[C++ PATCH] PR c++/87513 - 'sorry' mangling PMF template-id.

[Jason Merrill]

Here build_offset_ref calls build_qualified_name to make a SCOPE_REF because
the dependent template arguments make type_dependent_expression_p (member)
true.  We could probably work hard to prevent this, but it doesn't seem
necessary, and it's easy to fix write_expression to handle the result.

Tested x86_64-pc-linux-gnu, applying to trunk.

	* mangle.c (write_expression): Handle SCOPE_REF to BASELINK.
---
 gcc/cp/mangle.c                            | 3 ++-
 gcc/testsuite/g++.dg/cpp0x/decltype-tid1.C | 9 +++++++++
 gcc/cp/ChangeLog                           | 5 +++++
 3 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/decltype-tid1.C

diff --git a/gcc/cp/mangle.c b/gcc/cp/mangle.c
index f550b7550db..777c4775bfd 100644
--- a/gcc/cp/mangle.c
+++ b/gcc/cp/mangle.c
@@ -3003,7 +3003,8 @@ write_expression (tree expr)
 	{
 	  scope = TREE_OPERAND (expr, 0);
 	  member = TREE_OPERAND (expr, 1);
-	  gcc_assert (!BASELINK_P (member));
+	  if (BASELINK_P (member))
+	    member = BASELINK_FUNCTIONS (member);
 	}
       else
 	{
diff --git a/gcc/testsuite/g++.dg/cpp0x/decltype-tid1.C b/gcc/testsuite/g++.dg/cpp0x/decltype-tid1.C
new file mode 100644
index 00000000000..03285022087
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/decltype-tid1.C
@@ -0,0 +1,9 @@
+// PR c++/87513
+// { dg-do compile { target c++11 } }
+
+struct A { template <long> void foo (); };
+template <long t> auto bar () -> decltype (&A::foo<t>);
+void foo ()
+{
+  bar<0> ();
+}
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 02e0845f1d7..dc0d4a20814 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2019-02-19  Jason Merrill  <jason@redhat.com>
+
+	PR c++/87513 - 'sorry' mangling PMF template-id.
+	* mangle.c (write_expression): Handle SCOPE_REF to BASELINK.
+
 2019-02-19  Jason Merrill  <jason@redhat.com>
 
 	PR c++/88380 - wrong-code with flexible array and NSDMI.

base-commit: 7102567e1ab9828e12b6c5fdc2cd3432c6a7aed5
-- 
2.20.1