Index: gcc/include/filenames.h
===================================================================
--- gcc.orig/include/filenames.h	2011-02-28 19:16:35.000000000 +0100
+++ gcc/include/filenames.h	2011-03-08 11:11:10.909109700 +0100
@@ -75,6 +75,8 @@ extern int filename_cmp (const char *s1,
 
 extern int filename_ncmp (const char *s1, const char *s2,
 			  size_t n);
+extern char *filename_dirchr (const char *p);
+extern char *filename_dirrchr (const char *p);
 
 #ifdef __cplusplus
 }
Index: gcc/libiberty/filename_cmp.c
===================================================================
--- gcc.orig/libiberty/filename_cmp.c	2011-02-28 19:16:35.000000000 +0100
+++ gcc/libiberty/filename_cmp.c	2011-03-08 11:43:32.797198100 +0100
@@ -125,3 +125,70 @@ filename_ncmp (const char *s1, const cha
   return 0;
 #endif
 }
+
+/*
+
+@deftypefn Extension int filename_dirchr (const char *@var{p})
+
+The returned value is similar to what @code{strchr} would return for
+searching for a directory separator.
+
+This function does not normalize file name.  However, it does handle
+the fact that on DOS-like file systems, forward and backward slashes
+are directory separators.
+
+@end deftypefn
+
+*/
+
+char *
+filename_dirchr (const char *p)
+{
+  char *r;
+#ifdef HAVE_DOS_BASED_FILE_SYSTEM
+  char *r2;
+#endif
+  if (!p)
+    return NULL;
+  r = strchr (p, '/');
+#ifdef HAVE_DOS_BASED_FILE_SYSTEM
+  r2 = strchr (p, '\\');
+  if (!r || (r2 && r2 < r))
+    r = r2;
+#endif
+  return r;
+}
+
+/*
+
+@deftypefn Extension int filename_dirrchr (const char *@var{p})
+
+The returned value is similar to what @code{strrchr} would return for
+searching for a directory separator.
+
+This function does not normalize file name.  However, it does handle
+the fact that on DOS-like file systems, forward and backward slashes
+are directory separators.
+
+@end deftypefn
+
+*/
+
+char *
+filename_dirrchr (const char *p)
+{
+  char *r;
+#ifdef HAVE_DOS_BASED_FILE_SYSTEM
+  char *r2;
+#endif
+
+  if (!p)
+    return NULL;
+  r = strrchr (p, '/');
+#ifdef HAVE_DOS_BASED_FILE_SYSTEM
+  r2 = strrchr (p, '\\');
+  if (!r || (r2 && r2 > r))
+    r = r2;
+#endif
+  return r;
+}
Index: gcc/libiberty/functions.texi
===================================================================
--- gcc.orig/libiberty/functions.texi	2011-02-28 19:16:35.000000000 +0100
+++ gcc/libiberty/functions.texi	2011-03-08 11:43:42.314406700 +0100
@@ -296,6 +296,30 @@ and backward slashes are equal.
 
 @end deftypefn
 
+@c filename_cmp.c:131
+@deftypefn Extension int filename_dirchr (const char *@var{p})
+
+The returned value is similar to what @code{strchr} would return for
+searching for a directory separator.
+
+This function does not normalize file name.  However, it does handle
+the fact that on DOS-like file systems, forward and backward slashes
+are directory separators.
+
+@end deftypefn
+
+@c filename_cmp.c:164
+@deftypefn Extension int filename_dirrchr (const char *@var{p})
+
+The returned value is similar to what @code{strrchr} would return for
+searching for a directory separator.
+
+This function does not normalize file name.  However, it does handle
+the fact that on DOS-like file systems, forward and backward slashes
+are directory separators.
+
+@end deftypefn
+
 @c filename_cmp.c:81
 @deftypefn Extension int filename_ncmp (const char *@var{s1}, const char *@var{s2}, size_t @var{n})