This reverts commit 1eeb8e8b15, reversing
changes made to 324bf2b9fd.
Unfortunately the assert desugaring change is not backwards compatible,
see RUST-145770.
Code such as
```rust
#[derive(Debug)]
struct F {
data: bool
}
impl std::ops::Not for F {
type Output = bool;
fn not(self) -> Self::Output { !self.data }
}
fn main() {
let f = F { data: true };
assert!(f);
}
```
would be broken by the assert desugaring change. We may need to land
the change over an edition boundary, or limit the editions that the
desugaring change impacts.
Strip frontmatter in fewer places
* Stop stripping frontmatter in `proc_macro::Literal::from_str` (RUST-146132)
* Stop stripping frontmatter in expr-ctxt (but not item-ctxt!) `include`s (RUST-145945)
* Stop stripping shebang (!) in `proc_macro::Literal::from_str`
* Not a breaking change because it did compare spans already to ensure there wasn't extra whitespace or comments (`Literal::from_str("#!\n0")` already yields `Err(_)` thankfully!)
* Stop stripping frontmatter+shebang inside some rustdoc code where it doesn't make any observable difference (see self review comments)
* (Stop stripping frontmatter+shebang inside internal test code)
Fixes https://github.com/rust-lang/rust/issues/145945.
Fixes https://github.com/rust-lang/rust/issues/146132.
r? fee1-dead
add span to struct pattern rest (..)
Struct pattern rest (`..`) did not retain span information compared to normal fields. This patch adds span information for it.
The motivation of this patch comes from when I implemented this PR for Clippy: https://github.com/rust-lang/rust-clippy/pull/15000#discussion_r2134145163
It is possible to get the span of the Et cetera in a bit roundabout way, but I thought this would be nicer.
Use unnamed lifetime spans as primary spans for `MISMATCHED_LIFETIME_SYNTAXES`
Fixes https://github.com/rust-lang/rust/issues/145772
This PR changes the primary span(s) of the `MISMATCHED_LIFETIME_SYNTAXES` to point to the *unnamed* lifetime spans in both the inputs and *outputs* of the function signature. As reported in rust-lang/rust#145772, this should make it so that IDEs highlight the spans of the actionable part of this lint, rather than just the (possibly named) input spans like they do today.
This could be tweaked further perhaps, for example for `fn foo(_: T<'_>) -> T`, we don't need to highlight the elided lifetime if the actionable part is to change only the return type to `T<'_>`, but I think it's improvement on what's here today, so I think that should be follow-up since I think the logic might get a bit hairy.
cc ```@shepmaster```
Add lint against integer to pointer transmutes
# `integer_to_ptr_transmutes`
*warn-by-default*
The `integer_to_ptr_transmutes` lint detects integer to pointer transmutes where the resulting pointers are undefined behavior to dereference.
### Example
```rust
fn foo(a: usize) -> *const u8 {
unsafe {
std::mem::transmute::<usize, *const u8>(a)
}
}
```
```
warning: transmuting an integer to a pointer creates a pointer without provenance
--> a.rs:1:9
|
158 | std::mem::transmute::<usize, *const u8>(a)
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: this is dangerous because dereferencing the resulting pointer is undefined behavior
= note: exposed provenance semantics can be used to create a pointer based on some previously exposed provenance
= help: if you truly mean to create a pointer without provenance, use `std::ptr::without_provenance_mut`
= help: for more information about transmute, see <https://doc.rust-lang.org/std/mem/fn.transmute.html#transmutation-between-pointers-and-integers>
= help: for more information about exposed provenance, see <https://doc.rust-lang.org/std/ptr/index.html#exposed-provenance>
= note: `#[warn(integer_to_ptr_transmutes)]` on by default
help: use `std::ptr::with_exposed_provenance` instead to use a previously exposed provenance
|
158 - std::mem::transmute::<usize, *const u8>(a)
158 + std::ptr::with_exposed_provenance::<u8>(a)
|
```
### Explanation
Any attempt to use the resulting pointers are undefined behavior as the resulting pointers won't have any provenance.
Alternatively, `std::ptr::with_exposed_provenance` should be used, as they do not carry the provenance requirement or if the wanting to create pointers without provenance `std::ptr::without_provenance_mut` should be used.
See [std::mem::transmute] in the reference for more details.
[std::mem::transmute]: https://doc.rust-lang.org/std/mem/fn.transmute.html
--------
People are getting tripped up on this, see https://github.com/rust-lang/rust/issues/128409 and https://github.com/rust-lang/rust/issues/141220. There are >90 cases like these on [GitHub search](https://github.com/search?q=lang%3Arust+%2Ftransmute%3A%3A%3Cu%5B0-9%5D*.*%2C+%5C*const%2F&type=code).
Fixes https://github.com/rust-lang/rust-clippy/issues/13140
Fixes https://github.com/rust-lang/rust/issues/141220
Fixes https://github.com/rust-lang/rust/issues/145523
`@rustbot` labels +I-lang-nominated +T-lang
cc `@traviscross`
r? compiler
Prevent impossible combinations in `ast::ModKind`.
`ModKind::Loaded` has an `inline` field and a `had_parse_error` field. If the `inline` field is `Inline::Yes` then `had_parse_error` must be `Ok(())`.
This commit moves the `had_parse_error` field into the `Inline::No` variant. This makes it impossible to create the nonsensical combination of `inline == Inline::Yes` and `had_parse_error = Err(_)`.
r? ```@Urgau```
`ModKind::Loaded` has an `inline` field and a `had_parse_error` field.
If the `inline` field is `Inline::Yes` then `had_parse_error` must be
`Ok(())`.
This commit moves the `had_parse_error` field into the `Inline::No`
variant. This makes it impossible to create the nonsensical combination
of `inline == Inline::Yes` and `had_parse_error = Err(_)`.
Revert "Partially outline code inside the panic! macro".
This reverts https://github.com/rust-lang/rust/pull/115670
Without any tests/benchmarks that show some improvement, it's hard to know whether the change had any positive effect. (And if it did, whether that effect is still achieved today.)
Change the desugaring of `assert!` for better error output
In the desugaring of `assert!`, we now expand to a `match` expression instead of `if !cond {..}`.
The span of incorrect conditions will point only at the expression, and not the whole `assert!` invocation.
```
error[E0308]: mismatched types
--> $DIR/issue-14091.rs:2:13
|
LL | assert!(1,1);
| ^ expected `bool`, found integer
```
We no longer mention the expression needing to implement the `Not` trait.
```
error[E0308]: mismatched types
--> $DIR/issue-14091-2.rs:15:13
|
LL | assert!(x, x);
| ^ expected `bool`, found `BytePos`
```
Now `assert!(val)` desugars to:
```rust
match val {
true => {},
_ => $crate::panic::panic_2021!(),
}
```
Fix#122159.
resolve: Split extern prelude into two scopes
One scope for `extern crate` items and another for `--extern` options, with the former shadowing the latter.
If in a single scope some things can overwrite other things, especially with ad hoc restrictions like `MacroExpandedExternCrateCannotShadowExternArguments`, then it's not really a single scope.
So this PR splits `Scope::ExternPrelude` into two cleaner scopes.
This is similar to how https://github.com/rust-lang/rust/pull/144131 splits module scope into two scopes for globs and non-globs, but simpler.
Handle macros with multiple kinds, and improve errors
(I recommend reviewing this commit-by-commit.)
Switch to a bitflags `MacroKinds` to support macros with more than one kind
Review everything that uses `MacroKind`, and switch anything that could refer to more than one kind to use `MacroKinds`.
Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros, using the concrete `MacroRulesMacroExpander` type, and have it track which kinds it can handle. Eliminate the separate optional `attr_ext`, now that a `SyntaxExtension` can handle multiple macro kinds.
This also avoids the need to downcast when calling methods on `MacroRulesMacroExpander`, such as `get_unused_rule`.
Integrate macro kind checking into name resolution's `sub_namespace_match`, so that we only find a macro if it's the right type, and eliminate the special-case hack for attributes.
This allows detecting and report macro kind mismatches early, and more precisely, improving various error messages. In particular, this eliminates the case in `failed_to_match_macro` to check for a function-like invocation of a macro with no function-like rules.
Instead, macro kind mismatches now result in an unresolved macro, and we detect this case in `unresolved_macro_suggestions`, which now carefully distinguishes between a kind mismatch and other errors.
This also handles cases of forward-referenced attributes and cyclic attributes.
----
In this PR, I've minimally fixed up `rustdoc` so that it compiles and passes tests. This is just the minimal necessary fixes to handle the switch to `MacroKinds`, and it only works for macros that don't actually have multiple kinds. This will panic (with a `todo!`) if it encounters a macro with multiple kinds.
rustdoc needs further fixes to handle macros with multiple kinds, and to handle attributes and derive macros that aren't proc macros. I'd appreciate some help from a rustdoc expert on that.
----
r? ````````@petrochenkov````````
In the desugaring of `assert!`, we now expand to a `match` expression
instead of `if !cond {..}`.
The span of incorrect conditions will point only at the expression, and not
the whole `assert!` invocation.
```
error[E0308]: mismatched types
--> $DIR/issue-14091.rs:2:13
|
LL | assert!(1,1);
| ^ expected `bool`, found integer
```
We no longer mention the expression needing to implement the `Not` trait.
```
error[E0308]: mismatched types
--> $DIR/issue-14091-2.rs:15:13
|
LL | assert!(x, x);
| ^ expected `bool`, found `BytePos`
```
`assert!(val)` now desugars to:
```rust
match val {
true => {},
_ => $crate::panic::panic_2021!(),
}
```
Fix#122159.
We make some minor changes to some diagnostics to avoid span overlap on
type mismatch or inverted "expected"/"found" on type errors.
We remove some unnecessary parens from core, alloc and miri.
address review comments
This updates two clippy lints which had exceptions for `MacroKind::Bang`
macros to extend those exceptions to any macro, now that a macro_rules
macro can be any kind of macro.
Make no_mangle on foreign items explicit instead of implicit
for a followup PR I'm working on I need some foreign items to mangle. I could add a new attribute: `no_no_mangle` or something silly like that but by explicitly putting `no_mangle` in the codegen fn attrs of foreign items we can default it to `no_mangle` and then easily remove it when we don't want it.
I guess you'd know about this r? `@bjorn3.` Shouldn't be too hard to review :)
Builds on rust-lang/rust#144655 which should merge first.
Without any tests/benchmarks that show some improvement, it's hard to
know whether the change had any positive effect at all. (And if it did,
whether that effect is still achieved today.)
Account for new `assert!` desugaring in `!condition` suggestion
`rustc` in https://github.com/rust-lang/rust/pull/122661 is going to change the desugaring of `assert!` to be
```rust
match condition {
true => {}
_ => panic!(),
}
```
which will make the edge-case of `condition` being `impl Not<Output = bool>` while not being `bool` itself no longer a straightforward suggestion, but `!!condition` will coerce the expression to be `bool`, so it can be machine applicable.
Transposing https://github.com/rust-lang/rust-clippy/pull/15453/ to the rustc repo.
r? `````@samueltardieu`````
`rustc` is going to change the desugaring of `assert!` to be
```rust
match condition {
true => {}
_ => panic!(),
}
```
which will make the edge-case of `condition` being `impl Not<Output = bool>`
while not being `bool` itself no longer a straightforward suggestion,
but `!!condition` will coerce the expression to be `bool`, so it can be
machine applicable.
Distinguish prepending and replacing self ty in predicates
There are two kinds of functions called `with_self_ty`:
1. Prepends the `Self` type onto an `ExistentialPredicate` which lacks it in its internal representation.
2. Replaces the `Self` type of an existing predicate, either for diagnostics purposes or in the new trait solver when normalizing that self type.
This PR distinguishes these two because I often want to only grep for one of them. Namely, let's call it `with_replaced_self_ty` when all we're doing is replacing the self type.
Extend `is_case_difference` to handle digit-letter confusables
This PR extends `is_case_difference` to handle digit-letter confusables
Add support for detecting 0/O, 1/l, 5/S, 8/B, 9/g confusables in error suggestions.
r? `@estebank`
Deduplicate `IntTy`/`UintTy`/`FloatTy`.
There are identical definitions in `rustc_type_ir` and `rustc_ast`. This commit removes them and places a single definition in `rustc_ast_ir`. This requires adding `rust_span` as a dependency of `rustc_ast_ir`, but means a bunch of silly conversion functions can be removed.
r? `@fmease`
There are identical definitions in `rustc_type_ir` and `rustc_ast`. This
commit removes them and places a single definition in `rustc_ast_ir`.
This requires adding `rust_span` as a dependency of `rustc_ast_ir`, but
means a bunch of silly conversion functions can be removed.
The one annoying wrinkle is that the old version had differences in
their `Debug` impls, e.g. one printed `u32` while the other printed
`U32`. Some compiler error messages rely on the former (yuk), and some
clippy output depends on the latter. So the commit also changes clippy
to not rely on `Debug` and just implement what it needs itself.
Jieyou Xu