diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_lint/messages.ftl | 4 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/async_closures.rs | 129 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/impl_trait_overcaptures.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/lib.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_lint/src/multiple_supertrait_upcastable.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_lint_defs/src/builtin.rs | 13 | ||||
| -rw-r--r-- | compiler/rustc_lint_defs/src/lib.rs | 12 |
7 files changed, 152 insertions, 18 deletions
diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl index f048f6fe8ad..4f2d59b4c66 100644 --- a/compiler/rustc_lint/messages.ftl +++ b/compiler/rustc_lint/messages.ftl @@ -185,6 +185,10 @@ lint_cfg_attr_no_attributes = lint_check_name_unknown_tool = unknown lint tool: `{$tool_name}` +lint_closure_returning_async_block = closure returning async block can be made into an async closure + .label = this async block can be removed, and the closure can be turned into an async closure + .suggestion = turn this into an async closure + lint_command_line_source = `forbid` lint level was set on command line lint_confusable_identifier_pair = found both `{$existing_sym}` and `{$sym}` as identifiers, which look alike diff --git a/compiler/rustc_lint/src/async_closures.rs b/compiler/rustc_lint/src/async_closures.rs new file mode 100644 index 00000000000..33cc5738262 --- /dev/null +++ b/compiler/rustc_lint/src/async_closures.rs @@ -0,0 +1,129 @@ +use rustc_hir as hir; +use rustc_macros::{LintDiagnostic, Subdiagnostic}; +use rustc_session::{declare_lint, declare_lint_pass}; +use rustc_span::Span; + +use crate::{LateContext, LateLintPass}; + +declare_lint! { + /// The `closure_returning_async_block` lint detects cases where users + /// write a closure that returns an async block. + /// + /// ### Example + /// + /// ```rust + /// #![warn(closure_returning_async_block)] + /// let c = |x: &str| async {}; + /// ``` + /// + /// {{produces}} + /// + /// ### Explanation + /// + /// Using an async closure is preferable over a closure that returns an + /// async block, since async closures are less restrictive in how its + /// captures are allowed to be used. + /// + /// For example, this code does not work with a closure returning an async + /// block: + /// + /// ```rust,compile_fail + /// async fn callback(x: &str) {} + /// + /// let captured_str = String::new(); + /// let c = move || async { + /// callback(&captured_str).await; + /// }; + /// ``` + /// + /// But it does work with async closures: + /// + /// ```rust + /// #![feature(async_closure)] + /// + /// async fn callback(x: &str) {} + /// + /// let captured_str = String::new(); + /// let c = async move || { + /// callback(&captured_str).await; + /// }; + /// ``` + pub CLOSURE_RETURNING_ASYNC_BLOCK, + Allow, + "closure that returns `async {}` could be rewritten as an async closure", + @feature_gate = async_closure; +} + +declare_lint_pass!( + /// Lint for potential usages of async closures and async fn trait bounds. + AsyncClosureUsage => [CLOSURE_RETURNING_ASYNC_BLOCK] +); + +impl<'tcx> LateLintPass<'tcx> for AsyncClosureUsage { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>) { + let hir::ExprKind::Closure(&hir::Closure { + body, + kind: hir::ClosureKind::Closure, + fn_decl_span, + .. + }) = expr.kind + else { + return; + }; + + let mut body = cx.tcx.hir().body(body).value; + + // Only peel blocks that have no expressions. + while let hir::ExprKind::Block(&hir::Block { stmts: [], expr: Some(tail), .. }, None) = + body.kind + { + body = tail; + } + + let hir::ExprKind::Closure(&hir::Closure { + kind: + hir::ClosureKind::Coroutine(hir::CoroutineKind::Desugared( + hir::CoroutineDesugaring::Async, + hir::CoroutineSource::Block, + )), + fn_decl_span: async_decl_span, + .. + }) = body.kind + else { + return; + }; + + let deletion_span = cx.tcx.sess.source_map().span_extend_while_whitespace(async_decl_span); + + cx.tcx.emit_node_span_lint( + CLOSURE_RETURNING_ASYNC_BLOCK, + expr.hir_id, + fn_decl_span, + ClosureReturningAsyncBlock { + async_decl_span, + sugg: AsyncClosureSugg { + deletion_span, + insertion_span: fn_decl_span.shrink_to_lo(), + }, + }, + ); + } +} + +#[derive(LintDiagnostic)] +#[diag(lint_closure_returning_async_block)] +struct ClosureReturningAsyncBlock { + #[label] + async_decl_span: Span, + #[subdiagnostic] + sugg: AsyncClosureSugg, +} + +#[derive(Subdiagnostic)] +#[multipart_suggestion(lint_suggestion, applicability = "maybe-incorrect")] +struct AsyncClosureSugg { + #[suggestion_part(code = "")] + deletion_span: Span, + #[suggestion_part(code = "async ")] + insertion_span: Span, +} diff --git a/compiler/rustc_lint/src/impl_trait_overcaptures.rs b/compiler/rustc_lint/src/impl_trait_overcaptures.rs index d4f6d388d9f..0860413190c 100644 --- a/compiler/rustc_lint/src/impl_trait_overcaptures.rs +++ b/compiler/rustc_lint/src/impl_trait_overcaptures.rs @@ -11,7 +11,7 @@ use rustc_middle::ty::{ self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, }; use rustc_session::{declare_lint, declare_lint_pass}; -use rustc_span::{sym, Span}; +use rustc_span::Span; use crate::fluent_generated as fluent; use crate::{LateContext, LateLintPass}; @@ -57,7 +57,7 @@ declare_lint! { pub IMPL_TRAIT_OVERCAPTURES, Allow, "`impl Trait` will capture more lifetimes than possibly intended in edition 2024", - @feature_gate = sym::precise_capturing; + @feature_gate = precise_capturing; //@future_incompatible = FutureIncompatibleInfo { // reason: FutureIncompatibilityReason::EditionSemanticsChange(Edition::Edition2024), // reference: "<FIXME>", @@ -91,7 +91,7 @@ declare_lint! { pub IMPL_TRAIT_REDUNDANT_CAPTURES, Warn, "redundant precise-capturing `use<...>` syntax on an `impl Trait`", - @feature_gate = sym::precise_capturing; + @feature_gate = precise_capturing; } declare_lint_pass!( diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs index 868a44a980a..b6927cf60b6 100644 --- a/compiler/rustc_lint/src/lib.rs +++ b/compiler/rustc_lint/src/lib.rs @@ -41,6 +41,7 @@ #![feature(trait_upcasting)] // tidy-alphabetical-end +mod async_closures; mod async_fn_in_trait; pub mod builtin; mod context; @@ -87,6 +88,7 @@ use rustc_hir::def_id::LocalModDefId; use rustc_middle::query::Providers; use rustc_middle::ty::TyCtxt; +use async_closures::AsyncClosureUsage; use async_fn_in_trait::AsyncFnInTrait; use builtin::*; use deref_into_dyn_supertrait::*; @@ -229,6 +231,7 @@ late_lint_methods!( MapUnitFn: MapUnitFn, MissingDebugImplementations: MissingDebugImplementations, MissingDoc: MissingDoc, + AsyncClosureUsage: AsyncClosureUsage, AsyncFnInTrait: AsyncFnInTrait, NonLocalDefinitions: NonLocalDefinitions::default(), ImplTraitOvercaptures: ImplTraitOvercaptures, diff --git a/compiler/rustc_lint/src/multiple_supertrait_upcastable.rs b/compiler/rustc_lint/src/multiple_supertrait_upcastable.rs index 445dcd41e5d..93dd5e764c6 100644 --- a/compiler/rustc_lint/src/multiple_supertrait_upcastable.rs +++ b/compiler/rustc_lint/src/multiple_supertrait_upcastable.rs @@ -2,7 +2,6 @@ use crate::{LateContext, LateLintPass, LintContext}; use rustc_hir as hir; use rustc_session::{declare_lint, declare_lint_pass}; -use rustc_span::sym; declare_lint! { /// The `multiple_supertrait_upcastable` lint detects when an object-safe trait has multiple @@ -30,7 +29,7 @@ declare_lint! { pub MULTIPLE_SUPERTRAIT_UPCASTABLE, Allow, "detect when an object-safe trait has multiple supertraits", - @feature_gate = sym::multiple_supertrait_upcastable; + @feature_gate = multiple_supertrait_upcastable; } declare_lint_pass!(MultipleSupertraitUpcastable => [MULTIPLE_SUPERTRAIT_UPCASTABLE]); diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 48e20a586c6..aa7844f4012 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -9,7 +9,6 @@ use crate::{declare_lint, declare_lint_pass, FutureIncompatibilityReason}; use rustc_span::edition::Edition; -use rustc_span::symbol::sym; declare_lint_pass! { /// Does nothing as a lint pass, but registers some `Lint`s @@ -463,7 +462,7 @@ declare_lint! { pub MUST_NOT_SUSPEND, Allow, "use of a `#[must_not_suspend]` value across a yield point", - @feature_gate = rustc_span::symbol::sym::must_not_suspend; + @feature_gate = must_not_suspend; } declare_lint! { @@ -1647,7 +1646,7 @@ declare_lint! { pub RUST_2024_INCOMPATIBLE_PAT, Allow, "detects patterns whose meaning will change in Rust 2024", - @feature_gate = sym::ref_pat_eat_one_layer_2024; + @feature_gate = ref_pat_eat_one_layer_2024; // FIXME uncomment below upon stabilization /*@future_incompatible = FutureIncompatibleInfo { reason: FutureIncompatibilityReason::EditionSemanticsChange(Edition::Edition2024), @@ -2695,7 +2694,7 @@ declare_lint! { pub FUZZY_PROVENANCE_CASTS, Allow, "a fuzzy integer to pointer cast is used", - @feature_gate = sym::strict_provenance; + @feature_gate = strict_provenance; } declare_lint! { @@ -2741,7 +2740,7 @@ declare_lint! { pub LOSSY_PROVENANCE_CASTS, Allow, "a lossy pointer to integer cast is used", - @feature_gate = sym::strict_provenance; + @feature_gate = strict_provenance; } declare_lint! { @@ -3925,7 +3924,7 @@ declare_lint! { pub NON_EXHAUSTIVE_OMITTED_PATTERNS, Allow, "detect when patterns of types marked `non_exhaustive` are missed", - @feature_gate = sym::non_exhaustive_omitted_patterns_lint; + @feature_gate = non_exhaustive_omitted_patterns_lint; } declare_lint! { @@ -4045,7 +4044,7 @@ declare_lint! { pub TEST_UNSTABLE_LINT, Deny, "this unstable lint is only for testing", - @feature_gate = sym::test_unstable_lint; + @feature_gate = test_unstable_lint; } declare_lint! { diff --git a/compiler/rustc_lint_defs/src/lib.rs b/compiler/rustc_lint_defs/src/lib.rs index b44eb252167..f87f19e1700 100644 --- a/compiler/rustc_lint_defs/src/lib.rs +++ b/compiler/rustc_lint_defs/src/lib.rs @@ -865,7 +865,7 @@ macro_rules! declare_lint { ); ); ($(#[$attr:meta])* $vis: vis $NAME: ident, $Level: ident, $desc: expr, - $(@feature_gate = $gate:expr;)? + $(@feature_gate = $gate:ident;)? $(@future_incompatible = FutureIncompatibleInfo { reason: $reason:expr, $($field:ident : $val:expr),* $(,)* @@ -879,7 +879,7 @@ macro_rules! declare_lint { desc: $desc, is_externally_loaded: false, $($v: true,)* - $(feature_gate: Some($gate),)? + $(feature_gate: Some(rustc_span::symbol::sym::$gate),)? $(future_incompatible: Some($crate::FutureIncompatibleInfo { reason: $reason, $($field: $val,)* @@ -895,21 +895,21 @@ macro_rules! declare_lint { macro_rules! declare_tool_lint { ( $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level: ident, $desc: expr - $(, @feature_gate = $gate:expr;)? + $(, @feature_gate = $gate:ident;)? ) => ( $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false $(, @feature_gate = $gate;)?} ); ( $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr, report_in_external_macro: $rep:expr - $(, @feature_gate = $gate:expr;)? + $(, @feature_gate = $gate:ident;)? ) => ( $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, $rep $(, @feature_gate = $gate;)?} ); ( $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr, $external:expr - $(, @feature_gate = $gate:expr;)? + $(, @feature_gate = $gate:ident;)? ) => ( $(#[$attr])* $vis static $NAME: &$crate::Lint = &$crate::Lint { @@ -920,7 +920,7 @@ macro_rules! declare_tool_lint { report_in_external_macro: $external, future_incompatible: None, is_externally_loaded: true, - $(feature_gate: Some($gate),)? + $(feature_gate: Some(rustc_span::symbol::sym::$gate),)? crate_level_only: false, ..$crate::Lint::default_fields_for_macro() }; |