blob: 312765d3e6d03db080e12d5ea71c4da601dce7c8 [file] [log] [blame]
//! HTML formatting module
//!
//! This module contains a large number of `Display` implementations for
//! various types in `rustdoc::clean`.
//!
//! These implementations all emit HTML. As an internal implementation detail,
//! some of them support an alternate format that emits text, but that should
//! not be used external to this module.
use std::borrow::Cow;
use std::cell::Cell;
use std::fmt::{self, Display, Write};
use std::iter::{self, once};
use rustc_ast as ast;
use rustc_attr::{ConstStability, StabilityLevel};
use rustc_data_structures::captures::Captures;
use rustc_data_structures::fx::FxHashSet;
use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LOCAL_CRATE};
use rustc_metadata::creader::{CStore, LoadedMacro};
use rustc_middle::ty;
use rustc_middle::ty::TyCtxt;
use rustc_span::symbol::kw;
use rustc_span::{sym, Symbol};
use rustc_target::spec::abi::Abi;
use itertools::Itertools;
use crate::clean::{
self, types::ExternalLocation, utils::find_nearest_parent_module, ExternalCrate, PrimitiveType,
};
use crate::formats::cache::Cache;
use crate::formats::item_type::ItemType;
use crate::html::escape::Escape;
use crate::html::render::Context;
use crate::passes::collect_intra_doc_links::UrlFragment;
use super::url_parts_builder::estimate_item_path_byte_length;
use super::url_parts_builder::UrlPartsBuilder;
pub(crate) trait Print {
fn print(self, buffer: &mut Buffer);
}
impl<F> Print for F
where
F: FnOnce(&mut Buffer),
{
fn print(self, buffer: &mut Buffer) {
(self)(buffer)
}
}
impl Print for String {
fn print(self, buffer: &mut Buffer) {
buffer.write_str(&self);
}
}
impl Print for &'_ str {
fn print(self, buffer: &mut Buffer) {
buffer.write_str(self);
}
}
#[derive(Debug, Clone)]
pub(crate) struct Buffer {
for_html: bool,
buffer: String,
}
impl core::fmt::Write for Buffer {
#[inline]
fn write_str(&mut self, s: &str) -> fmt::Result {
self.buffer.write_str(s)
}
#[inline]
fn write_char(&mut self, c: char) -> fmt::Result {
self.buffer.write_char(c)
}
#[inline]
fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> fmt::Result {
self.buffer.write_fmt(args)
}
}
impl Buffer {
pub(crate) fn empty_from(v: &Buffer) -> Buffer {
Buffer { for_html: v.for_html, buffer: String::new() }
}
pub(crate) fn html() -> Buffer {
Buffer { for_html: true, buffer: String::new() }
}
pub(crate) fn new() -> Buffer {
Buffer { for_html: false, buffer: String::new() }
}
pub(crate) fn is_empty(&self) -> bool {
self.buffer.is_empty()
}
pub(crate) fn into_inner(self) -> String {
self.buffer
}
pub(crate) fn push(&mut self, c: char) {
self.buffer.push(c);
}
pub(crate) fn push_str(&mut self, s: &str) {
self.buffer.push_str(s);
}
pub(crate) fn push_buffer(&mut self, other: Buffer) {
self.buffer.push_str(&other.buffer);
}
// Intended for consumption by write! and writeln! (std::fmt) but without
// the fmt::Result return type imposed by fmt::Write (and avoiding the trait
// import).
pub(crate) fn write_str(&mut self, s: &str) {
self.buffer.push_str(s);
}
// Intended for consumption by write! and writeln! (std::fmt) but without
// the fmt::Result return type imposed by fmt::Write (and avoiding the trait
// import).
pub(crate) fn write_fmt(&mut self, v: fmt::Arguments<'_>) {
self.buffer.write_fmt(v).unwrap();
}
pub(crate) fn to_display<T: Print>(mut self, t: T) -> String {
t.print(&mut self);
self.into_inner()
}
pub(crate) fn reserve(&mut self, additional: usize) {
self.buffer.reserve(additional)
}
pub(crate) fn len(&self) -> usize {
self.buffer.len()
}
}
pub(crate) fn comma_sep<T: Display>(
items: impl Iterator<Item = T>,
space_after_comma: bool,
) -> impl Display {
display_fn(move |f| {
for (i, item) in items.enumerate() {
if i != 0 {
write!(f, ",{}", if space_after_comma { " " } else { "" })?;
}
item.fmt(f)?;
}
Ok(())
})
}
pub(crate) fn print_generic_bounds<'a, 'tcx: 'a>(
bounds: &'a [clean::GenericBound],
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
let mut bounds_dup = FxHashSet::default();
for (i, bound) in bounds.iter().filter(|b| bounds_dup.insert(*b)).enumerate() {
if i > 0 {
f.write_str(" + ")?;
}
bound.print(cx).fmt(f)?;
}
Ok(())
})
}
impl clean::GenericParamDef {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| match &self.kind {
clean::GenericParamDefKind::Lifetime { outlives } => {
write!(f, "{}", self.name)?;
if !outlives.is_empty() {
f.write_str(": ")?;
for (i, lt) in outlives.iter().enumerate() {
if i != 0 {
f.write_str(" + ")?;
}
write!(f, "{}", lt.print())?;
}
}
Ok(())
}
clean::GenericParamDefKind::Type { bounds, default, .. } => {
f.write_str(self.name.as_str())?;
if !bounds.is_empty() {
f.write_str(": ")?;
print_generic_bounds(bounds, cx).fmt(f)?;
}
if let Some(ref ty) = default {
f.write_str(" = ")?;
ty.print(cx).fmt(f)?;
}
Ok(())
}
clean::GenericParamDefKind::Const { ty, default, .. } => {
write!(f, "const {}: ", self.name)?;
ty.print(cx).fmt(f)?;
if let Some(default) = default {
f.write_str(" = ")?;
if f.alternate() {
write!(f, "{default}")?;
} else {
write!(f, "{}", Escape(default))?;
}
}
Ok(())
}
})
}
}
impl clean::Generics {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
let mut real_params = self.params.iter().filter(|p| !p.is_synthetic_param()).peekable();
if real_params.peek().is_none() {
return Ok(());
}
if f.alternate() {
write!(f, "<{:#}>", comma_sep(real_params.map(|g| g.print(cx)), true))
} else {
write!(f, "&lt;{}&gt;", comma_sep(real_params.map(|g| g.print(cx)), true))
}
})
}
}
#[derive(Clone, Copy, PartialEq, Eq)]
pub(crate) enum Ending {
Newline,
NoNewline,
}
/// * The Generics from which to emit a where-clause.
/// * The number of spaces to indent each line with.
/// * Whether the where-clause needs to add a comma and newline after the last bound.
pub(crate) fn print_where_clause<'a, 'tcx: 'a>(
gens: &'a clean::Generics,
cx: &'a Context<'tcx>,
indent: usize,
ending: Ending,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
let mut where_predicates = gens
.where_predicates
.iter()
.map(|pred| {
display_fn(move |f| {
if f.alternate() {
f.write_str(" ")?;
} else {
f.write_str("\n")?;
}
match pred {
clean::WherePredicate::BoundPredicate { ty, bounds, bound_params } => {
print_higher_ranked_params_with_space(bound_params, cx).fmt(f)?;
ty.print(cx).fmt(f)?;
f.write_str(":")?;
if !bounds.is_empty() {
f.write_str(" ")?;
print_generic_bounds(bounds, cx).fmt(f)?;
}
Ok(())
}
clean::WherePredicate::RegionPredicate { lifetime, bounds } => {
// We don't need to check `alternate` since we can be certain that neither
// the lifetime nor the bounds contain any characters which need escaping.
write!(f, "{}:", lifetime.print())?;
if !bounds.is_empty() {
write!(f, " {}", print_generic_bounds(bounds, cx))?;
}
Ok(())
}
clean::WherePredicate::EqPredicate { lhs, rhs } => {
if f.alternate() {
write!(f, "{:#} == {:#}", lhs.print(cx), rhs.print(cx))
} else {
write!(f, "{} == {}", lhs.print(cx), rhs.print(cx))
}
}
}
})
})
.peekable();
if where_predicates.peek().is_none() {
return Ok(());
}
let where_preds = comma_sep(where_predicates, false);
let clause = if f.alternate() {
if ending == Ending::Newline {
format!(" where{where_preds},")
} else {
format!(" where{where_preds}")
}
} else {
let mut br_with_padding = String::with_capacity(6 * indent + 28);
br_with_padding.push('\n');
let where_indent = 3;
let padding_amount = if ending == Ending::Newline {
indent + 4
} else if indent == 0 {
4
} else {
indent + where_indent + "where ".len()
};
for _ in 0..padding_amount {
br_with_padding.push(' ');
}
let where_preds = where_preds.to_string().replace('\n', &br_with_padding);
if ending == Ending::Newline {
let mut clause = " ".repeat(indent.saturating_sub(1));
write!(clause, "<div class=\"where\">where{where_preds},</div>")?;
clause
} else {
// insert a newline after a single space but before multiple spaces at the start
if indent == 0 {
format!("\n<span class=\"where\">where{where_preds}</span>")
} else {
// put the first one on the same line as the 'where' keyword
let where_preds = where_preds.replacen(&br_with_padding, " ", 1);
let mut clause = br_with_padding;
// +1 is for `\n`.
clause.truncate(indent + 1 + where_indent);
write!(clause, "<span class=\"where\">where{where_preds}</span>")?;
clause
}
}
};
write!(f, "{clause}")
})
}
impl clean::Lifetime {
pub(crate) fn print(&self) -> impl Display + '_ {
self.0.as_str()
}
}
impl clean::Constant {
pub(crate) fn print(&self, tcx: TyCtxt<'_>) -> impl Display + '_ {
let expr = self.expr(tcx);
display_fn(
move |f| {
if f.alternate() { f.write_str(&expr) } else { write!(f, "{}", Escape(&expr)) }
},
)
}
}
impl clean::PolyTrait {
fn print<'a, 'tcx: 'a>(&'a self, cx: &'a Context<'tcx>) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
print_higher_ranked_params_with_space(&self.generic_params, cx).fmt(f)?;
self.trait_.print(cx).fmt(f)
})
}
}
impl clean::GenericBound {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| match self {
clean::GenericBound::Outlives(lt) => write!(f, "{}", lt.print()),
clean::GenericBound::TraitBound(ty, modifier) => {
f.write_str(match modifier {
hir::TraitBoundModifier::None => "",
hir::TraitBoundModifier::Maybe => "?",
hir::TraitBoundModifier::Negative => "!",
// `const` and `~const` trait bounds are experimental; don't render them.
hir::TraitBoundModifier::Const | hir::TraitBoundModifier::MaybeConst => "",
})?;
ty.print(cx).fmt(f)
}
})
}
}
impl clean::GenericArgs {
fn print<'a, 'tcx: 'a>(&'a self, cx: &'a Context<'tcx>) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
match self {
clean::GenericArgs::AngleBracketed { args, bindings } => {
if !args.is_empty() || !bindings.is_empty() {
if f.alternate() {
f.write_str("<")?;
} else {
f.write_str("&lt;")?;
}
let mut comma = false;
for arg in args.iter() {
if comma {
f.write_str(", ")?;
}
comma = true;
if f.alternate() {
write!(f, "{:#}", arg.print(cx))?;
} else {
write!(f, "{}", arg.print(cx))?;
}
}
for binding in bindings.iter() {
if comma {
f.write_str(", ")?;
}
comma = true;
if f.alternate() {
write!(f, "{:#}", binding.print(cx))?;
} else {
write!(f, "{}", binding.print(cx))?;
}
}
if f.alternate() {
f.write_str(">")?;
} else {
f.write_str("&gt;")?;
}
}
}
clean::GenericArgs::Parenthesized { inputs, output } => {
f.write_str("(")?;
let mut comma = false;
for ty in inputs.iter() {
if comma {
f.write_str(", ")?;
}
comma = true;
ty.print(cx).fmt(f)?;
}
f.write_str(")")?;
if let Some(ref ty) = *output {
if f.alternate() {
write!(f, " -> {:#}", ty.print(cx))?;
} else {
write!(f, " -&gt; {}", ty.print(cx))?;
}
}
}
}
Ok(())
})
}
}
// Possible errors when computing href link source for a `DefId`
#[derive(PartialEq, Eq)]
pub(crate) enum HrefError {
/// This item is known to rustdoc, but from a crate that does not have documentation generated.
///
/// This can only happen for non-local items.
///
/// # Example
///
/// Crate `a` defines a public trait and crate `b` – the target crate that depends on `a` –
/// implements it for a local type.
/// We document `b` but **not** `a` (we only _build_ the latter – with `rustc`):
///
/// ```sh
/// rustc a.rs --crate-type=lib
/// rustdoc b.rs --crate-type=lib --extern=a=liba.rlib
/// ```
///
/// Now, the associated items in the trait impl want to link to the corresponding item in the
/// trait declaration (see `html::render::assoc_href_attr`) but it's not available since their
/// *documentation (was) not built*.
DocumentationNotBuilt,
/// This can only happen for non-local items when `--document-private-items` is not passed.
Private,
// Not in external cache, href link should be in same page
NotInExternalCache,
}
// Panics if `syms` is empty.
pub(crate) fn join_with_double_colon(syms: &[Symbol]) -> String {
let mut s = String::with_capacity(estimate_item_path_byte_length(syms.len()));
s.push_str(syms[0].as_str());
for sym in &syms[1..] {
s.push_str("::");
s.push_str(sym.as_str());
}
s
}
/// This function is to get the external macro path because they are not in the cache used in
/// `href_with_root_path`.
fn generate_macro_def_id_path(
def_id: DefId,
cx: &Context<'_>,
root_path: Option<&str>,
) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
let tcx = cx.tcx();
let crate_name = tcx.crate_name(def_id.krate);
let cache = cx.cache();
let fqp = clean::inline::item_relative_path(tcx, def_id);
let mut relative = fqp.iter().copied();
let cstore = CStore::from_tcx(tcx);
// We need this to prevent a `panic` when this function is used from intra doc links...
if !cstore.has_crate_data(def_id.krate) {
debug!("No data for crate {crate_name}");
return Err(HrefError::NotInExternalCache);
}
// Check to see if it is a macro 2.0 or built-in macro.
// More information in <https://rust-lang.github.io/rfcs/1584-macros.html>.
let is_macro_2 = match cstore.load_macro_untracked(def_id, tcx) {
LoadedMacro::MacroDef(def, _) => {
// If `ast_def.macro_rules` is `true`, then it's not a macro 2.0.
matches!(&def.kind, ast::ItemKind::MacroDef(ast_def) if !ast_def.macro_rules)
}
_ => false,
};
let mut path = if is_macro_2 {
once(crate_name).chain(relative).collect()
} else {
vec![crate_name, relative.next_back().unwrap()]
};
if path.len() < 2 {
// The minimum we can have is the crate name followed by the macro name. If shorter, then
// it means that `relative` was empty, which is an error.
debug!("macro path cannot be empty!");
return Err(HrefError::NotInExternalCache);
}
if let Some(last) = path.last_mut() {
*last = Symbol::intern(&format!("macro.{}.html", last.as_str()));
}
let url = match cache.extern_locations[&def_id.krate] {
ExternalLocation::Remote(ref s) => {
// `ExternalLocation::Remote` always end with a `/`.
format!("{s}{path}", path = path.iter().map(|p| p.as_str()).join("/"))
}
ExternalLocation::Local => {
// `root_path` always end with a `/`.
format!(
"{root_path}{path}",
root_path = root_path.unwrap_or(""),
path = path.iter().map(|p| p.as_str()).join("/")
)
}
ExternalLocation::Unknown => {
debug!("crate {crate_name} not in cache when linkifying macros");
return Err(HrefError::NotInExternalCache);
}
};
Ok((url, ItemType::Macro, fqp))
}
fn generate_item_def_id_path(
mut def_id: DefId,
original_def_id: DefId,
cx: &Context<'_>,
root_path: Option<&str>,
original_def_kind: DefKind,
) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
use crate::rustc_trait_selection::infer::TyCtxtInferExt;
use crate::rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
use rustc_middle::traits::ObligationCause;
let tcx = cx.tcx();
let crate_name = tcx.crate_name(def_id.krate);
// No need to try to infer the actual parent item if it's not an associated item from the `impl`
// block.
if def_id != original_def_id && matches!(tcx.def_kind(def_id), DefKind::Impl { .. }) {
let infcx = tcx.infer_ctxt().build();
def_id = infcx
.at(&ObligationCause::dummy(), tcx.param_env(def_id))
.query_normalize(ty::Binder::dummy(tcx.type_of(def_id).instantiate_identity()))
.map(|resolved| infcx.resolve_vars_if_possible(resolved.value))
.ok()
.and_then(|normalized| normalized.skip_binder().ty_adt_def())
.map(|adt| adt.did())
.unwrap_or(def_id);
}
let relative = clean::inline::item_relative_path(tcx, def_id);
let fqp: Vec<Symbol> = once(crate_name).chain(relative).collect();
let def_kind = tcx.def_kind(def_id);
let shortty = def_kind.into();
let module_fqp = to_module_fqp(shortty, &fqp);
let mut is_remote = false;
let url_parts = url_parts(cx.cache(), def_id, &module_fqp, &cx.current, &mut is_remote)?;
let (url_parts, shortty, fqp) = make_href(root_path, shortty, url_parts, &fqp, is_remote)?;
if def_id == original_def_id {
return Ok((url_parts, shortty, fqp));
}
let kind = ItemType::from_def_kind(original_def_kind, Some(def_kind));
Ok((format!("{url_parts}#{kind}.{}", tcx.item_name(original_def_id)), shortty, fqp))
}
fn to_module_fqp(shortty: ItemType, fqp: &[Symbol]) -> &[Symbol] {
if shortty == ItemType::Module { fqp } else { &fqp[..fqp.len() - 1] }
}
fn url_parts(
cache: &Cache,
def_id: DefId,
module_fqp: &[Symbol],
relative_to: &[Symbol],
is_remote: &mut bool,
) -> Result<UrlPartsBuilder, HrefError> {
match cache.extern_locations[&def_id.krate] {
ExternalLocation::Remote(ref s) => {
*is_remote = true;
let s = s.trim_end_matches('/');
let mut builder = UrlPartsBuilder::singleton(s);
builder.extend(module_fqp.iter().copied());
Ok(builder)
}
ExternalLocation::Local => Ok(href_relative_parts(module_fqp, relative_to).collect()),
ExternalLocation::Unknown => Err(HrefError::DocumentationNotBuilt),
}
}
fn make_href(
root_path: Option<&str>,
shortty: ItemType,
mut url_parts: UrlPartsBuilder,
fqp: &[Symbol],
is_remote: bool,
) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
if !is_remote && let Some(root_path) = root_path {
let root = root_path.trim_end_matches('/');
url_parts.push_front(root);
}
debug!(?url_parts);
match shortty {
ItemType::Module => {
url_parts.push("index.html");
}
_ => {
let prefix = shortty.as_str();
let last = fqp.last().unwrap();
url_parts.push_fmt(format_args!("{prefix}.{last}.html"));
}
}
Ok((url_parts.finish(), shortty, fqp.to_vec()))
}
pub(crate) fn href_with_root_path(
original_did: DefId,
cx: &Context<'_>,
root_path: Option<&str>,
) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
let tcx = cx.tcx();
let def_kind = tcx.def_kind(original_did);
let did = match def_kind {
DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst | DefKind::Variant => {
// documented on their parent's page
tcx.parent(original_did)
}
// If this a constructor, we get the parent (either a struct or a variant) and then
// generate the link for this item.
DefKind::Ctor(..) => return href_with_root_path(tcx.parent(original_did), cx, root_path),
DefKind::ExternCrate => {
// Link to the crate itself, not the `extern crate` item.
if let Some(local_did) = original_did.as_local() {
tcx.extern_mod_stmt_cnum(local_did).unwrap_or(LOCAL_CRATE).as_def_id()
} else {
original_did
}
}
_ => original_did,
};
let cache = cx.cache();
let relative_to = &cx.current;
if !original_did.is_local() {
// If we are generating an href for the "jump to def" feature, then the only case we want
// to ignore is if the item is `doc(hidden)` because we can't link to it.
if root_path.is_some() {
if tcx.is_doc_hidden(original_did) {
return Err(HrefError::Private);
}
} else if !cache.effective_visibilities.is_directly_public(tcx, did)
&& !cache.document_private
&& !cache.primitive_locations.values().any(|&id| id == did)
{
return Err(HrefError::Private);
}
}
let mut is_remote = false;
let (fqp, shortty, url_parts) = match cache.paths.get(&did) {
Some(&(ref fqp, shortty)) => (fqp, shortty, {
let module_fqp = to_module_fqp(shortty, fqp.as_slice());
debug!(?fqp, ?shortty, ?module_fqp);
href_relative_parts(module_fqp, relative_to).collect()
}),
None => {
// Associated items are handled differently with "jump to def". The anchor is generated
// directly here whereas for intra-doc links, we have some extra computation being
// performed there.
let def_id_to_get = if root_path.is_some() { original_did } else { did };
if let Some(&(ref fqp, shortty)) = cache.external_paths.get(&def_id_to_get) {
let module_fqp = to_module_fqp(shortty, fqp);
(fqp, shortty, url_parts(cache, did, module_fqp, relative_to, &mut is_remote)?)
} else if matches!(def_kind, DefKind::Macro(_)) {
return generate_macro_def_id_path(did, cx, root_path);
} else if did.is_local() {
return Err(HrefError::Private);
} else {
return generate_item_def_id_path(did, original_did, cx, root_path, def_kind);
}
}
};
make_href(root_path, shortty, url_parts, fqp, is_remote)
}
pub(crate) fn href(
did: DefId,
cx: &Context<'_>,
) -> Result<(String, ItemType, Vec<Symbol>), HrefError> {
href_with_root_path(did, cx, None)
}
/// Both paths should only be modules.
/// This is because modules get their own directories; that is, `std::vec` and `std::vec::Vec` will
/// both need `../iter/trait.Iterator.html` to get at the iterator trait.
pub(crate) fn href_relative_parts<'fqp>(
fqp: &'fqp [Symbol],
relative_to_fqp: &[Symbol],
) -> Box<dyn Iterator<Item = Symbol> + 'fqp> {
for (i, (f, r)) in fqp.iter().zip(relative_to_fqp.iter()).enumerate() {
// e.g. linking to std::iter from std::vec (`dissimilar_part_count` will be 1)
if f != r {
let dissimilar_part_count = relative_to_fqp.len() - i;
let fqp_module = &fqp[i..fqp.len()];
return Box::new(
iter::repeat(sym::dotdot)
.take(dissimilar_part_count)
.chain(fqp_module.iter().copied()),
);
}
}
// e.g. linking to std::sync::atomic from std::sync
if relative_to_fqp.len() < fqp.len() {
Box::new(fqp[relative_to_fqp.len()..fqp.len()].iter().copied())
// e.g. linking to std::sync from std::sync::atomic
} else if fqp.len() < relative_to_fqp.len() {
let dissimilar_part_count = relative_to_fqp.len() - fqp.len();
Box::new(iter::repeat(sym::dotdot).take(dissimilar_part_count))
// linking to the same module
} else {
Box::new(iter::empty())
}
}
pub(crate) fn link_tooltip(did: DefId, fragment: &Option<UrlFragment>, cx: &Context<'_>) -> String {
let cache = cx.cache();
let Some((fqp, shortty)) = cache.paths.get(&did).or_else(|| cache.external_paths.get(&did))
else {
return String::new();
};
let mut buf = Buffer::new();
let fqp = if *shortty == ItemType::Primitive {
// primitives are documented in a crate, but not actually part of it
&fqp[fqp.len() - 1..]
} else {
&fqp
};
if let &Some(UrlFragment::Item(id)) = fragment {
write!(buf, "{} ", cx.tcx().def_descr(id));
for component in fqp {
write!(buf, "{component}::");
}
write!(buf, "{}", cx.tcx().item_name(id));
} else if !fqp.is_empty() {
let mut fqp_it = fqp.into_iter();
write!(buf, "{shortty} {}", fqp_it.next().unwrap());
for component in fqp_it {
write!(buf, "::{component}");
}
}
buf.into_inner()
}
/// Used to render a [`clean::Path`].
fn resolved_path<'cx>(
w: &mut fmt::Formatter<'_>,
did: DefId,
path: &clean::Path,
print_all: bool,
use_absolute: bool,
cx: &'cx Context<'_>,
) -> fmt::Result {
let last = path.segments.last().unwrap();
if print_all {
for seg in &path.segments[..path.segments.len() - 1] {
write!(w, "{}::", if seg.name == kw::PathRoot { "" } else { seg.name.as_str() })?;
}
}
if w.alternate() {
write!(w, "{}{:#}", &last.name, last.args.print(cx))?;
} else {
let path = if use_absolute {
if let Ok((_, _, fqp)) = href(did, cx) {
format!(
"{path}::{anchor}",
path = join_with_double_colon(&fqp[..fqp.len() - 1]),
anchor = anchor(did, *fqp.last().unwrap(), cx)
)
} else {
last.name.to_string()
}
} else {
anchor(did, last.name, cx).to_string()
};
write!(w, "{path}{args}", args = last.args.print(cx))?;
}
Ok(())
}
fn primitive_link(
f: &mut fmt::Formatter<'_>,
prim: clean::PrimitiveType,
name: fmt::Arguments<'_>,
cx: &Context<'_>,
) -> fmt::Result {
primitive_link_fragment(f, prim, name, "", cx)
}
fn primitive_link_fragment(
f: &mut fmt::Formatter<'_>,
prim: clean::PrimitiveType,
name: fmt::Arguments<'_>,
fragment: &str,
cx: &Context<'_>,
) -> fmt::Result {
let m = &cx.cache();
let mut needs_termination = false;
if !f.alternate() {
match m.primitive_locations.get(&prim) {
Some(&def_id) if def_id.is_local() => {
let len = cx.current.len();
let path = if len == 0 {
let cname_sym = ExternalCrate { crate_num: def_id.krate }.name(cx.tcx());
format!("{cname_sym}/")
} else {
"../".repeat(len - 1)
};
write!(
f,
"<a class=\"primitive\" href=\"{}primitive.{}.html{fragment}\">",
path,
prim.as_sym()
)?;
needs_termination = true;
}
Some(&def_id) => {
let loc = match m.extern_locations[&def_id.krate] {
ExternalLocation::Remote(ref s) => {
let cname_sym = ExternalCrate { crate_num: def_id.krate }.name(cx.tcx());
let builder: UrlPartsBuilder =
[s.as_str().trim_end_matches('/'), cname_sym.as_str()]
.into_iter()
.collect();
Some(builder)
}
ExternalLocation::Local => {
let cname_sym = ExternalCrate { crate_num: def_id.krate }.name(cx.tcx());
Some(if cx.current.first() == Some(&cname_sym) {
iter::repeat(sym::dotdot).take(cx.current.len() - 1).collect()
} else {
iter::repeat(sym::dotdot)
.take(cx.current.len())
.chain(iter::once(cname_sym))
.collect()
})
}
ExternalLocation::Unknown => None,
};
if let Some(mut loc) = loc {
loc.push_fmt(format_args!("primitive.{}.html", prim.as_sym()));
write!(f, "<a class=\"primitive\" href=\"{}{fragment}\">", loc.finish())?;
needs_termination = true;
}
}
None => {}
}
}
Display::fmt(&name, f)?;
if needs_termination {
write!(f, "</a>")?;
}
Ok(())
}
fn tybounds<'a, 'tcx: 'a>(
bounds: &'a [clean::PolyTrait],
lt: &'a Option<clean::Lifetime>,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
for (i, bound) in bounds.iter().enumerate() {
if i > 0 {
write!(f, " + ")?;
}
bound.print(cx).fmt(f)?;
}
if let Some(lt) = lt {
// We don't need to check `alternate` since we can be certain that
// the lifetime doesn't contain any characters which need escaping.
write!(f, " + {}", lt.print())?;
}
Ok(())
})
}
fn print_higher_ranked_params_with_space<'a, 'tcx: 'a>(
params: &'a [clean::GenericParamDef],
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
if !params.is_empty() {
f.write_str(if f.alternate() { "for<" } else { "for&lt;" })?;
comma_sep(params.iter().map(|lt| lt.print(cx)), true).fmt(f)?;
f.write_str(if f.alternate() { "> " } else { "&gt; " })?;
}
Ok(())
})
}
pub(crate) fn anchor<'a, 'cx: 'a>(
did: DefId,
text: Symbol,
cx: &'cx Context<'_>,
) -> impl Display + 'a {
let parts = href(did, cx);
display_fn(move |f| {
if let Ok((url, short_ty, fqp)) = parts {
write!(
f,
r#"<a class="{short_ty}" href="{url}" title="{short_ty} {path}">{text}</a>"#,
path = join_with_double_colon(&fqp),
)
} else {
f.write_str(text.as_str())
}
})
}
fn fmt_type<'cx>(
t: &clean::Type,
f: &mut fmt::Formatter<'_>,
use_absolute: bool,
cx: &'cx Context<'_>,
) -> fmt::Result {
trace!("fmt_type(t = {t:?})");
match *t {
clean::Generic(name) => f.write_str(name.as_str()),
clean::Type::Path { ref path } => {
// Paths like `T::Output` and `Self::Output` should be rendered with all segments.
let did = path.def_id();
resolved_path(f, did, path, path.is_assoc_ty(), use_absolute, cx)
}
clean::DynTrait(ref bounds, ref lt) => {
f.write_str("dyn ")?;
tybounds(bounds, lt, cx).fmt(f)
}
clean::Infer => write!(f, "_"),
clean::Primitive(clean::PrimitiveType::Never) => {
primitive_link(f, PrimitiveType::Never, format_args!("!"), cx)
}
clean::Primitive(prim) => {
primitive_link(f, prim, format_args!("{}", prim.as_sym().as_str()), cx)
}
clean::BareFunction(ref decl) => {
print_higher_ranked_params_with_space(&decl.generic_params, cx).fmt(f)?;
decl.unsafety.print_with_space().fmt(f)?;
print_abi_with_space(decl.abi).fmt(f)?;
if f.alternate() {
f.write_str("fn")?;
} else {
primitive_link(f, PrimitiveType::Fn, format_args!("fn"), cx)?;
}
decl.decl.print(cx).fmt(f)
}
clean::Tuple(ref typs) => match &typs[..] {
&[] => primitive_link(f, PrimitiveType::Unit, format_args!("()"), cx),
[one] => {
if let clean::Generic(name) = one {
primitive_link(f, PrimitiveType::Tuple, format_args!("({name},)"), cx)
} else {
write!(f, "(")?;
one.print(cx).fmt(f)?;
write!(f, ",)")
}
}
many => {
let generic_names: Vec<Symbol> = many
.iter()
.filter_map(|t| match t {
clean::Generic(name) => Some(*name),
_ => None,
})
.collect();
let is_generic = generic_names.len() == many.len();
if is_generic {
primitive_link(
f,
PrimitiveType::Tuple,
format_args!("({})", generic_names.iter().map(|s| s.as_str()).join(", ")),
cx,
)
} else {
write!(f, "(")?;
for (i, item) in many.iter().enumerate() {
if i != 0 {
write!(f, ", ")?;
}
item.print(cx).fmt(f)?;
}
write!(f, ")")
}
}
},
clean::Slice(ref t) => match **t {
clean::Generic(name) => {
primitive_link(f, PrimitiveType::Slice, format_args!("[{name}]"), cx)
}
_ => {
write!(f, "[")?;
t.print(cx).fmt(f)?;
write!(f, "]")
}
},
clean::Array(ref t, ref n) => match **t {
clean::Generic(name) if !f.alternate() => primitive_link(
f,
PrimitiveType::Array,
format_args!("[{name}; {n}]", n = Escape(n)),
cx,
),
_ => {
write!(f, "[")?;
t.print(cx).fmt(f)?;
if f.alternate() {
write!(f, "; {n}")?;
} else {
write!(f, "; ")?;
primitive_link(
f,
PrimitiveType::Array,
format_args!("{n}", n = Escape(n)),
cx,
)?;
}
write!(f, "]")
}
},
clean::RawPointer(m, ref t) => {
let m = match m {
hir::Mutability::Mut => "mut",
hir::Mutability::Not => "const",
};
if matches!(**t, clean::Generic(_)) || t.is_assoc_ty() {
let ty = t.print(cx);
if f.alternate() {
primitive_link(
f,
clean::PrimitiveType::RawPointer,
format_args!("*{m} {ty:#}"),
cx,
)
} else {
primitive_link(
f,
clean::PrimitiveType::RawPointer,
format_args!("*{m} {ty}"),
cx,
)
}
} else {
primitive_link(f, clean::PrimitiveType::RawPointer, format_args!("*{m} "), cx)?;
t.print(cx).fmt(f)
}
}
clean::BorrowedRef { lifetime: ref l, mutability, type_: ref ty } => {
let lt = display_fn(|f| match l {
Some(l) => write!(f, "{} ", l.print()),
_ => Ok(()),
});
let m = mutability.print_with_space();
let amp = if f.alternate() { "&" } else { "&amp;" };
if let clean::Generic(name) = **ty {
return primitive_link(
f,
PrimitiveType::Reference,
format_args!("{amp}{lt}{m}{name}"),
cx,
);
}
write!(f, "{amp}{lt}{m}")?;
let needs_parens = match **ty {
clean::DynTrait(ref bounds, ref trait_lt)
if bounds.len() > 1 || trait_lt.is_some() =>
{
true
}
clean::ImplTrait(ref bounds) if bounds.len() > 1 => true,
_ => false,
};
if needs_parens {
f.write_str("(")?;
}
fmt_type(ty, f, use_absolute, cx)?;
if needs_parens {
f.write_str(")")?;
}
Ok(())
}
clean::ImplTrait(ref bounds) => {
f.write_str("impl ")?;
print_generic_bounds(bounds, cx).fmt(f)
}
clean::QPath(box clean::QPathData {
ref assoc,
ref self_type,
ref trait_,
should_show_cast,
}) => {
// FIXME(inherent_associated_types): Once we support non-ADT self-types (#106719),
// we need to surround them with angle brackets in some cases (e.g. `<dyn …>::P`).
if f.alternate() {
if let Some(trait_) = trait_
&& should_show_cast
{
write!(f, "<{:#} as {:#}>::", self_type.print(cx), trait_.print(cx))?
} else {
write!(f, "{:#}::", self_type.print(cx))?
}
} else {
if let Some(trait_) = trait_
&& should_show_cast
{
write!(f, "&lt;{} as {}&gt;::", self_type.print(cx), trait_.print(cx))?
} else {
write!(f, "{}::", self_type.print(cx))?
}
};
// It's pretty unsightly to look at `<A as B>::C` in output, and
// we've got hyperlinking on our side, so try to avoid longer
// notation as much as possible by making `C` a hyperlink to trait
// `B` to disambiguate.
//
// FIXME: this is still a lossy conversion and there should probably
// be a better way of representing this in general? Most of
// the ugliness comes from inlining across crates where
// everything comes in as a fully resolved QPath (hard to
// look at).
if !f.alternate() {
// FIXME(inherent_associated_types): We always link to the very first associated
// type (in respect to source order) that bears the given name (`assoc.name`) and that is
// affiliated with the computed `DefId`. This is obviously incorrect when we have
// multiple impl blocks. Ideally, we would thread the `DefId` of the assoc ty itself
// through here and map it to the corresponding HTML ID that was generated by
// `render::Context::derive_id` when the impl blocks were rendered.
// There is no such mapping unfortunately.
// As a hack, we could badly imitate `derive_id` here by keeping *count* when looking
// for the assoc ty `DefId` in `tcx.associated_items(self_ty_did).in_definition_order()`
// considering privacy, `doc(hidden)`, etc.
// I don't feel like that right now :cold_sweat:.
let parent_href = match trait_ {
Some(trait_) => href(trait_.def_id(), cx).ok(),
None => self_type.def_id(cx.cache()).and_then(|did| href(did, cx).ok()),
};
if let Some((url, _, path)) = parent_href {
write!(
f,
"<a class=\"associatedtype\" href=\"{url}#{shortty}.{name}\" \
title=\"type {path}::{name}\">{name}</a>",
shortty = ItemType::AssocType,
name = assoc.name,
path = join_with_double_colon(&path),
)
} else {
write!(f, "{}", assoc.name)
}
} else {
write!(f, "{}", assoc.name)
}?;
assoc.args.print(cx).fmt(f)
}
}
}
impl clean::Type {
pub(crate) fn print<'b, 'a: 'b, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'b + Captures<'tcx> {
display_fn(move |f| fmt_type(self, f, false, cx))
}
}
impl clean::Path {
pub(crate) fn print<'b, 'a: 'b, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'b + Captures<'tcx> {
display_fn(move |f| resolved_path(f, self.def_id(), self, false, false, cx))
}
}
impl clean::Impl {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
use_absolute: bool,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
f.write_str("impl")?;
self.generics.print(cx).fmt(f)?;
f.write_str(" ")?;
if let Some(ref ty) = self.trait_ {
match self.polarity {
ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => {}
ty::ImplPolarity::Negative => write!(f, "!")?,
}
ty.print(cx).fmt(f)?;
write!(f, " for ")?;
}
if let clean::Type::Tuple(types) = &self.for_
&& let [clean::Type::Generic(name)] = &types[..]
&& (self.kind.is_fake_variadic() || self.kind.is_auto())
{
// Hardcoded anchor library/core/src/primitive_docs.rs
// Link should match `# Trait implementations`
primitive_link_fragment(
f,
PrimitiveType::Tuple,
format_args!("({name}₁, {name}₂, …, {name}ₙ)"),
"#trait-implementations-1",
cx,
)?;
} else if let clean::BareFunction(bare_fn) = &self.for_
&& let [clean::Argument { type_: clean::Type::Generic(name), .. }] =
&bare_fn.decl.inputs.values[..]
&& (self.kind.is_fake_variadic() || self.kind.is_auto())
{
// Hardcoded anchor library/core/src/primitive_docs.rs
// Link should match `# Trait implementations`
print_higher_ranked_params_with_space(&bare_fn.generic_params, cx).fmt(f)?;
bare_fn.unsafety.print_with_space().fmt(f)?;
print_abi_with_space(bare_fn.abi).fmt(f)?;
let ellipsis = if bare_fn.decl.c_variadic { ", ..." } else { "" };
primitive_link_fragment(
f,
PrimitiveType::Tuple,
format_args!("fn({name}₁, {name}₂, …, {name}ₙ{ellipsis})"),
"#trait-implementations-1",
cx,
)?;
// Write output.
if !bare_fn.decl.output.is_unit() {
write!(f, " -> ")?;
fmt_type(&bare_fn.decl.output, f, use_absolute, cx)?;
}
} else if let Some(ty) = self.kind.as_blanket_ty() {
fmt_type(ty, f, use_absolute, cx)?;
} else {
fmt_type(&self.for_, f, use_absolute, cx)?;
}
print_where_clause(&self.generics, cx, 0, Ending::Newline).fmt(f)
})
}
}
impl clean::Arguments {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
for (i, input) in self.values.iter().enumerate() {
write!(f, "{}: ", input.name)?;
input.type_.print(cx).fmt(f)?;
if i + 1 < self.values.len() {
write!(f, ", ")?;
}
}
Ok(())
})
}
}
// Implements Write but only counts the bytes "written".
struct WriteCounter(usize);
impl std::fmt::Write for WriteCounter {
fn write_str(&mut self, s: &str) -> fmt::Result {
self.0 += s.len();
Ok(())
}
}
// Implements Display by emitting the given number of spaces.
struct Indent(usize);
impl Display for Indent {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
(0..self.0).for_each(|_| {
f.write_char(' ').unwrap();
});
Ok(())
}
}
impl clean::FnDecl {
pub(crate) fn print<'b, 'a: 'b, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'b + Captures<'tcx> {
display_fn(move |f| {
let ellipsis = if self.c_variadic { ", ..." } else { "" };
if f.alternate() {
write!(
f,
"({args:#}{ellipsis}){arrow:#}",
args = self.inputs.print(cx),
ellipsis = ellipsis,
arrow = self.print_output(cx)
)
} else {
write!(
f,
"({args}{ellipsis}){arrow}",
args = self.inputs.print(cx),
ellipsis = ellipsis,
arrow = self.print_output(cx)
)
}
})
}
/// * `header_len`: The length of the function header and name. In other words, the number of
/// characters in the function declaration up to but not including the parentheses.
/// This is expected to go into a `<pre>`/`code-header` block, so indentation and newlines
/// are preserved.
/// * `indent`: The number of spaces to indent each successive line with, if line-wrapping is
/// necessary.
pub(crate) fn full_print<'a, 'tcx: 'a>(
&'a self,
header_len: usize,
indent: usize,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
// First, generate the text form of the declaration, with no line wrapping, and count the bytes.
let mut counter = WriteCounter(0);
write!(&mut counter, "{:#}", display_fn(|f| { self.inner_full_print(None, f, cx) }))
.unwrap();
// If the text form was over 80 characters wide, we will line-wrap our output.
let line_wrapping_indent =
if header_len + counter.0 > 80 { Some(indent) } else { None };
// Generate the final output. This happens to accept `{:#}` formatting to get textual
// output but in practice it is only formatted with `{}` to get HTML output.
self.inner_full_print(line_wrapping_indent, f, cx)
})
}
fn inner_full_print(
&self,
// For None, the declaration will not be line-wrapped. For Some(n),
// the declaration will be line-wrapped, with an indent of n spaces.
line_wrapping_indent: Option<usize>,
f: &mut fmt::Formatter<'_>,
cx: &Context<'_>,
) -> fmt::Result {
let amp = if f.alternate() { "&" } else { "&amp;" };
write!(f, "(")?;
if let Some(n) = line_wrapping_indent
&& !self.inputs.values.is_empty()
{
write!(f, "\n{}", Indent(n + 4))?;
}
for (i, input) in self.inputs.values.iter().enumerate() {
if i > 0 {
match line_wrapping_indent {
None => write!(f, ", ")?,
Some(n) => write!(f, ",\n{}", Indent(n + 4))?,
};
}
if let Some(selfty) = input.to_self() {
match selfty {
clean::SelfValue => {
write!(f, "self")?;
}
clean::SelfBorrowed(Some(ref lt), mutability) => {
write!(
f,
"{amp}{lifetime} {mutability}self",
lifetime = lt.print(),
mutability = mutability.print_with_space(),
)?;
}
clean::SelfBorrowed(None, mutability) => {
write!(
f,
"{amp}{mutability}self",
mutability = mutability.print_with_space(),
)?;
}
clean::SelfExplicit(ref typ) => {
write!(f, "self: ")?;
typ.print(cx).fmt(f)?;
}
}
} else {
if input.is_const {
write!(f, "const ")?;
}
write!(f, "{}: ", input.name)?;
input.type_.print(cx).fmt(f)?;
}
}
if self.c_variadic {
match line_wrapping_indent {
None => write!(f, ", ...")?,
Some(n) => write!(f, "\n{}...", Indent(n + 4))?,
};
}
match line_wrapping_indent {
None => write!(f, ")")?,
Some(n) => write!(f, "\n{})", Indent(n))?,
};
self.print_output(cx).fmt(f)
}
fn print_output<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| match &self.output {
clean::Tuple(tys) if tys.is_empty() => Ok(()),
ty if f.alternate() => {
write!(f, " -> {:#}", ty.print(cx))
}
ty => write!(f, " -&gt; {}", ty.print(cx)),
})
}
}
pub(crate) fn visibility_print_with_space<'a, 'tcx: 'a>(
item: &clean::Item,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
use std::fmt::Write as _;
let vis: Cow<'static, str> = match item.visibility(cx.tcx()) {
None => "".into(),
Some(ty::Visibility::Public) => "pub ".into(),
Some(ty::Visibility::Restricted(vis_did)) => {
// FIXME(camelid): This may not work correctly if `item_did` is a module.
// However, rustdoc currently never displays a module's
// visibility, so it shouldn't matter.
let parent_module = find_nearest_parent_module(cx.tcx(), item.item_id.expect_def_id());
if vis_did.is_crate_root() {
"pub(crate) ".into()
} else if parent_module == Some(vis_did) {
// `pub(in foo)` where `foo` is the parent module
// is the same as no visibility modifier
"".into()
} else if parent_module.and_then(|parent| find_nearest_parent_module(cx.tcx(), parent))
== Some(vis_did)
{
"pub(super) ".into()
} else {
let path = cx.tcx().def_path(vis_did);
debug!("path={path:?}");
// modified from `resolved_path()` to work with `DefPathData`
let last_name = path.data.last().unwrap().data.get_opt_name().unwrap();
let anchor = anchor(vis_did, last_name, cx);
let mut s = "pub(in ".to_owned();
for seg in &path.data[..path.data.len() - 1] {
let _ = write!(s, "{}::", seg.data.get_opt_name().unwrap());
}
let _ = write!(s, "{anchor}) ");
s.into()
}
}
};
let is_doc_hidden = item.is_doc_hidden();
display_fn(move |f| {
if is_doc_hidden {
f.write_str("#[doc(hidden)] ")?;
}
f.write_str(&vis)
})
}
/// This function is the same as print_with_space, except that it renders no links.
/// It's used for macros' rendered source view, which is syntax highlighted and cannot have
/// any HTML in it.
pub(crate) fn visibility_to_src_with_space<'a, 'tcx: 'a>(
visibility: Option<ty::Visibility<DefId>>,
tcx: TyCtxt<'tcx>,
item_did: DefId,
is_doc_hidden: bool,
) -> impl Display + 'a + Captures<'tcx> {
let vis: Cow<'static, str> = match visibility {
None => "".into(),
Some(ty::Visibility::Public) => "pub ".into(),
Some(ty::Visibility::Restricted(vis_did)) => {
// FIXME(camelid): This may not work correctly if `item_did` is a module.
// However, rustdoc currently never displays a module's
// visibility, so it shouldn't matter.
let parent_module = find_nearest_parent_module(tcx, item_did);
if vis_did.is_crate_root() {
"pub(crate) ".into()
} else if parent_module == Some(vis_did) {
// `pub(in foo)` where `foo` is the parent module
// is the same as no visibility modifier
"".into()
} else if parent_module.and_then(|parent| find_nearest_parent_module(tcx, parent))
== Some(vis_did)
{
"pub(super) ".into()
} else {
format!("pub(in {}) ", tcx.def_path_str(vis_did)).into()
}
}
};
display_fn(move |f| {
if is_doc_hidden {
f.write_str("#[doc(hidden)] ")?;
}
f.write_str(&vis)
})
}
pub(crate) trait PrintWithSpace {
fn print_with_space(&self) -> &str;
}
impl PrintWithSpace for hir::Unsafety {
fn print_with_space(&self) -> &str {
match self {
hir::Unsafety::Unsafe => "unsafe ",
hir::Unsafety::Normal => "",
}
}
}
impl PrintWithSpace for hir::IsAsync {
fn print_with_space(&self) -> &str {
match self {
hir::IsAsync::Async(_) => "async ",
hir::IsAsync::NotAsync => "",
}
}
}
impl PrintWithSpace for hir::Mutability {
fn print_with_space(&self) -> &str {
match self {
hir::Mutability::Not => "",
hir::Mutability::Mut => "mut ",
}
}
}
pub(crate) fn print_constness_with_space(
c: &hir::Constness,
s: Option<ConstStability>,
) -> &'static str {
match (c, s) {
// const stable or when feature(staged_api) is not set
(
hir::Constness::Const,
Some(ConstStability { level: StabilityLevel::Stable { .. }, .. }),
)
| (hir::Constness::Const, None) => "const ",
// const unstable or not const
_ => "",
}
}
impl clean::Import {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| match self.kind {
clean::ImportKind::Simple(name) => {
if name == self.source.path.last() {
write!(f, "use {};", self.source.print(cx))
} else {
write!(f, "use {source} as {name};", source = self.source.print(cx))
}
}
clean::ImportKind::Glob => {
if self.source.path.segments.is_empty() {
write!(f, "use *;")
} else {
write!(f, "use {}::*;", self.source.print(cx))
}
}
})
}
}
impl clean::ImportSource {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| match self.did {
Some(did) => resolved_path(f, did, &self.path, true, false, cx),
_ => {
for seg in &self.path.segments[..self.path.segments.len() - 1] {
write!(f, "{}::", seg.name)?;
}
let name = self.path.last();
if let hir::def::Res::PrimTy(p) = self.path.res {
primitive_link(
f,
PrimitiveType::from(p),
format_args!("{}", name.as_str()),
cx,
)?;
} else {
f.write_str(name.as_str())?;
}
Ok(())
}
})
}
}
impl clean::TypeBinding {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| {
f.write_str(self.assoc.name.as_str())?;
self.assoc.args.print(cx).fmt(f)?;
match self.kind {
clean::TypeBindingKind::Equality { ref term } => {
f.write_str(" = ")?;
term.print(cx).fmt(f)?;
}
clean::TypeBindingKind::Constraint { ref bounds } => {
if !bounds.is_empty() {
f.write_str(": ")?;
print_generic_bounds(bounds, cx).fmt(f)?;
}
}
}
Ok(())
})
}
}
pub(crate) fn print_abi_with_space(abi: Abi) -> impl Display {
display_fn(move |f| {
let quot = if f.alternate() { "\"" } else { "&quot;" };
match abi {
Abi::Rust => Ok(()),
abi => write!(f, "extern {0}{1}{0} ", quot, abi.name()),
}
})
}
pub(crate) fn print_default_space<'a>(v: bool) -> &'a str {
if v { "default " } else { "" }
}
impl clean::GenericArg {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| match self {
clean::GenericArg::Lifetime(lt) => lt.print().fmt(f),
clean::GenericArg::Type(ty) => ty.print(cx).fmt(f),
clean::GenericArg::Const(ct) => ct.print(cx.tcx()).fmt(f),
clean::GenericArg::Infer => Display::fmt("_", f),
})
}
}
impl clean::Term {
pub(crate) fn print<'a, 'tcx: 'a>(
&'a self,
cx: &'a Context<'tcx>,
) -> impl Display + 'a + Captures<'tcx> {
display_fn(move |f| match self {
clean::Term::Type(ty) => ty.print(cx).fmt(f),
clean::Term::Constant(ct) => ct.print(cx.tcx()).fmt(f),
})
}
}
pub(crate) fn display_fn(f: impl FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl Display {
struct WithFormatter<F>(Cell<Option<F>>);
impl<F> Display for WithFormatter<F>
where
F: FnOnce(&mut fmt::Formatter<'_>) -> fmt::Result,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
(self.0.take()).unwrap()(f)
}
}
WithFormatter(Cell::new(Some(f)))
}