From: Qing Zhao <qing.zhao@oracle.com>
Date: Fri, 1 Dec 2017 18:20:45 +0000 (+0000)
Subject: Fix an undefined behavior in fortran/decl.c
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8a302cb2b3cfc170254cf1d9fdc4dc2a681c15d1;p=gcc.git

Fix an undefined behavior in fortran/decl.c

From-SVN: r255332
---

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index b7f8a5856e4..e5865dc892d 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,8 @@
+2017-12-01  Qing Zhao  <qing.zhao@oracle.com>
+
+	* decl.c (gfc_get_pdt_instance): Adjust the call to sprintf
+	to avoid the same buffer being both source and destination.
+
 2017-12-01  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/83224
diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index 67e1c5bf314..d46083c0a93 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -3362,7 +3362,7 @@ gfc_get_pdt_instance (gfc_actual_arglist *param_list, gfc_symbol **sym,
 	}
 
       gfc_extract_int (kind_expr, &kind_value);
-      sprintf (name, "%s_%d", name, kind_value);
+      sprintf (name + strlen (name), "_%d", kind_value);
 
       if (!name_seen && actual_param)
 	actual_param = actual_param->next;