use std::assert_matches::debug_assert_matches;
use std::fmt::Write as _;
use std::mem;
use std::sync::LazyLock as Lazy;
use rustc_ast::tokenstream::TokenTree;
use rustc_hir::def::{DefKind, Res};
use rustc_hir::def_id::{DefId, LocalDefId, LOCAL_CRATE};
use rustc_metadata::rendered_const;
use rustc_middle::mir;
use rustc_middle::ty::{self, GenericArgKind, GenericArgsRef, TyCtxt, TypeVisitableExt};
use rustc_span::symbol::{kw, sym, Symbol};
use thin_vec::{thin_vec, ThinVec};
use tracing::{debug, warn};
use {rustc_ast as ast, rustc_hir as hir};
use crate::clean::auto_trait::synthesize_auto_trait_impls;
use crate::clean::blanket_impl::synthesize_blanket_impls;
use crate::clean::render_macro_matchers::render_macro_matcher;
use crate::clean::{
clean_doc_module, clean_middle_const, clean_middle_region, clean_middle_ty, inline,
AssocItemConstraint, AssocItemConstraintKind, Crate, ExternalCrate, Generic, GenericArg,
GenericArgs, ImportSource, Item, ItemKind, Lifetime, Path, PathSegment, Primitive,
PrimitiveType, Term, Type,
};
use crate::core::DocContext;
use crate::html::format::visibility_to_src_with_space;
#[cfg(test)]
mod tests;
pub(crate) fn krate(cx: &mut DocContext<'_>) -> Crate {
let module = crate::visit_ast::RustdocVisitor::new(cx).visit();
let mut module = clean_doc_module(&module, cx);
match *module.kind {
ItemKind::ModuleItem(ref module) => {
for it in &module.items {
if cx.tcx.is_compiler_builtins(it.item_id.krate()) {
cx.cache.masked_crates.insert(it.item_id.krate());
} else if it.is_extern_crate()
&& it.attrs.has_doc_flag(sym::masked)
&& let Some(def_id) = it.item_id.as_def_id()
&& let Some(local_def_id) = def_id.as_local()
&& let Some(cnum) = cx.tcx.extern_mod_stmt_cnum(local_def_id)
{
cx.cache.masked_crates.insert(cnum);
}
}
}
_ => unreachable!(),
}
let local_crate = ExternalCrate { crate_num: LOCAL_CRATE };
let primitives = local_crate.primitives(cx.tcx);
let keywords = local_crate.keywords(cx.tcx);
{
let ItemKind::ModuleItem(ref mut m) = *module.kind else { unreachable!() };
m.items.extend(primitives.iter().map(|&(def_id, prim)| {
Item::from_def_id_and_parts(
def_id,
Some(prim.as_sym()),
ItemKind::PrimitiveItem(prim),
cx,
)
}));
m.items.extend(keywords.into_iter().map(|(def_id, kw)| {
Item::from_def_id_and_parts(def_id, Some(kw), ItemKind::KeywordItem, cx)
}));
}
Crate { module, external_traits: cx.external_traits.clone() }
}
pub(crate) fn clean_middle_generic_args<'tcx>(
cx: &mut DocContext<'tcx>,
args: ty::Binder<'tcx, &'tcx [ty::GenericArg<'tcx>]>,
mut has_self: bool,
owner: DefId,
) -> Vec<GenericArg> {
let (args, bound_vars) = (args.skip_binder(), args.bound_vars());
if args.is_empty() {
return Vec::new();
}
let generics = cx.tcx.generics_of(owner);
let args = if !has_self && generics.parent.is_none() && generics.has_self {
has_self = true;
[cx.tcx.types.trait_object_dummy_self.into()]
.into_iter()
.chain(args.iter().copied())
.collect::<Vec<_>>()
.into()
} else {
std::borrow::Cow::from(args)
};
let mut elision_has_failed_once_before = false;
let clean_arg = |(index, &arg): (usize, &ty::GenericArg<'tcx>)| {
if has_self && index == 0 {
return None;
}
let param = generics.param_at(index, cx.tcx);
if param.is_host_effect() {
return None;
}
let arg = ty::Binder::bind_with_vars(arg, bound_vars);
if !elision_has_failed_once_before && let Some(default) = param.default_value(cx.tcx) {
let default = default.instantiate(cx.tcx, args.as_ref());
if can_elide_generic_arg(arg, arg.rebind(default)) {
return None;
}
elision_has_failed_once_before = true;
}
match arg.skip_binder().unpack() {
GenericArgKind::Lifetime(lt) => {
Some(GenericArg::Lifetime(clean_middle_region(lt).unwrap_or(Lifetime::elided())))
}
GenericArgKind::Type(ty) => Some(GenericArg::Type(clean_middle_ty(
arg.rebind(ty),
cx,
None,
Some(crate::clean::ContainerTy::Regular {
ty: owner,
args: arg.rebind(args.as_ref()),
arg: index,
}),
))),
GenericArgKind::Const(ct) => {
Some(GenericArg::Const(Box::new(clean_middle_const(arg.rebind(ct), cx))))
}
}
};
let offset = if has_self { 1 } else { 0 };
let mut clean_args = Vec::with_capacity(args.len().saturating_sub(offset));
clean_args.extend(args.iter().enumerate().rev().filter_map(clean_arg));
clean_args.reverse();
clean_args
}
fn can_elide_generic_arg<'tcx>(
actual: ty::Binder<'tcx, ty::GenericArg<'tcx>>,
default: ty::Binder<'tcx, ty::GenericArg<'tcx>>,
) -> bool {
debug_assert_matches!(
(actual.skip_binder().unpack(), default.skip_binder().unpack()),
(ty::GenericArgKind::Lifetime(_), ty::GenericArgKind::Lifetime(_))
| (ty::GenericArgKind::Type(_), ty::GenericArgKind::Type(_))
| (ty::GenericArgKind::Const(_), ty::GenericArgKind::Const(_))
);
if actual.has_infer() || default.has_infer() {
return false;
}
if actual.has_escaping_bound_vars() || default.has_escaping_bound_vars() {
return false;
}
actual.skip_binder() == default.skip_binder()
}
fn clean_middle_generic_args_with_constraints<'tcx>(
cx: &mut DocContext<'tcx>,
did: DefId,
has_self: bool,
constraints: ThinVec<AssocItemConstraint>,
ty_args: ty::Binder<'tcx, GenericArgsRef<'tcx>>,
) -> GenericArgs {
let args = clean_middle_generic_args(cx, ty_args.map_bound(|args| &args[..]), has_self, did);
if cx.tcx.fn_trait_kind_from_def_id(did).is_some() {
let ty = ty_args
.iter()
.nth(if has_self { 1 } else { 0 })
.unwrap()
.map_bound(|arg| arg.expect_ty());
let inputs =
match ty.skip_binder().kind() {
ty::Tuple(tys) => tys.iter().map(|t| clean_middle_ty(ty.rebind(t), cx, None, None)).collect::<Vec<_>>().into(),
_ => return GenericArgs::AngleBracketed { args: args.into(), constraints },
};
let output = constraints.into_iter().next().and_then(|binding| match binding.kind {
AssocItemConstraintKind::Equality { term: Term::Type(ty) }
if ty != Type::Tuple(Vec::new()) =>
{
Some(Box::new(ty))
}
_ => None,
});
GenericArgs::Parenthesized { inputs, output }
} else {
GenericArgs::AngleBracketed { args: args.into(), constraints }
}
}
pub(super) fn clean_middle_path<'tcx>(
cx: &mut DocContext<'tcx>,
did: DefId,
has_self: bool,
constraints: ThinVec<AssocItemConstraint>,
args: ty::Binder<'tcx, GenericArgsRef<'tcx>>,
) -> Path {
let def_kind = cx.tcx.def_kind(did);
let name = cx.tcx.opt_item_name(did).unwrap_or(kw::Empty);
Path {
res: Res::Def(def_kind, did),
segments: thin_vec![PathSegment {
name,
args: clean_middle_generic_args_with_constraints(cx, did, has_self, constraints, args),
}],
}
}
pub(crate) fn qpath_to_string(p: &hir::QPath<'_>) -> String {
let segments = match *p {
hir::QPath::Resolved(_, path) => &path.segments,
hir::QPath::TypeRelative(_, segment) => return segment.ident.to_string(),
hir::QPath::LangItem(lang_item, ..) => return lang_item.name().to_string(),
};
let mut s = String::new();
for (i, seg) in segments.iter().enumerate() {
if i > 0 {
s.push_str("::");
}
if seg.ident.name != kw::PathRoot {
s.push_str(seg.ident.as_str());
}
}
s
}
pub(crate) fn build_deref_target_impls(
cx: &mut DocContext<'_>,
items: &[Item],
ret: &mut Vec<Item>,
) {
let tcx = cx.tcx;
for item in items {
let target = match *item.kind {
ItemKind::AssocTypeItem(ref t, _) => &t.type_,
_ => continue,
};
if let Some(prim) = target.primitive_type() {
let _prof_timer = tcx.sess.prof.generic_activity("build_primitive_inherent_impls");
for did in prim.impls(tcx).filter(|did| !did.is_local()) {
cx.with_param_env(did, |cx| {
inline::build_impl(cx, did, None, ret);
});
}
} else if let Type::Path { path } = target {
let did = path.def_id();
if !did.is_local() {
cx.with_param_env(did, |cx| {
inline::build_impls(cx, did, None, ret);
});
}
}
}
}
pub(crate) fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
use rustc_hir::*;
debug!("trying to get a name from pattern: {p:?}");
Symbol::intern(&match p.kind {
PatKind::Wild | PatKind::Err(_) | PatKind::Never | PatKind::Struct(..) => {
return kw::Underscore;
}
PatKind::Binding(_, _, ident, _) => return ident.name,
PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
PatKind::Or(pats) => {
pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
}
PatKind::Tuple(elts, _) => format!(
"({})",
elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
),
PatKind::Box(p) => return name_from_pat(p),
PatKind::Deref(p) => format!("deref!({})", name_from_pat(p)),
PatKind::Ref(p, _) => return name_from_pat(p),
PatKind::Lit(..) => {
warn!(
"tried to get argument name from PatKind::Lit, which is silly in function arguments"
);
return Symbol::intern("()");
}
PatKind::Range(..) => return kw::Underscore,
PatKind::Slice(begin, ref mid, end) => {
let begin = begin.iter().map(|p| name_from_pat(p).to_string());
let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(p))).into_iter();
let end = end.iter().map(|p| name_from_pat(p).to_string());
format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
}
})
}
pub(crate) fn print_const(cx: &DocContext<'_>, n: ty::Const<'_>) -> String {
match n.kind() {
ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args: _ }) => {
let s = if let Some(def) = def.as_local() {
rendered_const(cx.tcx, cx.tcx.hir().body_owned_by(def), def)
} else {
inline::print_inlined_const(cx.tcx, def)
};
s
}
ty::ConstKind::Value(ty, ty::ValTree::Leaf(scalar))
if *ty.kind() == ty::Uint(ty::UintTy::Usize) =>
{
scalar.to_string()
}
_ => n.to_string(),
}
}
pub(crate) fn print_evaluated_const(
tcx: TyCtxt<'_>,
def_id: DefId,
with_underscores: bool,
with_type: bool,
) -> Option<String> {
tcx.const_eval_poly(def_id).ok().and_then(|val| {
let ty = tcx.type_of(def_id).instantiate_identity();
match (val, ty.kind()) {
(_, &ty::Ref(..)) => None,
(mir::ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
(mir::ConstValue::Scalar(_), _) => {
let const_ = mir::Const::from_value(val, ty);
Some(print_const_with_custom_print_scalar(tcx, const_, with_underscores, with_type))
}
_ => None,
}
})
}
fn format_integer_with_underscore_sep(num: &str) -> String {
let num_chars: Vec<_> = num.chars().collect();
let mut num_start_index = if num_chars.first() == Some(&'-') { 1 } else { 0 };
let chunk_size = match num[num_start_index..].as_bytes() {
[b'0', b'b' | b'x', ..] => {
num_start_index += 2;
4
}
[b'0', b'o', ..] => {
num_start_index += 2;
let remaining_chars = num_chars.len() - num_start_index;
if remaining_chars <= 6 {
return num.to_string();
}
3
}
_ => 3,
};
num_chars[..num_start_index]
.iter()
.chain(num_chars[num_start_index..].rchunks(chunk_size).rev().intersperse(&['_']).flatten())
.collect()
}
fn print_const_with_custom_print_scalar<'tcx>(
tcx: TyCtxt<'tcx>,
ct: mir::Const<'tcx>,
with_underscores: bool,
with_type: bool,
) -> String {
match (ct, ct.ty().kind()) {
(mir::Const::Val(mir::ConstValue::Scalar(int), _), ty::Uint(ui)) => {
let mut output = if with_underscores {
format_integer_with_underscore_sep(&int.to_string())
} else {
int.to_string()
};
if with_type {
output += ui.name_str();
}
output
}
(mir::Const::Val(mir::ConstValue::Scalar(int), _), ty::Int(i)) => {
let ty = ct.ty();
let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
let sign_extended_data = int.assert_scalar_int().to_int(size);
let mut output = if with_underscores {
format_integer_with_underscore_sep(&sign_extended_data.to_string())
} else {
sign_extended_data.to_string()
};
if with_type {
output += i.name_str();
}
output
}
_ => ct.to_string(),
}
}
pub(crate) fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
if let hir::Node::Expr(expr) = tcx.hir_node(hir_id) {
if let hir::ExprKind::Lit(_) = &expr.kind {
return true;
}
if let hir::ExprKind::Unary(hir::UnOp::Neg, expr) = &expr.kind
&& let hir::ExprKind::Lit(_) = &expr.kind
{
return true;
}
}
false
}
pub(crate) fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
debug!("resolve_type({path:?})");
match path.res {
Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } if path.segments.len() == 1 => {
Type::SelfTy
}
Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => Generic(path.segments[0].name),
_ => {
let _ = register_res(cx, path.res);
Type::Path { path }
}
}
}
pub(crate) fn synthesize_auto_trait_and_blanket_impls(
cx: &mut DocContext<'_>,
item_def_id: DefId,
) -> impl Iterator<Item = Item> {
let auto_impls = cx
.sess()
.prof
.generic_activity("synthesize_auto_trait_impls")
.run(|| synthesize_auto_trait_impls(cx, item_def_id));
let blanket_impls = cx
.sess()
.prof
.generic_activity("synthesize_blanket_impls")
.run(|| synthesize_blanket_impls(cx, item_def_id));
auto_impls.into_iter().chain(blanket_impls)
}
pub(crate) fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
use DefKind::*;
debug!("register_res({res:?})");
let (kind, did) = match res {
Res::Def(
kind @ (AssocTy
| AssocFn
| AssocConst
| Variant
| Fn
| TyAlias { .. }
| Enum
| Trait
| Struct
| Union
| Mod
| ForeignTy
| Const
| Static { .. }
| Macro(..)
| TraitAlias),
did,
) => (kind.into(), did),
_ => panic!("register_res: unexpected {res:?}"),
};
if did.is_local() {
return did;
}
inline::record_extern_fqn(cx, did, kind);
did
}
pub(crate) fn resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource {
ImportSource {
did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
path,
}
}
pub(crate) fn enter_impl_trait<'tcx, F, R>(cx: &mut DocContext<'tcx>, f: F) -> R
where
F: FnOnce(&mut DocContext<'tcx>) -> R,
{
let old_bounds = mem::take(&mut cx.impl_trait_bounds);
let r = f(cx);
assert!(cx.impl_trait_bounds.is_empty());
cx.impl_trait_bounds = old_bounds;
r
}
pub(crate) fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
if def_id.is_top_level_module() {
Some(def_id)
} else {
let mut current = def_id;
while let Some(parent) = tcx.opt_parent(current) {
if tcx.def_kind(parent) == DefKind::Mod {
return Some(parent);
}
current = parent;
}
None
}
}
pub(crate) fn has_doc_flag(tcx: TyCtxt<'_>, did: DefId, flag: Symbol) -> bool {
attrs_have_doc_flag(tcx.get_attrs(did, sym::doc), flag)
}
pub(crate) fn attrs_have_doc_flag<'a>(
mut attrs: impl Iterator<Item = &'a ast::Attribute>,
flag: Symbol,
) -> bool {
attrs
.any(|attr| attr.meta_item_list().is_some_and(|l| rustc_attr::list_contains_name(&l, flag)))
}
pub(crate) const DOC_RUST_LANG_ORG_CHANNEL: &str = env!("DOC_RUST_LANG_ORG_CHANNEL");
pub(crate) static DOC_CHANNEL: Lazy<&'static str> =
Lazy::new(|| DOC_RUST_LANG_ORG_CHANNEL.rsplit('/').find(|c| !c.is_empty()).unwrap());
pub(super) fn render_macro_arms<'a>(
tcx: TyCtxt<'_>,
matchers: impl Iterator<Item = &'a TokenTree>,
arm_delim: &str,
) -> String {
let mut out = String::new();
for matcher in matchers {
writeln!(
out,
" {matcher} => {{ ... }}{arm_delim}",
matcher = render_macro_matcher(tcx, matcher),
)
.unwrap();
}
out
}
pub(super) fn display_macro_source(
cx: &mut DocContext<'_>,
name: Symbol,
def: &ast::MacroDef,
def_id: DefId,
vis: ty::Visibility<DefId>,
is_doc_hidden: bool,
) -> String {
let matchers = def.body.tokens.chunks(4).map(|arm| &arm[0]);
if def.macro_rules {
format!("macro_rules! {name} {{\n{arms}}}", arms = render_macro_arms(cx.tcx, matchers, ";"))
} else {
if matchers.len() <= 1 {
format!(
"{vis}macro {name}{matchers} {{\n ...\n}}",
vis = visibility_to_src_with_space(Some(vis), cx.tcx, def_id, is_doc_hidden),
matchers = matchers
.map(|matcher| render_macro_matcher(cx.tcx, matcher))
.collect::<String>(),
)
} else {
format!(
"{vis}macro {name} {{\n{arms}}}",
vis = visibility_to_src_with_space(Some(vis), cx.tcx, def_id, is_doc_hidden),
arms = render_macro_arms(cx.tcx, matchers, ","),
)
}
}
}
pub(crate) fn inherits_doc_hidden(
tcx: TyCtxt<'_>,
mut def_id: LocalDefId,
stop_at: Option<LocalDefId>,
) -> bool {
while let Some(id) = tcx.opt_local_parent(def_id) {
if let Some(stop_at) = stop_at
&& id == stop_at
{
return false;
}
def_id = id;
if tcx.is_doc_hidden(def_id.to_def_id()) {
return true;
} else if matches!(
tcx.hir_node_by_def_id(def_id),
hir::Node::Item(hir::Item { kind: hir::ItemKind::Impl(_), .. })
) {
return false;
}
}
false
}
#[inline]
pub(crate) fn should_ignore_res(res: Res) -> bool {
matches!(res, Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..))
}