Re: RFA: fix PR python/11915

[Tom Tromey <tromey at redhat dot com>]

>>>>> "Eli" == Eli Zaretskii <eliz@gnu.org> writes:

Eli> "Inclusive upper bound"?  Does this mean that if the argument is N,
Eli> then the array will have N+1 members, from zero to N?  That sounds
Eli> against the intuition, doesn't it?

Yes, but it is the only way to allow an array whose upper bound is
MAXINT.  I think it is also consistent with Type.range.

>> +given, the first argument is the lower bound of the array, and the
>> +second argument is the upper bound of the array.

Eli> Will the reader know whether negative arguments are allowed (provided
Eli> that the second is greater than the first)?  Or is it a good idea to
Eli> tell explicitly?

I added a note.  New patch appended.

Tom

2010-08-20  Tom Tromey  <tromey@redhat.com>

	PR python/11915:
	* python/py-type.c (typy_array): New function.
	(type_object_methods): Add "array".

2010-08-20  Tom Tromey  <tromey@redhat.com>

	PR python/11915:
	* gdb.texinfo (Types In Python): Document array method.

2010-08-20  Tom Tromey  <tromey@redhat.com>

	PR python/11915:
	* gdb.python/py-type.exp (test_fields): Add tests for array.

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index ba1607c..7750361 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -20916,6 +20916,15 @@ but it can be @code{None} in some situations.
 @end table
 @end defmethod
 
+@defmethod Type array @var{n1} @r{[}@var{n2}@r{]}
+Return a new @code{gdb.Type} object which represents an array of this
+type.  If one argument is given, it is the inclusive upper bound of
+the array; in this case the lower bound is zero.  If two arguments are
+given, the first argument is the lower bound of the array, and the
+second argument is the upper bound of the array.  An array's length
+must not be negative, but the bounds can be.
+@end defmethod
+
 @defmethod Type const
 Return a new @code{gdb.Type} object which represents a
 @code{const}-qualified variant of this type.
diff --git a/gdb/python/py-type.c b/gdb/python/py-type.c
index 529f301..ea6c8e5 100644
--- a/gdb/python/py-type.c
+++ b/gdb/python/py-type.c
@@ -262,6 +262,54 @@ typy_strip_typedefs (PyObject *self, PyObject *args)
   return type_to_type_object (check_typedef (type));
 }
 
+/* Return an array type.  */
+
+static PyObject *
+typy_array (PyObject *self, PyObject *args)
+{
+  int n1, n2;
+  PyObject *n2_obj = NULL;
+  struct type *array = NULL;
+  struct type *type = ((type_object *) self)->type;
+  volatile struct gdb_exception except;
+
+  if (! PyArg_ParseTuple (args, "i|O", &n1, &n2_obj))
+    return NULL;
+
+  if (n2_obj)
+    {
+      if (!PyInt_Check (n2_obj))
+	{
+	  PyErr_SetString (PyExc_RuntimeError,
+			   _("Array bound must be an integer"));
+	  return NULL;
+	}
+      n2 = (int) PyInt_AsLong (n2_obj);
+      if (PyErr_Occurred ())
+	return NULL;
+    }
+  else
+    {
+      n2 = n1;
+      n1 = 0;
+    }
+
+  if (n2 < n1)
+    {
+      PyErr_SetString (PyExc_ValueError,
+		       _("Array length must not be negative"));
+      return NULL;
+    }
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    {
+      array = lookup_array_range_type (type, n1, n2);
+    }
+  GDB_PY_HANDLE_EXCEPTION (except);
+
+  return type_to_type_object (array);
+}
+
 /* Return a Type object which represents a pointer to SELF.  */
 static PyObject *
 typy_pointer (PyObject *self, PyObject *args)
@@ -836,6 +884,9 @@ static PyGetSetDef type_object_getset[] =
 
 static PyMethodDef type_object_methods[] =
 {
+  { "array", typy_array, METH_VARARGS,
+    "array (N) -> Type\n\
+Return a type which represents an array of N objects of this type." },
   { "const", typy_const, METH_NOARGS,
     "const () -> Type\n\
 Return a const variant of this type." },
diff --git a/gdb/testsuite/gdb.python/py-type.exp b/gdb/testsuite/gdb.python/py-type.exp
index 6e5bd0e..095711f 100644
--- a/gdb/testsuite/gdb.python/py-type.exp
+++ b/gdb/testsuite/gdb.python/py-type.exp
@@ -97,6 +97,11 @@ proc test_fields {lang} {
   gdb_test "python fields = ar.type.fields()"
   gdb_test "python print len(fields)" "1" "Check the number of fields"
   gdb_test "python print fields\[0\].type" "<range type>" "Check array field type"
+
+  gdb_test "python print ar\[0\].cast(ar\[0\].type.array(1))" \
+      ".1, 2." "cast to array with one argument"
+  gdb_test "python print ar\[0\].cast(ar\[0\].type.array(0, 1))" \
+      ".1, 2." "cast to array with two arguments"
 }
 
 proc test_base_class {} {