The members of an explicit specialization of a class template don't have the
template parameters of that class template, so we shouldn't try to provide
arguments for them. Only set outer_args when the class is an instantiation.
Tested x86_64-pc-linux-gnu, applying to trunk.
* pt.c (do_class_deduction): Don't include explicit specialization
args in outer_args.
---
gcc/cp/pt.c | 2 +-
gcc/testsuite/g++.dg/cpp1z/class-deduction63.C | 11 +++++++++++
gcc/cp/ChangeLog | 4 ++++
3 files changed, 16 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1z/class-deduction63.C
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 76fb625a068..42dd095a6b0 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -27224,7 +27224,7 @@ do_class_deduction (tree ptype, tree tmpl, tree init,
int flags,
tree outer_args = NULL_TREE;
if (DECL_CLASS_SCOPE_P (tmpl)
- && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (tmpl)))
+ && CLASSTYPE_TEMPLATE_INSTANTIATION (DECL_CONTEXT (tmpl)))
{
outer_args = CLASSTYPE_TI_ARGS (DECL_CONTEXT (tmpl));
type = TREE_TYPE (most_general_template (tmpl));
diff --git a/gcc/testsuite/g++.dg/cpp1z/class-deduction63.C
b/gcc/testsuite/g++.dg/cpp1z/class-deduction63.C
new file mode 100644
index 00000000000..4fc66fcbe15
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/class-deduction63.C
@@ -0,0 +1,11 @@
+// PR c++/88869
+// { dg-do compile { target c++17 } }
+
+template <typename> struct B;
+template <> struct B<int> {
+ template <typename T> struct C {
+ T e;
+ C (T f) : e(f) {}
+ };
+ void foo () { C c (42); }
+};
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 2f99f2b95c8..013bca59380 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
2019-02-21 Jason Merrill <[email protected]>
+ PR c++/88869 - C++17 ICE with CTAD and explicit specialization.
+ * pt.c (do_class_deduction): Don't include explicit specialization
+ args in outer_args.
+
PR c++/89422 - ICE with -g and lambda in default arg in template.
* pt.c (tsubst_function_decl): SET_DECL_FRIEND_CONTEXT sooner.
base-commit: b6700c1afdd5e39fe9e886578f8404dc53390f74
--
2.20.1
