c++: Prune dead functions.

I was looking at the LCOV coverage report for the C++ FE and
found a bunch of unused functions that I think we can remove.
Obviously, I left alone various dump_* and debug_* routines.
I haven't removed cp_build_function_call although it is also
currently unused.

* lambda_return_type: was used in parser.c in GCC 7, unused since r255950,
* classtype_has_non_deleted_copy_ctor: appeared in GCC 10, its usage
  was removed in c++/95350,
* contains_wildcard_p: used in GCC 9, unused since r276764,
* get_template_head_requirements: seems to never have been used,
* check_constrained_friend: seems to never have been used,
* subsumes_constraints: unused since r276764,
* push_void_library_fn: usage removed in r248328,
* get_template_parms_at_level: unused since r157857,
* get_pattern_parm: unused since r275387.

(Some of the seemingly unused functions, such as set_global_friend, are
actually used in libcc1.)

gcc/cp/ChangeLog:

	* class.c (classtype_has_non_deleted_copy_ctor): Remove.
	* constraint.cc (contains_wildcard_p): Likewise.
	(get_template_head_requirements): Likewise.
	(check_constrained_friend): Likewise.
	(subsumes_constraints): Likewise.
	* cp-tree.h (classtype_has_non_deleted_copy_ctor): Likewise.
	(push_void_library_fn): Likewise.
	(get_pattern_parm): Likewise.
	(get_template_parms_at_level): Likewise.
	(lambda_return_type): Likewise.
	(get_template_head_requirements): Likewise.
	(check_constrained_friend): Likewise.
	(subsumes_constraints): Likewise.
	* decl.c (push_void_library_fn): Likewise.
	* lambda.c (lambda_return_type): Likewise.
	* pt.c (get_template_parms_at_level): Likewise.
	(get_pattern_parm): Likewise.

1 files changed, 0 insertions, 62 deletions

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 30fccc4..03ce8eb 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -278,21 +278,6 @@ get_concept_check_template (tree t)
   return tmpl;
 }
 
-/* Returns true if any of the arguments in the template argument list is
-   a wildcard or wildcard pack.  */
-
-bool
-contains_wildcard_p (tree args)
-{
-  for (int i = 0; i < TREE_VEC_LENGTH (args); ++i)
-    {
-      tree arg = TREE_VEC_ELT (args, i);
-      if (TREE_CODE (arg) == WILDCARD_DECL)
-	return true;
-    }
-  return false;
-}
-
 /*---------------------------------------------------------------------------
                     Resolution of qualified concept names
 ---------------------------------------------------------------------------*/
@@ -1310,18 +1295,6 @@ maybe_substitute_reqs_for (tree reqs, const_tree decl_)
   return reqs;
 }
 
-/* Returns the template-head requires clause for the template
-   declaration T or NULL_TREE if none.  */
-
-tree
-get_template_head_requirements (tree t)
-{
-  tree ci = get_constraints (t);
-  if (!ci)
-    return NULL_TREE;
-  return CI_TEMPLATE_REQS (ci);
-}
-
 /* Returns the trailing requires clause of the declarator of
    a template declaration T or NULL_TREE if none.  */
 
@@ -3469,31 +3442,6 @@ check_function_concept (tree fn)
   return NULL_TREE;
 }
 
-
-// Check that a constrained friend declaration function declaration,
-// FN, is admissible. This is the case only when the declaration depends
-// on template parameters and does not declare a specialization.
-void
-check_constrained_friend (tree fn, tree reqs)
-{
-  if (fn == error_mark_node)
-    return;
-  gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
-
-  // If there are not constraints, this cannot be an error.
-  if (!reqs)
-    return;
-
-  // Constrained friend functions that don't depend on template
-  // arguments are effectively meaningless.
-  if (!uses_template_parms (TREE_TYPE (fn)))
-    {
-      error_at (location_of (fn),
-		"constrained friend does not depend on template parameters");
-      return;
-    }
-}
-
 /*---------------------------------------------------------------------------
                         Equivalence of constraints
 ---------------------------------------------------------------------------*/
@@ -3521,16 +3469,6 @@ equivalently_constrained (tree d1, tree d2)
                      Partial ordering of constraints
 ---------------------------------------------------------------------------*/
 
-/* Returns true when the constraints in A subsume those in B.  */
-
-bool
-subsumes_constraints (tree a, tree b)
-{
-  gcc_assert (!a || TREE_CODE (a) == CONSTRAINT_INFO);
-  gcc_assert (!b || TREE_CODE (b) == CONSTRAINT_INFO);
-  return subsumes (a, b);
-}
-
 /* Returns true when the constraints in CI strictly subsume
    the associated constraints of TMPL.  */