Fix compiler docs

compiler/rustc_hir_analysis/src/check/check.rs

@@ -707,10 +707,12 @@ pub(super) fn check_opaque_for_cycles<'tcx>(
 /// check those cases in the `param_env` of that function, which may have
 /// bounds not on this opaque type:
 ///
-/// type X<T> = impl Clone
+/// ```ignore (illustrative)
+/// type X<T> = impl Clone;
 /// fn f<T: Clone>(t: T) -> X<T> {
 ///     t
 /// }
+/// ```
 ///
 /// Without this check the above code is incorrectly accepted: we would ICE if
 /// some tried, for example, to clone an `Option<X<&mut ()>>`.

compiler/rustc_hir_analysis/src/constrained_generic_params.rs

@@ -114,9 +114,9 @@ pub fn identify_constrained_generic_params<'tcx>(
 /// ```
 /// The impl's predicates are collected from left to right. Ignoring
 /// the implicit `Sized` bounds, these are
-///   * T: Debug
+///   * `T: Debug`
-///   * U: Iterator
+///   * `U: Iterator`
-///   * <U as Iterator>::Item = T -- a desugared ProjectionPredicate
+///   * `<U as Iterator>::Item = T` -- a desugared ProjectionPredicate
 ///
 /// When we, for example, try to go over the trait-reference
 /// `IntoIter<u32> as Trait`, we substitute the impl parameters with fresh
@@ -132,12 +132,16 @@ pub fn identify_constrained_generic_params<'tcx>(
 ///
 /// We *do* have to be somewhat careful when projection targets contain
 /// projections themselves, for example in
+///
+/// ```ignore (illustrative)
 ///     impl<S,U,V,W> Trait for U where
 /// /* 0 */   S: Iterator<Item = U>,
 /// /* - */   U: Iterator,
 /// /* 1 */   <U as Iterator>::Item: ToOwned<Owned=(W,<V as Iterator>::Item)>
 /// /* 2 */   W: Iterator<Item = V>
 /// /* 3 */   V: Debug
+/// ```
+///
 /// we have to evaluate the projections in the order I wrote them:
 /// `V: Debug` requires `V` to be evaluated. The only projection that
 /// *determines* `V` is 2 (1 contains it, but *does not determine it*,

compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs

@@ -130,8 +130,10 @@ fn check_always_applicable(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node
 ///
 /// Example
 ///
+/// ```ignore (illustrative)
 /// impl<A, B> Foo<A> for B { /* impl2 */ }
 /// impl<C> Foo<Vec<C>> for C { /* impl1 */ }
+/// ```
 ///
 /// Would return `S1 = [C]` and `S2 = [Vec<C>, C]`.
 fn get_impl_substs<'tcx>(
@@ -225,13 +227,17 @@ fn unconstrained_parent_impl_substs<'tcx>(
 ///
 /// For example forbid the following:
 ///
+/// ```ignore (illustrative)
 /// impl<A> Tr for A { }
 /// impl<B> Tr for (B, B) { }
+/// ```
 ///
 /// Note that only consider the unconstrained parameters of the base impl:
 ///
+/// ```ignore (illustrative)
 /// impl<S, I: IntoIterator<Item = S>> Tr<S> for I { }
 /// impl<T> Tr<T> for Vec<T> { }
+/// ```
 ///
 /// The substs for the parent impl here are `[T, Vec<T>]`, which repeats `T`,
 /// but `S` is constrained in the parent impl, so `parent_substs` is only
@@ -256,8 +262,10 @@ fn check_duplicate_params<'tcx>(
 ///
 /// For example forbid the following:
 ///
+/// ```ignore (illustrative)
 /// impl<A> Tr for A { }
 /// impl Tr for &'static i32 { }
+/// ```
 fn check_static_lifetimes<'tcx>(
     tcx: TyCtxt<'tcx>,
     parent_substs: &Vec<GenericArg<'tcx>>,

compiler/rustc_hir_analysis/src/mem_categorization.rs

@@ -184,7 +184,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
     ///   modes #42640) may look like `Some(x)` but in fact have
     ///   implicit deref patterns attached (e.g., it is really
     ///   `&Some(x)`). In that case, we return the "outermost" type
-    ///   (e.g., `&Option<T>).
+    ///   (e.g., `&Option<T>`).
     pub(crate) fn pat_ty_adjusted(&self, pat: &hir::Pat<'_>) -> McResult<Ty<'tcx>> {
         // Check for implicit `&` types wrapping the pattern; note
         // that these are never attached to binding patterns, so

compiler/rustc_middle/src/thir.rs

@@ -203,7 +203,7 @@ pub enum StmtKind<'tcx> {
         /// `let pat: ty = <INIT>`
         initializer: Option<ExprId>,
 
-        /// `let pat: ty = <INIT> else { <ELSE> }
+        /// `let pat: ty = <INIT> else { <ELSE> }`
         else_block: Option<BlockId>,
 
         /// The lint level for this `let` statement.

compiler/rustc_middle/src/ty/adt.rs

@@ -332,13 +332,13 @@ impl<'tcx> AdtDef<'tcx> {
         self.flags().contains(AdtFlags::IS_PHANTOM_DATA)
     }
 
-    /// Returns `true` if this is Box<T>.
+    /// Returns `true` if this is `Box<T>`.
     #[inline]
     pub fn is_box(self) -> bool {
         self.flags().contains(AdtFlags::IS_BOX)
     }
 
-    /// Returns `true` if this is UnsafeCell<T>.
+    /// Returns `true` if this is `UnsafeCell<T>`.
     #[inline]
     pub fn is_unsafe_cell(self) -> bool {
         self.flags().contains(AdtFlags::IS_UNSAFE_CELL)

compiler/rustc_parse/src/lib.rs

@@ -39,7 +39,8 @@ mod errors;
 // uses a HOF to parse anything, and <source> includes file and
 // `source_str`.
 
-/// A variant of 'panictry!' that works on a Vec<Diagnostic> instead of a single DiagnosticBuilder.
+/// A variant of 'panictry!' that works on a `Vec<Diagnostic>` instead of a single
+/// `DiagnosticBuilder`.
 macro_rules! panictry_buffer {
     ($handler:expr, $e:expr) => {{
         use rustc_errors::FatalError;

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -66,13 +66,13 @@ impl<'tcx> AutoTraitFinder<'tcx> {
     /// struct Foo<T> { data: Box<T> }
     /// ```
     ///
-    /// then this might return that Foo<T>: Send if T: Send (encoded in the AutoTraitResult type).
+    /// then this might return that `Foo<T>: Send` if `T: Send` (encoded in the AutoTraitResult
-    /// The analysis attempts to account for custom impls as well as other complex cases. This
+    /// type). The analysis attempts to account for custom impls as well as other complex cases.
-    /// result is intended for use by rustdoc and other such consumers.
+    /// This result is intended for use by rustdoc and other such consumers.
     ///
     /// (Note that due to the coinductive nature of Send, the full and correct result is actually
     /// quite simple to generate. That is, when a type has no custom impl, it is Send iff its field
-    /// types are all Send. So, in our example, we might have that Foo<T>: Send if Box<T>: Send.
+    /// types are all Send. So, in our example, we might have that `Foo<T>: Send` if `Box<T>: Send`.
     /// But this is often not the best way to present to the user.)
     ///
     /// Warning: The API should be considered highly unstable, and it may be refactored or removed

compiler/rustc_trait_selection/src/traits/project.rs

@@ -62,7 +62,8 @@ enum ProjectionCandidate<'tcx> {
     /// From a where-clause in the env or object type
     ParamEnv(ty::PolyProjectionPredicate<'tcx>),
 
-    /// From the definition of `Trait` when you have something like <<A as Trait>::B as Trait2>::C
+    /// From the definition of `Trait` when you have something like
+    /// `<<A as Trait>::B as Trait2>::C`.
     TraitDef(ty::PolyProjectionPredicate<'tcx>),
 
     /// Bounds specified on an object type
@@ -1367,7 +1368,7 @@ fn assemble_candidates_from_param_env<'cx, 'tcx>(
     );
 }
 
-/// In the case of a nested projection like <<A as Foo>::FooT as Bar>::BarT, we may find
+/// In the case of a nested projection like `<<A as Foo>::FooT as Bar>::BarT`, we may find
 /// that the definition of `Foo` has some clues:
 ///
 /// ```ignore (illustrative)

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -826,7 +826,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     /// must be met of course). One obvious case this comes up is
     /// marker traits like `Send`. Think of a linked list:
     ///
-    ///    struct List<T> { data: T, next: Option<Box<List<T>>> }
+    ///     struct List<T> { data: T, next: Option<Box<List<T>>> }
     ///
     /// `Box<List<T>>` will be `Send` if `T` is `Send` and
     /// `Option<Box<List<T>>>` is `Send`, and in turn