re PR c++/83734 (ice in cxx_eval _statement_list, at cp/constexpr.c:3869)

	PR c++/83734
	* constexpr.c (cxx_eval_statement_list): Ignore DEBUG_BEGIN_STMTs
	in STATEMENT_LIST.  Remove unneeded assert.

	* g++.dg/cpp0x/pr83734.C: New test.

From-SVN: r256397

gcc/cp/ChangeLog

+2018-01-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/83734
+	* constexpr.c (cxx_eval_statement_list): Ignore DEBUG_BEGIN_STMTs
+	in STATEMENT_LIST.  Remove unneeded assert.
+
 2018-01-03  Richard Sandiford  <richard.sandiford@linaro.org>
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>

gcc/cp/constexpr.c

@@ -3851,6 +3851,8 @@ cxx_eval_statement_list (const constexpr_ctx *ctx, tree t,
   for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
     {
       tree stmt = tsi_stmt (i);
+      if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT)
+	continue;
       r = cxx_eval_constant_expression (ctx, stmt, false,
 					non_constant_p, overflow_p,
 					jump_target);
@@ -3859,14 +3861,6 @@ cxx_eval_statement_list (const constexpr_ctx *ctx, tree t,
       if (returns (jump_target) || breaks (jump_target))
 	break;
     }
-  /* Make sure we don't use the "result" of a debug-only marker.  That
-     would be wrong.  We should be using the result of the previous
-     statement, or NULL if there isn't one.  In practice, this should
-     never happen: the statement after the marker should override the
-     result of the marker, so its value shouldn't survive in R.  Now,
-     should that ever change, we'll need some fixing here to stop
-     markers from modifying the generated executable code.  */
-  gcc_checking_assert (!r || TREE_CODE (r) != DEBUG_BEGIN_STMT);
   return r;
 }
 

gcc/testsuite/ChangeLog

+2018-01-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/83734
+	* g++.dg/cpp0x/pr83734.C: New test.
+
 2017-01-09 Carl Love  <cel@us.ibm.com>
 
 	* gcc.target/powerpc/builtins-1.c (main): Add tests for vec_mergee and

gcc/testsuite/g++.dg/cpp0x/pr83734.C

+// PR c++/83734
+// { dg-do compile { target c++11 } }
+// { dg-options "-g -O2" }
+
+struct A { constexpr A () { typedef int T; } };
+A a;