Fix intra-doc links for inherent impls that are both lang items and not the default impl

Cargo.lock

@@ -4106,6 +4106,7 @@ dependencies = [
  "rustc-rayon",
  "serde",
  "serde_json",
+ "smallvec 1.4.2",
  "tempfile",
 ]
 

src/librustdoc/Cargo.toml

@@ -14,5 +14,6 @@ minifier = "0.0.33"
 rayon = { version = "0.3.0", package = "rustc-rayon" }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+smallvec = "1.0"
 tempfile = "3"
 itertools = "0.8"

src/librustdoc/clean/types.rs

@@ -3,6 +3,7 @@ use std::default::Default;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::iter::FromIterator;
+use std::lazy::SyncOnceCell as OnceCell;
 use std::num::NonZeroU32;
 use std::rc::Rc;
 use std::sync::Arc;
@@ -19,12 +20,14 @@ use rustc_hir::lang_items;
 use rustc_hir::Mutability;
 use rustc_index::vec::IndexVec;
 use rustc_middle::middle::stability;
+use rustc_middle::ty::TyCtxt;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::source_map::DUMMY_SP;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{self, FileName};
 use rustc_target::abi::VariantIdx;
 use rustc_target::spec::abi::Abi;
+use smallvec::{smallvec, SmallVec};
 
 use crate::clean::cfg::Cfg;
 use crate::clean::external_path;
@@ -1264,6 +1267,86 @@ impl PrimitiveType {
         }
     }
 
+    pub fn impls(&self, tcx: TyCtxt<'_>) -> &'static SmallVec<[DefId; 4]> {
+        Self::all_impls(tcx).get(self).expect("missing impl for primitive type")
+    }
+
+    pub fn all_impls(tcx: TyCtxt<'_>) -> &'static FxHashMap<PrimitiveType, SmallVec<[DefId; 4]>> {
+        static CELL: OnceCell<FxHashMap<PrimitiveType, SmallVec<[DefId; 4]>>> = OnceCell::new();
+
+        CELL.get_or_init(move || {
+            use self::PrimitiveType::*;
+
+            /// A macro to create a FxHashMap.
+            ///
+            /// Example:
+            ///
+            /// ```
+            /// let letters = map!{"a" => "b", "c" => "d"};
+            /// ```
+            ///
+            /// Trailing commas are allowed.
+            /// Commas between elements are required (even if the expression is a block).
+            macro_rules! map {
+                ($( $key: expr => $val: expr ),* $(,)*) => {{
+                    let mut map = ::rustc_data_structures::fx::FxHashMap::default();
+                    $( map.insert($key, $val); )*
+                    map
+                }}
+            }
+
+            let single = |a: Option<DefId>| a.into_iter().collect();
+            let both = |a: Option<DefId>, b: Option<DefId>| -> SmallVec<_> {
+                a.into_iter().chain(b).collect()
+            };
+
+            let lang_items = tcx.lang_items();
+            map! {
+                Isize => single(lang_items.isize_impl()),
+                I8 => single(lang_items.i8_impl()),
+                I16 => single(lang_items.i16_impl()),
+                I32 => single(lang_items.i32_impl()),
+                I64 => single(lang_items.i64_impl()),
+                I128 => single(lang_items.i128_impl()),
+                Usize => single(lang_items.usize_impl()),
+                U8 => single(lang_items.u8_impl()),
+                U16 => single(lang_items.u16_impl()),
+                U32 => single(lang_items.u32_impl()),
+                U64 => single(lang_items.u64_impl()),
+                U128 => single(lang_items.u128_impl()),
+                F32 => both(lang_items.f32_impl(), lang_items.f32_runtime_impl()),
+                F64 => both(lang_items.f64_impl(), lang_items.f64_runtime_impl()),
+                Char => single(lang_items.char_impl()),
+                Bool => single(lang_items.bool_impl()),
+                Str => both(lang_items.str_impl(), lang_items.str_alloc_impl()),
+                Slice => {
+                    lang_items
+                        .slice_impl()
+                        .into_iter()
+                        .chain(lang_items.slice_u8_impl())
+                        .chain(lang_items.slice_alloc_impl())
+                        .chain(lang_items.slice_u8_alloc_impl())
+                        .collect()
+                },
+                Array => single(lang_items.array_impl()),
+                Tuple => smallvec![],
+                Unit => smallvec![],
+                RawPointer => {
+                    lang_items
+                        .const_ptr_impl()
+                        .into_iter()
+                        .chain(lang_items.mut_ptr_impl())
+                        .chain(lang_items.const_slice_ptr_impl())
+                        .chain(lang_items.mut_slice_ptr_impl())
+                        .collect()
+                },
+                Reference => smallvec![],
+                Fn => smallvec![],
+                Never => smallvec![],
+            }
+        })
+    }
+
     pub fn to_url_str(&self) -> &'static str {
         self.as_str()
     }

src/librustdoc/clean/utils.rs

@@ -351,7 +351,6 @@ pub fn qpath_to_string(p: &hir::QPath<'_>) -> String {
 }
 
 pub fn build_deref_target_impls(cx: &DocContext<'_>, items: &[Item], ret: &mut Vec<Item>) {
-    use self::PrimitiveType::*;
     let tcx = cx.tcx;
 
     for item in items {
@@ -370,34 +369,7 @@ pub fn build_deref_target_impls(cx: &DocContext<'_>, items: &[Item], ret: &mut V
                 None => continue,
             },
         };
-        let did = match primitive {
-            Isize => tcx.lang_items().isize_impl(),
-            I8 => tcx.lang_items().i8_impl(),
-            I16 => tcx.lang_items().i16_impl(),
-            I32 => tcx.lang_items().i32_impl(),
-            I64 => tcx.lang_items().i64_impl(),
-            I128 => tcx.lang_items().i128_impl(),
-            Usize => tcx.lang_items().usize_impl(),
-            U8 => tcx.lang_items().u8_impl(),
-            U16 => tcx.lang_items().u16_impl(),
-            U32 => tcx.lang_items().u32_impl(),
-            U64 => tcx.lang_items().u64_impl(),
-            U128 => tcx.lang_items().u128_impl(),
-            F32 => tcx.lang_items().f32_impl(),
-            F64 => tcx.lang_items().f64_impl(),
-            Char => tcx.lang_items().char_impl(),
-            Bool => tcx.lang_items().bool_impl(),
-            Str => tcx.lang_items().str_impl(),
-            Slice => tcx.lang_items().slice_impl(),
-            Array => tcx.lang_items().array_impl(),
-            Tuple => None,
-            Unit => None,
-            RawPointer => tcx.lang_items().const_ptr_impl(),
-            Reference => None,
-            Fn => None,
-            Never => None,
-        };
-        if let Some(did) = did {
+        for &did in primitive.impls(tcx) {
             if !did.is_local() {
                 inline::build_impl(cx, did, None, ret);
             }

src/librustdoc/lib.rs

@@ -12,6 +12,7 @@
 #![feature(ptr_offset_from)]
 #![feature(crate_visibility_modifier)]
 #![feature(never_type)]
+#![feature(once_cell)]
 #![recursion_limit = "256"]
 
 #[macro_use]

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -16,6 +16,7 @@ use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::Ident;
 use rustc_span::symbol::Symbol;
 use rustc_span::DUMMY_SP;
+use smallvec::SmallVec;
 
 use std::cell::Cell;
 use std::ops::Range;
@@ -270,18 +271,26 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
                 .ok_or(ErrorKind::ResolutionFailure)?;
 
             if let Some((path, prim)) = is_primitive(&path, TypeNS) {
-                let did = primitive_impl(cx, &path).ok_or(ErrorKind::ResolutionFailure)?;
-                return cx
-                    .tcx
-                    .associated_items(did)
-                    .filter_by_name_unhygienic(item_name)
-                    .next()
-                    .and_then(|item| match item.kind {
-                        ty::AssocKind::Fn => Some("method"),
-                        _ => None,
-                    })
-                    .map(|out| (prim, Some(format!("{}#{}.{}", path, out, item_name))))
-                    .ok_or(ErrorKind::ResolutionFailure);
+                for &impl_ in primitive_impl(cx, &path).ok_or(ErrorKind::ResolutionFailure)? {
+                    let link = cx
+                        .tcx
+                        .associated_items(impl_)
+                        .find_by_name_and_namespace(
+                            cx.tcx,
+                            Ident::with_dummy_span(item_name),
+                            ns,
+                            impl_,
+                        )
+                        .and_then(|item| match item.kind {
+                            ty::AssocKind::Fn => Some("method"),
+                            _ => None,
+                        })
+                        .map(|out| (prim, Some(format!("{}#{}.{}", path, out, item_name))));
+                    if let Some(link) = link {
+                        return Ok(link);
+                    }
+                }
+                return Err(ErrorKind::ResolutionFailure);
             }
 
             let (_, ty_res) = cx
@@ -1238,26 +1247,6 @@ fn is_primitive(path_str: &str, ns: Namespace) -> Option<(&'static str, Res)> {
     }
 }
 
-fn primitive_impl(cx: &DocContext<'_>, path_str: &str) -> Option<DefId> {
-    let tcx = cx.tcx;
-    match path_str {
-        "u8" => tcx.lang_items().u8_impl(),
-        "u16" => tcx.lang_items().u16_impl(),
-        "u32" => tcx.lang_items().u32_impl(),
-        "u64" => tcx.lang_items().u64_impl(),
-        "u128" => tcx.lang_items().u128_impl(),
-        "usize" => tcx.lang_items().usize_impl(),
-        "i8" => tcx.lang_items().i8_impl(),
-        "i16" => tcx.lang_items().i16_impl(),
-        "i32" => tcx.lang_items().i32_impl(),
-        "i64" => tcx.lang_items().i64_impl(),
-        "i128" => tcx.lang_items().i128_impl(),
-        "isize" => tcx.lang_items().isize_impl(),
-        "f32" => tcx.lang_items().f32_impl(),
-        "f64" => tcx.lang_items().f64_impl(),
-        "str" => tcx.lang_items().str_impl(),
-        "bool" => tcx.lang_items().bool_impl(),
-        "char" => tcx.lang_items().char_impl(),
-        _ => None,
-    }
+fn primitive_impl(cx: &DocContext<'_>, path_str: &str) -> Option<&'static SmallVec<[DefId; 4]>> {
+    Some(PrimitiveType::from_symbol(Symbol::intern(path_str))?.impls(cx.tcx))
 }

src/librustdoc/passes/collect_trait_impls.rs

@@ -34,40 +34,7 @@ pub fn collect_trait_impls(krate: Crate, cx: &DocContext<'_>) -> Crate {
     }
 
     // Also try to inline primitive impls from other crates.
-    let lang_items = cx.tcx.lang_items();
-    let primitive_impls = [
-        lang_items.isize_impl(),
-        lang_items.i8_impl(),
-        lang_items.i16_impl(),
-        lang_items.i32_impl(),
-        lang_items.i64_impl(),
-        lang_items.i128_impl(),
-        lang_items.usize_impl(),
-        lang_items.u8_impl(),
-        lang_items.u16_impl(),
-        lang_items.u32_impl(),
-        lang_items.u64_impl(),
-        lang_items.u128_impl(),
-        lang_items.f32_impl(),
-        lang_items.f64_impl(),
-        lang_items.f32_runtime_impl(),
-        lang_items.f64_runtime_impl(),
-        lang_items.bool_impl(),
-        lang_items.char_impl(),
-        lang_items.str_impl(),
-        lang_items.array_impl(),
-        lang_items.slice_impl(),
-        lang_items.slice_u8_impl(),
-        lang_items.str_alloc_impl(),
-        lang_items.slice_alloc_impl(),
-        lang_items.slice_u8_alloc_impl(),
-        lang_items.const_ptr_impl(),
-        lang_items.mut_ptr_impl(),
-        lang_items.const_slice_ptr_impl(),
-        lang_items.mut_slice_ptr_impl(),
-    ];
-
-    for def_id in primitive_impls.iter().filter_map(|&def_id| def_id) {
+    for &def_id in PrimitiveType::all_impls(cx.tcx).values().flatten() {
         if !def_id.is_local() {
             inline::build_impl(cx, def_id, None, &mut new_items);
 

src/test/rustdoc/intra-link-primitive-non-default-impl.rs

@@ -0,0 +1,32 @@
+#![deny(broken_intra_doc_links)]
+
+// ignore-tidy-linelength
+
+// @has intra_link_primitive_non_default_impl/fn.str_methods.html
+/// [`str::trim`]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.str.html#method.trim"]' 'str::trim'
+/// [`str::to_lowercase`]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.str.html#method.to_lowercase"]' 'str::to_lowercase'
+/// [`str::into_boxed_bytes`]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.str.html#method.into_boxed_bytes"]' 'str::into_boxed_bytes'
+/// [`str::replace`]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.str.html#method.replace"]' 'str::replace'
+pub fn str_methods() {}
+
+// @has intra_link_primitive_non_default_impl/fn.f32_methods.html
+/// [f32::powi]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.f32.html#method.powi"]' 'f32::powi'
+/// [f32::sqrt]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.f32.html#method.sqrt"]' 'f32::sqrt'
+/// [f32::mul_add]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.f32.html#method.mul_add"]' 'f32::mul_add'
+pub fn f32_methods() {}
+
+// @has intra_link_primitive_non_default_impl/fn.f64_methods.html
+/// [`f64::powi`]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.f64.html#method.powi"]' 'f64::powi'
+/// [`f64::sqrt`]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.f64.html#method.sqrt"]' 'f64::sqrt'
+/// [`f64::mul_add`]
+// @has - '//*[@href="https://doc.rust-lang.org/nightly/std/primitive.f64.html#method.mul_add"]' 'f64::mul_add'
+pub fn f64_methods() {}