old-cross-binutils/gdb/python/py-symbol.c
Tom Tromey 74f910c87c PR python/14634:
* python/py-symbol.c (sympy_dealloc): Check for NULL symbol.
testsuite
	* gdb.python/py-symbol.exp: Test symbol destructor.
2012-10-15 15:20:27 +00:00

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/* Python interface to symbols.
Copyright (C) 2008-2012 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 "block.h"
#include "exceptions.h"
#include "frame.h"
#include "symtab.h"
#include "python-internal.h"
#include "objfiles.h"
typedef struct sympy_symbol_object {
PyObject_HEAD
/* The GDB symbol structure this object is wrapping. */
struct symbol *symbol;
/* A symbol object is associated with an objfile, so keep track with
doubly-linked list, rooted in the objfile. This lets us
invalidate the underlying struct symbol when the objfile is
deleted. */
struct sympy_symbol_object *prev;
struct sympy_symbol_object *next;
} symbol_object;
/* Require a valid symbol. All access to symbol_object->symbol should be
gated by this call. */
#define SYMPY_REQUIRE_VALID(symbol_obj, symbol) \
do { \
symbol = symbol_object_to_symbol (symbol_obj); \
if (symbol == NULL) \
{ \
PyErr_SetString (PyExc_RuntimeError, \
_("Symbol is invalid.")); \
return NULL; \
} \
} while (0)
static const struct objfile_data *sympy_objfile_data_key;
static PyObject *
sympy_str (PyObject *self)
{
PyObject *result;
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
result = PyString_FromString (SYMBOL_PRINT_NAME (symbol));
return result;
}
static PyObject *
sympy_get_type (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
if (SYMBOL_TYPE (symbol) == NULL)
{
Py_INCREF (Py_None);
return Py_None;
}
return type_to_type_object (SYMBOL_TYPE (symbol));
}
static PyObject *
sympy_get_symtab (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
return symtab_to_symtab_object (SYMBOL_SYMTAB (symbol));
}
static PyObject *
sympy_get_name (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
return PyString_FromString (SYMBOL_NATURAL_NAME (symbol));
}
static PyObject *
sympy_get_linkage_name (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
return PyString_FromString (SYMBOL_LINKAGE_NAME (symbol));
}
static PyObject *
sympy_get_print_name (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
return sympy_str (self);
}
static PyObject *
sympy_get_addr_class (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
return PyInt_FromLong (SYMBOL_CLASS (symbol));
}
static PyObject *
sympy_is_argument (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
return PyBool_FromLong (SYMBOL_IS_ARGUMENT (symbol));
}
static PyObject *
sympy_is_constant (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
enum address_class class;
SYMPY_REQUIRE_VALID (self, symbol);
class = SYMBOL_CLASS (symbol);
return PyBool_FromLong (class == LOC_CONST || class == LOC_CONST_BYTES);
}
static PyObject *
sympy_is_function (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
enum address_class class;
SYMPY_REQUIRE_VALID (self, symbol);
class = SYMBOL_CLASS (symbol);
return PyBool_FromLong (class == LOC_BLOCK);
}
static PyObject *
sympy_is_variable (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
enum address_class class;
SYMPY_REQUIRE_VALID (self, symbol);
class = SYMBOL_CLASS (symbol);
return PyBool_FromLong (!SYMBOL_IS_ARGUMENT (symbol)
&& (class == LOC_LOCAL || class == LOC_REGISTER
|| class == LOC_STATIC || class == LOC_COMPUTED
|| class == LOC_OPTIMIZED_OUT));
}
/* Implementation of gdb.Symbol.needs_frame -> Boolean.
Returns true iff the symbol needs a frame for evaluation. */
static PyObject *
sympy_needs_frame (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
volatile struct gdb_exception except;
int result = 0;
SYMPY_REQUIRE_VALID (self, symbol);
TRY_CATCH (except, RETURN_MASK_ALL)
{
result = symbol_read_needs_frame (symbol);
}
GDB_PY_HANDLE_EXCEPTION (except);
if (result)
Py_RETURN_TRUE;
Py_RETURN_FALSE;
}
/* Implementation of gdb.Symbol.line -> int.
Returns the line number at which the symbol was defined. */
static PyObject *
sympy_line (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
SYMPY_REQUIRE_VALID (self, symbol);
return PyInt_FromLong (SYMBOL_LINE (symbol));
}
/* Implementation of gdb.Symbol.is_valid (self) -> Boolean.
Returns True if this Symbol still exists in GDB. */
static PyObject *
sympy_is_valid (PyObject *self, PyObject *args)
{
struct symbol *symbol = NULL;
symbol = symbol_object_to_symbol (self);
if (symbol == NULL)
Py_RETURN_FALSE;
Py_RETURN_TRUE;
}
/* Implementation of gdb.Symbol.value (self[, frame]) -> gdb.Value. Returns
the value of the symbol, or an error in various circumstances. */
static PyObject *
sympy_value (PyObject *self, PyObject *args)
{
struct symbol *symbol = NULL;
struct frame_info *frame_info = NULL;
PyObject *frame_obj = NULL;
struct value *value = NULL;
volatile struct gdb_exception except;
if (!PyArg_ParseTuple (args, "|O", &frame_obj))
return NULL;
if (frame_obj != NULL && !PyObject_TypeCheck (frame_obj, &frame_object_type))
{
PyErr_SetString (PyExc_TypeError, "argument is not a frame");
return NULL;
}
SYMPY_REQUIRE_VALID (self, symbol);
if (SYMBOL_CLASS (symbol) == LOC_TYPEDEF)
{
PyErr_SetString (PyExc_TypeError, "cannot get the value of a typedef");
return NULL;
}
TRY_CATCH (except, RETURN_MASK_ALL)
{
if (frame_obj != NULL)
{
frame_info = frame_object_to_frame_info (frame_obj);
if (frame_info == NULL)
error (_("invalid frame"));
}
if (symbol_read_needs_frame (symbol) && frame_info == NULL)
error (_("symbol requires a frame to compute its value"));
value = read_var_value (symbol, frame_info);
}
GDB_PY_HANDLE_EXCEPTION (except);
return value_to_value_object (value);
}
/* Given a symbol, and a symbol_object that has previously been
allocated and initialized, populate the symbol_object with the
struct symbol data. Also, register the symbol_object life-cycle
with the life-cycle of the object file associated with this
symbol, if needed. */
static void
set_symbol (symbol_object *obj, struct symbol *symbol)
{
obj->symbol = symbol;
obj->prev = NULL;
if (SYMBOL_SYMTAB (symbol))
{
obj->next = objfile_data (SYMBOL_SYMTAB (symbol)->objfile,
sympy_objfile_data_key);
if (obj->next)
obj->next->prev = obj;
set_objfile_data (SYMBOL_SYMTAB (symbol)->objfile,
sympy_objfile_data_key, obj);
}
else
obj->next = NULL;
}
/* Create a new symbol object (gdb.Symbol) that encapsulates the struct
symbol object from GDB. */
PyObject *
symbol_to_symbol_object (struct symbol *sym)
{
symbol_object *sym_obj;
sym_obj = PyObject_New (symbol_object, &symbol_object_type);
if (sym_obj)
set_symbol (sym_obj, sym);
return (PyObject *) sym_obj;
}
/* Return the symbol that is wrapped by this symbol object. */
struct symbol *
symbol_object_to_symbol (PyObject *obj)
{
if (! PyObject_TypeCheck (obj, &symbol_object_type))
return NULL;
return ((symbol_object *) obj)->symbol;
}
static void
sympy_dealloc (PyObject *obj)
{
symbol_object *sym_obj = (symbol_object *) obj;
if (sym_obj->prev)
sym_obj->prev->next = sym_obj->next;
else if (sym_obj->symbol && SYMBOL_SYMTAB (sym_obj->symbol))
{
set_objfile_data (SYMBOL_SYMTAB (sym_obj->symbol)->objfile,
sympy_objfile_data_key, sym_obj->next);
}
if (sym_obj->next)
sym_obj->next->prev = sym_obj->prev;
sym_obj->symbol = NULL;
}
/* Implementation of
gdb.lookup_symbol (name [, block] [, domain]) -> (symbol, is_field_of_this)
A tuple with 2 elements is always returned. The first is the symbol
object or None, the second is a boolean with the value of
is_a_field_of_this (see comment in lookup_symbol_in_language). */
PyObject *
gdbpy_lookup_symbol (PyObject *self, PyObject *args, PyObject *kw)
{
int domain = VAR_DOMAIN, is_a_field_of_this = 0;
const char *name;
static char *keywords[] = { "name", "block", "domain", NULL };
struct symbol *symbol = NULL;
PyObject *block_obj = NULL, *ret_tuple, *sym_obj, *bool_obj;
const struct block *block = NULL;
volatile struct gdb_exception except;
if (! PyArg_ParseTupleAndKeywords (args, kw, "s|O!i", keywords, &name,
&block_object_type, &block_obj, &domain))
return NULL;
if (block_obj)
block = block_object_to_block (block_obj);
else
{
struct frame_info *selected_frame;
volatile struct gdb_exception except;
TRY_CATCH (except, RETURN_MASK_ALL)
{
selected_frame = get_selected_frame (_("No frame selected."));
block = get_frame_block (selected_frame, NULL);
}
GDB_PY_HANDLE_EXCEPTION (except);
}
TRY_CATCH (except, RETURN_MASK_ALL)
{
symbol = lookup_symbol (name, block, domain, &is_a_field_of_this);
}
GDB_PY_HANDLE_EXCEPTION (except);
ret_tuple = PyTuple_New (2);
if (!ret_tuple)
return NULL;
if (symbol)
{
sym_obj = symbol_to_symbol_object (symbol);
if (!sym_obj)
{
Py_DECREF (ret_tuple);
return NULL;
}
}
else
{
sym_obj = Py_None;
Py_INCREF (Py_None);
}
PyTuple_SET_ITEM (ret_tuple, 0, sym_obj);
bool_obj = is_a_field_of_this? Py_True : Py_False;
Py_INCREF (bool_obj);
PyTuple_SET_ITEM (ret_tuple, 1, bool_obj);
return ret_tuple;
}
/* Implementation of
gdb.lookup_global_symbol (name [, domain]) -> symbol or None. */
PyObject *
gdbpy_lookup_global_symbol (PyObject *self, PyObject *args, PyObject *kw)
{
int domain = VAR_DOMAIN;
const char *name;
static char *keywords[] = { "name", "domain", NULL };
struct symbol *symbol = NULL;
PyObject *sym_obj;
volatile struct gdb_exception except;
if (! PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords, &name,
&domain))
return NULL;
TRY_CATCH (except, RETURN_MASK_ALL)
{
symbol = lookup_symbol_global (name, NULL, domain);
}
GDB_PY_HANDLE_EXCEPTION (except);
if (symbol)
{
sym_obj = symbol_to_symbol_object (symbol);
if (!sym_obj)
return NULL;
}
else
{
sym_obj = Py_None;
Py_INCREF (Py_None);
}
return sym_obj;
}
/* This function is called when an objfile is about to be freed.
Invalidate the symbol as further actions on the symbol would result
in bad data. All access to obj->symbol should be gated by
SYMPY_REQUIRE_VALID which will raise an exception on invalid
symbols. */
static void
del_objfile_symbols (struct objfile *objfile, void *datum)
{
symbol_object *obj = datum;
while (obj)
{
symbol_object *next = obj->next;
obj->symbol = NULL;
obj->next = NULL;
obj->prev = NULL;
obj = next;
}
}
void
gdbpy_initialize_symbols (void)
{
if (PyType_Ready (&symbol_object_type) < 0)
return;
/* Register an objfile "free" callback so we can properly
invalidate symbol when an object file that is about to be
deleted. */
sympy_objfile_data_key
= register_objfile_data_with_cleanup (NULL, del_objfile_symbols);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_UNDEF", LOC_UNDEF);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_CONST", LOC_CONST);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_STATIC", LOC_STATIC);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REGISTER", LOC_REGISTER);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_ARG", LOC_ARG);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REF_ARG", LOC_REF_ARG);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_LOCAL", LOC_LOCAL);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_TYPEDEF", LOC_TYPEDEF);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_LABEL", LOC_LABEL);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_BLOCK", LOC_BLOCK);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_CONST_BYTES",
LOC_CONST_BYTES);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_UNRESOLVED",
LOC_UNRESOLVED);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_OPTIMIZED_OUT",
LOC_OPTIMIZED_OUT);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_COMPUTED", LOC_COMPUTED);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REGPARM_ADDR",
LOC_REGPARM_ADDR);
PyModule_AddIntConstant (gdb_module, "SYMBOL_UNDEF_DOMAIN", UNDEF_DOMAIN);
PyModule_AddIntConstant (gdb_module, "SYMBOL_VAR_DOMAIN", VAR_DOMAIN);
PyModule_AddIntConstant (gdb_module, "SYMBOL_STRUCT_DOMAIN", STRUCT_DOMAIN);
PyModule_AddIntConstant (gdb_module, "SYMBOL_LABEL_DOMAIN", LABEL_DOMAIN);
PyModule_AddIntConstant (gdb_module, "SYMBOL_VARIABLES_DOMAIN",
VARIABLES_DOMAIN);
PyModule_AddIntConstant (gdb_module, "SYMBOL_FUNCTIONS_DOMAIN",
FUNCTIONS_DOMAIN);
PyModule_AddIntConstant (gdb_module, "SYMBOL_TYPES_DOMAIN", TYPES_DOMAIN);
Py_INCREF (&symbol_object_type);
PyModule_AddObject (gdb_module, "Symbol", (PyObject *) &symbol_object_type);
}
static PyGetSetDef symbol_object_getset[] = {
{ "type", sympy_get_type, NULL,
"Type of the symbol.", NULL },
{ "symtab", sympy_get_symtab, NULL,
"Symbol table in which the symbol appears.", NULL },
{ "name", sympy_get_name, NULL,
"Name of the symbol, as it appears in the source code.", NULL },
{ "linkage_name", sympy_get_linkage_name, NULL,
"Name of the symbol, as used by the linker (i.e., may be mangled).",
NULL },
{ "print_name", sympy_get_print_name, NULL,
"Name of the symbol in a form suitable for output.\n\
This is either name or linkage_name, depending on whether the user asked GDB\n\
to display demangled or mangled names.", NULL },
{ "addr_class", sympy_get_addr_class, NULL, "Address class of the symbol." },
{ "is_argument", sympy_is_argument, NULL,
"True if the symbol is an argument of a function." },
{ "is_constant", sympy_is_constant, NULL,
"True if the symbol is a constant." },
{ "is_function", sympy_is_function, NULL,
"True if the symbol is a function or method." },
{ "is_variable", sympy_is_variable, NULL,
"True if the symbol is a variable." },
{ "needs_frame", sympy_needs_frame, NULL,
"True if the symbol requires a frame for evaluation." },
{ "line", sympy_line, NULL,
"The source line number at which the symbol was defined." },
{ NULL } /* Sentinel */
};
static PyMethodDef symbol_object_methods[] = {
{ "is_valid", sympy_is_valid, METH_NOARGS,
"is_valid () -> Boolean.\n\
Return true if this symbol is valid, false if not." },
{ "value", sympy_value, METH_VARARGS,
"value ([frame]) -> gdb.Value\n\
Return the value of the symbol." },
{NULL} /* Sentinel */
};
PyTypeObject symbol_object_type = {
PyObject_HEAD_INIT (NULL)
0, /*ob_size*/
"gdb.Symbol", /*tp_name*/
sizeof (symbol_object), /*tp_basicsize*/
0, /*tp_itemsize*/
sympy_dealloc, /*tp_dealloc*/
0, /*tp_print*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_compare*/
0, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash */
0, /*tp_call*/
sympy_str, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
"GDB symbol object", /*tp_doc */
0, /*tp_traverse */
0, /*tp_clear */
0, /*tp_richcompare */
0, /*tp_weaklistoffset */
0, /*tp_iter */
0, /*tp_iternext */
symbol_object_methods, /*tp_methods */
0, /*tp_members */
symbol_object_getset /*tp_getset */
};