Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 798 insertions, 0 deletions

diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
new file mode 100644
index 000000000..716a4c9ea
--- /dev/null
+++ b/src/librustdoc/json/conversions.rs
@@ -0,0 +1,798 @@
+//! These from impls are used to create the JSON types which get serialized. They're very close to
+//! the `clean` types but with some fields removed or stringified to simplify the output and not
+//! expose unstable compiler internals.
+
+#![allow(rustc::default_hash_types)]
+
+use std::convert::From;
+use std::fmt;
+
+use rustc_ast::ast;
+use rustc_hir::{def::CtorKind, def_id::DefId};
+use rustc_middle::ty::{self, TyCtxt};
+use rustc_span::{Pos, Symbol};
+use rustc_target::spec::abi::Abi as RustcAbi;
+
+use rustdoc_json_types::*;
+
+use crate::clean::utils::print_const_expr;
+use crate::clean::{self, ItemId};
+use crate::formats::item_type::ItemType;
+use crate::json::JsonRenderer;
+
+impl JsonRenderer<'_> {
+    pub(super) fn convert_item(&self, item: clean::Item) -> Option<Item> {
+        let deprecation = item.deprecation(self.tcx);
+        let links = self
+            .cache
+            .intra_doc_links
+            .get(&item.item_id)
+            .into_iter()
+            .flatten()
+            .map(|clean::ItemLink { link, did, .. }| {
+                (link.clone(), from_item_id((*did).into(), self.tcx))
+            })
+            .collect();
+        let docs = item.attrs.collapsed_doc_value();
+        let attrs = item
+            .attrs
+            .other_attrs
+            .iter()
+            .map(rustc_ast_pretty::pprust::attribute_to_string)
+            .collect();
+        let span = item.span(self.tcx);
+        let clean::Item { name, attrs: _, kind: _, visibility, item_id, cfg: _ } = item;
+        let inner = match *item.kind {
+            clean::KeywordItem => return None,
+            clean::StrippedItem(ref inner) => {
+                match &**inner {
+                    // We document non-empty stripped modules as with `Module::is_stripped` set to
+                    // `true`, to prevent contained items from being orphaned for downstream users,
+                    // as JSON does no inlining.
+                    clean::ModuleItem(m) if !m.items.is_empty() => from_clean_item(item, self.tcx),
+                    _ => return None,
+                }
+            }
+            _ => from_clean_item(item, self.tcx),
+        };
+        Some(Item {
+            id: from_item_id_with_name(item_id, self.tcx, name),
+            crate_id: item_id.krate().as_u32(),
+            name: name.map(|sym| sym.to_string()),
+            span: self.convert_span(span),
+            visibility: self.convert_visibility(visibility),
+            docs,
+            attrs,
+            deprecation: deprecation.map(from_deprecation),
+            inner,
+            links,
+        })
+    }
+
+    fn convert_span(&self, span: clean::Span) -> Option<Span> {
+        match span.filename(self.sess()) {
+            rustc_span::FileName::Real(name) => {
+                if let Some(local_path) = name.into_local_path() {
+                    let hi = span.hi(self.sess());
+                    let lo = span.lo(self.sess());
+                    Some(Span {
+                        filename: local_path,
+                        begin: (lo.line, lo.col.to_usize()),
+                        end: (hi.line, hi.col.to_usize()),
+                    })
+                } else {
+                    None
+                }
+            }
+            _ => None,
+        }
+    }
+
+    fn convert_visibility(&self, v: clean::Visibility) -> Visibility {
+        use clean::Visibility::*;
+        match v {
+            Public => Visibility::Public,
+            Inherited => Visibility::Default,
+            Restricted(did) if did.is_crate_root() => Visibility::Crate,
+            Restricted(did) => Visibility::Restricted {
+                parent: from_item_id(did.into(), self.tcx),
+                path: self.tcx.def_path(did).to_string_no_crate_verbose(),
+            },
+        }
+    }
+}
+
+pub(crate) trait FromWithTcx<T> {
+    fn from_tcx(f: T, tcx: TyCtxt<'_>) -> Self;
+}
+
+pub(crate) trait IntoWithTcx<T> {
+    fn into_tcx(self, tcx: TyCtxt<'_>) -> T;
+}
+
+impl<T, U> IntoWithTcx<U> for T
+where
+    U: FromWithTcx<T>,
+{
+    fn into_tcx(self, tcx: TyCtxt<'_>) -> U {
+        U::from_tcx(self, tcx)
+    }
+}
+
+pub(crate) fn from_deprecation(deprecation: rustc_attr::Deprecation) -> Deprecation {
+    #[rustfmt::skip]
+    let rustc_attr::Deprecation { since, note, is_since_rustc_version: _, suggestion: _ } = deprecation;
+    Deprecation { since: since.map(|s| s.to_string()), note: note.map(|s| s.to_string()) }
+}
+
+impl FromWithTcx<clean::GenericArgs> for GenericArgs {
+    fn from_tcx(args: clean::GenericArgs, tcx: TyCtxt<'_>) -> Self {
+        use clean::GenericArgs::*;
+        match args {
+            AngleBracketed { args, bindings } => GenericArgs::AngleBracketed {
+                args: args.into_vec().into_iter().map(|a| a.into_tcx(tcx)).collect(),
+                bindings: bindings.into_iter().map(|a| a.into_tcx(tcx)).collect(),
+            },
+            Parenthesized { inputs, output } => GenericArgs::Parenthesized {
+                inputs: inputs.into_vec().into_iter().map(|a| a.into_tcx(tcx)).collect(),
+                output: output.map(|a| (*a).into_tcx(tcx)),
+            },
+        }
+    }
+}
+
+impl FromWithTcx<clean::GenericArg> for GenericArg {
+    fn from_tcx(arg: clean::GenericArg, tcx: TyCtxt<'_>) -> Self {
+        use clean::GenericArg::*;
+        match arg {
+            Lifetime(l) => GenericArg::Lifetime(l.0.to_string()),
+            Type(t) => GenericArg::Type(t.into_tcx(tcx)),
+            Const(box c) => GenericArg::Const(c.into_tcx(tcx)),
+            Infer => GenericArg::Infer,
+        }
+    }
+}
+
+impl FromWithTcx<clean::Constant> for Constant {
+    fn from_tcx(constant: clean::Constant, tcx: TyCtxt<'_>) -> Self {
+        let expr = constant.expr(tcx);
+        let value = constant.value(tcx);
+        let is_literal = constant.is_literal(tcx);
+        Constant { type_: constant.type_.into_tcx(tcx), expr, value, is_literal }
+    }
+}
+
+impl FromWithTcx<clean::TypeBinding> for TypeBinding {
+    fn from_tcx(binding: clean::TypeBinding, tcx: TyCtxt<'_>) -> Self {
+        TypeBinding {
+            name: binding.assoc.name.to_string(),
+            args: binding.assoc.args.into_tcx(tcx),
+            binding: binding.kind.into_tcx(tcx),
+        }
+    }
+}
+
+impl FromWithTcx<clean::TypeBindingKind> for TypeBindingKind {
+    fn from_tcx(kind: clean::TypeBindingKind, tcx: TyCtxt<'_>) -> Self {
+        use clean::TypeBindingKind::*;
+        match kind {
+            Equality { term } => TypeBindingKind::Equality(term.into_tcx(tcx)),
+            Constraint { bounds } => {
+                TypeBindingKind::Constraint(bounds.into_iter().map(|a| a.into_tcx(tcx)).collect())
+            }
+        }
+    }
+}
+
+/// It generates an ID as follows:
+///
+/// `CRATE_ID:ITEM_ID[:NAME_ID]` (if there is no name, NAME_ID is not generated).
+pub(crate) fn from_item_id(item_id: ItemId, tcx: TyCtxt<'_>) -> Id {
+    from_item_id_with_name(item_id, tcx, None)
+}
+
+// FIXME: this function (and appending the name at the end of the ID) should be removed when
+// reexports are not inlined anymore for json format. It should be done in #93518.
+pub(crate) fn from_item_id_with_name(item_id: ItemId, tcx: TyCtxt<'_>, name: Option<Symbol>) -> Id {
+    struct DisplayDefId<'a>(DefId, TyCtxt<'a>, Option<Symbol>);
+
+    impl<'a> fmt::Display for DisplayDefId<'a> {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            let name = match self.2 {
+                Some(name) => format!(":{}", name.as_u32()),
+                None => self
+                    .1
+                    .opt_item_name(self.0)
+                    .map(|n| format!(":{}", n.as_u32()))
+                    .unwrap_or_default(),
+            };
+            write!(f, "{}:{}{}", self.0.krate.as_u32(), u32::from(self.0.index), name)
+        }
+    }
+
+    match item_id {
+        ItemId::DefId(did) => Id(format!("{}", DisplayDefId(did, tcx, name))),
+        ItemId::Blanket { for_, impl_id } => {
+            Id(format!("b:{}-{}", DisplayDefId(impl_id, tcx, None), DisplayDefId(for_, tcx, name)))
+        }
+        ItemId::Auto { for_, trait_ } => {
+            Id(format!("a:{}-{}", DisplayDefId(trait_, tcx, None), DisplayDefId(for_, tcx, name)))
+        }
+        ItemId::Primitive(ty, krate) => Id(format!("p:{}:{}", krate.as_u32(), ty.as_sym())),
+    }
+}
+
+fn from_clean_item(item: clean::Item, tcx: TyCtxt<'_>) -> ItemEnum {
+    use clean::ItemKind::*;
+    let name = item.name;
+    let is_crate = item.is_crate();
+    let header = item.fn_header(tcx);
+
+    match *item.kind {
+        ModuleItem(m) => {
+            ItemEnum::Module(Module { is_crate, items: ids(m.items, tcx), is_stripped: false })
+        }
+        ImportItem(i) => ItemEnum::Import(i.into_tcx(tcx)),
+        StructItem(s) => ItemEnum::Struct(s.into_tcx(tcx)),
+        UnionItem(u) => ItemEnum::Union(u.into_tcx(tcx)),
+        StructFieldItem(f) => ItemEnum::StructField(f.into_tcx(tcx)),
+        EnumItem(e) => ItemEnum::Enum(e.into_tcx(tcx)),
+        VariantItem(v) => ItemEnum::Variant(v.into_tcx(tcx)),
+        FunctionItem(f) => ItemEnum::Function(from_function(f, header.unwrap(), tcx)),
+        ForeignFunctionItem(f) => ItemEnum::Function(from_function(f, header.unwrap(), tcx)),
+        TraitItem(t) => ItemEnum::Trait(t.into_tcx(tcx)),
+        TraitAliasItem(t) => ItemEnum::TraitAlias(t.into_tcx(tcx)),
+        MethodItem(m, _) => ItemEnum::Method(from_function_method(m, true, header.unwrap(), tcx)),
+        TyMethodItem(m) => ItemEnum::Method(from_function_method(m, false, header.unwrap(), tcx)),
+        ImplItem(i) => ItemEnum::Impl(i.into_tcx(tcx)),
+        StaticItem(s) => ItemEnum::Static(s.into_tcx(tcx)),
+        ForeignStaticItem(s) => ItemEnum::Static(s.into_tcx(tcx)),
+        ForeignTypeItem => ItemEnum::ForeignType,
+        TypedefItem(t) => ItemEnum::Typedef(t.into_tcx(tcx)),
+        OpaqueTyItem(t) => ItemEnum::OpaqueTy(t.into_tcx(tcx)),
+        ConstantItem(c) => ItemEnum::Constant(c.into_tcx(tcx)),
+        MacroItem(m) => ItemEnum::Macro(m.source),
+        ProcMacroItem(m) => ItemEnum::ProcMacro(m.into_tcx(tcx)),
+        PrimitiveItem(p) => ItemEnum::PrimitiveType(p.as_sym().to_string()),
+        TyAssocConstItem(ty) => ItemEnum::AssocConst { type_: ty.into_tcx(tcx), default: None },
+        AssocConstItem(ty, default) => {
+            ItemEnum::AssocConst { type_: ty.into_tcx(tcx), default: Some(default.expr(tcx)) }
+        }
+        TyAssocTypeItem(g, b) => ItemEnum::AssocType {
+            generics: (*g).into_tcx(tcx),
+            bounds: b.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+            default: None,
+        },
+        AssocTypeItem(t, b) => ItemEnum::AssocType {
+            generics: t.generics.into_tcx(tcx),
+            bounds: b.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+            default: Some(t.item_type.unwrap_or(t.type_).into_tcx(tcx)),
+        },
+        // `convert_item` early returns `None` for stripped items and keywords.
+        KeywordItem => unreachable!(),
+        StrippedItem(inner) => {
+            match *inner {
+                ModuleItem(m) => ItemEnum::Module(Module {
+                    is_crate,
+                    items: ids(m.items, tcx),
+                    is_stripped: true,
+                }),
+                // `convert_item` early returns `None` for stripped items we're not including
+                _ => unreachable!(),
+            }
+        }
+        ExternCrateItem { ref src } => ItemEnum::ExternCrate {
+            name: name.as_ref().unwrap().to_string(),
+            rename: src.map(|x| x.to_string()),
+        },
+    }
+}
+
+impl FromWithTcx<clean::Struct> for Struct {
+    fn from_tcx(struct_: clean::Struct, tcx: TyCtxt<'_>) -> Self {
+        let fields_stripped = struct_.has_stripped_entries();
+        let clean::Struct { struct_type, generics, fields } = struct_;
+        Struct {
+            struct_type: from_ctor_kind(struct_type),
+            generics: generics.into_tcx(tcx),
+            fields_stripped,
+            fields: ids(fields, tcx),
+            impls: Vec::new(), // Added in JsonRenderer::item
+        }
+    }
+}
+
+impl FromWithTcx<clean::Union> for Union {
+    fn from_tcx(union_: clean::Union, tcx: TyCtxt<'_>) -> Self {
+        let fields_stripped = union_.has_stripped_entries();
+        let clean::Union { generics, fields } = union_;
+        Union {
+            generics: generics.into_tcx(tcx),
+            fields_stripped,
+            fields: ids(fields, tcx),
+            impls: Vec::new(), // Added in JsonRenderer::item
+        }
+    }
+}
+
+pub(crate) fn from_ctor_kind(struct_type: CtorKind) -> StructType {
+    match struct_type {
+        CtorKind::Fictive => StructType::Plain,
+        CtorKind::Fn => StructType::Tuple,
+        CtorKind::Const => StructType::Unit,
+    }
+}
+
+pub(crate) fn from_fn_header(header: &rustc_hir::FnHeader) -> Header {
+    Header {
+        async_: header.is_async(),
+        const_: header.is_const(),
+        unsafe_: header.is_unsafe(),
+        abi: convert_abi(header.abi),
+    }
+}
+
+fn convert_abi(a: RustcAbi) -> Abi {
+    match a {
+        RustcAbi::Rust => Abi::Rust,
+        RustcAbi::C { unwind } => Abi::C { unwind },
+        RustcAbi::Cdecl { unwind } => Abi::Cdecl { unwind },
+        RustcAbi::Stdcall { unwind } => Abi::Stdcall { unwind },
+        RustcAbi::Fastcall { unwind } => Abi::Fastcall { unwind },
+        RustcAbi::Aapcs { unwind } => Abi::Aapcs { unwind },
+        RustcAbi::Win64 { unwind } => Abi::Win64 { unwind },
+        RustcAbi::SysV64 { unwind } => Abi::SysV64 { unwind },
+        RustcAbi::System { unwind } => Abi::System { unwind },
+        _ => Abi::Other(a.to_string()),
+    }
+}
+
+impl FromWithTcx<clean::Generics> for Generics {
+    fn from_tcx(generics: clean::Generics, tcx: TyCtxt<'_>) -> Self {
+        Generics {
+            params: generics.params.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+            where_predicates: generics
+                .where_predicates
+                .into_iter()
+                .map(|x| x.into_tcx(tcx))
+                .collect(),
+        }
+    }
+}
+
+impl FromWithTcx<clean::GenericParamDef> for GenericParamDef {
+    fn from_tcx(generic_param: clean::GenericParamDef, tcx: TyCtxt<'_>) -> Self {
+        GenericParamDef {
+            name: generic_param.name.to_string(),
+            kind: generic_param.kind.into_tcx(tcx),
+        }
+    }
+}
+
+impl FromWithTcx<clean::GenericParamDefKind> for GenericParamDefKind {
+    fn from_tcx(kind: clean::GenericParamDefKind, tcx: TyCtxt<'_>) -> Self {
+        use clean::GenericParamDefKind::*;
+        match kind {
+            Lifetime { outlives } => GenericParamDefKind::Lifetime {
+                outlives: outlives.into_iter().map(|lt| lt.0.to_string()).collect(),
+            },
+            Type { did: _, bounds, default, synthetic } => GenericParamDefKind::Type {
+                bounds: bounds.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+                default: default.map(|x| (*x).into_tcx(tcx)),
+                synthetic,
+            },
+            Const { did: _, ty, default } => GenericParamDefKind::Const {
+                type_: (*ty).into_tcx(tcx),
+                default: default.map(|x| *x),
+            },
+        }
+    }
+}
+
+impl FromWithTcx<clean::WherePredicate> for WherePredicate {
+    fn from_tcx(predicate: clean::WherePredicate, tcx: TyCtxt<'_>) -> Self {
+        use clean::WherePredicate::*;
+        match predicate {
+            BoundPredicate { ty, bounds, bound_params } => WherePredicate::BoundPredicate {
+                type_: ty.into_tcx(tcx),
+                bounds: bounds.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+                generic_params: bound_params
+                    .into_iter()
+                    .map(|x| GenericParamDef {
+                        name: x.0.to_string(),
+                        kind: GenericParamDefKind::Lifetime { outlives: vec![] },
+                    })
+                    .collect(),
+            },
+            RegionPredicate { lifetime, bounds } => WherePredicate::RegionPredicate {
+                lifetime: lifetime.0.to_string(),
+                bounds: bounds.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+            },
+            EqPredicate { lhs, rhs } => {
+                WherePredicate::EqPredicate { lhs: lhs.into_tcx(tcx), rhs: rhs.into_tcx(tcx) }
+            }
+        }
+    }
+}
+
+impl FromWithTcx<clean::GenericBound> for GenericBound {
+    fn from_tcx(bound: clean::GenericBound, tcx: TyCtxt<'_>) -> Self {
+        use clean::GenericBound::*;
+        match bound {
+            TraitBound(clean::PolyTrait { trait_, generic_params }, modifier) => {
+                // FIXME: should `trait_` be a clean::Path equivalent in JSON?
+                let trait_ = clean::Type::Path { path: trait_ }.into_tcx(tcx);
+                GenericBound::TraitBound {
+                    trait_,
+                    generic_params: generic_params.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+                    modifier: from_trait_bound_modifier(modifier),
+                }
+            }
+            Outlives(lifetime) => GenericBound::Outlives(lifetime.0.to_string()),
+        }
+    }
+}
+
+pub(crate) fn from_trait_bound_modifier(
+    modifier: rustc_hir::TraitBoundModifier,
+) -> TraitBoundModifier {
+    use rustc_hir::TraitBoundModifier::*;
+    match modifier {
+        None => TraitBoundModifier::None,
+        Maybe => TraitBoundModifier::Maybe,
+        MaybeConst => TraitBoundModifier::MaybeConst,
+    }
+}
+
+impl FromWithTcx<clean::Type> for Type {
+    fn from_tcx(ty: clean::Type, tcx: TyCtxt<'_>) -> Self {
+        use clean::Type::{
+            Array, BareFunction, BorrowedRef, DynTrait, Generic, ImplTrait, Infer, Primitive,
+            QPath, RawPointer, Slice, Tuple,
+        };
+
+        match ty {
+            clean::Type::Path { path } => Type::ResolvedPath {
+                name: path.whole_name(),
+                id: from_item_id(path.def_id().into(), tcx),
+                args: path.segments.last().map(|args| Box::new(args.clone().args.into_tcx(tcx))),
+                param_names: Vec::new(),
+            },
+            DynTrait(mut bounds, lt) => {
+                let first_trait = bounds.remove(0).trait_;
+
+                Type::ResolvedPath {
+                    name: first_trait.whole_name(),
+                    id: from_item_id(first_trait.def_id().into(), tcx),
+                    args: first_trait
+                        .segments
+                        .last()
+                        .map(|args| Box::new(args.clone().args.into_tcx(tcx))),
+                    param_names: bounds
+                        .into_iter()
+                        .map(|t| {
+                            clean::GenericBound::TraitBound(t, rustc_hir::TraitBoundModifier::None)
+                        })
+                        .chain(lt.map(clean::GenericBound::Outlives))
+                        .map(|bound| bound.into_tcx(tcx))
+                        .collect(),
+                }
+            }
+            Generic(s) => Type::Generic(s.to_string()),
+            Primitive(p) => Type::Primitive(p.as_sym().to_string()),
+            BareFunction(f) => Type::FunctionPointer(Box::new((*f).into_tcx(tcx))),
+            Tuple(t) => Type::Tuple(t.into_iter().map(|x| x.into_tcx(tcx)).collect()),
+            Slice(t) => Type::Slice(Box::new((*t).into_tcx(tcx))),
+            Array(t, s) => Type::Array { type_: Box::new((*t).into_tcx(tcx)), len: s },
+            ImplTrait(g) => Type::ImplTrait(g.into_iter().map(|x| x.into_tcx(tcx)).collect()),
+            Infer => Type::Infer,
+            RawPointer(mutability, type_) => Type::RawPointer {
+                mutable: mutability == ast::Mutability::Mut,
+                type_: Box::new((*type_).into_tcx(tcx)),
+            },
+            BorrowedRef { lifetime, mutability, type_ } => Type::BorrowedRef {
+                lifetime: lifetime.map(|l| l.0.to_string()),
+                mutable: mutability == ast::Mutability::Mut,
+                type_: Box::new((*type_).into_tcx(tcx)),
+            },
+            QPath { assoc, self_type, trait_, .. } => {
+                // FIXME: should `trait_` be a clean::Path equivalent in JSON?
+                let trait_ = clean::Type::Path { path: trait_ }.into_tcx(tcx);
+                Type::QualifiedPath {
+                    name: assoc.name.to_string(),
+                    args: Box::new(assoc.args.clone().into_tcx(tcx)),
+                    self_type: Box::new((*self_type).into_tcx(tcx)),
+                    trait_: Box::new(trait_),
+                }
+            }
+        }
+    }
+}
+
+impl FromWithTcx<clean::Term> for Term {
+    fn from_tcx(term: clean::Term, tcx: TyCtxt<'_>) -> Term {
+        match term {
+            clean::Term::Type(ty) => Term::Type(FromWithTcx::from_tcx(ty, tcx)),
+            clean::Term::Constant(c) => Term::Constant(FromWithTcx::from_tcx(c, tcx)),
+        }
+    }
+}
+
+impl FromWithTcx<clean::BareFunctionDecl> for FunctionPointer {
+    fn from_tcx(bare_decl: clean::BareFunctionDecl, tcx: TyCtxt<'_>) -> Self {
+        let clean::BareFunctionDecl { unsafety, generic_params, decl, abi } = bare_decl;
+        FunctionPointer {
+            header: Header {
+                unsafe_: matches!(unsafety, rustc_hir::Unsafety::Unsafe),
+                const_: false,
+                async_: false,
+                abi: convert_abi(abi),
+            },
+            generic_params: generic_params.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+            decl: decl.into_tcx(tcx),
+        }
+    }
+}
+
+impl FromWithTcx<clean::FnDecl> for FnDecl {
+    fn from_tcx(decl: clean::FnDecl, tcx: TyCtxt<'_>) -> Self {
+        let clean::FnDecl { inputs, output, c_variadic } = decl;
+        FnDecl {
+            inputs: inputs
+                .values
+                .into_iter()
+                .map(|arg| (arg.name.to_string(), arg.type_.into_tcx(tcx)))
+                .collect(),
+            output: match output {
+                clean::FnRetTy::Return(t) => Some(t.into_tcx(tcx)),
+                clean::FnRetTy::DefaultReturn => None,
+            },
+            c_variadic,
+        }
+    }
+}
+
+impl FromWithTcx<clean::Trait> for Trait {
+    fn from_tcx(trait_: clean::Trait, tcx: TyCtxt<'_>) -> Self {
+        let is_auto = trait_.is_auto(tcx);
+        let is_unsafe = trait_.unsafety(tcx) == rustc_hir::Unsafety::Unsafe;
+        let clean::Trait { items, generics, bounds, .. } = trait_;
+        Trait {
+            is_auto,
+            is_unsafe,
+            items: ids(items, tcx),
+            generics: generics.into_tcx(tcx),
+            bounds: bounds.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+            implementations: Vec::new(), // Added in JsonRenderer::item
+        }
+    }
+}
+
+impl FromWithTcx<Box<clean::Impl>> for Impl {
+    fn from_tcx(impl_: Box<clean::Impl>, tcx: TyCtxt<'_>) -> Self {
+        let provided_trait_methods = impl_.provided_trait_methods(tcx);
+        let clean::Impl { unsafety, generics, trait_, for_, items, polarity, kind } = *impl_;
+        // FIXME: should `trait_` be a clean::Path equivalent in JSON?
+        let trait_ = trait_.map(|path| clean::Type::Path { path }.into_tcx(tcx));
+        // FIXME: use something like ImplKind in JSON?
+        let (synthetic, blanket_impl) = match kind {
+            clean::ImplKind::Normal | clean::ImplKind::FakeVaradic => (false, None),
+            clean::ImplKind::Auto => (true, None),
+            clean::ImplKind::Blanket(ty) => (false, Some(*ty)),
+        };
+        let negative_polarity = match polarity {
+            ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => false,
+            ty::ImplPolarity::Negative => true,
+        };
+        Impl {
+            is_unsafe: unsafety == rustc_hir::Unsafety::Unsafe,
+            generics: generics.into_tcx(tcx),
+            provided_trait_methods: provided_trait_methods
+                .into_iter()
+                .map(|x| x.to_string())
+                .collect(),
+            trait_,
+            for_: for_.into_tcx(tcx),
+            items: ids(items, tcx),
+            negative: negative_polarity,
+            synthetic,
+            blanket_impl: blanket_impl.map(|x| x.into_tcx(tcx)),
+        }
+    }
+}
+
+pub(crate) fn from_function(
+    function: Box<clean::Function>,
+    header: rustc_hir::FnHeader,
+    tcx: TyCtxt<'_>,
+) -> Function {
+    let clean::Function { decl, generics } = *function;
+    Function {
+        decl: decl.into_tcx(tcx),
+        generics: generics.into_tcx(tcx),
+        header: from_fn_header(&header),
+    }
+}
+
+pub(crate) fn from_function_method(
+    function: Box<clean::Function>,
+    has_body: bool,
+    header: rustc_hir::FnHeader,
+    tcx: TyCtxt<'_>,
+) -> Method {
+    let clean::Function { decl, generics } = *function;
+    Method {
+        decl: decl.into_tcx(tcx),
+        generics: generics.into_tcx(tcx),
+        header: from_fn_header(&header),
+        has_body,
+    }
+}
+
+impl FromWithTcx<clean::Enum> for Enum {
+    fn from_tcx(enum_: clean::Enum, tcx: TyCtxt<'_>) -> Self {
+        let variants_stripped = enum_.has_stripped_entries();
+        let clean::Enum { variants, generics } = enum_;
+        Enum {
+            generics: generics.into_tcx(tcx),
+            variants_stripped,
+            variants: ids(variants, tcx),
+            impls: Vec::new(), // Added in JsonRenderer::item
+        }
+    }
+}
+
+impl FromWithTcx<clean::VariantStruct> for Struct {
+    fn from_tcx(struct_: clean::VariantStruct, tcx: TyCtxt<'_>) -> Self {
+        let fields_stripped = struct_.has_stripped_entries();
+        let clean::VariantStruct { struct_type, fields } = struct_;
+        Struct {
+            struct_type: from_ctor_kind(struct_type),
+            generics: Generics { params: vec![], where_predicates: vec![] },
+            fields_stripped,
+            fields: ids(fields, tcx),
+            impls: Vec::new(),
+        }
+    }
+}
+
+impl FromWithTcx<clean::Variant> for Variant {
+    fn from_tcx(variant: clean::Variant, tcx: TyCtxt<'_>) -> Self {
+        use clean::Variant::*;
+        match variant {
+            CLike => Variant::Plain,
+            Tuple(fields) => Variant::Tuple(
+                fields
+                    .into_iter()
+                    .map(|f| {
+                        if let clean::StructFieldItem(ty) = *f.kind {
+                            ty.into_tcx(tcx)
+                        } else {
+                            unreachable!()
+                        }
+                    })
+                    .collect(),
+            ),
+            Struct(s) => Variant::Struct(ids(s.fields, tcx)),
+        }
+    }
+}
+
+impl FromWithTcx<clean::Import> for Import {
+    fn from_tcx(import: clean::Import, tcx: TyCtxt<'_>) -> Self {
+        use clean::ImportKind::*;
+        match import.kind {
+            Simple(s) => Import {
+                source: import.source.path.whole_name(),
+                name: s.to_string(),
+                id: import.source.did.map(ItemId::from).map(|i| from_item_id(i, tcx)),
+                glob: false,
+            },
+            Glob => Import {
+                source: import.source.path.whole_name(),
+                name: import
+                    .source
+                    .path
+                    .last_opt()
+                    .unwrap_or_else(|| Symbol::intern("*"))
+                    .to_string(),
+                id: import.source.did.map(ItemId::from).map(|i| from_item_id(i, tcx)),
+                glob: true,
+            },
+        }
+    }
+}
+
+impl FromWithTcx<clean::ProcMacro> for ProcMacro {
+    fn from_tcx(mac: clean::ProcMacro, _tcx: TyCtxt<'_>) -> Self {
+        ProcMacro {
+            kind: from_macro_kind(mac.kind),
+            helpers: mac.helpers.iter().map(|x| x.to_string()).collect(),
+        }
+    }
+}
+
+pub(crate) fn from_macro_kind(kind: rustc_span::hygiene::MacroKind) -> MacroKind {
+    use rustc_span::hygiene::MacroKind::*;
+    match kind {
+        Bang => MacroKind::Bang,
+        Attr => MacroKind::Attr,
+        Derive => MacroKind::Derive,
+    }
+}
+
+impl FromWithTcx<Box<clean::Typedef>> for Typedef {
+    fn from_tcx(typedef: Box<clean::Typedef>, tcx: TyCtxt<'_>) -> Self {
+        let clean::Typedef { type_, generics, item_type: _ } = *typedef;
+        Typedef { type_: type_.into_tcx(tcx), generics: generics.into_tcx(tcx) }
+    }
+}
+
+impl FromWithTcx<clean::OpaqueTy> for OpaqueTy {
+    fn from_tcx(opaque: clean::OpaqueTy, tcx: TyCtxt<'_>) -> Self {
+        OpaqueTy {
+            bounds: opaque.bounds.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+            generics: opaque.generics.into_tcx(tcx),
+        }
+    }
+}
+
+impl FromWithTcx<clean::Static> for Static {
+    fn from_tcx(stat: clean::Static, tcx: TyCtxt<'_>) -> Self {
+        Static {
+            type_: stat.type_.into_tcx(tcx),
+            mutable: stat.mutability == ast::Mutability::Mut,
+            expr: stat.expr.map(|e| print_const_expr(tcx, e)).unwrap_or_default(),
+        }
+    }
+}
+
+impl FromWithTcx<clean::TraitAlias> for TraitAlias {
+    fn from_tcx(alias: clean::TraitAlias, tcx: TyCtxt<'_>) -> Self {
+        TraitAlias {
+            generics: alias.generics.into_tcx(tcx),
+            params: alias.bounds.into_iter().map(|x| x.into_tcx(tcx)).collect(),
+        }
+    }
+}
+
+impl FromWithTcx<ItemType> for ItemKind {
+    fn from_tcx(kind: ItemType, _tcx: TyCtxt<'_>) -> Self {
+        use ItemType::*;
+        match kind {
+            Module => ItemKind::Module,
+            ExternCrate => ItemKind::ExternCrate,
+            Import => ItemKind::Import,
+            Struct => ItemKind::Struct,
+            Union => ItemKind::Union,
+            Enum => ItemKind::Enum,
+            Function => ItemKind::Function,
+            Typedef => ItemKind::Typedef,
+            OpaqueTy => ItemKind::OpaqueTy,
+            Static => ItemKind::Static,
+            Constant => ItemKind::Constant,
+            Trait => ItemKind::Trait,
+            Impl => ItemKind::Impl,
+            TyMethod | Method => ItemKind::Method,
+            StructField => ItemKind::StructField,
+            Variant => ItemKind::Variant,
+            Macro => ItemKind::Macro,
+            Primitive => ItemKind::Primitive,
+            AssocConst => ItemKind::AssocConst,
+            AssocType => ItemKind::AssocType,
+            ForeignType => ItemKind::ForeignType,
+            Keyword => ItemKind::Keyword,
+            TraitAlias => ItemKind::TraitAlias,
+            ProcAttribute => ItemKind::ProcAttribute,
+            ProcDerive => ItemKind::ProcDerive,
+        }
+    }
+}
+
+fn ids(items: impl IntoIterator<Item = clean::Item>, tcx: TyCtxt<'_>) -> Vec<Id> {
+    items
+        .into_iter()
+        .filter(|x| !x.is_stripped() && !x.is_keyword())
+        .map(|i| from_item_id_with_name(i.item_id, tcx, i.name))
+        .collect()
+}