While extending the `option_map_or_err_ok` lint (warn by default,
"style") to recognize η-expanded forms of `Ok`, as in
```rust
// Should suggest `opt.ok_or("foobar")`
let _ = opt.map_or(Err("foobar"), |x| Ok(x));
```
I discovered that the `manual_ok_or` lint (allow by default, "pedantic")
already covered exactly the cases handled by `option_map_or_err_ok`,
including the one I was adding. Apparently, `option_map_or_err_ok` was
added without realizing that the lint already existed under the
`manual_ok_or` name. As a matter of fact, artifacts of this second lint
were even present in the first lint `stderr` file and went unnoticed for
more than a year.
This PR:
- deprecates `option_map_or_err_ok` with a message saying to use
`manual_ok_or`
- moves `manual_ok_or` from "pedantic" to "style" (the category in which
`option_map_or_err_ok` was)
In addition, I think that this lint, which is short, machine applicable,
and leads to shorter and clearer code with less arguments (`Ok`
disappears) and the removal of one level of call (`Err(x)` is replaced
by `x`), is a reason by itself to be in "style".
changelog: [`option_map_or_err_ok` and `manual_ok_or`]: move
`manual_ok_or` from "pedantic" to "style", and deprecate the redundant
style lint `option_map_or_err_ok`.
Removing the `.as_ref()` or `.as_mut()` as the top-level expression in a
closure may change the type of the result. In this case, it may be
better not to lint rather than proposing a fix that would not work.
changelog: [`useless_asref`]: do not remove the `.as_ref()` or
`.as_mut()` call if this would change the type of the enclosing closure
Fix#14088
By assuming that a recursive type is normalizable within the deeper
calls to `is_normalizable_helper()`, more cases can be handled by this
function.
In order to fix stack overflows, a recursion limit has also been added
for recursive generic type instantiations.
Fix#9798Fix#10508Fix#11915
changelog: [`large_enum_variant`]: more precise detection of variants
with large size differences
Proposing to replace
```rust
let mut x = PathBuf::from("/foo");
x.push("/bar");
```
by
```rust
let mut x = PathBuf::from("/foo");
x.push("bar");
```
changes the content of `x` (`/bar` ⇒ `/foo/bar`). This is not equivalent
and should not be `MachineApplicable`, even if the original code is
suspicious.
changelog: none
Fix the version of `doc_overindented_list_items`. It actually will be in
1.86.0, not 1.80.0.
(https://github.com/rust-lang/rust/pull/136209 has a milestone of
1.86.0)
changelog: none
- `reindent_multiline()` always returns the result of
`reindent_multiline_inner()` which returns a `String`. Make
`reindent_multiline()` return a `String` as well, instead of a
systematically owned `Cow<'_, str>`.
- There is no reason for `reindent_multiline()` to force a caller to
build a `Cow<'_, str>` instead of passing a `&str` directly, especially
considering that a `String` will always be returned.
Also, both the input parameter and return value (of type `Cow<'_, str>`)
shared the same (elided) lifetime for no reason: this worked only
because the result was always the `Cow::Owned` variant which is
compatible with any lifetime.
As a consequence, the signature changes from:
```rust
fn reindent_multiline(s: Cow<'_, str>, …) -> Cow<'_, str> { … }
```
to
```rust
fn reindent_multiline(s: &str, …) -> String { … }
```
changelog: none
`MachineApplicable` is appropriate for the applicability of this lint.
changelog: [`if_then_some_else_none`]: change the applicability to
`MachineApplicable`
Labeled blocks cannot be used as-is in the "then" or "else" part of an
`if` expression. They must be enclosed in an anonymous block.
Fix#14099
changelog: [`match_bool`]: fix suggestion when the rewritten block has a
label
fixes#12407
I think it is meaningful to emit a warning even if the span is in a
macro.
changelog: [`manual_async_fn`]: don't emit suggestion inside macro
Counting in bytes for a pointer to `u8` is legitimate and must not
trigger the lint. Also, this prevents linting the
`{std,core}::ptr::write_bytes` as it manipulates bytes.
Fix#6590
changelog: [`size_of_in_element_count`]: do not lint if the pointee type
is `u8`
fixes#12670
Continuation of #12688. r? @Jarcho if you don't mind?
changelog: [`manual_unwrap_or_default`] fix wrong suggestions when
condition type is uncertain
#[contracts::requires(...)] + #[contracts::ensures(...)]
cc https://github.com/rust-lang/rust/issues/128044
Updated contract support: attribute syntax for preconditions and postconditions, implemented via a series of desugarings that culminates in:
1. a compile-time flag (`-Z contract-checks`) that, similar to `-Z ub-checks`, attempts to ensure that the decision of enabling/disabling contract checks is delayed until the end user program is compiled,
2. invocations of lang-items that handle invoking the precondition, building a checker for the post-condition, and invoking that post-condition checker at the return sites for the function, and
3. intrinsics for the actual evaluation of pre- and post-condition predicates that third-party verification tools can intercept and reinterpret for their own purposes (e.g. creating shims of behavior that abstract away the function body and replace it solely with the pre- and post-conditions).
Known issues:
* My original intent, as described in the MCP (https://github.com/rust-lang/compiler-team/issues/759) was to have a rustc-prefixed attribute namespace (like rustc_contracts::requires). But I could not get things working when I tried to do rewriting via a rustc-prefixed builtin attribute-macro. So for now it is called `contracts::requires`.
* Our attribute macro machinery does not provide direct support for attribute arguments that are parsed like rust expressions. I spent some time trying to add that (e.g. something that would parse the attribute arguments as an AST while treating the remainder of the items as a token-tree), but its too big a lift for me to undertake. So instead I hacked in something approximating that goal, by semi-trivially desugaring the token-tree attribute contents into internal AST constucts. This may be too fragile for the long-term.
* (In particular, it *definitely* breaks when you try to add a contract to a function like this: `fn foo1(x: i32) -> S<{ 23 }> { ... }`, because its token-tree based search for where to inject the internal AST constructs cannot immediately see that the `{ 23 }` is within a generics list. I think we can live for this for the short-term, i.e. land the work, and continue working on it while in parallel adding a new attribute variant that takes a token-tree attribute alongside an AST annotation, which would completely resolve the issue here.)
* the *intent* of `-Z contract-checks` is that it behaves like `-Z ub-checks`, in that we do not prematurely commit to including or excluding the contract evaluation in upstream crates (most notably, `core` and `std`). But the current test suite does not actually *check* that this is the case. Ideally the test suite would be extended with a multi-crate test that explores the matrix of enabling/disabling contracts on both the upstream lib and final ("leaf") bin crates.
- `reindent_multiline()` always returns the result of
`reindent_multiline_inner()` which returns a `String`. Make
`reindent_multiline()` return a `String` as well, instead of a
systematically owned `Cow<'_, str>`.
- There is no reason for `reindent_multiline()` to force a caller to
build a `Cow<'_, str>` instead of passing a `&str` directly,
especially considering that a `String` will always be returned.
Also, both the input parameter and return value (of type `Cow<'_, str>`)
shared the same (elided) lifetime for no reason: this worked only because
the result was always the `Cow::Owned` variant which is compatible with
any lifetime.
As a consequence, the signature changes from:
```rust
fn reindent_multiline(s: Cow<'_, str>, …) -> Cow<'_, str> { … }
```
to
```rust
fn reindent_multiline(s: &str, …) -> String { … }
```
Hey folks. It's been a while since I added the `as_slice` method to
`Option`, and I totally forgot about a lint to suggest it. Well, I had
some time around Christmas, so here it is now.
---
changelog: add [`manual_option_as_slice`] lint
includes post-developed commit: do not suggest internal-only keywords as corrections to parse failures.
includes post-developed commit: removed tabs that creeped in into rustfmt tool source code.
includes post-developed commit, placating rustfmt self dogfooding.
includes post-developed commit: add backquotes to prevent markdown checking from trying to treat an attr as a markdown hyperlink/
includes post-developed commit: fix lowering to keep contracts from being erroneously inherited by nested bodies (like closures).
Rebase Conflicts:
- compiler/rustc_parse/src/parser/diagnostics.rs
- compiler/rustc_parse/src/parser/item.rs
- compiler/rustc_span/src/hygiene.rs
Remove contracts keywords from diagnostic messages
