re PR gcov-profile/58602 (.gcno files not truncated at gcov_close)

	PR gcov-profile/58602
        * gcc/gcov-io.c (gcov_open): Open with truncation when mode<0

From-SVN: r207441

gcc/ChangeLog

+2014-02-03  Laurent Aflonsi  <laurent.alfonsi@st.com>
+
+	PR gcov-profile/58602
+	* gcc/gcov-io.c (gcov_open): Open with truncation when mode<0
+
 2014-02-03  Jan Hubicka  <hubicka@ucw.cz>
 
 	PR ipa/59831

gcc/gcov-io.c

@@ -149,9 +149,15 @@ gcov_open (const char *name, int mode)
       /* pass mode (ignored) for compatibility */
       fd = open (name, O_RDONLY, S_IRUSR | S_IWUSR);
     }
-  else
+  else if (mode < 0)
+     {
+       /* Write mode - acquire a write-lock.  */
+       s_flock.l_type = F_WRLCK;
+      fd = open (name, O_RDWR | O_CREAT | O_TRUNC, 0666);
+    }
+  else /* mode == 0 */
     {
-      /* Write mode - acquire a write-lock.  */
+      /* Read-Write mode - acquire a write-lock.  */
       s_flock.l_type = F_WRLCK;
       fd = open (name, O_RDWR | O_CREAT, 0666);
     }