Permit ty::Bool in const generics for v0 mangling
This should unbreak using new-symbol-mangling = true in config.toml (once it lands in beta anyway).
Fixes#76365 (well, it will, but seems fine to close as soon as we have support)
r? @eddyb (for mangling) but I'm okay with some other reviewer too :)
Bypass const_item_mutation if const's type has Drop impl
Follow-up to #75573. This PR disables the const_item_mutation lint in cases that the const has a Drop impl which observes the mutation.
```rust
struct Log { msg: &'static str }
const LOG: Log = Log { msg: "" };
impl Drop for Log {
fn drop(&mut self) { println!("{}", self.msg); }
}
LOG.msg = "wow"; // prints "wow"
```
r? @Aaron1011
Add `-Zprecise-enum-drop-elaboration`
Its purpose is to assist in debugging #77382 and #74551. Passing `-Zprecise-enum-drop-elaboration=no` will turn off the added precision that seems to be causing issues on some platforms. This assumes that we can reproduce #77382 on the latest master. I should have done this earlier. Oh well.
cc @cuviper
r? @pnkfelix
resolve: prohibit anon const non-static lifetimes
Fixes#75323, fixes#74447 and fixes#73375.
This PR prohibits non-static lifetimes in anonymous constants when only the `min_const_generics` feature is enabled. ~~To do so, `to_region_vid`'s `bug!` had to be changed into a delayed bug, which unfortunately required providing it a `TyCtxt`.~~
---
~~While I am happy with how the implementation of the error turned out in `rustc_passes::check_const`, emitting an error wasn't sufficient to avoid hitting the ICE later. I also tried implementing the error in `rustc_mir::transform::check_consts::validation` and that worked, but it didn't silence the ICE either. To silence the ICE, I changed it to a delayed bug which worked but was more invasive that I would have liked, and required I return an incorrect lifetime. It's possible that this check should be implemented earlier in the compiler to make the invasive changes unnecessary, but I wasn't sure where that would be and wanted to get some feedback first.~~
The approach taken by this PR has been changed to implement the error in name resolution, which ended up being much simpler.
cc @rust-lang/wg-const-eval
r? @lcnr
This commit modifies name resolution to emit an error when non-static
lifetimes are used in anonymous constants when the `min_const_generics`
feature is enabled.
Signed-off-by: David Wood <david@davidtw.co>
Disable the SimplifyArmIdentity mir-opt
The optimization still has some bugs that need to be worked out
such as #77359.
We can try re-enabling this again after the known issues are resolved.
r? `@oli-obk`
Related: https://github.com/rust-lang/rust/issues/66741
Guarded with `#![feature(default_alloc_error_handler)]` a default
`alloc_error_handler` is called, if a custom allocator is used and no
other custom `#[alloc_error_handler]` is defined.
The panic message does not contain the size anymore, because it would
pull in the fmt machinery, which would blow up the code size
significantly.
rustc_metadata: Do not forget to encode inherent impls for foreign types
So I tried to move FFI interface for LLVM from `rustc_codegen_llvm` to `rustc_llvm` and immediately encountered this fascinating issue.
Fixes https://github.com/rust-lang/rust/issues/46665.
Overhaul const-checking diagnostics
The primary purpose of this PR was to remove `NonConstOp::STOPS_CONST_CHECKING`, which causes any additional errors found by the const-checker to be silenced. I used this flag to preserve diagnostic parity with `qualify_min_const_fn.rs`, which has since been removed.
However, simply removing the flag caused a deluge of errors in some cases, since an error would be emitted any time a local or temporary had a wrong type. To remedy this, I added an alternative system (`DiagnosticImportance`) to silence additional error messages that were likely to distract the user from the underlying issue. When an error of the highest importance occurs, all less important errors are silenced. When no error of the highest importance occurs, all less important errors are emitted after checking is complete. Following the suggestions from the important error is usually enough to fix the less important errors, so this should lead to better UX most of the time.
There's also some unrelated diagnostics improvements in this PR isolated in their own commits. Splitting them out would be possible, but a bit of a pain. This isn't as tidy as some of my other PRs, but it should *only* affect diagnostics, never whether or not something passes const-checking. Note that there are a few trivial exceptions to this, like banning `Yield` in all const-contexts, not just `const fn`.
As always, meant to be reviewed commit-by-commit.
r? `@oli-obk`
adt_destructor by default also validates the Drop impl using
dropck::check_drop_impl, which contains an expect_local(). This
leads to ICE in check_const_item_mutation if the const's type is
not a local type.
thread 'rustc' panicked at 'DefId::expect_local: `DefId(5:4805 ~ alloc[d7e9]::vec::{impl#50})` isn't local', compiler/rustc_span/src/def_id.rs:174:43
stack backtrace:
0: rust_begin_unwind
1: rustc_span::def_id::DefId::expect_local::{{closure}}
2: rustc_typeck::check::dropck::check_drop_impl
3: rustc_middle::ty::util::<impl rustc_middle::ty::context::TyCtxt>::calculate_dtor::{{closure}}
4: rustc_middle::ty::trait_def::<impl rustc_middle::ty::context::TyCtxt>::for_each_relevant_impl
5: rustc_middle::ty::util::<impl rustc_middle::ty::context::TyCtxt>::calculate_dtor
6: rustc_typeck::check::adt_destructor
7: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::adt_destructor>::compute
8: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
9: rustc_query_system::query::plumbing::get_query_impl
10: rustc_mir::transform::check_const_item_mutation::ConstMutationChecker::is_const_item_without_destructor
Stable hashing: add comments and tests concerning platform-independence
SipHasher128 implements short_write in an endian-independent way, yet
its write_xxx Hasher trait methods undo this endian-independence by byte
swapping the integer inputs on big-endian hardware. StableHasher then
adds endian-independence back by also byte-swapping on big-endian
hardware prior to invoking SipHasher128.
This double swap may have the appearance of being a no-op, but is in
fact by design. In particular, we really do want SipHasher128 to be
platform-dependent, in order to be consistent with the libstd SipHasher.
Try to clarify this intent. Also, add and update a couple of unit tests.
---
Previous commit text:
~SipHasher128: fix platform-independence confusion~
~StableHasher is supposed to ensure platform independence by converting
integers to little-endian and extending isize and usize to 64 bits as
necessary, but in fact, much of that work is already handled by
SipHasher128.~
~In particular, SipHasher128 implements short_write in an
endian-independent way, yet both StableHasher and SipHasher128
additionally attempt to achieve endian-independence by byte swapping on
BE hardware before invoking short writes. This double swap has no
effect, so let's remove it.~
~Because short_write is endian-independent, SipHasher128 is already
handling part of the platform-independence, and it would be somewhat
difficult to make it *not* handle that part with the current
implementation. As splitting platform-independence responsibilities
between StableHasher and SipHasher128 would be confusing, let's make
SipHasher128 handle all of it.~
~Finally, update some incorrect comments and increase test coverage.
Unit tests pass on both LE and BE systems.~
const evaluatable: improve `TooGeneric` handling
Instead of emitting an error in `fulfill`, we now correctly stall on inference variables.
As `const_eval_resolve` returns `ErrorHandled::TooGeneric` when encountering generic parameters on which
we actually do want to error, we check for inference variables and eagerly emit an error if they don't exist, returning `ErrorHandled::Reported` instead.
Also contains a small bugfix for `ConstEquate` where we previously only stalled on type variables. This is probably a leftover from
when we did not yet support stalling on const inference variables.
r? @oli-obk cc @varkor @eddyb
Defer Apple SDKROOT detection to link time.
This defers the detection of the SDKROOT for Apple iOS/tvOS targets to link time, instead of when the `Target` is defined. This allows commands that don't need to link to work (like `rustdoc` or `rustc --print=target-list`). This also makes `--print=target-list` a bit faster.
This also removes the note in the platform support documentation about these targets being missing. When I wrote it, I misunderstood how the SDKROOT stuff worked.
Notes:
* This means that JSON spec targets can't explicitly override these flags. I think that is probably fine, as I believe the value is generally required, and can be set with the SDKROOT environment variable.
* This changes `x86_64-apple-tvos` to use `appletvsimulator`. I think the original code was wrong (it was using `iphonesimulator`). Also, `x86_64-apple-tvos` seems broken in general, and I cannot build it locally. The `data_layout` does not appear to be correct (it is a copy of the arm64 layout instead of the x86_64 layout). I have not tried building Apple's LLVM to see if that helps, but I suspect it is just wrong (I'm uncertain since I don't know how the tvOS simulator works with its bitcode-only requirements).
* I'm tempted to remove the use of `Result` for built-in target definitions, since I don't think they should be fallible. This was added in https://github.com/rust-lang/rust/pull/34980, but that only relates to JSON definitions. I think the built-in targets shouldn't fail. I can do this now, or not.
Fixes#36156Fixes#76584
Fix recursive nonterminal expansion during pretty-print/reparse check
Makes progress towards #43081
In PR #73084, we started recursively expanded nonterminals during the
pretty-print/reparse check, allowing them to be properly compared
against the reparsed tokenstream.
Unfortunately, the recursive logic in that PR only handles the case
where a nonterminal appears inside a `TokenTree::Delimited`. If a
nonterminal appears directly in the expanded tokens of another
nonterminal, the inner nonterminal will not be expanded.
This PR fixes the recursive expansion of nonterminals, ensuring that
they are expanded wherever they occur.
Rollup of 12 pull requests
Successful merges:
- #77037 (more tiny clippy cleanups)
- #77233 (BTreeMap: keep an eye out on the size of the main components)
- #77280 (Ensure that all LLVM components requested by tests are available on CI)
- #77284 (library: Forward compiler-builtins "mem" feature)
- #77296 (liveness: Use Option::None to represent absent live nodes)
- #77322 (Add unstable book docs for `-Zunsound-mir-opts`)
- #77328 (Use `rtassert!` instead of `assert!` from the child process after fork() in std::sys::unix::process::Command::spawn())
- #77331 (Add test for async/await combined with const-generics.)
- #77338 (Fix typo in alloc vec comment)
- #77340 (Alloc vec use imported path)
- #77345 (Add test for issue #74761)
- #77348 (Update books)
Failed merges:
r? `@ghost`
Add support for cmse_nonsecure_entry attribute
This pull request adds the `cmse_nonsecure_entry` attribute under an unstable feature.
I was not sure if it was fine for me to send directly the pull-request or if I should submit a RFC first. I was told on Zulip that it was fine to do so but please close it if I need first submit a RFC or follow another process instead.
The `cmse_nonsecure_entry` attribute is a LLVM attribute that will be available in LLVM 11. I plan to rebase on the [upgrade PR](https://github.com/rust-lang/rust/pull/73526) once merged to make this one compile.
This attribute modifies code generation of the function as explained [here](https://developer.arm.com/documentation/ecm0359818/latest/) to make it work with the TrustZone-M hardware feature. This feature is only available on `thumbv8m` targets so I created an error for that if one tries to use this attribute for another target.
I added this attribute in Rust as any other LLVM attribute are added but since this one is target-dependent I am not sure if it was the best thing to do. Please indicate me if you think of other ways, like isolating target-dependent attributes together.
----------------
Tracking issue: https://github.com/rust-lang/rust/issues/75835
This patch adds support for the LLVM cmse_nonsecure_entry attribute.
This is a target-dependent attribute that only has sense for the
thumbv8m Rust targets.
You can find more information about this attribute here:
https://developer.arm.com/documentation/ecm0359818/latest/
Signed-off-by: Hugues de Valon <hugues.devalon@arm.com>
Secure entry functions do not support if arguments are passed on the
stack. An "unsupported" diagnostic will be emitted by LLVM if that is
the case.
This commits adds support in Rust for that diagnostic so that an error
will be output if that is the case!
Signed-off-by: Hugues de Valon <hugues.devalon@arm.com>
SipHasher128 implements short_write in an endian-independent way, yet
its write_xxx Hasher trait methods undo this endian-independence by byte
swapping the integer inputs on big-endian hardware. StableHasher then
adds endian-independence back by also byte-swapping on big-endian
hardware prior to invoking SipHasher128.
This double swap may have the appearance of being a no-op, but is in
fact by design. In particular, we really do want SipHasher128 to be
platform-dependent, in order to be consistent with the libstd SipHasher.
Try to clarify this intent. Also, add and update a couple of unit tests.
This helper function was meant to reduce code duplication between
const-checking pre- and post-drop-elaboration. Most of the functionality
is only relevant for the pre-drop-elaboration pass.
Liveness refactoring continued
* Move body_owner field from IrMaps to Liveness (the only user of the field).
* Use upvars instead of FnKind to check for closures (avoids FnKind, will be useful when checking all bodies, not just fns).
* Use visit_param to add variables corresponding to params.
* Store upvars_mentioned inside Liveness struct.
* Inline visitor implementation for IrMaps, avoiding unnecessary indirection.
* Test interaction with automatically_derived attribute (not covered by any of existing tests).
No functional changes intended.
expand: Stop normalizing `NtIdent`s before passing them to built-in macros
Built-in macros should be able to deal with `NtIdents` in the input by themselves like any other parser code.
You can't imagine how bad mutable AST visitors are, *especially* if they are modifying tokens.
This is one step towards removing token visiting from the visitor infrastructure (https://github.com/rust-lang/rust/pull/77271 also works in this direction.)
Optimize `IntRange::from_pat`, then shrink `ParamEnv`
Resolves#77058.
r? `@Mark-Simulacrum`
cc `@vandenheuvel`
Looking at the output of `perf report` for #76244, the hot instructions seemed to be around the call to `pat_constructor` in `IntRange::from_pat`. I carried out an obvious optimization, but it actually made the instruction count higher (see #77075). However, it seems to have mitigated whatever was causing the pipeline stalls, so when combined with #76244, it's a net win.
As you can see below, the regression in #76244 seems to have originated from something measured by `stalled-cycles-backend`. I'll try to collect some finer-grained stats to see if I can isolate it. I wish I had a better idea of what was going on here. I'd like to prevent the regression from reappearing in the future due to small changes in unrelated code.
<details>
<summary>Current `master`:</summary>
```
Performance counter stats for 'cargo +baseline-stage1 check':
2,275.67 msec task-clock:u # 0.998 CPUs utilized
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
49,826 page-faults:u # 0.022 M/sec
5,117,221,678 cycles:u # 2.249 GHz
299,655,943 stalled-cycles-frontend:u # 5.86% frontend cycles idle
2,284,213,395 stalled-cycles-backend:u # 44.64% backend cycles idle
8,051,871,959 instructions:u # 1.57 insn per cycle
# 0.28 stalled cycles per insn
1,359,589,402 branches:u # 597.447 M/sec
7,359,347 branch-misses:u # 0.54% of all branches
2.281030026 seconds time elapsed
2.108197000 seconds user
0.164183000 seconds sys
```
</details>
<details>
<summary>Shrink `ParamEnv` without changing `IntRange::from_pat`:</summary>
```
Performance counter stats for 'cargo +perf-stage1 check':
2,751.79 msec task-clock:u # 0.996 CPUs utilized
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
50,103 page-faults:u # 0.018 M/sec
6,260,590,019 cycles:u # 2.275 GHz
317,355,920 stalled-cycles-frontend:u # 5.07% frontend cycles idle
3,397,743,582 stalled-cycles-backend:u # 54.27% backend cycles idle
8,276,224,367 instructions:u # 1.32 insn per cycle
# 0.41 stalled cycles per insn
1,370,453,386 branches:u # 498.023 M/sec
7,281,031 branch-misses:u # 0.53% of all branches
2.763265838 seconds time elapsed
2.544578000 seconds user
0.204548000 seconds sys
```
</details>
<details>
<summary>Shrink `ParamEnv` and change `IntRange::from_pat`: </summary>
```
Performance counter stats for 'cargo +perf-stage1 check':
2,295.57 msec task-clock:u # 0.996 CPUs utilized
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
49,959 page-faults:u # 0.022 M/sec
5,151,407,066 cycles:u # 2.244 GHz
324,517,829 stalled-cycles-frontend:u # 6.30% frontend cycles idle
2,301,671,001 stalled-cycles-backend:u # 44.68% backend cycles idle
8,130,868,329 instructions:u # 1.58 insn per cycle
# 0.28 stalled cycles per insn
1,356,618,512 branches:u # 590.972 M/sec
7,323,800 branch-misses:u # 0.54% of all branches
2.304509653 seconds time elapsed
2.128090000 seconds user
0.163909000 seconds sys
```
</details>
