rustdoc support for FRTs

Author: BennoLossin

src/librustdoc/clean/mod.rs

@@ -1834,6 +1834,9 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
         TyKind::UnsafeBinder(unsafe_binder_ty) => {
             UnsafeBinder(Box::new(clean_unsafe_binder_ty(unsafe_binder_ty, cx)))
         }
+        TyKind::FieldOf(container, field_path) => Field(Box::new(clean_ty(container, cx)), {
+            field_path.iter().map(|field| field.as_str()).intersperse(".").collect()
+        }),
         // Rustdoc handles `TyKind::Err`s by turning them into `Type::Infer`s.
         TyKind::Infer(())
         | TyKind::Err(_)
@@ -2077,6 +2080,7 @@ pub(crate) fn clean_middle_ty<'tcx>(
             let path = clean_middle_path(cx, did, false, ThinVec::new(), bound_ty.rebind(args));
             Type::Path { path }
         }
+        ty::Field(..) => todo!("FIXME(field_projections): no idea what to do here"),
         ty::Foreign(did) => {
             inline::record_extern_fqn(cx, did, ItemType::ForeignType);
             let path = clean_middle_path(

src/librustdoc/clean/types.rs

@@ -30,7 +30,7 @@ use {rustc_ast as ast, rustc_hir as hir};
 
 pub(crate) use self::ItemKind::*;
 pub(crate) use self::Type::{
-    Array, BareFunction, BorrowedRef, DynTrait, Generic, ImplTrait, Infer, Primitive, QPath,
+    Array, BareFunction, BorrowedRef, DynTrait, Field, Generic, ImplTrait, Infer, Primitive, QPath,
     RawPointer, SelfTy, Slice, Tuple, UnsafeBinder,
 };
 use crate::clean::cfg::Cfg;
@@ -1568,6 +1568,9 @@ pub(crate) enum Type {
     ImplTrait(Vec<GenericBound>),
 
     UnsafeBinder(Box<UnsafeBinderTy>),
+
+    /// Field representing type `field_of!(container, field_path)`
+    Field(Box<Type>, Box<str>),
 }
 
 impl Type {
@@ -1764,7 +1767,9 @@ impl Type {
             Type::Pat(..) => PrimitiveType::Pat,
             RawPointer(..) => PrimitiveType::RawPointer,
             QPath(box QPathData { self_type, .. }) => return self_type.def_id(cache),
-            Generic(_) | SelfTy | Infer | ImplTrait(_) | UnsafeBinder(_) => return None,
+            Field(..) | Generic(_) | SelfTy | Infer | ImplTrait(_) | UnsafeBinder(_) => {
+                return None;
+            }
         };
         Primitive(t).def_id(cache)
     }

src/librustdoc/html/format.rs

@@ -1034,6 +1034,13 @@ fn fmt_type(
             print_generic_bounds(bounds, cx).fmt(f)
         }
         clean::QPath(qpath) => qpath.print(cx).fmt(f),
+        clean::Field(container, field_path) => {
+            f.write_str("field_of!(")?;
+            fmt_type(&container, f, use_absolute, cx)?;
+            f.write_str(", ")?;
+            f.write_str(field_path)?;
+            f.write_str(")")
+        }
     }
 }
 

src/librustdoc/html/render/search_index.rs

@@ -2050,6 +2050,7 @@ fn get_index_type_id(
         }
         // Not supported yet
         clean::Type::Pat(..)
+        | clean::Field(..)
         | clean::Generic(_)
         | clean::SelfTy
         | clean::ImplTrait(_)

src/librustdoc/json/conversions.rs

@@ -554,7 +554,7 @@ impl FromClean<rustc_hir::TraitBoundModifiers> for TraitBoundModifier {
 impl FromClean<clean::Type> for Type {
     fn from_clean(ty: &clean::Type, renderer: &JsonRenderer<'_>) -> Self {
         use clean::Type::{
-            Array, BareFunction, BorrowedRef, Generic, ImplTrait, Infer, Primitive, QPath,
+            Array, BareFunction, BorrowedRef, Field, Generic, ImplTrait, Infer, Primitive, QPath,
             RawPointer, SelfTy, Slice, Tuple, UnsafeBinder,
         };
 
@@ -592,6 +592,8 @@ impl FromClean<clean::Type> for Type {
             QPath(qpath) => qpath.into_json(renderer),
             // FIXME(unsafe_binder): Implement rustdoc-json.
             UnsafeBinder(_) => todo!(),
+            // FIXME(field_projections): Implement
+            Field(..) => todo!(),
         }
     }
 }

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -564,6 +564,7 @@ impl<'tcx> LinkCollector<'_, 'tcx> {
             ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did, .. }, _)), _) | ty::Foreign(did) => {
                 Res::from_def_id(self.cx.tcx, did)
             }
+            ty::Field(..) => bug!("FIXME(field_projections): what to do here?"),
             ty::Alias(..)
             | ty::Closure(..)
             | ty::CoroutineClosure(..)