Adds a basic assembly test checking that each target can produce assembly
and update the target tier policy to require this.
Signed-off-by: David Wood <david@davidtw.co>
Rework how diagnostic lints are stored.
`Diagnostic::code` has the type `DiagnosticId`, which has `Error` and
`Lint` variants. Plus `Diagnostic::is_lint` is a bool, which should be
redundant w.r.t. `Diagnostic::code`.
Seems simple. Except it's possible for a lint to have an error code, in
which case its `code` field is recorded as `Error`, and `is_lint` is
required to indicate that it's a lint. This is what happens with
`derive(LintDiagnostic)` lints. Which means those lints don't have a
lint name or a `has_future_breakage` field because those are stored in
the `DiagnosticId::Lint`.
It's all a bit messy and confused and seems unintentional.
This commit:
- removes `DiagnosticId`;
- changes `Diagnostic::code` to `Option<String>`, which means both
errors and lints can straightforwardly have an error code;
- changes `Diagnostic::is_lint` to `Option<IsLint>`, where `IsLint` is a
new type containing a lint name and a `has_future_breakage` bool, so
all lints can have those, error code or not.
r? `@oli-obk`
fix fn/const items implied bounds and wf check (rebase)
A rebase of #104098, see that PR for discussion. This is pretty much entirely the work of `@aliemjay.` I received his permission for this rebase.
---
These are two distinct changes (edit: actually three, see below):
1. Wf-check all fn item args. This is a soundness fix.
Fixes#104005
2. Use implied bounds from impl header in borrowck of associated functions/consts. This strictly accepts more code and helps to mitigate the impact of other breaking changes.
Fixes#98852Fixes#102611
The first is a breaking change and will likely have a big impact without the the second one. See the first commit for how it breaks libstd.
Landing the second one without the first will allow more incorrect code to pass. For example an exploit of #104005 would be as simple as:
```rust
use core::fmt::Display;
trait ExtendLt<Witness> {
fn extend(self) -> Box<dyn Display>;
}
impl<T: Display> ExtendLt<&'static T> for T {
fn extend(self) -> Box<dyn Display> {
Box::new(self)
}
}
fn main() {
let val = (&String::new()).extend();
println!("{val}");
}
```
The third change is to to check WF of user type annotations before normalizing them (fixes#104764, fixes#104763). It is mutually dependent on the second change above: an attempt to land it separately in #104746 caused several crater regressions that can all be mitigated by using the implied from the impl header. It is also necessary for the soundness of associated consts that use the implied bounds of impl header. See #104763 and how the third commit fixes the soundness issue in `tests/ui/wf/wf-associated-const.rs` that was introduces by the previous commit.
r? types
I added `tcx` argument to `internal` to force 'tcx to be the same
lifetime as TyCtxt. The only other solution I could think is to change
this function to be `unsafe`.
Cache local DefId-keyed queries without hashing
This caches local DefId-keyed queries using just an IndexVec. This costs ~5% extra max-rss at most but brings significant runtime improvement, up to 13% cycle counts (mean: 4%) on primary benchmarks. It's possible that further tweaks could reduce the memory overhead further but this win seems worth landing despite the increased memory, particularly with regards to eliminating the present set in non-incr or storing it inline (skip list?) with the main data.
We tried applying this scheme to all keys in the [first perf run] but found that it carried a significant memory hit (50%). instructions/cycle counts were also much more mixed, though that may have been due to the lack of the present set optimization (needed for fast iter() calls in incremental scenarios).
Closes https://github.com/rust-lang/rust/issues/45275
[first perf run]: https://perf.rust-lang.org/compare.html?start=30dfb9e046aeb878db04332c74de76e52fb7db10&end=6235575300d8e6e2cc6f449cb9048722ef43f9c7&stat=instructions:u
Simplify the `run` macro to avoid sometimes unnecessary dependency
on `TyCtxt`. Instead, users can use the new internal method `tcx()`.
Additionally, extend the macro to accept closures that may capture
variables.
These are non-backward compatible changes, but they only affect
internal APIs which are provided today as helper functions until we
have a stable API to start the compiler.
Lint `overlapping_ranges_endpoints` directly instead of collecting into a Vec
In https://github.com/rust-lang/rust/pull/119396 I was a bit silly: I was trying to avoid any lints being fired from within the exhaustiveness algorithm for some vague aesthetic/reusability reason that doesn't really hold. This PR fixes that: instead of passing a `&mut Vec` around I just added a method to the `TypeCx` trait.
r? `@compiler-errors`
Simplify `closure_env_ty` and `closure_env_param`
Random cleanup that I found when working on async closures. This makes it easier to separate the latter into a new tykind.
Make sure to instantiate placeholders correctly in old solver
When creating the query substitution guess for an input placeholder type like `!1_T` (in universe 1), we were guessing the response substitution with something like `!0_T`. This failed to unify with `!1_T`, causing an ICE.
This PR reworks the query substitution guess code to work a bit more like the new solver. I'm *pretty* sure this is correct, though I'd really appreciate some scrutiny from someone (*cough* lcnr) who knows a bit more about query instantiation :)
Fixes#119941
r? lcnr
Sandwich MIR optimizations between DSE.
This PR reorders MIR optimization passes in an attempt to increase their efficiency.
- Stop running CopyProp before GVN, it's useless as GVN will do the same thing anyway. Instead, we perform CopyProp at the end of the pipeline, to ensure we do not emit copy/move chains.
- Run DSE before GVN, as it increases the probability to have single-assignment locals.
- Run DSE after the final CopyProp to turn copies into moves.
r? `@ghost`
Avoid some redundant work in GVN
The first 2 commits are about reducing the perf effect.
Third commit avoids doing redundant work: is a local is SSA, it already has been simplified, and the resulting value is in `self.locals`. No need to call any code on it.
The last commit avoids removing some storage statements.
r? wg-mir-opt
Foreign maps are used to cache external DefIds, typically backed by
metadata decoding. In the future we might skip caching `V` there (since
loading from metadata usually is already cheap enough), but for now this
cuts down on the impact to memory usage and time to None-init a bunch of
memory. Foreign data is usually much sparser, since we're not usually
loading *all* entries from the foreign crate(s).
never patterns: Check bindings wrt never patterns
Never patterns:
- Shouldn't contain bindings since they never match anything;
- Don't count when checking that or-patterns have consistent bindings.
r? `@compiler-errors`
Use `zip_eq` to enforce that things being zipped have equal sizes
Some `zip`s are best enforced to be equal, since size mismatches suggest deeper bugs in the compiler.
Fix `allow_internal_unstable` for `(min_)specialization`
Fixes#119950
Blocked on #119949 (comment doesn't make sense until that merges)
I'd like to follow this up and look for more instances of not properly checking spans for features but I wanted to fix the motivating issue.
`OutputTypeParameterMismatch` -> `SignatureMismatch`
I'm probably missing something that made this rename more complicated. What did you end up getting stuck on when renaming this selection error, `@lcnr?`
**also** I renamed the `FulfillmentErrorCode` variants. This is just churn but I wanted to do it forever. I can move it out of this PR if desired.
r? lcnr
Silence some follow-up errors [3/x]
this is one piece of the requested cleanups from https://github.com/rust-lang/rust/pull/117449
Keep error types around, even in obligations.
These help silence follow-up errors, as we now figure out that some types (most notably inference variables) are equal to an error type.
But it also allows figuring out more types in the presence of errors, possibly causing more errors.
coverage: Simplify building the coverage graph with `CoverageSuccessors`
This is a collection of simplifications to the code that builds the *basic coverage block* graph, which is a simplified view of the MIR control-flow graph that ignores panics and merges straight-line sequences of blocks into a single BCB node.
The biggest change is to how we determine the coverage-relevant successors of a block. Previously we would call `Terminator::successors` and apply some ad-hoc postprocessing, but with this PR we instead have our own `match` on the terminator kind that produces a coverage-specific enum `CoverageSuccessors`. That enum also includes information about whether a block has exactly one successor that it can be chained into as part of a single BCB.
Exhaustiveness: remove the need for arena-allocation within the algorithm
After https://github.com/rust-lang/rust/pull/119688, exhaustiveness checking doesn't need access to the arena anymore. This simplifies the lifetime story and makes it compile on stable without the extra dependency.
r? `@compiler-errors`
Inverting the condition lets us merge the two `Ok(false)` paths. I also
find the inverted condition easier to read: "all the things that must be
true for trimming to occur", instead of "any of the things that must be
true for trimming to not occur".
Don't ICE when noting GAT bounds in `report_no_match_method_error`
We can encounter `BindingObligation`s from GATs that we should handle in `report_no_match_method_error`. I assume we can encounter them from methods, though I didn't really feel like wasting my time creating a repro.
Fixes#119942
Make `InferCtxtExt::could_impl_trait` more precise, less ICEy
The implementation for `InferCtxtExt::could_impl_trait` was very wrong. Along with being pretty poorly named, way too specific to ADTs, it was also doing impl substitution wrong -- this caused an ICE (#119915).
This PR generalizes that code, gives it a clearer name, makes it stop using the new trait solver (lol), and fixes some fallout bad suggestions that are made worse with the code fix.
Fixes#119915
`Diagnostic::code` has the type `DiagnosticId`, which has `Error` and
`Lint` variants. Plus `Diagnostic::is_lint` is a bool, which should be
redundant w.r.t. `Diagnostic::code`.
Seems simple. Except it's possible for a lint to have an error code, in
which case its `code` field is recorded as `Error`, and `is_lint` is
required to indicate that it's a lint. This is what happens with
`derive(LintDiagnostic)` lints. Which means those lints don't have a
lint name or a `has_future_breakage` field because those are stored in
the `DiagnosticId::Lint`.
It's all a bit messy and confused and seems unintentional.
This commit:
- removes `DiagnosticId`;
- changes `Diagnostic::code` to `Option<String>`, which means both
errors and lints can straightforwardly have an error code;
- changes `Diagnostic::is_lint` to `Option<IsLint>`, where `IsLint` is a
new type containing a lint name and a `has_future_breakage` bool, so
all lints can have those, error code or not.
This also switches from `split_off(0)` to `std::mem::take` when emptying the
accumulated list of blocks, because `split_off(0)` handles capacity in a way
that is unintuitive when used in a loop.
The old loop had two separate places where it would flush the acumulated list
of straight-line blocks into a new BCB. One occurred at the start of the loop
body when the current block couldn't be chained into, and the other occurred at
the end of the loop body when the current block couldn't be chained from.
The latter check can be hoisted to the start of the loop body by making it
examine the previous block (which has added itself to the list) instead of the
current block. With that done, we can combine the two separate flushes into one
flush with two possible trigger conditions.
Filtering out unreachable successors is only needed by the main graph traversal
loop, so we can move the filtering step into that loop instead, eliminating the
need to pass the MIR body into `bcb_filtered_successors`.
store the segment name when resolution fails
Fixes#112672
The `find_cfg_stripped` does indeed get executed within `smart_resolve_report_errors`. However, this error is not reported as it is subsequently overridden by `parent_err`. (See: https://github.com/rust-lang/rust/blob/master/compiler/rustc_resolve/src/late.rs#L3760)
This PR changes `last_segment` to `segment`, which stores the name of the failed resolution, and ensures that the result of `find_cfg_stripped` is also included in `parent_err`.
r? ```@Nilstrieb```
Suggest Upgrading Compiler for Gated Features
This PR addresses #117318
I have a few questions:
1. Do we want to specify the current version and release date of the compiler? I have added this in via environment variables, which I found in the code for the rustc cli where it handles the `--version` flag
a. How can I handle the changing message in the tests?
3. Do we want to only show this message when the compiler is old?
a. How can we determine when the compiler is old?
I'll wait until we figure out the message to bless the tests
Move platform modules into `sys::pal`
This is the initial step of #117276. `sys` just re-exports everything from the current `sys` for now, I'll move the implementations for the individual features one-by-one after this PR merges.
Taint `_` placeholder types in trait impl method signatures
We report an error right below for them, but that kind of broken type can cause subsequent ICEs.
fixes#119867
Allow `~const` on associated type bounds again
This follows from [this Zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/419616-t-compiler.2Fproject-const-traits/topic/projections.20on.20.28~.29const.20Trait.20.26.20.28~.29const.20assoc.20ty.20bounds).
Basically in my opinion, it makes sense to allow `~const` on associated type bounds again since they're quite useful even though we haven't implemented the proposed syntax `<Ty as ~const Trait>::Proj`/`<Ty as const Trait>::Proj` yet; that can happen as a follow-up.
This already allows more code to compile since `T::Assoc` where `T` is a type parameter and where the predicate `<T as ~const Trait>` is in the environment gets elaborated to (pseudo) `<T as ~const Trait>::Assoc`.
```rs
#[const_trait]
trait Trait {
type Assoc: ~const Trait;
fn func() -> i32;
}
const fn function<T: ~const Trait>() -> i32 {
T::Assoc::func()
}
```
`~const` associated type bounds also work together with `const` bounds:
```rs
struct Type<const N: i32>;
fn procedure<T: const Trait>() -> Type<{ T::Assoc::func() }> { // `Trait` comes from above
Type
}
```
NB: This PR also starts allowing `~const` bounds in the generics and the where-clause of trait associated types since it's trivial to support them. However, I don't know if those bounds are actually useful. Maybe we should continue to reject them?
For reference, it wouldn't make any sense to allow `~const Trait` in GACs (generic associated constants, `generic_const_items`) because they'd be absolutely useless (contrary to `const Trait`).
~~[``@]rustbot`` ping project-const-traits~~
r? project-const-traits
Varargs support for system ABI
This PR allows functions with the `system` ABI to be variadic (under the `extended_varargs_abi_support` feature tracked in #100189). On x86 windows, the `system` ABI is equivalent to `C` for variadic functions. On other platforms, `system` is already equivalent to `C`.
Fixes#110505
Overhaul `-Ztreat-err-as-bug`
It's current behaviour is surprising, in a bad way. This also makes the implementation more complex than it needs to be.
r? `@oli-obk`
Add explicit `none()` value variant in check-cfg
This PR adds an explicit none value variant in check-cfg values: `values(none())`.
Currently the only way to define the none variant is with an empty `values()` which means that if someone has a cfg that takes none and strings they need to use two invocations: `--check-cfg=cfg(foo) --check-cfg=cfg(foo, values("bar"))`.
Which would now be `--check-cfg=cfg(foo, values(none(),"bar"))`, this is simpler and easier to understand.
`--check-cfg=cfg(foo)`, `--check-cfg=cfg(foo, values())` and `--check-cfg=cfg(foo, values(none()))` would be equivalent.
*Another motivation for doing this is to make empty `values()` actually means no-values, but this is orthogonal to this PR and adding `none()` is sufficient in it-self.*
`@rustbot` label +F-check-cfg
r? `@petrochenkov`
`-Ztreat-err-as-bug` treats normal errors and delayed bugs equally,
which can lead to some really surprising results.
This commit changes `-Ztreat-err-as-bug` so it ignores delayed bugs,
unless they get promoted to proper bugs and are printed.
This feels to me much simpler and more logical. And it simplifies the
implementation:
- The `-Ztreat-err-as-bug` check is removed from in
`DiagCtxt::{delayed_bug,span_delayed_bug}`.
- `treat_err_as_bug` doesn't need to count delayed bugs.
- The `-Ztreat-err-as-bug` panic message is simpler, because it doesn't
have to mention delayed bugs.
Output of delayed bugs is now more consistent. They're always printed
the same way. Previously when they triggered `-Ztreat-err-as-bug` they
would be printed slightly differently, via `span_bug` in
`span_delayed_bug` or `delayed_bug`.
A minor behaviour change: the "no errors encountered even though
`span_delayed_bug` issued" printed before delayed bugs is now a note
rather than a bug. This is done so it doesn't get counted as an error
that might trigger `-Ztreat-err-as-bug`, which would be silly.
This means that if you use `-Ztreat-err-as-bug=1` and there are no
normal errors but there are delayed bugs, the first delayed bug will be
shown (and the panic will happen after it's printed).
Also, I have added a second note saying "those delayed bugs will now be
shown as internal compiler errors". I think this makes it clearer what
is happening, because the whole concept of delayed bugs is non-obvious.
There are some test changes.
- equality-in-canonical-query.rs: Minor output changes, and the error
count reduces by one because the "no errors encountered even though
`span_delayed_bug` issued" message is no longer counted as an error.
- rpit_tait_equality_in_canonical_query.rs: Ditto.
- storage-live.rs: The query stack disappears because these delayed bugs
are now printed at the end, rather than when they are created.
- storage-return.rs, span_delayed_bug.rs: now need
`-Zeagerly-emit-delayed-bugs` because they need the delayed bugs
emitted immediately to preserve behaviour.
Fix unused_parens issue when cast is followed LT
Fixes#117142
The original check only checks `a as (i32) < 0`, this fix extends it to handle `b + a as (i32) < 0`.
A better way is maybe we suggest `(a as i32) < 0` instead of suppressing the warning, maybe following PR could improve it.
Add more information to `visit_projection_elem`
Without the starting place, it's hard to retrieve any useful information from visiting a projection.
Note: I still need to add a test.
Give me a way to emit all the delayed bugs as errors (add `-Zeagerly-emit-delayed-bugs`)
This is probably a *better* way to inspect all the delayed bugs in a program that what exists currently (and therefore makes it very easy to choose the right number `N` with `-Zemit-err-as-bug=N`, though I guess the naming is a bit ironic when you pair both of the flags together, but that feels like naming bikeshed more than anything).
This pacifies my only concern with https://github.com/rust-lang/rust/pull/119871#issuecomment-1888170259, because (afaict?) that PR doesn't allow you to intercept a delayed bug's stack trace anymore, which as someone who debugs the compiler a lot, is something that I can *promise* that I do.
r? `@nnethercote` or `@oli-obk`
Remove special-casing around `AliasKind::Opaque` when structurally resolving in new solver
This fixes a few inconsistencies around where we don't eagerly resolve opaques to their (locally-defined) hidden types in the new solver. It essentially allows this code to work:
```rust
fn main() {
type Tait = impl Sized;
struct S {
i: i32,
}
let x: Tait = S { i: 0 };
println!("{}", x.i);
}
```
Since `Tait` is defined in `main`, we are able to poke through the type of `x` with deref.
r? lcnr
Exhaustiveness: track overlapping ranges precisely
The `overlapping_range_endpoints` lint has false positives, e.g. https://github.com/rust-lang/rust/issues/117648. I expected that removing these false positives would have too much of a perf impact but never measured it. This PR is an experiment to see if the perf loss is manageable.
r? `@ghost`
Register even erroneous impls
Otherwise the specialization graph fails to pick it up, even though other code assumes that all impl blocks have an entry in the specialization graph.
also includes an unrelated cleanup of the specialization graph query
fixes #119827
Set `c_str_literals` stabilization version back to `CURRENT_RUSTC_VERSION`
`c_str_literals`'s stabilization has been delayed to 1.77 (https://github.com/rust-lang/rust/pull/119528).
next solver: provisional cache
this adds the cache removed in #115843. However, it should now correctly track whether a provisional result depends on an inductive or coinductive stack.
While working on this, I was using the following doc: https://hackmd.io/VsQPjW3wSTGUSlmgwrDKOA. I don't think it's too helpful to understanding this, but am somewhat hopeful that the inline comments are more useful.
There are quite a few future perf improvements here. Given that this is already very involved I don't believe it is worth it (for now). While working on this PR one of my few attempts to significantly improve perf ended up being unsound again because I was not careful enough ✨
r? `@compiler-errors`
By making it an `EscapeError` instead of a `LitError`. This makes it
like the other errors produced when checking string literals contents,
e.g. for invalid escape sequences or bare CR chars.
NOTE: this means these errors are issued earlier, before expansion,
which changes behaviour. It will be possible to move the check back to
the later point if desired. If that happens, it's likely that all the
string literal contents checks will be delayed together.
One nice thing about this: the old approach had some code in
`report_lit_error` to calculate the span of the nul char from a range.
This code used a hardwired `+2` to account for the `c"` at the start of
a C string literal, but this should have changed to a `+3` for raw C
string literals to account for the `cr"`, which meant that the caret in
`cr"` nul error messages was one short of where it should have been. The
new approach doesn't need any of this and avoids the off-by-one error.
There are two places that handle normal delayed bugs. This commit
factors out some repeated code.
Also, we can use `std::mem::take` instead of `std::mem::replace`.
