From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19693 invoked by alias); 11 Jan 2012 21:06:18 -0000 Received: (qmail 19669 invoked by uid 22791); 11 Jan 2012 21:06:16 -0000 X-SWARE-Spam-Status: No, hits=-1.4 required=5.0 tests=AWL,BAYES_00,TW_PD,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from router-304.cs.umd.edu (HELO bacon.cs.umd.edu) (128.8.127.145) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 11 Jan 2012 21:06:02 +0000 Received: from wireless-206-196-163-53.umd.edu (wireless-206-196-163-53.umd.edu [206.196.163.53]) (Authenticated sender: khooyp) by bacon.cs.umd.edu (Postfix) with ESMTPSA id DC7EAB4015D; Wed, 11 Jan 2012 16:05:59 -0500 (EST) Subject: Re: Make the "python" command resemble the standard Python interpreter Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/mixed; boundary=Apple-Mail-8-116408753 From: Khoo Yit Phang In-Reply-To: Date: Wed, 11 Jan 2012 21:06:00 -0000 Cc: Khoo Yit Phang , gdb-patches@sourceware.org Message-Id: <19AA588F-ED95-47C6-A562-6FF30AF22A38@cs.umd.edu> References: <94906C8E-C23D-4DA3-989D-DDCCFA20FC35@cs.umd.edu> <48619020-0550-4888-9F05-158DB065252B@cs.umd.edu> To: Kevin Pouget X-CSD-MailScanner-ID: DC7EAB4015D.AD64E X-CSD-MailScanner: Found to be clean X-CSD-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-50, required 5, autolearn=not spam, ALL_TRUSTED -50.00) X-CSD-MailScanner-From: khooyp@cs.umd.edu X-CSD-MailScanner-Watermark: 1326920760.27943@IfxqpUtqxByw9M1Imomo2w Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2012-01/txt/msg00372.txt.bz2 --Apple-Mail-8-116408753 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Content-length: 1743 Hi, On Jan 11, 2012, at 2:03 PM, Kevin Pouget wrote: > On Wed, Jan 11, 2012 at 7:48 PM, Khoo Yit Phang wrote: >>=20 >> It also hooks GDB's readline wrappers (command_line_input) to Python so = that line editing > and history editing works. Additionally, Python's stand= ard readline module is stubbed out >> because it conflicts with GDB's use of readline. >=20 > that's interesting! I noticed that there's conflict between Python and > GDB readline; do you thing that this hook could also be used to fix > PDB's commandline prompt? (when you run "python import > pdb;pdb.set_trace()", history and left/right arrow don't work > properly) Unfortunately no, and actually, my previous patch causes pdb.set_trace() to= not work at all since since my dummy readline methods just throws exceptio= ns. Attached is a new patch that uses another way to disable the readline modul= e, which works with pdb.set_trace(). However, readline support still doesn'= t work with pdb. The reason is because pdb uses raw_input, which in turn us= es sys.stdin/sys.stdout to determine whether to use readline, but GDB repla= ces sys.stdin/sys.stdout with it's own file-like objects that isn't recogni= zed as a tty by Python. It should be possible to replace raw_input with one that works with GDB, bu= t that can be another patch. Making Python's readline module work under GDB is not possible, since it re= -initializes libreadline and generally assumes that libreadline is complete= ly under Python's control (and libreadline itself has no support for nestin= g/reentrancy). It should also be possible to write a wrapper module around readline that a= voids conflicts with GDB, but that'll take some more work. Yit January 11, 2012 --Apple-Mail-8-116408753 Content-Disposition: attachment; filename=python-interactive.diff Content-Type: application/octet-stream; name="python-interactive.diff" Content-Transfer-Encoding: 7bit Content-length: 9747 # HG changeset patch # Parent 9f7d0a74b37f443edf5a7446fcadc806aea32f21 Make the "python" command resemble the standard Python interpreter. - Use Py_single_input mode to interpret "python" with arguments, so that results of expressions are printed. - Use Python's built-in interactive loop for "python" without arguments. - Hook PyOS_ReadlineFunctionPointer to command_line_input to provide readline support. - Block importing of the standard Python readline module using a sys.meta_path loader to prevent conflicts with GDB. gdb/ChangeLog: 2012-01-11 Khoo Yit Phang Make the "python" command resemble the standard Python interpreter. * 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 (eval_python_command): New function. (eval_python_from_control_command): Call eval_python_command instead of PyRun_SimpleString. (python_command): For "python" with arguments, call eval_python_command. For "python" without arguments, call PyRun_InteractiveLoop if from_tty is true, other call execute_control_command_untraced. diff --git a/gdb/Makefile.in b/gdb/Makefile.in --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -283,6 +283,7 @@ py-finishbreakpoint.o \ py-frame.o \ py-function.o \ + py-gdb-readline.o \ py-inferior.o \ py-infthread.o \ py-lazy-string.o \ @@ -315,6 +316,7 @@ 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 \ @@ -2071,6 +2073,10 @@ $(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 --- /dev/null +++ b/gdb/python/py-gdb-readline.c @@ -0,0 +1,133 @@ +/* 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) + { + struct cleanup *cleanup = gdbpy_suspend_sigint_handler (); + + p = command_line_input (prompt, 0, "python"); + do_cleanups (cleanup); + } + + /* Detect Ctrl-C and treat as KeyboardInterrupt. */ + 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); + + /* Detect "end" like process_next_line in cli/cli-script.c. */ + p_start = remove_trailing_whitespace (p, p + n); + p_end = skip_spaces (p_start); + while (p_start < p_end && (*p_start == ' ' || *p_start == '\t')) + p_start++; + + /* Treat "end" as EOF. */ + if (p_end - p_start == 3 && !strncmp (p_start, "end", 3)) + { + q = PyMem_Malloc (1); + if (q != NULL) + q[0] = '\0'; + return q; + } + + /* 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 --- a/gdb/python/python-internal.h +++ b/gdb/python/python-internal.h @@ -234,6 +234,7 @@ 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 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -279,6 +279,44 @@ return script; } +/* Evaluate a Python command like PyRun_SimpleString, but uses + Py_single_input which prints the result of expressions if the input + is from tty, and Py_file_input otherwise. */ + +static void +eval_python_command (const char *command, int from_tty) +{ + struct cleanup *cleanup; + PyObject *m, *d, *v; + + cleanup = ensure_python_env (get_current_arch (), current_language); + + m = PyImport_AddModule ("__main__"); + if (m == NULL) + error (_("Error while executing Python code.")); + + d = PyModule_GetDict (m); + v = PyRun_StringFlags (command, + from_tty ? Py_single_input : Py_file_input, + d, d, NULL); + if (v == NULL) + { + int interrupt = PyErr_ExceptionMatches (PyExc_KeyboardInterrupt); + + PyErr_Print (); + if (! interrupt) + error (_("Error while executing Python code.")); + } + else + { + Py_DECREF (v); + if (Py_FlushLine ()) + PyErr_Clear (); + } + + do_cleanups (cleanup); +} + /* Take a command line structure representing a 'python' command, and evaluate its body using the Python interpreter. */ @@ -292,13 +330,10 @@ if (cmd->body_count != 1) error (_("Invalid \"python\" block structure.")); - cleanup = ensure_python_env (get_current_arch (), current_language); + script = compute_python_string (cmd->body_list[0]); + cleanup = make_cleanup (xfree, script); - script = compute_python_string (cmd->body_list[0]); - ret = PyRun_SimpleString (script); - xfree (script); - if (ret) - error (_("Error while executing Python code.")); + eval_python_command (script, 0); do_cleanups (cleanup); } @@ -316,18 +351,26 @@ while (arg && *arg && isspace (*arg)) ++arg; if (arg && *arg) - { - ensure_python_env (get_current_arch (), current_language); - - if (PyRun_SimpleString (arg)) - error (_("Error while executing Python code.")); - } + eval_python_command (arg, from_tty); else { - struct command_line *l = get_command_line (python_control, ""); + if (from_tty) + { + int err; - make_cleanup_free_command_lines (&l); - execute_control_command_untraced (l); + ensure_python_env (get_current_arch (), current_language); + err = PyRun_InteractiveLoop(instream, ""); + dont_repeat (); + if (err && ! PyErr_ExceptionMatches (PyExc_KeyboardInterrupt)) + error(_("Error while executing Python code.")); + } + else + { + struct command_line *l = get_command_line (python_control, ""); + + make_cleanup_free_command_lines (&l); + execute_control_command_untraced (l); + } } do_cleanups (cleanup); @@ -1280,6 +1323,7 @@ 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 (); --Apple-Mail-8-116408753--