binutils-gdb/gdb/python/py-block.c
Tom Tromey 08b8a139c9 Rewrite registry.h
This rewrites registry.h, removing all the macros and replacing it
with relatively ordinary template classes.  The result is less code
than the previous setup.  It replaces large macros with a relatively
straightforward C++ class, and now manages its own cleanup.

The existing type-safe "key" class is replaced with the equivalent
template class.  This approach ended up requiring relatively few
changes to the users of the registry code in gdb -- code using the key
system just required a small change to the key's declaration.

All existing users of the old C-like API are now converted to use the
type-safe API.  This mostly involved changing explicit deletion
functions to be an operator() in a deleter class.

The old "save/free" two-phase process is removed, and replaced with a
single "free" phase.  No existing code used both phases.

The old "free" callbacks took a parameter for the enclosing container
object.  However, this wasn't truly needed and is removed here as
well.
2022-07-28 14:16:50 -06:00

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/* Python interface to blocks.
Copyright (C) 2008-2022 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 "dictionary.h"
#include "symtab.h"
#include "python-internal.h"
#include "objfiles.h"
struct block_object {
PyObject_HEAD
/* The GDB block structure that represents a frame's code block. */
const struct block *block;
/* The backing object file. There is no direct relationship in GDB
between a block and an object file. When a block is created also
store a pointer to the object file for later use. */
struct objfile *objfile;
/* Keep track of all blocks with a doubly-linked list. Needed for
block invalidation if the source object file has been freed. */
block_object *prev;
block_object *next;
};
struct block_syms_iterator_object {
PyObject_HEAD
/* The block. */
const struct block *block;
/* The iterator for that block. */
struct block_iterator iter;
/* Has the iterator been initialized flag. */
int initialized_p;
/* Pointer back to the original source block object. Needed to
check if the block is still valid, and has not been invalidated
when an object file has been freed. */
block_object *source;
};
/* Require a valid block. All access to block_object->block should be
gated by this call. */
#define BLPY_REQUIRE_VALID(block_obj, block) \
do { \
block = block_object_to_block (block_obj); \
if (block == NULL) \
{ \
PyErr_SetString (PyExc_RuntimeError, \
_("Block is invalid.")); \
return NULL; \
} \
} while (0)
/* Require a valid block. This macro is called during block iterator
creation, and at each next call. */
#define BLPY_ITER_REQUIRE_VALID(block_obj) \
do { \
if (block_obj->block == NULL) \
{ \
PyErr_SetString (PyExc_RuntimeError, \
_("Source block for iterator is invalid.")); \
return NULL; \
} \
} while (0)
/* This is called when an objfile is about to be freed.
Invalidate the block as further actions on the block would result
in bad data. All access to obj->symbol should be gated by
BLPY_REQUIRE_VALID which will raise an exception on invalid
blocks. */
struct blpy_deleter
{
void operator() (block_object *obj)
{
while (obj)
{
block_object *next = obj->next;
obj->block = NULL;
obj->objfile = NULL;
obj->next = NULL;
obj->prev = NULL;
obj = next;
}
}
};
extern PyTypeObject block_syms_iterator_object_type
CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("block_syms_iterator_object");
static const registry<objfile>::key<block_object, blpy_deleter>
blpy_objfile_data_key;
static PyObject *
blpy_iter (PyObject *self)
{
block_syms_iterator_object *block_iter_obj;
const struct block *block = NULL;
BLPY_REQUIRE_VALID (self, block);
block_iter_obj = PyObject_New (block_syms_iterator_object,
&block_syms_iterator_object_type);
if (block_iter_obj == NULL)
return NULL;
block_iter_obj->block = block;
block_iter_obj->initialized_p = 0;
Py_INCREF (self);
block_iter_obj->source = (block_object *) self;
return (PyObject *) block_iter_obj;
}
static PyObject *
blpy_get_start (PyObject *self, void *closure)
{
const struct block *block = NULL;
BLPY_REQUIRE_VALID (self, block);
return gdb_py_object_from_ulongest (block->start ()).release ();
}
static PyObject *
blpy_get_end (PyObject *self, void *closure)
{
const struct block *block = NULL;
BLPY_REQUIRE_VALID (self, block);
return gdb_py_object_from_ulongest (block->end ()).release ();
}
static PyObject *
blpy_get_function (PyObject *self, void *closure)
{
struct symbol *sym;
const struct block *block;
BLPY_REQUIRE_VALID (self, block);
sym = block->function ();
if (sym)
return symbol_to_symbol_object (sym);
Py_RETURN_NONE;
}
static PyObject *
blpy_get_superblock (PyObject *self, void *closure)
{
const struct block *block;
const struct block *super_block;
block_object *self_obj = (block_object *) self;
BLPY_REQUIRE_VALID (self, block);
super_block = block->superblock ();
if (super_block)
return block_to_block_object (super_block, self_obj->objfile);
Py_RETURN_NONE;
}
/* Return the global block associated to this block. */
static PyObject *
blpy_get_global_block (PyObject *self, void *closure)
{
const struct block *block;
const struct block *global_block;
block_object *self_obj = (block_object *) self;
BLPY_REQUIRE_VALID (self, block);
global_block = block_global_block (block);
return block_to_block_object (global_block,
self_obj->objfile);
}
/* Return the static block associated to this block. Return None
if we cannot get the static block (this is the global block). */
static PyObject *
blpy_get_static_block (PyObject *self, void *closure)
{
const struct block *block;
const struct block *static_block;
block_object *self_obj = (block_object *) self;
BLPY_REQUIRE_VALID (self, block);
if (block->superblock () == NULL)
Py_RETURN_NONE;
static_block = block_static_block (block);
return block_to_block_object (static_block, self_obj->objfile);
}
/* Implementation of gdb.Block.is_global (self) -> Boolean.
Returns True if this block object is a global block. */
static PyObject *
blpy_is_global (PyObject *self, void *closure)
{
const struct block *block;
BLPY_REQUIRE_VALID (self, block);
if (block->superblock ())
Py_RETURN_FALSE;
Py_RETURN_TRUE;
}
/* Implementation of gdb.Block.is_static (self) -> Boolean.
Returns True if this block object is a static block. */
static PyObject *
blpy_is_static (PyObject *self, void *closure)
{
const struct block *block;
BLPY_REQUIRE_VALID (self, block);
if (block->superblock () != NULL
&& block->superblock ()->superblock () == NULL)
Py_RETURN_TRUE;
Py_RETURN_FALSE;
}
/* Given a string, returns the gdb.Symbol representing that symbol in this
block. If such a symbol does not exist, returns NULL with a Python
exception. */
static PyObject *
blpy_getitem (PyObject *self, PyObject *key)
{
const struct block *block;
BLPY_REQUIRE_VALID (self, block);
gdb::unique_xmalloc_ptr<char> name = python_string_to_host_string (key);
if (name == nullptr)
return nullptr;
lookup_name_info lookup_name (name.get(), symbol_name_match_type::FULL);
/* We use ALL_BLOCK_SYMBOLS_WITH_NAME instead of block_lookup_symbol so
that we can look up symbols irrespective of the domain, matching the
iterator. It would be confusing if the iterator returns symbols you
can't find via getitem. */
struct block_iterator iter;
struct symbol *sym = nullptr;
ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym)
{
/* Just stop at the first match */
break;
}
if (sym == nullptr)
{
PyErr_SetObject (PyExc_KeyError, key);
return nullptr;
}
return symbol_to_symbol_object (sym);
}
static void
blpy_dealloc (PyObject *obj)
{
block_object *block = (block_object *) obj;
if (block->prev)
block->prev->next = block->next;
else if (block->objfile)
blpy_objfile_data_key.set (block->objfile, block->next);
if (block->next)
block->next->prev = block->prev;
block->block = NULL;
Py_TYPE (obj)->tp_free (obj);
}
/* Given a block, and a block_object that has previously been
allocated and initialized, populate the block_object with the
struct block data. Also, register the block_object life-cycle
with the life-cycle of the object file associated with this
block, if needed. */
static void
set_block (block_object *obj, const struct block *block,
struct objfile *objfile)
{
obj->block = block;
obj->prev = NULL;
if (objfile)
{
obj->objfile = objfile;
obj->next = blpy_objfile_data_key.get (objfile);
if (obj->next)
obj->next->prev = obj;
blpy_objfile_data_key.set (objfile, obj);
}
else
obj->next = NULL;
}
/* Create a new block object (gdb.Block) that encapsulates the struct
block object from GDB. */
PyObject *
block_to_block_object (const struct block *block, struct objfile *objfile)
{
block_object *block_obj;
block_obj = PyObject_New (block_object, &block_object_type);
if (block_obj)
set_block (block_obj, block, objfile);
return (PyObject *) block_obj;
}
/* Return struct block reference that is wrapped by this object. */
const struct block *
block_object_to_block (PyObject *obj)
{
if (! PyObject_TypeCheck (obj, &block_object_type))
return NULL;
return ((block_object *) obj)->block;
}
/* Return a reference to the block iterator. */
static PyObject *
blpy_block_syms_iter (PyObject *self)
{
block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) self;
BLPY_ITER_REQUIRE_VALID (iter_obj->source);
Py_INCREF (self);
return self;
}
/* Return the next symbol in the iteration through the block's
dictionary. */
static PyObject *
blpy_block_syms_iternext (PyObject *self)
{
block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) self;
struct symbol *sym;
BLPY_ITER_REQUIRE_VALID (iter_obj->source);
if (!iter_obj->initialized_p)
{
sym = block_iterator_first (iter_obj->block, &(iter_obj->iter));
iter_obj->initialized_p = 1;
}
else
sym = block_iterator_next (&(iter_obj->iter));
if (sym == NULL)
{
PyErr_SetString (PyExc_StopIteration, _("Symbol is null."));
return NULL;
}
return symbol_to_symbol_object (sym);
}
static void
blpy_block_syms_dealloc (PyObject *obj)
{
block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) obj;
Py_XDECREF (iter_obj->source);
Py_TYPE (obj)->tp_free (obj);
}
/* Implementation of gdb.Block.is_valid (self) -> Boolean.
Returns True if this block object still exists in GDB. */
static PyObject *
blpy_is_valid (PyObject *self, PyObject *args)
{
const struct block *block;
block = block_object_to_block (self);
if (block == NULL)
Py_RETURN_FALSE;
Py_RETURN_TRUE;
}
/* Implementation of gdb.BlockIterator.is_valid (self) -> Boolean.
Returns True if this block iterator object still exists in GDB */
static PyObject *
blpy_iter_is_valid (PyObject *self, PyObject *args)
{
block_syms_iterator_object *iter_obj =
(block_syms_iterator_object *) self;
if (iter_obj->source->block == NULL)
Py_RETURN_FALSE;
Py_RETURN_TRUE;
}
int
gdbpy_initialize_blocks (void)
{
block_object_type.tp_new = PyType_GenericNew;
if (PyType_Ready (&block_object_type) < 0)
return -1;
block_syms_iterator_object_type.tp_new = PyType_GenericNew;
if (PyType_Ready (&block_syms_iterator_object_type) < 0)
return -1;
if (gdb_pymodule_addobject (gdb_module, "Block",
(PyObject *) &block_object_type) < 0)
return -1;
return gdb_pymodule_addobject (gdb_module, "BlockIterator",
(PyObject *) &block_syms_iterator_object_type);
}
static PyMethodDef block_object_methods[] = {
{ "is_valid", blpy_is_valid, METH_NOARGS,
"is_valid () -> Boolean.\n\
Return true if this block is valid, false if not." },
{NULL} /* Sentinel */
};
static gdb_PyGetSetDef block_object_getset[] = {
{ "start", blpy_get_start, NULL, "Start address of the block.", NULL },
{ "end", blpy_get_end, NULL, "End address of the block.", NULL },
{ "function", blpy_get_function, NULL,
"Symbol that names the block, or None.", NULL },
{ "superblock", blpy_get_superblock, NULL,
"Block containing the block, or None.", NULL },
{ "global_block", blpy_get_global_block, NULL,
"Block containing the global block.", NULL },
{ "static_block", blpy_get_static_block, NULL,
"Block containing the static block.", NULL },
{ "is_static", blpy_is_static, NULL,
"Whether this block is a static block.", NULL },
{ "is_global", blpy_is_global, NULL,
"Whether this block is a global block.", NULL },
{ NULL } /* Sentinel */
};
static PyMappingMethods block_object_as_mapping = {
NULL,
blpy_getitem,
NULL
};
PyTypeObject block_object_type = {
PyVarObject_HEAD_INIT (NULL, 0)
"gdb.Block", /*tp_name*/
sizeof (block_object), /*tp_basicsize*/
0, /*tp_itemsize*/
blpy_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*/
&block_object_as_mapping, /*tp_as_mapping*/
0, /*tp_hash */
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
"GDB block object", /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
blpy_iter, /* tp_iter */
0, /* tp_iternext */
block_object_methods, /* tp_methods */
0, /* tp_members */
block_object_getset /* tp_getset */
};
static PyMethodDef block_iterator_object_methods[] = {
{ "is_valid", blpy_iter_is_valid, METH_NOARGS,
"is_valid () -> Boolean.\n\
Return true if this block iterator is valid, false if not." },
{NULL} /* Sentinel */
};
PyTypeObject block_syms_iterator_object_type = {
PyVarObject_HEAD_INIT (NULL, 0)
"gdb.BlockIterator", /*tp_name*/
sizeof (block_syms_iterator_object), /*tp_basicsize*/
0, /*tp_itemsize*/
blpy_block_syms_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*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
"GDB block syms iterator object", /*tp_doc */
0, /*tp_traverse */
0, /*tp_clear */
0, /*tp_richcompare */
0, /*tp_weaklistoffset */
blpy_block_syms_iter, /*tp_iter */
blpy_block_syms_iternext, /*tp_iternext */
block_iterator_object_methods /*tp_methods */
};