diff --git a/gdb/python/py-value.c b/gdb/python/py-value.c index df25179..69194b0 100644 --- a/gdb/python/py-value.c +++ b/gdb/python/py-value.c @@ -573,6 +573,7 @@ valpy_getitem (PyObject *self, PyObject *key) value_object *self_value = (value_object *) self; char *field = NULL; PyObject *base_class_type_object = NULL; + long bitpos = -1; volatile struct gdb_exception except; PyObject *result = NULL; @@ -614,10 +615,41 @@ valpy_getitem (PyObject *self, PyObject *key) if (name_obj == NULL) return NULL; - field = python_string_to_host_string (name_obj); - Py_DECREF (name_obj); - if (field == NULL) - return NULL; + if (name_obj != Py_None) + { + field = python_string_to_host_string (name_obj); + Py_DECREF (name_obj); + name_obj = NULL; + if (field == NULL) + return NULL; + } + + if (name_obj == Py_None || field[0] == '\0') + { + PyObject *bitpos_obj; + int valid; + + Py_XDECREF (name_obj); + xfree (field); + field = NULL; + + if (!PyObject_HasAttrString (key, "bitpos")) + { + PyErr_SetString (PyExc_AttributeError, + _("gdb.Field object has no name and no " + "'bitpos' attribute.")); + + return NULL; + } + bitpos_obj = PyObject_GetAttrString (key, "bitpos"); + if (bitpos_obj == NULL) + return NULL; + + valid = gdb_py_int_as_long (bitpos_obj, &bitpos); + Py_DECREF (bitpos_obj); + if (!valid) + return NULL; + } } } @@ -629,6 +661,8 @@ valpy_getitem (PyObject *self, PyObject *key) if (field) res_val = value_struct_elt (&tmp, NULL, field, 0, NULL); + else if (bitpos >= 0) + res_val = value_struct_elt_bitpos (&tmp, bitpos, "struct/class/union"); else if (base_class_type_object != NULL) { struct type *base_class_type, *val_type; diff --git a/gdb/testsuite/gdb.python/py-value-cc.cc b/gdb/testsuite/gdb.python/py-value-cc.cc index 80094ec..8b9aa5a 100644 --- a/gdb/testsuite/gdb.python/py-value-cc.cc +++ b/gdb/testsuite/gdb.python/py-value-cc.cc @@ -30,8 +30,15 @@ class B : public A { char a; }; +struct X +{ + union { int x; char y; }; + union { int a; char b; }; +}; + typedef B Btd; typedef int *int_ptr; +typedef X Xtd; int func (const A &a) @@ -57,6 +64,13 @@ func (const A &a) U u; u.a = 99; + X x; + x.x = 101; + x.a = 102; + + X *x_ptr = &x; + Xtd *xtd = &x; + return 0; /* Break here. */ } diff --git a/gdb/testsuite/gdb.python/py-value-cc.exp b/gdb/testsuite/gdb.python/py-value-cc.exp index eacaf2e..08dc462 100644 --- a/gdb/testsuite/gdb.python/py-value-cc.exp +++ b/gdb/testsuite/gdb.python/py-value-cc.exp @@ -53,6 +53,12 @@ gdb_test_no_output "python b_ref = gdb.parse_and_eval('b_ref')" "init b_ref" gdb_test_no_output "python b_td = gdb.parse_and_eval('b_td')" "init b_td" gdb_test_no_output "python u = gdb.parse_and_eval('u')" "init u" gdb_test_no_output "python u_fields = u.type.fields()" "init u_fields" +gdb_test_no_output "python x = gdb.parse_and_eval('x')" "init x" +gdb_test_no_output "python x_fields = x.type.fields()" "init x_fields" +gdb_test_no_output "python x_ptr = gdb.parse_and_eval('x_ptr')" "init x_ptr" +gdb_test_no_output "python xtd = gdb.parse_and_eval('xtd')" "init xtd" + +gdb_test "python print(b\[b_fields\[1\]\])" "97 'a'" "b.a via field" gdb_test "python print(b\[b_fields\[1\]\])" "97 'a'" "b.a via field" gdb_test "python print(b\[b_fields\[0\]\].type)" "A" \ @@ -79,3 +85,11 @@ gdb_test "python print(b_td\[b_fields\[0\]\]\['a'\])" "100" \ gdb_test "python print(u\[u_fields\[0\]\])" "99.*" "u's first field via field" gdb_test "python print(u\[u_fields\[1\]\])" "99.*" "u's second field via field" + +gdb_test "python print len(x_fields)" "2" "number for fields in u" +gdb_test "python print x\[x_fields\[0\]\]\['x'\]" "101" "x.x via field" +gdb_test "python print x\[x_fields\[1\]\]\['a'\]" "102" "x.a via field" +gdb_test "python print x_ptr\[x_fields\[0\]\]\['x'\]" "101" "x_ptr->x via field" +gdb_test "python print x_ptr\[x_fields\[1\]\]\['a'\]" "102" "x_ptr->a via field" +gdb_test "python print xtd\[x_fields\[0\]\]\['x'\]" "101" "xtd->x via field" +gdb_test "python print xtd\[x_fields\[1\]\]\['a'\]" "102" "xtd->a via field" diff --git a/gdb/valops.c b/gdb/valops.c index d43c758..f147854 100644 --- a/gdb/valops.c +++ b/gdb/valops.c @@ -2248,6 +2248,49 @@ value_struct_elt (struct value **argp, struct value **args, return v; } +/* Given *ARGP, a value of type structure or union, or a pointer/reference + to a structure or union, extract and return its component (field) at the + specified BITPOS. + Returns NULL if BITPOS is invalid. */ + +struct value * +value_struct_elt_bitpos (struct value **argp, int bitpos, const char *err) +{ + struct type *t; + struct value *v; + int i; + int nbases; + + *argp = coerce_array (*argp); + + t = check_typedef (value_type (*argp)); + + while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF) + { + *argp = value_ind (*argp); + if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC) + *argp = coerce_array (*argp); + t = check_typedef (value_type (*argp)); + } + + if (TYPE_CODE (t) != TYPE_CODE_STRUCT + && TYPE_CODE (t) != TYPE_CODE_UNION) + error (_("Attempt to extract a component of a value that is not a %s."), + err); + + for (i = TYPE_N_BASECLASSES (t); i < TYPE_NFIELDS (t); i++) + { + if (!field_is_static (&TYPE_FIELD (t, i)) + && bitpos == TYPE_FIELD_BITPOS (t, i)) + return value_primitive_field (*argp, 0, i, t); + } + + error (_("Attempt to extract a component with an invalid bitpos.")); + + /* Never hit. */ + return NULL; +} + /* Search through the methods of an object (and its bases) to find a specified method. Return the pointer to the fn_field list of overloaded instances. diff --git a/gdb/value.h b/gdb/value.h index 6b158df..a279803 100644 --- a/gdb/value.h +++ b/gdb/value.h @@ -670,6 +670,10 @@ extern struct value *value_struct_elt (struct value **argp, const char *name, int *static_memfuncp, const char *err); +extern struct value *value_struct_elt_bitpos (struct value **argp, + int bitpos, + const char *err); + extern struct value *value_aggregate_elt (struct type *curtype, char *name, struct type *expect_type,