From a2444ce97021c7a1e9afe05d014435c4c6933659 Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Mon, 26 Feb 2018 21:45:12 -0500
Subject: [PATCH] PR c++/84441 - ICE with base initialized from ?:

	* call.c (unsafe_copy_elision_p): Handle COND_EXPR.

From-SVN: r258022
---
 gcc/cp/ChangeLog                      |  3 +++
 gcc/cp/call.c                         |  9 +++++++++
 gcc/testsuite/g++.dg/cpp0x/elision3.C | 21 +++++++++++++++++++++
 3 files changed, 33 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/elision3.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index fe5c7864f3a..e34611324c4 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2018-02-26  Jason Merrill  <jason@redhat.com>
 
+	PR c++/84441 - ICE with base initialized from ?:
+	* call.c (unsafe_copy_elision_p): Handle COND_EXPR.
+
 	PR c++/84520 - ICE with generic lambda in NSDMI.
 	* lambda.c (lambda_expr_this_capture): Don't look for fake NSDMI
 	'this' in a generic lambda instantiation.
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index c47befdbf7f..11fe28292fb 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -7580,6 +7580,15 @@ unsafe_copy_elision_p (tree target, tree exp)
   /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR.  */
   while (TREE_CODE (init) == COMPOUND_EXPR)
     init = TREE_OPERAND (init, 1);
+  if (TREE_CODE (init) == COND_EXPR)
+    {
+      /* We'll end up copying from each of the arms of the COND_EXPR directly
+	 into the target, so look at them. */
+      if (tree op = TREE_OPERAND (init, 1))
+	if (unsafe_copy_elision_p (target, op))
+	  return true;
+      return unsafe_copy_elision_p (target, TREE_OPERAND (init, 2));
+    }
   return (TREE_CODE (init) == AGGR_INIT_EXPR
 	  && !AGGR_INIT_VIA_CTOR_P (init));
 }
diff --git a/gcc/testsuite/g++.dg/cpp0x/elision3.C b/gcc/testsuite/g++.dg/cpp0x/elision3.C
new file mode 100644
index 00000000000..7c5c8b9f0b9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/elision3.C
@@ -0,0 +1,21 @@
+// PR c++/84441
+// { dg-do compile { target c++11 } }
+
+struct B {
+  int *b;
+};
+struct A {
+  B b;
+  A (A &&);
+};
+struct C {
+  A c;
+  int d;
+};
+C bar ();
+struct D : C {
+  D ()
+    : C (0 ? bar () : bar ())
+  {}
+};
+D d;
-- 
2.30.2