The compiler already has special support for fixing up verbatim paths with disks
on Windows to something that can be correctly passed down to gcc, and this
commit adds support for verbatim UNC paths as well.
Closes#25505
The compiler already has special support for fixing up verbatim paths with disks
on Windows to something that can be correctly passed down to gcc, and this
commit adds support for verbatim UNC paths as well.
Closes#25505
This commit is an implementation of [RFC 1040][rfc] which is a redesign of the
currently-unstable `Duration` type. The API of the type has been scaled back to
be more conservative and it also no longer supports negative durations.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1040-duration-reform.md
The inner `duration` module of the `time` module has now been hidden (as
`Duration` is reexported) and the feature name for this type has changed from
`std_misc` to `duration`. All APIs accepting durations have also been audited to
take a more flavorful feature name instead of `std_misc`.
Closes#24874
This commit is an implementation of [RFC 1040][rfc] which is a redesign of the
currently-unstable `Duration` type. The API of the type has been scaled back to
be more conservative and it also no longer supports negative durations.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1040-duration-reform.md
The inner `duration` module of the `time` module has now been hidden (as
`Duration` is reexported) and the feature name for this type has changed from
`std_misc` to `duration`. All APIs accepting durations have also been audited to
take a more flavorful feature name instead of `std_misc`.
Closes#24874
There is no subtyping relationship between the types (or their non-freshened
variants), so they can not be merged.
Fixes#22645Fixes#24352Fixes#23825
Should fix#25235 (no test in issue).
Should fix#19976 (test is outdated).
There were still some mentions of `~[T]` and `~T`, mostly in comments and debugging statements. I tried to do my best to preserve meaning, but I might have gotten some wrong-- I'm happy to fix anything :)
Turns out that a verbatim path was leaking through to gcc via the PATH
environment variable (pointing to the bundled gcc provided by the main
distribution) which was wreaking havoc when gcc itself was run. The fix here is
to just stop passing verbatim paths down by adding more liberal uses of
`fix_windows_verbatim_for_gcc`.
Closes#25072
The former stopped making sense when we started interning substs and made
TraitRef a 2-word copy type, and I'm moving the latter into an arena as
they live as long as the type context.
This commit removes all the old casting/generic traits from `std::num` that are
no longer in use by the standard library. This additionally removes the old
`strconv` module which has not seen much use in quite a long time. All generic
functionality has been supplanted with traits in the `num` crate and the
`strconv` module is supplanted with the [rust-strconv crate][rust-strconv].
[rust-strconv]: https://github.com/lifthrasiir/rust-strconv
This is a breaking change due to the removal of these deprecated crates, and the
alternative crates are listed above.
[breaking-change]
I'm on a quest to slowly refactor a lot of the inference code. A first step for that is moving the "pure data structures" out so as to simplify what's left. This PR moves `snapshot_vec`, `graph`, and `unify` into their own crate (`librustc_data_structures`). They can then be unit-tested, benchmarked, etc more easily. As a benefit, I improved the performance of unification slightly on the benchmark I added vs the original code.
r? @nrc
This makes it illegal to have unconstrained lifetimes that appear in an associated type definition. Arguably, we should prohibit all unconstrained lifetimes -- but it would break various macros. It'd be good to evaluate how large a break change it would be. But this seems like the minimal change we need to do to establish soundness, so we should land it regardless. Another variant would be to prohibit all lifetimes that appear in any impl item, not just associated types. I don't think that's necessary for soundness -- associated types are different because they can be projected -- but it would feel a bit more consistent and "obviously" safe. I'll experiment with that in the meantime.
r? @aturon
Fixes#22077.
Function params which outlive everything in the body (incl
temporaries). Thus if we assign them their own `CodeExtent`, the
region inference can properly show that it is sound to have
temporaries with destructors that reference the parameters (because
such temporaries will be dropped before the parameters are).
This allows us to address issue 23338 in a clean way.
As a drive-by, fix a mistake in the tyencode for
`CodeExtent::BlockRemainder`.
The primary purpose of this PR is to add blanket impls for the `Fn` traits of the following (simplified) form:
impl<F:Fn> Fn for &F
impl<F:FnMut> FnMut for &mut F
However, this wound up requiring two changes:
1. A slight hack so that `x()` where `x: &mut F` is translated to `FnMut::call_mut(&mut *x, ())` vs `FnMut::call_mut(&mut x, ())`. This is achieved by just autoderef'ing one time when calling something whose type is `&F` or `&mut F`.
2. Making the infinite recursion test in trait matching a bit more tailored. This involves adding a notion of "matching" types that looks to see if types are potentially unifiable (it's an approximation).
The PR also includes various small refactorings to the inference code that are aimed at moving the unification and other code into a library (I've got that particular change in a branch, these changes just lead the way there by removing unnecessary dependencies between the compiler and the more general unification code).
Note that per rust-lang/rfcs#1023, adding impls like these would be a breaking change in the future.
cc @japaric
cc @alexcrichton
cc @aturon
Fixes#23015.
local only if matches `FUNDAMENTAL(LocalType)`, where `FUNDAMENTAL`
includes `&T` and types marked as fundamental (which includes `Box`).
Also apply these tests to negative reasoning.
This commit cleans out a large amount of deprecated APIs from the standard
library and some of the facade crates as well, updating all users in the
compiler and in tests as it goes along.
This upcast coercion currently preserves the vtable for the object, but
eventually it can be used to create a derived vtable. The upcast
coercion is not introduced into method dispatch; see comment on #18737
for information about why. Fixes#18737.
The end result is that common fields (id, name, attributes, etc.) are stored in now-structures `ImplItem` and `TraitItem`.
The signature of a method is no longer duplicated between methods with a body (default/impl) and those without, they now share `MethodSig`.
This is also a [breaking-change] because of minor bugfixes and changes to syntax extensions:
* `pub fn` methods in a trait no longer parse - remove the `pub`, it has no meaning anymore
* `MacResult::make_methods` is now `make_impl_items` and the return type has changed accordingly
* `quote_method` is gone, because `P<ast::Method>` doesn't exist and it couldn't represent a full method anyways - could be replaced by `quote_impl_item`/`quote_trait_item` in the future, but I do hope we realize how silly that combinatorial macro expansion is and settle on a single `quote` macro + some type hints - or just no types at all (only token-trees)
r? @nikomatsakis This is necessary (hopefully also sufficient) for associated constants.
The main gist of this PR is commit 1077efb which removes the list of supertraits from the `TraitDef` and pulls them into a separate table, which is accessed via `lookup_super_predicates`. This is analogous to `lookup_predicates`, which gets the complete where clause. This allows us to create the `TraitDef`, which contains the list generics and so forth, without fully knowing the list of supertraits. This in turn allows the *supertrait listing* to contain references to associated types like `<Self as Foo>::Item`, which were previously impossible because conversion required having the `TraitDef` for `Foo`.
We do not yet support `Self::Item` in a supertrait listing. This doesn't work because to convert that, it attempts to expand out the full set of supertraits, which are in the process of being created. This could potentially be worked out by having the expansion of supertraits proceed in a lazy fashion, but we'd have to define shadowing rules for associated types which we don't currently have.
Along the way (in 9de9ec5) I also removed the restriction against duplicate bounds and generalized the code so that it can handle having the same supertrait multiple times with different arguments, e.g. `Foo : Bar<i32> + Bar<u32>`. This restriction was serving no particular purpose, since the same trait could be extended multiple times indirectly, and in the era of multidispatch it is actively harmful.
This is technically a [breaking-change] because it affects the definition of a super-trait. Anything in a where clause that looks like `where Self : Foo` is now considered a supertrait. Because cycles are disallowed in supertraits, that could lead to some errors. This has not been observed in any existing code.
r? @nrc
This commit deprecates the majority of std::old_io::fs in favor of std::fs and
its new functionality. Some functions remain non-deprecated but are now behind a
feature gate called `old_fs`. These functions will be deprecated once
suitable replacements have been implemented.
The compiler has been migrated to new `std::fs` and `std::path` APIs where
appropriate as part of this change.
us to construct trait-references and do other things without forcing a
full evaluation of the supertraits. One downside of this scheme is that
we must invoke `ensure_super_predicates` before using any construct that
might require knowing about the super-predicates.
Many of the core rust libraries have places that rely on integer
wrapping behaviour. These places have been altered to use the wrapping_*
methods:
* core:#️⃣:sip - A number of macros
* core::str - The `maximal_suffix` method in `TwoWaySearcher`
* rustc::util::nodemap - Implementation of FnvHash
* rustc_back::sha2 - A number of macros and other places
* rand::isaac - Isaac64Rng, changed to use the Wrapping helper type
Some places had "benign" underflow. This is when underflow or overflow
occurs, but the unspecified value is not used due to other conditions.
* collections::bit::Bitv - underflow when `self.nbits` is zero.
* collections:#️⃣:{map,table} - Underflow when searching an empty
table. Did cause undefined behaviour in this case due to an
out-of-bounds ptr::offset based on the underflowed index. However the
resulting pointers would never be read from.
* syntax::ext::deriving::encodable - Underflow when calculating the
index of the last field in a variant with no fields.
These cases were altered to avoid the underflow, often by moving the
underflowing operation to a place where underflow could not happen.
There was one case that relied on the fact that unsigned arithmetic and
two's complement arithmetic are identical with wrapping semantics. This
was changed to use the wrapping_* methods.
Finally, the calculation of variant discriminants could overflow if the
preceeding discriminant was `U64_MAX`. The logic in `rustc::middle::ty`
for this was altered to avoid the overflow completely, while the
remaining places were changed to use wrapping methods. This is because
`rustc::middle::ty::enum_variants` now throws an error when the
calculated discriminant value overflows a `u64`.
This behaviour can be triggered by the following code:
```
enum Foo {
A = U64_MAX,
B
}
```
This commit also implements the remaining integer operators for
Wrapped<T>.
type-outlives works for closure types so that it ensures that all upvars
outlive the region in question. This gives the same guarantees but
without introducing artificial regions (and gives better error messages
to boot).
