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, 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 module = crate::visit_ast::RustdocVisitor::new(cx).visit();
31 let mut externs = Vec::new();
32 for &cnum in cx.tcx.crates(()).iter() {
33 externs.push(ExternalCrate { crate_num: cnum });
34 // Analyze doc-reachability for extern items
35 LibEmbargoVisitor::new(cx).visit_lib(cnum);
37 externs.sort_unstable_by_key(|e| e.crate_num);
39 // Clean the crate, translating the entire librustc_ast AST to one that is
40 // understood by rustdoc.
41 let mut module = module.clean(cx);
44 ItemKind::ModuleItem(ref module) => {
45 for it in &module.items {
46 // `compiler_builtins` should be masked too, but we can't apply
47 // `#[doc(masked)]` to the injected `extern crate` because it's unstable.
48 if it.is_extern_crate()
49 && (it.attrs.has_doc_flag(sym::masked)
50 || cx.tcx.is_compiler_builtins(it.def_id.krate()))
52 cx.cache.masked_crates.insert(it.def_id.krate());
59 let local_crate = ExternalCrate { crate_num: LOCAL_CRATE };
60 let src = local_crate.src(cx.tcx);
61 let name = local_crate.name(cx.tcx);
62 let primitives = local_crate.primitives(cx.tcx);
63 let keywords = local_crate.keywords(cx.tcx);
65 let m = match *module.kind {
66 ItemKind::ModuleItem(ref mut m) => m,
69 m.items.extend(primitives.iter().map(|&(def_id, prim)| {
70 Item::from_def_id_and_parts(
73 ItemKind::PrimitiveItem(prim),
77 m.items.extend(keywords.into_iter().map(|(def_id, kw)| {
78 Item::from_def_id_and_parts(def_id, Some(kw), ItemKind::KeywordItem(kw), cx)
88 external_traits: cx.external_traits.clone(),
93 fn external_generic_args(
94 cx: &mut DocContext<'_>,
97 bindings: Vec<TypeBinding>,
98 substs: SubstsRef<'_>,
100 let mut skip_self = has_self;
101 let mut ty_kind = None;
102 let args: Vec<_> = substs
104 .filter_map(|kind| match kind.unpack() {
105 GenericArgKind::Lifetime(lt) => match lt {
106 ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrAnon(_), .. }) => {
107 Some(GenericArg::Lifetime(Lifetime::elided()))
109 _ => lt.clean(cx).map(GenericArg::Lifetime),
111 GenericArgKind::Type(_) if skip_self => {
115 GenericArgKind::Type(ty) => {
116 ty_kind = Some(ty.kind());
117 Some(GenericArg::Type(ty.clean(cx)))
119 GenericArgKind::Const(ct) => Some(GenericArg::Const(Box::new(ct.clean(cx)))),
123 if cx.tcx.fn_trait_kind_from_lang_item(did).is_some() {
124 let inputs = match ty_kind.unwrap() {
125 ty::Tuple(tys) => tys.iter().map(|t| t.expect_ty().clean(cx)).collect(),
126 _ => return GenericArgs::AngleBracketed { args, bindings },
129 // FIXME(#20299) return type comes from a projection now
130 // match types[1].kind {
131 // ty::Tuple(ref v) if v.is_empty() => None, // -> ()
132 // _ => Some(types[1].clean(cx))
134 GenericArgs::Parenthesized { inputs, output }
136 GenericArgs::AngleBracketed { args, bindings }
140 pub(super) fn external_path(
141 cx: &mut DocContext<'_>,
144 bindings: Vec<TypeBinding>,
145 substs: SubstsRef<'_>,
147 let def_kind = cx.tcx.def_kind(did);
148 let name = cx.tcx.item_name(did);
150 res: Res::Def(def_kind, did),
151 segments: vec![PathSegment {
153 args: external_generic_args(cx, did, has_self, bindings, substs),
158 /// Remove the generic arguments from a path.
159 crate fn strip_path_generics(path: Path) -> Path {
163 .map(|s| PathSegment {
165 args: GenericArgs::AngleBracketed { args: vec![], bindings: vec![] },
169 Path { res: path.res, segments }
172 crate fn qpath_to_string(p: &hir::QPath<'_>) -> String {
173 let segments = match *p {
174 hir::QPath::Resolved(_, ref path) => &path.segments,
175 hir::QPath::TypeRelative(_, ref segment) => return segment.ident.to_string(),
176 hir::QPath::LangItem(lang_item, ..) => return lang_item.name().to_string(),
179 let mut s = String::new();
180 for (i, seg) in segments.iter().enumerate() {
184 if seg.ident.name != kw::PathRoot {
185 s.push_str(&seg.ident.as_str());
191 crate fn build_deref_target_impls(cx: &mut DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
195 let target = match *item.kind {
196 ItemKind::TypedefItem(ref t, true) => &t.type_,
200 if let Some(prim) = target.primitive_type() {
201 for &did in prim.impls(tcx).iter().filter(|did| !did.is_local()) {
202 inline::build_impl(cx, None, did, None, ret);
204 } else if let ResolvedPath { did, .. } = *target {
206 inline::build_impls(cx, None, did, None, ret);
212 crate fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
214 debug!("trying to get a name from pattern: {:?}", p);
216 Symbol::intern(&match p.kind {
217 PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
218 PatKind::Binding(_, _, ident, _) => return ident.name,
219 PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
220 PatKind::Or(ref pats) => {
221 pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
223 PatKind::Tuple(ref elts, _) => format!(
225 elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
227 PatKind::Box(ref p) => return name_from_pat(&**p),
228 PatKind::Ref(ref p, _) => return name_from_pat(&**p),
229 PatKind::Lit(..) => {
231 "tried to get argument name from PatKind::Lit, which is silly in function arguments"
233 return Symbol::intern("()");
235 PatKind::Range(..) => return kw::Underscore,
236 PatKind::Slice(ref begin, ref mid, ref end) => {
237 let begin = begin.iter().map(|p| name_from_pat(p).to_string());
238 let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
239 let end = end.iter().map(|p| name_from_pat(p).to_string());
240 format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
245 crate fn print_const(cx: &DocContext<'_>, n: &'tcx ty::Const<'_>) -> String {
247 ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs_: _, promoted }) => {
248 let mut s = if let Some(def) = def.as_local() {
249 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def.did);
250 print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(hir_id))
252 inline::print_inlined_const(cx.tcx, def.did)
254 if let Some(promoted) = promoted {
255 s.push_str(&format!("::{:?}", promoted))
260 let mut s = n.to_string();
261 // array lengths are obviously usize
262 if s.ends_with("_usize") {
263 let n = s.len() - "_usize".len();
265 if s.ends_with(": ") {
266 let n = s.len() - ": ".len();
275 crate fn print_evaluated_const(tcx: TyCtxt<'_>, def_id: DefId) -> Option<String> {
276 tcx.const_eval_poly(def_id).ok().and_then(|val| {
277 let ty = tcx.type_of(def_id);
278 match (val, ty.kind()) {
279 (_, &ty::Ref(..)) => None,
280 (ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
281 (ConstValue::Scalar(_), _) => {
282 let const_ = ty::Const::from_value(tcx, val, ty);
283 Some(print_const_with_custom_print_scalar(tcx, const_))
290 fn format_integer_with_underscore_sep(num: &str) -> String {
291 let num_chars: Vec<_> = num.chars().collect();
292 let mut num_start_index = if num_chars.get(0) == Some(&'-') { 1 } else { 0 };
293 let chunk_size = match num[num_start_index..].as_bytes() {
294 [b'0', b'b' | b'x', ..] => {
295 num_start_index += 2;
298 [b'0', b'o', ..] => {
299 num_start_index += 2;
300 let remaining_chars = num_chars.len() - num_start_index;
301 if remaining_chars <= 6 {
302 // don't add underscores to Unix permissions like 0755 or 100755
303 return num.to_string();
310 num_chars[..num_start_index]
312 .chain(num_chars[num_start_index..].rchunks(chunk_size).rev().intersperse(&['_']).flatten())
316 fn print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: &'tcx ty::Const<'tcx>) -> String {
317 // Use a slightly different format for integer types which always shows the actual value.
318 // For all other types, fallback to the original `pretty_print_const`.
319 match (ct.val, ct.ty.kind()) {
320 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Uint(ui)) => {
321 format!("{}{}", format_integer_with_underscore_sep(&int.to_string()), ui.name_str())
323 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Int(i)) => {
324 let ty = tcx.lift(ct.ty).unwrap();
325 let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
326 let data = int.assert_bits(size);
327 let sign_extended_data = size.sign_extend(data) as i128;
331 format_integer_with_underscore_sep(&sign_extended_data.to_string()),
339 crate fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
340 if let hir::Node::Expr(expr) = tcx.hir().get(hir_id) {
341 if let hir::ExprKind::Lit(_) = &expr.kind {
345 if let hir::ExprKind::Unary(hir::UnOp::Neg, expr) = &expr.kind {
346 if let hir::ExprKind::Lit(_) = &expr.kind {
355 crate fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String {
357 let value = &hir.body(body).value;
359 let snippet = if !value.span.from_expansion() {
360 tcx.sess.source_map().span_to_snippet(value.span).ok()
365 snippet.unwrap_or_else(|| rustc_hir_pretty::id_to_string(&hir, body.hir_id))
368 /// Given a type Path, resolve it to a Type using the TyCtxt
369 crate fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
370 debug!("resolve_type({:?})", path);
373 Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
374 Res::SelfTy(..) if path.segments.len() == 1 => Generic(kw::SelfUpper),
375 Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => Generic(path.segments[0].name),
377 let did = register_res(cx, path.res);
378 ResolvedPath { path, did }
383 crate fn get_auto_trait_and_blanket_impls(
384 cx: &mut DocContext<'tcx>,
386 ) -> impl Iterator<Item = Item> {
390 .generic_activity("get_auto_trait_impls")
391 .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(item_def_id));
392 let blanket_impls = cx
395 .generic_activity("get_blanket_impls")
396 .run(|| BlanketImplFinder { cx }.get_blanket_impls(item_def_id));
397 auto_impls.into_iter().chain(blanket_impls)
400 /// If `res` has a documentation page associated, store it in the cache.
402 /// This is later used by [`href()`] to determine the HTML link for the item.
404 /// [`href()`]: crate::html::format::href
405 crate fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
407 debug!("register_res({:?})", res);
409 let (did, kind) = match res {
410 Res::Def(DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst, i) => {
411 // associated items are documented, but on the page of their parent
412 (cx.tcx.parent(i).unwrap(), ItemType::Trait)
414 Res::Def(DefKind::Variant, i) => {
415 // variant items are documented, but on the page of their parent
416 (cx.tcx.parent(i).expect("cannot get parent def id"), ItemType::Enum)
418 // Each of these have their own page.
422 (Fn | TyAlias | Enum | Trait | Struct | Union | Mod | ForeignTy | Const | Static
423 | Macro(..) | TraitAlias),
425 ) => (i, kind.into()),
426 // This is part of a trait definition; document the trait.
427 Res::SelfTy(Some(trait_def_id), _) => (trait_def_id, ItemType::Trait),
428 // This is an inherent impl; it doesn't have its own page.
429 Res::SelfTy(None, Some((impl_def_id, _))) => return impl_def_id,
430 Res::SelfTy(None, None)
435 | Res::NonMacroAttr(_)
436 | Res::Err => return res.def_id(),
438 TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst | OpaqueTy
439 | Field | LifetimeParam | GlobalAsm | Impl | Closure | Generator,
446 inline::record_extern_fqn(cx, did, kind);
447 if let ItemType::Trait = kind {
448 inline::record_extern_trait(cx, did);
453 crate fn resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource {
455 did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
460 crate fn enter_impl_trait<F, R>(cx: &mut DocContext<'_>, f: F) -> R
462 F: FnOnce(&mut DocContext<'_>) -> R,
464 let old_bounds = mem::take(&mut cx.impl_trait_bounds);
466 assert!(cx.impl_trait_bounds.is_empty());
467 cx.impl_trait_bounds = old_bounds;
471 /// Find the nearest parent module of a [`DefId`].
472 crate fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
473 if def_id.is_top_level_module() {
474 // The crate root has no parent. Use it as the root instead.
477 let mut current = def_id;
478 // The immediate parent might not always be a module.
479 // Find the first parent which is.
480 while let Some(parent) = tcx.parent(current) {
481 if tcx.def_kind(parent) == DefKind::Mod {
490 /// Checks for the existence of `hidden` in the attribute below if `flag` is `sym::hidden`:
497 /// This function exists because it runs on `hir::Attributes` whereas the other is a
498 /// `clean::Attributes` method.
499 crate fn has_doc_flag(attrs: ty::Attributes<'_>, flag: Symbol) -> bool {
500 attrs.iter().any(|attr| {
501 attr.has_name(sym::doc)
502 && attr.meta_item_list().map_or(false, |l| rustc_attr::list_contains_name(&l, flag))
506 /// A link to `doc.rust-lang.org` that includes the channel name. Use this instead of manual links
507 /// so that the channel is consistent.
509 /// Set by `bootstrap::Builder::doc_rust_lang_org_channel` in order to keep tests passing on beta/stable.
510 crate const DOC_RUST_LANG_ORG_CHANNEL: &'static str = env!("DOC_RUST_LANG_ORG_CHANNEL");
512 /// Render a sequence of macro arms in a format suitable for displaying to the user
513 /// as part of an item declaration.
514 pub(super) fn render_macro_arms<'a>(
515 matchers: impl Iterator<Item = &'a TokenTree>,
518 let mut out = String::new();
519 for matcher in matchers {
520 writeln!(out, " {} => {{ ... }}{}", render_macro_matcher(matcher), arm_delim).unwrap();
525 /// Render a macro matcher in a format suitable for displaying to the user
526 /// as part of an item declaration.
527 pub(super) fn render_macro_matcher(matcher: &TokenTree) -> String {
528 rustc_ast_pretty::pprust::tt_to_string(matcher)
531 pub(super) fn display_macro_source(
532 cx: &mut DocContext<'_>,
536 vis: impl Clean<Visibility>,
538 let tts: Vec<_> = def.body.inner_tokens().into_trees().collect();
539 // Extract the spans of all matchers. They represent the "interface" of the macro.
540 let matchers = tts.chunks(4).map(|arm| &arm[0]);
543 format!("macro_rules! {} {{\n{}}}", name, render_macro_arms(matchers, ";"))
545 let vis = vis.clean(cx);
547 if matchers.len() <= 1 {
549 "{}macro {}{} {{\n ...\n}}",
550 vis.to_src_with_space(cx.tcx, def_id),
552 matchers.map(render_macro_matcher).collect::<String>(),
556 "{}macro {} {{\n{}}}",
557 vis.to_src_with_space(cx.tcx, def_id),
559 render_macro_arms(matchers, ","),