diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3974808c07..29ffa1e962 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2019-08-06  Tom Tromey  <tom@tromey.com>
+
+	* gdb_obstack.h (obstack_strdup): Define.
+	* gdb_obstack.c (obstack_strdup): Don't define.
+
 2019-08-06  Tom Tromey  <tom@tromey.com>
 
 	* xcoffread.c (SYMNAME_ALLOC, process_xcoff_symbol): Use
diff --git a/gdb/gdb_obstack.c b/gdb/gdb_obstack.c
index 0bf4abb82f..01257120d0 100644
--- a/gdb/gdb_obstack.c
+++ b/gdb/gdb_obstack.c
@@ -45,13 +45,3 @@ obconcat (struct obstack *obstackp, ...)
 
   return (char *) obstack_finish (obstackp);
 }
-
-/* See gdb_obstack.h.  */
-
-char *
-obstack_strdup (struct obstack *obstackp, const char *string)
-{
-  char *obstring = (char *) obstack_alloc (obstackp, strlen (string) + 1);
-  strcpy (obstring, string);
-  return obstring;
-}
diff --git a/gdb/gdb_obstack.h b/gdb/gdb_obstack.h
index 143fcf7179..829e2f959c 100644
--- a/gdb/gdb_obstack.h
+++ b/gdb/gdb_obstack.h
@@ -89,7 +89,11 @@ extern char *obconcat (struct obstack *obstackp, ...) ATTRIBUTE_SENTINEL;
 /* Duplicate STRING, returning an equivalent string that's allocated on the
    obstack OBSTACKP.  */
 
-extern char *obstack_strdup (struct obstack *obstackp, const char *string);
+static inline char *
+obstack_strdup (struct obstack *obstackp, const char *string)
+{
+  return (char *) obstack_copy0 (obstackp, string, strlen (string));
+}
 
 /* An obstack that frees itself on scope exit.  */
 struct auto_obstack : obstack