binutils-gdb/gdb/python/py-symbol.c
Tom Tromey 51e78fc5fa Update symbol domain and location values for Python
In the distant past, there was no distinction between domain_enum and
search_domain.  At that point, there were two sets of enumerators in a
single enum -- which is why these were eventually split.  This
confusion leaked out to the Python API as well, as noted in
PR python/21765.

This patch deprecates the constants that aren't useful to the Python
API.  They are left in place for now, but removed from the
documentation.  Also, their values are changed so that, if used, they
might work.  Finally, missing domains and location constants are
added.

gdb/ChangeLog
2018-10-06  Tom Tromey  <tom@tromey.com>

	PR python/21765:
	* python/py-symbol.c (gdbpy_initialize_symbols): Redefine
	SYMBOL_VARIABLES_DOMAIN, SYMBOL_FUNCTIONS_DOMAIN,
	SYMBOL_TYPES_DOMAIN.  Define SYMBOL_MODULE_DOMAIN,
	SYMBOL_COMMON_BLOCK_DOMAIN, SYMBOL_LOC_COMMON_BLOCK.

gdb/doc/ChangeLog
2018-10-06  Tom Tromey  <tom@tromey.com>

	PR python/21765:
	* python.texi (Symbols In Python): Document the module and
	common-block domains.  Remove documentation for incorrect
	domains.
2018-10-06 23:20:55 -06:00

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/* Python interface to symbols.
Copyright (C) 2008-2018 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 "frame.h"
#include "symtab.h"
#include "python-internal.h"
#include "objfiles.h"
#include "py-ref.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);
if (!SYMBOL_OBJFILE_OWNED (symbol))
Py_RETURN_NONE;
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 theclass;
SYMPY_REQUIRE_VALID (self, symbol);
theclass = SYMBOL_CLASS (symbol);
return PyBool_FromLong (theclass == LOC_CONST || theclass == LOC_CONST_BYTES);
}
static PyObject *
sympy_is_function (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
enum address_class theclass;
SYMPY_REQUIRE_VALID (self, symbol);
theclass = SYMBOL_CLASS (symbol);
return PyBool_FromLong (theclass == LOC_BLOCK);
}
static PyObject *
sympy_is_variable (PyObject *self, void *closure)
{
struct symbol *symbol = NULL;
enum address_class theclass;
SYMPY_REQUIRE_VALID (self, symbol);
theclass = SYMBOL_CLASS (symbol);
return PyBool_FromLong (!SYMBOL_IS_ARGUMENT (symbol)
&& (theclass == LOC_LOCAL || theclass == LOC_REGISTER
|| theclass == LOC_STATIC || theclass == LOC_COMPUTED
|| theclass == 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;
int result = 0;
SYMPY_REQUIRE_VALID (self, symbol);
TRY
{
result = symbol_read_needs_frame (symbol);
}
CATCH (except, RETURN_MASK_ALL)
{
GDB_PY_HANDLE_EXCEPTION (except);
}
END_CATCH
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;
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
{
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"));
/* TODO: currently, we have no way to recover the block in which SYMBOL
was found, so we have no block to pass to read_var_value. This will
yield an incorrect value when symbol is not local to FRAME_INFO (this
can happen with nested functions). */
value = read_var_value (symbol, NULL, frame_info);
}
CATCH (except, RETURN_MASK_ALL)
{
GDB_PY_HANDLE_EXCEPTION (except);
}
END_CATCH
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_OBJFILE_OWNED (symbol)
&& symbol_symtab (symbol) != NULL)
{
struct objfile *objfile = symbol_objfile (symbol);
obj->next = ((struct sympy_symbol_object *)
objfile_data (objfile, sympy_objfile_data_key));
if (obj->next)
obj->next->prev = obj;
set_objfile_data (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 != NULL
&& SYMBOL_OBJFILE_OWNED (sym_obj->symbol)
&& symbol_symtab (sym_obj->symbol) != NULL)
{
set_objfile_data (symbol_objfile (sym_obj->symbol),
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;
struct field_of_this_result is_a_field_of_this;
const char *name;
static const char *keywords[] = { "name", "block", "domain", NULL };
struct symbol *symbol = NULL;
PyObject *block_obj = NULL, *sym_obj, *bool_obj;
const struct block *block = NULL;
if (!gdb_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;
TRY
{
selected_frame = get_selected_frame (_("No frame selected."));
block = get_frame_block (selected_frame, NULL);
}
CATCH (except, RETURN_MASK_ALL)
{
GDB_PY_HANDLE_EXCEPTION (except);
}
END_CATCH
}
TRY
{
symbol = lookup_symbol (name, block, (domain_enum) domain,
&is_a_field_of_this).symbol;
}
CATCH (except, RETURN_MASK_ALL)
{
GDB_PY_HANDLE_EXCEPTION (except);
}
END_CATCH
gdbpy_ref<> ret_tuple (PyTuple_New (2));
if (ret_tuple == NULL)
return NULL;
if (symbol)
{
sym_obj = symbol_to_symbol_object (symbol);
if (!sym_obj)
return NULL;
}
else
{
sym_obj = Py_None;
Py_INCREF (Py_None);
}
PyTuple_SET_ITEM (ret_tuple.get (), 0, sym_obj);
bool_obj = (is_a_field_of_this.type != NULL) ? Py_True : Py_False;
Py_INCREF (bool_obj);
PyTuple_SET_ITEM (ret_tuple.get (), 1, bool_obj);
return ret_tuple.release ();
}
/* 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 const char *keywords[] = { "name", "domain", NULL };
struct symbol *symbol = NULL;
PyObject *sym_obj;
if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords, &name,
&domain))
return NULL;
TRY
{
symbol = lookup_global_symbol (name, NULL, (domain_enum) domain).symbol;
}
CATCH (except, RETURN_MASK_ALL)
{
GDB_PY_HANDLE_EXCEPTION (except);
}
END_CATCH
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 = (symbol_object *) datum;
while (obj)
{
symbol_object *next = obj->next;
obj->symbol = NULL;
obj->next = NULL;
obj->prev = NULL;
obj = next;
}
}
int
gdbpy_initialize_symbols (void)
{
if (PyType_Ready (&symbol_object_type) < 0)
return -1;
/* 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);
if (PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_UNDEF", LOC_UNDEF) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_CONST",
LOC_CONST) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_STATIC",
LOC_STATIC) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REGISTER",
LOC_REGISTER) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_ARG",
LOC_ARG) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REF_ARG",
LOC_REF_ARG) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_LOCAL",
LOC_LOCAL) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_TYPEDEF",
LOC_TYPEDEF) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_LABEL",
LOC_LABEL) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_BLOCK",
LOC_BLOCK) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_CONST_BYTES",
LOC_CONST_BYTES) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_UNRESOLVED",
LOC_UNRESOLVED) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_OPTIMIZED_OUT",
LOC_OPTIMIZED_OUT) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_COMPUTED",
LOC_COMPUTED) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_COMMON_BLOCK",
LOC_COMMON_BLOCK) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REGPARM_ADDR",
LOC_REGPARM_ADDR) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_UNDEF_DOMAIN",
UNDEF_DOMAIN) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_VAR_DOMAIN",
VAR_DOMAIN) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_STRUCT_DOMAIN",
STRUCT_DOMAIN) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_MODULE_DOMAIN",
MODULE_DOMAIN) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_COMMON_BLOCK_DOMAIN",
COMMON_BLOCK_DOMAIN) < 0)
return -1;
/* These remain defined for compatibility, but as they were never
correct, they are no longer documented. Eventually we can remove
them. These exist because at one time, enum search_domain and
enum domain_enum_tag were combined -- but different values were
used differently. Here we try to give them values that will make
sense if they are passed to gdb.lookup_symbol. */
if (PyModule_AddIntConstant (gdb_module, "SYMBOL_VARIABLES_DOMAIN",
VAR_DOMAIN) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_FUNCTIONS_DOMAIN",
VAR_DOMAIN) < 0
|| PyModule_AddIntConstant (gdb_module, "SYMBOL_TYPES_DOMAIN",
VAR_DOMAIN) < 0)
return -1;
return gdb_pymodule_addobject (gdb_module, "Symbol",
(PyObject *) &symbol_object_type);
}
static gdb_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 = {
PyVarObject_HEAD_INIT (NULL, 0)
"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 */
};