...of the type being matched.
This change will result in a better diagnostic for code like the following:
```rust
enum Enum {
Foo,
Bar
}
fn f(x: Enum) {
match x {
Foo => (),
Bar => ()
}
}
```
which would currently simply fail with an unreachable pattern error
on the 2nd arm.
The user is advised to either use a qualified path in the patterns
or import the variants explicitly into the scope.
The type aliases json::JsonString and json::JsonObject were originally
prefixed with 'json' to prevent collisions with (at the time) the enums
json::String and json::Object respectively. Now that enum namespacing
has landed, this 'json' prefix is redundant and can be removed:
json::JsonArray -> json::Array
json::JsonObject -> json::Object
In addition, this commit also unpublicizes all of the re-exports in this
JSON module, as a part of #19253
[breaking-change]
- Add `IntoCow` trait, and put it in the prelude
- Add `is_owned`/`is_borrowed` methods to `Cow`
- Add `CowString`/`CowVec` type aliases (to `Cow<'_, String, str>`/`Cow<'_, Vec, [T]>` respectively)
- `Cow` implements: `Show`, `Hash`, `[Partial]{Eq,Ord}`
- `impl BorrowFrom<Cow<'a, T, B>> for B`
[breaking-change]s:
- `IntoMaybeOwned` has been removed from the prelude
- libcollections: `SendStr` is now an alias to `CowString<'static>` (it was aliased to `MaybeOwned<'static>`)
- libgraphviz:
- `LabelText` variants now wrap `CowString` instead of `MaybeOwned`
- `Nodes` and `Edges` are now type aliases to `CowVec` (they were aliased to `MaybeOwnedVec`)
- libstd/path: `Display::as_maybe_owned` has been renamed to `Display::as_cow` and now returns a `CowString`
- These functions now accept/return `Cow` instead of `MaybeOwned[Vector]`:
- libregex: `Replacer::reg_replace`
- libcollections: `str::from_utf8_lossy`
- libgraphviz: `Id::new`, `Id::name`, `LabelText::pre_escaped_content`
- libstd: `TaskBuilder::named`
r? @aturon
It looks like currently kinds required by traits are not propagated when they are wrapped in a TyTrait. Additionally, in SelectionContext::builtin_bound, no attempt is made to check whether the target trait or its supertraits require the kind specified.
This PR alters SelectionContext::builtin_bound to examine all supertraits in the target trait's bounds recursively for required kinds.
Alternatively, the kinds could be added to the TyTrait upon creation (by just setting its builtin_bounds to the union of the bounds requested in this instance and the bounds required by the trait), this option may have less overhead during compilation but information is lost about which kinds were explicitly requested for this instance (vs those specified by traits/supertraits) would be lost.
Code to fragment paths into pieces based on subparts being moved around, e.g. moving `x.1` out of a tuple `(A,B,C)` leaves behind the fragments `x.0: A` and `x.2: C`. Further discussion in borrowck/doc.rs.
Includes differentiation between assigned_fragments and moved_fragments, support for all-but-one array fragments, and instrumentation to print out the moved/assigned/unmmoved/parents for each function, factored out into a separate submodule.
These fragments can then be used by `trans` to inject stack-local dynamic drop flags. (They also can be hooked up with dataflow to reduce the expected number of injected flags.)
The tests use new "//~| ERROR" follow syntax.
Includes a test for moves involving array elements. It was easier
than i realized to get something naive off the ground here.
All of the enum components had a redundant 'Type' specifier: TypeSymlink, TypeDirectory, TypeFile. This change removes them, replacing them with a namespace: FileType::Symlink, FileType::Directory, and FileType::RegularFile.
RegularFile is used instead of just File, as File by itself could be mistakenly thought of as referring to the struct.
[breaking-change]
This commit removes the `std::local_data` module in favor of a new
`std::thread_local` module providing thread local storage. The module provides
two variants of TLS: one which owns its contents and one which is based on
scoped references. Each implementation has pros and cons listed in the
documentation.
Both flavors have accessors through a function called `with` which yield a
reference to a closure provided. Both flavors also panic if a reference cannot
be yielded and provide a function to test whether an access would panic or not.
This is an implementation of [RFC 461][rfc] and full details can be found in
that RFC.
This is a breaking change due to the removal of the `std::local_data` module.
All users can migrate to the new thread local system like so:
thread_local!(static FOO: Rc<RefCell<Option<T>>> = Rc::new(RefCell::new(None)))
The old `local_data` module inherently contained the `Rc<RefCell<Option<T>>>` as
an implementation detail which must now be explicitly stated by users.
[rfc]: https://github.com/rust-lang/rfcs/pull/461
[breaking-change]
Closes https://github.com/rust-lang/rust/issues/19077
I would appreciate any guidance on how to write a test for this. I saw some examples in `test/pretty`, but there are different ways to test... With or without `.pp` files, with a `pp-exact` comment, etc.
This breaks code like
```
let t = (42i, 42i);
... t.0::<int> ...;
```
Change this code to not contain an unused type parameter. For example:
```
let t = (42i, 42i);
... t.0 ...;
```
Closes https://github.com/rust-lang/rust/issues/19096
[breaking-change]
r? @aturon
Previously, the entire runtime API surface was publicly exposed, but
that is neither necessary nor desirable. This commit hides most of the
module, using librustrt directly as needed. The arrangement will need to
be revisited when rustrt is pulled into std.
[breaking-change]
In the general case, at least, it is not possible to make an object out of an unsized type. This is because the object type would have to store the fat pointer information for the `self` value *and* the vtable -- meaning it'd have to be a fat pointer with three words -- but for the compiler to know that the object requires three words, it would have to know the self-type of the object (is `self` a thin or fat pointer?), which of course it doesn't.
Fixes#18333.
r? @nick29581
Use the expected type to infer the argument/return types of unboxed closures. Also, in `||` expressions, use the expected type to decide if the result should be a boxed or unboxed closure (and if an unboxed closure, what kind).
This supercedes PR #19089, which was already reviewed by @pcwalton.
Futureproof Rust for fancier suffixed literals. The Rust compiler tokenises a literal followed immediately (no whitespace) by an identifier as a single token: (for example) the text sequences `"foo"bar`, `1baz` and `1u1024` are now a single token rather than the pairs `"foo"` `bar`, `1` `baz` and `1u` `1024` respectively.
The compiler rejects all such suffixes in the parser, except for the 12 numeric suffixes we have now.
I'm fairly sure this will affect very few programs, since it's not currently legal to have `<literal><identifier>` in a Rust program, except in a macro invocation. Any macro invocation relying on this behaviour can simply separate the two tokens with whitespace: `foo!("bar"baz)` becomes `foo!("bar" baz)`.
This implements [RFC 463](https://github.com/rust-lang/rfcs/blob/master/text/0463-future-proof-literal-suffixes.md), and so closes https://github.com/rust-lang/rust/issues/19088.
This commit applies the stabilization of std::fmt as outlined in [RFC 380][rfc].
There are a number of breaking changes as a part of this commit which will need
to be handled to migrated old code:
* A number of formatting traits have been removed: String, Bool, Char, Unsigned,
Signed, and Float. It is recommended to instead use Show wherever possible or
to use adaptor structs to implement other methods of formatting.
* The format specifier for Boolean has changed from `t` to `b`.
* The enum `FormatError` has been renamed to `Error` as well as becoming a unit
struct instead of an enum. The `WriteError` variant no longer exists.
* The `format_args_method!` macro has been removed with no replacement. Alter
code to use the `format_args!` macro instead.
* The public fields of a `Formatter` have become read-only with no replacement.
Use a new formatting string to alter the formatting flags in combination with
the `write!` macro. The fields can be accessed through accessor methods on the
`Formatter` structure.
Other than these breaking changes, the contents of std::fmt should now also all
contain stability markers. Most of them are still #[unstable] or #[experimental]
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0380-stabilize-std-fmt.md
[breaking-change]
Closes#18904
Ensure that the type parameters passed to methods outlive the call expression.
Fixes#18899.
This is yet another case of forgotten to consistently enforce the constraints in every instance where they apply. Might be nice to try and refactor to make this whole thing more DRY, but for now here's a targeted fix.
r? @pcwalton
This fixes#17388.
Note that we don't check type parameters in trait-references and so on, so we accept some nonsense (I opened https://github.com/rust-lang/rust/issues/18865). (It may be easier to just add support for `T::Foo` and deprecate the qpath code until we can implement it more robustly using the trait lookup infrastructure, not sure.)
This adds an optional suffix at the end of a literal token:
`"foo"bar`. An actual use of a suffix in a expression (or other literal
that the compiler reads) is rejected in the parser.
This doesn't switch the handling of numbers to this system, and doesn't
outlaw illegal suffixes for them yet.
This commit applies the stabilization of std::fmt as outlined in [RFC 380][rfc].
There are a number of breaking changes as a part of this commit which will need
to be handled to migrated old code:
* A number of formatting traits have been removed: String, Bool, Char, Unsigned,
Signed, and Float. It is recommended to instead use Show wherever possible or
to use adaptor structs to implement other methods of formatting.
* The format specifier for Boolean has changed from `t` to `b`.
* The enum `FormatError` has been renamed to `Error` as well as becoming a unit
struct instead of an enum. The `WriteError` variant no longer exists.
* The `format_args_method!` macro has been removed with no replacement. Alter
code to use the `format_args!` macro instead.
* The public fields of a `Formatter` have become read-only with no replacement.
Use a new formatting string to alter the formatting flags in combination with
the `write!` macro. The fields can be accessed through accessor methods on the
`Formatter` structure.
Other than these breaking changes, the contents of std::fmt should now also all
contain stability markers. Most of them are still #[unstable] or #[experimental]
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0380-stabilize-std-fmt.md
[breaking-change]
Closes#18904
Make old-fashioned functions in the `std::os` module utilize `IoResult`.
I'm still investigating the possibility to include more functions in this pull request. Currently, it covers `getcwd()`, `make_absolute()`, and `change_dir()`. The issues covered by this PR are #16946 and #16315.
A few concerns:
- Should we provide `OsError` in distinction from `IoError`? I'm saying this because in Python, those two are distinguished. One advantage that we keep using `IoError` is that we can make the error cascade down other functions whose return type also includes `IoError`. An example of such functions is `std::io::TempDir::new_in()`, which uses `os::make_absolute()` as well as returns `IoResult<TempDir>`.
- `os::getcwd()` uses an internal buffer whose size is 2048 bytes, which is passed to `getcwd(3)`. There is no upper limitation of file paths in the POSIX standard, but typically it is set to 4096 bytes such as in Linux. Should we increase the buffer size? One thing that makes me nervous is that the size of 2048 bytes already seems a bit excessive, thinking that in normal cases, there would be no filenames that even exceeds 512 bytes.
Fixes#16946.
Fixes#16315.
Any ideas are welcomed. Thanks!
os::change_dir() returns bool, without a meaningful error message.
Change it to return IoResult<()> to indicate what IoError caused the
failure.
Fixes#16315.
[breaking-change]
os::getcwd() panics if the current directory is not available. According
to getcwd(3), there are three cases:
- EACCES: Permission denied.
- ENOENT: The current working directory has been removed.
- ERANGE: The buffer size is less than the actual absolute path.
This commit makes os::getcwd() return IoResult<Path>, not just Path,
preventing it from panicking.
As os::make_absolute() depends on os::getcwd(), it is also modified to
return IoResult<Path>.
Fixes#16946.
[breaking-change]
The trait has an obvious, sensible implementation directly on vectors so
the MemWriter wrapper is unnecessary. This will halt the trend towards
providing all of the vector methods on MemWriter along with eliminating
the noise caused by conversions between the two types. It also provides
the useful default Writer methods on Vec<u8>.
After the type is removed and code has been migrated, it would make
sense to add a new implementation of MemWriter with seeking support. The
simple use cases can be covered with vectors alone, and ones with the
need for seeks can use a new MemWriter implementation.
Following [the collections reform RFC](https://github.com/rust-lang/rfcs/pull/235), this PR:
* Adds a new `borrow` module to libcore. The module contains traits for borrowing data (`BorrowFrom` and `BorrowFromMut`), generalized cloning (`ToOwned`), and a clone-on-write smartpointer (`Cow`).
* Deprecates the `_equiv` family of methods on `HashMap` and `HashSet` by instead generalizing the "normal" methods like `get` and `remove` to use the new `std::borrow` infrastructure.
* Generalizes `TreeMap`, `TreeSet`, `BTreeMap` and `BTreeSet` to use the new `std::borrow` infrastructure for lookups.
[breaking-change]
This is especially useful for declaring a static with external linkage in an executable. There isn't any way to do that currently since we mark everything in an executable as internal by default.
Also, a quick fix to have the no-compiler-rt target option respected when building staticlibs as well.
groundwork for better performance.
Key points:
- Separate out determining which method to use from actually selecting
a method (this should enable caching, as well as the pcwalton fast-reject strategy).
- Merge the impl selection back into method resolution and don't rely on
trait matching (this should perform better but also is needed to resolve some
kind of conflicts, see e.g. `method-two-traits-distinguished-via-where-clause.rs`)
- Purge a lot of out-of-date junk and coercions from method lookups.
This breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:
```
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
=>
```
pub use self::Foo::{A, B};
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
or
```
pub enum Foo {
A,
B
}
fn main() {
let a = Foo::A;
}
```
[breaking-change]
This was a simple case of substitutions being applied inconsistently. I haven't investigated why type parameters are actually showing up in the closure type here, but trans needs to handle them correctly in any case.
This implements a considerable portion of rust-lang/rfcs#369 (tracked in #18640). Some interpretations had to be made in order to get this to work. The breaking changes are listed below:
[breaking-change]
- `core::num::{Num, Unsigned, Primitive}` have been deprecated and their re-exports removed from the `{std, core}::prelude`.
- `core::num::{Zero, One, Bounded}` have been deprecated. Use the static methods on `core::num::{Float, Int}` instead. There is no equivalent to `Zero::is_zero`. Use `(==)` with `{Float, Int}::zero` instead.
- `Signed::abs_sub` has been moved to `std::num::FloatMath`, and is no longer implemented for signed integers.
- `core::num::Signed` has been removed, and its methods have been moved to `core::num::Float` and a new trait, `core::num::SignedInt`. The methods now take the `self` parameter by value.
- `core::num::{Saturating, CheckedAdd, CheckedSub, CheckedMul, CheckedDiv}` have been removed, and their methods moved to `core::num::Int`. Their parameters are now taken by value. This means that
- `std::time::Duration` no longer implements `core::num::{Zero, CheckedAdd, CheckedSub}` instead defining the required methods non-polymorphically.
- `core::num::{zero, one, abs, signum}` have been deprecated. Use their respective methods instead.
- The `core::num::{next_power_of_two, is_power_of_two, checked_next_power_of_two}` functions have been deprecated in favor of methods defined a new trait, `core::num::UnsignedInt`
- `core::iter::{AdditiveIterator, MultiplicativeIterator}` are now only implemented for the built-in numeric types.
- `core::iter::{range, range_inclusive, range_step, range_step_inclusive}` now require `core::num::Int` to be implemented for the type they a re parametrized over.
This patch tweaks the stability inheritance infrastructure so that
`#{stable]` attributes are not inherited. Doing so solves two problems:
1. It allows us to mark module *names* as stable without accidentally
marking the items they contain as stable.
2. It means that a `#[stable]` attribution must always appear directly
on the item it applies to, which makes it easier for reviewers to catch
changes to stable APIs.
Fixes#17484
Adds a method for printing a fatal error and also a help message to the
parser and uses this in a variety of places to improve error messages.
Closes#12213.
This commit deprecates the entire libtime library in favor of the
externally-provided libtime in the rust-lang organization. Users of the
`libtime` crate as-is today should add this to their Cargo manifests:
[dependencies.time]
git = "https://github.com/rust-lang/time"
To implement this transition, a new function `Duration::span` was added to the
`std::time::Duration` time. This function takes a closure and then returns the
duration of time it took that closure to execute. This interface will likely
improve with `FnOnce` unboxed closures as moving in and out will be a little
easier.
Due to the deprecation of the in-tree crate, this is a:
[breaking-change]
cc #18855, some of the conversions in the `src/test/bench` area may have been a
little nicer with that implemented
This PR includes a sequence of commits that gradually dismantles the `librustrt` `rtio` system -- the main trait previously used to abstract over green and native io. It also largely dismantles `libnative`, moving much of its code into `libstd` and refactoring as it does so.
TL;DR:
* Before this PR: `rustc hello.rs && wc -c hello` produces 715,996
* After this PR: `rustc hello.rs && wc -c hello` produces 368,100
That is, this PR reduces the footprint of hello world by ~50%.
This is a major step toward #17325 (i.e. toward implementing the [runtime removal RFC](https://github.com/rust-lang/rfcs/pull/230).) What remains is to pull out the scheduling, synchronization and task infrastructure, and to remove `libgreen`. These will be done soon in a follow-up PR.
Part of the work here is eliminating the `rtio` abstraction, which in many cases means bringing the implementation of io closer to the actual API presented in `std::io`.
Another aspect of this PR is the creation of two new, *private* modules within `std` that implement io:
* The `sys` module, which represents a platform-specific implementation of a number of low-level abstractions that are used directly within `std::io` and `std::os`. These "abstractions" are left largely the same as they were in `libnative` (except for the removal of `Arc` in file descriptors), but they are expected to evolve greatly over time. Organizationally, there are `sys/unix/` and `sys/windows/` directories which both implement the entire `sys` module hierarchy; this means that nearly all of the platform-specific code is isolated and you can get a handle on each platform in isolation.
* The `sys_common` module, which is rooted at `sys/common`, and provides a few pieces of private, low-level, but cross-platform functionality.
In the long term, the `sys` modules will provide hooks for exposing high-level platform-specific APIs as part of `libstd`. The first such API will be access to file descriptors from `std::io` abstractions, but a bit of design work remains before that step can be taken.
The `sys_common` module includes some traits (like `AsFileDesc`) which allow communication of private details between modules in disparate locations in the hierarchy; this helps overcome the relatively simple hierarchical privacy system in Rust.
To emphasize: the organization in `sys` is *very preliminary* and the main goal was to migrate away from `rtio` as quickly and simply as possible. The design will certainly evolve over time, and all of the details are currently private.
Along the way, this PR also entirely removes signal handling, since it was only supported on `librustuv` which was removed a while ago.
Because of the removal of APIs from `libnative` and `librustrt`, and the removal of signal handling, this is a:
[breaking-change]
Some of these APIs will return in public from from `std` over time.
r? @alexcrichton
Various miscellaneous changes pushing towards HRTB support:
1. Update parser and adjust ast to support `for<'a,'b>` syntax, both in closures and trait bounds. Warn on the old syntax (not error, for stage0).
2. Refactor TyTrait representation to include a TraitRef.
3. Purge `once_fns` feature gate and `once` keyword.
r? @pcwalton
This is a [breaking-change]:
- The `once_fns` feature is now officially deprecated. Rewrite using normal closures or unboxed closures.
- The new `for`-based syntax now issues warnings (but not yet errors):
- `fn<'a>(T) -> U` becomes `for<'a> fn(T) -> U`
- `<'a> |T| -> U` becomes `for<'a> |T| -> U`
`FnOnce` environments that fit within an `int` are passed to the closure by value. For some reason there was an assert that this would only happen if there were 1 or 0 free variables, but it can also happen if there are multiple variables that happen to fit.
Closes#18652
This commit implements processing these two attributes at the crate level as
well as at the item level. When #[cfg] is applied at the crate level, then the
entire crate will be omitted if the cfg doesn't match. The #[cfg_attr] attribute
is processed as usual in that the attribute is included or not depending on
whether the cfg matches.
This was spurred on by motivations of #18585 where #[cfg_attr] annotations will
be applied at the crate-level.
cc #18585
This resolves some issues that remained after adding support for monomorphizing unboxed closures in trans.
There were a few places where a set of substitutions for an unboxed closure type were dropped on the floor and later recalculated from scratch based on the def ID, but this failed spectacularly when the closure originated from a different param environment. The substitutions are now plumbed through end-to-end. Closes#18661
There was also a conflict in the meaning of the self param space within the body of the unboxed closure. Trans attempted to insert the unboxed closure type as the self type, but this could conflict with the self type from the param environment when an unboxed closure was used within a default method on a trait. Since the body of an unboxed closure cannot refer to its own self type or value, there's no need for it to actually use the self space. The downstream consumers of the substitutions in trans do not seem to need it either since they look up the type of the closure some other way, so I just stopped setting it. Closes#18685.
r? @pcwalton @nikomatsakis
This commit implements processing these two attributes at the crate level as
well as at the item level. When #[cfg] is applied at the crate level, then the
entire crate will be omitted if the cfg doesn't match. The #[cfg_attr] attribute
is processed as usual in that the attribute is included or not depending on
whether the cfg matches.
This was spurred on by motivations of #18585 where #[cfg_attr] annotations will
be applied at the crate-level.
cc #18585
