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, Type, TypeBinding, Visibility,
7 use crate::core::DocContext;
8 use crate::formats::item_type::ItemType;
9 use crate::visit_lib::LibEmbargoVisitor;
12 use rustc_ast::tokenstream::TokenTree;
13 use rustc_data_structures::thin_vec::ThinVec;
15 use rustc_hir::def::{DefKind, Res};
16 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
17 use rustc_middle::mir::interpret::ConstValue;
18 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
19 use rustc_middle::ty::{self, DefIdTree, TyCtxt};
20 use rustc_session::parse::ParseSess;
21 use rustc_span::source_map::FilePathMapping;
22 use rustc_span::symbol::{kw, sym, Symbol};
23 use std::fmt::Write as _;
29 crate fn krate(cx: &mut DocContext<'_>) -> Crate {
30 let module = crate::visit_ast::RustdocVisitor::new(cx).visit();
32 for &cnum in cx.tcx.crates(()) {
33 // Analyze doc-reachability for extern items
34 LibEmbargoVisitor::new(cx).visit_lib(cnum);
37 // Clean the crate, translating the entire librustc_ast AST to one that is
38 // understood by rustdoc.
39 let mut module = module.clean(cx);
42 ItemKind::ModuleItem(ref module) => {
43 for it in &module.items {
44 // `compiler_builtins` should be masked too, but we can't apply
45 // `#[doc(masked)]` to the injected `extern crate` because it's unstable.
46 if it.is_extern_crate()
47 && (it.attrs.has_doc_flag(sym::masked)
48 || cx.tcx.is_compiler_builtins(it.def_id.krate()))
50 cx.cache.masked_crates.insert(it.def_id.krate());
57 let local_crate = ExternalCrate { crate_num: LOCAL_CRATE };
58 let primitives = local_crate.primitives(cx.tcx);
59 let keywords = local_crate.keywords(cx.tcx);
61 let m = match *module.kind {
62 ItemKind::ModuleItem(ref mut m) => m,
65 m.items.extend(primitives.iter().map(|&(def_id, prim)| {
66 Item::from_def_id_and_parts(
69 ItemKind::PrimitiveItem(prim),
73 m.items.extend(keywords.into_iter().map(|(def_id, kw)| {
74 Item::from_def_id_and_parts(def_id, Some(kw), ItemKind::KeywordItem(kw), cx)
78 Crate { module, primitives, external_traits: cx.external_traits.clone() }
81 fn external_generic_args(
82 cx: &mut DocContext<'_>,
85 bindings: Vec<TypeBinding>,
86 substs: SubstsRef<'_>,
88 let mut skip_self = has_self;
89 let mut ty_kind = None;
90 let args: Vec<_> = substs
92 .filter_map(|kind| match kind.unpack() {
93 GenericArgKind::Lifetime(lt) => match lt {
94 ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrAnon(_), .. }) => {
95 Some(GenericArg::Lifetime(Lifetime::elided()))
97 _ => lt.clean(cx).map(GenericArg::Lifetime),
99 GenericArgKind::Type(_) if skip_self => {
103 GenericArgKind::Type(ty) => {
104 ty_kind = Some(ty.kind());
105 Some(GenericArg::Type(ty.clean(cx)))
107 GenericArgKind::Const(ct) => Some(GenericArg::Const(Box::new(ct.clean(cx)))),
111 if cx.tcx.fn_trait_kind_from_lang_item(did).is_some() {
112 let inputs = match ty_kind.unwrap() {
113 ty::Tuple(tys) => tys.iter().map(|t| t.expect_ty().clean(cx)).collect(),
114 _ => return GenericArgs::AngleBracketed { args, bindings: bindings.into() },
117 // FIXME(#20299) return type comes from a projection now
118 // match types[1].kind {
119 // ty::Tuple(ref v) if v.is_empty() => None, // -> ()
120 // _ => Some(types[1].clean(cx))
122 GenericArgs::Parenthesized { inputs, output }
124 GenericArgs::AngleBracketed { args, bindings: bindings.into() }
128 pub(super) fn external_path(
129 cx: &mut DocContext<'_>,
132 bindings: Vec<TypeBinding>,
133 substs: SubstsRef<'_>,
135 let def_kind = cx.tcx.def_kind(did);
136 let name = cx.tcx.item_name(did);
138 res: Res::Def(def_kind, did),
139 segments: vec![PathSegment {
141 args: external_generic_args(cx, did, has_self, bindings, substs),
146 /// Remove the generic arguments from a path.
147 crate fn strip_path_generics(mut path: Path) -> Path {
148 for ps in path.segments.iter_mut() {
149 ps.args = GenericArgs::AngleBracketed { args: vec![], bindings: ThinVec::new() }
155 crate fn qpath_to_string(p: &hir::QPath<'_>) -> String {
156 let segments = match *p {
157 hir::QPath::Resolved(_, path) => &path.segments,
158 hir::QPath::TypeRelative(_, segment) => return segment.ident.to_string(),
159 hir::QPath::LangItem(lang_item, ..) => return lang_item.name().to_string(),
162 let mut s = String::new();
163 for (i, seg) in segments.iter().enumerate() {
167 if seg.ident.name != kw::PathRoot {
168 s.push_str(seg.ident.as_str());
174 crate fn build_deref_target_impls(cx: &mut DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
178 let target = match *item.kind {
179 ItemKind::TypedefItem(ref t, true) => &t.type_,
183 if let Some(prim) = target.primitive_type() {
184 let _prof_timer = cx.tcx.sess.prof.generic_activity("build_primitive_inherent_impls");
185 for &did in prim.impls(tcx).iter().filter(|did| !did.is_local()) {
186 inline::build_impl(cx, None, did, None, ret);
188 } else if let Type::Path { path } = target {
189 let did = path.def_id();
191 inline::build_impls(cx, None, did, None, ret);
197 crate fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
199 debug!("trying to get a name from pattern: {:?}", p);
201 Symbol::intern(&match p.kind {
202 PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
203 PatKind::Binding(_, _, ident, _) => return ident.name,
204 PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
205 PatKind::Or(pats) => {
206 pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
208 PatKind::Tuple(elts, _) => format!(
210 elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
212 PatKind::Box(p) => return name_from_pat(&*p),
213 PatKind::Ref(p, _) => return name_from_pat(&*p),
214 PatKind::Lit(..) => {
216 "tried to get argument name from PatKind::Lit, which is silly in function arguments"
218 return Symbol::intern("()");
220 PatKind::Range(..) => return kw::Underscore,
221 PatKind::Slice(begin, ref mid, end) => {
222 let begin = begin.iter().map(|p| name_from_pat(p).to_string());
223 let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
224 let end = end.iter().map(|p| name_from_pat(p).to_string());
225 format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
230 crate fn print_const(cx: &DocContext<'_>, n: &ty::Const<'_>) -> String {
232 ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) => {
233 let mut s = if let Some(def) = def.as_local() {
234 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def.did);
235 print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(hir_id))
237 inline::print_inlined_const(cx.tcx, def.did)
239 if let Some(promoted) = promoted {
240 s.push_str(&format!("::{:?}", promoted))
245 let mut s = n.to_string();
246 // array lengths are obviously usize
247 if s.ends_with("_usize") {
248 let n = s.len() - "_usize".len();
250 if s.ends_with(": ") {
251 let n = s.len() - ": ".len();
260 crate fn print_evaluated_const(tcx: TyCtxt<'_>, def_id: DefId) -> Option<String> {
261 tcx.const_eval_poly(def_id).ok().and_then(|val| {
262 let ty = tcx.type_of(def_id);
263 match (val, ty.kind()) {
264 (_, &ty::Ref(..)) => None,
265 (ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
266 (ConstValue::Scalar(_), _) => {
267 let const_ = ty::Const::from_value(tcx, val, ty);
268 Some(print_const_with_custom_print_scalar(tcx, const_))
275 fn format_integer_with_underscore_sep(num: &str) -> String {
276 let num_chars: Vec<_> = num.chars().collect();
277 let mut num_start_index = if num_chars.get(0) == Some(&'-') { 1 } else { 0 };
278 let chunk_size = match num[num_start_index..].as_bytes() {
279 [b'0', b'b' | b'x', ..] => {
280 num_start_index += 2;
283 [b'0', b'o', ..] => {
284 num_start_index += 2;
285 let remaining_chars = num_chars.len() - num_start_index;
286 if remaining_chars <= 6 {
287 // don't add underscores to Unix permissions like 0755 or 100755
288 return num.to_string();
295 num_chars[..num_start_index]
297 .chain(num_chars[num_start_index..].rchunks(chunk_size).rev().intersperse(&['_']).flatten())
301 fn print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: &ty::Const<'_>) -> String {
302 // Use a slightly different format for integer types which always shows the actual value.
303 // For all other types, fallback to the original `pretty_print_const`.
304 match (ct.val, ct.ty.kind()) {
305 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Uint(ui)) => {
306 format!("{}{}", format_integer_with_underscore_sep(&int.to_string()), ui.name_str())
308 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Int(i)) => {
309 let ty = tcx.lift(ct.ty).unwrap();
310 let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
311 let data = int.assert_bits(size);
312 let sign_extended_data = size.sign_extend(data) as i128;
316 format_integer_with_underscore_sep(&sign_extended_data.to_string()),
324 crate fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
325 if let hir::Node::Expr(expr) = tcx.hir().get(hir_id) {
326 if let hir::ExprKind::Lit(_) = &expr.kind {
330 if let hir::ExprKind::Unary(hir::UnOp::Neg, expr) = &expr.kind {
331 if let hir::ExprKind::Lit(_) = &expr.kind {
340 crate fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String {
342 let value = &hir.body(body).value;
344 let snippet = if !value.span.from_expansion() {
345 tcx.sess.source_map().span_to_snippet(value.span).ok()
350 snippet.unwrap_or_else(|| rustc_hir_pretty::id_to_string(&hir, body.hir_id))
353 /// Given a type Path, resolve it to a Type using the TyCtxt
354 crate fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
355 debug!("resolve_type({:?})", path);
358 Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
359 Res::SelfTy(..) if path.segments.len() == 1 => Generic(kw::SelfUpper),
360 Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => Generic(path.segments[0].name),
362 let _ = register_res(cx, path.res);
368 crate fn get_auto_trait_and_blanket_impls(
369 cx: &mut DocContext<'_>,
371 ) -> impl Iterator<Item = Item> {
375 .generic_activity("get_auto_trait_impls")
376 .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(item_def_id));
377 let blanket_impls = cx
380 .generic_activity("get_blanket_impls")
381 .run(|| BlanketImplFinder { cx }.get_blanket_impls(item_def_id));
382 auto_impls.into_iter().chain(blanket_impls)
385 /// If `res` has a documentation page associated, store it in the cache.
387 /// This is later used by [`href()`] to determine the HTML link for the item.
389 /// [`href()`]: crate::html::format::href
390 crate fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
392 debug!("register_res({:?})", res);
394 let (did, kind) = match res {
395 // These should be added to the cache using `record_extern_fqn`.
397 kind @ (AssocTy | AssocFn | AssocConst | Variant | Fn | TyAlias | Enum | Trait | Struct
398 | Union | Mod | ForeignTy | Const | Static | Macro(..) | TraitAlias),
400 ) => (i, kind.into()),
401 // This is part of a trait definition; document the trait.
402 Res::SelfTy(Some(trait_def_id), _) => (trait_def_id, ItemType::Trait),
403 // This is an inherent impl; it doesn't have its own page.
404 Res::SelfTy(None, Some((impl_def_id, _))) => return impl_def_id,
405 Res::SelfTy(None, None)
410 | Res::NonMacroAttr(_)
411 | Res::Err => return res.def_id(),
413 TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst
414 | InlineConst | OpaqueTy | Field | LifetimeParam | GlobalAsm | Impl | Closure
422 inline::record_extern_fqn(cx, did, kind);
423 if let ItemType::Trait = kind {
424 inline::record_extern_trait(cx, did);
429 crate fn resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource {
431 did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
436 crate fn enter_impl_trait<F, R>(cx: &mut DocContext<'_>, f: F) -> R
438 F: FnOnce(&mut DocContext<'_>) -> R,
440 let old_bounds = mem::take(&mut cx.impl_trait_bounds);
442 assert!(cx.impl_trait_bounds.is_empty());
443 cx.impl_trait_bounds = old_bounds;
447 /// Find the nearest parent module of a [`DefId`].
448 crate fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
449 if def_id.is_top_level_module() {
450 // The crate root has no parent. Use it as the root instead.
453 let mut current = def_id;
454 // The immediate parent might not always be a module.
455 // Find the first parent which is.
456 while let Some(parent) = tcx.parent(current) {
457 if tcx.def_kind(parent) == DefKind::Mod {
466 /// Checks for the existence of `hidden` in the attribute below if `flag` is `sym::hidden`:
473 /// This function exists because it runs on `hir::Attributes` whereas the other is a
474 /// `clean::Attributes` method.
475 crate fn has_doc_flag(attrs: ty::Attributes<'_>, flag: Symbol) -> bool {
476 attrs.iter().any(|attr| {
477 attr.has_name(sym::doc)
478 && attr.meta_item_list().map_or(false, |l| rustc_attr::list_contains_name(&l, flag))
482 /// A link to `doc.rust-lang.org` that includes the channel name. Use this instead of manual links
483 /// so that the channel is consistent.
485 /// Set by `bootstrap::Builder::doc_rust_lang_org_channel` in order to keep tests passing on beta/stable.
486 crate const DOC_RUST_LANG_ORG_CHANNEL: &str = env!("DOC_RUST_LANG_ORG_CHANNEL");
488 /// Render a sequence of macro arms in a format suitable for displaying to the user
489 /// as part of an item declaration.
490 pub(super) fn render_macro_arms<'a>(
492 matchers: impl Iterator<Item = &'a TokenTree>,
495 let mut out = String::new();
496 for matcher in matchers {
497 writeln!(out, " {} => {{ ... }}{}", render_macro_matcher(tcx, matcher), arm_delim)
503 /// Render a macro matcher in a format suitable for displaying to the user
504 /// as part of an item declaration.
505 pub(super) fn render_macro_matcher(tcx: TyCtxt<'_>, matcher: &TokenTree) -> String {
506 if let Some(snippet) = snippet_equal_to_token(tcx, matcher) {
509 rustc_ast_pretty::pprust::tt_to_string(matcher)
513 /// Find the source snippet for this token's Span, reparse it, and return the
514 /// snippet if the reparsed TokenTree matches the argument TokenTree.
515 fn snippet_equal_to_token(tcx: TyCtxt<'_>, matcher: &TokenTree) -> Option<String> {
516 // Find what rustc thinks is the source snippet.
517 // This may not actually be anything meaningful if this matcher was itself
518 // generated by a macro.
519 let source_map = tcx.sess.source_map();
520 let span = matcher.span();
521 let snippet = source_map.span_to_snippet(span).ok()?;
524 let sess = ParseSess::new(FilePathMapping::empty());
525 let file_name = source_map.span_to_filename(span);
527 match rustc_parse::maybe_new_parser_from_source_str(&sess, file_name, snippet.clone()) {
528 Ok(parser) => parser,
529 Err(diagnostics) => {
530 for mut diagnostic in diagnostics {
537 // Reparse a single token tree.
538 let mut reparsed_trees = match parser.parse_all_token_trees() {
539 Ok(reparsed_trees) => reparsed_trees,
540 Err(mut diagnostic) => {
545 if reparsed_trees.len() != 1 {
548 let reparsed_tree = reparsed_trees.pop().unwrap();
550 // Compare against the original tree.
551 if reparsed_tree.eq_unspanned(matcher) { Some(snippet) } else { None }
554 pub(super) fn display_macro_source(
555 cx: &mut DocContext<'_>,
561 let tts: Vec<_> = def.body.inner_tokens().into_trees().collect();
562 // Extract the spans of all matchers. They represent the "interface" of the macro.
563 let matchers = tts.chunks(4).map(|arm| &arm[0]);
566 format!("macro_rules! {} {{\n{}}}", name, render_macro_arms(cx.tcx, matchers, ";"))
568 if matchers.len() <= 1 {
570 "{}macro {}{} {{\n ...\n}}",
571 vis.to_src_with_space(cx.tcx, def_id),
573 matchers.map(|matcher| render_macro_matcher(cx.tcx, matcher)).collect::<String>(),
577 "{}macro {} {{\n{}}}",
578 vis.to_src_with_space(cx.tcx, def_id),
580 render_macro_arms(cx.tcx, matchers, ","),