1 /* Readline support for Python. 2 3 Copyright (C) 2012-2023 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 "defs.h" 21 #include "python-internal.h" 22 #include "top.h" 23 #include "cli/cli-utils.h" 24 25 /* Readline function suitable for PyOS_ReadlineFunctionPointer, which 26 is used for Python's interactive parser and raw_input. In both 27 cases, sys_stdin and sys_stdout are always stdin and stdout 28 respectively, as far as I can tell; they are ignored and 29 command_line_input is used instead. */ 30 31 static char * 32 gdbpy_readline_wrapper (FILE *sys_stdin, FILE *sys_stdout, 33 #if PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 4 34 const char *prompt) 35 #else 36 char *prompt) 37 #endif 38 { 39 int n; 40 const char *p = NULL; 41 std::string buffer; 42 char *q; 43 44 try 45 { 46 p = command_line_input (buffer, prompt, "python"); 47 } 48 /* Handle errors by raising Python exceptions. */ 49 catch (const gdb_exception &except) 50 { 51 /* Detect user interrupt (Ctrl-C). */ 52 if (except.reason == RETURN_QUIT) 53 return NULL; 54 55 /* The thread state is nulled during gdbpy_readline_wrapper, 56 with the original value saved in the following undocumented 57 variable (see Python's Parser/myreadline.c and 58 Modules/readline.c). */ 59 PyEval_RestoreThread (_PyOS_ReadlineTState); 60 gdbpy_convert_exception (except); 61 PyEval_SaveThread (); 62 return NULL; 63 } 64 65 /* Detect EOF (Ctrl-D). */ 66 if (p == NULL) 67 { 68 q = (char *) PyMem_RawMalloc (1); 69 if (q != NULL) 70 q[0] = '\0'; 71 return q; 72 } 73 74 n = strlen (p); 75 76 /* Copy the line to Python and return. */ 77 q = (char *) PyMem_RawMalloc (n + 2); 78 if (q != NULL) 79 { 80 strcpy (q, p); 81 q[n] = '\n'; 82 q[n + 1] = '\0'; 83 } 84 return q; 85 } 86 87 /* Initialize Python readline support. */ 88 89 void 90 gdbpy_initialize_gdb_readline (void) 91 { 92 /* Python's readline module conflicts with GDB's use of readline 93 since readline is not reentrant. Ideally, a reentrant wrapper to 94 GDB's readline should be implemented to replace Python's readline 95 and prevent conflicts. For now, this file implements a 96 sys.meta_path finder that simply fails to import the readline 97 module. */ 98 if (PyRun_SimpleString ("\ 99 import sys\n\ 100 \n\ 101 class GdbRemoveReadlineFinder:\n\ 102 def find_module(self, fullname, path=None):\n\ 103 if fullname == 'readline' and path is None:\n\ 104 return self\n\ 105 return None\n\ 106 \n\ 107 def load_module(self, fullname):\n\ 108 raise ImportError('readline module disabled under GDB')\n\ 109 \n\ 110 sys.meta_path.append(GdbRemoveReadlineFinder())\n\ 111 ") == 0) 112 PyOS_ReadlineFunctionPointer = gdbpy_readline_wrapper; 113 } 114 115