--- /dev/null
+/* Python interface to values.
+
+ Copyright (C) 2008 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "defs.h"
+#include "charset.h"
+#include "value.h"
+#include "exceptions.h"
+#include "language.h"
+#include "dfp.h"
+
+/* List of all values which are currently exposed to Python. It is
+ maintained so that when an objfile is discarded, preserve_values
+ can copy the values' types if needed. This is declared
+ unconditionally to reduce the number of uses of HAVE_PYTHON in the
+ generic code. */
+struct value *values_in_python;
+
+#ifdef HAVE_PYTHON
+
+#include "python-internal.h"
+
+/* Even though Python scalar types directly map to host types, we use
+ target types here to remain consistent with the the values system in
+ GDB (which uses target arithmetic). */
+
+/* Python's integer type corresponds to C's long type. */
+#define builtin_type_pyint builtin_type (current_gdbarch)->builtin_long
+
+/* Python's float type corresponds to C's double type. */
+#define builtin_type_pyfloat builtin_type (current_gdbarch)->builtin_double
+
+/* Python's long type corresponds to C's long long type. */
+#define builtin_type_pylong builtin_type (current_gdbarch)->builtin_long_long
+
+#define builtin_type_pybool \
+ language_bool_type (current_language, current_gdbarch)
+
+typedef struct {
+ PyObject_HEAD
+ struct value *value;
+ int owned_by_gdb;
+} value_object;
+
+static void valpy_dealloc (PyObject *obj);
+static PyObject *valpy_new (PyTypeObject *subtype, PyObject *args,
+ PyObject *keywords);
+static Py_ssize_t valpy_length (PyObject *self);
+static PyObject *valpy_getitem (PyObject *self, PyObject *key);
+static int valpy_setitem (PyObject *self, PyObject *key, PyObject *value);
+static PyObject *valpy_str (PyObject *self);
+static PyObject *valpy_add (PyObject *self, PyObject *other);
+static PyObject *valpy_subtract (PyObject *self, PyObject *other);
+static PyObject *valpy_multiply (PyObject *self, PyObject *other);
+static PyObject *valpy_divide (PyObject *self, PyObject *other);
+static PyObject *valpy_remainder (PyObject *self, PyObject *other);
+static PyObject *valpy_power (PyObject *self, PyObject *other, PyObject *unused);
+static PyObject *valpy_negative (PyObject *self);
+static PyObject *valpy_positive (PyObject *self);
+static PyObject *valpy_absolute (PyObject *self);
+static int valpy_nonzero (PyObject *self);
+static PyObject *valpy_richcompare (PyObject *self, PyObject *other, int op);
+static PyObject *valpy_dereference (PyObject *self, PyObject *args);
+
+static PyMethodDef value_object_methods[] = {
+ { "dereference", valpy_dereference, METH_NOARGS, "Dereferences the value." },
+ {NULL} /* Sentinel */
+};
+
+static PyNumberMethods value_object_as_number = {
+ valpy_add,
+ valpy_subtract,
+ valpy_multiply,
+ valpy_divide,
+ valpy_remainder,
+ NULL, /* nb_divmod */
+ valpy_power, /* nb_power */
+ valpy_negative, /* nb_negative */
+ valpy_positive, /* nb_positive */
+ valpy_absolute, /* nb_absolute */
+ valpy_nonzero /* nb_nonzero */
+};
+
+static PyMappingMethods value_object_as_mapping = {
+ valpy_length,
+ valpy_getitem,
+ valpy_setitem
+};
+
+PyTypeObject value_object_type = {
+ PyObject_HEAD_INIT (NULL)
+ 0, /*ob_size*/
+ "gdb.Value", /*tp_name*/
+ sizeof (value_object), /*tp_basicsize*/
+ 0, /*tp_itemsize*/
+ valpy_dealloc, /*tp_dealloc*/
+ 0, /*tp_print*/
+ 0, /*tp_getattr*/
+ 0, /*tp_setattr*/
+ 0, /*tp_compare*/
+ 0, /*tp_repr*/
+ &value_object_as_number, /*tp_as_number*/
+ 0, /*tp_as_sequence*/
+ &value_object_as_mapping, /*tp_as_mapping*/
+ 0, /*tp_hash */
+ 0, /*tp_call*/
+ valpy_str, /*tp_str*/
+ 0, /*tp_getattro*/
+ 0, /*tp_setattro*/
+ 0, /*tp_as_buffer*/
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES, /*tp_flags*/
+ "GDB value object", /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ valpy_richcompare, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ 0, /* tp_iter */
+ 0, /* tp_iternext */
+ value_object_methods /* tp_methods */
+};
+
+
+/* Called by the Python interpreter when deallocating a value object. */
+static void
+valpy_dealloc (PyObject *obj)
+{
+ value_object *self = (value_object *) obj;
+
+ value_remove_from_list (&values_in_python, self->value);
+
+ if (!self->owned_by_gdb)
+ value_free (self->value);
+ self->ob_type->tp_free (self);
+}
+
+/* Called when a new gdb.Value object needs to be allocated. */
+static PyObject *
+valpy_new (PyTypeObject *subtype, PyObject *args, PyObject *keywords)
+{
+ struct value *value = NULL; /* Initialize to appease gcc warning. */
+ value_object *value_obj;
+ volatile struct gdb_exception except;
+
+ if (PyTuple_Size (args) != 1)
+ {
+ PyErr_SetString (PyExc_TypeError, _("Value object creation takes only "
+ "1 argument"));
+ return NULL;
+ }
+
+ value_obj = (value_object *) subtype->tp_alloc (subtype, 1);
+ if (value_obj == NULL)
+ {
+ PyErr_SetString (PyExc_MemoryError, _("Could not allocate memory to "
+ "create Value object."));
+ return NULL;
+ }
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ value = convert_value_from_python (PyTuple_GetItem (args, 0));
+ }
+ if (except.reason < 0)
+ {
+ subtype->tp_free (value_obj);
+ return PyErr_Format (except.reason == RETURN_QUIT
+ ? PyExc_KeyboardInterrupt : PyExc_TypeError,
+ "%s", except.message);
+ }
+
+ value_obj->value = value;
+ release_value (value);
+ value_prepend_to_list (&values_in_python, value);
+
+ return (PyObject *) value_obj;
+}
+
+/* Given a value of a pointer type, apply the C unary * operator to it. */
+static PyObject *
+valpy_dereference (PyObject *self, PyObject *args)
+{
+ struct value *res_val = NULL; /* Initialize to appease gcc warning. */
+ volatile struct gdb_exception except;
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ res_val = value_ind (((value_object *) self)->value);
+ }
+ GDB_PY_HANDLE_EXCEPTION (except);
+
+ return value_to_value_object (res_val);
+}
+
+static Py_ssize_t
+valpy_length (PyObject *self)
+{
+ /* We don't support getting the number of elements in a struct / class. */
+ PyErr_SetString (PyExc_NotImplementedError,
+ "Invalid operation on gdb.Value.");
+ return -1;
+}
+
+/* Given string name of an element inside structure, return its value
+ object. */
+static PyObject *
+valpy_getitem (PyObject *self, PyObject *key)
+{
+ value_object *self_value = (value_object *) self;
+ char *field;
+ struct value *res_val = NULL; /* Initialize to appease gcc warning. */
+ struct cleanup *old;
+ volatile struct gdb_exception except;
+
+ field = python_string_to_target_string (key);
+ if (field == NULL)
+ return NULL;
+
+ old = make_cleanup (xfree, field);
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ res_val = value_struct_elt (&self_value->value, NULL, field, 0, NULL);
+ }
+ GDB_PY_HANDLE_EXCEPTION (except);
+
+ do_cleanups (old);
+
+ return value_to_value_object (res_val);
+}
+
+static int
+valpy_setitem (PyObject *self, PyObject *key, PyObject *value)
+{
+ PyErr_Format (PyExc_NotImplementedError,
+ _("Setting of struct elements is not currently supported."));
+ return -1;
+}
+
+/* Called by the Python interpreter to obtain string representation
+ of the object. */
+static PyObject *
+valpy_str (PyObject *self)
+{
+ char *s = NULL;
+ long dummy;
+ struct ui_file *stb;
+ struct cleanup *old_chain;
+ PyObject *result;
+ volatile struct gdb_exception except;
+
+ stb = mem_fileopen ();
+ old_chain = make_cleanup_ui_file_delete (stb);
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ common_val_print (((value_object *) self)->value, stb, 0, 0, 0,
+ Val_pretty_default, current_language);
+ s = ui_file_xstrdup (stb, &dummy);
+ }
+ GDB_PY_HANDLE_EXCEPTION (except);
+
+ do_cleanups (old_chain);
+
+ result = PyUnicode_Decode (s, strlen (s), host_charset (), NULL);
+ xfree (s);
+
+ return result;
+}
+
+enum valpy_opcode
+{
+ VALPY_ADD,
+ VALPY_SUB,
+ VALPY_MUL,
+ VALPY_DIV,
+ VALPY_REM,
+ VALPY_POW
+};
+
+/* If TYPE is a reference, return the target; otherwise return TYPE. */
+#define STRIP_REFERENCE(TYPE) \
+ ((TYPE_CODE (TYPE) == TYPE_CODE_REF) ? (TYPE_TARGET_TYPE (TYPE)) : (TYPE))
+
+/* Returns a value object which is the result of applying the operation
+ specified by OPCODE to the given arguments. */
+static PyObject *
+valpy_binop (enum valpy_opcode opcode, PyObject *self, PyObject *other)
+{
+ struct value *res_val = NULL; /* Initialize to appease gcc warning. */
+ volatile struct gdb_exception except;
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ struct value *arg1, *arg2;
+
+ /* If the gdb.Value object is the second operand, then it will be passed
+ to us as the OTHER argument, and SELF will be an entirely different
+ kind of object, altogether. Because of this, we can't assume self is
+ a gdb.Value object and need to convert it from python as well. */
+ arg1 = convert_value_from_python (self);
+ arg2 = convert_value_from_python (other);
+
+ switch (opcode)
+ {
+ case VALPY_ADD:
+ {
+ struct type *ltype = value_type (arg1);
+ struct type *rtype = value_type (arg2);
+
+ CHECK_TYPEDEF (ltype);
+ ltype = STRIP_REFERENCE (ltype);
+ CHECK_TYPEDEF (rtype);
+ rtype = STRIP_REFERENCE (rtype);
+
+ if (TYPE_CODE (ltype) == TYPE_CODE_PTR)
+ res_val = value_ptradd (arg1, arg2);
+ else if (TYPE_CODE (rtype) == TYPE_CODE_PTR)
+ res_val = value_ptradd (arg2, arg1);
+ else
+ res_val = value_binop (arg1, arg2, BINOP_ADD);
+ }
+ break;
+ case VALPY_SUB:
+ {
+ struct type *ltype = value_type (arg1);
+ struct type *rtype = value_type (arg2);
+
+ CHECK_TYPEDEF (ltype);
+ ltype = STRIP_REFERENCE (ltype);
+ CHECK_TYPEDEF (rtype);
+ rtype = STRIP_REFERENCE (rtype);
+
+ if (TYPE_CODE (ltype) == TYPE_CODE_PTR)
+ {
+ if (TYPE_CODE (rtype) == TYPE_CODE_PTR)
+ /* A ptrdiff_t for the target would be preferable
+ here. */
+ res_val = value_from_longest (builtin_type_pyint,
+ value_ptrdiff (arg1, arg2));
+ else
+ res_val = value_ptrsub (arg1, arg2);
+ }
+ else
+ res_val = value_binop (arg1, arg2, BINOP_SUB);
+ }
+ break;
+ case VALPY_MUL:
+ res_val = value_binop (arg1, arg2, BINOP_MUL);
+ break;
+ case VALPY_DIV:
+ res_val = value_binop (arg1, arg2, BINOP_DIV);
+ break;
+ case VALPY_REM:
+ res_val = value_binop (arg1, arg2, BINOP_REM);
+ break;
+ case VALPY_POW:
+ res_val = value_binop (arg1, arg2, BINOP_EXP);
+ break;
+ }
+ }
+ GDB_PY_HANDLE_EXCEPTION (except);
+
+ return value_to_value_object (res_val);
+}
+
+static PyObject *
+valpy_add (PyObject *self, PyObject *other)
+{
+ return valpy_binop (VALPY_ADD, self, other);
+}
+
+static PyObject *
+valpy_subtract (PyObject *self, PyObject *other)
+{
+ return valpy_binop (VALPY_SUB, self, other);
+}
+
+static PyObject *
+valpy_multiply (PyObject *self, PyObject *other)
+{
+ return valpy_binop (VALPY_MUL, self, other);
+}
+
+static PyObject *
+valpy_divide (PyObject *self, PyObject *other)
+{
+ return valpy_binop (VALPY_DIV, self, other);
+}
+
+static PyObject *
+valpy_remainder (PyObject *self, PyObject *other)
+{
+ return valpy_binop (VALPY_REM, self, other);
+}
+
+static PyObject *
+valpy_power (PyObject *self, PyObject *other, PyObject *unused)
+{
+ /* We don't support the ternary form of pow. I don't know how to express
+ that, so let's just throw NotImplementedError to at least do something
+ about it. */
+ if (unused != Py_None)
+ {
+ PyErr_SetString (PyExc_NotImplementedError,
+ "Invalid operation on gdb.Value.");
+ return NULL;
+ }
+
+ return valpy_binop (VALPY_POW, self, other);
+}
+
+static PyObject *
+valpy_negative (PyObject *self)
+{
+ struct value *val = NULL;
+ volatile struct gdb_exception except;
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ val = value_neg (((value_object *) self)->value);
+ }
+ GDB_PY_HANDLE_EXCEPTION (except);
+
+ return value_to_value_object (val);
+}
+
+static PyObject *
+valpy_positive (PyObject *self)
+{
+ struct value *copy = value_copy (((value_object *) self)->value);
+
+ return value_to_value_object (copy);
+}
+
+static PyObject *
+valpy_absolute (PyObject *self)
+{
+ if (value_less (((value_object *) self)->value,
+ value_from_longest (builtin_type_int8, 0)))
+ return valpy_negative (self);
+ else
+ return valpy_positive (self);
+}
+
+/* Implements boolean evaluation of gdb.Value. */
+static int
+valpy_nonzero (PyObject *self)
+{
+ value_object *self_value = (value_object *) self;
+ struct type *type;
+
+ type = check_typedef (value_type (self_value->value));
+
+ if (is_integral_type (type) || TYPE_CODE (type) == TYPE_CODE_PTR)
+ return !!value_as_long (self_value->value);
+ else if (TYPE_CODE (type) == TYPE_CODE_FLT)
+ return value_as_double (self_value->value) != 0;
+ else if (TYPE_CODE (type) == TYPE_CODE_DECFLOAT)
+ return !decimal_is_zero (value_contents (self_value->value),
+ TYPE_LENGTH (type));
+ else
+ {
+ PyErr_SetString (PyExc_TypeError, _("Attempted truth testing on invalid "
+ "gdb.Value type."));
+ return 0;
+ }
+}
+
+/* Implements comparison operations for value objects. */
+static PyObject *
+valpy_richcompare (PyObject *self, PyObject *other, int op)
+{
+ int result = 0;
+ struct value *value_self, *value_other;
+ volatile struct gdb_exception except;
+
+ if (PyObject_TypeCheck (other, &value_object_type))
+ value_other = ((value_object *) other)->value;
+ else if (PyInt_Check (other))
+ {
+ LONGEST l;
+
+ l = PyInt_AsLong (other);
+ if (PyErr_Occurred ())
+ return NULL;
+
+ value_other = value_from_longest (builtin_type_pyint, l);
+ }
+ else if (PyFloat_Check (other))
+ {
+ DOUBLEST d;
+
+ d = PyFloat_AsDouble (other);
+ if (PyErr_Occurred ())
+ return NULL;
+
+ value_other = value_from_double (builtin_type_pyfloat, d);
+ }
+ else if (PyString_Check (other) || PyUnicode_Check (other))
+ {
+ char *str;
+
+ str = python_string_to_target_string (other);
+ value_other = value_from_string (str);
+ xfree (str);
+ }
+ else if (other == Py_None)
+ /* Comparing with None is special. From what I can tell, in Python
+ None is smaller than anything else. */
+ switch (op) {
+ case Py_LT:
+ case Py_LE:
+ case Py_EQ:
+ Py_RETURN_FALSE;
+ case Py_NE:
+ case Py_GT:
+ case Py_GE:
+ Py_RETURN_TRUE;
+ default:
+ /* Can't happen. */
+ PyErr_SetString (PyExc_NotImplementedError,
+ "Invalid operation on gdb.Value.");
+ return NULL;
+ }
+ else
+ {
+ PyErr_SetString (PyExc_NotImplementedError,
+ "Operation not supported on gdb.Value of this type.");
+ return NULL;
+ }
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ switch (op) {
+ case Py_LT:
+ result = value_less (((value_object *) self)->value, value_other);
+ break;
+ case Py_LE:
+ result = value_less (((value_object *) self)->value, value_other)
+ || value_equal (((value_object *) self)->value, value_other);
+ break;
+ case Py_EQ:
+ result = value_equal (((value_object *) self)->value, value_other);
+ break;
+ case Py_NE:
+ result = !value_equal (((value_object *) self)->value, value_other);
+ break;
+ case Py_GT:
+ result = value_less (value_other, ((value_object *) self)->value);
+ break;
+ case Py_GE:
+ result = value_less (value_other, ((value_object *) self)->value)
+ || value_equal (((value_object *) self)->value, value_other);
+ break;
+ default:
+ /* Can't happen. */
+ PyErr_SetString (PyExc_NotImplementedError,
+ "Invalid operation on gdb.Value.");
+ return NULL;
+ }
+ }
+ GDB_PY_HANDLE_EXCEPTION (except);
+
+ if (result == 1)
+ Py_RETURN_TRUE;
+
+ Py_RETURN_FALSE;
+}
+
+/* Returns an object for a value which is released from the all_values chain,
+ so its lifetime is not bound to the execution of a command. */
+PyObject *
+value_to_value_object (struct value *val)
+{
+ value_object *val_obj;
+
+ val_obj = PyObject_New (value_object, &value_object_type);
+ if (val_obj != NULL)
+ {
+ val_obj->value = val;
+ release_value (val);
+ value_prepend_to_list (&values_in_python, val);
+ }
+
+ return (PyObject *) val_obj;
+}
+
+/* Try to convert a Python value to a gdb value. If the value cannot
+ be converted, throw a gdb exception. */
+
+struct value *
+convert_value_from_python (PyObject *obj)
+{
+ struct value *value = NULL; /* -Wall */
+ PyObject *target_str, *unicode_str;
+ struct cleanup *old;
+
+ if (! obj)
+ error (_("Internal error while converting Python value."));
+
+ if (PyBool_Check (obj))
+ value = value_from_longest (builtin_type_pybool, obj == Py_True);
+ else if (PyInt_Check (obj))
+ value = value_from_longest (builtin_type_pyint, PyInt_AsLong (obj));
+ else if (PyLong_Check (obj))
+ {
+ LONGEST l = PyLong_AsLongLong (obj);
+ if (! PyErr_Occurred ())
+ value = value_from_longest (builtin_type_pylong, l);
+ }
+ else if (PyFloat_Check (obj))
+ {
+ double d = PyFloat_AsDouble (obj);
+ if (! PyErr_Occurred ())
+ value = value_from_double (builtin_type_pyfloat, d);
+ }
+ else if (PyString_Check (obj) || PyUnicode_Check (obj))
+ {
+ char *s;
+
+ s = python_string_to_target_string (obj);
+ if (s == NULL)
+ return NULL;
+
+ old = make_cleanup (xfree, s);
+ value = value_from_string (s);
+ do_cleanups (old);
+ }
+ else if (PyObject_TypeCheck (obj, &value_object_type))
+ value = ((value_object *) obj)->value;
+ else
+ error (_("Could not convert Python object: %s"),
+ PyString_AsString (PyObject_Str (obj)));
+
+ if (PyErr_Occurred ())
+ error (_("Error converting Python value."));
+
+ return value;
+}
+
+/* Returns value object in the ARGth position in GDB's history. */
+PyObject *
+gdbpy_get_value_from_history (PyObject *self, PyObject *args)
+{
+ int i;
+ struct value *res_val = NULL; /* Initialize to appease gcc warning. */
+ volatile struct gdb_exception except;
+
+ if (!PyArg_ParseTuple (args, "i", &i))
+ return NULL;
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ res_val = access_value_history (i);
+ }
+ GDB_PY_HANDLE_EXCEPTION (except);
+
+ return value_to_value_object (res_val);
+}
+
+void
+gdbpy_initialize_values (void)
+{
+ value_object_type.tp_new = valpy_new;
+ if (PyType_Ready (&value_object_type) < 0)
+ return;
+
+ Py_INCREF (&value_object_type);
+ PyModule_AddObject (gdb_module, "Value", (PyObject *) &value_object_type);
+
+ values_in_python = NULL;
+}
+
+#endif /* HAVE_PYTHON */
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