918229560c
While digging into a different memory corruption error, I happened to notice one coming from the linetable code. In a couple of spots, the wrong termination condition was used in a loop, leading gdb to read one element past the end of the linetable. Built and regtested on x86-64 Fedora 18. Also verified using valgrind. I'm checking this in. 2013-11-14 Tom Tromey <tromey@redhat.com> * python/py-linetable.c (ltpy_has_line) (ltpy_get_all_source_lines): Fix loop termination condition.
622 lines
16 KiB
C
622 lines
16 KiB
C
/* Python interface to line tables.
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Copyright (C) 2013 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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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 "python-internal.h"
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#include "exceptions.h"
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typedef struct {
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PyObject_HEAD
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/* The line table source line. */
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int line;
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/* The pc associated with the source line. */
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CORE_ADDR pc;
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} linetable_entry_object;
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static PyTypeObject linetable_entry_object_type
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CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_entry_object");
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typedef struct {
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PyObject_HEAD
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/* The symtab python object. We store the Python object here as the
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underlying symtab can become invalid, and we have to run validity
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checks on it. */
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PyObject *symtab;
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} linetable_object;
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static PyTypeObject linetable_object_type
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CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_object");
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typedef struct {
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PyObject_HEAD
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/* The current entry in the line table for the iterator */
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int current_index;
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/* Pointer back to the original source line table object. Needed to
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check if the line table is still valid, and has not been invalidated
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when an object file has been freed. */
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PyObject *source;
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} ltpy_iterator_object;
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static PyTypeObject ltpy_iterator_object_type
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CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("ltpy_iterator_object");
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/* Internal helper function to extract gdb.Symtab from a gdb.Linetable
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object. */
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static PyObject *
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get_symtab (PyObject *linetable)
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{
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linetable_object *lt = (linetable_object *) linetable;
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return lt->symtab;
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}
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#define LTPY_REQUIRE_VALID(lt_obj, symtab) \
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do { \
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symtab = symtab_object_to_symtab (get_symtab (lt_obj)); \
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if (symtab == NULL) \
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{ \
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PyErr_SetString (PyExc_RuntimeError, \
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_("Symbol Table in line table is invalid."));\
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return NULL; \
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} \
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} while (0)
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/* Helper function to create a line table object that wraps a
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gdb.Symtab object. */
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PyObject *
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symtab_to_linetable_object (PyObject *symtab)
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{
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linetable_object *ltable;
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ltable = PyObject_New (linetable_object, &linetable_object_type);
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if (ltable != NULL)
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{
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ltable->symtab = symtab;
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Py_INCREF (symtab);
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}
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return (PyObject *) ltable;
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}
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/* Internal helper function to build a line table object from a line
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and an address. */
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static PyObject *
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build_linetable_entry (int line, CORE_ADDR address)
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{
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linetable_entry_object *obj;
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obj = PyObject_New (linetable_entry_object,
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&linetable_entry_object_type);
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if (obj != NULL)
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{
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obj->line = line;
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obj->pc = address;
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}
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return (PyObject *) obj;
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}
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/* Internal helper function to build a Python Tuple from a GDB Vector.
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A line table entry can have multiple PCs for a given source line.
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Construct a Tuple of all entries for the given source line, LINE
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from the line table VEC. Construct one line table entry object per
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address. */
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static PyObject *
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build_line_table_tuple_from_pcs (int line, VEC (CORE_ADDR) *vec)
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{
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int vec_len = 0;
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PyObject *tuple;
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CORE_ADDR pc;
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int i;
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vec_len = VEC_length (CORE_ADDR, vec);
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if (vec_len < 1)
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Py_RETURN_NONE;
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tuple = PyTuple_New (vec_len);
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if (tuple == NULL)
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return NULL;
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for (i = 0; VEC_iterate (CORE_ADDR, vec, i, pc); ++i)
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{
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PyObject *obj = build_linetable_entry (line, pc);
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if (obj == NULL)
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{
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Py_DECREF (tuple);
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tuple = NULL;
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break;
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}
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else if (PyTuple_SetItem (tuple, i, obj) != 0)
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{
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Py_DECREF (obj);
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Py_DECREF (tuple);
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tuple = NULL;
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break;
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}
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}
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return tuple;
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}
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/* Implementation of gdb.LineTable.line (self) -> Tuple. Returns a
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tuple of LineTableEntry objects associated with this line from the
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in the line table. */
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static PyObject *
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ltpy_get_pcs_for_line (PyObject *self, PyObject *args)
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{
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struct symtab *symtab;
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int py_line;
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struct linetable_entry *best_entry = NULL;
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linetable_entry_object *result;
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VEC (CORE_ADDR) *pcs = NULL;
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PyObject *tuple;
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volatile struct gdb_exception except;
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LTPY_REQUIRE_VALID (self, symtab);
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if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
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return NULL;
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TRY_CATCH (except, RETURN_MASK_ALL)
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{
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pcs = find_pcs_for_symtab_line (symtab, py_line, &best_entry);
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}
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GDB_PY_HANDLE_EXCEPTION (except);
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tuple = build_line_table_tuple_from_pcs (py_line, pcs);
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VEC_free (CORE_ADDR, pcs);
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return tuple;
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}
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/* Implementation of gdb.LineTable.has_line (self, line) -> Boolean.
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Returns a Python Boolean indicating whether a source line has any
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line table entries corresponding to it. */
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static PyObject *
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ltpy_has_line (PyObject *self, PyObject *args)
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{
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struct symtab *symtab;
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int py_line;
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int index;
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LTPY_REQUIRE_VALID (self, symtab);
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if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
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return NULL;
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if (LINETABLE (symtab) == NULL)
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{
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PyErr_SetString (PyExc_RuntimeError,
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_("Linetable information not found in symbol table"));
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return NULL;
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}
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for (index = 0; index < LINETABLE (symtab)->nitems; index++)
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{
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struct linetable_entry *item = &(symtab->linetable->item[index]);
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if (item->line == py_line)
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Py_RETURN_TRUE;
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}
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Py_RETURN_FALSE;
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}
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/* Implementation of gdb.LineTable.source_lines (self) -> FrozenSet.
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Returns a Python FrozenSet that contains source line entries in the
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line table. This function will just return the source lines
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without corresponding addresses. */
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static PyObject *
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ltpy_get_all_source_lines (PyObject *self, PyObject *args)
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{
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struct symtab *symtab;
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Py_ssize_t index;
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PyObject *source_list, *source_dict, *line;
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struct linetable_entry *item;
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Py_ssize_t list_size;
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LTPY_REQUIRE_VALID (self, symtab);
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if (LINETABLE (symtab) == NULL)
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{
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PyErr_SetString (PyExc_RuntimeError,
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_("Linetable information not found in symbol table"));
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return NULL;
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}
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source_dict = PyDict_New ();
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if (source_dict == NULL)
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return NULL;
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for (index = 0; index < LINETABLE (symtab)->nitems; index++)
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{
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item = &(LINETABLE (symtab)->item[index]);
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/* 0 is used to signify end of line table information. Do not
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include in the source set. */
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if (item->line > 0)
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{
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line = gdb_py_object_from_longest (item->line);
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if (line == NULL)
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{
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Py_DECREF (source_dict);
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return NULL;
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}
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if (PyDict_SetItem (source_dict, line, Py_None) == -1)
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{
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Py_DECREF (line);
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Py_DECREF (source_dict);
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return NULL;
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}
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Py_DECREF (line);
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}
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}
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source_list = PyDict_Keys (source_dict);
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Py_DECREF (source_dict);
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return source_list;
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}
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/* Implementation of gdb.Linetable.is_valid (self) -> Boolean.
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Returns True if this line table object still exists in GDB. */
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static PyObject *
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ltpy_is_valid (PyObject *self, PyObject *args)
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{
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struct symtab *symtab = NULL;
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linetable_object *obj = (linetable_object *) self;
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symtab = symtab_object_to_symtab (get_symtab (self));
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if (symtab == NULL)
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Py_RETURN_FALSE;
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Py_RETURN_TRUE;
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}
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/* Deconstructor for the line table object. Decrement the reference
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to the symbol table object before calling the default free. */
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static void
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ltpy_dealloc (PyObject *self)
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{
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linetable_object *obj = (linetable_object *) self;
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Py_DECREF (obj->symtab);
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Py_TYPE (self)->tp_free (self);
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}
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/* Initialize LineTable, LineTableEntry and LineTableIterator
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objects. */
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int
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gdbpy_initialize_linetable (void)
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{
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if (PyType_Ready (&linetable_object_type) < 0)
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return -1;
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if (PyType_Ready (&linetable_entry_object_type) < 0)
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return -1;
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if (PyType_Ready (<py_iterator_object_type) < 0)
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return -1;
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Py_INCREF (&linetable_object_type);
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Py_INCREF (&linetable_entry_object_type);
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Py_INCREF (<py_iterator_object_type);
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if (gdb_pymodule_addobject (gdb_module, "LineTable",
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(PyObject *) &linetable_object_type) < 0)
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return -1;
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if (gdb_pymodule_addobject (gdb_module, "LineTableEntry",
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(PyObject *) &linetable_entry_object_type) < 0)
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return -1;
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if (gdb_pymodule_addobject (gdb_module, "LineTableIterator",
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(PyObject *) <py_iterator_object_type) < 0)
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return -1;
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return 0;
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}
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/* Linetable entry object get functions. */
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/* Implementation of gdb.LineTableEntry.line (self) -> Long. Returns
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a long integer associated with the line table entry. */
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static PyObject *
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ltpy_entry_get_line (PyObject *self, void *closure)
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{
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linetable_entry_object *obj = (linetable_entry_object *) self;
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return gdb_py_object_from_longest (obj->line);
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}
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/* Implementation of gdb.LineTableEntry.pc (self) -> Long. Returns a
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a long integer associated with the PC of the line table entry. */
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static PyObject *
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ltpy_entry_get_pc (PyObject *self, void *closure)
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{
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linetable_entry_object *obj = (linetable_entry_object *) self;
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return gdb_py_object_from_longest (obj->pc);
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}
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/* Linetable iterator functions. */
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/* Return a new line table iterator. */
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static PyObject *
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ltpy_iter (PyObject *self)
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{
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ltpy_iterator_object *ltpy_iter_obj;
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struct symtab *symtab = NULL;
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LTPY_REQUIRE_VALID (self, symtab);
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ltpy_iter_obj = PyObject_New (ltpy_iterator_object,
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<py_iterator_object_type);
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if (ltpy_iter_obj == NULL)
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return NULL;
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ltpy_iter_obj->current_index = 0;
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ltpy_iter_obj->source = self;
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Py_INCREF (self);
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return (PyObject *) ltpy_iter_obj;
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}
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static void
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ltpy_iterator_dealloc (PyObject *obj)
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{
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ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) obj;
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Py_DECREF (iter_obj->source);
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}
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/* Return a reference to the line table iterator. */
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static PyObject *
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ltpy_iterator (PyObject *self)
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{
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ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
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struct symtab *symtab;
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LTPY_REQUIRE_VALID (iter_obj->source, symtab);
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Py_INCREF (self);
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return self;
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}
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/* Return the next line table entry in the iteration through the line
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table data structure. */
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static PyObject *
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ltpy_iternext (PyObject *self)
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{
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ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
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struct symtab *symtab;
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int index;
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PyObject *obj;
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struct linetable_entry *item;
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LTPY_REQUIRE_VALID (iter_obj->source, symtab);
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if (iter_obj->current_index >= LINETABLE (symtab)->nitems)
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goto stop_iteration;
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item = &(LINETABLE (symtab)->item[iter_obj->current_index]);
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/* Skip over internal entries such as 0. 0 signifies the end of
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line table data and is not useful to the API user. */
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while (item->line < 1)
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{
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iter_obj->current_index++;
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/* Exit if the internal value is the last item in the line table. */
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if (iter_obj->current_index >= symtab->linetable->nitems)
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goto stop_iteration;
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item = &(symtab->linetable->item[iter_obj->current_index]);
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}
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obj = build_linetable_entry (item->line, item->pc);
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iter_obj->current_index++;
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return obj;
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stop_iteration:
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PyErr_SetNone (PyExc_StopIteration);
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return NULL;
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}
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/* Implementation of gdb.LinetableIterator.is_valid (self) -> Boolean.
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Returns True if this line table iterator object still exists in
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GDB. */
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static PyObject *
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ltpy_iter_is_valid (PyObject *self, PyObject *args)
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{
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struct symtab *symtab = NULL;
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ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
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symtab = symtab_object_to_symtab (get_symtab (iter_obj->source));
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if (symtab == NULL)
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Py_RETURN_FALSE;
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Py_RETURN_TRUE;
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}
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static PyMethodDef linetable_object_methods[] = {
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{ "line", ltpy_get_pcs_for_line, METH_VARARGS,
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"line (lineno) -> Tuple\n\
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Return executable locations for a given source line." },
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{ "has_line", ltpy_has_line, METH_VARARGS,
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"has_line (lineno) -> Boolean\n\
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Return TRUE if this line has executable information, FALSE if not." },
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{ "source_lines", ltpy_get_all_source_lines, METH_NOARGS,
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"source_lines () -> FrozenSet\n\
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Return a frozen set of all executable source lines." },
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{ "is_valid", ltpy_is_valid, METH_NOARGS,
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"is_valid () -> Boolean.\n\
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Return True if this Linetable is valid, False if not." },
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{NULL} /* Sentinel */
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};
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static PyTypeObject linetable_object_type = {
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PyVarObject_HEAD_INIT (NULL, 0)
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"gdb.LineTable", /*tp_name*/
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sizeof (linetable_object), /*tp_basicsize*/
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0, /*tp_itemsize*/
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ltpy_dealloc, /*tp_dealloc*/
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0, /*tp_print*/
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0, /*tp_getattr*/
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0, /*tp_setattr*/
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0, /*tp_compare*/
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0, /*tp_repr*/
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0, /*tp_as_number*/
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0, /*tp_as_sequence*/
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0, /*tp_as_mapping*/
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0, /*tp_hash */
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0, /*tp_call*/
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0, /*tp_str*/
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0, /*tp_getattro*/
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0, /*tp_setattro*/
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0, /*tp_as_buffer*/
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Py_TPFLAGS_DEFAULT, /*tp_flags*/
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"GDB line table object", /* tp_doc */
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0, /* tp_traverse */
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0, /* tp_clear */
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0, /* tp_richcompare */
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0, /* tp_weaklistoffset */
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ltpy_iter, /* tp_iter */
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0, /* tp_iternext */
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linetable_object_methods, /* tp_methods */
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0, /* tp_members */
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0, /* tp_getset */
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0, /* tp_base */
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0, /* tp_dict */
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0, /* tp_descr_get */
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0, /* tp_descr_set */
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0, /* tp_dictoffset */
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0, /* tp_init */
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0, /* tp_alloc */
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};
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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 */
|
||
};
|
||
|
||
static 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 | Py_TPFLAGS_HAVE_ITER, /*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 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 */
|
||
};
|
||
|
||
static 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 */
|
||
};
|