gdb/python/python.c

   1 /* General python/gdb code
   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 #include "defs.h"
  21 #include "arch-utils.h"
  22 #include "command.h"
  23 #include "ui-out.h"
  24 #include "cli/cli-script.h"
  25 #include "gdbcmd.h"
  26 #include "progspace.h"
  27 #include "objfiles.h"
  28 #include "value.h"
  29 #include "language.h"
  30 #include "exceptions.h"
  31 #include "event-loop.h"
  32 #include "serial.h"
  33 #include "python.h"
  34
  35 #include <ctype.h>
  36
  37 /* True if we should print the stack when catching a Python error,
  38    false otherwise.  */
  39 static int gdbpy_should_print_stack = 0;
  40
  41 #ifdef HAVE_PYTHON
  42
  43 #include "libiberty.h"
  44 #include "cli/cli-decode.h"
  45 #include "charset.h"
  46 #include "top.h"
  47 #include "solib.h"
  48 #include "python-internal.h"
  49 #include "linespec.h"
  50 #include "source.h"
  51 #include "version.h"
  52 #include "target.h"
  53 #include "gdbthread.h"
  54 #include "observer.h"
  55
  56 static PyMethodDef GdbMethods[];
  57
  58 PyObject *gdb_module;
  59
  60 /* Some string constants we may wish to use.  */
  61 PyObject *gdbpy_to_string_cst;
  62 PyObject *gdbpy_children_cst;
  63 PyObject *gdbpy_display_hint_cst;
  64 PyObject *gdbpy_doc_cst;
  65 PyObject *gdbpy_enabled_cst;
  66 PyObject *gdbpy_value_cst;
  67
  68 /* The GdbError exception.  */
  69 PyObject *gdbpy_gdberror_exc;
  70
  71 /* The `gdb.error' base class.  */
  72 PyObject *gdbpy_gdb_error;
  73
  74 /* The `gdb.MemoryError' exception.  */
  75 PyObject *gdbpy_gdb_memory_error;
  76
  77 /* Architecture and language to be used in callbacks from
  78    the Python interpreter.  */
  79 struct gdbarch *python_gdbarch;
  80 const struct language_defn *python_language;
  81
  82 /* Restore global language and architecture and Python GIL state
  83    when leaving the Python interpreter.  */
  84
  85 struct python_env
  86 {
  87   PyGILState_STATE state;
  88   struct gdbarch *gdbarch;
  89   const struct language_defn *language;
  90   PyObject *error_type, *error_value, *error_traceback;
  91 };
  92
  93 static void
  94 restore_python_env (void *p)
  95 {
  96   struct python_env *env = (struct python_env *)p;
  97
  98   /* Leftover Python error is forbidden by Python Exception Handling.  */
  99   if (PyErr_Occurred ())
 100     {
 101       /* This order is similar to the one calling error afterwards. */
 102       gdbpy_print_stack ();
 103       warning (_("internal error: Unhandled Python exception"));
 104     }
 105
 106   PyErr_Restore (env->error_type, env->error_value, env->error_traceback);
 107
 108   PyGILState_Release (env->state);
 109   python_gdbarch = env->gdbarch;
 110   python_language = env->language;
 111   xfree (env);
 112 }
 113
 114 /* Called before entering the Python interpreter to install the
 115    current language and architecture to be used for Python values.  */
 116
 117 struct cleanup *
 118 ensure_python_env (struct gdbarch *gdbarch,
 119                    const struct language_defn *language)
 120 {
 121   struct python_env *env = xmalloc (sizeof *env);
 122
 123   env->state = PyGILState_Ensure ();
 124   env->gdbarch = python_gdbarch;
 125   env->language = python_language;
 126
 127   python_gdbarch = gdbarch;
 128   python_language = language;
 129
 130   /* Save it and ensure ! PyErr_Occurred () afterwards.  */
 131   PyErr_Fetch (&env->error_type, &env->error_value, &env->error_traceback);
 132
 133   return make_cleanup (restore_python_env, env);
 134 }
 135
 136
 137 /* Given a command_line, return a command string suitable for passing
 138    to Python.  Lines in the string are separated by newlines.  The
 139    return value is allocated using xmalloc and the caller is
 140    responsible for freeing it.  */
 141
 142 static char *
 143 compute_python_string (struct command_line *l)
 144 {
 145   struct command_line *iter;
 146   char *script = NULL;
 147   int size = 0;
 148   int here;
 149
 150   for (iter = l; iter; iter = iter->next)
 151     size += strlen (iter->line) + 1;
 152
 153   script = xmalloc (size + 1);
 154   here = 0;
 155   for (iter = l; iter; iter = iter->next)
 156     {
 157       int len = strlen (iter->line);
 158
 159       strcpy (&script[here], iter->line);
 160       here += len;
 161       script[here++] = '\n';
 162     }
 163   script[here] = '\0';
 164   return script;
 165 }
 166
 167 /* Take a command line structure representing a 'python' command, and
 168    evaluate its body using the Python interpreter.  */
 169
 170 void
 171 eval_python_from_control_command (struct command_line *cmd)
 172 {
 173   int ret;
 174   char *script;
 175   struct cleanup *cleanup;
 176
 177   if (cmd->body_count != 1)
 178     error (_("Invalid \"python\" block structure."));
 179
 180   cleanup = ensure_python_env (get_current_arch (), current_language);
 181
 182   script = compute_python_string (cmd->body_list[0]);
 183   ret = PyRun_SimpleString (script);
 184   xfree (script);
 185   if (ret)
 186     {
 187       gdbpy_print_stack ();
 188       error (_("Error while executing Python code."));
 189     }
 190
 191   do_cleanups (cleanup);
 192 }
 193
 194 /* Implementation of the gdb "python" command.  */
 195
 196 static void
 197 python_command (char *arg, int from_tty)
 198 {
 199   struct cleanup *cleanup;
 200
 201   cleanup = ensure_python_env (get_current_arch (), current_language);
 202   while (arg && *arg && isspace (*arg))
 203     ++arg;
 204   if (arg && *arg)
 205     {
 206       if (PyRun_SimpleString (arg))
 207         {
 208           gdbpy_print_stack ();
 209           error (_("Error while executing Python code."));
 210         }
 211     }
 212   else
 213     {
 214       struct command_line *l = get_command_line (python_control, "");
 215
 216       make_cleanup_free_command_lines (&l);
 217       execute_control_command_untraced (l);
 218     }
 219
 220   do_cleanups (cleanup);
 221 }
 222
 223 \f
 224
 225 /* Transform a gdb parameters's value into a Python value.  May return
 226    NULL (and set a Python exception) on error.  Helper function for
 227    get_parameter.  */
 228 PyObject *
 229 gdbpy_parameter_value (enum var_types type, void *var)
 230 {
 231   switch (type)
 232     {
 233     case var_string:
 234     case var_string_noescape:
 235     case var_optional_filename:
 236     case var_filename:
 237     case var_enum:
 238       {
 239         char *str = * (char **) var;
 240
 241         if (! str)
 242           str = "";
 243         return PyString_Decode (str, strlen (str), host_charset (), NULL);
 244       }
 245
 246     case var_boolean:
 247       {
 248         if (* (int *) var)
 249           Py_RETURN_TRUE;
 250         else
 251           Py_RETURN_FALSE;
 252       }
 253
 254     case var_auto_boolean:
 255       {
 256         enum auto_boolean ab = * (enum auto_boolean *) var;
 257
 258         if (ab == AUTO_BOOLEAN_TRUE)
 259           Py_RETURN_TRUE;
 260         else if (ab == AUTO_BOOLEAN_FALSE)
 261           Py_RETURN_FALSE;
 262         else
 263           Py_RETURN_NONE;
 264       }
 265
 266     case var_integer:
 267       if ((* (int *) var) == INT_MAX)
 268         Py_RETURN_NONE;
 269       /* Fall through.  */
 270     case var_zinteger:
 271       return PyLong_FromLong (* (int *) var);
 272
 273     case var_uinteger:
 274       {
 275         unsigned int val = * (unsigned int *) var;
 276
 277         if (val == UINT_MAX)
 278           Py_RETURN_NONE;
 279         return PyLong_FromUnsignedLong (val);
 280       }
 281     }
 282
 283   return PyErr_Format (PyExc_RuntimeError,
 284                        _("Programmer error: unhandled type."));
 285 }
 286
 287 /* A Python function which returns a gdb parameter's value as a Python
 288    value.  */
 289
 290 PyObject *
 291 gdbpy_parameter (PyObject *self, PyObject *args)
 292 {
 293   struct cmd_list_element *alias, *prefix, *cmd;
 294   const char *arg;
 295   char *newarg;
 296   int found = -1;
 297   volatile struct gdb_exception except;
 298
 299   if (! PyArg_ParseTuple (args, "s", &arg))
 300     return NULL;
 301
 302   newarg = concat ("show ", arg, (char *) NULL);
 303
 304   TRY_CATCH (except, RETURN_MASK_ALL)
 305     {
 306       found = lookup_cmd_composition (newarg, &alias, &prefix, &cmd);
 307     }
 308   xfree (newarg);
 309   GDB_PY_HANDLE_EXCEPTION (except);
 310   if (!found)
 311     return PyErr_Format (PyExc_RuntimeError,
 312                          _("Could not find parameter `%s'."), arg);
 313
 314   if (! cmd->var)
 315     return PyErr_Format (PyExc_RuntimeError,
 316                          _("`%s' is not a parameter."), arg);
 317   return gdbpy_parameter_value (cmd->var_type, cmd->var);
 318 }
 319
 320 /* Wrapper for target_charset.  */
 321
 322 static PyObject *
 323 gdbpy_target_charset (PyObject *self, PyObject *args)
 324 {
 325   const char *cset = target_charset (python_gdbarch);
 326
 327   return PyUnicode_Decode (cset, strlen (cset), host_charset (), NULL);
 328 }
 329
 330 /* Wrapper for target_wide_charset.  */
 331
 332 static PyObject *
 333 gdbpy_target_wide_charset (PyObject *self, PyObject *args)
 334 {
 335   const char *cset = target_wide_charset (python_gdbarch);
 336
 337   return PyUnicode_Decode (cset, strlen (cset), host_charset (), NULL);
 338 }
 339
 340 /* A Python function which evaluates a string using the gdb CLI.  */
 341
 342 static PyObject *
 343 execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
 344 {
 345   const char *arg;
 346   PyObject *from_tty_obj = NULL, *to_string_obj = NULL;
 347   int from_tty, to_string;
 348   volatile struct gdb_exception except;
 349   static char *keywords[] = {"command", "from_tty", "to_string", NULL };
 350   char *result = NULL;
 351
 352   if (! PyArg_ParseTupleAndKeywords (args, kw, "s|O!O!", keywords, &arg,
 353                                      &PyBool_Type, &from_tty_obj,
 354                                      &PyBool_Type, &to_string_obj))
 355     return NULL;
 356
 357   from_tty = 0;
 358   if (from_tty_obj)
 359     {
 360       int cmp = PyObject_IsTrue (from_tty_obj);
 361       if (cmp < 0)
 362         return NULL;
 363       from_tty = cmp;
 364     }
 365
 366   to_string = 0;
 367   if (to_string_obj)
 368     {
 369       int cmp = PyObject_IsTrue (to_string_obj);
 370       if (cmp < 0)
 371         return NULL;
 372       to_string = cmp;
 373     }
 374
 375   TRY_CATCH (except, RETURN_MASK_ALL)
 376     {
 377       /* Copy the argument text in case the command modifies it.  */
 378       char *copy = xstrdup (arg);
 379       struct cleanup *cleanup = make_cleanup (xfree, copy);
 380
 381       prevent_dont_repeat ();
 382       if (to_string)
 383         result = execute_command_to_string (copy, from_tty);
 384       else
 385         {
 386           result = NULL;
 387           execute_command (copy, from_tty);
 388         }
 389
 390       do_cleanups (cleanup);
 391     }
 392   GDB_PY_HANDLE_EXCEPTION (except);
 393
 394   /* Do any commands attached to breakpoint we stopped at.  */
 395   bpstat_do_actions ();
 396
 397   if (result)
 398     {
 399       PyObject *r = PyString_FromString (result);
 400       xfree (result);
 401       return r;
 402     }
 403   Py_RETURN_NONE;
 404 }
 405
 406 /* Implementation of gdb.solib_name (Long) -> String.
 407    Returns the name of the shared library holding a given address, or None.  */
 408
 409 static PyObject *
 410 gdbpy_solib_name (PyObject *self, PyObject *args)
 411 {
 412   char *soname;
 413   PyObject *str_obj;
 414   gdb_py_longest pc;
 415
 416   if (!PyArg_ParseTuple (args, GDB_PY_LL_ARG, &pc))
 417     return NULL;
 418
 419   soname = solib_name_from_address (current_program_space, pc);
 420   if (soname)
 421     str_obj = PyString_Decode (soname, strlen (soname), host_charset (), NULL);
 422   else
 423     {
 424       str_obj = Py_None;
 425       Py_INCREF (Py_None);
 426     }
 427
 428   return str_obj;
 429 }
 430
 431 /* A Python function which is a wrapper for decode_line_1.  */
 432
 433 static PyObject *
 434 gdbpy_decode_line (PyObject *self, PyObject *args)
 435 {
 436   struct symtabs_and_lines sals = { NULL, 0 }; /* Initialize to
 437                                                   appease gcc.  */
 438   struct symtab_and_line sal;
 439   const char *arg = NULL;
 440   char *copy = NULL;
 441   struct cleanup *cleanups;
 442   PyObject *result = NULL;
 443   PyObject *return_result = NULL;
 444   PyObject *unparsed = NULL;
 445   volatile struct gdb_exception except;
 446
 447   if (! PyArg_ParseTuple (args, "|s", &arg))
 448     return NULL;
 449
 450   cleanups = ensure_python_env (get_current_arch (), current_language);
 451
 452   TRY_CATCH (except, RETURN_MASK_ALL)
 453     {
 454       if (arg)
 455         {
 456           copy = xstrdup (arg);
 457           make_cleanup (xfree, copy);
 458           sals = decode_line_1 (&copy, 0, 0, 0, 0);
 459           make_cleanup (xfree, sals.sals);
 460         }
 461       else
 462         {
 463           set_default_source_symtab_and_line ();
 464           sal = get_current_source_symtab_and_line ();
 465           sals.sals = &sal;
 466           sals.nelts = 1;
 467         }
 468     }
 469   if (except.reason < 0)
 470     {
 471       do_cleanups (cleanups);
 472       /* We know this will always throw.  */
 473       GDB_PY_HANDLE_EXCEPTION (except);
 474     }
 475
 476   if (sals.nelts)
 477     {
 478       int i;
 479
 480       result = PyTuple_New (sals.nelts);
 481       if (! result)
 482         goto error;
 483       for (i = 0; i < sals.nelts; ++i)
 484         {
 485           PyObject *obj;
 486           char *str;
 487
 488           obj = symtab_and_line_to_sal_object (sals.sals[i]);
 489           if (! obj)
 490             {
 491               Py_DECREF (result);
 492               goto error;
 493             }
 494
 495           PyTuple_SetItem (result, i, obj);
 496         }
 497     }
 498   else
 499     {
 500       result = Py_None;
 501       Py_INCREF (Py_None);
 502     }
 503
 504   return_result = PyTuple_New (2);
 505   if (! return_result)
 506     {
 507       Py_DECREF (result);
 508       goto error;
 509     }
 510
 511   if (copy && strlen (copy) > 0)
 512     unparsed = PyString_FromString (copy);
 513   else
 514     {
 515       unparsed = Py_None;
 516       Py_INCREF (Py_None);
 517     }
 518
 519   PyTuple_SetItem (return_result, 0, unparsed);
 520   PyTuple_SetItem (return_result, 1, result);
 521
 522   do_cleanups (cleanups);
 523
 524   return return_result;
 525
 526  error:
 527   do_cleanups (cleanups);
 528   return NULL;
 529 }
 530
 531 /* Parse a string and evaluate it as an expression.  */
 532 static PyObject *
 533 gdbpy_parse_and_eval (PyObject *self, PyObject *args)
 534 {
 535   const char *expr_str;
 536   struct value *result = NULL;
 537   volatile struct gdb_exception except;
 538
 539   if (!PyArg_ParseTuple (args, "s", &expr_str))
 540     return NULL;
 541
 542   TRY_CATCH (except, RETURN_MASK_ALL)
 543     {
 544       char *copy = xstrdup (expr_str);
 545       struct cleanup *cleanup = make_cleanup (xfree, copy);
 546
 547       result = parse_and_eval (copy);
 548       do_cleanups (cleanup);
 549     }
 550   GDB_PY_HANDLE_EXCEPTION (except);
 551
 552   return value_to_value_object (result);
 553 }
 554
 555 /* Read a file as Python code.  STREAM is the input file; FILE is the
 556    name of the file.
 557    STREAM is not closed, that is the caller's responsibility.  */
 558
 559 void
 560 source_python_script (FILE *stream, const char *file)
 561 {
 562   struct cleanup *cleanup;
 563
 564   cleanup = ensure_python_env (get_current_arch (), current_language);
 565
 566   /* Note: If an exception occurs python will print the traceback and
 567      clear the error indicator.  */
 568   PyRun_SimpleFile (stream, file);
 569
 570   do_cleanups (cleanup);
 571 }
 572
 573 \f
 574
 575 /* Posting and handling events.  */
 576
 577 /* A single event.  */
 578 struct gdbpy_event
 579 {
 580   /* The Python event.  This is just a callable object.  */
 581   PyObject *event;
 582   /* The next event.  */
 583   struct gdbpy_event *next;
 584 };
 585
 586 /* All pending events.  */
 587 static struct gdbpy_event *gdbpy_event_list;
 588 /* The final link of the event list.  */
 589 static struct gdbpy_event **gdbpy_event_list_end;
 590
 591 /* We use a file handler, and not an async handler, so that we can
 592    wake up the main thread even when it is blocked in poll().  */
 593 static struct serial *gdbpy_event_fds[2];
 594
 595 /* The file handler callback.  This reads from the internal pipe, and
 596    then processes the Python event queue.  This will always be run in
 597    the main gdb thread.  */
 598
 599 static void
 600 gdbpy_run_events (struct serial *scb, void *context)
 601 {
 602   struct cleanup *cleanup;
 603   int r;
 604
 605   cleanup = ensure_python_env (get_current_arch (), current_language);
 606
 607   /* Flush the fd.  Do this before flushing the events list, so that
 608      any new event post afterwards is sure to re-awake the event
 609      loop.  */
 610   while (serial_readchar (gdbpy_event_fds[0], 0) >= 0)
 611     ;
 612
 613   while (gdbpy_event_list)
 614     {
 615       /* Dispatching the event might push a new element onto the event
 616          loop, so we update here "atomically enough".  */
 617       struct gdbpy_event *item = gdbpy_event_list;
 618       gdbpy_event_list = gdbpy_event_list->next;
 619       if (gdbpy_event_list == NULL)
 620         gdbpy_event_list_end = &gdbpy_event_list;
 621
 622       /* Ignore errors.  */
 623       if (PyObject_CallObject (item->event, NULL) == NULL)
 624         PyErr_Clear ();
 625
 626       Py_DECREF (item->event);
 627       xfree (item);
 628     }
 629
 630   do_cleanups (cleanup);
 631 }
 632
 633 /* Submit an event to the gdb thread.  */
 634 static PyObject *
 635 gdbpy_post_event (PyObject *self, PyObject *args)
 636 {
 637   struct gdbpy_event *event;
 638   PyObject *func;
 639   int wakeup;
 640
 641   if (!PyArg_ParseTuple (args, "O", &func))
 642     return NULL;
 643
 644   if (!PyCallable_Check (func))
 645     {
 646       PyErr_SetString (PyExc_RuntimeError,
 647                        _("Posted event is not callable"));
 648       return NULL;
 649     }
 650
 651   Py_INCREF (func);
 652
 653   /* From here until the end of the function, we have the GIL, so we
 654      can operate on our global data structures without worrying.  */
 655   wakeup = gdbpy_event_list == NULL;
 656
 657   event = XNEW (struct gdbpy_event);
 658   event->event = func;
 659   event->next = NULL;
 660   *gdbpy_event_list_end = event;
 661   gdbpy_event_list_end = &event->next;
 662
 663   /* Wake up gdb when needed.  */
 664   if (wakeup)
 665     {
 666       char c = 'q';             /* Anything. */
 667
 668       if (serial_write (gdbpy_event_fds[1], &c, 1))
 669         return PyErr_SetFromErrno (PyExc_IOError);
 670     }
 671
 672   Py_RETURN_NONE;
 673 }
 674
 675 /* Initialize the Python event handler.  */
 676 static void
 677 gdbpy_initialize_events (void)
 678 {
 679   if (serial_pipe (gdbpy_event_fds) == 0)
 680     {
 681       gdbpy_event_list_end = &gdbpy_event_list;
 682       serial_async (gdbpy_event_fds[0], gdbpy_run_events, NULL);
 683     }
 684 }
 685
 686 \f
 687
 688 static void
 689 before_prompt_hook (const char *current_gdb_prompt)
 690 {
 691   struct cleanup *cleanup;
 692   char *prompt = NULL;
 693
 694   cleanup = ensure_python_env (get_current_arch (), current_language);
 695
 696   if (PyObject_HasAttrString (gdb_module, "prompt_hook"))
 697     {
 698       PyObject *hook;
 699
 700       hook = PyObject_GetAttrString (gdb_module, "prompt_hook");
 701       if (hook == NULL)
 702         goto fail;
 703
 704       if (PyCallable_Check (hook))
 705         {
 706           PyObject *result;
 707           PyObject *current_prompt;
 708
 709           current_prompt = PyString_FromString (current_gdb_prompt);
 710           if (current_prompt == NULL)
 711             goto fail;
 712
 713           result = PyObject_CallFunctionObjArgs (hook, current_prompt, NULL);
 714
 715           Py_DECREF (current_prompt);
 716
 717           if (result == NULL)
 718             goto fail;
 719
 720           make_cleanup_py_decref (result);
 721
 722           /* Return type should be None, or a String.  If it is None,
 723              fall through, we will not set a prompt.  If it is a
 724              string, set  PROMPT.  Anything else, set an exception.  */
 725           if (result != Py_None && ! PyString_Check (result))
 726             {
 727               PyErr_Format (PyExc_RuntimeError,
 728                             _("Return from prompt_hook must " \
 729                               "be either a Python string, or None"));
 730               goto fail;
 731             }
 732
 733           if (result != Py_None)
 734             {
 735               prompt = python_string_to_host_string (result);
 736
 737               if (prompt == NULL)
 738                 goto fail;
 739               else
 740                 make_cleanup (xfree, prompt);
 741             }
 742         }
 743     }
 744
 745   /* If a prompt has been set, PROMPT will not be NULL.  If it is
 746      NULL, do not set the prompt.  */
 747   if (prompt != NULL)
 748     set_prompt (prompt, 0);
 749
 750   do_cleanups (cleanup);
 751   return;
 752
 753  fail:
 754   gdbpy_print_stack ();
 755   do_cleanups (cleanup);
 756   return;
 757 }
 758
 759 \f
 760
 761 /* Printing.  */
 762
 763 /* A python function to write a single string using gdb's filtered
 764    output stream .  The optional keyword STREAM can be used to write
 765    to a particular stream.  The default stream is to gdb_stdout.  */
 766
 767 static PyObject *
 768 gdbpy_write (PyObject *self, PyObject *args, PyObject *kw)
 769 {
 770   const char *arg;
 771   static char *keywords[] = {"text", "stream", NULL };
 772   int stream_type = 0;
 773
 774   if (! PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords, &arg,
 775                                      &stream_type))
 776     return NULL;
 777
 778   switch (stream_type)
 779     {
 780     case 1:
 781       {
 782         fprintf_filtered (gdb_stderr, "%s", arg);
 783         break;
 784       }
 785     case 2:
 786       {
 787         fprintf_filtered (gdb_stdlog, "%s", arg);
 788         break;
 789       }
 790     default:
 791       fprintf_filtered (gdb_stdout, "%s", arg);
 792     }
 793
 794   Py_RETURN_NONE;
 795 }
 796
 797 /* A python function to flush a gdb stream.  The optional keyword
 798    STREAM can be used to flush a particular stream.  The default stream
 799    is gdb_stdout.  */
 800
 801 static PyObject *
 802 gdbpy_flush (PyObject *self, PyObject *args, PyObject *kw)
 803 {
 804   static char *keywords[] = {"stream", NULL };
 805   int stream_type = 0;
 806
 807   if (! PyArg_ParseTupleAndKeywords (args, kw, "|i", keywords,
 808                                      &stream_type))
 809     return NULL;
 810
 811   switch (stream_type)
 812     {
 813     case 1:
 814       {
 815         gdb_flush (gdb_stderr);
 816         break;
 817       }
 818     case 2:
 819       {
 820         gdb_flush (gdb_stdlog);
 821         break;
 822       }
 823     default:
 824       gdb_flush (gdb_stdout);
 825     }
 826
 827   Py_RETURN_NONE;
 828 }
 829
 830 /* Print a python exception trace, or print nothing and clear the
 831    python exception, depending on gdbpy_should_print_stack.  Only call
 832    this if a python exception is set.  */
 833 void
 834 gdbpy_print_stack (void)
 835 {
 836   if (gdbpy_should_print_stack)
 837     {
 838       PyErr_Print ();
 839       /* PyErr_Print doesn't necessarily end output with a newline.
 840          This works because Python's stdout/stderr is fed through
 841          printf_filtered.  */
 842       begin_line ();
 843     }
 844   else
 845     PyErr_Clear ();
 846 }
 847
 848 \f
 849
 850 /* Return the current Progspace.
 851    There always is one.  */
 852
 853 static PyObject *
 854 gdbpy_get_current_progspace (PyObject *unused1, PyObject *unused2)
 855 {
 856   PyObject *result;
 857
 858   result = pspace_to_pspace_object (current_program_space);
 859   if (result)
 860     Py_INCREF (result);
 861   return result;
 862 }
 863
 864 /* Return a sequence holding all the Progspaces.  */
 865
 866 static PyObject *
 867 gdbpy_progspaces (PyObject *unused1, PyObject *unused2)
 868 {
 869   struct program_space *ps;
 870   PyObject *list;
 871
 872   list = PyList_New (0);
 873   if (!list)
 874     return NULL;
 875
 876   ALL_PSPACES (ps)
 877   {
 878     PyObject *item = pspace_to_pspace_object (ps);
 879
 880     if (!item || PyList_Append (list, item) == -1)
 881       {
 882         Py_DECREF (list);
 883         return NULL;
 884       }
 885   }
 886
 887   return list;
 888 }
 889
 890 \f
 891
 892 /* The "current" objfile.  This is set when gdb detects that a new
 893    objfile has been loaded.  It is only set for the duration of a call to
 894    source_python_script_for_objfile; it is NULL at other times.  */
 895 static struct objfile *gdbpy_current_objfile;
 896
 897 /* Set the current objfile to OBJFILE and then read STREAM,FILE as
 898    Python code.  */
 899
 900 void
 901 source_python_script_for_objfile (struct objfile *objfile,
 902                                   FILE *stream, const char *file)
 903 {
 904   struct cleanup *cleanups;
 905
 906   cleanups = ensure_python_env (get_objfile_arch (objfile), current_language);
 907   gdbpy_current_objfile = objfile;
 908
 909   /* Note: If an exception occurs python will print the traceback and
 910      clear the error indicator.  */
 911   PyRun_SimpleFile (stream, file);
 912
 913   do_cleanups (cleanups);
 914   gdbpy_current_objfile = NULL;
 915 }
 916
 917 /* Return the current Objfile, or None if there isn't one.  */
 918
 919 static PyObject *
 920 gdbpy_get_current_objfile (PyObject *unused1, PyObject *unused2)
 921 {
 922   PyObject *result;
 923
 924   if (! gdbpy_current_objfile)
 925     Py_RETURN_NONE;
 926
 927   result = objfile_to_objfile_object (gdbpy_current_objfile);
 928   if (result)
 929     Py_INCREF (result);
 930   return result;
 931 }
 932
 933 /* Return a sequence holding all the Objfiles.  */
 934
 935 static PyObject *
 936 gdbpy_objfiles (PyObject *unused1, PyObject *unused2)
 937 {
 938   struct objfile *objf;
 939   PyObject *list;
 940
 941   list = PyList_New (0);
 942   if (!list)
 943     return NULL;
 944
 945   ALL_OBJFILES (objf)
 946   {
 947     PyObject *item = objfile_to_objfile_object (objf);
 948
 949     if (!item || PyList_Append (list, item) == -1)
 950       {
 951         Py_DECREF (list);
 952         return NULL;
 953       }
 954   }
 955
 956   return list;
 957 }
 958
 959 #else /* HAVE_PYTHON */
 960
 961 /* Dummy implementation of the gdb "python" command.  */
 962
 963 static void
 964 python_command (char *arg, int from_tty)
 965 {
 966   while (arg && *arg && isspace (*arg))
 967     ++arg;
 968   if (arg && *arg)
 969     error (_("Python scripting is not supported in this copy of GDB."));
 970   else
 971     {
 972       struct command_line *l = get_command_line (python_control, "");
 973       struct cleanup *cleanups = make_cleanup_free_command_lines (&l);
 974
 975       execute_control_command_untraced (l);
 976       do_cleanups (cleanups);
 977     }
 978 }
 979
 980 void
 981 eval_python_from_control_command (struct command_line *cmd)
 982 {
 983   error (_("Python scripting is not supported in this copy of GDB."));
 984 }
 985
 986 void
 987 source_python_script (FILE *stream, const char *file)
 988 {
 989   throw_error (UNSUPPORTED_ERROR,
 990                _("Python scripting is not supported in this copy of GDB."));
 991 }
 992
 993 int
 994 gdbpy_should_stop (struct breakpoint_object *bp_obj)
 995 {
 996   internal_error (__FILE__, __LINE__,
 997                   _("gdbpy_should_stop called when Python scripting is  " \
 998                     "not supported."));
 999 }
1000
1001 int
1002 gdbpy_breakpoint_has_py_cond (struct breakpoint_object *bp_obj)
1003 {
1004   internal_error (__FILE__, __LINE__,
1005                   _("gdbpy_breakpoint_has_py_cond called when Python " \
1006                     "scripting is not supported."));
1007 }
1008
1009 #endif /* HAVE_PYTHON */
1010
1011 \f
1012
1013 /* Lists for 'maint set python' commands.  */
1014
1015 static struct cmd_list_element *maint_set_python_list;
1016 static struct cmd_list_element *maint_show_python_list;
1017
1018 /* Lists for 'set python' commands.  */
1019
1020 static struct cmd_list_element *user_set_python_list;
1021 static struct cmd_list_element *user_show_python_list;
1022
1023 /* Function for use by 'maint set python' prefix command.  */
1024
1025 static void
1026 maint_set_python (char *args, int from_tty)
1027 {
1028   help_list (maint_set_python_list, "maintenance set python ",
1029              class_deprecated, gdb_stdout);
1030 }
1031
1032 /* Function for use by 'maint show python' prefix command.  */
1033
1034 static void
1035 maint_show_python (char *args, int from_tty)
1036 {
1037   cmd_show_list (maint_show_python_list, from_tty, "");
1038 }
1039
1040 /* Function for use by 'set python' prefix command.  */
1041
1042 static void
1043 user_set_python (char *args, int from_tty)
1044 {
1045   help_list (user_set_python_list, "set python ", all_commands,
1046              gdb_stdout);
1047 }
1048
1049 /* Function for use by 'show python' prefix command.  */
1050
1051 static void
1052 user_show_python (char *args, int from_tty)
1053 {
1054   cmd_show_list (user_show_python_list, from_tty, "");
1055 }
1056
1057 /* Initialize the Python code.  */
1058
1059 /* Provide a prototype to silence -Wmissing-prototypes.  */
1060 extern initialize_file_ftype _initialize_python;
1061
1062 void
1063 _initialize_python (void)
1064 {
1065   char *cmd_name;
1066   struct cmd_list_element *cmd;
1067
1068   add_com ("python", class_obscure, python_command,
1069 #ifdef HAVE_PYTHON
1070            _("\
1071 Evaluate a Python command.\n\
1072 \n\
1073 The command can be given as an argument, for instance:\n\
1074 \n\
1075     python print 23\n\
1076 \n\
1077 If no argument is given, the following lines are read and used\n\
1078 as the Python commands.  Type a line containing \"end\" to indicate\n\
1079 the end of the command.")
1080 #else /* HAVE_PYTHON */
1081            _("\
1082 Evaluate a Python command.\n\
1083 \n\
1084 Python scripting is not supported in this copy of GDB.\n\
1085 This command is only a placeholder.")
1086 #endif /* HAVE_PYTHON */
1087            );
1088
1089   add_prefix_cmd ("python", no_class, maint_show_python,
1090                   _("Prefix command for python maintenance settings."),
1091                   &maint_show_python_list, "maintenance show python ", 0,
1092                   &maintenance_show_cmdlist);
1093   add_prefix_cmd ("python", no_class, maint_set_python,
1094                   _("Prefix command for python maintenance settings."),
1095                   &maint_set_python_list, "maintenance set python ", 0,
1096                   &maintenance_set_cmdlist);
1097
1098   add_setshow_boolean_cmd ("print-stack", class_maintenance,
1099                            &gdbpy_should_print_stack, _("\
1100 Enable or disable printing of Python stack dump on error."), _("\
1101 Show whether Python stack will be printed on error."), _("\
1102 Enables or disables printing of Python stack traces."),
1103                            NULL, NULL,
1104                            &maint_set_python_list,
1105                            &maint_show_python_list);
1106
1107   /* Deprecate maint set/show python print-stack in favour of
1108      non-maintenance alternatives.  */
1109   cmd_name = "print-stack";
1110   cmd = lookup_cmd (&cmd_name, maint_set_python_list, "", -1, 0);
1111   deprecate_cmd (cmd, "set python print-stack");
1112   cmd_name = "print-stack"; /* Reset name.  */
1113   cmd = lookup_cmd (&cmd_name, maint_show_python_list, "", -1, 0);
1114   deprecate_cmd (cmd, "show python print-stack");
1115
1116   /* Add set/show python print-stack.  */
1117   add_prefix_cmd ("python", no_class, user_show_python,
1118                   _("Prefix command for python preference settings."),
1119                   &user_show_python_list, "show python ", 0,
1120                   &showlist);
1121
1122   add_prefix_cmd ("python", no_class, user_set_python,
1123                   _("Prefix command for python preference settings."),
1124                   &user_set_python_list, "set python ", 0,
1125                   &setlist);
1126
1127   add_setshow_boolean_cmd ("print-stack", no_class,
1128                            &gdbpy_should_print_stack, _("\
1129 Enable or disable printing of Python stack dump on error."), _("\
1130 Show whether Python stack will be printed on error."), _("\
1131 Enables or disables printing of Python stack traces."),
1132                            NULL, NULL,
1133                            &user_set_python_list,
1134                            &user_show_python_list);
1135
1136 #ifdef HAVE_PYTHON
1137 #ifdef WITH_PYTHON_PATH
1138   /* Work around problem where python gets confused about where it is,
1139      and then can't find its libraries, etc.
1140      NOTE: Python assumes the following layout:
1141      /foo/bin/python
1142      /foo/lib/pythonX.Y/...
1143      This must be done before calling Py_Initialize.  */
1144   Py_SetProgramName (concat (ldirname (python_libdir), SLASH_STRING, "bin",
1145                              SLASH_STRING, "python", NULL));
1146 #endif
1147
1148   Py_Initialize ();
1149   PyEval_InitThreads ();
1150
1151   gdb_module = Py_InitModule ("gdb", GdbMethods);
1152
1153   /* The casts to (char*) are for python 2.4.  */
1154   PyModule_AddStringConstant (gdb_module, "VERSION", (char*) version);
1155   PyModule_AddStringConstant (gdb_module, "HOST_CONFIG", (char*) host_name);
1156   PyModule_AddStringConstant (gdb_module, "TARGET_CONFIG",
1157                               (char*) target_name);
1158
1159   /* Add stream constants.  */
1160   PyModule_AddIntConstant (gdb_module, "STDOUT", 0);
1161   PyModule_AddIntConstant (gdb_module, "STDERR", 1);
1162   PyModule_AddIntConstant (gdb_module, "STDLOG", 2);
1163
1164   /* gdb.parameter ("data-directory") doesn't necessarily exist when the python
1165      script below is run (depending on order of _initialize_* functions).
1166      Define the initial value of gdb.PYTHONDIR here.  */
1167   {
1168     char *gdb_pythondir;
1169
1170     gdb_pythondir = concat (gdb_datadir, SLASH_STRING, "python", NULL);
1171     PyModule_AddStringConstant (gdb_module, "PYTHONDIR", gdb_pythondir);
1172     xfree (gdb_pythondir);
1173   }
1174
1175   gdbpy_gdb_error = PyErr_NewException ("gdb.error", PyExc_RuntimeError, NULL);
1176   PyModule_AddObject (gdb_module, "error", gdbpy_gdb_error);
1177
1178   gdbpy_gdb_memory_error = PyErr_NewException ("gdb.MemoryError",
1179                                                gdbpy_gdb_error, NULL);
1180   PyModule_AddObject (gdb_module, "MemoryError", gdbpy_gdb_memory_error);
1181
1182   gdbpy_gdberror_exc = PyErr_NewException ("gdb.GdbError", NULL, NULL);
1183   PyModule_AddObject (gdb_module, "GdbError", gdbpy_gdberror_exc);
1184
1185   gdbpy_initialize_auto_load ();
1186   gdbpy_initialize_values ();
1187   gdbpy_initialize_frames ();
1188   gdbpy_initialize_commands ();
1189   gdbpy_initialize_symbols ();
1190   gdbpy_initialize_symtabs ();
1191   gdbpy_initialize_blocks ();
1192   gdbpy_initialize_functions ();
1193   gdbpy_initialize_parameters ();
1194   gdbpy_initialize_types ();
1195   gdbpy_initialize_pspace ();
1196   gdbpy_initialize_objfile ();
1197   gdbpy_initialize_breakpoints ();
1198   gdbpy_initialize_lazy_string ();
1199   gdbpy_initialize_thread ();
1200   gdbpy_initialize_inferior ();
1201   gdbpy_initialize_events ();
1202
1203   gdbpy_initialize_eventregistry ();
1204   gdbpy_initialize_py_events ();
1205   gdbpy_initialize_event ();
1206   gdbpy_initialize_stop_event ();
1207   gdbpy_initialize_signal_event ();
1208   gdbpy_initialize_breakpoint_event ();
1209   gdbpy_initialize_continue_event ();
1210   gdbpy_initialize_exited_event ();
1211   gdbpy_initialize_thread_event ();
1212
1213   observer_attach_before_prompt (before_prompt_hook);
1214
1215   PyRun_SimpleString ("import gdb");
1216   PyRun_SimpleString ("gdb.pretty_printers = []");
1217
1218   gdbpy_to_string_cst = PyString_FromString ("to_string");
1219   gdbpy_children_cst = PyString_FromString ("children");
1220   gdbpy_display_hint_cst = PyString_FromString ("display_hint");
1221   gdbpy_doc_cst = PyString_FromString ("__doc__");
1222   gdbpy_enabled_cst = PyString_FromString ("enabled");
1223   gdbpy_value_cst = PyString_FromString ("value");
1224
1225   /* Release the GIL while gdb runs.  */
1226   PyThreadState_Swap (NULL);
1227   PyEval_ReleaseLock ();
1228
1229 #endif /* HAVE_PYTHON */
1230 }
1231
1232 #ifdef HAVE_PYTHON
1233
1234 /* Perform the remaining python initializations.
1235    These must be done after GDB is at least mostly initialized.
1236    E.g., The "info pretty-printer" command needs the "info" prefix
1237    command installed.  */
1238
1239 void
1240 finish_python_initialization (void)
1241 {
1242   struct cleanup *cleanup;
1243
1244   cleanup = ensure_python_env (get_current_arch (), current_language);
1245
1246   PyRun_SimpleString ("\
1247 import os\n\
1248 import sys\n\
1249 \n\
1250 class GdbOutputFile:\n\
1251   def close(self):\n\
1252     # Do nothing.\n\
1253     return None\n\
1254 \n\
1255   def isatty(self):\n\
1256     return False\n\
1257 \n\
1258   def write(self, s):\n\
1259     gdb.write(s, stream=gdb.STDOUT)\n   \
1260 \n\
1261   def writelines(self, iterable):\n\
1262     for line in iterable:\n\
1263       self.write(line)\n\
1264 \n\
1265   def flush(self):\n\
1266     gdb.flush()\n\
1267 \n\
1268 sys.stdout = GdbOutputFile()\n\
1269 \n\
1270 class GdbOutputErrorFile:\n\
1271   def close(self):\n\
1272     # Do nothing.\n\
1273     return None\n\
1274 \n\
1275   def isatty(self):\n\
1276     return False\n\
1277 \n\
1278   def write(self, s):\n\
1279     gdb.write(s, stream=gdb.STDERR)\n           \
1280 \n\
1281   def writelines(self, iterable):\n\
1282     for line in iterable:\n\
1283       self.write(line)\n \
1284 \n\
1285   def flush(self):\n\
1286     gdb.flush()\n\
1287 \n\
1288 sys.stderr = GdbOutputErrorFile()\n\
1289 \n\
1290 # Ideally this would live in the gdb module, but it's intentionally written\n\
1291 # in python, and we need this to bootstrap the gdb module.\n\
1292 \n\
1293 def GdbSetPythonDirectory (dir):\n\
1294   \"Set gdb.PYTHONDIR and update sys.path,etc.\"\n\
1295   old_dir = gdb.PYTHONDIR\n\
1296   gdb.PYTHONDIR = dir\n\
1297   # GDB's python scripts are stored inside gdb.PYTHONDIR.  So insert\n\
1298   # that directory name at the start of sys.path to allow the Python\n\
1299   # interpreter to find them.\n\
1300   if old_dir in sys.path:\n\
1301     sys.path.remove (old_dir)\n\
1302   sys.path.insert (0, gdb.PYTHONDIR)\n\
1303 \n\
1304   # Tell python where to find submodules of gdb.\n\
1305   gdb.__path__ = [gdb.PYTHONDIR + '/gdb']\n\
1306 \n\
1307   # The gdb module is implemented in C rather than in Python.  As a result,\n\
1308   # the associated __init.py__ script is not not executed by default when\n\
1309   # the gdb module gets imported.  Execute that script manually if it\n\
1310   # exists.\n\
1311   ipy = gdb.PYTHONDIR + '/gdb/__init__.py'\n\
1312   if os.path.exists (ipy):\n\
1313     execfile (ipy)\n\
1314 \n\
1315 # Install the default gdb.PYTHONDIR.\n\
1316 GdbSetPythonDirectory (gdb.PYTHONDIR)\n\
1317 # Default prompt hook does nothing.\n\
1318 prompt_hook = None\n\
1319 ");
1320
1321   do_cleanups (cleanup);
1322 }
1323
1324 #endif /* HAVE_PYTHON */
1325
1326 \f
1327
1328 #ifdef HAVE_PYTHON
1329
1330 static PyMethodDef GdbMethods[] =
1331 {
1332   { "history", gdbpy_history, METH_VARARGS,
1333     "Get a value from history" },
1334   { "execute", (PyCFunction) execute_gdb_command, METH_VARARGS | METH_KEYWORDS,
1335     "Execute a gdb command" },
1336   { "parameter", gdbpy_parameter, METH_VARARGS,
1337     "Return a gdb parameter's value" },
1338
1339   { "breakpoints", gdbpy_breakpoints, METH_NOARGS,
1340     "Return a tuple of all breakpoint objects" },
1341
1342   { "default_visualizer", gdbpy_default_visualizer, METH_VARARGS,
1343     "Find the default visualizer for a Value." },
1344
1345   { "current_progspace", gdbpy_get_current_progspace, METH_NOARGS,
1346     "Return the current Progspace." },
1347   { "progspaces", gdbpy_progspaces, METH_NOARGS,
1348     "Return a sequence of all progspaces." },
1349
1350   { "current_objfile", gdbpy_get_current_objfile, METH_NOARGS,
1351     "Return the current Objfile being loaded, or None." },
1352   { "objfiles", gdbpy_objfiles, METH_NOARGS,
1353     "Return a sequence of all loaded objfiles." },
1354
1355   { "newest_frame", gdbpy_newest_frame, METH_NOARGS,
1356     "newest_frame () -> gdb.Frame.\n\
1357 Return the newest frame object." },
1358   { "selected_frame", gdbpy_selected_frame, METH_NOARGS,
1359     "selected_frame () -> gdb.Frame.\n\
1360 Return the selected frame object." },
1361   { "frame_stop_reason_string", gdbpy_frame_stop_reason_string, METH_VARARGS,
1362     "stop_reason_string (Integer) -> String.\n\
1363 Return a string explaining unwind stop reason." },
1364
1365   { "lookup_type", (PyCFunction) gdbpy_lookup_type,
1366     METH_VARARGS | METH_KEYWORDS,
1367     "lookup_type (name [, block]) -> type\n\
1368 Return a Type corresponding to the given name." },
1369   { "lookup_symbol", (PyCFunction) gdbpy_lookup_symbol,
1370     METH_VARARGS | METH_KEYWORDS,
1371     "lookup_symbol (name [, block] [, domain]) -> (symbol, is_field_of_this)\n\
1372 Return a tuple with the symbol corresponding to the given name (or None) and\n\
1373 a boolean indicating if name is a field of the current implied argument\n\
1374 `this' (when the current language is object-oriented)." },
1375   { "lookup_global_symbol", (PyCFunction) gdbpy_lookup_global_symbol,
1376     METH_VARARGS | METH_KEYWORDS,
1377     "lookup_global_symbol (name [, domain]) -> symbol\n\
1378 Return the symbol corresponding to the given name (or None)." },
1379   { "block_for_pc", gdbpy_block_for_pc, METH_VARARGS,
1380     "Return the block containing the given pc value, or None." },
1381   { "solib_name", gdbpy_solib_name, METH_VARARGS,
1382     "solib_name (Long) -> String.\n\
1383 Return the name of the shared library holding a given address, or None." },
1384   { "decode_line", gdbpy_decode_line, METH_VARARGS,
1385     "decode_line (String) -> Tuple.  Decode a string argument the way\n\
1386 that 'break' or 'edit' does.  Return a tuple containing two elements.\n\
1387 The first element contains any unparsed portion of the String parameter\n\
1388 (or None if the string was fully parsed).  The second element contains\n\
1389 a tuple that contains all the locations that match, represented as\n\
1390 gdb.Symtab_and_line objects (or None)."},
1391   { "parse_and_eval", gdbpy_parse_and_eval, METH_VARARGS,
1392     "parse_and_eval (String) -> Value.\n\
1393 Parse String as an expression, evaluate it, and return the result as a Value."
1394   },
1395
1396   { "post_event", gdbpy_post_event, METH_VARARGS,
1397     "Post an event into gdb's event loop." },
1398
1399   { "target_charset", gdbpy_target_charset, METH_NOARGS,
1400     "target_charset () -> string.\n\
1401 Return the name of the current target charset." },
1402   { "target_wide_charset", gdbpy_target_wide_charset, METH_NOARGS,
1403     "target_wide_charset () -> string.\n\
1404 Return the name of the current target wide charset." },
1405
1406   { "string_to_argv", gdbpy_string_to_argv, METH_VARARGS,
1407     "string_to_argv (String) -> Array.\n\
1408 Parse String and return an argv-like array.\n\
1409 Arguments are separate by spaces and may be quoted."
1410   },
1411   { "write", (PyCFunction)gdbpy_write, METH_VARARGS | METH_KEYWORDS,
1412     "Write a string using gdb's filtered stream." },
1413   { "flush", (PyCFunction)gdbpy_flush, METH_VARARGS | METH_KEYWORDS,
1414     "Flush gdb's filtered stdout stream." },
1415   { "selected_thread", gdbpy_selected_thread, METH_NOARGS,
1416     "selected_thread () -> gdb.InferiorThread.\n\
1417 Return the selected thread object." },
1418   { "inferiors", gdbpy_inferiors, METH_NOARGS,
1419     "inferiors () -> (gdb.Inferior, ...).\n\
1420 Return a tuple containing all inferiors." },
1421   {NULL, NULL, 0, NULL}
1422 };
1423
1424 #endif /* HAVE_PYTHON */