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
;
161 PyErr_Fetch (&ptype
, &pvalue
, &ptraceback
);
163 /* Try to fetch an error message contained within ptype, pvalue.
164 When fetching the error message we need to make our own copy,
165 we no longer own ptype, pvalue after the call to PyErr_Restore. */
167 msg
= gdbpy_exception_to_string (ptype
, pvalue
);
168 make_cleanup (xfree
, msg
);
172 /* An error occurred computing the string representation of the
173 error message. This is rare, but we should inform the user. */
174 printf_filtered (_("An error occurred in a Python command\n"
175 "and then another occurred computing the "
176 "error message.\n"));
177 gdbpy_print_stack ();
180 /* Don't print the stack for gdb.GdbError exceptions.
181 It is generally used to flag user errors.
183 We also don't want to print "Error occurred in Python command"
184 for user errors. However, a missing message for gdb.GdbError
185 exceptions is arguably a bug, so we flag it as such. */
187 if (! PyErr_GivenExceptionMatches (ptype
, gdbpy_gdberror_exc
)
188 || msg
== NULL
|| *msg
== '\0')
190 PyErr_Restore (ptype
, pvalue
, ptraceback
);
191 gdbpy_print_stack ();
192 if (msg
!= NULL
&& *msg
!= '\0')
193 error (_("Error occurred in Python command: %s"), msg
);
195 error (_("Error occurred in Python command."));
201 Py_XDECREF (ptraceback
);
207 do_cleanups (cleanup
);
210 /* Helper function for the Python command completers (both "pure"
211 completer and brkchar handler). This function takes COMMAND, TEXT
212 and WORD and tries to call the Python method for completion with
215 This function is usually called twice: once when we are figuring out
216 the break characters to be used, and another to perform the real
217 completion itself. The reason for this two step dance is that we
218 need to know the set of "brkchars" to use early on, before we
219 actually try to perform the completion. But if a Python command
220 supplies a "complete" method then we have to call that method
221 first: it may return as its result the kind of completion to
222 perform and that will in turn specify which brkchars to use. IOW,
223 we need the result of the "complete" method before we actually
224 perform the completion. The only situation when this function is
225 not called twice is when the user uses the "complete" command: in
226 this scenario, there is no call to determine the "brkchars".
228 Ideally, it would be nice to cache the result of the first call (to
229 determine the "brkchars") and return this value directly in the
230 second call (to perform the actual completion). However, due to
231 the peculiarity of the "complete" command mentioned above, it is
232 possible to put GDB in a bad state if you perform a TAB-completion
233 and then a "complete"-completion sequentially. Therefore, we just
234 recalculate everything twice for TAB-completions.
236 This function returns the PyObject representing the Python method
240 cmdpy_completer_helper (struct cmd_list_element
*command
,
241 const char *text
, const char *word
)
243 cmdpy_object
*obj
= (cmdpy_object
*) get_cmd_context (command
);
244 PyObject
*textobj
, *wordobj
;
248 error (_("Invalid invocation of Python command object."));
249 if (!PyObject_HasAttr ((PyObject
*) obj
, complete_cst
))
251 /* If there is no complete method, don't error. */
255 textobj
= PyUnicode_Decode (text
, strlen (text
), host_charset (), NULL
);
257 error (_("Could not convert argument to Python string."));
258 wordobj
= PyUnicode_Decode (word
, strlen (word
), host_charset (), NULL
);
262 error (_("Could not convert argument to Python string."));
265 resultobj
= PyObject_CallMethodObjArgs ((PyObject
*) obj
, complete_cst
,
266 textobj
, wordobj
, NULL
);
271 /* Just swallow errors here. */
275 Py_XINCREF (resultobj
);
280 /* Python function called to determine the break characters of a
281 certain completer. We are only interested in knowing if the
282 completer registered by the user will return one of the integer
283 codes (see COMPLETER_* symbols). */
286 cmdpy_completer_handle_brkchars (struct cmd_list_element
*command
,
287 const char *text
, const char *word
)
289 PyObject
*resultobj
= NULL
;
290 struct cleanup
*cleanup
;
292 cleanup
= ensure_python_env (get_current_arch (), current_language
);
294 /* Calling our helper to obtain the PyObject of the Python
296 resultobj
= cmdpy_completer_helper (command
, text
, word
);
298 /* Check if there was an error. */
299 if (resultobj
== NULL
)
302 if (PyInt_Check (resultobj
))
304 /* User code may also return one of the completion constants,
305 thus requesting that sort of completion. We are only
306 interested in this kind of return. */
309 if (!gdb_py_int_as_long (resultobj
, &value
))
314 else if (value
>= 0 && value
< (long) N_COMPLETERS
)
316 /* This is the core of this function. Depending on which
317 completer type the Python function returns, we have to
318 adjust the break characters accordingly. */
319 set_gdb_completion_word_break_characters
320 (completers
[value
].completer
);
326 Py_XDECREF (resultobj
);
327 do_cleanups (cleanup
);
330 /* Called by gdb for command completion. */
332 static VEC (char_ptr
) *
333 cmdpy_completer (struct cmd_list_element
*command
,
334 const char *text
, const char *word
)
336 PyObject
*resultobj
= NULL
;
337 VEC (char_ptr
) *result
= NULL
;
338 struct cleanup
*cleanup
;
340 cleanup
= ensure_python_env (get_current_arch (), current_language
);
342 /* Calling our helper to obtain the PyObject of the Python
344 resultobj
= cmdpy_completer_helper (command
, text
, word
);
346 /* If the result object of calling the Python function is NULL, it
347 means that there was an error. In this case, just give up and
349 if (resultobj
== NULL
)
353 if (PyInt_Check (resultobj
))
355 /* User code may also return one of the completion constants,
356 thus requesting that sort of completion. */
359 if (! gdb_py_int_as_long (resultobj
, &value
))
364 else if (value
>= 0 && value
< (long) N_COMPLETERS
)
365 result
= completers
[value
].completer (command
, text
, word
);
369 PyObject
*iter
= PyObject_GetIter (resultobj
);
375 while ((elt
= PyIter_Next (iter
)) != NULL
)
379 if (! gdbpy_is_string (elt
))
381 /* Skip problem elements. */
385 item
= python_string_to_host_string (elt
);
389 /* Skip problem elements. */
393 VEC_safe_push (char_ptr
, result
, item
);
398 /* If we got some results, ignore problems. Otherwise, report
400 if (result
!= NULL
&& PyErr_Occurred ())
406 Py_XDECREF (resultobj
);
407 do_cleanups (cleanup
);
412 /* Helper for cmdpy_init which locates the command list to use and
413 pulls out the command name.
415 NAME is the command name list. The final word in the list is the
416 name of the new command. All earlier words must be existing prefix
419 *BASE_LIST is set to the final prefix command's list of
422 START_LIST is the list in which the search starts.
424 This function returns the xmalloc()d name of the new command. On
425 error sets the Python error and returns NULL. */
428 gdbpy_parse_command_name (const char *name
,
429 struct cmd_list_element
***base_list
,
430 struct cmd_list_element
**start_list
)
432 struct cmd_list_element
*elt
;
433 int len
= strlen (name
);
436 const char *prefix_text2
;
439 /* Skip trailing whitespace. */
440 for (i
= len
- 1; i
>= 0 && (name
[i
] == ' ' || name
[i
] == '\t'); --i
)
444 PyErr_SetString (PyExc_RuntimeError
, _("No command name found."));
449 /* Find first character of the final word. */
450 for (; i
> 0 && (isalnum (name
[i
- 1])
451 || name
[i
- 1] == '-'
452 || name
[i
- 1] == '_');
455 result
= (char *) xmalloc (lastchar
- i
+ 2);
456 memcpy (result
, &name
[i
], lastchar
- i
+ 1);
457 result
[lastchar
- i
+ 1] = '\0';
459 /* Skip whitespace again. */
460 for (--i
; i
>= 0 && (name
[i
] == ' ' || name
[i
] == '\t'); --i
)
464 *base_list
= start_list
;
468 prefix_text
= (char *) xmalloc (i
+ 2);
469 memcpy (prefix_text
, name
, i
+ 1);
470 prefix_text
[i
+ 1] = '\0';
472 prefix_text2
= prefix_text
;
473 elt
= lookup_cmd_1 (&prefix_text2
, *start_list
, NULL
, 1);
474 if (elt
== NULL
|| elt
== CMD_LIST_AMBIGUOUS
)
476 PyErr_Format (PyExc_RuntimeError
, _("Could not find command prefix %s."),
486 *base_list
= elt
->prefixlist
;
490 PyErr_Format (PyExc_RuntimeError
, _("'%s' is not a prefix command."),
497 /* Object initializer; sets up gdb-side structures for command.
499 Use: __init__(NAME, COMMAND_CLASS [, COMPLETER_CLASS][, PREFIX]]).
501 NAME is the name of the command. It may consist of multiple words,
502 in which case the final word is the name of the new command, and
503 earlier words must be prefix commands.
505 COMMAND_CLASS is the kind of command. It should be one of the COMMAND_*
506 constants defined in the gdb module.
508 COMPLETER_CLASS is the kind of completer. If not given, the
509 "complete" method will be used. Otherwise, it should be one of the
510 COMPLETE_* constants defined in the gdb module.
512 If PREFIX is True, then this command is a prefix command.
514 The documentation for the command is taken from the doc string for
518 cmdpy_init (PyObject
*self
, PyObject
*args
, PyObject
*kw
)
520 cmdpy_object
*obj
= (cmdpy_object
*) self
;
523 int completetype
= -1;
524 char *docstring
= NULL
;
525 struct cmd_list_element
**cmd_list
;
526 char *cmd_name
, *pfx_name
;
527 static char *keywords
[] = { "name", "command_class", "completer_class",
529 PyObject
*is_prefix
= NULL
;
534 /* Note: this is apparently not documented in Python. We return
535 0 for success, -1 for failure. */
536 PyErr_Format (PyExc_RuntimeError
,
537 _("Command object already initialized."));
541 if (! PyArg_ParseTupleAndKeywords (args
, kw
, "si|iO",
542 keywords
, &name
, &cmdtype
,
543 &completetype
, &is_prefix
))
546 if (cmdtype
!= no_class
&& cmdtype
!= class_run
547 && cmdtype
!= class_vars
&& cmdtype
!= class_stack
548 && cmdtype
!= class_files
&& cmdtype
!= class_support
549 && cmdtype
!= class_info
&& cmdtype
!= class_breakpoint
550 && cmdtype
!= class_trace
&& cmdtype
!= class_obscure
551 && cmdtype
!= class_maintenance
&& cmdtype
!= class_user
)
553 PyErr_Format (PyExc_RuntimeError
, _("Invalid command class argument."));
557 if (completetype
< -1 || completetype
>= (int) N_COMPLETERS
)
559 PyErr_Format (PyExc_RuntimeError
,
560 _("Invalid completion type argument."));
564 cmd_name
= gdbpy_parse_command_name (name
, &cmd_list
, &cmdlist
);
569 if (is_prefix
!= NULL
)
571 cmp
= PyObject_IsTrue (is_prefix
);
576 /* Make a normalized form of the command name. */
577 pfx_name
= (char *) xmalloc (strlen (name
) + 2);
583 /* Skip whitespace. */
584 while (name
[i
] == ' ' || name
[i
] == '\t')
586 /* Copy non-whitespace characters. */
587 while (name
[i
] && name
[i
] != ' ' && name
[i
] != '\t')
588 pfx_name
[out
++] = name
[i
++];
589 /* Add a single space after each word -- including the final
591 pfx_name
[out
++] = ' ';
593 pfx_name
[out
] = '\0';
601 if (PyObject_HasAttr (self
, gdbpy_doc_cst
))
603 PyObject
*ds_obj
= PyObject_GetAttr (self
, gdbpy_doc_cst
);
605 if (ds_obj
&& gdbpy_is_string (ds_obj
))
607 docstring
= python_string_to_host_string (ds_obj
);
608 if (docstring
== NULL
)
620 docstring
= xstrdup (_("This command is not documented."));
626 struct cmd_list_element
*cmd
;
632 /* If we have our own "invoke" method, then allow unknown
634 allow_unknown
= PyObject_HasAttr (self
, invoke_cst
);
635 cmd
= add_prefix_cmd (cmd_name
, (enum command_class
) cmdtype
,
636 NULL
, docstring
, &obj
->sub_list
,
637 pfx_name
, allow_unknown
, cmd_list
);
640 cmd
= add_cmd (cmd_name
, (enum command_class
) cmdtype
, NULL
,
641 docstring
, cmd_list
);
643 /* There appears to be no API to set this. */
644 cmd
->func
= cmdpy_function
;
645 cmd
->destroyer
= cmdpy_destroyer
;
648 set_cmd_context (cmd
, self
);
649 set_cmd_completer (cmd
, ((completetype
== -1) ? cmdpy_completer
650 : completers
[completetype
].completer
));
651 if (completetype
== -1)
652 set_cmd_completer_handle_brkchars (cmd
,
653 cmdpy_completer_handle_brkchars
);
655 CATCH (except
, RETURN_MASK_ALL
)
661 PyErr_Format (except
.reason
== RETURN_QUIT
662 ? PyExc_KeyboardInterrupt
: PyExc_RuntimeError
,
663 "%s", except
.message
);
673 /* Initialize the 'commands' code. */
676 gdbpy_initialize_commands (void)
680 cmdpy_object_type
.tp_new
= PyType_GenericNew
;
681 if (PyType_Ready (&cmdpy_object_type
) < 0)
684 /* Note: alias and user are special; pseudo appears to be unused,
685 and there is no reason to expose tui, I think. */
686 if (PyModule_AddIntConstant (gdb_module
, "COMMAND_NONE", no_class
) < 0
687 || PyModule_AddIntConstant (gdb_module
, "COMMAND_RUNNING", class_run
) < 0
688 || PyModule_AddIntConstant (gdb_module
, "COMMAND_DATA", class_vars
) < 0
689 || PyModule_AddIntConstant (gdb_module
, "COMMAND_STACK", class_stack
) < 0
690 || PyModule_AddIntConstant (gdb_module
, "COMMAND_FILES", class_files
) < 0
691 || PyModule_AddIntConstant (gdb_module
, "COMMAND_SUPPORT",
693 || PyModule_AddIntConstant (gdb_module
, "COMMAND_STATUS", class_info
) < 0
694 || PyModule_AddIntConstant (gdb_module
, "COMMAND_BREAKPOINTS",
695 class_breakpoint
) < 0
696 || PyModule_AddIntConstant (gdb_module
, "COMMAND_TRACEPOINTS",
698 || PyModule_AddIntConstant (gdb_module
, "COMMAND_OBSCURE",
700 || PyModule_AddIntConstant (gdb_module
, "COMMAND_MAINTENANCE",
701 class_maintenance
) < 0
702 || PyModule_AddIntConstant (gdb_module
, "COMMAND_USER", class_user
) < 0)
705 for (i
= 0; i
< N_COMPLETERS
; ++i
)
707 if (PyModule_AddIntConstant (gdb_module
, completers
[i
].name
, i
) < 0)
711 if (gdb_pymodule_addobject (gdb_module
, "Command",
712 (PyObject
*) &cmdpy_object_type
) < 0)
715 invoke_cst
= PyString_FromString ("invoke");
716 if (invoke_cst
== NULL
)
718 complete_cst
= PyString_FromString ("complete");
719 if (complete_cst
== NULL
)
727 static PyMethodDef cmdpy_object_methods
[] =
729 { "dont_repeat", cmdpy_dont_repeat
, METH_NOARGS
,
730 "Prevent command repetition when user enters empty line." },
735 PyTypeObject cmdpy_object_type
=
737 PyVarObject_HEAD_INIT (NULL
, 0)
738 "gdb.Command", /*tp_name*/
739 sizeof (cmdpy_object
), /*tp_basicsize*/
748 0, /*tp_as_sequence*/
756 Py_TPFLAGS_DEFAULT
| Py_TPFLAGS_BASETYPE
, /*tp_flags*/
757 "GDB command object", /* tp_doc */
760 0, /* tp_richcompare */
761 0, /* tp_weaklistoffset */
764 cmdpy_object_methods
, /* tp_methods */
769 0, /* tp_descr_get */
770 0, /* tp_descr_set */
771 0, /* tp_dictoffset */
772 cmdpy_init
, /* tp_init */
778 /* Utility to build a buildargv-like result from ARGS.
779 This intentionally parses arguments the way libiberty/argv.c:buildargv
780 does. It splits up arguments in a reasonable way, and we want a standard
781 way of parsing arguments. Several gdb commands use buildargv to parse their
782 arguments. Plus we want to be able to write compatible python
783 implementations of gdb commands. */
786 gdbpy_string_to_argv (PyObject
*self
, PyObject
*args
)
791 if (!PyArg_ParseTuple (args
, "s", &input
))
794 py_argv
= PyList_New (0);
798 /* buildargv uses NULL to represent an empty argument list, but we can't use
799 that in Python. Instead, if ARGS is "" then return an empty list.
800 This undoes the NULL -> "" conversion that cmdpy_function does. */
804 char **c_argv
= gdb_buildargv (input
);
807 for (i
= 0; c_argv
[i
] != NULL
; ++i
)
809 PyObject
*argp
= PyString_FromString (c_argv
[i
]);
812 || PyList_Append (py_argv
, argp
) < 0)