Add test for issue 125668
closes: #125668
The issue stemmed from improper handling of const {} blocks used in array length expressions. As of rustc 1.80.0-nightly (804421dff 2024-06-07), this ICE no longer occurs and the code compiles successfully 😀
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```
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
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
Let CStrings be either 1 or 2 byte aligned.
We see a regression on the `tests/assembly/cstring-merging.rs` test on s390x.
Some architectures (like s390x) require strings to be 2 byte aligned. Therefor the section name will be marked with a .2 postfix on this architectures.
Allowing a section name with a .1 or .2 postfix will make the test pass on either platform.
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.
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
Use `compiletest-ignore-dir` for bootstrap self-tests
Follow-up to #139705 and #139740.
I did another survey pass over `//@ ignore-test` under `tests/`, and this is the only 2 non-tests that should use `compiletest-ignore-dir`.
r? `@Zalathar` (or compiler/bootstrap)
Add test for issue 34834
closes: #34834
This PR adds a UI test for a case where a trait with an associated type using a higher-ranked trait bound (HRTB) failed to compile in Rust 1.55.0 but succeeded starting from 1.56.0.
```rust
pub trait Provides<'a> {
type Item;
}
pub trait Selector: for<'a> Provides<'a> {
type Namespace: PartialEq + for<'a> PartialEq<<Self as Provides<'a>>::Item>;
fn get_namespace(&self) -> <Self as Provides>::Item;
}
pub struct MySelector;
impl<'a> Provides<'a> for MySelector {
type Item = &'a str;
}
impl Selector for MySelector {
type Namespace = String;
fn get_namespace(&self) -> &str {
unimplemented!()
}
}
fn main() {}
```
* ❌ [compile fail (rustc: 1.55.0)](https://godbolt.org/z/T1jY1Ebo6)
* ⭕ [compile pass (rustc: 1.56.0)](https://godbolt.org/z/e4jo11Ma7)
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
Rollup of 8 pull requests
Successful merges:
- #139127 (Fix up partial res of segment in primitive resolution hack)
- #139392 (Detect and provide suggestion for `&raw EXPR`)
- #139767 (Visit place in `BackwardIncompatibleDropHint` statement)
- #139777 (Remove `define_debug_via_print` for `ExistentialProjection`, use regular structural debug impl)
- #139796 (ptr docs: add missing backtics around 'usize')
- #139801 (Add myself to mailmap)
- #139804 (use `realpath` in `bootstrap.py` when creating build-dir)
- #139807 (Improve wording of post-merge report)
r? `@ghost`
`@rustbot` modify labels: rollup
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
Some architectures (like s390x) require strings to be 2 byte aligned.
Therefor the section name will be marked with a .2 postfix on this
architectures.
Allowing a section name with a .1 or .2 postfix will make the test pass
on either platform.
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.
