gdb/python/py-cmd.c

   1 /* gdb commands implemented in Python
   2
   3    Copyright (C) 2008, 2009, 2010, 2011 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 "arch-utils.h"
  23 #include "value.h"
  24 #include "exceptions.h"
  25 #include "python-internal.h"
  26 #include "charset.h"
  27 #include "gdbcmd.h"
  28 #include "cli/cli-decode.h"
  29 #include "completer.h"
  30 #include "language.h"
  31
  32 /* Struct representing built-in completion types.  */
  33 struct cmdpy_completer
  34 {
  35   /* Python symbol name.  */
  36   char *name;
  37   /* Completion function.  */
  38   char **(*completer) (struct cmd_list_element *, char *, char *);
  39 };
  40
  41 static struct cmdpy_completer completers[] =
  42 {
  43   { "COMPLETE_NONE", noop_completer },
  44   { "COMPLETE_FILENAME", filename_completer },
  45   { "COMPLETE_LOCATION", location_completer },
  46   { "COMPLETE_COMMAND", command_completer },
  47   { "COMPLETE_SYMBOL", make_symbol_completion_list_fn },
  48 };
  49
  50 #define N_COMPLETERS (sizeof (completers) / sizeof (completers[0]))
  51
  52 /* A gdb command.  For the time being only ordinary commands (not
  53    set/show commands) are allowed.  */
  54 struct cmdpy_object
  55 {
  56   PyObject_HEAD
  57
  58   /* The corresponding gdb command object, or NULL if the command is
  59      no longer installed.  */
  60   struct cmd_list_element *command;
  61
  62   /* A prefix command requires storage for a list of its sub-commands.
  63      A pointer to this is passed to add_prefix_command, and to add_cmd
  64      for sub-commands of that prefix.  If this Command is not a prefix
  65      command, then this field is unused.  */
  66   struct cmd_list_element *sub_list;
  67 };
  68
  69 typedef struct cmdpy_object cmdpy_object;
  70
  71 static PyTypeObject cmdpy_object_type;
  72
  73
  74 /* Constants used by this module.  */
  75 static PyObject *invoke_cst;
  76 static PyObject *complete_cst;
  77
  78 \f
  79
  80 /* Python function which wraps dont_repeat.  */
  81 static PyObject *
  82 cmdpy_dont_repeat (PyObject *self, PyObject *args)
  83 {
  84   dont_repeat ();
  85   Py_RETURN_NONE;
  86 }
  87
  88 \f
  89
  90 /* Called if the gdb cmd_list_element is destroyed.  */
  91
  92 static void
  93 cmdpy_destroyer (struct cmd_list_element *self, void *context)
  94 {
  95   cmdpy_object *cmd;
  96   struct cleanup *cleanup;
  97
  98   cleanup = ensure_python_env (get_current_arch (), current_language);
  99
 100   /* Release our hold on the command object.  */
 101   cmd = (cmdpy_object *) context;
 102   cmd->command = NULL;
 103   Py_DECREF (cmd);
 104
 105   /* We allocated the name, doc string, and perhaps the prefix
 106      name.  */
 107   xfree (self->name);
 108   xfree (self->doc);
 109   xfree (self->prefixname);
 110
 111   do_cleanups (cleanup);
 112 }
 113
 114 /* Called by gdb to invoke the command.  */
 115
 116 static void
 117 cmdpy_function (struct cmd_list_element *command, char *args, int from_tty)
 118 {
 119   cmdpy_object *obj = (cmdpy_object *) get_cmd_context (command);
 120   PyObject *argobj, *ttyobj, *result;
 121   struct cleanup *cleanup;
 122
 123   cleanup = ensure_python_env (get_current_arch (), current_language);
 124
 125   if (! obj)
 126     error (_("Invalid invocation of Python command object."));
 127   if (! PyObject_HasAttr ((PyObject *) obj, invoke_cst))
 128     {
 129       if (obj->command->prefixname)
 130         {
 131           /* A prefix command does not need an invoke method.  */
 132           do_cleanups (cleanup);
 133           return;
 134         }
 135       error (_("Python command object missing 'invoke' method."));
 136     }
 137
 138   if (! args)
 139     args = "";
 140   argobj = PyUnicode_Decode (args, strlen (args), host_charset (), NULL);
 141   if (! argobj)
 142     {
 143       gdbpy_print_stack ();
 144       error (_("Could not convert arguments to Python string."));
 145     }
 146
 147   ttyobj = from_tty ? Py_True : Py_False;
 148   Py_INCREF (ttyobj);
 149   result = PyObject_CallMethodObjArgs ((PyObject *) obj, invoke_cst, argobj,
 150                                        ttyobj, NULL);
 151   Py_DECREF (argobj);
 152   Py_DECREF (ttyobj);
 153
 154   if (! result)
 155     {
 156       PyObject *ptype, *pvalue, *ptraceback;
 157       char *msg;
 158
 159       PyErr_Fetch (&ptype, &pvalue, &ptraceback);
 160
 161       /* Try to fetch an error message contained within ptype, pvalue.
 162          When fetching the error message we need to make our own copy,
 163          we no longer own ptype, pvalue after the call to PyErr_Restore.  */
 164
 165       msg = gdbpy_exception_to_string (ptype, pvalue);
 166       make_cleanup (xfree, msg);
 167
 168       if (msg == NULL)
 169         {
 170           /* An error occurred computing the string representation of the
 171              error message.  This is rare, but we should inform the user.  */
 172           printf_filtered (_("An error occurred in a Python command\n"
 173                              "and then another occurred computing the "
 174                              "error message.\n"));
 175           gdbpy_print_stack ();
 176         }
 177
 178       /* Don't print the stack for gdb.GdbError exceptions.
 179          It is generally used to flag user errors.
 180
 181          We also don't want to print "Error occurred in Python command"
 182          for user errors.  However, a missing message for gdb.GdbError
 183          exceptions is arguably a bug, so we flag it as such.  */
 184
 185       if (! PyErr_GivenExceptionMatches (ptype, gdbpy_gdberror_exc)
 186           || msg == NULL || *msg == '\0')
 187         {
 188           PyErr_Restore (ptype, pvalue, ptraceback);
 189           gdbpy_print_stack ();
 190           if (msg != NULL && *msg != '\0')
 191             error (_("Error occurred in Python command: %s"), msg);
 192           else
 193             error (_("Error occurred in Python command."));
 194         }
 195       else
 196         {
 197           Py_XDECREF (ptype);
 198           Py_XDECREF (pvalue);
 199           Py_XDECREF (ptraceback);
 200           error ("%s", msg);
 201         }
 202     }
 203
 204   Py_DECREF (result);
 205   do_cleanups (cleanup);
 206 }
 207
 208 /* Called by gdb for command completion.  */
 209 static char **
 210 cmdpy_completer (struct cmd_list_element *command, char *text, char *word)
 211 {
 212   cmdpy_object *obj = (cmdpy_object *) get_cmd_context (command);
 213   PyObject *textobj, *wordobj, *resultobj = NULL;
 214   char **result = NULL;
 215   struct cleanup *cleanup;
 216
 217   cleanup = ensure_python_env (get_current_arch (), current_language);
 218
 219   if (! obj)
 220     error (_("Invalid invocation of Python command object."));
 221   if (! PyObject_HasAttr ((PyObject *) obj, complete_cst))
 222     {
 223       /* If there is no complete method, don't error -- instead, just
 224          say that there are no completions.  */
 225       goto done;
 226     }
 227
 228   textobj = PyUnicode_Decode (text, strlen (text), host_charset (), NULL);
 229   if (! textobj)
 230     error (_("Could not convert argument to Python string."));
 231   wordobj = PyUnicode_Decode (word, strlen (word), host_charset (), NULL);
 232   if (! wordobj)
 233     error (_("Could not convert argument to Python string."));
 234
 235   resultobj = PyObject_CallMethodObjArgs ((PyObject *) obj, complete_cst,
 236                                           textobj, wordobj, NULL);
 237   Py_DECREF (textobj);
 238   Py_DECREF (wordobj);
 239   if (! resultobj)
 240     {
 241       /* Just swallow errors here.  */
 242       PyErr_Clear ();
 243       goto done;
 244     }
 245   make_cleanup_py_decref (resultobj);
 246
 247   result = NULL;
 248   if (PySequence_Check (resultobj))
 249     {
 250       Py_ssize_t i, len = PySequence_Size (resultobj);
 251       Py_ssize_t out;
 252
 253       if (len < 0)
 254         goto done;
 255
 256       result = (char **) xmalloc ((len + 1) * sizeof (char *));
 257       for (i = out = 0; i < len; ++i)
 258         {
 259           PyObject *elt = PySequence_GetItem (resultobj, i);
 260
 261           if (elt == NULL || ! gdbpy_is_string (elt))
 262             {
 263               /* Skip problem elements.  */
 264               PyErr_Clear ();
 265               continue;
 266             }
 267           result[out] = python_string_to_host_string (elt);
 268           if (result[out] == NULL)
 269             {
 270               /* Skip problem elements.  */
 271               PyErr_Clear ();
 272               continue;
 273             }
 274           ++out;
 275         }
 276       result[out] = NULL;
 277     }
 278   else if (PyInt_Check (resultobj))
 279     {
 280       /* User code may also return one of the completion constants,
 281          thus requesting that sort of completion.  */
 282       long value;
 283
 284       if (! gdb_py_int_as_long (resultobj, &value))
 285         {
 286           /* Ignore.  */
 287           PyErr_Clear ();
 288         }
 289       else if (value >= 0 && value < (long) N_COMPLETERS)
 290         result = completers[value].completer (command, text, word);
 291     }
 292
 293  done:
 294
 295   do_cleanups (cleanup);
 296
 297   return result;
 298 }
 299
 300 /* Helper for cmdpy_init which locates the command list to use and
 301    pulls out the command name.
 302
 303    TEXT is the command name list.  The final word in the list is the
 304    name of the new command.  All earlier words must be existing prefix
 305    commands.
 306
 307    *BASE_LIST is set to the final prefix command's list of
 308    *sub-commands.
 309
 310    START_LIST is the list in which the search starts.
 311
 312    This function returns the xmalloc()d name of the new command.  On
 313    error sets the Python error and returns NULL.  */
 314 char *
 315 gdbpy_parse_command_name (char *text,
 316                           struct cmd_list_element ***base_list,
 317                           struct cmd_list_element **start_list)
 318 {
 319   struct cmd_list_element *elt;
 320   int len = strlen (text);
 321   int i, lastchar;
 322   char *prefix_text;
 323   char *result;
 324
 325   /* Skip trailing whitespace.  */
 326   for (i = len - 1; i >= 0 && (text[i] == ' ' || text[i] == '\t'); --i)
 327     ;
 328   if (i < 0)
 329     {
 330       PyErr_SetString (PyExc_RuntimeError, _("No command name found."));
 331       return NULL;
 332     }
 333   lastchar = i;
 334
 335   /* Find first character of the final word.  */
 336   for (; i > 0 && (isalnum (text[i - 1])
 337                    || text[i - 1] == '-'
 338                    || text[i - 1] == '_');
 339        --i)
 340     ;
 341   result = xmalloc (lastchar - i + 2);
 342   memcpy (result, &text[i], lastchar - i + 1);
 343   result[lastchar - i + 1] = '\0';
 344
 345   /* Skip whitespace again.  */
 346   for (--i; i >= 0 && (text[i] == ' ' || text[i] == '\t'); --i)
 347     ;
 348   if (i < 0)
 349     {
 350       *base_list = start_list;
 351       return result;
 352     }
 353
 354   prefix_text = xmalloc (i + 2);
 355   memcpy (prefix_text, text, i + 1);
 356   prefix_text[i + 1] = '\0';
 357
 358   text = prefix_text;
 359   elt = lookup_cmd_1 (&text, *start_list, NULL, 1);
 360   if (!elt || elt == (struct cmd_list_element *) -1)
 361     {
 362       PyErr_Format (PyExc_RuntimeError, _("Could not find command prefix %s."),
 363                     prefix_text);
 364       xfree (prefix_text);
 365       xfree (result);
 366       return NULL;
 367     }
 368
 369   if (elt->prefixlist)
 370     {
 371       xfree (prefix_text);
 372       *base_list = elt->prefixlist;
 373       return result;
 374     }
 375
 376   PyErr_Format (PyExc_RuntimeError, _("'%s' is not a prefix command."),
 377                 prefix_text);
 378   xfree (prefix_text);
 379   xfree (result);
 380   return NULL;
 381 }
 382
 383 /* Object initializer; sets up gdb-side structures for command.
 384
 385    Use: __init__(NAME, COMMAND_CLASS [, COMPLETER_CLASS][, PREFIX]]).
 386
 387    NAME is the name of the command.  It may consist of multiple words,
 388    in which case the final word is the name of the new command, and
 389    earlier words must be prefix commands.
 390
 391    COMMAND_CLASS is the kind of command.  It should be one of the COMMAND_*
 392    constants defined in the gdb module.
 393
 394    COMPLETER_CLASS is the kind of completer.  If not given, the
 395    "complete" method will be used.  Otherwise, it should be one of the
 396    COMPLETE_* constants defined in the gdb module.
 397
 398    If PREFIX is True, then this command is a prefix command.
 399
 400    The documentation for the command is taken from the doc string for
 401    the python class.
 402
 403 */
 404 static int
 405 cmdpy_init (PyObject *self, PyObject *args, PyObject *kw)
 406 {
 407   cmdpy_object *obj = (cmdpy_object *) self;
 408   char *name;
 409   int cmdtype;
 410   int completetype = -1;
 411   char *docstring = NULL;
 412   volatile struct gdb_exception except;
 413   struct cmd_list_element **cmd_list;
 414   char *cmd_name, *pfx_name;
 415   static char *keywords[] = { "name", "command_class", "completer_class",
 416                               "prefix", NULL };
 417   PyObject *is_prefix = NULL;
 418   int cmp;
 419
 420   if (obj->command)
 421     {
 422       /* Note: this is apparently not documented in Python.  We return
 423          0 for success, -1 for failure.  */
 424       PyErr_Format (PyExc_RuntimeError,
 425                     _("Command object already initialized."));
 426       return -1;
 427     }
 428
 429   if (! PyArg_ParseTupleAndKeywords (args, kw, "si|iO",
 430                                      keywords, &name, &cmdtype,
 431                           &completetype, &is_prefix))
 432     return -1;
 433
 434   if (cmdtype != no_class && cmdtype != class_run
 435       && cmdtype != class_vars && cmdtype != class_stack
 436       && cmdtype != class_files && cmdtype != class_support
 437       && cmdtype != class_info && cmdtype != class_breakpoint
 438       && cmdtype != class_trace && cmdtype != class_obscure
 439       && cmdtype != class_maintenance)
 440     {
 441       PyErr_Format (PyExc_RuntimeError, _("Invalid command class argument."));
 442       return -1;
 443     }
 444
 445   if (completetype < -1 || completetype >= (int) N_COMPLETERS)
 446     {
 447       PyErr_Format (PyExc_RuntimeError,
 448                     _("Invalid completion type argument."));
 449       return -1;
 450     }
 451
 452   cmd_name = gdbpy_parse_command_name (name, &cmd_list, &cmdlist);
 453   if (! cmd_name)
 454     return -1;
 455
 456   pfx_name = NULL;
 457   if (is_prefix != NULL)
 458     {
 459       cmp = PyObject_IsTrue (is_prefix);
 460       if (cmp == 1)
 461         {
 462           int i, out;
 463
 464           /* Make a normalized form of the command name.  */
 465           pfx_name = xmalloc (strlen (name) + 2);
 466
 467           i = 0;
 468           out = 0;
 469           while (name[i])
 470             {
 471               /* Skip whitespace.  */
 472               while (name[i] == ' ' || name[i] == '\t')
 473                 ++i;
 474               /* Copy non-whitespace characters.  */
 475               while (name[i] && name[i] != ' ' && name[i] != '\t')
 476                 pfx_name[out++] = name[i++];
 477               /* Add a single space after each word -- including the final
 478                  word.  */
 479               pfx_name[out++] = ' ';
 480             }
 481           pfx_name[out] = '\0';
 482         }
 483       else if (cmp < 0)
 484         {
 485           xfree (cmd_name);
 486           return -1;
 487         }
 488     }
 489   if (PyObject_HasAttr (self, gdbpy_doc_cst))
 490     {
 491       PyObject *ds_obj = PyObject_GetAttr (self, gdbpy_doc_cst);
 492
 493       if (ds_obj && gdbpy_is_string (ds_obj))
 494         {
 495           docstring = python_string_to_host_string (ds_obj);
 496           if (docstring == NULL)
 497             {
 498               xfree (cmd_name);
 499               xfree (pfx_name);
 500               return -1;
 501             }
 502         }
 503     }
 504   if (! docstring)
 505     docstring = xstrdup (_("This command is not documented."));
 506
 507   Py_INCREF (self);
 508
 509   TRY_CATCH (except, RETURN_MASK_ALL)
 510     {
 511       struct cmd_list_element *cmd;
 512
 513       if (pfx_name)
 514         {
 515           int allow_unknown;
 516
 517           /* If we have our own "invoke" method, then allow unknown
 518              sub-commands.  */
 519           allow_unknown = PyObject_HasAttr (self, invoke_cst);
 520           cmd = add_prefix_cmd (cmd_name, (enum command_class) cmdtype,
 521                                 NULL, docstring, &obj->sub_list,
 522                                 pfx_name, allow_unknown, cmd_list);
 523         }
 524       else
 525         cmd = add_cmd (cmd_name, (enum command_class) cmdtype, NULL,
 526                        docstring, cmd_list);
 527
 528       /* There appears to be no API to set this.  */
 529       cmd->func = cmdpy_function;
 530       cmd->destroyer = cmdpy_destroyer;
 531
 532       obj->command = cmd;
 533       set_cmd_context (cmd, self);
 534       set_cmd_completer (cmd, ((completetype == -1) ? cmdpy_completer
 535                                : completers[completetype].completer));
 536     }
 537   if (except.reason < 0)
 538     {
 539       xfree (cmd_name);
 540       xfree (docstring);
 541       xfree (pfx_name);
 542       Py_DECREF (self);
 543       PyErr_Format (except.reason == RETURN_QUIT
 544                     ? PyExc_KeyboardInterrupt : PyExc_RuntimeError,
 545                     "%s", except.message);
 546       return -1;
 547     }
 548   return 0;
 549 }
 550
 551 \f
 552
 553 /* Initialize the 'commands' code.  */
 554 void
 555 gdbpy_initialize_commands (void)
 556 {
 557   int i;
 558
 559   if (PyType_Ready (&cmdpy_object_type) < 0)
 560     return;
 561
 562   /* Note: alias and user are special; pseudo appears to be unused,
 563      and there is no reason to expose tui or xdb, I think.  */
 564   if (PyModule_AddIntConstant (gdb_module, "COMMAND_NONE", no_class) < 0
 565       || PyModule_AddIntConstant (gdb_module, "COMMAND_RUNNING", class_run) < 0
 566       || PyModule_AddIntConstant (gdb_module, "COMMAND_DATA", class_vars) < 0
 567       || PyModule_AddIntConstant (gdb_module, "COMMAND_STACK", class_stack) < 0
 568       || PyModule_AddIntConstant (gdb_module, "COMMAND_FILES", class_files) < 0
 569       || PyModule_AddIntConstant (gdb_module, "COMMAND_SUPPORT",
 570                                   class_support) < 0
 571       || PyModule_AddIntConstant (gdb_module, "COMMAND_STATUS", class_info) < 0
 572       || PyModule_AddIntConstant (gdb_module, "COMMAND_BREAKPOINTS",
 573                                   class_breakpoint) < 0
 574       || PyModule_AddIntConstant (gdb_module, "COMMAND_TRACEPOINTS",
 575                                   class_trace) < 0
 576       || PyModule_AddIntConstant (gdb_module, "COMMAND_OBSCURE",
 577                                   class_obscure) < 0
 578       || PyModule_AddIntConstant (gdb_module, "COMMAND_MAINTENANCE",
 579                                   class_maintenance) < 0)
 580     return;
 581
 582   for (i = 0; i < N_COMPLETERS; ++i)
 583     {
 584       if (PyModule_AddIntConstant (gdb_module, completers[i].name, i) < 0)
 585         return;
 586     }
 587
 588   Py_INCREF (&cmdpy_object_type);
 589   PyModule_AddObject (gdb_module, "Command",
 590                       (PyObject *) &cmdpy_object_type);
 591
 592   invoke_cst = PyString_FromString ("invoke");
 593   complete_cst = PyString_FromString ("complete");
 594 }
 595
 596 \f
 597
 598 static PyMethodDef cmdpy_object_methods[] =
 599 {
 600   { "dont_repeat", cmdpy_dont_repeat, METH_NOARGS,
 601     "Prevent command repetition when user enters empty line." },
 602
 603   { 0 }
 604 };
 605
 606 static PyTypeObject cmdpy_object_type =
 607 {
 608   PyObject_HEAD_INIT (NULL)
 609   0,                              /*ob_size*/
 610   "gdb.Command",                  /*tp_name*/
 611   sizeof (cmdpy_object),          /*tp_basicsize*/
 612   0,                              /*tp_itemsize*/
 613   0,                              /*tp_dealloc*/
 614   0,                              /*tp_print*/
 615   0,                              /*tp_getattr*/
 616   0,                              /*tp_setattr*/
 617   0,                              /*tp_compare*/
 618   0,                              /*tp_repr*/
 619   0,                              /*tp_as_number*/
 620   0,                              /*tp_as_sequence*/
 621   0,                              /*tp_as_mapping*/
 622   0,                              /*tp_hash */
 623   0,                              /*tp_call*/
 624   0,                              /*tp_str*/
 625   0,                              /*tp_getattro*/
 626   0,                              /*tp_setattro*/
 627   0,                              /*tp_as_buffer*/
 628   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
 629   "GDB command object",           /* tp_doc */
 630   0,                              /* tp_traverse */
 631   0,                              /* tp_clear */
 632   0,                              /* tp_richcompare */
 633   0,                              /* tp_weaklistoffset */
 634   0,                              /* tp_iter */
 635   0,                              /* tp_iternext */
 636   cmdpy_object_methods,           /* tp_methods */
 637   0,                              /* tp_members */
 638   0,                              /* tp_getset */
 639   0,                              /* tp_base */
 640   0,                              /* tp_dict */
 641   0,                              /* tp_descr_get */
 642   0,                              /* tp_descr_set */
 643   0,                              /* tp_dictoffset */
 644   cmdpy_init,                     /* tp_init */
 645   0,                              /* tp_alloc */
 646   PyType_GenericNew               /* tp_new */
 647 };
 648
 649 \f
 650
 651 /* Utility to build a buildargv-like result from ARGS.
 652    This intentionally parses arguments the way libiberty/argv.c:buildargv
 653    does.  It splits up arguments in a reasonable way, and we want a standard
 654    way of parsing arguments.  Several gdb commands use buildargv to parse their
 655    arguments.  Plus we want to be able to write compatible python
 656    implementations of gdb commands.  */
 657
 658 PyObject *
 659 gdbpy_string_to_argv (PyObject *self, PyObject *args)
 660 {
 661   PyObject *py_argv;
 662   char *input;
 663
 664   if (!PyArg_ParseTuple (args, "s", &input))
 665     return NULL;
 666
 667   py_argv = PyList_New (0);
 668
 669   /* buildargv uses NULL to represent an empty argument list, but we can't use
 670      that in Python.  Instead, if ARGS is "" then return an empty list.
 671      This undoes the NULL -> "" conversion that cmdpy_function does.  */
 672
 673   if (*input != '\0')
 674     {
 675       char **c_argv = gdb_buildargv (input);
 676       int i;
 677
 678       for (i = 0; c_argv[i] != NULL; ++i)
 679         {
 680           PyObject *argp = PyString_FromString (c_argv[i]);
 681
 682           if (argp == NULL
 683               || PyList_Append (py_argv, argp) < 0)
 684             {
 685               if (argp != NULL)
 686                 {
 687                   Py_DECREF (argp);
 688                 }
 689               Py_DECREF (py_argv);
 690               freeargv (c_argv);
 691               return NULL;
 692             }
 693         }
 694
 695       freeargv (c_argv);
 696     }
 697
 698   return py_argv;
 699 }