coverage: Move most per-function coverage info into `mir::Body`
Currently, all of the coverage information collected by the `InstrumentCoverage` pass is smuggled through MIR in the form of individual `StatementKind::Coverage` statements, which must then be reassembled by coverage codegen.
That's awkward for a number of reasons:
- While some of the coverage statements do care about their specific position in the MIR control-flow graph, many of them don't, and are just tacked onto the function's first BB as metadata carriers.
- MIR inlining can result in coverage statements being duplicated, so coverage codegen has to jump through hoops to avoid emitting duplicate mappings.
- MIR optimizations that would delete coverage statements need to carefully copy them into the function's first BB so as not to omit them from coverage reports.
- The order in which coverage codegen sees coverage statements is dependent on MIR optimizations/inlining, which can cause unnecessary churn in the emitted coverage mappings.
- We don't have a good way to annotate MIR-level functions with extra coverage info that doesn't belong in a statement.
---
This PR therefore takes most of the per-function coverage info and stores it in a field in `mir::Body` as `Option<Box<FunctionCoverageInfo>>`.
(This adds one pointer to the size of `mir::Body`, even when coverage is not enabled.)
Coverage statements still need to be injected into MIR in some cases, but only when they actually affect codegen (counters) or are needed to detect code that has been optimized away as unreachable (counters/expressions).
---
By the end of this PR, the information stored in `FunctionCoverageInfo` is:
- A hash of the function's source code (needed by LLVM's coverage map format)
- The number of coverage counters added by coverage instrumentation
- A table of coverage expressions, associating each expression ID with its operator (add or subtract) and its two operands
- The list of mappings, associating each covered code region with a counter/expression/zero value
---
~~This is built on top of #115301, so I'll rebase and roll a reviewer once that lands.~~
r? `@ghost`
`@rustbot` label +A-code-coverage
This new description reflects the changes made in this PR, and should hopefully
be more useful to non-coverage developers who need to care about coverage
statements.
Even though expression details are now stored in the info structure, we still
need to inject `ExpressionUsed` statements into MIR, because if one is missing
during codegen then we know that it was optimized out and we can remap all of
its associated code regions to zero.
Previously, mappings were attached to individual coverage statements in MIR.
That necessitated special handling in MIR optimizations to avoid deleting those
statements, since otherwise codegen would be unable to reassemble the original
list of mappings.
With this change, a function's list of mappings is now attached to its MIR
body, and survives intact even if individual statements are deleted by
optimizations.
Don't compare host param by name
Seems sketchy to be searching for `sym::host` by name, especially when we can get the actual index with not very much work.
r? fee1-dead
Coverage codegen can now allocate arrays based on the number of
counters/expressions originally used by the instrumentor.
The existing query that inspects coverage statements is still used for
determining the number of counters passed to `llvm.instrprof.increment`. If
some high-numbered counters were removed by MIR optimizations, the instrumented
binary can potentially use less memory and disk space at runtime.
This allows coverage information to be attached to the function as a whole when
appropriate, instead of being smuggled through coverage statements in the
function's basic blocks.
As an example, this patch moves the `function_source_hash` value out of
individual `CoverageKind::Counter` statements and into the per-function info.
When synthesizing unused functions for coverage purposes, the absence of this
info is taken to indicate that a function was not eligible for coverage and
should not be synthesized.
Remove lots of generics from `ty::print`
All of these generics mostly resolve to the same thing, which means we can remove them, greatly simplifying the types involved in pretty printing and unlocking another simplification (that is not performed in this PR): Using `&mut self` instead of passing `self` through the return type.
cc `@eddyb` you probably know why it's like this, just checking in and making sure I didn't do anything bad
r? oli-obk
These are `Self` in almost all printers except one, which can just store
the state as a field instead. This simplifies the printer and allows for
further simplifications, for example using `&mut self` instead of
passing around the printer.
THIR unsafety checking was getting a cycle of
function unsafety checking
-> building THIR for the function
-> evaluating pattern inline constants in the function
-> building MIR for the inline constant
-> checking unsafety of functions (so that THIR can be stolen)
This is fixed by not stealing THIR when generating MIR but instead when
unsafety checking.
This leaves an issue with pattern inline constants not being unsafety
checked because they are evaluated away when generating THIR.
To fix that we now represent inline constants in THIR patterns and
visit them in THIR unsafety checking.
don't UB on dangling ptr deref, instead check inbounds on projections
This implements https://github.com/rust-lang/reference/pull/1387 in Miri. See that PR for what the change is about.
Detecting dangling references in `let x = &...;` is now done by validity checking only, so some tests need to have validity checking enabled. There is no longer inherently a "nodangle" check in evaluating the expression `&*ptr` (aside from the aliasing model).
r? `@oli-obk`
Based on:
- https://github.com/rust-lang/reference/pull/1387
- https://github.com/rust-lang/rust/pull/115524
interpret: clean up AllocBytes
Fixes https://github.com/rust-lang/miri/issues/2836
Nothing has moved here in half a year, so let's just remove these unused stubs -- they need a proper re-design anyway.
r? `@oli-obk`
Format all the let-chains in compiler crates
Since rust-lang/rustfmt#5910 has landed, soon we will have support for formatting let-chains (as soon as rustfmt syncs and beta gets bumped).
This PR applies the changes [from master rustfmt to rust-lang/rust eagerly](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/out.20formatting.20of.20prs/near/374997516), so that the next beta bump does not have to deal with a 200+ file diff and can remain concerned with other things like `cfg(bootstrap)` -- #113637 was a pain to land, for example, because of let-else.
I will also add this commit to the ignore list after it has landed.
The commands that were run -- I'm not great at bash-foo, but this applies rustfmt to every compiler crate, and then reverts the two crates that should probably be formatted out-of-tree.
```
~/rustfmt $ ls -1d ~/rust/compiler/* | xargs -I@ cargo run --bin rustfmt -- `@/src/lib.rs` --config-path ~/rust --edition=2021 # format all of the compiler crates
~/rust $ git checkout HEAD -- compiler/rustc_codegen_{gcc,cranelift} # revert changes to cg-gcc and cg-clif
```
cc `@rust-lang/rustfmt`
r? `@WaffleLapkin` or `@Nilstrieb` who said they may be able to review this purely mechanical PR :>
cc `@Mark-Simulacrum` and `@petrochenkov,` who had some thoughts on the order of operations with big formatting changes in https://github.com/rust-lang/rust/pull/95262#issue-1178993801. I think the situation has changed since then, given that let-chains support exists on master rustfmt now, and I'm fairly confident that this formatting PR should land even if *bootstrap* rustfmt doesn't yet format let-chains in order to lessen the burden of the next beta bump.
Relate alias ty with variance
In the new solver, turns out that the subst-relate branch of the alias-relate predicate was relating args invariantly even for opaques, which have variance 💀.
This change is a bit more invasive, but I'd rather not special-case it [here](aeaa5c30e5/compiler/rustc_trait_selection/src/solve/alias_relate.rs (L171-L190)) and then have it break elsewhere. I'm doing a perf run to see if the extra call to `def_kind` is that expensive, if it is, I'll reconsider.
r? ``@lcnr``
Extend `impl`'s `def_span` to include its where clauses
Typically, we highlight the def-span of an impl in a diagnostic due to either:
1. coherence error
2. trait evaluation cycle
3. invalid implementation of built-in trait
I find that an impl's where clauses are very often required to understanding why these errors come about, which is unfortunate since where clauses may be located on different lines and don't show up in the error. This PR expands the def-span of impls to include these where clauses.
r? cjgillot since you've touched this code a while back to make some spans shorter, but you can also reassign to wg-diagnostics or compiler if you're busy or have no strong opinions.
improve the suggestion of `generic_bound_failure`
- Fixes#115375
- suggest the bound in the correct scope: trait or impl header vs assoc item. See `tests/ui/suggestions/lifetimes/type-param-bound-scope.rs`
- don't suggest a lifetime name that conflicts with the other late-bound regions of the function:
```rust
type Inv<'a> = *mut &'a ();
fn check_bound<'a, T: 'a>(_: T, _: Inv<'a>) {}
fn test<'a, T>(_: &'a str, t: T, lt: Inv<'_>) { // suggests a new name `'a`
check_bound(t, lt); //~ ERROR
}
```
Generalize small dominators optimization
* Use small dominators optimization from 640ede7b0a more generally.
* Merge `DefLocation` and `LocationExtended` since they serve the same purpose.
remove Key impls for types that involve an AllocId
I don't understand how but somehow that leads to issues like https://github.com/rust-lang/rust/issues/83085? Anyway removing unused impls doesn't seem like a bad idea. The concerning part is that of course nothing will stop us from having such impls again in the future, alongside re-introducing bugs like #83085.
r? `@oli-obk`
Bring back generic parameters for indices in rustc_abi and make it compile on stable
This effectively reverses https://github.com/rust-lang/rust/pull/107163, allowing rust-analyzer to depend on this crate again,
It also moves some glob imports / expands them in the first commit because they made it more difficult for me to reason about things.
The word "active" is currently used in two different and confusing ways:
- `ACTIVE_FEATURES` actually means "available unstable features"
- `Features::active_features` actually means "features declared in the
crate's code", which can include feature within `ACTIVE_FEATURES` but
also others.
(This is also distinct from "enabled" features which includes declared
features but also some edition-specific features automatically enabled
depending on the edition in use.)
This commit changes the `Features::active_features` to
`Features::declared_features` which actually matches its meaning.
Likewise, `Features::active` becomes `Features::declared`.
Remove the `TypedArena::alloc_from_iter` specialization.
It was added in #78569. It's complicated and doesn't actually help
performance.
r? `@cjgillot`
All other impls replace type generics with `()` (or a type implementing the necessery traits)
and lifetimes with `'static`, do the same for those impls.
coverage: Allow each coverage statement to have multiple code regions
The original implementation of coverage instrumentation was built around the assumption that a coverage counter/expression would be associated with *up to one* code region. When it was discovered that *multiple* regions would sometimes need to share a counter, a workaround was found: for the remaining regions, the instrumentor would create a fresh expression that adds zero to the existing counter/expression.
That got the job done, but resulted in some awkward code, and produces unnecessarily complicated coverage maps in the final binary.
---
This PR removes that tension by changing `StatementKind::Coverage`'s code region field from `Option<CodeRegion>` to `Vec<CodeRegion>`.
The changes on the codegen side are fairly straightforward. As long as each `CoverageKind::Counter` only injects one `llvm.instrprof.increment`, the rest of coverage codegen is happy to handle multiple regions mapped to the same counter/expression, with only minor option-to-vec adjustments.
On the instrumentor/mir-transform side, we can get rid of the code that creates extra (x + 0) expressions. Instead we gather all of the code regions associated with a single BCB, and inject them all into one coverage statement.
---
There are several patches here but they can be divided in to three phases:
- Preparatory work
- Actually switching over to multiple regions per coverage statement
- Cleaning up
So viewing the patches individually may be easier.
a small wf and clause cleanup
- remove `Clause::from_projection_clause`, instead use `ToPredicate`
- change `predicate_obligations` to directly take a `Clause`
- remove some unnecessary `&`
- use clause in `min_specialization` checks where easily applicable
Rollup of 5 pull requests
Successful merges:
- #115863 (Add check_unused_messages in tidy)
- #116210 (Ensure that `~const` trait bounds on associated functions are in const traits or impls)
- #116358 (Rename both of the `Match` relations)
- #116371 (Remove unused features from `rustc_llvm`.)
- #116374 (Print normalized ty)
r? `@ghost`
`@rustbot` modify labels: rollup
When these methods were originally written, I wasn't aware that
`newtype_index!` already supports addition with ordinary numbers, without
needing to unwrap and re-wrap.
Cleanup number handling in match exhaustiveness
Doing a little bit of cleanup; handling number constants was somewhat messy. In particular, this:
- evals float consts once instead of repetitively
- reduces `Constructor` from 88 bytes to 56 (`mir::Const` is big!)
The `fast_try_eval_bits` function was mostly constructed from inlining existing code but I don't fully understand it; I don't follow how consts work and are evaluated very well.
Assorted improvements for `rustc_middle::mir::traversal`
r? `@cjgillot`
I'm not _entirely_ sure about all changes, although I do like all of them. If you'd like I can drop some commits. Best reviewed on a commit-by-commit basis, I think, since they are fairly isolated.
Implement a global value numbering MIR optimization
The aim of this pass is to avoid repeated computations by reusing past assignments. It is based on an analysis of SSA locals, in order to perform a restricted form of common subexpression elimination.
By opportunity, this pass allows for some simplifications by combining assignments. For instance, this pass could be able to see through projections of aggregates to directly reuse the aggregate field (not in this PR).
We handle references by assigning a different "provenance" index to each `Ref`/`AddressOf` rvalue. This ensure that we do not spuriously merge borrows that should not be merged. Meanwhile, we consider all the derefs of an immutable reference to a freeze type to give the same value:
```rust
_a = *_b // _b is &Freeze
_c = *_b // replaced by _c = _a
```
Don't store lazyness in `DefKind::TyAlias`
1. Don't store lazyness of a type alias in its `DefKind`, but instead via a query.
2. This allows us to treat type aliases as lazy if `#[feature(lazy_type_alias)]` *OR* if the alias contains a TAIT, rather than having checks for both in separate parts of the codebase.
r? `@oli-obk` cc `@fmease`
Check that closure/generator's interior/capture types are sized
check that closure upvars and generator interiors are sized. this check is only necessary when `unsized_fn_params` or `unsized_locals` is enabled, so only check if those are active.
Fixes#93622Fixes#61335Fixes#68543
adjust how closure/generator types are printed
I saw `&[closure@$DIR/issue-20862.rs:2:5]` and I thought it is a slice type, because that's usually what `&[_]` is... it took me a while to realize that this is just a confusing printer and actually there's no slice. Let's use something that cannot be mistaken for a regular type.
give FutureIncompatibilityReason variants more explicit names
Also make the `reason` field mandatory when declaring a lint, to make sure this is a deliberate decision.
Move `DepKind` to `rustc_query_system` and define it as `u16`
This moves the `DepKind` type to `rustc_query_system` where it's defined with an inner `u16` field. This decouples it from `rustc_middle` and is a step towards letting other crates define dep kinds. It also allows some type parameters to be removed. The `DepKind` trait is replaced with a `Deps` trait. That's used when some operations or information about dep kinds which is unavailable in `rustc_query_system` are still needed.
r? `@cjgillot`
rustc_hir_analysis: add a helper to check function the signature mismatches
This function is now used to check `#[panic_handler]`, `start` lang item, `main`, `#[start]` and intrinsic functions.
The diagnosis produced are now closer to the ones produced by trait/impl method signature mismatch.
This is the first time I do anything with rustc_hir_analysis/rustc_hir_typeck, so comments and suggestions about things I did wrong or that could be improved will be appreciated.
Suggest desugaring to return-position `impl Future` when an `async fn` in trait fails an auto trait bound
First commit allows us to store the span of the `async` keyword in HIR.
Second commit implements a suggestion to desugar an `async fn` to a return-position `impl Future` in trait to slightly improve the `Send` situation being discussed in #115822.
This suggestion is only made when `#![feature(return_type_notation)]` is not enabled -- if it is, we should instead suggest an appropriate where-clause bound.
coverage: Don't bother renumbering expressions on the Rust side
The LLVM API that we use to encode coverage mappings already has its own code for removing unused coverage expressions and renumbering the rest.
This lets us get rid of our own complex renumbering code, making it easier to change our coverage code in other ways.
---
Now that we have tests for coverage mappings (#114843), I've been able to verify that this PR doesn't make the coverage mappings worse, thanks to an explicit simplification step.
rename mir::Constant -> mir::ConstOperand, mir::ConstKind -> mir::Const
Also, be more consistent with the `to/eval_bits` methods... we had some that take a type and some that take a size, and then sometimes the one that takes a type is called `bits_for_ty`.
Turns out that `ty::Const`/`mir::ConstKind` carry their type with them, so we don't need to even pass the type to those `eval_bits` functions at all.
However this is not properly consistent yet: in `ty` we have most of the methods on `ty::Const`, but in `mir` we have them on `mir::ConstKind`. And indeed those two types are the ones that correspond to each other. So `mir::ConstantKind` should actually be renamed to `mir::Const`. But what to do with `mir::Constant`? It carries around a span, that's really more like a constant operand that appears as a MIR operand... it's more suited for `syntax.rs` than `consts.rs`, but the bigger question is, which name should it get if we want to align the `mir` and `ty` types? `ConstOperand`? `ConstOp`? `Literal`? It's not a literal but it has a field called `literal` so it would at least be consistently wrong-ish...
``@oli-obk`` any ideas?
Prevent promotion of const fn calls in inline consts
We don't wanna make that mistake we did for statics and consts worse by letting more code use it.
r? ``@RalfJung``
cc https://github.com/rust-lang/rust/issues/76001
The LLVM API that we use to encode coverage mappings already has its own code
for removing unused coverage expressions and renumbering the rest.
This lets us get rid of our own complex renumbering code, making it easier to
change our coverage code in other ways.
adjust ConstValue::Slice to work for arbitrary slice types
valtrees have already been assuming that this works; this PR makes it a reality. Also further restrict `ConstValue::Slice` to what it is actually used for; this even shrinks `ConstValue` from 32 to 24 bytes which is a nice win. :)
The alternative to this approach is to make `ConstValue::Slice` work really only for `&str`/`&[u8]` literals, and never return it in `op_to_const`. That would make `op_to_const` very clean. We could then even remove the `meta` field; the length would always be `data.inner().len()`. We could *almost* just use a `Symbol` instead of a `ConstAllocation`, but we have to support byte strings and there doesn't seem to be an interned representation of them (or rather, `ConstAllocation` *is* their interned representation). In this world, valtrees of slice reference types would then become noticeably more expensive to turn into a `ConstValue` -- but does that matter? Specifically for `&str`/`&[u8]` we could still use the optimized representation if we wanted.
If byte strings were already interned somewhere I'd gravitate towards the alternative, but the way things stand, we need a `ConstAllocation` case anyway to support byte strings, and then we might as well support arbitrary slices. (Or we say that byte strings don't get an optimized representation at all. Such a performance cliff between `str` and byte strings is probably unexpected, though due to the lack of interning for byte strings I think there might already be a performance cliff there.)
clean up unneeded `ToPredicate` impls
Part of #107250.
Removed all totally unused impls. And inlined two impls not need to satisify trait bound.
r? `@oli-obk`
miri: reduce code duplication in some SSE/SSE2 intrinsics
Reduces code duplication in the Miri implementation of some SSE and SSE2 using generics and rustc_const_eval helper functions.
There are also some other minor changes.
r? `@RalfJung`
Pretty-print argument-position impl trait to name it.
This removes a corner case.
RPIT and TAIT keep having no name, and it would be wrong to use the one in HIR (Ident::empty), so I make this case ICE.
rustc_target/riscv: Fix passing of transparent unions with only one non-ZST member
This ensures that `MaybeUninit<T>` has the same ABI as `T` when passed through an `extern "C"` function.
Fixes https://github.com/rust-lang/rust/issues/115481.
r? `@RalfJung`
This function is now used to check `#[panic_handler]`, `start` lang item, `main`, `#[start]` and intrinsic functions.
The diagnosis produced are now closer to the ones produced by trait/impl method signature mismatch.
move things out of mir/mod.rs
This moves a bunch of things out of `mir/mod.rs`:
- all const-related stuff to a new file consts.rs
- all statement/place/operand-related stuff to a new file statement.rs
- all pretty-printing related stuff to pretty.rs
`mod.rs` started out with 3100 lines and ends up with 1600. :)
Also there was some pretty-printing stuff in terminator.rs, that also got moved to pretty.rs, and I reordered things in pretty.rs so that it can be grouped by functionality.
Only the commit "use pretty_print_const_value from MIR constant 'extra' printing" has any behavior changes; it resolves the issue of having a fancy and a very crude pretty-printer for `ConstValue`.
r? `@oli-obk`
Make `TyKind::Adt`'s `Debug` impl be more pretty
Currently `{:?}` on `Ty` for a `TyKind::Adt` would print as `Adt(Foo, [])`. This PR changes it to be `Foo` when there are no generics or `Foo<T>`/`Foo<T, U>` when there _are_ generics. Example from debug log:
`├─0ms DEBUG rustc_hir_analysis::astconv return=Bar<T/#0, U/#1>`
I should have done this in my initial PR for a prettier TyKind: Debug impl but I thought I would need to be accessing generics_of to figure out where in the "path" the generics would have to go??? but no, adts literally only have a single place the generics can go (on the end). Feel a bit silly about this :)
r? `@oli-obk`
move required_consts check to general post-mono-check function
This factors some code that is common between the interpreter and the codegen backends into shared helper functions. Also as a side-effect the interpreter now uses the same `eval` functions as everyone else to get the evaluated MIR constants.
Also this is in preparation for another post-mono check that will be needed for (the current hackfix for) https://github.com/rust-lang/rust/issues/115709: ensuring that all locals are dynamically sized.
I didn't expect this to change diagnostics, but it's just cycle errors that change.
r? `@oli-obk`
nop_lift macros: ensure that we are using the right interner
Right now someone could put down the wrong list name when using these macros, and everything would still build. Nothing does a type-check to ensure that the `$set` contains element of type `Self::Lifted`. Let's fix that.
For lists this is fairly easy; for the other interners we need to unwrap some newtypes which makes this more complicated.
It's easier to pass it in to the one method that needs it
(`highlighting_region_vid`) than to store it in the type. This means
`RegionHighlightMode` can impl `Default`.
`#[diagnostic::on_unimplemented]` without filters
This commit adds support for a `#[diagnostic::on_unimplemented]` attribute with the following options:
* `message` to customize the primary error message
* `note` to add a customized note message to an error message
* `label` to customize the label part of the error message
The relevant behavior is specified in [RFC-3366](https://rust-lang.github.io/rfcs/3366-diagnostic-attribute-namespace.html)
Accept additional user-defined syntax classes in fenced code blocks
Part of #79483.
This is a re-opening of https://github.com/rust-lang/rust/pull/79454 after a big update/cleanup. I also converted the syntax to pandoc as suggested by `@notriddle:` the idea is to be as compatible as possible with the existing instead of having our own syntax.
## Motivation
From the original issue: https://github.com/rust-lang/rust/issues/78917
> The technique used by `inline-c-rs` can be ported to other languages. It's just super fun to see C code inside Rust documentation that is also tested by `cargo doc`. I'm sure this technique can be used by other languages in the future.
Having custom CSS classes for syntax highlighting will allow tools like `highlight.js` to be used in order to provide highlighting for languages other than Rust while not increasing technical burden on rustdoc.
## What is the feature about?
In short, this PR changes two things, both related to codeblocks in doc comments in Rust documentation:
* Allow to disable generation of `language-*` CSS classes with the `custom` attribute.
* Add your own CSS classes to a code block so that you can use other tools to highlight them.
#### The `custom` attribute
Let's start with the new `custom` attribute: it will disable the generation of the `language-*` CSS class on the generated HTML code block. For example:
```rust
/// ```custom,c
/// int main(void) {
/// return 0;
/// }
/// ```
```
The generated HTML code block will not have `class="language-c"` because the `custom` attribute has been set. The `custom` attribute becomes especially useful with the other thing added by this feature: adding your own CSS classes.
#### Adding your own CSS classes
The second part of this feature is to allow users to add CSS classes themselves so that they can then add a JS library which will do it (like `highlight.js` or `prism.js`), allowing to support highlighting for other languages than Rust without increasing burden on rustdoc. To disable the automatic `language-*` CSS class generation, you need to use the `custom` attribute as well.
This allow users to write the following:
```rust
/// Some code block with `{class=language-c}` as the language string.
///
/// ```custom,{class=language-c}
/// int main(void) {
/// return 0;
/// }
/// ```
fn main() {}
```
This will notably produce the following HTML:
```html
<pre class="language-c">
int main(void) {
return 0;
}</pre>
```
Instead of:
```html
<pre class="rust rust-example-rendered">
<span class="ident">int</span> <span class="ident">main</span>(<span class="ident">void</span>) {
<span class="kw">return</span> <span class="number">0</span>;
}
</pre>
```
To be noted, we could have written `{.language-c}` to achieve the same result. `.` and `class=` have the same effect.
One last syntax point: content between parens (`(like this)`) is now considered as comment and is not taken into account at all.
In addition to this, I added an `unknown` field into `LangString` (the parsed code block "attribute") because of cases like this:
```rust
/// ```custom,class:language-c
/// main;
/// ```
pub fn foo() {}
```
Without this `unknown` field, it would generate in the DOM: `<pre class="language-class:language-c language-c">`, which is quite bad. So instead, it now stores all unknown tags into the `unknown` field and use the first one as "language". So in this case, since there is no unknown tag, it'll simply generate `<pre class="language-c">`. I added tests to cover this.
Finally, I added a parser for the codeblock attributes to make it much easier to maintain. It'll be pretty easy to extend.
As to why this syntax for adding attributes was picked: it's [Pandoc's syntax](https://pandoc.org/MANUAL.html#extension-fenced_code_attributes). Even if it seems clunkier in some cases, it's extensible, and most third-party Markdown renderers are smart enough to ignore Pandoc's brace-delimited attributes (from [this comment](https://github.com/rust-lang/rust/pull/110800#issuecomment-1522044456)).
## Raised concerns
#### It's not obvious when the `language-*` attribute generation will be added or not.
It is added by default. If you want to disable it, you will need to use the `custom` attribute.
#### Why not using HTML in markdown directly then?
Code examples in most languages are likely to contain `<`, `>`, `&` and `"` characters. These characters [require escaping](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/pre) when written inside the `<pre>` element. Using the \`\`\` code blocks allows rustdoc to take care of escaping, which means doc authors can paste code samples directly without manually converting them to HTML.
cc `@poliorcetics`
r? `@notriddle`
Properly consider binder vars in `HasTypeFlagsVisitor`
Given a PolyTraitRef like `for<'a> Ty: Trait` (where neither `Ty` nor `Trait` mention `'a`), we do *not* return true for `.has_type_flags(TypeFlags::HAS_LATE_BOUND)`, even though binders are supposed to act as if they have late-bound vars even if they don't mention them in their bound value: 31ae3b2bdb. This is because we use `HasTypeFlagsVisitor`, which only computes the type flags for `Ty`, `Const` and `Region` and `Predicates`, and we consequently skip any binders (and setting flags for their vars) that are not contained in one of these types.
This ends up causing a problem, because when we call `TyCtxt::erase_regions` (which both erases regions *and* anonymizes bound vars), we will skip such a PolyTraitRef, not anonymizing it, and therefore not making it structurally equal to other binders. This breaks vtable computations.
This PR computes the flags for all binders we enter in `HasTypeFlagsVisitor` if we're looking for `TypeFlags::HAS_LATE_BOUND` (or `TypeFlags::HAS_{RE,TY,CT}_LATE_BOUND`).
Fixes#115807
treat host effect params as erased in codegen
This fixes the changes brought to codegen tests when effect params are added to libcore, by not attempting to monomorphize functions that get the host param by being `const fn`.
r? `@oli-obk`
some ConstValue refactoring
In particular, use AllocId instead of Allocation in ConstValue::ByRef. This helps avoid redundant AllocIds when a `ByRef` constant gets put back into the interpreter.
r? `@oli-obk`
Fixes https://github.com/rust-lang/rust/issues/105536
This fixes the changes brought to codegen tests when effect params are
added to libcore, by not attempting to monomorphize functions that get
the host param by being `const fn`.
some inspect improvements
split from #114810 because I still want to experiment a bunch with that PR and these changes are self-contained.
r? `@compiler-errors`
Rework `no_coverage` to `coverage(off)`
As discussed at the tail of https://github.com/rust-lang/rust/issues/84605 this replaces the `no_coverage` attribute with a `coverage` attribute that takes sub-parameters (currently `off` and `on`) to control the coverage instrumentation.
Allows future-proofing for things like `coverage(off, reason="Tested live", issue="#12345")` or similar.
Remove `verbose_generic_activity_with_arg`
This removes `verbose_generic_activity_with_arg` and changes users to `generic_activity_with_arg`. This keeps the output of `-Z time` readable while these repeated events are still available with the self profiling mechanism.
This commit adds support for a `#[diagnostic::on_unimplemented]`
attribute with the following options:
* `message` to customize the primary error message
* `note` to add a customized note message to an error message
* `label` to customize the label part of the error message
Co-authored-by: León Orell Valerian Liehr <me@fmease.dev>
Co-authored-by: Michael Goulet <michael@errs.io>
interpret: change ABI-compat test to be type-based
This makes the test consistent across targets. Otherwise the chances are very high that ABI mismatches get accepted on x86_64 but still fail on many other targets with more complicated ABIs.
This implements (most of) the rules described in https://github.com/rust-lang/rust/pull/115476.
also handle 2 panics when dumping proof trees for the whole test suite
- need to actually tell the proof tree builder about overflow
- need to handle a recursion_limit of 0 :<
Enable incremental-relative-spans by default.
This was enabled on nightly in https://github.com/rust-lang/rust/pull/84762.
It has been a while, without obvious bugs. It's time to enable it by default for incremental runs.
The `Debug` impl for `Ty` just calls the `Display` impl for `Ty`. This
is surprising and annoying. In particular, it means `Debug` doesn't show
as much information as `Debug` for `TyKind` does. And `Debug` is used in
some user-facing error messages, which seems bad.
This commit changes the `Debug` impl for `Ty` to call the `Debug` impl
for `TyKind`. It also does a number of follow-up changes to preserve
existing output, many of which involve inserting
`with_no_trimmed_paths!` calls. It also adds `Display` impls for
`UserType` and `Canonical`.
Some tests have changes to expected output:
- Those that use the `rustc_abi(debug)` attribute.
- Those that use the `EMIT_MIR` annotation.
In each case the output is slightly uglier than before. This isn't
ideal, but it's pretty weird (particularly for the attribute) that the
output is using `Debug` in the first place. They're fairly obscure
attributes (I hadn't heard of them) so I'm not worried by this.
For `async-is-unwindsafe.stderr`, there is one line that now lacks a
full path. This is a consistency improvement, because all the other
mentions of `Context` in this test lack a path.
Avoid a `source_span` query when encoding Spans into query results
This avoids a `source_span` query when encoding `Span`s into query results. It's not sound to execute queries here as the query caches can be locked and the dep graph is no longer writable.
r? `@cjgillot`
Use `Freeze` for `SourceFile`
This uses the `Freeze` type in `SourceFile` to let accessing `external_src` and `lines` be lock-free.
Behavior of `add_external_src` is changed to set `ExternalSourceKind::AbsentErr` on a hash mismatch which matches the documentation. `ExternalSourceKind::Unneeded` was removed as it's unused.
Based on https://github.com/rust-lang/rust/pull/115401.
Don't suggest dereferencing to unsized type
Rudimentary check that the self type is Sized. I don't really like any of this diagnostics code -- it's really messy and also really prone to false positives and negatives, but oh well.
Fixes#115569
Print the path of a return-position impl trait in trait when `return_type_notation` is enabled
When we're printing a return-position impl trait in trait, we usually just print it like an opaque. This is *usually* fine, but can be confusing when using `return_type_notation`. Print the path of the method from where the RPITIT originates when this feature gate is enabled.
Implement refinement lint for RPITIT
Implements a lint that warns against accidentally refining an RPITIT in an implementation. This is not a hard error, and can be suppressed with `#[allow(refining_impl_trait)]`, since this behavior may be desirable -- the lint just serves as an acknowledgement from the impl author that they understand that the types they write in the implementation are an API guarantee.
This compares bounds syntactically, not semantically -- semantic implication is more difficult and essentially relies on adding the ability to keep the RPITIT hidden in the trait system so that things can be proven about the type that shows up in the impl without its own bounds leaking through, either via a new reveal mode or something else. This was experimentally implemented in #111931.
Somewhat opinionated choices:
1. Putting the lint behind `refining_impl_trait` rather than a blanket `refine` lint. This could be changed, but I like keeping the lint specialized to RPITITs so the explanation can be tailored to it.
2. This PR does not include the `#[refine]` attribute or the feature gate, since it's kind of orthogonal and can be added in a separate PR.
r? `@oli-obk`
Use a specialized varint + bitpacking scheme for DepGraph encoding
The previous scheme here uses leb128 to encode the edge tables that represent the incr comp dependency graph. The problem with that scheme is that leb128 has overhead for larger values, and generally relies on the distribution of encoded values being heavily skewed towards smaller values. That is definitely not the case for a dep node index, since they are handed out sequentially and the whole range is covered, the distribution is actually biased in the opposite direction: Most dep nodes are large.
This PR implements a different varint encoding scheme. Instead of applying varint encoding to individual dep node indices (which is extremely branchy) we now apply it per node.
While being built, each node now stores its edges in a `SmallVec` with a bit of extra logic to track the max value of each edge. Then we varint encode the whole batch. This is a gamble: We save on space by only claiming 2 bits per node instead of ~3 bits per edge which is a nice savings but needs to balance out with the space overhead that a single large index in a node with a lot of edges will encode unnecessary bytes in each of that node's edge indices.
Then, to keep the runtime overhead of this encoding scheme down we deserialize our indices by loading 4 bytes for each then masking off the bytes that are't ours. This is much less code and branches than leb128, but relies on having some readable bytes past the end of each edge list. We explicitly add such padding to the in-memory data during decoding. And we also do this decoding lazily, turning a dense on-disk encoding into a peak memory reduction.
Then we apply a bit-packing scheme; since in https://github.com/rust-lang/rust/pull/115391 we now have unused bits on `DepKind`, we use those unused bits (currently there are 7!) to store the 2 bits that we need for the byte width of the edges in each node, then use the remaining bits to store the length of the edge list, if it fits.
r? `@nnethercote`
Represent MIR composite debuginfo as projections instead of aggregates
Composite debuginfo for MIR is currently represented as
```
debug name => Type { projection1 => place1, projection2 => place2 };
```
ie. a single `VarDebugInfo` object with that name, and its value a `VarDebugInfoContents::Composite`.
This PR proposes to reverse the representation to be
```
debug name.projection1 => place1;
debug name.projection2 => place2;
```
ie. multiple `VarDebugInfo` objects with each their projection.
This simplifies the handling of composite debuginfo by the compiler by avoiding weird nesting.
Based on https://github.com/rust-lang/rust/pull/115139
Add `FreezeLock` type and use it to store `Definitions`
This adds a `FreezeLock` type which allows mutation using a lock until the value is frozen where it can be accessed lock-free. It's used to store `Definitions` in `Untracked` instead of a `RwLock`. Unlike the current scheme of leaking read guards this doesn't deadlock if definitions is written to after no mutation are expected.
Use relative positions inside a SourceFile.
This allows to remove the normalization of start positions for hashing, and simplify allocation of global address space.
cc `@Zoxc`
Encode DepKind as u16
The derived Encodable/Decodable impls serialize/deserialize as a varint, which results in a lot of code size around the encoding/decoding of these types which isn't justified: The full range of values here is rather small but doesn't quite fit in to a `u8`. Growing _all_ serialized `DepKind` to 2 bytes costs us on average 1% size in the incr comp dep graph, which I plan to recoup in https://github.com/rust-lang/rust/pull/110050 by taking advantage of the unused bits in all the serialized `DepKind`.
r? `@nnethercote`
Make `get_return_block()` return `Some` only for HIR nodes in body
Fixes#114918
The issue occurred while compiling the following input:
```rust
fn uwu() -> [(); { () }] {
loop {}
}
```
It was caused by the code below trying to suggest a missing return type which resulted in a const eval cycle: 1bd043098e/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs (L68-L75)
The root cause was `get_return_block()` returning an `Fn` node for a node in the return type (i.e. the second `()` in the return type `[(); { () }]` of the input) although it is supposed to do so only for nodes that lie in the body of the function and return `None` otherwise (at least as per my understanding).
The PR fixes the issue by fixing this behaviour of `get_return_block()`.
Remove conditional use of `Sharded` from query state
`Sharded` is already a zero cost abstraction, so it shouldn't affect the performance of the single thread compiler if LLVM does its job.
r? `@cjgillot`
Allow explicit `#[repr(Rust)]`
This is identical to no `repr()` at all. For `Rust, packed` and `Rust, align(x)`, it should be the same as no `Rust` at all (as, afaik, `#[repr(align(16))]` uses the Rust ABI.)
The main use case for this is being able to explicitly say "I want to use the Rust ABI" in very very rare circumstances where the first obvious choice would be the C ABI yet is undesirable, which is already possible with functions as `extern "Rust"`. This would be useful for silencing https://github.com/rust-lang/rust-clippy/pull/11253. It's also more consistent with `extern`.
The lack of this also tripped me up a bit when I was new to Rust, as I expected this to be possible.
Point at return type when it influences non-first `match` arm
When encountering code like
```rust
fn foo() -> i32 {
match 0 {
1 => return 0,
2 => "",
_ => 1,
}
}
```
Point at the return type and not at the prior arm, as that arm has type `!` which isn't influencing the arm corresponding to arm `2`.
Fix#78124.
Couple of global state and driver refactors
* Remove some unused global mutable state
* Remove a couple of unnecessary queries (both driver and `TyCtxt` queries)
* Remove an unnecessary use of `FxIndexMap`
When encountering code like
```rust
fn foo() -> i32 {
match 0 {
1 => return 0,
2 => "",
_ => 1,
}
}
```
Point at the return type and not at the prior arm, as that arm has type
`!` which isn't influencing the arm corresponding to arm `2`.
Fix#78124.
feat: `riscv-interrupt-{m,s}` calling conventions
Similar to prior support added for the mips430, avr, and x86 targets this change implements the rough equivalent of clang's [`__attribute__((interrupt))`][clang-attr] for riscv targets, enabling e.g.
```rust
static mut CNT: usize = 0;
pub extern "riscv-interrupt-m" fn isr_m() {
unsafe {
CNT += 1;
}
}
```
to produce highly effective assembly like:
```asm
pub extern "riscv-interrupt-m" fn isr_m() {
420003a0: 1141 addi sp,sp,-16
unsafe {
CNT += 1;
420003a2: c62a sw a0,12(sp)
420003a4: c42e sw a1,8(sp)
420003a6: 3fc80537 lui a0,0x3fc80
420003aa: 63c52583 lw a1,1596(a0) # 3fc8063c <_ZN12esp_riscv_rt3CNT17hcec3e3a214887d53E.0>
420003ae: 0585 addi a1,a1,1
420003b0: 62b52e23 sw a1,1596(a0)
}
}
420003b4: 4532 lw a0,12(sp)
420003b6: 45a2 lw a1,8(sp)
420003b8: 0141 addi sp,sp,16
420003ba: 30200073 mret
```
(disassembly via `riscv64-unknown-elf-objdump -C -S --disassemble ./esp32c3-hal/target/riscv32imc-unknown-none-elf/release/examples/gpio_interrupt`)
This outcome is superior to hand-coded interrupt routines which, lacking visibility into any non-assembly body of the interrupt handler, have to be very conservative and save the [entire CPU state to the stack frame][full-frame-save]. By instead asking LLVM to only save the registers that it uses, we defer the decision to the tool with the best context: it can more accurately account for the cost of spills if it knows that every additional register used is already at the cost of an implicit spill.
At the LLVM level, this is apparently [implemented by] marking every register as "[callee-save]," matching the semantics of an interrupt handler nicely (it has to leave the CPU state just as it found it after its `{m|s}ret`).
This approach is not suitable for every interrupt handler, as it makes no attempt to e.g. save the state in a user-accessible stack frame. For a full discussion of those challenges and tradeoffs, please refer to [the interrupt calling conventions RFC][rfc].
Inside rustc, this implementation differs from prior art because LLVM does not expose the "all-saved" function flavor as a calling convention directly, instead preferring to use an attribute that allows for differentiating between "machine-mode" and "superivsor-mode" interrupts.
Finally, some effort has been made to guide those who may not yet be aware of the differences between machine-mode and supervisor-mode interrupts as to why no `riscv-interrupt` calling convention is exposed through rustc, and similarly for why `riscv-interrupt-u` makes no appearance (as it would complicate future LLVM upgrades).
[clang-attr]: https://clang.llvm.org/docs/AttributeReference.html#interrupt-risc-v
[full-frame-save]: 9281af2ecf/src/lib.rs (L440-L469)
[implemented by]: b7fb2a3fec/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp (L61-L67)
[callee-save]: 973f1fe7a8/llvm/lib/Target/RISCV/RISCVCallingConv.td (L30-L37)
[rfc]: https://github.com/rust-lang/rfcs/pull/3246
Similar to prior support added for the mips430, avr, and x86 targets
this change implements the rough equivalent of clang's
[`__attribute__((interrupt))`][clang-attr] for riscv targets, enabling
e.g.
```rust
static mut CNT: usize = 0;
pub extern "riscv-interrupt-m" fn isr_m() {
unsafe {
CNT += 1;
}
}
```
to produce highly effective assembly like:
```asm
pub extern "riscv-interrupt-m" fn isr_m() {
420003a0: 1141 addi sp,sp,-16
unsafe {
CNT += 1;
420003a2: c62a sw a0,12(sp)
420003a4: c42e sw a1,8(sp)
420003a6: 3fc80537 lui a0,0x3fc80
420003aa: 63c52583 lw a1,1596(a0) # 3fc8063c <_ZN12esp_riscv_rt3CNT17hcec3e3a214887d53E.0>
420003ae: 0585 addi a1,a1,1
420003b0: 62b52e23 sw a1,1596(a0)
}
}
420003b4: 4532 lw a0,12(sp)
420003b6: 45a2 lw a1,8(sp)
420003b8: 0141 addi sp,sp,16
420003ba: 30200073 mret
```
(disassembly via `riscv64-unknown-elf-objdump -C -S --disassemble ./esp32c3-hal/target/riscv32imc-unknown-none-elf/release/examples/gpio_interrupt`)
This outcome is superior to hand-coded interrupt routines which, lacking
visibility into any non-assembly body of the interrupt handler, have to
be very conservative and save the [entire CPU state to the stack
frame][full-frame-save]. By instead asking LLVM to only save the
registers that it uses, we defer the decision to the tool with the best
context: it can more accurately account for the cost of spills if it
knows that every additional register used is already at the cost of an
implicit spill.
At the LLVM level, this is apparently [implemented by] marking every
register as "[callee-save]," matching the semantics of an interrupt
handler nicely (it has to leave the CPU state just as it found it after
its `{m|s}ret`).
This approach is not suitable for every interrupt handler, as it makes
no attempt to e.g. save the state in a user-accessible stack frame. For
a full discussion of those challenges and tradeoffs, please refer to
[the interrupt calling conventions RFC][rfc].
Inside rustc, this implementation differs from prior art because LLVM
does not expose the "all-saved" function flavor as a calling convention
directly, instead preferring to use an attribute that allows for
differentiating between "machine-mode" and "superivsor-mode" interrupts.
Finally, some effort has been made to guide those who may not yet be
aware of the differences between machine-mode and supervisor-mode
interrupts as to why no `riscv-interrupt` calling convention is exposed
through rustc, and similarly for why `riscv-interrupt-u` makes no
appearance (as it would complicate future LLVM upgrades).
[clang-attr]: https://clang.llvm.org/docs/AttributeReference.html#interrupt-risc-v
[full-frame-save]: 9281af2ecf/src/lib.rs (L440-L469)
[implemented by]: b7fb2a3fec/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp (L61-L67)
[callee-save]: 973f1fe7a8/llvm/lib/Target/RISCV/RISCVCallingConv.td (L30-L37)
[rfc]: https://github.com/rust-lang/rfcs/pull/3246
Map RPIT duplicated lifetimes back to fn captured lifetimes
Use the [`lifetime_mapping`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_hir/hir/struct.OpaqueTy.html#structfield.lifetime_mapping) to map an RPIT's captured lifetimes back to the early- or late-bound lifetimes from its parent function. We may be going thru several layers of mapping, since opaques can be nested, so we introduce `TyCtxt::map_rpit_lifetime_to_fn_lifetime` to loop through several opaques worth of mapping, and handle turning it into a `ty::Region` as well.
We can then use this instead of the identity substs for RPITs in `check_opaque_meets_bounds` to address #114285.
We can then also use `map_rpit_lifetime_to_fn_lifetime` to properly install bidirectional-outlives predicates for both RPITs and RPITITs. This addresses #114601.
I based this on #114574, but I don't actually know how much of that PR we still need, so some code may be redundant now... 🤷
---
Fixes#114597Fixes#114579Fixes#114285
Also fixes#114601, since it turns out we had other bugs with RPITITs and their duplicated lifetime params 😅.
Supersedes #114574
r? `@oli-obk`
Store the laziness of type aliases in their `DefKind`
Previously, we would treat paths referring to type aliases as *lazy* type aliases if the current crate had lazy type aliases enabled independently of whether the crate which the alias was defined in had the feature enabled or not.
With this PR, the laziness of a type alias depends on the crate it is defined in. This generally makes more sense to me especially if / once lazy type aliases become the default in a new edition and we need to think about *edition interoperability*:
Consider the hypothetical case where the dependency crate has an older edition (and thus eager type aliases), it exports a type alias with bounds & a where-clause (which are void but technically valid), the dependent crate has the latest edition (and thus lazy type aliases) and it uses that type alias. Arguably, the bounds should *not* be checked since at any time, the dependency crate should be allowed to change the bounds at will with a *non*-major version bump & without negatively affecting downstream crates.
As for the reverse case (dependency: lazy type aliases, dependent: eager type aliases), I guess it rules out anything from slight confusion to mild annoyance from upstream crate authors that would be caused by the compiler ignoring the bounds of their type aliases in downstream crates with older editions.
---
This fixes#114468 since before, my assumption that the type alias associated with a given weak projection was lazy (and therefore had its variances computed) did not necessarily hold in cross-crate scenarios (which [I kinda had a hunch about](https://github.com/rust-lang/rust/pull/114253#discussion_r1278608099)) as outlined above. Now it does hold.
`@rustbot` label F-lazy_type_alias
r? `@oli-obk`
Add documentation to has_deref
Documentation of `has_deref` needed some polish to be more clear about where it should be used and what's it's purpose.
cc https://github.com/rust-lang/rust/issues/114401
r? `@RalfJung`
Convert builtin "global" late lints to run per module
The compiler currently has 4 non-incremental lints:
1. `clashing_extern_declarations`;
2. `missing_debug_implementations`;
3. ~`unnameable_test_items`;~ changed by https://github.com/rust-lang/rust/pull/114414
4. `missing_docs`.
Non-incremental lints get reexecuted for each compilation, which is slow. Moreover, those lints are allow-by-default, so run for nothing most of the time. This PR attempts to make them more incremental-friendly.
`clashing_extern_declarations` is moved to a standalone query.
`missing_debug_implementation` can use `non_blanket_impls_for_ty` instead of recomputing it.
`missing_docs` is harder as it needs to track if there is a `doc(hidden)` module surrounding. I hack around this using the lint level engine. That's easy to implement and allows to re-enable the lint for a re-exported module, while a more proper solution would reuse the same device as `unnameable_test_items`.
update overflow handling in the new trait solver
implements https://hackmd.io/QY0dfEOgSNWwU4oiGnVRLw?view. I want to clean up this doc and add it to the rustc-dev-guide, but I think this PR is ready for merge as is, even without the dev-guide entry.
r? `@compiler-errors`
Rework upcasting confirmation to support upcasting to fewer projections in target bounds
This PR implements a modified trait upcasting algorithm that is resilient to changes in the number of associated types in the bounds of the source and target trait objects.
It does this by equating each bound of the target trait ref individually against the bounds of the source trait ref, rather than doing them all together by constructing a new trait object.
#### The new way we do trait upcasting confirmation
1. Equate the target trait object's principal trait ref with one of the supertraits of the source trait object's principal.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2509-L2525)
2. Make sure that every auto trait in the *target* trait object is present in the source trait ref's bounds.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2559-L2562)
3. For each projection in the *target* trait object, make sure there is exactly one projection that equates with it in the source trait ref's bound. If there is more than one, bail with ambiguity.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2526-L2557)
* Since there may be more than one that applies, we probe first to check that there is exactly one, then we equate it outside of a probe once we know that it's unique.
4. Make sure the lifetime of the source trait object outlives the lifetime of the target.
<details>
<summary>Meanwhile, this is how we used to do upcasting:</summary>
1. For each supertrait of the source trait object, take that supertrait, append the source object's projection bounds, and the *target* trait object's auto trait bounds, and make this into a new object type:
d12c6e947c/compiler/rustc_trait_selection/src/traits/select/confirmation.rs (L915-L929)
2. Then equate it with the target trait object:
d12c6e947c/compiler/rustc_trait_selection/src/traits/select/confirmation.rs (L936)
This will be a type mismatch if the target trait object has fewer projection bounds, since we compare the bounds structurally in relate:
d12c6e947c/compiler/rustc_middle/src/ty/relate.rs (L696-L698)
</details>
Fixes#114035
Also fixes#114113, because I added a normalize call in the old solver.
r? types
resolve before canonicalization in new solver, ICE if unresolved
Fold the values with a resolver before canonicalization instead of making it happen within canonicalization.
This allows us to filter trivial region constraints from the external constraints.
r? ``@lcnr``
Perform OpaqueCast field projection on HIR, too.
fixes#105819
This is necessary for closure captures in 2021 edition, as they capture individual fields, not the full mentioned variables. So it may try to capture a field of an opaque (because the hidden type is known to be something with a field).
See https://github.com/rust-lang/rust/pull/99806 for when and why we added OpaqueCast to MIR.
Add `internal_features` lint
Implements https://github.com/rust-lang/compiler-team/issues/596
Also requires some more test blessing for codegen tests etc
`@jyn514` had the idea of just `allow`ing the lint by default in the test suite. I'm not sure whether this is a good idea, but it's definitely one worth considering. Additional input encouraged.
const validation: point at where we found a pointer but expected an integer
Instead of validation just printing "unable to turn pointer into bytes", make this a regular validation error that says where in the value the bad pointer was found. Also distinguish "expected integer, got pointer" from "expected pointer, got partial pointer or mix of pointers".
To avoid duplicating things too much I refactored the diagnostics for validity a bit, so that "got uninit, expected X" and "got pointer, expected X" can share the "X" part. Also all the errors emitted for validation are now grouped under `const_eval_validation` so that they are in a single group in the ftl file.
r? `@oli-obk`
It lints against features that are inteded to be internal to the
compiler and standard library. Implements MCP #596.
We allow `internal_features` in the standard library and compiler as those
use many features and this _is_ the standard library from the "internal to the compiler and
standard library" after all.
Marking some features as internal wasn't exactly the most scientific approach, I just marked some
mostly obvious features. While there is a categorization in the macro,
it's not very well upheld (should probably be fixed in another PR).
We always pass `-Ainternal_features` in the testsuite
About 400 UI tests and several other tests use internal features.
Instead of throwing the attribute on each one, just always allow them.
There's nothing wrong with testing internal features^^
Miri: fix error on dangling pointer inbounds offset
We used to claim that the pointer was "dereferenced", but that is just not true.
Can be reviewed commit-by-commit. The first commit is an unrelated rename that didn't seem worth splitting into its own PR.
r? `@oli-obk`
Don't check unnecessarily that impl trait is RPIT
We have this random `return_type_impl_trait` function to detect if a function returns an RPIT which is used in outlives suggestions, but removing it doesn't actually change any diagnostics. Let's just remove it.
Also, suppress a spurious outlives error from a ReError.
Fixes#114274
Operand types are now tracked explicitly, so there is no need to reserve ID 0
for the special always-zero counter.
As part of the renumbering, this change fixes an off-by-one error in the way
counters were counted by the `coverageinfo` query. As a result, functions
should now have exactly the number of counters they actually need, instead of
always having an extra counter that is never used.
Operand types are now tracked explicitly, so there is no need for expression
IDs to avoid counter IDs by descending from `u32::MAX`. Instead they can just
count up from 0, and can be used directly as indices when necessary.
Because the three kinds of operand are now distinguished explicitly, we no
longer need fiddly code to disambiguate counter IDs and expression IDs based on
the total number of counters/expressions in a function.
This does increase the size of operands from 4 bytes to 8 bytes, but that
shouldn't be a big deal since they are mostly stored inside boxed structures,
and the current coverage code is not particularly size-optimized anyway.
The actual motivation here is to prevent `rustfmt` from suddenly reformatting
these enum variants onto a single line, when they become slightly shorter in
the future.
But there's no harm in adding some helpful documentation at the same time.
Map RPITIT's opaque type bounds back from projections to opaques
An RPITIT in a program's AST is eventually translated into both a projection GAT and an opaque. The opaque is used for default trait methods, like:
```
trait Foo {
fn bar() -> impl Sized { 0i32 }
}
```
The item bounds for both the projection and opaque are identical, and both have a *projection* self ty. This is mostly okay, since we can normalize this projection within the default trait method body to the opaque, but it does two things:
1. it leads to bugs in places where we don't normalize item bounds, like `deduce_future_output_from_obligations`
2. it leads to extra match arms that are both suspicious looking and also easy to miss
This PR maps the opaque type bounds of the RPITIT's *opaque* back to the opaque's self type to avoid this quirk. Then we can fix the UI test for #108304 (1.) and also remove a bunch of match arms (2.).
Fixes#108304
r? `@spastorino`
Rollup of 7 pull requests
Successful merges:
- #114099 (privacy: no nominal visibility for assoc fns )
- #114128 (When flushing delayed span bugs, write to the ICE dump file even if it doesn't exist)
- #114138 (Adjust spans correctly for fn -> method suggestion)
- #114146 (Skip reporting item name when checking RPITIT GAT's associated type bounds hold)
- #114147 (Insert RPITITs that were shadowed by missing ADTs that resolve to [type error])
- #114155 (Replace a lazy `RefCell<Option<T>>` with `OnceCell<T>`)
- #114164 (Add regression test for `--cap-lints allow` and trait bounds warning)
r? `@ghost`
`@rustbot` modify labels: rollup
When `staged_api` is enabled, effective visibilities are computed earlier
and this can trigger an ICE in some cases.
In particular, if a impl of a trait method has a visibility then an error
will be reported for that, but when privacy invariants are being checked,
the effective visibility will still be greater than the nominal visbility
and that will trigger a `span_bug!`.
However, this invariant - that effective visibilites are limited to
nominal visibility - doesn't make sense for associated functions.
Signed-off-by: David Wood <david@davidtw.co>
new unstable option: -Zwrite-long-types-to-disk
This option guards the logic of writing long type names in files and instead using short forms in error messages in rustc_middle/ty/error behind a flag. The main motivation for this change is to disable this behaviour when running ui tests.
This logic can be triggered by running tests in a directory that has a long enough path, e.g. /my/very-long-path/where/rust-codebase/exists/
This means ui tests can fail depending on how long the path to their file is.
Some ui tests actually rely on this behaviour for their assertions, so for those we enable the flag manually.
Normalize the RHS of an `Unsize` goal in the new solver
`Unsize` goals are... tricky. Not only do they structurally match on their self type, but they're also structural on their other type parameter. I'm pretty certain that it is both incomplete and also just plain undesirable to not consider normalizing the RHS of an unsize goal. More practically, I'd like for this code to work:
```rust
trait A {}
trait B: A {}
impl A for usize {}
impl B for usize {}
trait Mirror {
type Assoc: ?Sized;
}
impl<T: ?Sized> Mirror for T {
type Assoc = T;
}
fn main() {
// usize: Unsize<dyn B>
let x = Box::new(1usize) as Box<<dyn B as Mirror>::Assoc>;
// dyn A: Unsize<dyn B>
let y = x as Box<<dyn A as Mirror>::Assoc>;
}
```
---
In order to achieve this, we add `EvalCtxt::normalize_non_self_ty` (naming modulo bikeshedding), which *must* be used for all non-self type arguments that are structurally matched in candidate assembly. Currently this is only necessary for `Unsize`'s argument, but I could see future traits requiring this (hopefully rarely) in the future. It uses `repeat_while_none` to limit infinite looping, and normalizes the self type until it is no longer an alias.
Also, we need to fix feature gate detection for `trait_upcasting` and `unsized_tuple_coercion` when HIR typeck has unnormalized types. We can do that by checking the `ImplSource` returned by selection, which necessitates adding a new impl source for tuple upcasting.
interpret: Unify projections for MPlaceTy, PlaceTy, OpTy
For ~forever, we didn't really have proper shared code for handling projections into those three types. This is mostly because `PlaceTy` projections require `&mut self`: they might have to `force_allocate` to be able to represent a project part-way into a local.
This PR finally fixes that, by enhancing `Place::Local` with an `offset` so that such an optimized place can point into a part of a place without having requiring an in-memory representation. If we later write to that place, we will still do `force_allocate` -- for now we don't have an optimized path in `write_immediate` that would avoid allocation for partial overwrites of immediately stored locals. But in `write_immediate` we have `&mut self` so at least this no longer pollutes all our type signatures.
(Ironically, I seem to distantly remember that many years ago, `Place::Local` *did* have an `offset`, and I removed it to simplify things. I guess I didn't realize why it was so useful... I am also not sure if this was actually used to achieve place projection on `&self` back then.)
The `offset` had type `Option<Size>`, where `None` represent "no projection was applied". This is needed because locals *can* be unsized (when they are arguments) but `Place::Local` cannot store metadata: if the offset is `None`, this refers to the entire local, so we can use the metadata of the local itself (which must be indirect); if a projection gets applied, since the local is indirect, it will turn into a `Place::Ptr`. (Note that even for indirect locals we can have `Place::Local`: when the local appears in MIR, we always start with `Place::Local`, and only check `frame.locals` later. We could eagerly normalize to `Place::Ptr` but I don't think that would actually simplify things much.)
Having done all that, we can finally properly abstract projections: we have a new `Projectable` trait that has the basic methods required for projecting, and then all projection methods are implemented for anything that implements that trait. We can even implement it for `ImmTy`! (Not that we need that, but it seems neat.) The visitor can be greatly simplified; it doesn't need its own trait any more but it can use the `Projectable` trait. We also don't need the separate `Mut` visitor any more; that was required only to reflect that projections on `PlaceTy` needed `&mut self`.
It is possible that there are some more `&mut self` that can now become `&self`... I guess we'll notice that over time.
r? `@oli-obk`
This is necessary for closure captures in 2021 edition, as they capture individual fields, not the full mentioned variables. So it may try to capture a field of an opaque (because the hidden type is known to be something with a field).
rustdoc: handle cross-crate RPITITs correctly
Filter out the internal associated types synthesized during the desugaring of RPITITs, they really shouldn't show up in the docs.
This also fixes#113929 since we're no longer invoking `is_impossible_associated_item` (renamed from `is_impossible_method`) which cannot handle them (leading to an ICE). I don't think it makes sense to try to make `is_impossible_associated_item` handle this exotic kind of associated type (CC original author `@compiler-errors).`
@ T-rustdoc reviewers, currently I'm throwing out ITIT assoc tys before cleaning assoc tys at each usage-site. I'm thinking about making `clean_middle_assoc_item` return an `Option<_>` instead and doing the check inside of it to prevent any call sites from forgetting the check for ITITs. Since I wasn't sure if you would like that approach, I didn't go through with it. Let me know what you think.
<details><summary>Explanation on why <code>is_impossible_associated_item(itit_assoc_ty)</code> leads to an ICE</summary>
Given the following code:
```rs
pub trait Trait { fn def<T>() -> impl Default {} }
impl Trait for () {}
```
The generated associated type looks something like (simplified):
```rs
type {opaque#0}<T>: Default = impl Default; // the name is actually `kw::Empty` but this is the `def_path_str` repr
```
The query `is_impossible_associated_item` goes through all predicates of the associated item – in this case `<T as Sized>` – to check if they contain any generic parameters from the (generic) associated type itself. For predicates that don't contain any *own* generics, it does further processing, part of which is instantiating the predicate with the generic arguments of the impl block (which is only correct if they truly don't contain any own generics since they wouldn't get instantiated this way leading to an ICE).
It checks if `parent_def_id(T) == assoc_ty_def_id` to get to know if `T` is owned by the assoc ty. Unfortunately this doesn't work for ITIT assoc tys. In this case, the parent of `T` is `Trait::def` (!) which is the associated function (I'm pretty sure this is very intentional) which is of course not equal to the assoc ty `Trait::{opaque#0}`.
</details>
`@rustbot` label A-cross-crate-reexports
This option guards the logic of writing long type names in files and
instead using short forms in error messages in rustc_middle/ty/error
behind a flag. The main motivation for this change is to disable this
behaviour when running ui tests.
This logic can be triggered by running tests in a directory that has a
long enough path, e.g. /my/very-long-path/where/rust-codebase/exists/
This means ui tests can fail depending on how long the path to their
file is.
Some ui tests actually rely on this behaviour for their assertions,
so for those we enable the flag manually.
Rollup of 4 pull requests
Successful merges:
- #113887 (new solver: add a separate cache for coherence)
- #113910 (Add FnPtr ty to SMIR)
- #113913 (error/E0691: include alignment in error message)
- #113914 (rustc_target: drop duplicate code)
r? `@ghost`
`@rustbot` modify labels: rollup
Still more complexity, but this allows computing exact `NaiveLayout`s
for null-optimized enums, and thus allows calls like
`transmute::<Option<&T>, &U>()` to work in generic contexts.
THis significantly complicates `NaiveLayout` logic, but is necessary to
ensure that bounds like `NonNull<T>: PointerLike` hold in generic
contexts.
Also implement exact layout computation for structs.
Querify unused trait check.
This code transitively loads information for all bodies, and from resolutions. As it does not return a value, it should be beneficial to have it as a query.
Don't translate compiler-internal bug messages
These are not very useful to be translated, as
* translators would get really weird and bad english versions to start out from,
* compiler devs have to do some work for what is supposed to be dead code and just a sanity check,
* the target audience is other compiler devs.
r? `@davidtwco`
Make it clearer that edition functions are `>=`, not `==`
r? `@Nilstrieb`
We could also perhaps derive `Ord` on `Edition` and use comparison operators.
Add the `no-builtins` attribute to functions when `no_builtins` is applied at the crate level.
**When `no_builtins` is applied at the crate level, we should add the `no-builtins` attribute to each function to ensure it takes effect in LTO.**
This is also the reason why no_builtins does not take effect in LTO as mentioned in #35540.
Now, `#![no_builtins]` should be similar to `-fno-builtin` in clang/gcc, see https://clang.godbolt.org/z/z4j6Wsod5.
Next, we should make `#![no_builtins]` participate in LTO again. That makes sense, as LTO also takes into consideration function-level instruction optimizations, such as the MachineOutliner. More importantly, when a user writes a large `#![no_builtins]` crate, they would like this crate to participate in LTO as well.
We should also add a function-level no_builtins attribute to allow users to have more control over it. This is similar to Clang's `__attribute__((no_builtin))` feature, see https://clang.godbolt.org/z/Wod6KK6eq. Before implementing this feature, maybe we should discuss whether to support more fine-grained control, such as `__attribute__((no_builtin("memcpy")))`.
Related discussions:
- #109821
- #35540
Next (a separate pull request?):
- [ ] Revert #35637
- [ ] Add a function-level `no_builtin` attribute?
Safe Transmute: Fix ICE (due to UnevaluatedConst)
This patch updates the code that looks at the `Assume` type when evaluating if transmutation is possible. An ICE was being triggered in the case that the `Assume` parameter contained an unevaluated const (in this test case, due to a function with missing parameter names).
Fixes#110892
This patch updates the code that looks at the `Assume` type when evaluating if
transmutation is possible. An ICE was being triggered in the case that the
`Assume` parameter contained an unevaluated const (in this test case, due to a
function with missing parameter names).
Fixes#110892
Use u64 for incr comp allocation offsets
Fixes https://github.com/rust-lang/rust/issues/76037
Fixes https://github.com/rust-lang/rust/issues/95780
Fixes https://github.com/rust-lang/rust/issues/111613
These issues are all reporting ICEs caused by using `u32` to store offsets to allocations in the incremental compilation cache. This PR aims to lift that limitation by changing the offset type in question to `u64`.
There are two perf runs in this PR. The first reports a regression, and the second does not. The changes are the same in both. I rebased the PR then did the second perf run because I noticed that the primary regression in it was very commonly seen in spurious regression reports.
I do not know what the perf run will report when this is merged. I would not be surprised to see regression or neutral, but the cachegrind diffs for the regression point at `try_mark_previous_green` which is a common source of inexplicable regressions and I don't think should be perturbed by this PR.
I'm not opposed to adding a regression test such as
```rust
fn main() {
println!("{}", [37; 1 << 30].len());
}
```
But that program takes 1 minute to compile and consumes 4.6 GB of memory then writes that much to disk. Is that a concerning amount of resource use for a test?
r? `@nnethercote`
Streamline size estimates (take 2)
This was merged in #113684 but then [something happened](https://github.com/rust-lang/rust/pull/113684#issuecomment-1636811985):
> There has been a bors issue that lead to the merge commit of this PR getting purged from master.
> You'll have to make a new PR to reapply it.
So this is exactly the same changes.
`@bors` r=wesleywiser
Add support for inherent projections in new solver
Not hard to support these, and it cuts out a really big chunk of failing UI tests with `--compare-mode=next-solver`
r? `@lcnr` (feel free to reassign, anyone can review this)
This means we call `MonoItem::size_estimate` (which involves a query)
less often: just once per mono item, and then once more per inline item
placement. After that we can reuse the stored value as necessary. This
means `CodegenUnit::compute_size_estimate` is cheaper.
Resurrect: rustc_target: Add alignment to indirectly-passed by-value types, correcting the alignment of byval on x86 in the process.
Same as #111551, which I [accidentally closed](https://github.com/rust-lang/rust/pull/111551#issuecomment-1571222612) :/
---
This resurrects PR #103830, which has sat idle for a while.
Beyond #103830, this also:
- fixes byval alignment for types containing vectors on Darwin (see `tests/codegen/align-byval-vector.rs`)
- fixes byval alignment for overaligned types on x86 Windows (see `tests/codegen/align-byval.rs`)
- fixes ABI for types with 128bit requested alignment on ARM64 Linux (see `tests/codegen/aarch64-struct-align-128.rs`)
r? `@nikic`
---
`@pcwalton's` original PR description is reproduced below:
Commit 88e4d2c from five years ago removed
support for alignment on indirectly-passed arguments because of problems with
the `i686-pc-windows-msvc` target. Unfortunately, the `memcpy` optimizations I
recently added to LLVM 16 depend on this to forward `memcpy`s. This commit
attempts to fix the problems with `byval` parameters on that target and now
correctly adds the `align` attribute.
The problem is summarized in [this comment] by `@eddyb.` Briefly, 32-bit x86 has
special alignment rules for `byval` parameters: for the most part, their
alignment is forced to 4. This is not well-documented anywhere but in the Clang
source. I looked at the logic in Clang `TargetInfo.cpp` and tried to replicate
it here. The relevant methods in that file are
`X86_32ABIInfo::getIndirectResult()` and
`X86_32ABIInfo::getTypeStackAlignInBytes()`. The `align` parameter attribute
for `byval` parameters in LLVM must match the platform ABI, or miscompilations
will occur. Note that this doesn't use the approach suggested by eddyb, because
I felt it was overkill to store the alignment in `on_stack` when special
handling is really only needed for 32-bit x86.
As a side effect, this should fix#80127, because it will make the `align`
parameter attribute for `byval` parameters match the platform ABI on LLVM
x86-64.
[this comment]: #80822 (comment)
Make it clearer that we're just checking for an RPITIT
Tiny nit to use `is_impl_trait_in_trait` more, to make it clearer that we're just checking whether a def-id is an RPITIT, rather than doing something meaningful with the `opt_rpitit_info`.
r? `@spastorino`
Use maybe_body_owned_by for multiple suggestions
This is a continued work from https://github.com/rust-lang/rust/pull/113567
We have several other suggestions not working for closure, this PR use `maybe_body_owned_by` to fix them and add test cases for them.
Add a cache for `maybe_lint_level_root_bounded`
`maybe_lint_level_root_bounded` is called many times and traces node sub-paths many times. This PR adds a cache that lets many of these tracings be skipped, avoiding lots of calls to functions like `Map::attrs` and `Map::parent_id`.
r? `@cjgillot`
refactor proof tree formatting
mostly:
- handle indentation via a separate formatter
- change nested to use a closure
tested it after rebasing on top of #113536 and everything looks good.
r? `````@BoxyUwU`````
miri: protect Move() function arguments during the call
This gives `Move` operands a meaning specific to function calls:
- for the duration of the call, the place the operand comes from is protected, making all read and write accesses insta-UB.
- the contents of that place are reset to `Uninit`, so looking at them again after the function returns, we cannot observe their contents
Turns out we can replace the existing "retag return place" hack with the exact same sort of protection on the return place, which is nicely symmetric.
Fixes https://github.com/rust-lang/rust/issues/112564
Fixes https://github.com/rust-lang/miri/issues/2927
This starts with a Miri rustc-push, since we'd otherwise conflict with a PR that recently landed in Miri.
(The "miri tree borrows" commit is an unrelated cleanup I noticed while doing the PR. I can remove it if you prefer.)
r? `@oli-obk`
Introduce `trait DebugWithInfcx` to debug format types with universe info
Seeing universes of infer vars is valuable for debugging but currently we have no way of easily debug formatting a type with the universes of all the infer vars shown. In the future I hope to augment the new solver's proof tree output with a `DebugWithInfcx` impl so that it can show universes but I left that out of this PR as it would be non trivial and this is already large and complex enough.
The goal here is to make the various abstractions taking `T: Debug` able to use the codepath for printing out universes, that way we can do `debug!("{:?}", my_x)` and have `my_x` have universes shown, same for the `write!` macro. It's not possible to put the `Infcx: InferCtxtLike<I>` into the formatter argument to `Debug::fmt` so it has to go into the self ty. For this we introduce the type `OptWithInfcx<I: Interner, Infcx: InferCtxtLike<I>, T>` which has the data `T` optionally coupled with the infcx (more on why it's optional later).
Because of coherence/orphan rules it's not possible to write the impl `Debug for OptWithInfcx<..., MyType>` when `OptWithInfcx` is in a upstream crate. This necessitates a blanket impl in the crate defining `OptWithInfcx` like so: `impl<T: DebugWithInfcx> Debug for OptWithInfcx<..., T>`. It is not intended for people to manually call `DebugWithInfcx::fmt`, the `Debug` impl for `OptWithInfcx` should be preferred.
The infcx has to be optional in `OptWithInfcx` as otherwise we would end up with a large amount of code duplication. Almost all types that want to be used with `OptWithInfcx` do not themselves need access to the infcx so if we were to not optional we would end up with large `Debug` and `DebugWithInfcx` impls that were practically identical other than that when formatting their fields we wrap the field in `OptWithInfcx` instead of formatting it alone.
The only types that need access to the infcx themselves are ty/const/region infer vars, everything else is implemented by having the `Debug` impl defer to `OptWithInfcx` with no infcx available. The `DebugWithInfcx` impl is pretty much just the standard `Debug` impl except that instead of recursively formatting fields with `write!(f, "{x:?}")` we must do `write!(f, "{:?}", opt_infcx.wrap(x))`. This is some pretty rough boilerplate but I could not think of an alternative unfortunately.
`OptWithInfcx::wrap` is an eager `Option::map` because 99% of callsites were discarding the existing data in `OptWithInfcx` and did not need lazy evaluation.
A trait `InferCtxtLike` was added instead of using `InferCtxt<'tcx>` as we need to implement `DebugWithInfcx` for types living in `rustc_type_ir` which are generic over an interner and do not have access to `InferCtxt` since it lives in `rustc_infer`. Additionally I suspect that adding universe info to new solver proof tree output will require an implementation of `InferCtxtLike` for something that is not an `InferCtxt` although this is not the primary motivaton.
---
To summarize:
- There is a type `OptWithInfcx` which bundles some data optionally with an infcx with allows us to pass an infcx into a `Debug` impl. It's optional instead of being there unconditionally so that we can share code for `Debug` and `DebugWithInfcx` impls that don't care about whether there is an infcx available but have fields that might care.
- There is a trait `DebugWithInfcx` which allows downstream crates to add impls of the form `Debug for OptWithInfcx<...>` which would normally be forbidden by orphan rules/coherence.
- There is a trait `InferCtxtLike` to allow us to implement `DebugWithInfcx` for types that live in `rustc_type_ir`
This allows debug formatting various `ty::*` structures with universes shown by using the `Debug` impl for `OptWithInfcx::new(ty, infcx)`
---
This PR does not add `DebugWithInfcx` impls to absolutely _everything_ that should realistically have them, for example you cannot use `OptWithInfcx<Obligation<Predicate>>`. I am leaving this to a future PR to do so as it would likely be a lot more work to do.
Rename `adjustment::PointerCast` and variants using it to `PointerCoercion`
It makes it sounds like the `ExprKind` and `Rvalue` are supposed to represent all pointer related casts, when in reality their just used to share a little enum variants. Make it clear there these are only coercions and that people who see this and think "why are so many pointer related casts not in these variants" aren't insane.
This enum was added in #59987. I'm not sure whether the variant sharing is actually worth it, but this at least makes it less confusing.
r? oli-obk
It makes it sound like the `ExprKind` and `Rvalue` are supposed to represent all pointer related
casts, when in reality their just used to share a some enum variants. Make it clear there these
are only coercion to make it clear why only some pointer related "casts" are in the enum.
Move `TyCtxt::mk_x` to `Ty::new_x` where applicable
Part of rust-lang/compiler-team#616
turns out there's a lot of places we construct `Ty` this is a ridiculously huge PR :S
r? `@oli-obk`
Specialize `try_destructure_mir_constant` for its sole user (pretty printing)
We can't remove the query, as we need to invoke it from rustc_middle, but can only implement it in mir interpretation/const eval.
r? `@RalfJung` for a first round.
While we could move all the logic into pretty printing, that would end up duplicating a bit of code with const eval, which doesn't seem great either.
Rollup of 8 pull requests
Successful merges:
- #113010 (rust-installer & rls: remove exclusion from rustfmt & tidy )
- #113317 ( -Ztrait-solver=next: stop depending on old solver)
- #113319 (`TypeParameterDefinition` always require a `DefId`)
- #113320 (Add some extra information to opaque type cycle errors)
- #113321 (Move `ty::ConstKind` to `rustc_type_ir`)
- #113337 (Winnow specialized impls during selection in new solver)
- #113355 (Move most coverage code out of `rustc_codegen_ssa`)
- #113356 (Add support for NetBSD/riscv64 aka. riscv64gc-unknown-netbsd.)
r? `@ghost`
`@rustbot` modify labels: rollup
Winnow specialized impls during selection in new solver
We need to be able to winnow impls that are specialized by more specific impls in order for codegen to be able to proceed.
r? ``@lcnr``
Move `ty::ConstKind` to `rustc_type_ir`
Needed this in another PR for custom debug impls, and this will also be required to move the new solver into a separate crate that does not use `TyCtxt` so that r-a and friends can depend on the trait solver.
Rebased on top of #113325, only the second and third commits needs reviewing
Add some extra information to opaque type cycle errors
Plus a bunch of cleanups.
This should help users debug query cycles due to auto trait checking. We'll probably want to fix cycle errors in most (or all?) cases by looking at the current item's hidden types (new solver does this), and by delaying the auto trait checks to after typeck.
Effects/keyword generics MVP
This adds `feature(effects)`, which adds `const host: bool` to the generics of const functions, const traits and const impls. This will be used to replace the current logic around const traits.
r? `@oli-obk`
Make simd_shuffle_indices use valtrees
This removes the second-to-last user of the `destructure_mir_constant` query. So in a follow-up we can remove the query and just move the query provider function directly into pretty printing (which is the last user).
cc `@rust-lang/clippy` there's a small functional change, but I think it is correct?
Make `UnwindAction::Continue` explicit in MIR dump
Makes it easier to spot unwinding related issues in MIR by making `UnwindAction::Continue` explicit, just like all other `UnwindAction`s.
Migrate `TyCtxt::predicates_of` and `ParamEnv::caller_bounds` to `Clause`
The last big change in the series.
I will follow-up with additional filed issues once this PR lands:
- [ ] Investigate making `TypeFoldable<TyCtxt<'tcx>> for ty::Clause<'tcx>` implementation less weird: 2efe091705/compiler/rustc_middle/src/ty/structural_impls.rs (L672)
- [ ] Clean up the elaborator since it should only be emitting child clauses, not predicates
- [ ] Rename identifiers like `pred` and `predicates` to `clause` if they're actually clauses around the codebase
- [ ] Validate that all of the `ToPredicate` impls are acutally still needed, or prune them if they're not
r? `@ghost` until the other branch lands
Various impl trait in assoc tys cleanups
r? `@compiler-errors`
All commits except for the last are pure refactorings. 274dab5bd658c97886a8987340bf50ae57900c39 allows struct fields to participate in deciding whether a function has an opaque in its signature.
best reviewed commit by commit
Migrate `item_bounds` to `ty::Clause`
Should be simpler than the next PR that's coming up. Last three commits are the relevant ones.
r? ``@oli-obk`` or ``@lcnr``
Don't ICE on unnormalized struct tail in layout computation
1. We try to compute a `SizeSkeleton` even if a layout error occurs, but we really only need to do this if we get `LayoutError::Unknown`, since that means our type is too polymorphic to actually compute the full layout. If we have other errors, like `LayoutError::NormalizationError` or `LayoutError::Cycle`, then we can't really make any progress, since this represents an actual error.
2. Avoid using `normalize_erasing_regions` and `struct_tail_erasing_lifetimes` since those ICE on normalization errors, and since we may call `layout_of` in HIR typeck, we don't know for certain that we're on the happy path.
Fixes#112736
Inline before merging cgus
Because CGU merging relies on CGU sizes, but the CGU sizes before inlining aren't accurate.
This change doesn't have much effect on compile perf, but it makes follow-on changes that involve more sophisticated reasoning about CGU sizes much easier.
r? `@wesleywiser`
- Rename `create_size_estimate` as `compute_size_estimate`, because that
makes more sense for the second and subsequent calls for each CGU.
- Change `CodegenUnit::size_estimate` from `Option<usize>` to `usize`.
We can still assert that `compute_size_estimate` is called first.
- Move the size estimation for `place_mono_items` inside the function,
for consistency with `merge_codegen_units`.
Because CGU merging relies on CGU sizes, but the CGU sizes before
inlining aren't accurate.
This requires tweaking how the sizes are updated during merging: if CGU
A and B both have an inlined function F, then `size(A + B)` will be a
little less than `size(A) + size(B)`, because `A + B` will only have one
copy of F. Also, the minimum CGU size is increased because it now has to
account for inlined functions.
This change doesn't have much effect on compile perf, but it makes
follow-on changes that involve more sophisticated reasoning about CGU
sizes much easier.
Add a fully fledged `Clause` type, rename old `Clause` to `ClauseKind`
Does two basic things before I put up a more delicate set of PRs (along the lines of #112714, but hopefully much cleaner) that migrate existing usages of `ty::Predicate` to `ty::Clause` (`predicates_of`/`item_bounds`/`ParamEnv::caller_bounds`).
1. Rename `Clause` to `ClauseKind`, so it's parallel with `PredicateKind`.
2. Add a new `Clause` type which is parallel to `Predicate`.
* This type exposes `Clause::kind(self) -> Binder<'tcx, ClauseKind<'tcx>>` which is parallel to `Predicate::kind` 😸
The new `Clause` type essentially acts as a newtype wrapper around `Predicate` that asserts that it is specifically a `PredicateKind::Clause`. Turns out from experimentation[^1] that this is not negative performance-wise, which is wonderful, since this a much simpler design than something that requires encoding the discriminant into the alignment bits of a predicate kind, or something else like that...
r? ``@lcnr`` or ``@oli-obk``
[^1]: https://github.com/rust-lang/rust/pull/112714#issuecomment-1595653910
Merge `BorrowKind::Unique` into `BorrowKind::Mut`
Fixes#112072
Might have conflict with #112070
r? `@lcnr`
I'm not sure what's the suitable change in a couple places.
Add `implement_via_object` to `rustc_deny_explicit_impl` to control object candidate assembly
Some built-in traits are special, since they are used to prove facts about the program that are important for later phases of compilation such as codegen and CTFE. For example, the `Unsize` trait is used to assert to the compiler that we are able to unsize a type into another type. It doesn't have any methods because it doesn't actually *instruct* the compiler how to do this unsizing, but this is later used (alongside an exhaustive match of combinations of unsizeable types) during codegen to generate unsize coercion code.
Due to this, these built-in traits are incompatible with the type erasure provided by object types. For example, the existence of `dyn Unsize<T>` does not mean that the compiler is able to unsize `Box<dyn Unsize<T>>` into `Box<T>`, since `Unsize` is a *witness* to the fact that a type can be unsized, and it doesn't actually encode that unsizing operation in its vtable as mentioned above.
The old trait solver gets around this fact by having complex control flow that never considers object bounds for certain built-in traits:
2f896da247/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs (L61-L132)
However, candidate assembly in the new solver is much more lovely, and I'd hate to add this list of opt-out cases into the new solver. Instead of maintaining this complex and hard-coded control flow, instead we can make this a property of the trait via a built-in attribute. We already have such a build attribute that's applied to every single trait that we care about: `rustc_deny_explicit_impl`. This PR adds `implement_via_object` as a meta-item to that attribute that allows us to opt a trait out of object-bound candidate assembly as well.
r? `@lcnr`
Switch the BB CFG cache from postorder to RPO
The `BasicBlocks` CFG cache is interesting:
- it stores a postorder, but `traversal::postorder` doesn't use it
- `traversal::reverse_postorder` does traverse the postorder cache backwards
- we do more RPO traversals than postorder traversals (around 20x on the perf.rlo benchmarks IIRC) but it's not cached
- a couple places here and there were manually reversing the non-cached postorder traversal
This PR switches the order of the cache, and makes a bit more use of it. This is a tiny win locally, but it's also for consistency and aesthetics.
r? `@ghost`
Make `Bound::predicates` use `Clause`
Part of #107250
`Bound::predicates` returns an iterator over `Binder<_, Clause>` instead of `Predicate`.
I tried updating `explicit_predicates_of` as well, but it seems that it needs a lot more change than I thought. Will do it in a separate PR instead.
Add `<meta charset="utf-8">` to `-Zdump-mir-spanview` output
Without an explicit `<meta charset>` declaration, some browsers (e.g. Safari) won't detect the page encoding as UTF-8, causing unicode characters in the dump output to display incorrectly.
Add `AliasKind::Weak` for type aliases.
`type Foo<T: Debug> = Bar<T>;` does not check `T: Debug` at use sites of `Foo<NotDebug>`, because in contrast to a
```rust
trait Identity {
type Identity;
}
impl<T: Debug> Identity for T {
type Identity = T;
}
<NotDebug as Identity>::Identity
```
type aliases do not exist in the type system, but are expanded to their aliased type immediately when going from HIR to the type layer.
Similarly:
* a private type alias for a public type is a completely fine thing, even though it makes it a bit hard to write out complex times sometimes
* rustdoc expands the type alias, even though often times users use them for documentation purposes
* diagnostics show the expanded type, which is confusing if the user wrote a type alias and the diagnostic talks about another type that they don't know about.
For type alias impl trait, these issues do not actually apply in most cases, but sometimes you have a type alias impl trait like `type Foo<T: Debug> = (impl Debug, Bar<T>);`, which only really checks it for `impl Debug`, but by accident prevents `Bar<T>` from only being instantiated after proving `T: Debug`. This PR makes sure that we always check these bounds explicitly and don't rely on an implementation accident.
To not break all the type aliases out there, we only use it when the type alias contains an opaque type. We can decide to do this for all type aliases over an edition.
Or we can later extend this to more types if we figure out the back-compat concerns with suddenly checking such bounds.
As a side effect, easily allows fixing https://github.com/rust-lang/rust/issues/108617, which I did.
fixes https://github.com/rust-lang/rust/issues/108617
Make assumption functions in new solver take `Binder<'tcx, Clause<'tcx>>`
We just use an if-let to match on an optional clause at all the places where we transition from `Predicate` -> `Clause`, but I assume that when things like item-bounds and param-env start to only store `Clause`s then those can just be trivially dropped.
r? ``@lcnr``
Opportunistically resolve regions in new solver
Use `opportunistic_resolve_var` during canonicalization to collapse some regions.
We have to start using `CanonicalVarValues::is_identity_modulo_regions`. We also have to modify that function to consider responses like `['static, ^0, '^1, ^2]` to be an "identity" response, since because we opportunistically resolve regions, there's no longer a 1:1 mapping between canonical var values and bound var indices in the response...
There's one nasty side-effect -- one test (`tests/ui/dyn-star/param-env-infer.rs`) starts to ICE because the certainty goes from `Yes` to `Maybe(Overflow)`... Not exactly sure why, though? Putting this up for discussion/investigation.
r? ```@lcnr```
This commit reverts a change made in #111425.
It was believed that this change was necessary for implementing type privacy lints, but #111801 showed that it was not necessary.
Quite opposite, the revert fixes some issues.
Remember names of `cfg`-ed out items to mention them in diagnostics
# Examples
## `serde::Deserialize` without the `derive` feature (a classic beginner mistake)
I had to slightly modify serde so that it uses explicit re-exports instead of a glob re-export. (Update: a serde PR was merged that adds the manual re-exports)
```
error[E0433]: failed to resolve: could not find `Serialize` in `serde`
--> src/main.rs:1:17
|
1 | #[derive(serde::Serialize)]
| ^^^^^^^^^ could not find `Serialize` in `serde`
|
note: crate `serde` has an item named `Serialize` but it is inactive because its cfg predicate evaluated to false
--> /home/gh-Nilstrieb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/serde-1.0.160/src/lib.rs:343:1
|
343 | #[cfg(feature = "serde_derive")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
344 | pub use serde_derive::{Deserialize, Serialize};
| ^^^^^^^^^
= note: the item is gated behind the `serde_derive` feature
= note: see https://doc.rust-lang.org/cargo/reference/features.html for how to activate a crate's feature
```
(the suggestion is not ideal but that's serde's fault)
I already tested the metadata size impact locally by compiling the `windows` crate without any features. `800k` -> `809k`
r? `@ghost`
Add `-Ztrait-solver=next-coherence`
Flag that conditionally uses the trait solver *only* during coherence, for more testing and/or eventual partial-migration onto the trait solver (in the medium- to long-term).
* This still uses the selection context in some of the coherence methods I think, so it's not "complete". Putting this up for review and/or for further work in-tree.
* I probably need to spend a bit more time making sure that we don't sneakily create any other infcx's during coherence that also need the new solver enabled.
r? `@lcnr`
Emit an error when return-type-notation is used with type/const params
These are not intended to be supported initially, even though the compiler supports them internally...
- Switch TypeId to 128 bits
- Hack around the fact that tracing-subscriber dislikes how TypeId is hashed
- Remove lowering of type_id128 from rustc_codegen_llvm
- Remove unnecessary `type_id128` intrinsic (just change return type of `type_id`)
- Only hash the lower 64 bits of the TypeId
- Reword comment
Normalize anon consts in new solver
We don't do any of that `expand_abstract_consts` stuff so this isn't sufficient to make GCE work, but it does allow, e.g. `[(); 1]: Default`, to solve.
r? `@BoxyUwU`
Require that const param tys implement `ConstParamTy`
1. Require that const param tys implement `ConstParamTy` instead of using `search_for_adt_const_param_violation`
2. Add `StructuralPartialEq` as a supertrait for `ConstParamTy`, since we need to make sure that we derive *both* `PartialEq` and `Eq`
3. Implement `ConstParamTy` for tuples up to 12 (or whatever the default for tuples is)
4. Add some custom diagnostics to `ConstParamTy` errors, to avoid regressions from (1.). It's still not as great as it could be -- will point out inline in comments.
r? `@BoxyUwU`
Use translatable diagnostics in `rustc_const_eval`
This PR:
* adds a `no_span` parameter to `note` / `help` attributes when using `Subdiagnostic` to allow adding notes/helps without using a span
* has minor tweaks and changes to error messages
`#[cfg]`s are frequently used to gate crate content behind cargo
features. This can lead to very confusing errors when features are
missing. For example, `serde` doesn't have the `derive` feature by
default. Therefore, `serde::Serialize` fails to resolve with a generic
error, even though the macro is present in the docs.
This commit adds a list of all stripped item names to metadata. This is
filled during macro expansion and then, through a fed query, persisted
in metadata. The downstream resolver can then access the metadata to
look at possible candidates for mentioning in the errors.
This slightly increases metadata (800k->809k for the feature-heavy
windows crate), but not enough to really matter.
Preserve substs in opaques recorded in typeck results
This means that we now prepopulate MIR with opaques with the right substs.
The first commit is a hack that I think we discussed, having to do with `DefiningAnchor::Bubble` basically being equivalent to `DefiningAnchor::Error` in the new solver, so having to use `DefiningAnchor::Bind` instead, lol.
r? `@lcnr`
Replace const eval limit by a lint and add an exponential backoff warning
The lint triggers at the first power of 2 that comes after 1 million function calls or traversed back-edges (takes less than a second on usual programs). After the first emission, an unsilenceable warning is repeated at every following power of 2 terminators, causing it to get reported less and less the longer the evaluation runs.
cc `@rust-lang/wg-const-eval`
fixes#93481closes#67217
Only rewrite valtree-constants to patterns and keep other constants opaque
Now that we can reliably fall back to comparing constants with `PartialEq::eq` to the match scrutinee, we can
1. eagerly try to convert constants to valtrees
2. then deeply convert the valtree to a pattern
3. if the to-valtree conversion failed, create an "opaque constant" pattern.
This PR specifically avoids any behavioral changes or major cleanups. What we can now do as follow ups is
* move the two remaining call sites to `destructure_mir_constant` off that query
* make valtree to pattern conversion infallible
* this needs to be done after careful analysis of the effects. There may be user visible changes from that.
based on https://github.com/rust-lang/rust/pull/111768
move `super_relate_consts` hack to `normalize_param_env_or_error`
`super_relate_consts` has as hack in it to work around the fact that `normalize_param_env_or_error` is broken. When relating two constants we attempt to evaluate them (aka normalize them). This is not an issue in any way specific to const generics, type aliases also have the same issue as demonstrated in [this code](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=84b6d3956a2c852a04b60782476b56c9).
Since the hack in `super_relate_consts` only exists to make `normalize_param_env_or_error` emit less errors move it to `normalize_param_env_or_error`. This makes `super_relate_consts` act more like the normal plain structural equality its supposed to and should help ensure that the hack doesnt accidentally affect other situations.
r? `@compiler-errors`
change `BorrowKind::Unique` to be a mutating `PlaceContext`
fixes#112056
I believe that `BorrowKind::Unique` is a footgun in general, so I added a FIXME and opened https://github.com/rust-lang/rust/issues/112072. This is a bit too involved for this PR though.
refactor and cleanup the leak check, add it to new solver
ended up being a bit more involved than I wanted but is hopefully still easy enough to review as a single PR, can split it into separate ones otherwise.
this can be reviewed commit by commit:
a473d55cdb9284aa2b01282d1b529a2a4d26547b 31a686646534ca006d906ec757ece4e771d6f973 949039c107852a5e36361c08b62821a0613656f5 242917bf5170d9a723c6c8e23e9d9d0c2fa8dc9d ed2b25a7aa28be3184be9e3022c2796a30eaad87 are all pretty straightforward.
03dd83b4c3f4ff27558f5c8ab859bd9f83db1d04 makes it easier to refactor coherence in a later commit, see the commit description, cc `@oli-obk`
4fe311d807a77b6270f384e41689bf5d58f46aec I don't quite remember what we wanted to test here, this definitely doesn't test that the occurs check doesn't cause incorrect errors in coherence, also cc `@oli-obk` here. I may end up writing a new test for this myself later.
5c200d88a91b75bd0875b973150655bd581ef97a is the main refactor of the leak check, changing it to take the `outer_universe` instead of getting it from a snapshot. Using a snapshot requires us to be in a probe which we aren't in the new solver, it also just feels dirty as snapshots don't really have anything to do with universes.
with all of this cfc230d54188d9c7ed867a9a0d1f51be77b485f9 is now kind of trivial.
r? `@nikomatsakis`
`EarlyBinder::new` -> `EarlyBinder::bind`
for consistency with `Binder::bind`. it may make sense to also add `EarlyBinder::dummy` in places where we know that no parameters exist, but I left that out of this PR.
r? `@jackh726` `@kylematsuda`
Make `TyKind: Debug` have less verbose output
Current `TyKind: Debug` impl is basically unusable for debugging, its too verbose even for verbose debugging 🤣 This PR replaces the debug logic for `TyKind` with a more manual debug impl instead of a hand expanded derived impl. This should help make #107084 more reasonable to land since the output of `Ty: Debug` will be better.
This isn't a fully completed change to the `Debug` impl of `TyKind` as there's still logic from the derive macro for some variants. Some of the variants are also not consisten with the `-Zverbose` printing of `Ty`, ideally `-Zverbose` printing of `Ty` would also just defer to the debug impl instead of having lots of checks in pretty printing. I plan on fixing this in follow up PRs since it seems tricky to do in this one and its already a large PR 😅
Use `Cow` in `{D,Subd}iagnosticMessage`.
Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most compelling change ever, but it might be worth merging.
This requires changing the `impl<'a> From<&'a str>` impls to `impl From<&'static str>`, which involves a bunch of knock-on changes that require/result in call sites being a little more precise about exactly what kind of string they use to create errors, and not just `&str`. This will result in fewer unnecessary allocations, though this will not have any notable perf effects given that these are error paths.
Note that I was lazy within Clippy, using `to_string` in a few places to preserve the existing string imprecision. I could have used `impl Into<{D,Subd}iagnosticMessage>` in various places as is done in the compiler, but that would have required changes to *many* call sites (mostly changing `&format("...")` to `format!("...")`) which didn't seem worthwhile.
r? `@WaffleLapkin`
Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most
compelling change ever, but it might be worth merging.
This requires changing the `impl<'a> From<&'a str>` impls to `impl
From<&'static str>`, which involves a bunch of knock-on changes that
require/result in call sites being a little more precise about exactly
what kind of string they use to create errors, and not just `&str`. This
will result in fewer unnecessary allocations, though this will not have
any notable perf effects given that these are error paths.
Note that I was lazy within Clippy, using `to_string` in a few places to
preserve the existing string imprecision. I could have used `impl
Into<{D,Subd}iagnosticMessage>` in various places as is done in the
compiler, but that would have required changes to *many* call sites
(mostly changing `&format("...")` to `format!("...")`) which didn't seem
worthwhile.
MIR: opt-in normalization of `BasicBlock` and `Local` numbering
This doesn't matter at all for actual codegen, but after spending some time reading pre-codegen MIR, I was wishing I didn't have to jump around so much in reading post-inlining code.
So this add two passes that are off by default for every mir level, but can be enabled (`-Zmir-enable-passes=+ReorderBasicBlocks,+ReorderLocals`) for humans.
Add warn-by-default lint when local binding shadows exported glob re-export item
This PR introduces a warn-by-default rustc lint for when a local binding (a use statement, or a type declaration) produces a name which shadows an exported glob re-export item, causing the name from the exported glob re-export to be hidden (see #111336).
### Unresolved Questions
- [x] ~~Is this approach correct? While it passes the UI tests, I'm not entirely convinced it is correct.~~ Seems to be ok now.
- [x] ~~What should the lint be called / how should it be worded? I don't like calling `use x::*;` or `struct Foo;` a "local binding" but they are `NameBinding`s internally if I'm not mistaken.~~ ~~The lint is called `local_binding_shadows_glob_reexport` for now, unless a better name is suggested.~~ `hidden_glob_reexports`.
Fixes#111336.
Rollup of 5 pull requests
Successful merges:
- #111384 (Fix linking Mac Catalyst by including LC_BUILD_VERSION in object files)
- #111899 (CGU cleanups)
- #111940 (Clarify safety concern of `io::Read::read` is only relevant in unsafe code)
- #111947 (Add test for RPIT defined with different hidden types with different substs)
- #111951 (Correct comment on privately uninhabited pattern.)
Failed merges:
- #111954 (improve error message for calling a method on a raw pointer with an unknown pointee)
r? `@ghost`
`@rustbot` modify labels: rollup
Handle opaques in the new solver (take 2?)
Implement a new strategy for handling opaques in the new solver.
First, queries now carry both their defining anchor and the opaques that were defined in the inference context at the time of canonicalization. These are both used to pre-populate the inference context used by the canonical query.
Second, use the normalizes-to goal to handle opaque types in the new solver. This means that opaques are handled like projection aliases, but with their own rules:
* Can only define opaques if they're "defining uses" (i.e. have unique params in all their substs).
* Can only define opaques that are from the anchor.
* Opaque type definitions are modulo regions. So that means `Opaque<'?0r> = HiddenTy1` and `Opaque<?'1r> = HiddenTy2` equate `HiddenTy1` and `HiddenTy2` instead of defining them as different opaque type keys.
Don't leak the function that is called on drop
It probably wasn't causing problems anyway, but still, a `// this leaks, please don't pass anything that owns memory` is not sustainable.
I could implement a version which does not require `Option`, but it would require `unsafe`, at which point it's probably not worth it.
Use `Option::is_some_and` and `Result::is_ok_and` in the compiler
`.is_some_and(..)`/`.is_ok_and(..)` replace `.map_or(false, ..)` and `.map(..).unwrap_or(false)`, making the code more readable.
This PR is a sibling of https://github.com/rust-lang/rust/pull/111873#issuecomment-1561316515
Preprocess and cache dominator tree
Preprocessing dominators has a very strong effect for https://github.com/rust-lang/rust/pull/111344.
That pass checks that assignments dominate their uses repeatedly. Using the unprocessed dominator tree caused a quadratic runtime (number of bbs x depth of the dominator tree).
This PR also caches the dominator tree and the pre-processed dominators in the MIR cfg cache.
Rebase of https://github.com/rust-lang/rust/pull/107157
cc `@tmiasko`
Pretty-print inherent projections correctly
Previously, we were trying to pretty-print inherent projections with `Printer::print_def_path` which is incorrect since
it expects the substitutions to be of a certain format (parents substs followed by own substs) which doesn't hold for
inherent projections (self type subst followed by own substs).
Now we print inherent projections manually.
Fixes#111390.
Fixes#111397.
Lacking tests! Is there a test suite / compiletest flags for the pretty-printer? In most if not all cases,
inherent projections are normalized away before they get the chance to appear in diagnostics.
If I were to create regression tests for linked issues, they would need to be `mir-opt` tests to exercise
`-Zdump-mir=all` (right?) which doesn't feel quite adequate to me.
`@rustbot` label F-inherent_associated_types
Check opaques for mismatch during writeback
Revive #111705.
I realized that we don't need to put any substs in the writeback results since all of the hidden types have already been remapped. See the comment in `compiler/rustc_middle/src/ty/typeck_results.rs`, which should make that clear for other explorers of the codebase.
Additionally, we need to do some diagnostic stashing because the diagnostics we produce during HIR typeck is very poor and we should prefer the diagnostic that comes from MIR, if we have one.
r? `@oli-obk`
fix recursion depth handling after confirmation
fixes#111729
I think having to use `Obligation::with_depth` correctly everywhere is very hard because e.g. the nested obligations from `eq` currently do not have the correct obligation depth.
The new solver [completely removes `recursion_depth` from obligations](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/traits/solve/struct.Goal.html) and instead tracks the depth in the solver itself which is far easier to get right. Moving the old solver towards this shouldn't be that hard but is probably somewhat annoying.
r? `@matthewjasper`
Add extra debug assertions for equality for Adt/Variant/FieldDef
Would've made it easier to both catch and test https://github.com/rust-lang/rust/pull/111494. Maybe not worth it, since it does mean that the compiler is doing extra work when debug-assertions are enabled, but also that's what debug assertions are for :^)
This is a revival of #111523 because I think I pushed an empty branch and bors got a bit too excited it closed the PR.
Fix dependency tracking for debugger visualizers
This PR fixes dependency tracking for debugger visualizer files by changing the `debugger_visualizers` query to an `eval_always` query that scans the AST while it is still available. This way the set of visualizer files is already available when dep-info is emitted. Since the query is turned into an `eval_always` query, dependency tracking will now reliably detect changes to the visualizer script files themselves.
TODO:
- [x] perf.rlo
- [x] Needs a bit more documentation in some places
- [x] Needs regression test for the incr. comp. case
Fixes https://github.com/rust-lang/rust/issues/111226
Fixes https://github.com/rust-lang/rust/issues/111227
Fixes https://github.com/rust-lang/rust/issues/111295
r? `@wesleywiser`
cc `@gibbyfree`
Only depend on CFG_VERSION in rustc_interface
This avoids having to rebuild the whole compiler on each commit when `omit-git-hash = false`.
cc https://github.com/rust-lang/rust/issues/76720 - this won't fix it, and I'm not suggesting we turn this on by default, but it will make it less painful for people who do have `omit-git-hash` on as a workaround.
Merge query property modules into one
This merges all the query modules that defines types into a single module per query with a normal naming convention for type aliases.
r? ``@cjgillot``
debug format `Const`'s less verbosely
Not user visible change only visible to people debugging const generics.
Currently debug output for `ty::Const` is super verbose (even for `-Zverbose` lol), things like printing infer vars as `Infer(Var(?0c))` instead of just `?0c`, bound vars and placeholders not using `^0_1` or `!0_1` syntax respectively. With these changes its imo better but not perfect:
`Const { ty: usize, kind: ^0_1 }`
is still a lot for not much information. not entirely sure what to do about that so not dealing with it yet.
Need to do formatting for `ConstKind::Expr` at some point too since rn it sucks (doesn't even print anything with `Display`) not gonna do that in this PR either.
r? `@compiler-errors`
Erase `ReError` properly
Fixes#111341
Since we check whether a type has free regions before erasing (to short circuit unnecesary folding), we need to consider `ReError` as a free region, or else we'll skip it when erasing a type that only mentions `ReError`.
cc `@nnethercote`
Handle error body in generator layout
Fixes#111468
I feel like making this query return `Option<GeneratorLayout>` might be better but had some issues with that approach
Suppress "erroneous constant used" for constants tainted by errors
When constant evaluation fails because its MIR is tainted by errors,
suppress note indicating that erroneous constant was used, since those
errors have to be fixed regardless of the constant being used or not.
Fixes#110891.
Error message all end up passing into a function as an `impl
Into<{D,Subd}iagnosticMessage>`. If an error message is creatd as
`&format("...")` that means we allocate a string (in the `format!`
call), then take a reference, and then clone (allocating again) the
reference to produce the `{D,Subd}iagnosticMessage`, which is silly.
This commit removes the leading `&` from a lot of these cases. This
means the original `String` is moved into the
`{D,Subd}iagnosticMessage`, avoiding the double allocations. This
requires changing some function argument types from `&str` to `String`
(when all arguments are `String`) or `impl
Into<{D,Subd}iagnosticMessage>` (when some arguments are `String` and
some are `&str`).
Combine three generalizer implementations
Fixes#111092Fixes#109505
This code is a bit delicate and there were subtle changes between them, so I'll leave inline comments where further inspection is needed.
Regarding this comment from #109813 -- "add tests triggering all codepaths: at least the combine and the const generalizer", can't really do that now, and I don't really know how we'd get a higher-ranked const error since non-lifetime binders doesn't *really* support `for<const ..>` (it errors out when you try to use it).
r? `@lcnr`
Move expansion of query macros in rustc_middle to rustc_middle::query
This moves the expansion of `define_callbacks!` and `define_feedable!` from `rustc_middle::ty::query` to `rustc_middle::query`.
This means that types used in queries are both imported and used in `rustc_middle::query` instead of being split between these modules. It also decouples `rustc_middle::ty::query` further from `rustc_middle` which is helpful since we want to move `rustc_middle::ty::query` to the query system crates.
Rename const error methods for consistency
renames `ty::Const`'s methods for creating a `ConstKind::Error` to be in the same naming style as `ty::Ty`'s equivalent methods.
r? `@BoxyUwU`
When constant evaluation fails because its MIR is tainted by errors,
suppress note indicating that erroneous constant was used, since those
errors have to be fixed regardless of the constant being used or not.
Use dynamic dispatch for queries
This replaces most concrete query values `V` with `MaybeUninit<[u8; { size_of::<V>() }]>` reducing the code instantiated by queries. The compile time of `rustc_query_impl` is reduced by 27%. It is an alternative to https://github.com/rust-lang/rust/pull/107937 which uses unstable const generics while this uses a `EraseType` trait which maps query values to their erased variant.
This is achieved by introducing an `Erased` type which does sanity check with `cfg(debug_assertions)`. The query caches gets instantiated with these erased types leaving the code in `rustc_query_system` unaware of them. `rustc_query_system` is changed to use instances of `QueryConfig` so that `rustc_query_impl` can pass in `DynamicConfig` which holds a pointer to a virtual table.
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check</td><td align="right">1.7055s</td><td align="right">1.6949s</td><td align="right"> -0.62%</td></tr><tr><td>🟣 <b>hyper</b>:check</td><td align="right">0.2547s</td><td align="right">0.2528s</td><td align="right"> -0.73%</td></tr><tr><td>🟣 <b>regex</b>:check</td><td align="right">0.9590s</td><td align="right">0.9553s</td><td align="right"> -0.39%</td></tr><tr><td>🟣 <b>syn</b>:check</td><td align="right">1.5457s</td><td align="right">1.5440s</td><td align="right"> -0.11%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check</td><td align="right">5.9092s</td><td align="right">5.9009s</td><td align="right"> -0.14%</td></tr><tr><td>Total</td><td align="right">10.3741s</td><td align="right">10.3479s</td><td align="right"> -0.25%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">0.9960s</td><td align="right"> -0.40%</td></tr></table>
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check:initial</td><td align="right">2.0605s</td><td align="right">2.0575s</td><td align="right"> -0.15%</td></tr><tr><td>🟣 <b>hyper</b>:check:initial</td><td align="right">0.3218s</td><td align="right">0.3216s</td><td align="right"> -0.07%</td></tr><tr><td>🟣 <b>regex</b>:check:initial</td><td align="right">1.1848s</td><td align="right">1.1839s</td><td align="right"> -0.07%</td></tr><tr><td>🟣 <b>syn</b>:check:initial</td><td align="right">1.9409s</td><td align="right">1.9376s</td><td align="right"> -0.17%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check:initial</td><td align="right">7.3105s</td><td align="right">7.2928s</td><td align="right"> -0.24%</td></tr><tr><td>Total</td><td align="right">12.8185s</td><td align="right">12.7935s</td><td align="right"> -0.20%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">0.9986s</td><td align="right"> -0.14%</td></tr></table>
<table><tr><td rowspan="2">Benchmark</td><td colspan="1"><b>Before</b></th><td colspan="2"><b>After</b></th></tr><tr><td align="right">Time</td><td align="right">Time</td><td align="right">%</th></tr><tr><td>🟣 <b>clap</b>:check:unchanged</td><td align="right">0.4606s</td><td align="right">0.4617s</td><td align="right"> 0.24%</td></tr><tr><td>🟣 <b>hyper</b>:check:unchanged</td><td align="right">0.1335s</td><td align="right">0.1336s</td><td align="right"> 0.08%</td></tr><tr><td>🟣 <b>regex</b>:check:unchanged</td><td align="right">0.3324s</td><td align="right">0.3346s</td><td align="right"> 0.65%</td></tr><tr><td>🟣 <b>syn</b>:check:unchanged</td><td align="right">0.6268s</td><td align="right">0.6307s</td><td align="right"> 0.64%</td></tr><tr><td>🟣 <b>syntex_syntax</b>:check:unchanged</td><td align="right">1.8248s</td><td align="right">1.8508s</td><td align="right">💔 1.43%</td></tr><tr><td>Total</td><td align="right">3.3779s</td><td align="right">3.4113s</td><td align="right"> 0.99%</td></tr><tr><td>Summary</td><td align="right">1.0000s</td><td align="right">1.0061s</td><td align="right"> 0.61%</td></tr></table>
It's based on https://github.com/rust-lang/rust/pull/108167.
r? `@cjgillot`
Allow MIR debuginfo to point to a variable's address
MIR optimizations currently do not to operate on borrowed locals.
When enabling #106285, many borrows will be left as-is because they are used in debuginfo. This pass allows to replace this pattern directly in MIR debuginfo:
```rust
a => _1
_1 = &raw? mut? _2
```
becomes
```rust
a => &_2
// No statement to borrow _2.
```
This pass is implemented as a drive-by in ReferencePropagation MIR pass.
This transformation allows following following MIR opts to treat _2 as an unborrowed local, and optimize it as such, even in builds with debuginfo.
In codegen, when encountering `a => &..&_2`, we create a list of allocas:
```llvm
store ptr %_2.dbg.spill, ptr %a.ref0.dbg.spill
store ptr %a.ref0.dbg.spill, ptr %a.ref1.dbg.spill
...
call void `@llvm.dbg.declare(metadata` ptr %a.ref{n}.dbg.spill, /* ... */)
```
Caveat: this transformation looses the exact type, we do not differentiate `a` as a immutable, mutable reference or a raw pointer. Everything is declared to `*mut` to codegen. I'm not convinced this is a blocker.
Introduce `DynSend` and `DynSync` auto trait for parallel compiler
part of parallel-rustc #101566
This PR introduces `DynSend / DynSync` trait and `FromDyn / IntoDyn` structure in rustc_data_structure::marker. `FromDyn` can dynamically check data structures for thread safety when switching to parallel environments (such as calling `par_for_each_in`). This happens only when `-Z threads > 1` so it doesn't affect single-threaded mode's compile efficiency.
r? `@cjgillot`
Note user-facing types of coercion failure
When coercing, for example, `Box<A>` into `Box<dyn B>`, make sure that any failure notes mention *those* specific types, rather than mentioning inner types, like "the cast from `A` to `dyn B`".
I expect end-users are often confused when we skip layers of types and only mention the "innermost" part of a coercion, especially when other notes point at HIR, e.g. #111406.
Require impl Trait in associated types to appear in method signatures
This implements the limited version of TAIT that was proposed in https://github.com/rust-lang/rust/issues/107645#issuecomment-1477899536
Similar to `impl Trait` in return types, `impl Trait` in associated types may only be used within the impl block which it is a part of. To make everything simpler and forward compatible to getting desugared to a plain type alias impl trait in the future, we're requiring that any associated functions or constants that want to register hidden types must be using the associated type in their signature (type of the constant or argument/return type of the associated method. Where bounds mentioning the associated type are ignored).
We have preexisting tests checking that this works transitively across multiple associated types in situations like
```rust
impl Foo for Bar {
type A = impl Trait;
type B = impl Iterator<Item = Self::A>;
fn foo() -> Self::B { ...... }
}
```
Uplift `clippy::{drop,forget}_{ref,copy}` lints
This PR aims at uplifting the `clippy::drop_ref`, `clippy::drop_copy`, `clippy::forget_ref` and `clippy::forget_copy` lints.
Those lints are/were declared in the correctness category of clippy because they lint on useless and most probably is not what the developer wanted.
## `drop_ref` and `forget_ref`
The `drop_ref` and `forget_ref` lint checks for calls to `std::mem::drop` or `std::mem::forget` with a reference instead of an owned value.
### Example
```rust
let mut lock_guard = mutex.lock();
std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
// still locked
operation_that_requires_mutex_to_be_unlocked();
```
### Explanation
Calling `drop` or `forget` on a reference will only drop the reference itself, which is a no-op. It will not call the `drop` or `forget` method on the underlying referenced value, which is likely what was intended.
## `drop_copy` and `forget_copy`
The `drop_copy` and `forget_copy` lint checks for calls to `std::mem::forget` or `std::mem::drop` with a value that derives the Copy trait.
### Example
```rust
let x: i32 = 42; // i32 implements Copy
std::mem::forget(x) // A copy of x is passed to the function, leaving the
// original unaffected
```
### Explanation
Calling `std::mem::forget` [does nothing for types that implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html) since the value will be copied and moved into the function on invocation.
-----
Followed the instructions for uplift a clippy describe here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
cc `@m-ou-se` (as T-libs-api leader because the uplifting was discussed in a recent meeting)
Shrink `SelectionError` a lot
`SelectionError` used to be 80 bytes (on 64 bit). That's quite big. Especially because the selection cache contained `Result<_, SelectionError>. The Ok type is only 32 bytes, so the 80 bytes significantly inflate the size of the cache.
Most variants of the `SelectionError` seem to be hard errors, only `Unimplemented` shows up in practice (for cranelift-codegen, it occupies 23.4% of all cache entries). We can just box away the biggest variant, `OutputTypeParameterMismatch`, to get the size down to 16 bytes, well within the size of the Ok type inside the cache.
Prevent ICE with broken borrow in closure
r? `@Nilstrieb`
Fixes#108683
This solution isn't ideal, I'm hoping to find a way to continue compilation without ICEing.
Switch to `EarlyBinder` for `thir_abstract_const` query
Part of the work to finish https://github.com/rust-lang/rust/issues/105779.
This PR adds `EarlyBinder` to the return type of the `thir_abstract_const` query and removes `bound_abstract_const`.
r? `@compiler-errors`
Implement SSA-based reference propagation
Rust has a tendency to create a lot of short-lived borrows, in particular for method calls. This PR aims to remove those short-lived borrows with a const-propagation dedicated to pointers to local places.
This pass aims to transform the following pattern:
```
_1 = &raw? mut? PLACE;
_3 = *_1;
_4 = &raw? mut? *_1;
```
Into
```
_1 = &raw? mut? PLACE;
_3 = PLACE;
_4 = &raw? mut? PLACE;
```
where `PLACE` is a direct or an indirect place expression.
By removing indirection, this pass should help both dest-prop and const-prop to handle more cases.
This optimization is distinct from const-prop and dataflow const-prop since the borrow-reborrow patterns needs to preserve borrowck invariants, especially the uniqueness property of mutable references.
The pointed-to places are computed using a SSA analysis. We suppose that removable borrows are typically temporaries from autoref, so they are by construction assigned only once, and a SSA analysis is enough to catch them. For each local, we store both where and how it is used, in order to efficiently compute the all-or-nothing property. Thanks to `Derefer`, we only have to track locals, not places in general.
---
There are 3 properties that need to be upheld for this transformation to be legal:
- place constness: `PLACE` must refer to the same memory wherever it appears;
- pointer liveness: we must not introduce dereferences of dangling pointers;
- `&mut` borrow uniqueness.
## Constness
If `PLACE` is an indirect projection, if its of the form `(*LOCAL).PROJECTIONS` where:
- `LOCAL` is SSA;
- all projections in `PROJECTIONS` are constant (no dereference and no indexing).
If `PLACE` is a direct projection of a local, we consider it as constant if:
- the local is always live, or it has a single `StorageLive` that dominates all uses;
- all projections are constant.
# Liveness
When performing a substitution, we must take care not to introduce uses of dangling locals.
Using a dangling borrow is UB. Therefore, we assume that for any use of `*x`, where `x` is a borrow, the pointed-to memory is live.
Limitations:
- occurrences of `*x` in an `&raw mut? *x` are accepted;
- raw pointers are allowed to be dangling.
In those 2 case, we do not substitute anything, to be on the safe side.
**Open question:** we do not differentiate borrows of ZST and non-ZST. The UB rules may be
different depending on the layout. Having a different treatment would effectively prevent this
pass from running on polymorphic MIR, which defeats the purpose of MIR opts.
## Uniqueness
For `&mut` borrows, we also need to preserve the uniqueness property:
we must avoid creating a state where we interleave uses of `*_1` and `_2`.
To do it, we only perform full substitution of mutable borrows:
we replace either all or none of the occurrences of `*_1`.
Some care has to be taken when `_1` is copied in other locals.
```
_1 = &raw? mut? _2;
_3 = *_1;
_4 = _1
_5 = *_4
```
In such cases, fully substituting `_1` means fully substituting all of the copies.
For immutable borrows, we do not need to preserve such uniqueness property,
so we perform all the possible substitutions without removing the `_1 = &_2` statement.
Revert "Populate effective visibilities in `rustc_privacy`"
This reverts commit cff85f22f5, cc #110907. It needs to be fixed, but there are too many issues being reported that I wanted to put up a revert until a proper fix can be committed.
Fixes a ton of issues where private but still reachable impls were missing during codegen:
Fixes#111320Fixes#111321Fixes#111334Fixes#111357Fixes#111368Fixes#111373Fixes#111377Fixes#111386Fixes#111387
`@bors` p=1
r? `@petrochenkov`
`SelectionError` used to be 80 bytes (on 64 bit). That's quite big.
Especially because the selection cache contained `Result<_,
SelectionError>. The Ok type is only 32 bytes, so the 80 bytes
significantly inflate the size of the cache.
Most variants of the `SelectionError` seem to be hard errors, only
`Unimplemented` shows up in practice (for cranelift-codegen, it occupies
23.4% of all cache entries). We can just box away the biggest variant,
`OutputTypeParameterMismatch`, to get the size down to 16 bytes, well
within the size of the Ok type inside the cache.
Min specialization improvements
- Don't allow specialization impls with no items, such implementations are probably not correct and only occur as mistakes in the compiler and standard library
- Fix a missing normalization call
- Adds spans for lifetime errors from overly general specializations
Closes#79457Closes#109815
Introduce `AliasKind::Inherent` for inherent associated types
Allows us to check (possibly generic) inherent associated types for well-formedness.
Type inference now also works properly.
Follow-up to #105961. Supersedes #108430.
Fixes#106722.
Fixes#108957.
Fixes#109768.
Fixes#109789.
Fixes#109790.
~Not to be merged before #108860 (`AliasKind::Weak`).~
CC `@jackh726`
r? `@compiler-errors`
`@rustbot` label T-types F-inherent_associated_types
Fix lifetime suggestion for type aliases with objects in them
Fixes an issue identified in https://github.com/rust-lang/rust/issues/110761#issuecomment-1520678479
This suggestion, like many other borrowck suggestions, are very fragile and there are other ways to trigger strange behavior even after this PR, so this is just a small improvement and not a total rework 💀
Make `(try_)subst_and_normalize_erasing_regions` take `EarlyBinder`
Changes `subst_and_normalize_erasing_regions` and `try_subst_and_normalize_erasing_regions` to take `EarlyBinder<T>` instead of `T`.
(related to #105779)
This was suggested by `@BoxyUwU` in https://github.com/rust-lang/rust/pull/107753#discussion_r1105828139. After changing `type_of` to return `EarlyBinder`, there were several places where the binder was immediately skipped to call `tcx.subst_and_normalize_erasing_regions`, only for the binder to be reconstructed inside of that method.
r? `@BoxyUwU`
Support return-type bounds on associated methods from supertraits
Support `T: Trait<method(): Bound>` when `method` comes from a supertrait, aligning it with the behavior of associated type bounds (both equality and trait bounds).
The only wrinkle is that I have to extend `super_predicates_that_define_assoc_type` to look for *all* items, not just `AssocKind::Ty`. This will also be needed to support `feature(associated_const_equality)` as well, which is subtly broken when it comes to supertraits, though this PR does not fix those yet. There's a slight chance there's a perf regression here, in which case I guess I could split it out into a separate query.
More robust debug assertions for `Instance::resolve` on built-in traits with non-standard trait items
In #111264, a user added a new item to the `Future` trait, but the code in [`resolve_associated_item`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ty_utils/instance/fn.resolve_associated_item.html) implicitly assumes that the `Future` trait is defined with only one method (`Future::poll`) and treats the generator body as the implementation of that method.
This PR adds some debug assertions to make sure that that new methods defined on `Future`/`Generator`/etc. don't accidentally resolve to the wrong item when they are added, and adds a helpful comment guiding a compiler dev (or curious `#![no_core]` user) to what must be done to support adding new associated items to these built-in implementations.
I am open to discuss whether a test should be added, but I chose against it because I opted to make these `bug!()`s instead of, e.g., diagnostics or fatal errors. Arguably it doesn't need a test because it's not a bug that can be triggered by an end user, and internal-facing misuses of core kind of touch on rust-lang/compiler-team#620 -- however, I think the assertions I added in this PR are still a very useful way to make sure this bug doesn't waste debugging resources down the line.
Fixes#111264
Use fulfillment to check `Drop` impl compatibility
Use an `ObligationCtxt` to ensure that a `Drop` impl does not have stricter requirements than the ADT that it's implemented for, rather than using a `SimpleEqRelation` to (more or less) syntactically equate predicates on an ADT with predicates on an impl.
r? types
### Some background
The old code reads:
```rust
// An earlier version of this code attempted to do this checking
// via the traits::fulfill machinery. However, it ran into trouble
// since the fulfill machinery merely turns outlives-predicates
// 'a:'b and T:'b into region inference constraints. It is simpler
// just to look for all the predicates directly.
```
I'm not sure what this means, but perhaps in the 8 years since that this comment was written (cc #23638) it's gotten easier to process region constraints after doing fulfillment? I don't know how this logic differs from anything we do in the `compare_impl_item` module. Ironically, later on it says:
```rust
// However, it may be more efficient in the future to batch
// the analysis together via the fulfill (see comment above regarding
// the usage of the fulfill machinery), rather than the
// repeated `.iter().any(..)` calls.
```
Also:
* Removes `SimpleEqRelation` which was far too syntactical in its relation.
* Fixes#110557
Such implementations are usually mistakes and are not used in the
compiler or standard library (after this commit) so forbid them with
`min_specialization`.
check array type of repeat exprs is wf
Fixes#111091
Also makes sure that we actually renumber regions in the length of repeat exprs which we previously weren't doing and would cause ICEs in `adt_const_params` + `generic_const_exprs` from attempting to prove the wf goals when the length was an unevaluated constant with `'erased` in the `ty` field of `Const`
The duplicate errors are caused by the fact that `const_arg_to_const`/`array_len_to_const` in `FnCtxt` adds a `WellFormed` goal for the created `Const` which is also checked by the added `WellFormed(array_ty)`. I don't want to change this to just emit a `T: Sized` goal for the element type since that would ignore `ConstArgHasType` wf requirements and generally uncomfortable with the idea of trying to sync up `wf::obligations` for arrays and the code in hir typeck for repeat exprs.
r? `@compiler-errors`
correctly recurse when expanding anon consts
recursing with `super_fold_with` is wrong in case `bac` is itself normalizable, the test that was supposed to test for this being wrong did not actually test for this in reality because of the usage of `{ (N) }` instead of `{{ N }}`. The former resulting in a simple `ConstKind::Param` instead of `ConstKind::Unevaluated`. Tbh generally this test seems very brittle and it will be a lot easier to test once we have normalization of assoc consts since then we can just test that `T::ASSOC` normalizes to some `U::OTHER` which normalizes to some third thing.
r? `@compiler-errors`
Explicitly reject negative and reservation drop impls
Fixes#110858
It doesn't really make sense for a type to have a `!Drop` impl. Or at least, I don't want us to implicitly assign a meaning to it by the way the compiler *currently* handles it (incompletely), and rather I would like to see a PR (or an RFC...) assign a meaning to `!Drop` if we actually wanted one for it.
In #110927 the encode/decode methods for `i8`, `char`, `bool`, and `str`
were made inherent. This commit removes some unnecessary implementations
of these methods that were missed in that PR.
Add cross-language LLVM CFI support to the Rust compiler
This PR adds cross-language LLVM Control Flow Integrity (CFI) support to the Rust compiler by adding the `-Zsanitizer-cfi-normalize-integers` option to be used with Clang `-fsanitize-cfi-icall-normalize-integers` for normalizing integer types (see https://reviews.llvm.org/D139395).
It provides 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). For more information about LLVM CFI and cross-language LLVM CFI support for the Rust compiler, see design document in the tracking issue #89653.
Cross-language LLVM CFI can be enabled with -Zsanitizer=cfi and -Zsanitizer-cfi-normalize-integers, and requires proper (i.e., non-rustc) LTO (i.e., -Clinker-plugin-lto).
Thank you again, ``@bjorn3,`` ``@nikic,`` ``@samitolvanen,`` and the Rust community for all the help!
This commit adds cross-language LLVM Control Flow Integrity (CFI)
support to the Rust compiler by adding the
`-Zsanitizer-cfi-normalize-integers` option to be used with Clang
`-fsanitize-cfi-icall-normalize-integers` for normalizing integer types
(see https://reviews.llvm.org/D139395).
It provides 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). For more
information about LLVM CFI and cross-language LLVM CFI support for the
Rust compiler, see design document in the tracking issue #89653.
Cross-language LLVM CFI can be enabled with -Zsanitizer=cfi and
-Zsanitizer-cfi-normalize-integers, and requires proper (i.e.,
non-rustc) LTO (i.e., -Clinker-plugin-lto).
Avoid ICEing miri on layout query cycles
Miri has special logic for catching panics during interpretation. Raising a fatal error in rustc uses unwinding to abort compilation. Thus miri ends up catching that fatal error and thinks it saw an ICE. While we should probably change that to ignore `Fatal` payloads, I think it's also neat to continue compilation after a layout query cycle 😆
Query cycles now (in addition to reporting an error just like before), return `Err(Cycle)` instead of raising a fatal error. This allows the interpreter to wind down via the regular error paths.
r? `@RalfJung` for a first round, feel free to reroll for the compiler team once the miri side looks good
Implement negative bounds for internal testing purposes
Implements partial support the `!` negative polarity on trait bounds. This is incomplete, but should allow us to at least be able to play with the feature.
Not even gonna consider them as a public-facing feature, but I'm implementing them because would've been nice to have in UI tests, for example in #110671.
Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
Make some simple queries no longer cache on disk
I don't think we need to cache queries with really simple local providers, like loading hir and accessing an attr
r? `@ghost`
Tweak await span to not contain dot
Fixes a discrepancy between method calls and await expressions where the latter are desugared to have a span that *contains* the dot (i.e. `.await`) but method call identifiers don't contain the dot. This leads to weird suggestions suggestions in borrowck -- see linked issue.
Fixes#110761
This mostly touches a bunch of tests to tighten their `await` span.
Remove `QueryEngine` trait
This removes the `QueryEngine` trait and `Queries` from `rustc_query_impl` and replaced them with function pointers and fields in `QuerySystem`. As a side effect `OnDiskCache` is moved back into `rustc_middle` and the `OnDiskCache` trait is also removed.
This has a couple of benefits.
- `TyCtxt` is used in the query system instead of the removed `QueryCtxt` which is larger.
- Function pointers are more flexible to work with. A variant of https://github.com/rust-lang/rust/pull/107802 is included which avoids the double indirection. For https://github.com/rust-lang/rust/pull/108938 we can name entry point `__rust_end_short_backtrace` to avoid some overhead. For https://github.com/rust-lang/rust/pull/108062 it avoids the duplicate `QueryEngine` structs.
- `QueryContext` now implements `DepContext` which avoids many `dep_context()` calls in `rustc_query_system`.
- The `rustc_driver` size is reduced by 0.33%, hopefully that means some bootstrap improvements.
- This avoids the unsafe code around the `QueryEngine` trait.
r? `@cjgillot`
