Polymorphization
This PR implements an analysis to detect when functions could remain polymorphic during code generation.
Fixes#46477
r? @eddyb
cc @rust-lang/wg-mir-opt @nikomatsakis @pnkfelix
disallow non-static lifetimes in const generics
Disallow non-static lifetimes in const generics in order to to patch over an ICE caused when we encounter a non-static lifetime in a const generic during borrow checking. This restriction may be relaxed in the future, but we need more discussion before then, and in the meantime we should still deal with this ICE.
Fixes issue #60814
wf: check foreign fn decls for well-formedness
Fixes#73252 and fixes#73253.
This PR extends current well-formedness checking to apply to foreign function declarations, re-using the existing machinery for regular functions. In doing this, later parts of the compiler (such as the `improper_ctypes` lint) can rely on being operations not failing as a result of invalid code which would normally be caught earlier.
This commit introduces a `FiniteBitSet` type which replaces the manual
bit manipulation which was being performed in polymorphization.
Signed-off-by: David Wood <david@davidtw.co>
This commit replaces the `-Z polymorphize-errors` debugging flag with a
`#[rustc_polymorphize_error]` attribute for use on functions.
Signed-off-by: David Wood <david@davidtw.co>
This commit normalizes function signatures for instances before
substituting, a workaround for polymorphization considering
parameters unused when they show up in the signature, but not the
body (due to being normalized).
Unfortunately, this causes test output to change with the parallel
compiler only.
Signed-off-by: David Wood <david@davidtw.co>
This commit implements the `unused_generic_params` query, an initial
version of polymorphization which detects when an item does not use
generic parameters and is being needlessly monomorphized as a result.
Signed-off-by: David Wood <david@davidtw.co>
This commit extends current well-formedness checking to apply to foreign
function declarations, re-using the existing machinery for regular
functions. In doing this, later parts of the compiler (such as the
`improper_ctypes` lint) can rely on being operations not failing as a
result of invalid code which would normally be caught earlier.
Signed-off-by: David Wood <david@davidtw.co>
do not try fetching the ancestors of errored trait impls
fixes#74483
While building the specialization graph, we use `tcx.all_impls` which discards impls with incorrect self types,
we do however call `trait_def.ancestors` with these impls which caused an ICE as they aren't part of the
specialization graph.
This has been put in place to patch over an ICE caused when we encounter
a non-static lifetime in a const generic during borrow checking. This
restriction may be relaxed in the future, but we need more discussion
before then, and in the meantime we should still deal with this ICE.
Fixes issue #60814
Make unreachable_unchecked a const fn
This PR makes `std::hint::unreachable_unchecked` a const fn so we can use it inside a const function.
r? @RalfJung
Fixes#53188.
rustc_metadata: Make crate loading fully speculative
Instead of reporting `span_err`s on the spot crate loading errors are now wrapped into the `CrateError` enum and returned, so they are reported only at the top level `resolve_crate` call, and not reported at all if we are resolving speculatively with `maybe_resolve_crate`.
As a result we can attempt loading crates for error recovery (e.g. import suggestions) without any risk of producing extra errors.
Also, this means better separation between error reporting and actual logic.
Fixes https://github.com/rust-lang/rust/issues/55103
Fixes https://github.com/rust-lang/rust/issues/56590
improper_ctypes_definitions: allow `Box`
Addresses https://github.com/rust-lang/rust/pull/72700#issuecomment-659449386.
This PR stops linting against `Box` in `extern "C" fn`s for the `improper_ctypes_definitions` lint - boxes are documented to be FFI-safe.
cc @alexcrichton @CryZe
Compare tagged/niche-filling layout and pick the best one
Finishes up #71045, and so fixes#63866.
cc @eddyb
r? @nikomatsakis (since @eddyb wrote the first commit)
Make some Option methods const
Tracking issue: #67441
Constantify the following methods of `Option`:
- `as_ref`
- `is_some`
- `is_none`
- `iter` (not sure about this one, but it is possible, and will be useful when const traits are a thing)
cc @rust-lang/wg-const-eval @rust-lang/libs
This commit stops linting against `Box` in `extern "C" fn`s for the
`improper_ctypes_definitions` lint - boxes are documented to be
FFI-safe.
Signed-off-by: David Wood <david@davidtw.co>
const generics triage
I went through all const generics issues and closed all issues which are already fixed.
Some issues already have a regression test but were not closed. Also doing this as part of this PR.
uff r? @eddyb @varkor
closes#61936closes#62878closes#63695closes#67144closes#68596closes#69816closes#70217closes#70507closes#70586closes#71348closes#71805closes#73120closes#73508closes#73730closes#74255
Constify most non-trait `Duration` methods as described in #72440
The remaining methods could probably be made const once https://github.com/rust-lang/rust/pull/72449 lands with support for `f<32|64>::is_finite()`.
