diff --git a/clang-tools-extra/clang-tidy/modernize/UseConstraintsCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseConstraintsCheck.cpp
--- a/clang-tools-extra/clang-tidy/modernize/UseConstraintsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseConstraintsCheck.cpp
@@ -254,28 +254,6 @@
   return Body->getBeginLoc();
 }
 
-static Token getPreviousToken(SourceLocation &Location, const SourceManager &SM,
-                              const LangOptions &LangOpts,
-                              bool SkipComments = false) {
-  Token Token;
-  Token.setKind(tok::unknown);
-
-  Location = Location.getLocWithOffset(-1);
-  if (Location.isInvalid())
-    return Token;
-
-  auto StartOfFile = SM.getLocForStartOfFile(SM.getFileID(Location));
-  while (Location != StartOfFile) {
-    Location = Lexer::GetBeginningOfToken(Location, SM, LangOpts);
-    if (!Lexer::getRawToken(Location, Token, SM, LangOpts) &&
-        (!SkipComments || !Token.is(tok::comment))) {
-      break;
-    }
-    Location = Location.getLocWithOffset(-1);
-  }
-  return Token;
-}
-
 bool isPrimaryExpression(const Expr *Expression) {
   // This function is an incomplete approximation of checking whether
   // an Expr is a primary expression. In particular, if this function
@@ -300,7 +278,10 @@
   if (PrevTokenLoc.isInvalid())
     return std::nullopt;
 
-  Token PrevToken = getPreviousToken(PrevTokenLoc, SM, LangOpts);
+  const bool SkipComments = false;
+  Token PrevToken;
+  std::tie(PrevToken, PrevTokenLoc) = utils::lexer::getPreviousTokenAndStart(
+      PrevTokenLoc, SM, LangOpts, SkipComments);
   bool EndsWithDoubleSlash =
       PrevToken.is(tok::comment) &&
       Lexer::getSourceText(CharSourceRange::getCharRange(
diff --git a/clang-tools-extra/clang-tidy/utils/LexerUtils.h b/clang-tools-extra/clang-tidy/utils/LexerUtils.h
--- a/clang-tools-extra/clang-tidy/utils/LexerUtils.h
+++ b/clang-tools-extra/clang-tidy/utils/LexerUtils.h
@@ -13,6 +13,7 @@
 #include "clang/Basic/TokenKinds.h"
 #include "clang/Lex/Lexer.h"
 #include <optional>
+#include <utility>
 
 namespace clang {
 
@@ -23,6 +24,9 @@
 /// Returns previous token or ``tok::unknown`` if not found.
 Token getPreviousToken(SourceLocation Location, const SourceManager &SM,
                        const LangOptions &LangOpts, bool SkipComments = true);
+std::pair<Token, SourceLocation>
+getPreviousTokenAndStart(SourceLocation Location, const SourceManager &SM,
+                         const LangOptions &LangOpts, bool SkipComments = true);
 
 SourceLocation findPreviousTokenStart(SourceLocation Start,
                                       const SourceManager &SM,
diff --git a/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp b/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp
--- a/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp
+++ b/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp
@@ -10,17 +10,19 @@
 #include "clang/AST/AST.h"
 #include "clang/Basic/SourceManager.h"
 #include <optional>
+#include <utility>
 
 namespace clang::tidy::utils::lexer {
 
-Token getPreviousToken(SourceLocation Location, const SourceManager &SM,
-                       const LangOptions &LangOpts, bool SkipComments) {
+std::pair<Token, SourceLocation>
+getPreviousTokenAndStart(SourceLocation Location, const SourceManager &SM,
+                         const LangOptions &LangOpts, bool SkipComments) {
   Token Token;
   Token.setKind(tok::unknown);
 
   Location = Location.getLocWithOffset(-1);
   if (Location.isInvalid())
-      return Token;
+    return {Token, Location};
 
   auto StartOfFile = SM.getLocForStartOfFile(SM.getFileID(Location));
   while (Location != StartOfFile) {
@@ -31,6 +33,13 @@
     }
     Location = Location.getLocWithOffset(-1);
   }
+  return {Token, Location};
+}
+
+Token getPreviousToken(SourceLocation Location, const SourceManager &SM,
+                       const LangOptions &LangOpts, bool SkipComments) {
+  auto [Token, Start] =
+      getPreviousTokenAndStart(Location, SM, LangOpts, SkipComments);
   return Token;
 }