gdb/python/py-param.c

   1 /* GDB parameters implemented in Python
   2
   3    Copyright (C) 2008-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   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.
  11
  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.
  16
  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/>.  */
  19
  20
  21 #include "defs.h"
  22 #include "value.h"
  23 #include "python-internal.h"
  24 #include "charset.h"
  25 #include "gdbcmd.h"
  26 #include "cli/cli-decode.h"
  27 #include "completer.h"
  28 #include "language.h"
  29 #include "arch-utils.h"
  30
  31 /* Parameter constants and their values.  */
  32 struct parm_constant
  33 {
  34   const char *name;
  35   int value;
  36 };
  37
  38 struct parm_constant parm_constants[] =
  39 {
  40   { "PARAM_BOOLEAN", var_boolean }, /* ARI: var_boolean */
  41   { "PARAM_AUTO_BOOLEAN", var_auto_boolean },
  42   { "PARAM_UINTEGER", var_uinteger },
  43   { "PARAM_INTEGER", var_integer },
  44   { "PARAM_STRING", var_string },
  45   { "PARAM_STRING_NOESCAPE", var_string_noescape },
  46   { "PARAM_OPTIONAL_FILENAME", var_optional_filename },
  47   { "PARAM_FILENAME", var_filename },
  48   { "PARAM_ZINTEGER", var_zinteger },
  49   { "PARAM_ZUINTEGER", var_zuinteger },
  50   { "PARAM_ZUINTEGER_UNLIMITED", var_zuinteger_unlimited },
  51   { "PARAM_ENUM", var_enum },
  52   { NULL, 0 }
  53 };
  54
  55 /* A union that can hold anything described by enum var_types.  */
  56 union parmpy_variable
  57 {
  58   /* Hold an integer value, for boolean and integer types.  */
  59   int intval;
  60
  61   /* Hold an auto_boolean.  */
  62   enum auto_boolean autoboolval;
  63
  64   /* Hold an unsigned integer value, for uinteger.  */
  65   unsigned int uintval;
  66
  67   /* Hold a string, for the various string types.  */
  68   char *stringval;
  69
  70   /* Hold a string, for enums.  */
  71   const char *cstringval;
  72 };
  73
  74 /* A GDB parameter.  */
  75 struct parmpy_object
  76 {
  77   PyObject_HEAD
  78
  79   /* The type of the parameter.  */
  80   enum var_types type;
  81
  82   /* The value of the parameter.  */
  83   union parmpy_variable value;
  84
  85   /* For an enum command, the possible values.  The vector is
  86      allocated with xmalloc, as is each element.  It is
  87      NULL-terminated.  */
  88   const char **enumeration;
  89 };
  90
  91 typedef struct parmpy_object parmpy_object;
  92
  93 extern PyTypeObject parmpy_object_type
  94     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("parmpy_object");
  95
  96 /* Some handy string constants.  */
  97 static PyObject *set_doc_cst;
  98 static PyObject *show_doc_cst;
  99
 100 \f
 101
 102 /* Get an attribute.  */
 103 static PyObject *
 104 get_attr (PyObject *obj, PyObject *attr_name)
 105 {
 106   if (PyString_Check (attr_name)
 107 #ifdef IS_PY3K
 108       && ! PyUnicode_CompareWithASCIIString (attr_name, "value"))
 109 #else
 110       && ! strcmp (PyString_AsString (attr_name), "value"))
 111 #endif
 112     {
 113       parmpy_object *self = (parmpy_object *) obj;
 114
 115       return gdbpy_parameter_value (self->type, &self->value);
 116     }
 117
 118   return PyObject_GenericGetAttr (obj, attr_name);
 119 }
 120
 121 /* Set a parameter value from a Python value.  Return 0 on success.  Returns
 122    -1 on error, with a python exception set.  */
 123 static int
 124 set_parameter_value (parmpy_object *self, PyObject *value)
 125 {
 126   int cmp;
 127
 128   switch (self->type)
 129     {
 130     case var_string:
 131     case var_string_noescape:
 132     case var_optional_filename:
 133     case var_filename:
 134       if (! gdbpy_is_string (value)
 135           && (self->type == var_filename
 136               || value != Py_None))
 137         {
 138           PyErr_SetString (PyExc_RuntimeError,
 139                            _("String required for filename."));
 140
 141           return -1;
 142         }
 143       if (value == Py_None)
 144         {
 145           xfree (self->value.stringval);
 146           if (self->type == var_optional_filename)
 147             self->value.stringval = xstrdup ("");
 148           else
 149             self->value.stringval = NULL;
 150         }
 151       else
 152         {
 153           gdb::unique_xmalloc_ptr<char>
 154             string (python_string_to_host_string (value));
 155           if (string == NULL)
 156             return -1;
 157
 158           xfree (self->value.stringval);
 159           self->value.stringval = string.release ();
 160         }
 161       break;
 162
 163     case var_enum:
 164       {
 165         int i;
 166
 167         if (! gdbpy_is_string (value))
 168           {
 169             PyErr_SetString (PyExc_RuntimeError,
 170                              _("ENUM arguments must be a string."));
 171             return -1;
 172           }
 173
 174         gdb::unique_xmalloc_ptr<char>
 175           str (python_string_to_host_string (value));
 176         if (str == NULL)
 177           return -1;
 178         for (i = 0; self->enumeration[i]; ++i)
 179           if (! strcmp (self->enumeration[i], str.get ()))
 180             break;
 181         if (! self->enumeration[i])
 182           {
 183             PyErr_SetString (PyExc_RuntimeError,
 184                              _("The value must be member of an enumeration."));
 185             return -1;
 186           }
 187         self->value.cstringval = self->enumeration[i];
 188         break;
 189       }
 190
 191     case var_boolean:
 192       if (! PyBool_Check (value))
 193         {
 194           PyErr_SetString (PyExc_RuntimeError,
 195                            _("A boolean argument is required."));
 196           return -1;
 197         }
 198       cmp = PyObject_IsTrue (value);
 199       if (cmp < 0)
 200           return -1;
 201       self->value.intval = cmp;
 202       break;
 203
 204     case var_auto_boolean:
 205       if (! PyBool_Check (value) && value != Py_None)
 206         {
 207           PyErr_SetString (PyExc_RuntimeError,
 208                            _("A boolean or None is required"));
 209           return -1;
 210         }
 211
 212       if (value == Py_None)
 213         self->value.autoboolval = AUTO_BOOLEAN_AUTO;
 214       else
 215         {
 216           cmp = PyObject_IsTrue (value);
 217           if (cmp < 0 )
 218             return -1;
 219           if (cmp == 1)
 220             self->value.autoboolval = AUTO_BOOLEAN_TRUE;
 221           else
 222             self->value.autoboolval = AUTO_BOOLEAN_FALSE;
 223         }
 224       break;
 225
 226     case var_integer:
 227     case var_zinteger:
 228     case var_uinteger:
 229     case var_zuinteger:
 230     case var_zuinteger_unlimited:
 231       {
 232         long l;
 233         int ok;
 234
 235         if (! PyInt_Check (value))
 236           {
 237             PyErr_SetString (PyExc_RuntimeError,
 238                              _("The value must be integer."));
 239             return -1;
 240           }
 241
 242         if (! gdb_py_int_as_long (value, &l))
 243           return -1;
 244
 245         switch (self->type)
 246           {
 247           case var_uinteger:
 248             if (l == 0)
 249               l = UINT_MAX;
 250             /* Fall through.  */
 251           case var_zuinteger:
 252             ok = (l >= 0 && l <= UINT_MAX);
 253             break;
 254
 255           case var_zuinteger_unlimited:
 256             ok = (l >= -1 && l <= INT_MAX);
 257             break;
 258
 259           case var_integer:
 260             ok = (l >= INT_MIN && l <= INT_MAX);
 261             if (l == 0)
 262               l = INT_MAX;
 263             break;
 264
 265           case var_zinteger:
 266             ok = (l >= INT_MIN && l <= INT_MAX);
 267             break;
 268
 269           default:
 270             gdb_assert_not_reached ("unknown var_ constant");
 271           }
 272
 273         if (! ok)
 274           {
 275             PyErr_SetString (PyExc_RuntimeError,
 276                              _("Range exceeded."));
 277             return -1;
 278           }
 279
 280         if (self->type == var_uinteger || self->type == var_zuinteger)
 281           self->value.uintval = (unsigned) l;
 282         else
 283           self->value.intval = (int) l;
 284         break;
 285       }
 286
 287     default:
 288       PyErr_SetString (PyExc_RuntimeError,
 289                        _("Unhandled type in parameter value."));
 290       return -1;
 291     }
 292
 293   return 0;
 294 }
 295
 296 /* Set an attribute.  Returns -1 on error, with a python exception set.  */
 297 static int
 298 set_attr (PyObject *obj, PyObject *attr_name, PyObject *val)
 299 {
 300   if (PyString_Check (attr_name)
 301 #ifdef IS_PY3K
 302       && ! PyUnicode_CompareWithASCIIString (attr_name, "value"))
 303 #else
 304       && ! strcmp (PyString_AsString (attr_name), "value"))
 305 #endif
 306     {
 307       if (!val)
 308         {
 309           PyErr_SetString (PyExc_RuntimeError,
 310                            _("Cannot delete a parameter's value."));
 311           return -1;
 312         }
 313       return set_parameter_value ((parmpy_object *) obj, val);
 314     }
 315
 316   return PyObject_GenericSetAttr (obj, attr_name, val);
 317 }
 318
 319 /* A helper function which returns a documentation string for an
 320    object. */
 321
 322 static gdb::unique_xmalloc_ptr<char>
 323 get_doc_string (PyObject *object, PyObject *attr)
 324 {
 325   gdb::unique_xmalloc_ptr<char> result;
 326
 327   if (PyObject_HasAttr (object, attr))
 328     {
 329       gdbpy_ref<> ds_obj (PyObject_GetAttr (object, attr));
 330
 331       if (ds_obj != NULL && gdbpy_is_string (ds_obj.get ()))
 332         {
 333           result = python_string_to_host_string (ds_obj.get ());
 334           if (result == NULL)
 335             gdbpy_print_stack ();
 336         }
 337     }
 338   if (! result)
 339     result.reset (xstrdup (_("This command is not documented.")));
 340   return result;
 341 }
 342
 343 /* Helper function which will execute a METHOD in OBJ passing the
 344    argument ARG.  ARG can be NULL.  METHOD should return a Python
 345    string.  If this function returns NULL, there has been an error and
 346    the appropriate exception set.  */
 347 static gdb::unique_xmalloc_ptr<char>
 348 call_doc_function (PyObject *obj, PyObject *method, PyObject *arg)
 349 {
 350   gdb::unique_xmalloc_ptr<char> data;
 351   gdbpy_ref<> result (PyObject_CallMethodObjArgs (obj, method, arg, NULL));
 352
 353   if (result == NULL)
 354     return NULL;
 355
 356   if (gdbpy_is_string (result.get ()))
 357     {
 358       data = python_string_to_host_string (result.get ());
 359       if (! data)
 360         return NULL;
 361     }
 362   else
 363     {
 364       PyErr_SetString (PyExc_RuntimeError,
 365                        _("Parameter must return a string value."));
 366       return NULL;
 367     }
 368
 369   return data;
 370 }
 371
 372 /* A callback function that is registered against the respective
 373    add_setshow_* set_doc prototype.  This function will either call
 374    the Python function "get_set_string" or extract the Python
 375    attribute "set_doc" and return the contents as a string.  If
 376    neither exist, insert a string indicating the Parameter is not
 377    documented.  */
 378 static void
 379 get_set_value (const char *args, int from_tty,
 380                struct cmd_list_element *c)
 381 {
 382   PyObject *obj = (PyObject *) get_cmd_context (c);
 383   gdb::unique_xmalloc_ptr<char> set_doc_string;
 384
 385   gdbpy_enter enter_py (get_current_arch (), current_language);
 386   gdbpy_ref<> set_doc_func (PyString_FromString ("get_set_string"));
 387
 388   if (set_doc_func == NULL)
 389     {
 390       gdbpy_print_stack ();
 391       return;
 392     }
 393
 394   if (PyObject_HasAttr (obj, set_doc_func.get ()))
 395     {
 396       set_doc_string = call_doc_function (obj, set_doc_func.get (), NULL);
 397       if (! set_doc_string)
 398         gdbpy_handle_exception ();
 399     }
 400
 401   const char *str = set_doc_string.get ();
 402   if (str != nullptr && str[0] != '\0')
 403     fprintf_filtered (gdb_stdout, "%s\n", str);
 404 }
 405
 406 /* A callback function that is registered against the respective
 407    add_setshow_* show_doc prototype.  This function will either call
 408    the Python function "get_show_string" or extract the Python
 409    attribute "show_doc" and return the contents as a string.  If
 410    neither exist, insert a string indicating the Parameter is not
 411    documented.  */
 412 static void
 413 get_show_value (struct ui_file *file, int from_tty,
 414                 struct cmd_list_element *c,
 415                 const char *value)
 416 {
 417   PyObject *obj = (PyObject *) get_cmd_context (c);
 418   gdb::unique_xmalloc_ptr<char> show_doc_string;
 419
 420   gdbpy_enter enter_py (get_current_arch (), current_language);
 421   gdbpy_ref<> show_doc_func (PyString_FromString ("get_show_string"));
 422
 423   if (show_doc_func == NULL)
 424     {
 425       gdbpy_print_stack ();
 426       return;
 427     }
 428
 429   if (PyObject_HasAttr (obj, show_doc_func.get ()))
 430     {
 431       gdbpy_ref<> val_obj (PyString_FromString (value));
 432
 433       if (val_obj == NULL)
 434         {
 435           gdbpy_print_stack ();
 436           return;
 437         }
 438
 439       show_doc_string = call_doc_function (obj, show_doc_func.get (),
 440                                            val_obj.get ());
 441       if (! show_doc_string)
 442         {
 443           gdbpy_print_stack ();
 444           return;
 445         }
 446
 447       fprintf_filtered (file, "%s\n", show_doc_string.get ());
 448     }
 449   else
 450     {
 451       /* We have to preserve the existing < GDB 7.3 API.  If a
 452          callback function does not exist, then attempt to read the
 453          show_doc attribute.  */
 454       show_doc_string  = get_doc_string (obj, show_doc_cst);
 455       fprintf_filtered (file, "%s %s\n", show_doc_string.get (), value);
 456     }
 457 }
 458 \f
 459
 460 /* A helper function that dispatches to the appropriate add_setshow
 461    function.  */
 462 static void
 463 add_setshow_generic (int parmclass, enum command_class cmdclass,
 464                      const char *cmd_name, parmpy_object *self,
 465                      const char *set_doc, const char *show_doc,
 466                      const char *help_doc,
 467                      struct cmd_list_element **set_list,
 468                      struct cmd_list_element **show_list)
 469 {
 470   struct cmd_list_element *param = NULL;
 471   const char *tmp_name = NULL;
 472
 473   switch (parmclass)
 474     {
 475     case var_boolean:
 476
 477       add_setshow_boolean_cmd (cmd_name, cmdclass,
 478                                &self->value.intval, set_doc, show_doc,
 479                                help_doc, get_set_value, get_show_value,
 480                                set_list, show_list);
 481
 482       break;
 483
 484     case var_auto_boolean:
 485       add_setshow_auto_boolean_cmd (cmd_name, cmdclass,
 486                                     &self->value.autoboolval,
 487                                     set_doc, show_doc, help_doc,
 488                                     get_set_value, get_show_value,
 489                                     set_list, show_list);
 490       break;
 491
 492     case var_uinteger:
 493       add_setshow_uinteger_cmd (cmd_name, cmdclass,
 494                                 &self->value.uintval, set_doc, show_doc,
 495                                 help_doc, get_set_value, get_show_value,
 496                                 set_list, show_list);
 497       break;
 498
 499     case var_integer:
 500       add_setshow_integer_cmd (cmd_name, cmdclass,
 501                                &self->value.intval, set_doc, show_doc,
 502                                help_doc, get_set_value, get_show_value,
 503                                set_list, show_list); break;
 504
 505     case var_string:
 506       add_setshow_string_cmd (cmd_name, cmdclass,
 507                               &self->value.stringval, set_doc, show_doc,
 508                               help_doc, get_set_value, get_show_value,
 509                               set_list, show_list); break;
 510
 511     case var_string_noescape:
 512       add_setshow_string_noescape_cmd (cmd_name, cmdclass,
 513                                        &self->value.stringval,
 514                                        set_doc, show_doc, help_doc,
 515                                        get_set_value, get_show_value,
 516                                        set_list, show_list);
 517
 518       break;
 519
 520     case var_optional_filename:
 521       add_setshow_optional_filename_cmd (cmd_name, cmdclass,
 522                                          &self->value.stringval, set_doc,
 523                                          show_doc, help_doc, get_set_value,
 524                                          get_show_value, set_list,
 525                                          show_list);
 526       break;
 527
 528     case var_filename:
 529       add_setshow_filename_cmd (cmd_name, cmdclass,
 530                                 &self->value.stringval, set_doc, show_doc,
 531                                 help_doc, get_set_value, get_show_value,
 532                                 set_list, show_list); break;
 533
 534     case var_zinteger:
 535       add_setshow_zinteger_cmd (cmd_name, cmdclass,
 536                                 &self->value.intval, set_doc, show_doc,
 537                                 help_doc, get_set_value, get_show_value,
 538                                 set_list, show_list);
 539       break;
 540
 541     case var_zuinteger:
 542       add_setshow_zuinteger_cmd (cmd_name, cmdclass,
 543                                 &self->value.uintval, set_doc, show_doc,
 544                                 help_doc, get_set_value, get_show_value,
 545                                 set_list, show_list);
 546       break;
 547
 548     case var_zuinteger_unlimited:
 549       add_setshow_zuinteger_unlimited_cmd (cmd_name, cmdclass,
 550                                            &self->value.intval, set_doc,
 551                                            show_doc, help_doc, get_set_value,
 552                                            get_show_value,
 553                                            set_list, show_list);
 554       break;
 555
 556     case var_enum:
 557       add_setshow_enum_cmd (cmd_name, cmdclass, self->enumeration,
 558                             &self->value.cstringval, set_doc, show_doc,
 559                             help_doc, get_set_value, get_show_value,
 560                             set_list, show_list);
 561       /* Initialize the value, just in case.  */
 562       self->value.cstringval = self->enumeration[0];
 563       break;
 564     }
 565
 566   /* Lookup created parameter, and register Python object against the
 567      parameter context.  Perform this task against both lists.  */
 568   tmp_name = cmd_name;
 569   param = lookup_cmd (&tmp_name, *show_list, "", 0, 1);
 570   if (param)
 571     set_cmd_context (param, self);
 572
 573   tmp_name = cmd_name;
 574   param = lookup_cmd (&tmp_name, *set_list, "", 0, 1);
 575   if (param)
 576     set_cmd_context (param, self);
 577 }
 578
 579 /* A helper which computes enum values.  Returns 1 on success.  Returns 0 on
 580    error, with a python exception set.  */
 581 static int
 582 compute_enum_values (parmpy_object *self, PyObject *enum_values)
 583 {
 584   Py_ssize_t size, i;
 585
 586   if (! enum_values)
 587     {
 588       PyErr_SetString (PyExc_RuntimeError,
 589                        _("An enumeration is required for PARAM_ENUM."));
 590       return 0;
 591     }
 592
 593   if (! PySequence_Check (enum_values))
 594     {
 595       PyErr_SetString (PyExc_RuntimeError,
 596                        _("The enumeration is not a sequence."));
 597       return 0;
 598     }
 599
 600   size = PySequence_Size (enum_values);
 601   if (size < 0)
 602     return 0;
 603   if (size == 0)
 604     {
 605       PyErr_SetString (PyExc_RuntimeError,
 606                        _("The enumeration is empty."));
 607       return 0;
 608     }
 609
 610   gdb_argv holder (XCNEWVEC (char *, size + 1));
 611   char **enumeration = holder.get ();
 612
 613   for (i = 0; i < size; ++i)
 614     {
 615       gdbpy_ref<> item (PySequence_GetItem (enum_values, i));
 616
 617       if (item == NULL)
 618         return 0;
 619       if (! gdbpy_is_string (item.get ()))
 620         {
 621           PyErr_SetString (PyExc_RuntimeError,
 622                            _("The enumeration item not a string."));
 623           return 0;
 624         }
 625       enumeration[i] = python_string_to_host_string (item.get ()).release ();
 626       if (enumeration[i] == NULL)
 627         return 0;
 628     }
 629
 630   self->enumeration = const_cast<const char**> (holder.release ());
 631   return 1;
 632 }
 633
 634 /* Object initializer; sets up gdb-side structures for command.
 635
 636    Use: __init__(NAME, CMDCLASS, PARMCLASS, [ENUM])
 637
 638    NAME is the name of the parameter.  It may consist of multiple
 639    words, in which case the final word is the name of the new command,
 640    and earlier words must be prefix commands.
 641
 642    CMDCLASS is the kind of command.  It should be one of the COMMAND_*
 643    constants defined in the gdb module.
 644
 645    PARMCLASS is the type of the parameter.  It should be one of the
 646    PARAM_* constants defined in the gdb module.
 647
 648    If PARMCLASS is PARAM_ENUM, then the final argument should be a
 649    collection of strings.  These strings are the valid values for this
 650    parameter.
 651
 652    The documentation for the parameter is taken from the doc string
 653    for the python class.
 654
 655    Returns -1 on error, with a python exception set.  */
 656
 657 static int
 658 parmpy_init (PyObject *self, PyObject *args, PyObject *kwds)
 659 {
 660   parmpy_object *obj = (parmpy_object *) self;
 661   const char *name;
 662   gdb::unique_xmalloc_ptr<char> set_doc, show_doc, doc;
 663   char *cmd_name;
 664   int parmclass, cmdtype;
 665   PyObject *enum_values = NULL;
 666   struct cmd_list_element **set_list, **show_list;
 667
 668   if (! PyArg_ParseTuple (args, "sii|O", &name, &cmdtype, &parmclass,
 669                           &enum_values))
 670     return -1;
 671
 672   if (cmdtype != no_class && cmdtype != class_run
 673       && cmdtype != class_vars && cmdtype != class_stack
 674       && cmdtype != class_files && cmdtype != class_support
 675       && cmdtype != class_info && cmdtype != class_breakpoint
 676       && cmdtype != class_trace && cmdtype != class_obscure
 677       && cmdtype != class_maintenance)
 678     {
 679       PyErr_Format (PyExc_RuntimeError, _("Invalid command class argument."));
 680       return -1;
 681     }
 682
 683   if (parmclass != var_boolean /* ARI: var_boolean */
 684       && parmclass != var_auto_boolean
 685       && parmclass != var_uinteger && parmclass != var_integer
 686       && parmclass != var_string && parmclass != var_string_noescape
 687       && parmclass != var_optional_filename && parmclass != var_filename
 688       && parmclass != var_zinteger && parmclass != var_zuinteger
 689       && parmclass != var_zuinteger_unlimited && parmclass != var_enum)
 690     {
 691       PyErr_SetString (PyExc_RuntimeError,
 692                        _("Invalid parameter class argument."));
 693       return -1;
 694     }
 695
 696   if (enum_values && parmclass != var_enum)
 697     {
 698       PyErr_SetString (PyExc_RuntimeError,
 699                        _("Only PARAM_ENUM accepts a fourth argument."));
 700       return -1;
 701     }
 702   if (parmclass == var_enum)
 703     {
 704       if (! compute_enum_values (obj, enum_values))
 705         return -1;
 706     }
 707   else
 708     obj->enumeration = NULL;
 709   obj->type = (enum var_types) parmclass;
 710   memset (&obj->value, 0, sizeof (obj->value));
 711
 712   cmd_name = gdbpy_parse_command_name (name, &set_list,
 713                                        &setlist);
 714
 715   if (! cmd_name)
 716     return -1;
 717   xfree (cmd_name);
 718   cmd_name = gdbpy_parse_command_name (name, &show_list,
 719                                        &showlist);
 720   if (! cmd_name)
 721     return -1;
 722
 723   set_doc = get_doc_string (self, set_doc_cst);
 724   show_doc = get_doc_string (self, show_doc_cst);
 725   doc = get_doc_string (self, gdbpy_doc_cst);
 726
 727   Py_INCREF (self);
 728
 729   try
 730     {
 731       add_setshow_generic (parmclass, (enum command_class) cmdtype,
 732                            cmd_name, obj,
 733                            set_doc.get (), show_doc.get (),
 734                            doc.get (), set_list, show_list);
 735     }
 736   catch (const gdb_exception &except)
 737     {
 738       xfree (cmd_name);
 739       Py_DECREF (self);
 740       gdbpy_convert_exception (except);
 741       return -1;
 742     }
 743
 744   return 0;
 745 }
 746
 747 \f
 748
 749 /* Initialize the 'parameters' module.  */
 750 int
 751 gdbpy_initialize_parameters (void)
 752 {
 753   int i;
 754
 755   parmpy_object_type.tp_new = PyType_GenericNew;
 756   if (PyType_Ready (&parmpy_object_type) < 0)
 757     return -1;
 758
 759   set_doc_cst = PyString_FromString ("set_doc");
 760   if (! set_doc_cst)
 761     return -1;
 762   show_doc_cst = PyString_FromString ("show_doc");
 763   if (! show_doc_cst)
 764     return -1;
 765
 766   for (i = 0; parm_constants[i].name; ++i)
 767     {
 768       if (PyModule_AddIntConstant (gdb_module,
 769                                    parm_constants[i].name,
 770                                    parm_constants[i].value) < 0)
 771         return -1;
 772     }
 773
 774   return gdb_pymodule_addobject (gdb_module, "Parameter",
 775                                  (PyObject *) &parmpy_object_type);
 776 }
 777
 778 \f
 779
 780 PyTypeObject parmpy_object_type =
 781 {
 782   PyVarObject_HEAD_INIT (NULL, 0)
 783   "gdb.Parameter",                /*tp_name*/
 784   sizeof (parmpy_object),         /*tp_basicsize*/
 785   0,                              /*tp_itemsize*/
 786   0,                              /*tp_dealloc*/
 787   0,                              /*tp_print*/
 788   0,                              /*tp_getattr*/
 789   0,                              /*tp_setattr*/
 790   0,                              /*tp_compare*/
 791   0,                              /*tp_repr*/
 792   0,                              /*tp_as_number*/
 793   0,                              /*tp_as_sequence*/
 794   0,                              /*tp_as_mapping*/
 795   0,                              /*tp_hash */
 796   0,                              /*tp_call*/
 797   0,                              /*tp_str*/
 798   get_attr,                       /*tp_getattro*/
 799   set_attr,                       /*tp_setattro*/
 800   0,                              /*tp_as_buffer*/
 801   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
 802   "GDB parameter object",         /* tp_doc */
 803   0,                              /* tp_traverse */
 804   0,                              /* tp_clear */
 805   0,                              /* tp_richcompare */
 806   0,                              /* tp_weaklistoffset */
 807   0,                              /* tp_iter */
 808   0,                              /* tp_iternext */
 809   0,                              /* tp_methods */
 810   0,                              /* tp_members */
 811   0,                              /* tp_getset */
 812   0,                              /* tp_base */
 813   0,                              /* tp_dict */
 814   0,                              /* tp_descr_get */
 815   0,                              /* tp_descr_set */
 816   0,                              /* tp_dictoffset */
 817   parmpy_init,                    /* tp_init */
 818   0,                              /* tp_alloc */
 819 };