Guile: add value-{rvalue-,}reference-value

The Guile API doesn't currently have an equivalent to the Python API's
Value.reference_value() or Value.rvalue_reference_value(). This commit
adds a procedure with equivalent semantics to the Guile API.

gdb/ChangeLog:

	* NEWS (Guile API): Note the addition of new procedures.
	* guile/scm-value.c (gdbscm_reference_value): Add helper function
	for reference value creation.
	(gdbscm_value_reference_value): Add implementation of
	value-reference-value procedure.
	(gdbscm_value_rvalue_reference_value): Add implementation of
	value-rvalue-reference-value procedure.
	(value_functions): Add value-reference-value procedure.  Add
	value-rvalue-reference-value procedure.

gdb/doc/ChangeLog:

	* guile.texi (Values From Inferior In Guile): Add documentation
	for value-reference-value.  Add documentation for
	value-rvalue-reference-value.

gdb/testsuite/ChangeLog:

	* gdb.guile/scm-value.exp (test_value_in_inferior): Add test for
	value-reference-value.  Add test for value-rvalue-reference-value.

1 files changed, 42 insertions, 0 deletions

diff --git a/gdb/guile/scm-value.c b/gdb/guile/scm-value.c
index f50e8b5..a07bc7d 100644
--- a/gdb/guile/scm-value.c
+++ b/gdb/guile/scm-value.c
@@ -488,6 +488,38 @@ gdbscm_value_referenced_value (SCM self)
     });
 }
 
+static SCM
+gdbscm_reference_value (SCM self, enum type_code refcode)
+{
+  value_smob *v_smob
+    = vlscm_get_value_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
+  struct value *value = v_smob->value;
+
+  return gdbscm_wrap ([=]
+    {
+      scoped_value_mark free_values;
+
+      struct value *res_val = value_ref (value, refcode);
+      return vlscm_scm_from_value (res_val);
+    });
+}
+
+/* (value-reference-value <gdb:value>) -> <gdb:value> */
+
+static SCM
+gdbscm_value_reference_value (SCM self)
+{
+  return gdbscm_reference_value (self, TYPE_CODE_REF);
+}
+
+/* (value-rvalue-reference-value <gdb:value>) -> <gdb:value> */
+
+static SCM
+gdbscm_value_rvalue_reference_value (SCM self)
+{
+  return gdbscm_reference_value (self, TYPE_CODE_RVALUE_REF);
+}
+
 /* (value-type <gdb:value>) -> <gdb:type> */
 
 static SCM
@@ -1352,6 +1384,16 @@ For example, for a value which is a reference to an 'int' pointer ('int *'),\n\
 value-dereference will result in a value of type 'int' while\n\
 value-referenced-value will result in a value of type 'int *'." },
 
+  { "value-reference-value", 1, 0, 0,
+    as_a_scm_t_subr (gdbscm_value_reference_value),
+    "\
+Return a <gdb:value> object which is a reference to the given value." },
+
+  { "value-rvalue-reference-value", 1, 0, 0,
+    as_a_scm_t_subr (gdbscm_value_rvalue_reference_value),
+    "\
+Return a <gdb:value> object which is an rvalue reference to the given value." },
+
   { "value-field", 2, 0, 0, as_a_scm_t_subr (gdbscm_value_field),
     "\
 Return the specified field of the value.\n\