--- a/gcc/config/linux.h	Thu Oct 25 07:37:49 2018 +0900
+++ b/gcc/config/linux.h	Thu Feb 13 11:34:05 2020 +0900
@@ -2,7 +2,7 @@
    MMU, using ELF at the compiler level but possibly FLT for final
    linked executables and shared libraries in some no-MMU cases, and
    possibly with a choice of libc implementations.
-   Copyright (C) 1995-2018 Free Software Foundation, Inc.
+   Copyright (C) 1995-2020 Free Software Foundation, Inc.
    Contributed by Eric Youngdale.
    Modified for stabs-in-ELF by H.J. Lu (hjl@lucon.org).
 
@@ -53,6 +53,19 @@
 	builtin_assert ("system=posix");			\
     } while (0)
 
+#define GNU_USER_TARGET_D_OS_VERSIONS()				\
+    do {							\
+	builtin_version ("linux");				\
+	if (OPTION_GLIBC)					\
+	  builtin_version ("CRuntime_Glibc");			\
+	else if (OPTION_UCLIBC)					\
+	  builtin_version ("CRuntime_UClibc");			\
+	else if (OPTION_BIONIC)					\
+	  builtin_version ("CRuntime_Bionic");			\
+	else if (OPTION_MUSL)					\
+	  builtin_version ("CRuntime_Musl");			\
+    } while (0)
+
 /* Determine which dynamic linker to use depending on whether GLIBC or
    uClibc or Bionic or musl is the default C library and whether
    -muclibc or -mglibc or -mbionic or -mmusl has been passed to change