From 9a453da5cac7b6610cd342a7bea256acba5e61e1 Mon Sep 17 00:00:00 2001
From: Patrick Palka <ppalka@redhat.com>
Date: Thu, 23 Apr 2020 17:26:46 -0400
Subject: [PATCH] c++: zero_init_expr_p of dependent expression

This fixes an ICE coming from mangle.c:write_expression when building the
testsuite of range-v3; the added testcase is a reduced reproducer for the ICE.

gcc/cp/ChangeLog:

	* tree.c (zero_init_expr_p): Use uses_template_parms instead of
	dependent_type_p.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/dependent3.C: New test.
---
 gcc/cp/ChangeLog                        |  3 +++
 gcc/cp/tree.c                           |  2 +-
 gcc/testsuite/ChangeLog                 |  2 ++
 gcc/testsuite/g++.dg/cpp0x/dependent3.C | 28 +++++++++++++++++++++++++
 4 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/dependent3.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 6506f288e05..043e6aaddf4 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2020-04-23  Patrick Palka  <ppalka@redhat.com>
 
+	* tree.c (zero_init_expr_p): Use uses_template_parms instead of
+	dependent_type_p.
+
 	PR c++/94645
 	* pt.c (template_class_depth): Walk into the DECL_FRIEND_CONTEXT of a
 	friend declaration rather than into its CP_DECL_CONTEXT.
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 090c565c093..8840932dba2 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -4486,7 +4486,7 @@ bool
 zero_init_expr_p (tree t)
 {
   tree type = TREE_TYPE (t);
-  if (!type || dependent_type_p (type))
+  if (!type || uses_template_parms (type))
     return false;
   if (zero_init_p (type))
     return initializer_zerop (t);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e0df5bc0a99..7c6fc644332 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,7 @@
 2020-04-23  Patrick Palka  <ppalka@redhat.com>
 
+	* g++.dg/cpp0x/dependent3.C: New test.
+
 	PR c++/94645
 	* g++.dg/cpp2a/concepts-lambda6.C: New test.
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/dependent3.C b/gcc/testsuite/g++.dg/cpp0x/dependent3.C
new file mode 100644
index 00000000000..caf7e1cd4a4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/dependent3.C
@@ -0,0 +1,28 @@
+// { dg-do compile { target c++11 } }
+
+template<typename c>
+struct d
+{
+  using e = c;
+};
+
+template<class f>
+struct g
+{
+  using h = typename d<f>::e;
+
+  template<class i, class j>
+  auto operator()(i, j k) -> decltype(h{k});
+};
+
+template<class l>
+void m()
+{
+  int a[1];
+  l{}(a, a);
+}
+
+int main()
+{
+  m<g<int *>>();
+}
-- 
2.30.2