1 use crate::clean::auto_trait::AutoTraitFinder;
2 use crate::clean::blanket_impl::BlanketImplFinder;
3 use crate::clean::{
4 inline, Clean, Crate, ExternalCrate, Generic, GenericArg, GenericArgs, ImportSource, Item,
5 ItemKind, Lifetime, Path, PathSegment, Primitive, PrimitiveType, Type, TypeBinding, Visibility,
6 };
7 use crate::core::DocContext;
8 use crate::formats::item_type::ItemType;
9 use crate::visit_lib::LibEmbargoVisitor;
10
11 use rustc_ast as ast;
12 use rustc_ast::tokenstream::TokenTree;
13 use rustc_hir as hir;
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 _;
21 use std::mem;
22
23 #[cfg(test)]
24 mod tests;
25
krate(cx: &mut DocContext<'_>) -> Crate26 crate fn krate(cx: &mut DocContext<'_>) -> Crate {
27 let module = crate::visit_ast::RustdocVisitor::new(cx).visit();
28
29 for &cnum in cx.tcx.crates(()) {
30 // Analyze doc-reachability for extern items
31 LibEmbargoVisitor::new(cx).visit_lib(cnum);
32 }
33
34 // Clean the crate, translating the entire librustc_ast AST to one that is
35 // understood by rustdoc.
36 let mut module = module.clean(cx);
37
38 match *module.kind {
39 ItemKind::ModuleItem(ref module) => {
40 for it in &module.items {
41 // `compiler_builtins` should be masked too, but we can't apply
42 // `#[doc(masked)]` to the injected `extern crate` because it's unstable.
43 if it.is_extern_crate()
44 && (it.attrs.has_doc_flag(sym::masked)
45 || cx.tcx.is_compiler_builtins(it.def_id.krate()))
46 {
47 cx.cache.masked_crates.insert(it.def_id.krate());
48 }
49 }
50 }
51 _ => unreachable!(),
52 }
53
54 let local_crate = ExternalCrate { crate_num: LOCAL_CRATE };
55 let primitives = local_crate.primitives(cx.tcx);
56 let keywords = local_crate.keywords(cx.tcx);
57 {
58 let m = match *module.kind {
59 ItemKind::ModuleItem(ref mut m) => m,
60 _ => unreachable!(),
61 };
62 m.items.extend(primitives.iter().map(|&(def_id, prim)| {
63 Item::from_def_id_and_parts(
64 def_id,
65 Some(prim.as_sym()),
66 ItemKind::PrimitiveItem(prim),
67 cx,
68 )
69 }));
70 m.items.extend(keywords.into_iter().map(|(def_id, kw)| {
71 Item::from_def_id_and_parts(def_id, Some(kw), ItemKind::KeywordItem(kw), cx)
72 }));
73 }
74
75 Crate { module, primitives, external_traits: cx.external_traits.clone(), collapsed: false }
76 }
77
external_generic_args( cx: &mut DocContext<'_>, did: DefId, has_self: bool, bindings: Vec<TypeBinding>, substs: SubstsRef<'_>, ) -> GenericArgs78 fn external_generic_args(
79 cx: &mut DocContext<'_>,
80 did: DefId,
81 has_self: bool,
82 bindings: Vec<TypeBinding>,
83 substs: SubstsRef<'_>,
84 ) -> GenericArgs {
85 let mut skip_self = has_self;
86 let mut ty_kind = None;
87 let args: Vec<_> = substs
88 .iter()
89 .filter_map(|kind| match kind.unpack() {
90 GenericArgKind::Lifetime(lt) => match lt {
91 ty::ReLateBound(_, ty::BoundRegion { kind: ty::BrAnon(_), .. }) => {
92 Some(GenericArg::Lifetime(Lifetime::elided()))
93 }
94 _ => lt.clean(cx).map(GenericArg::Lifetime),
95 },
96 GenericArgKind::Type(_) if skip_self => {
97 skip_self = false;
98 None
99 }
100 GenericArgKind::Type(ty) => {
101 ty_kind = Some(ty.kind());
102 Some(GenericArg::Type(ty.clean(cx)))
103 }
104 GenericArgKind::Const(ct) => Some(GenericArg::Const(Box::new(ct.clean(cx)))),
105 })
106 .collect();
107
108 if cx.tcx.fn_trait_kind_from_lang_item(did).is_some() {
109 let inputs = match ty_kind.unwrap() {
110 ty::Tuple(tys) => tys.iter().map(|t| t.expect_ty().clean(cx)).collect(),
111 _ => return GenericArgs::AngleBracketed { args, bindings },
112 };
113 let output = None;
114 // FIXME(#20299) return type comes from a projection now
115 // match types[1].kind {
116 // ty::Tuple(ref v) if v.is_empty() => None, // -> ()
117 // _ => Some(types[1].clean(cx))
118 // };
119 GenericArgs::Parenthesized { inputs, output }
120 } else {
121 GenericArgs::AngleBracketed { args, bindings }
122 }
123 }
124
external_path( cx: &mut DocContext<'_>, did: DefId, has_self: bool, bindings: Vec<TypeBinding>, substs: SubstsRef<'_>, ) -> Path125 pub(super) fn external_path(
126 cx: &mut DocContext<'_>,
127 did: DefId,
128 has_self: bool,
129 bindings: Vec<TypeBinding>,
130 substs: SubstsRef<'_>,
131 ) -> Path {
132 let def_kind = cx.tcx.def_kind(did);
133 let name = cx.tcx.item_name(did);
134 Path {
135 res: Res::Def(def_kind, did),
136 segments: vec![PathSegment {
137 name,
138 args: external_generic_args(cx, did, has_self, bindings, substs),
139 }],
140 }
141 }
142
143 /// Remove the generic arguments from a path.
strip_path_generics(path: Path) -> Path144 crate fn strip_path_generics(path: Path) -> Path {
145 let segments = path
146 .segments
147 .iter()
148 .map(|s| PathSegment {
149 name: s.name,
150 args: GenericArgs::AngleBracketed { args: vec![], bindings: vec![] },
151 })
152 .collect();
153
154 Path { res: path.res, segments }
155 }
156
qpath_to_string(p: &hir::QPath<'_>) -> String157 crate fn qpath_to_string(p: &hir::QPath<'_>) -> String {
158 let segments = match *p {
159 hir::QPath::Resolved(_, path) => &path.segments,
160 hir::QPath::TypeRelative(_, segment) => return segment.ident.to_string(),
161 hir::QPath::LangItem(lang_item, ..) => return lang_item.name().to_string(),
162 };
163
164 let mut s = String::new();
165 for (i, seg) in segments.iter().enumerate() {
166 if i > 0 {
167 s.push_str("::");
168 }
169 if seg.ident.name != kw::PathRoot {
170 s.push_str(&seg.ident.as_str());
171 }
172 }
173 s
174 }
175
build_deref_target_impls(cx: &mut DocContext<'_>, items: &[Item], ret: &mut Vec<Item>)176 crate fn build_deref_target_impls(cx: &mut DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
177 let tcx = cx.tcx;
178
179 for item in items {
180 let target = match *item.kind {
181 ItemKind::TypedefItem(ref t, true) => &t.type_,
182 _ => continue,
183 };
184
185 if let Some(prim) = target.primitive_type() {
186 for &did in prim.impls(tcx).iter().filter(|did| !did.is_local()) {
187 inline::build_impl(cx, None, did, None, ret);
188 }
189 } else if let Type::Path { path } = target {
190 let did = path.def_id();
191 if !did.is_local() {
192 inline::build_impls(cx, None, did, None, ret);
193 }
194 }
195 }
196 }
197
name_from_pat(p: &hir::Pat<'_>) -> Symbol198 crate fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
199 use rustc_hir::*;
200 debug!("trying to get a name from pattern: {:?}", p);
201
202 Symbol::intern(&match p.kind {
203 PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
204 PatKind::Binding(_, _, ident, _) => return ident.name,
205 PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
206 PatKind::Or(pats) => {
207 pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
208 }
209 PatKind::Tuple(elts, _) => format!(
210 "({})",
211 elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
212 ),
213 PatKind::Box(p) => return name_from_pat(&*p),
214 PatKind::Ref(p, _) => return name_from_pat(&*p),
215 PatKind::Lit(..) => {
216 warn!(
217 "tried to get argument name from PatKind::Lit, which is silly in function arguments"
218 );
219 return Symbol::intern("()");
220 }
221 PatKind::Range(..) => return kw::Underscore,
222 PatKind::Slice(begin, ref mid, end) => {
223 let begin = begin.iter().map(|p| name_from_pat(p).to_string());
224 let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
225 let end = end.iter().map(|p| name_from_pat(p).to_string());
226 format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
227 }
228 })
229 }
230
print_const(cx: &DocContext<'_>, n: &'tcx ty::Const<'_>) -> String231 crate fn print_const(cx: &DocContext<'_>, n: &'tcx ty::Const<'_>) -> String {
232 match n.val {
233 ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs_: _, promoted }) => {
234 let mut s = if let Some(def) = def.as_local() {
235 let hir_id = cx.tcx.hir().local_def_id_to_hir_id(def.did);
236 print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(hir_id))
237 } else {
238 inline::print_inlined_const(cx.tcx, def.did)
239 };
240 if let Some(promoted) = promoted {
241 s.push_str(&format!("::{:?}", promoted))
242 }
243 s
244 }
245 _ => {
246 let mut s = n.to_string();
247 // array lengths are obviously usize
248 if s.ends_with("_usize") {
249 let n = s.len() - "_usize".len();
250 s.truncate(n);
251 if s.ends_with(": ") {
252 let n = s.len() - ": ".len();
253 s.truncate(n);
254 }
255 }
256 s
257 }
258 }
259 }
260
print_evaluated_const(tcx: TyCtxt<'_>, def_id: DefId) -> Option<String>261 crate fn print_evaluated_const(tcx: TyCtxt<'_>, def_id: DefId) -> Option<String> {
262 tcx.const_eval_poly(def_id).ok().and_then(|val| {
263 let ty = tcx.type_of(def_id);
264 match (val, ty.kind()) {
265 (_, &ty::Ref(..)) => None,
266 (ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
267 (ConstValue::Scalar(_), _) => {
268 let const_ = ty::Const::from_value(tcx, val, ty);
269 Some(print_const_with_custom_print_scalar(tcx, const_))
270 }
271 _ => None,
272 }
273 })
274 }
275
format_integer_with_underscore_sep(num: &str) -> String276 fn format_integer_with_underscore_sep(num: &str) -> String {
277 let num_chars: Vec<_> = num.chars().collect();
278 let mut num_start_index = if num_chars.get(0) == Some(&'-') { 1 } else { 0 };
279 let chunk_size = match num[num_start_index..].as_bytes() {
280 [b'0', b'b' | b'x', ..] => {
281 num_start_index += 2;
282 4
283 }
284 [b'0', b'o', ..] => {
285 num_start_index += 2;
286 let remaining_chars = num_chars.len() - num_start_index;
287 if remaining_chars <= 6 {
288 // don't add underscores to Unix permissions like 0755 or 100755
289 return num.to_string();
290 }
291 3
292 }
293 _ => 3,
294 };
295
296 num_chars[..num_start_index]
297 .iter()
298 .chain(num_chars[num_start_index..].rchunks(chunk_size).rev().intersperse(&['_']).flatten())
299 .collect()
300 }
301
print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: &'tcx ty::Const<'tcx>) -> String302 fn print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: &'tcx ty::Const<'tcx>) -> String {
303 // Use a slightly different format for integer types which always shows the actual value.
304 // For all other types, fallback to the original `pretty_print_const`.
305 match (ct.val, ct.ty.kind()) {
306 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Uint(ui)) => {
307 format!("{}{}", format_integer_with_underscore_sep(&int.to_string()), ui.name_str())
308 }
309 (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Int(i)) => {
310 let ty = tcx.lift(ct.ty).unwrap();
311 let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
312 let data = int.assert_bits(size);
313 let sign_extended_data = size.sign_extend(data) as i128;
314
315 format!(
316 "{}{}",
317 format_integer_with_underscore_sep(&sign_extended_data.to_string()),
318 i.name_str()
319 )
320 }
321 _ => ct.to_string(),
322 }
323 }
324
is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool325 crate fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
326 if let hir::Node::Expr(expr) = tcx.hir().get(hir_id) {
327 if let hir::ExprKind::Lit(_) = &expr.kind {
328 return true;
329 }
330
331 if let hir::ExprKind::Unary(hir::UnOp::Neg, expr) = &expr.kind {
332 if let hir::ExprKind::Lit(_) = &expr.kind {
333 return true;
334 }
335 }
336 }
337
338 false
339 }
340
print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String341 crate fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String {
342 let hir = tcx.hir();
343 let value = &hir.body(body).value;
344
345 let snippet = if !value.span.from_expansion() {
346 tcx.sess.source_map().span_to_snippet(value.span).ok()
347 } else {
348 None
349 };
350
351 snippet.unwrap_or_else(|| rustc_hir_pretty::id_to_string(&hir, body.hir_id))
352 }
353
354 /// Given a type Path, resolve it to a Type using the TyCtxt
resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type355 crate fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
356 debug!("resolve_type({:?})", path);
357
358 match path.res {
359 Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
360 Res::SelfTy(..) if path.segments.len() == 1 => Generic(kw::SelfUpper),
361 Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => Generic(path.segments[0].name),
362 _ => {
363 let _ = register_res(cx, path.res);
364 Type::Path { path }
365 }
366 }
367 }
368
get_auto_trait_and_blanket_impls( cx: &mut DocContext<'tcx>, item_def_id: DefId, ) -> impl Iterator<Item = Item>369 crate fn get_auto_trait_and_blanket_impls(
370 cx: &mut DocContext<'tcx>,
371 item_def_id: DefId,
372 ) -> impl Iterator<Item = Item> {
373 let auto_impls = cx
374 .sess()
375 .prof
376 .generic_activity("get_auto_trait_impls")
377 .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(item_def_id));
378 let blanket_impls = cx
379 .sess()
380 .prof
381 .generic_activity("get_blanket_impls")
382 .run(|| BlanketImplFinder { cx }.get_blanket_impls(item_def_id));
383 auto_impls.into_iter().chain(blanket_impls)
384 }
385
386 /// If `res` has a documentation page associated, store it in the cache.
387 ///
388 /// This is later used by [`href()`] to determine the HTML link for the item.
389 ///
390 /// [`href()`]: crate::html::format::href
register_res(cx: &mut DocContext<'_>, res: Res) -> DefId391 crate fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
392 use DefKind::*;
393 debug!("register_res({:?})", res);
394
395 let (did, kind) = match res {
396 // These should be added to the cache using `record_extern_fqn`.
397 Res::Def(
398 kind
399 @
400 (AssocTy | AssocFn | AssocConst | Variant | Fn | TyAlias | Enum | Trait | Struct
401 | Union | Mod | ForeignTy | Const | Static | Macro(..) | TraitAlias),
402 i,
403 ) => (i, kind.into()),
404 // This is part of a trait definition; document the trait.
405 Res::SelfTy(Some(trait_def_id), _) => (trait_def_id, ItemType::Trait),
406 // This is an inherent impl; it doesn't have its own page.
407 Res::SelfTy(None, Some((impl_def_id, _))) => return impl_def_id,
408 Res::SelfTy(None, None)
409 | Res::PrimTy(_)
410 | Res::ToolMod
411 | Res::SelfCtor(_)
412 | Res::Local(_)
413 | Res::NonMacroAttr(_)
414 | Res::Err => return res.def_id(),
415 Res::Def(
416 TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst
417 | InlineConst | OpaqueTy | Field | LifetimeParam | GlobalAsm | Impl | Closure
418 | Generator,
419 id,
420 ) => return id,
421 };
422 if did.is_local() {
423 return did;
424 }
425 inline::record_extern_fqn(cx, did, kind);
426 if let ItemType::Trait = kind {
427 inline::record_extern_trait(cx, did);
428 }
429 did
430 }
431
resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource432 crate fn resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource {
433 ImportSource {
434 did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
435 path,
436 }
437 }
438
enter_impl_trait<F, R>(cx: &mut DocContext<'_>, f: F) -> R where F: FnOnce(&mut DocContext<'_>) -> R,439 crate fn enter_impl_trait<F, R>(cx: &mut DocContext<'_>, f: F) -> R
440 where
441 F: FnOnce(&mut DocContext<'_>) -> R,
442 {
443 let old_bounds = mem::take(&mut cx.impl_trait_bounds);
444 let r = f(cx);
445 assert!(cx.impl_trait_bounds.is_empty());
446 cx.impl_trait_bounds = old_bounds;
447 r
448 }
449
450 /// Find the nearest parent module of a [`DefId`].
find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId>451 crate fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
452 if def_id.is_top_level_module() {
453 // The crate root has no parent. Use it as the root instead.
454 Some(def_id)
455 } else {
456 let mut current = def_id;
457 // The immediate parent might not always be a module.
458 // Find the first parent which is.
459 while let Some(parent) = tcx.parent(current) {
460 if tcx.def_kind(parent) == DefKind::Mod {
461 return Some(parent);
462 }
463 current = parent;
464 }
465 None
466 }
467 }
468
469 /// Checks for the existence of `hidden` in the attribute below if `flag` is `sym::hidden`:
470 ///
471 /// ```
472 /// #[doc(hidden)]
473 /// pub fn foo() {}
474 /// ```
475 ///
476 /// This function exists because it runs on `hir::Attributes` whereas the other is a
477 /// `clean::Attributes` method.
has_doc_flag(attrs: ty::Attributes<'_>, flag: Symbol) -> bool478 crate fn has_doc_flag(attrs: ty::Attributes<'_>, flag: Symbol) -> bool {
479 attrs.iter().any(|attr| {
480 attr.has_name(sym::doc)
481 && attr.meta_item_list().map_or(false, |l| rustc_attr::list_contains_name(&l, flag))
482 })
483 }
484
485 /// A link to `doc.rust-lang.org` that includes the channel name. Use this instead of manual links
486 /// so that the channel is consistent.
487 ///
488 /// Set by `bootstrap::Builder::doc_rust_lang_org_channel` in order to keep tests passing on beta/stable.
489 crate const DOC_RUST_LANG_ORG_CHANNEL: &str = env!("DOC_RUST_LANG_ORG_CHANNEL");
490
491 /// Render a sequence of macro arms in a format suitable for displaying to the user
492 /// as part of an item declaration.
render_macro_arms<'a>( matchers: impl Iterator<Item = &'a TokenTree>, arm_delim: &str, ) -> String493 pub(super) fn render_macro_arms<'a>(
494 matchers: impl Iterator<Item = &'a TokenTree>,
495 arm_delim: &str,
496 ) -> String {
497 let mut out = String::new();
498 for matcher in matchers {
499 writeln!(out, " {} => {{ ... }}{}", render_macro_matcher(matcher), arm_delim).unwrap();
500 }
501 out
502 }
503
504 /// Render a macro matcher in a format suitable for displaying to the user
505 /// as part of an item declaration.
render_macro_matcher(matcher: &TokenTree) -> String506 pub(super) fn render_macro_matcher(matcher: &TokenTree) -> String {
507 rustc_ast_pretty::pprust::tt_to_string(matcher)
508 }
509
display_macro_source( cx: &mut DocContext<'_>, name: Symbol, def: &ast::MacroDef, def_id: DefId, vis: Visibility, ) -> String510 pub(super) fn display_macro_source(
511 cx: &mut DocContext<'_>,
512 name: Symbol,
513 def: &ast::MacroDef,
514 def_id: DefId,
515 vis: Visibility,
516 ) -> String {
517 let tts: Vec<_> = def.body.inner_tokens().into_trees().collect();
518 // Extract the spans of all matchers. They represent the "interface" of the macro.
519 let matchers = tts.chunks(4).map(|arm| &arm[0]);
520
521 if def.macro_rules {
522 format!("macro_rules! {} {{\n{}}}", name, render_macro_arms(matchers, ";"))
523 } else {
524 if matchers.len() <= 1 {
525 format!(
526 "{}macro {}{} {{\n ...\n}}",
527 vis.to_src_with_space(cx.tcx, def_id),
528 name,
529 matchers.map(render_macro_matcher).collect::<String>(),
530 )
531 } else {
532 format!(
533 "{}macro {} {{\n{}}}",
534 vis.to_src_with_space(cx.tcx, def_id),
535 name,
536 render_macro_arms(matchers, ","),
537 )
538 }
539 }
540 }
541