Consider `()` within types to be FFI-safe, and `()` to be FFI-safe as a
return type (incl. when in a transparent newtype).
Signed-off-by: David Wood <david@davidtw.co>
`()` is normally FFI-unsafe, but is FFI-safe when used as a return type.
It is also desirable that a transparent newtype for `()` is FFI-safe when
used as a return type.
In order to support this, when an type was deemed FFI-unsafe, because of
a `()` type, and was used in return type - then the type was considered
FFI-safe. However, this was the wrong approach - it didn't check that the
`()` was part of a transparent newtype! The consequence of this is that
the presence of a `()` type in a more complex return type would make it
the entire type be considered safe (as long as the `()` type was the
first that the lint found) - which is obviously incorrect.
Instead, this logic is removed, and a unit return type or a transparent
wrapper around a unit is checked for directly for functions and fn-ptrs.
Signed-off-by: David Wood <david@davidtw.co>
Better diagnostics for dlltool errors.
When dlltool fails, show the full command that was executed. In particular, llvm-dlltool is not very helpful, printing a generic usage message rather than what actually went wrong, so stdout and stderr aren't of much use when troubleshooting.
allow opaques to be defined by trait queries, again
This basically reverts #112963.
Moreover, all call-sites of `enter_canonical_trait_query` can now define opaque types, see the ui test `defined-by-user-annotation.rs`.
Fixes#113689
r? `@compiler-errors` `@oli-obk`
Restrict recursive opaque type check
We have a recursive opaque check in writeback to avoid inferring the hidden of an opaque type to be itself:
33a2c2487a/compiler/rustc_hir_typeck/src/writeback.rs (L556-L575)
Issue #113619 treats `make_option2` as not defining the TAIT `TestImpl` since it is inferred to have the definition `TestImpl := B<TestImpl>`, which fails this check. This regressed in #102700 (5d15beb591), I think due to the refactoring that made us record the hidden types of TAITs during writeback.
However, nothing actually seems to go bad if we relax this recursion checker to only check for directly recursive definitions. This PR fixes#113619 by changing this recursive check from being a visitor to just checking that the hidden type is exactly the same as the opaque being inferred.
Alternatively, we may be able to fix#113619 by restricting this recursion check only to RPITs/async fns. It seems to only be possible to use misuse the recursion check to cause ICEs for TAITs (though I didn't try too hard to create a bad RPIT example... may be possible, actually.)
r? `@oli-obk`
--
Fixes#113314
Fix removal span calculation of `unused_qualifications` suggestion
Given a path such as `std::ops::Index<str>`, calculate the unnecessary qualification removal span by computing the beginning of the entire span until the ident span of the last path segment, which handles generic arguments and lifetime arguments in the last path segment. Previous logic only kept the ident span of the last path segment which is incorrect.
Closes#113808.
Safe Transmute: Fix ICE (due to UnevaluatedConst)
This patch updates the code that looks at the `Assume` type when evaluating if transmutation is possible. An ICE was being triggered in the case that the `Assume` parameter contained an unevaluated const (in this test case, due to a function with missing parameter names).
Fixes#110892
When dlltool fails, show the full command that was executed. In
particular, llvm-dlltool is not very helpful, printing a generic usage
message rather than what actually went wrong, so stdout and stderr
aren't of much use when troubleshooting.
miri: fail when calling a function that requires an unavailable target feature
miri will report an UB when calling a function that has a `#[target_feature(enable = ...)]` attribute is called and the required feature is not available.
"Available features" are the same that `is_x86_feature_detected!` (or equivalent) reports to be available during miri execution (which can be enabled or disabled with the `-C target-feature` flag).
This patch updates the code that looks at the `Assume` type when evaluating if
transmutation is possible. An ICE was being triggered in the case that the
`Assume` parameter contained an unevaluated const (in this test case, due to a
function with missing parameter names).
Fixes#110892
Generate safe stable code for derives on empty enums
Generate `match *self {}` instead of `unsafe { core::intrinsics::unreachable() }`.
This is:
1. safe
2. stable
for the benefit of everyone looking at these derived impls through `cargo expand`.
[Both expansions compile to the same code at all optimization levels (including `0`).](https://rust.godbolt.org/z/P79joGMh3)
Add support for inherent projections in new solver
Not hard to support these, and it cuts out a really big chunk of failing UI tests with `--compare-mode=next-solver`
r? `@lcnr` (feel free to reassign, anyone can review this)
Generate `match *self {}` instead of `unsafe { core::intrinsics::unreachable() }`.
This is:
1. safe
2. stable
for the benefit of everyone looking at these derived impls through `cargo expand`.
Both expansions compile to the same code at all optimization levels (including `0`).
Don't call `predicate_must_hold`-esque functions during fulfillment in intercrate
Fixes#113415
Given that this only happens in `translate_substs`, I don't actually think that this is something that you can weaponize, but it's still sketchy regardless.
r? `@lcnr`
Check entry type as part of item type checking.
This code is currently executed inside the root `analysis` query.
Instead, check it during `check_for_entry_fn(CRATE_DEF_ID)` to hopefully avoid some re-executions.
`CRATE_DEF_ID` is chosen by considering that entry fn are typically at crate root, so the corresponding HIR should already be in the dependencies.
Add `#[rustc_confusables]` attribute to allow targeted "no method" error suggestions on standard library types
After this PR, the standard library developer can annotate methods on e.g. `BTreeSet::push` with `#[rustc_confusables("insert")]`. When the user mistypes `btreeset.push()`, `BTreeSet::insert` will be suggested if there are no other candidates to suggest. This PR lays the foundations for contributors to add `rustc_confusables` annotations to standard library types for targeted suggestions, as specified in #59450, or to address cases such as #108437.
### Example
Assume `BTreeSet` is the standard library type:
```
// Standard library definition
#![feature(rustc_attrs)]
struct BTreeSet;
impl BTreeSet {
#[rustc_confusables("push")]
fn insert(&self) {}
}
// User code
fn main() {
let x = BTreeSet {};
x.push();
}
```
A new suggestion (which has lower precedence than suggestions for misspellings and only is shown when there are no misspellings suggestions) will be added to hint the user maybe they intended to write `x.insert()` instead:
```
error[E0599]: no method named `push` found for struct `BTreeSet` in the current scope
--> test.rs:12:7
|
3 | struct BTreeSet;
| --------------- method `push` not found for this struct
...
12 | x.push();
| ^^^^ method not found in `BTreeSet`
|
help: you might have meant to use `insert`
|
12 | x.insert();
| ~~~~~~
error: aborting due to previous error
```
Hide `compiler_builtins` in the prelude
This crate is a private implementation detail. We only need to insert it into the crate graph for linking and should not expose any of its public API.
Fixes#113533
"no method" errors on standard library types
The standard library developer can annotate methods on e.g.
`BTreeSet::push` with `#[rustc_confusables("insert")]`. When the user
mistypes `btreeset.push()`, `BTreeSet::insert` will be suggested if
there are no other candidates to suggest.
Implement "items do not inherit unsafety" note for THIR unsafeck
Implements the "items do not inherit unsafety from separate enclosing items" note from the MIR unsafety checker in the THIR unsafety checker (`-Z thir-unsafeck`) to maintain parity between the two unsafety checkers. The logic to find the separate enclosing item is nearly the same as in the MIR unsafety checker.
Structurally normalize in selection
We need to do this because of the fact that we're checking the `Ty::kind` on a type during selection, but goals passed into select are not necessarily normalized.
Right now, we're (kinda) unnecessarily normalizing the RHS of a trait upcasting goal, which is broken for different reasons (#113393). But I'm waiting for this PR to land before discussing that one.
r? `@lcnr`
Resurrect: rustc_target: Add alignment to indirectly-passed by-value types, correcting the alignment of byval on x86 in the process.
Same as #111551, which I [accidentally closed](https://github.com/rust-lang/rust/pull/111551#issuecomment-1571222612) :/
---
This resurrects PR #103830, which has sat idle for a while.
Beyond #103830, this also:
- fixes byval alignment for types containing vectors on Darwin (see `tests/codegen/align-byval-vector.rs`)
- fixes byval alignment for overaligned types on x86 Windows (see `tests/codegen/align-byval.rs`)
- fixes ABI for types with 128bit requested alignment on ARM64 Linux (see `tests/codegen/aarch64-struct-align-128.rs`)
r? `@nikic`
---
`@pcwalton's` original PR description is reproduced below:
Commit 88e4d2c from five years ago removed
support for alignment on indirectly-passed arguments because of problems with
the `i686-pc-windows-msvc` target. Unfortunately, the `memcpy` optimizations I
recently added to LLVM 16 depend on this to forward `memcpy`s. This commit
attempts to fix the problems with `byval` parameters on that target and now
correctly adds the `align` attribute.
The problem is summarized in [this comment] by `@eddyb.` Briefly, 32-bit x86 has
special alignment rules for `byval` parameters: for the most part, their
alignment is forced to 4. This is not well-documented anywhere but in the Clang
source. I looked at the logic in Clang `TargetInfo.cpp` and tried to replicate
it here. The relevant methods in that file are
`X86_32ABIInfo::getIndirectResult()` and
`X86_32ABIInfo::getTypeStackAlignInBytes()`. The `align` parameter attribute
for `byval` parameters in LLVM must match the platform ABI, or miscompilations
will occur. Note that this doesn't use the approach suggested by eddyb, because
I felt it was overkill to store the alignment in `on_stack` when special
handling is really only needed for 32-bit x86.
As a side effect, this should fix#80127, because it will make the `align`
parameter attribute for `byval` parameters match the platform ABI on LLVM
x86-64.
[this comment]: #80822 (comment)
Allow escaping bound vars during `normalize_erasing_regions` in new solver
Add `AllowEscapingBoundVars` to `deeply_normalize`, and use it in the new solver in the `query_normalize` routine.
Ideally, we'd make all `query_normalize` calls handle pass in `AllowEscapingBoundVars` individually, because really the only `query_normalize` call that needs `AllowEscapingBoundVars::Yes` is the one in `try_normalize_generic_arg_after_erasing_regions`, but I think that's kind of overkill. I am happy to be convinced otherwise, though.
r? `@lcnr`
Use maybe_body_owned_by for multiple suggestions
This is a continued work from https://github.com/rust-lang/rust/pull/113567
We have several other suggestions not working for closure, this PR use `maybe_body_owned_by` to fix them and add test cases for them.
This crate is a private implementation detail. We only need to insert it
into the crate graph for linking and should not expose any of its public
API.
Fixes#113533
Eliminate ZST allocations in `Box` and `Vec`
This PR fixes 2 issues with `Box` and `RawVec` related to ZST allocations. Specifically, the `Allocator` trait requires that:
- If you allocate a zero-sized layout then you must later deallocate it, otherwise the allocator may leak memory.
- You cannot pass a ZST pointer to the allocator that you haven't previously allocated.
These restrictions exist because an allocator implementation is allowed to allocate non-zero amounts of memory for a zero-sized allocation. For example, `malloc` in libc does this.
Currently, ZSTs are handled differently in `Box` and `Vec`:
- `Vec` never allocates when `T` is a ZST or if the vector capacity is 0.
- `Box` just blindly passes everything on to the allocator, including ZSTs.
This causes problems due to the free conversions between `Box<[T]>` and `Vec<T>`, specifically that ZST allocations could get leaked or a dangling pointer could be passed to `deallocate`.
This PR fixes this by changing `Box` to not allocate for zero-sized values and slices. It also fixes a bug in `RawVec::shrink` where shrinking to a size of zero did not actually free the backing memory.
Implement selection for `Unsize` for better coercion behavior
In order for much of coercion to succeed, we need to be able to deal with partial ambiguity of `Unsize` traits during selection. However, I pessimistically implemented selection in the new trait solver to just bail out with ambiguity if it was a built-in impl:
9227ff28af/compiler/rustc_trait_selection/src/solve/eval_ctxt/select.rs (L126)
This implements a proper "rematch" procedure for dealing with built-in `Unsize` goals, so that even if the goal is ambiguous, we are able to get nested obligations which are used in the coercion selection-like loop:
9227ff28af/compiler/rustc_hir_typeck/src/coercion.rs (L702)
Second commit just moves a `resolve_vars_if_possible` call to fix a bug where we weren't detecting a trait upcasting to occur.
r? ``@lcnr``
(re-)tighten sourceinfo span of adjustments in MIR
Diagnostics rely on the spans of MIR statements being (approximately) correct in order to give suggestions relative to that span (i.e. `shrink_to_hi` and `shrink_to_lo`).
I discovered that we're *intentionally* lowering THIR exprs with their parent expr's span if they come from adjustments that are due to a parent expression. While I understand why that may be desirable to demonstrate the relationship of an adjustment and the expression that requires it, it leads to
1. very verbose borrowck output
2. incorrect spans for suggestions
Some diagnostics get around that by giving suggestions relative to other spans we've collected during MIR lowering, such as the span of the method's identifier (e.g. `name` in `.name()`), but this doesn't work too well when things come from desugaring.
I assume it also has lead to numerous tweaks and complications to diagnostics code down the road, which this PR doesn't necessarily aim to fix but may open the gates to fixing later... The last three commits are simplifications due to the fact that we can assume that the move span actually points to what is being moved (and a test).
This regressed in #89110, which was debated somewhat in #90286. cc `@Aaron1011` who originally made this change.
r? diagnostics
Fixes#113547Fixes#111016
Rollup of 4 pull requests
Successful merges:
- #112717 (Implement a few more rvalue translation to smir)
- #113310 (Don't suggest `impl Trait` in path position)
- #113497 (Support explicit 32-bit MIPS ABI for the synthetic object)
- #113560 (Lint against misplaced where-clauses on associated types in traits)
r? `@ghost`
`@rustbot` modify labels: rollup
Lint against misplaced where-clauses on associated types in traits
Extends the scope of the lint `deprecated_where_clause_location` (#89122) from associated types in impls to associated types in any location (impl or trait). This is only relevant for `#![feature(associated_type_defaults)]`. Previously we didn't warn on the following code for example:
```rs
#![feature(associated_type_defaults)]
trait Trait { type Assoc where u32: Copy = (); }
```
Personally I would've preferred to emit a *hard* error here instead of a lint warning since the feature is unstable but unfortunately we are constrained by back compat as associated type defaults won't necessarily trigger the feature-gate error if they are inside of a macro call (since they use a post-expansion feature-gate due to historical reasons, see also #66004).
I've renamed and moved related preexisting tests: 1. They test AST validation passes not the parser & thus shouldn't live in `parser/` (historical reasons?). 2. One test file was named after type aliases even though it tests assoc tys.
`@rustbot` label A-lint
Structurally resolve in pattern matching when peeling refs in new solver
Let me know if you want me to commit the minimized test:
```rust
fn test() {}
fn test2() {}
fn main() {
let tests: &[(_, fn())] = &[
("test", test),
("test2", test2),
];
for (a, b) in tests {
todo!();
}
}
```
In that test above, the match scrutinee is `<std::vec::Iter<(&'static str, fn())> as Iterator>::Item`, which we cannot peel the refs from.
We also need to structurally resolve in the loop, since structural resolve is inherently shallow. I haven't come up with a test where this matters, but I can if you care.
Also, I removed two other calls to `resolve_vars_with_obligations` in diagnostics code that I'm pretty convinced are not useful.
r? `@lcnr`
Enable coinduction support for Safe Transmute
This patch adds the `#[rustc_coinductive]` annotation to `BikeshedIntrinsicFrom`, so that it's possible to compute transmutability for recursive types.
## Motivation
Safe Transmute currently already supports references (#110662). However, if a type is implemented recursively, it leads to an infinite loop when we try to check if transmutation is safe.
A couple simple examples that one might want to write, that are currently not possible to check transmutability for:
```rs
#[repr(C)] struct A(&'static B);
#[repr(C)] struct B(&'static A);
```
```rs
#[repr(C)]
enum IList<'a> { Nil, Cons(isize, &'a IList<'a>) }
#[repr(C)]
enum UList<'a> { Nil, Cons(usize, &'a UList<'a>) }
```
Previously, `@jswrenn` was considering writing a co-inductive solver from scratch, just for the `rustc_tranmsute` crate. Later on as I started working on Safe Transmute myself, I came across the `#[rustc_coinductive]` annotation, which is currently only being used for the `Sized` trait. Leveraging this trait actually solved the problem entirely, and it saves a lot of duplicate work that would have had to happen in `rustc_transmute`.
Uplift `clippy::fn_null_check` lint
This PR aims at uplifting the `clippy::fn_null_check` lint into rustc.
## `incorrect_fn_null_checks`
(warn-by-default)
The `incorrect_fn_null_checks` lint checks for expression that checks if a function pointer is null.
### Example
```rust
let fn_ptr: fn() = /* somehow obtained nullable function pointer */
if (fn_ptr as *const ()).is_null() { /* ... */ }
```
### Explanation
Function pointers are assumed to be non-null, checking for their nullity is incorrect.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
Replace RPITIT current impl with new strategy that lowers as a GAT
This PR replaces the current implementation of RPITITs with the new implementation that we had under -Zlower-impl-trait-in-trait-to-assoc-ty flag that lowers the RPIT as a GAT on the trait and on the impls that implement that trait.
Opening this PR as a draft because this goes after #112682, ~#112981~ and ~#112983~.
As soon as those are merged, I can rebase and we should run perf, crater and test a lot.
r? `@compiler-errors`
Add filter with following segment while lookup typo for path
From the discussion: https://github.com/rust-lang/rust/pull/112917#discussion_r1239150173
Seems we can not get the assoc items for `Struct`, `Enum` in the resolving phase.
A obvious filter is avoid suggesting the same name with the following segment path.
Use `following_seg` can extend the function `smart_resolve_partial_mod_path_errors` for more scenarios, such as `std::sync_error::atomic::AtomicBool` in test case.
r? `@estebank`
Don't call `query_normalize` when reporting similar impls
Firstly, It's sketchy to be using `query_normalize` at all during HIR typeck -- it's asking for an ICE 😅. Secondly, we're normalizing an impl trait ref that potentially has parameter types in `ty::ParamEnv::empty()`, which is kinda sketchy as well.
The only UI test change from removing this normalization is that we don't evaluate anonymous constants in impls, which end up giving us really ugly suggestions:
```
error[E0277]: the trait bound `[X; 35]: Default` is not satisfied
--> /home/gh-compiler-errors/test.rs:4:5
|
4 | <[X; 35] as Default>::default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `[X; 35]`
|
= help: the following other types implement trait `Default`:
&[T]
&mut [T]
[T; 32]
[T; core::::array::{impl#30}::{constant#0}]
[T; core::::array::{impl#31}::{constant#0}]
[T; core::::array::{impl#32}::{constant#0}]
[T; core::::array::{impl#33}::{constant#0}]
[T; core::::array::{impl#34}::{constant#0}]
and 27 others
```
So just fold the impls with a `BottomUpFolder` that calls `ty::Const::eval`. This doesn't work totally correctly with generic-const-exprs, but it's fine for stable code, and this is error reporting after all.
Structurally normalize again for byte string lit pat checking
We need to structurally normalize the pointee of a match scrutinee when trying to match byte string patterns -- we used[^1] to call `structurally_resolve_type`, which errors for type vars[^2], but lcnr added `try_structurally_resolve_type`[^3] in the mean time, which is the right thing to use here since it's totally opportunistic.
Fixes rust-lang/trait-system-refactor-initiative#38
[^1]: #112428
[^2]: #112993
[^3]: #113086
Reveal opaques in new solver
We were testing against the wrong reveal mode 😨
Also a couple of misc commits that I don't want to really put in separate prs
r? ``@lcnr``
tests: unset `RUSTC_LOG_COLOR` in a test
Setting `RUSTC_LOG_COLOR=always` is sometimes useful if tools that one pipes `RUSTC_LOG` into support coloured output, but it makes this test fail because it has a `.stderr` file with `WARN` log output.
Rollup of 8 pull requests
Successful merges:
- #113413 (Add needs-triage to all new issues)
- #113426 (Don't ICE in `resolve_bound_vars` when associated return-type bounds are in bad positions)
- #113427 (Remove `variances_of` on RPITIT GATs, remove its one use-case)
- #113441 (miri: check that assignments do not self-overlap)
- #113453 (Remove unused from_method from rustc_on_unimplemented)
- #113456 (Avoid calling report_forbidden_specialization for RPITITs)
- #113466 (Update cargo)
- #113467 (Fix comment of `fn_can_unwind`)
r? `@ghost`
`@rustbot` modify labels: rollup
Remove unused from_method from rustc_on_unimplemented
Fixes#113439
`on_unimplemented_note` was calling `item_name` for RPITITs and that produced ICEs. I've added a regression test for that but also have removed `from_method` symbol entirely because it wasn't even used and by doing that the `item_name` call was also removed.
r? ``@compiler-errors``
Do not assert >1 RPITITs on collect_return_position_impl_trait_in_trait_tys
Fixes#113403
Assert on collect_return_position_impl_trait_in_trait_tys is not correct when we call it from type_of(GAT). The included test is an example of a situation that collector collects 0 types.
r? `@compiler-errors`
Prefer object candidates in new selection
`dyn Any` shouldn't be using [this implementation](https://doc.rust-lang.org/std/any/trait.Any.html#impl-Any-for-T) during codegen.
Prefer object candidates over other candidates, except for other object candidates.
Revert "alloc: Allow comparing Boxs over different allocators", add regression test
Temporary fix for #113283
Adds a test to fix the regression introduced in 001b081cc1 and revert that commit. The test fails without the revert.
Dont ICE for `dyn* Trait: Trait` (built-in object) goals during selection in new trait solver
We were ICEing too eagerly during selection for `dyn*` goals -- both for dyn unsizing candidates and for built-in object candidates. The former should only be performed on `dyn` objects, but the latter are totally fine.
Revert the lexing of `c"…"` string literals
Fixes \[after beta-backport\] #113235.
Further progress is tracked in #113333.
This PR *manually* reverts parts of #108801 (since a git-revert would've been too coarse-grained & messy)
and git-reverts #111647.
CC `@fee1-dead` (#108801) `@klensy` (#111647)
r? `@compiler-errors`
`@rustbot` label F-c_str_literals beta-nominated
Rollup of 8 pull requests
Successful merges:
- #113010 (rust-installer & rls: remove exclusion from rustfmt & tidy )
- #113317 ( -Ztrait-solver=next: stop depending on old solver)
- #113319 (`TypeParameterDefinition` always require a `DefId`)
- #113320 (Add some extra information to opaque type cycle errors)
- #113321 (Move `ty::ConstKind` to `rustc_type_ir`)
- #113337 (Winnow specialized impls during selection in new solver)
- #113355 (Move most coverage code out of `rustc_codegen_ssa`)
- #113356 (Add support for NetBSD/riscv64 aka. riscv64gc-unknown-netbsd.)
r? `@ghost`
`@rustbot` modify labels: rollup
Winnow specialized impls during selection in new solver
We need to be able to winnow impls that are specialized by more specific impls in order for codegen to be able to proceed.
r? ``@lcnr``
Add some extra information to opaque type cycle errors
Plus a bunch of cleanups.
This should help users debug query cycles due to auto trait checking. We'll probably want to fix cycle errors in most (or all?) cases by looking at the current item's hidden types (new solver does this), and by delaying the auto trait checks to after typeck.
Effects/keyword generics MVP
This adds `feature(effects)`, which adds `const host: bool` to the generics of const functions, const traits and const impls. This will be used to replace the current logic around const traits.
r? `@oli-obk`
implement `ConstEvaluatable` goals in new solver
this only supports stable const generics. `feature(generic_const_exprs)` needs to extend that function is non-trivial ways. Leaving this for someone else or some later date.
r? `@BoxyUwU`
Remove chalk support from the compiler
Removes chalk (`-Ztrait-solver=chalk`) from the compiler and prunes any dead code resulting from this, mainly:
* Remove the chalk compatibility layer in `compiler/rustc_traits/src/chalk`
* Remove the chalk flag `-Ztrait-solver=chalk` and its `TraitEngine` implementation
* Remove `TypeWellFormedFromEnv` (and its many `bug!()` match arms)
* Remove the chalk migration mode from compiletest
* Remove the `chalkify` UI tests (do we want to keep any of these, but migrate them to `-Ztrait-solver=next`??)
Fulfills rust-lang/types-team#93.
r? `@jackh726`
Verify that `PartialEq` implementations do not break type inference
when comparing types across different allocators. This catches a
regression in current nightly introduced in 001b081cc1 (alloc: Allow
comparing `Box`s over different allocators")
`Box` is the only type that currently impelements this, but tests are
included for `Rc` and `Arc` to prevent future regresssions.
Make RPITITs assume/require their parent method's predicates
Removes a FIXME from the `param_env` query where we were manually adding the parent function's predicates to the RPITIT's assumptions.
r? `@spastorino`
lint/ctypes: ext. abi fn-ptr in internal abi fn
Fixes#94223.
- In the improper ctypes lint, instead of skipping functions with internal ABIs, check that the signature doesn't contain any fn-ptr types with external ABIs that aren't FFI-safe.
- When computing the ABI for fn-ptr types, remove an `unwrap` that assumed FFI-safe types in foreign fn-ptr types.
- I'm not certain that this is the correct approach.
Extend previous checks for external ABI fn-ptrs to use in internal
statics, constants, type aliases and algebraic data types.
Signed-off-by: David Wood <david.wood@huawei.com>
Extend previous commit's support for checking for external fn-ptrs in
internal fn types to report errors for multiple found fn-ptrs.
Signed-off-by: David Wood <david.wood@huawei.com>
Instead of skipping functions with internal ABIs, check that the
signature doesn't contain any fn-ptr types with external ABIs that
aren't FFI-safe.
Signed-off-by: David Wood <david.wood@huawei.com>
Fix `dropping_copy_types` lint from linting in match-arm with side-effects
This PR fixes an issue with the `dropping_copy_types` and `dropping_references` lints when not all patterns that can have side-effects were detected and ignored.
Nearly _fixes_ https://github.com/rust-lang/rust/issues/112653 (will need beta-backport to completely fix the issue)
r? ``@Nilstrieb``
Implement most of MCP510
This implements most of what remains to be done for MCP510:
- turns `-C link-self-contained` into a `+`/`-` list of components, like `-C link-self-contained=+linker,+crto,+libc,+unwind,+sanitizers,+mingw`. The scaffolding is present for all these expected components to be implemented and stabilized in the future on their own time. This PR only handles the `-Zgcc-ld=lld` subset of these link-self-contained components as `-Clink-self-contained=+linker`
- handles `-C link-self-contained=y|n` as-is today, for compatibility with `rustc_codegen_ssa:🔙🔗:self_contained`'s [explicit opt-in and opt-out](9eee230cd0/compiler/rustc_codegen_ssa/src/back/link.rs (L1671-L1676)).
- therefore supports our plan to opt out of `rust-lld` (when it's enabled by default) even for current `-Clink-self-contained` users, with e.g. `-Clink-self-contained -Clink-self-contained=-linker`
- turns `add_gcc_ld_path` into its expected final form, by using the `-C link-self-contained=+linker` CLI flag, and whether the `LinkerFlavor` has the expected `Cc::Yes` and `Lld::Yes` shape (this is not yet the case in practice for any CLI linker flavor)
- makes the [new clean linker flavors](https://github.com/rust-lang/rust/pull/96827#issuecomment-1208441595) selectable in the CLI in addition to the legacy ones, in order to opt-in to using `cc` and `lld` to emulate `-Zgcc-ld=lld`
- ensure the new `-C link-self-contained` components, and `-C linker-flavor`s are unstable, and require `-Z unstable-options` to be used
The up-to-date set of flags for the future stable CLI version of `-Zgcc-ld=lld` is currently: `-Clink-self-contained=+linker -Clinker-flavor=gnu-lld-cc -Zunstable-options`.
It's possible we'll also need to do something for distros that don't ship `rust-lld`, but maybe there are already no tool search paths to be added to `cc` in this situation anyways.
r? `@petrochenkov`
Error when RPITITs' hidden types capture more lifetimes than their trait definitions
This implements a stricter set of captures rules for RPITITs. They now may only capture:
1. Lifetimes from the impl header (both the self type and any trait substs -- we may want to restrict just to the self type's lifetimes, but the PR makes that easy to do, too)
2. Lifetimes mentioned by the `impl Trait` in the trait method's definition.
Namely, they may not mention lifetimes from the method (early or late) that are not mentioned in the `impl Trait`.
cc #105258 which I think was trying to do this too, though I'm not super familiar with what exactly differs from that or why that one was broken.
cc #112194 (doesn't fix this issue per se, because it's still an open question, but I think this is objectively better than the status quo, and gets us closer to resolving that issue.)
Technically is a fix for the ICE in #108580, but it turns that issue into an error now. We can decide separately whether or not nested RPITITs should capture lifetimes from their parents.
r? ``@oli-obk``
fix(resolve): skip assertion judgment when NonModule is dummy
Fixes#85992
## Why #85992 panic
During `resolve_imports`, the `path_res` of the import `issue_85992_extern_2::Outcome` is pointing to `external::issue_85992_extern_2` instead of `crate::issue_85992_extern_2`. As a result `import.imported_module.set` had been executed.
Attached 1: the state of `early_resolve_ident_in_lexical_scope` during the `resolve_imports` for `use issue_85992_extern_2::Outcome` is as follows:
|iter in `visit_scopes` | `scope` | `result.binding` |
| - | - | - |
| init | - | - |
| 0 | `CrateRoot` | Err(Determined) |
| 1 | `ExternPrelude` | pointing to the `issue_85992_extern_2`(external) |
However, during finalization for `issue_85992_extern_2::Outcome`, the `innermost_result` was pointed to `crate::issue_85992_extern_2` and no ambiguity was generated, leading to a panic.
Attached 2: the state of `early_resolve_ident_in_lexical_scope` during the `finalize_import` for `use issue_85992_extern_2::Outcome` is as follows:
|iter in `visit_scopes` | `scope` | `result.binding` | `innermost_result` |
| - | - | - | - |
| init | - | - | `None` |
| 0 | `CrateRoot` | pointing to `use crate::issue_85992_extern_2` **(introdcued by dummy)** | same as `result` but with a `Some` wapper|
| 1 | `ExternPrelude` | pointing to the `issue_85992_extern_2`(external) | smae as above |
## Try to solve
Skip assertion judgment when `NonModule` is dummy
r? `@petrochenkov`
Test benchmarks with `-Z panic-abort-tests`
During test execution, when a `#[bench]` benchmark is encountered it's executed once to check whether it works. Unfortunately that was not compatible with `-Z panic-abort-tests`: the feature works by spawning a subprocess for each test, which prevents the use of dynamic tests as we cannot pass closures to child processes, and before this PR the conversion from benchmark to test was done by turning benchmarks into dynamic tests whose closures execute the benchmark once.
The approach this PR took was to add two new kinds of `TestFn`s: `StaticBenchAsTestFn` and `DynBenchAsTestFn` (⚠️ **this is a breaking change** ⚠️). With that change, a `StaticBenchFn` can be converted into a `StaticBenchAsTestFn` without creating dynamic tests, and making it possible to test `#[bench]` functions with `-Z panic-abort-tests`. The subprocess test runner also had to be updated to perform the conversion from benchmark to test when appropriate.
Along with the bug fix, in the first commit I refactored how tests are executed: rather than executing the test function in multiple places across `libtest`, there is now a private `TestFn::into_runnable()` method, which returns either a `RunnableTest` or `RunnableBench`, on which you can call the `run()` method. This simplified the rest of the changes in the PR.
This PR is best reviewed commit-by-commit.
Fixes https://github.com/rust-lang/rust/issues/73509
Use structured suggestion when telling user about `for<'a>`
```
error[E0637]: `&` without an explicit lifetime name cannot be used here
--> $DIR/E0637.rs:13:13
|
LL | T: Into<&u32>,
| ^ explicit lifetime name needed here
|
help: consider introducing a higher-ranked lifetime here
|
LL | T: for<'a> Into<&'a u32>,
| +++++++ ++
```
Encode item bounds for `DefKind::ImplTraitPlaceholder`
This was lost in a refactoring -- `hir::ItemKind::OpaqueTy` doesn't always map to `DefKind::Opaque`, specifically for RPITITs, so the check was migrated subtly wrong, and unfortunately I never had a test for this 🙃Fixes#113155
r? ``@cjgillot``
Account for late-bound vars from parent arg-position impl trait
We should be reporting an error like we do for late-bound args coming from a parent APIT.
Fixes#113016
suggest `slice::swap` for `mem::swap(&mut x[0], &mut x[1])` borrowck error
Recently saw someone ask why this code (example slightly modified):
```rs
fn main() {
let mut foo = [1, 2];
std::mem::swap(&mut foo[0], &mut foo[1]);
}
```
triggers this error and how to fix it:
```
error[E0499]: cannot borrow `foo[_]` as mutable more than once at a time
--> src/main.rs:4:33
|
4 | std::mem::swap(&mut foo[0], &mut foo[1]);
| -------------- ----------- ^^^^^^^^^^^ second mutable borrow occurs here
| | |
| | first mutable borrow occurs here
| first borrow later used by call
|
= help: consider using `.split_at_mut(position)` or similar method to obtain two mutable non-overlapping sub-slices
```
The current help message is nice and goes in the right direction, but I think we can do better for this specific instance and suggest `slice::swap`, which makes this compile
```
error[E0637]: `&` without an explicit lifetime name cannot be used here
--> $DIR/E0637.rs:13:13
|
LL | T: Into<&u32>,
| ^ explicit lifetime name needed here
|
help: consider introducing a higher-ranked lifetime here
|
LL | T: for<'a> Into<&'a u32>,
| +++++++ ++
```
This patch adds the `#[rustc_coinductive]` annotation to
`BikeshedIntrinsicFrom`, so that it's possible to compute transmutability for
recursive types.
Normalize opaques with late-bound vars again
We have a hack in the compiler where if an opaque has escaping late-bound vars, we skip revealing it even though we *could* reveal it from a technical perspective. First of all, this is weird, since we really should be revealing all opaques in `Reveal::All` mode. Second of all, it causes subtle bugs (linked below).
I attempted to fix this in #100980, which was unfortunately reverted due to perf regressions on codebases that used really deeply nested futures in some interesting ways. The worst of which was #103423, which caused the project to hang on build. Another one was #104842, which was just a slow-down, but not a hang. I took some time afterwards to investigate how to rework `normalize_erasing_regions` to take advantage of better caching, but that effort kinda fizzled out (#104133).
However, recently, I was made aware of more bugs whose root cause is not revealing opaques during codegen. That made me want to fix this again -- in the process, interestingly, I took the the minimized example from https://github.com/rust-lang/rust/issues/103423#issuecomment-1292947043, and it doesn't seem to hang any more...
Thinking about this harder, there have been some changes to the way we lower and typecheck async futures that may have reduced the pathologically large number of outlives obligations (see description of #103423) that we were encountering when normalizing opaques with bound vars the last time around:
* #104321 (lower `async { .. }` directly as a generator that implements `Future`, removing the `from_generator` shim)
* #104833 (removing an `identity_future` fn that was wrapping desugared future generators)
... so given that I can see:
* No significant regression on rust perf bot (https://github.com/rust-lang/rust/pull/107620#issuecomment-1600070317)
* No timeouts in crater run I did (https://github.com/rust-lang/rust/pull/107620#issuecomment-1605428952, rechecked failing crates in https://github.com/rust-lang/rust/pull/107620#issuecomment-1605973434)
... and given that this PR:
* Fixes#104601
* Fixes#107557
* Fixes#109464
* Allows us to remove a `DefiningAnchor::Bubble` from codegen (75a8f68183)
I'm inclined to give this another shot at landing this. Best case, it just works -- worst case, we get more examples to study how we need to improve the compiler to make this work.
r? types
`early_warn` is called
Skip `colored-session-opt-error.rs` on Windows hosts
This is very cursed as to why it fails on Windows CI specifically:
- The test emits a *warning*.
- *Warnings*, and only warnings *specifically*, have a different
256-color between Windows and non-Windows hosts (other levels
`set_intense(true)` unconditionally):
e69c7306e2/compiler/rustc_errors/src/lib.rs (L1792-L1794)
Therefore, I added `// ignore-windows` test header to skip this test on
Windows (it's sufficient to test color is enabled on at least one
non-Windows host).
Setting `RUSTC_LOG_COLOR=always` is sometimes useful if tools that one
pipes `RUSTC_LOG` into support coloured output, but it makes this test
fail.
Signed-off-by: David Wood <david@davidtw.co>
Rollup of 5 pull requests
Successful merges:
- #112946 (Improve cgu naming and ordering)
- #113048 (Fix build on Solaris where fd-lock cannot be used.)
- #113100 (Fix display of long items in search results)
- #113107 (add check for ConstKind::Value(_) to in_operand())
- #113119 (rustdoc: Reduce internal function visibility.)
r? `@ghost`
`@rustbot` modify labels: rollup
Test that we require implementing trait items whose bounds don't hold in the current impl
I initially tried to make most of these pass, but that's a big can of worms, so I'm just adding them as tests, considering we have no tests for these things.
Make associated type bounds in supertrait position implied
`trait A: B<Assoc: C> {}` should be able to imply both `Self: B` and `<Self as B>::Assoc: C`. Adjust the way that we collect implied predicates to do so.
Fixes#112573Fixes#112568
add check for ConstKind::Value(_) to in_operand()
Added check for valtree value to close#113012 which fixes the issue, although I am not sure if adding the check there is sound or not cc `@oli-obk`
add note for non-exhaustive matches with guards
Associated issue: #92197
When a match statement includes guards on every match arm (and is therefore necessarily non-exhaustive), add a note to the error E0004 diagnostic noting this.
Validate fluent variable references in tests
Closes#101109
Under `cfg(test)`, the `fluent_messages` macro will emit a list of variables referenced by each message and its attributes. The derive attribute will now emit a `#[test]` that checks that each referenced variable exists in the structure it's applied to.
mir opt + codegen: handle subtyping
fixes#107205
the same issue was caused in multiple places:
- mir opts: both copy and destination propagation
- codegen: assigning operands to locals (which also propagates values)
I changed codegen to always update the type in the operands used for locals which should guard against any new occurrences of this bug going forward. I don't know how to make mir optimizations more resilient here. Hopefully the added tests will be enough to detect any trivially wrong optimizations going forward.
Add tests impl via obj unless denied
Fixes#112737
Add simple tests to check feature change in #112320 is performing as expected.
Note:
- Unsure about filenames, locations & function signature names (tried to make them something sensible)
Make compiletest aware of targets without dynamic linking
Some parts of the compiletest internals and some tests require dynamic linking to work, which is not supported by all targets. Before this PR, this was handled by if branches matching on the target name.
This PR loads whether a target supports dynamic linking or not from the target spec, and adds a `// needs-dynamic-linking` attribute for tests that require it. Note that I was not able to replace all the old conditions based on the target name, as some targets have `dynamic_linking: true` in their spec but pretend they don't have it in compiletest.
Also, to get this to work I had to *partially* revert #111472 (cc `@djkoloski` `@tmandry` `@bjorn3).` On one hand, only the target spec contains whether a target supports dynamic linking, but on the other hand a subset of the fields can be overridden through `-C` flags (as far as I'm aware only `-C panic=$strategy`). The solution I came up with is to take the target spec as the base, and then override the panic strategy based on `--print=cfg`. Hopefully that should not break y'all again.
