rust-analyzer/crates/hir/src/doc_links.rs
Aleksey Kladov 663749beab Minor
2020-08-25 12:48:00 +02:00

231 lines
8.2 KiB
Rust

//! Resolves links in markdown documentation.
use std::iter::once;
use hir_def::{db::DefDatabase, resolver::Resolver};
use itertools::Itertools;
use syntax::ast::Path;
use url::Url;
use crate::{db::HirDatabase, Adt, AsName, Crate, Hygiene, ItemInNs, ModPath, ModuleDef};
pub fn resolve_doc_link<T: Resolvable + Clone, D: DefDatabase + HirDatabase>(
db: &D,
definition: &T,
link_text: &str,
link_target: &str,
) -> Option<(String, String)> {
try_resolve_intra(db, definition, link_text, &link_target).or_else(|| {
let definition = definition.clone().try_into_module_def()?;
try_resolve_path(db, &definition, &link_target)
.map(|target| (target, link_text.to_string()))
})
}
/// Try to resolve path to local documentation via intra-doc-links (i.e. `super::gateway::Shard`).
///
/// See [RFC1946](https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md).
fn try_resolve_intra<T: Resolvable, D: DefDatabase + HirDatabase>(
db: &D,
definition: &T,
link_text: &str,
link_target: &str,
) -> Option<(String, String)> {
// Set link_target for implied shortlinks
let link_target =
if link_target.is_empty() { link_text.trim_matches('`') } else { link_target };
let doclink = IntraDocLink::from(link_target);
// Parse link as a module path
let path = Path::parse(doclink.path).ok()?;
let modpath = ModPath::from_src(path, &Hygiene::new_unhygienic()).unwrap();
// Resolve it relative to symbol's location (according to the RFC this should consider small scopes)
let resolver = definition.resolver(db)?;
let resolved = resolver.resolve_module_path_in_items(db, &modpath);
let (defid, namespace) = match doclink.namespace {
// FIXME: .or(resolved.macros)
None => resolved
.types
.map(|t| (t.0, Namespace::Types))
.or(resolved.values.map(|t| (t.0, Namespace::Values)))?,
Some(ns @ Namespace::Types) => (resolved.types?.0, ns),
Some(ns @ Namespace::Values) => (resolved.values?.0, ns),
// FIXME:
Some(Namespace::Macros) => return None,
};
// Get the filepath of the final symbol
let def: ModuleDef = defid.into();
let module = def.module(db)?;
let krate = module.krate();
let ns = match namespace {
Namespace::Types => ItemInNs::Types(defid),
Namespace::Values => ItemInNs::Values(defid),
// FIXME:
Namespace::Macros => None?,
};
let import_map = db.import_map(krate.into());
let path = import_map.path_of(ns)?;
Some((
get_doc_url(db, &krate)?
.join(&format!("{}/", krate.display_name(db)?))
.ok()?
.join(&path.segments.iter().map(|name| name.to_string()).join("/"))
.ok()?
.join(&get_symbol_filename(db, &def)?)
.ok()?
.into_string(),
strip_prefixes_suffixes(link_text).to_string(),
))
}
/// Try to resolve path to local documentation via path-based links (i.e. `../gateway/struct.Shard.html`).
fn try_resolve_path(db: &dyn HirDatabase, moddef: &ModuleDef, link_target: &str) -> Option<String> {
if !link_target.contains("#") && !link_target.contains(".html") {
return None;
}
let ns = ItemInNs::Types(moddef.clone().into());
let module = moddef.module(db)?;
let krate = module.krate();
let import_map = db.import_map(krate.into());
let base = once(format!("{}", krate.display_name(db)?))
.chain(import_map.path_of(ns)?.segments.iter().map(|name| format!("{}", name)))
.join("/");
get_doc_url(db, &krate)
.and_then(|url| url.join(&base).ok())
.and_then(|url| {
get_symbol_filename(db, moddef).as_deref().map(|f| url.join(f).ok()).flatten()
})
.and_then(|url| url.join(link_target).ok())
.map(|url| url.into_string())
}
/// Strip prefixes, suffixes, and inline code marks from the given string.
fn strip_prefixes_suffixes(mut s: &str) -> &str {
s = s.trim_matches('`');
[
(TYPES.0.iter(), TYPES.1.iter()),
(VALUES.0.iter(), VALUES.1.iter()),
(MACROS.0.iter(), MACROS.1.iter()),
]
.iter()
.for_each(|(prefixes, suffixes)| {
prefixes.clone().for_each(|prefix| s = s.trim_start_matches(*prefix));
suffixes.clone().for_each(|suffix| s = s.trim_end_matches(*suffix));
});
let s = s.trim_start_matches("@").trim();
s
}
fn get_doc_url(db: &dyn HirDatabase, krate: &Crate) -> Option<Url> {
krate
.get_html_root_url(db)
.or_else(||
// Fallback to docs.rs
// FIXME: Specify an exact version here. This may be difficult, as multiple versions of the same crate could exist.
Some(format!("https://docs.rs/{}/*/", krate.display_name(db)?)))
.and_then(|s| Url::parse(&s).ok())
}
/// Get the filename and extension generated for a symbol by rustdoc.
///
/// Example: `struct.Shard.html`
fn get_symbol_filename(db: &dyn HirDatabase, definition: &ModuleDef) -> Option<String> {
Some(match definition {
ModuleDef::Adt(adt) => match adt {
Adt::Struct(s) => format!("struct.{}.html", s.name(db)),
Adt::Enum(e) => format!("enum.{}.html", e.name(db)),
Adt::Union(u) => format!("union.{}.html", u.name(db)),
},
ModuleDef::Module(_) => "index.html".to_string(),
ModuleDef::Trait(t) => format!("trait.{}.html", t.name(db)),
ModuleDef::TypeAlias(t) => format!("type.{}.html", t.name(db)),
ModuleDef::BuiltinType(t) => format!("primitive.{}.html", t.as_name()),
ModuleDef::Function(f) => format!("fn.{}.html", f.name(db)),
ModuleDef::EnumVariant(ev) => {
format!("enum.{}.html#variant.{}", ev.parent_enum(db).name(db), ev.name(db))
}
ModuleDef::Const(c) => format!("const.{}.html", c.name(db)?),
ModuleDef::Static(s) => format!("static.{}.html", s.name(db)?),
})
}
struct IntraDocLink<'s> {
path: &'s str,
namespace: Option<Namespace>,
}
impl<'s> From<&'s str> for IntraDocLink<'s> {
fn from(s: &'s str) -> Self {
Self { path: strip_prefixes_suffixes(s), namespace: Namespace::from_intra_spec(s) }
}
}
#[derive(PartialEq, Eq, Hash, Copy, Clone, Debug)]
enum Namespace {
Types,
Values,
Macros,
}
static TYPES: ([&str; 7], [&str; 0]) =
(["type", "struct", "enum", "mod", "trait", "union", "module"], []);
static VALUES: ([&str; 8], [&str; 1]) =
(["value", "function", "fn", "method", "const", "static", "mod", "module"], ["()"]);
static MACROS: ([&str; 1], [&str; 1]) = (["macro"], ["!"]);
impl Namespace {
/// Extract the specified namespace from an intra-doc-link if one exists.
///
/// # Examples
///
/// * `struct MyStruct` -> `Namespace::Types`
/// * `panic!` -> `Namespace::Macros`
/// * `fn@from_intra_spec` -> `Namespace::Values`
fn from_intra_spec(s: &str) -> Option<Self> {
[
(Namespace::Types, (TYPES.0.iter(), TYPES.1.iter())),
(Namespace::Values, (VALUES.0.iter(), VALUES.1.iter())),
(Namespace::Macros, (MACROS.0.iter(), MACROS.1.iter())),
]
.iter()
.filter(|(_ns, (prefixes, suffixes))| {
prefixes
.clone()
.map(|prefix| {
s.starts_with(*prefix)
&& s.chars()
.nth(prefix.len() + 1)
.map(|c| c == '@' || c == ' ')
.unwrap_or(false)
})
.any(|cond| cond)
|| suffixes
.clone()
.map(|suffix| {
s.starts_with(*suffix)
&& s.chars()
.nth(suffix.len() + 1)
.map(|c| c == '@' || c == ' ')
.unwrap_or(false)
})
.any(|cond| cond)
})
.map(|(ns, (_, _))| *ns)
.next()
}
}
/// Sealed trait used solely for the generic bound on [`resolve_doc_link`].
pub trait Resolvable {
fn resolver<D: DefDatabase + HirDatabase>(&self, db: &D) -> Option<Resolver>;
fn try_into_module_def(self) -> Option<ModuleDef>;
}