Index: clang-tools-extra/clangd/Diagnostics.cpp
===================================================================
--- clang-tools-extra/clangd/Diagnostics.cpp
+++ clang-tools-extra/clangd/Diagnostics.cpp
@@ -18,6 +18,7 @@
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Lex/Lexer.h"
+#include "clang/Lex/Token.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
@@ -102,12 +103,18 @@
     if (R.getBegin() == R.getEnd() && Loc == R.getBegin())
       FallbackRange = halfOpenToRange(M, R);
   }
-  if (FallbackRange)
-    return *FallbackRange;
-  // If no suitable range is found, just use the token at the location.
-  auto R = Lexer::makeFileCharRange(CharSourceRange::getTokenRange(Loc), M, L);
-  if (!R.isValid()) // Fall back to location only, let the editor deal with it.
-    R = CharSourceRange::getCharRange(Loc);
+  // If we can't get the token at the location, fall back to using the location
+  // and let the editor deal with it.
+  auto R = CharSourceRange::getCharRange(Loc);
+  Token Tok;
+  if(!Lexer::getRawToken(Loc, Tok, M, L, true)) {
+    bool IsTokenComment = Tok.isNot(tok::comment);
+    // If the token at the location is a comment, just use the location.
+    // Otherwise use the token.
+    if (!IsTokenComment && FallbackRange)
+      return *FallbackRange;
+    else R = CharSourceRange::getTokenRange(Tok.getLocation(), Tok.getEndLoc());
+  }
   return halfOpenToRange(M, R);
 }
 
Index: clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
+++ clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
@@ -101,6 +101,7 @@
   Annotations Test(R"cpp(
     namespace test{};
     void $decl[[foo]]();
+    class T{$explicit[[]]$constructor[[T]](int a);};
     int main() {
       $typo[[go\
 o]]();
@@ -112,8 +113,10 @@
       test::$nomembernamespace[[test]];
     }
   )cpp");
+  auto TU = TestTU::withCode(Test.code());
+  TU.ClangTidyChecks = "-*,google-explicit-constructor";
   EXPECT_THAT(
-      TestTU::withCode(Test.code()).build().getDiagnostics(),
+      TU.build().getDiagnostics(),
       ElementsAre(
           // This range spans lines.
           AllOf(Diag(Test.range("typo"),
@@ -135,7 +138,13 @@
                "of type 'const char [4]'"),
           Diag(Test.range("nomember"), "no member named 'y' in 'Foo'"),
           Diag(Test.range("nomembernamespace"),
-               "no member named 'test' in namespace 'test'")));
+               "no member named 'test' in namespace 'test'"),
+          // We make sure here that the entire token is highlighted
+          AllOf(Diag(Test.range("constructor"),
+                     "single-argument constructors must be marked explicit to "
+                     "avoid unintentional implicit conversions"),
+                WithFix(Fix(Test.range("explicit"), "explicit ",
+                            "insert 'explicit '")))));
 }
 
 TEST(DiagnosticsTest, FlagsMatter) {