binutils-gdb/gdb/python/py-gdb-readline.c

113 lines
3.2 KiB
C

/* Readline support for Python.
Copyright (C) 2012-2014 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 "exceptions.h"
#include "top.h"
#include "cli/cli-utils.h"
#include <string.h>
#include <stddef.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,
char *prompt)
{
int n;
char *p = NULL, *q;
volatile struct gdb_exception except;
TRY_CATCH (except, RETURN_MASK_ALL)
p = command_line_input (prompt, 0, "python");
/* Detect user interrupt (Ctrl-C). */
if (except.reason == RETURN_QUIT)
return NULL;
/* Handle errors by raising Python exceptions. */
if (except.reason < 0)
{
/* 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 = PyMem_Malloc (1);
if (q != NULL)
q[0] = '\0';
return q;
}
n = strlen (p);
/* Copy the line to Python and return. */
q = PyMem_Malloc (n + 2);
if (q != NULL)
{
strncpy (q, p, n);
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;
}