re PR sanitizer/70342 (g++ -fsanitize=undefined never finishes compiling (>24h)…

re PR sanitizer/70342 (g++ -fsanitize=undefined never finishes compiling (>24h) in qtxmlpatterns test suite)

	PR sanitizer/70342
	* fold-const.c (tree_single_nonzero_warnv_p): For TARGET_EXPR, use
	TARGET_EXPR_SLOT as a base.

	* g++.dg/ubsan/null-7.C: New test.

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

From-SVN: r235637

gcc/ChangeLog

+2016-04-29  Marek Polacek  <polacek@redhat.com>
+	    Jakub Jelinek  <jakub@redhat.com>
+
+	PR sanitizer/70342
+	* fold-const.c (tree_single_nonzero_warnv_p): For TARGET_EXPR, use
+	TARGET_EXPR_SLOT as a base.
+
 2016-04-29  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* config/arc/arc.md (*loadqi_update): Replace use of 'rI'

gcc/fold-const.c

@@ -13534,6 +13534,9 @@ tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
 	if (!DECL_P (base))
 	  base = get_base_address (base);
 
+	if (base && TREE_CODE (base) == TARGET_EXPR)
+	  base = TARGET_EXPR_SLOT (base);
+
 	if (!base)
 	  return false;
 

gcc/testsuite/ChangeLog

+2016-04-29  Marek Polacek  <polacek@redhat.com>
+
+	PR sanitizer/70342
+	* g++.dg/ubsan/null-7.C: New test.
+
 2016-04-29  Dominik Vogt  <vogt@linux.vnet.ibm.com>
 
 	PR/69089

gcc/testsuite/g++.dg/ubsan/null-7.C

+// PR sanitizer/70342
+// { dg-do compile }
+// { dg-options "-fsanitize=null" }
+
+class A {};
+class B {
+public:
+  B(A);
+};
+class C {
+public:
+  C operator<<(B);
+};
+class D {
+  D(const int &);
+  C m_blackList;
+};
+D::D(const int &) {
+  m_blackList << A() << A() << A() << A() << A() << A() << A() << A() << A()
+              << A() << A() << A() << A() << A() << A() << A() << A() << A()
+              << A() << A() << A() << A() << A() << A() << A() << A() << A()
+              << A() << A() << A() << A() << A() << A() << A() << A() << A()
+              << A() << A() << A() << A() << A() << A() << A() << A() << A();
+}