Files
binutils-gdb/gdb/python/py-gdb-readline.c
Kevin Buettner b940a061c0 Python QUIT processing updates
See the previous patches in this series for the motivation behind
these changes.

This commit contains updates to Python's QUIT handling.  Ideally, we'd
like to throw gdb_exception_forced_quit through the extension
language; I made an attempt to do this for gdb_exception_quit in an
earlier version of this patch, but Pedro pointed out that it is
(almost certainly) not safe to do so.

Still, we definitely don't want to swallow the exception representing
a SIGTERM for GDB, nor do we want to force modules written in the
extension language to have to explicitly handle this case.  Since the
idea is for GDB to cleanup and quit for this exception, we'll simply
call quit_force() just as if the gdb_exception_forced_quit propagation
had managed to make it back to the top level.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=26761
Tested-by: Tom de Vries <tdevries@suse.de>
Approved-By: Pedro Alves <pedro@palves.net>
2023-02-27 16:20:39 -07:00

119 lines
3.3 KiB
C

/* Readline support for Python.
Copyright (C) 2012-2023 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"
#include "top.h"
#include "cli/cli-utils.h"
/* Readline function suitable for PyOS_ReadlineFunctionPointer, which
is used for Python's interactive parser and raw_input. In both
cases, sys_stdin and sys_stdout are always stdin and stdout
respectively, as far as I can tell; they are ignored and
command_line_input is used instead. */
static char *
gdbpy_readline_wrapper (FILE *sys_stdin, FILE *sys_stdout,
#if PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 4
const char *prompt)
#else
char *prompt)
#endif
{
int n;
const char *p = NULL;
std::string buffer;
char *q;
try
{
p = command_line_input (buffer, prompt, "python");
}
/* Handle errors by raising Python exceptions. */
catch (const gdb_exception_forced_quit &e)
{
quit_force (NULL, 0);
}
catch (const gdb_exception &except)
{
/* Detect user interrupt (Ctrl-C). */
if (except.reason == RETURN_QUIT)
return NULL;
/* The thread state is nulled during gdbpy_readline_wrapper,
with the original value saved in the following undocumented
variable (see Python's Parser/myreadline.c and
Modules/readline.c). */
PyEval_RestoreThread (_PyOS_ReadlineTState);
gdbpy_convert_exception (except);
PyEval_SaveThread ();
return NULL;
}
/* Detect EOF (Ctrl-D). */
if (p == NULL)
{
q = (char *) PyMem_RawMalloc (1);
if (q != NULL)
q[0] = '\0';
return q;
}
n = strlen (p);
/* Copy the line to Python and return. */
q = (char *) PyMem_RawMalloc (n + 2);
if (q != NULL)
{
strcpy (q, p);
q[n] = '\n';
q[n + 1] = '\0';
}
return q;
}
/* Initialize Python readline support. */
void
gdbpy_initialize_gdb_readline (void)
{
/* Python's readline module conflicts with GDB's use of readline
since readline is not reentrant. Ideally, a reentrant wrapper to
GDB's readline should be implemented to replace Python's readline
and prevent conflicts. For now, this file implements a
sys.meta_path finder that simply fails to import the readline
module. */
if (PyRun_SimpleString ("\
import sys\n\
\n\
class GdbRemoveReadlineFinder:\n\
def find_module(self, fullname, path=None):\n\
if fullname == 'readline' and path is None:\n\
return self\n\
return None\n\
\n\
def load_module(self, fullname):\n\
raise ImportError('readline module disabled under GDB')\n\
\n\
sys.meta_path.append(GdbRemoveReadlineFinder())\n\
") == 0)
PyOS_ReadlineFunctionPointer = gdbpy_readline_wrapper;
}