c++: consteval-defarg1.C test variant for templates

We weren't recognizing a default argument for a consteval member function as
being in immediate function context because there was no function parameter
scope to look at.

The following testcase is an attempt to test it with templates, both
non-dependent and dependent consteval calls in both function and class
templates, and with r11-5694 it now passes.

2020-12-03  Jakub Jelinek  <jakub@redhat.com>

	* g++.dg/cpp2a/consteval-defarg2.C: New test.

1 files changed, 29 insertions, 0 deletions

diff --git a/gcc/testsuite/g++.dg/cpp2a/consteval-defarg2.C b/gcc/testsuite/g++.dg/cpp2a/consteval-defarg2.C
new file mode 100644
index 0000000..e8462c8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/consteval-defarg2.C
@@ -0,0 +1,29 @@
+// Test that late-parsed default args have the same consteval semantics.
+// { dg-do compile { target c++20 } }
+
+template <int N>
+consteval bool foo (bool x) { if (x) throw N; return false; }
+consteval bool qux (bool x) { if (x) throw 1; return false; }
+template <int N>
+consteval bool bar (bool x = foo<N> (true)) { return true; }
+template <int N>
+consteval bool corge (bool x = qux (true)) { return true; }
+template <int N>
+struct S
+{
+  consteval static bool baz (bool x = foo<N> (true)) { return true; }
+  consteval static bool garply (bool x = qux (true)) { return true; }
+};
+struct T
+{
+  template <int N>
+  consteval static bool baz (bool x = foo<N> (true)) { return true; }
+  template <int N>
+  consteval static bool garply (bool x = qux (true)) { return true; }
+};
+constexpr bool a = bar<0> (true);
+constexpr bool b = corge<0> (true);
+constexpr bool c = S<0>::baz (true);
+constexpr bool d = S<0>::garply (true);
+constexpr bool e = T::baz<0> (true);
+constexpr bool f = T::garply<0> (true);