re PR tree-optimization/64121 (ICE: SSA corruption with -O -fsanitize=undefined)

	PR sanitizer/64121
	* ubsan.c (instrument_object_size): Stop searching if the base
	occurs in abnormal phi.

	* c-c++-common/ubsan/pr64121.c: New test.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r218222

gcc/ChangeLog

 2014-12-01  Marek Polacek  <polacek@redhat.com>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/64121
+	* ubsan.c (instrument_object_size): Stop searching if the base
+	occurs in abnormal phi.
+
+2014-12-01  Marek Polacek  <polacek@redhat.com>
 
 	PR sanitizer/63956
 	* ubsan.c (is_ubsan_builtin_p): Check also built-in class.

gcc/testsuite/ChangeLog

 2014-12-01  Marek Polacek  <polacek@redhat.com>
 
+	PR sanitizer/64121
+	* c-c++-common/ubsan/pr64121.c: New test.
+
+2014-12-01  Marek Polacek  <polacek@redhat.com>
+
 	PR sanitizer/63956
 	* c-c++-common/ubsan/shift-5.c: Add xfails.
 	* g++.dg/ubsan/div-by-zero-1.C: Don't use -w.  Add xfail.

gcc/testsuite/c-c++-common/ubsan/pr64121.c

+/* PR sanitizer/64121 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=undefined -Wno-pointer-arith" } */
+
+extern int tab[16];
+
+void
+execute (int *ip, int x)
+{
+  int *xp = tab;
+base:
+  if (x)
+    return;
+  *xp++ = *ip;
+  goto *(&&base + *ip);
+}

gcc/ubsan.c

@@ -1563,7 +1563,14 @@ instrument_object_size (gimple_stmt_iterator *gsi, bool is_lhs)
 	      && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (def_stmt))))
 	  || (is_gimple_assign (def_stmt)
 	      && gimple_assign_rhs_code (def_stmt) == POINTER_PLUS_EXPR))
-	base = gimple_assign_rhs1 (def_stmt);
+	{
+	  tree rhs1 = gimple_assign_rhs1 (def_stmt);
+	  if (TREE_CODE (rhs1) == SSA_NAME
+	    && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs1))
+	    break;
+	  else
+	    base = rhs1;
+	}
       else
 	break;
     }