From d78aecf47261c3bb6b03966db5d1db4564e98b1b Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Thu, 15 Feb 2018 21:47:19 -0500
Subject: [PATCH] PR c++/83227 - C++17 ICE with init-list derived-to-base
 conversion.

	* call.c (convert_like_real): Don't use the copy-list-initialization
	shortcut for ck_base.

From-SVN: r257720
---
 gcc/cp/ChangeLog                        |  4 ++++
 gcc/cp/call.c                           |  9 +++++----
 gcc/testsuite/g++.dg/cpp0x/initlist98.C | 17 +++++++++++++++++
 3 files changed, 26 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/initlist98.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 33746aeb23e..ecd52d04b97 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2018-02-15  Jason Merrill  <jason@redhat.com>
 
+	PR c++/83227 - C++17 ICE with init-list derived-to-base conversion.
+	* call.c (convert_like_real): Don't use the copy-list-initialization
+	shortcut for ck_base.
+
 	PR c++/84045 - ICE with typedef and noexcept.
 	* except.c (build_noexcept_spec): Use strip_typedefs_expr.
 
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 7176e4afa15..5698ff60a4d 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -6938,6 +6938,11 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
 	  && DECL_INHERITED_CTOR (current_function_decl))
 	return expr;
 
+      if (TREE_CODE (expr) == TARGET_EXPR
+	  && TARGET_EXPR_LIST_INIT_P (expr))
+	/* Copy-list-initialization doesn't actually involve a copy.  */
+	return expr;
+
       /* Fall through.  */
     case ck_base:
       if (convs->kind == ck_base && !convs->need_temporary_p)
@@ -6964,10 +6969,6 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
       if (convs->rvaluedness_matches_p)
 	/* standard_conversion got LOOKUP_PREFER_RVALUE.  */
 	flags |= LOOKUP_PREFER_RVALUE;
-      if (TREE_CODE (expr) == TARGET_EXPR
-	  && TARGET_EXPR_LIST_INIT_P (expr))
-	/* Copy-list-initialization doesn't actually involve a copy.  */
-	return expr;
       expr = build_temp (expr, totype, flags, &diag_kind, complain);
       if (diag_kind && complain)
 	{
diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist98.C b/gcc/testsuite/g++.dg/cpp0x/initlist98.C
new file mode 100644
index 00000000000..4f2fcd20219
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist98.C
@@ -0,0 +1,17 @@
+// PR c++/83227
+// { dg-do compile { target c++11 } }
+
+#include <initializer_list>
+
+template <typename d> struct f {
+  f(std::initializer_list<d>) {}
+};
+
+struct h {};
+struct i : h {
+  i();
+};
+void foo(f<h>);
+int main() {
+  foo({i{}});
+}
-- 
2.30.2