` to instead be represented with a HIR expression. This is both because it's no longer necessary to represent this operand as an anon const, since it's *just* a path expression, and also more importantly to sidestep yet another ICE (https://github.com/rust-lang/rust/issues/137179), which has to do with the existing code breaking an invariant of def-id creation and anon consts. Specifically, we are not allowed to synthesize a def-id for an anon const when that anon const contains expressions with def-ids whose parent is *not* that anon const. This is somewhat related to https://github.com/rust-lang/rust/pull/130443#issuecomment-2445678945, which is also a place in the compiler where synthesizing anon consts leads to def-id parenting issue.
As a side-effect, this consolidates the type checking for inline and global asm, so it allows us to simplify `InlineAsmCtxt` a bit. It also allows us to delete a bit of hacky code from anon const `type_of` which was there to detect `sym fn` operands specifically. This also could be generalized to support `const` asm operands with types with lifetimes in them. Since we specifically reject these consts today, I'm not going to change the representation of those consts (but they'd just be turned into inline consts).
r? oli-obk -- mostly b/c you're patient and also understand the breadth of the code that this touches, please reassign if you don't want to review this.
Fixes#111709Fixes#96304Fixes#137179
Use `edition = "2024"` in the compiler (redux)
Most of this is binding mode changes, which I fixed by running `x.py fix`.
Also adds some miscellaneous `unsafe` blocks for new unsafe standard library functions (the setenv ones), and a missing `unsafe extern` block in some enzyme codegen code, and fixes some precise capturing lifetime changes (but only when they led to errors).
cc ``@ehuss`` ``@traviscross``
Prune dead regionck code
We never encounter `ObligationCauseCode`s that correspond to region obligations that originate from "within" a body, since we don't do HIR regionck anymore on bodies. So prune some dead code.
fix ICE in layout computation with unnormalizable const
The first commit reverts half of 7a667d206c, where I removed a case from `layout_of` for handling non-generic unevaluated consts in array length, that I incorrectly assumed to be unreachable. This can actually happen with the combination of `feature(generic_const_exprs)` and `feature(trivial_bounds)`, because GCE makes anon consts inherit their parent's predicates and with an impossible predicate like `u8: A` it's possible to have an array whose length is an associated const like `<u8 as A>::B` that is not generic, but also can't be normalized:
```rust
#![feature(generic_const_exprs)]
#![feature(trivial_bounds)]
trait A {
const B: usize;
}
// With GCE + trivial bounds this definition is not a compile error.
// Computing the layout of this type shouldn't ICE.
struct S([u8; <u8 as A>::B])
where
u8: A;
```
---
The first commit also incidentally fixes https://github.com/rust-lang/rust/issues/137308, which also managed to get an unnormalizable assoc const into an array length:
```rust
trait A {
const B: usize;
}
impl<C: ?Sized> A for u8 { //~ ERROR: the type parameter `C` is not constrained
const B: usize = 42;
}
// Computing the layout of this type shouldn't ICE, even with the compile error above.
struct S([u8; <u8 as A>::B]);
```
This happens, because we bail out from `codegen_select_candidate` with an error if the selected impl has unconstrained params to avoid leaking infer vars out of a query. `Instance::try_resolve` will then return `Ok(None)`, which for assoc consts roughly means "this const can't be evaluated in a generic context" and is treated as such: 71e06b9c59/compiler/rustc_middle/src/mir/interpret/queries.rs (L84) (and this can ICE if the const isn't generic: https://github.com/rust-lang/rust/issues/135617).
However, here `<u8 as A>::B` is definitely not "too generic" and also not unresolvable due to an unsatisfiable `u8: A` bound, so I've included the second commit to change the result of `Instance::try_resolve` from `Ok(None)` to `Err(ErrorGuaranteed)` when resolving an assoc item to an impl with unconstrained generic params. This has the effect that `<u8 as A>::B` will now be normalized to `ConstKind::Error` in the example above.
This properly fixes https://github.com/rust-lang/rust/issues/137308, by no longer treating `<u8 as A>::B` as unresolvable even though it clearly has a unique impl that it resolves to. It also has the effect of changing the layout error from `Unknown` ("the type may be valid but has no sensible layout") to `ReferencesError` ("a non-layout error is reported elsewhere") which seems more appropriate.
r? ```@compiler-errors```
Ignore fake borrows for packed field check
We should not emit unaligned packed field reference errors for the fake borrows that we generate during match lowering.
These fake borrows are there to ensure in *borrow-checking* that we don't modify the value being matched (which is why this only occurs when there's a match guard, in this case `if true`), but they are removed after the MIR is processed by `CleanupPostBorrowck`, since they're really just there to cause borrowck errors if necessary.
I modified `PlaceContext::is_borrow` since that's used by the packed field check:
17c1c329a5/compiler/rustc_mir_transform/src/check_packed_ref.rs (L40)
It's only used in one other place, in the SROA optimization (by which fake borrows are removed, so it doesn't matter):
17c1c329a5/compiler/rustc_mir_dataflow/src/value_analysis.rs (L922)
Fixes https://github.com/rust-lang/rust/issues/137250
Do not deduplicate list of associated types provided by dyn principal
## Background
The way that we handle a dyn trait type's projection bounds is very *structural* today. A dyn trait is represented as a list of `PolyExistentialPredicate`s, which in most cases will be a principal trait (like `Iterator`) and a list of projections (like `Item = u32`). Importantly, the list of projections comes from user-written associated type bounds on the type *and* from elaborating the projections from the principal's supertraits.
For example, given a set of traits like:
```rust
trait Foo<T> {
type Assoc;
}
trait Bar<A, B>: Foo<A, Assoc = A> + Foo<B, Assoc = B> {}
```
For the type `dyn Bar<i32, u32>`, the list of projections will be something like `[Foo<i32>::Assoc = i32, Foo<u32>::Assoc = u32]`. We deduplicate these projections when they're identical, so for `dyn Bar<(), ()>` would be something like `[Foo<()>::Assoc = ()]`.
## Shortcomings 1: inference
We face problems when we begin to mix this structural notion of projection bounds with inference and associated type normalization. For example, let's try calling a generic function that takes `dyn Bar<A, B>` with a value of type `dyn Bar<(), ()>`:
```rust
trait Foo<T> {
type Assoc;
}
trait Bar<A, B>: Foo<A, Assoc = A> + Foo<B, Assoc = B> {}
fn call_bar<A, B>(_: &dyn Bar<A, B>) {}
fn test(x: &dyn Bar<(), ()>) {
call_bar(x);
// ^ ERROR mismatched types
}
```
```
error[E0308]: mismatched types
--> /home/mgx/test.rs:10:14
|
10 | call_bar(x);
| -------- ^ expected trait `Bar<_, _>`, found trait `Bar<(), ()>`
```
What's going on here? Well, when calling `call_bar`, the generic signature `&dyn Bar<?A, ?B>` does not unify with `&dyn Bar<(), ()>` because the list of projections differ -- `[Foo<?A>::Assoc = ?A, Foo<?B>::Assoc = ?B]` vs `[Foo<()>::Assoc = ()]`.
A simple solution to this may be to unify the principal traits first, then attempt to deduplicate them after inference. In this case, if we constrain `?A = ?B = ()`, then we would be able to deduplicate those projections in the first list.
However, this idea is still pretty fragile, and it's not a complete solution.
## Shortcomings 2: normalization
Consider a slightly modified example:
```rust
//@ compile-flags: -Znext-solver
trait Mirror {
type Assoc;
}
impl<T> Mirror for T {
type Assoc = T;
}
fn call_bar(_: &dyn Bar<(), <() as Mirror>::Assoc>) {}
fn test(x: &dyn Bar<(), ()>) {
call_bar(x);
}
```
This fails in the new solver. In this example, we try to unify `dyn Bar<(), ()>` and `dyn Bar<(), <() as Mirror>::Assoc>`. We are faced with the same problem even though there are no inference variables, and making this work relies on eagerly and deeply normalizing all projections so that they can be structurally deduplicated.
This is incompatible with how we handle associated types in the new trait solver, and while we could perhaps support it with some major gymnastics in the new solver, it suggests more fundamental shortcomings with how we deal with projection bounds in the new solver.
## Shortcomings 3: redundant projections
Consider a final example:
```rust
trait Foo {
type Assoc;
}
trait Bar: Foo<Assoc = ()> {}
fn call_bar1(_: &dyn Bar) {}
fn call_bar2(_: &dyn Bar<Assoc = ()>) {}
fn main() {
let x: &dyn Bar<Assoc = _> = todo!();
call_bar1(x);
//~^ ERROR mismatched types
call_bar2(x);
//~^ ERROR mismatched types
}
```
In this case, we have a user-written associated type bound (`Assoc = _`) which overlaps the bound that comes from the supertrait projection of `Bar` (namely, `Foo<Assoc = ()>`). In a similar way to the two examples above, this causes us to have a projection list mismatch that the compiler is not able to deduplicate.
## Solution
### Do not deduplicate after elaborating projections when lowering `dyn` types
The root cause of this issue has to do with mismatches of the deduplicated projection list before and after substitution or inference. This PR aims to avoid these issues by *never* deduplicating the projection list after elaborating the list of projections from the *identity* substituted principal trait ref.
For example,
```rust
trait Foo<T> {
type Assoc;
}
trait Bar<A, B>: Foo<A, Assoc = A> + Foo<B, Assoc = B> {}
```
When computing the projections for `dyn Bar<(), ()>`, before this PR we'd elaborate `Bar<(), ()>` to find a (deduplicated) projection list of `[Foo<()>::Assoc = ()]`.
After this PR, we take the principal trait and use its *identity* substitutions `Bar<A, B>` during elaboration, giving us projections `[Foo<A>::Assoc = A, Foo<B>::Assoc = B]`. Only after this elaboration do we substitute `A = (), B = ()` to get `[Foo<()>::Assoc = (), Foo<()>::Assoc = ()]`. This allows the type to be unified with the projections for `dyn Bar<?A, ?B>`, which are `[Foo<?A>::Assoc = ?A, Foo<?B>::Assoc = ?B]`.
This helps us avoid shorcomings 1 noted above.
### Do not deduplicate projections when relating `dyn` types
Similarly, we also do not call deduplicate when relating dyn types. This means that the list of projections does not differ depending on if the type has been normalized or not, which should avoid shortcomings 2 noted above.
Following from the example above, when relating projection lists like `[Foo<()>::Assoc = (), Foo<()>::Assoc = ()]` and `[Foo<?A>::Assoc = ?A, Foo<?B>::Assoc = ?B]`, the latter won't be deduplicated to a list of length 1 which would immediately fail to relate to the latter which is a list of length 2.
### Implement proper precedence between supertrait and user-written projection bounds when lowering `dyn` types
```rust
trait Foo {
type Assoc;
}
trait Bar: Foo<Assoc = ()> {}
```
Given a type like `dyn Foo<Assoc = _>`, we used to previously include *both* the supertrait and user-written associated type bounds in the projection list, giving us `[Foo::Assoc = (), Foo::Assoc = _]`. This would never unify with `dyn Foo`. However, this PR implements a strategy which overwrites the supertrait associated type bound with the one provided by the user, giving us a projection list of `[Foo::Assoc = _]`.
Why is this OK? Well, if a user wrote an associated type bound that is unsatisfiable (e.g. `dyn Bar<Assoc = i32>`) then the dyn type would never implement `Bar` or `Foo` anyways. If the user wrote something that is either structurally equal or equal modulo normalization to the supertrait bound, then it should be unaffected. And if the user wrote something that needs inference guidance (e.g. `dyn Bar<Assoc = _>`), then it'll be constrained when proving `dyn Bar<Assoc = _>: Bar`.
Importantly, this differs from the strategy in https://github.com/rust-lang/rust/pull/133397, which preferred the *supertrait* bound and ignored the user-written bound. While that's also theoretically justifiable in its own way, it does lead to code which does not (and probably should not) compile either today or after this PR, like:
```rust
trait IteratorOfUnit: Iterator<Item = ()> {}
impl<T> IteratorOfUnit for T where T: Iterator<Item = ()> {}
fn main() {
let iter = [()].into_iter();
let iter: &dyn IteratorOfUnit<Item = i32> = &iter;
}
```
### Conclusion
This is a far less invasive change compared to #133397, and doesn't necessarily necessitate the addition of new lints or any breakage of existing code. While we could (and possibly should) eventually introduce lints to warn users of redundant or mismatched associated type bounds, we don't *need* to do so as part of fixing this unsoundness, which leads me to believe this is a much safer solution.
