Feature gate the `rustdoc::missing_doc_code_examples` lint
Moves the lint from being implicitly active on nightly `rustdoc` to requiring a feature to activate, like other unstable lints.
Uses the new tracking issue https://github.com/rust-lang/rust/issues/101730
The `<*const T>::guaranteed_*` methods now return an option for the unknown case
cc https://github.com/rust-lang/rust/issues/53020#issuecomment-1236932443
I chose `0` for "not equal" and `1` for "equal" and left `2` for the unknown case so backends can just forward to raw pointer equality and it works ✨
r? `@fee1-dead` or `@lcnr`
cc `@rust-lang/wg-const-eval`
Tweak future opaque ty pretty printing
1. The `Return` type of a generator doesn't need to be a lang item just for diagnostic printing of types
2. We shouldn't suppress the `Output = Ty` of a opaque future if the type is a int or float var.
Debuginfo line information for macro invocations are collapsed by
default - line information are replaced by the line of the outermost
expansion site. Using `-Zdebug-macros` disables this behaviour.
When the `collapse_debuginfo` feature is enabled, the default behaviour
is reversed so that debuginfo is not collapsed by default. In addition,
the `#[collapse_debuginfo]` attribute is available and can be applied to
macro definitions which will then have their line information collapsed.
Signed-off-by: David Wood <david.wood@huawei.com>
Make `const_eval_select` a real intrinsic
This fixes issues where `track_caller` functions do not have nice panic
messages anymore when there is a call to the function, and uses the
MIR system to replace the call instead of dispatching via lang items.
Fixes#100696.
safe transmute: use `Assume` struct to provide analysis options
This task was left as a TODO in #92268; resolving it brings [`BikeshedIntrinsicFrom`](https://doc.rust-lang.org/nightly/core/mem/trait.BikeshedIntrinsicFrom.html) more in line with the API defined in [MCP411](https://github.com/rust-lang/compiler-team/issues/411).
**Before:**
```rust
pub unsafe trait BikeshedIntrinsicFrom<
Src,
Context,
const ASSUME_ALIGNMENT: bool,
const ASSUME_LIFETIMES: bool,
const ASSUME_VALIDITY: bool,
const ASSUME_VISIBILITY: bool,
> where
Src: ?Sized,
{}
```
**After:**
```rust
pub unsafe trait BikeshedIntrinsicFrom<Src, Context, const ASSUME: Assume = { Assume::NOTHING }>
where
Src: ?Sized,
{}
```
`Assume::visibility` has also been renamed to `Assume::safety`, as library safety invariants are what's actually being assumed; visibility is just the mechanism by which it is currently checked (and that may change).
r? `@oli-obk`
---
Related:
- https://github.com/rust-lang/compiler-team/issues/411
- https://github.com/rust-lang/rust/issues/99571
Support `#[unix_sigpipe = "inherit|sig_dfl"]` on `fn main()` to prevent ignoring `SIGPIPE`
When enabled, programs don't have to explicitly handle `ErrorKind::BrokenPipe` any longer. Currently, the program
```rust
fn main() { loop { println!("hello world"); } }
```
will print an error if used with a short-lived pipe, e.g.
% ./main | head -n 1
hello world
thread 'main' panicked at 'failed printing to stdout: Broken pipe (os error 32)', library/std/src/io/stdio.rs:1016:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
by enabling `#[unix_sigpipe = "sig_dfl"]` like this
```rust
#![feature(unix_sigpipe)]
#[unix_sigpipe = "sig_dfl"]
fn main() { loop { println!("hello world"); } }
```
there is no error, because `SIGPIPE` will not be ignored and thus the program will be killed appropriately:
% ./main | head -n 1
hello world
The current libstd behaviour of ignoring `SIGPIPE` before `fn main()` can be explicitly requested by using `#[unix_sigpipe = "sig_ign"]`.
With `#[unix_sigpipe = "inherit"]`, no change at all is made to `SIGPIPE`, which typically means the behaviour will be the same as `#[unix_sigpipe = "sig_dfl"]`.
See https://github.com/rust-lang/rust/issues/62569 and referenced issues for discussions regarding the `SIGPIPE` problem itself
See the [this](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Proposal.3A.20First.20step.20towards.20solving.20the.20SIGPIPE.20problem) Zulip topic for more discussions, including about this PR.
Tracking issue: https://github.com/rust-lang/rust/issues/97889
Uplift the `let_underscore` lints from clippy into rustc.
This PR resolves#97241.
This PR adds three lints from clippy--`let_underscore_drop`, `let_underscore_lock`, and `let_underscore_must_use`, which are meant to capture likely-incorrect uses of `let _ = ...` bindings (in particular, doing this on a type with a non-trivial `Drop` causes the `Drop` to occur immediately, instead of at the end of the scope. For a type like `MutexGuard`, this effectively releases the lock immediately, which is almost certainly the wrong behavior)
In porting the lints from clippy I had to copy over a bunch of utility functions from `clippy_util` that these lints also relied upon. Is that the right approach?
Note that I've set the `must_use` and `drop` lints to Allow by default and set `lock` to Deny by default (this matches the same settings that clippy has). In talking with `@estebank` he informed me to do a Crater run (I am not sure what type of Crater run to request here--I think it's just "check only"?)
On the linked issue, there's some discussion about using `must_use` and `Drop` together as a heuristic for when to warn--I did not implement this yet.
r? `@estebank`
Do not report too many expr field candidates
When considering "this expressions' field has a {field/method}" suggestions:
1. Don't report methods that are out of scope
2. Use `span_suggestions` instead of reporting each field candidate, which caps the number of suggestions to 4
4. Blacklist some common traits like `Clone` and `Deref`
Fixes#100894
This makes it possible to instruct libstd to never touch the signal
handler for `SIGPIPE`, which makes programs pipeable by default (e.g.
with `./your-program | head -n 1`) without `ErrorKind::BrokenPipe`
errors.
Add pointer masking convenience functions
This PR adds the following public API:
```rust
impl<T: ?Sized> *const T {
fn mask(self, mask: usize) -> *const T;
}
impl<T: ?Sized> *mut T {
fn mask(self, mask: usize) -> *const T;
}
// mod intrinsics
fn mask<T>(ptr: *const T, mask: usize) -> *const T
```
This is equivalent to `ptr.map_addr(|a| a & mask)` but also uses a cool llvm intrinsic.
Proposed in https://github.com/rust-lang/rust/pull/95643#issuecomment-1121562352
cc `@Gankra` `@scottmcm` `@RalfJung`
r? rust-lang/libs-api
In the MIR pretty printing, it can sometimes happen that the span of the
statement is outside the span of the body (for example through
inlining). In this case, don't display a relative span but an absolute
span. This will make the mir-opt-tests a little more prone to diffs
again, but the impact should be small.
This commit adds the following functions all of which have a signature
`pointer, usize -> pointer`:
- `<*mut T>::mask`
- `<*const T>::mask`
- `intrinsics::ptr_mask`
These functions are equivalent to `.map_addr(|a| a & mask)` but they
utilize `llvm.ptrmask` llvm intrinsic.
*masks your pointers*
Add the diagnostic translation lints to crates that don't emit them
Some of these have a note saying that they should build on a stable compiler, does that mean they shouldn't get these lints? Or can we cfg them out on those?
Lazily decode SourceFile from metadata
Currently, source files from foreign crates are decoded up-front from metadata.
Spans from those crates were matched with the corresponding source using binary search among those files.
This PR changes the strategy by matching spans to files during encoding. This allows to decode source files on-demand, instead of up-front. The on-disk format for spans becomes: `<tag> <position from start of file> <length> <file index> <crate (if foreign file)>`.
rustc_metadata: dedupe strings to prevent multiple copies in rmeta/query cache blow file size
r? `@cjgillot`
Encodes strings in rmeta/query cache so duplicated ones will be encoded as offsets to first strings, reducing file size.
Implement `#[rustc_default_body_unstable]`
This PR implements a new stability attribute — `#[rustc_default_body_unstable]`.
`#[rustc_default_body_unstable]` controls the stability of default bodies in traits.
For example:
```rust
pub trait Trait {
#[rustc_default_body_unstable(feature = "feat", isssue = "none")]
fn item() {}
}
```
In order to implement `Trait` user needs to either
- implement `item` (even though it has a default implementation)
- enable `#![feature(feat)]`
This is useful in conjunction with [`#[rustc_must_implement_one_of]`](https://github.com/rust-lang/rust/pull/92164), we may want to relax requirements for a trait, for example allowing implementing either of `PartialEq::{eq, ne}`, but do so in a safe way — making implementation of only `PartialEq::ne` unstable.
r? `@Aaron1011`
cc `@nrc` (iirc you were interested in this wrt `read_buf`), `@danielhenrymantilla` (you were interested in the related `#[rustc_must_implement_one_of]`)
P.S. This is my first time working with stability attributes, so I'm not sure if I did everything right 😅
This initial implementation handles transmutations between types with specified layouts, except when references are involved.
Co-authored-by: Igor null <m1el.2027@gmail.com>
Some command-line options accessible through `sess.opts` are best
accessed through wrapper functions on `Session`, `TyCtxt` or otherwise,
rather than through field access on the option struct in the `Session`.
Adds a new lint which triggers on those options that should be accessed
through a wrapper function so that this is prohibited. Options are
annotated with a new attribute `rustc_lint_opt_deny_field_access` which
can specify the error message (i.e. "use this other function instead")
to be emitted.
A simpler alternative would be to simply rename the options in the
option type so that it is clear they should not be used, however this
doesn't prevent uses, just discourages them. Another alternative would
be to make the option fields private, and adding accessor functions on
the option types, however the wrapper functions sometimes rely on
additional state from `Session` or `TyCtxt` which wouldn't be available
in an function on the option type, so the accessor would simply make the
field available and its use would be discouraged too.
Signed-off-by: David Wood <david.wood@huawei.com>
codegen: use new {re,de,}allocator annotations in llvm
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
r? `@nikic`
This obviates the patch that teaches LLVM internals about
_rust_{re,de}alloc functions by putting annotations directly in the IR
for the optimizer.
The sole test change is required to anchor FileCheck to the body of the
`box_uninitialized` method, so it doesn't see the `allocalign` on
`__rust_alloc` and get mad about the string `alloca` showing up. Since I
was there anyway, I added some checks on the attributes to prove the
right attributes got set.
While we're here, we also emit allocator attributes on
__rust_alloc_zeroed. This should allow LLVM to perform more
optimizations for zeroed blocks, and probably fixes#90032. [This
comment](https://github.com/rust-lang/rust/issues/24194#issuecomment-308791157)
mentions "weird UB-like behaviour with bitvec iterators in
rustc_data_structures" so we may need to back this change out if things
go wrong.
The new test cases require LLVM 15, so we copy them into LLVM
14-supporting versions, which we can delete when we drop LLVM 14.
This attribute allows to mark default body of a trait function as
unstable. This means that implementing the trait without implementing
the function will require enabling unstable feature.
This is useful in conjunction with `#[rustc_must_implement_one_of]`,
we may want to relax requirements for a trait, for example allowing
implementing either of `PartialEq::{eq, ne}`, but do so in a safe way
-- making implementation of only `PartialEq::ne` unstable.
rmeta: avoid embedding `StabilityLevel::Unstable` reason multiple times into .rmeta\.rlib files
Avoids bloating size of some rmeta\rlib files by not placing default string for `StabilityLevel::Unstable` reason multiple times, affects only stdlib\rustc artifacts. For stdlib cuts about 3% (diff of total size for patched\unpatched *.rmeta files of stage1-std) of file size, depending on crates.
fixes#88180
Add support for LLVM ShadowCallStack.
LLVMs ShadowCallStack provides backward edge control flow integrity protection by using a separate shadow stack to store and retrieve a function's return address.
LLVM currently only supports this for AArch64 targets. The x18 register is used to hold the pointer to the shadow stack, and therefore this only works on ABIs which reserve x18. Further details are available in the [LLVM ShadowCallStack](https://clang.llvm.org/docs/ShadowCallStack.html) docs.
# Usage
`-Zsanitizer=shadow-call-stack`
# Comments/Caveats
* Currently only enabled for the aarch64-linux-android target
* Requires the platform to define a runtime to initialize the shadow stack, see the [LLVM docs](https://clang.llvm.org/docs/ShadowCallStack.html) for more detail.
make vtable pointers entirely opaque
This implements the scheme discussed in https://github.com/rust-lang/unsafe-code-guidelines/issues/338: vtable pointers should be considered entirely opaque and not even readable by Rust code, similar to function pointers.
- We have a new kind of `GlobalAlloc` that symbolically refers to a vtable.
- Miri uses that kind of allocation when generating a vtable.
- The codegen backends, upon encountering such an allocation, call `vtable_allocation` to obtain an actually dataful allocation for this vtable.
- We need new intrinsics to obtain the size and align from a vtable (for some `ptr::metadata` APIs), since direct accesses are UB now.
I had to touch quite a bit of code that I am not very familiar with, so some of this might not make much sense...
r? `@oli-obk`
Adds a simple helper function to the `SourceMap` for extending a `Span`
to encompass the entire line it is on - useful for suggestions where
removing a line is the suggested action.
Signed-off-by: David Wood <david.wood@huawei.com>
If part of a feature is stabilized and a new feature is added for the
remaining parts, then the `implied_by` attribute can be used to indicate
which now-stable feature previously contained a item. If the now-stable
feature is still active (if the user has only just updated rustc, for
example) then there will not be an stability error for uses of the item
from the implied feature.
Signed-off-by: David Wood <david.wood@huawei.com>
Improve the function pointer docs
This is #97842 but for function pointers instead of tuples. The concept is basically the same.
* Reduce duplicate impls; show `fn (T₁, T₂, …, Tₙ)` and include a sentence saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
https://notriddle.com/notriddle-rustdoc-test/std/primitive.fn.html
remove allow(rustc::potential_query_instability) in rustc_span
Also, avoid sorting before debug output as iteration order can now be
relied upon.
Related #84447
Implement `for<>` lifetime binder for closures
This PR implements RFC 3216 ([TI](https://github.com/rust-lang/rust/issues/97362)) and allows code like the following:
```rust
let _f = for<'a, 'b> |a: &'a A, b: &'b B| -> &'b C { b.c(a) };
// ^^^^^^^^^^^--- new!
```
cc ``@Aaron1011`` ``@cjgillot``
Always create elided lifetime parameters for functions
Anonymous and elided lifetimes in functions are sometimes (async fns) --and sometimes not (regular fns)-- desugared to implicit generic parameters.
This difference of treatment makes it some downstream analyses more complicated to handle. This step is a pre-requisite to perform lifetime elision resolution on AST.
There is currently an inconsistency in the treatment of argument-position impl-trait for functions and async fns:
```rust
trait Foo<'a> {}
fn foo(t: impl Foo<'_>) {} //~ ERROR missing lifetime specifier
async fn async_foo(t: impl Foo<'_>) {} //~ OK
fn bar(t: impl Iterator<Item = &'_ u8>) {} //~ ERROR missing lifetime specifier
async fn async_bar(t: impl Iterator<Item = &'_ u8>) {} //~ OK
```
The current implementation reports "missing lifetime specifier" on `foo`, but **accepts it** in `async_foo`.
This PR **proposes to accept** the anonymous lifetime in both cases as an extra generic lifetime parameter.
This change would be insta-stable, so let's ping t-lang.
Anonymous lifetimes in GAT bindings keep being forbidden:
```rust
fn foo(t: impl Foo<Assoc<'_> = Bar<'_>>) {}
^^ ^^
forbidden ok
```
I started a discussion here: https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Anonymous.20lifetimes.20in.20universal.20impl-trait/near/284968606
r? ``@petrochenkov``
Implement `SourceMap::is_span_accessible`
This patch adds `SourceMap::is_span_accessible` and replaces `span_to_snippet(span).is_ok()` and `span_to_snippet(span).is_err()` with it. This removes a `&str` to `String` conversion.
Miscellaneous inlining improvements
Add `#[inline]` to a few trivial non-generic methods from a perf report
that otherwise wouldn't be candidates for inlining.
Use less string interning
This removes string interning in a couple of places where doing so won't result in perf improvements. I also switched one place to use pre-interned symbols.
This commit adds new methods that combine sequences of existing
formatting methods.
- `Formatter::debug_{tuple,struct}_field[12345]_finish`, equivalent to a
`Formatter::debug_{tuple,struct}` + N x `Debug{Tuple,Struct}::field` +
`Debug{Tuple,Struct}::finish` call sequence.
- `Formatter::debug_{tuple,struct}_fields_finish` is similar, but can
handle any number of fields by using arrays.
These new methods are all marked as `doc(hidden)` and unstable. They are
intended for the compiler's own use.
Special-casing up to 5 fields gives significantly better performance
results than always using arrays (as was tried in #95637).
The commit also changes the `Debug` deriving code to use these new methods. For
example, where the old `Debug` code for a struct with two fields would be like
this:
```
fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
match *self {
Self {
f1: ref __self_0_0,
f2: ref __self_0_1,
} => {
let debug_trait_builder = &mut ::core::fmt::Formatter::debug_struct(f, "S2");
let _ = ::core::fmt::DebugStruct::field(debug_trait_builder, "f1", &&(*__self_0_0));
let _ = ::core::fmt::DebugStruct::field(debug_trait_builder, "f2", &&(*__self_0_1));
::core::fmt::DebugStruct::finish(debug_trait_builder)
}
}
}
```
the new code is like this:
```
fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
match *self {
Self {
f1: ref __self_0_0,
f2: ref __self_0_1,
} => ::core::fmt::Formatter::debug_struct_field2_finish(
f,
"S2",
"f1",
&&(*__self_0_0),
"f2",
&&(*__self_0_1),
),
}
}
```
This shrinks the code produced for `Debug` instances
considerably, reducing compile times and binary sizes.
Co-authored-by: Scott McMurray <scottmcm@users.noreply.github.com>
Mention formatting macros when encountering `ArgumentV1` method in const
Also open to just closing this if it's overkill. There are a lot of other distracting error messages around, so maybe it's not worth fixing just this one.
Fixes#93665
[RFC 2011] Minimal initial implementation
Tracking issue: #44838
Third step of #96496
Implementation has ~290 LOC with the bare minimum to be in a functional state. Currently only searches for binary operations to mimic what `assert_eq!` and `assert_ne!` already do.
r? `@oli-obk`
Remove `rustc_deprecated` diagnostics
Follow-up on #95960. The diagnostics will remain until the next bootstrap, at which point people will have had six weeks to adjust.
``@rustbot`` label +A-diagnostics
r? ``@compiler-errors``
Rename rustc_serialize::opaque::Encoder as MemEncoder.
This avoids the name clash with `rustc_serialize::Encoder` (a trait),
and allows lots qualifiers to be removed and imports to be simplified
(e.g. fewer `as` imports).
(This was previously merged as commit 5 in #94732 and then was reverted
in #97905 because of a perf regression caused by commit 4 in #94732.)
r? ```@bjorn3```
lint: add diagnostic translation migration lints
Introduce allow-by-default lints for checking whether diagnostics are written in
`SessionDiagnostic` or `AddSubdiagnostic` impls and whether diagnostics are translatable. These lints can be denied for modules once they are fully migrated to impls and translation.
These lints are intended to be temporary - once all diagnostics have been changed then we can just change the APIs we have and that will enforce these constraints thereafter.
r? `````@oli-obk`````
This avoids the name clash with `rustc_serialize::Encoder` (a trait),
and allows lots qualifiers to be removed and imports to be simplified
(e.g. fewer `as` imports).
(This was previously merged as commit 5 in #94732 and then was reverted
in #97905 because of a perf regression caused by commit 4 in #94732.)
Introduce allow-by-default lints for checking whether diagnostics are
written in `SessionDiagnostic`/`AddSubdiagnostic` impls and whether
diagnostics are translatable. These lints can be denied for modules once
they are fully migrated to impls and translation.
Signed-off-by: David Wood <david.wood@huawei.com>
This commit adds a new unstable attribute, `#[doc(tuple_varadic)]`, that
shows a 1-tuple as `(T, ...)` instead of just `(T,)`, and links to a section
in the tuple primitive docs that talks about these.
This avoids the name clash with `rustc_serialize::Encoder` (a trait),
and allows lots qualifiers to be removed and imports to be simplified
(e.g. fewer `as` imports).
There are two impls of the `Encoder` trait: `opaque::Encoder` and
`opaque::FileEncoder`. The former encodes into memory and is infallible, the
latter writes to file and is fallible.
Currently, standard `Result`/`?`/`unwrap` error handling is used, but this is a
bit verbose and has non-trivial cost, which is annoying given how rare failures
are (especially in the infallible `opaque::Encoder` case).
This commit changes how `Encoder` fallibility is handled. All the `emit_*`
methods are now infallible. `opaque::Encoder` requires no great changes for
this. `opaque::FileEncoder` now implements a delayed error handling strategy.
If a failure occurs, it records this via the `res` field, and all subsequent
encoding operations are skipped if `res` indicates an error has occurred. Once
encoding is complete, the new `finish` method is called, which returns a
`Result`. In other words, there is now a single `Result`-producing method
instead of many of them.
This has very little effect on how any file errors are reported if
`opaque::FileEncoder` has any failures.
Much of this commit is boring mechanical changes, removing `Result` return
values and `?` or `unwrap` from expressions. The more interesting parts are as
follows.
- serialize.rs: The `Encoder` trait gains an `Ok` associated type. The
`into_inner` method is changed into `finish`, which returns
`Result<Vec<u8>, !>`.
- opaque.rs: The `FileEncoder` adopts the delayed error handling
strategy. Its `Ok` type is a `usize`, returning the number of bytes
written, replacing previous uses of `FileEncoder::position`.
- Various methods that take an encoder now consume it, rather than being
passed a mutable reference, e.g. `serialize_query_result_cache`.
Add support for emitting functions with `coldcc` to LLVM
The eventual goal is to try using this for things like the internal panicking stuff, to see whether it helps.
Using diagnostic items avoids having to update the paths if the guard
types ever get moved around for some reason. Additionally, it also greatly
simplifies the `is_sync_lock` check.
Lazify `SourceFile::lines`.
`SourceFile::lines` is a big part of metadata. It's stored in a compressed form
(a difference list) to save disk space. Decoding it is a big fraction of
compile time for very small crates/programs.
This commit introduces a new type `SourceFileLines` which has a `Lines`
form and a `Diffs` form. The latter is used when the metadata is first
read, and it is only decoded into the `Lines` form when line data is
actually needed. This avoids the decoding cost for many files,
especially in `std`. It's a performance win of up to 15% for tiny
crates/programs where metadata decoding is a high part of compilation
costs.
A `RefCell` is needed because the methods that access lines data (which can
trigger decoding) take `&self` rather than `&mut self`. To allow for this,
`SourceFile::lines` now takes a `FnMut` that operates on the lines slice rather
than returning the lines slice.
r? `@Mark-Simulacrum`
`SourceFile::lines` is a big part of metadata. It's stored in a compressed form
(a difference list) to save disk space. Decoding it is a big fraction of
compile time for very small crates/programs.
This commit introduces a new type `SourceFileLines` which has a `Lines`
form and a `Diffs` form. The latter is used when the metadata is first
read, and it is only decoded into the `Lines` form when line data is
actually needed. This avoids the decoding cost for many files,
especially in `std`. It's a performance win of up to 15% for tiny
crates/programs where metadata decoding is a high part of compilation
costs.
A `Lock` is needed because the methods that access lines data (which can
trigger decoding) take `&self` rather than `&mut self`. To allow for this,
`SourceFile::lines` now takes a `FnMut` that operates on the lines slice rather
than returning the lines slice.
This commit adds an alternative content boxing syntax,
and uses it inside alloc.
The usage inside the very performance relevant code in
liballoc is the only remaining relevant usage of box syntax
in the compiler (outside of tests, which are comparatively
easy to port).
box syntax was originally designed to be used by all Rust
developers. This introduces a replacement syntax more tailored
to only being used inside the Rust compiler, and with it,
lays the groundwork for eventually removing box syntax.
Replace `#[default_method_body_is_const]` with `#[const_trait]`
pulled out of #96077
related issues: #67792 and #92158
cc `@fee1-dead`
This is groundwork to only allowing `impl const Trait` for traits that are marked with `#[const_trait]`. This is necessary to prevent adding a new default method from becoming a breaking change (as it could be a non-const fn).
Add support for embedding pretty printers via `#[debugger_visualizer]` attribute
Initial support for [RFC 3191](https://github.com/rust-lang/rfcs/pull/3191) in PR https://github.com/rust-lang/rust/pull/91779 was scoped to supporting embedding NatVis files using a new attribute. This PR implements the pretty printer support as stated in the RFC mentioned above.
This change includes embedding pretty printers in the `.debug_gdb_scripts` just as the pretty printers for rustc are embedded today. Also added additional tests for embedded pretty printers. Additionally cleaned up error checking so all error checking is done up front regardless of the current target.
RFC: https://github.com/rust-lang/rfcs/pull/3191
