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 let mut externs = Vec::new();
33 for &cnum in cx.tcx.crates(()).iter() {
34 externs.push(ExternalCrate { crate_num: cnum });
35 // Analyze doc-reachability for extern items
36 LibEmbargoVisitor::new(cx).visit_lib(cnum);
38 externs.sort_unstable_by_key(|e| e.crate_num);
40 // Clean the crate, translating the entire librustc_ast AST to one that is
41 // understood by rustdoc.
42 let mut module = module.clean(cx);
45 ItemKind::ModuleItem(ref module) => {
46 for it in &module.items {
47 // `compiler_builtins` should be masked too, but we can't apply
48 // `#[doc(masked)]` to the injected `extern crate` because it's unstable.
49 if it.is_extern_crate()
50 && (it.attrs.has_doc_flag(sym::masked)
51 || cx.tcx.is_compiler_builtins(it.def_id.krate()))
53 cx.cache.masked_crates.insert(it.def_id.krate());
60 let local_crate = ExternalCrate { crate_num: LOCAL_CRATE };
61 let src = local_crate.src(cx.tcx);
62 let name = local_crate.name(cx.tcx);
63 let primitives = local_crate.primitives(cx.tcx);
64 let keywords = local_crate.keywords(cx.tcx);
66 let m = match *module.kind {
67 ItemKind::ModuleItem(ref mut m) => m,
70 m.items.extend(primitives.iter().map(|&(def_id, prim)| {
71 Item::from_def_id_and_parts(
74 ItemKind::PrimitiveItem(prim),
78 m.items.extend(keywords.into_iter().map(|(def_id, kw)| {
79 Item::from_def_id_and_parts(def_id, Some(kw), ItemKind::KeywordItem(kw), cx)
89 external_traits: cx.external_traits.clone(),
94 fn external_generic_args(
95 cx: &mut DocContext<'_>,
98 bindings: Vec<TypeBinding>,
99 substs: SubstsRef<'_>,
101 let mut skip_self = has_self;
102 let mut ty_kind = None;
103 let args: Vec<_> = substs
105 .filter_map(|kind| match kind.unpack() {
106 GenericArgKind::Lifetime(lt) => match lt {
107 ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrAnon(_), .. }) => {
108 Some(GenericArg::Lifetime(Lifetime::elided()))
110 _ => lt.clean(cx).map(GenericArg::Lifetime),
112 GenericArgKind::Type(_) if skip_self => {
116 GenericArgKind::Type(ty) => {
117 ty_kind = Some(ty.kind());
118 Some(GenericArg::Type(ty.clean(cx)))
120 GenericArgKind::Const(ct) => Some(GenericArg::Const(Box::new(ct.clean(cx)))),
124 if cx.tcx.fn_trait_kind_from_lang_item(did).is_some() {
125 let inputs = match ty_kind.unwrap() {
126 ty::Tuple(tys) => tys.iter().map(|t| t.expect_ty().clean(cx)).collect(),
127 _ => return GenericArgs::AngleBracketed { args, bindings },
130 // FIXME(#20299) return type comes from a projection now
131 // match types[1].kind {
132 // ty::Tuple(ref v) if v.is_empty() => None, // -> ()
133 // _ => Some(types[1].clean(cx))
135 GenericArgs::Parenthesized { inputs, output }
137 GenericArgs::AngleBracketed { args, bindings }
141 pub(super) fn external_path(
142 cx: &mut DocContext<'_>,
145 bindings: Vec<TypeBinding>,
146 substs: SubstsRef<'_>,
148 let def_kind = cx.tcx.def_kind(did);
149 let name = cx.tcx.item_name(did);
152 res: Res::Def(def_kind, did),
153 segments: vec![PathSegment {
155 args: external_generic_args(cx, did, has_self, bindings, substs),
160 crate fn strip_type(ty: Type) -> Type {
162 Type::ResolvedPath { path, did, is_generic } => {
163 Type::ResolvedPath { path: strip_path(&path), did, is_generic }
165 Type::DynTrait(mut bounds, lt) => {
166 let first = bounds.remove(0);
167 let stripped_trait = strip_type(first.trait_);
171 PolyTrait { trait_: stripped_trait, generic_params: first.generic_params },
173 Type::DynTrait(bounds, lt)
175 Type::Tuple(inner_tys) => {
176 Type::Tuple(inner_tys.iter().map(|t| strip_type(t.clone())).collect())
178 Type::Slice(inner_ty) => Type::Slice(Box::new(strip_type(*inner_ty))),
179 Type::Array(inner_ty, s) => Type::Array(Box::new(strip_type(*inner_ty)), s),
180 Type::RawPointer(m, inner_ty) => Type::RawPointer(m, Box::new(strip_type(*inner_ty))),
181 Type::BorrowedRef { lifetime, mutability, type_ } => {
182 Type::BorrowedRef { lifetime, mutability, type_: Box::new(strip_type(*type_)) }
184 Type::QPath { name, self_type, trait_, self_def_id } => Type::QPath {
187 self_type: Box::new(strip_type(*self_type)),
188 trait_: Box::new(strip_type(*trait_)),
194 crate fn strip_path(path: &Path) -> Path {
198 .map(|s| PathSegment {
200 args: GenericArgs::AngleBracketed { args: vec![], bindings: vec![] },
204 Path { global: path.global, res: path.res, segments }
207 crate fn qpath_to_string(p: &hir::QPath<'_>) -> String {
208 let segments = match *p {
209 hir::QPath::Resolved(_, ref path) => &path.segments,
210 hir::QPath::TypeRelative(_, ref segment) => return segment.ident.to_string(),
211 hir::QPath::LangItem(lang_item, ..) => return lang_item.name().to_string(),
214 let mut s = String::new();
215 for (i, seg) in segments.iter().enumerate() {
219 if seg.ident.name != kw::PathRoot {
220 s.push_str(&seg.ident.as_str());
226 crate fn build_deref_target_impls(cx: &mut DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
230 let target = match *item.kind {
231 ItemKind::TypedefItem(ref t, true) => &t.type_,
235 if let Some(prim) = target.primitive_type() {
236 for &did in prim.impls(tcx).iter().filter(|did| !did.is_local()) {
237 inline::build_impl(cx, None, did, None, ret);
239 } else if let ResolvedPath { did, .. } = *target {
241 inline::build_impls(cx, None, did, None, ret);
247 crate fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
249 debug!("trying to get a name from pattern: {:?}", p);
251 Symbol::intern(&match p.kind {
252 PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
253 PatKind::Binding(_, _, ident, _) => return ident.name,
254 PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
255 PatKind::Or(ref pats) => {
256 pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
258 PatKind::Tuple(ref elts, _) => format!(
260 elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
262 PatKind::Box(ref p) => return name_from_pat(&**p),
263 PatKind::Ref(ref p, _) => return name_from_pat(&**p),
264 PatKind::Lit(..) => {
266 "tried to get argument name from PatKind::Lit, which is silly in function arguments"
268 return Symbol::intern("()");
270 PatKind::Range(..) => return kw::Underscore,
271 PatKind::Slice(ref begin, ref mid, ref end) => {
272 let begin = begin.iter().map(|p| name_from_pat(p).to_string());
273 let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
274 let end = end.iter().map(|p| name_from_pat(p).to_string());
275 format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
280 crate fn print_const(cx: &DocContext<'_>, n: &'tcx ty::Const<'_>) -> String {
282 ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs_: _, promoted }) => {
283 let mut s = if let Some(def) = def.as_local() {
284 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def.did);
285 print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(hir_id))
287 inline::print_inlined_const(cx.tcx, def.did)
289 if let Some(promoted) = promoted {
290 s.push_str(&format!("::{:?}", promoted))
295 let mut s = n.to_string();
296 // array lengths are obviously usize
297 if s.ends_with("_usize") {
298 let n = s.len() - "_usize".len();
300 if s.ends_with(": ") {
301 let n = s.len() - ": ".len();
310 crate fn print_evaluated_const(tcx: TyCtxt<'_>, def_id: DefId) -> Option<String> {
311 tcx.const_eval_poly(def_id).ok().and_then(|val| {
312 let ty = tcx.type_of(def_id);
313 match (val, ty.kind()) {
314 (_, &ty::Ref(..)) => None,
315 (ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
316 (ConstValue::Scalar(_), _) => {
317 let const_ = ty::Const::from_value(tcx, val, ty);
318 Some(print_const_with_custom_print_scalar(tcx, const_))
325 fn format_integer_with_underscore_sep(num: &str) -> String {
326 let num_chars: Vec<_> = num.chars().collect();
327 let mut num_start_index = if num_chars.get(0) == Some(&'-') { 1 } else { 0 };
328 let chunk_size = match num[num_start_index..].as_bytes() {
329 [b'0', b'b' | b'x', ..] => {
330 num_start_index += 2;
333 [b'0', b'o', ..] => {
334 num_start_index += 2;
335 let remaining_chars = num_chars.len() - num_start_index;
336 if remaining_chars <= 6 {
337 // don't add underscores to Unix permissions like 0755 or 100755
338 return num.to_string();
345 num_chars[..num_start_index]
347 .chain(num_chars[num_start_index..].rchunks(chunk_size).rev().intersperse(&['_']).flatten())
351 fn print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: &'tcx ty::Const<'tcx>) -> String {
352 // Use a slightly different format for integer types which always shows the actual value.
353 // For all other types, fallback to the original `pretty_print_const`.
354 match (ct.val, ct.ty.kind()) {
355 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Uint(ui)) => {
356 format!("{}{}", format_integer_with_underscore_sep(&int.to_string()), ui.name_str())
358 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Int(i)) => {
359 let ty = tcx.lift(ct.ty).unwrap();
360 let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
361 let data = int.assert_bits(size);
362 let sign_extended_data = size.sign_extend(data) as i128;
366 format_integer_with_underscore_sep(&sign_extended_data.to_string()),
374 crate fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
375 if let hir::Node::Expr(expr) = tcx.hir().get(hir_id) {
376 if let hir::ExprKind::Lit(_) = &expr.kind {
380 if let hir::ExprKind::Unary(hir::UnOp::Neg, expr) = &expr.kind {
381 if let hir::ExprKind::Lit(_) = &expr.kind {
390 crate fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String {
392 let value = &hir.body(body).value;
394 let snippet = if !value.span.from_expansion() {
395 tcx.sess.source_map().span_to_snippet(value.span).ok()
400 snippet.unwrap_or_else(|| rustc_hir_pretty::id_to_string(&hir, body.hir_id))
403 /// Given a type Path, resolve it to a Type using the TyCtxt
404 crate fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
405 debug!("resolve_type({:?})", path);
407 let is_generic = match path.res {
408 Res::PrimTy(p) => return Primitive(PrimitiveType::from(p)),
409 Res::SelfTy(..) if path.segments.len() == 1 => {
410 return Generic(kw::SelfUpper);
412 Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => {
413 return Generic(path.segments[0].name);
415 Res::SelfTy(..) | Res::Def(DefKind::TyParam | DefKind::AssocTy, _) => true,
418 let did = register_res(cx, path.res);
419 ResolvedPath { path, did, is_generic }
422 crate fn get_auto_trait_and_blanket_impls(
423 cx: &mut DocContext<'tcx>,
425 ) -> impl Iterator<Item = Item> {
429 .generic_activity("get_auto_trait_impls")
430 .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(item_def_id));
431 let blanket_impls = cx
434 .generic_activity("get_blanket_impls")
435 .run(|| BlanketImplFinder { cx }.get_blanket_impls(item_def_id));
436 auto_impls.into_iter().chain(blanket_impls)
439 /// If `res` has a documentation page associated, store it in the cache.
441 /// This is later used by [`href()`] to determine the HTML link for the item.
443 /// [`href()`]: crate::html::format::href
444 crate fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
446 debug!("register_res({:?})", res);
448 let (did, kind) = match res {
449 Res::Def(DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst, i) => {
450 // associated items are documented, but on the page of their parent
451 (cx.tcx.parent(i).unwrap(), ItemType::Trait)
453 Res::Def(DefKind::Variant, i) => {
454 // variant items are documented, but on the page of their parent
455 (cx.tcx.parent(i).expect("cannot get parent def id"), ItemType::Enum)
457 // Each of these have their own page.
461 (Fn | TyAlias | Enum | Trait | Struct | Union | Mod | ForeignTy | Const | Static
462 | Macro(..) | TraitAlias),
464 ) => (i, kind.into()),
465 // This is part of a trait definition; document the trait.
466 Res::SelfTy(Some(trait_def_id), _) => (trait_def_id, ItemType::Trait),
467 // This is an inherent impl; it doesn't have its own page.
468 Res::SelfTy(None, Some((impl_def_id, _))) => return impl_def_id,
469 Res::SelfTy(None, None)
474 | Res::NonMacroAttr(_)
475 | Res::Err => return res.def_id(),
477 TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst | OpaqueTy
478 | Field | LifetimeParam | GlobalAsm | Impl | Closure | Generator,
485 inline::record_extern_fqn(cx, did, kind);
486 if let ItemType::Trait = kind {
487 inline::record_extern_trait(cx, did);
492 crate fn resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource {
494 did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
499 crate fn enter_impl_trait<F, R>(cx: &mut DocContext<'_>, f: F) -> R
501 F: FnOnce(&mut DocContext<'_>) -> R,
503 let old_bounds = mem::take(&mut cx.impl_trait_bounds);
505 assert!(cx.impl_trait_bounds.is_empty());
506 cx.impl_trait_bounds = old_bounds;
510 /// Find the nearest parent module of a [`DefId`].
511 crate fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
512 if def_id.is_top_level_module() {
513 // The crate root has no parent. Use it as the root instead.
516 let mut current = def_id;
517 // The immediate parent might not always be a module.
518 // Find the first parent which is.
519 while let Some(parent) = tcx.parent(current) {
520 if tcx.def_kind(parent) == DefKind::Mod {
529 /// Checks for the existence of `hidden` in the attribute below if `flag` is `sym::hidden`:
536 /// This function exists because it runs on `hir::Attributes` whereas the other is a
537 /// `clean::Attributes` method.
538 crate fn has_doc_flag(attrs: ty::Attributes<'_>, flag: Symbol) -> bool {
539 attrs.iter().any(|attr| {
540 attr.has_name(sym::doc)
541 && attr.meta_item_list().map_or(false, |l| rustc_attr::list_contains_name(&l, flag))
545 /// A link to `doc.rust-lang.org` that includes the channel name. Use this instead of manual links
546 /// so that the channel is consistent.
548 /// Set by `bootstrap::Builder::doc_rust_lang_org_channel` in order to keep tests passing on beta/stable.
549 crate const DOC_RUST_LANG_ORG_CHANNEL: &'static str = env!("DOC_RUST_LANG_ORG_CHANNEL");
551 /// Render a sequence of macro arms in a format suitable for displaying to the user
552 /// as part of an item declaration.
553 pub(super) fn render_macro_arms<'a>(
554 matchers: impl Iterator<Item = &'a TokenTree>,
557 let mut out = String::new();
558 for matcher in matchers {
559 writeln!(out, " {} => {{ ... }}{}", render_macro_matcher(matcher), arm_delim).unwrap();
564 /// Render a macro matcher in a format suitable for displaying to the user
565 /// as part of an item declaration.
566 pub(super) fn render_macro_matcher(matcher: &TokenTree) -> String {
567 rustc_ast_pretty::pprust::tt_to_string(matcher)
570 pub(super) fn display_macro_source(
571 cx: &mut DocContext<'_>,
575 vis: impl Clean<Visibility>,
577 let tts: Vec<_> = def.body.inner_tokens().into_trees().collect();
578 // Extract the spans of all matchers. They represent the "interface" of the macro.
579 let matchers = tts.chunks(4).map(|arm| &arm[0]);
582 format!("macro_rules! {} {{\n{}}}", name, render_macro_arms(matchers, ";"))
584 let vis = vis.clean(cx);
586 if matchers.len() <= 1 {
588 "{}macro {}{} {{\n ...\n}}",
589 vis.to_src_with_space(cx.tcx, def_id),
591 matchers.map(render_macro_matcher).collect::<String>(),
595 "{}macro {} {{\n{}}}",
596 vis.to_src_with_space(cx.tcx, def_id),
598 render_macro_arms(matchers, ","),