normalize use of backticks in compiler messages for librustc_lint

src/librustc_lint/builtin.rs

@@ -591,7 +591,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDebugImplementations {
         if !self.impling_types.as_ref().unwrap().contains(&item.hir_id) {
             cx.span_lint(MISSING_DEBUG_IMPLEMENTATIONS,
                          item.span,
-                         "type does not implement `fmt::Debug`; consider adding #[derive(Debug)] \
+                         "type does not implement `fmt::Debug`; consider adding `#[derive(Debug)]` \
                           or a manual implementation")
         }
     }
@@ -867,7 +867,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidNoMangleItems {
                 if attr::contains_name(&it.attrs, sym::no_mangle) {
                     // Const items do not refer to a particular location in memory, and therefore
                     // don't have anything to attach a symbol to
-                    let msg = "const items should never be #[no_mangle]";
+                    let msg = "const items should never be `#[no_mangle]`";
                     let mut err = cx.struct_span_lint(NO_MANGLE_CONST_ITEMS, it.span, msg);
 
                     // account for "pub const" (#45562)
@@ -1358,7 +1358,7 @@ impl EarlyLintPass for EllipsisInclusiveRangePatterns {
 declare_lint! {
     UNNAMEABLE_TEST_ITEMS,
     Warn,
-    "detects an item that cannot be named being marked as #[test_case]",
+    "detects an item that cannot be named being marked as `#[test_case]`",
     report_in_external_macro: true
 }
 

src/librustc_lint/lib.rs

@@ -481,9 +481,9 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
     store.register_removed("resolve_trait_on_defaulted_unit",
         "converted into hard error, see https://github.com/rust-lang/rust/issues/48950");
     store.register_removed("private_no_mangle_fns",
-        "no longer a warning, #[no_mangle] functions always exported");
+        "no longer a warning, `#[no_mangle]` functions always exported");
     store.register_removed("private_no_mangle_statics",
-        "no longer a warning, #[no_mangle] statics always exported");
+        "no longer a warning, `#[no_mangle]` statics always exported");
     store.register_removed("bad_repr",
         "replaced with a generic attribute input check");
     store.register_removed("duplicate_matcher_binding_name",

src/librustc_lint/unused.rs

@@ -24,7 +24,7 @@ use log::debug;
 declare_lint! {
     pub UNUSED_MUST_USE,
     Warn,
-    "unused result of a type flagged as #[must_use]",
+    "unused result of a type flagged as `#[must_use]`",
     report_in_external_macro: true
 }
 
@@ -316,7 +316,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedAttributes {
 
         let name = attr.name_or_empty();
         if !attr::is_used(attr) {
-            debug!("Emitting warning for: {:?}", attr);
+            debug!("emitting warning for: {:?}", attr);
             cx.span_lint(UNUSED_ATTRIBUTES, attr.span, "unused attribute");
             // Is it a builtin attribute that must be used at the crate level?
             let known_crate = attr_info.map(|&&(_, ty, ..)| {
@@ -332,7 +332,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedAttributes {
                 let msg = match attr.style {
                     ast::AttrStyle::Outer => {
                         "crate-level attribute should be an inner attribute: add an exclamation \
-                         mark: #![foo]"
+                         mark: `#![foo]`"
                     }
                     ast::AttrStyle::Inner => "crate-level attribute should be in the root module",
                 };
@@ -570,9 +570,9 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedAllocation {
             if let adjustment::Adjust::Borrow(adjustment::AutoBorrow::Ref(_, m)) = adj.kind {
                 let msg = match m {
                     adjustment::AutoBorrowMutability::Immutable =>
-                        "unnecessary allocation, use & instead",
+                        "unnecessary allocation, use `&` instead",
                     adjustment::AutoBorrowMutability::Mutable { .. }=>
-                        "unnecessary allocation, use &mut instead"
+                        "unnecessary allocation, use `&mut` instead"
                 };
                 cx.span_lint(UNUSED_ALLOCATION, e.span, msg);
             }

src/test/ui-fulldeps/plugin-attr-register-deny.stderr

@@ -10,7 +10,7 @@ note: lint level defined here
 LL | #![deny(unused_attributes)]
    |         ^^^^^^^^^^^^^^^^^
 
-error: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
+error: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
   --> $DIR/plugin-attr-register-deny.rs:14:5
    |
 LL |     #[bar]