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.
Impl Default for ranges
Couldn't find an issue about it.
`Range` and friends probably can implement `Default` if `Idx: Default`. For example, the following would be possible:
```rust
#[derive(Default)]
struct Foo(core::ops::RangeToInclusive<u64>);
let _ = [1, 2, 3].get(core::ops::Range::default());
core::ops::RangeFrom::<u8>::default().take(20).for_each(|x| { dbg!(x); });
fn stuff<T: Default>() { let instance = T::default(); ... more stuff }
stuff::<core::ops::RangeTo<f32>>();
```
Maybe there are some concerns about safety or misunderstandings?
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 records the results of `unused_generic_params` in crate
metadata, hopefully improving performance.
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 makes valid shim asserts more specific - checking for the
specific types that are valid for a given type of shim - and removes
asserts for types which require substitutions.
Signed-off-by: David Wood <david@davidtw.co>
This commit adds type metadata for generic parameters (that arise from
polymorphization). Generic parameter metadata is considered zero-sized
and named after the generic parameter.
Signed-off-by: David Wood <david@davidtw.co>
This commit skips generating debuginfo type metadata if substitutions
are required by the type. This avoids ICEs that result from layouts
of types with substitutions being computed.
Signed-off-by: David Wood <david@davidtw.co>
This commit adds doc comments to the `param_at`, `region_param` and
`const_param` methods on the `Generics` struct.
Signed-off-by: David Wood <david@davidtw.co>
This commit modifies the `substitute_normalize_and_test_predicates`
query, renaming it to `impossible_predicates` and only checking
predicates which do not require substs. By making this change,
polymorphization doesn't have to explicitly support vtables.
Signed-off-by: David Wood <david@davidtw.co>
This commit modifies the `STILL_FURTHER_SPECIALIZABLE` flag so that the
flag isn't set by the parent substs of closures or generators.
Signed-off-by: David Wood <david@davidtw.co>
This commit renames `should_monomorphize_locally` to
`should_codegen_locally` which better describes what the function
determines once polymorphization is added.
Signed-off-by: David Wood <david@davidtw.co>
This commit avoids a natural, free-range double substitution error by
monomorphizing the projection element before getting the type.
Signed-off-by: David Wood <david@davidtw.co>
Use italics for O notation
In documentation, I think it makes sense to italicize O notation (*O(n)*) as opposed to using back-ticks (`O(n)`). Visually, back-ticks focus the reader on the literal characters being used, making them ideal for representing code. Using italics, as far I can tell, more closely follows typographic conventions in mathematics and computer science.
Just a suggestion, of course! 😇
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>
std: Fix compilation without backtrace feature
This should hopefully handle #74484 but in any case fixes compilation of
the standard library without the `backtrace` feature. The need for this
feature is somewhat unclear now because the `backtrace` crate should
always compile (no more C code!) but we can handle that later if
necessary.
fix documentation surrounding the `in` and `for` keywords
Addresses #74529
The `in` keyword incorrectly referenced the `Iterator` trait. This reference was changed to `IntoIterator` without changing the underlying link.
Additionally, the `IntoIterator` trait was referenced towards the end of the documentation for `for`. An additional reference was added earlier and broadened the existing documentation from any iterator to anything that can be turned into an iterator.
Only skip impls of foreign unstable traits
Previously unstable impls were skipped, which meant that any impl with an unstable method would get skipped.
Fixes#74531.
Add myself to toolstate change notifications for rustfmt
I'd like to get the toolstate change notifications for rustfmt as well so that I'll know when things break.
Have spoken with @topecongiro about this offline already.
Improve documentation for `core::fmt` internals
The public interface of `core::fmt` is well-documented, but the internals have very minimal documentation.
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.
Improve Read::read_exact documentation
Fixes#72186.
For now I simply added a link to `Read::read` and held off changing the text in `Read::read_exact`. I can do it if it is deemed necessary.
@rustbot modify labels: C-enhancement, T-libs
This should hopefully handle #74484 but in any case fixes compilation of
the standard library without the `backtrace` feature. The need for this
feature is somewhat unclear now because the `backtrace` crate should
always compile (no more C code!) but we can handle that later if
necessary.
Teach bootstrap install and dist commands about TargetSelection
With this, we can now use a target JSON file to build a
cross-compiler:
```
x.py install --host ../aarch64-apple-darwin.json --target aarch64-apple-darwin
```
r? @Mark-Simulacrum
