remove build warnings

Code blocks that are not annotated are assumed to be Rust

3 files changed, 5 insertions, 3 deletions

diff --git a/src/librustc_parse/parser/diagnostics.rs b/src/librustc_parse/parser/diagnostics.rs
index 552f3d798ae..da6d863f239 100644
--- a/src/librustc_parse/parser/diagnostics.rs
+++ b/src/librustc_parse/parser/diagnostics.rs
@@ -579,11 +579,13 @@ impl<'a> Parser<'a> {
     /// Keep in mind that given that `outer_op.is_comparison()` holds and comparison ops are left
     /// associative we can infer that we have:
     ///
+    /// ```text
     ///           outer_op
     ///           /   \
     ///     inner_op   r2
     ///        /  \
     ///      l1    r1
+    /// ```
     pub(super) fn check_no_chained_comparison(
         &mut self,
         inner_op: &Expr,
diff --git a/src/librustc_parse/parser/generics.rs b/src/librustc_parse/parser/generics.rs
index 3442c5081c1..f4729e306f8 100644
--- a/src/librustc_parse/parser/generics.rs
+++ b/src/librustc_parse/parser/generics.rs
@@ -8,7 +8,7 @@ use rustc_span::symbol::{kw, sym};
 impl<'a> Parser<'a> {
     /// Parses bounds of a lifetime parameter `BOUND + BOUND + BOUND`, possibly with trailing `+`.
     ///
-    /// ```
+    /// ```text
     /// BOUND = LT_BOUND (e.g., `'a`)
     /// ```
     fn parse_lt_param_bounds(&mut self) -> GenericBounds {
diff --git a/src/librustc_parse/parser/item.rs b/src/librustc_parse/parser/item.rs
index 798eb85f36f..ae8a20f209b 100644
--- a/src/librustc_parse/parser/item.rs
+++ b/src/librustc_parse/parser/item.rs
@@ -743,7 +743,7 @@ impl<'a> Parser<'a> {
 
     /// Parses a `UseTree`.
     ///
-    /// ```
+    /// ```text
     /// USE_TREE = [`::`] `*` |
     ///            [`::`] `{` USE_TREE_LIST `}` |
     ///            PATH `::` `*` |
@@ -792,7 +792,7 @@ impl<'a> Parser<'a> {
 
     /// Parses a `UseTreeKind::Nested(list)`.
     ///
-    /// ```
+    /// ```text
     /// USE_TREE_LIST = Ø | (USE_TREE `,`)* USE_TREE [`,`]
     /// ```
     fn parse_use_tree_list(&mut self) -> PResult<'a, Vec<(UseTree, ast::NodeId)>> {