5 files changed, 65 insertions, 321 deletions

diff --git a/crates/hir/Cargo.toml b/crates/hir/Cargo.toml
index 72f941c46..6dc5ad63b 100644
--- a/crates/hir/Cargo.toml
+++ b/crates/hir/Cargo.toml
@@ -15,7 +15,6 @@ rustc-hash = "1.1.0"
 either = "1.5.3"
 arrayvec = "0.5.1"
 itertools = "0.9.0"
-url = "2.1.1"
 
 stdx = { path = "../stdx", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
diff --git a/crates/hir/src/attrs.rs b/crates/hir/src/attrs.rs
index e5a539cb8..c3e820d89 100644
--- a/crates/hir/src/attrs.rs
+++ b/crates/hir/src/attrs.rs
@@ -1,20 +1,32 @@
 //! Attributes & documentation for hir types.
 use hir_def::{
-    attr::Attrs,
-    docs::Documentation,
-    resolver::{HasResolver, Resolver},
-    AdtId, AttrDefId, FunctionId, GenericDefId, ModuleId, StaticId, TraitId, VariantId,
+    attr::Attrs, docs::Documentation, path::ModPath, resolver::HasResolver, AttrDefId, ModuleDefId,
 };
+use hir_expand::hygiene::Hygiene;
 use hir_ty::db::HirDatabase;
+use syntax::ast;
 
 use crate::{
-    doc_links::Resolvable, Adt, Const, Enum, EnumVariant, Field, Function, GenericDef, ImplDef,
-    Local, MacroDef, Module, ModuleDef, Static, Struct, Trait, TypeAlias, TypeParam, Union,
+    Adt, Const, Enum, EnumVariant, Field, Function, MacroDef, Module, ModuleDef, Static, Struct,
+    Trait, TypeAlias, Union,
 };
 
 pub trait HasAttrs {
     fn attrs(self, db: &dyn HirDatabase) -> Attrs;
     fn docs(self, db: &dyn HirDatabase) -> Option<Documentation>;
+    fn resolve_doc_path(
+        self,
+        db: &dyn HirDatabase,
+        link: &str,
+        ns: Option<Namespace>,
+    ) -> Option<ModuleDef>;
+}
+
+#[derive(PartialEq, Eq, Hash, Copy, Clone, Debug)]
+pub enum Namespace {
+    Types,
+    Values,
+    Macros,
 }
 
 macro_rules! impl_has_attrs {
@@ -28,6 +40,10 @@ macro_rules! impl_has_attrs {
                 let def = AttrDefId::$def_id(self.into());
                 db.documentation(def)
             }
+            fn resolve_doc_path(self, db: &dyn HirDatabase, link: &str, ns: Option<Namespace>) -> Option<ModuleDef> {
+                let def = AttrDefId::$def_id(self.into());
+                resolve_doc_path(db, def, link, ns).map(ModuleDef::from)
+            }
         }
     )*};
 }
@@ -54,83 +70,42 @@ macro_rules! impl_has_attrs_adt {
             fn docs(self, db: &dyn HirDatabase) -> Option<Documentation> {
                 Adt::$adt(self).docs(db)
             }
+            fn resolve_doc_path(self, db: &dyn HirDatabase, link: &str, ns: Option<Namespace>) -> Option<ModuleDef> {
+                Adt::$adt(self).resolve_doc_path(db, link, ns)
+            }
         }
     )*};
 }
 
 impl_has_attrs_adt![Struct, Union, Enum];
 
-impl Resolvable for ModuleDef {
-    fn resolver(&self, db: &dyn HirDatabase) -> Option<Resolver> {
-        Some(match self {
-            ModuleDef::Module(m) => ModuleId::from(m.clone()).resolver(db.upcast()),
-            ModuleDef::Function(f) => FunctionId::from(f.clone()).resolver(db.upcast()),
-            ModuleDef::Adt(adt) => AdtId::from(adt.clone()).resolver(db.upcast()),
-            ModuleDef::EnumVariant(ev) => {
-                GenericDefId::from(GenericDef::from(ev.clone())).resolver(db.upcast())
-            }
-            ModuleDef::Const(c) => {
-                GenericDefId::from(GenericDef::from(c.clone())).resolver(db.upcast())
-            }
-            ModuleDef::Static(s) => StaticId::from(s.clone()).resolver(db.upcast()),
-            ModuleDef::Trait(t) => TraitId::from(t.clone()).resolver(db.upcast()),
-            ModuleDef::TypeAlias(t) => ModuleId::from(t.module(db)).resolver(db.upcast()),
-            // FIXME: This should be a resolver relative to `std/core`
-            ModuleDef::BuiltinType(_t) => None?,
-        })
-    }
-
-    fn try_into_module_def(self) -> Option<ModuleDef> {
-        Some(self)
-    }
-}
-
-impl Resolvable for TypeParam {
-    fn resolver(&self, db: &dyn HirDatabase) -> Option<Resolver> {
-        Some(ModuleId::from(self.module(db)).resolver(db.upcast()))
-    }
-
-    fn try_into_module_def(self) -> Option<ModuleDef> {
-        None
-    }
-}
-
-impl Resolvable for MacroDef {
-    fn resolver(&self, db: &dyn HirDatabase) -> Option<Resolver> {
-        Some(ModuleId::from(self.module(db)?).resolver(db.upcast()))
-    }
-
-    fn try_into_module_def(self) -> Option<ModuleDef> {
-        None
-    }
-}
-
-impl Resolvable for Field {
-    fn resolver(&self, db: &dyn HirDatabase) -> Option<Resolver> {
-        Some(VariantId::from(self.parent_def(db)).resolver(db.upcast()))
-    }
-
-    fn try_into_module_def(self) -> Option<ModuleDef> {
-        None
-    }
-}
-
-impl Resolvable for ImplDef {
-    fn resolver(&self, db: &dyn HirDatabase) -> Option<Resolver> {
-        Some(ModuleId::from(self.module(db)).resolver(db.upcast()))
-    }
-
-    fn try_into_module_def(self) -> Option<ModuleDef> {
-        None
-    }
-}
-
-impl Resolvable for Local {
-    fn resolver(&self, db: &dyn HirDatabase) -> Option<Resolver> {
-        Some(ModuleId::from(self.module(db)).resolver(db.upcast()))
-    }
-
-    fn try_into_module_def(self) -> Option<ModuleDef> {
-        None
-    }
+fn resolve_doc_path(
+    db: &dyn HirDatabase,
+    def: AttrDefId,
+    link: &str,
+    ns: Option<Namespace>,
+) -> Option<ModuleDefId> {
+    let resolver = match def {
+        AttrDefId::ModuleId(it) => it.resolver(db.upcast()),
+        AttrDefId::FieldId(it) => it.parent.resolver(db.upcast()),
+        AttrDefId::AdtId(it) => it.resolver(db.upcast()),
+        AttrDefId::FunctionId(it) => it.resolver(db.upcast()),
+        AttrDefId::EnumVariantId(it) => it.parent.resolver(db.upcast()),
+        AttrDefId::StaticId(it) => it.resolver(db.upcast()),
+        AttrDefId::ConstId(it) => it.resolver(db.upcast()),
+        AttrDefId::TraitId(it) => it.resolver(db.upcast()),
+        AttrDefId::TypeAliasId(it) => it.resolver(db.upcast()),
+        AttrDefId::ImplId(it) => it.resolver(db.upcast()),
+        AttrDefId::MacroDefId(_) => return None,
+    };
+    let path = ast::Path::parse(link).ok()?;
+    let modpath = ModPath::from_src(path, &Hygiene::new_unhygienic()).unwrap();
+    let resolved = resolver.resolve_module_path_in_items(db.upcast(), &modpath);
+    let def = match ns {
+        Some(Namespace::Types) => resolved.take_types()?,
+        Some(Namespace::Values) => resolved.take_values()?,
+        Some(Namespace::Macros) => return None,
+        None => resolved.iter_items().find_map(|it| it.as_module_def_id())?,
+    };
+    Some(def.into())
 }
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index c2ee20dbb..c2fc819e7 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -196,6 +196,16 @@ impl ModuleDef {
         }
     }
 
+    pub fn canonical_path(&self, db: &dyn HirDatabase) -> Option<String> {
+        let mut segments = Vec::new();
+        segments.push(self.name(db)?.to_string());
+        for m in self.module(db)?.path_to_root(db) {
+            segments.extend(m.name(db).map(|it| it.to_string()))
+        }
+        segments.reverse();
+        Some(segments.join("::"))
+    }
+
     pub fn definition_visibility(&self, db: &dyn HirDatabase) -> Option<Visibility> {
         let module = match self {
             ModuleDef::Module(it) => it.parent(db)?,
diff --git a/crates/hir/src/doc_links.rs b/crates/hir/src/doc_links.rs
deleted file mode 100644
index ddaffbec2..000000000
--- a/crates/hir/src/doc_links.rs
+++ /dev/null
@@ -1,238 +0,0 @@
-//! Resolves links in markdown documentation.
-
-use std::iter::once;
-
-use hir_def::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>(
-    db: &dyn HirDatabase,
-    definition: &T,
-    link_text: &str,
-    link_target: &str,
-) -> Option<(String, String)> {
-    let resolver = definition.resolver(db)?;
-    let module_def = definition.clone().try_into_module_def();
-    resolve_doc_link_impl(db, &resolver, module_def, link_text, link_target)
-}
-
-fn resolve_doc_link_impl(
-    db: &dyn HirDatabase,
-    resolver: &Resolver,
-    module_def: Option<ModuleDef>,
-    link_text: &str,
-    link_target: &str,
-) -> Option<(String, String)> {
-    try_resolve_intra(db, &resolver, link_text, &link_target).or_else(|| {
-        try_resolve_path(db, &module_def?, &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(
-    db: &dyn HirDatabase,
-    resolver: &Resolver,
-    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();
-
-    let resolved = resolver.resolve_module_path_in_items(db.upcast(), &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(&self, db: &dyn HirDatabase) -> Option<Resolver>;
-    fn try_into_module_def(self) -> Option<ModuleDef>;
-}
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 03915ea1b..b9d9c7e25 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -27,19 +27,17 @@ pub mod diagnostics;
 
 mod from_id;
 mod code_model;
-mod doc_links;
 mod attrs;
 mod has_source;
 
 pub use crate::{
-    attrs::HasAttrs,
+    attrs::{HasAttrs, Namespace},
     code_model::{
         Access, Adt, AsAssocItem, AssocItem, AssocItemContainer, Callable, CallableKind, Const,
         Crate, CrateDependency, DefWithBody, Enum, EnumVariant, Field, FieldSource, Function,
         GenericDef, HasVisibility, ImplDef, Local, MacroDef, Module, ModuleDef, ScopeDef, Static,
         Struct, Trait, Type, TypeAlias, TypeParam, Union, VariantDef, Visibility,
     },
-    doc_links::resolve_doc_link,
     has_source::HasSource,
     semantics::{original_range, PathResolution, Semantics, SemanticsScope},
 };