/* Python interface to values. Copyright (C) 2008-2019 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 . */ #include "defs.h" #include "charset.h" #include "value.h" #include "language.h" #include "target-float.h" #include "valprint.h" #include "infcall.h" #include "expression.h" #include "cp-abi.h" #include "python.h" #include "python-internal.h" /* Even though Python scalar types directly map to host types, we use target types here to remain consistent with 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 (python_gdbarch)->builtin_long /* Python's float type corresponds to C's double type. */ #define builtin_type_pyfloat builtin_type (python_gdbarch)->builtin_double /* Python's long type corresponds to C's long long type. */ #define builtin_type_pylong builtin_type (python_gdbarch)->builtin_long_long /* Python's long type corresponds to C's long long type. Unsigned version. */ #define builtin_type_upylong builtin_type \ (python_gdbarch)->builtin_unsigned_long_long #define builtin_type_pybool \ language_bool_type (python_language, python_gdbarch) #define builtin_type_pychar \ language_string_char_type (python_language, python_gdbarch) typedef struct value_object { PyObject_HEAD struct value_object *next; struct value_object *prev; struct value *value; PyObject *address; PyObject *type; PyObject *dynamic_type; } value_object; /* 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 variable is unnecessarily initialized to NULL in order to work around a linker bug on MacOS. */ static value_object *values_in_python = NULL; /* Called by the Python interpreter when deallocating a value object. */ static void valpy_dealloc (PyObject *obj) { value_object *self = (value_object *) obj; /* Remove SELF from the global list. */ if (self->prev) self->prev->next = self->next; else { gdb_assert (values_in_python == self); values_in_python = self->next; } if (self->next) self->next->prev = self->prev; value_decref (self->value); Py_XDECREF (self->address); Py_XDECREF (self->type); Py_XDECREF (self->dynamic_type); Py_TYPE (self)->tp_free (self); } /* Helper to push a Value object on the global list. */ static void note_value (value_object *value_obj) { value_obj->next = values_in_python; if (value_obj->next) value_obj->next->prev = value_obj; value_obj->prev = NULL; values_in_python = value_obj; } /* Convert a python object OBJ with type TYPE to a gdb value. The python object in question must conform to the python buffer protocol. On success, return the converted value, otherwise nullptr. */ static struct value * convert_buffer_and_type_to_value (PyObject *obj, struct type *type) { Py_buffer_up buffer_up; Py_buffer py_buf; if (PyObject_CheckBuffer (obj) && PyObject_GetBuffer (obj, &py_buf, PyBUF_SIMPLE) == 0) { /* Got a buffer, py_buf, out of obj. Cause it to be released when it goes out of scope. */ buffer_up.reset (&py_buf); } else { PyErr_SetString (PyExc_TypeError, _("Object must support the python buffer protocol.")); return nullptr; } if (TYPE_LENGTH (type) > py_buf.len) { PyErr_SetString (PyExc_ValueError, _("Size of type is larger than that of buffer object.")); return nullptr; } return value_from_contents (type, (const gdb_byte *) py_buf.buf); } /* Called when a new gdb.Value object needs to be allocated. Returns NULL on error, with a python exception set. */ static PyObject * valpy_new (PyTypeObject *subtype, PyObject *args, PyObject *kwargs) { static const char *keywords[] = { "val", "type", NULL }; PyObject *val_obj = nullptr; PyObject *type_obj = nullptr; if (!gdb_PyArg_ParseTupleAndKeywords (args, kwargs, "O|O", keywords, &val_obj, &type_obj)) return nullptr; struct type *type = nullptr; if (type_obj != nullptr) { type = type_object_to_type (type_obj); if (type == nullptr) { PyErr_SetString (PyExc_TypeError, _("type argument must be a gdb.Type.")); return nullptr; } } value_object *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; } struct value *value; if (type == nullptr) value = convert_value_from_python (val_obj); else value = convert_buffer_and_type_to_value (val_obj, type); if (value == nullptr) { subtype->tp_free (value_obj); return NULL; } value_obj->value = release_value (value).release (); value_obj->address = NULL; value_obj->type = NULL; value_obj->dynamic_type = NULL; note_value (value_obj); return (PyObject *) value_obj; } /* Iterate over all the Value objects, calling preserve_one_value on each. */ void gdbpy_preserve_values (const struct extension_language_defn *extlang, struct objfile *objfile, htab_t copied_types) { value_object *iter; for (iter = values_in_python; iter; iter = iter->next) preserve_one_value (iter->value, objfile, copied_types); } /* Given a value of a pointer type, apply the C unary * operator to it. */ static PyObject * valpy_dereference (PyObject *self, PyObject *args) { PyObject *result = NULL; TRY { struct value *res_val; scoped_value_mark free_values; res_val = value_ind (((value_object *) self)->value); result = value_to_value_object (res_val); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } /* Given a value of a pointer type or a reference type, return the value referenced. The difference between this function and valpy_dereference is that the latter applies * unary operator to a value, which need not always result in the value referenced. For example, for a value which is a reference to an 'int' pointer ('int *'), valpy_dereference will result in a value of type 'int' while valpy_referenced_value will result in a value of type 'int *'. */ static PyObject * valpy_referenced_value (PyObject *self, PyObject *args) { PyObject *result = NULL; TRY { struct value *self_val, *res_val; scoped_value_mark free_values; self_val = ((value_object *) self)->value; switch (TYPE_CODE (check_typedef (value_type (self_val)))) { case TYPE_CODE_PTR: res_val = value_ind (self_val); break; case TYPE_CODE_REF: case TYPE_CODE_RVALUE_REF: res_val = coerce_ref (self_val); break; default: error(_("Trying to get the referenced value from a value which is " "neither a pointer nor a reference.")); } result = value_to_value_object (res_val); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } /* Return a value which is a reference to the value. */ static PyObject * valpy_reference_value (PyObject *self, PyObject *args, enum type_code refcode) { PyObject *result = NULL; TRY { struct value *self_val; scoped_value_mark free_values; self_val = ((value_object *) self)->value; result = value_to_value_object (value_ref (self_val, refcode)); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } static PyObject * valpy_lvalue_reference_value (PyObject *self, PyObject *args) { return valpy_reference_value (self, args, TYPE_CODE_REF); } static PyObject * valpy_rvalue_reference_value (PyObject *self, PyObject *args) { return valpy_reference_value (self, args, TYPE_CODE_RVALUE_REF); } /* Return a "const" qualified version of the value. */ static PyObject * valpy_const_value (PyObject *self, PyObject *args) { PyObject *result = NULL; TRY { struct value *self_val, *res_val; scoped_value_mark free_values; self_val = ((value_object *) self)->value; res_val = make_cv_value (1, 0, self_val); result = value_to_value_object (res_val); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } /* Return "&value". */ static PyObject * valpy_get_address (PyObject *self, void *closure) { value_object *val_obj = (value_object *) self; if (!val_obj->address) { TRY { struct value *res_val; scoped_value_mark free_values; res_val = value_addr (val_obj->value); val_obj->address = value_to_value_object (res_val); } CATCH (except, RETURN_MASK_ALL) { val_obj->address = Py_None; Py_INCREF (Py_None); } END_CATCH } Py_XINCREF (val_obj->address); return val_obj->address; } /* Return type of the value. */ static PyObject * valpy_get_type (PyObject *self, void *closure) { value_object *obj = (value_object *) self; if (!obj->type) { obj->type = type_to_type_object (value_type (obj->value)); if (!obj->type) return NULL; } Py_INCREF (obj->type); return obj->type; } /* Return dynamic type of the value. */ static PyObject * valpy_get_dynamic_type (PyObject *self, void *closure) { value_object *obj = (value_object *) self; struct type *type = NULL; if (obj->dynamic_type != NULL) { Py_INCREF (obj->dynamic_type); return obj->dynamic_type; } TRY { struct value *val = obj->value; scoped_value_mark free_values; type = value_type (val); type = check_typedef (type); if (((TYPE_CODE (type) == TYPE_CODE_PTR) || TYPE_IS_REFERENCE (type)) && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_STRUCT)) { struct value *target; int was_pointer = TYPE_CODE (type) == TYPE_CODE_PTR; if (was_pointer) target = value_ind (val); else target = coerce_ref (val); type = value_rtti_type (target, NULL, NULL, NULL); if (type) { if (was_pointer) type = lookup_pointer_type (type); else type = lookup_lvalue_reference_type (type); } } else if (TYPE_CODE (type) == TYPE_CODE_STRUCT) type = value_rtti_type (val, NULL, NULL, NULL); else { /* Re-use object's static type. */ type = NULL; } } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (type == NULL) obj->dynamic_type = valpy_get_type (self, NULL); else obj->dynamic_type = type_to_type_object (type); Py_XINCREF (obj->dynamic_type); return obj->dynamic_type; } /* Implementation of gdb.Value.lazy_string ([encoding] [, length]) -> string. Return a PyObject representing a lazy_string_object type. A lazy string is a pointer to a string with an optional encoding and length. If ENCODING is not given, encoding is set to None. If an ENCODING is provided the encoding parameter is set to ENCODING, but the string is not encoded. If LENGTH is provided then the length parameter is set to LENGTH. Otherwise if the value is an array of known length then the array's length is used. Otherwise the length will be set to -1 (meaning first null of appropriate with). Note: In order to not break any existing uses this allows creating lazy strings from anything. PR 20769. E.g., gdb.parse_and_eval("my_int_variable").lazy_string(). "It's easier to relax restrictions than it is to impose them after the fact." So we should be flagging any unintended uses as errors, but it's perhaps too late for that. */ static PyObject * valpy_lazy_string (PyObject *self, PyObject *args, PyObject *kw) { gdb_py_longest length = -1; struct value *value = ((value_object *) self)->value; const char *user_encoding = NULL; static const char *keywords[] = { "encoding", "length", NULL }; PyObject *str_obj = NULL; if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "|s" GDB_PY_LL_ARG, keywords, &user_encoding, &length)) return NULL; if (length < -1) { PyErr_SetString (PyExc_ValueError, _("Invalid length.")); return NULL; } TRY { scoped_value_mark free_values; struct type *type, *realtype; CORE_ADDR addr; type = value_type (value); realtype = check_typedef (type); switch (TYPE_CODE (realtype)) { case TYPE_CODE_ARRAY: { LONGEST array_length = -1; LONGEST low_bound, high_bound; /* PR 20786: There's no way to specify an array of length zero. Record a length of [0,-1] which is how Ada does it. Anything we do is broken, but this one possible solution. */ if (get_array_bounds (realtype, &low_bound, &high_bound)) array_length = high_bound - low_bound + 1; if (length == -1) length = array_length; else if (array_length == -1) { type = lookup_array_range_type (TYPE_TARGET_TYPE (realtype), 0, length - 1); } else if (length != array_length) { /* We need to create a new array type with the specified length. */ if (length > array_length) error (_("Length is larger than array size.")); type = lookup_array_range_type (TYPE_TARGET_TYPE (realtype), low_bound, low_bound + length - 1); } addr = value_address (value); break; } case TYPE_CODE_PTR: /* If a length is specified we defer creating an array of the specified width until we need to. */ addr = value_as_address (value); break; default: /* Should flag an error here. PR 20769. */ addr = value_address (value); break; } str_obj = gdbpy_create_lazy_string_object (addr, length, user_encoding, type); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return str_obj; } /* Implementation of gdb.Value.string ([encoding] [, errors] [, length]) -> string. Return Unicode string with value contents. If ENCODING is not given, the string is assumed to be encoded in the target's charset. If LENGTH is provided, only fetch string to the length provided. */ static PyObject * valpy_string (PyObject *self, PyObject *args, PyObject *kw) { int length = -1; gdb::unique_xmalloc_ptr buffer; struct value *value = ((value_object *) self)->value; const char *encoding = NULL; const char *errors = NULL; const char *user_encoding = NULL; const char *la_encoding = NULL; struct type *char_type; static const char *keywords[] = { "encoding", "errors", "length", NULL }; if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "|ssi", keywords, &user_encoding, &errors, &length)) return NULL; TRY { LA_GET_STRING (value, &buffer, &length, &char_type, &la_encoding); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH encoding = (user_encoding && *user_encoding) ? user_encoding : la_encoding; return PyUnicode_Decode ((const char *) buffer.get (), length * TYPE_LENGTH (char_type), encoding, errors); } /* A helper function that implements the various cast operators. */ static PyObject * valpy_do_cast (PyObject *self, PyObject *args, enum exp_opcode op) { PyObject *type_obj, *result = NULL; struct type *type; if (! PyArg_ParseTuple (args, "O", &type_obj)) return NULL; type = type_object_to_type (type_obj); if (! type) { PyErr_SetString (PyExc_RuntimeError, _("Argument must be a type.")); return NULL; } TRY { struct value *val = ((value_object *) self)->value; struct value *res_val; scoped_value_mark free_values; if (op == UNOP_DYNAMIC_CAST) res_val = value_dynamic_cast (type, val); else if (op == UNOP_REINTERPRET_CAST) res_val = value_reinterpret_cast (type, val); else { gdb_assert (op == UNOP_CAST); res_val = value_cast (type, val); } result = value_to_value_object (res_val); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } /* Implementation of the "cast" method. */ static PyObject * valpy_cast (PyObject *self, PyObject *args) { return valpy_do_cast (self, args, UNOP_CAST); } /* Implementation of the "dynamic_cast" method. */ static PyObject * valpy_dynamic_cast (PyObject *self, PyObject *args) { return valpy_do_cast (self, args, UNOP_DYNAMIC_CAST); } /* Implementation of the "reinterpret_cast" method. */ static PyObject * valpy_reinterpret_cast (PyObject *self, PyObject *args) { return valpy_do_cast (self, args, UNOP_REINTERPRET_CAST); } 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; } /* Return 1 if the gdb.Field object FIELD is present in the value V. Returns 0 otherwise. If any Python error occurs, -1 is returned. */ static int value_has_field (struct value *v, PyObject *field) { struct type *parent_type, *val_type; enum type_code type_code; gdbpy_ref<> type_object (PyObject_GetAttrString (field, "parent_type")); int has_field = 0; if (type_object == NULL) return -1; parent_type = type_object_to_type (type_object.get ()); if (parent_type == NULL) { PyErr_SetString (PyExc_TypeError, _("'parent_type' attribute of gdb.Field object is not a" "gdb.Type object.")); return -1; } TRY { val_type = value_type (v); val_type = check_typedef (val_type); if (TYPE_IS_REFERENCE (val_type) || TYPE_CODE (val_type) == TYPE_CODE_PTR) val_type = check_typedef (TYPE_TARGET_TYPE (val_type)); type_code = TYPE_CODE (val_type); if ((type_code == TYPE_CODE_STRUCT || type_code == TYPE_CODE_UNION) && types_equal (val_type, parent_type)) has_field = 1; else has_field = 0; } CATCH (except, RETURN_MASK_ALL) { GDB_PY_SET_HANDLE_EXCEPTION (except); } END_CATCH return has_field; } /* Return the value of a flag FLAG_NAME in a gdb.Field object FIELD. Returns 1 if the flag value is true, 0 if it is false, and -1 if a Python error occurs. */ static int get_field_flag (PyObject *field, const char *flag_name) { gdbpy_ref<> flag_object (PyObject_GetAttrString (field, flag_name)); if (flag_object == NULL) return -1; return PyObject_IsTrue (flag_object.get ()); } /* Return the "type" attribute of a gdb.Field object. Returns NULL on error, with a Python exception set. */ static struct type * get_field_type (PyObject *field) { gdbpy_ref<> ftype_obj (PyObject_GetAttrString (field, "type")); struct type *ftype; if (ftype_obj == NULL) return NULL; ftype = type_object_to_type (ftype_obj.get ()); if (ftype == NULL) PyErr_SetString (PyExc_TypeError, _("'type' attribute of gdb.Field object is not a " "gdb.Type object.")); return ftype; } /* Given string name or a gdb.Field object corresponding to an element inside a structure, return its value object. Returns NULL on error, with a python exception set. */ static PyObject * valpy_getitem (PyObject *self, PyObject *key) { struct gdb_exception except = exception_none; value_object *self_value = (value_object *) self; gdb::unique_xmalloc_ptr field; struct type *base_class_type = NULL, *field_type = NULL; long bitpos = -1; PyObject *result = NULL; if (gdbpy_is_string (key)) { field = python_string_to_host_string (key); if (field == NULL) return NULL; } else if (gdbpy_is_field (key)) { int is_base_class, valid_field; valid_field = value_has_field (self_value->value, key); if (valid_field < 0) return NULL; else if (valid_field == 0) { PyErr_SetString (PyExc_TypeError, _("Invalid lookup for a field not contained in " "the value.")); return NULL; } is_base_class = get_field_flag (key, "is_base_class"); if (is_base_class < 0) return NULL; else if (is_base_class > 0) { base_class_type = get_field_type (key); if (base_class_type == NULL) return NULL; } else { gdbpy_ref<> name_obj (PyObject_GetAttrString (key, "name")); if (name_obj == NULL) return NULL; if (name_obj != Py_None) { field = python_string_to_host_string (name_obj.get ()); if (field == NULL) return NULL; } else { if (!PyObject_HasAttrString (key, "bitpos")) { PyErr_SetString (PyExc_AttributeError, _("gdb.Field object has no name and no " "'bitpos' attribute.")); return NULL; } gdbpy_ref<> bitpos_obj (PyObject_GetAttrString (key, "bitpos")); if (bitpos_obj == NULL) return NULL; if (!gdb_py_int_as_long (bitpos_obj.get (), &bitpos)) return NULL; field_type = get_field_type (key); if (field_type == NULL) return NULL; } } } TRY { struct value *tmp = self_value->value; struct value *res_val = NULL; scoped_value_mark free_values; if (field) res_val = value_struct_elt (&tmp, NULL, field.get (), NULL, "struct/class/union"); else if (bitpos >= 0) res_val = value_struct_elt_bitpos (&tmp, bitpos, field_type, "struct/class/union"); else if (base_class_type != NULL) { struct type *val_type; val_type = check_typedef (value_type (tmp)); if (TYPE_CODE (val_type) == TYPE_CODE_PTR) res_val = value_cast (lookup_pointer_type (base_class_type), tmp); else if (TYPE_CODE (val_type) == TYPE_CODE_REF) res_val = value_cast (lookup_lvalue_reference_type (base_class_type), tmp); else if (TYPE_CODE (val_type) == TYPE_CODE_RVALUE_REF) res_val = value_cast (lookup_rvalue_reference_type (base_class_type), tmp); else res_val = value_cast (base_class_type, tmp); } else { /* Assume we are attempting an array access, and let the value code throw an exception if the index has an invalid type. */ struct value *idx = convert_value_from_python (key); if (idx != NULL) { /* Check the value's type is something that can be accessed via a subscript. */ struct type *type; tmp = coerce_ref (tmp); type = check_typedef (value_type (tmp)); if (TYPE_CODE (type) != TYPE_CODE_ARRAY && TYPE_CODE (type) != TYPE_CODE_PTR) error (_("Cannot subscript requested type.")); else res_val = value_subscript (tmp, value_as_long (idx)); } } if (res_val) result = value_to_value_object (res_val); } CATCH (ex, RETURN_MASK_ALL) { except = ex; } END_CATCH GDB_PY_HANDLE_EXCEPTION (except); return result; } 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 perform an inferior function call on the value. Returns NULL on error, with a python exception set. */ static PyObject * valpy_call (PyObject *self, PyObject *args, PyObject *keywords) { Py_ssize_t args_count; struct value *function = ((value_object *) self)->value; struct value **vargs = NULL; struct type *ftype = NULL; PyObject *result = NULL; TRY { ftype = check_typedef (value_type (function)); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (TYPE_CODE (ftype) != TYPE_CODE_FUNC) { PyErr_SetString (PyExc_RuntimeError, _("Value is not callable (not TYPE_CODE_FUNC).")); return NULL; } if (! PyTuple_Check (args)) { PyErr_SetString (PyExc_TypeError, _("Inferior arguments must be provided in a tuple.")); return NULL; } args_count = PyTuple_Size (args); if (args_count > 0) { int i; vargs = XALLOCAVEC (struct value *, args_count); for (i = 0; i < args_count; i++) { PyObject *item = PyTuple_GetItem (args, i); if (item == NULL) return NULL; vargs[i] = convert_value_from_python (item); if (vargs[i] == NULL) return NULL; } } TRY { scoped_value_mark free_values; value *return_value = call_function_by_hand (function, NULL, gdb::make_array_view (vargs, args_count)); result = value_to_value_object (return_value); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } /* Called by the Python interpreter to obtain string representation of the object. */ static PyObject * valpy_str (PyObject *self) { struct value_print_options opts; get_user_print_options (&opts); opts.deref_ref = 0; string_file stb; TRY { common_val_print (((value_object *) self)->value, &stb, 0, &opts, python_language); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return PyUnicode_Decode (stb.c_str (), stb.size (), host_charset (), NULL); } /* Implements gdb.Value.is_optimized_out. */ static PyObject * valpy_get_is_optimized_out (PyObject *self, void *closure) { struct value *value = ((value_object *) self)->value; int opt = 0; TRY { opt = value_optimized_out (value); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (opt) Py_RETURN_TRUE; Py_RETURN_FALSE; } /* Implements gdb.Value.is_lazy. */ static PyObject * valpy_get_is_lazy (PyObject *self, void *closure) { struct value *value = ((value_object *) self)->value; int opt = 0; TRY { opt = value_lazy (value); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (opt) Py_RETURN_TRUE; Py_RETURN_FALSE; } /* Implements gdb.Value.fetch_lazy (). */ static PyObject * valpy_fetch_lazy (PyObject *self, PyObject *args) { struct value *value = ((value_object *) self)->value; TRY { if (value_lazy (value)) value_fetch_lazy (value); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH Py_RETURN_NONE; } /* Calculate and return the address of the PyObject as the value of the builtin __hash__ call. */ static Py_hash_t valpy_hash (PyObject *self) { return (intptr_t) self; } enum valpy_opcode { VALPY_ADD, VALPY_SUB, VALPY_MUL, VALPY_DIV, VALPY_REM, VALPY_POW, VALPY_LSH, VALPY_RSH, VALPY_BITAND, VALPY_BITOR, VALPY_BITXOR }; /* If TYPE is a reference, return the target; otherwise return TYPE. */ #define STRIP_REFERENCE(TYPE) \ (TYPE_IS_REFERENCE (TYPE) ? (TYPE_TARGET_TYPE (TYPE)) : (TYPE)) /* Helper for valpy_binop. Returns a value object which is the result of applying the operation specified by OPCODE to the given arguments. Throws a GDB exception on error. */ static PyObject * valpy_binop_throw (enum valpy_opcode opcode, PyObject *self, PyObject *other) { PyObject *result = NULL; struct value *arg1, *arg2; struct value *res_val = NULL; enum exp_opcode op = OP_NULL; int handled = 0; scoped_value_mark free_values; /* 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); if (arg1 == NULL) return NULL; arg2 = convert_value_from_python (other); if (arg2 == NULL) return NULL; switch (opcode) { case VALPY_ADD: { struct type *ltype = value_type (arg1); struct type *rtype = value_type (arg2); ltype = check_typedef (ltype); ltype = STRIP_REFERENCE (ltype); rtype = check_typedef (rtype); rtype = STRIP_REFERENCE (rtype); handled = 1; if (TYPE_CODE (ltype) == TYPE_CODE_PTR && is_integral_type (rtype)) res_val = value_ptradd (arg1, value_as_long (arg2)); else if (TYPE_CODE (rtype) == TYPE_CODE_PTR && is_integral_type (ltype)) res_val = value_ptradd (arg2, value_as_long (arg1)); else { handled = 0; op = BINOP_ADD; } } break; case VALPY_SUB: { struct type *ltype = value_type (arg1); struct type *rtype = value_type (arg2); ltype = check_typedef (ltype); ltype = STRIP_REFERENCE (ltype); rtype = check_typedef (rtype); rtype = STRIP_REFERENCE (rtype); handled = 1; if (TYPE_CODE (ltype) == TYPE_CODE_PTR && 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 if (TYPE_CODE (ltype) == TYPE_CODE_PTR && is_integral_type (rtype)) res_val = value_ptradd (arg1, - value_as_long (arg2)); else { handled = 0; op = BINOP_SUB; } } break; case VALPY_MUL: op = BINOP_MUL; break; case VALPY_DIV: op = BINOP_DIV; break; case VALPY_REM: op = BINOP_REM; break; case VALPY_POW: op = BINOP_EXP; break; case VALPY_LSH: op = BINOP_LSH; break; case VALPY_RSH: op = BINOP_RSH; break; case VALPY_BITAND: op = BINOP_BITWISE_AND; break; case VALPY_BITOR: op = BINOP_BITWISE_IOR; break; case VALPY_BITXOR: op = BINOP_BITWISE_XOR; break; } if (!handled) { if (binop_user_defined_p (op, arg1, arg2)) res_val = value_x_binop (arg1, arg2, op, OP_NULL, EVAL_NORMAL); else res_val = value_binop (arg1, arg2, op); } if (res_val) result = value_to_value_object (res_val); return result; } /* Returns a value object which is the result of applying the operation specified by OPCODE to the given arguments. Returns NULL on error, with a python exception set. */ static PyObject * valpy_binop (enum valpy_opcode opcode, PyObject *self, PyObject *other) { PyObject *result = NULL; TRY { result = valpy_binop_throw (opcode, self, other); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } 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) { PyObject *result = NULL; TRY { /* Perhaps overkill, but consistency has some virtue. */ scoped_value_mark free_values; struct value *val; val = value_neg (((value_object *) self)->value); result = value_to_value_object (val); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return result; } static PyObject * valpy_positive (PyObject *self) { return value_to_value_object (((value_object *) self)->value); } static PyObject * valpy_absolute (PyObject *self) { struct value *value = ((value_object *) self)->value; int isabs = 1; TRY { scoped_value_mark free_values; if (value_less (value, value_zero (value_type (value), not_lval))) isabs = 0; } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (isabs) return valpy_positive (self); else return valpy_negative (self); } /* Implements boolean evaluation of gdb.Value. */ static int valpy_nonzero (PyObject *self) { struct gdb_exception except = exception_none; value_object *self_value = (value_object *) self; struct type *type; int nonzero = 0; /* Appease GCC warning. */ TRY { type = check_typedef (value_type (self_value->value)); if (is_integral_type (type) || TYPE_CODE (type) == TYPE_CODE_PTR) nonzero = !!value_as_long (self_value->value); else if (is_floating_value (self_value->value)) nonzero = !target_float_is_zero (value_contents (self_value->value), type); else /* All other values are True. */ nonzero = 1; } CATCH (ex, RETURN_MASK_ALL) { except = ex; } END_CATCH /* This is not documented in the Python documentation, but if this function fails, return -1 as slot_nb_nonzero does (the default Python nonzero function). */ GDB_PY_SET_HANDLE_EXCEPTION (except); return nonzero; } /* Implements ~ for value objects. */ static PyObject * valpy_invert (PyObject *self) { struct value *val = NULL; TRY { val = value_complement (((value_object *) self)->value); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return value_to_value_object (val); } /* Implements left shift for value objects. */ static PyObject * valpy_lsh (PyObject *self, PyObject *other) { return valpy_binop (VALPY_LSH, self, other); } /* Implements right shift for value objects. */ static PyObject * valpy_rsh (PyObject *self, PyObject *other) { return valpy_binop (VALPY_RSH, self, other); } /* Implements bitwise and for value objects. */ static PyObject * valpy_and (PyObject *self, PyObject *other) { return valpy_binop (VALPY_BITAND, self, other); } /* Implements bitwise or for value objects. */ static PyObject * valpy_or (PyObject *self, PyObject *other) { return valpy_binop (VALPY_BITOR, self, other); } /* Implements bitwise xor for value objects. */ static PyObject * valpy_xor (PyObject *self, PyObject *other) { return valpy_binop (VALPY_BITXOR, self, other); } /* Helper for valpy_richcompare. Implements comparison operations for value objects. Returns true/false on success. Returns -1 with a Python exception set if a Python error is detected. Throws a GDB exception on other errors (memory error, etc.). */ static int valpy_richcompare_throw (PyObject *self, PyObject *other, int op) { int result; struct value *value_other; struct value *value_self; scoped_value_mark free_values; value_other = convert_value_from_python (other); if (value_other == NULL) return -1; value_self = ((value_object *) self)->value; switch (op) { case Py_LT: result = value_less (value_self, value_other); break; case Py_LE: result = value_less (value_self, value_other) || value_equal (value_self, value_other); break; case Py_EQ: result = value_equal (value_self, value_other); break; case Py_NE: result = !value_equal (value_self, value_other); break; case Py_GT: result = value_less (value_other, value_self); break; case Py_GE: result = (value_less (value_other, value_self) || value_equal (value_self, value_other)); break; default: /* Can't happen. */ PyErr_SetString (PyExc_NotImplementedError, _("Invalid operation on gdb.Value.")); result = -1; break; } return result; } /* Implements comparison operations for value objects. Returns NULL on error, with a python exception set. */ static PyObject * valpy_richcompare (PyObject *self, PyObject *other, int op) { int result = 0; 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; } TRY { result = valpy_richcompare_throw (self, other, op); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH /* In this case, the Python exception has already been set. */ if (result < 0) return NULL; if (result == 1) Py_RETURN_TRUE; Py_RETURN_FALSE; } #ifndef IS_PY3K /* Implements conversion to int. */ static PyObject * valpy_int (PyObject *self) { struct value *value = ((value_object *) self)->value; struct type *type = value_type (value); LONGEST l = 0; TRY { if (is_floating_value (value)) { type = builtin_type_pylong; value = value_cast (type, value); } if (!is_integral_type (type) && TYPE_CODE (type) != TYPE_CODE_PTR) error (_("Cannot convert value to int.")); l = value_as_long (value); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (TYPE_UNSIGNED (type)) return gdb_py_object_from_ulongest (l).release (); else return gdb_py_object_from_longest (l).release (); } #endif /* Implements conversion to long. */ static PyObject * valpy_long (PyObject *self) { struct value *value = ((value_object *) self)->value; struct type *type = value_type (value); LONGEST l = 0; TRY { if (is_floating_value (value)) { type = builtin_type_pylong; value = value_cast (type, value); } type = check_typedef (type); if (!is_integral_type (type) && TYPE_CODE (type) != TYPE_CODE_PTR) error (_("Cannot convert value to long.")); l = value_as_long (value); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (TYPE_UNSIGNED (type)) return gdb_py_long_from_ulongest (l); else return gdb_py_long_from_longest (l); } /* Implements conversion to float. */ static PyObject * valpy_float (PyObject *self) { struct value *value = ((value_object *) self)->value; struct type *type = value_type (value); double d = 0; TRY { type = check_typedef (type); if (TYPE_CODE (type) == TYPE_CODE_FLT && is_floating_value (value)) d = target_float_to_host_double (value_contents (value), type); else if (TYPE_CODE (type) == TYPE_CODE_INT) { /* Note that valpy_long accepts TYPE_CODE_PTR and some others here here -- but casting a pointer or bool to a float seems wrong. */ d = value_as_long (value); } else error (_("Cannot convert value to float.")); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return PyFloat_FromDouble (d); } /* 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 = release_value (val).release (); val_obj->address = NULL; val_obj->type = NULL; val_obj->dynamic_type = NULL; note_value (val_obj); } return (PyObject *) val_obj; } /* Returns a borrowed reference to the struct value corresponding to the given value object. */ struct value * value_object_to_value (PyObject *self) { value_object *real; if (! PyObject_TypeCheck (self, &value_object_type)) return NULL; real = (value_object *) self; return real->value; } /* Try to convert a Python value to a gdb value. If the value cannot be converted, set a Python exception and return NULL. Returns a reference to a new value on the all_values chain. */ struct value * convert_value_from_python (PyObject *obj) { struct value *value = NULL; /* -Wall */ int cmp; gdb_assert (obj != NULL); TRY { if (PyBool_Check (obj)) { cmp = PyObject_IsTrue (obj); if (cmp >= 0) value = value_from_longest (builtin_type_pybool, cmp); } /* Make a long logic check first. In Python 3.x, internally, all integers are represented as longs. In Python 2.x, there is still a differentiation internally between a PyInt and a PyLong. Explicitly do this long check conversion first. In GDB, for Python 3.x, we #ifdef PyInt = PyLong. This check has to be done first to ensure we do not lose information in the conversion process. */ else if (PyLong_Check (obj)) { LONGEST l = PyLong_AsLongLong (obj); if (PyErr_Occurred ()) { /* If the error was an overflow, we can try converting to ULONGEST instead. */ if (PyErr_ExceptionMatches (PyExc_OverflowError)) { gdbpy_err_fetch fetched_error; gdbpy_ref<> zero (PyInt_FromLong (0)); /* Check whether obj is positive. */ if (PyObject_RichCompareBool (obj, zero.get (), Py_GT) > 0) { ULONGEST ul; ul = PyLong_AsUnsignedLongLong (obj); if (! PyErr_Occurred ()) value = value_from_ulongest (builtin_type_upylong, ul); } else { /* There's nothing we can do. */ fetched_error.restore (); } } } else value = value_from_longest (builtin_type_pylong, l); } #if PY_MAJOR_VERSION == 2 else if (PyInt_Check (obj)) { long l = PyInt_AsLong (obj); if (! PyErr_Occurred ()) value = value_from_longest (builtin_type_pyint, l); } #endif else if (PyFloat_Check (obj)) { double d = PyFloat_AsDouble (obj); if (! PyErr_Occurred ()) { value = allocate_value (builtin_type_pyfloat); target_float_from_host_double (value_contents_raw (value), value_type (value), d); } } else if (gdbpy_is_string (obj)) { gdb::unique_xmalloc_ptr s = python_string_to_target_string (obj); if (s != NULL) value = value_cstring (s.get (), strlen (s.get ()), builtin_type_pychar); } else if (PyObject_TypeCheck (obj, &value_object_type)) value = value_copy (((value_object *) obj)->value); else if (gdbpy_is_lazy_string (obj)) { PyObject *result; result = PyObject_CallMethodObjArgs (obj, gdbpy_value_cst, NULL); value = value_copy (((value_object *) result)->value); } else #ifdef IS_PY3K PyErr_Format (PyExc_TypeError, _("Could not convert Python object: %S."), obj); #else PyErr_Format (PyExc_TypeError, _("Could not convert Python object: %s."), PyString_AsString (PyObject_Str (obj))); #endif } CATCH (except, RETURN_MASK_ALL) { gdbpy_convert_exception (except); return NULL; } END_CATCH return value; } /* Returns value object in the ARGth position in GDB's history. */ PyObject * gdbpy_history (PyObject *self, PyObject *args) { int i; struct value *res_val = NULL; /* Initialize to appease gcc warning. */ if (!PyArg_ParseTuple (args, "i", &i)) return NULL; TRY { res_val = access_value_history (i); } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH return value_to_value_object (res_val); } /* Return the value of a convenience variable. */ PyObject * gdbpy_convenience_variable (PyObject *self, PyObject *args) { const char *varname; struct value *res_val = NULL; if (!PyArg_ParseTuple (args, "s", &varname)) return NULL; TRY { struct internalvar *var = lookup_only_internalvar (varname); if (var != NULL) { res_val = value_of_internalvar (python_gdbarch, var); if (TYPE_CODE (value_type (res_val)) == TYPE_CODE_VOID) res_val = NULL; } } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH if (res_val == NULL) Py_RETURN_NONE; return value_to_value_object (res_val); } /* Set the value of a convenience variable. */ PyObject * gdbpy_set_convenience_variable (PyObject *self, PyObject *args) { const char *varname; PyObject *value_obj; struct value *value = NULL; if (!PyArg_ParseTuple (args, "sO", &varname, &value_obj)) return NULL; /* None means to clear the variable. */ if (value_obj != Py_None) { value = convert_value_from_python (value_obj); if (value == NULL) return NULL; } TRY { if (value == NULL) { struct internalvar *var = lookup_only_internalvar (varname); if (var != NULL) clear_internalvar (var); } else { struct internalvar *var = lookup_internalvar (varname); set_internalvar (var, value); } } CATCH (except, RETURN_MASK_ALL) { GDB_PY_HANDLE_EXCEPTION (except); } END_CATCH Py_RETURN_NONE; } /* Returns 1 in OBJ is a gdb.Value object, 0 otherwise. */ int gdbpy_is_value_object (PyObject *obj) { return PyObject_TypeCheck (obj, &value_object_type); } int gdbpy_initialize_values (void) { if (PyType_Ready (&value_object_type) < 0) return -1; return gdb_pymodule_addobject (gdb_module, "Value", (PyObject *) &value_object_type); } static gdb_PyGetSetDef value_object_getset[] = { { "address", valpy_get_address, NULL, "The address of the value.", NULL }, { "is_optimized_out", valpy_get_is_optimized_out, NULL, "Boolean telling whether the value is optimized " "out (i.e., not available).", NULL }, { "type", valpy_get_type, NULL, "Type of the value.", NULL }, { "dynamic_type", valpy_get_dynamic_type, NULL, "Dynamic type of the value.", NULL }, { "is_lazy", valpy_get_is_lazy, NULL, "Boolean telling whether the value is lazy (not fetched yet\n\ from the inferior). A lazy value is fetched when needed, or when\n\ the \"fetch_lazy()\" method is called.", NULL }, {NULL} /* Sentinel */ }; static PyMethodDef value_object_methods[] = { { "cast", valpy_cast, METH_VARARGS, "Cast the value to the supplied type." }, { "dynamic_cast", valpy_dynamic_cast, METH_VARARGS, "dynamic_cast (gdb.Type) -> gdb.Value\n\ Cast the value to the supplied type, as if by the C++ dynamic_cast operator." }, { "reinterpret_cast", valpy_reinterpret_cast, METH_VARARGS, "reinterpret_cast (gdb.Type) -> gdb.Value\n\ Cast the value to the supplied type, as if by the C++\n\ reinterpret_cast operator." }, { "dereference", valpy_dereference, METH_NOARGS, "Dereferences the value." }, { "referenced_value", valpy_referenced_value, METH_NOARGS, "Return the value referenced by a TYPE_CODE_REF or TYPE_CODE_PTR value." }, { "reference_value", valpy_lvalue_reference_value, METH_NOARGS, "Return a value of type TYPE_CODE_REF referencing this value." }, { "rvalue_reference_value", valpy_rvalue_reference_value, METH_NOARGS, "Return a value of type TYPE_CODE_RVALUE_REF referencing this value." }, { "const_value", valpy_const_value, METH_NOARGS, "Return a 'const' qualied version of the same value." }, { "lazy_string", (PyCFunction) valpy_lazy_string, METH_VARARGS | METH_KEYWORDS, "lazy_string ([encoding] [, length]) -> lazy_string\n\ Return a lazy string representation of the value." }, { "string", (PyCFunction) valpy_string, METH_VARARGS | METH_KEYWORDS, "string ([encoding] [, errors] [, length]) -> string\n\ Return Unicode string representation of the value." }, { "fetch_lazy", valpy_fetch_lazy, METH_NOARGS, "Fetches the value from the inferior, if it was lazy." }, {NULL} /* Sentinel */ }; static PyNumberMethods value_object_as_number = { valpy_add, valpy_subtract, valpy_multiply, #ifndef IS_PY3K valpy_divide, #endif 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 */ valpy_invert, /* nb_invert */ valpy_lsh, /* nb_lshift */ valpy_rsh, /* nb_rshift */ valpy_and, /* nb_and */ valpy_xor, /* nb_xor */ valpy_or, /* nb_or */ #ifdef IS_PY3K valpy_long, /* nb_int */ NULL, /* reserved */ #else NULL, /* nb_coerce */ valpy_int, /* nb_int */ valpy_long, /* nb_long */ #endif valpy_float, /* nb_float */ #ifndef IS_PY3K NULL, /* nb_oct */ NULL, /* nb_hex */ #endif NULL, /* nb_inplace_add */ NULL, /* nb_inplace_subtract */ NULL, /* nb_inplace_multiply */ #ifndef IS_PY3K NULL, /* nb_inplace_divide */ #endif NULL, /* nb_inplace_remainder */ NULL, /* nb_inplace_power */ NULL, /* nb_inplace_lshift */ NULL, /* nb_inplace_rshift */ NULL, /* nb_inplace_and */ NULL, /* nb_inplace_xor */ NULL, /* nb_inplace_or */ NULL, /* nb_floor_divide */ valpy_divide, /* nb_true_divide */ NULL, /* nb_inplace_floor_divide */ NULL, /* nb_inplace_true_divide */ #ifndef HAVE_LIBPYTHON2_4 /* This was added in Python 2.5. */ valpy_long, /* nb_index */ #endif /* HAVE_LIBPYTHON2_4 */ }; static PyMappingMethods value_object_as_mapping = { valpy_length, valpy_getitem, valpy_setitem }; PyTypeObject value_object_type = { PyVarObject_HEAD_INIT (NULL, 0) "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*/ valpy_hash, /*tp_hash*/ valpy_call, /*tp_call*/ valpy_str, /*tp_str*/ 0, /*tp_getattro*/ 0, /*tp_setattro*/ 0, /*tp_as_buffer*/ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES | Py_TPFLAGS_BASETYPE, /*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 */ 0, /* tp_members */ value_object_getset, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ 0, /* tp_dictoffset */ 0, /* tp_init */ 0, /* tp_alloc */ valpy_new /* tp_new */ };