This commit is an implementation of [RFC 563][rfc] which adds a new
`cfg(debug_assertions)` directive which is specially recognized and calculated
by the compiler. The flag is turned off at any optimization level greater than 1
and may also be explicitly controlled through the `-C debug-assertions`
flag.
[rfc]: https://github.com/rust-lang/rfcs/pull/563
The `debug_assert!` and `debug_assert_eq!` macros now respect this instead of
the `ndebug` variable and `ndebug` no longer holds any meaning to the standard
library.
Code which was previously relying on `not(ndebug)` to gate expensive code should
be updated to rely on `debug_assertions` instead.
Closes#22492
[breaking-change]
This module is now superseded by the `std::process` module. This module still
has some room to expand to get quite back up to parity with the `old_io`
version, and there is a [tracking issue][issue] for feature requests as well as
known room for expansion.
[issue]: https://github.com/rust-lang/rfcs/issues/941
[breaking-change]
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
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!("{}", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
This concretely improves type inference of some cases (see included
test). I assume the compiler struggles to reason about multiple layers
of generic type parameters (even with associated-type equalities) but
*can* understand pure associated types, since they are always directly
computable from the input types.
According to Apple arm64 calling convention varargs always are passed
through stack. Since `open` is actually a vararg function on Darwin's,
it means that older declaration caused permissions to be taken from
stack, while passed through register => it set file permissions
to garbage and it was simply impossible to read/delete files after they
were created.
They way this commit handles it is to preserve compatibility with
existing code - it simply creates a shim unsafe function so all existing
callers continue work as nothing happened.
It had been a source of huge bloat in rustdoc outputs. Of course,
we can simply disable compiler docs (as `rustc` generates over 90M
of HTML) but this approach fares better even after such decision.
Each directory now has `sidebar-items.js`, which immediately calls
`initSidebarItems` with a JSON sidebar data. This file is shared
throughout every item in the sidebar. The current item is
highlighted via a separate JS snippet (`window.sidebarCurrent`).
The JS file is designed to be loaded asynchronously, as the sidebar
is rendered before the content and slow sidebar loading blocks
the entire rendering. For the minimal accessibility without JS,
links to the parent items are left in HTML.
In the future, it might also be possible to integrate crates data
with the same fashion: `sidebar-items.js` at the root path will do
that. (Currently rustdoc skips writing JS in that case.)
This has a huge impact on the size of rustdoc outputs. Originally
it was 326MB uncompressed (37.7MB gzipped, 6.1MB xz compressed);
it is 169MB uncompressed (11.9MB gzipped, 5.9MB xz compressed) now.
The sidebar JS only takes 10MB uncompressed & 0.3MB gzipped.
Automatic has-same-types testing methodology can be found in #22501.
Because most of them don't work with `--pretty=typed`, compile-fail tests were manually audited.
r? @aturon
Automatic has-same-types testing methodology can be found in #22501.
Because most of them don't work with `--pretty=typed`, compile-fail tests were manually audited.
r? @aturon
This same source is being built in the Cargo ecosystem and hence needs to build
on stable Rust as well. This commit places the `no_std` attribute along with the
`no_std` feature behind a `cfg_attr` flag so they are not processed when
compiled on crates.io
This stability attribute was left out by accident and the stability pass has
since picked up the ability to check for this. As a result, crates are currently
getting warnings for implementations of `Index`.
Updates to the bison grammar to account for recent grammar additions and new tests. In particular:
* Support parsing `impl MyTrait for .. { }`
* Support parsing ExprQualifiedPaths without \"as TRAIT_REF\" such as `<Foo>::bar(&Foo)`
* Support parsing \"for\" clauses at the beginning of where clauses such as `where for<'a, 'b> &'a T: Bar<'b>`
Currently, the list of files linted in `tidy.py` is unordered. It seems more appropriate for more frequently appearing files (like `.rs`) to appear at the top of the list and for \"other files\" to appear at the very end. This PR also changes the wildcard import of `check_license()` into an explicit one.
```
Before: After:
* linted 4 .sh files * linted 5034 .rs files
* linted 4 .h files * linted 29 .c files
* linted 29 .c files * linted 28 .py files
* linted 2 .js files * linted 4 .sh files
* linted 0 other files * linted 4 .h files
* linted 28 .py files * linted 2 .js files
* linted 5034 .rs files * linted 0 other files
```
r? @brson
