API: Reduce parameters for AstContext::emit_lint and add docs

marker_adapter/src/context.rs

@@ -2,16 +2,12 @@
 #![allow(clippy::needless_lifetimes)]
 
 use marker_api::{
-    ast::{
-        item::{Body, ItemKind},
-        ty::SemTyKind,
-        BodyId, ExpnId, ExpnInfo, ExprId, FileInfo, FilePos, ItemId, Span, SpanId, SpanPos, SpanSource, SymbolId,
-        TyDefId,
-    },
+    ast::{ty::SemTyKind, ExpnId, ExpnInfo, ExprId, FileInfo, FilePos, SpanId, SpanPos, SpanSource, SymbolId},
     context::DriverCallbacks,
-    diagnostic::{Diagnostic, EmissionNode},
+    diagnostic::Diagnostic,
     ffi::{self, FfiOption},
     lint::{Level, Lint},
+    prelude::*,
 };
 
 /// ### Safety
@@ -59,7 +55,7 @@ impl<'ast> DriverContextWrapper<'ast> {
 
 // False positive because `EmissionNode` are non-exhaustive
 #[allow(improper_ctypes_definitions)]
-extern "C" fn lint_level_at<'ast>(data: &'ast (), lint: &'static Lint, node: EmissionNode) -> Level {
+extern "C" fn lint_level_at<'ast>(data: &'ast (), lint: &'static Lint, node: NodeId) -> Level {
     unsafe { as_driver_cx(data) }.lint_level_at(lint, node)
 }
 
@@ -129,7 +125,7 @@ unsafe fn as_driver_cx<'ast>(data: &'ast ()) -> &'ast dyn DriverContext<'ast> {
 }
 
 pub trait DriverContext<'ast> {
-    fn lint_level_at(&'ast self, lint: &'static Lint, node: EmissionNode) -> Level;
+    fn lint_level_at(&'ast self, lint: &'static Lint, node: NodeId) -> Level;
     fn emit_diag(&'ast self, diag: &Diagnostic<'_, 'ast>);
 
     fn item(&'ast self, api_id: ItemId) -> Option<ItemKind<'ast>>;

marker_api/src/ast/common/id.rs

@@ -39,6 +39,8 @@ macro_rules! new_id {
 
 use new_id;
 
+use crate::private::Sealed;
+
 new_id!(
     /// This ID uniquely identifies a crate during linting.
     pub CrateId: u32
@@ -144,3 +146,63 @@ new_id! {
     /// This ID uniquely identifies a statement during linting.
     pub StmtId: u64
 }
+
+#[repr(C)]
+#[non_exhaustive]
+#[derive(Debug, Clone, Copy)]
+pub enum NodeId {
+    Expr(ExprId),
+    Item(ItemId),
+    Stmt(StmtId),
+    Body(BodyId),
+    Field(FieldId),
+    Variant(VariantId),
+}
+
+macro_rules! impl_into_node_id_for {
+    ($variant:ident, $ty:ty) => {
+        impl From<$ty> for NodeId {
+            fn from(value: $ty) -> Self {
+                NodeId::$variant(value)
+            }
+        }
+
+        impl From<&$ty> for NodeId {
+            fn from(value: &$ty) -> Self {
+                NodeId::$variant(*value)
+            }
+        }
+    };
+}
+
+impl_into_node_id_for!(Expr, ExprId);
+impl_into_node_id_for!(Item, ItemId);
+impl_into_node_id_for!(Stmt, StmtId);
+impl_into_node_id_for!(Body, BodyId);
+impl_into_node_id_for!(Field, FieldId);
+impl_into_node_id_for!(Variant, VariantId);
+
+pub trait HasNodeId: Sealed {
+    /// Returns the [`NodeId`] of the identifiable node
+    fn node_id(&self) -> NodeId;
+}
+
+impl<N: HasNodeId> HasNodeId for &N {
+    fn node_id(&self) -> NodeId {
+        (*self).node_id()
+    }
+}
+
+macro_rules! impl_identifiable_for {
+    ($ty:ty$(, use $data_trait:path)?) => {
+        impl<'ast> $crate::ast::HasNodeId for $ty {
+            fn node_id(&self) -> $crate::ast::NodeId {
+                $(
+                    use $data_trait;
+                )*
+                self.id().into()
+            }
+        }
+    };
+}
+pub(crate) use impl_identifiable_for;

marker_api/src/ast/common/span.rs

@@ -1,6 +1,6 @@
 use std::marker::PhantomData;
 
-use crate::{context::with_cx, diagnostic::Applicability, ffi};
+use crate::{context::with_cx, diagnostic::Applicability, ffi, private::Sealed};
 
 use super::{ExpnId, MacroId, SpanId, SpanSrcId, SymbolId};
 
@@ -386,6 +386,13 @@ impl<'ast> Span<'ast> {
     }
 }
 
+impl<'ast> HasSpan<'ast> for Span<'ast> {
+    fn span(&self) -> &Span<'ast> {
+        self
+    }
+}
+impl Sealed for Span<'_> {}
+
 #[cfg(feature = "driver-api")]
 impl<'ast> Span<'ast> {
     #[must_use]
@@ -509,11 +516,14 @@ impl<'ast> Ident<'ast> {
     pub fn name(&self) -> &str {
         with_cx(self, |cx| cx.symbol_str(self.sym))
     }
+}
 
-    pub fn span(&self) -> &Span<'ast> {
+impl<'ast> HasSpan<'ast> for Ident<'ast> {
+    fn span(&self) -> &Span<'ast> {
         with_cx(self, |cx| cx.span(self.span))
     }
 }
+impl<'ast> crate::private::Sealed for Ident<'ast> {}
 
 #[cfg(feature = "driver-api")]
 impl<'ast> Ident<'ast> {
@@ -570,3 +580,28 @@ impl_ident_eq_for!(
     std::ffi::OsString,
     std::borrow::Cow<'_, str>
 );
+
+/// A trait for nodes, that provide a [`Span`].
+pub trait HasSpan<'ast>: Sealed {
+    /// This returns the [`Span`] of the implementing AST node.
+    fn span(&self) -> &Span<'ast>;
+}
+
+/// This macro implements the [`HasSpan`] trait for data types, that provide a
+/// `span()` method.
+macro_rules! impl_spanned_for {
+    ($ty:ty) => {
+        impl<'ast> $crate::ast::HasSpan<'ast> for $ty {
+            fn span(&self) -> &$crate::ast::Span<'ast> {
+                self.span()
+            }
+        }
+    };
+}
+pub(crate) use impl_spanned_for;
+
+impl<'ast, N: HasSpan<'ast>> HasSpan<'ast> for &N {
+    fn span(&self) -> &Span<'ast> {
+        (*self).span()
+    }
+}

marker_api/src/ast/expr.rs

@@ -1,6 +1,6 @@
-use crate::{private::Sealed, CtorBlocker};
+use crate::{prelude::EmissionNode, private::Sealed, CtorBlocker};
 
-use super::{ty::SemTyKind, ExprId, Span, SpanId};
+use super::{ty::SemTyKind, ExprId, HasNodeId, HasSpan, Span, SpanId};
 
 use std::{fmt::Debug, marker::PhantomData};
 
@@ -27,13 +27,10 @@ pub use unstable_expr::*;
 ///
 /// This trait is only meant to be implemented inside this crate. The `Sealed`
 /// super trait prevents external implementations.
-pub trait ExprData<'ast>: Debug + Sealed {
+pub trait ExprData<'ast>: Debug + EmissionNode<'ast> + HasSpan<'ast> + HasNodeId + Sealed {
     /// Returns the [`ExprId`] of this expression.
     fn id(&self) -> ExprId;
 
-    /// Returns the [`Span`] of this expression.
-    fn span(&self) -> &Span<'ast>;
-
     /// Returns the semantic type of this expression.
     fn ty(&self) -> SemTyKind<'ast>;
 
@@ -93,6 +90,8 @@ impl<'ast> ExprKind<'ast> {
     impl_expr_kind_fn!(ExprKind: precedence() -> ExprPrecedence);
 }
 
+crate::ast::impl_spanned_for!(ExprKind<'ast>);
+crate::ast::impl_identifiable_for!(ExprKind<'ast>);
 impl Sealed for ExprKind<'_> {}
 
 #[repr(C)]
@@ -117,6 +116,10 @@ impl<'ast> LitExprKind<'ast> {
     impl_expr_kind_fn!(LitExprKind: precedence() -> ExprPrecedence);
 }
 
+crate::ast::impl_spanned_for!(LitExprKind<'ast>);
+crate::ast::impl_identifiable_for!(LitExprKind<'ast>);
+impl Sealed for LitExprKind<'_> {}
+
 impl<'ast> From<LitExprKind<'ast>> for ExprKind<'ast> {
     fn from(value: LitExprKind<'ast>) -> Self {
         match value {
@@ -313,10 +316,6 @@ macro_rules! impl_expr_data {
                 self.data.id
             }
 
-            fn span(&self) -> &crate::ast::Span<'ast> {
-                $crate::context::with_cx(self, |cx| cx.span(self.data.span))
-            }
-
             fn ty(&self) -> $crate::ast::ty::SemTyKind<'ast> {
                 $crate::context::with_cx(self, |cx| cx.expr_ty(self.data.id))
             }
@@ -328,6 +327,13 @@ macro_rules! impl_expr_data {
             }
         }
 
+        impl<'ast> $crate::ast::HasSpan<'ast> for $self_ty {
+            fn span(&self) -> &crate::ast::Span<'ast> {
+                $crate::context::with_cx(self, |cx| cx.span(self.data.span))
+            }
+        }
+        $crate::ast::impl_identifiable_for!($self_ty, use $crate::ast::expr::ExprData);
+
         impl<'ast> $crate::private::Sealed for $self_ty {}
 
         impl<'ast> From<&'ast $self_ty> for $crate::ast::expr::ExprKind<'ast> {

marker_api/src/ast/expr/lit_expr.rs

@@ -62,7 +62,7 @@ impl<'ast> CharLitExpr<'ast> {
 /// can be hardware-dependent. For exact value checks, it might be better to check
 /// the written float literal by getting the code snipped from the expression span.
 /// See:
-/// * [`ExprData::span()`](`super::ExprData::span`)
+/// * [`HasSpan::span()`](`super::HasSpan::span`)
 /// * [`Span::snippet()`](`crate::ast::Span::snippet`)
 ///
 /// All integer literals are unsigned, negative numbers have a unary negation

marker_api/src/ast/item.rs

@@ -1,10 +1,11 @@
 use std::{fmt::Debug, marker::PhantomData};
 
+use crate::diagnostic::EmissionNode;
 use crate::private::Sealed;
 use crate::CtorBlocker;
 
 use super::expr::ExprKind;
-use super::{Ident, ItemId, Span, SpanId};
+use super::{HasNodeId, HasSpan, Ident, ItemId, Span, SpanId};
 
 // Item implementations
 mod extern_crate_item;
@@ -36,15 +37,11 @@ pub use unstable_item::*;
 ///
 /// This trait is only meant to be implemented inside this crate. The `Sealed`
 /// super trait prevents external implementations.
-pub trait ItemData<'ast>: Debug + Sealed {
+pub trait ItemData<'ast>: Debug + EmissionNode<'ast> + HasSpan<'ast> + HasNodeId + Sealed {
     /// Returns the [`ItemId`] of this item. This is a unique identifier used for comparison
     /// and to request items from the [`AstContext`](`crate::context::AstContext`).
     fn id(&self) -> ItemId;
 
-    /// The [`Span`] of the entire item. This span should be used for general item related
-    /// diagnostics.
-    fn span(&self) -> &Span<'ast>;
-
     /// The [`Visibility`] of this item.
     fn visibility(&self) -> &Visibility<'ast>;
 
@@ -93,8 +90,12 @@ impl<'ast> ItemKind<'ast> {
     impl_item_type_fn!(ItemKind: attrs() -> ());
 }
 
+crate::ast::impl_spanned_for!(ItemKind<'ast>);
+crate::ast::impl_identifiable_for!(ItemKind<'ast>);
+impl<'ast> crate::private::Sealed for ItemKind<'ast> {}
+
 #[non_exhaustive]
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone)]
 pub enum AssocItemKind<'ast> {
     TyAlias(&'ast TyAliasItem<'ast>, CtorBlocker),
     Const(&'ast ConstItem<'ast>, CtorBlocker),
@@ -111,6 +112,10 @@ impl<'ast> AssocItemKind<'ast> {
     // FIXME: Potentially add a field to the items to optionally store the owner id
 }
 
+crate::ast::impl_spanned_for!(AssocItemKind<'ast>);
+crate::ast::impl_identifiable_for!(AssocItemKind<'ast>);
+impl<'ast> crate::private::Sealed for AssocItemKind<'ast> {}
+
 impl<'ast> From<AssocItemKind<'ast>> for ItemKind<'ast> {
     fn from(value: AssocItemKind<'ast>) -> Self {
         match value {
@@ -122,7 +127,7 @@ impl<'ast> From<AssocItemKind<'ast>> for ItemKind<'ast> {
 }
 
 #[non_exhaustive]
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone)]
 pub enum ExternItemKind<'ast> {
     Static(&'ast StaticItem<'ast>, CtorBlocker),
     Fn(&'ast FnItem<'ast>, CtorBlocker),
@@ -137,6 +142,10 @@ impl<'ast> ExternItemKind<'ast> {
     impl_item_type_fn!(ExternItemKind: as_item() -> ItemKind<'ast>);
 }
 
+crate::ast::impl_spanned_for!(ExternItemKind<'ast>);
+crate::ast::impl_identifiable_for!(ExternItemKind<'ast>);
+impl<'ast> crate::private::Sealed for ExternItemKind<'ast> {}
+
 impl<'ast> From<ExternItemKind<'ast>> for ItemKind<'ast> {
     fn from(value: ExternItemKind<'ast>) -> Self {
         match value {
@@ -193,10 +202,6 @@ macro_rules! impl_item_data {
                 self.data.id
             }
 
-            fn span(&self) -> &crate::ast::Span<'ast> {
-                $crate::context::with_cx(self, |cx| cx.span(self.data.span))
-            }
-
             fn visibility(&self) -> &crate::ast::item::Visibility<'ast> {
                 &self.data.vis
             }
@@ -212,6 +217,13 @@ macro_rules! impl_item_data {
             fn attrs(&self) {}
         }
 
+        impl<'ast> $crate::ast::HasSpan<'ast> for $self_name<'ast> {
+            fn span(&self) -> &crate::ast::Span<'ast> {
+                $crate::context::with_cx(self, |cx| cx.span(self.data.span))
+            }
+        }
+
+        $crate::ast::impl_identifiable_for!($self_name<'ast>, use $crate::ast::item::ItemData);
         impl $crate::private::Sealed for $self_name<'_> {}
 
         impl<'ast> From<&'ast $self_name<'ast>> for crate::ast::item::ItemKind<'ast> {