541 lines
15 KiB
C
541 lines
15 KiB
C
/* Python interface to stack frames
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||
|
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Copyright (C) 2008, 2009 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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||
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "charset.h"
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#include "block.h"
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#include "frame.h"
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#include "exceptions.h"
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#include "symtab.h"
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#include "stack.h"
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#include "value.h"
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#include "python-internal.h"
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typedef struct {
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PyObject_HEAD
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struct frame_id frame_id;
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struct gdbarch *gdbarch;
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/* Marks that the FRAME_ID member actually holds the ID of the frame next
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to this, and not this frames' ID itself. This is a hack to permit Python
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frame objects which represent invalid frames (i.e., the last frame_info
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in a corrupt stack). The problem arises from the fact that this code
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relies on FRAME_ID to uniquely identify a frame, which is not always true
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for the last "frame" in a corrupt stack (it can have a null ID, or the same
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ID as the previous frame). Whenever get_prev_frame returns NULL, we
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record the frame_id of the next frame and set FRAME_ID_IS_NEXT to 1. */
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int frame_id_is_next;
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} frame_object;
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/* Require a valid frame. This must be called inside a TRY_CATCH, or
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another context in which a gdb exception is allowed. */
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#define FRAPY_REQUIRE_VALID(frame_obj, frame) \
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do { \
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frame = frame_object_to_frame_info (frame_obj); \
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if (frame == NULL) \
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error ("Frame is invalid."); \
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} while (0)
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static PyTypeObject frame_object_type;
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/* Returns the frame_info object corresponding to the given Python Frame
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||
object. If the frame doesn't exist anymore (the frame id doesn't
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correspond to any frame in the inferior), returns NULL. */
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static struct frame_info *
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frame_object_to_frame_info (frame_object *frame_obj)
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{
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struct frame_info *frame;
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frame = frame_find_by_id (frame_obj->frame_id);
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if (frame == NULL)
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return NULL;
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if (frame_obj->frame_id_is_next)
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frame = get_prev_frame (frame);
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return frame;
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}
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/* Called by the Python interpreter to obtain string representation
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of the object. */
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static PyObject *
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frapy_str (PyObject *self)
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{
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char *s;
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long len;
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PyObject *result;
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struct ui_file *strfile;
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strfile = mem_fileopen ();
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fprint_frame_id (strfile, ((frame_object *) self)->frame_id);
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s = ui_file_xstrdup (strfile, &len);
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result = PyString_FromString (s);
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xfree (s);
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return result;
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}
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/* Implementation of gdb.Frame.is_valid (self) -> Boolean.
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Returns True if the frame corresponding to the frame_id of this
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object still exists in the inferior. */
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static PyObject *
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frapy_is_valid (PyObject *self, PyObject *args)
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{
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struct frame_info *frame;
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frame = frame_object_to_frame_info ((frame_object *) self);
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if (frame == NULL)
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Py_RETURN_FALSE;
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Py_RETURN_TRUE;
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}
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/* Implementation of gdb.Frame.name (self) -> String.
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Returns the name of the function corresponding to this frame. */
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static PyObject *
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frapy_name (PyObject *self, PyObject *args)
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{
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struct frame_info *frame;
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char *name;
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enum language lang;
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PyObject *result;
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volatile struct gdb_exception except;
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TRY_CATCH (except, RETURN_MASK_ALL)
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{
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FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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find_frame_funname (frame, &name, &lang);
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}
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GDB_PY_HANDLE_EXCEPTION (except);
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if (name)
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result = PyUnicode_Decode (name, strlen (name), host_charset (), NULL);
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else
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{
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result = Py_None;
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Py_INCREF (Py_None);
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}
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return result;
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}
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/* Implementation of gdb.Frame.type (self) -> Integer.
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Returns the frame type, namely one of the gdb.*_FRAME constants. */
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static PyObject *
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frapy_type (PyObject *self, PyObject *args)
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{
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struct frame_info *frame;
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enum frame_type type = NORMAL_FRAME;/* Initialize to appease gcc warning. */
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volatile struct gdb_exception except;
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TRY_CATCH (except, RETURN_MASK_ALL)
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{
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FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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type = get_frame_type (frame);
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}
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GDB_PY_HANDLE_EXCEPTION (except);
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return PyInt_FromLong (type);
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}
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/* Implementation of gdb.Frame.unwind_stop_reason (self) -> Integer.
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Returns one of the gdb.FRAME_UNWIND_* constants. */
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static PyObject *
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frapy_unwind_stop_reason (PyObject *self, PyObject *args)
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{
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struct frame_info *frame = NULL; /* Initialize to appease gcc warning. */
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volatile struct gdb_exception except;
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enum unwind_stop_reason stop_reason;
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TRY_CATCH (except, RETURN_MASK_ALL)
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{
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FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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}
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GDB_PY_HANDLE_EXCEPTION (except);
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stop_reason = get_frame_unwind_stop_reason (frame);
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return PyInt_FromLong (stop_reason);
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}
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/* Implementation of gdb.Frame.pc (self) -> Long.
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Returns the frame's resume address. */
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static PyObject *
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frapy_pc (PyObject *self, PyObject *args)
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{
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CORE_ADDR pc = 0; /* Initialize to appease gcc warning. */
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struct frame_info *frame;
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volatile struct gdb_exception except;
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TRY_CATCH (except, RETURN_MASK_ALL)
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{
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FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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pc = get_frame_pc (frame);
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}
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GDB_PY_HANDLE_EXCEPTION (except);
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return PyLong_FromUnsignedLongLong (pc);
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}
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/* Convert a frame_info struct to a Python Frame object.
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Sets a Python exception and returns NULL on error. */
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static frame_object *
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frame_info_to_frame_object (struct frame_info *frame)
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{
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frame_object *frame_obj;
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frame_obj = PyObject_New (frame_object, &frame_object_type);
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if (frame_obj == NULL)
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{
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PyErr_SetString (PyExc_MemoryError, "Could not allocate frame object.");
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return NULL;
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}
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/* Try to get the previous frame, to determine if this is the last frame
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in a corrupt stack. If so, we need to store the frame_id of the next
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frame and not of this one (which is possibly invalid). */
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if (get_prev_frame (frame) == NULL
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&& get_frame_unwind_stop_reason (frame) != UNWIND_NO_REASON
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&& get_next_frame (frame) != NULL)
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{
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frame_obj->frame_id = get_frame_id (get_next_frame (frame));
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frame_obj->frame_id_is_next = 1;
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}
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else
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{
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frame_obj->frame_id = get_frame_id (frame);
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frame_obj->frame_id_is_next = 0;
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}
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frame_obj->gdbarch = get_frame_arch (frame);
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return frame_obj;
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}
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/* Implementation of gdb.Frame.older (self) -> gdb.Frame.
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Returns the frame immediately older (outer) to this frame, or None if
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there isn't one. */
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static PyObject *
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frapy_older (PyObject *self, PyObject *args)
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{
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struct frame_info *frame, *prev;
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volatile struct gdb_exception except;
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PyObject *prev_obj = NULL; /* Initialize to appease gcc warning. */
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TRY_CATCH (except, RETURN_MASK_ALL)
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{
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FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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prev = get_prev_frame (frame);
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if (prev)
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prev_obj = (PyObject *) frame_info_to_frame_object (prev);
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||
else
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{
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Py_INCREF (Py_None);
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prev_obj = Py_None;
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}
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}
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GDB_PY_HANDLE_EXCEPTION (except);
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return prev_obj;
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}
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/* Implementation of gdb.Frame.newer (self) -> gdb.Frame.
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Returns the frame immediately newer (inner) to this frame, or None if
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there isn't one. */
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||
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static PyObject *
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frapy_newer (PyObject *self, PyObject *args)
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{
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struct frame_info *frame, *next;
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volatile struct gdb_exception except;
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PyObject *next_obj = NULL; /* Initialize to appease gcc warning. */
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TRY_CATCH (except, RETURN_MASK_ALL)
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{
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||
FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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next = get_next_frame (frame);
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if (next)
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||
next_obj = (PyObject *) frame_info_to_frame_object (next);
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||
else
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||
{
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||
Py_INCREF (Py_None);
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||
next_obj = Py_None;
|
||
}
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||
}
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GDB_PY_HANDLE_EXCEPTION (except);
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||
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||
return next_obj;
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||
}
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||
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/* Implementation of gdb.Frame.read_var_value (self, variable) -> gdb.Value.
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Returns the value of the given variable in this frame. The argument must be
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a string. Returns None if GDB can't find the specified variable. */
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||
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static PyObject *
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frapy_read_var (PyObject *self, PyObject *args)
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||
{
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||
struct frame_info *frame;
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||
PyObject *sym_obj;
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||
struct symbol *var = NULL; /* gcc-4.3.2 false warning. */
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||
struct value *val = NULL;
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||
volatile struct gdb_exception except;
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||
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||
if (!PyArg_ParseTuple (args, "O", &sym_obj))
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return NULL;
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||
|
||
if (gdbpy_is_string (sym_obj))
|
||
{
|
||
char *var_name;
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||
struct block *block = NULL;
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||
struct cleanup *cleanup;
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||
volatile struct gdb_exception except;
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||
|
||
var_name = python_string_to_target_string (sym_obj);
|
||
if (!var_name)
|
||
return NULL;
|
||
cleanup = make_cleanup (xfree, var_name);
|
||
|
||
TRY_CATCH (except, RETURN_MASK_ALL)
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||
{
|
||
FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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||
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||
block = block_for_pc (get_frame_address_in_block (frame));
|
||
var = lookup_symbol (var_name, block, VAR_DOMAIN, NULL);
|
||
}
|
||
GDB_PY_HANDLE_EXCEPTION (except);
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||
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||
if (!var)
|
||
{
|
||
PyErr_Format (PyExc_ValueError,
|
||
_("variable '%s' not found"), var_name);
|
||
do_cleanups (cleanup);
|
||
|
||
return NULL;
|
||
}
|
||
|
||
do_cleanups (cleanup);
|
||
}
|
||
else
|
||
{
|
||
PyErr_SetString (PyExc_TypeError,
|
||
_("argument must be a symbol or string"));
|
||
return NULL;
|
||
}
|
||
|
||
TRY_CATCH (except, RETURN_MASK_ALL)
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||
{
|
||
FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
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||
|
||
val = read_var_value (var, frame);
|
||
}
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||
GDB_PY_HANDLE_EXCEPTION (except);
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||
|
||
if (val)
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||
return value_to_value_object (val);
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||
|
||
Py_RETURN_NONE;
|
||
}
|
||
|
||
/* Implementation of gdb.selected_frame () -> gdb.Frame.
|
||
Returns the selected frame object. */
|
||
|
||
PyObject *
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||
gdbpy_selected_frame (PyObject *self, PyObject *args)
|
||
{
|
||
struct frame_info *frame;
|
||
frame_object *frame_obj = NULL; /* Initialize to appease gcc warning. */
|
||
volatile struct gdb_exception except;
|
||
|
||
TRY_CATCH (except, RETURN_MASK_ALL)
|
||
{
|
||
frame = get_selected_frame ("No frame is currently selected.");
|
||
frame_obj = frame_info_to_frame_object (frame);
|
||
}
|
||
GDB_PY_HANDLE_EXCEPTION (except);
|
||
|
||
return (PyObject *) frame_obj;
|
||
}
|
||
|
||
/* Implementation of gdb.stop_reason_string (Integer) -> String.
|
||
Return a string explaining the unwind stop reason. */
|
||
|
||
PyObject *
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||
gdbpy_frame_stop_reason_string (PyObject *self, PyObject *args)
|
||
{
|
||
int reason;
|
||
const char *str;
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||
|
||
if (!PyArg_ParseTuple (args, "i", &reason))
|
||
return NULL;
|
||
|
||
if (reason < 0 || reason > UNWIND_NO_SAVED_PC)
|
||
{
|
||
PyErr_SetString (PyExc_ValueError, "Invalid frame stop reason.");
|
||
return NULL;
|
||
}
|
||
|
||
str = frame_stop_reason_string (reason);
|
||
return PyUnicode_Decode (str, strlen (str), host_charset (), NULL);
|
||
}
|
||
|
||
/* Implements the equality comparison for Frame objects.
|
||
All other comparison operators will throw a TypeError Python exception,
|
||
as they aren't valid for frames. */
|
||
|
||
static PyObject *
|
||
frapy_richcompare (PyObject *self, PyObject *other, int op)
|
||
{
|
||
int result;
|
||
|
||
if (!PyObject_TypeCheck (other, &frame_object_type)
|
||
|| (op != Py_EQ && op != Py_NE))
|
||
{
|
||
Py_INCREF (Py_NotImplemented);
|
||
return Py_NotImplemented;
|
||
}
|
||
|
||
if (frame_id_eq (((frame_object *) self)->frame_id,
|
||
((frame_object *) other)->frame_id))
|
||
result = Py_EQ;
|
||
else
|
||
result = Py_NE;
|
||
|
||
if (op == result)
|
||
Py_RETURN_TRUE;
|
||
Py_RETURN_FALSE;
|
||
}
|
||
|
||
/* Sets up the Frame API in the gdb module. */
|
||
|
||
void
|
||
gdbpy_initialize_frames (void)
|
||
{
|
||
if (PyType_Ready (&frame_object_type) < 0)
|
||
return;
|
||
|
||
/* Note: These would probably be best exposed as class attributes of Frame,
|
||
but I don't know how to do it except by messing with the type's dictionary.
|
||
That seems too messy. */
|
||
PyModule_AddIntConstant (gdb_module, "NORMAL_FRAME", NORMAL_FRAME);
|
||
PyModule_AddIntConstant (gdb_module, "DUMMY_FRAME", DUMMY_FRAME);
|
||
PyModule_AddIntConstant (gdb_module, "SIGTRAMP_FRAME", SIGTRAMP_FRAME);
|
||
PyModule_AddIntConstant (gdb_module, "SENTINEL_FRAME", SENTINEL_FRAME);
|
||
PyModule_AddIntConstant (gdb_module,
|
||
"FRAME_UNWIND_NO_REASON", UNWIND_NO_REASON);
|
||
PyModule_AddIntConstant (gdb_module,
|
||
"FRAME_UNWIND_NULL_ID", UNWIND_NULL_ID);
|
||
PyModule_AddIntConstant (gdb_module,
|
||
"FRAME_UNWIND_FIRST_ERROR", UNWIND_FIRST_ERROR);
|
||
PyModule_AddIntConstant (gdb_module,
|
||
"FRAME_UNWIND_INNER_ID", UNWIND_INNER_ID);
|
||
PyModule_AddIntConstant (gdb_module,
|
||
"FRAME_UNWIND_SAME_ID", UNWIND_SAME_ID);
|
||
PyModule_AddIntConstant (gdb_module,
|
||
"FRAME_UNWIND_NO_SAVED_PC", UNWIND_NO_SAVED_PC);
|
||
|
||
Py_INCREF (&frame_object_type);
|
||
PyModule_AddObject (gdb_module, "Frame", (PyObject *) &frame_object_type);
|
||
}
|
||
|
||
|
||
|
||
static PyMethodDef frame_object_methods[] = {
|
||
{ "is_valid", frapy_is_valid, METH_NOARGS,
|
||
"is_valid () -> Boolean.\n\
|
||
Return true if this frame is valid, false if not." },
|
||
{ "name", frapy_name, METH_NOARGS,
|
||
"name () -> String.\n\
|
||
Return the function name of the frame, or None if it can't be determined." },
|
||
{ "type", frapy_type, METH_NOARGS,
|
||
"type () -> Integer.\n\
|
||
Return the type of the frame." },
|
||
{ "unwind_stop_reason", frapy_unwind_stop_reason, METH_NOARGS,
|
||
"unwind_stop_reason () -> Integer.\n\
|
||
Return the reason why it's not possible to find frames older than this." },
|
||
{ "pc", frapy_pc, METH_NOARGS,
|
||
"pc () -> Long.\n\
|
||
Return the frame's resume address." },
|
||
{ "older", frapy_older, METH_NOARGS,
|
||
"older () -> gdb.Frame.\n\
|
||
Return the frame that called this frame." },
|
||
{ "newer", frapy_newer, METH_NOARGS,
|
||
"newer () -> gdb.Frame.\n\
|
||
Return the frame called by this frame." },
|
||
{ "read_var", frapy_read_var, METH_VARARGS,
|
||
"read_var (variable) -> gdb.Value.\n\
|
||
Return the value of the variable in this frame." },
|
||
{NULL} /* Sentinel */
|
||
};
|
||
|
||
static PyTypeObject frame_object_type = {
|
||
PyObject_HEAD_INIT (NULL)
|
||
0, /* ob_size */
|
||
"gdb.Frame", /* tp_name */
|
||
sizeof (frame_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 */
|
||
frapy_str, /* tp_str */
|
||
0, /* tp_getattro */
|
||
0, /* tp_setattro */
|
||
0, /* tp_as_buffer */
|
||
Py_TPFLAGS_DEFAULT, /* tp_flags */
|
||
"GDB frame object", /* tp_doc */
|
||
0, /* tp_traverse */
|
||
0, /* tp_clear */
|
||
frapy_richcompare, /* tp_richcompare */
|
||
0, /* tp_weaklistoffset */
|
||
0, /* tp_iter */
|
||
0, /* tp_iternext */
|
||
frame_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 */
|
||
PyType_GenericNew /* tp_new */
|
||
};
|