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rust/rust/fc5a7077ca43894de1ea0d3f9f56ac627ceef5c7/./src/librustdoc/clean/mod.rs
blob: f54339429fa58cb60b4ee744acf8237b3424d868 [file]
//! This module defines the primary IR[^1] used in rustdoc together with the procedures that
//! transform rustc data types into it.
//!
//! This IR — commonly referred to as the *cleaned AST* — is modeled after the [AST][rustc_ast].
//!
//! There are two kinds of transformation — *cleaning* — procedures:
//!
//! 1. Cleans [HIR][hir] types. Used for user-written code and inlined local re-exports
//! both found in the local crate.
//! 2. Cleans [`rustc_middle::ty`] types. Used for inlined cross-crate re-exports and anything
//! output by the trait solver (e.g., when synthesizing blanket and auto-trait impls).
//! They usually have `ty` or `middle` in their name.
//!
//! Their name is prefixed by `clean_`.
//!
//! Both the HIR and the `rustc_middle::ty` IR are quite removed from the source code.
//! The cleaned AST on the other hand is closer to it which simplifies the rendering process.
//! Furthermore, operating on a single IR instead of two avoids duplicating efforts down the line.
//!
//! This IR is consumed by both the HTML and the JSON backend.
//!
//! [^1]: Intermediate representation.
mod auto_trait;
mod blanket_impl;
pub(crate) mod cfg;
pub(crate) mod inline;
mod render_macro_matchers;
mod simplify;
pub(crate) mod types;
pub(crate) mod utils;
use std::borrow::Cow;
use std::collections::BTreeMap;
use std::mem;
use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet, IndexEntry};
use rustc_data_structures::thin_vec::ThinVec;
use rustc_errors::codes::*;
use rustc_errors::{FatalError, struct_span_code_err};
use rustc_hir as hir;
use rustc_hir::attrs::{AttributeKind, DocAttribute, DocInline};
use rustc_hir::def::{CtorKind, DefKind, MacroKinds, Res};
use rustc_hir::def_id::{DefId, DefIdMap, DefIdSet, LOCAL_CRATE, LocalDefId};
use rustc_hir::{LangItem, PredicateOrigin, find_attr};
use rustc_hir_analysis::{lower_const_arg_for_rustdoc, lower_ty};
use rustc_middle::metadata::Reexport;
use rustc_middle::middle::resolve_bound_vars as rbv;
use rustc_middle::ty::{self, AdtKind, GenericArgsRef, Ty, TyCtxt, TypeVisitableExt, TypingMode};
use rustc_middle::{bug, span_bug};
use rustc_span::ExpnKind;
use rustc_span::hygiene::{AstPass, MacroKind};
use rustc_span::symbol::{Ident, Symbol, kw};
use rustc_trait_selection::traits::wf::object_region_bounds;
use tracing::{debug, instrument};
use utils::*;
pub(crate) use self::cfg::{CfgInfo, extract_cfg_from_attrs};
pub(crate) use self::types::*;
pub(crate) use self::utils::{krate, register_res, synthesize_auto_trait_and_blanket_impls};
use crate::core::DocContext;
use crate::formats::item_type::ItemType;
use crate::visit_ast::Module as DocModule;
pub(crate) fn clean_doc_module<'tcx>(doc: &DocModule<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
let mut items: Vec<Item> = vec![];
let mut inserted = FxHashSet::default();
items.extend(doc.foreigns.iter().map(|(item, renamed, import_id)| {
let item = clean_maybe_renamed_foreign_item(cx, item, *renamed, *import_id);
if let Some(name) = item.name
&& (cx.document_hidden() || !item.is_doc_hidden())
{
inserted.insert((item.type_(), name));
}
item
}));
items.extend(doc.mods.iter().filter_map(|x| {
if !inserted.insert((ItemType::Module, x.name)) {
return None;
}
let item = clean_doc_module(x, cx);
if !cx.document_hidden() && item.is_doc_hidden() {
// Hidden modules are stripped at a later stage.
// If a hidden module has the same name as a visible one, we want
// to keep both of them around.
inserted.remove(&(ItemType::Module, x.name));
}
Some(item)
}));
// Split up glob imports from all other items.
//
// This covers the case where somebody does an import which should pull in an item,
// but there's already an item with the same namespace and same name. Rust gives
// priority to the not-imported one, so we should, too.
items.extend(doc.items.values().flat_map(|(item, renamed, import_ids)| {
// First, lower everything other than glob imports.
if matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
return Vec::new();
}
let v = clean_maybe_renamed_item(cx, item, *renamed, import_ids);
for item in &v {
if let Some(name) = item.name
&& (cx.document_hidden() || !item.is_doc_hidden())
{
inserted.insert((item.type_(), name));
}
}
v
}));
items.extend(doc.inlined_foreigns.iter().flat_map(|((_, renamed), (res, local_import_id))| {
let Some(def_id) = res.opt_def_id() else { return Vec::new() };
let name = renamed.unwrap_or_else(|| cx.tcx.item_name(def_id));
let import = cx.tcx.hir_expect_item(*local_import_id);
match import.kind {
hir::ItemKind::Use(path, kind) => {
let hir::UsePath { segments, span, .. } = *path;
let path = hir::Path { segments, res: *res, span };
clean_use_statement_inner(
import,
Some(name),
&path,
kind,
cx,
&mut Default::default(),
)
}
_ => unreachable!(),
}
}));
items.extend(doc.items.values().flat_map(|(item, renamed, _)| {
// Now we actually lower the imports, skipping everything else.
if let hir::ItemKind::Use(path, hir::UseKind::Glob) = item.kind {
clean_use_statement(item, *renamed, path, hir::UseKind::Glob, cx, &mut inserted)
} else {
// skip everything else
Vec::new()
}
}));
// determine if we should display the inner contents or
// the outer `mod` item for the source code.
let span = Span::new({
let where_outer = doc.where_outer(cx.tcx);
let sm = cx.sess().source_map();
let outer = sm.lookup_char_pos(where_outer.lo());
let inner = sm.lookup_char_pos(doc.where_inner.lo());
if outer.file.start_pos == inner.file.start_pos {
// mod foo { ... }
where_outer
} else {
// mod foo; (and a separate SourceFile for the contents)
doc.where_inner
}
});
let kind = ModuleItem(Module { items, span });
generate_item_with_correct_attrs(
cx,
kind,
doc.def_id.to_def_id(),
doc.name,
doc.import_id.as_slice(),
doc.renamed,
)
}
fn is_glob_import(tcx: TyCtxt<'_>, import_id: LocalDefId) -> bool {
if let hir::Node::Item(item) = tcx.hir_node_by_def_id(import_id)
&& let hir::ItemKind::Use(_, use_kind) = item.kind
{
use_kind == hir::UseKind::Glob
} else {
false
}
}
fn generate_item_with_correct_attrs(
cx: &mut DocContext<'_>,
kind: ItemKind,
def_id: DefId,
name: Symbol,
import_ids: &[LocalDefId],
renamed: Option<Symbol>,
) -> Item {
let target_attrs = inline::load_attrs(cx, def_id);
let attrs = if !import_ids.is_empty() {
let mut attrs = Vec::with_capacity(import_ids.len());
let mut is_inline = false;
for import_id in import_ids.iter().copied() {
// glob reexports are treated the same as `#[doc(inline)]` items.
//
// For glob re-exports the item may or may not exist to be re-exported (potentially the
// cfgs on the path up until the glob can be removed, and only cfgs on the globbed item
// itself matter), for non-inlined re-exports see #85043.
let import_is_inline = find_attr!(
inline::load_attrs(cx, import_id.to_def_id()),
Doc(d)
if d.inline.first().is_some_and(|(inline, _)| *inline == DocInline::Inline)
) || (is_glob_import(cx.tcx, import_id)
&& (cx.document_hidden() || !cx.tcx.is_doc_hidden(def_id)));
attrs.extend(get_all_import_attributes(cx, import_id, def_id, is_inline));
is_inline = is_inline || import_is_inline;
}
add_without_unwanted_attributes(&mut attrs, target_attrs, is_inline, None);
attrs
} else {
// We only keep the item's attributes.
target_attrs.iter().map(|attr| (Cow::Borrowed(attr), None)).collect()
};
let attrs = Attributes::from_hir_iter(attrs.iter().map(|(attr, did)| (&**attr, *did)), false);
let name = renamed.or(Some(name));
let mut item = Item::from_def_id_and_attrs_and_parts(def_id, name, kind, attrs, None);
// FIXME (GuillaumeGomez): Should we also make `inline_stmt_id` a `Vec` instead of an `Option`?
item.inner.inline_stmt_id = import_ids.first().copied();
item
}
fn clean_generic_bound<'tcx>(
bound: &hir::GenericBound<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Option<GenericBound> {
Some(match bound {
hir::GenericBound::Outlives(lt) => GenericBound::Outlives(clean_lifetime(lt, cx)),
hir::GenericBound::Trait(t) => {
// `T: [const] Destruct` is hidden because `T: Destruct` is a no-op.
if let hir::BoundConstness::Maybe(_) = t.modifiers.constness
&& cx.tcx.lang_items().destruct_trait() == Some(t.trait_ref.trait_def_id().unwrap())
{
return None;
}
GenericBound::TraitBound(clean_poly_trait_ref(t, cx), t.modifiers)
}
hir::GenericBound::Use(args, ..) => {
GenericBound::Use(args.iter().map(|arg| clean_precise_capturing_arg(arg, cx)).collect())
}
})
}
pub(crate) fn clean_trait_ref_with_constraints<'tcx>(
cx: &mut DocContext<'tcx>,
trait_ref: ty::PolyTraitRef<'tcx>,
constraints: ThinVec<AssocItemConstraint>,
) -> Path {
let kind = ItemType::from_def_id(trait_ref.def_id(), cx.tcx);
if !matches!(kind, ItemType::Trait | ItemType::TraitAlias) {
span_bug!(cx.tcx.def_span(trait_ref.def_id()), "`TraitRef` had unexpected kind {kind:?}");
}
inline::record_extern_fqn(cx, trait_ref.def_id(), kind);
let path = clean_middle_path(
cx,
trait_ref.def_id(),
true,
constraints,
trait_ref.map_bound(|tr| tr.args),
);
debug!(?trait_ref);
path
}
fn clean_poly_trait_ref_with_constraints<'tcx>(
cx: &mut DocContext<'tcx>,
poly_trait_ref: ty::PolyTraitRef<'tcx>,
constraints: ThinVec<AssocItemConstraint>,
) -> GenericBound {
GenericBound::TraitBound(
PolyTrait {
trait_: clean_trait_ref_with_constraints(cx, poly_trait_ref, constraints),
generic_params: clean_bound_vars(poly_trait_ref.bound_vars(), cx),
},
hir::TraitBoundModifiers::NONE,
)
}
fn clean_lifetime(lifetime: &hir::Lifetime, cx: &DocContext<'_>) -> Lifetime {
if let Some(
rbv::ResolvedArg::EarlyBound(did)
| rbv::ResolvedArg::LateBound(_, _, did)
| rbv::ResolvedArg::Free(_, did),
) = cx.tcx.named_bound_var(lifetime.hir_id)
&& let Some(lt) = cx.args.get(&did.to_def_id()).and_then(|arg| arg.as_lt())
{
return *lt;
}
Lifetime(lifetime.ident.name)
}
pub(crate) fn clean_precise_capturing_arg(
arg: &hir::PreciseCapturingArg<'_>,
cx: &DocContext<'_>,
) -> PreciseCapturingArg {
match arg {
hir::PreciseCapturingArg::Lifetime(lt) => {
PreciseCapturingArg::Lifetime(clean_lifetime(lt, cx))
}
hir::PreciseCapturingArg::Param(param) => PreciseCapturingArg::Param(param.ident.name),
}
}
pub(crate) fn clean_const_item_rhs<'tcx>(
ct_rhs: hir::ConstItemRhs<'tcx>,
parent: DefId,
) -> ConstantKind {
match ct_rhs {
hir::ConstItemRhs::Body(body) => ConstantKind::Local { def_id: parent, body },
hir::ConstItemRhs::TypeConst(ct) => clean_const(ct),
}
}
pub(crate) fn clean_const<'tcx>(constant: &hir::ConstArg<'tcx>) -> ConstantKind {
match &constant.kind {
hir::ConstArgKind::Path(qpath) => {
ConstantKind::Path { path: qpath_to_string(qpath).into() }
}
hir::ConstArgKind::Struct(..) => {
// FIXME(mgca): proper printing :3
ConstantKind::Path { path: "/* STRUCT EXPR */".to_string().into() }
}
hir::ConstArgKind::TupleCall(..) => {
ConstantKind::Path { path: "/* TUPLE CALL */".to_string().into() }
}
hir::ConstArgKind::Tup(..) => {
// FIXME(mgca): proper printing :3
ConstantKind::Path { path: "/* TUPLE EXPR */".to_string().into() }
}
hir::ConstArgKind::Array(..) => {
ConstantKind::Path { path: "/* ARRAY EXPR */".to_string().into() }
}
hir::ConstArgKind::Anon(anon) => ConstantKind::Anonymous { body: anon.body },
hir::ConstArgKind::Infer(..) | hir::ConstArgKind::Error(..) => ConstantKind::Infer,
hir::ConstArgKind::Literal { .. } => {
ConstantKind::Path { path: "/* LITERAL */".to_string().into() }
}
}
}
pub(crate) fn clean_middle_const<'tcx>(
constant: ty::Binder<'tcx, ty::Const<'tcx>>,
_cx: &mut DocContext<'tcx>,
) -> ConstantKind {
// FIXME: instead of storing the stringified expression, store `self` directly instead.
ConstantKind::TyConst { expr: constant.skip_binder().to_string().into() }
}
pub(crate) fn clean_middle_region<'tcx>(
region: ty::Region<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Option<Lifetime> {
region.get_name(cx.tcx).map(Lifetime)
}
fn clean_where_predicate<'tcx>(
predicate: &hir::WherePredicate<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Option<WherePredicate> {
if !predicate.kind.in_where_clause() {
return None;
}
Some(match predicate.kind {
hir::WherePredicateKind::BoundPredicate(wbp) => {
let bound_params = wbp
.bound_generic_params
.iter()
.map(|param| clean_generic_param(cx, None, param))
.collect();
WherePredicate::BoundPredicate {
ty: clean_ty(wbp.bounded_ty, cx),
bounds: wbp.bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
bound_params,
}
}
hir::WherePredicateKind::RegionPredicate(wrp) => WherePredicate::RegionPredicate {
lifetime: clean_lifetime(wrp.lifetime, cx),
bounds: wrp.bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
},
// We should never actually reach this case because these predicates should've already been
// rejected in an earlier compiler pass. This feature isn't fully implemented (#20041).
hir::WherePredicateKind::EqPredicate(_) => bug!("EqPredicate"),
})
}
pub(crate) fn clean_predicate<'tcx>(
predicate: ty::Clause<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Option<WherePredicate> {
let bound_predicate = predicate.kind();
match bound_predicate.skip_binder() {
ty::ClauseKind::Trait(pred) => clean_poly_trait_predicate(bound_predicate.rebind(pred), cx),
ty::ClauseKind::RegionOutlives(pred) => Some(clean_region_outlives_predicate(pred, cx)),
ty::ClauseKind::TypeOutlives(pred) => {
Some(clean_type_outlives_predicate(bound_predicate.rebind(pred), cx))
}
ty::ClauseKind::Projection(pred) => {
Some(clean_projection_predicate(bound_predicate.rebind(pred), cx))
}
// FIXME(generic_const_exprs): should this do something?
ty::ClauseKind::ConstEvaluatable(..)
| ty::ClauseKind::WellFormed(..)
| ty::ClauseKind::ConstArgHasType(..)
| ty::ClauseKind::UnstableFeature(..)
// FIXME(const_trait_impl): We can probably use this `HostEffect` pred to render `~const`.
| ty::ClauseKind::HostEffect(_) => None,
}
}
fn clean_poly_trait_predicate<'tcx>(
pred: ty::PolyTraitPredicate<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Option<WherePredicate> {
// `T: [const] Destruct` is hidden because `T: Destruct` is a no-op.
// FIXME(const_trait_impl) check constness
if Some(pred.skip_binder().def_id()) == cx.tcx.lang_items().destruct_trait() {
return None;
}
let poly_trait_ref = pred.map_bound(|pred| pred.trait_ref);
Some(WherePredicate::BoundPredicate {
ty: clean_middle_ty(poly_trait_ref.self_ty(), cx, None, None),
bounds: vec![clean_poly_trait_ref_with_constraints(cx, poly_trait_ref, ThinVec::new())],
bound_params: Vec::new(),
})
}
fn clean_region_outlives_predicate<'tcx>(
pred: ty::RegionOutlivesPredicate<'tcx>,
cx: &mut DocContext<'tcx>,
) -> WherePredicate {
let ty::OutlivesPredicate(a, b) = pred;
WherePredicate::RegionPredicate {
lifetime: clean_middle_region(a, cx).expect("failed to clean lifetime"),
bounds: vec![GenericBound::Outlives(
clean_middle_region(b, cx).expect("failed to clean bounds"),
)],
}
}
fn clean_type_outlives_predicate<'tcx>(
pred: ty::Binder<'tcx, ty::TypeOutlivesPredicate<'tcx>>,
cx: &mut DocContext<'tcx>,
) -> WherePredicate {
let ty::OutlivesPredicate(ty, lt) = pred.skip_binder();
WherePredicate::BoundPredicate {
ty: clean_middle_ty(pred.rebind(ty), cx, None, None),
bounds: vec![GenericBound::Outlives(
clean_middle_region(lt, cx).expect("failed to clean lifetimes"),
)],
bound_params: Vec::new(),
}
}
fn clean_middle_term<'tcx>(
term: ty::Binder<'tcx, ty::Term<'tcx>>,
cx: &mut DocContext<'tcx>,
) -> Term {
match term.skip_binder().kind() {
ty::TermKind::Ty(ty) => Term::Type(clean_middle_ty(term.rebind(ty), cx, None, None)),
ty::TermKind::Const(c) => Term::Constant(clean_middle_const(term.rebind(c), cx)),
}
}
fn clean_hir_term<'tcx>(
assoc_item: Option<DefId>,
term: &hir::Term<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Term {
match term {
hir::Term::Ty(ty) => Term::Type(clean_ty(ty, cx)),
hir::Term::Const(c) => {
// FIXME(generic_const_items): this should instantiate with the alias item's args
let ty = cx.tcx.type_of(assoc_item.unwrap()).instantiate_identity();
let ct = lower_const_arg_for_rustdoc(cx.tcx, c, ty);
Term::Constant(clean_middle_const(ty::Binder::dummy(ct), cx))
}
}
}
fn clean_projection_predicate<'tcx>(
pred: ty::Binder<'tcx, ty::ProjectionPredicate<'tcx>>,
cx: &mut DocContext<'tcx>,
) -> WherePredicate {
WherePredicate::EqPredicate {
lhs: clean_projection(pred.map_bound(|p| p.projection_term), cx, None),
rhs: clean_middle_term(pred.map_bound(|p| p.term), cx),
}
}
fn clean_projection<'tcx>(
proj: ty::Binder<'tcx, ty::AliasTerm<'tcx>>,
cx: &mut DocContext<'tcx>,
parent_def_id: Option<DefId>,
) -> QPathData {
let trait_ = clean_trait_ref_with_constraints(
cx,
proj.map_bound(|proj| proj.trait_ref(cx.tcx)),
ThinVec::new(),
);
let self_type = clean_middle_ty(proj.map_bound(|proj| proj.self_ty()), cx, None, None);
let self_def_id = match parent_def_id {
Some(parent_def_id) => cx.tcx.opt_parent(parent_def_id).or(Some(parent_def_id)),
None => self_type.def_id(&cx.cache),
};
let should_fully_qualify = should_fully_qualify_path(self_def_id, &trait_, &self_type);
QPathData {
assoc: projection_to_path_segment(proj, cx),
self_type,
should_fully_qualify,
trait_: Some(trait_),
}
}
fn should_fully_qualify_path(self_def_id: Option<DefId>, trait_: &Path, self_type: &Type) -> bool {
!trait_.segments.is_empty()
&& self_def_id
.zip(Some(trait_.def_id()))
.map_or(!self_type.is_self_type(), |(id, trait_)| id != trait_)
}
fn projection_to_path_segment<'tcx>(
proj: ty::Binder<'tcx, ty::AliasTerm<'tcx>>,
cx: &mut DocContext<'tcx>,
) -> PathSegment {
let def_id = proj.skip_binder().def_id;
let generics = cx.tcx.generics_of(def_id);
PathSegment {
name: cx.tcx.item_name(def_id),
args: GenericArgs::AngleBracketed {
args: clean_middle_generic_args(
cx,
proj.map_bound(|ty| &ty.args[generics.parent_count..]),
false,
def_id,
),
constraints: Default::default(),
},
}
}
fn clean_generic_param_def(
def: &ty::GenericParamDef,
defaults: ParamDefaults,
cx: &mut DocContext<'_>,
) -> GenericParamDef {
let (name, kind) = match def.kind {
ty::GenericParamDefKind::Lifetime => {
(def.name, GenericParamDefKind::Lifetime { outlives: ThinVec::new() })
}
ty::GenericParamDefKind::Type { has_default, synthetic, .. } => {
let default = if let ParamDefaults::Yes = defaults
&& has_default
{
Some(clean_middle_ty(
ty::Binder::dummy(cx.tcx.type_of(def.def_id).instantiate_identity()),
cx,
Some(def.def_id),
None,
))
} else {
None
};
(
def.name,
GenericParamDefKind::Type {
bounds: ThinVec::new(), // These are filled in from the where-clauses.
default: default.map(Box::new),
synthetic,
},
)
}
ty::GenericParamDefKind::Const { has_default } => (
def.name,
GenericParamDefKind::Const {
ty: Box::new(clean_middle_ty(
ty::Binder::dummy(cx.tcx.type_of(def.def_id).instantiate_identity()),
cx,
Some(def.def_id),
None,
)),
default: if let ParamDefaults::Yes = defaults
&& has_default
{
Some(Box::new(
cx.tcx.const_param_default(def.def_id).instantiate_identity().to_string(),
))
} else {
None
},
},
),
};
GenericParamDef { name, def_id: def.def_id, kind }
}
/// Whether to clean generic parameter defaults or not.
enum ParamDefaults {
Yes,
No,
}
fn clean_generic_param<'tcx>(
cx: &mut DocContext<'tcx>,
generics: Option<&hir::Generics<'tcx>>,
param: &hir::GenericParam<'tcx>,
) -> GenericParamDef {
let (name, kind) = match param.kind {
hir::GenericParamKind::Lifetime { .. } => {
let outlives = if let Some(generics) = generics {
generics
.outlives_for_param(param.def_id)
.filter(|bp| !bp.in_where_clause)
.flat_map(|bp| bp.bounds)
.map(|bound| match bound {
hir::GenericBound::Outlives(lt) => clean_lifetime(lt, cx),
_ => panic!(),
})
.collect()
} else {
ThinVec::new()
};
(param.name.ident().name, GenericParamDefKind::Lifetime { outlives })
}
hir::GenericParamKind::Type { ref default, synthetic } => {
let bounds = if let Some(generics) = generics {
generics
.bounds_for_param(param.def_id)
.filter(|bp| bp.origin != PredicateOrigin::WhereClause)
.flat_map(|bp| bp.bounds)
.filter_map(|x| clean_generic_bound(x, cx))
.collect()
} else {
ThinVec::new()
};
(
param.name.ident().name,
GenericParamDefKind::Type {
bounds,
default: default.map(|t| clean_ty(t, cx)).map(Box::new),
synthetic,
},
)
}
hir::GenericParamKind::Const { ty, default } => (
param.name.ident().name,
GenericParamDefKind::Const {
ty: Box::new(clean_ty(ty, cx)),
default: default.map(|ct| {
Box::new(
lower_const_arg_for_rustdoc(cx.tcx, ct, lower_ty(cx.tcx, ty)).to_string(),
)
}),
},
),
};
GenericParamDef { name, def_id: param.def_id.to_def_id(), kind }
}
/// Synthetic type-parameters are inserted after normal ones.
/// In order for normal parameters to be able to refer to synthetic ones,
/// scans them first.
fn is_impl_trait(param: &hir::GenericParam<'_>) -> bool {
match param.kind {
hir::GenericParamKind::Type { synthetic, .. } => synthetic,
_ => false,
}
}
/// This can happen for `async fn`, e.g. `async fn f<'_>(&'_ self)`.
///
/// See `lifetime_to_generic_param` in `rustc_ast_lowering` for more information.
fn is_elided_lifetime(param: &hir::GenericParam<'_>) -> bool {
matches!(
param.kind,
hir::GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Elided(_) }
)
}
pub(crate) fn clean_generics<'tcx>(
gens: &hir::Generics<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Generics {
let impl_trait_params = gens
.params
.iter()
.filter(|param| is_impl_trait(param))
.map(|param| {
let param = clean_generic_param(cx, Some(gens), param);
match param.kind {
GenericParamDefKind::Lifetime { .. } => unreachable!(),
GenericParamDefKind::Type { ref bounds, .. } => {
cx.impl_trait_bounds.insert(param.def_id.into(), bounds.to_vec());
}
GenericParamDefKind::Const { .. } => unreachable!(),
}
param
})
.collect::<Vec<_>>();
let mut bound_predicates = FxIndexMap::default();
let mut region_predicates = FxIndexMap::default();
let mut eq_predicates = ThinVec::default();
for pred in gens.predicates.iter().filter_map(|x| clean_where_predicate(x, cx)) {
match pred {
WherePredicate::BoundPredicate { ty, bounds, bound_params } => {
match bound_predicates.entry(ty) {
IndexEntry::Vacant(v) => {
v.insert((bounds, bound_params));
}
IndexEntry::Occupied(mut o) => {
// we merge both bounds.
for bound in bounds {
if !o.get().0.contains(&bound) {
o.get_mut().0.push(bound);
}
}
for bound_param in bound_params {
if !o.get().1.contains(&bound_param) {
o.get_mut().1.push(bound_param);
}
}
}
}
}
WherePredicate::RegionPredicate { lifetime, bounds } => {
match region_predicates.entry(lifetime) {
IndexEntry::Vacant(v) => {
v.insert(bounds);
}
IndexEntry::Occupied(mut o) => {
// we merge both bounds.
for bound in bounds {
if !o.get().contains(&bound) {
o.get_mut().push(bound);
}
}
}
}
}
WherePredicate::EqPredicate { lhs, rhs } => {
eq_predicates.push(WherePredicate::EqPredicate { lhs, rhs });
}
}
}
let mut params = ThinVec::with_capacity(gens.params.len());
// In this loop, we gather the generic parameters (`<'a, B: 'a>`) and check if they have
// bounds in the where predicates. If so, we move their bounds into the where predicates
// while also preventing duplicates.
for p in gens.params.iter().filter(|p| !is_impl_trait(p) && !is_elided_lifetime(p)) {
let mut p = clean_generic_param(cx, Some(gens), p);
match &mut p.kind {
GenericParamDefKind::Lifetime { outlives } => {
if let Some(region_pred) = region_predicates.get_mut(&Lifetime(p.name)) {
// We merge bounds in the `where` clause.
for outlive in outlives.drain(..) {
let outlive = GenericBound::Outlives(outlive);
if !region_pred.contains(&outlive) {
region_pred.push(outlive);
}
}
}
}
GenericParamDefKind::Type { bounds, synthetic: false, .. } => {
if let Some(bound_pred) = bound_predicates.get_mut(&Type::Generic(p.name)) {
// We merge bounds in the `where` clause.
for bound in bounds.drain(..) {
if !bound_pred.0.contains(&bound) {
bound_pred.0.push(bound);
}
}
}
}
GenericParamDefKind::Type { .. } | GenericParamDefKind::Const { .. } => {
// nothing to do here.
}
}
params.push(p);
}
params.extend(impl_trait_params);
Generics {
params,
where_predicates: bound_predicates
.into_iter()
.map(|(ty, (bounds, bound_params))| WherePredicate::BoundPredicate {
ty,
bounds,
bound_params,
})
.chain(
region_predicates
.into_iter()
.map(|(lifetime, bounds)| WherePredicate::RegionPredicate { lifetime, bounds }),
)
.chain(eq_predicates)
.collect(),
}
}
fn clean_ty_generics<'tcx>(cx: &mut DocContext<'tcx>, def_id: DefId) -> Generics {
clean_ty_generics_inner(cx, cx.tcx.generics_of(def_id), cx.tcx.explicit_predicates_of(def_id))
}
fn clean_ty_generics_inner<'tcx>(
cx: &mut DocContext<'tcx>,
gens: &ty::Generics,
preds: ty::GenericPredicates<'tcx>,
) -> Generics {
// Don't populate `cx.impl_trait_bounds` before cleaning where clauses,
// since `clean_predicate` would consume them.
let mut impl_trait = BTreeMap::<u32, Vec<GenericBound>>::default();
let params: ThinVec<_> = gens
.own_params
.iter()
.filter(|param| match param.kind {
ty::GenericParamDefKind::Lifetime => !param.is_anonymous_lifetime(),
ty::GenericParamDefKind::Type { synthetic, .. } => {
if param.name == kw::SelfUpper {
debug_assert_eq!(param.index, 0);
return false;
}
if synthetic {
impl_trait.insert(param.index, vec![]);
return false;
}
true
}
ty::GenericParamDefKind::Const { .. } => true,
})
.map(|param| clean_generic_param_def(param, ParamDefaults::Yes, cx))
.collect();
// param index -> [(trait DefId, associated type name & generics, term)]
let mut impl_trait_proj =
FxHashMap::<u32, Vec<(DefId, PathSegment, ty::Binder<'_, ty::Term<'_>>)>>::default();
let where_predicates = preds
.predicates
.iter()
.flat_map(|(pred, _)| {
let mut proj_pred = None;
let param_idx = {
let bound_p = pred.kind();
match bound_p.skip_binder() {
ty::ClauseKind::Trait(pred) if let ty::Param(param) = pred.self_ty().kind() => {
Some(param.index)
}
ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(ty, _reg))
if let ty::Param(param) = ty.kind() =>
{
Some(param.index)
}
ty::ClauseKind::Projection(p)
if let ty::Param(param) = p.projection_term.self_ty().kind() =>
{
proj_pred = Some(bound_p.rebind(p));
Some(param.index)
}
_ => None,
}
};
if let Some(param_idx) = param_idx
&& let Some(bounds) = impl_trait.get_mut(&param_idx)
{
let pred = clean_predicate(*pred, cx)?;
bounds.extend(pred.get_bounds().into_iter().flatten().cloned());
if let Some(pred) = proj_pred {
let lhs = clean_projection(pred.map_bound(|p| p.projection_term), cx, None);
impl_trait_proj.entry(param_idx).or_default().push((
lhs.trait_.unwrap().def_id(),
lhs.assoc,
pred.map_bound(|p| p.term),
));
}
return None;
}
Some(pred)
})
.collect::<Vec<_>>();
for (idx, mut bounds) in impl_trait {
let mut has_sized = false;
bounds.retain(|b| {
if b.is_sized_bound(cx) {
has_sized = true;
false
} else if b.is_meta_sized_bound(cx) {
// FIXME(sized-hierarchy): Always skip `MetaSized` bounds so that only `?Sized`
// is shown and none of the new sizedness traits leak into documentation.
false
} else {
true
}
});
if !has_sized {
bounds.push(GenericBound::maybe_sized(cx));
}
// Move trait bounds to the front.
bounds.sort_by_key(|b| !b.is_trait_bound());
// Add back a `Sized` bound if there are no *trait* bounds remaining (incl. `?Sized`).
// Since all potential trait bounds are at the front we can just check the first bound.
if bounds.first().is_none_or(|b| !b.is_trait_bound()) {
bounds.insert(0, GenericBound::sized(cx));
}
if let Some(proj) = impl_trait_proj.remove(&idx) {
for (trait_did, name, rhs) in proj {
let rhs = clean_middle_term(rhs, cx);
simplify::merge_bounds(cx, &mut bounds, trait_did, name, &rhs);
}
}
cx.impl_trait_bounds.insert(idx.into(), bounds);
}
// Now that `cx.impl_trait_bounds` is populated, we can process
// remaining predicates which could contain `impl Trait`.
let where_predicates =
where_predicates.into_iter().flat_map(|p| clean_predicate(*p, cx)).collect();
let mut generics = Generics { params, where_predicates };
simplify::sized_bounds(cx, &mut generics);
generics.where_predicates = simplify::where_clauses(cx, generics.where_predicates);
generics
}
fn clean_ty_alias_inner_type<'tcx>(
ty: Ty<'tcx>,
cx: &mut DocContext<'tcx>,
ret: &mut Vec<Item>,
) -> Option<TypeAliasInnerType> {
let ty::Adt(adt_def, args) = ty.kind() else {
return None;
};
if !adt_def.did().is_local() {
cx.with_param_env(adt_def.did(), |cx| {
inline::build_impls(cx, adt_def.did(), None, ret);
});
}
Some(if adt_def.is_enum() {
let variants: rustc_index::IndexVec<_, _> = adt_def
.variants()
.iter()
.map(|variant| clean_variant_def_with_args(variant, args, cx))
.collect();
if !adt_def.did().is_local() {
inline::record_extern_fqn(cx, adt_def.did(), ItemType::Enum);
}
TypeAliasInnerType::Enum {
variants,
is_non_exhaustive: adt_def.is_variant_list_non_exhaustive(),
}
} else {
let variant = adt_def
.variants()
.iter()
.next()
.unwrap_or_else(|| bug!("a struct or union should always have one variant def"));
let fields: Vec<_> =
clean_variant_def_with_args(variant, args, cx).kind.inner_items().cloned().collect();
if adt_def.is_struct() {
if !adt_def.did().is_local() {
inline::record_extern_fqn(cx, adt_def.did(), ItemType::Struct);
}
TypeAliasInnerType::Struct { ctor_kind: variant.ctor_kind(), fields }
} else {
if !adt_def.did().is_local() {
inline::record_extern_fqn(cx, adt_def.did(), ItemType::Union);
}
TypeAliasInnerType::Union { fields }
}
})
}
fn clean_proc_macro<'tcx>(
item: &hir::Item<'tcx>,
name: &mut Symbol,
kind: MacroKind,
cx: &mut DocContext<'tcx>,
) -> ItemKind {
if kind != MacroKind::Derive {
return ProcMacroItem(ProcMacro { kind, helpers: vec![] });
}
let attrs = cx.tcx.hir_attrs(item.hir_id());
let Some((trait_name, helper_attrs)) = find_attr!(attrs, ProcMacroDerive { trait_name, helper_attrs, ..} => (*trait_name, helper_attrs))
else {
return ProcMacroItem(ProcMacro { kind, helpers: vec![] });
};
*name = trait_name;
let helpers = helper_attrs.iter().copied().collect();
ProcMacroItem(ProcMacro { kind, helpers })
}
fn clean_fn_or_proc_macro<'tcx>(
item: &hir::Item<'tcx>,
sig: &hir::FnSig<'tcx>,
generics: &hir::Generics<'tcx>,
body_id: hir::BodyId,
name: &mut Symbol,
cx: &mut DocContext<'tcx>,
) -> ItemKind {
let attrs = cx.tcx.hir_attrs(item.hir_id());
let macro_kind = if find_attr!(attrs, ProcMacro(..)) {
Some(MacroKind::Bang)
} else if find_attr!(attrs, ProcMacroDerive { .. }) {
Some(MacroKind::Derive)
} else if find_attr!(attrs, ProcMacroAttribute(..)) {
Some(MacroKind::Attr)
} else {
None
};
match macro_kind {
Some(kind) => clean_proc_macro(item, name, kind, cx),
None => {
let mut func = clean_function(cx, sig, generics, ParamsSrc::Body(body_id));
clean_fn_decl_legacy_const_generics(&mut func, attrs);
FunctionItem(func)
}
}
}
/// This is needed to make it more "readable" when documenting functions using
/// `rustc_legacy_const_generics`. More information in
/// <https://github.com/rust-lang/rust/issues/83167>.
fn clean_fn_decl_legacy_const_generics(func: &mut Function, attrs: &[hir::Attribute]) {
let Some(indexes) = find_attr!(attrs, RustcLegacyConstGenerics{fn_indexes,..} => fn_indexes)
else {
return;
};
for (pos, (index, _)) in indexes.iter().enumerate() {
let GenericParamDef { name, kind, .. } = func.generics.params.remove(0);
if let GenericParamDefKind::Const { ty, .. } = kind {
func.decl
.inputs
.insert(*index, Parameter { name: Some(name), type_: *ty, is_const: true });
} else {
panic!("unexpected non const in position {pos}");
}
}
}
enum ParamsSrc<'tcx> {
Body(hir::BodyId),
Idents(&'tcx [Option<Ident>]),
}
fn clean_function<'tcx>(
cx: &mut DocContext<'tcx>,
sig: &hir::FnSig<'tcx>,
generics: &hir::Generics<'tcx>,
params: ParamsSrc<'tcx>,
) -> Box<Function> {
let (generics, decl) = enter_impl_trait(cx, |cx| {
// NOTE: Generics must be cleaned before params.
let generics = clean_generics(generics, cx);
let params = match params {
ParamsSrc::Body(body_id) => clean_params_via_body(cx, sig.decl.inputs, body_id),
// Let's not perpetuate anon params from Rust 2015; use `_` for them.
ParamsSrc::Idents(idents) => clean_params(cx, sig.decl.inputs, idents, |ident| {
Some(ident.map_or(kw::Underscore, |ident| ident.name))
}),
};
let decl = clean_fn_decl_with_params(cx, sig.decl, Some(&sig.header), params);
(generics, decl)
});
Box::new(Function { decl, generics })
}
fn clean_params<'tcx>(
cx: &mut DocContext<'tcx>,
types: &[hir::Ty<'tcx>],
idents: &[Option<Ident>],
postprocess: impl Fn(Option<Ident>) -> Option<Symbol>,
) -> Vec<Parameter> {
types
.iter()
.enumerate()
.map(|(i, ty)| Parameter {
name: postprocess(idents[i]),
type_: clean_ty(ty, cx),
is_const: false,
})
.collect()
}
fn clean_params_via_body<'tcx>(
cx: &mut DocContext<'tcx>,
types: &[hir::Ty<'tcx>],
body_id: hir::BodyId,
) -> Vec<Parameter> {
types
.iter()
.zip(cx.tcx.hir_body(body_id).params)
.map(|(ty, param)| Parameter {
name: Some(name_from_pat(param.pat)),
type_: clean_ty(ty, cx),
is_const: false,
})
.collect()
}
fn clean_fn_decl_with_params<'tcx>(
cx: &mut DocContext<'tcx>,
decl: &hir::FnDecl<'tcx>,
header: Option<&hir::FnHeader>,
params: Vec<Parameter>,
) -> FnDecl {
let mut output = match decl.output {
hir::FnRetTy::Return(typ) => clean_ty(typ, cx),
hir::FnRetTy::DefaultReturn(..) => Type::Tuple(Vec::new()),
};
if let Some(header) = header
&& header.is_async()
{
output = output.sugared_async_return_type();
}
FnDecl { inputs: params, output, c_variadic: decl.c_variadic }
}
fn clean_poly_fn_sig<'tcx>(
cx: &mut DocContext<'tcx>,
did: Option<DefId>,
sig: ty::PolyFnSig<'tcx>,
) -> FnDecl {
let mut output = clean_middle_ty(sig.output(), cx, None, None);
// If the return type isn't an `impl Trait`, we can safely assume that this
// function isn't async without needing to execute the query `asyncness` at
// all which gives us a noticeable performance boost.
if let Some(did) = did
&& let Type::ImplTrait(_) = output
&& cx.tcx.asyncness(did).is_async()
{
output = output.sugared_async_return_type();
}
let mut idents = did.map(|did| cx.tcx.fn_arg_idents(did)).unwrap_or_default().iter().copied();
// If this comes from a fn item, let's not perpetuate anon params from Rust 2015; use `_` for them.
// If this comes from a fn ptr ty, we just keep params unnamed since it's more conventional stylistically.
// Since the param name is not part of the semantic type, these params never bear a name unlike
// in the HIR case, thus we can't perform any fancy fallback logic unlike `clean_bare_fn_ty`.
let fallback = did.map(|_| kw::Underscore);
let params = sig
.inputs()
.iter()
.map(|ty| Parameter {
name: idents.next().flatten().map(|ident| ident.name).or(fallback),
type_: clean_middle_ty(ty.map_bound(|ty| *ty), cx, None, None),
is_const: false,
})
.collect();
FnDecl { inputs: params, output, c_variadic: sig.skip_binder().c_variadic }
}
fn clean_trait_ref<'tcx>(trait_ref: &hir::TraitRef<'tcx>, cx: &mut DocContext<'tcx>) -> Path {
let path = clean_path(trait_ref.path, cx);
register_res(cx, path.res);
path
}
fn clean_poly_trait_ref<'tcx>(
poly_trait_ref: &hir::PolyTraitRef<'tcx>,
cx: &mut DocContext<'tcx>,
) -> PolyTrait {
PolyTrait {
trait_: clean_trait_ref(&poly_trait_ref.trait_ref, cx),
generic_params: poly_trait_ref
.bound_generic_params
.iter()
.filter(|p| !is_elided_lifetime(p))
.map(|x| clean_generic_param(cx, None, x))
.collect(),
}
}
fn clean_trait_item<'tcx>(trait_item: &hir::TraitItem<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
let local_did = trait_item.owner_id.to_def_id();
cx.with_param_env(local_did, |cx| {
let inner = match trait_item.kind {
hir::TraitItemKind::Const(ty, Some(default), _) => {
ProvidedAssocConstItem(Box::new(Constant {
generics: enter_impl_trait(cx, |cx| clean_generics(trait_item.generics, cx)),
kind: clean_const_item_rhs(default, local_did),
type_: clean_ty(ty, cx),
}))
}
hir::TraitItemKind::Const(ty, None, _) => {
let generics = enter_impl_trait(cx, |cx| clean_generics(trait_item.generics, cx));
RequiredAssocConstItem(generics, Box::new(clean_ty(ty, cx)))
}
hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
let m = clean_function(cx, sig, trait_item.generics, ParamsSrc::Body(body));
MethodItem(m, Defaultness::from_trait_item(trait_item.defaultness))
}
hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Required(idents)) => {
let m = clean_function(cx, sig, trait_item.generics, ParamsSrc::Idents(idents));
RequiredMethodItem(m, Defaultness::from_trait_item(trait_item.defaultness))
}
hir::TraitItemKind::Type(bounds, Some(default)) => {
let generics = enter_impl_trait(cx, |cx| clean_generics(trait_item.generics, cx));
let bounds = bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect();
let item_type =
clean_middle_ty(ty::Binder::dummy(lower_ty(cx.tcx, default)), cx, None, None);
AssocTypeItem(
Box::new(TypeAlias {
type_: clean_ty(default, cx),
generics,
inner_type: None,
item_type: Some(item_type),
}),
bounds,
)
}
hir::TraitItemKind::Type(bounds, None) => {
let generics = enter_impl_trait(cx, |cx| clean_generics(trait_item.generics, cx));
let bounds = bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect();
RequiredAssocTypeItem(generics, bounds)
}
};
Item::from_def_id_and_parts(local_did, Some(trait_item.ident.name), inner, cx)
})
}
pub(crate) fn clean_impl_item<'tcx>(
impl_: &hir::ImplItem<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Item {
let local_did = impl_.owner_id.to_def_id();
cx.with_param_env(local_did, |cx| {
let inner = match impl_.kind {
hir::ImplItemKind::Const(ty, expr) => ImplAssocConstItem(Box::new(Constant {
generics: clean_generics(impl_.generics, cx),
kind: clean_const_item_rhs(expr, local_did),
type_: clean_ty(ty, cx),
})),
hir::ImplItemKind::Fn(ref sig, body) => {
let m = clean_function(cx, sig, impl_.generics, ParamsSrc::Body(body));
let defaultness = match impl_.impl_kind {
hir::ImplItemImplKind::Inherent { .. } => hir::Defaultness::Final,
hir::ImplItemImplKind::Trait { defaultness, .. } => defaultness,
};
MethodItem(m, Defaultness::from_impl_item(defaultness))
}
hir::ImplItemKind::Type(hir_ty) => {
let type_ = clean_ty(hir_ty, cx);
let generics = clean_generics(impl_.generics, cx);
let item_type =
clean_middle_ty(ty::Binder::dummy(lower_ty(cx.tcx, hir_ty)), cx, None, None);
AssocTypeItem(
Box::new(TypeAlias {
type_,
generics,
inner_type: None,
item_type: Some(item_type),
}),
Vec::new(),
)
}
};
Item::from_def_id_and_parts(local_did, Some(impl_.ident.name), inner, cx)
})
}
pub(crate) fn clean_middle_assoc_item(assoc_item: &ty::AssocItem, cx: &mut DocContext<'_>) -> Item {
let tcx = cx.tcx;
let kind = match assoc_item.kind {
ty::AssocKind::Const { .. } => {
let ty = clean_middle_ty(
ty::Binder::dummy(tcx.type_of(assoc_item.def_id).instantiate_identity()),
cx,
Some(assoc_item.def_id),
None,
);
let mut generics = clean_ty_generics(cx, assoc_item.def_id);
simplify::move_bounds_to_generic_parameters(&mut generics);
match assoc_item.container {
ty::AssocContainer::InherentImpl | ty::AssocContainer::TraitImpl(_) => {
ImplAssocConstItem(Box::new(Constant {
generics,
kind: ConstantKind::Extern { def_id: assoc_item.def_id },
type_: ty,
}))
}
ty::AssocContainer::Trait => {
if tcx.defaultness(assoc_item.def_id).has_value() {
ProvidedAssocConstItem(Box::new(Constant {
generics,
kind: ConstantKind::Extern { def_id: assoc_item.def_id },
type_: ty,
}))
} else {
RequiredAssocConstItem(generics, Box::new(ty))
}
}
}
}
ty::AssocKind::Fn { has_self, .. } => {
let mut item = inline::build_function(cx, assoc_item.def_id);
if has_self {
let self_ty = match assoc_item.container {
ty::AssocContainer::InherentImpl | ty::AssocContainer::TraitImpl(_) => {
tcx.type_of(assoc_item.container_id(tcx)).instantiate_identity()
}
ty::AssocContainer::Trait => tcx.types.self_param,
};
let self_param_ty =
tcx.fn_sig(assoc_item.def_id).instantiate_identity().input(0).skip_binder();
if self_param_ty == self_ty {
item.decl.inputs[0].type_ = SelfTy;
} else if let ty::Ref(_, ty, _) = *self_param_ty.kind()
&& ty == self_ty
{
match item.decl.inputs[0].type_ {
BorrowedRef { ref mut type_, .. } => **type_ = SelfTy,
_ => unreachable!(),
}
}
}
let defaultness = assoc_item.defaultness(tcx);
let (provided, defaultness) = match assoc_item.container {
ty::AssocContainer::Trait => {
(defaultness.has_value(), Defaultness::from_trait_item(defaultness))
}
ty::AssocContainer::InherentImpl | ty::AssocContainer::TraitImpl(_) => {
(true, Defaultness::from_impl_item(defaultness))
}
};
if provided {
MethodItem(item, defaultness)
} else {
RequiredMethodItem(item, defaultness)
}
}
ty::AssocKind::Type { .. } => {
let my_name = assoc_item.name();
fn param_eq_arg(param: &GenericParamDef, arg: &GenericArg) -> bool {
match (&param.kind, arg) {
(GenericParamDefKind::Type { .. }, GenericArg::Type(Type::Generic(ty)))
if *ty == param.name =>
{
true
}
(GenericParamDefKind::Lifetime { .. }, GenericArg::Lifetime(Lifetime(lt)))
if *lt == param.name =>
{
true
}
(GenericParamDefKind::Const { .. }, GenericArg::Const(c)) => match &**c {
ConstantKind::TyConst { expr } => **expr == *param.name.as_str(),
_ => false,
},
_ => false,
}
}
let mut predicates = tcx.explicit_predicates_of(assoc_item.def_id).predicates;
if let ty::AssocContainer::Trait = assoc_item.container {
let bounds = tcx.explicit_item_bounds(assoc_item.def_id).iter_identity_copied();
predicates = tcx.arena.alloc_from_iter(bounds.chain(predicates.iter().copied()));
}
let mut generics = clean_ty_generics_inner(
cx,
tcx.generics_of(assoc_item.def_id),
ty::GenericPredicates { parent: None, predicates },
);
simplify::move_bounds_to_generic_parameters(&mut generics);
if let ty::AssocContainer::Trait = assoc_item.container {
// Move bounds that are (likely) directly attached to the associated type
// from the where-clause to the associated type.
// There is no guarantee that this is what the user actually wrote but we have
// no way of knowing.
let mut bounds: Vec<GenericBound> = Vec::new();
generics.where_predicates.retain_mut(|pred| match *pred {
WherePredicate::BoundPredicate {
ty:
QPath(box QPathData {
ref assoc,
ref self_type,
trait_: Some(ref trait_),
..
}),
bounds: ref mut pred_bounds,
..
} => {
if assoc.name != my_name {
return true;
}
if trait_.def_id() != assoc_item.container_id(tcx) {
return true;
}
if *self_type != SelfTy {
return true;
}
match &assoc.args {
GenericArgs::AngleBracketed { args, constraints } => {
if !constraints.is_empty()
|| generics
.params
.iter()
.zip(args.iter())
.any(|(param, arg)| !param_eq_arg(param, arg))
{
return true;
}
}
GenericArgs::Parenthesized { .. } => {
// The only time this happens is if we're inside the rustdoc for Fn(),
// which only has one associated type, which is not a GAT, so whatever.
}
GenericArgs::ReturnTypeNotation => {
// Never move these.
}
}
bounds.extend(mem::take(pred_bounds));
false
}
_ => true,
});
bounds.retain(|b| {
// FIXME(sized-hierarchy): Always skip `MetaSized` bounds so that only `?Sized`
// is shown and none of the new sizedness traits leak into documentation.
!b.is_meta_sized_bound(cx)
});
// Our Sized/?Sized bound didn't get handled when creating the generics
// because we didn't actually get our whole set of bounds until just now
// (some of them may have come from the trait). If we do have a sized
// bound, we remove it, and if we don't then we add the `?Sized` bound
// at the end.
match bounds.iter().position(|b| b.is_sized_bound(cx)) {
Some(i) => {
bounds.remove(i);
}
None => bounds.push(GenericBound::maybe_sized(cx)),
}
if tcx.defaultness(assoc_item.def_id).has_value() {
AssocTypeItem(
Box::new(TypeAlias {
type_: clean_middle_ty(
ty::Binder::dummy(
tcx.type_of(assoc_item.def_id).instantiate_identity(),
),
cx,
Some(assoc_item.def_id),
None,
),
generics,
inner_type: None,
item_type: None,
}),
bounds,
)
} else {
RequiredAssocTypeItem(generics, bounds)
}
} else {
AssocTypeItem(
Box::new(TypeAlias {
type_: clean_middle_ty(
ty::Binder::dummy(
tcx.type_of(assoc_item.def_id).instantiate_identity(),
),
cx,
Some(assoc_item.def_id),
None,
),
generics,
inner_type: None,
item_type: None,
}),
// Associated types inside trait or inherent impls are not allowed to have
// item bounds. Thus we don't attempt to move any bounds there.
Vec::new(),
)
}
}
};
Item::from_def_id_and_parts(assoc_item.def_id, Some(assoc_item.name()), kind, cx)
}
fn first_non_private_clean_path<'tcx>(
cx: &mut DocContext<'tcx>,
path: &hir::Path<'tcx>,
new_path_segments: &'tcx [hir::PathSegment<'tcx>],
new_path_span: rustc_span::Span,
) -> Path {
let new_hir_path =
hir::Path { segments: new_path_segments, res: path.res, span: new_path_span };
let mut new_clean_path = clean_path(&new_hir_path, cx);
// In here we need to play with the path data one last time to provide it the
// missing `args` and `res` of the final `Path` we get, which, since it comes
// from a re-export, doesn't have the generics that were originally there, so
// we add them by hand.
if let Some(path_last) = path.segments.last().as_ref()
&& let Some(new_path_last) = new_clean_path.segments[..].last_mut()
&& let Some(path_last_args) = path_last.args.as_ref()
&& path_last.args.is_some()
{
assert!(new_path_last.args.is_empty());
new_path_last.args = clean_generic_args(None, path_last_args, cx);
}
new_clean_path
}
/// The goal of this function is to return the first `Path` which is not private (ie not private
/// or `doc(hidden)`). If it's not possible, it'll return the "end type".
///
/// If the path is not a re-export or is public, it'll return `None`.
fn first_non_private<'tcx>(
cx: &mut DocContext<'tcx>,
hir_id: hir::HirId,
path: &hir::Path<'tcx>,
) -> Option<Path> {
let target_def_id = path.res.opt_def_id()?;
let (parent_def_id, ident) = match &path.segments {
[] => return None,
// Relative paths are available in the same scope as the owner.
[leaf] => (cx.tcx.local_parent(hir_id.owner.def_id), leaf.ident),
// So are self paths.
[parent, leaf] if parent.ident.name == kw::SelfLower => {
(cx.tcx.local_parent(hir_id.owner.def_id), leaf.ident)
}
// Crate paths are not. We start from the crate root.
[parent, leaf] if matches!(parent.ident.name, kw::Crate | kw::PathRoot) => {
(LOCAL_CRATE.as_def_id().as_local()?, leaf.ident)
}
[parent, leaf] if parent.ident.name == kw::Super => {
let parent_mod = cx.tcx.parent_module(hir_id);
if let Some(super_parent) = cx.tcx.opt_local_parent(parent_mod.to_local_def_id()) {
(super_parent, leaf.ident)
} else {
// If we can't find the parent of the parent, then the parent is already the crate.
(LOCAL_CRATE.as_def_id().as_local()?, leaf.ident)
}
}
// Absolute paths are not. We start from the parent of the item.
[.., parent, leaf] => (parent.res.opt_def_id()?.as_local()?, leaf.ident),
};
// First we try to get the `DefId` of the item.
for child in
cx.tcx.module_children_local(parent_def_id).iter().filter(move |c| c.ident == ident)
{
if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = child.res {
continue;
}
if let Some(def_id) = child.res.opt_def_id()
&& target_def_id == def_id
{
let mut last_path_res = None;
'reexps: for reexp in child.reexport_chain.iter() {
if let Some(use_def_id) = reexp.id()
&& let Some(local_use_def_id) = use_def_id.as_local()
&& let hir::Node::Item(item) = cx.tcx.hir_node_by_def_id(local_use_def_id)
&& let hir::ItemKind::Use(path, hir::UseKind::Single(_)) = item.kind
{
for res in path.res.present_items() {
if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = res {
continue;
}
if (cx.document_hidden() ||
!cx.tcx.is_doc_hidden(use_def_id)) &&
// We never check for "cx.document_private()"
// because if a re-export is not fully public, it's never
// documented.
cx.tcx.local_visibility(local_use_def_id).is_public()
{
break 'reexps;
}
last_path_res = Some((path, res));
continue 'reexps;
}
}
}
if !child.reexport_chain.is_empty() {
// So in here, we use the data we gathered from iterating the reexports. If
// `last_path_res` is set, it can mean two things:
//
// 1. We found a public reexport.
// 2. We didn't find a public reexport so it's the "end type" path.
if let Some((new_path, _)) = last_path_res {
return Some(first_non_private_clean_path(
cx,
path,
new_path.segments,
new_path.span,
));
}
// If `last_path_res` is `None`, it can mean two things:
//
// 1. The re-export is public, no need to change anything, just use the path as is.
// 2. Nothing was found, so let's just return the original path.
return None;
}
}
}
None
}
fn clean_qpath<'tcx>(hir_ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type {
let hir::Ty { hir_id, span, ref kind } = *hir_ty;
let hir::TyKind::Path(qpath) = kind else { unreachable!() };
match qpath {
hir::QPath::Resolved(None, path) => {
if let Res::Def(DefKind::TyParam, did) = path.res {
if let Some(new_ty) = cx.args.get(&did).and_then(|p| p.as_ty()).cloned() {
return new_ty;
}
if let Some(bounds) = cx.impl_trait_bounds.remove(&did.into()) {
return ImplTrait(bounds);
}
}
if let Some(expanded) = maybe_expand_private_type_alias(cx, path) {
expanded
} else {
// First we check if it's a private re-export.
let path = if let Some(path) = first_non_private(cx, hir_id, path) {
path
} else {
clean_path(path, cx)
};
resolve_type(cx, path)
}
}
hir::QPath::Resolved(Some(qself), p) => {
// Try to normalize `<X as Y>::T` to a type
let ty = lower_ty(cx.tcx, hir_ty);
// `hir_to_ty` can return projection types with escaping vars for GATs, e.g. `<() as Trait>::Gat<'_>`
if !ty.has_escaping_bound_vars()
&& let Some(normalized_value) = normalize(cx, ty::Binder::dummy(ty))
{
return clean_middle_ty(normalized_value, cx, None, None);
}
let trait_segments = &p.segments[..p.segments.len() - 1];
let trait_def = cx.tcx.parent(p.res.def_id());
let trait_ = self::Path {
res: Res::Def(DefKind::Trait, trait_def),
segments: trait_segments.iter().map(|x| clean_path_segment(x, cx)).collect(),
};
register_res(cx, trait_.res);
let self_def_id = DefId::local(qself.hir_id.owner.def_id.local_def_index);
let self_type = clean_ty(qself, cx);
let should_fully_qualify =
should_fully_qualify_path(Some(self_def_id), &trait_, &self_type);
Type::QPath(Box::new(QPathData {
assoc: clean_path_segment(p.segments.last().expect("segments were empty"), cx),
should_fully_qualify,
self_type,
trait_: Some(trait_),
}))
}
hir::QPath::TypeRelative(qself, segment) => {
let ty = lower_ty(cx.tcx, hir_ty);
let self_type = clean_ty(qself, cx);
let (trait_, should_fully_qualify) = match ty.kind() {
ty::Alias(ty::Projection, proj) => {
let res = Res::Def(DefKind::Trait, proj.trait_ref(cx.tcx).def_id);
let trait_ = clean_path(&hir::Path { span, res, segments: &[] }, cx);
register_res(cx, trait_.res);
let self_def_id = res.opt_def_id();
let should_fully_qualify =
should_fully_qualify_path(self_def_id, &trait_, &self_type);
(Some(trait_), should_fully_qualify)
}
ty::Alias(ty::Inherent, _) => (None, false),
// Rustdoc handles `ty::Error`s by turning them into `Type::Infer`s.
ty::Error(_) => return Type::Infer,
_ => bug!("clean: expected associated type, found `{ty:?}`"),
};
Type::QPath(Box::new(QPathData {
assoc: clean_path_segment(segment, cx),
should_fully_qualify,
self_type,
trait_,
}))
}
}
}
fn maybe_expand_private_type_alias<'tcx>(
cx: &mut DocContext<'tcx>,
path: &hir::Path<'tcx>,
) -> Option<Type> {
let Res::Def(DefKind::TyAlias, def_id) = path.res else { return None };
// Substitute private type aliases
let def_id = def_id.as_local()?;
let alias = if !cx.cache.effective_visibilities.is_exported(cx.tcx, def_id.to_def_id())
&& !cx.current_type_aliases.contains_key(&def_id.to_def_id())
{
&cx.tcx.hir_expect_item(def_id).kind
} else {
return None;
};
let hir::ItemKind::TyAlias(_, generics, ty) = alias else { return None };
let final_seg = &path.segments.last().expect("segments were empty");
let mut args = DefIdMap::default();
let generic_args = final_seg.args();
let mut indices: hir::GenericParamCount = Default::default();
for param in generics.params.iter() {
match param.kind {
hir::GenericParamKind::Lifetime { .. } => {
let mut j = 0;
let lifetime = generic_args.args.iter().find_map(|arg| match arg {
hir::GenericArg::Lifetime(lt) => {
if indices.lifetimes == j {
return Some(lt);
}
j += 1;
None
}
_ => None,
});
if let Some(lt) = lifetime {
let lt = if !lt.is_anonymous() {
clean_lifetime(lt, cx)
} else {
Lifetime::elided()
};
args.insert(param.def_id.to_def_id(), GenericArg::Lifetime(lt));
}
indices.lifetimes += 1;
}
hir::GenericParamKind::Type { ref default, .. } => {
let mut j = 0;
let type_ = generic_args.args.iter().find_map(|arg| match arg {
hir::GenericArg::Type(ty) => {
if indices.types == j {
return Some(ty.as_unambig_ty());
}
j += 1;
None
}
_ => None,
});
if let Some(ty) = type_.or(*default) {
args.insert(param.def_id.to_def_id(), GenericArg::Type(clean_ty(ty, cx)));
}
indices.types += 1;
}
// FIXME(#82852): Instantiate const parameters.
hir::GenericParamKind::Const { .. } => {}
}
}
Some(cx.enter_alias(args, def_id.to_def_id(), |cx| {
cx.with_param_env(def_id.to_def_id(), |cx| clean_ty(ty, cx))
}))
}
pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type {
use rustc_hir::*;
match ty.kind {
TyKind::Never => Primitive(PrimitiveType::Never),
TyKind::Ptr(ref m) => RawPointer(m.mutbl, Box::new(clean_ty(m.ty, cx))),
TyKind::Ref(l, ref m) => {
let lifetime = if l.is_anonymous() { None } else { Some(clean_lifetime(l, cx)) };
BorrowedRef { lifetime, mutability: m.mutbl, type_: Box::new(clean_ty(m.ty, cx)) }
}
TyKind::Slice(ty) => Slice(Box::new(clean_ty(ty, cx))),
TyKind::Pat(ty, pat) => Type::Pat(Box::new(clean_ty(ty, cx)), format!("{pat:?}").into()),
TyKind::FieldOf(ty, hir::TyFieldPath { variant, field }) => {
let field_str = if let Some(variant) = variant {
format!("{variant}.{field}")
} else {
format!("{field}")
};
Type::FieldOf(Box::new(clean_ty(ty, cx)), field_str.into())
}
TyKind::Array(ty, const_arg) => {
// NOTE(min_const_generics): We can't use `const_eval_poly` for constants
// as we currently do not supply the parent generics to anonymous constants
// but do allow `ConstKind::Param`.
//
// `const_eval_poly` tries to first substitute generic parameters which
// results in an ICE while manually constructing the constant and using `eval`
// does nothing for `ConstKind::Param`.
let length = match const_arg.kind {
hir::ConstArgKind::Infer(..) | hir::ConstArgKind::Error(..) => "_".to_string(),
hir::ConstArgKind::Anon(hir::AnonConst { def_id, .. }) => {
let ct = lower_const_arg_for_rustdoc(cx.tcx, const_arg, cx.tcx.types.usize);
let typing_env = ty::TypingEnv::post_analysis(cx.tcx, *def_id);
let ct = cx.tcx.normalize_erasing_regions(typing_env, ct);
print_const(cx, ct)
}
hir::ConstArgKind::Struct(..)
| hir::ConstArgKind::Path(..)
| hir::ConstArgKind::TupleCall(..)
| hir::ConstArgKind::Tup(..)
| hir::ConstArgKind::Array(..)
| hir::ConstArgKind::Literal { .. } => {
let ct = lower_const_arg_for_rustdoc(cx.tcx, const_arg, cx.tcx.types.usize);
print_const(cx, ct)
}
};
Array(Box::new(clean_ty(ty, cx)), length.into())
}
TyKind::Tup(tys) => Tuple(tys.iter().map(|ty| clean_ty(ty, cx)).collect()),
TyKind::OpaqueDef(ty) => {
ImplTrait(ty.bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect())
}
TyKind::Path(_) => clean_qpath(ty, cx),
TyKind::TraitObject(bounds, lifetime) => {
let bounds = bounds.iter().map(|bound| clean_poly_trait_ref(bound, cx)).collect();
let lifetime = if !lifetime.is_elided() {
Some(clean_lifetime(lifetime.pointer(), cx))
} else {
None
};
DynTrait(bounds, lifetime)
}
TyKind::FnPtr(barefn) => BareFunction(Box::new(clean_bare_fn_ty(barefn, cx))),
TyKind::UnsafeBinder(unsafe_binder_ty) => {
UnsafeBinder(Box::new(clean_unsafe_binder_ty(unsafe_binder_ty, cx)))
}
// Rustdoc handles `TyKind::Err`s by turning them into `Type::Infer`s.
TyKind::Infer(())
| TyKind::Err(_)
| TyKind::InferDelegation(..)
| TyKind::TraitAscription(_) => Infer,
}
}
/// Returns `None` if the type could not be normalized
fn normalize<'tcx>(
cx: &DocContext<'tcx>,
ty: ty::Binder<'tcx, Ty<'tcx>>,
) -> Option<ty::Binder<'tcx, Ty<'tcx>>> {
// HACK: low-churn fix for #79459 while we wait for a trait normalization fix
if !cx.tcx.sess.opts.unstable_opts.normalize_docs {
return None;
}
use rustc_middle::traits::ObligationCause;
use rustc_trait_selection::infer::TyCtxtInferExt;
use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
// Try to normalize `<X as Y>::T` to a type
let infcx = cx.tcx.infer_ctxt().build(TypingMode::non_body_analysis());
let normalized = infcx
.at(&ObligationCause::dummy(), cx.param_env)
.query_normalize(ty)
.map(|resolved| infcx.resolve_vars_if_possible(resolved.value));
match normalized {
Ok(normalized_value) => {
debug!("normalized {ty:?} to {normalized_value:?}");
Some(normalized_value)
}
Err(err) => {
debug!("failed to normalize {ty:?}: {err:?}");
None
}
}
}
fn clean_trait_object_lifetime_bound<'tcx>(
region: ty::Region<'tcx>,
container: Option<ContainerTy<'_, 'tcx>>,
preds: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
tcx: TyCtxt<'tcx>,
) -> Option<Lifetime> {
if can_elide_trait_object_lifetime_bound(region, container, preds, tcx) {
return None;
}
// Since there is a semantic difference between an implicitly elided (i.e. "defaulted") object
// lifetime and an explicitly elided object lifetime (`'_`), we intentionally don't hide the
// latter contrary to `clean_middle_region`.
match region.kind() {
ty::ReStatic => Some(Lifetime::statik()),
ty::ReEarlyParam(region) => Some(Lifetime(region.name)),
ty::ReBound(_, ty::BoundRegion { kind: ty::BoundRegionKind::Named(def_id), .. }) => {
Some(Lifetime(tcx.item_name(def_id)))
}
ty::ReBound(..)
| ty::ReLateParam(_)
| ty::ReVar(_)
| ty::RePlaceholder(_)
| ty::ReErased
| ty::ReError(_) => None,
}
}
fn can_elide_trait_object_lifetime_bound<'tcx>(
region: ty::Region<'tcx>,
container: Option<ContainerTy<'_, 'tcx>>,
preds: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
tcx: TyCtxt<'tcx>,
) -> bool {
// Below we quote extracts from https://doc.rust-lang.org/stable/reference/lifetime-elision.html#default-trait-object-lifetimes
// > If the trait object is used as a type argument of a generic type then the containing type is
// > first used to try to infer a bound.
let default = container
.map_or(ObjectLifetimeDefault::Empty, |container| container.object_lifetime_default(tcx));
// > If there is a unique bound from the containing type then that is the default
// If there is a default object lifetime and the given region is lexically equal to it, elide it.
match default {
ObjectLifetimeDefault::Static => return region.kind() == ty::ReStatic,
// FIXME(fmease): Don't compare lexically but respect de Bruijn indices etc. to handle shadowing correctly.
ObjectLifetimeDefault::Arg(default) => {
return region.get_name(tcx) == default.get_name(tcx);
}
// > If there is more than one bound from the containing type then an explicit bound must be specified
// Due to ambiguity there is no default trait-object lifetime and thus elision is impossible.
// Don't elide the lifetime.
ObjectLifetimeDefault::Ambiguous => return false,
// There is no meaningful bound. Further processing is needed...
ObjectLifetimeDefault::Empty => {}
}
// > If neither of those rules apply, then the bounds on the trait are used:
match *object_region_bounds(tcx, preds) {
// > If the trait has no lifetime bounds, then the lifetime is inferred in expressions
// > and is 'static outside of expressions.
// FIXME: If we are in an expression context (i.e. fn bodies and const exprs) then the default is
// `'_` and not `'static`. Only if we are in a non-expression one, the default is `'static`.
// Note however that at the time of this writing it should be fine to disregard this subtlety
// as we neither render const exprs faithfully anyway (hiding them in some places or using `_` instead)
// nor show the contents of fn bodies.
[] => region.kind() == ty::ReStatic,
// > If the trait is defined with a single lifetime bound then that bound is used.
// > If 'static is used for any lifetime bound then 'static is used.
// FIXME(fmease): Don't compare lexically but respect de Bruijn indices etc. to handle shadowing correctly.
[object_region] => object_region.get_name(tcx) == region.get_name(tcx),
// There are several distinct trait regions and none are `'static`.
// Due to ambiguity there is no default trait-object lifetime and thus elision is impossible.
// Don't elide the lifetime.
_ => false,
}
}
#[derive(Debug)]
pub(crate) enum ContainerTy<'a, 'tcx> {
Ref(ty::Region<'tcx>),
Regular {
ty: DefId,
/// The arguments *have* to contain an arg for the self type if the corresponding generics
/// contain a self type.
args: ty::Binder<'tcx, &'a [ty::GenericArg<'tcx>]>,
arg: usize,
},
}
impl<'tcx> ContainerTy<'_, 'tcx> {
fn object_lifetime_default(self, tcx: TyCtxt<'tcx>) -> ObjectLifetimeDefault<'tcx> {
match self {
Self::Ref(region) => ObjectLifetimeDefault::Arg(region),
Self::Regular { ty: container, args, arg: index } => {
let (DefKind::Struct
| DefKind::Union
| DefKind::Enum
| DefKind::TyAlias
| DefKind::Trait) = tcx.def_kind(container)
else {
return ObjectLifetimeDefault::Empty;
};
let generics = tcx.generics_of(container);
debug_assert_eq!(generics.parent_count, 0);
let param = generics.own_params[index].def_id;
let default = tcx.object_lifetime_default(param);
match default {
rbv::ObjectLifetimeDefault::Param(lifetime) => {
// The index is relative to the parent generics but since we don't have any,
// we don't need to translate it.
let index = generics.param_def_id_to_index[&lifetime];
let arg = args.skip_binder()[index as usize].expect_region();
ObjectLifetimeDefault::Arg(arg)
}
rbv::ObjectLifetimeDefault::Empty => ObjectLifetimeDefault::Empty,
rbv::ObjectLifetimeDefault::Static => ObjectLifetimeDefault::Static,
rbv::ObjectLifetimeDefault::Ambiguous => ObjectLifetimeDefault::Ambiguous,
}
}
}
}
}
#[derive(Debug, Clone, Copy)]
pub(crate) enum ObjectLifetimeDefault<'tcx> {
Empty,
Static,
Ambiguous,
Arg(ty::Region<'tcx>),
}
#[instrument(level = "trace", skip(cx), ret)]
pub(crate) fn clean_middle_ty<'tcx>(
bound_ty: ty::Binder<'tcx, Ty<'tcx>>,
cx: &mut DocContext<'tcx>,
parent_def_id: Option<DefId>,
container: Option<ContainerTy<'_, 'tcx>>,
) -> Type {
let bound_ty = normalize(cx, bound_ty).unwrap_or(bound_ty);
match *bound_ty.skip_binder().kind() {
ty::Never => Primitive(PrimitiveType::Never),
ty::Bool => Primitive(PrimitiveType::Bool),
ty::Char => Primitive(PrimitiveType::Char),
ty::Int(int_ty) => Primitive(int_ty.into()),
ty::Uint(uint_ty) => Primitive(uint_ty.into()),
ty::Float(float_ty) => Primitive(float_ty.into()),
ty::Str => Primitive(PrimitiveType::Str),
ty::Slice(ty) => Slice(Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None, None))),
ty::Pat(ty, pat) => Type::Pat(
Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None, None)),
format!("{pat:?}").into_boxed_str(),
),
ty::Array(ty, n) => {
let n = cx.tcx.normalize_erasing_regions(cx.typing_env(), n);
let n = print_const(cx, n);
Array(Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None, None)), n.into())
}
ty::RawPtr(ty, mutbl) => {
RawPointer(mutbl, Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None, None)))
}
ty::Ref(r, ty, mutbl) => BorrowedRef {
lifetime: clean_middle_region(r, cx),
mutability: mutbl,
type_: Box::new(clean_middle_ty(
bound_ty.rebind(ty),
cx,
None,
Some(ContainerTy::Ref(r)),
)),
},
ty::FnDef(..) | ty::FnPtr(..) => {
// FIXME: should we merge the outer and inner binders somehow?
let sig = bound_ty.skip_binder().fn_sig(cx.tcx);
let decl = clean_poly_fn_sig(cx, None, sig);
let generic_params = clean_bound_vars(sig.bound_vars(), cx);
BareFunction(Box::new(BareFunctionDecl {
safety: sig.safety(),
generic_params,
decl,
abi: sig.abi(),
}))
}
ty::UnsafeBinder(inner) => {
let generic_params = clean_bound_vars(inner.bound_vars(), cx);
let ty = clean_middle_ty(inner.into(), cx, None, None);
UnsafeBinder(Box::new(UnsafeBinderTy { generic_params, ty }))
}
ty::Adt(def, args) => {
let did = def.did();
let kind = match def.adt_kind() {
AdtKind::Struct => ItemType::Struct,
AdtKind::Union => ItemType::Union,
AdtKind::Enum => ItemType::Enum,
};
inline::record_extern_fqn(cx, did, kind);
let path = clean_middle_path(cx, did, false, ThinVec::new(), bound_ty.rebind(args));
Type::Path { path }
}
ty::Foreign(did) => {
inline::record_extern_fqn(cx, did, ItemType::ForeignType);
let path = clean_middle_path(
cx,
did,
false,
ThinVec::new(),
ty::Binder::dummy(ty::GenericArgs::empty()),
);
Type::Path { path }
}
ty::Dynamic(obj, reg) => {
// HACK: pick the first `did` as the `did` of the trait object. Someone
// might want to implement "native" support for marker-trait-only
// trait objects.
let mut dids = obj.auto_traits();
let did = obj
.principal_def_id()
.or_else(|| dids.next())
.unwrap_or_else(|| panic!("found trait object `{bound_ty:?}` with no traits?"));
let args = match obj.principal() {
Some(principal) => principal.map_bound(|p| p.args),
// marker traits have no args.
_ => ty::Binder::dummy(ty::GenericArgs::empty()),
};
inline::record_extern_fqn(cx, did, ItemType::Trait);
let lifetime = clean_trait_object_lifetime_bound(reg, container, obj, cx.tcx);
let mut bounds = dids
.map(|did| {
let empty = ty::Binder::dummy(ty::GenericArgs::empty());
let path = clean_middle_path(cx, did, false, ThinVec::new(), empty);
inline::record_extern_fqn(cx, did, ItemType::Trait);
PolyTrait { trait_: path, generic_params: Vec::new() }
})
.collect::<Vec<_>>();
let constraints = obj
.projection_bounds()
.map(|pb| AssocItemConstraint {
assoc: projection_to_path_segment(
pb.map_bound(|pb| {
pb.with_self_ty(cx.tcx, cx.tcx.types.trait_object_dummy_self)
.projection_term
}),
cx,
),
kind: AssocItemConstraintKind::Equality {
term: clean_middle_term(pb.map_bound(|pb| pb.term), cx),
},
})
.collect();
let late_bound_regions: FxIndexSet<_> = obj
.iter()
.flat_map(|pred| pred.bound_vars())
.filter_map(|var| match var {
ty::BoundVariableKind::Region(ty::BoundRegionKind::Named(def_id)) => {
let name = cx.tcx.item_name(def_id);
if name != kw::UnderscoreLifetime {
Some(GenericParamDef::lifetime(def_id, name))
} else {
None
}
}
_ => None,
})
.collect();
let late_bound_regions = late_bound_regions.into_iter().collect();
let path = clean_middle_path(cx, did, false, constraints, args);
bounds.insert(0, PolyTrait { trait_: path, generic_params: late_bound_regions });
DynTrait(bounds, lifetime)
}
ty::Tuple(t) => {
Tuple(t.iter().map(|t| clean_middle_ty(bound_ty.rebind(t), cx, None, None)).collect())
}
ty::Alias(ty::Projection, alias_ty @ ty::AliasTy { def_id, args, .. }) => {
if cx.tcx.is_impl_trait_in_trait(def_id) {
clean_middle_opaque_bounds(cx, def_id, args)
} else {
Type::QPath(Box::new(clean_projection(
bound_ty.rebind(alias_ty.into()),
cx,
parent_def_id,
)))
}
}
ty::Alias(ty::Inherent, alias_ty @ ty::AliasTy { def_id, .. }) => {
let alias_ty = bound_ty.rebind(alias_ty);
let self_type = clean_middle_ty(alias_ty.map_bound(|ty| ty.self_ty()), cx, None, None);
Type::QPath(Box::new(QPathData {
assoc: PathSegment {
name: cx.tcx.item_name(def_id),
args: GenericArgs::AngleBracketed {
args: clean_middle_generic_args(
cx,
alias_ty.map_bound(|ty| ty.args.as_slice()),
true,
def_id,
),
constraints: Default::default(),
},
},
should_fully_qualify: false,
self_type,
trait_: None,
}))
}
ty::Alias(ty::Free, ty::AliasTy { def_id, args, .. }) => {
if cx.tcx.features().lazy_type_alias() {
// Free type alias `data` represents the `type X` in `type X = Y`. If we need `Y`,
// we need to use `type_of`.
let path =
clean_middle_path(cx, def_id, false, ThinVec::new(), bound_ty.rebind(args));
Type::Path { path }
} else {
let ty = cx.tcx.type_of(def_id).instantiate(cx.tcx, args);
clean_middle_ty(bound_ty.rebind(ty), cx, None, None)
}
}
ty::Param(ref p) => {
if let Some(bounds) = cx.impl_trait_bounds.remove(&p.index.into()) {
ImplTrait(bounds)
} else if p.name == kw::SelfUpper {
SelfTy
} else {
Generic(p.name)
}
}
ty::Bound(_, ref ty) => match ty.kind {
ty::BoundTyKind::Param(def_id) => Generic(cx.tcx.item_name(def_id)),
ty::BoundTyKind::Anon => panic!("unexpected anonymous bound type variable"),
},
ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => {
// If it's already in the same alias, don't get an infinite loop.
if cx.current_type_aliases.contains_key(&def_id) {
let path =
clean_middle_path(cx, def_id, false, ThinVec::new(), bound_ty.rebind(args));
Type::Path { path }
} else {
*cx.current_type_aliases.entry(def_id).or_insert(0) += 1;
// Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
// by looking up the bounds associated with the def_id.
let ty = clean_middle_opaque_bounds(cx, def_id, args);
if let Some(count) = cx.current_type_aliases.get_mut(&def_id) {
*count -= 1;
if *count == 0 {
cx.current_type_aliases.remove(&def_id);
}
}
ty
}
}
ty::Closure(..) => panic!("Closure"),
ty::CoroutineClosure(..) => panic!("CoroutineClosure"),
ty::Coroutine(..) => panic!("Coroutine"),
ty::Placeholder(..) => panic!("Placeholder"),
ty::CoroutineWitness(..) => panic!("CoroutineWitness"),
ty::Infer(..) => panic!("Infer"),
ty::Error(_) => FatalError.raise(),
}
}
fn clean_middle_opaque_bounds<'tcx>(
cx: &mut DocContext<'tcx>,
impl_trait_def_id: DefId,
args: ty::GenericArgsRef<'tcx>,
) -> Type {
let mut has_sized = false;
let bounds: Vec<_> = cx
.tcx
.explicit_item_bounds(impl_trait_def_id)
.iter_instantiated_copied(cx.tcx, args)
.collect();
let mut bounds = bounds
.iter()
.filter_map(|(bound, _)| {
let bound_predicate = bound.kind();
let trait_ref = match bound_predicate.skip_binder() {
ty::ClauseKind::Trait(tr) => bound_predicate.rebind(tr.trait_ref),
ty::ClauseKind::TypeOutlives(ty::OutlivesPredicate(_ty, reg)) => {
return clean_middle_region(reg, cx).map(GenericBound::Outlives);
}
_ => return None,
};
// FIXME(sized-hierarchy): Always skip `MetaSized` bounds so that only `?Sized`
// is shown and none of the new sizedness traits leak into documentation.
if cx.tcx.is_lang_item(trait_ref.def_id(), LangItem::MetaSized) {
return None;
}
if let Some(sized) = cx.tcx.lang_items().sized_trait()
&& trait_ref.def_id() == sized
{
has_sized = true;
return None;
}
let bindings: ThinVec<_> = bounds
.iter()
.filter_map(|(bound, _)| {
let bound = bound.kind();
if let ty::ClauseKind::Projection(proj_pred) = bound.skip_binder()
&& proj_pred.projection_term.trait_ref(cx.tcx) == trait_ref.skip_binder()
{
return Some(AssocItemConstraint {
assoc: projection_to_path_segment(
bound.rebind(proj_pred.projection_term),
cx,
),
kind: AssocItemConstraintKind::Equality {
term: clean_middle_term(bound.rebind(proj_pred.term), cx),
},
});
}
None
})
.collect();
Some(clean_poly_trait_ref_with_constraints(cx, trait_ref, bindings))
})
.collect::<Vec<_>>();
if !has_sized {
bounds.push(GenericBound::maybe_sized(cx));
}
// Move trait bounds to the front.
bounds.sort_by_key(|b| !b.is_trait_bound());
// Add back a `Sized` bound if there are no *trait* bounds remaining (incl. `?Sized`).
// Since all potential trait bounds are at the front we can just check the first bound.
if bounds.first().is_none_or(|b| !b.is_trait_bound()) {
bounds.insert(0, GenericBound::sized(cx));
}
if let Some(args) = cx.tcx.rendered_precise_capturing_args(impl_trait_def_id) {
bounds.push(GenericBound::Use(
args.iter()
.map(|arg| match arg {
hir::PreciseCapturingArgKind::Lifetime(lt) => {
PreciseCapturingArg::Lifetime(Lifetime(*lt))
}
hir::PreciseCapturingArgKind::Param(param) => {
PreciseCapturingArg::Param(*param)
}
})
.collect(),
));
}
ImplTrait(bounds)
}
pub(crate) fn clean_field<'tcx>(field: &hir::FieldDef<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
clean_field_with_def_id(field.def_id.to_def_id(), field.ident.name, clean_ty(field.ty, cx), cx)
}
pub(crate) fn clean_middle_field(field: &ty::FieldDef, cx: &mut DocContext<'_>) -> Item {
clean_field_with_def_id(
field.did,
field.name,
clean_middle_ty(
ty::Binder::dummy(cx.tcx.type_of(field.did).instantiate_identity()),
cx,
Some(field.did),
None,
),
cx,
)
}
pub(crate) fn clean_field_with_def_id(
def_id: DefId,
name: Symbol,
ty: Type,
cx: &mut DocContext<'_>,
) -> Item {
Item::from_def_id_and_parts(def_id, Some(name), StructFieldItem(ty), cx)
}
pub(crate) fn clean_variant_def(variant: &ty::VariantDef, cx: &mut DocContext<'_>) -> Item {
let discriminant = match variant.discr {
ty::VariantDiscr::Explicit(def_id) => Some(Discriminant { expr: None, value: def_id }),
ty::VariantDiscr::Relative(_) => None,
};
let kind = match variant.ctor_kind() {
Some(CtorKind::Const) => VariantKind::CLike,
Some(CtorKind::Fn) => VariantKind::Tuple(
variant.fields.iter().map(|field| clean_middle_field(field, cx)).collect(),
),
None => VariantKind::Struct(VariantStruct {
fields: variant.fields.iter().map(|field| clean_middle_field(field, cx)).collect(),
}),
};
Item::from_def_id_and_parts(
variant.def_id,
Some(variant.name),
VariantItem(Variant { kind, discriminant }),
cx,
)
}
pub(crate) fn clean_variant_def_with_args<'tcx>(
variant: &ty::VariantDef,
args: &GenericArgsRef<'tcx>,
cx: &mut DocContext<'tcx>,
) -> Item {
let discriminant = match variant.discr {
ty::VariantDiscr::Explicit(def_id) => Some(Discriminant { expr: None, value: def_id }),
ty::VariantDiscr::Relative(_) => None,
};
use rustc_middle::traits::ObligationCause;
use rustc_trait_selection::infer::TyCtxtInferExt;
use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
let infcx = cx.tcx.infer_ctxt().build(TypingMode::non_body_analysis());
let kind = match variant.ctor_kind() {
Some(CtorKind::Const) => VariantKind::CLike,
Some(CtorKind::Fn) => VariantKind::Tuple(
variant
.fields
.iter()
.map(|field| {
let ty = cx.tcx.type_of(field.did).instantiate(cx.tcx, args);
// normalize the type to only show concrete types
// note: we do not use try_normalize_erasing_regions since we
// do care about showing the regions
let ty = infcx
.at(&ObligationCause::dummy(), cx.param_env)
.query_normalize(ty)
.map(|normalized| normalized.value)
.unwrap_or(ty);
clean_field_with_def_id(
field.did,
field.name,
clean_middle_ty(ty::Binder::dummy(ty), cx, Some(field.did), None),
cx,
)
})
.collect(),
),
None => VariantKind::Struct(VariantStruct {
fields: variant
.fields
.iter()
.map(|field| {
let ty = cx.tcx.type_of(field.did).instantiate(cx.tcx, args);
// normalize the type to only show concrete types
// note: we do not use try_normalize_erasing_regions since we
// do care about showing the regions
let ty = infcx
.at(&ObligationCause::dummy(), cx.param_env)
.query_normalize(ty)
.map(|normalized| normalized.value)
.unwrap_or(ty);
clean_field_with_def_id(
field.did,
field.name,
clean_middle_ty(ty::Binder::dummy(ty), cx, Some(field.did), None),
cx,
)
})
.collect(),
}),
};
Item::from_def_id_and_parts(
variant.def_id,
Some(variant.name),
VariantItem(Variant { kind, discriminant }),
cx,
)
}
fn clean_variant_data<'tcx>(
variant: &hir::VariantData<'tcx>,
disr_expr: &Option<&hir::AnonConst>,
cx: &mut DocContext<'tcx>,
) -> Variant {
let discriminant = disr_expr
.map(|disr| Discriminant { expr: Some(disr.body), value: disr.def_id.to_def_id() });
let kind = match variant {
hir::VariantData::Struct { fields, .. } => VariantKind::Struct(VariantStruct {
fields: fields.iter().map(|x| clean_field(x, cx)).collect(),
}),
hir::VariantData::Tuple(..) => {
VariantKind::Tuple(variant.fields().iter().map(|x| clean_field(x, cx)).collect())
}
hir::VariantData::Unit(..) => VariantKind::CLike,
};
Variant { discriminant, kind }
}
fn clean_path<'tcx>(path: &hir::Path<'tcx>, cx: &mut DocContext<'tcx>) -> Path {
Path {
res: path.res,
segments: path.segments.iter().map(|x| clean_path_segment(x, cx)).collect(),
}
}
fn clean_generic_args<'tcx>(
trait_did: Option<DefId>,
generic_args: &hir::GenericArgs<'tcx>,
cx: &mut DocContext<'tcx>,
) -> GenericArgs {
match generic_args.parenthesized {
hir::GenericArgsParentheses::No => {
let args = generic_args
.args
.iter()
.map(|arg| match arg {
hir::GenericArg::Lifetime(lt) if !lt.is_anonymous() => {
GenericArg::Lifetime(clean_lifetime(lt, cx))
}
hir::GenericArg::Lifetime(_) => GenericArg::Lifetime(Lifetime::elided()),
hir::GenericArg::Type(ty) => GenericArg::Type(clean_ty(ty.as_unambig_ty(), cx)),
hir::GenericArg::Const(ct) => {
GenericArg::Const(Box::new(clean_const(ct.as_unambig_ct())))
}
hir::GenericArg::Infer(_inf) => GenericArg::Infer,
})
.collect();
let constraints = generic_args
.constraints
.iter()
.map(|c| {
clean_assoc_item_constraint(
trait_did.expect("only trait ref has constraints"),
c,
cx,
)
})
.collect::<ThinVec<_>>();
GenericArgs::AngleBracketed { args, constraints }
}
hir::GenericArgsParentheses::ParenSugar => {
let Some((inputs, output)) = generic_args.paren_sugar_inputs_output() else {
bug!();
};
let inputs = inputs.iter().map(|x| clean_ty(x, cx)).collect();
let output = match output.kind {
hir::TyKind::Tup(&[]) => None,
_ => Some(Box::new(clean_ty(output, cx))),
};
GenericArgs::Parenthesized { inputs, output }
}
hir::GenericArgsParentheses::ReturnTypeNotation => GenericArgs::ReturnTypeNotation,
}
}
fn clean_path_segment<'tcx>(
path: &hir::PathSegment<'tcx>,
cx: &mut DocContext<'tcx>,
) -> PathSegment {
let trait_did = match path.res {
hir::def::Res::Def(DefKind::Trait | DefKind::TraitAlias, did) => Some(did),
_ => None,
};
PathSegment { name: path.ident.name, args: clean_generic_args(trait_did, path.args(), cx) }
}
fn clean_bare_fn_ty<'tcx>(
bare_fn: &hir::FnPtrTy<'tcx>,
cx: &mut DocContext<'tcx>,
) -> BareFunctionDecl {
let (generic_params, decl) = enter_impl_trait(cx, |cx| {
// NOTE: Generics must be cleaned before params.
let generic_params = bare_fn
.generic_params
.iter()
.filter(|p| !is_elided_lifetime(p))
.map(|x| clean_generic_param(cx, None, x))
.collect();
// Since it's more conventional stylistically, elide the name of all params called `_`
// unless there's at least one interestingly named param in which case don't elide any
// name since mixing named and unnamed params is less legible.
let filter = |ident: Option<Ident>| {
ident.map(|ident| ident.name).filter(|&ident| ident != kw::Underscore)
};
let fallback =
bare_fn.param_idents.iter().copied().find_map(filter).map(|_| kw::Underscore);
let params = clean_params(cx, bare_fn.decl.inputs, bare_fn.param_idents, |ident| {
filter(ident).or(fallback)
});
let decl = clean_fn_decl_with_params(cx, bare_fn.decl, None, params);
(generic_params, decl)
});
BareFunctionDecl { safety: bare_fn.safety, abi: bare_fn.abi, decl, generic_params }
}
fn clean_unsafe_binder_ty<'tcx>(
unsafe_binder_ty: &hir::UnsafeBinderTy<'tcx>,
cx: &mut DocContext<'tcx>,
) -> UnsafeBinderTy {
let generic_params = unsafe_binder_ty
.generic_params
.iter()
.filter(|p| !is_elided_lifetime(p))
.map(|x| clean_generic_param(cx, None, x))
.collect();
let ty = clean_ty(unsafe_binder_ty.inner_ty, cx);
UnsafeBinderTy { generic_params, ty }
}
pub(crate) fn reexport_chain(
tcx: TyCtxt<'_>,
import_def_id: LocalDefId,
target_def_id: DefId,
) -> &[Reexport] {
for child in tcx.module_children_local(tcx.local_parent(import_def_id)) {
if child.res.opt_def_id() == Some(target_def_id)
&& child.reexport_chain.first().and_then(|r| r.id()) == Some(import_def_id.to_def_id())
{
return &child.reexport_chain;
}
}
&[]
}
/// Collect attributes from the whole import chain.
fn get_all_import_attributes<'hir>(
cx: &mut DocContext<'hir>,
import_def_id: LocalDefId,
target_def_id: DefId,
is_inline: bool,
) -> Vec<(Cow<'hir, hir::Attribute>, Option<DefId>)> {
let mut attrs = Vec::new();
let mut first = true;
for def_id in reexport_chain(cx.tcx, import_def_id, target_def_id)
.iter()
.flat_map(|reexport| reexport.id())
{
let import_attrs = inline::load_attrs(cx, def_id);
if first {
// This is the "original" reexport so we get all its attributes without filtering them.
attrs = import_attrs.iter().map(|attr| (Cow::Borrowed(attr), Some(def_id))).collect();
first = false;
// We don't add attributes of an intermediate re-export if it has `#[doc(hidden)]`.
} else if cx.document_hidden() || !cx.tcx.is_doc_hidden(def_id) {
add_without_unwanted_attributes(&mut attrs, import_attrs, is_inline, Some(def_id));
}
}
attrs
}
/// When inlining items, we merge their attributes (and all the reexports attributes too) with the
/// final reexport. For example:
///
/// ```ignore (just an example)
/// #[doc(hidden, cfg(feature = "foo"))]
/// pub struct Foo;
///
/// #[doc(cfg(feature = "bar"))]
/// #[doc(hidden, no_inline)]
/// pub use Foo as Foo1;
///
/// #[doc(inline)]
/// pub use Foo2 as Bar;
/// ```
///
/// So `Bar` at the end will have both `cfg(feature = "...")`. However, we don't want to merge all
/// attributes so we filter out the following ones:
/// * `doc(inline)`
/// * `doc(no_inline)`
/// * `doc(hidden)`
fn add_without_unwanted_attributes<'hir>(
attrs: &mut Vec<(Cow<'hir, hir::Attribute>, Option<DefId>)>,
new_attrs: &'hir [hir::Attribute],
is_inline: bool,
import_parent: Option<DefId>,
) {
for attr in new_attrs {
match attr {
hir::Attribute::Parsed(AttributeKind::DocComment { .. }) => {
attrs.push((Cow::Borrowed(attr), import_parent));
}
hir::Attribute::Parsed(AttributeKind::Doc(box d)) => {
// Remove attributes from `normal` that should not be inherited by `use` re-export.
let DocAttribute {
aliases,
hidden,
inline,
cfg,
auto_cfg: _,
auto_cfg_change: _,
fake_variadic: _,
keyword: _,
attribute: _,
masked: _,
notable_trait: _,
search_unbox: _,
html_favicon_url: _,
html_logo_url: _,
html_playground_url: _,
html_root_url: _,
html_no_source: _,
issue_tracker_base_url: _,
rust_logo: _,
test_attrs: _,
no_crate_inject: _,
} = d;
let mut attr = DocAttribute::default();
if is_inline {
attr.cfg = cfg.clone();
} else {
attr.inline = inline.clone();
attr.hidden = hidden.clone();
}
attr.aliases = aliases.clone();
attrs.push((
Cow::Owned(hir::Attribute::Parsed(AttributeKind::Doc(Box::new(attr)))),
import_parent,
));
}
// We discard `#[cfg(...)]` attributes unless we're inlining
hir::Attribute::Parsed(AttributeKind::CfgTrace(..)) if !is_inline => {}
// We keep all other attributes
_ => {
attrs.push((Cow::Borrowed(attr), import_parent));
}
}
}
}
fn clean_maybe_renamed_item<'tcx>(
cx: &mut DocContext<'tcx>,
item: &hir::Item<'tcx>,
renamed: Option<Symbol>,
import_ids: &[LocalDefId],
) -> Vec<Item> {
use hir::ItemKind;
fn get_name(
cx: &DocContext<'_>,
item: &hir::Item<'_>,
renamed: Option<Symbol>,
) -> Option<Symbol> {
renamed.or_else(|| cx.tcx.hir_opt_name(item.hir_id()))
}
let def_id = item.owner_id.to_def_id();
cx.with_param_env(def_id, |cx| {
// These kinds of item either don't need a `name` or accept a `None` one so we handle them
// before.
match item.kind {
ItemKind::Impl(ref impl_) => {
// If `renamed` is `Some()` for an `impl`, it means it's been inlined because we use
// it as a marker to indicate that this is an inlined impl and that we should
// generate an impl placeholder and not a "real" impl item.
return clean_impl(impl_, item.owner_id.def_id, cx, renamed.is_some());
}
ItemKind::Use(path, kind) => {
return clean_use_statement(
item,
get_name(cx, item, renamed),
path,
kind,
cx,
&mut FxHashSet::default(),
);
}
_ => {}
}
let mut name = get_name(cx, item, renamed).unwrap();
let kind = match item.kind {
ItemKind::Static(mutability, _, ty, body_id) => StaticItem(Static {
type_: Box::new(clean_ty(ty, cx)),
mutability,
expr: Some(body_id),
}),
ItemKind::Const(_, generics, ty, rhs) => ConstantItem(Box::new(Constant {
generics: clean_generics(generics, cx),
type_: clean_ty(ty, cx),
kind: clean_const_item_rhs(rhs, def_id),
})),
ItemKind::TyAlias(_, generics, ty) => {
*cx.current_type_aliases.entry(def_id).or_insert(0) += 1;
let rustdoc_ty = clean_ty(ty, cx);
let type_ =
clean_middle_ty(ty::Binder::dummy(lower_ty(cx.tcx, ty)), cx, None, None);
let generics = clean_generics(generics, cx);
if let Some(count) = cx.current_type_aliases.get_mut(&def_id) {
*count -= 1;
if *count == 0 {
cx.current_type_aliases.remove(&def_id);
}
}
let ty = cx.tcx.type_of(def_id).instantiate_identity();
let mut ret = Vec::new();
let inner_type = clean_ty_alias_inner_type(ty, cx, &mut ret);
ret.push(generate_item_with_correct_attrs(
cx,
TypeAliasItem(Box::new(TypeAlias {
generics,
inner_type,
type_: rustdoc_ty,
item_type: Some(type_),
})),
item.owner_id.def_id.to_def_id(),
name,
import_ids,
renamed,
));
return ret;
}
ItemKind::Enum(_, generics, def) => EnumItem(Enum {
variants: def.variants.iter().map(|v| clean_variant(v, cx)).collect(),
generics: clean_generics(generics, cx),
}),
ItemKind::TraitAlias(_, _, generics, bounds) => TraitAliasItem(TraitAlias {
generics: clean_generics(generics, cx),
bounds: bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
}),
ItemKind::Union(_, generics, variant_data) => UnionItem(Union {
generics: clean_generics(generics, cx),
fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(),
}),
ItemKind::Struct(_, generics, variant_data) => StructItem(Struct {
ctor_kind: variant_data.ctor_kind(),
generics: clean_generics(generics, cx),
fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(),
}),
// FIXME: handle attributes and derives that aren't proc macros, and macros with
// multiple kinds
ItemKind::Macro(_, macro_def, MacroKinds::BANG) => MacroItem(Macro {
source: display_macro_source(cx, name, macro_def),
macro_rules: macro_def.macro_rules,
}),
ItemKind::Macro(_, _, MacroKinds::ATTR) => {
clean_proc_macro(item, &mut name, MacroKind::Attr, cx)
}
ItemKind::Macro(_, _, MacroKinds::DERIVE) => {
clean_proc_macro(item, &mut name, MacroKind::Derive, cx)
}
ItemKind::Macro(_, _, _) => todo!("Handle macros with multiple kinds"),
// proc macros can have a name set by attributes
ItemKind::Fn { ref sig, generics, body: body_id, .. } => {
clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
}
ItemKind::Trait(_, _, _, _, generics, bounds, item_ids) => {
let items = item_ids
.iter()
.map(|&ti| clean_trait_item(cx.tcx.hir_trait_item(ti), cx))
.collect();
TraitItem(Box::new(Trait {
def_id,
items,
generics: clean_generics(generics, cx),
bounds: bounds.iter().filter_map(|x| clean_generic_bound(x, cx)).collect(),
}))
}
ItemKind::ExternCrate(orig_name, _) => {
return clean_extern_crate(item, name, orig_name, cx);
}
_ => span_bug!(item.span, "not yet converted"),
};
vec![generate_item_with_correct_attrs(
cx,
kind,
item.owner_id.def_id.to_def_id(),
name,
import_ids,
renamed,
)]
})
}
fn clean_variant<'tcx>(variant: &hir::Variant<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
let kind = VariantItem(clean_variant_data(&variant.data, &variant.disr_expr, cx));
Item::from_def_id_and_parts(variant.def_id.to_def_id(), Some(variant.ident.name), kind, cx)
}
fn clean_impl<'tcx>(
impl_: &hir::Impl<'tcx>,
def_id: LocalDefId,
cx: &mut DocContext<'tcx>,
// If true, this is an inlined impl and it will be handled later on in the code.
// In here, we will generate a placeholder for it in order to be able to compute its
// `doc_cfg` info.
is_inlined: bool,
) -> Vec<Item> {
let tcx = cx.tcx;
let mut ret = Vec::new();
let trait_ = match impl_.of_trait {
Some(t) => {
if is_inlined {
return vec![Item::from_def_id_and_parts(
def_id.to_def_id(),
None,
PlaceholderImplItem,
cx,
)];
}
Some(clean_trait_ref(&t.trait_ref, cx))
}
None => None,
};
let items = impl_
.items
.iter()
.map(|&ii| clean_impl_item(tcx.hir_impl_item(ii), cx))
.collect::<Vec<_>>();
// If this impl block is an implementation of the Deref trait, then we
// need to try inlining the target's inherent impl blocks as well.
if trait_.as_ref().map(|t| t.def_id()) == tcx.lang_items().deref_trait() {
build_deref_target_impls(cx, &items, &mut ret);
}
let for_ = clean_ty(impl_.self_ty, cx);
let type_alias =
for_.def_id(&cx.cache).and_then(|alias_def_id: DefId| match tcx.def_kind(alias_def_id) {
DefKind::TyAlias => Some(clean_middle_ty(
ty::Binder::dummy(tcx.type_of(def_id).instantiate_identity()),
cx,
Some(def_id.to_def_id()),
None,
)),
_ => None,
});
let is_deprecated = tcx
.lookup_deprecation(def_id.to_def_id())
.is_some_and(|deprecation| deprecation.is_in_effect());
let mut make_item = |trait_: Option<Path>, for_: Type, items: Vec<Item>| {
let kind = ImplItem(Box::new(Impl {
safety: match impl_.of_trait {
Some(of_trait) => of_trait.safety,
None => hir::Safety::Safe,
},
generics: clean_generics(impl_.generics, cx),
trait_,
for_,
items,
polarity: if impl_.of_trait.is_some() {
tcx.impl_polarity(def_id)
} else {
ty::ImplPolarity::Positive
},
kind: if utils::has_doc_flag(tcx, def_id.to_def_id(), |d| d.fake_variadic.is_some()) {
ImplKind::FakeVariadic
} else {
ImplKind::Normal
},
is_deprecated,
}));
Item::from_def_id_and_parts(def_id.to_def_id(), None, kind, cx)
};
if let Some(type_alias) = type_alias {
ret.push(make_item(trait_.clone(), type_alias, items.clone()));
}
ret.push(make_item(trait_, for_, items));
ret
}
fn clean_extern_crate<'tcx>(
krate: &hir::Item<'tcx>,
name: Symbol,
orig_name: Option<Symbol>,
cx: &mut DocContext<'tcx>,
) -> Vec<Item> {
// this is the ID of the `extern crate` statement
let cnum = cx.tcx.extern_mod_stmt_cnum(krate.owner_id.def_id).unwrap_or(LOCAL_CRATE);
// this is the ID of the crate itself
let crate_def_id = cnum.as_def_id();
let attrs = cx.tcx.hir_attrs(krate.hir_id());
let ty_vis = cx.tcx.visibility(krate.owner_id);
let please_inline = ty_vis.is_public()
&& attrs.iter().any(|a| {
matches!(
a,
hir::Attribute::Parsed(AttributeKind::Doc(d))
if d.inline.first().is_some_and(|(i, _)| *i == DocInline::Inline))
})
&& !cx.is_json_output();
let krate_owner_def_id = krate.owner_id.def_id;
if please_inline
&& let Some(items) = inline::try_inline(
cx,
Res::Def(DefKind::Mod, crate_def_id),
name,
Some((attrs, Some(krate_owner_def_id))),
&mut Default::default(),
)
{
return items;
}
vec![Item::from_def_id_and_parts(
krate_owner_def_id.to_def_id(),
Some(name),
ExternCrateItem { src: orig_name },
cx,
)]
}
fn clean_use_statement<'tcx>(
import: &hir::Item<'tcx>,
name: Option<Symbol>,
path: &hir::UsePath<'tcx>,
kind: hir::UseKind,
cx: &mut DocContext<'tcx>,
inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
) -> Vec<Item> {
let mut items = Vec::new();
let hir::UsePath { segments, ref res, span } = *path;
for res in res.present_items() {
let path = hir::Path { segments, res, span };
items.append(&mut clean_use_statement_inner(import, name, &path, kind, cx, inlined_names));
}
items
}
fn clean_use_statement_inner<'tcx>(
import: &hir::Item<'tcx>,
name: Option<Symbol>,
path: &hir::Path<'tcx>,
kind: hir::UseKind,
cx: &mut DocContext<'tcx>,
inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
) -> Vec<Item> {
if should_ignore_res(path.res) {
return Vec::new();
}
// We need this comparison because some imports (for std types for example)
// are "inserted" as well but directly by the compiler and they should not be
// taken into account.
if import.span.ctxt().outer_expn_data().kind == ExpnKind::AstPass(AstPass::StdImports) {
return Vec::new();
}
let visibility = cx.tcx.visibility(import.owner_id);
let attrs = cx.tcx.hir_attrs(import.hir_id());
let inline_attr = find_attr!(
attrs,
Doc(d) if d.inline.first().is_some_and(|(i, _)| *i == DocInline::Inline) => d
)
.and_then(|d| d.inline.first());
let pub_underscore = visibility.is_public() && name == Some(kw::Underscore);
let current_mod = cx.tcx.parent_module_from_def_id(import.owner_id.def_id);
let import_def_id = import.owner_id.def_id;
// The parent of the module in which this import resides. This
// is the same as `current_mod` if that's already the top
// level module.
let parent_mod = cx.tcx.parent_module_from_def_id(current_mod.to_local_def_id());
// This checks if the import can be seen from a higher level module.
// In other words, it checks if the visibility is the equivalent of
// `pub(super)` or higher. If the current module is the top level
// module, there isn't really a parent module, which makes the results
// meaningless. In this case, we make sure the answer is `false`.
let is_visible_from_parent_mod =
visibility.is_accessible_from(parent_mod, cx.tcx) && !current_mod.is_top_level_module();
if pub_underscore && let Some((_, inline_span)) = inline_attr {
struct_span_code_err!(
cx.tcx.dcx(),
*inline_span,
E0780,
"anonymous imports cannot be inlined"
)
.with_span_label(import.span, "anonymous import")
.emit();
}
// We consider inlining the documentation of `pub use` statements, but we
// forcefully don't inline if this is not public or if the
// #[doc(no_inline)] attribute is present.
// Don't inline doc(hidden) imports so they can be stripped at a later stage.
let mut denied = cx.is_json_output()
|| !(visibility.is_public() || (cx.document_private() && is_visible_from_parent_mod))
|| pub_underscore
|| attrs.iter().any(|a| matches!(
a,
hir::Attribute::Parsed(AttributeKind::Doc(d))
if d.hidden.is_some() || d.inline.first().is_some_and(|(i, _)| *i == DocInline::NoInline)
));
// Also check whether imports were asked to be inlined, in case we're trying to re-export a
// crate in Rust 2018+
let path = clean_path(path, cx);
let inner = if kind == hir::UseKind::Glob {
if !denied {
let mut visited = DefIdSet::default();
if let Some(items) = inline::try_inline_glob(
cx,
path.res,
current_mod,
&mut visited,
inlined_names,
import,
) {
return items;
}
}
Import::new_glob(resolve_use_source(cx, path), true)
} else {
let name = name.unwrap();
if inline_attr.is_none()
&& let Res::Def(DefKind::Mod, did) = path.res
&& !did.is_local()
&& did.is_crate_root()
{
// if we're `pub use`ing an extern crate root, don't inline it unless we
// were specifically asked for it
denied = true;
}
if !denied
&& let Some(mut items) = inline::try_inline(
cx,
path.res,
name,
Some((attrs, Some(import_def_id))),
&mut Default::default(),
)
{
items.push(Item::from_def_id_and_parts(
import_def_id.to_def_id(),
None,
ImportItem(Import::new_simple(name, resolve_use_source(cx, path), false)),
cx,
));
return items;
}
Import::new_simple(name, resolve_use_source(cx, path), true)
};
vec![Item::from_def_id_and_parts(import_def_id.to_def_id(), None, ImportItem(inner), cx)]
}
fn clean_maybe_renamed_foreign_item<'tcx>(
cx: &mut DocContext<'tcx>,
item: &hir::ForeignItem<'tcx>,
renamed: Option<Symbol>,
import_id: Option<LocalDefId>,
) -> Item {
let def_id = item.owner_id.to_def_id();
cx.with_param_env(def_id, |cx| {
let kind = match item.kind {
hir::ForeignItemKind::Fn(sig, idents, generics) => ForeignFunctionItem(
clean_function(cx, &sig, generics, ParamsSrc::Idents(idents)),
sig.header.safety(),
),
hir::ForeignItemKind::Static(ty, mutability, safety) => ForeignStaticItem(
Static { type_: Box::new(clean_ty(ty, cx)), mutability, expr: None },
safety,
),
hir::ForeignItemKind::Type => ForeignTypeItem,
};
generate_item_with_correct_attrs(
cx,
kind,
item.owner_id.def_id.to_def_id(),
item.ident.name,
import_id.as_slice(),
renamed,
)
})
}
fn clean_assoc_item_constraint<'tcx>(
trait_did: DefId,
constraint: &hir::AssocItemConstraint<'tcx>,
cx: &mut DocContext<'tcx>,
) -> AssocItemConstraint {
AssocItemConstraint {
assoc: PathSegment {
name: constraint.ident.name,
args: clean_generic_args(None, constraint.gen_args, cx),
},
kind: match constraint.kind {
hir::AssocItemConstraintKind::Equality { ref term } => {
let assoc_tag = match term {
hir::Term::Ty(_) => ty::AssocTag::Type,
hir::Term::Const(_) => ty::AssocTag::Const,
};
let assoc_item = cx
.tcx
.associated_items(trait_did)
.find_by_ident_and_kind(cx.tcx, constraint.ident, assoc_tag, trait_did)
.map(|item| item.def_id);
AssocItemConstraintKind::Equality { term: clean_hir_term(assoc_item, term, cx) }
}
hir::AssocItemConstraintKind::Bound { bounds } => AssocItemConstraintKind::Bound {
bounds: bounds.iter().filter_map(|b| clean_generic_bound(b, cx)).collect(),
},
},
}
}
fn clean_bound_vars<'tcx>(
bound_vars: &ty::List<ty::BoundVariableKind<'tcx>>,
cx: &mut DocContext<'tcx>,
) -> Vec<GenericParamDef> {
bound_vars
.into_iter()
.filter_map(|var| match var {
ty::BoundVariableKind::Region(ty::BoundRegionKind::Named(def_id)) => {
let name = cx.tcx.item_name(def_id);
if name != kw::UnderscoreLifetime {
Some(GenericParamDef::lifetime(def_id, name))
} else {
None
}
}
ty::BoundVariableKind::Ty(ty::BoundTyKind::Param(def_id)) => {
let name = cx.tcx.item_name(def_id);
Some(GenericParamDef {
name,
def_id,
kind: GenericParamDefKind::Type {
bounds: ThinVec::new(),
default: None,
synthetic: false,
},
})
}
// FIXME(non_lifetime_binders): Support higher-ranked const parameters.
ty::BoundVariableKind::Const => None,
_ => None,
})
.collect()
}