1 use crate::clean::auto_trait::AutoTraitFinder;
2 use crate::clean::blanket_impl::BlanketImplFinder;
4 inline, Clean, Crate, ExternalCrate, Generic, GenericArg, GenericArgs, ImportSource, Item,
5 ItemKind, Lifetime, Path, PathSegment, PolyTrait, Primitive, PrimitiveType, ResolvedPath, Type,
6 TypeBinding, Visibility,
8 use crate::core::DocContext;
9 use crate::formats::item_type::ItemType;
12 use rustc_ast::tokenstream::TokenTree;
14 use rustc_hir::def::{DefKind, Res};
15 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
16 use rustc_middle::mir::interpret::ConstValue;
17 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
18 use rustc_middle::ty::{self, DefIdTree, TyCtxt};
19 use rustc_span::symbol::{kw, sym, Symbol};
20 use std::fmt::Write as _;
26 crate fn krate(cx: &mut DocContext<'_>) -> Crate {
27 use crate::visit_lib::LibEmbargoVisitor;
29 let krate = cx.tcx.hir().krate();
30 let module = crate::visit_ast::RustdocVisitor::new(cx).visit(krate);
32 cx.cache.deref_trait_did = cx.tcx.lang_items().deref_trait();
33 cx.cache.deref_mut_trait_did = cx.tcx.lang_items().deref_mut_trait();
34 cx.cache.owned_box_did = cx.tcx.lang_items().owned_box();
36 let mut externs = Vec::new();
37 for &cnum in cx.tcx.crates(()).iter() {
38 externs.push(ExternalCrate { crate_num: cnum });
39 // Analyze doc-reachability for extern items
40 LibEmbargoVisitor::new(cx).visit_lib(cnum);
42 externs.sort_unstable_by_key(|e| e.crate_num);
44 // Clean the crate, translating the entire librustc_ast AST to one that is
45 // understood by rustdoc.
46 let mut module = module.clean(cx);
49 ItemKind::ModuleItem(ref module) => {
50 for it in &module.items {
51 // `compiler_builtins` should be masked too, but we can't apply
52 // `#[doc(masked)]` to the injected `extern crate` because it's unstable.
53 if it.is_extern_crate()
54 && (it.attrs.has_doc_flag(sym::masked)
55 || cx.tcx.is_compiler_builtins(it.def_id.krate()))
57 cx.cache.masked_crates.insert(it.def_id.krate());
64 let local_crate = ExternalCrate { crate_num: LOCAL_CRATE };
65 let src = local_crate.src(cx.tcx);
66 let name = local_crate.name(cx.tcx);
67 let primitives = local_crate.primitives(cx.tcx);
68 let keywords = local_crate.keywords(cx.tcx);
70 let m = match *module.kind {
71 ItemKind::ModuleItem(ref mut m) => m,
74 m.items.extend(primitives.iter().map(|&(def_id, prim)| {
75 Item::from_def_id_and_parts(
78 ItemKind::PrimitiveItem(prim),
82 m.items.extend(keywords.into_iter().map(|(def_id, kw)| {
83 Item::from_def_id_and_parts(def_id, Some(kw), ItemKind::KeywordItem(kw), cx)
93 external_traits: cx.external_traits.clone(),
98 fn external_generic_args(
99 cx: &mut DocContext<'_>,
100 trait_did: Option<DefId>,
102 bindings: Vec<TypeBinding>,
103 substs: SubstsRef<'_>,
105 let mut skip_self = has_self;
106 let mut ty_kind = None;
107 let args: Vec<_> = substs
109 .filter_map(|kind| match kind.unpack() {
110 GenericArgKind::Lifetime(lt) => match lt {
111 ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrAnon(_), .. }) => {
112 Some(GenericArg::Lifetime(Lifetime::elided()))
114 _ => lt.clean(cx).map(GenericArg::Lifetime),
116 GenericArgKind::Type(_) if skip_self => {
120 GenericArgKind::Type(ty) => {
121 ty_kind = Some(ty.kind());
122 Some(GenericArg::Type(ty.clean(cx)))
124 GenericArgKind::Const(ct) => Some(GenericArg::Const(ct.clean(cx))),
129 // Attempt to sugar an external path like Fn<(A, B,), C> to Fn(A, B) -> C
130 Some(did) if cx.tcx.fn_trait_kind_from_lang_item(did).is_some() => {
131 assert!(ty_kind.is_some());
132 let inputs = match ty_kind {
133 Some(ty::Tuple(ref tys)) => tys.iter().map(|t| t.expect_ty().clean(cx)).collect(),
134 _ => return GenericArgs::AngleBracketed { args, bindings },
137 // FIXME(#20299) return type comes from a projection now
138 // match types[1].kind {
139 // ty::Tuple(ref v) if v.is_empty() => None, // -> ()
140 // _ => Some(types[1].clean(cx))
142 GenericArgs::Parenthesized { inputs, output }
144 _ => GenericArgs::AngleBracketed { args, bindings },
148 // trait_did should be set to a trait's DefId if called on a TraitRef, in order to sugar
149 // from Fn<(A, B,), C> to Fn(A, B) -> C
150 pub(super) fn external_path(
151 cx: &mut DocContext<'_>,
153 trait_did: Option<DefId>,
155 bindings: Vec<TypeBinding>,
156 substs: SubstsRef<'_>,
161 segments: vec![PathSegment {
163 args: external_generic_args(cx, trait_did, has_self, bindings, substs),
168 crate fn strip_type(ty: Type) -> Type {
170 Type::ResolvedPath { path, did, is_generic } => {
171 Type::ResolvedPath { path: strip_path(&path), did, is_generic }
173 Type::DynTrait(mut bounds, lt) => {
174 let first = bounds.remove(0);
175 let stripped_trait = strip_type(first.trait_);
179 PolyTrait { trait_: stripped_trait, generic_params: first.generic_params },
181 Type::DynTrait(bounds, lt)
183 Type::Tuple(inner_tys) => {
184 Type::Tuple(inner_tys.iter().map(|t| strip_type(t.clone())).collect())
186 Type::Slice(inner_ty) => Type::Slice(Box::new(strip_type(*inner_ty))),
187 Type::Array(inner_ty, s) => Type::Array(Box::new(strip_type(*inner_ty)), s),
188 Type::RawPointer(m, inner_ty) => Type::RawPointer(m, Box::new(strip_type(*inner_ty))),
189 Type::BorrowedRef { lifetime, mutability, type_ } => {
190 Type::BorrowedRef { lifetime, mutability, type_: Box::new(strip_type(*type_)) }
192 Type::QPath { name, self_type, trait_, self_def_id } => Type::QPath {
195 self_type: Box::new(strip_type(*self_type)),
196 trait_: Box::new(strip_type(*trait_)),
202 crate fn strip_path(path: &Path) -> Path {
206 .map(|s| PathSegment {
208 args: GenericArgs::AngleBracketed { args: vec![], bindings: vec![] },
212 Path { global: path.global, res: path.res, segments }
215 crate fn qpath_to_string(p: &hir::QPath<'_>) -> String {
216 let segments = match *p {
217 hir::QPath::Resolved(_, ref path) => &path.segments,
218 hir::QPath::TypeRelative(_, ref segment) => return segment.ident.to_string(),
219 hir::QPath::LangItem(lang_item, ..) => return lang_item.name().to_string(),
222 let mut s = String::new();
223 for (i, seg) in segments.iter().enumerate() {
227 if seg.ident.name != kw::PathRoot {
228 s.push_str(&seg.ident.as_str());
234 crate fn build_deref_target_impls(cx: &mut DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
238 let target = match *item.kind {
239 ItemKind::TypedefItem(ref t, true) => &t.type_,
243 if let Some(prim) = target.primitive_type() {
244 for &did in prim.impls(tcx).iter().filter(|did| !did.is_local()) {
245 inline::build_impl(cx, None, did, None, ret);
247 } else if let ResolvedPath { did, .. } = *target {
249 inline::build_impls(cx, None, did, None, ret);
255 crate fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
257 debug!("trying to get a name from pattern: {:?}", p);
259 Symbol::intern(&match p.kind {
260 PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
261 PatKind::Binding(_, _, ident, _) => return ident.name,
262 PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
263 PatKind::Or(ref pats) => {
264 pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
266 PatKind::Tuple(ref elts, _) => format!(
268 elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
270 PatKind::Box(ref p) => return name_from_pat(&**p),
271 PatKind::Ref(ref p, _) => return name_from_pat(&**p),
272 PatKind::Lit(..) => {
274 "tried to get argument name from PatKind::Lit, which is silly in function arguments"
276 return Symbol::intern("()");
278 PatKind::Range(..) => return kw::Underscore,
279 PatKind::Slice(ref begin, ref mid, ref end) => {
280 let begin = begin.iter().map(|p| name_from_pat(p).to_string());
281 let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
282 let end = end.iter().map(|p| name_from_pat(p).to_string());
283 format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
288 crate fn print_const(cx: &DocContext<'_>, n: &'tcx ty::Const<'_>) -> String {
290 ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) => {
291 let mut s = if let Some(def) = def.as_local() {
292 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def.did);
293 print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(hir_id))
295 inline::print_inlined_const(cx.tcx, def.did)
297 if let Some(promoted) = promoted {
298 s.push_str(&format!("::{:?}", promoted))
303 let mut s = n.to_string();
304 // array lengths are obviously usize
305 if s.ends_with("_usize") {
306 let n = s.len() - "_usize".len();
308 if s.ends_with(": ") {
309 let n = s.len() - ": ".len();
318 crate fn print_evaluated_const(tcx: TyCtxt<'_>, def_id: DefId) -> Option<String> {
319 tcx.const_eval_poly(def_id).ok().and_then(|val| {
320 let ty = tcx.type_of(def_id);
321 match (val, ty.kind()) {
322 (_, &ty::Ref(..)) => None,
323 (ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
324 (ConstValue::Scalar(_), _) => {
325 let const_ = ty::Const::from_value(tcx, val, ty);
326 Some(print_const_with_custom_print_scalar(tcx, const_))
333 fn format_integer_with_underscore_sep(num: &str) -> String {
334 let num_chars: Vec<_> = num.chars().collect();
335 let mut num_start_index = if num_chars.get(0) == Some(&'-') { 1 } else { 0 };
336 let chunk_size = match num[num_start_index..].as_bytes() {
337 [b'0', b'b' | b'x', ..] => {
338 num_start_index += 2;
341 [b'0', b'o', ..] => {
342 num_start_index += 2;
343 let remaining_chars = num_chars.len() - num_start_index;
344 if remaining_chars <= 6 {
345 // don't add underscores to Unix permissions like 0755 or 100755
346 return num.to_string();
353 num_chars[..num_start_index]
355 .chain(num_chars[num_start_index..].rchunks(chunk_size).rev().intersperse(&['_']).flatten())
359 fn print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: &'tcx ty::Const<'tcx>) -> String {
360 // Use a slightly different format for integer types which always shows the actual value.
361 // For all other types, fallback to the original `pretty_print_const`.
362 match (ct.val, ct.ty.kind()) {
363 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Uint(ui)) => {
364 format!("{}{}", format_integer_with_underscore_sep(&int.to_string()), ui.name_str())
366 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Int(i)) => {
367 let ty = tcx.lift(ct.ty).unwrap();
368 let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
369 let data = int.assert_bits(size);
370 let sign_extended_data = size.sign_extend(data) as i128;
374 format_integer_with_underscore_sep(&sign_extended_data.to_string()),
382 crate fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
383 if let hir::Node::Expr(expr) = tcx.hir().get(hir_id) {
384 if let hir::ExprKind::Lit(_) = &expr.kind {
388 if let hir::ExprKind::Unary(hir::UnOp::Neg, expr) = &expr.kind {
389 if let hir::ExprKind::Lit(_) = &expr.kind {
398 crate fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String {
400 let value = &hir.body(body).value;
402 let snippet = if !value.span.from_expansion() {
403 tcx.sess.source_map().span_to_snippet(value.span).ok()
408 snippet.unwrap_or_else(|| rustc_hir_pretty::id_to_string(&hir, body.hir_id))
411 /// Given a type Path, resolve it to a Type using the TyCtxt
412 crate fn resolve_type(cx: &mut DocContext<'_>, path: Path, id: hir::HirId) -> Type {
413 debug!("resolve_type({:?},{:?})", path, id);
415 let is_generic = match path.res {
416 Res::PrimTy(p) => return Primitive(PrimitiveType::from(p)),
417 Res::SelfTy(..) if path.segments.len() == 1 => {
418 return Generic(kw::SelfUpper);
420 Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => {
421 return Generic(Symbol::intern(&path.whole_name()));
423 Res::SelfTy(..) | Res::Def(DefKind::TyParam | DefKind::AssocTy, _) => true,
426 let did = register_res(cx, path.res);
427 ResolvedPath { path, did, is_generic }
430 crate fn get_auto_trait_and_blanket_impls(
431 cx: &mut DocContext<'tcx>,
433 ) -> impl Iterator<Item = Item> {
437 .generic_activity("get_auto_trait_impls")
438 .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(item_def_id));
439 let blanket_impls = cx
442 .generic_activity("get_blanket_impls")
443 .run(|| BlanketImplFinder { cx }.get_blanket_impls(item_def_id));
444 auto_impls.into_iter().chain(blanket_impls)
447 /// If `res` has a documentation page associated, store it in the cache.
449 /// This is later used by [`href()`] to determine the HTML link for the item.
451 /// [`href()`]: crate::html::format::href
452 crate fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
454 debug!("register_res({:?})", res);
456 let (did, kind) = match res {
457 Res::Def(DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst, i) => {
458 // associated items are documented, but on the page of their parent
459 (cx.tcx.parent(i).unwrap(), ItemType::Trait)
461 Res::Def(DefKind::Variant, i) => {
462 // variant items are documented, but on the page of their parent
463 (cx.tcx.parent(i).expect("cannot get parent def id"), ItemType::Enum)
465 // Each of these have their own page.
469 (Fn | TyAlias | Enum | Trait | Struct | Union | Mod | ForeignTy | Const | Static
470 | Macro(..) | TraitAlias),
472 ) => (i, kind.into()),
473 // This is part of a trait definition; document the trait.
474 Res::SelfTy(Some(trait_def_id), _) => (trait_def_id, ItemType::Trait),
475 // This is an inherent impl; it doesn't have its own page.
476 Res::SelfTy(None, Some((impl_def_id, _))) => return impl_def_id,
477 Res::SelfTy(None, None)
482 | Res::NonMacroAttr(_)
483 | Res::Err => return res.def_id(),
485 TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst | OpaqueTy
486 | Field | LifetimeParam | GlobalAsm | Impl | Closure | Generator,
493 inline::record_extern_fqn(cx, did, kind);
494 if let ItemType::Trait = kind {
495 inline::record_extern_trait(cx, did);
500 crate fn resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource {
502 did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
507 crate fn enter_impl_trait<F, R>(cx: &mut DocContext<'_>, f: F) -> R
509 F: FnOnce(&mut DocContext<'_>) -> R,
511 let old_bounds = mem::take(&mut cx.impl_trait_bounds);
513 assert!(cx.impl_trait_bounds.is_empty());
514 cx.impl_trait_bounds = old_bounds;
518 /// Find the nearest parent module of a [`DefId`].
519 crate fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
520 if def_id.is_top_level_module() {
521 // The crate root has no parent. Use it as the root instead.
524 let mut current = def_id;
525 // The immediate parent might not always be a module.
526 // Find the first parent which is.
527 while let Some(parent) = tcx.parent(current) {
528 if tcx.def_kind(parent) == DefKind::Mod {
537 /// Checks for the existence of `hidden` in the attribute below if `flag` is `sym::hidden`:
544 /// This function exists because it runs on `hir::Attributes` whereas the other is a
545 /// `clean::Attributes` method.
546 crate fn has_doc_flag(attrs: ty::Attributes<'_>, flag: Symbol) -> bool {
547 attrs.iter().any(|attr| {
548 attr.has_name(sym::doc)
549 && attr.meta_item_list().map_or(false, |l| rustc_attr::list_contains_name(&l, flag))
553 /// A link to `doc.rust-lang.org` that includes the channel name. Use this instead of manual links
554 /// so that the channel is consistent.
556 /// Set by `bootstrap::Builder::doc_rust_lang_org_channel` in order to keep tests passing on beta/stable.
557 crate const DOC_RUST_LANG_ORG_CHANNEL: &'static str = env!("DOC_RUST_LANG_ORG_CHANNEL");
559 /// Render a sequence of macro arms in a format suitable for displaying to the user
560 /// as part of an item declaration.
561 pub(super) fn render_macro_arms<'a>(
562 matchers: impl Iterator<Item = &'a TokenTree>,
565 let mut out = String::new();
566 for matcher in matchers {
567 writeln!(out, " {} => {{ ... }}{}", render_macro_matcher(matcher), arm_delim).unwrap();
572 /// Render a macro matcher in a format suitable for displaying to the user
573 /// as part of an item declaration.
574 pub(super) fn render_macro_matcher(matcher: &TokenTree) -> String {
575 rustc_ast_pretty::pprust::tt_to_string(matcher)
578 pub(super) fn display_macro_source(
579 cx: &mut DocContext<'_>,
583 vis: impl Clean<Visibility>,
585 let tts: Vec<_> = def.body.inner_tokens().into_trees().collect();
586 // Extract the spans of all matchers. They represent the "interface" of the macro.
587 let matchers = tts.chunks(4).map(|arm| &arm[0]);
590 format!("macro_rules! {} {{\n{}}}", name, render_macro_arms(matchers, ";"))
592 let vis = vis.clean(cx);
594 if matchers.len() <= 1 {
596 "{}macro {}{} {{\n ...\n}}",
597 vis.to_src_with_space(cx.tcx, def_id),
599 matchers.map(render_macro_matcher).collect::<String>(),
603 "{}macro {} {{\n{}}}",
604 vis.to_src_with_space(cx.tcx, def_id),
606 render_macro_arms(matchers, ","),