binutils-gdb/gdb/python/py-linetable.c
Andrew Burgess 3965bff5b9 gdb/python: add mechanism to manage Python initialization functions
Currently, when we add a new python sub-system to GDB,
e.g. py-inferior.c, we end up having to create a new function like
gdbpy_initialize_inferior, which then has to be called from the
function do_start_initialization in python.c.

In some cases (py-micmd.c and py-tui.c), we have two functions
gdbpy_initialize_*, and gdbpy_finalize_*, with the second being called
from finalize_python which is also in python.c.

This commit proposes a mechanism to manage these initialization and
finalization calls, this means that adding a new Python subsystem will
no longer require changes to python.c or python-internal.h, instead,
the initialization and finalization functions will be registered
directly from the sub-system file, e.g. py-inferior.c, or py-micmd.c.

The initialization and finalization functions are managed through a
new class gdbpy_initialize_file in python-internal.h.  This class
contains a single global vector of all the initialization and
finalization functions.

In each Python sub-system we create a new gdbpy_initialize_file
object, the object constructor takes care of registering the two
callback functions.

Now from python.c we can call static functions on the
gdbpy_initialize_file class which take care of walking the callback
list and invoking each callback in turn.

To slightly simplify the Python sub-system files I added a new macro
GDBPY_INITIALIZE_FILE, which hides the need to create an object.  We
can now just do this:

  GDBPY_INITIALIZE_FILE (gdbpy_initialize_registers);

One possible problem with this change is that there is now no
guaranteed ordering of how the various sub-systems are initialized (or
finalized).  To try and avoid dependencies creeping in I have added a
use of the environment variable GDB_REVERSE_INIT_FUNCTIONS, this is
the same environment variable used in the generated init.c file.

Just like with init.c, when this environment variable is set we
reverse the list of Python initialization (and finalization)
functions.  As there is already a test that starts GDB with the
environment variable set then this should offer some level of
protection against dependencies creeping in - though for full
protection I guess we'd need to run all gdb.python/*.exp tests with
the variable set.

I have tested this patch with the environment variable set, and saw no
regressions, so I think we are fine right now.

One other change of note was for gdbpy_initialize_gdb_readline, this
function previously returned void.  In order to make this function
have the correct signature I've updated its return type to int, and we
now return 0 to indicate success.

All of the other initialize (and finalize) functions have been made
static within their respective sub-system files.

There should be no user visible changes after this commit.
2023-05-05 18:24:42 +01:00

595 lines
16 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Python interface to line tables.
Copyright (C) 2013-2023 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 "python-internal.h"
struct linetable_entry_object {
PyObject_HEAD
/* The line table source line. */
int line;
/* The pc associated with the source line. */
CORE_ADDR pc;
};
extern PyTypeObject linetable_entry_object_type
CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_entry_object");
struct linetable_object {
PyObject_HEAD
/* The symtab python object. We store the Python object here as the
underlying symtab can become invalid, and we have to run validity
checks on it. */
PyObject *symtab;
};
extern PyTypeObject linetable_object_type
CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_object");
struct ltpy_iterator_object {
PyObject_HEAD
/* The current entry in the line table for the iterator */
int current_index;
/* Pointer back to the original source line table object. Needed to
check if the line table is still valid, and has not been invalidated
when an object file has been freed. */
PyObject *source;
};
extern PyTypeObject ltpy_iterator_object_type
CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("ltpy_iterator_object");
/* Internal helper function to extract gdb.Symtab from a gdb.LineTable
object. */
static PyObject *
get_symtab (PyObject *linetable)
{
linetable_object *lt = (linetable_object *) linetable;
return lt->symtab;
}
#define LTPY_REQUIRE_VALID(lt_obj, symtab) \
do { \
symtab = symtab_object_to_symtab (get_symtab (lt_obj)); \
if (symtab == NULL) \
{ \
PyErr_SetString (PyExc_RuntimeError, \
_("Symbol Table in line table is invalid."));\
return NULL; \
} \
} while (0)
/* Helper function to create a line table object that wraps a
gdb.Symtab object. */
PyObject *
symtab_to_linetable_object (PyObject *symtab)
{
linetable_object *ltable;
ltable = PyObject_New (linetable_object, &linetable_object_type);
if (ltable != NULL)
{
ltable->symtab = symtab;
Py_INCREF (symtab);
}
return (PyObject *) ltable;
}
/* Internal helper function to build a line table object from a line
and an address. */
static PyObject *
build_linetable_entry (int line, CORE_ADDR address)
{
linetable_entry_object *obj;
obj = PyObject_New (linetable_entry_object,
&linetable_entry_object_type);
if (obj != NULL)
{
obj->line = line;
obj->pc = address;
}
return (PyObject *) obj;
}
/* Internal helper function to build a Python Tuple from a vector.
A line table entry can have multiple PCs for a given source line.
Construct a Tuple of all entries for the given source line, LINE
from the line table PCS. Construct one line table entry object per
address. */
static PyObject *
build_line_table_tuple_from_pcs (int line, const std::vector<CORE_ADDR> &pcs)
{
int i;
if (pcs.size () < 1)
Py_RETURN_NONE;
gdbpy_ref<> tuple (PyTuple_New (pcs.size ()));
if (tuple == NULL)
return NULL;
for (i = 0; i < pcs.size (); ++i)
{
CORE_ADDR pc = pcs[i];
gdbpy_ref<> obj (build_linetable_entry (line, pc));
if (obj == NULL)
return NULL;
else if (PyTuple_SetItem (tuple.get (), i, obj.release ()) != 0)
return NULL;
}
return tuple.release ();
}
/* Implementation of gdb.LineTable.line (self) -> Tuple. Returns a
tuple of LineTableEntry objects associated with this line from the
in the line table. */
static PyObject *
ltpy_get_pcs_for_line (PyObject *self, PyObject *args)
{
struct symtab *symtab;
gdb_py_longest py_line;
const linetable_entry *best_entry = nullptr;
std::vector<CORE_ADDR> pcs;
LTPY_REQUIRE_VALID (self, symtab);
if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
return NULL;
try
{
pcs = find_pcs_for_symtab_line (symtab, py_line, &best_entry);
}
catch (const gdb_exception &except)
{
GDB_PY_HANDLE_EXCEPTION (except);
}
return build_line_table_tuple_from_pcs (py_line, pcs);
}
/* Implementation of gdb.LineTable.has_line (self, line) -> Boolean.
Returns a Python Boolean indicating whether a source line has any
line table entries corresponding to it. */
static PyObject *
ltpy_has_line (PyObject *self, PyObject *args)
{
struct symtab *symtab;
gdb_py_longest py_line;
int index;
LTPY_REQUIRE_VALID (self, symtab);
if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
return NULL;
if (symtab->linetable () == NULL)
{
PyErr_SetString (PyExc_RuntimeError,
_("Linetable information not found in symbol table"));
return NULL;
}
for (index = 0; index < symtab->linetable ()->nitems; index++)
{
const linetable_entry *item = &(symtab->linetable ()->item[index]);
if (item->line == py_line)
Py_RETURN_TRUE;
}
Py_RETURN_FALSE;
}
/* Implementation of gdb.LineTable.source_lines (self) -> List.
Returns a Python List that contains source line entries in the
line table. This function will just return the source lines
without corresponding addresses. */
static PyObject *
ltpy_get_all_source_lines (PyObject *self, PyObject *args)
{
struct symtab *symtab;
Py_ssize_t index;
LTPY_REQUIRE_VALID (self, symtab);
if (symtab->linetable () == NULL)
{
PyErr_SetString (PyExc_RuntimeError,
_("Linetable information not found in symbol table"));
return NULL;
}
gdbpy_ref<> source_dict (PyDict_New ());
if (source_dict == NULL)
return NULL;
for (index = 0; index < symtab->linetable ()->nitems; index++)
{
const linetable_entry *item = &(symtab->linetable ()->item[index]);
/* 0 is used to signify end of line table information. Do not
include in the source set. */
if (item->line > 0)
{
gdbpy_ref<> line = gdb_py_object_from_longest (item->line);
if (line == NULL)
return NULL;
if (PyDict_SetItem (source_dict.get (), line.get (), Py_None) == -1)
return NULL;
}
}
return PyDict_Keys (source_dict.get ());
}
/* Implementation of gdb.LineTable.is_valid (self) -> Boolean.
Returns True if this line table object still exists in GDB. */
static PyObject *
ltpy_is_valid (PyObject *self, PyObject *args)
{
struct symtab *symtab = NULL;
symtab = symtab_object_to_symtab (get_symtab (self));
if (symtab == NULL)
Py_RETURN_FALSE;
Py_RETURN_TRUE;
}
/* Deconstructor for the line table object. Decrement the reference
to the symbol table object before calling the default free. */
static void
ltpy_dealloc (PyObject *self)
{
linetable_object *obj = (linetable_object *) self;
Py_DECREF (obj->symtab);
Py_TYPE (self)->tp_free (self);
}
/* Initialize LineTable, LineTableEntry and LineTableIterator
objects. */
static int CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
gdbpy_initialize_linetable (void)
{
if (PyType_Ready (&linetable_object_type) < 0)
return -1;
if (PyType_Ready (&linetable_entry_object_type) < 0)
return -1;
if (PyType_Ready (&ltpy_iterator_object_type) < 0)
return -1;
Py_INCREF (&linetable_object_type);
Py_INCREF (&linetable_entry_object_type);
Py_INCREF (&ltpy_iterator_object_type);
if (gdb_pymodule_addobject (gdb_module, "LineTable",
(PyObject *) &linetable_object_type) < 0)
return -1;
if (gdb_pymodule_addobject (gdb_module, "LineTableEntry",
(PyObject *) &linetable_entry_object_type) < 0)
return -1;
if (gdb_pymodule_addobject (gdb_module, "LineTableIterator",
(PyObject *) &ltpy_iterator_object_type) < 0)
return -1;
return 0;
}
/* LineTable entry object get functions. */
/* Implementation of gdb.LineTableEntry.line (self) -> Long. Returns
a long integer associated with the line table entry. */
static PyObject *
ltpy_entry_get_line (PyObject *self, void *closure)
{
linetable_entry_object *obj = (linetable_entry_object *) self;
return gdb_py_object_from_longest (obj->line).release ();
}
/* Implementation of gdb.LineTableEntry.pc (self) -> Long. Returns a
a long integer associated with the PC of the line table entry. */
static PyObject *
ltpy_entry_get_pc (PyObject *self, void *closure)
{
linetable_entry_object *obj = (linetable_entry_object *) self;
return gdb_py_object_from_ulongest (obj->pc).release ();
}
/* LineTable iterator functions. */
/* Return a new line table iterator. */
static PyObject *
ltpy_iter (PyObject *self)
{
ltpy_iterator_object *ltpy_iter_obj;
struct symtab *symtab = NULL;
LTPY_REQUIRE_VALID (self, symtab);
ltpy_iter_obj = PyObject_New (ltpy_iterator_object,
&ltpy_iterator_object_type);
if (ltpy_iter_obj == NULL)
return NULL;
ltpy_iter_obj->current_index = 0;
ltpy_iter_obj->source = self;
Py_INCREF (self);
return (PyObject *) ltpy_iter_obj;
}
static void
ltpy_iterator_dealloc (PyObject *obj)
{
ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) obj;
Py_DECREF (iter_obj->source);
Py_TYPE (obj)->tp_free (obj);
}
/* Return a reference to the line table iterator. */
static PyObject *
ltpy_iterator (PyObject *self)
{
ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
struct symtab *symtab;
LTPY_REQUIRE_VALID (iter_obj->source, symtab);
Py_INCREF (self);
return self;
}
/* Return the next line table entry in the iteration through the line
table data structure. */
static PyObject *
ltpy_iternext (PyObject *self)
{
ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
struct symtab *symtab;
PyObject *obj;
LTPY_REQUIRE_VALID (iter_obj->source, symtab);
if (iter_obj->current_index >= symtab->linetable ()->nitems)
{
PyErr_SetNone (PyExc_StopIteration);
return NULL;
}
const linetable_entry *item
= &(symtab->linetable ()->item[iter_obj->current_index]);
/* Skip over internal entries such as 0. 0 signifies the end of
line table data and is not useful to the API user. */
while (item->line < 1)
{
iter_obj->current_index++;
/* Exit if the internal value is the last item in the line table. */
if (iter_obj->current_index >= symtab->linetable ()->nitems)
{
PyErr_SetNone (PyExc_StopIteration);
return NULL;
}
item = &(symtab->linetable ()->item[iter_obj->current_index]);
}
struct objfile *objfile = symtab->compunit ()->objfile ();
obj = build_linetable_entry (item->line, item->pc (objfile));
iter_obj->current_index++;
return obj;
}
/* Implementation of gdb.LineTableIterator.is_valid (self) -> Boolean.
Returns True if this line table iterator object still exists in
GDB. */
static PyObject *
ltpy_iter_is_valid (PyObject *self, PyObject *args)
{
struct symtab *symtab = NULL;
ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
symtab = symtab_object_to_symtab (get_symtab (iter_obj->source));
if (symtab == NULL)
Py_RETURN_FALSE;
Py_RETURN_TRUE;
}
GDBPY_INITIALIZE_FILE (gdbpy_initialize_linetable);
static PyMethodDef linetable_object_methods[] = {
{ "line", ltpy_get_pcs_for_line, METH_VARARGS,
"line (lineno) -> Tuple\n\
Return executable locations for a given source line." },
{ "has_line", ltpy_has_line, METH_VARARGS,
"has_line (lineno) -> Boolean\n\
Return TRUE if this line has executable information, FALSE if not." },
{ "source_lines", ltpy_get_all_source_lines, METH_NOARGS,
"source_lines () -> List\n\
Return a list of all executable source lines." },
{ "is_valid", ltpy_is_valid, METH_NOARGS,
"is_valid () -> Boolean.\n\
Return True if this LineTable is valid, False if not." },
{NULL} /* Sentinel */
};
PyTypeObject linetable_object_type = {
PyVarObject_HEAD_INIT (NULL, 0)
"gdb.LineTable", /*tp_name*/
sizeof (linetable_object), /*tp_basicsize*/
0, /*tp_itemsize*/
ltpy_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 line table object", /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
ltpy_iter, /* tp_iter */
0, /* tp_iternext */
linetable_object_methods, /* tp_methods */
0, /* tp_members */
0, /* 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 */
};
static PyMethodDef ltpy_iterator_methods[] = {
{ "is_valid", ltpy_iter_is_valid, METH_NOARGS,
"is_valid () -> Boolean.\n\
Return True if this LineTable iterator is valid, False if not." },
{NULL} /* Sentinel */
};
PyTypeObject ltpy_iterator_object_type = {
PyVarObject_HEAD_INIT (NULL, 0)
"gdb.LineTableIterator", /*tp_name*/
sizeof (ltpy_iterator_object), /*tp_basicsize*/
0, /*tp_itemsize*/
ltpy_iterator_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 line table iterator object", /*tp_doc */
0, /*tp_traverse */
0, /*tp_clear */
0, /*tp_richcompare */
0, /*tp_weaklistoffset */
ltpy_iterator, /*tp_iter */
ltpy_iternext, /*tp_iternext */
ltpy_iterator_methods /*tp_methods */
};
static gdb_PyGetSetDef linetable_entry_object_getset[] = {
{ "line", ltpy_entry_get_line, NULL,
"The line number in the source file.", NULL },
{ "pc", ltpy_entry_get_pc, NULL,
"The memory address for this line number.", NULL },
{ NULL } /* Sentinel */
};
PyTypeObject linetable_entry_object_type = {
PyVarObject_HEAD_INIT (NULL, 0)
"gdb.LineTableEntry", /*tp_name*/
sizeof (linetable_entry_object), /*tp_basicsize*/
0, /*tp_itemsize*/
0, /*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 line table entry object", /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
0, /* tp_members */
linetable_entry_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 */
};