Auto merge of #80119 - GuillaumeGomez:str-to-symbol, r=jyn514

Continue String to Symbol conversion in rustdoc

Follow-up of https://github.com/rust-lang/rust/pull/80091.

This PR is already big enough so I'll stop here before the next one.

r? `@jyn514`

src/librustdoc/clean/auto_trait.rs

@@ -61,10 +61,10 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                             .params
                             .iter()
                             .filter_map(|param| match param.kind {
-                                ty::GenericParamDefKind::Lifetime => Some(param.name.to_string()),
+                                ty::GenericParamDefKind::Lifetime => Some(param.name),
                                 _ => None,
                             })
-                            .map(|name| (name.clone(), Lifetime(name)))
+                            .map(|name| (name, Lifetime(name)))
                             .collect();
                         let lifetime_predicates = self.handle_lifetimes(&region_data, &names_map);
                         let new_generics = self.param_env_to_generics(
@@ -145,21 +145,21 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
     fn get_lifetime(
         &self,
         region: Region<'_>,
-        names_map: &FxHashMap<String, Lifetime>,
+        names_map: &FxHashMap<Symbol, Lifetime>,
     ) -> Lifetime {
         self.region_name(region)
             .map(|name| {
                 names_map.get(&name).unwrap_or_else(|| {
-                    panic!("Missing lifetime with name {:?} for {:?}", name, region)
+                    panic!("Missing lifetime with name {:?} for {:?}", name.as_str(), region)
                 })
             })
             .unwrap_or(&Lifetime::statik())
             .clone()
     }
 
-    fn region_name(&self, region: Region<'_>) -> Option<String> {
+    fn region_name(&self, region: Region<'_>) -> Option<Symbol> {
         match region {
-            &ty::ReEarlyBound(r) => Some(r.name.to_string()),
+            &ty::ReEarlyBound(r) => Some(r.name),
             _ => None,
         }
     }
@@ -177,7 +177,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
     fn handle_lifetimes<'cx>(
         &self,
         regions: &RegionConstraintData<'cx>,
-        names_map: &FxHashMap<String, Lifetime>,
+        names_map: &FxHashMap<Symbol, Lifetime>,
     ) -> Vec<WherePredicate> {
         // Our goal is to 'flatten' the list of constraints by eliminating
         // all intermediate RegionVids. At the end, all constraints should

src/librustdoc/clean/inline.rs

@@ -486,13 +486,13 @@ fn build_module(cx: &DocContext<'_>, did: DefId, visited: &mut FxHashSet<DefId>)
                         const_stability: None,
                         deprecation: None,
                         kind: clean::ImportItem(clean::Import::new_simple(
-                            item.ident.to_string(),
+                            item.ident.name,
                             clean::ImportSource {
                                 path: clean::Path {
                                     global: false,
                                     res: item.res,
                                     segments: vec![clean::PathSegment {
-                                        name: clean::PrimitiveType::from(p).as_str().to_string(),
+                                        name: clean::PrimitiveType::from(p).as_sym(),
                                         args: clean::GenericArgs::AngleBracketed {
                                             args: Vec::new(),
                                             bindings: Vec::new(),
@@ -562,11 +562,11 @@ fn build_macro(cx: &DocContext<'_>, did: DefId, name: Symbol) -> clean::ItemKind
                     .collect::<String>()
             );
 
-            clean::MacroItem(clean::Macro { source, imported_from: Some(imported_from).clean(cx) })
+            clean::MacroItem(clean::Macro { source, imported_from: Some(imported_from) })
         }
         LoadedMacro::ProcMacro(ext) => clean::ProcMacroItem(clean::ProcMacro {
             kind: ext.macro_kind(),
-            helpers: ext.helper_attrs.clean(cx),
+            helpers: ext.helper_attrs,
         }),
     }
 }

src/librustdoc/clean/mod.rs

@@ -379,7 +379,7 @@ impl Clean<Lifetime> for hir::Lifetime {
             }
             _ => {}
         }
-        Lifetime(self.name.ident().to_string())
+        Lifetime(self.name.ident().name)
     }
 }
 
@@ -397,9 +397,9 @@ impl Clean<Lifetime> for hir::GenericParam<'_> {
                     for bound in bounds {
                         s.push_str(&format!(" + {}", bound.name.ident()));
                     }
-                    Lifetime(s)
+                    Lifetime(Symbol::intern(&s))
                 } else {
-                    Lifetime(self.name.ident().to_string())
+                    Lifetime(self.name.ident().name)
                 }
             }
             _ => panic!(),
@@ -423,16 +423,16 @@ impl Clean<Constant> for hir::ConstArg {
 
 impl Clean<Lifetime> for ty::GenericParamDef {
     fn clean(&self, _cx: &DocContext<'_>) -> Lifetime {
-        Lifetime(self.name.to_string())
+        Lifetime(self.name)
     }
 }
 
 impl Clean<Option<Lifetime>> for ty::RegionKind {
-    fn clean(&self, cx: &DocContext<'_>) -> Option<Lifetime> {
+    fn clean(&self, _cx: &DocContext<'_>) -> Option<Lifetime> {
         match *self {
             ty::ReStatic => Some(Lifetime::statik()),
-            ty::ReLateBound(_, ty::BrNamed(_, name)) => Some(Lifetime(name.to_string())),
-            ty::ReEarlyBound(ref data) => Some(Lifetime(data.name.clean(cx))),
+            ty::ReLateBound(_, ty::BrNamed(_, name)) => Some(Lifetime(name)),
+            ty::ReEarlyBound(ref data) => Some(Lifetime(data.name)),
 
             ty::ReLateBound(..)
             | ty::ReFree(..)
@@ -897,7 +897,7 @@ fn clean_fn_or_proc_macro(
                     }
                 }
             }
-            ProcMacroItem(ProcMacro { kind, helpers: helpers.clean(cx) })
+            ProcMacroItem(ProcMacro { kind, helpers })
         }
         None => {
             let mut func = (sig, generics, body_id).clean(cx);
@@ -1914,7 +1914,7 @@ impl Clean<GenericArgs> for hir::GenericArgs<'_> {
 
 impl Clean<PathSegment> for hir::PathSegment<'_> {
     fn clean(&self, cx: &DocContext<'_>) -> PathSegment {
-        PathSegment { name: self.ident.name.clean(cx), args: self.generic_args().clean(cx) }
+        PathSegment { name: self.ident.name, args: self.generic_args().clean(cx) }
     }
 }
 
@@ -2132,7 +2132,6 @@ fn clean_extern_crate(
             return items;
         }
     }
-    let path = orig_name.map(|x| x.to_string());
     // FIXME: using `from_def_id_and_kind` breaks `rustdoc/masked` for some reason
     vec![Item {
         name: None,
@@ -2143,7 +2142,7 @@ fn clean_extern_crate(
         stability: None,
         const_stability: None,
         deprecation: None,
-        kind: ExternCrateItem(name.clean(cx), path),
+        kind: ExternCrateItem(name, orig_name),
     }]
 }
 
@@ -2215,7 +2214,7 @@ impl Clean<Vec<Item>> for doctree::Import<'_> {
                         const_stability: None,
                         deprecation: None,
                         kind: ImportItem(Import::new_simple(
-                            self.name.clean(cx),
+                            self.name,
                             resolve_use_source(cx, path),
                             false,
                         )),
@@ -2223,7 +2222,7 @@ impl Clean<Vec<Item>> for doctree::Import<'_> {
                     return items;
                 }
             }
-            Import::new_simple(name.clean(cx), resolve_use_source(cx, path), true)
+            Import::new_simple(name, resolve_use_source(cx, path), true)
         };
 
         vec![Item {

src/librustdoc/clean/types.rs

@@ -295,7 +295,7 @@ impl Item {
 
 #[derive(Clone, Debug)]
 crate enum ItemKind {
-    ExternCrateItem(String, Option<String>),
+    ExternCrateItem(Symbol, Option<Symbol>),
     ImportItem(Import),
     StructItem(Struct),
     UnionItem(Union),
@@ -877,21 +877,19 @@ impl GenericBound {
 }
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
-crate struct Lifetime(pub String);
+crate struct Lifetime(pub Symbol);
 
 impl Lifetime {
-    crate fn get_ref<'a>(&'a self) -> &'a str {
-        let Lifetime(ref s) = *self;
-        let s: &'a str = s;
-        s
+    crate fn get_ref(&self) -> SymbolStr {
+        self.0.as_str()
     }
 
     crate fn statik() -> Lifetime {
-        Lifetime("'static".to_string())
+        Lifetime(kw::StaticLifetime)
     }
 
     crate fn elided() -> Lifetime {
-        Lifetime("'_".to_string())
+        Lifetime(kw::UnderscoreLifetime)
     }
 }
 
@@ -1675,13 +1673,17 @@ crate struct Path {
 }
 
 impl Path {
-    crate fn last_name(&self) -> &str {
+    crate fn last(&self) -> Symbol {
+        self.segments.last().expect("segments were empty").name
+    }
+
+    crate fn last_name(&self) -> SymbolStr {
         self.segments.last().expect("segments were empty").name.as_str()
     }
 
     crate fn whole_name(&self) -> String {
         String::from(if self.global { "::" } else { "" })
-            + &self.segments.iter().map(|s| s.name.clone()).collect::<Vec<_>>().join("::")
+            + &self.segments.iter().map(|s| s.name.to_string()).collect::<Vec<_>>().join("::")
     }
 }
 
@@ -1700,7 +1702,7 @@ crate enum GenericArgs {
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
 crate struct PathSegment {
-    crate name: String,
+    crate name: Symbol,
     crate args: GenericArgs,
 }
 
@@ -1777,7 +1779,7 @@ crate struct Import {
 }
 
 impl Import {
-    crate fn new_simple(name: String, source: ImportSource, should_be_displayed: bool) -> Self {
+    crate fn new_simple(name: Symbol, source: ImportSource, should_be_displayed: bool) -> Self {
         Self { kind: ImportKind::Simple(name), source, should_be_displayed }
     }
 
@@ -1789,7 +1791,7 @@ impl Import {
 #[derive(Clone, Debug)]
 crate enum ImportKind {
     // use source as str;
-    Simple(String),
+    Simple(Symbol),
     // use source::*;
     Glob,
 }
@@ -1803,13 +1805,13 @@ crate struct ImportSource {
 #[derive(Clone, Debug)]
 crate struct Macro {
     crate source: String,
-    crate imported_from: Option<String>,
+    crate imported_from: Option<Symbol>,
 }
 
 #[derive(Clone, Debug)]
 crate struct ProcMacro {
     crate kind: MacroKind,
-    crate helpers: Vec<String>,
+    crate helpers: Vec<Symbol>,
 }
 
 /// An type binding on an associated type (e.g., `A = Bar` in `Foo<A = Bar>` or

src/librustdoc/clean/utils.rs

@@ -153,7 +153,7 @@ pub(super) fn external_path(
         global: false,
         res: Res::Err,
         segments: vec![PathSegment {
-            name: name.to_string(),
+            name,
             args: external_generic_args(cx, trait_did, has_self, bindings, substs),
         }],
     }