diff --git a/clippy.toml b/clippy.toml index 8c405ac6a4e..62ed55beb1f 100644 --- a/clippy.toml +++ b/clippy.toml @@ -1,7 +1,10 @@ avoid-breaking-exported-api = false -# use the various `span_lint_*` methods instead, which also add a link to the docs -disallowed-methods = [ - "rustc_lint::context::LintContext::span_lint", - "rustc_middle::ty::context::TyCtxt::node_span_lint" -] +[[disallowed-methods]] +path = "rustc_lint::context::LintContext::span_lint" +reason = "this function does not add a link to our documentation, please use the `clippy_utils::diagnostics::span_lint*` functions instead" + + +[[disallowed-methods]] +path = "rustc_middle::ty::context::TyCtxt::node_span_lint" +reason = "this function does not add a link to our documentation, please use the `clippy_utils::diagnostics::span_lint_hir*` functions instead" diff --git a/clippy_utils/src/diagnostics.rs b/clippy_utils/src/diagnostics.rs index 6ed46e5dde0..0352696f93e 100644 --- a/clippy_utils/src/diagnostics.rs +++ b/clippy_utils/src/diagnostics.rs @@ -36,6 +36,20 @@ fn docs_link(diag: &mut Diag<'_, ()>, lint: &'static Lint) { /// Usually it's nicer to provide more context for lint messages. /// Be sure the output is understandable when you use this method. /// +/// NOTE: Lint emissions are always bound to a node in the HIR, which is used to determine +/// the lint level. +/// For the `span_lint` function, the node that was passed into the `LintPass::check_*` function is +/// used. +/// +/// If you're emitting the lint at the span of a different node than the one provided by the +/// `LintPass::check_*` function, consider using [`span_lint_hir`] instead. +/// This is needed for `#[allow]` and `#[expect]` attributes to work on the node +/// highlighted in the displayed warning. +/// +/// If you're unsure which function you should use, you can test if the `#[allow]` attribute works +/// where you would expect it to. +/// If it doesn't, you likely need to use [`span_lint_hir`] instead. +/// /// # Example /// /// ```ignore @@ -61,6 +75,20 @@ pub fn span_lint(cx: &T, lint: &'static Lint, sp: impl Into( /// /// If you change the signature, remember to update the internal lint `CollapsibleCalls` /// +/// NOTE: Lint emissions are always bound to a node in the HIR, which is used to determine +/// the lint level. +/// For the `span_lint_and_note` function, the node that was passed into the `LintPass::check_*` +/// function is used. +/// +/// If you're emitting the lint at the span of a different node than the one provided by the +/// `LintPass::check_*` function, consider using [`span_lint_hir_and_then`] instead. +/// This is needed for `#[allow]` and `#[expect]` attributes to work on the node +/// highlighted in the displayed warning. +/// +/// If you're unsure which function you should use, you can test if the `#[allow]` attribute works +/// where you would expect it to. +/// If it doesn't, you likely need to use [`span_lint_hir_and_then`] instead. +/// /// # Example /// /// ```text @@ -139,6 +181,20 @@ pub fn span_lint_and_note( /// /// If you need to customize your lint output a lot, use this function. /// If you change the signature, remember to update the internal lint `CollapsibleCalls` +/// +/// NOTE: Lint emissions are always bound to a node in the HIR, which is used to determine +/// the lint level. +/// For the `span_lint_and_then` function, the node that was passed into the `LintPass::check_*` +/// function is used. +/// +/// If you're emitting the lint at the span of a different node than the one provided by the +/// `LintPass::check_*` function, consider using [`span_lint_hir_and_then`] instead. +/// This is needed for `#[allow]` and `#[expect]` attributes to work on the node +/// highlighted in the displayed warning. +/// +/// If you're unsure which function you should use, you can test if the `#[allow]` attribute works +/// where you would expect it to. +/// If it doesn't, you likely need to use [`span_lint_hir_and_then`] instead. pub fn span_lint_and_then(cx: &C, lint: &'static Lint, sp: S, msg: &str, f: F) where C: LintContext, @@ -152,6 +208,30 @@ pub fn span_lint_and_then(cx: &C, lint: &'static Lint, sp: S, msg: &str }); } +/// Like [`span_lint`], but emits the lint at the node identified by the given `HirId`. +/// +/// This is in contrast to [`span_lint`], which always emits the lint at the node that was last +/// passed to the `LintPass::check_*` function. +/// +/// The `HirId` is used for checking lint level attributes and to fulfill lint expectations defined +/// via the `#[expect]` attribute. +/// +/// For example: +/// ```ignore +/// fn f() { /* */ +/// +/// #[allow(clippy::some_lint)] +/// let _x = /* */; +/// } +/// ``` +/// If `some_lint` does its analysis in `LintPass::check_fn` (at ``) and emits a lint at +/// `` using [`span_lint`], then allowing the lint at `` as attempted in the snippet +/// will not work! +/// Even though that is where the warning points at, which would be confusing to users. +/// +/// Instead, use this function and also pass the `HirId` of ``, which will let +/// the compiler check lint level attributes at the place of the expression and +/// the `#[allow]` will work. pub fn span_lint_hir(cx: &LateContext<'_>, lint: &'static Lint, hir_id: HirId, sp: Span, msg: &str) { #[expect(clippy::disallowed_methods)] cx.tcx.node_span_lint(lint, hir_id, sp, msg.to_string(), |diag| { @@ -159,6 +239,30 @@ pub fn span_lint_hir(cx: &LateContext<'_>, lint: &'static Lint, hir_id: HirId, s }); } +/// Like [`span_lint_and_then`], but emits the lint at the node identified by the given `HirId`. +/// +/// This is in contrast to [`span_lint_and_then`], which always emits the lint at the node that was +/// last passed to the `LintPass::check_*` function. +/// +/// The `HirId` is used for checking lint level attributes and to fulfill lint expectations defined +/// via the `#[expect]` attribute. +/// +/// For example: +/// ```ignore +/// fn f() { /* */ +/// +/// #[allow(clippy::some_lint)] +/// let _x = /* */; +/// } +/// ``` +/// If `some_lint` does its analysis in `LintPass::check_fn` (at ``) and emits a lint at +/// `` using [`span_lint`], then allowing the lint at `` as attempted in the snippet +/// will not work! +/// Even though that is where the warning points at, which would be confusing to users. +/// +/// Instead, use this function and also pass the `HirId` of ``, which will let +/// the compiler check lint level attributes at the place of the expression and +/// the `#[allow]` will work. pub fn span_lint_hir_and_then( cx: &LateContext<'_>, lint: &'static Lint, @@ -182,6 +286,20 @@ pub fn span_lint_hir_and_then( /// /// If you change the signature, remember to update the internal lint `CollapsibleCalls` /// +/// NOTE: Lint emissions are always bound to a node in the HIR, which is used to determine +/// the lint level. +/// For the `span_lint_and_sugg` function, the node that was passed into the `LintPass::check_*` +/// function is used. +/// +/// If you're emitting the lint at the span of a different node than the one provided by the +/// `LintPass::check_*` function, consider using [`span_lint_hir_and_then`] instead. +/// This is needed for `#[allow]` and `#[expect]` attributes to work on the node +/// highlighted in the displayed warning. +/// +/// If you're unsure which function you should use, you can test if the `#[allow]` attribute works +/// where you would expect it to. +/// If it doesn't, you likely need to use [`span_lint_hir_and_then`] instead. +/// /// # Example /// /// ```text diff --git a/tests/ui-internal/disallow_span_lint.stderr b/tests/ui-internal/disallow_span_lint.stderr index ae5d6843406..cfc590bed36 100644 --- a/tests/ui-internal/disallow_span_lint.stderr +++ b/tests/ui-internal/disallow_span_lint.stderr @@ -4,6 +4,7 @@ error: use of a disallowed method `rustc_lint::context::LintContext::span_lint` LL | cx.span_lint(lint, span, msg, |_| {}); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | + = note: this function does not add a link to our documentation, please use the `clippy_utils::diagnostics::span_lint*` functions instead (from clippy.toml) = note: `-D clippy::disallowed-methods` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::disallowed_methods)]` @@ -12,6 +13,8 @@ error: use of a disallowed method `rustc_middle::ty::context::TyCtxt::node_span_ | LL | tcx.node_span_lint(lint, hir_id, span, msg, |_| {}); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: this function does not add a link to our documentation, please use the `clippy_utils::diagnostics::span_lint_hir*` functions instead (from clippy.toml) error: aborting due to 2 previous errors