PR c++/89948 - ICE with break in statement-expr.

	* constexpr.c (cxx_eval_statement_list): Jumping out of a
	statement-expr is non-constant.

From-SVN: r270161

gcc/cp/ChangeLog

 2019-04-04  Jason Merrill  <jason@redhat.com>
 
+	PR c++/89948 - ICE with break in statement-expr.
+	* constexpr.c (cxx_eval_statement_list): Jumping out of a
+	statement-expr is non-constant.
+
+2019-04-04  Jason Merrill  <jason@redhat.com>
+
 	PR c++/89966 - error with non-type auto tparm.
 	* pt.c (do_auto_deduction): Clear tf_partial.
 

gcc/cp/constexpr.c

@@ -4153,6 +4153,15 @@ cxx_eval_statement_list (const constexpr_ctx *ctx, tree t,
       if (returns (jump_target) || breaks (jump_target))
 	break;
     }
+  if (*jump_target && jump_target == &local_target)
+    {
+      /* We aren't communicating the jump to our caller, so give up.  We don't
+	 need to support evaluation of jumps out of statement-exprs.  */
+      if (!ctx->quiet)
+	error_at (cp_expr_loc_or_loc (r, input_location),
+		  "statement is not a constant expression");
+      *non_constant_p = true;
+    }
   return r;
 }
 

gcc/testsuite/g++.dg/ext/stmtexpr23.C

+// PR c++/89948
+// { dg-options "" }
+
+void f ()
+{
+  int a = 0;
+  for (;;)
+    for (;a=+({break;1;});)
+      {}
+}