1 /* gdb commands implemented in Python
3 Copyright (C) 2008-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
22 #include "arch-utils.h"
24 #include "python-internal.h"
27 #include "cli/cli-decode.h"
28 #include "completer.h"
31 /* Struct representing built-in completion types. */
32 struct cmdpy_completer
34 /* Python symbol name.
35 This isn't a const char * for Python 2.4's sake.
36 PyModule_AddIntConstant only takes a char *, sigh. */
38 /* Completion function. */
39 completer_ftype
*completer
;
42 static const struct cmdpy_completer completers
[] =
44 { "COMPLETE_NONE", noop_completer
},
45 { "COMPLETE_FILENAME", filename_completer
},
46 { "COMPLETE_LOCATION", location_completer
},
47 { "COMPLETE_COMMAND", command_completer
},
48 { "COMPLETE_SYMBOL", make_symbol_completion_list_fn
},
49 { "COMPLETE_EXPRESSION", expression_completer
},
52 #define N_COMPLETERS (sizeof (completers) / sizeof (completers[0]))
54 /* A gdb command. For the time being only ordinary commands (not
55 set/show commands) are allowed. */
60 /* The corresponding gdb command object, or NULL if the command is
61 no longer installed. */
62 struct cmd_list_element
*command
;
64 /* A prefix command requires storage for a list of its sub-commands.
65 A pointer to this is passed to add_prefix_command, and to add_cmd
66 for sub-commands of that prefix. If this Command is not a prefix
67 command, then this field is unused. */
68 struct cmd_list_element
*sub_list
;
71 typedef struct cmdpy_object cmdpy_object
;
73 extern PyTypeObject cmdpy_object_type
74 CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("cmdpy_object");
76 /* Constants used by this module. */
77 static PyObject
*invoke_cst
;
78 static PyObject
*complete_cst
;
82 /* Python function which wraps dont_repeat. */
84 cmdpy_dont_repeat (PyObject
*self
, PyObject
*args
)
92 /* Called if the gdb cmd_list_element is destroyed. */
95 cmdpy_destroyer (struct cmd_list_element
*self
, void *context
)
98 struct cleanup
*cleanup
;
100 cleanup
= ensure_python_env (get_current_arch (), current_language
);
102 /* Release our hold on the command object. */
103 cmd
= (cmdpy_object
*) context
;
107 /* We allocated the name, doc string, and perhaps the prefix
109 xfree ((char *) self
->name
);
110 xfree ((char *) self
->doc
);
111 xfree ((char *) self
->prefixname
);
113 do_cleanups (cleanup
);
116 /* Called by gdb to invoke the command. */
119 cmdpy_function (struct cmd_list_element
*command
, char *args
, int from_tty
)
121 cmdpy_object
*obj
= (cmdpy_object
*) get_cmd_context (command
);
122 PyObject
*argobj
, *ttyobj
, *result
;
123 struct cleanup
*cleanup
;
125 cleanup
= ensure_python_env (get_current_arch (), current_language
);
128 error (_("Invalid invocation of Python command object."));
129 if (! PyObject_HasAttr ((PyObject
*) obj
, invoke_cst
))
131 if (obj
->command
->prefixname
)
133 /* A prefix command does not need an invoke method. */
134 do_cleanups (cleanup
);
137 error (_("Python command object missing 'invoke' method."));
142 argobj
= PyUnicode_Decode (args
, strlen (args
), host_charset (), NULL
);
145 gdbpy_print_stack ();
146 error (_("Could not convert arguments to Python string."));
149 ttyobj
= from_tty
? Py_True
: Py_False
;
151 result
= PyObject_CallMethodObjArgs ((PyObject
*) obj
, invoke_cst
, argobj
,
158 PyObject
*ptype
, *pvalue
, *ptraceback
;
160 PyErr_Fetch (&ptype
, &pvalue
, &ptraceback
);
162 /* Try to fetch an error message contained within ptype, pvalue.
163 When fetching the error message we need to make our own copy,
164 we no longer own ptype, pvalue after the call to PyErr_Restore. */
166 gdb::unique_xmalloc_ptr
<char>
167 msg (gdbpy_exception_to_string (ptype
, pvalue
));
171 /* An error occurred computing the string representation of the
172 error message. This is rare, but we should inform the user. */
173 printf_filtered (_("An error occurred in a Python command\n"
174 "and then another occurred computing the "
175 "error message.\n"));
176 gdbpy_print_stack ();
179 /* Don't print the stack for gdb.GdbError exceptions.
180 It is generally used to flag user errors.
182 We also don't want to print "Error occurred in Python command"
183 for user errors. However, a missing message for gdb.GdbError
184 exceptions is arguably a bug, so we flag it as such. */
186 if (! PyErr_GivenExceptionMatches (ptype
, gdbpy_gdberror_exc
)
187 || msg
== NULL
|| *msg
== '\0')
189 PyErr_Restore (ptype
, pvalue
, ptraceback
);
190 gdbpy_print_stack ();
191 if (msg
!= NULL
&& *msg
!= '\0')
192 error (_("Error occurred in Python command: %s"), msg
.get ());
194 error (_("Error occurred in Python command."));
200 Py_XDECREF (ptraceback
);
201 error ("%s", msg
.get ());
206 do_cleanups (cleanup
);
209 /* Helper function for the Python command completers (both "pure"
210 completer and brkchar handler). This function takes COMMAND, TEXT
211 and WORD and tries to call the Python method for completion with
214 This function is usually called twice: once when we are figuring out
215 the break characters to be used, and another to perform the real
216 completion itself. The reason for this two step dance is that we
217 need to know the set of "brkchars" to use early on, before we
218 actually try to perform the completion. But if a Python command
219 supplies a "complete" method then we have to call that method
220 first: it may return as its result the kind of completion to
221 perform and that will in turn specify which brkchars to use. IOW,
222 we need the result of the "complete" method before we actually
223 perform the completion. The only situation when this function is
224 not called twice is when the user uses the "complete" command: in
225 this scenario, there is no call to determine the "brkchars".
227 Ideally, it would be nice to cache the result of the first call (to
228 determine the "brkchars") and return this value directly in the
229 second call (to perform the actual completion). However, due to
230 the peculiarity of the "complete" command mentioned above, it is
231 possible to put GDB in a bad state if you perform a TAB-completion
232 and then a "complete"-completion sequentially. Therefore, we just
233 recalculate everything twice for TAB-completions.
235 This function returns the PyObject representing the Python method
239 cmdpy_completer_helper (struct cmd_list_element
*command
,
240 const char *text
, const char *word
)
242 cmdpy_object
*obj
= (cmdpy_object
*) get_cmd_context (command
);
243 PyObject
*textobj
, *wordobj
;
247 error (_("Invalid invocation of Python command object."));
248 if (!PyObject_HasAttr ((PyObject
*) obj
, complete_cst
))
250 /* If there is no complete method, don't error. */
254 textobj
= PyUnicode_Decode (text
, strlen (text
), host_charset (), NULL
);
256 error (_("Could not convert argument to Python string."));
257 wordobj
= PyUnicode_Decode (word
, strlen (word
), host_charset (), NULL
);
261 error (_("Could not convert argument to Python string."));
264 resultobj
= PyObject_CallMethodObjArgs ((PyObject
*) obj
, complete_cst
,
265 textobj
, wordobj
, NULL
);
270 /* Just swallow errors here. */
274 Py_XINCREF (resultobj
);
279 /* Python function called to determine the break characters of a
280 certain completer. We are only interested in knowing if the
281 completer registered by the user will return one of the integer
282 codes (see COMPLETER_* symbols). */
285 cmdpy_completer_handle_brkchars (struct cmd_list_element
*command
,
286 const char *text
, const char *word
)
288 PyObject
*resultobj
= NULL
;
289 struct cleanup
*cleanup
;
291 cleanup
= ensure_python_env (get_current_arch (), current_language
);
293 /* Calling our helper to obtain the PyObject of the Python
295 resultobj
= cmdpy_completer_helper (command
, text
, word
);
297 /* Check if there was an error. */
298 if (resultobj
== NULL
)
301 if (PyInt_Check (resultobj
))
303 /* User code may also return one of the completion constants,
304 thus requesting that sort of completion. We are only
305 interested in this kind of return. */
308 if (!gdb_py_int_as_long (resultobj
, &value
))
313 else if (value
>= 0 && value
< (long) N_COMPLETERS
)
315 /* This is the core of this function. Depending on which
316 completer type the Python function returns, we have to
317 adjust the break characters accordingly. */
318 set_gdb_completion_word_break_characters
319 (completers
[value
].completer
);
325 Py_XDECREF (resultobj
);
326 do_cleanups (cleanup
);
329 /* Called by gdb for command completion. */
331 static VEC (char_ptr
) *
332 cmdpy_completer (struct cmd_list_element
*command
,
333 const char *text
, const char *word
)
335 PyObject
*resultobj
= NULL
;
336 VEC (char_ptr
) *result
= NULL
;
337 struct cleanup
*cleanup
;
339 cleanup
= ensure_python_env (get_current_arch (), current_language
);
341 /* Calling our helper to obtain the PyObject of the Python
343 resultobj
= cmdpy_completer_helper (command
, text
, word
);
345 /* If the result object of calling the Python function is NULL, it
346 means that there was an error. In this case, just give up and
348 if (resultobj
== NULL
)
352 if (PyInt_Check (resultobj
))
354 /* User code may also return one of the completion constants,
355 thus requesting that sort of completion. */
358 if (! gdb_py_int_as_long (resultobj
, &value
))
363 else if (value
>= 0 && value
< (long) N_COMPLETERS
)
364 result
= completers
[value
].completer (command
, text
, word
);
368 PyObject
*iter
= PyObject_GetIter (resultobj
);
374 while ((elt
= PyIter_Next (iter
)) != NULL
)
377 if (! gdbpy_is_string (elt
))
379 /* Skip problem elements. */
383 gdb::unique_xmalloc_ptr
<char>
384 item (python_string_to_host_string (elt
));
388 /* Skip problem elements. */
392 VEC_safe_push (char_ptr
, result
, item
.release ());
397 /* If we got some results, ignore problems. Otherwise, report
399 if (result
!= NULL
&& PyErr_Occurred ())
405 Py_XDECREF (resultobj
);
406 do_cleanups (cleanup
);
411 /* Helper for cmdpy_init which locates the command list to use and
412 pulls out the command name.
414 NAME is the command name list. The final word in the list is the
415 name of the new command. All earlier words must be existing prefix
418 *BASE_LIST is set to the final prefix command's list of
421 START_LIST is the list in which the search starts.
423 This function returns the xmalloc()d name of the new command. On
424 error sets the Python error and returns NULL. */
427 gdbpy_parse_command_name (const char *name
,
428 struct cmd_list_element
***base_list
,
429 struct cmd_list_element
**start_list
)
431 struct cmd_list_element
*elt
;
432 int len
= strlen (name
);
435 const char *prefix_text2
;
438 /* Skip trailing whitespace. */
439 for (i
= len
- 1; i
>= 0 && (name
[i
] == ' ' || name
[i
] == '\t'); --i
)
443 PyErr_SetString (PyExc_RuntimeError
, _("No command name found."));
448 /* Find first character of the final word. */
449 for (; i
> 0 && (isalnum (name
[i
- 1])
450 || name
[i
- 1] == '-'
451 || name
[i
- 1] == '_');
454 result
= (char *) xmalloc (lastchar
- i
+ 2);
455 memcpy (result
, &name
[i
], lastchar
- i
+ 1);
456 result
[lastchar
- i
+ 1] = '\0';
458 /* Skip whitespace again. */
459 for (--i
; i
>= 0 && (name
[i
] == ' ' || name
[i
] == '\t'); --i
)
463 *base_list
= start_list
;
467 prefix_text
= (char *) xmalloc (i
+ 2);
468 memcpy (prefix_text
, name
, i
+ 1);
469 prefix_text
[i
+ 1] = '\0';
471 prefix_text2
= prefix_text
;
472 elt
= lookup_cmd_1 (&prefix_text2
, *start_list
, NULL
, 1);
473 if (elt
== NULL
|| elt
== CMD_LIST_AMBIGUOUS
)
475 PyErr_Format (PyExc_RuntimeError
, _("Could not find command prefix %s."),
485 *base_list
= elt
->prefixlist
;
489 PyErr_Format (PyExc_RuntimeError
, _("'%s' is not a prefix command."),
496 /* Object initializer; sets up gdb-side structures for command.
498 Use: __init__(NAME, COMMAND_CLASS [, COMPLETER_CLASS][, PREFIX]]).
500 NAME is the name of the command. It may consist of multiple words,
501 in which case the final word is the name of the new command, and
502 earlier words must be prefix commands.
504 COMMAND_CLASS is the kind of command. It should be one of the COMMAND_*
505 constants defined in the gdb module.
507 COMPLETER_CLASS is the kind of completer. If not given, the
508 "complete" method will be used. Otherwise, it should be one of the
509 COMPLETE_* constants defined in the gdb module.
511 If PREFIX is True, then this command is a prefix command.
513 The documentation for the command is taken from the doc string for
517 cmdpy_init (PyObject
*self
, PyObject
*args
, PyObject
*kw
)
519 cmdpy_object
*obj
= (cmdpy_object
*) self
;
522 int completetype
= -1;
523 char *docstring
= NULL
;
524 struct cmd_list_element
**cmd_list
;
525 char *cmd_name
, *pfx_name
;
526 static char *keywords
[] = { "name", "command_class", "completer_class",
528 PyObject
*is_prefix
= NULL
;
533 /* Note: this is apparently not documented in Python. We return
534 0 for success, -1 for failure. */
535 PyErr_Format (PyExc_RuntimeError
,
536 _("Command object already initialized."));
540 if (! PyArg_ParseTupleAndKeywords (args
, kw
, "si|iO",
541 keywords
, &name
, &cmdtype
,
542 &completetype
, &is_prefix
))
545 if (cmdtype
!= no_class
&& cmdtype
!= class_run
546 && cmdtype
!= class_vars
&& cmdtype
!= class_stack
547 && cmdtype
!= class_files
&& cmdtype
!= class_support
548 && cmdtype
!= class_info
&& cmdtype
!= class_breakpoint
549 && cmdtype
!= class_trace
&& cmdtype
!= class_obscure
550 && cmdtype
!= class_maintenance
&& cmdtype
!= class_user
)
552 PyErr_Format (PyExc_RuntimeError
, _("Invalid command class argument."));
556 if (completetype
< -1 || completetype
>= (int) N_COMPLETERS
)
558 PyErr_Format (PyExc_RuntimeError
,
559 _("Invalid completion type argument."));
563 cmd_name
= gdbpy_parse_command_name (name
, &cmd_list
, &cmdlist
);
568 if (is_prefix
!= NULL
)
570 cmp
= PyObject_IsTrue (is_prefix
);
575 /* Make a normalized form of the command name. */
576 pfx_name
= (char *) xmalloc (strlen (name
) + 2);
582 /* Skip whitespace. */
583 while (name
[i
] == ' ' || name
[i
] == '\t')
585 /* Copy non-whitespace characters. */
586 while (name
[i
] && name
[i
] != ' ' && name
[i
] != '\t')
587 pfx_name
[out
++] = name
[i
++];
588 /* Add a single space after each word -- including the final
590 pfx_name
[out
++] = ' ';
592 pfx_name
[out
] = '\0';
600 if (PyObject_HasAttr (self
, gdbpy_doc_cst
))
602 PyObject
*ds_obj
= PyObject_GetAttr (self
, gdbpy_doc_cst
);
604 if (ds_obj
&& gdbpy_is_string (ds_obj
))
606 docstring
= python_string_to_host_string (ds_obj
).release ();
607 if (docstring
== NULL
)
619 docstring
= xstrdup (_("This command is not documented."));
625 struct cmd_list_element
*cmd
;
631 /* If we have our own "invoke" method, then allow unknown
633 allow_unknown
= PyObject_HasAttr (self
, invoke_cst
);
634 cmd
= add_prefix_cmd (cmd_name
, (enum command_class
) cmdtype
,
635 NULL
, docstring
, &obj
->sub_list
,
636 pfx_name
, allow_unknown
, cmd_list
);
639 cmd
= add_cmd (cmd_name
, (enum command_class
) cmdtype
, NULL
,
640 docstring
, cmd_list
);
642 /* There appears to be no API to set this. */
643 cmd
->func
= cmdpy_function
;
644 cmd
->destroyer
= cmdpy_destroyer
;
647 set_cmd_context (cmd
, self
);
648 set_cmd_completer (cmd
, ((completetype
== -1) ? cmdpy_completer
649 : completers
[completetype
].completer
));
650 if (completetype
== -1)
651 set_cmd_completer_handle_brkchars (cmd
,
652 cmdpy_completer_handle_brkchars
);
654 CATCH (except
, RETURN_MASK_ALL
)
660 PyErr_Format (except
.reason
== RETURN_QUIT
661 ? PyExc_KeyboardInterrupt
: PyExc_RuntimeError
,
662 "%s", except
.message
);
672 /* Initialize the 'commands' code. */
675 gdbpy_initialize_commands (void)
679 cmdpy_object_type
.tp_new
= PyType_GenericNew
;
680 if (PyType_Ready (&cmdpy_object_type
) < 0)
683 /* Note: alias and user are special; pseudo appears to be unused,
684 and there is no reason to expose tui, I think. */
685 if (PyModule_AddIntConstant (gdb_module
, "COMMAND_NONE", no_class
) < 0
686 || PyModule_AddIntConstant (gdb_module
, "COMMAND_RUNNING", class_run
) < 0
687 || PyModule_AddIntConstant (gdb_module
, "COMMAND_DATA", class_vars
) < 0
688 || PyModule_AddIntConstant (gdb_module
, "COMMAND_STACK", class_stack
) < 0
689 || PyModule_AddIntConstant (gdb_module
, "COMMAND_FILES", class_files
) < 0
690 || PyModule_AddIntConstant (gdb_module
, "COMMAND_SUPPORT",
692 || PyModule_AddIntConstant (gdb_module
, "COMMAND_STATUS", class_info
) < 0
693 || PyModule_AddIntConstant (gdb_module
, "COMMAND_BREAKPOINTS",
694 class_breakpoint
) < 0
695 || PyModule_AddIntConstant (gdb_module
, "COMMAND_TRACEPOINTS",
697 || PyModule_AddIntConstant (gdb_module
, "COMMAND_OBSCURE",
699 || PyModule_AddIntConstant (gdb_module
, "COMMAND_MAINTENANCE",
700 class_maintenance
) < 0
701 || PyModule_AddIntConstant (gdb_module
, "COMMAND_USER", class_user
) < 0)
704 for (i
= 0; i
< N_COMPLETERS
; ++i
)
706 if (PyModule_AddIntConstant (gdb_module
, completers
[i
].name
, i
) < 0)
710 if (gdb_pymodule_addobject (gdb_module
, "Command",
711 (PyObject
*) &cmdpy_object_type
) < 0)
714 invoke_cst
= PyString_FromString ("invoke");
715 if (invoke_cst
== NULL
)
717 complete_cst
= PyString_FromString ("complete");
718 if (complete_cst
== NULL
)
726 static PyMethodDef cmdpy_object_methods
[] =
728 { "dont_repeat", cmdpy_dont_repeat
, METH_NOARGS
,
729 "Prevent command repetition when user enters empty line." },
734 PyTypeObject cmdpy_object_type
=
736 PyVarObject_HEAD_INIT (NULL
, 0)
737 "gdb.Command", /*tp_name*/
738 sizeof (cmdpy_object
), /*tp_basicsize*/
747 0, /*tp_as_sequence*/
755 Py_TPFLAGS_DEFAULT
| Py_TPFLAGS_BASETYPE
, /*tp_flags*/
756 "GDB command object", /* tp_doc */
759 0, /* tp_richcompare */
760 0, /* tp_weaklistoffset */
763 cmdpy_object_methods
, /* tp_methods */
768 0, /* tp_descr_get */
769 0, /* tp_descr_set */
770 0, /* tp_dictoffset */
771 cmdpy_init
, /* tp_init */
777 /* Utility to build a buildargv-like result from ARGS.
778 This intentionally parses arguments the way libiberty/argv.c:buildargv
779 does. It splits up arguments in a reasonable way, and we want a standard
780 way of parsing arguments. Several gdb commands use buildargv to parse their
781 arguments. Plus we want to be able to write compatible python
782 implementations of gdb commands. */
785 gdbpy_string_to_argv (PyObject
*self
, PyObject
*args
)
790 if (!PyArg_ParseTuple (args
, "s", &input
))
793 py_argv
= PyList_New (0);
797 /* buildargv uses NULL to represent an empty argument list, but we can't use
798 that in Python. Instead, if ARGS is "" then return an empty list.
799 This undoes the NULL -> "" conversion that cmdpy_function does. */
803 char **c_argv
= gdb_buildargv (input
);
806 for (i
= 0; c_argv
[i
] != NULL
; ++i
)
808 PyObject
*argp
= PyString_FromString (c_argv
[i
]);
811 || PyList_Append (py_argv
, argp
) < 0)