Rollup merge of rust-lang#105880 - Nilstrieb:make-newtypes-less-not-rust, r=oli-obk

Improve syntax of `newtype_index`

This makes it more like proper Rust and also makes the implementation a lot simpler.

Mostly just turns weird flags in the body into proper attributes.

It should probably also be converted to an attribute macro instead of function-like, but that can be done in a future PR.

Author: matthiaskrgr

compiler/rustc_ast/src/ast.rs

@@ -2554,10 +2554,9 @@ pub enum AttrStyle {
 }
 
 rustc_index::newtype_index! {
-    pub struct AttrId {
-        ENCODABLE = custom
-        DEBUG_FORMAT = "AttrId({})"
-    }
+    #[custom_encodable]
+    #[debug_format = "AttrId({})]"]
+    pub struct AttrId {}
 }
 
 impl<S: Encoder> Encodable<S> for AttrId {

compiler/rustc_ast/src/node_id.rs

@@ -8,9 +8,8 @@ rustc_index::newtype_index! {
     /// This is later turned into [`DefId`] and `HirId` for the HIR.
     ///
     /// [`DefId`]: rustc_span::def_id::DefId
-    pub struct NodeId {
-        DEBUG_FORMAT = "NodeId({})"
-    }
+    #[debug_format = "NodeId({})"]
+    pub struct NodeId {}
 }
 
 rustc_data_structures::define_id_collections!(NodeMap, NodeSet, NodeMapEntry, NodeId);

compiler/rustc_borrowck/src/constraints/mod.rs

@@ -115,13 +115,11 @@ impl<'tcx> fmt::Debug for OutlivesConstraint<'tcx> {
 }
 
 rustc_index::newtype_index! {
-    pub struct OutlivesConstraintIndex {
-        DEBUG_FORMAT = "OutlivesConstraintIndex({})"
-    }
+    #[debug_format = "OutlivesConstraintIndex({})"]
+    pub struct OutlivesConstraintIndex {}
 }
 
 rustc_index::newtype_index! {
-    pub struct ConstraintSccIndex {
-        DEBUG_FORMAT = "ConstraintSccIndex({})"
-    }
+    #[debug_format = "ConstraintSccIndex({})"]
+    pub struct ConstraintSccIndex {}
 }

compiler/rustc_borrowck/src/dataflow.rs

@@ -108,9 +108,8 @@ impl_visitable! {
 }
 
 rustc_index::newtype_index! {
-    pub struct BorrowIndex {
-        DEBUG_FORMAT = "bw{}"
-    }
+    #[debug_format = "bw{}"]
+    pub struct BorrowIndex {}
 }
 
 /// `Borrows` stores the data used in the analyses that track the flow

compiler/rustc_borrowck/src/location.rs

@@ -20,9 +20,8 @@ pub struct LocationTable {
 }
 
 rustc_index::newtype_index! {
-    pub struct LocationIndex {
-        DEBUG_FORMAT = "LocationIndex({})"
-    }
+    #[debug_format = "LocationIndex({})"]
+    pub struct LocationIndex {}
 }
 
 #[derive(Copy, Clone, Debug)]

compiler/rustc_borrowck/src/member_constraints.rs

@@ -55,9 +55,8 @@ pub(crate) struct NllMemberConstraint<'tcx> {
 }
 
 rustc_index::newtype_index! {
-    pub(crate) struct NllMemberConstraintIndex {
-        DEBUG_FORMAT = "MemberConstraintIndex({})"
-    }
+    #[debug_format = "MemberConstraintIndex({})"]
+    pub(crate) struct NllMemberConstraintIndex {}
 }
 
 impl Default for MemberConstraintSet<'_, ty::RegionVid> {

compiler/rustc_borrowck/src/region_infer/values.rs

@@ -90,12 +90,14 @@ impl RegionValueElements {
 rustc_index::newtype_index! {
     /// A single integer representing a `Location` in the MIR control-flow
     /// graph. Constructed efficiently from `RegionValueElements`.
-    pub struct PointIndex { DEBUG_FORMAT = "PointIndex({})" }
+    #[debug_format = "PointIndex({})"]
+    pub struct PointIndex {}
 }
 
 rustc_index::newtype_index! {
     /// A single integer representing a `ty::Placeholder`.
-    pub struct PlaceholderIndex { DEBUG_FORMAT = "PlaceholderIndex({})" }
+    #[debug_format = "PlaceholderIndex({})"]
+    pub struct PlaceholderIndex {}
 }
 
 /// An individual element in a region value -- the value of a

compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs

@@ -46,7 +46,7 @@ struct Appearance {
 }
 
 rustc_index::newtype_index! {
-    pub struct AppearanceIndex { .. }
+    pub struct AppearanceIndex {}
 }
 
 impl vll::LinkElem for Appearance {

compiler/rustc_data_structures/src/graph/dominators/mod.rs

@@ -22,7 +22,7 @@ struct PreOrderFrame<Iter> {
 }
 
 rustc_index::newtype_index! {
-    struct PreorderIndex { .. }
+    struct PreorderIndex {}
 }
 
 pub fn dominators<G: ControlFlowGraph>(graph: G) -> Dominators<G::Node> {

compiler/rustc_hir/src/hir_id.rs

@@ -138,7 +138,7 @@ rustc_index::newtype_index! {
     /// an "item-like" to something else can be implemented by a `Vec` instead of a
     /// tree or hash map.
     #[derive(HashStable_Generic)]
-    pub struct ItemLocalId { .. }
+    pub struct ItemLocalId {}
 }
 
 impl ItemLocalId {

compiler/rustc_hir_analysis/src/coherence/inherent_impls_overlap.rs

@@ -198,10 +198,10 @@ impl<'tcx> InherentOverlapChecker<'tcx> {
             // entire graph when there are many connected regions.
 
             rustc_index::newtype_index! {
-                pub struct RegionId {
-                    ENCODABLE = custom
-                }
+                #[custom_encodable]
+                pub struct RegionId {}
             }
+
             struct ConnectedRegion {
                 idents: SmallVec<[Symbol; 8]>,
                 impl_blocks: FxHashSet<usize>,

compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs

@@ -4,15 +4,13 @@ use rustc_index::vec::IndexVec;
 use rustc_middle::ty::error::TypeError;
 
 rustc_index::newtype_index! {
-    pub(crate) struct ExpectedIdx {
-        DEBUG_FORMAT = "ExpectedIdx({})",
-    }
+    #[debug_format = "ExpectedIdx({})"]
+    pub(crate) struct ExpectedIdx {}
 }
 
 rustc_index::newtype_index! {
-    pub(crate) struct ProvidedIdx {
-        DEBUG_FORMAT = "ProvidedIdx({})",
-    }
+    #[debug_format = "ProvidedIdx({})"]
+    pub(crate) struct ProvidedIdx {}
 }
 
 impl ExpectedIdx {

compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs

@@ -96,15 +96,13 @@ fn for_each_consumable<'tcx>(hir: Map<'tcx>, place: TrackedValue, mut f: impl Fn
 }
 
 rustc_index::newtype_index! {
-    pub struct PostOrderId {
-        DEBUG_FORMAT = "id({})",
-    }
+    #[debug_format = "id({})"]
+    pub struct PostOrderId {}
 }
 
 rustc_index::newtype_index! {
-    pub struct TrackedValueIndex {
-        DEBUG_FORMAT = "hidx({})",
-    }
+    #[debug_format = "hidx({})"]
+    pub struct TrackedValueIndex {}
 }
 
 /// Identifies a value whose drop state we need to track.

compiler/rustc_index/src/vec/tests.rs

@@ -3,7 +3,10 @@
 // Allows the macro invocation below to work
 use crate as rustc_index;
 
-rustc_macros::newtype_index!(struct MyIdx { MAX = 0xFFFF_FFFA });
+rustc_macros::newtype_index! {
+    #[max = 0xFFFF_FFFA]
+    struct MyIdx {}
+}
 
 #[test]
 fn index_size_is_optimized() {

compiler/rustc_infer/src/infer/region_constraints/leak_check.rs

@@ -357,15 +357,13 @@ impl<'tcx> SccUniverse<'tcx> {
 }
 
 rustc_index::newtype_index! {
-    struct LeakCheckNode {
-        DEBUG_FORMAT = "LeakCheckNode({})"
-    }
+    #[debug_format = "LeakCheckNode({})"]
+    struct LeakCheckNode {}
 }
 
 rustc_index::newtype_index! {
-    struct LeakCheckScc {
-        DEBUG_FORMAT = "LeakCheckScc({})"
-    }
+    #[debug_format = "LeakCheckScc({})"]
+    struct LeakCheckScc {}
 }
 
 /// Represents the graph of constraints. For each `R1: R2` constraint we create

compiler/rustc_lint/src/levels.rs

@@ -39,9 +39,9 @@ struct LintLevelSets {
 }
 
 rustc_index::newtype_index! {
+    #[custom_encodable] // we don't need encoding
     struct LintStackIndex {
-        ENCODABLE = custom, // we don't need encoding
-        const COMMAND_LINE = 0,
+        const COMMAND_LINE = 0;
     }
 }