rust/clippy_lints/src/async_yields_async.rs
xFrednet d647696c1f
Added clippy::version attribute to all normal lints
So, some context for this, well, more a story. I'm not used to scripting, I've never really scripted anything, even if it's a valuable skill. I just never really needed it. Now, `@flip1995` correctly suggested using a script for this in `rust-clippy#7813`...

And I decided to write a script using nushell because why not? This was a mistake... I spend way more time on this than I would like to admit. It has definitely been more than 4 hours. It shouldn't take that long, but me being new to scripting and nushell just wasn't a good mixture... Anyway, here is the script that creates another script which adds the versions. Fun...

Just execute this on the `gh-pages` branch and the resulting `replacer.sh` in `clippy_lints` and it should all work.

```nu
mv v0.0.212 rust-1.00.0;
mv beta rust-1.57.0;
mv master rust-1.58.0;

let paths = (open ./rust-1.58.0/lints.json | select id id_span | flatten | select id path);
let versions = (
    ls | where name =~ "rust-" | select name | format {name}/lints.json |
    each { open $it | select id | insert version $it | str substring "5,11" version} |
    group-by id | rotate counter-clockwise id version |
    update version {get version | first 1} | flatten | select id version);
$paths | each { |row|
    let version = ($versions | where id == ($row.id) | format {version})
    let idu = ($row.id | str upcase)
    $"sed -i '0,/($idu),/{s/pub ($idu),/#[clippy::version = "($version)"]\n    pub ($idu),/}' ($row.path)"
} | str collect ";" | str find-replace --all '1.00.0' 'pre 1.29.0' | save "replacer.sh";
```

And this still has some problems, but at this point I just want to be done -.-
2021-11-10 19:48:31 +01:00

88 lines
3.2 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::source::snippet;
use clippy_utils::ty::implements_trait;
use rustc_errors::Applicability;
use rustc_hir::{AsyncGeneratorKind, Body, BodyId, ExprKind, GeneratorKind, QPath};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
/// ### What it does
/// Checks for async blocks that yield values of types
/// that can themselves be awaited.
///
/// ### Why is this bad?
/// An await is likely missing.
///
/// ### Example
/// ```rust
/// async fn foo() {}
///
/// fn bar() {
/// let x = async {
/// foo()
/// };
/// }
/// ```
/// Use instead:
/// ```rust
/// async fn foo() {}
///
/// fn bar() {
/// let x = async {
/// foo().await
/// };
/// }
/// ```
#[clippy::version = "1.48.0"]
pub ASYNC_YIELDS_ASYNC,
correctness,
"async blocks that return a type that can be awaited"
}
declare_lint_pass!(AsyncYieldsAsync => [ASYNC_YIELDS_ASYNC]);
impl<'tcx> LateLintPass<'tcx> for AsyncYieldsAsync {
fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
use AsyncGeneratorKind::{Block, Closure};
// For functions, with explicitly defined types, don't warn.
// XXXkhuey maybe we should?
if let Some(GeneratorKind::Async(Block | Closure)) = body.generator_kind {
if let Some(future_trait_def_id) = cx.tcx.lang_items().future_trait() {
let body_id = BodyId {
hir_id: body.value.hir_id,
};
let typeck_results = cx.tcx.typeck_body(body_id);
let expr_ty = typeck_results.expr_ty(&body.value);
if implements_trait(cx, expr_ty, future_trait_def_id, &[]) {
let return_expr_span = match &body.value.kind {
// XXXkhuey there has to be a better way.
ExprKind::Block(block, _) => block.expr.map(|e| e.span),
ExprKind::Path(QPath::Resolved(_, path)) => Some(path.span),
_ => None,
};
if let Some(return_expr_span) = return_expr_span {
span_lint_and_then(
cx,
ASYNC_YIELDS_ASYNC,
return_expr_span,
"an async construct yields a type which is itself awaitable",
|db| {
db.span_label(body.value.span, "outer async construct");
db.span_label(return_expr_span, "awaitable value not awaited");
db.span_suggestion(
return_expr_span,
"consider awaiting this value",
format!("{}.await", snippet(cx, return_expr_span, "..")),
Applicability::MaybeIncorrect,
);
},
);
}
}
}
}
}
}