From 037bbc8eeaf8e6f3a5e185e78268aa71a1159ae7 Mon Sep 17 00:00:00 2001 From: Yit Phang Khoo Date: Wed, 22 Aug 2012 21:04:55 +0000 Subject: [PATCH] Enable readline in Python in a GDB-specific way and block the standard Python readline module to prevent conflicts with GDB. * Makefile.in (SUBDIR_PYTHON_OBS): Add py-gdb-readline.o. (SUBDIR_PYTHON_SRCS): Add python/py-gdb-readline.c. (py-gdb-readline.o): Add rule to compile python/py-gdb-readline.c. * python/py-gdb-readline.c: New file. * python/python-internal.h (gdbpy_initialize_gdb_readline): New prototype. * python/python.c (_initialize_python): Call gdbpy_initialize_gdb_readline. --- gdb/ChangeLog | 13 ++++ gdb/Makefile.in | 6 ++ gdb/python/py-gdb-readline.c | 113 +++++++++++++++++++++++++++++++++++ gdb/python/python-internal.h | 1 + gdb/python/python.c | 1 + 5 files changed, 134 insertions(+) create mode 100644 gdb/python/py-gdb-readline.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index ac628ceb58..cb690760e3 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2012-08-22 Khoo Yit Phang + + Enable readline in Python in a GDB-specific way and block the + standard Python readline module to prevent conflicts with GDB. + * Makefile.in (SUBDIR_PYTHON_OBS): Add py-gdb-readline.o. + (SUBDIR_PYTHON_SRCS): Add python/py-gdb-readline.c. + (py-gdb-readline.o): Add rule to compile python/py-gdb-readline.c. + * python/py-gdb-readline.c: New file. + * python/python-internal.h (gdbpy_initialize_gdb_readline): New + prototype. + * python/python.c (_initialize_python): Call + gdbpy_initialize_gdb_readline. + 2012-08-22 Keith Seitz * defs.h: Include build-gnulib/config.h diff --git a/gdb/Makefile.in b/gdb/Makefile.in index bb1f0bc5ef..5d5574e480 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -280,6 +280,7 @@ SUBDIR_PYTHON_OBS = \ py-finishbreakpoint.o \ py-frame.o \ py-function.o \ + py-gdb-readline.o \ py-inferior.o \ py-infthread.o \ py-lazy-string.o \ @@ -312,6 +313,7 @@ SUBDIR_PYTHON_SRCS = \ python/py-finishbreakpoint.c \ python/py-frame.c \ python/py-function.c \ + python/py-gdb-readline.c \ python/py-inferior.c \ python/py-infthread.c \ python/py-lazy-string.c \ @@ -2083,6 +2085,10 @@ py-function.o: $(srcdir)/python/py-function.c $(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-function.c $(POSTCOMPILE) +py-gdb-readline.o: $(srcdir)/python/py-gdb-readline.c + $(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-gdb-readline.c + $(POSTCOMPILE) + py-inferior.o: $(srcdir)/python/py-inferior.c $(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-inferior.c $(POSTCOMPILE) diff --git a/gdb/python/py-gdb-readline.c b/gdb/python/py-gdb-readline.c new file mode 100644 index 0000000000..b5e0705f8b --- /dev/null +++ b/gdb/python/py-gdb-readline.c @@ -0,0 +1,113 @@ +/* Readline support for Python. + + Copyright (C) 2012 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 . */ + +#include "defs.h" +#include "python-internal.h" +#include "exceptions.h" +#include "top.h" +#include "cli/cli-utils.h" +#include "gdb_string.h" + +#include + +/* 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, *p_start, *p_end, *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. */ + 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\ +"); + + PyOS_ReadlineFunctionPointer = gdbpy_readline_wrapper; +} + diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h index bae61c28da..aa3678bc83 100644 --- a/gdb/python/python-internal.h +++ b/gdb/python/python-internal.h @@ -232,6 +232,7 @@ struct symtab *symtab_object_to_symtab (PyObject *obj); struct symtab_and_line *sal_object_to_symtab_and_line (PyObject *obj); struct frame_info *frame_object_to_frame_info (PyObject *frame_obj); +void gdbpy_initialize_gdb_readline (void); void gdbpy_initialize_auto_load (void); void gdbpy_initialize_values (void); void gdbpy_initialize_frames (void); diff --git a/gdb/python/python.c b/gdb/python/python.c index ad735ceaf2..1e59d1e5d1 100644 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -1389,6 +1389,7 @@ message == an error message without a stack will be printed."), gdbpy_gdberror_exc = PyErr_NewException ("gdb.GdbError", NULL, NULL); PyModule_AddObject (gdb_module, "GdbError", gdbpy_gdberror_exc); + gdbpy_initialize_gdb_readline (); gdbpy_initialize_auto_load (); gdbpy_initialize_values (); gdbpy_initialize_frames ();