[_LIBC] (start_of_data): Use weak ref to __data_start; use &etext if not

present.

diff --git a/src/mem-limits.h b/src/mem-limits.h
index e814de10f0d8ab817d3a39a9a9a51958ece1e71d..c63e0b4839900907761df5cf7a3e7af4fc27ec48 100644 (file)
--- a/src/mem-limits.h
+++ b/src/mem-limits.h
@@ -29,8 +29,9 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #include <sys/resource.h>
 #define BSD4_2                 /* Tell code below to use getrlimit.  */
 
-extern int __data_start;
-#define start_of_data()        &__data_start
+/* Old Linux startup code won't define __data_start.  */
+extern int __data_start; weak_symbol (__data_start)
+#define start_of_data()        (&__data_start ?: &etext)
 
 #else /* not _LIBC */
 
@@ -88,7 +89,7 @@ extern char etext;
 #endif
 #endif
 
-#else  /* not emacs */ 
+#else  /* not emacs */
 extern char etext;
 #define start_of_data() &etext
 #endif /* not emacs */