diff --git a/compiler/rustc_ast/src/util/literal.rs b/compiler/rustc_ast/src/util/literal.rs
index 536b385606c..8f342175f7d 100644
--- a/compiler/rustc_ast/src/util/literal.rs
+++ b/compiler/rustc_ast/src/util/literal.rs
@@ -2,12 +2,9 @@
 
 use crate::ast::{self, Lit, LitKind};
 use crate::token::{self, Token};
-
-use rustc_lexer::unescape::{unescape_byte, unescape_char};
-use rustc_lexer::unescape::{unescape_byte_literal, unescape_literal, Mode};
+use rustc_lexer::unescape::{byte_from_char, unescape_byte, unescape_char, unescape_literal, Mode};
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
-
 use std::ascii;
 
 pub enum LitError {
@@ -109,13 +106,11 @@ impl LitKind {
                 let s = symbol.as_str();
                 let mut buf = Vec::with_capacity(s.len());
                 let mut error = Ok(());
-                unescape_byte_literal(&s, Mode::ByteStr, &mut |_, unescaped_byte| {
-                    match unescaped_byte {
-                        Ok(c) => buf.push(c),
-                        Err(err) => {
-                            if err.is_fatal() {
-                                error = Err(LitError::LexerError);
-                            }
+                unescape_literal(&s, Mode::ByteStr, &mut |_, c| match c {
+                    Ok(c) => buf.push(byte_from_char(c)),
+                    Err(err) => {
+                        if err.is_fatal() {
+                            error = Err(LitError::LexerError);
                         }
                     }
                 });
@@ -127,13 +122,11 @@ impl LitKind {
                 let bytes = if s.contains('\r') {
                     let mut buf = Vec::with_capacity(s.len());
                     let mut error = Ok(());
-                    unescape_byte_literal(&s, Mode::RawByteStr, &mut |_, unescaped_byte| {
-                        match unescaped_byte {
-                            Ok(c) => buf.push(c),
-                            Err(err) => {
-                                if err.is_fatal() {
-                                    error = Err(LitError::LexerError);
-                                }
+                    unescape_literal(&s, Mode::RawByteStr, &mut |_, c| match c {
+                        Ok(c) => buf.push(byte_from_char(c)),
+                        Err(err) => {
+                            if err.is_fatal() {
+                                error = Err(LitError::LexerError);
                             }
                         }
                     });
diff --git a/compiler/rustc_lexer/src/unescape.rs b/compiler/rustc_lexer/src/unescape.rs
index db7bf02e71a..8d5eac29452 100644
--- a/compiler/rustc_lexer/src/unescape.rs
+++ b/compiler/rustc_lexer/src/unescape.rs
@@ -93,19 +93,6 @@ where
     }
 }
 
-/// Takes a contents of a byte, byte string or raw byte string (without quotes)
-/// and produces a sequence of bytes or errors.
-/// Values are returned through invoking of the provided callback.
-pub fn unescape_byte_literal<F>(src: &str, mode: Mode, callback: &mut F)
-where
-    F: FnMut(Range<usize>, Result<u8, EscapeError>),
-{
-    debug_assert!(mode.is_byte());
-    unescape_literal(src, mode, &mut |range, result| {
-        callback(range, result.map(byte_from_char));
-    })
-}
-
 /// Takes a contents of a char literal (without quotes), and returns an
 /// unescaped char or an error
 pub fn unescape_char(src: &str) -> Result<char, (usize, EscapeError)> {
@@ -351,7 +338,8 @@ where
     }
 }
 
-fn byte_from_char(c: char) -> u8 {
+#[inline]
+pub fn byte_from_char(c: char) -> u8 {
     let res = c as u32;
     debug_assert!(res <= u8::MAX as u32, "guaranteed because of Mode::ByteStr");
     res as u8
diff --git a/compiler/rustc_lexer/src/unescape/tests.rs b/compiler/rustc_lexer/src/unescape/tests.rs
index 008edef5a63..00c8401efdf 100644
--- a/compiler/rustc_lexer/src/unescape/tests.rs
+++ b/compiler/rustc_lexer/src/unescape/tests.rs
@@ -246,10 +246,10 @@ fn test_unescape_byte_good() {
 fn test_unescape_byte_str_good() {
     fn check(literal_text: &str, expected: &[u8]) {
         let mut buf = Ok(Vec::with_capacity(literal_text.len()));
-        unescape_byte_literal(literal_text, Mode::ByteStr, &mut |range, c| {
+        unescape_literal(literal_text, Mode::ByteStr, &mut |range, c| {
             if let Ok(b) = &mut buf {
                 match c {
-                    Ok(c) => b.push(c),
+                    Ok(c) => b.push(byte_from_char(c)),
                     Err(e) => buf = Err((range, e)),
                 }
             }
@@ -280,15 +280,13 @@ fn test_unescape_raw_str() {
 
 #[test]
 fn test_unescape_raw_byte_str() {
-    fn check(literal: &str, expected: &[(Range<usize>, Result<u8, EscapeError>)]) {
+    fn check(literal: &str, expected: &[(Range<usize>, Result<char, EscapeError>)]) {
         let mut unescaped = Vec::with_capacity(literal.len());
-        unescape_byte_literal(literal, Mode::RawByteStr, &mut |range, res| {
-            unescaped.push((range, res))
-        });
+        unescape_literal(literal, Mode::RawByteStr, &mut |range, res| unescaped.push((range, res)));
         assert_eq!(unescaped, expected);
     }
 
     check("\r", &[(0..1, Err(EscapeError::BareCarriageReturnInRawString))]);
     check("🦀", &[(0..4, Err(EscapeError::NonAsciiCharInByte))]);
-    check("🦀a", &[(0..4, Err(EscapeError::NonAsciiCharInByte)), (4..5, Ok(byte_from_char('a')))]);
+    check("🦀a", &[(0..4, Err(EscapeError::NonAsciiCharInByte)), (4..5, Ok('a'))]);
 }
diff --git a/src/tools/rust-analyzer/crates/syntax/src/validation.rs b/src/tools/rust-analyzer/crates/syntax/src/validation.rs
index b9f2b513235..1eea2346451 100644
--- a/src/tools/rust-analyzer/crates/syntax/src/validation.rs
+++ b/src/tools/rust-analyzer/crates/syntax/src/validation.rs
@@ -5,9 +5,7 @@
 mod block;
 
 use rowan::Direction;
-use rustc_lexer::unescape::{
-    self, unescape_byte, unescape_byte_literal, unescape_char, unescape_literal, Mode,
-};
+use rustc_lexer::unescape::{self, unescape_byte, unescape_char, unescape_literal, Mode};
 
 use crate::{
     algo,
@@ -143,7 +141,7 @@ fn validate_literal(literal: ast::Literal, acc: &mut Vec<SyntaxError>) {
         ast::LiteralKind::ByteString(s) => {
             if !s.is_raw() {
                 if let Some(without_quotes) = unquote(text, 2, '"') {
-                    unescape_byte_literal(without_quotes, Mode::ByteStr, &mut |range, char| {
+                    unescape_literal(without_quotes, Mode::ByteStr, &mut |range, char| {
                         if let Err(err) = char {
                             push_err(2, (range.start, err));
                         }