diagnostics: remove inconsistent English article "this" from E0107
Consider [`tests/ui/const-generics/generic_const_exprs/issue-102768.stderr`][issue-102768.stderr], the error message where it gives additional notes about where the associated type is defined, and how the dead code lint doesn't have an article, like in [`tests/ui/lint/dead-code/issue-85255.stderr`][issue-85255.stderr]. They don't have articles, so it seems unnecessary to have one here.
[issue-102768.stderr]: 07c993eba8/tests/ui/const-generics/generic_const_exprs/issue-102768.stderr
[issue-85255.stderr]: 07c993eba8/tests/ui/lint/dead-code/issue-85255.stderr
Fix `is_terminal`'s handling of long paths on Windows.
As reported in sunfishcode/is-terminal#18, there are situations where `GetFileInformationByHandleEx` can write a file name length that is longer than the provided buffer. To avoid deferencing memory past the end of the buffer, use a bounds-checked function to form a slice to the buffer and handle the out-of-bounds case.
This ports the fix from sunfishcode/is-terminal#19 to std's `is_terminal` implementation.
parser: provide better suggestions and errors on closures with braces missing
We currently provide wrong suggestions and unhelpful errors on closure bodies with braces missing.
For example, given the following code:
```rust
fn main() {
let _x = Box::new(|x|x+1;);
}
```
the current output is:
```
error: expected expression, found `)`
--> ./main.rs:2:30
|
2 | let _x = Box::new(|x|x+1;);
| ^ expected expression
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^
3 | }
| ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ this is the parsed closure...
3 | }
| - ...but likely you meant the closure to end here
help: try adding braces
|
2 ~ let _x = Box::new(|x| {x+1;);
3 ~ }}
|
error: expected `;`, found `}`
--> ./main.rs:2:32
|
2 | let _x = Box::new(|x|x+1;);
| ^ help: add `;` here
3 | }
| - unexpected token
error: aborting due to 3 previous errors
```
We got 3 errors, but all but the second are unnecessary or just wrong.
This commit allows outputting correct suggestions and errors. The above code would output like this:
```
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^ ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ - ...but likely you meant the closure to end here
| |
| this is the parsed closure...
help: try adding braces
|
2 | let _x = Box::new(|x| {x+1;});
| + +
error: aborting due to previous error
```
Fixes https://github.com/rust-lang/rust/issues/107959.
r? diagnostics
Fix ICE in 'duplicate diagnostic item' diagnostic
Not sure how to add this in a test; I found it by mistakenly running `cargo fix --lib -p std` rather than `x fix` at the root.
std: time: Avoid to use "was created" in elapsed() description
".. since this instant was created" is inaccurate and misleading, consider the following case:
```rust
let i1 = Instant::now(); // i1 is created at T1
let i2 = i1 + Duration::from_nanos(0); // i2 is "created" at T2
i2.elapsed(); // at T3
```
Per the current description, `elapsed()` at T3 should return T3 - T2?
To avoid the inaccuracy, removes the "was created" in the description of {Instant,SystemTime}::elapsed().
And since these types represent times, it's OK to use prepostions with them, e.g. "since this instant".
Add test for bad cast with deferred projection equality
1. Unification during coercion (`Coerce::unify`) needs to consider deferred projection obligations (at least pass over them with `predicate_may_hold` or something, to disqualify any totally wrong unifications) -- otherwise, we'll shallowly consider `<u8 as Add>::Output` and `char` as coercible during `FnCtxt::try_coerce`, which will fail later when the nested obligations are registered and processed.
2. Cast checking needs to be able to structurally normalize types so it sees `u8` instead of `<u8 as Add>::Output`. Otherwise it'll always consider the latter as part of a non-primitive cast. Currently `FnCtxt::normalize` doesn't do anything useful here, interestingly.
I tried looking into both of these and it's not immediately clear where to refactor existing typeck code to fix this (at least the latter), but I'm gonna commit a test for it at least so we don't forget. This is one of the issues that's keeping us from building larger projects.
implement const iterator using `rustc_do_not_const_check`
Previous experiment: #102225.
Explanation: rather than making all default methods work under `const` all at once, this uses `rustc_do_not_const_check` as a workaround to "trick" the compiler to not run any checks on those other default methods. Any const implementations are only required to implement the `next` method. Any actual calls to the trait methods other than `next` will either error in compile time (at CTFE runs), or run the methods correctly if they do not have any non-const operations. This is extremely easy to maintain, remove, or improve.
This resolves an inconsistency in naming style for functions
on the parser, between functions parsing specific kinds of items
and those for expressions, favoring the parse_item_[sth] style
used by functions for items. There are multiple advantages
of that style:
* functions of both categories are collected in the same place
in the rustdoc output.
* it helps with autocompletion, as you can narrow down your
search for a function to those about expressions.
* it mirrors rust's path syntax where less specific things
come first, then it gets more specific, i.e.
std::collections::hash_map::Entry
The disadvantage is that it doesn't "read like a sentence"
any more, but I think the advantages weigh more greatly.
This change was mostly application of this command:
sed -i -E 's/(fn |\.)parse_([[:alnum:]_]+)_expr/\1parse_expr_\2/' compiler/rustc_parse/src/parser/*.rs
Plus very minor fixes outside of rustc_parse, and an invocation
of x fmt.
This makes sure that the interface of `miri_host_to_target_path` is compatible with `CStr` for targets where `c_char` is unsigned (such as ARM). This commit changes the signature of `miri_host_to_target_path` in the README and in all test cases.
(This is a large commit. The changes to
`compiler/rustc_middle/src/ty/context.rs` are the most important ones.)
The current naming scheme is a mess, with a mix of `_intern_`, `intern_`
and `mk_` prefixes, with little consistency. In particular, in many
cases it's easy to use an iterator interner when a (preferable) slice
interner is available.
The guiding principles of the new naming system:
- No `_intern_` prefixes.
- The `intern_` prefix is for internal operations.
- The `mk_` prefix is for external operations.
- For cases where there is a slice interner and an iterator interner,
the former is `mk_foo` and the latter is `mk_foo_from_iter`.
Also, `slice_interners!` and `direct_interners!` can now be `pub` or
non-`pub`, which helps enforce the internal/external operations
division.
It's not perfect, but I think it's a clear improvement.
The following lists show everything that was renamed.
slice_interners
- const_list
- mk_const_list -> mk_const_list_from_iter
- intern_const_list -> mk_const_list
- substs
- mk_substs -> mk_substs_from_iter
- intern_substs -> mk_substs
- check_substs -> check_and_mk_substs (this is a weird one)
- canonical_var_infos
- intern_canonical_var_infos -> mk_canonical_var_infos
- poly_existential_predicates
- mk_poly_existential_predicates -> mk_poly_existential_predicates_from_iter
- intern_poly_existential_predicates -> mk_poly_existential_predicates
- _intern_poly_existential_predicates -> intern_poly_existential_predicates
- predicates
- mk_predicates -> mk_predicates_from_iter
- intern_predicates -> mk_predicates
- _intern_predicates -> intern_predicates
- projs
- intern_projs -> mk_projs
- place_elems
- mk_place_elems -> mk_place_elems_from_iter
- intern_place_elems -> mk_place_elems
- bound_variable_kinds
- mk_bound_variable_kinds -> mk_bound_variable_kinds_from_iter
- intern_bound_variable_kinds -> mk_bound_variable_kinds
direct_interners
- region
- intern_region (unchanged)
- const
- mk_const_internal -> intern_const
- const_allocation
- intern_const_alloc -> mk_const_alloc
- layout
- intern_layout -> mk_layout
- adt_def
- intern_adt_def -> mk_adt_def_from_data (unusual case, hard to avoid)
- alloc_adt_def(!) -> mk_adt_def
- external_constraints
- intern_external_constraints -> mk_external_constraints
Other
- type_list
- mk_type_list -> mk_type_list_from_iter
- intern_type_list -> mk_type_list
- tup
- mk_tup -> mk_tup_from_iter
- intern_tup -> mk_tup
All the slice interners have a wrapper that handles the empty slice
case. We can instead handle this in the `slice_interners!` macro,
avoiding the need for most of the wrappers, and allowing the interner
functions to be renamed from `_intern_foos` to `intern_foos`.
The two exceptions:
- intern_predicates: I kept this wrapper because there's a FIXME
comment about a possible future change.
- intern_poly_existential_predicates: I kept this wrapper because it
asserts that the slice is empty and sorted.
Add new lint no_mangle_with_rust_abi
Fixes issue #10347
This PR adds a new lint `no_mangle_with_rust_abi` that suggests converting a function to the C ABI to if the function has the `#[no_mangle]` attribute and `Abi == Abi::Rust`. It will not run for any of the other variants defined in [rustc_target::spec::abi::Abi](https://doc.rust-lang.org/beta/nightly-rustc/rustc_target/spec/abi/enum.Abi.html), nor suggest any conversion other than conversion to the C ABI.
Functions that explicitly opt into the Rust ABI with `extern "Rust"` are ignored by this lint.
---
changelog: [`no_mangle_with_rust_abi`]: add lint that converts Rust ABI functions with the `#[no_mangle]` attribute to C ABI
Previously, there were two queries to check whether a type allows the
0x01 or zeroed bitpattern.
I am planning on adding a further initness to check, truly uninit for
MaybeUninit, which would make this three queries. This seems overkill
for such a small feature, so this PR unifies them into one.
Consider `tests/ui/const-generics/generic_const_exprs/issue-102768.stderr`,
the error message where it gives additional notes about where the associated
type is defined, and how the dead code lint doesn't have an article,
like in `tests/ui/lint/dead-code/issue-85255.stderr`. They don't have
articles, so it seems unnecessary to have one here.
Fix more false positives for `extra_unused_type_parameters`
Builds on #10321. All empty functions are no longer linted, instead of just those that have trait bounds on them. Also, if a trait bound contains a non-public trait (un-exported, but still potentially reachable), then the corresponding type parameter isn't linted.
Finally, added support for the `avoid_breaking_exported_api` config option.
r? `@flip1995`
changelog: none
As reported in sunfishcode/is-terminal#18, there are situations where
`GetFileInformationByHandleEx` can write a file name length that is
longer than the provided buffer. To avoid deferencing memory past the
end of the buffer, use a bounds-checked function to form a slice to
the buffer and handle the out-of-bounds case.
This ports the fix from sunfishcode/is-terminal#19 to std's `is_terminal`
implementation.
As a part of drop elaboration, we identify dead unwinds, i.e., unwind
edges on a drop terminators which are known to be unreachable, because
there is no need to drop anything.
Previously, the data flow framework was informed about the dead unwinds,
and it assumed those edges are absent from MIR. Unfortunately, the data
flow framework wasn't consistent in maintaining this assumption.
In particular, if a block was reachable only through a dead unwind edge,
its state was propagated to other blocks still. This became an issue in
the context of change removes DropAndReplace terminator, since it
introduces initialization into cleanup blocks.
To avoid this issue, remove unreachable unwind edges before the drop
elaboration, and elaborate only blocks that remain reachable.
We currently provide wrong suggestions and unhelpful errors on closure
bodies with braces missing. For example, given the following code:
```
fn main() {
let _x = Box::new(|x|x+1;);
}
```
the current output is like this:
```
error: expected expression, found `)`
--> ./main.rs:2:30
|
2 | let _x = Box::new(|x|x+1;);
| ^ expected expression
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^
3 | }
| ^
|
...
help: try adding braces
|
2 ~ let _x = Box::new(|x| {x+1;);
3 ~ }}
...
error: expected `;`, found `}`
--> ./main.rs:2:32
|
2 | let _x = Box::new(|x|x+1;);
| ^ help: add `;` here
3 | }
| - unexpected token
error: aborting due to 3 previous errors
```
This commit allows outputting correct suggestions and errors. The above
code would output like this:
```
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^ ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ - ...but likely you meant the closure to end here
| |
| this is the parsed closure...
help: try adding braces
|
2 | let _x = Box::new(|x| {x+1;});
| + +
error: aborting due to previous error
```
