/* gdb commands implemented in Python Copyright (C) 2008-2015 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 "arch-utils.h" #include "value.h" #include "python-internal.h" #include "charset.h" #include "gdbcmd.h" #include "cli/cli-decode.h" #include "completer.h" #include "language.h" /* Struct representing built-in completion types. */ struct cmdpy_completer { /* Python symbol name. This isn't a const char * for Python 2.4's sake. PyModule_AddIntConstant only takes a char *, sigh. */ char *name; /* Completion function. */ completer_ftype *completer; }; static const struct cmdpy_completer completers[] = { { "COMPLETE_NONE", noop_completer }, { "COMPLETE_FILENAME", filename_completer }, { "COMPLETE_LOCATION", location_completer }, { "COMPLETE_COMMAND", command_completer }, { "COMPLETE_SYMBOL", make_symbol_completion_list_fn }, { "COMPLETE_EXPRESSION", expression_completer }, }; #define N_COMPLETERS (sizeof (completers) / sizeof (completers[0])) /* A gdb command. For the time being only ordinary commands (not set/show commands) are allowed. */ struct cmdpy_object { PyObject_HEAD /* The corresponding gdb command object, or NULL if the command is no longer installed. */ struct cmd_list_element *command; /* A prefix command requires storage for a list of its sub-commands. A pointer to this is passed to add_prefix_command, and to add_cmd for sub-commands of that prefix. If this Command is not a prefix command, then this field is unused. */ struct cmd_list_element *sub_list; }; typedef struct cmdpy_object cmdpy_object; extern PyTypeObject cmdpy_object_type CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("cmdpy_object"); /* Constants used by this module. */ static PyObject *invoke_cst; static PyObject *complete_cst; /* Python function which wraps dont_repeat. */ static PyObject * cmdpy_dont_repeat (PyObject *self, PyObject *args) { dont_repeat (); Py_RETURN_NONE; } /* Called if the gdb cmd_list_element is destroyed. */ static void cmdpy_destroyer (struct cmd_list_element *self, void *context) { cmdpy_object *cmd; struct cleanup *cleanup; cleanup = ensure_python_env (get_current_arch (), current_language); /* Release our hold on the command object. */ cmd = (cmdpy_object *) context; cmd->command = NULL; Py_DECREF (cmd); /* We allocated the name, doc string, and perhaps the prefix name. */ xfree ((char *) self->name); xfree ((char *) self->doc); xfree ((char *) self->prefixname); do_cleanups (cleanup); } /* Called by gdb to invoke the command. */ static void cmdpy_function (struct cmd_list_element *command, char *args, int from_tty) { cmdpy_object *obj = (cmdpy_object *) get_cmd_context (command); PyObject *argobj, *ttyobj, *result; struct cleanup *cleanup; cleanup = ensure_python_env (get_current_arch (), current_language); if (! obj) error (_("Invalid invocation of Python command object.")); if (! PyObject_HasAttr ((PyObject *) obj, invoke_cst)) { if (obj->command->prefixname) { /* A prefix command does not need an invoke method. */ do_cleanups (cleanup); return; } error (_("Python command object missing 'invoke' method.")); } if (! args) args = ""; argobj = PyUnicode_Decode (args, strlen (args), host_charset (), NULL); if (! argobj) { gdbpy_print_stack (); error (_("Could not convert arguments to Python string.")); } ttyobj = from_tty ? Py_True : Py_False; Py_INCREF (ttyobj); result = PyObject_CallMethodObjArgs ((PyObject *) obj, invoke_cst, argobj, ttyobj, NULL); Py_DECREF (argobj); Py_DECREF (ttyobj); if (! result) { PyObject *ptype, *pvalue, *ptraceback; char *msg; PyErr_Fetch (&ptype, &pvalue, &ptraceback); /* Try to fetch an error message contained within ptype, pvalue. When fetching the error message we need to make our own copy, we no longer own ptype, pvalue after the call to PyErr_Restore. */ msg = gdbpy_exception_to_string (ptype, pvalue); make_cleanup (xfree, msg); if (msg == NULL) { /* An error occurred computing the string representation of the error message. This is rare, but we should inform the user. */ printf_filtered (_("An error occurred in a Python command\n" "and then another occurred computing the " "error message.\n")); gdbpy_print_stack (); } /* Don't print the stack for gdb.GdbError exceptions. It is generally used to flag user errors. We also don't want to print "Error occurred in Python command" for user errors. However, a missing message for gdb.GdbError exceptions is arguably a bug, so we flag it as such. */ if (! PyErr_GivenExceptionMatches (ptype, gdbpy_gdberror_exc) || msg == NULL || *msg == '\0') { PyErr_Restore (ptype, pvalue, ptraceback); gdbpy_print_stack (); if (msg != NULL && *msg != '\0') error (_("Error occurred in Python command: %s"), msg); else error (_("Error occurred in Python command.")); } else { Py_XDECREF (ptype); Py_XDECREF (pvalue); Py_XDECREF (ptraceback); error ("%s", msg); } } Py_DECREF (result); do_cleanups (cleanup); } /* Helper function for the Python command completers (both "pure" completer and brkchar handler). This function takes COMMAND, TEXT and WORD and tries to call the Python method for completion with these arguments. It also takes HANDLE_BRKCHARS_P, an argument to identify whether it is being called from the brkchar handler or from the "pure" completer. In the first case, it effectively calls the Python method for completion, and records the PyObject in a static variable (used as a "cache"). In the second case, it just returns that variable, without actually calling the Python method again. This saves us one Python method call. The reason for this two step dance is that we need to know the set of "brkchars" to use early on, before we actually try to perform the completion. But if a Python command supplies a "complete" method then we have to call that method first: it may return as its result the kind of completion to perform and that will in turn specify which brkchars to use. IOW, we need the result of the "complete" method before we actually perform the completion. It is important to mention that this function is built on the assumption that the calls to cmdpy_completer_handle_brkchars and cmdpy_completer will be subsequent with nothing intervening. This is true for our completer mechanism. This function returns the PyObject representing the Python method call. */ static PyObject * cmdpy_completer_helper (struct cmd_list_element *command, const char *text, const char *word, int handle_brkchars_p) { cmdpy_object *obj = (cmdpy_object *) get_cmd_context (command); PyObject *textobj, *wordobj; /* This static variable will server as a "cache" for us, in order to store the PyObject that results from calling the Python function. */ static PyObject *resultobj = NULL; if (handle_brkchars_p) { /* If we were called to handle brkchars, it means this is the first function call of two that will happen in a row. Therefore, we need to call the completer ourselves, and cache the return value in the static variable RESULTOBJ. Then, in the second call, we can just use the value of RESULTOBJ to do our job. */ if (resultobj != NULL) Py_DECREF (resultobj); resultobj = NULL; if (obj == NULL) error (_("Invalid invocation of Python command object.")); if (!PyObject_HasAttr ((PyObject *) obj, complete_cst)) { /* If there is no complete method, don't error. */ return NULL; } textobj = PyUnicode_Decode (text, strlen (text), host_charset (), NULL); if (textobj == NULL) error (_("Could not convert argument to Python string.")); wordobj = PyUnicode_Decode (word, sizeof (word), host_charset (), NULL); if (wordobj == NULL) { Py_DECREF (textobj); error (_("Could not convert argument to Python string.")); } resultobj = PyObject_CallMethodObjArgs ((PyObject *) obj, complete_cst, textobj, wordobj, NULL); Py_DECREF (textobj); Py_DECREF (wordobj); if (!resultobj) { /* Just swallow errors here. */ PyErr_Clear (); } Py_XINCREF (resultobj); } return resultobj; } /* Python function called to determine the break characters of a certain completer. We are only interested in knowing if the completer registered by the user will return one of the integer codes (see COMPLETER_* symbols). */ static void cmdpy_completer_handle_brkchars (struct cmd_list_element *command, const char *text, const char *word) { PyObject *resultobj = NULL; struct cleanup *cleanup; cleanup = ensure_python_env (get_current_arch (), current_language); /* Calling our helper to obtain the PyObject of the Python function. */ resultobj = cmdpy_completer_helper (command, text, word, 1); /* Check if there was an error. */ if (resultobj == NULL) goto done; if (PyInt_Check (resultobj)) { /* User code may also return one of the completion constants, thus requesting that sort of completion. We are only interested in this kind of return. */ long value; if (!gdb_py_int_as_long (resultobj, &value)) { /* Ignore. */ PyErr_Clear (); } else if (value >= 0 && value < (long) N_COMPLETERS) { /* This is the core of this function. Depending on which completer type the Python function returns, we have to adjust the break characters accordingly. */ set_gdb_completion_word_break_characters (completers[value].completer); } } done: /* We do not call Py_XDECREF here because RESULTOBJ will be used in the subsequent call to cmdpy_completer function. */ do_cleanups (cleanup); } /* Called by gdb for command completion. */ static VEC (char_ptr) * cmdpy_completer (struct cmd_list_element *command, const char *text, const char *word) { PyObject *resultobj = NULL; VEC (char_ptr) *result = NULL; struct cleanup *cleanup; cleanup = ensure_python_env (get_current_arch (), current_language); /* Calling our helper to obtain the PyObject of the Python function. */ resultobj = cmdpy_completer_helper (command, text, word, 0); /* If the result object of calling the Python function is NULL, it means that there was an error. In this case, just give up and return NULL. */ if (resultobj == NULL) goto done; result = NULL; if (PyInt_Check (resultobj)) { /* User code may also return one of the completion constants, thus requesting that sort of completion. */ long value; if (! gdb_py_int_as_long (resultobj, &value)) { /* Ignore. */ PyErr_Clear (); } else if (value >= 0 && value < (long) N_COMPLETERS) result = completers[value].completer (command, text, word); } else { PyObject *iter = PyObject_GetIter (resultobj); PyObject *elt; if (iter == NULL) goto done; while ((elt = PyIter_Next (iter)) != NULL) { char *item; if (! gdbpy_is_string (elt)) { /* Skip problem elements. */ Py_DECREF (elt); continue; } item = python_string_to_host_string (elt); Py_DECREF (elt); if (item == NULL) { /* Skip problem elements. */ PyErr_Clear (); continue; } VEC_safe_push (char_ptr, result, item); } Py_DECREF (iter); /* If we got some results, ignore problems. Otherwise, report the problem. */ if (result != NULL && PyErr_Occurred ()) PyErr_Clear (); } done: do_cleanups (cleanup); return result; } /* Helper for cmdpy_init which locates the command list to use and pulls out the command name. NAME is the command name list. The final word in the list is the name of the new command. All earlier words must be existing prefix commands. *BASE_LIST is set to the final prefix command's list of *sub-commands. START_LIST is the list in which the search starts. This function returns the xmalloc()d name of the new command. On error sets the Python error and returns NULL. */ char * gdbpy_parse_command_name (const char *name, struct cmd_list_element ***base_list, struct cmd_list_element **start_list) { struct cmd_list_element *elt; int len = strlen (name); int i, lastchar; char *prefix_text; const char *prefix_text2; char *result; /* Skip trailing whitespace. */ for (i = len - 1; i >= 0 && (name[i] == ' ' || name[i] == '\t'); --i) ; if (i < 0) { PyErr_SetString (PyExc_RuntimeError, _("No command name found.")); return NULL; } lastchar = i; /* Find first character of the final word. */ for (; i > 0 && (isalnum (name[i - 1]) || name[i - 1] == '-' || name[i - 1] == '_'); --i) ; result = xmalloc (lastchar - i + 2); memcpy (result, &name[i], lastchar - i + 1); result[lastchar - i + 1] = '\0'; /* Skip whitespace again. */ for (--i; i >= 0 && (name[i] == ' ' || name[i] == '\t'); --i) ; if (i < 0) { *base_list = start_list; return result; } prefix_text = xmalloc (i + 2); memcpy (prefix_text, name, i + 1); prefix_text[i + 1] = '\0'; prefix_text2 = prefix_text; elt = lookup_cmd_1 (&prefix_text2, *start_list, NULL, 1); if (elt == NULL || elt == CMD_LIST_AMBIGUOUS) { PyErr_Format (PyExc_RuntimeError, _("Could not find command prefix %s."), prefix_text); xfree (prefix_text); xfree (result); return NULL; } if (elt->prefixlist) { xfree (prefix_text); *base_list = elt->prefixlist; return result; } PyErr_Format (PyExc_RuntimeError, _("'%s' is not a prefix command."), prefix_text); xfree (prefix_text); xfree (result); return NULL; } /* Object initializer; sets up gdb-side structures for command. Use: __init__(NAME, COMMAND_CLASS [, COMPLETER_CLASS][, PREFIX]]). NAME is the name of the command. It may consist of multiple words, in which case the final word is the name of the new command, and earlier words must be prefix commands. COMMAND_CLASS is the kind of command. It should be one of the COMMAND_* constants defined in the gdb module. COMPLETER_CLASS is the kind of completer. If not given, the "complete" method will be used. Otherwise, it should be one of the COMPLETE_* constants defined in the gdb module. If PREFIX is True, then this command is a prefix command. The documentation for the command is taken from the doc string for the python class. */ static int cmdpy_init (PyObject *self, PyObject *args, PyObject *kw) { cmdpy_object *obj = (cmdpy_object *) self; const char *name; int cmdtype; int completetype = -1; char *docstring = NULL; volatile struct gdb_exception except; struct cmd_list_element **cmd_list; char *cmd_name, *pfx_name; static char *keywords[] = { "name", "command_class", "completer_class", "prefix", NULL }; PyObject *is_prefix = NULL; int cmp; if (obj->command) { /* Note: this is apparently not documented in Python. We return 0 for success, -1 for failure. */ PyErr_Format (PyExc_RuntimeError, _("Command object already initialized.")); return -1; } if (! PyArg_ParseTupleAndKeywords (args, kw, "si|iO", keywords, &name, &cmdtype, &completetype, &is_prefix)) return -1; if (cmdtype != no_class && cmdtype != class_run && cmdtype != class_vars && cmdtype != class_stack && cmdtype != class_files && cmdtype != class_support && cmdtype != class_info && cmdtype != class_breakpoint && cmdtype != class_trace && cmdtype != class_obscure && cmdtype != class_maintenance && cmdtype != class_user) { PyErr_Format (PyExc_RuntimeError, _("Invalid command class argument.")); return -1; } if (completetype < -1 || completetype >= (int) N_COMPLETERS) { PyErr_Format (PyExc_RuntimeError, _("Invalid completion type argument.")); return -1; } cmd_name = gdbpy_parse_command_name (name, &cmd_list, &cmdlist); if (! cmd_name) return -1; pfx_name = NULL; if (is_prefix != NULL) { cmp = PyObject_IsTrue (is_prefix); if (cmp == 1) { int i, out; /* Make a normalized form of the command name. */ pfx_name = xmalloc (strlen (name) + 2); i = 0; out = 0; while (name[i]) { /* Skip whitespace. */ while (name[i] == ' ' || name[i] == '\t') ++i; /* Copy non-whitespace characters. */ while (name[i] && name[i] != ' ' && name[i] != '\t') pfx_name[out++] = name[i++]; /* Add a single space after each word -- including the final word. */ pfx_name[out++] = ' '; } pfx_name[out] = '\0'; } else if (cmp < 0) { xfree (cmd_name); return -1; } } if (PyObject_HasAttr (self, gdbpy_doc_cst)) { PyObject *ds_obj = PyObject_GetAttr (self, gdbpy_doc_cst); if (ds_obj && gdbpy_is_string (ds_obj)) { docstring = python_string_to_host_string (ds_obj); if (docstring == NULL) { xfree (cmd_name); xfree (pfx_name); Py_DECREF (ds_obj); return -1; } } Py_XDECREF (ds_obj); } if (! docstring) docstring = xstrdup (_("This command is not documented.")); Py_INCREF (self); TRY_CATCH (except, RETURN_MASK_ALL) { struct cmd_list_element *cmd; if (pfx_name) { int allow_unknown; /* If we have our own "invoke" method, then allow unknown sub-commands. */ allow_unknown = PyObject_HasAttr (self, invoke_cst); cmd = add_prefix_cmd (cmd_name, (enum command_class) cmdtype, NULL, docstring, &obj->sub_list, pfx_name, allow_unknown, cmd_list); } else cmd = add_cmd (cmd_name, (enum command_class) cmdtype, NULL, docstring, cmd_list); /* There appears to be no API to set this. */ cmd->func = cmdpy_function; cmd->destroyer = cmdpy_destroyer; obj->command = cmd; set_cmd_context (cmd, self); set_cmd_completer (cmd, ((completetype == -1) ? cmdpy_completer : completers[completetype].completer)); if (completetype == -1) set_cmd_completer_handle_brkchars (cmd, cmdpy_completer_handle_brkchars); } if (except.reason < 0) { xfree (cmd_name); xfree (docstring); xfree (pfx_name); Py_DECREF (self); PyErr_Format (except.reason == RETURN_QUIT ? PyExc_KeyboardInterrupt : PyExc_RuntimeError, "%s", except.message); return -1; } return 0; } /* Initialize the 'commands' code. */ int gdbpy_initialize_commands (void) { int i; cmdpy_object_type.tp_new = PyType_GenericNew; if (PyType_Ready (&cmdpy_object_type) < 0) return -1; /* Note: alias and user are special; pseudo appears to be unused, and there is no reason to expose tui or xdb, I think. */ if (PyModule_AddIntConstant (gdb_module, "COMMAND_NONE", no_class) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_RUNNING", class_run) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_DATA", class_vars) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_STACK", class_stack) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_FILES", class_files) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_SUPPORT", class_support) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_STATUS", class_info) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_BREAKPOINTS", class_breakpoint) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_TRACEPOINTS", class_trace) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_OBSCURE", class_obscure) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_MAINTENANCE", class_maintenance) < 0 || PyModule_AddIntConstant (gdb_module, "COMMAND_USER", class_user) < 0) return -1; for (i = 0; i < N_COMPLETERS; ++i) { if (PyModule_AddIntConstant (gdb_module, completers[i].name, i) < 0) return -1; } if (gdb_pymodule_addobject (gdb_module, "Command", (PyObject *) &cmdpy_object_type) < 0) return -1; invoke_cst = PyString_FromString ("invoke"); if (invoke_cst == NULL) return -1; complete_cst = PyString_FromString ("complete"); if (complete_cst == NULL) return -1; return 0; } static PyMethodDef cmdpy_object_methods[] = { { "dont_repeat", cmdpy_dont_repeat, METH_NOARGS, "Prevent command repetition when user enters empty line." }, { 0 } }; PyTypeObject cmdpy_object_type = { PyVarObject_HEAD_INIT (NULL, 0) "gdb.Command", /*tp_name*/ sizeof (cmdpy_object), /*tp_basicsize*/ 0, /*tp_itemsize*/ 0, /*tp_dealloc*/ 0, /*tp_print*/ 0, /*tp_getattr*/ 0, /*tp_setattr*/ 0, /*tp_compare*/ 0, /*tp_repr*/ 0, /*tp_as_number*/ 0, /*tp_as_sequence*/ 0, /*tp_as_mapping*/ 0, /*tp_hash */ 0, /*tp_call*/ 0, /*tp_str*/ 0, /*tp_getattro*/ 0, /*tp_setattro*/ 0, /*tp_as_buffer*/ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ "GDB command object", /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ cmdpy_object_methods, /* tp_methods */ 0, /* tp_members */ 0, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ 0, /* tp_dictoffset */ cmdpy_init, /* tp_init */ 0, /* tp_alloc */ }; /* Utility to build a buildargv-like result from ARGS. This intentionally parses arguments the way libiberty/argv.c:buildargv does. It splits up arguments in a reasonable way, and we want a standard way of parsing arguments. Several gdb commands use buildargv to parse their arguments. Plus we want to be able to write compatible python implementations of gdb commands. */ PyObject * gdbpy_string_to_argv (PyObject *self, PyObject *args) { PyObject *py_argv; const char *input; if (!PyArg_ParseTuple (args, "s", &input)) return NULL; py_argv = PyList_New (0); if (py_argv == NULL) return NULL; /* buildargv uses NULL to represent an empty argument list, but we can't use that in Python. Instead, if ARGS is "" then return an empty list. This undoes the NULL -> "" conversion that cmdpy_function does. */ if (*input != '\0') { char **c_argv = gdb_buildargv (input); int i; for (i = 0; c_argv[i] != NULL; ++i) { PyObject *argp = PyString_FromString (c_argv[i]); if (argp == NULL || PyList_Append (py_argv, argp) < 0) { Py_XDECREF (argp); Py_DECREF (py_argv); freeargv (c_argv); return NULL; } Py_DECREF (argp); } freeargv (c_argv); } return py_argv; }