Handle another negated literal in `eat_token_lit`.
Extends the change from #139653, which was on expressions, to literals.
Fixes#140098.
r? ``@petrochenkov``
improve diagnostic for raw pointer field access with ->
This PR enhances the error messages emitted by the Rust compiler when users attempt to use the `->` operator for field access on raw pointers or when dereferencing is needed. The changes aim to provide clearer guidance, by suggesting the correct use of the `.` operator and explicit dereferencing.
**Before:**
```
help: `xs` is a raw pointer; try dereferencing it
|
LL | (*xs)->count += 1;
| ++ +
```
**Now:**
```
help: use `.` on a dereferenced raw pointer instead
|
LL - xs->count += 1;
LL + (*xs).count += 1;
|
```
I added extra clarification in the message. Since this error occurs in the parser, we can't be certain that the type is a raw pointer. That's why the message includes only a small note in brackets. (In contrast, the message above is emitted in HIR, where we *can* check whether it's a raw pointer.)
**Before:**
```
--> main.rs:11:11
|
11 | xs->count += 1;
| ^^
|
= help: the . operator will dereference the value if needed
```
**After:**
```
--> main.rs:11:11
|
11 | xs->count += 1;
| ^^
|
= help: the `.` operator will automatically dereference the value, except if the value is a raw pointer
```
Improve diagnostics for pointer arithmetic += and -= (fixes#137391)
**Description**:
This PR improves the diagnostic message for cases where a binary assignment operation like `ptr += offset` or `ptr -= offset` is attempted on `*mut T`. These operations are not allowed, and the compiler previously suggested calling `.add()` or `.wrapping_add()`, which is misleading if not assigned.
This PR updates the diagnostics to suggest assigning the result of `.wrapping_add()` or `.wrapping_sub()` back to the pointer, e.g.:
**Examples**
For this code
```rust
let mut arr = [0u8; 10];
let mut ptr = arr.as_mut_ptr();
ptr += 2;
```
it will say:
```rust
10 | ptr += 2;
| ---^^^^^
| |
| cannot use `+=` on type `*mut u8`
|
help: consider replacing `ptr += offset` with `ptr = ptr.wrapping_add(offset)` or `ptr.add(offset)`
|
10 - ptr += 2;
10 + ptr = ptr.wrapping_add(2);
```
**Related issue**: #137391
cc `@nabijaczleweli` for context (issue author)
Construct OutputType using macro and print [=FILENAME] help info
Closes#139805
Use define_output_types to define variants of OutputType, as well as refactor all of its methods for clarity. This way no variant is missed when pattern matching or output help messages.
On top of that, I optimized for `emit` help messages.
r? ```@jieyouxu```
This commit adjusts feature implication of the RISC-V ISA for better
feature detection from the user perspective.
The main rule is:
If the feature A is a functional superset of the feature B (A ⊃ B),
A is to imply B, even if this implication is not on the manual.
Such implications (not directly referred in the ISA manual) are commented
as "A ⊃ B" which means "A is a (functional) superset of B".
1. Zbc → Zbkc (add as a superset)
The Zbkc extension is a subset of the Zbc extension
(Zbc - "clmulr" instruction == Zbkc)
2. Zkr → (nothing) (remove dependency to Zicsr)
Implication to the Zicsr extension is removed because (although nearly
harmless), the Zkr extension (or the "seed" CSR section) defines its own
subset of the Zicsr extension.
3. Zvbb → Zvkb (comment as a superset)
This implication was already there but not denoted as a functional
superset. This commit adds the comment.
4. Zvfh → Zvfhmin (comment as a superset)
This is similar to the case above (Zvbb → Zvkb).
5. Zvfh → Zve32f (add implication per the ISA specification)
This dependency is on the ISA manual but was missing (due to the fact
that Zvfh indirectly implies Zve32f on the current implementation
through Zvfh → Zvfhmin, which is a functional relation).
This commit ensures that this is *also* ISA-compliant in the
source code level (there's no functional changes though).
6. Zvknhb → Zvknha (add as a superset)
The Zvknhb extension (SHA-256 / SHA-512) is a functional superset of
the Zvknha extension (SHA-256 only).
Remove `token::{Open,Close}Delim`
By replacing them with `{Open,Close}{Param,Brace,Bracket,Invisible}`.
PR #137902 made `ast::TokenKind` more like `lexer::TokenKind` by
replacing the compound `BinOp{,Eq}(BinOpToken)` variants with fieldless
variants `Plus`, `Minus`, `Star`, etc. This commit does a similar thing
with delimiters. It also makes `ast::TokenKind` more similar to
`parser::TokenType`.
This requires a few new methods:
- `TokenKind::is_{,open_,close_}delim()` replace various kinds of
pattern matches.
- `Delimiter::as_{open,close}_token_kind` are used to convert
`Delimiter` values to `TokenKind`.
Despite these additions, it's a net reduction in lines of code. This is
because e.g. `token::OpenParen` is so much shorter than
`token::OpenDelim(Delimiter::Parenthesis)` that many multi-line forms
reduce to single line forms. And many places where the number of lines
doesn't change are still easier to read, just because the names are
shorter, e.g.:
```
- } else if self.token != token::CloseDelim(Delimiter::Brace) {
+ } else if self.token != token::CloseBrace {
```
r? `@petrochenkov`
Currently the graphviz code does a `results.visit_with` call while also
holding a `ResultsCursor` on the `results`. That is both kinds of
results traversals at the same time, which is awkward. This commit moves
the `results.visit_with` part earlier so the two results traversals
don't overlap.
Fix error when an intra doc link is trying to resolve an empty associated item
Fixes https://github.com/rust-lang/rust/issues/140026.
Assigning ```@nnethercote``` since they're the one who wrote the initial change.
I updated rustdoc code instead of compiler's because I think it makes more sense that the caller ensures on their side that the name they're looking for isn't empty.
r? ```@nnethercote```
Stabilize `naked_functions`
tracking issue: https://github.com/rust-lang/rust/issues/90957
request for stabilization on tracking issue: https://github.com/rust-lang/rust/issues/90957#issuecomment-2539270352
reference PR: https://github.com/rust-lang/reference/pull/1689
# Request for Stabilization
Two years later, we're ready to try this again. Even though this issue is already marked as having passed FCP, given the amount of time that has passed and the changes in implementation strategy, we should follow the process again.
## Summary
The `naked_functions` feature has two main parts: the `#[naked]` function attribute, and the `naked_asm!` macro.
An example of a naked function:
```rust
const THREE: usize = 3;
#[naked]
pub extern "sysv64" fn add_n(number: usize) -> usize {
// SAFETY: the validity of the used registers
// is guaranteed according to the "sysv64" ABI
unsafe {
core::arch::naked_asm!(
"add rdi, {}",
"mov rax, rdi",
"ret",
const THREE,
)
}
}
```
When the `#[naked]` attribute is applied to a function, the compiler won't emit a [function prologue](https://en.wikipedia.org/wiki/Function_prologue_and_epilogue) or epilogue when generating code for this function. This attribute is analogous to [`__attribute__((naked))`](https://developer.arm.com/documentation/100067/0608/Compiler-specific-Function--Variable--and-Type-Attributes/--attribute----naked---function-attribute) in C. The use of this feature allows the programmer to have precise control over the assembly that is generated for a given function.
The body of a naked function must consist of a single `naked_asm!` invocation, a heavily restricted variant of the `asm!` macro: the only legal operands are `const` and `sym`, and the only legal options are `raw` and `att_syntax`. In lieu of specifying operands, the `naked_asm!` within a naked function relies on the function's calling convention to determine the validity of registers.
## Documentation
The Rust Reference: https://github.com/rust-lang/reference/pull/1689
(Previous PR: https://github.com/rust-lang/reference/pull/1153)
## Tests
* [tests/run-make/naked-symbol-visiblity](https://github.com/rust-lang/rust/tree/master/tests/codegen/naked-fn) verifies that `pub`, `#[no_mangle]` and `#[linkage = "..."]` work correctly for naked functions
* [tests/codegen/naked-fn](https://github.com/rust-lang/rust/tree/master/tests/codegen/naked-fn) has tests for function alignment, use of generics, and validates the exact assembly output on linux, macos, windows and thumb
* [tests/ui/asm/naked-*](https://github.com/rust-lang/rust/tree/master/tests/ui/asm) tests for incompatible attributes, generating errors around incorrect use of `naked_asm!`, etc
## Interaction with other (unstable) features
### [fn_align](https://github.com/rust-lang/rust/issues/82232)
Combining `#[naked]` with `#[repr(align(N))]` works well, and is tested e.g. here
- https://github.com/rust-lang/rust/blob/master/tests/codegen/naked-fn/aligned.rs
- https://github.com/rust-lang/rust/blob/master/tests/codegen/naked-fn/min-function-alignment.rs
It's tested extensively because we do need to explicitly support the `repr(align)` attribute (and make sure we e.g. don't mistake powers of two for number of bytes).
## History
This feature was originally proposed in [RFC 1201](https://github.com/rust-lang/rfcs/pull/1201), filed on 2015-07-10 and accepted on 2016-03-21. Support for this feature was added in [#32410](https://github.com/rust-lang/rust/pull/32410), landing on 2016-03-23. Development languished for several years as it was realized that the semantics given in RFC 1201 were insufficiently specific. To address this, a minimal subset of naked functions was specified by [RFC 2972](https://github.com/rust-lang/rfcs/pull/2972), filed on 2020-08-07 and accepted on 2021-11-16. Prior to the acceptance of RFC 2972, all of the stricter behavior specified by RFC 2972 was implemented as a series of warn-by-default lints that would trigger on existing uses of the `naked` attribute; these lints became hard errors in [#93153](https://github.com/rust-lang/rust/pull/93153) on 2022-01-22. As a result, today RFC 2972 has completely superseded RFC 1201 in describing the semantics of the `naked` attribute.
More recently, the `naked_asm!` macro was added to replace the earlier use of a heavily restricted `asm!` invocation. The `naked_asm!` name is clearer in error messages, and provides a place for documenting the specific requirements of inline assembly in naked functions.
The implementation strategy was changed to emitting a global assembly block. In effect, an extern function
```rust
extern "C" fn foo() {
core::arch::naked_asm!("ret")
}
```
is emitted as something similar to
```rust
core::arch::global_asm!(
"foo:",
"ret"
);
extern "C" {
fn foo();
}
```
The codegen approach was chosen over the llvm naked function attribute because:
- the rust compiler can guarantee the behavior (no sneaky additional instructions, no inlining, etc.)
- behavior is the same on all backends (llvm, cranelift, gcc, etc)
Finally, there is now an allow list of compatible attributes on naked functions, so that e.g. `#[inline]` is rejected with an error. The `#[target_feature]` attribute on naked functions was later made separately unstable, because implementing it is complex and we did not want to block naked functions themselves on how target features work on them. See also https://github.com/rust-lang/rust/issues/138568.
relevant PRs for these recent changes
- https://github.com/rust-lang/rust/pull/127853
- https://github.com/rust-lang/rust/pull/128651
- https://github.com/rust-lang/rust/pull/128004
- https://github.com/rust-lang/rust/pull/138570
-
### Various historical notes
#### `noreturn`
[RFC 2972](https://github.com/rust-lang/rfcs/blob/master/text/2972-constrained-naked.md) mentions that naked functions
> must have a body which contains only a single asm!() statement which:
> iii. must contain the noreturn option.
Instead of `asm!`, the current implementation mandates that the body contain a single `naked_asm!` statement. The `naked_asm!` macro is a heavily restricted version of the `asm!` macro, making it easier to talk about and document the rules of assembly in naked functions and give dedicated error messages.
For `naked_asm!`, the behavior of the `asm!`'s `noreturn` option is implicit. The `noreturn` option means that it is UB for control flow to fall through the end of the assembly block. With `asm!`, this option is usually used for blocks that diverge (and thus have no return and can be typed as `!`). With `naked_asm!`, the intent is different: usually naked funtions do return, but they must do so from within the assembly block. The `noreturn` option was used so that the compiler would not itself also insert a `ret` instruction at the very end.
#### padding / `ud2`
A `naked_asm!` block that violates the safety assumption that control flow must not fall through the end of the assembly block is UB. Because no return instruction is emitted, whatever bytes follow the naked function will be executed, resulting in truly undefined behavior. There has been discussion whether rustc should emit an invalid instruction (e.g. `ud2` on x86) after the `naked_asm!` block to at least fail early in the case of an invalid `naked_asm!`. It was however decided that it is more useful to guarantee that `#[naked]` functions NEVER contain any instructions besides those in the `naked_asm!` block.
# unresolved questions
None
r? ``@Amanieu``
I've validated the tests on x86_64 and aarch64
Don't ICE on pending obligations from deep normalization in a loop
See the comment I left inline in `compiler/rustc_trait_selection/src/traits/normalize.rs`.
Fixes https://github.com/rust-lang/rust/issues/133868
r? lcnr
Instead of `ResultsCursor`.
This partly undoes the second commit from #132346; possible because
`Results::as_result_cursor` (which doesn't consume the `Results`) is now
available. Delaying the `ResultsCursor` construction will facilitate the
next couple of commits.
By replacing them with `{Open,Close}{Param,Brace,Bracket,Invisible}`.
PR #137902 made `ast::TokenKind` more like `lexer::TokenKind` by
replacing the compound `BinOp{,Eq}(BinOpToken)` variants with fieldless
variants `Plus`, `Minus`, `Star`, etc. This commit does a similar thing
with delimiters. It also makes `ast::TokenKind` more similar to
`parser::TokenType`.
This requires a few new methods:
- `TokenKind::is_{,open_,close_}delim()` replace various kinds of
pattern matches.
- `Delimiter::as_{open,close}_token_kind` are used to convert
`Delimiter` values to `TokenKind`.
Despite these additions, it's a net reduction in lines of code. This is
because e.g. `token::OpenParen` is so much shorter than
`token::OpenDelim(Delimiter::Parenthesis)` that many multi-line forms
reduce to single line forms. And many places where the number of lines
doesn't change are still easier to read, just because the names are
shorter, e.g.:
```
- } else if self.token != token::CloseDelim(Delimiter::Brace) {
+ } else if self.token != token::CloseBrace {
```
transmutability: remove NFA intermediate representation
Prior to this commit, the transmutability analysis used an intermediate NFA representation of type layout. We then determinized this representation into a DFA, upon which we ran the core transmutability analysis. Unfortunately, determinizing NFAs is expensive. In this commit, we avoid NFAs entirely by observing that Rust `union`s are the only source of nondeterminism and that it is comparatively cheap to compute the DFA union of DFAs.
We also implement Graphviz DOT debug formatting of DFAs.
Fixesrust-lang/project-safe-transmute#23Fixesrust-lang/project-safe-transmute#24
r? ``@compiler-errors``
simd intrinsics with mask: accept unsigned integer masks, and fix some of the errors
It's not clear at all why the mask would have to be signed, it is anyway interpreted bitwise. The backend should just make sure that works no matter the surface-level type; our LLVM backend already does this correctly. The note of "the mask may be widened, which only has the correct behavior for signed integers" explains... nothing? Why can't the code do the widening correctly? If necessary, just cast to the signed type first...
Also while we are at it, fix the errors. For simd_masked_load/store, the errors talked about the "third argument" but they meant the first argument (the mask is the first argument there). They also used the wrong type for `expected_element`.
I have extremely low confidence in the GCC part of this PR.
See [discussion on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/257879-project-portable-simd/topic/On.20the.20sign.20of.20masks)
Prior to this commit, the transmutability analysis used an intermediate
NFA representation of type layout. We then determinized this
representation into a DFA, upon which we ran the core transmutability
analysis. Unfortunately, determinizing NFAs is expensive. In this
commit, we avoid NFAs entirely by observing that Rust `union`s are the
only source of nondeterminism and that it is comparatively cheap to
compute the DFA union of DFAs.
We also implement Graphviz DOT debug formatting of DFAs.
Fixesrust-lang/project-safe-transmute#23Fixesrust-lang/project-safe-transmute#24
Remove early exits from JumpThreading.
This removes early exits from https://github.com/rust-lang/rust/pull/131203 as I asked during review.
The correctness of the backtracking is `mutated_statement` clearing all relevant conditions. If `process_statement` fails to insert a new condition, for instance by const-eval failure, `mutated_statement` still removes the obsolete conditions from the state.
r? `@compiler-errors`
Do not remove trivial `SwitchInt` in analysis MIR
This PR ensures that we don't prematurely remove trivial `SwitchInt` terminators which affects both the borrow-checking and runtime semantics (i.e. UB) of the code. Previously the `SimplifyCfg` optimization was removing `SwitchInt` terminators when they was "trivial", i.e. when all arms branched to the same basic block, even if that `SwitchInt` terminator had the side-effect of reading an operand which (for example) may not be initialized or may point to an invalid place in memory.
This behavior is unlike all other optimizations, which are only applied after "analysis" (i.e. borrow-checking) is finished, and which Miri disables to make sure the compiler doesn't silently remove UB.
Fixing this code "breaks" (i.e. unmasks) code that used to borrow-check but no longer does, like:
```rust
fn foo() {
let x;
let (0 | _) = x;
}
```
This match expression should perform a read because `_` does not shadow the `0` literal pattern, and the compiler should have to read the match scrutinee to compare it to 0. I've checked that this behavior does not actually manifest in practice via a crater run which came back clean: https://github.com/rust-lang/rust/pull/139042#issuecomment-2767436367
As a side-note, it may be tempting to suggest that this is actually a good thing or that we should preserve this behavior. If we wanted to make this work (i.e. trivially optimize out reads from matches that are redundant like `0 | _`), then we should be enabling this behavior *after* fixing this. However, I think it's kinda unprincipled, and for example other variations of the code don't even work today, e.g.:
```rust
fn foo() {
let x;
let (0.. | _) = x;
}
```
Move `pal::env` to `std::sys::env_consts`
Combine the `std::env::consts` platform implementations as a single file. Use the Unix file as the base, since it has 28 entries, and fold the 8 singleton platforms into it. The Unix file was roughly grouped into Linux, Apple, BSD, and everything else, roughly in alphabetical order. Alphabetically order them to make it easier to maintain and discard the Unix-specific groups to generalize it to all platforms.
I'd prefer to have no fallback implementation, as I consider it a bug; however TEEOS, Trusty, and Xous have no definitions here. Since they otherwise have `pal` abstractions, that indicates that there are several platforms without `pal` abstractions which are also missing here. To support unsupported, create a little macro to handle the fallback case and not introduce ordering between the `cfg`s like `cfg_if!`.
I've named the module `std::sys::env_consts`, because they are used in `std::env::consts` and I intend to use the name `std::sys::env` for the combination of `Args` and `Vars`.
cc `@joboet` `@ChrisDenton`
Tracked in #117276.
Don't canonicalize crate paths
When printing paths in diagnostic we should favour printing the paths that were passed in rather than resolving all symlinks.
This PR changes the form of the crate path but it should only really affect diagnostics as filesystem functions won't care which path is used. The uncanonicalized path was already used as a fallback for when canonicalization failed.
This is a partial alternative to #139823.
Don't assemble non-env/bound candidates if projection is rigid
Putting this up for an initial review, it's still missing comments, clean-up, and possibly a tweak to deal with ambiguities in the `BestObligation` folder.
This PR fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/173. Specifically, we're creating an unnecessary query cycle in normalization by assembling an *impl candidate* even if we know later on during `merge_candidates` that we'll be filtering out that impl candidate.
This PR adjusts the `merge_candidates` to assemble *only* env/bound candidates if we have `TraitGoalProvenVia::ParamEnv | TraitGoalProvenVia::AliasBound`.
I'll leave some thoughts/comments in the code.
r? lcnr
Rewrite on_unimplemented format string parser.
This PR rewrites the format string parser for `rustc_on_unimplemented` and `diagnostic::on_unimplemented`. I plan on moving this code (and more) into the new attribute parsing system soon and wanted to PR it separately.
This PR introduces some minor differences though:
- `rustc_on_unimplemented` on trait *implementations* is no longer checked/used - this is actually never used (outside of some tests) so I plan on removing it in the future.
- for `rustc_on_unimplemented`, it introduces the `{This}` argument in favor of `{ThisTraitname}` (to be removed later). It'll be easier to parse.
- for `rustc_on_unimplemented`, `Self` can now consistently be used as a filter, rather than just `_Self`. It used to not match correctly on for example `Self = "[{integer}]"`
- Some error messages now have better spans.
Fixes https://github.com/rust-lang/rust/issues/130627
Re-remove `AdtFlags::IS_ANONYMOUS`
Removed in #138296.
I accidentally re-added it in #137043 while resolving merge conflicts. This PR re-removes it.
r? ``@compiler-errors`` (sorry)
Disable has_thread_local on i686-win7-windows-msvc
On Windows 7 32-bit, the alignment characteristic of the TLS Directory don't appear to be respected by the PE Loader, leading to crashes. As a result, let's disable has_thread_local to make sure TLS goes through the emulation layer.
Fixes#138903
Implement `pin!()` using `super let`
Tracking issue for super let: https://github.com/rust-lang/rust/issues/139076
This uses `super let` to implement `pin!()`.
This means we can remove [the hack](https://github.com/rust-lang/rust/pull/138717) we had to put in to fix https://github.com/rust-lang/rust/issues/138596.
It also means we can remove the original hack to make `pin!()` work, which used a questionable public-but-unstable field rather than a proper private field.
While `super let` is still unstable and subject to change, it seems safe to assume that future Rust will always have a way to express `pin!()` in a compatible way, considering `pin!()` is already stable.
It'd help [the experiment](https://github.com/rust-lang/rust/issues/139076) to have `pin!()` use `super let`, so we can get some more experience with it.
On Windows 7 32-bit, the alignment characteristic of the TLS Directory
don't appear to be respected by the PE Loader, leading to crashes. As
a result, let's disable has_thread_local to make sure TLS goes through
the emulation layer.
- With `Context` wrapped by `SmirInterface`, the stable-mir's TLV stores a pointer to `SmirInterface`, while the rustc-specific TLV stores a pointer to tables.
- This PR make the `rustc_smir` mod public.
avoid overflow when generating debuginfo for expanding recursive types
Fixes#135093Fixes#121538Fixes#107362Fixes#100618Fixes#115994
The overflow happens because expanding recursive types keep creating new nested types when recurring into sub fields.
I fixed that by returning an empty stub node when expanding recursion is detected.
deref patterns: implement implicit deref patterns
This implements implicit deref patterns (per https://hackmd.io/4qDDMcvyQ-GDB089IPcHGg#Implicit-deref-patterns) and adds tests and an unstable book chapter.
Best reviewed commit-by-commit. Overall there's a lot of additions, but a lot of that is tests, documentation, and simple(?) refactoring.
Tracking issue: #87121
r? ``@Nadrieril``
Change `InterpCx::instantiate*` function visibility to pub
For some ongoing work in Miri we need to be able to access `instantiate_from_current_frame_and_normalize_erasing_regions` and `instantiate_from_frame_and_normalize_erasing_regions` on `InterpCx`.
r? `@RalfJung`
Ignore zero-sized types in wasm future-compat warning
This commit fixes a false positive of the warning triggered for #138762 and the fix is to codify that zero-sized types are "safe" in both the old and new ABIs.
Autodiff batching2
~I will rebase it once my first PR landed.~ done.
This autodiff batch mode is more similar to scalar autodiff, since it still only takes one shadow argument.
However, that argument is supposed to be `width` times larger.
r? `@oli-obk`
Tracking:
- https://github.com/rust-lang/rust/issues/124509
do not emit `OpaqueCast` projections with `-Znext-solver`
We normalize opaque types in their defining scope if the new solver is enabled. This means projections do not contain any 'revealable' opaque types we need to worry about. We either have a type which has been normalized by writeback or we need to normalize it anyways.
r? ```@compiler-errors``` ```@oli-obk```
Hide unstable print kinds within emit_unknown_print_request_help in stable channel
Fixes#138698
We need to get the channel from `matches`. However, since `matches`(Line 1169) is constructed after `rustc_optgroups` (Line1165, where `RustcOptGroup::value_hint` is generated, i.e. what `rustc --print print` prints), I've left it unchanged here for now.
2da29dbe8f/compiler/rustc_driver_impl/src/lib.rs (L1161-L1169)
There is actually a way to manually parse the `--crate-name` parameter, but I'm afraid that's an unorthodox practice. So I conservatively just modified `emit_unknown_print_request_help` to print different parameters depending on whether they are nightly or not when passing the error parameter.
r? ```@jieyouxu```
Fix replacing supertrait aliases in `ReplaceProjectionWith`
The new solver has a procedure called `predicates_for_object_candidate`, which elaborates the super-bounds and item-bounds that are required to hold for a dyn trait to implement something via a built-in object impl.
In that procedure, there is a folder called `ReplaceProjectionWith` which is responsible for replacing projections that reference `Self`, so that we don't encounter cycles when we then go on to normalize those projections in the process of proving these super-bounds.
That folder had a few problems: Firstly, it wasn't actually checking that this was a super bound originating from `Self`. Secondly, it only accounted for a *single* projection type def id, but trait objects can have multiple (i.e. `trait Foo<A, B>: Bar<A, Assoc = A> + Bar<B, Assoc = B>`).
To fix the first, it's simple enough to just add an equality check for the self ty. To fix the second, I implemented a matching step that's very similar to the `projection_may_match` check we have for upcasting, since on top of having multiple choices, we need to deal with both non-structural matches and ambiguity.
This probably lacks a bit of documentation, but I think it works pretty well.
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/171
r? lcnr
This commit fixes a false positive of the warning triggered for #138762
and the fix is to codify that zero-sized types are "safe" in both the
old and new ABIs.
Rollup of 9 pull requests
Successful merges:
- #135340 (Add `explicit_extern_abis` Feature and Enforce Explicit ABIs)
- #139440 (rustc_target: RISC-V: feature addition batch 2)
- #139667 (cfi: Remove #[no_sanitize(cfi)] for extern weak functions)
- #139828 (Don't require rigid alias's trait to hold)
- #139854 (Improve parse errors for stray lifetimes in type position)
- #139889 (Clean UI tests 3 of n)
- #139894 (Fix `opt-dist` CLI flag and make it work without LLD)
- #139900 (stepping into impls for normalization is unproductive)
- #139915 (replace some #[rustc_intrinsic] usage with use of the libcore declarations)
r? `@ghost`
`@rustbot` modify labels: rollup
Move eager translation to a method on Diag
This will allow us to eagerly translate messages on a top-level diagnostic, such as a `LintDiagnostic`. As a bonus, we can remove the awkward closure passed into Subdiagnostic and make better use of `Into`.
r? `@nnethercote`
Consistent with treating Ctor Call as Struct in liveness analysis
Fixes#139627
When `ExprKind::Call` is a `Ctor`, skips the checking of `expr` and only checks the arguments, thus being consistent with `ExprKind::Struct`.
r? compiler
Stabilize `cfg_boolean_literals`
Closes#131204
`@rustbot` labels +T-lang +I-lang-nominated
This will end up conflicting with the test in #138293 so whichever doesn't land first will need updating
--
# Stabilization Report
## General design
### What is the RFC for this feature and what changes have occurred to the user-facing design since the RFC was finalized?
[RFC 3695](https://github.com/rust-lang/rfcs/pull/3695), none.
### What behavior are we committing to that has been controversial? Summarize the major arguments pro/con.
None
### Are there extensions to this feature that remain unstable? How do we know that we are not accidentally committing to those?
None
## Has a call-for-testing period been conducted? If so, what feedback was received?
Yes; only positive feedback was received.
## Implementation quality
### Summarize the major parts of the implementation and provide links into the code (or to PRs)
Implemented in [#131034](https://github.com/rust-lang/rust/pull/131034).
### Summarize existing test coverage of this feature
- [Basic usage, including `#[cfg()]`, `cfg!()` and `#[cfg_attr()]`](6d71251cf9/tests/ui/cfg/true-false.rs)
- [`--cfg=true/false` on the command line being accessible via `r#true/r#false`](6d71251cf9/tests/ui/cfg/raw-true-false.rs)
- [Interaction with the unstable `#[doc(cfg(..))]` feature](https://github.com/rust-lang/rust/tree/6d71251/tests/rustdoc-ui/cfg-boolean-literal.rs)
- [Denying `--check-cfg=cfg(true/false)`](https://github.com/rust-lang/rust/tree/6d71251/tests/ui/check-cfg/invalid-arguments.rs)
- Ensuring `--cfg false` on the command line doesn't change the meaning of `cfg(false)`: `tests/ui/cfg/cmdline-false.rs`
- Ensuring both `cfg(true)` and `cfg(false)` on the same item result in it being disabled: `tests/ui/cfg/both-true-false.rs`
### What outstanding bugs in the issue tracker involve this feature? Are they stabilization-blocking?
The above mentioned issue; it should not block as it interacts with another unstable feature.
### What FIXMEs are still in the code for that feature and why is it ok to leave them there?
None
### Summarize contributors to the feature by name for recognition and assuredness that people involved in the feature agree with stabilization
- `@clubby789` (RFC)
- `@Urgau` (Implementation in rustc)
### Which tools need to be adjusted to support this feature. Has this work been done?
`rustdoc`'s unstable`#[doc(cfg(..)]` has been updated to respect it. `cargo` has been updated with a forward compatibility lint to enable supporting it in cargo once stabilized.
## Type system and execution rules
### What updates are needed to the reference/specification? (link to PRs when they exist)
A few lines to be added to the reference for configuration predicates, specified in the RFC.
This will allow us to eagerly translate messages on a top-level
diagnostic, such as a `LintDiagnostic`. As a bonus, we can remove the
awkward closure passed into Subdiagnostic and make better use of
`Into`.
I'm removing empty identifiers everywhere, because in practice they
always mean "no identifier" rather than "empty identifier". (An empty
identifier is impossible.) It's better to use `Option` to mean "no
identifier" because you then can't forget about the "no identifier"
possibility.
Some specifics:
- When testing an attribute for a single name, the commit uses the
`has_name` method.
- When testing an attribute for multiple names, the commit uses the new
`has_any_name` method.
- When using `match` on an attribute, the match arms now have `Some` on
them.
In the tests, we now avoid printing empty identifiers by not printing
the identifier in the `error:` line at all, instead letting the carets
point out the problem.
stepping into impls for normalization is unproductive
See the inline comment. This builds on the reasoning from #136824 (https://gist.github.com/lcnr/c49d887bbd34f5d05c36d1cf7a1bf5a5). Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/176.
Looking at the end of the gist:
> The only ways to project out of a constructor are the following:
> - accessing an associated item, either its type or its item bounds
> - accessing super predicates
Detecting cases where we accessing the type of an associated item is easy, it's simply when we normalize. I don't yet know how to detect whether we step out of an impl by accessing item bounds. Once we also detect these cases we should be able to soundly support arbitrary coinductive traits. Luckily this does not matter for this PR :>
r? `@compiler-errors` cc `@nikomatsakis`
Improve parse errors for stray lifetimes in type position
While technically & syntactically speaking lifetimes do begin[^1] types in type contexts (this essentially excludes generic argument lists) and require a following `+` to form a complete type (`'a +` denotes a bare trait object type), the likelihood that a user meant to write a lifetime-prefixed bare trait object type in *modern* editions (Rust ≥2021) when placing a lifetime into a type context is incredibly low (they would need to add at least three tokens to turn it into a *semantically* well-formed TOT: `'a` → `dyn 'a + Trait`).
Therefore let's *lie* in modern editions (just like in PR https://github.com/rust-lang/rust/pull/131239, a precedent if you will) by stating "*expected type, found lifetime*" in such cases which is a lot more a approachable, digestible and friendly compared to "*lifetime in trait object type must be followed by `+`*" (as added in PR https://github.com/rust-lang/rust/pull/69760).
I've also added recovery for "ampersand-less" reference types (e.g., `'a ()`, `'a mut Ty`) in modern editions because it was trivial to do and I think it's not unlikely to occur in practice.
Fixes#133413.
[^1]: For example, in the context of decl macros, this implies that a lone `'a` always matches syntax fragment `ty` ("even if" there's a later macro matcher expecting syntax fragment `lifetime`). Rephrased, lifetimes (in type contexts) *commit* to the type parser.
Don't require rigid alias's trait to hold
See test for write-up. TL;DR is that we don't need the trait bound to hold, since we enforce it during WF.
I think this is preferable to introducing (if we even could do so) a more specific hack around coroutine interiors, higher ranked types, etc, since this is just a manifestation of more pervasive issues w/ lifetime erasure in coroutines. This just doesn't manifest in the old solver b/c it doesn't try to prove `T: Trait` holds when rigidly projecting `<T as Trait>::Assoc`.
It's pretty clear that this affects quite a few traits (https://github.com/rust-lang/rust/pull/139763), so I think this needs fixing.
r? lcnr
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/177
Add `explicit_extern_abis` Feature and Enforce Explicit ABIs
The unstable `explicit_extern_abis` feature is introduced, requiring explicit ABIs in `extern` blocks. Hard errors will be enforced with this feature enabled in a future edition.
RFC rust-lang/rfcs#3722
Update #134986
fix for multiple `#[repr(align(N))]` on functions
tracking issue: https://github.com/rust-lang/rust/issues/82232
fixes https://github.com/rust-lang/rust/issues/132464
The behavior of align is specified at https://doc.rust-lang.org/reference/type-layout.html#r-layout.repr.alignment.align
> For align, if the specified alignment is less than the alignment of the type without the align modifier, then the alignment is unaffected.
So in effect that means that the maximum of the specified alignments should be chosen. That is also the current behavior for `align` on ADTs:
```rust
#![feature(fn_align)]
#[repr(C, align(32), align(64))]
struct Foo {
x: u64,
}
const _: () = assert!(core::mem::align_of::<Foo>() == 64);
// See the godbolt LLVM output: the alignment of this function is 32
#[no_mangle]
#[repr(align(32))]
#[repr(align(64))]
fn foo() {}
// The current logic just picks the first alignment: the alignment of this function is 64
#[no_mangle]
#[repr(align(64))]
#[repr(align(32))]
fn bar() {}
```
https://godbolt.org/z/scco435jEafa859f812/compiler/rustc_middle/src/ty/mod.rs (L1529-L1532)
The https://github.com/rust-lang/rust/issues/132464 issue is really about parsing/representing the attribute, which has already been improved and now uses the "parse, don't validate" attribute approach. That means the behavior is already different from what the issue describes: on current `main`, the first value is chosen. This PR fixes a logic error, where we just did not check for the effect of two or more `align` modifiers. In combination, that fixes the issue.
cc ``@jdonszelmann`` if you do have further thoughs here
parser: Remove old diagnostic notes for type ascription syntax
Type ascription syntax was removed by #109128 in 2023, so “remove this again in a few months” is long overdue.
Happily, this also reduces the amount of parser diagnostic code that cares whether the compiler is unstable.
---
See also the recent #138898, which removed some other related dead code but declined to touch the diagnostics.
It's possible that some of these parser tests are no longer useful at all, but I haven't investigated them for this PR.
Rename `LifetimeName` as `LifetimeKind`.
It's a much better name, more consistent with how we name such things.
Also rename `Lifetime::res` as `Lifetime::kind` to match. I suspect this field used to have the type `LifetimeRes` and then the type was changed but the field name remained the same.
r? ``@BoxyUwU``
Fix `register_group_alias` for tools
In clippy we're looking at renaming `clippy::all` and registering an alias for it but currently that doesn't work for tools
The `lint_ids` of the alias are now populated at the time of registration to make it easier to handle
Use a session counter to make anon dep nodes unique
This changes the unique session hash used to ensure unique anon dep nodes per session from a timestamp to a counter.
This is nicer for debugging as it makes the dep graph deterministic.
hygiene: Rename semi-transparent to semi-opaque
"Semi-transparent" is just too damn long for a name, especially when used multiple times on a single line, it bothered me when working on #139083.
An optimist sees a macro as semi-opaque, a pessimist sees it as semi-transparent.
Or is it the other way round?
Add minimal x86_64-lynx-lynxos178 support.
Add minimal x86_64-lynx-lynxos178 support. It's possible to build no_std
programs with this compiler.
## Tier 3 Target Policy
> A tier 3 target must have a designated developer or developers (the "target
maintainers") on record to be CCed when issues arise regarding the target. (The
mechanism to track and CC such developers may evolve over time.)
Tim Newsome (`@tnewsome-lynx)` will be the designated developer for
x86_64-lynx-lynxos178 support.
> Targets must use naming consistent with any existing targets; for instance, a
target for the same CPU or OS as an existing Rust target should use the same
name for that CPU or OS. Targets should normally use the same names and naming
conventions as used elsewhere in the broader ecosystem beyond Rust (such as in
other toolchains), unless they have a very good reason to diverge. Changing the
name of a target can be highly disruptive, especially once the target reaches a
higher tier, so getting the name right is important even for a tier 3 target.
I believe the target is named appropriately.
> Target names should not introduce undue confusion or ambiguity unless
absolutely necessary to maintain ecosystem compatibility. For example, if the
name of the target makes people extremely likely to form incorrect beliefs about
what it targets, the name should be changed or augmented to disambiguate it.
The target name is not confusing.
> If possible, use only letters, numbers, dashes and underscores for the name.
Periods (.) are known to cause issues in Cargo.
Done.
> Tier 3 targets may have unusual requirements to build or use, but must not
create legal issues or impose onerous legal terms for the Rust project or for
Rust developers or users.
> The target must not introduce license incompatibilities.
> Anything added to the Rust repository must be under the standard Rust license
(MIT OR Apache-2.0).
All this new code is licensed under the Apache-2.0 license.
> The target must not cause the Rust tools or libraries built for any other host
(even when supporting cross-compilation to the target) to depend on any new
dependency less permissive than the Rust licensing policy. This applies whether
the dependency is a Rust crate that would require adding new license exceptions
(as specified by the tidy tool in the rust-lang/rust repository), or whether the
dependency is a native library or binary. In other words, the introduction of
the target must not cause a user installing or running a version of Rust or the
Rust tools to be subject to any new license requirements.
Done.
> Compiling, linking, and emitting functional binaries, libraries, or other code
for the target (whether hosted on the target itself or cross-compiling from
another target) must not depend on proprietary (non-FOSS) libraries. Host tools
built for the target itself may depend on the ordinary runtime libraries
supplied by the platform and commonly used by other applications built for the
target, but those libraries must not be required for code generation for the
target; cross-compilation to the target must not require such libraries at all.
For instance, rustc built for the target may depend on a common proprietary C
runtime library or console output library, but must not depend on a proprietary
code generation library or code optimization library. Rust's license permits
such combinations, but the Rust project has no interest in maintaining such
combinations within the scope of Rust itself, even at tier 3.
I think we're in the clear here. We do link against some static libraries that
are proprietary (like libm and libc), but those are not used to generate code.
E.g. the VxWorks target requires `wr-c++` to be installed, which is not
publically available.
> "onerous" here is an intentionally subjective term. At a minimum, "onerous"
legal/licensing terms include but are not limited to: non-disclosure
requirements, non-compete requirements, contributor license agreements (CLAs) or
equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional
on the employer or employment of any particular Rust developers, revocable
terms, any requirements that create liability for the Rust project or its
developers or users, or any requirements that adversely affect the livelihood or
prospects of the Rust project or its developers or users.
Our intention is to allow anyone with access to LynxOS CDK to use Rust for it.
> Neither this policy nor any decisions made regarding targets shall create any
binding agreement or estoppel by any party. If any member of an approving Rust
team serves as one of the maintainers of a target, or has any legal or
employment requirement (explicit or implicit) that might affect their decisions
regarding a target, they must recuse themselves from any approval decisions
regarding the target's tier status, though they may otherwise participate in
discussions.
> This requirement does not prevent part or all of this policy from being cited
in an explicit contract or work agreement (e.g. to implement or maintain support
for a target). This requirement exists to ensure that a developer or team
responsible for reviewing and approving a target does not face any legal threats
or obligations that would prevent them from freely exercising their judgment in
such approval, even if such judgment involves subjective matters or goes beyond
the letter of these requirements.
No problem.
> Tier 3 targets should attempt to implement as much of the standard libraries
as possible and appropriate (core for most targets, alloc for targets that can
support dynamic memory allocation, std for targets with an operating system or
equivalent layer of system-provided functionality), but may leave some code
unimplemented (either unavailable or stubbed out as appropriate), whether
because the target makes it impossible to implement or challenging to implement.
The authors of pull requests are not obligated to avoid calling any portions of
the standard library on the basis of a tier 3 target not implementing those
portions.
With this first PR, only core is supported. I am working on support for the std
library and intend to submit that once all the tests are passing.
> The target must provide documentation for the Rust community explaining how to
build for the target, using cross-compilation if possible. If the target
supports running binaries, or running tests (even if they do not pass), the
documentation must explain how to run such binaries or tests for the target,
using emulation if possible or dedicated hardware if necessary.
This is documented in `src/doc/rustc/src/platform-support/lynxos178.md`.
> Tier 3 targets must not impose burden on the authors of pull requests, or
other developers in the community, to maintain the target. In particular, do not
post comments (automated or manual) on a PR that derail or suggest a block on
the PR based on a tier 3 target. Do not send automated messages or notifications
(via any medium, including via `@)` to a PR author or others involved with a PR
regarding a tier 3 target, unless they have opted into such messages.
> Backlinks such as those generated by the issue/PR tracker when linking to an
issue or PR are not considered a violation of this policy, within reason.
However, such messages (even on a separate repository) must not generate
notifications to anyone involved with a PR who has not requested such
notifications.
Understood.
> Patches adding or updating tier 3 targets must not break any existing tier 2
or tier 1 target, and must not knowingly break another tier 3 target without
approval of either the compiler team or the maintainers of the other tier 3
target.
> In particular, this may come up when working on closely related targets, such
as variations of the same architecture with different features. Avoid
introducing unconditional uses of features that another variation of the target
may not have; use conditional compilation or runtime detection, as appropriate,
to let each target run code supported by that target.
As far as I know this change does not affect any other targets.
> Tier 3 targets must be able to produce assembly using at least one of rustc's
supported backends from any host target. (Having support in a fork of the
backend is not sufficient, it must be upstream.)
Many targets produce assembly for x86_64 so that also works for LynxOS-178.
See the doc comment on `ResolvedPat` for more information. This and the
next couple commits split resolution apart from checking for path,
struct, and tuple struct patterns, in order to find the pattern's type
before peeling the scrutinee. This helps us avoid peeling the scrutinee
when the pattern could match it.
The reason this handles errors from resolution after peeling is for
struct and tuple struct patterns: we check their subpatterns even when
they fail to resolve, to potentially catch more resolution errors. By
doing this after peeling, we're able to use the updated `PatInfo`. I
don't know if there's currently any observable difference from using the
outdated `PatInfo`, but it could potentially be a source of subtle
diagnostic bugs in the future, so I'm opting to peel first.
Since this uses `pat_adjustments`, I've also tweaked the documentation
to mention implicit deref patterns and made sure the pattern migration
diagnostic logic accounts for it. I'll adjust `ExprUseVisitor` in a
later commit and add some tests there for closure capture inference.
Don't compute name of associated item if it's an RPITIT
Use `Option::then` in favor of `Option::then_some` to not compute `AssocItem::name` if it fails the condition. Alternatively, I'd be open to changing this just to an `if`.
Fixes https://github.com/rust-lang/rust/issues/139873
r? ```@nnethercote```
Make CodeStats' type_sizes public
Add another way to get type sizes in CodeStats. I find it weird that the only way to get this information in block for all types is via printing directly to stdout. So this PR adds that flexibility.
Add unstable parsing of `--extern foo::bar=libbar.rlib` command line options
This is a tiny step towards implementing the rustc side of support for implementing packages as optional namespaces (#122349). We add support for parsing command line options like `--extern foo::bar=libbar.rlib` when the `-Z namespaced-crates` option is present.
We don't do anything further with them. The next step is to plumb this down to the name resolver.
This PR also generally refactors the extern argument parsing code and adds some unit tests to make it clear what forms should be accepted with and without the flag.
cc ```@epage``` ```@ehuss```
Stabilize `-Zdwarf-version` as `-Cdwarf-version`
I propose stabilizing `-Zdwarf-version` as `-Cdwarf-version`. This PR adds a new `-Cdwarf-version` flag, leaving the unstable `-Z` flag as is to ease the transition period. The `-Z` flag will be removed in the future.
# `-Zdwarf-version` stabilization report
## What is the RFC for this feature and what changes have occurred to the user-facing design since the RFC was finalized?
No RFC/MCP, this flag was added in https://github.com/rust-lang/rust/pull/98350 and was not deemed large enough to require additional process.
The tracking issue for this feature is #103057.
## What behavior are we committing to that has been controversial? Summarize the major arguments pro/con.
None that has been extensively debated but there are a few questions that could have been chosen differently:
1. What should the flag name be?
The current flag name is very specific to DWARF. Other debuginfo formats exist (msvc's CodeView format or https://en.wikipedia.org/wiki/Stabs) so we could have chosen to generalize the flag name (`-{C,Z} debuginfo-version=dwarf-5` for example). While this would extend cleanly to support formats other than DWARF, there are some downsides to this design. Neither CodeView nor Stabs have specification or format versions so it's not clear what values would be supported beyond `dwarf-{2,3,4,5}` or `codeview`. We would also need to take care to ensure the name does not lead users to think they can pick a format other than one supported by the target. For instance, what would `--target x86_64-pc-windows-msvc -Cdebuginfo-version=dwarf-5` do?
2. What is the behavior when flag is used on targets that do not support DWARF?
Currently, passing `-{C,Z} dwarf-version` on targets like `*-windows-msvc` does not do anything. It may be preferable to emit a warning alerting the user that the flag has no effect on the target platform. Alternatively, we could emit an error but this could be annoying since it would require the use of target specific RUSTFLAGS to use the flag correctly (and there isn't a way to target "any platform that uses DWARF" using cfgs).
3. Does the precompiled standard library potentially using a different version of DWARF a problem?
I don't believe this is an issue as debuggers (and other such tools) already must deal with the possibility that an application uses different DWARF versions across its statically or dynamically linked libraries.
## Are there extensions to this feature that remain unstable? How do we know that we are not accidentally committing to those.
No extensions per se, although future DWARF versions could be considered as such. At present, we validate the requested DWARF version is between 2 and 5 (inclusive) so new DWARF versions will not automatically be supported until the validation logic is adjusted.
## Summarize the major parts of the implementation and provide links into the code (or to PRs)
- Targets define their preferred or default DWARF version: 34a5ea911c/compiler/rustc_target/src/spec/mod.rs (L2369)
- We use the target default but this can be overriden by `-{C,Z} dwarf-version` 34a5ea911c/compiler/rustc_session/src/session.rs (L738)
- The flag is validated 34a5ea911c/compiler/rustc_session/src/session.rs (L1253-L1258)
- When debuginfo is generated, we tell LLVM to use the requested value or the target default 34a5ea911c/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs (L106)
## Summarize existing test coverage of this feature
- Test that we actually generate the appropriate DWARF version
- https://github.com/rust-lang/rust/blob/master/tests/assembly/dwarf5.rs
- https://github.com/rust-lang/rust/blob/master/tests/assembly/dwarf4.rs
- Test that LTO with different DWARF versions picks the highest version
- https://github.com/rust-lang/rust/blob/master/tests/assembly/dwarf-mixed-versions-lto.rs
- Test DWARF versions 2-5 are valid while 0, 1 and 6 report an error
- https://github.com/rust-lang/rust/blob/master/tests/ui/debuginfo/dwarf-versions.rs
- Ensure LLVM does not report a warning when LTO'ing different DWARF versions together
- https://github.com/rust-lang/rust/blob/master/tests/ui/lto/dwarf-mixed-versions-lto.rs
## Has a call-for-testing period been conducted? If so, what feedback was received?
No call-for-testing has been conducted but Rust for Linux has been using this flag without issue.
## What outstanding bugs in the issue tracker involve this feature? Are they stabilization-blocking?
All reported bugs have been resolved.
## Summarize contributors to the feature by name for recognition and assuredness that people involved in the feature agree with stabilization
- Initial implementation in https://github.com/rust-lang/rust/pull/98350 by `@pcwalton`
- Stop emitting `.debug_pubnames` and `.debug_pubtypes` when using DWARF 5 in https://github.com/rust-lang/rust/pull/117962 by `@weihanglo.`
- Refactoring & cleanups (#135739), fix LLVM warning on LTO with different DWARF versions (#136659) and argument validation (#136746) by `@wesleywiser`
## What FIXMEs are still in the code for that feature and why is it ok to leave them there?
No FIXMEs related to this feature.
## What static checks are done that are needed to prevent undefined behavior?
This feature cannot cause undefined behavior.
We ensure the DWARF version is one of the supported values [here](34a5ea911c/compiler/rustc_session/src/session.rs (L1255-L1257)).
## In what way does this feature interact with the reference/specification, and are those edits prepared?
No changes to reference/spec, unstable rustc docs are moved to the stable book as part of the stabilization PR.
## Does this feature introduce new expressions and can they produce temporaries? What are the lifetimes of those temporaries?
No.
## What other unstable features may be exposed by this feature?
`-Zembed-source` requires use of DWARF 5 extensions but has its own feature gate.
## What is tooling support like for this feature, w.r.t rustdoc, clippy, rust-analzyer, rustfmt, etc.?
No support needed for rustdoc, clippy, rust-analyzer, rustfmt or rustup.
Cargo could expose this as an option in build profiles but I would expect the decision as to what version should be used would be made for the entire crate graph at build time rather than by individual package authors.
cc-rs has support for detecting the presence of `-{C,Z} dwarf-version` in `RUSTFLAGS` and providing the corresponding flag to Clang/gcc (https://github.com/rust-lang/cc-rs/pull/1395).
---
Closes#103057
Split `TypeFolder` and `FallibleTypeFolder` atwain
Right now there is a coherence problem with `TypeFolder` and `FallibleTypeFolder`. Namely, it's impossible to implement a `FallibleTypeFolder` that is generic over interner, b/c it has a *downstream* conflict with the blanket impl:
```
impl<I, F> FallibleTypeFolder<I> for F where F: TypeFolder<I> {}
```
Because downstream crates may implement `TypeFolder<SomeLocalInterner>` for the fallible type folder.
This PR removes the relationship between `FallibleTypeFolder` and `TypeFolder`; it leads to *modest* code duplication, but otherwise does not affect perf and really doesn't matter in general.
The "B" extension is ratified as a combination of three extensions: "Zba",
"Zbb" and "Zbs". To maximize discoverability of the RISC-V target features,
this commit makes use of the "B" extension instead of its three members.
This way, `#[cfg(target_feature = "b")]` can also be used instead of:
`#[cfg(all(target_feature = "zba", target_feature = "zbb", target_feature = "zbs"))]`
This commit adds unprivileged ratified extensions that are either
dicoverable from the `riscv_hwprobe` syscall of the Linux kernel (as of
version 6.14) plus 1 minus 3 extensions.
Plus 1:
* "B"
This is a combination of "Zba", "Zbb" and "Zbs".
Note:
Although not required by the RISC-V specification, it is convenient to
imply "B" from its three members (will be implemented in LLVM 21/22) but
this is not yet implemented in Rust due to current implication handling.
It still implies three members *from* "B".
Minus 2:
* "Zcf" (target_arch = "riscv32" only)
This is the compression instruction subset corresponding "F".
This is implied from RV32 + "C" + "F" but this complex handling is
not yet supported by Rust's feature handling.
* "Zcd"
This is the compression instruction subset corresponding "D".
This is implied from "C" + "D" but this complex handling is
not yet supported by Rust's feature handling.
* "Supm"
Unlike regular RISC-V extensions, "Supm" and "Sspm" extensions do not
provide any specific architectural features / constraints but requires
*some* mechanisms to control pointer masking for the current mode.
For instance, reported existence of the "Supm" extension in Linux means
that `prctl` system call to control pointer masking is available and
there are alternative ways to detect the existence.
Notes:
* Because this commit adds the "Zca" extension (an integer subset of the
"C" extension), the "C" extension is modified to imply "Zca".
It's a much better name, more consistent with how we name such things.
Also rename `Lifetime::res` as `Lifetime::kind` to match. I suspect this
field used to have the type `LifetimeRes` and then the type was changed
but the field name remained the same.
Remove safe remove
`safe_remove_dir_all` and `safe_remove_file` use `canonicalize` to workaround a `MAX_PATH` limitation. However, this has not been needed in a long time, since the standard library handles this situation itself.
I've kept `safe_remove_file` (without `canonicalize`) because it also returns `Ok` if the file is not found. While, `safe_remove_file` is only used twice, matching on the error kind is sufficiently verbose that maybe it's still worth it?
Normalize ADT field in `find_tails_for_unsizing`
See the comment inline and in the test.
TL;DR is that we're getting getting a type from a `type_of` query and then matching on it structurally in codegen, so we're obligated to normalize it. The fact that this wasn't triggered earlier is that all of the types that have `CoerceUnsized` implementations never encounter aliases when peeling the ADT down to their base reference/ptr type.
**NOTE**: I also renamed some things and reorganized the function a bit.
Fixes#139812Fixes#74451, which I didn't think was interesting enough to add another test.
r? oli-obk
Reject test executables when not supported by target
Currently, compiling tests for SOLID produces an ICE, because SOLID does not support executables.
See https://github.com/rust-lang/rust/issues/138047
Namely, use a more sensical primary span.
Don't pretty-print AST nodes for the diagnostic message. Why:
* It's lossy (e.g., it doesn't replicate trailing `+`s in trait objects.
* It's prone to leak error nodes (printed as `(/*ERROR*/)`) since
the LHS can easily represent recovered code (e.g., `fn(i32?) + T`).
This is pretty weird code. As the `HACK` comment indicates, we push the
empty ident here only to make the path longer, so certain checks to
occur within `lint_if_path_starts_with_module`. `dummy` is a better
choice because it explicitly communicates that the actual value doesn't
matter.
These were low value even before #137978 resulted in empty names being
used much less. (Why check for non-emptiness in these three places?
There are thousands of places in the compiler you could check.)
Overhaul `AssocItem`
`AssocItem` has multiple fields that only make sense some of the time. E.g. the `name` can be empty if it's an RPITIT associated type. It's clearer and less error prone if these fields are moved to the relevant `kind` variants.
r? ``@fee1-dead``
Allow const patterns of matches to contain pattern types
Trying to pattern match on a type containing a pattern type will currently fail with an ICE
```rust
error: internal compiler error: compiler/rustc_mir_build/src/builder/matches/test.rs:459:18: invalid type for non-scalar compare: (u32) is 1..
--> src/main.rs:22:5
|
22 | TWO => {}
| ^^^
```
because the compiler tries to generate a MIR `BinOp(Eq)` operation on a pattern type, which is not supported. While we could support that, there are side effects of allowing this (none that would compile, but the compiler would simultaneously think it could `==` pattern types and that it could not because `PartialEq` is not implemented. So instead I change the logic for pattern matching to transmute pattern types to their base type before comparing.
r? ```@BoxyUwU```
cc #123646 ```@scottmcm``` ```@joshtriplett```
Enable contracts for const functions
Use `const_eval_select!()` macro to enable contract checking only at runtime. The existing contract logic relies on closures, which are not supported in constant functions.
This commit also removes one level of indirection for ensures clauses since we no longer build a closure around the ensures predicate.
Resolves#136925
**Call-out:** This is still a draft PR since CI is broken due to a new warning message for unreachable code when the bottom of the function is indeed unreachable. It's not clear to me why the warning wasn't triggered before.
r? ```@compiler-errors```
Printing "no pattern" as `_` isn't ideal, but better than crashing, and
HIR pretty-printing already has plenty of imperfections. The added `f2`
and `f6` examples are ones that triggered the crash.
Note that some of the added examples are printed badly, e.g.
`fn(, ...)`. The next commit will fix those.
Fixes#139633.
To accurately reflect that RPITIT assoc items don't have a name. This
avoids the use of `kw::Empty` to mean "no name", which is error prone.
Helps with #137978.
Specify `--print info=file` syntax in `--help`
Closes#139794
I moved the listing of information that can be printed to the help string as it's getting rather long and it makes the `[=FILE]` part easier to see
re-use `Sized` fast-path
There's an existing fast path for the `type_op_prove_predicate` predicate, checking for trivially `Sized` types, which can be re-used when evaluating obligations within queries. This should improve performance and was found to be beneficial in #137944.
r? types
Remove `define_debug_via_print` for `ExistentialProjection`, use regular structural debug impl
The pretty print impl for `ExistentialProjection` always prints `AssocItem = Ty`:
6e83046233/compiler/rustc_middle/src/ty/print/pretty.rs (L3293-L3299)
We can't change this, b/c it's used for both pretty printing dyn types and for legacy symbol mangling.
Unfortunately, we also use this printing procedure for `Debug` impls. That means that it leaves out the *trait name* and *trait args* when debug printing an `ExistentialProjection` (or an `ExistentialPredicate` which has a variant for `ExistentialProjection`). This leads to awkward situations, like the two seemingly identical existential projection predicates present in a `dyn Trait` type using the definition below:
```rust
trait Super { type Assoc; }
trait Foo: Super<A, Assoc = i32> + Super<B, Assoc = i32> {}
```
Namely, they both just render as `Projection(Assoc = i32)`! This makes debugging `dyn Trait` type system bugs really hard, so let's use the *regular* debug impl for `ExistentialProjection`.
Visit place in `BackwardIncompatibleDropHint` statement
Remove a weird hack from the `LocalUpdater` where we were manually visiting the place stored in a `StatementKind::BackwardIncompatibleDropHint` because the MIR visitor impls weren't doing so.
Also, clean up `BackwardIncompatibleDropHint`s in `CleanupPostBorrowck`, since they're not needed for runtime MIR.
Detect and provide suggestion for `&raw EXPR`
When emitting an error in the parser, and we detect that the previous token was `raw` and we *could* have consumed `const`/`mut`, suggest that this may have been a mistyped raw ref expr. To do this, we add `const`/`mut` to the expected token set when parsing `&raw` as an expression (which does not affect the "good path" of parsing, for the record).
This is kind of a rudimentary error improvement, since it doesn't actually attempt to recover anything, leading to some other knock-on errors b/c we still treat `&raw` as the expression that was parsed... but at least we add the suggestion! I don't think the parser grammar means we can faithfully recover `&raw EXPR` early, i.e. during `parse_expr_borrow`.
Fixes#133231
Fix up partial res of segment in primitive resolution hack
There is a hack in the resolver:
```
// In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
// don't report an error right away, but try to fallback to a primitive type.
```
This fixes up the resolution for primitives which would otherwise resolve to a module, but we weren't also updating the res of the path segment, leading to weird diagnostics.
We explicitly call `self.r.partial_res_map.insert` instead of `record_partial_res` b/c we have recorded a partial res already, and we specifically want to override it.
cc https://github.com/rust-lang/rust/issues/139095#issuecomment-2764371934
While LLVM is rather permissive in this regards, some other codegen
backends demand that once you declare a function for definition you
actually define contents of the function, which doesn't happen for naked
functions as we actually generate assembly for them.
Rollup of 9 pull requests
Successful merges:
- #138336 (Improve `-Z crate-attr` diagnostics)
- #139636 (Encode dep node edge count as u32 instead of usize)
- #139666 (cleanup `mir_borrowck`)
- #139695 (compiletest: consistently use `camino::{Utf8Path,Utf8PathBuf}` throughout)
- #139699 (Proactively update coroutine drop shim's phase to account for later passes applied during shim query)
- #139718 (enforce unsafe attributes in pre-2024 editions by default)
- #139722 (Move some things to rustc_type_ir)
- #139760 (UI tests: migrate remaining compile time `error-pattern`s to line annotations when possible)
- #139776 (Switch attrs to `diagnostic::on_unimplemented`)
r? `@ghost`
`@rustbot` modify labels: rollup
`hir::AssocItem` currently has a boolean `fn_has_self_parameter` field,
which is misplaced, because it's only relevant for associated fns, not
for associated consts or types. This commit moves it (and renames it) to
the `AssocKind::Fn` variant, where it belongs.
This requires introducing a new C-style enum, `AssocTag`, which is like
`AssocKind` but without the fields. This is because `AssocKind` values
are passed to various functions like `find_by_ident_and_kind` to
indicate what kind of associated item should be searched for, and having
to specify `has_self` isn't relevant there.
New methods:
- Predicates `AssocItem::is_fn` and `AssocItem::is_method`.
- `AssocItem::as_tag` which converts `AssocItem::kind` to `AssocTag`.
Removed `find_by_name_and_kinds`, which is unused.
`AssocItem::descr` can now distinguish between methods and associated
functions, which slightly improves some error messages.
Move some things to rustc_type_ir
This moves
- `PatternKind`
- `FlagComputation`
- `TypeWalker`
into rustc_type_ir.
Not strictly required for rust-analyzer next-solve integration, but helps with code duplication.
r? types
enforce unsafe attributes in pre-2024 editions by default
New unsafe attributes should emit an error when used without the `unsafe(...)` in all editions.
The `no_mangle`, `link_section` and `export_name` attributes are exceptions, and can still be used without an unsafe in earlier editions. The only attributes for which this change is relevant right now are `#[ffi_const]` and `#[ffi_pure]`.
This change is required for making `#[unsafe(naked)]` sound in pre-2024 editions.
Improve `-Z crate-attr` diagnostics
- Show the `#![ ... ]` in the span (to make it clear that it should not
be included in the CLI argument)
- Show more detailed errors when the crate has valid token trees but
invalid syntax.
Previously, `crate-attr=feature(foo),feature(bar)` would just say
"invalid crate attribute" and point at the comma. Now, it explicitly
says that the comma was unexpected, which is useful when using
`--error-format=short`. It also fixes the column to show the correct
span.
- Recover from parse errors. Previously we would abort immediately on
syntax errors; now we go on to try and type-check the rest of the
crate.
The new diagnostic code also happens to be slightly shorter.
r? diagnostics
fix smir's run! doc and import
This PR
* adds missing `extern crate rustc_middle` in `rustc_smir::run!` docstring
* adds missing `use rustc_smir::rustc_internal` in `run_driver!` scope
* also adjust some tests that don't need to import rustc_internalany more
