Sync rustc_codegen_cranelift
I did a large refactoring of the intrinsics module to remove the intrinsic_match macro which is not very clear to other people. This also enables rustfmt to run on this code. While I already did a sync yesterday, I am going to do another sync again to avoid potential conflicts as those will likely be painful to resolve.
r? ``@ghost``
``@rustbot`` label +A-codegen +A-cranelift +T-compiler
Check that RPITs constrained by a recursive call in a closure are compatible
Fixes#99073
Adapts a similar visitor pattern to `find_opaque_ty_constraints` (that we use to check TAITs), but with some changes:
0. Only walk the "OnlyBody" children, instead of all items in the RPIT's defining scope
1. Only walk through the body's children if we found a constraining usage
2. Don't actually do any inference, just do a comparison and error if they're mismatched
----
r? `@oli-obk` -- you know all this impl-trait stuff best... is this the right approach? I can explain the underlying issue better if you'd like, in case that might reveal a better solution. Not sure if it's possible to gather up the closure's defining usages of the RPIT while borrowck'ing the outer function, that might be a better place to put this check...
Add a brief comment explaining why the diagnostic migration lints aren't
included in the `rustc::internal` diagnostic group.
Signed-off-by: David Wood <david.wood@huawei.com>
passes: port more of `check_attr` module
Continues from #99213.
Port more diagnostics in `rustc_passes::check_attr` to using the diagnostic derive and translation machinery.
r? `@compiler-errors`
Prefer visibility map parents that are not `doc(hidden)` first
Far simpler approach to #98876.
This only fixes the case where the parent is `doc(hidden)`, not where the child is `doc(hidden)` since I don't know how to get the attrs on the import statement given a `ModChild`... I'll try to follow up with that, but this is a good first step.
codegen: use new {re,de,}allocator annotations in llvm
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
r? `@nikic`
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
While we're here, we also emit allocator attributes on
__rust_alloc_zeroed. This should allow LLVM to perform more
optimizations for zeroed blocks, and probably fixes#90032. [This
comment](https://github.com/rust-lang/rust/issues/24194#issuecomment-308791157)
mentions "weird UB-like behaviour with bitvec iterators in
rustc_data_structures" so we may need to back this change out if things
go wrong.
The new test cases require LLVM 15, so we copy them into LLVM
14-supporting versions, which we can delete when we drop LLVM 14.
Rollup of 5 pull requests
Successful merges:
- #99618 (handle consts with param/infer in `const_eval_resolve` better)
- #99666 (Restore `Opaque` behavior to coherence check)
- #99692 (interpret, ptr_offset_from: refactor and test too-far-apart check)
- #99739 (Remove erroneous E0133 code from an error message.)
- #99748 (Use full type name instead of just saying `impl Trait` in "captures lifetime" error)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Use full type name instead of just saying `impl Trait` in "captures lifetime" error
I think this is very useful, especially when there's >1 `impl Trait`, and it just means passing around a bit more info that we already have access to.
Remove erroneous E0133 code from an error message.
This error message is about `derive` and `packed`, but E0133 is for
"Unsafe code was used outside of an unsafe function or block".
r? ``@estebank``
interpret, ptr_offset_from: refactor and test too-far-apart check
We didn't have any tests for the "too far apart" message, and indeed that check mostly relied on the in-bounds check and was otherwise probably not entirely correct... so I rewrote that check, and it is before the in-bounds check so we can test it separately.
Restore `Opaque` behavior to coherence check
Fixes#99663.
This broke in 84c3fcd2a0. I'm not exactly certain that adding this behavior back is necessarily correct, but at least the UI test I provided may stimulate some thoughts.
I think delaying a bug here is certainly not correct in the case of opaques -- if we want to change coherence behavior for opaques, then we should at least be emitting a new error.
r? ``@lcnr``
handle consts with param/infer in `const_eval_resolve` better
This PR addresses [this thread here](https://github.com/rust-lang/rust/pull/99449#discussion_r924141230). Was this the change you were looking for ``@lcnr?``
Interestingly, one test has begun to pass. Was that expected?
r? ``@lcnr``
Sync rustc_codegen_cranelift
This time most of the changes are bugfixes. No exciting new features to report. Thanks `@matthiaskrgr` for reporting a bunch of crashes!
r? `@ghost`
`@rustbot` label +A-codegen +A-cranelift +T-compiler
Remove reachable coverage without counters
Remove reachable coverage without counters to maintain invariant that
either there is no coverage at all or there is a live coverage counter
left that provides the function source hash.
The motivating example would be a following closure:
```rust
let f = |x: bool| {
debug_assert!(x);
};
```
Which, with span changes from #93967, with disabled debug assertions,
after the final CFG simplifications but before removal of dead blocks,
gives rise to MIR:
```rust
fn main::{closure#0}(_1: &[closure@a.rs:2:13: 2:22], _2: bool) -> () {
debug x => _2;
let mut _0: ();
bb0: {
Coverage::Expression(4294967295) = 1 - 2;
return;
}
...
}
```
Which also makes the initial instrumentation quite suspect, although
this pull request doesn't attempt to address that aspect directly.
Fixes#98833.
r? ``@wesleywiser`` ``@richkadel``
Remove some explicit `self.infcx` for `FnCtxt`, which already derefs into `InferCtxt`
The use of `self.infcx.method_on_infcx` vs `self.method_on_infcx` when `self` is a `FnCtxt` is a bit inconsistent, so I'm moving some `self.infcx` usages I found to just use autoderef
Slightly improve mismatched GAT where clause error
This makes the error reporting a bit more standardized between `where` on GATs and functions.
cc #99206 (`@BoxyUwU),` don't want to mark this as as "fixed" because they're still not perfect, but this is still an improvement IMO so I want to land it incrementally.
regarding "consider adding where clause to trait definition", we don't actually do that for methods as far as i can tell? i could file an issue to look into that maybe.
Enable raw-dylib for bin crates
Fixes#93842
When `raw-dylib` is used in a `bin` crate, we need to collect all of the `raw-dylib` functions, generate the import library and add that to the linker command line.
I also changed the tests so that 1) the C++ dlls are created after the Rust dlls, thus there is no chance of accidentally using them in the Rust linking process and 2) disabled generating import libraries when building with MSVC.
Rollup of 9 pull requests
Successful merges:
- #92390 (Constify a few `(Partial)Ord` impls)
- #97077 (Simplify some code that depend on Deref)
- #98710 (correct the output of a `capacity` method example)
- #99084 (clarify how write_bytes can lead to UB due to invalid values)
- #99178 (Lighten up const_prop_lint, reusing const_prop)
- #99673 (don't ICE on invalid dyn calls)
- #99703 (Expose size_hint() for TokenStream's iterator)
- #99709 (`Inherited` always has `TypeckResults` available)
- #99713 (Fix sidebar background)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Simplify some code that depend on Deref
Now that we can assume #97025 works, it's safe to expect Deref is always in the first place of projections. With this, I was able to simplify some code that depended on Deref's place in projections. When we are able to move Derefer before `ElaborateDrops` successfully we will be able to optimize more places.
r? `@oli-obk`
Resolve function lifetime elision on the AST
~Based on https://github.com/rust-lang/rust/pull/97720~
Lifetime elision for functions is purely syntactic in nature, so can be resolved on the AST.
This PR replicates the elision logic and diagnostics on the AST, and replaces HIR-based resolution by a `delay_span_bug`.
This refactor allows for more consistent diagnostics, which don't have to guess the original code from HIR.
r? `@petrochenkov`
Remove reachable coverage without counters to maintain invariant that
either there is no coverage at all or there is a live coverage counter
left that provides the function source hash.
The motivating example would be a following closure:
```rust
let f = |x: bool| {
debug_assert!(x);
};
```
Which, with span changes from #93967, with disabled debug assertions,
after the final CFG simplifications but before removal of dead blocks,
gives rise to MIR:
```rust
fn main::{closure#0}(_1: &[closure@a.rs:2:13: 2:22], _2: bool) -> () {
debug x => _2;
let mut _0: ();
bb0: {
Coverage::Expression(4294967295) = 1 - 2;
return;
}
...
}
```
Use `VecMap::get` in `ConstraintLocator::check`
Also rename the `def_id` param to `item_def_id` because that's easily confused with `self.def_id` (which is the opaque ty did).
Add `sign-ext` target feature to the WASM target
Some target features are still missing from that list.
See #97808 for basically the same PR by `@alexcrichton.`
Related issue: #96472.
PR introducing this issue: #87402.
Improve error messages involving `derive` and `packed`.
There are two errors involving `derive` and `packed`.
```
`#[derive]` can't be derived on a `#[repr(packed)]` struct with type or const parameters
`#[derive]` can't be derived on a `#[repr(packed)]` struct that does not derive Copy
```
The second one overstates things. It is possible to use derive on a
repr(packed) struct that doesn't derive Copy in two cases.
- If all the fields within the struct meet the required alignment: 1 for
`repr(packed)`, or `N` for `repr(packed(N))`.
- If `Default` is the only trait derived.
This commit improves things in a few ways.
- Changes the errors to say `this trait can't be derived on this ...`.
This is more accurate, because it's just *this* trait and *this*
packed struct that are a problem, not *all* derived traits on *all*
packed structs.
- Adds more details to the "ERROR" lines in the test case, enough to
distinguish between the two error messages.
- Adds more cases to the test case that don't cause errors, e.g. `Default`
derives.
- Uses a wider variety of builtin traits in the test case, for better coverage.
r? `@estebank`
Address issue #99265 by checking each positionally used argument
to see if the argument is named and adding a lint to use the name
instead. This way, when named arguments are used positionally in a
different order than their argument order, the suggested lint is
correct.
For example:
```
println!("{b} {}", a=1, b=2);
```
This will now generate the suggestion:
```
println!("{b} {a}", a=1, b=2);
```
Additionally, this check now also correctly replaces or inserts
only where the positional argument is (or would be if implicit).
Also, width and precision are replaced with their argument names
when they exists.
Since the issues were so closely related, this fix for issue #99265
also fixes issue #99266.
Fixes#99265Fixes#99266
rmeta: avoid embedding `StabilityLevel::Unstable` reason multiple times into .rmeta\.rlib files
Avoids bloating size of some rmeta\rlib files by not placing default string for `StabilityLevel::Unstable` reason multiple times, affects only stdlib\rustc artifacts. For stdlib cuts about 3% (diff of total size for patched\unpatched *.rmeta files of stage1-std) of file size, depending on crates.
fixes#88180
There are two errors involving `derive` and `packed`.
```
`#[derive]` can't be derived on a `#[repr(packed)]` struct with type or const parameters
`#[derive]` can't be derived on a `#[repr(packed)]` struct that does not derive Copy
```
The second one overstates things. It is possible to use derive on a
repr(packed) struct that doesn't derive Copy in two cases.
- If all the fields within the struct meet the required alignment: 1 for
`repr(packed)`, or `N` for `repr(packed(N))`.
- If `Default` is the only trait derived.
This commit improves things in a few ways.
- Changes the errors to say `$TRAIT can't be derived on this ...`.
This is more accurate, because it's just $TRAIT and *this* packed
struct that are a problem, not *all* derived traits on *all* packed
structs.
- Adds more details to the "ERROR" lines in the test case, enough to
distinguish between the two error messages.
- Adds more cases to the test case that don't cause errors, e.g. `Default`
derives.
- Uses a wider variety of builtin traits in the test case, for better coverage.
Update doc comments that refer to config parameter
This commit updates the `source_file_to_parser` and the
`maybe_source_file_to_parse` function's doc comments which currently
refer to a `config` parameter. The doc comments have been updated to
refer to the `session` parameter similar to the doc comment for
`try_file_to_source_file`, which also takes a `&Session` parameter.
remove some provenance-related machine hooks that Miri no longer needs
Then we can make `scalar_to_ptr` a method on `Scalar`. :)
Fixes https://github.com/rust-lang/miri/issues/2188
r? `@oli-obk`
This commit updates the source_file_to_parser and the
maybe_source_file_to_parse function's doc comments which currently
refer to a config parameter. The doc comments have been updated to
refer to the 'session' parameter similar to the doc comment for
try_file_to_source_file, which also takes a &Session parameter.
Upgrade indexmap and thorin-dwp to use hashbrown 0.12
This removes the last dependencies on hashbrown 0.11.
This also upgrades to hashbrown 0.12.3 to fix a double-free (#99372).
Add fine-grained LLVM CFI support to the Rust compiler
This PR improves the LLVM Control Flow Integrity (CFI) support in the Rust compiler by providing forward-edge control flow protection for Rust-compiled code only by aggregating function pointers in groups identified by their return and parameter types.
Forward-edge control flow protection for C or C++ and Rust -compiled code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code share the same virtual address space) will be provided in later work as part of this project by identifying C char and integer type uses at the time types are encoded (see Type metadata in the design document in the tracking issue https://github.com/rust-lang/rust/issues/89653).
LLVM CFI can be enabled with -Zsanitizer=cfi and requires LTO (i.e., -Clto).
Thank you again, `@eddyb,` `@nagisa,` `@pcc,` and `@tmiasko` for all the help!
Rollup of 6 pull requests
Successful merges:
- #99298 (Make `ui-fulldeps/gated-plugins` and `ui-fulldeps/multiple-plugins` tests stage 2 only)
- #99396 (Add some additional double-adjustment regression tests)
- #99449 (Do not resolve associated const when there is no provided value)
- #99595 (Mark atomics as unsupported on thumbv6m)
- #99627 (Lock stdout once when listing tests)
- #99638 (Remove Clean trait implementation for hir::Ty and middle::Ty)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Mark atomics as unsupported on thumbv6m
The thumbv6m target does not support atomics. Historically, LLVM
had a bug where atomic load/stores for this target were emitted
as plain load/stores rather than as libatomic calls. This was
fixed in https://reviews.llvm.org/D120026, which will be part of
LLVM 15. As we require that "atomic support" does not use libatomic,
we need to indicate that this target does not have native atomics.
Do not resolve associated const when there is no provided value
Fixes#98629, since now we just delay a bug when we're not able to evaluate a const item due to the value not actually being provided by anything. This means compilation proceeds forward to where the "missing item in impl" error is emitted.
----
The root issue here is that when we're looking for the defining `LeafDef` in `resolve_associated_item`, we end up getting the trait's AssocItem instead of the impl's AssocItem (which does not exist). This resolution "succeeds" even if the trait's item has no default value, and then since this item has no value to evaluate, it turns into a const eval error.
This root issue becomes problematic (as in #98629) when this const eval error happens in wfcheck (for example, due to normalizing the param-env of something that references this const). Since this happens sooner than the check that an impl actually provides all of the items that a trait requires (which happens during later typecheck), we end up aborting compilation early with only this un-informative message.
I'm not exactly sure _why_ this bug arises due to #96591 -- perhaps valtrees are evaluated more eagerly than in the old system?
r? ``@oli-obk`` or ``@lcnr`` since y'all are familiar with const eval and reviewed #96591, though feel free to reassign.
This is a regression from stable to beta, so I would be open to considering this for beta backport. It seems correct to me, especially given the improvements in the other UI tests this PR touches, but may have some side-effects that I'm unaware of...?
Add support for LLVM ShadowCallStack.
LLVMs ShadowCallStack provides backward edge control flow integrity protection by using a separate shadow stack to store and retrieve a function's return address.
LLVM currently only supports this for AArch64 targets. The x18 register is used to hold the pointer to the shadow stack, and therefore this only works on ABIs which reserve x18. Further details are available in the [LLVM ShadowCallStack](https://clang.llvm.org/docs/ShadowCallStack.html) docs.
# Usage
`-Zsanitizer=shadow-call-stack`
# Comments/Caveats
* Currently only enabled for the aarch64-linux-android target
* Requires the platform to define a runtime to initialize the shadow stack, see the [LLVM docs](https://clang.llvm.org/docs/ShadowCallStack.html) for more detail.
This commit improves the LLVM Control Flow Integrity (CFI) support in
the Rust compiler by providing forward-edge control flow protection for
Rust-compiled code only by aggregating function pointers in groups
identified by their return and parameter types.
Forward-edge control flow protection for C or C++ and Rust -compiled
code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code
share the same virtual address space) will be provided in later work as
part of this project by identifying C char and integer type uses at the
time types are encoded (see Type metadata in the design document in the
tracking issue #89653).
LLVM CFI can be enabled with -Zsanitizer=cfi and requires LTO (i.e.,
-Clto).
Use span_bug in case of unexpected rib kind
Extremely minor QOL change to improve the ICE compiler output in case
this default match case is encountered (an unexpected rib kind).
I have limited experience in this area of the compiler; please let me know
if a span more precise than `param.ident.span` is more applicable.
Fix hack that remaps env constness.
WARNING: might have perf implications.
Are there any more problems with having a constness in the `ParamEnv` now? :)
r? `@oli-obk`
The thumbv6m target does not support atomics. Historically, LLVM
had a bug where atomic load/stores for this target were emitted
as plain load/stores rather than as libatomic calls. This was
fixed in https://reviews.llvm.org/D120026, which will be part of
LLVM 15. As we require that "atomic support" does not use libatomic,
we need to indicate that this target does not have native atomics.
Improve suggestions for returning binding
Fixes#99525
Also reworks the cause codes for match and if a bit, I think cleaning them up in a positive way.
We no longer need to call `could_remove_semicolon` in successful code, which might save a few cycles?
Fix unreachable coverage generation for inlined functions
To generate a function coverage we need at least one coverage counter,
so a coverage from unreachable blocks is retained only when some live
counters remain.
The previous implementation incorrectly retained unreachable coverage,
because it didn't account for the fact that those live counters can
belong to another function due to inlining.
Fixes#98833.
make vtable pointers entirely opaque
This implements the scheme discussed in https://github.com/rust-lang/unsafe-code-guidelines/issues/338: vtable pointers should be considered entirely opaque and not even readable by Rust code, similar to function pointers.
- We have a new kind of `GlobalAlloc` that symbolically refers to a vtable.
- Miri uses that kind of allocation when generating a vtable.
- The codegen backends, upon encountering such an allocation, call `vtable_allocation` to obtain an actually dataful allocation for this vtable.
- We need new intrinsics to obtain the size and align from a vtable (for some `ptr::metadata` APIs), since direct accesses are UB now.
I had to touch quite a bit of code that I am not very familiar with, so some of this might not make much sense...
r? `@oli-obk`
move `considering_regions` to the infcx
it seems weird to prove some obligations which constrain inference vars while ignoring regions in a context which considers regions. This is especially weird because even for a fulfillment context with ignored regions, we still added region outlives bounds when directly relating regions.
tbh our handling of regions is still very weird, but at least this is a step in the right direction imo.
r? rust-lang/types
Allow to disable thinLTO buffer to support lto-embed-bitcode lld feature
Hello
This change is to fix issue (https://github.com/rust-lang/rust/issues/84395) in which passing "-lto-embed-bitcode=optimized" to lld when linking rust code via linker-plugin-lto doesn't produce the expected result.
Instead of emitting a single unified module into a llvmbc section of the linked elf, it emits multiple submodules.
This is caused because rustc emits the BC modules after running llvm `createWriteThinLTOBitcodePass` pass.
Which in turn triggers a thinLTO linkage and causes the said issue.
This patch allows via compiler flag (-Cemit-thin-lto=<bool>) to select between running `createWriteThinLTOBitcodePass` and `createBitcodeWriterPass`.
Note this pattern of selecting between those 2 passes is common inside of LLVM code.
The default is to match the old behavior.
Only compile #[used] as llvm.compiler.used for ELF targets
This returns `#[used]` to how it worked prior to the LLVM 13 update. The intention is not that this is a stable promise.
I'll add tests later today. The tests will test things that we don't actually promise, though.
It's a deliberately small patch, mostly comments. And assuming it's reviewed and lands in time, IMO it should at least be considered for uplifting to beta (so that it can be in 1.59), as the change broke many crates in the ecosystem, even if they are relying on behavior that is not guaranteed.
# Background
LLVM has two ways of preventing removal of an unused variable: `llvm.compiler.used`, which must be present in object files, but allows the linker to remove the value, and `llvm.used` which is supposed to apply to the linker as well, if possible.
Prior to LLVM 13, `llvm.used` and `llvm.compiler.used` were the same on ELF targets, although they were different elsewhere. Prior to our update to LLVM 13, we compiled `#[used]` using `llvm.used` unconditionally, even though we only ever promised behavior like `llvm.compiler.used`.
In LLVM 13, ELF targets gained some support for preventing linker removal of `llvm.used` via the SHF_RETAIN section flag. This has some compatibility issues though: Concretely: some older versions `ld.gold` (specifically ones prior to v2.36, released in Jan 2021) had a bug where it would fail to place a `#[used] #[link_section = ".init_array"]` static in between `__init_array_start`/`__init_array_end`, leading to code that does this failing to run a static constructor. This is technically not a thing we guarantee will work, is a common use case, and is needed in `libstd` (for example, to get access to `std::env::args()` even if Rust does not control `main`, such as when in a `cdylib` crate).
As a result, when updating to LLVM 13, we unconditionally switched to using `llvm.compiler.used`, which mirror the guarantees we make for `#[used]` and doesn't require the latest ld.gold. Unfortunately, this happened to break quite a bit of things in the ecosystem, as non-ELF targets had come to rely on `#[used]` being slightly stronger. In particular, there are cases where it will even break static constructors on these targets[^initinit] (and in fact, breaks way more use cases, as Mach-O uses special sections as an interface to the OS/linker/loader in many places).
As a result, we only switch to `llvm.compiler.used` on ELF[^elfish] targets. The rationale here is:
1. It is (hopefully) identical to the semantics we used prior to the LLVM13 update as prior to that update we unconditionally used `llvm.used`, but on ELF `llvm.used` was the same as `llvm.compiler.used`.
2. It seems to be how Clang compiles this, and given that they have similar (but stronger) compatibility promises, that makes sense.
[^initinit]: For Mach-O targets: It is not always guaranteed that `__DATA,__mod_init_func` is a GC root if it does not have the `S_MOD_INIT_FUNC_POINTERS` flag which we cannot add. In most cases, when ld64 transformed this section into `__DATA_CONST,__mod_init_func` it gets applied, but it's not clear that that is intentional (let alone guaranteed), and the logic is complex enough that it probably happens sometimes, and people in the wild report it occurring.
[^elfish]: Actually, there's not a great way to tell if it's ELF, so I've approximated it.
This is pretty ad-hoc and hacky! We probably should have a firmer set of guarantees here, but this change should relax the pressure on coming up with that considerably, returning it to previous levels.
---
Unsure who should review so leaving it open, but for sure CC `@nikic`
Remove the unused StableSet and StableMap types from rustc_data_structures.
The current implementation is not "stable" in the same sense that `HashStable` and `StableHasher` are stable, i.e. across compilation sessions. So, in my opinion, it's better to remove those types (which are basically unused anyway) than to give the wrong impression that these are safe for incr. comp.
I plan to provide new "stable" collection types soon that can be used to replace `FxHashMap` and `FxHashSet` in query results (see [draft](69d03ac7a7)). It's unsound that `HashMap` and `HashSet` implement `HashStable` (see https://github.com/rust-lang/rust/issues/98890 for a recent P-critical bug caused by this) -- so we should make some progress there.
Rollup of 9 pull requests
Successful merges:
- #99212 (introduce `implied_by` in `#[unstable]` attribute)
- #99352 (Use `typeck_results` to avoid duplicate `ast_ty_to_ty` call)
- #99355 (better error for bad depth parameter on macro metavar expr)
- #99480 (Diagnostic width span is not added when '0$' is used as width in format strings)
- #99488 (compiletest: Allow using revisions with debuginfo tests.)
- #99489 (rustdoc UI fixes)
- #99508 (Avoid `Symbol` to `String` conversions)
- #99510 (adapt assembly/static-relocation-model test for LLVM change)
- #99516 (Use new tracking issue for proc_macro::tracked_*.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Diagnostic width span is not added when '0$' is used as width in format strings
When the following code is run rustc does not add diagnostic spans for the width argument. Such spans are necessary for a clippy lint that I am currently writing.
```rust
println!("Hello {1:0$}!", 5, "x");
// ^^
// Should have a span here
```
introduce `implied_by` in `#[unstable]` attribute
Requested by the library team [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/better.20support.20for.20partial.20stabilizations/near/285581519).
If part of a feature is stabilized and a new feature is added for the remaining parts, then the `implied_by` meta-item can be added to `#[unstable]` to indicate which now-stable feature was used previously.
```diagnostic
error: the feature `foo` has been partially stabilized since 1.62.0 and is succeeded by the feature `foobar`
--> $DIR/stability-attribute-implies-using-unstable.rs:3:12
|
LL | #![feature(foo)]
| ^^^
|
note: the lint level is defined here
--> $DIR/stability-attribute-implies-using-stable.rs:2:9
|
LL | #![deny(stable_features)]
| ^^^^^^^^^^^^^^^
help: if you are using features which are still unstable, change to using `foobar`
|
LL | #![feature(foobar)]
| ~~~~~~
help: if you are using features which are now stable, remove this line
|
LL - #![feature(foo)]
|
```
When a `#![feature(..)]` attribute still exists for the now-stable attribute, then there this has two effects:
- There will not be an stability error for uses of items from the implied feature which are still unstable (until the `#![feature(..)]` is removed or updated to the new feature).
- There will be an improved diagnostic for the remaining use of the feature attribute for the now-stable feature.
```rust
/// If part of a feature is stabilized and a new feature is added for the remaining parts,
/// then the `implied_by` attribute is used to indicate which now-stable feature previously
/// contained a item.
///
/// ```pseudo-Rust
/// #[unstable(feature = "foo", issue = "...")]
/// fn foo() {}
/// #[unstable(feature = "foo", issue = "...")]
/// fn foobar() {}
/// ```
///
/// ...becomes...
///
/// ```pseudo-Rust
/// #[stable(feature = "foo", since = "1.XX.X")]
/// fn foo() {}
/// #[unstable(feature = "foobar", issue = "...", implied_by = "foo")]
/// fn foobar() {}
/// ```
```
In the Zulip discussion, this was envisioned as `implies` on `#[stable]` but I went with `implied_by` on `#[unstable]` because it means that only the unstable attribute needs to be changed in future, not the new stable attribute, which seems less error-prone. It also isn't particularly feasible for me to detect whether items from the implied feature are used and then only suggest updating _or_ removing the `#![feature(..)]` as appropriate, so I always do both.
There's some new information in the cross-crate metadata as a result of this change, that's a little unfortunate, but without requiring that the `#[unstable]` and `#[stable]` attributes both contain the implication information, it's necessary:
```rust
/// This mapping is necessary unless both the `#[stable]` and `#[unstable]` attributes should
/// specify their implications (both `implies` and `implied_by`). If only one of the two
/// attributes do (as in the current implementation, `implied_by` in `#[unstable]`), then this
/// mapping is necessary for diagnostics. When a "unnecessary feature attribute" error is
/// reported, only the `#[stable]` attribute information is available, so the map is necessary
/// to know that the feature implies another feature. If it were reversed, and the `#[stable]`
/// attribute had an `implies` meta item, then a map would be necessary when avoiding a "use of
/// unstable feature" error for a feature that was implied.
```
I also change some comments to documentation comments in the compiler, add a helper for going from a `Span` to a `Span` for the entire line, and fix a incorrect part of the pre-existing stability attribute diagnostics.
cc `@yaahc`
interpret: rename Tag/PointerTag to Prov/Provenance
We were pretty inconsistent with calling this the "tag" vs the "provenance" of the pointer; I think we should consistently call it "provenance".
r? `@oli-obk`
Improves the diagnostic when a feature attribute is specified
unnecessarily but the feature implies another (i.e. it was partially
stabilized) to refer to the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
Adds a simple helper function to the `SourceMap` for extending a `Span`
to encompass the entire line it is on - useful for suggestions where
removing a line is the suggested action.
Signed-off-by: David Wood <david.wood@huawei.com>
If part of a feature is stabilized and a new feature is added for the
remaining parts, then the `implied_by` attribute can be used to indicate
which now-stable feature previously contained a item. If the now-stable
feature is still active (if the user has only just updated rustc, for
example) then there will not be an stability error for uses of the item
from the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
Rollup of 7 pull requests
Successful merges:
- #98101 (stdlib support for Apple WatchOS)
- #99345 (Do not allow typeck children items to constrain outer RPITs)
- #99383 (Formalize defining_use_anchor)
- #99436 (Add flag to configure `noalias` on `Box<T>`)
- #99483 (Fix a numerical underflow in tuple wrap suggestion)
- #99485 (Stop injecting `#[allow(unused_qualifications)]` in generated `derive` implementations)
- #99486 (Refactor: remove a string comparison between types in `check_str_addition`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Stop injecting `#[allow(unused_qualifications)]` in generated `derive` implementations
Currently, the `#[derive]` attribute always injects an `#[allow(unused_qualifications)]` attribute in the generated implementation. This results in an error when a derive is used in combination with `#![forbid(unused_qualifications)]`, because the `forbid` rule by definition cannot be overridden by `allow`.
It appears that the original issue that prompted the inclusion of `#[allow(unused_qualifications)]` (#19102) is no longer present in the current stable release, and the associated [test case](https://github.com/rust-lang/rust/blob/master/src/test/ui/issues/issue-19102.rs) still passes, so the `allow` is simply removed here.
Fixes#71898.
Fix a numerical underflow in tuple wrap suggestion
Fixes#99482
I'm a clown, I rewrote the arg mismatch algo to use well-typed indices to avoid things like this, but then I added my own indexing bug, lol.
Add flag to configure `noalias` on `Box<T>`
The aliasing rules of `Box<T>` are still not decided, but currently, `Box<T>` is unique and gets `noalias`. To aid making an informed decision about the future of `Box<T>`, this PR adds a flag `-Zbox-noalias` to configure `noalias` for `Box<T>` (for example, for benchmarking). The same flag already exists for `&mut T` `noalias`, where it was added because it was the problem of various miscompilations in LLVM.
For more information, see rust-lang/unsafe-code-guidelines#326
Formalize defining_use_anchor
This tackles issue #57961
Introduces new enum called `DefiningAnchor` that replaces `Option<LocalDefId>` of `defining_use_anchor`. Now every use of it is explicit and exhaustively matched, catching errors like one in the linked issue. This is not a perfect fix but it's a step in the right direction.
r? `@oli-obk`
Do not allow typeck children items to constrain outer RPITs
Fixes#99073 in a simpler and more conservative way than #99079. Simply raise a mismatched types error if we try to constrain an RPIT in an item that isn't the RPIT's parent.
r? `@oli-obk`
When an unexpected meta item is provided to `#[stable]`, the diagnostic
lists "since" and "note" as expected meta-items, however the surrounding
code actually expects "feature" and "since".
Signed-off-by: David Wood <david.wood@huawei.com>
Rollup of 5 pull requests
Successful merges:
- #98784 (Suggest returning local on "expected `ty`, found `()`" due to expr-less block)
- #98916 (Windows: Use `FindFirstFileW` for getting the metadata of locked system files)
- #99433 (Erase regions before comparing signatures of foreign fns.)
- #99452 (int_macros was only using to_xe_bytes_doc and not from_xe_bytes_doc)
- #99481 (Add regression test for #71547)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Erase regions before comparing signatures of foreign fns.
Fixes https://github.com/rust-lang/rust/issues/99276
The version with explicit lifetimes is probably tracked in another bug, but I could not find it.
Suggest returning local on "expected `ty`, found `()`" due to expr-less block
Putting this up for _initial_ review. Notably, this doesn't consider if the value has possibly been moved, or whether the type is `Copy`. It also provides a structured suggestion if there's one "preferred" binding that matches the type (i.e. one binding in the block or its parent), otherwise it just points them out if there's fewer than 4 of them.
Fixes#98177
r? `@estebank`
Enable check-cfg in stage0
Now that the bootstrap cargo supports `rustc-check-cfg` we can now enable it with `-Zcheck-cfg=output` and use it in `rustc_llvm` to unblock `--check-cfg` support in stage0.
r? `@Mark-Simulacrum`
Let's avoid using two different terms for the same thing -- let's just call it "provenance" everywhere.
In Miri, provenance consists of an AllocId and an SbTag (Stacked Borrows tag), which made this even more confusing.
Improve the function pointer docs
This is #97842 but for function pointers instead of tuples. The concept is basically the same.
* Reduce duplicate impls; show `fn (T₁, T₂, …, Tₙ)` and include a sentence saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
https://notriddle.com/notriddle-rustdoc-test/std/primitive.fn.html
interpret: make some large types not Copy
Also remove some unused trait impls (mostly HashStable).
This didn't find any unnecessary copies that I managed to avoid, but it might still be better to require explicit clone for these types? Not sure.
r? `@oli-obk`
* Reduce duplicate impls; show only the `fn (T)` and include a sentence
saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
use `par_for_each_in` in `par_body_owners` and `collect_crate_mono_items`
Using `par_iter` in non-parallel mode will cause the entire process to abort when any iteration panics. So we can use `par_for_each_in` instead to make the error message consistent with parallel mode. This means that the compiler will output more error messages in some cases. This fixes the following ui tests when set `parallel-compiler = true`:
```
[ui] src/test\ui\privacy\privacy2.rs
[ui] src/test\ui\privacy\privacy3.rs
[ui] src/test\ui\type_length_limit.rs
```
This refers to #68171
Updates #75760
Revert "Stabilize $$ in Rust 1.63.0"
This mechanically reverts commit 9edaa76adc, the one commit from #95860.
https://github.com/rust-lang/rust/issues/99035; the behavior of `$$crate` is potentially unexpected and not ready to be stabilized. https://github.com/rust-lang/rust/pull/99193 attempts to forbid `$$crate` without also destabilizing `$$` more generally.
`@rustbot` modify labels +T-compiler +T-lang +P-medium +beta-nominated +relnotes
(applying the labels I think are accurate from the issue and alternative partial revert)
cc `@Mark-Simulacrum`
use body's param-env when checking if type needs drop
The type comes from the body, so we should be using the body's param-env, as opposed to the ADT's param env, because we know less in the latter compared to the former.
Fixes#99375
Add E0790 as more specific variant of E0283
Fixes#81701
I think this should be good to go, there are only two things where I am somewhat unsure:
- Is there a better way to get the fully-qualified path for the suggestion? I tried `self.tcx.def_path_str`, but that didn't seem to always give a correct path for the context.
- Should all this be extracted into it's own method or is it fine where it is?
r? `@estebank`
