1 /* Readline support for Python.
2
3 Copyright (C) 2012-2024 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19
20 #include "python-internal.h"
21 #include "top.h"
22 #include "cli/cli-utils.h"
23
24 /* Readline function suitable for PyOS_ReadlineFunctionPointer, which
25 is used for Python's interactive parser and raw_input. In both
26 cases, sys_stdin and sys_stdout are always stdin and stdout
27 respectively, as far as I can tell; they are ignored and
28 command_line_input is used instead. */
29
30 static char *
gdbpy_readline_wrapper(FILE * sys_stdin,FILE * sys_stdout,const char * prompt)31 gdbpy_readline_wrapper (FILE *sys_stdin, FILE *sys_stdout,
32 #if PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 4
33 const char *prompt)
34 #else
35 char *prompt)
36 #endif
37 {
38 int n;
39 const char *p = NULL;
40 std::string buffer;
41 char *q;
42
43 try
44 {
45 p = command_line_input (buffer, prompt, "python");
46 }
47 /* Handle errors by raising Python exceptions. */
48 catch (const gdb_exception_forced_quit &e)
49 {
50 quit_force (NULL, 0);
51 }
52 catch (const gdb_exception &except)
53 {
54 /* Detect user interrupt (Ctrl-C). */
55 if (except.reason == RETURN_QUIT)
56 return NULL;
57
58
59 /* This readline callback is called without the GIL held. */
60 gdbpy_gil gil;
61
62 gdbpy_convert_exception (except);
63 return NULL;
64 }
65
66 /* Detect EOF (Ctrl-D). */
67 if (p == NULL)
68 {
69 q = (char *) PyMem_RawMalloc (1);
70 if (q != NULL)
71 q[0] = '\0';
72 return q;
73 }
74
75 n = strlen (p);
76
77 /* Copy the line to Python and return. */
78 q = (char *) PyMem_RawMalloc (n + 2);
79 if (q != NULL)
80 {
81 strcpy (q, p);
82 q[n] = '\n';
83 q[n + 1] = '\0';
84 }
85 return q;
86 }
87
88 /* Initialize Python readline support. */
89
90 static int CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
gdbpy_initialize_gdb_readline(void)91 gdbpy_initialize_gdb_readline (void)
92 {
93 /* Python's readline module conflicts with GDB's use of readline
94 since readline is not reentrant. Ideally, a reentrant wrapper to
95 GDB's readline should be implemented to replace Python's readline
96 and prevent conflicts. For now, this file implements a
97 sys.meta_path finder that simply fails to import the readline
98 module. */
99 if (PyRun_SimpleString ("\
100 import sys\n\
101 \n\
102 class GdbRemoveReadlineFinder:\n\
103 def find_module(self, fullname, path=None):\n\
104 if fullname == 'readline' and path is None:\n\
105 return self\n\
106 return None\n\
107 \n\
108 def load_module(self, fullname):\n\
109 raise ImportError('readline module disabled under GDB')\n\
110 \n\
111 sys.meta_path.append(GdbRemoveReadlineFinder())\n\
112 ") == 0)
113 PyOS_ReadlineFunctionPointer = gdbpy_readline_wrapper;
114
115 return 0;
116 }
117
118 GDBPY_INITIALIZE_FILE (gdbpy_initialize_gdb_readline);
119