Rollup merge of #108335 - compiler-errors:non_lifetime_binders-rustdo…

…c, r=GuillaumeGomez

rustdoc + rustdoc-json support for `feature(non_lifetime_binders)`

Makes `for<T> T: Trait` and `for<const N: usize> ..` in where clause operate correctly.

Fixes #108158

src/librustdoc/clean/mod.rs

@@ -31,7 +31,6 @@ use rustc_span::hygiene::{AstPass, MacroKind};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{self, ExpnKind};
 
-use std::assert_matches::assert_matches;
 use std::borrow::Cow;
 use std::collections::hash_map::Entry;
 use std::collections::BTreeMap;
@@ -270,15 +269,7 @@ fn clean_where_predicate<'tcx>(
             let bound_params = wbp
                 .bound_generic_params
                 .iter()
-                .map(|param| {
-                    // Higher-ranked params must be lifetimes.
-                    // Higher-ranked lifetimes can't have bounds.
-                    assert_matches!(
-                        param,
-                        hir::GenericParam { kind: hir::GenericParamKind::Lifetime { .. }, .. }
-                    );
-                    Lifetime(param.name.ident().name)
-                })
+                .map(|param| clean_generic_param(cx, None, param))
                 .collect();
             WherePredicate::BoundPredicate {
                 ty: clean_ty(wbp.bounded_ty, cx),
@@ -410,7 +401,7 @@ fn clean_projection_predicate<'tcx>(
         .collect_referenced_late_bound_regions(&pred)
         .into_iter()
         .filter_map(|br| match br {
-            ty::BrNamed(_, name) if br.is_named() => Some(Lifetime(name)),
+            ty::BrNamed(_, name) if br.is_named() => Some(GenericParamDef::lifetime(name)),
             _ => None,
         })
         .collect();
@@ -508,7 +499,6 @@ fn clean_generic_param_def<'tcx>(
         ty::GenericParamDefKind::Const { has_default } => (
             def.name,
             GenericParamDefKind::Const {
-                did: def.def_id,
                 ty: Box::new(clean_middle_ty(
                     ty::Binder::dummy(
                         cx.tcx
@@ -578,7 +568,6 @@ fn clean_generic_param<'tcx>(
         hir::GenericParamKind::Const { ty, default } => (
             param.name.ident().name,
             GenericParamDefKind::Const {
-                did: param.def_id.to_def_id(),
                 ty: Box::new(clean_ty(ty, cx)),
                 default: default
                     .map(|ct| Box::new(ty::Const::from_anon_const(cx.tcx, ct.def_id).to_string())),
@@ -831,7 +820,7 @@ fn clean_ty_generics<'tcx>(
                         p.get_bound_params()
                             .into_iter()
                             .flatten()
-                            .map(|param| GenericParamDef::lifetime(param.0))
+                            .cloned()
                             .collect(),
                     ));
                 }

src/librustdoc/clean/simplify.rs

@@ -49,11 +49,7 @@ pub(crate) fn where_clauses(cx: &DocContext<'_>, clauses: Vec<WP>) -> ThinVec<WP
     equalities.retain(|(lhs, rhs, bound_params)| {
         let Some((ty, trait_did, name)) = lhs.projection() else { return true; };
         let Some((bounds, _)) = tybounds.get_mut(ty) else { return true };
-        let bound_params = bound_params
-            .into_iter()
-            .map(|param| clean::GenericParamDef::lifetime(param.0))
-            .collect();
-        merge_bounds(cx, bounds, bound_params, trait_did, name, rhs)
+        merge_bounds(cx, bounds, bound_params.clone(), trait_did, name, rhs)
     });
 
     // And finally, let's reassemble everything

src/librustdoc/clean/types.rs

@@ -1236,9 +1236,9 @@ impl Lifetime {
 
 #[derive(Clone, Debug)]
 pub(crate) enum WherePredicate {
-    BoundPredicate { ty: Type, bounds: Vec<GenericBound>, bound_params: Vec<Lifetime> },
+    BoundPredicate { ty: Type, bounds: Vec<GenericBound>, bound_params: Vec<GenericParamDef> },
     RegionPredicate { lifetime: Lifetime, bounds: Vec<GenericBound> },
-    EqPredicate { lhs: Box<Type>, rhs: Box<Term>, bound_params: Vec<Lifetime> },
+    EqPredicate { lhs: Box<Type>, rhs: Box<Term>, bound_params: Vec<GenericParamDef> },
 }
 
 impl WherePredicate {
@@ -1250,7 +1250,7 @@ impl WherePredicate {
         }
     }
 
-    pub(crate) fn get_bound_params(&self) -> Option<&[Lifetime]> {
+    pub(crate) fn get_bound_params(&self) -> Option<&[GenericParamDef]> {
         match self {
             Self::BoundPredicate { bound_params, .. } | Self::EqPredicate { bound_params, .. } => {
                 Some(bound_params)
@@ -1264,7 +1264,7 @@ impl WherePredicate {
 pub(crate) enum GenericParamDefKind {
     Lifetime { outlives: Vec<Lifetime> },
     Type { did: DefId, bounds: Vec<GenericBound>, default: Option<Box<Type>>, synthetic: bool },
-    Const { did: DefId, ty: Box<Type>, default: Option<Box<String>> },
+    Const { ty: Box<Type>, default: Option<Box<String>> },
 }
 
 impl GenericParamDefKind {

src/librustdoc/html/format.rs

@@ -307,13 +307,13 @@ pub(crate) fn print_where_clause<'a, 'tcx: 'a>(
                                 write!(
                                     f,
                                     "for<{:#}> {ty_cx:#}: {generic_bounds:#}",
-                                    comma_sep(bound_params.iter().map(|lt| lt.print()), true)
+                                    comma_sep(bound_params.iter().map(|lt| lt.print(cx)), true)
                                 )
                             } else {
                                 write!(
                                     f,
                                     "for&lt;{}&gt; {ty_cx}: {generic_bounds}",
-                                    comma_sep(bound_params.iter().map(|lt| lt.print()), true)
+                                    comma_sep(bound_params.iter().map(|lt| lt.print(cx)), true)
                                 )
                             }
                         }

src/librustdoc/json/conversions.rs

@@ -456,7 +456,7 @@ impl FromWithTcx<clean::GenericParamDefKind> for GenericParamDefKind {
                 default: default.map(|x| (*x).into_tcx(tcx)),
                 synthetic,
             },
-            Const { did: _, ty, default } => GenericParamDefKind::Const {
+            Const { ty, default } => GenericParamDefKind::Const {
                 type_: (*ty).into_tcx(tcx),
                 default: default.map(|x| *x),
             },
@@ -473,9 +473,35 @@ impl FromWithTcx<clean::WherePredicate> for WherePredicate {
                 bounds: bounds.into_tcx(tcx),
                 generic_params: bound_params
                     .into_iter()
-                    .map(|x| GenericParamDef {
-                        name: x.0.to_string(),
-                        kind: GenericParamDefKind::Lifetime { outlives: vec![] },
+                    .map(|x| {
+                        let name = x.name.to_string();
+                        let kind = match x.kind {
+                            clean::GenericParamDefKind::Lifetime { outlives } => {
+                                GenericParamDefKind::Lifetime {
+                                    outlives: outlives.iter().map(|lt| lt.0.to_string()).collect(),
+                                }
+                            }
+                            clean::GenericParamDefKind::Type {
+                                did: _,
+                                bounds,
+                                default,
+                                synthetic,
+                            } => GenericParamDefKind::Type {
+                                bounds: bounds
+                                    .into_iter()
+                                    .map(|bound| bound.into_tcx(tcx))
+                                    .collect(),
+                                default: default.map(|ty| (*ty).into_tcx(tcx)),
+                                synthetic,
+                            },
+                            clean::GenericParamDefKind::Const { ty, default } => {
+                                GenericParamDefKind::Const {
+                                    type_: (*ty).into_tcx(tcx),
+                                    default: default.map(|d| *d),
+                                }
+                            }
+                        };
+                        GenericParamDef { name, kind }
                     })
                     .collect(),
             },

tests/rustdoc-json/non_lifetime_binders.rs

@@ -0,0 +1,24 @@
+// ignore-tidy-linelength
+
+#![feature(non_lifetime_binders)]
+#![allow(incomplete_features)]
+
+#![no_core]
+#![feature(lang_items, no_core)]
+
+#[lang = "sized"]
+pub trait Sized {}
+
+pub trait Trait {}
+
+#[lang = "phantom_data"]
+struct PhantomData<T_>;
+
+pub struct Wrapper<T_>(PhantomData<T_>);
+
+// @count "$.index[*][?(@.name=='foo')].inner.generics.where_predicates[0].bound_predicate.generic_params[*]" 2
+// @is "$.index[*][?(@.name=='foo')].inner.generics.where_predicates[0].bound_predicate.generic_params[0].name" \"\'a\"
+// @is "$.index[*][?(@.name=='foo')].inner.generics.where_predicates[0].bound_predicate.generic_params[0].kind" '{ "lifetime": { "outlives": [] } }'
+// @is "$.index[*][?(@.name=='foo')].inner.generics.where_predicates[0].bound_predicate.generic_params[1].name" \"T\"
+// @is "$.index[*][?(@.name=='foo')].inner.generics.where_predicates[0].bound_predicate.generic_params[1].kind" '{ "type": { "bounds": [], "default": null, "synthetic": false } }'
+pub fn foo() where for<'a, T> &'a Wrapper<T>: Trait {}

tests/rustdoc/non_lifetime_binders.rs

@@ -0,0 +1,9 @@
+#![feature(non_lifetime_binders)]
+#![allow(incomplete_features)]
+
+pub trait Trait {}
+
+pub struct Wrapper<T: ?Sized>(Box<T>);
+
+// @has non_lifetime_binders/fn.foo.html '//pre' "fn foo()where for<'a, T> &'a Wrapper<T>: Trait"
+pub fn foo() where for<'a, T> &'a Wrapper<T>: Trait {}