[PATCH] c++: Add !TYPE_P assert to type_dependent_expression_p [PR99080]

[Marek Polacek <polacek@redhat.com>]

As discussed here:
<https://gcc.gnu.org/pipermail/gcc-patches/2021-February/564629.html>,
type_dependent_expression_p should not be called with a type argument.

I promised I'd add an assert so here it is.  One place needed adjusting,
the comment explains why.

Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

	PR c++/99080

gcc/cp/ChangeLog:

	* pt.cc (type_dependent_expression_p): Assert !TYPE_P.
	* semantics.cc (finish_id_expression_1): Don't call
	type_dependent_expression_p for a type.
---
 gcc/cp/pt.cc        | 2 ++
 gcc/cp/semantics.cc | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 24bbe2f4060..89156cb88b4 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -27727,6 +27727,8 @@ type_dependent_expression_p (tree expression)
   if (expression == NULL_TREE || expression == error_mark_node)
     return false;
 
+  gcc_checking_assert (!TYPE_P (expression));
+
   STRIP_ANY_LOCATION_WRAPPER (expression);
 
   /* An unresolved name is always dependent.  */
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index cd7a2818feb..7f8502f49b0 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -4141,7 +4141,9 @@ finish_id_expression_1 (tree id_expression,
     }
   else
     {
-      bool dependent_p = type_dependent_expression_p (decl);
+      /* DECL could be e.g. UNBOUND_CLASS_TEMPLATE which is a type which
+	 t_d_e_p doesn't accept.  */
+      bool dependent_p = !TYPE_P (decl) && type_dependent_expression_p (decl);
 
       /* If the declaration was explicitly qualified indicate
 	 that.  The semantics of `A::f(3)' are different than

base-commit: 367740bf6d3a6627798b3955e5d85efc7549ef50
-- 
2.36.1