Consistently use 'supertrait'.

A subset of places referred to 'super-trait', so this changes them
to all use 'supertrait'. This matches 'supertype' and some other
usages. An exception is 'auto-trait' which is consistently used
in that manner.

Author: waywardmonkeys

compiler/rustc_driver/src/pretty.rs

@@ -88,7 +88,7 @@ trait PrinterSupport: pprust::PpAnn {
     /// Produces the pretty-print annotation object.
     ///
     /// (Rust does not yet support upcasting from a trait object to
-    /// an object for one of its super-traits.)
+    /// an object for one of its supertraits.)
     fn pp_ann(&self) -> &dyn pprust::PpAnn;
 }
 
@@ -104,7 +104,7 @@ trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
     /// Produces the pretty-print annotation object.
     ///
     /// (Rust does not yet support upcasting from a trait object to
-    /// an object for one of its super-traits.)
+    /// an object for one of its supertraits.)
     fn pp_ann(&self) -> &dyn pprust_hir::PpAnn;
 }
 

compiler/rustc_error_codes/src/error_codes/E0222.md

@@ -16,9 +16,9 @@ pub trait BoxCar : Box + Vehicle {}
 fn dent_object<COLOR>(c: dyn BoxCar<Color=COLOR>) {} // Invalid constraint
 ```
 
-In this example, `BoxCar` has two super-traits: `Vehicle` and `Box`. Both of
+In this example, `BoxCar` has two supertraits: `Vehicle` and `Box`. Both of
 these traits define an associated type `Color`. `BoxCar` inherits two types
-with that name from both super-traits. Because of this, we need to use the
+with that name from both supertraits. Because of this, we need to use the
 fully qualified path syntax to refer to the appropriate `Color` associated
 type, either `<BoxCar as Vehicle>::Color` or `<BoxCar as Box>::Color`, but this
 syntax is not allowed to be used in a function signature.

compiler/rustc_middle/src/ty/context.rs

@@ -2117,7 +2117,7 @@ impl<'tcx> TyCtxt<'tcx> {
         })
     }
 
-    /// Computes the def-ids of the transitive super-traits of `trait_def_id`. This (intentionally)
+    /// Computes the def-ids of the transitive supertraits of `trait_def_id`. This (intentionally)
     /// does not compute the full elaborated super-predicates but just the set of def-ids. It is used
     /// to identify which traits may define a given associated type to help avoid cycle errors.
     /// Returns a `DefId` iterator.

compiler/rustc_middle/src/ty/mod.rs

@@ -599,7 +599,7 @@ impl<'tcx> Predicate<'tcx> {
         //   where both `'x` and `'b` would have a DB index of 1.
         //   The substitution from the input trait-ref is therefore going to be
         //   `'a => 'x` (where `'x` has a DB index of 1).
-        // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
+        // - The supertrait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
         //   early-bound parameter and `'b' is a late-bound parameter with a
         //   DB index of 1.
         // - If we replace `'a` with `'x` from the input, it too will have

compiler/rustc_save_analysis/src/dump_visitor.rs

@@ -682,7 +682,7 @@ impl<'tcx> DumpVisitor<'tcx> {
             );
         }
 
-        // super-traits
+        // supertraits
         for super_bound in trait_refs.iter() {
             let (def_id, sub_span) = match *super_bound {
                 hir::GenericBound::Trait(ref trait_ref, _) => (

compiler/rustc_typeck/src/astconv/errors.rs

@@ -199,7 +199,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
     /// When there are any missing associated types, emit an E0191 error and attempt to supply a
     /// reasonable suggestion on how to write it. For the case of multiple associated types in the
-    /// same trait bound have the same name (as they come from different super-traits), we instead
+    /// same trait bound have the same name (as they come from different supertraits), we instead
     /// emit a generic note suggesting using a `where` clause to constraint instead.
     pub(crate) fn complain_about_missing_associated_types(
         &self,
@@ -340,7 +340,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                          using the fully-qualified path to the associated types";
         if !where_constraints.is_empty() && suggestions.is_empty() {
             // If there are duplicates associated type names and a single trait bound do not
-            // use structured suggestion, it means that there are multiple super-traits with
+            // use structured suggestion, it means that there are multiple supertraits with
             // the same associated type name.
             err.help(where_msg);
         }

compiler/rustc_typeck/src/astconv/mod.rs

@@ -1322,7 +1322,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             );
             first_trait.label_with_exp_info(&mut err, "first non-auto trait", "first use");
             err.help(&format!(
-                "consider creating a new trait with all of these as super-traits and using that \
+                "consider creating a new trait with all of these as supertraits and using that \
                  trait here instead: `trait NewTrait: {} {{}}`",
                 regular_traits
                     .iter()

compiler/rustc_typeck/src/check/method/probe.rs

@@ -964,7 +964,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         let trait_ref = ty::TraitRef::new(trait_def_id, trait_substs);
 
         if self.tcx.is_trait_alias(trait_def_id) {
-            // For trait aliases, assume all super-traits are relevant.
+            // For trait aliases, assume all supertraits are relevant.
             let bounds = iter::once(ty::Binder::dummy(trait_ref));
             self.elaborate_bounds(bounds, |this, new_trait_ref, item| {
                 let new_trait_ref = this.erase_late_bound_regions(new_trait_ref);