Remove the deprecated unstable `concat_idents!` macro
In [rust-lang/rust#137653], the lang and libs-API teams did a joint FCP to deprecate
and eventually remove the long-unstable `concat_idents!` macro. The
deprecation is landing in 1.88, so do the removal here (target version
1.90).
This macro has been superseded by the more recent `${concat(...)}`
metavariable expression language feature, which avoids some of the
limitations of `concat_idents!`. The metavar expression is unstably
available under the [`macro_metavar_expr_concat`] feature.
History is mildly interesting here: `concat_idents!` goes back to 2011
when it was introduced with 513276e595f8 ("Add #concat_idents[] and
#ident_to_str[]"). The syntax looks a bit different but it still works
about the same:
let asdf_fdsa = "<.<";
assert(#concat_idents[asd,f_f,dsa] == "<.<");
assert(#ident_to_str[use_mention_distinction]
== "use_mention_distinction");
(That test existed from introduction until its removal here.)
Closes: https://github.com/rust-lang/rust/issues/29599
[rust-lang/rust#137653]: https://github.com/rust-lang/rust/pull/137653
[`macro_metavar_expr_concat`]: https://github.com/rust-lang/rust/issues/124225
In [137653], the lang and libs-API teams did a joint FCP to deprecate
and eventually remove the long-unstable `concat_idents!` macro. The
deprecation is landing in 1.88, so do the removal here (target version
1.90).
This macro has been superseded by the more recent `${concat(...)}`
metavariable expression language feature, which avoids some of the
limitations of `concat_idents!`. The metavar expression is unstably
available under the [`macro_metavar_expr_concat`] feature.
History is mildly interesting here: `concat_idents!` goes back to 2011
when it was introduced with 513276e595f8 ("Add #concat_idents[] and
about the same:
let asdf_fdsa = "<.<";
assert(#concat_idents[asd,f_f,dsa] == "<.<");
assert(#ident_to_str[use_mention_distinction]
== "use_mention_distinction");
(That test existed from introduction until its removal here.)
Closes: https://www.github.com/rust-lang/rust/issues/29599
[137653]: https://www.github.com/rust-lang/rust/pull/137653
[`macro_metavar_expr_concat`]: https://www.github.com/rust-lang/rust/issues/124225
Use the same error as other invalid types for `concat_bytes!`, rather
than using `ConcatCStrLit` from `concat!`. Also add more information
with a note about why this doesn't work, and a suggestion to use a
null-terminated byte string instead.
Split `autodiff` into `autodiff_forward` and `autodiff_reverse`
This PR splits `#[autodiff]` macro so `#[autodiff(df, Reverse, args)]` would become `#[autodiff_reverse(df, args)]` and `#[autodiff(df, Forward, args)]` would become `#[autodiff_forwad(df, args)]`.
- Show the `#![ ... ]` in the span (to make it clear that it should not
be included in the CLI argument)
- Show more detailed errors when the crate has valid token trees but
invalid syntax.
Previously, `crate-attr=feature(foo),feature(bar)` would just say
"invalid crate attribute" and point at the comma. Now, it explicitly
says that the comma was unexpected, which is useful when using
`--error-format=short`. It also fixes the column to show the correct
span.
- Recover from parse errors. Previously we would abort immediately on
syntax errors; now we go on to try and type-check the rest of the
crate.
The new diagnostic code also happens to be slightly shorter.
Use orphaned error code for the same error it belonged to before.
```
error[E0665]: `#[derive(Default)]` on enum with no `#[default]`
--> $DIR/macros-nonfatal-errors.rs:42:10
|
LL | #[derive(Default)]
| ^^^^^^^
LL | / enum NoDeclaredDefault {
LL | | Foo,
LL | | Bar,
LL | | }
| |_- this enum needs a unit variant marked with `#[default]`
|
= note: this error originates in the derive macro `Default` (in Nightly builds, run with -Z macro-backtrace for more info)
help: make this unit variant default by placing `#[default]` on it
|
LL | #[default] Foo,
| ~~~~~~~~~~~~~~
help: make this unit variant default by placing `#[default]` on it
|
LL | #[default] Bar,
| ~~~~~~~~~~~~~~
```
Don't allow the `#[pointee]` attribute where it doesn't belong
Error if the `#[pointee]` attribute is applied to anything but generic type parameters.
Closes#128485
Related to #123430
improve error message when `global_asm!` uses `asm!` operands
follow-up to https://github.com/rust-lang/rust/pull/128207
what was
```
error: expected expression, found keyword `in`
--> src/lib.rs:1:31
|
1 | core::arch::global_asm!("{}", in(reg));
| ^^ expected expression
```
becomes
```
error: the `in` operand cannot be used with `global_asm!`
--> $DIR/parse-error.rs:150:19
|
LL | global_asm!("{}", in(reg));
| ^^ the `in` operand is not meaningful for global-scoped inline assembly, remove it
```
the span of the error is just the keyword, which means that we can't create a machine-applicable suggestion here. The alternative would be to attempt to parse the full operand, but then if there are syntax errors in the operand those would be presented to the user, even though the parser already knows that the output won't be valid. Also that would require more complexity in the parser.
So I think this is a nice improvement at very low cost.
This makes it possible for the `unsafe(...)` syntax to only be
valid at the top level, and the `NestedMetaItem`s will automatically
reject `unsafe(...)`.
`#[naked]`: report incompatible attributes
tracking issue: https://github.com/rust-lang/rust/issues/90957
this is a re-implementation of https://github.com/rust-lang/rust/pull/93809 by ``@bstrie`` which was closed 2 years ago due to inactivity.
This PR takes some of the final comments into account, specifically providing a little more context in error messages, and using an allow list to determine which attributes are compatible with `#[naked]`.
Notable attributes that are incompatible with `#[naked]` are:
* `#[inline]`
* `#[track_caller]`
* ~~`#[target_feature]`~~ (this is now allowed, see PR discussion)
* `#[test]`, `#[ignore]`, `#[should_panic]`
These attributes just directly conflict with what `#[naked]` should do.
Naked functions are still important for systems programming, embedded, and operating systems, so I'd like to move them forward.
These functions are only used in `rustc_builtin_macros`, so it makes
sense for them to live there. This allows them to be changed from `pub`
to `pub(crate)`.
Add asm goto support to `asm!`
Tracking issue: #119364
This PR implements asm-goto support, using the syntax described in "future possibilities" section of [RFC2873](https://rust-lang.github.io/rfcs/2873-inline-asm.html#asm-goto).
Currently I have only implemented the `label` part, not the `fallthrough` part (i.e. fallthrough is implicit). This doesn't reduce the expressive though, since you can use label-break to get arbitrary control flow or simply set a value and rely on jump threading optimisation to get the desired control flow. I can add that later if deemed necessary.
r? ``@Amanieu``
cc ``@ojeda``
If a raw string was used in the `env!` invocation, then it should also
be shown in the diagnostic messages as a raw string.
Signed-off-by: David Wood <david@davidtw.co>
