Re: RFC: add ability to "source" Python code

Thiago Jung Bauermann
2009-06-01T03:57:10Z

Hi folks,

I'm resurrecting this old thread. I believe it is important that we
settle this discussion before 7.0.

Em Qui, 2009-02-19 Ã s 12:05 -0800, Joel Brobecker escreveu:
> > Eli> I'm okay with this, but I think Tom had some valid reasons for
> > Eli> having Python scripts that don't have a certain extension.
> >
> > It is a convenience when using scratch files.
> > In practice I don't use -p much. I don't mind removing it.
>
> Ok, we can try without, and see if we get any request?

Agreed. I don't care much about -p either.

> So, where do you think we should go from now?
> a tri-state setting:
>
> 1. Use filename extension and evaluate accordingly.
> Error if the language was not compiled in.
>
> 2, Use filename extension and evaluate accordingly.
> Fallback to GDB scripting if the language was not compiled in.
>
> 3. No filename extension recognition, always treat sourced files
> as GDB scripts.
>
> Would that be acceptable to everyone?

This patch implements such tri-state setting:

(gdb) help set script-extension
Set mode for script filename extension recognition.
off == no filename extension recognition (all sourced files are GDB scripts)
soft == evaluate script according to filename extension, fallback to GDB script
hard == evaluate script according to filename extension, error if not supported

The default is 'soft'. When Python support is not compiled in, the code
always assumes a GDB script.

Is this good enough for everybody? Please ignore the documentation part
of the patch, I'll only update it when we have the code part ready to
commit.
--
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

2009-06-01 Tom Tromey <tromey@redhat.com>
Thiago Jung Bauermann <bauerman@br.ibm.com>

* python/python.c (source_python_script): New function.
* python/python.h (source_python_script): Declare.
* cli/cli-cmds.c (find_argument): New function.
(source_command): Use find_argument. Handle -p argument. Use
make_cleanup_restore_integer.
(source_verbose_cleanup): Remove.
(source_python): New global.
Include python.h.
(init_cli_cmds): Update.

2009-06-01 Tom Tromey <tromey@redhat.com>

* gdb.texinfo (File Options): Document -x on .py files.
(Command Files): Document source -p.

2009-06-01 Tom Tromey <tromey@redhat.com>
Thiago Jung Bauermann <bauerman@br.ibm.com>

* gdb.base/help.exp: Update "source" help text.
* gdb.python/source2.py: New file.
* gdb.python/source1: New file.
* gdb.python/python.exp: Test "source" command.

Index: gdb.git/gdb/cli/cli-cmds.c
===================================================================
--- gdb.git.orig/gdb/cli/cli-cmds.c 2009-06-01 00:51:11.000000000 -0300
+++ gdb.git/gdb/cli/cli-cmds.c 2009-06-01 00:52:37.000000000 -0300
@@ -19,6 +19,7 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */

#include "defs.h"
+#include "exceptions.h"
#include "readline/readline.h"
#include "readline/tilde.h"
#include "completer.h"
@@ -45,6 +46,8 @@
#include "cli/cli-setshow.h"
#include "cli/cli-cmds.h"

+#include "python/python.h"
+
#ifdef TUI
#include "tui/tui.h" /* For tui_active et.al. */
#endif
@@ -181,6 +184,21 @@ struct cmd_list_element *showchecklist;
int source_verbose = 0;
int trace_commands = 0;
\f
+/* 'script-extension' option support. */
+
+static const char script_ext_off[] = "off";
+static const char script_ext_soft[] = "soft";
+static const char script_ext_hard[] = "hard";
+
+static const char *script_ext_enums[] = {
+ script_ext_off,
+ script_ext_soft,
+ script_ext_hard,
+ NULL
+};
+
+static const char *script_ext_mode = script_ext_soft;
+\f
/* Utility used everywhere when at least one argument is needed and
none is supplied. */

@@ -432,18 +450,25 @@ cd_command (char *dir, int from_tty)
pwd_command ((char *) 0, 1);
}
\f
-void
-source_script (char *file, int from_tty)
+/* Show the current value of the 'script-extension' option. */
+
+static void
+show_script_ext_mode (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
{
- FILE *stream;
- struct cleanup *old_cleanups;
+ fprintf_filtered (file, _("\
+Script filename extension recognition is \"%s\".\n"),
+ value);
+}
+
+static int
+find_and_open_script (int from_tty, char **filep, FILE **streamp,
+ struct cleanup **cleanupp)
+{
+ char *file = *filep;
char *full_pathname = NULL;
int fd;
-
- if (file == NULL || *file == 0)
- {
- error (_("source command requires file name of file to source."));
- }
+ struct cleanup *old_cleanups;

file = tilde_expand (file);
old_cleanups = make_cleanup (xfree, file);
@@ -467,12 +492,58 @@ source_script (char *file, int from_tty)
else
{
do_cleanups (old_cleanups);
- return;
+ return 0;
}
}

- stream = fdopen (fd, FOPEN_RT);
- script_from_file (stream, file);
+ *streamp = fdopen (fd, FOPEN_RT);
+ *filep = file;
+ *cleanupp = old_cleanups;
+
+ return 1;
+}
+
+void
+source_script (char *file, int from_tty)
+{
+ FILE *stream;
+ struct cleanup *old_cleanups;
+
+ if (file == NULL || *file == 0)
+ {
+ error (_("source command requires file name of file to source."));
+ }
+
+ if (!find_and_open_script (from_tty, &file, &stream, &old_cleanups))
+ return;
+
+ if (script_ext_mode != script_ext_off
+ && strlen (file) > 3 && !strcmp (&file[strlen (file) - 3], ".py"))
+ {
+ volatile struct gdb_exception e;
+
+ TRY_CATCH (e, RETURN_MASK_ERROR)
+ {
+ source_python_script (stream, file);
+ }
+ if (e.reason < 0)
+ {
+ /* Should we fallback to ye olde GDB script mode? */
+ if (script_ext_mode == script_ext_soft
+ && e.reason == RETURN_ERROR && e.error == UNSUPPORTED_ERROR)
+ {
+ if (!find_and_open_script (from_tty, &file, &stream, &old_cleanups))
+ return;
+
+ script_from_file (stream, file);
+ }
+ else
+ /* Nope, just punt. */
+ throw_exception (e);
+ }
+ }
+ else
+ script_from_file (stream, file);

do_cleanups (old_cleanups);
}
@@ -1286,6 +1357,19 @@ when GDB is started."), gdbinit);
source_help_text, &cmdlist);
set_cmd_completer (c, filename_completer);

+ add_setshow_enum_cmd ("script-extension", class_support,
+ script_ext_enums, &script_ext_mode, _("\
+Set mode for script filename extension recognition."), _("\
+Show mode for script filename extension recognition."), _("\
+off == no filename extension recognition (all sourced files are GDB scripts)\n\
+soft == evaluate script according to filename extension, fallback to GDB script"
+ "\n\
+hard == evaluate script according to filename extension, error if not supported"
+ ),
+ NULL,
+ show_script_ext_mode,
+ &setlist, &showlist);
+
add_com ("quit", class_support, quit_command, _("Exit gdb."));
c = add_com ("help", class_support, help_command,
_("Print list of commands."));
Index: gdb.git/gdb/doc/gdb.texinfo
===================================================================
--- gdb.git.orig/gdb/doc/gdb.texinfo 2009-06-01 00:51:11.000000000 -0300
+++ gdb.git/gdb/doc/gdb.texinfo 2009-06-01 00:52:37.000000000 -0300
@@ -957,8 +957,11 @@ Connect to process ID @var{number}, as w
@itemx -x @var{file}
@cindex @code{--command}
@cindex @code{-x}
-Execute @value{GDBN} commands from file @var{file}. @xref{Command
-Files,, Command files}.
+Execute commands from file @var{file}. If @var{file} ends in
+@samp{.py}, then the file is evaluated as Python code. If Python
+support is not enabled in this @value{GDBN}, then the file is assumed to
+contain @value{GDBN} commands, regardless of its extension.
+@xref{Command Files,, Command files}.

@item -eval-command @var{command}
@itemx -ex @var{command}
@@ -18227,6 +18230,11 @@ If @code{-v}, for verbose mode, is given
each command as it is executed. The option must be given before
@var{filename}, and is interpreted as part of the filename anywhere else.

+If @var{filename} ends in @samp{.py}, then @value{GDBN} evaluates the
+contents of the file as Python code. If Python support is not compiled
+in to @value{GDBN}, then the file is assumed to contain @value{GDBN}
+commands, regardless of its extension.
+
Commands that would ask for confirmation if used interactively proceed
without asking when used in a command file. Many @value{GDBN} commands that
normally print messages to say what they are doing omit the messages
Index: gdb.git/gdb/python/python.c
===================================================================
--- gdb.git.orig/gdb/python/python.c 2009-06-01 00:51:11.000000000 -0300
+++ gdb.git/gdb/python/python.c 2009-06-01 00:52:37.000000000 -0300
@@ -18,6 +18,7 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */

#include "defs.h"
+#include "exceptions.h"
#include "command.h"
#include "ui-out.h"
#include "cli/cli-script.h"
@@ -275,6 +276,22 @@ execute_gdb_command (PyObject *self, PyO
Py_RETURN_NONE;
}

+/* Read a file as Python code. STREAM is the input file; FILE is the
+ name of the file. */
+
+void
+source_python_script (FILE *stream, char *file)
+{
+ PyGILState_STATE state;
+
+ state = PyGILState_Ensure ();
+
+ PyRun_SimpleFile (stream, file);
+
+ fclose (stream);
+ PyGILState_Release (state);
+}
+
\f

/* Printing. */
@@ -460,6 +477,14 @@ eval_python_from_control_command (struct
error (_("Python scripting is not supported in this copy of GDB."));
}

+void
+source_python_script (FILE *stream, char *file)
+{
+ fclose (stream);
+ throw_error (UNSUPPORTED_ERROR,
+ _("Python scripting is not supported in this copy of GDB."));
+}
+
#endif /* HAVE_PYTHON */

\f
Index: gdb.git/gdb/python/python.h
===================================================================
--- gdb.git.orig/gdb/python/python.h 2009-06-01 00:51:12.000000000 -0300
+++ gdb.git/gdb/python/python.h 2009-06-01 00:53:48.000000000 -0300
@@ -26,6 +26,8 @@ extern struct value *values_in_python;

void eval_python_from_control_command (struct command_line *);

+void source_python_script (FILE *stream, char *file);
+
int apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
int embedded_offset, CORE_ADDR address,
struct ui_file *stream, int recurse,
Index: gdb.git/gdb/testsuite/gdb.python/python.exp
===================================================================
--- gdb.git.orig/gdb/testsuite/gdb.python/python.exp 2009-06-01 00:52:37.000000000 -0300
+++ gdb.git/gdb/testsuite/gdb.python/python.exp 2009-06-01 00:55:50.000000000 -0300
@@ -27,8 +27,8 @@ gdb_start
gdb_reinitialize_dir $srcdir/$subdir

if ![python_supported] then {
- unsupported "python support is disabled"
- return -1
+ gdb_test "source $srcdir/$subdir/source2.py" "Error in sourced command file:.*"
+ return 0
}

gdb_py_test_multiple "multi-line python command" \
@@ -51,5 +51,7 @@ gdb_py_test_multiple "indented multi-lin
"foo ()" "" \
"end" "hello, world!"

+gdb_test "source $srcdir/$subdir/source2.py" "yes"
+
gdb_test "python print gdb.current_objfile()" "None"
gdb_test "python print gdb.objfiles()" "\\\[\\\]"
Index: gdb.git/gdb/testsuite/gdb.python/source1
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb.git/gdb/testsuite/gdb.python/source1 2009-06-01 00:52:37.000000000 -0300
@@ -0,0 +1,19 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2008, 2009 Free Software Foundation, Inc.
+
+# 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/>.
+
+# This is sourced as python; pick an expression that is not valid for gdb.
+print 'y%ss' % 'e'
Index: gdb.git/gdb/testsuite/gdb.python/source2.py
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb.git/gdb/testsuite/gdb.python/source2.py 2009-06-01 00:52:37.000000000 -0300
@@ -0,0 +1,18 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2008, 2009 Free Software Foundation, Inc.
+
+# 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/>.
+
+print 'y%ss' % 'e'
Index: gdb.git/gdb/exceptions.h
===================================================================
--- gdb.git.orig/gdb/exceptions.h 2009-06-01 00:51:12.000000000 -0300
+++ gdb.git/gdb/exceptions.h 2009-06-01 00:52:37.000000000 -0300
@@ -75,6 +75,9 @@ enum errors {
/* Error accessing memory. */
MEMORY_ERROR,

+ /* Feature is not supported in this copy of GDB. */
+ UNSUPPORTED_ERROR,
+
/* Add more errors here. */
NR_ERRORS
};