coverage: Rearrange the code for embedding per-function coverage metadata
This is a series of refactorings to the code that prepares and embeds per-function coverage metadata records (“covfun records”) in the `__llvm_covfun` linker section of the final binary. The `llvm-cov` tool reads this metadata from the binary when preparing a coverage report.
Beyond general cleanup, a big motivation behind these changes is to pave the way for re-landing an updated version of #133418.
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There should be no change in compiler output, as demonstrated by the absence of (meaningful) changes to coverage tests.
The first patch is just moving code around, so I suggest looking at the other patches to see the actual changes.
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try-job: x86_64-gnu
try-job: x86_64-msvc
try-job: aarch64-apple
A previous commit added a search for certain types of "shadowing"
situation where one method (in an outer smart pointer type, typically)
might hide or shadow the method in the pointee.
Performance investigation showed that the naïve approach is too slow -
this commit speeds it up, while being functionally the same.
This still does not actually cause the deshadowing check to emit any
errors; that comes in a subsequent commit which is where all the tests
live.
This is the first part of a series of commits which impact the
"deshadowing detection" in the arbitrary self types v2 RFC.
This commit should not have any functional changes, but may impact
performance. Subsequent commits add back the performance, and add error
checking to this new code such that it has a functional effect.
Rust prioritizes method candidates in this order:
1. By value;
2. By reference;
3. By mutable reference;
4. By const ptr.
5. By reborrowed pin.
Previously, if a suitable candidate was found in one of these earlier
categories, Rust wouldn't even move onto probing the other categories.
As part of the arbitrary self types work, we're going to need to change
that - even if we choose a method from one of the earlier categories, we
will sometimes need to probe later categories to search for methods that
we may be shadowing.
This commit adds those extra searches for shadowing, but it does not yet
produce an error when such shadowing problems are found. That will come
in a subsequent commit, by filling out the 'check_for_shadowing'
method.
This commit contains a naive approach to detecting these shadowing
problems, which shows what we've functionally looking to do. However,
it's too slow. The performance of this approach was explored in this
PR:
https://github.com/rust-lang/rust/pull/127812#issuecomment-2236911900
Subsequent commits will improve the speed of the search.
This commit makes no (intentional) functional change.
Previously, the picking process maintained two lists of extra
information useful for diagnostics:
* any unstable candidates which might have been picked
* any unsatisfied predicates
Previously, these were dealt with quite differently - the former list
was passed around as a function parameter; the latter lived in a RefCell
in the ProbeCtxt.
With this change we increase consistency by keeping them together in a
new PickDiagHints structure, passed as a parameter, with no need for
interior mutability.
The lifecycle of each of these lists remains fairly complex, so it's
explained with new comments in pick_core.
A further cleanup here would be to package the widely-used tuple
(ty::Predicate<'tcx>,
Option<ty::Predicate<'tcx>>,
Option<ObligationCause<'tcx>>)
into a named struct for UnsatisfiedPredicate. This seems worth doing but
it turns out that this tuple is used in dozens of places, so if we're
going to do this we should do it as a separate PR to avoid constant
rebase trouble.
In this new version of Arbitrary Self Types, we no longer use the Deref trait
exclusively when working out which self types are valid. Instead, we follow a
chain of Receiver traits. This enables methods to be called on smart pointer
types which fundamentally cannot support Deref (for instance because they are
wrappers for pointers that don't follow Rust's aliasing rules).
This includes:
* Changes to tests appropriately
* New tests for:
* The basics of the feature
* Ensuring lifetime elision works properly
* Generic Receivers
* A copy of the method subst test enhanced with Receiver
This is really the heart of the 'arbitrary self types v2' feature, and
is the most critical commit in the current PR.
Subsequent commits are focused on:
* Detecting "shadowing" problems, where a smart pointer type can hide
methods in the pointee.
* Diagnostics and cleanup.
Naming: in this commit, the "Autoderef" type is modified so that it no
longer solely focuses on the "Deref" trait, but can now consider the
"Receiver" trait instead. Should it be renamed, to something like
"TraitFollower"? This was considered, but rejected, because
* even in the Receiver case, it still considers built-in derefs
* the name Autoderef is short and snappy.
LoongArch psABI[^1] specifies that LSX vector types are passed via general-purpose
registers, while LASX vector types are passed indirectly through the stack.
This patch addresses the following warnings:
```
warning: this function call uses a SIMD vector type that is not currently supported with the chosen ABI
--> .../library/core/src/../../stdarch/crates/core_arch/src/loongarch64/lsx/generated.rs:3695:5
|
3695 | __lsx_vreplgr2vr_b(a)
| ^^^^^^^^^^^^^^^^^^^^^ function called here
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #116558 <https://github.com/rust-lang/rust/issues/116558>
= note: `#[warn(abi_unsupported_vector_types)]` on by default
```
[^1]: https://github.com/loongson/la-abi-specs/blob/release/lapcs.adoc
Rename `projection_def_id` to `item_def_id`
Renames `projection_def_id` to `item_def_id`, since `item_def_id` is what we call the analogous method for ~~`AliasTerm`/`AliasTy`~~ `PolyExistentialProjection`. I keep forgetting that this one is not called `item_def_id`.
Rudimentary heuristic to insert parentheses when needed for RPIT overcaptures lint
We don't have basically any preexisting machinery to detect when parentheses are needed for *types*. AFAICT, all of the diagnostics we have for opaques just... fail when they suggest `+ 'a` when that's ambiguous.
Fixes#132853
[AIX] keep profile-rt symbol alive
Clang passes `-u __llvm_profile_runtime` on AIX. https://reviews.llvm.org/D136192
We want to preserve the symbol in the case there are no instrumented object files.
Validate self in host predicates correctly
`assert_only_contains_predicates_from` was added to make sure that we are computing predicates for the correct self type for a given `PredicateFilter`. That was not implemented correctly for `PredicateFilter::SelfOnly` when there are const predicates.
Fixes#133526
`rustc_mir_dataflow` has a typedef `AbstractElem` that is equal to
`ProjectionElem<AbstractOperand, AbstractType>`. `AbstractOperand` and
`AbstractType` are both unit types. There is also has a trait `Lift` to
convert a `PlaceElem` to an `AbstractElem`.
But `rustc_mir_middle` already has a typedef `ProjectionKind` that is
equal to `ProjectionElem<(), ()>`, which is equivalent to
`AbstractElem`. So this commit reuses `ProjectionKind` in
`rustc_mir_dataflow`, removes `AbstractElem`, and simplifies the `Lift`
trait.
rustc_target: ppc64 target string fixes for LLVM 20
LLVM continues to clean these up, and we continue to make this consistent. This is similar to 9caced7bad, e985396145, and
a10e744faf.
```@rustbot``` label: +llvm-main
Add the `power8-crypto` target feature
Add the `power8-crypto` target feature. This will enable adding some new PPC intrinsics in stdarch (specifically AES, SHA and CLMUL intrinsics). The implied target feature is from [here](https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/PowerPC/PPC.td)
```@rustbot``` label A-target-feature O-PowerPC
When we expand a `mod foo;` and parse `foo.rs`, we now track whether that file had an unrecovered parse error that reached the end of the file. If so, we keep that information around. When resolving a path like `foo::bar`, we do not emit any errors for "`bar` not found in `foo`", as we know that the parse error might have caused `bar` to not be parsed and accounted for.
When this happens in an existing project, every path referencing `foo` would be an irrelevant compile error. Instead, we now skip emitting anything until `foo.rs` is fixed. Tellingly enough, we didn't have any test for errors caused by `mod` expansion.
Fix#97734.
Don't use `AsyncFnOnce::CallOnceFuture` bounds for signature deduction
We shouldn't be using `AsyncFnOnce::CallOnceFuture` projection bounds to deduce anything about the return type of an async closure, **only** `AsyncFnOnce::Output`. This was accidental b/c all we were looking at was the def id of the trait, rather than the projection. This PR fixes that.
This doesn't affect stable code, since `CallOnceFuture` bounds cannot be written on stable.
Fixes#134015
Make `Copy` unsafe to implement for ADTs with `unsafe` fields
As a rule, the application of `unsafe` to a declaration requires that use-sites of that declaration also entail `unsafe`. For example, a field declared `unsafe` may only be read in the lexical context of an `unsafe` block.
For nearly all safe traits, the safety obligations of fields are explicitly discharged when they are mentioned in method definitions. For example, idiomatically implementing `Clone` (a safe trait) for a type with unsafe fields will require `unsafe` to clone those fields.
Prior to this commit, `Copy` violated this rule. The trait is marked safe, and although it has no explicit methods, its implementation permits reads of `Self`.
This commit resolves this by making `Copy` conditionally safe to implement. It remains safe to implement for ADTs without unsafe fields, but unsafe to implement for ADTs with unsafe fields.
Tracking: #132922
r? ```@compiler-errors```
[AIX] Pass -bnoipath when adding rust upstream dynamic crates
Unlike ELF linkers, AIX doesn't feature `DT_SONAME` to override
the dependency name when outputing a shared library, which is something
we rely on for dylib crates.
See for reference:
bc145cec45/compiler/rustc_codegen_ssa/src/back/linker.rs (L464))
Thus, `ld` on AIX will use the full path to shared libraries as the dependency if passed it
by default unless `noipath` is passed, so pass it here so we don't end up with full path dependencies
for dylib crates.
LLVM continues to clean these up, and we continue to make this
consistent. This is similar to 9caced7bad,
e985396145, and
a10e744faf.
`@rustbot` label: +llvm-main
Stop pessimizing the use of local variables in core by skipping debug info for MIR temporaries in tiny (single-BB) functions.
For functions as simple as this -- `Pin::new`, etc -- nobody every actually wants debuginfo for them in the first place. They're more like intrinsics than real functions, and stepping over them is good.
coverage: Use a query to find counters/expressions that must be zero
As of #133446, this query (`coverage_ids_info`) determines which counter/expression IDs are unused. So with only a little extra work, we can take the code that was using that information to determine which coverage counters/expressions must be zero, and move that inside the query as well.
There should be no change in compiler output.
