diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -450,6 +450,7 @@
 def : DiagGroup<"inline">;
 def : DiagGroup<"invalid-pch">;
 def GNULabelsAsValue : DiagGroup<"gnu-label-as-value">;
+def GNULineMarker : DiagGroup<"gnu-line-marker">;
 def LiteralRange : DiagGroup<"literal-range">;
 def LocalTypeTemplateArgs : DiagGroup<"local-type-template-args",
                                       [CXX98CompatLocalTypeTemplateArgs]>;
diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td
--- a/clang/include/clang/Basic/DiagnosticLexKinds.td
+++ b/clang/include/clang/Basic/DiagnosticLexKinds.td
@@ -428,7 +428,8 @@
   "variadic macros are a Clang extension in OpenCL">;
 
 def ext_pp_gnu_line_directive : Extension<
-  "this style of line directive is a GNU extension">;
+  "this style of line directive is a GNU extension">,
+  InGroup<GNULineMarker>;
 
 def err_pp_invalid_directive : Error<"invalid preprocessing directive">;
 def err_pp_directive_required : Error<
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1346,9 +1346,14 @@
     IsFileEntry = true;
 
     PP.Lex(FlagTok);
-    if (FlagTok.is(tok::eod)) return false;
+    if (FlagTok.is(tok::eod)) {
+      PP.Diag(FlagTok, diag::ext_pp_gnu_line_directive);
+      return false;
+    }
     if (GetLineValue(FlagTok, FlagVal, diag::err_pp_linemarker_invalid_flag,PP))
       return true;
+
+    PP.Diag(FlagTok, diag::ext_pp_gnu_line_directive);
   } else if (FlagVal == 2) {
     IsFileExit = true;
 
diff --git a/clang/test/Misc/warning-flags.c b/clang/test/Misc/warning-flags.c
--- a/clang/test/Misc/warning-flags.c
+++ b/clang/test/Misc/warning-flags.c
@@ -90,4 +90,4 @@
 
 The list of warnings in -Wpedantic should NEVER grow.
 
-CHECK: Number in -Wpedantic (not covered by other -W flags): 28
+CHECK: Number in -Wpedantic (not covered by other -W flags): 27
diff --git a/clang/test/Preprocessor/line-directive.c b/clang/test/Preprocessor/line-directive.c
--- a/clang/test/Preprocessor/line-directive.c
+++ b/clang/test/Preprocessor/line-directive.c
@@ -9,7 +9,7 @@
 # 20 "" 2
 
 // a push/pop before any other line control
-# 10 "enter-0" 1
+# 10 "enter-0" 1 // expected-warning {{this style of line directive is a GNU extension}}
 # 11 "" 2 // pop to main file
 #error MAIN7
 // expected-error@-1{{MAIN7}}
@@ -30,7 +30,7 @@
 # 42 // expected-warning {{this style of line directive is a GNU extension}}
 # 42 "foo" // expected-warning {{this style of line directive is a GNU extension}}
 # 42 "foo" 2 // expected-error {{invalid line marker flag '2': cannot pop empty include stack}}
-# 42 "foo" 1 3  // enter
+# 42 "foo" 1 3  // enter expected-warning {{this style of line directive is a GNU extension}}
 # 42 "foo" 2 3  // exit
 # 42 "foo" 2 3 4 // expected-error {{invalid line marker flag '2': cannot pop empty include stack}}
 # 42 "foo" 3 4
@@ -116,8 +116,8 @@
 undefined t; // expected-error {{unknown type name 'undefined'}}
 
 # 115 "main" // expected-warning {{this style of line directive is a GNU extension}}
-# 116 "enter-1" 1
-# 117 "enter-2" 1
+# 116 "enter-1" 1 // expected-warning {{this style of line directive is a GNU extension}}
+# 117 "enter-2" 1 // expected-warning {{this style of line directive is a GNU extension}}
 # 118 "" 2 // pop to enter-1
 #error ENTER1
 // expected-error@-1{{ENTER1}}