diff --git a/ChangeLog b/ChangeLog
index 9605d767a80..0203aec84ad 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2020-04-20  Martin Liska  <mliska@suse.cz>
+
+	Backport from mainline
+	2020-04-17  Martin Liska  <mliska@suse.cz>
+		    Jonathan Yong <10walls@gmail.com>
+
+	PR gcov-profile/94570
+	* ltmain.sh: Do not define HAVE_DOS_BASED_FILE_SYSTEM
+	for CYGWIN.
+
 2020-03-12  Release Manager
 
 	* GCC 9.3.0 released.
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7df3a0d0990..ff0cc6373fe 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2020-04-20  Martin Liska  <mliska@suse.cz>
+
+	Backport from mainline
+	2020-04-17  Martin Liska  <mliska@suse.cz>
+		    Jonathan Yong <10walls@gmail.com>
+
+	PR gcov-profile/94570
+	* coverage.c (coverage_init): Use separator properly.
+
 2020-04-17  H.J. Lu  <hongjiu.lu@intel.com>
 
 	Backport from master
diff --git a/gcc/coverage.c b/gcc/coverage.c
index 1ffefd5f482..9be446a862d 100644
--- a/gcc/coverage.c
+++ b/gcc/coverage.c
@@ -1201,6 +1201,11 @@ coverage_obj_finish (vec<constructor_elt, va_gc> *ctor)
 void
 coverage_init (const char *filename)
 {
+#if HAVE_DOS_BASED_FILE_SYSTEM
+  const char *separator = "\\";
+#else
+  const char *separator = "/";
+#endif
   int len = strlen (filename);
   int prefix_len = 0;
 
@@ -1217,11 +1222,6 @@ coverage_init (const char *filename)
 	 of filename in order to prevent file path clashing.  */
       if (profile_data_prefix)
 	{
-#if HAVE_DOS_BASED_FILE_SYSTEM
-	  const char *separator = "\\";
-#else
-	  const char *separator = "/";
-#endif
 	  filename = concat (getpwd (), separator, filename, NULL);
 	  filename = mangle_path (filename);
 	  len = strlen (filename);
@@ -1240,7 +1240,7 @@ coverage_init (const char *filename)
   if (profile_data_prefix)
     {
       memcpy (da_file_name, profile_data_prefix, prefix_len);
-      da_file_name[prefix_len++] = '/';
+      da_file_name[prefix_len++] = *separator;
     }
   memcpy (da_file_name + prefix_len, filename, len);
   strcpy (da_file_name + prefix_len + len, GCOV_DATA_SUFFIX);
diff --git a/include/ChangeLog b/include/ChangeLog
index 1811056c182..e8e301dd8e7 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,13 @@
+2020-04-20  Martin Liska  <mliska@suse.cz>
+
+	Backport from mainline
+	2020-04-17  Martin Liska  <mliska@suse.cz>
+		    Jonathan Yong <10walls@gmail.com>
+
+	PR gcov-profile/94570
+	* filenames.h (defined): Do not define HAVE_DOS_BASED_FILE_SYSTEM
+	for CYGWIN.
+
 2020-03-12  Release Manager
 
 	* GCC 9.3.0 released.
diff --git a/include/filenames.h b/include/filenames.h
index 1bcfddb87ac..790a27db873 100644
--- a/include/filenames.h
+++ b/include/filenames.h
@@ -32,7 +32,8 @@ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
 extern "C" {
 #endif
 
-#if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined (__CYGWIN__)
+#if defined(__MSDOS__) || (defined(_WIN32) && ! defined(__CYGWIN__)) || \
+    defined(__OS2__)
 #  ifndef HAVE_DOS_BASED_FILE_SYSTEM
 #    define HAVE_DOS_BASED_FILE_SYSTEM 1
 #  endif
diff --git a/ltmain.sh b/ltmain.sh
index 79f9ba89af5..70990740b6c 100644
--- a/ltmain.sh
+++ b/ltmain.sh
@@ -3425,8 +3425,8 @@ int setenv (const char *, const char *, int);
 # define PATH_SEPARATOR ':'
 #endif
 
-#if defined (_WIN32) || defined (__MSDOS__) || defined (__DJGPP__) || \
-  defined (__OS2__)
+#if (defined (_WIN32) && ! defined(__CYGWIN__)) || defined (__MSDOS__) || \
+  defined (__DJGPP__) || defined (__OS2__)
 # define HAVE_DOS_BASED_FILE_SYSTEM
 # define FOPEN_WB "wb"
 # ifndef DIR_SEPARATOR_2