Python/sysmodule.c

   1
   2 /* System module */
   3
   4 /*
   5 Various bits of information used by the interpreter are collected in
   6 module 'sys'.
   7 Function member:
   8 - exit(sts): raise SystemExit
   9 Data members:
  10 - stdin, stdout, stderr: standard file objects
  11 - modules: the table of modules (dictionary)
  12 - path: module search path (list of strings)
  13 - argv: script arguments (list of strings)
  14 - ps1, ps2: optional primary and secondary prompts (strings)
  15 */
  16
  17 #include "Python.h"
  18 #include "structseq.h"
  19 #include "code.h"
  20 #include "frameobject.h"
  21 #include "eval.h"
  22
  23 #include "osdefs.h"
  24
  25 #ifdef MS_WINDOWS
  26 #define WIN32_LEAN_AND_MEAN
  27 #include "windows.h"
  28 #endif /* MS_WINDOWS */
  29
  30 #ifdef MS_COREDLL
  31 extern void *PyWin_DLLhModule;
  32 /* A string loaded from the DLL at startup: */
  33 extern const char *PyWin_DLLVersionString;
  34 #endif
  35
  36 #ifdef __VMS
  37 #include <unixlib.h>
  38 #endif
  39
  40 #ifdef MS_WINDOWS
  41 #include <windows.h>
  42 #endif
  43
  44 #ifdef HAVE_LANGINFO_H
  45 #include <locale.h>
  46 #include <langinfo.h>
  47 #endif
  48
  49 PyObject *
  50 PySys_GetObject(char *name)
  51 {
  52         PyThreadState *tstate = PyThreadState_GET();
  53         PyObject *sd = tstate->interp->sysdict;
  54         if (sd == NULL)
  55                 return NULL;
  56         return PyDict_GetItemString(sd, name);
  57 }
  58
  59 FILE *
  60 PySys_GetFile(char *name, FILE *def)
  61 {
  62         FILE *fp = NULL;
  63         PyObject *v = PySys_GetObject(name);
  64         if (v != NULL && PyFile_Check(v))
  65                 fp = PyFile_AsFile(v);
  66         if (fp == NULL)
  67                 fp = def;
  68         return fp;
  69 }
  70
  71 int
  72 PySys_SetObject(char *name, PyObject *v)
  73 {
  74         PyThreadState *tstate = PyThreadState_GET();
  75         PyObject *sd = tstate->interp->sysdict;
  76         if (v == NULL) {
  77                 if (PyDict_GetItemString(sd, name) == NULL)
  78                         return 0;
  79                 else
  80                         return PyDict_DelItemString(sd, name);
  81         }
  82         else
  83                 return PyDict_SetItemString(sd, name, v);
  84 }
  85
  86 static PyObject *
  87 sys_displayhook(PyObject *self, PyObject *o)
  88 {
  89         PyObject *outf;
  90         PyInterpreterState *interp = PyThreadState_GET()->interp;
  91         PyObject *modules = interp->modules;
  92         PyObject *builtins = PyDict_GetItemString(modules, "__builtin__");
  93
  94         if (builtins == NULL) {
  95                 PyErr_SetString(PyExc_RuntimeError, "lost __builtin__");
  96                 return NULL;
  97         }
  98
  99         /* Print value except if None */
 100         /* After printing, also assign to '_' */
 101         /* Before, set '_' to None to avoid recursion */
 102         if (o == Py_None) {
 103                 Py_INCREF(Py_None);
 104                 return Py_None;
 105         }
 106         if (PyObject_SetAttrString(builtins, "_", Py_None) != 0)
 107                 return NULL;
 108         if (Py_FlushLine() != 0)
 109                 return NULL;
 110         outf = PySys_GetObject("stdout");
 111         if (outf == NULL) {
 112                 PyErr_SetString(PyExc_RuntimeError, "lost sys.stdout");
 113                 return NULL;
 114         }
 115         if (PyFile_WriteObject(o, outf, 0) != 0)
 116                 return NULL;
 117         PyFile_SoftSpace(outf, 1);
 118         if (Py_FlushLine() != 0)
 119                 return NULL;
 120         if (PyObject_SetAttrString(builtins, "_", o) != 0)
 121                 return NULL;
 122         Py_INCREF(Py_None);
 123         return Py_None;
 124 }
 125
 126 PyDoc_STRVAR(displayhook_doc,
 127 "displayhook(object) -> None\n"
 128 "\n"
 129 "Print an object to sys.stdout and also save it in __builtin__.\n"
 130 );
 131
 132 static PyObject *
 133 sys_excepthook(PyObject* self, PyObject* args)
 134 {
 135         PyObject *exc, *value, *tb;
 136         if (!PyArg_UnpackTuple(args, "excepthook", 3, 3, &exc, &value, &tb))
 137                 return NULL;
 138         PyErr_Display(exc, value, tb);
 139         Py_INCREF(Py_None);
 140         return Py_None;
 141 }
 142
 143 PyDoc_STRVAR(excepthook_doc,
 144 "excepthook(exctype, value, traceback) -> None\n"
 145 "\n"
 146 "Handle an exception by displaying it with a traceback on sys.stderr.\n"
 147 );
 148
 149 static PyObject *
 150 sys_exc_info(PyObject *self, PyObject *noargs)
 151 {
 152         PyThreadState *tstate;
 153         tstate = PyThreadState_GET();
 154         return Py_BuildValue(
 155                 "(OOO)",
 156                 tstate->exc_type != NULL ? tstate->exc_type : Py_None,
 157                 tstate->exc_value != NULL ? tstate->exc_value : Py_None,
 158                 tstate->exc_traceback != NULL ?
 159                         tstate->exc_traceback : Py_None);
 160 }
 161
 162 PyDoc_STRVAR(exc_info_doc,
 163 "exc_info() -> (type, value, traceback)\n\
 164 \n\
 165 Return information about the most recent exception caught by an except\n\
 166 clause in the current stack frame or in an older stack frame."
 167 );
 168
 169 static PyObject *
 170 sys_exc_clear(PyObject *self, PyObject *noargs)
 171 {
 172         PyThreadState *tstate;
 173         PyObject *tmp_type, *tmp_value, *tmp_tb;
 174
 175         if (PyErr_WarnPy3k("sys.exc_clear() not supported in 3.x; "
 176                            "use except clauses", 1) < 0)
 177                 return NULL;
 178
 179         tstate = PyThreadState_GET();
 180         tmp_type = tstate->exc_type;
 181         tmp_value = tstate->exc_value;
 182         tmp_tb = tstate->exc_traceback;
 183         tstate->exc_type = NULL;
 184         tstate->exc_value = NULL;
 185         tstate->exc_traceback = NULL;
 186         Py_XDECREF(tmp_type);
 187         Py_XDECREF(tmp_value);
 188         Py_XDECREF(tmp_tb);
 189         /* For b/w compatibility */
 190         PySys_SetObject("exc_type", Py_None);
 191         PySys_SetObject("exc_value", Py_None);
 192         PySys_SetObject("exc_traceback", Py_None);
 193         Py_INCREF(Py_None);
 194         return Py_None;
 195 }
 196
 197 PyDoc_STRVAR(exc_clear_doc,
 198 "exc_clear() -> None\n\
 199 \n\
 200 Clear global information on the current exception.  Subsequent calls to\n\
 201 exc_info() will return (None,None,None) until another exception is raised\n\
 202 in the current thread or the execution stack returns to a frame where\n\
 203 another exception is being handled."
 204 );
 205
 206 static PyObject *
 207 sys_exit(PyObject *self, PyObject *args)
 208 {
 209         PyObject *exit_code = 0;
 210         if (!PyArg_UnpackTuple(args, "exit", 0, 1, &exit_code))
 211                 return NULL;
 212         /* Raise SystemExit so callers may catch it or clean up. */
 213         PyErr_SetObject(PyExc_SystemExit, exit_code);
 214         return NULL;
 215 }
 216
 217 PyDoc_STRVAR(exit_doc,
 218 "exit([status])\n\
 219 \n\
 220 Exit the interpreter by raising SystemExit(status).\n\
 221 If the status is omitted or None, it defaults to zero (i.e., success).\n\
 222 If the status is numeric, it will be used as the system exit status.\n\
 223 If it is another kind of object, it will be printed and the system\n\
 224 exit status will be one (i.e., failure)."
 225 );
 226
 227 #ifdef Py_USING_UNICODE
 228
 229 static PyObject *
 230 sys_getdefaultencoding(PyObject *self)
 231 {
 232         return PyString_FromString(PyUnicode_GetDefaultEncoding());
 233 }
 234
 235 PyDoc_STRVAR(getdefaultencoding_doc,
 236 "getdefaultencoding() -> string\n\
 237 \n\
 238 Return the current default string encoding used by the Unicode \n\
 239 implementation."
 240 );
 241
 242 static PyObject *
 243 sys_setdefaultencoding(PyObject *self, PyObject *args)
 244 {
 245         char *encoding;
 246         if (!PyArg_ParseTuple(args, "s:setdefaultencoding", &encoding))
 247                 return NULL;
 248         if (PyUnicode_SetDefaultEncoding(encoding))
 249                 return NULL;
 250         Py_INCREF(Py_None);
 251         return Py_None;
 252 }
 253
 254 PyDoc_STRVAR(setdefaultencoding_doc,
 255 "setdefaultencoding(encoding)\n\
 256 \n\
 257 Set the current default string encoding used by the Unicode implementation."
 258 );
 259
 260 static PyObject *
 261 sys_getfilesystemencoding(PyObject *self)
 262 {
 263         if (Py_FileSystemDefaultEncoding)
 264                 return PyString_FromString(Py_FileSystemDefaultEncoding);
 265         Py_INCREF(Py_None);
 266         return Py_None;
 267 }
 268
 269 PyDoc_STRVAR(getfilesystemencoding_doc,
 270 "getfilesystemencoding() -> string\n\
 271 \n\
 272 Return the encoding used to convert Unicode filenames in\n\
 273 operating system filenames."
 274 );
 275
 276 #endif
 277
 278 /*
 279  * Cached interned string objects used for calling the profile and
 280  * trace functions.  Initialized by trace_init().
 281  */
 282 static PyObject *whatstrings[7] = {NULL, NULL, NULL, NULL, NULL, NULL, NULL};
 283
 284 static int
 285 trace_init(void)
 286 {
 287         static char *whatnames[7] = {"call", "exception", "line", "return",
 288                                         "c_call", "c_exception", "c_return"};
 289         PyObject *name;
 290         int i;
 291         for (i = 0; i < 7; ++i) {
 292                 if (whatstrings[i] == NULL) {
 293                         name = PyString_InternFromString(whatnames[i]);
 294                         if (name == NULL)
 295                                 return -1;
 296                         whatstrings[i] = name;
 297                 }
 298         }
 299         return 0;
 300 }
 301
 302
 303 static PyObject *
 304 call_trampoline(PyThreadState *tstate, PyObject* callback,
 305                 PyFrameObject *frame, int what, PyObject *arg)
 306 {
 307         PyObject *args = PyTuple_New(3);
 308         PyObject *whatstr;
 309         PyObject *result;
 310
 311         if (args == NULL)
 312                 return NULL;
 313         Py_INCREF(frame);
 314         whatstr = whatstrings[what];
 315         Py_INCREF(whatstr);
 316         if (arg == NULL)
 317                 arg = Py_None;
 318         Py_INCREF(arg);
 319         PyTuple_SET_ITEM(args, 0, (PyObject *)frame);
 320         PyTuple_SET_ITEM(args, 1, whatstr);
 321         PyTuple_SET_ITEM(args, 2, arg);
 322
 323         /* call the Python-level function */
 324         PyFrame_FastToLocals(frame);
 325         result = PyEval_CallObject(callback, args);
 326         PyFrame_LocalsToFast(frame, 1);
 327         if (result == NULL)
 328                 PyTraceBack_Here(frame);
 329
 330         /* cleanup */
 331         Py_DECREF(args);
 332         return result;
 333 }
 334
 335 static int
 336 profile_trampoline(PyObject *self, PyFrameObject *frame,
 337                    int what, PyObject *arg)
 338 {
 339         PyThreadState *tstate = frame->f_tstate;
 340         PyObject *result;
 341
 342         if (arg == NULL)
 343                 arg = Py_None;
 344         result = call_trampoline(tstate, self, frame, what, arg);
 345         if (result == NULL) {
 346                 PyEval_SetProfile(NULL, NULL);
 347                 return -1;
 348         }
 349         Py_DECREF(result);
 350         return 0;
 351 }
 352
 353 static int
 354 trace_trampoline(PyObject *self, PyFrameObject *frame,
 355                  int what, PyObject *arg)
 356 {
 357         PyThreadState *tstate = frame->f_tstate;
 358         PyObject *callback;
 359         PyObject *result;
 360
 361         if (what == PyTrace_CALL)
 362                 callback = self;
 363         else
 364                 callback = frame->f_trace;
 365         if (callback == NULL)
 366                 return 0;
 367         result = call_trampoline(tstate, callback, frame, what, arg);
 368         if (result == NULL) {
 369                 PyEval_SetTrace(NULL, NULL);
 370                 Py_XDECREF(frame->f_trace);
 371                 frame->f_trace = NULL;
 372                 return -1;
 373         }
 374         if (result != Py_None) {
 375                 PyObject *temp = frame->f_trace;
 376                 frame->f_trace = NULL;
 377                 Py_XDECREF(temp);
 378                 frame->f_trace = result;
 379         }
 380         else {
 381                 Py_DECREF(result);
 382         }
 383         return 0;
 384 }
 385
 386 static PyObject *
 387 sys_settrace(PyObject *self, PyObject *args)
 388 {
 389         if (trace_init() == -1)
 390                 return NULL;
 391         if (args == Py_None)
 392                 PyEval_SetTrace(NULL, NULL);
 393         else
 394                 PyEval_SetTrace(trace_trampoline, args);
 395         Py_INCREF(Py_None);
 396         return Py_None;
 397 }
 398
 399 PyDoc_STRVAR(settrace_doc,
 400 "settrace(function)\n\
 401 \n\
 402 Set the global debug tracing function.  It will be called on each\n\
 403 function call.  See the debugger chapter in the library manual."
 404 );
 405
 406 static PyObject *
 407 sys_gettrace(PyObject *self, PyObject *args)
 408 {
 409         PyThreadState *tstate = PyThreadState_GET();
 410         PyObject *temp = tstate->c_traceobj;
 411
 412         if (temp == NULL)
 413                 temp = Py_None;
 414         Py_INCREF(temp);
 415         return temp;
 416 }
 417
 418 PyDoc_STRVAR(gettrace_doc,
 419 "gettrace()\n\
 420 \n\
 421 Return the global debug tracing function set with sys.settrace.\n\
 422 See the debugger chapter in the library manual."
 423 );
 424
 425 static PyObject *
 426 sys_setprofile(PyObject *self, PyObject *args)
 427 {
 428         if (trace_init() == -1)
 429                 return NULL;
 430         if (args == Py_None)
 431                 PyEval_SetProfile(NULL, NULL);
 432         else
 433                 PyEval_SetProfile(profile_trampoline, args);
 434         Py_INCREF(Py_None);
 435         return Py_None;
 436 }
 437
 438 PyDoc_STRVAR(setprofile_doc,
 439 "setprofile(function)\n\
 440 \n\
 441 Set the profiling function.  It will be called on each function call\n\
 442 and return.  See the profiler chapter in the library manual."
 443 );
 444
 445 static PyObject *
 446 sys_getprofile(PyObject *self, PyObject *args)
 447 {
 448         PyThreadState *tstate = PyThreadState_GET();
 449         PyObject *temp = tstate->c_profileobj;
 450
 451         if (temp == NULL)
 452                 temp = Py_None;
 453         Py_INCREF(temp);
 454         return temp;
 455 }
 456
 457 PyDoc_STRVAR(getprofile_doc,
 458 "getprofile()\n\
 459 \n\
 460 Return the profiling function set with sys.setprofile.\n\
 461 See the profiler chapter in the library manual."
 462 );
 463
 464 static PyObject *
 465 sys_setcheckinterval(PyObject *self, PyObject *args)
 466 {
 467         if (!PyArg_ParseTuple(args, "i:setcheckinterval", &_Py_CheckInterval))
 468                 return NULL;
 469         Py_INCREF(Py_None);
 470         return Py_None;
 471 }
 472
 473 PyDoc_STRVAR(setcheckinterval_doc,
 474 "setcheckinterval(n)\n\
 475 \n\
 476 Tell the Python interpreter to check for asynchronous events every\n\
 477 n instructions.  This also affects how often thread switches occur."
 478 );
 479
 480 static PyObject *
 481 sys_getcheckinterval(PyObject *self, PyObject *args)
 482 {
 483         return PyInt_FromLong(_Py_CheckInterval);
 484 }
 485
 486 PyDoc_STRVAR(getcheckinterval_doc,
 487 "getcheckinterval() -> current check interval; see setcheckinterval()."
 488 );
 489
 490 #ifdef WITH_TSC
 491 static PyObject *
 492 sys_settscdump(PyObject *self, PyObject *args)
 493 {
 494         int bool;
 495         PyThreadState *tstate = PyThreadState_Get();
 496
 497         if (!PyArg_ParseTuple(args, "i:settscdump", &bool))
 498                 return NULL;
 499         if (bool)
 500                 tstate->interp->tscdump = 1;
 501         else
 502                 tstate->interp->tscdump = 0;
 503         Py_INCREF(Py_None);
 504         return Py_None;
 505
 506 }
 507
 508 PyDoc_STRVAR(settscdump_doc,
 509 "settscdump(bool)\n\
 510 \n\
 511 If true, tell the Python interpreter to dump VM measurements to\n\
 512 stderr.  If false, turn off dump.  The measurements are based on the\n\
 513 processor's time-stamp counter."
 514 );
 515 #endif /* TSC */
 516
 517 static PyObject *
 518 sys_setrecursionlimit(PyObject *self, PyObject *args)
 519 {
 520         int new_limit;
 521         if (!PyArg_ParseTuple(args, "i:setrecursionlimit", &new_limit))
 522                 return NULL;
 523         if (new_limit <= 0) {
 524                 PyErr_SetString(PyExc_ValueError,
 525                                 "recursion limit must be positive");
 526                 return NULL;
 527         }
 528         Py_SetRecursionLimit(new_limit);
 529         Py_INCREF(Py_None);
 530         return Py_None;
 531 }
 532
 533 PyDoc_STRVAR(setrecursionlimit_doc,
 534 "setrecursionlimit(n)\n\
 535 \n\
 536 Set the maximum depth of the Python interpreter stack to n.  This\n\
 537 limit prevents infinite recursion from causing an overflow of the C\n\
 538 stack and crashing Python.  The highest possible limit is platform-\n\
 539 dependent."
 540 );
 541
 542 static PyObject *
 543 sys_getrecursionlimit(PyObject *self)
 544 {
 545         return PyInt_FromLong(Py_GetRecursionLimit());
 546 }
 547
 548 PyDoc_STRVAR(getrecursionlimit_doc,
 549 "getrecursionlimit()\n\
 550 \n\
 551 Return the current value of the recursion limit, the maximum depth\n\
 552 of the Python interpreter stack.  This limit prevents infinite\n\
 553 recursion from causing an overflow of the C stack and crashing Python."
 554 );
 555
 556 #ifdef MS_WINDOWS
 557 PyDoc_STRVAR(getwindowsversion_doc,
 558 "getwindowsversion()\n\
 559 \n\
 560 Return information about the running version of Windows.\n\
 561 The result is a tuple of (major, minor, build, platform, text)\n\
 562 All elements are numbers, except text which is a string.\n\
 563 Platform may be 0 for win32s, 1 for Windows 9x/ME, 2 for Windows NT/2000/XP\n\
 564 "
 565 );
 566
 567 static PyObject *
 568 sys_getwindowsversion(PyObject *self)
 569 {
 570         OSVERSIONINFO ver;
 571         ver.dwOSVersionInfoSize = sizeof(ver);
 572         if (!GetVersionEx(&ver))
 573                 return PyErr_SetFromWindowsErr(0);
 574         return Py_BuildValue("HHHHs",
 575                              ver.dwMajorVersion,
 576                              ver.dwMinorVersion,
 577                              ver.dwBuildNumber,
 578                              ver.dwPlatformId,
 579                              ver.szCSDVersion);
 580 }
 581
 582 #endif /* MS_WINDOWS */
 583
 584 #ifdef HAVE_DLOPEN
 585 static PyObject *
 586 sys_setdlopenflags(PyObject *self, PyObject *args)
 587 {
 588         int new_val;
 589         PyThreadState *tstate = PyThreadState_GET();
 590         if (!PyArg_ParseTuple(args, "i:setdlopenflags", &new_val))
 591                 return NULL;
 592         if (!tstate)
 593                 return NULL;
 594         tstate->interp->dlopenflags = new_val;
 595         Py_INCREF(Py_None);
 596         return Py_None;
 597 }
 598
 599 PyDoc_STRVAR(setdlopenflags_doc,
 600 "setdlopenflags(n) -> None\n\
 601 \n\
 602 Set the flags that will be used for dlopen() calls. Among other\n\
 603 things, this will enable a lazy resolving of symbols when importing\n\
 604 a module, if called as sys.setdlopenflags(0)\n\
 605 To share symbols across extension modules, call as\n\
 606 sys.setdlopenflags(dl.RTLD_NOW|dl.RTLD_GLOBAL)"
 607 );
 608
 609 static PyObject *
 610 sys_getdlopenflags(PyObject *self, PyObject *args)
 611 {
 612         PyThreadState *tstate = PyThreadState_GET();
 613         if (!tstate)
 614                 return NULL;
 615         return PyInt_FromLong(tstate->interp->dlopenflags);
 616 }
 617
 618 PyDoc_STRVAR(getdlopenflags_doc,
 619 "getdlopenflags() -> int\n\
 620 \n\
 621 Return the current value of the flags that are used for dlopen()\n\
 622 calls. The flag constants are defined in the dl module."
 623 );
 624 #endif
 625
 626 #ifdef USE_MALLOPT
 627 /* Link with -lmalloc (or -lmpc) on an SGI */
 628 #include <malloc.h>
 629
 630 static PyObject *
 631 sys_mdebug(PyObject *self, PyObject *args)
 632 {
 633         int flag;
 634         if (!PyArg_ParseTuple(args, "i:mdebug", &flag))
 635                 return NULL;
 636         mallopt(M_DEBUG, flag);
 637         Py_INCREF(Py_None);
 638         return Py_None;
 639 }
 640 #endif /* USE_MALLOPT */
 641
 642 static PyObject *
 643 sys_getsizeof(PyObject *self, PyObject *args, PyObject *kwds)
 644 {
 645         PyObject *res = NULL;
 646         static PyObject *str__sizeof__, *gc_head_size = NULL;
 647         static char *kwlist[] = {"object", "default", 0};
 648         PyObject *o, *dflt = NULL;
 649
 650         if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|O:getsizeof",
 651                                          kwlist, &o, &dflt))
 652                 return NULL;
 653
 654         /* Initialize static variable needed by _PyType_Lookup */
 655         if (str__sizeof__ == NULL) {
 656                 str__sizeof__ = PyString_InternFromString("__sizeof__");
 657                 if (str__sizeof__ == NULL)
 658                         return NULL;
 659         }
 660
 661         /* Initialize static variable for GC head size */
 662         if (gc_head_size == NULL) {
 663                 gc_head_size = PyInt_FromSsize_t(sizeof(PyGC_Head));
 664                 if (gc_head_size == NULL)
 665                         return NULL;
 666         }
 667
 668         /* Make sure the type is initialized. float gets initialized late */
 669         if (PyType_Ready(Py_TYPE(o)) < 0)
 670                 return NULL;
 671
 672         /* Instance of old-style class */
 673         if (PyInstance_Check(o))
 674                 res = PyInt_FromSsize_t(PyInstance_Type.tp_basicsize);
 675         /* all other objects */
 676         else {
 677                 PyObject *method = _PyType_Lookup(Py_TYPE(o),
 678                                                   str__sizeof__);
 679                 if (method == NULL)
 680                         PyErr_Format(PyExc_TypeError,
 681                                      "Type %.100s doesn't define __sizeof__",
 682                                      Py_TYPE(o)->tp_name);
 683                 else
 684                         res = PyObject_CallFunctionObjArgs(method, o, NULL);
 685         }
 686
 687         /* Has a default value been given? */
 688         if ((res == NULL) && (dflt != NULL) &&
 689             PyErr_ExceptionMatches(PyExc_TypeError))
 690         {
 691                 PyErr_Clear();
 692                 Py_INCREF(dflt);
 693                 return dflt;
 694         }
 695         else if (res == NULL)
 696                 return res;
 697
 698         /* add gc_head size */
 699         if (PyObject_IS_GC(o)) {
 700                 PyObject *tmp = res;
 701                 res = PyNumber_Add(tmp, gc_head_size);
 702                 Py_DECREF(tmp);
 703         }
 704         return res;
 705 }
 706
 707 PyDoc_STRVAR(getsizeof_doc,
 708 "getsizeof(object, default) -> int\n\
 709 \n\
 710 Return the size of object in bytes.");
 711
 712 static PyObject *
 713 sys_getrefcount(PyObject *self, PyObject *arg)
 714 {
 715         return PyInt_FromSsize_t(arg->ob_refcnt);
 716 }
 717
 718 #ifdef Py_REF_DEBUG
 719 static PyObject *
 720 sys_gettotalrefcount(PyObject *self)
 721 {
 722         return PyInt_FromSsize_t(_Py_GetRefTotal());
 723 }
 724 #endif /* Py_REF_DEBUG */
 725
 726 PyDoc_STRVAR(getrefcount_doc,
 727 "getrefcount(object) -> integer\n\
 728 \n\
 729 Return the reference count of object.  The count returned is generally\n\
 730 one higher than you might expect, because it includes the (temporary)\n\
 731 reference as an argument to getrefcount()."
 732 );
 733
 734 #ifdef COUNT_ALLOCS
 735 static PyObject *
 736 sys_getcounts(PyObject *self)
 737 {
 738         extern PyObject *get_counts(void);
 739
 740         return get_counts();
 741 }
 742 #endif
 743
 744 PyDoc_STRVAR(getframe_doc,
 745 "_getframe([depth]) -> frameobject\n\
 746 \n\
 747 Return a frame object from the call stack.  If optional integer depth is\n\
 748 given, return the frame object that many calls below the top of the stack.\n\
 749 If that is deeper than the call stack, ValueError is raised.  The default\n\
 750 for depth is zero, returning the frame at the top of the call stack.\n\
 751 \n\
 752 This function should be used for internal and specialized\n\
 753 purposes only."
 754 );
 755
 756 static PyObject *
 757 sys_getframe(PyObject *self, PyObject *args)
 758 {
 759         PyFrameObject *f = PyThreadState_GET()->frame;
 760         int depth = -1;
 761
 762         if (!PyArg_ParseTuple(args, "|i:_getframe", &depth))
 763                 return NULL;
 764
 765         while (depth > 0 && f != NULL) {
 766                 f = f->f_back;
 767                 --depth;
 768         }
 769         if (f == NULL) {
 770                 PyErr_SetString(PyExc_ValueError,
 771                                 "call stack is not deep enough");
 772                 return NULL;
 773         }
 774         Py_INCREF(f);
 775         return (PyObject*)f;
 776 }
 777
 778 PyDoc_STRVAR(current_frames_doc,
 779 "_current_frames() -> dictionary\n\
 780 \n\
 781 Return a dictionary mapping each current thread T's thread id to T's\n\
 782 current stack frame.\n\
 783 \n\
 784 This function should be used for specialized purposes only."
 785 );
 786
 787 static PyObject *
 788 sys_current_frames(PyObject *self, PyObject *noargs)
 789 {
 790         return _PyThread_CurrentFrames();
 791 }
 792
 793 PyDoc_STRVAR(call_tracing_doc,
 794 "call_tracing(func, args) -> object\n\
 795 \n\
 796 Call func(*args), while tracing is enabled.  The tracing state is\n\
 797 saved, and restored afterwards.  This is intended to be called from\n\
 798 a debugger from a checkpoint, to recursively debug some other code."
 799 );
 800
 801 static PyObject *
 802 sys_call_tracing(PyObject *self, PyObject *args)
 803 {
 804         PyObject *func, *funcargs;
 805         if (!PyArg_UnpackTuple(args, "call_tracing", 2, 2, &func, &funcargs))
 806                 return NULL;
 807         return _PyEval_CallTracing(func, funcargs);
 808 }
 809
 810 PyDoc_STRVAR(callstats_doc,
 811 "callstats() -> tuple of integers\n\
 812 \n\
 813 Return a tuple of function call statistics, if CALL_PROFILE was defined\n\
 814 when Python was built.  Otherwise, return None.\n\
 815 \n\
 816 When enabled, this function returns detailed, implementation-specific\n\
 817 details about the number of function calls executed. The return value is\n\
 818 a 11-tuple where the entries in the tuple are counts of:\n\
 819 0. all function calls\n\
 820 1. calls to PyFunction_Type objects\n\
 821 2. PyFunction calls that do not create an argument tuple\n\
 822 3. PyFunction calls that do not create an argument tuple\n\
 823    and bypass PyEval_EvalCodeEx()\n\
 824 4. PyMethod calls\n\
 825 5. PyMethod calls on bound methods\n\
 826 6. PyType calls\n\
 827 7. PyCFunction calls\n\
 828 8. generator calls\n\
 829 9. All other calls\n\
 830 10. Number of stack pops performed by call_function()"
 831 );
 832
 833 #ifdef __cplusplus
 834 extern "C" {
 835 #endif
 836
 837 #ifdef Py_TRACE_REFS
 838 /* Defined in objects.c because it uses static globals if that file */
 839 extern PyObject *_Py_GetObjects(PyObject *, PyObject *);
 840 #endif
 841
 842 #ifdef DYNAMIC_EXECUTION_PROFILE
 843 /* Defined in ceval.c because it uses static globals if that file */
 844 extern PyObject *_Py_GetDXProfile(PyObject *,  PyObject *);
 845 #endif
 846
 847 #ifdef __cplusplus
 848 }
 849 #endif
 850
 851 static PyObject *
 852 sys_clear_type_cache(PyObject* self, PyObject* args)
 853 {
 854         PyType_ClearCache();
 855         Py_RETURN_NONE;
 856 }
 857
 858 PyDoc_STRVAR(sys_clear_type_cache__doc__,
 859 "_clear_type_cache() -> None\n\
 860 Clear the internal type lookup cache.");
 861
 862
 863 static PyMethodDef sys_methods[] = {
 864         /* Might as well keep this in alphabetic order */
 865         {"callstats", (PyCFunction)PyEval_GetCallStats, METH_NOARGS,
 866          callstats_doc},
 867         {"_clear_type_cache",   sys_clear_type_cache,     METH_NOARGS,
 868          sys_clear_type_cache__doc__},
 869         {"_current_frames", sys_current_frames, METH_NOARGS,
 870          current_frames_doc},
 871         {"displayhook", sys_displayhook, METH_O, displayhook_doc},
 872         {"exc_info",    sys_exc_info, METH_NOARGS, exc_info_doc},
 873         {"exc_clear",   sys_exc_clear, METH_NOARGS, exc_clear_doc},
 874         {"excepthook",  sys_excepthook, METH_VARARGS, excepthook_doc},
 875         {"exit",        sys_exit, METH_VARARGS, exit_doc},
 876 #ifdef Py_USING_UNICODE
 877         {"getdefaultencoding", (PyCFunction)sys_getdefaultencoding,
 878          METH_NOARGS, getdefaultencoding_doc},
 879 #endif
 880 #ifdef HAVE_DLOPEN
 881         {"getdlopenflags", (PyCFunction)sys_getdlopenflags, METH_NOARGS,
 882          getdlopenflags_doc},
 883 #endif
 884 #ifdef COUNT_ALLOCS
 885         {"getcounts",   (PyCFunction)sys_getcounts, METH_NOARGS},
 886 #endif
 887 #ifdef DYNAMIC_EXECUTION_PROFILE
 888         {"getdxp",      _Py_GetDXProfile, METH_VARARGS},
 889 #endif
 890 #ifdef Py_USING_UNICODE
 891         {"getfilesystemencoding", (PyCFunction)sys_getfilesystemencoding,
 892          METH_NOARGS, getfilesystemencoding_doc},
 893 #endif
 894 #ifdef Py_TRACE_REFS
 895         {"getobjects",  _Py_GetObjects, METH_VARARGS},
 896 #endif
 897 #ifdef Py_REF_DEBUG
 898         {"gettotalrefcount", (PyCFunction)sys_gettotalrefcount, METH_NOARGS},
 899 #endif
 900         {"getrefcount", (PyCFunction)sys_getrefcount, METH_O, getrefcount_doc},
 901         {"getrecursionlimit", (PyCFunction)sys_getrecursionlimit, METH_NOARGS,
 902          getrecursionlimit_doc},
 903         {"getsizeof",   (PyCFunction)sys_getsizeof,
 904          METH_VARARGS | METH_KEYWORDS, getsizeof_doc},
 905         {"_getframe", sys_getframe, METH_VARARGS, getframe_doc},
 906 #ifdef MS_WINDOWS
 907         {"getwindowsversion", (PyCFunction)sys_getwindowsversion, METH_NOARGS,
 908          getwindowsversion_doc},
 909 #endif /* MS_WINDOWS */
 910 #ifdef USE_MALLOPT
 911         {"mdebug",      sys_mdebug, METH_VARARGS},
 912 #endif
 913 #ifdef Py_USING_UNICODE
 914         {"setdefaultencoding", sys_setdefaultencoding, METH_VARARGS,
 915          setdefaultencoding_doc},
 916 #endif
 917         {"setcheckinterval",    sys_setcheckinterval, METH_VARARGS,
 918          setcheckinterval_doc},
 919         {"getcheckinterval",    sys_getcheckinterval, METH_NOARGS,
 920          getcheckinterval_doc},
 921 #ifdef HAVE_DLOPEN
 922         {"setdlopenflags", sys_setdlopenflags, METH_VARARGS,
 923          setdlopenflags_doc},
 924 #endif
 925         {"setprofile",  sys_setprofile, METH_O, setprofile_doc},
 926         {"getprofile",  sys_getprofile, METH_NOARGS, getprofile_doc},
 927         {"setrecursionlimit", sys_setrecursionlimit, METH_VARARGS,
 928          setrecursionlimit_doc},
 929 #ifdef WITH_TSC
 930         {"settscdump", sys_settscdump, METH_VARARGS, settscdump_doc},
 931 #endif
 932         {"settrace",    sys_settrace, METH_O, settrace_doc},
 933         {"gettrace",    sys_gettrace, METH_NOARGS, gettrace_doc},
 934         {"call_tracing", sys_call_tracing, METH_VARARGS, call_tracing_doc},
 935         {NULL,          NULL}           /* sentinel */
 936 };
 937
 938 static PyObject *
 939 list_builtin_module_names(void)
 940 {
 941         PyObject *list = PyList_New(0);
 942         int i;
 943         if (list == NULL)
 944                 return NULL;
 945         for (i = 0; PyImport_Inittab[i].name != NULL; i++) {
 946                 PyObject *name = PyString_FromString(
 947                         PyImport_Inittab[i].name);
 948                 if (name == NULL)
 949                         break;
 950                 PyList_Append(list, name);
 951                 Py_DECREF(name);
 952         }
 953         if (PyList_Sort(list) != 0) {
 954                 Py_DECREF(list);
 955                 list = NULL;
 956         }
 957         if (list) {
 958                 PyObject *v = PyList_AsTuple(list);
 959                 Py_DECREF(list);
 960                 list = v;
 961         }
 962         return list;
 963 }
 964
 965 static PyObject *warnoptions = NULL;
 966
 967 void
 968 PySys_ResetWarnOptions(void)
 969 {
 970         if (warnoptions == NULL || !PyList_Check(warnoptions))
 971                 return;
 972         PyList_SetSlice(warnoptions, 0, PyList_GET_SIZE(warnoptions), NULL);
 973 }
 974
 975 void
 976 PySys_AddWarnOption(char *s)
 977 {
 978         PyObject *str;
 979
 980         if (warnoptions == NULL || !PyList_Check(warnoptions)) {
 981                 Py_XDECREF(warnoptions);
 982                 warnoptions = PyList_New(0);
 983                 if (warnoptions == NULL)
 984                         return;
 985         }
 986         str = PyString_FromString(s);
 987         if (str != NULL) {
 988                 PyList_Append(warnoptions, str);
 989                 Py_DECREF(str);
 990         }
 991 }
 992
 993 int
 994 PySys_HasWarnOptions(void)
 995 {
 996     return (warnoptions != NULL && (PyList_Size(warnoptions) > 0)) ? 1 : 0;
 997 }
 998
 999 /* XXX This doc string is too long to be a single string literal in VC++ 5.0.
1000    Two literals concatenated works just fine.  If you have a K&R compiler
1001    or other abomination that however *does* understand longer strings,
1002    get rid of the !!! comment in the middle and the quotes that surround it. */
1003 PyDoc_VAR(sys_doc) =
1004 PyDoc_STR(
1005 "This module provides access to some objects used or maintained by the\n\
1006 interpreter and to functions that interact strongly with the interpreter.\n\
1007 \n\
1008 Dynamic objects:\n\
1009 \n\
1010 argv -- command line arguments; argv[0] is the script pathname if known\n\
1011 path -- module search path; path[0] is the script directory, else ''\n\
1012 modules -- dictionary of loaded modules\n\
1013 \n\
1014 displayhook -- called to show results in an interactive session\n\
1015 excepthook -- called to handle any uncaught exception other than SystemExit\n\
1016   To customize printing in an interactive session or to install a custom\n\
1017   top-level exception handler, assign other functions to replace these.\n\
1018 \n\
1019 exitfunc -- if sys.exitfunc exists, this routine is called when Python exits\n\
1020   Assigning to sys.exitfunc is deprecated; use the atexit module instead.\n\
1021 \n\
1022 stdin -- standard input file object; used by raw_input() and input()\n\
1023 stdout -- standard output file object; used by the print statement\n\
1024 stderr -- standard error object; used for error messages\n\
1025   By assigning other file objects (or objects that behave like files)\n\
1026   to these, it is possible to redirect all of the interpreter's I/O.\n\
1027 \n\
1028 last_type -- type of last uncaught exception\n\
1029 last_value -- value of last uncaught exception\n\
1030 last_traceback -- traceback of last uncaught exception\n\
1031   These three are only available in an interactive session after a\n\
1032   traceback has been printed.\n\
1033 \n\
1034 exc_type -- type of exception currently being handled\n\
1035 exc_value -- value of exception currently being handled\n\
1036 exc_traceback -- traceback of exception currently being handled\n\
1037   The function exc_info() should be used instead of these three,\n\
1038   because it is thread-safe.\n\
1039 "
1040 )
1041 /* concatenating string here */
1042 PyDoc_STR(
1043 "\n\
1044 Static objects:\n\
1045 \n\
1046 float_info -- a dict with information about the float inplementation.\n\
1047 long_info -- a struct sequence with information about the long implementation.\n\
1048 maxint -- the largest supported integer (the smallest is -maxint-1)\n\
1049 maxsize -- the largest supported length of containers.\n\
1050 maxunicode -- the largest supported character\n\
1051 builtin_module_names -- tuple of module names built into this interpreter\n\
1052 version -- the version of this interpreter as a string\n\
1053 version_info -- version information as a named tuple\n\
1054 hexversion -- version information encoded as a single integer\n\
1055 copyright -- copyright notice pertaining to this interpreter\n\
1056 platform -- platform identifier\n\
1057 executable -- pathname of this Python interpreter\n\
1058 prefix -- prefix used to find the Python library\n\
1059 exec_prefix -- prefix used to find the machine-specific Python library\n\
1060 "
1061 )
1062 #ifdef MS_WINDOWS
1063 /* concatenating string here */
1064 PyDoc_STR(
1065 "dllhandle -- [Windows only] integer handle of the Python DLL\n\
1066 winver -- [Windows only] version number of the Python DLL\n\
1067 "
1068 )
1069 #endif /* MS_WINDOWS */
1070 PyDoc_STR(
1071 "__stdin__ -- the original stdin; don't touch!\n\
1072 __stdout__ -- the original stdout; don't touch!\n\
1073 __stderr__ -- the original stderr; don't touch!\n\
1074 __displayhook__ -- the original displayhook; don't touch!\n\
1075 __excepthook__ -- the original excepthook; don't touch!\n\
1076 \n\
1077 Functions:\n\
1078 \n\
1079 displayhook() -- print an object to the screen, and save it in __builtin__._\n\
1080 excepthook() -- print an exception and its traceback to sys.stderr\n\
1081 exc_info() -- return thread-safe information about the current exception\n\
1082 exc_clear() -- clear the exception state for the current thread\n\
1083 exit() -- exit the interpreter by raising SystemExit\n\
1084 getdlopenflags() -- returns flags to be used for dlopen() calls\n\
1085 getprofile() -- get the global profiling function\n\
1086 getrefcount() -- return the reference count for an object (plus one :-)\n\
1087 getrecursionlimit() -- return the max recursion depth for the interpreter\n\
1088 getsizeof() -- return the size of an object in bytes\n\
1089 gettrace() -- get the global debug tracing function\n\
1090 setcheckinterval() -- control how often the interpreter checks for events\n\
1091 setdlopenflags() -- set the flags to be used for dlopen() calls\n\
1092 setprofile() -- set the global profiling function\n\
1093 setrecursionlimit() -- set the max recursion depth for the interpreter\n\
1094 settrace() -- set the global debug tracing function\n\
1095 "
1096 )
1097 /* end of sys_doc */ ;
1098
1099 static int
1100 _check_and_flush (FILE *stream)
1101 {
1102   int prev_fail = ferror (stream);
1103   return fflush (stream) || prev_fail ? EOF : 0;
1104 }
1105
1106 /* Subversion branch and revision management */
1107 static const char _patchlevel_revision[] = PY_PATCHLEVEL_REVISION;
1108 static const char headurl[] = "$HeadURL$";
1109 static int svn_initialized;
1110 static char patchlevel_revision[50]; /* Just the number */
1111 static char branch[50];
1112 static char shortbranch[50];
1113 static const char *svn_revision;
1114
1115 static void
1116 svnversion_init(void)
1117 {
1118         const char *python, *br_start, *br_end, *br_end2, *svnversion;
1119         Py_ssize_t len;
1120         int istag;
1121
1122         if (svn_initialized)
1123                 return;
1124
1125         python = strstr(headurl, "/python/");
1126         if (!python) {
1127                 /* XXX quick hack to get bzr working */
1128                 *patchlevel_revision = '\0';
1129                 strcpy(branch, "");
1130                 strcpy(shortbranch, "unknown");
1131                 svn_revision = "";
1132                 return;
1133                 /* Py_FatalError("subversion keywords missing"); */
1134         }
1135
1136         br_start = python + 8;
1137         br_end = strchr(br_start, '/');
1138         assert(br_end);
1139
1140         /* Works even for trunk,
1141            as we are in trunk/Python/sysmodule.c */
1142         br_end2 = strchr(br_end+1, '/');
1143
1144         istag = strncmp(br_start, "tags", 4) == 0;
1145         if (strncmp(br_start, "trunk", 5) == 0) {
1146                 strcpy(branch, "trunk");
1147                 strcpy(shortbranch, "trunk");
1148
1149         }
1150         else if (istag || strncmp(br_start, "branches", 8) == 0) {
1151                 len = br_end2 - br_start;
1152                 strncpy(branch, br_start, len);
1153                 branch[len] = '\0';
1154
1155                 len = br_end2 - (br_end + 1);
1156                 strncpy(shortbranch, br_end + 1, len);
1157                 shortbranch[len] = '\0';
1158         }
1159         else {
1160                 Py_FatalError("bad HeadURL");
1161                 return;
1162         }
1163
1164
1165         svnversion = _Py_svnversion();
1166         if (strcmp(svnversion, "exported") != 0)
1167                 svn_revision = svnversion;
1168         else if (istag) {
1169                 len = strlen(_patchlevel_revision);
1170                 assert(len >= 13);
1171                 assert(len < (sizeof(patchlevel_revision) + 13));
1172                 strncpy(patchlevel_revision, _patchlevel_revision + 11,
1173                         len - 13);
1174                 patchlevel_revision[len - 13] = '\0';
1175                 svn_revision = patchlevel_revision;
1176         }
1177         else
1178                 svn_revision = "";
1179
1180         svn_initialized = 1;
1181 }
1182
1183 /* Return svnversion output if available.
1184    Else return Revision of patchlevel.h if on branch.
1185    Else return empty string */
1186 const char*
1187 Py_SubversionRevision()
1188 {
1189         svnversion_init();
1190         return svn_revision;
1191 }
1192
1193 const char*
1194 Py_SubversionShortBranch()
1195 {
1196         svnversion_init();
1197         return shortbranch;
1198 }
1199
1200
1201 PyDoc_STRVAR(flags__doc__,
1202 "sys.flags\n\
1203 \n\
1204 Flags provided through command line arguments or environment vars.");
1205
1206 static PyTypeObject FlagsType = {0, 0, 0, 0, 0, 0};
1207
1208 static PyStructSequence_Field flags_fields[] = {
1209         {"debug",               "-d"},
1210         {"py3k_warning",        "-3"},
1211         {"division_warning",    "-Q"},
1212         {"division_new",        "-Qnew"},
1213         {"inspect",             "-i"},
1214         {"interactive",         "-i"},
1215         {"optimize",            "-O or -OO"},
1216         {"dont_write_bytecode", "-B"},
1217         {"no_user_site",        "-s"},
1218         {"no_site",             "-S"},
1219         {"ignore_environment",  "-E"},
1220         {"tabcheck",            "-t or -tt"},
1221         {"verbose",             "-v"},
1222 #ifdef RISCOS
1223         {"riscos_wimp",         "???"},
1224 #endif
1225         /* {"unbuffered",               "-u"}, */
1226         {"unicode",             "-U"},
1227         /* {"skip_first",               "-x"}, */
1228         {"bytes_warning", "-b"},
1229         {0}
1230 };
1231
1232 static PyStructSequence_Desc flags_desc = {
1233         "sys.flags",    /* name */
1234         flags__doc__,   /* doc */
1235         flags_fields,   /* fields */
1236 #ifdef RISCOS
1237         16
1238 #else
1239         15
1240 #endif
1241 };
1242
1243 static PyObject*
1244 make_flags(void)
1245 {
1246         int pos = 0;
1247         PyObject *seq;
1248
1249         seq = PyStructSequence_New(&FlagsType);
1250         if (seq == NULL)
1251                 return NULL;
1252
1253 #define SetFlag(flag) \
1254         PyStructSequence_SET_ITEM(seq, pos++, PyInt_FromLong(flag))
1255
1256         SetFlag(Py_DebugFlag);
1257         SetFlag(Py_Py3kWarningFlag);
1258         SetFlag(Py_DivisionWarningFlag);
1259         SetFlag(_Py_QnewFlag);
1260         SetFlag(Py_InspectFlag);
1261         SetFlag(Py_InteractiveFlag);
1262         SetFlag(Py_OptimizeFlag);
1263         SetFlag(Py_DontWriteBytecodeFlag);
1264         SetFlag(Py_NoUserSiteDirectory);
1265         SetFlag(Py_NoSiteFlag);
1266         SetFlag(Py_IgnoreEnvironmentFlag);
1267         SetFlag(Py_TabcheckFlag);
1268         SetFlag(Py_VerboseFlag);
1269 #ifdef RISCOS
1270         SetFlag(Py_RISCOSWimpFlag);
1271 #endif
1272         /* SetFlag(saw_unbuffered_flag); */
1273         SetFlag(Py_UnicodeFlag);
1274         /* SetFlag(skipfirstline); */
1275     SetFlag(Py_BytesWarningFlag);
1276 #undef SetFlag
1277
1278         if (PyErr_Occurred()) {
1279                 return NULL;
1280         }
1281         return seq;
1282 }
1283
1284 PyDoc_STRVAR(version_info__doc__,
1285 "sys.version_info\n\
1286 \n\
1287 Version information as a named tuple.");
1288
1289 static PyTypeObject VersionInfoType = {0, 0, 0, 0, 0, 0};
1290
1291 static PyStructSequence_Field version_info_fields[] = {
1292         {"major", "Major release number"},
1293         {"minor", "Minor release number"},
1294         {"micro", "Patch release number"},
1295         {"releaselevel", "'alpha', 'beta', 'candidate', or 'release'"},
1296         {"serial", "Serial release number"},
1297         {0}
1298 };
1299
1300 static PyStructSequence_Desc version_info_desc = {
1301         "sys.version_info",     /* name */
1302         version_info__doc__,    /* doc */
1303         version_info_fields,    /* fields */
1304         5
1305 };
1306
1307 static PyObject *
1308 make_version_info(void)
1309 {
1310         PyObject *version_info;
1311         char *s;
1312         int pos = 0;
1313
1314         version_info = PyStructSequence_New(&VersionInfoType);
1315         if (version_info == NULL) {
1316                 return NULL;
1317         }
1318
1319         /*
1320          * These release level checks are mutually exclusive and cover
1321          * the field, so don't get too fancy with the pre-processor!
1322          */
1323 #if PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_ALPHA
1324         s = "alpha";
1325 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_BETA
1326         s = "beta";
1327 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_GAMMA
1328         s = "candidate";
1329 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_FINAL
1330         s = "final";
1331 #endif
1332
1333 #define SetIntItem(flag) \
1334         PyStructSequence_SET_ITEM(version_info, pos++, PyInt_FromLong(flag))
1335 #define SetStrItem(flag) \
1336         PyStructSequence_SET_ITEM(version_info, pos++, PyString_FromString(flag))
1337
1338         SetIntItem(PY_MAJOR_VERSION);
1339         SetIntItem(PY_MINOR_VERSION);
1340         SetIntItem(PY_MICRO_VERSION);
1341         SetStrItem(s);
1342         SetIntItem(PY_RELEASE_SERIAL);
1343 #undef SetIntItem
1344 #undef SetStrItem
1345
1346         if (PyErr_Occurred()) {
1347                 Py_CLEAR(version_info);
1348                 return NULL;
1349         }
1350         return version_info;
1351 }
1352
1353 PyObject *
1354 _PySys_Init(void)
1355 {
1356         PyObject *m, *v, *sysdict;
1357         PyObject *sysin, *sysout, *syserr;
1358         char *s;
1359
1360         m = Py_InitModule3("sys", sys_methods, sys_doc);
1361         if (m == NULL)
1362                 return NULL;
1363         sysdict = PyModule_GetDict(m);
1364 #define SET_SYS_FROM_STRING(key, value)                 \
1365         v = value;                                      \
1366         if (v != NULL)                                  \
1367                 PyDict_SetItemString(sysdict, key, v);  \
1368         Py_XDECREF(v)
1369
1370         /* Check that stdin is not a directory
1371         Using shell redirection, you can redirect stdin to a directory,
1372         crashing the Python interpreter. Catch this common mistake here
1373         and output a useful error message. Note that under MS Windows,
1374         the shell already prevents that. */
1375 #if !defined(MS_WINDOWS)
1376         {
1377                 struct stat sb;
1378                 if (fstat(fileno(stdin), &sb) == 0 &&
1379                     S_ISDIR(sb.st_mode)) {
1380                         /* There's nothing more we can do. */
1381                         /* Py_FatalError() will core dump, so just exit. */
1382                         PySys_WriteStderr("Python error: <stdin> is a directory, cannot continue\n");
1383                         exit(EXIT_FAILURE);
1384                 }
1385         }
1386 #endif
1387
1388         /* Closing the standard FILE* if sys.std* goes aways causes problems
1389          * for embedded Python usages. Closing them when somebody explicitly
1390          * invokes .close() might be possible, but the FAQ promises they get
1391          * never closed. However, we still need to get write errors when
1392          * writing fails (e.g. because stdout is redirected), so we flush the
1393          * streams and check for errors before the file objects are deleted.
1394          * On OS X, fflush()ing stdin causes an error, so we exempt stdin
1395          * from that procedure.
1396          */
1397         sysin = PyFile_FromFile(stdin, "<stdin>", "r", NULL);
1398         sysout = PyFile_FromFile(stdout, "<stdout>", "w", _check_and_flush);
1399         syserr = PyFile_FromFile(stderr, "<stderr>", "w", _check_and_flush);
1400         if (PyErr_Occurred())
1401                 return NULL;
1402
1403         PyDict_SetItemString(sysdict, "stdin", sysin);
1404         PyDict_SetItemString(sysdict, "stdout", sysout);
1405         PyDict_SetItemString(sysdict, "stderr", syserr);
1406         /* Make backup copies for cleanup */
1407         PyDict_SetItemString(sysdict, "__stdin__", sysin);
1408         PyDict_SetItemString(sysdict, "__stdout__", sysout);
1409         PyDict_SetItemString(sysdict, "__stderr__", syserr);
1410         PyDict_SetItemString(sysdict, "__displayhook__",
1411                              PyDict_GetItemString(sysdict, "displayhook"));
1412         PyDict_SetItemString(sysdict, "__excepthook__",
1413                              PyDict_GetItemString(sysdict, "excepthook"));
1414         Py_XDECREF(sysin);
1415         Py_XDECREF(sysout);
1416         Py_XDECREF(syserr);
1417
1418         SET_SYS_FROM_STRING("version",
1419                              PyString_FromString(Py_GetVersion()));
1420         SET_SYS_FROM_STRING("hexversion",
1421                              PyInt_FromLong(PY_VERSION_HEX));
1422         svnversion_init();
1423         SET_SYS_FROM_STRING("subversion",
1424                              Py_BuildValue("(ssz)", "CPython", branch,
1425                                           svn_revision));
1426         SET_SYS_FROM_STRING("dont_write_bytecode",
1427                              PyBool_FromLong(Py_DontWriteBytecodeFlag));
1428         SET_SYS_FROM_STRING("api_version",
1429                             PyInt_FromLong(PYTHON_API_VERSION));
1430         SET_SYS_FROM_STRING("copyright",
1431                             PyString_FromString(Py_GetCopyright()));
1432         SET_SYS_FROM_STRING("platform",
1433                             PyString_FromString(Py_GetPlatform()));
1434         SET_SYS_FROM_STRING("executable",
1435                             PyString_FromString(Py_GetProgramFullPath()));
1436         SET_SYS_FROM_STRING("prefix",
1437                             PyString_FromString(Py_GetPrefix()));
1438         SET_SYS_FROM_STRING("exec_prefix",
1439                             PyString_FromString(Py_GetExecPrefix()));
1440         SET_SYS_FROM_STRING("maxsize",
1441                             PyInt_FromSsize_t(PY_SSIZE_T_MAX));
1442         SET_SYS_FROM_STRING("maxint",
1443                             PyInt_FromLong(PyInt_GetMax()));
1444         SET_SYS_FROM_STRING("py3kwarning",
1445                             PyBool_FromLong(Py_Py3kWarningFlag));
1446         SET_SYS_FROM_STRING("float_info",
1447                             PyFloat_GetInfo());
1448         SET_SYS_FROM_STRING("long_info",
1449                             PyLong_GetInfo());
1450 #ifdef Py_USING_UNICODE
1451         SET_SYS_FROM_STRING("maxunicode",
1452                             PyInt_FromLong(PyUnicode_GetMax()));
1453 #endif
1454         SET_SYS_FROM_STRING("builtin_module_names",
1455                             list_builtin_module_names());
1456         {
1457                 /* Assumes that longs are at least 2 bytes long.
1458                    Should be safe! */
1459                 unsigned long number = 1;
1460                 char *value;
1461
1462                 s = (char *) &number;
1463                 if (s[0] == 0)
1464                         value = "big";
1465                 else
1466                         value = "little";
1467                 SET_SYS_FROM_STRING("byteorder",
1468                                     PyString_FromString(value));
1469         }
1470 #ifdef MS_COREDLL
1471         SET_SYS_FROM_STRING("dllhandle",
1472                             PyLong_FromVoidPtr(PyWin_DLLhModule));
1473         SET_SYS_FROM_STRING("winver",
1474                             PyString_FromString(PyWin_DLLVersionString));
1475 #endif
1476         if (warnoptions == NULL) {
1477                 warnoptions = PyList_New(0);
1478         }
1479         else {
1480                 Py_INCREF(warnoptions);
1481         }
1482         if (warnoptions != NULL) {
1483                 PyDict_SetItemString(sysdict, "warnoptions", warnoptions);
1484         }
1485
1486         /* version_info */
1487         if (VersionInfoType.tp_name == 0)
1488                 PyStructSequence_InitType(&VersionInfoType, &version_info_desc);
1489         SET_SYS_FROM_STRING("version_info", make_version_info());
1490         /* prevent user from creating new instances */
1491         VersionInfoType.tp_init = NULL;
1492         VersionInfoType.tp_new = NULL;
1493
1494         /* flags */
1495         if (FlagsType.tp_name == 0)
1496                 PyStructSequence_InitType(&FlagsType, &flags_desc);
1497         SET_SYS_FROM_STRING("flags", make_flags());
1498         /* prevent user from creating new instances */
1499         FlagsType.tp_init = NULL;
1500         FlagsType.tp_new = NULL;
1501
1502 #undef SET_SYS_FROM_STRING
1503         if (PyErr_Occurred())
1504                 return NULL;
1505         return m;
1506 }
1507
1508 static PyObject *
1509 makepathobject(char *path, int delim)
1510 {
1511         int i, n;
1512         char *p;
1513         PyObject *v, *w;
1514
1515         n = 1;
1516         p = path;
1517         while ((p = strchr(p, delim)) != NULL) {
1518                 n++;
1519                 p++;
1520         }
1521         v = PyList_New(n);
1522         if (v == NULL)
1523                 return NULL;
1524         for (i = 0; ; i++) {
1525                 p = strchr(path, delim);
1526                 if (p == NULL)
1527                         p = strchr(path, '\0'); /* End of string */
1528                 w = PyString_FromStringAndSize(path, (Py_ssize_t) (p - path));
1529                 if (w == NULL) {
1530                         Py_DECREF(v);
1531                         return NULL;
1532                 }
1533                 PyList_SetItem(v, i, w);
1534                 if (*p == '\0')
1535                         break;
1536                 path = p+1;
1537         }
1538         return v;
1539 }
1540
1541 void
1542 PySys_SetPath(char *path)
1543 {
1544         PyObject *v;
1545         if ((v = makepathobject(path, DELIM)) == NULL)
1546                 Py_FatalError("can't create sys.path");
1547         if (PySys_SetObject("path", v) != 0)
1548                 Py_FatalError("can't assign sys.path");
1549         Py_DECREF(v);
1550 }
1551
1552 static PyObject *
1553 makeargvobject(int argc, char **argv)
1554 {
1555         PyObject *av;
1556         if (argc <= 0 || argv == NULL) {
1557                 /* Ensure at least one (empty) argument is seen */
1558                 static char *empty_argv[1] = {""};
1559                 argv = empty_argv;
1560                 argc = 1;
1561         }
1562         av = PyList_New(argc);
1563         if (av != NULL) {
1564                 int i;
1565                 for (i = 0; i < argc; i++) {
1566 #ifdef __VMS
1567                         PyObject *v;
1568
1569                         /* argv[0] is the script pathname if known */
1570                         if (i == 0) {
1571                                 char* fn = decc$translate_vms(argv[0]);
1572                                 if ((fn == (char *)0) || fn == (char *)-1)
1573                                         v = PyString_FromString(argv[0]);
1574                                 else
1575                                         v = PyString_FromString(
1576                                                 decc$translate_vms(argv[0]));
1577                         } else
1578                                 v = PyString_FromString(argv[i]);
1579 #else
1580                         PyObject *v = PyString_FromString(argv[i]);
1581 #endif
1582                         if (v == NULL) {
1583                                 Py_DECREF(av);
1584                                 av = NULL;
1585                                 break;
1586                         }
1587                         PyList_SetItem(av, i, v);
1588                 }
1589         }
1590         return av;
1591 }
1592
1593 void
1594 PySys_SetArgv(int argc, char **argv)
1595 {
1596 #if defined(HAVE_REALPATH)
1597         char fullpath[MAXPATHLEN];
1598 #elif defined(MS_WINDOWS) && !defined(MS_WINCE)
1599         char fullpath[MAX_PATH];
1600 #endif
1601         PyObject *av = makeargvobject(argc, argv);
1602         PyObject *path = PySys_GetObject("path");
1603         if (av == NULL)
1604                 Py_FatalError("no mem for sys.argv");
1605         if (PySys_SetObject("argv", av) != 0)
1606                 Py_FatalError("can't assign sys.argv");
1607         if (path != NULL) {
1608                 char *argv0 = argv[0];
1609                 char *p = NULL;
1610                 Py_ssize_t n = 0;
1611                 PyObject *a;
1612 #ifdef HAVE_READLINK
1613                 char link[MAXPATHLEN+1];
1614                 char argv0copy[2*MAXPATHLEN+1];
1615                 int nr = 0;
1616                 if (argc > 0 && argv0 != NULL && strcmp(argv0, "-c") != 0)
1617                         nr = readlink(argv0, link, MAXPATHLEN);
1618                 if (nr > 0) {
1619                         /* It's a symlink */
1620                         link[nr] = '\0';
1621                         if (link[0] == SEP)
1622                                 argv0 = link; /* Link to absolute path */
1623                         else if (strchr(link, SEP) == NULL)
1624                                 ; /* Link without path */
1625                         else {
1626                                 /* Must join(dirname(argv0), link) */
1627                                 char *q = strrchr(argv0, SEP);
1628                                 if (q == NULL)
1629                                         argv0 = link; /* argv0 without path */
1630                                 else {
1631                                         /* Must make a copy */
1632                                         strcpy(argv0copy, argv0);
1633                                         q = strrchr(argv0copy, SEP);
1634                                         strcpy(q+1, link);
1635                                         argv0 = argv0copy;
1636                                 }
1637                         }
1638                 }
1639 #endif /* HAVE_READLINK */
1640 #if SEP == '\\' /* Special case for MS filename syntax */
1641                 if (argc > 0 && argv0 != NULL && strcmp(argv0, "-c") != 0) {
1642                         char *q;
1643 #if defined(MS_WINDOWS) && !defined(MS_WINCE)
1644                         /* This code here replaces the first element in argv with the full
1645                         path that it represents. Under CE, there are no relative paths so
1646                         the argument must be the full path anyway. */
1647                         char *ptemp;
1648                         if (GetFullPathName(argv0,
1649                                            sizeof(fullpath),
1650                                            fullpath,
1651                                            &ptemp)) {
1652                                 argv0 = fullpath;
1653                         }
1654 #endif
1655                         p = strrchr(argv0, SEP);
1656                         /* Test for alternate separator */
1657                         q = strrchr(p ? p : argv0, '/');
1658                         if (q != NULL)
1659                                 p = q;
1660                         if (p != NULL) {
1661                                 n = p + 1 - argv0;
1662                                 if (n > 1 && p[-1] != ':')
1663                                         n--; /* Drop trailing separator */
1664                         }
1665                 }
1666 #else /* All other filename syntaxes */
1667                 if (argc > 0 && argv0 != NULL && strcmp(argv0, "-c") != 0) {
1668 #if defined(HAVE_REALPATH)
1669                         if (realpath(argv0, fullpath)) {
1670                                 argv0 = fullpath;
1671                         }
1672 #endif
1673                         p = strrchr(argv0, SEP);
1674                 }
1675                 if (p != NULL) {
1676 #ifndef RISCOS
1677                         n = p + 1 - argv0;
1678 #else /* don't include trailing separator */
1679                         n = p - argv0;
1680 #endif /* RISCOS */
1681 #if SEP == '/' /* Special case for Unix filename syntax */
1682                         if (n > 1)
1683                                 n--; /* Drop trailing separator */
1684 #endif /* Unix */
1685                 }
1686 #endif /* All others */
1687                 a = PyString_FromStringAndSize(argv0, n);
1688                 if (a == NULL)
1689                         Py_FatalError("no mem for sys.path insertion");
1690                 if (PyList_Insert(path, 0, a) < 0)
1691                         Py_FatalError("sys.path.insert(0) failed");
1692                 Py_DECREF(a);
1693         }
1694         Py_DECREF(av);
1695 }
1696
1697
1698 /* APIs to write to sys.stdout or sys.stderr using a printf-like interface.
1699    Adapted from code submitted by Just van Rossum.
1700
1701    PySys_WriteStdout(format, ...)
1702    PySys_WriteStderr(format, ...)
1703
1704       The first function writes to sys.stdout; the second to sys.stderr.  When
1705       there is a problem, they write to the real (C level) stdout or stderr;
1706       no exceptions are raised.
1707
1708       Both take a printf-style format string as their first argument followed
1709       by a variable length argument list determined by the format string.
1710
1711       *** WARNING ***
1712
1713       The format should limit the total size of the formatted output string to
1714       1000 bytes.  In particular, this means that no unrestricted "%s" formats
1715       should occur; these should be limited using "%.<N>s where <N> is a
1716       decimal number calculated so that <N> plus the maximum size of other
1717       formatted text does not exceed 1000 bytes.  Also watch out for "%f",
1718       which can print hundreds of digits for very large numbers.
1719
1720  */
1721
1722 static void
1723 mywrite(char *name, FILE *fp, const char *format, va_list va)
1724 {
1725         PyObject *file;
1726         PyObject *error_type, *error_value, *error_traceback;
1727
1728         PyErr_Fetch(&error_type, &error_value, &error_traceback);
1729         file = PySys_GetObject(name);
1730         if (file == NULL || PyFile_AsFile(file) == fp)
1731                 vfprintf(fp, format, va);
1732         else {
1733                 char buffer[1001];
1734                 const int written = PyOS_vsnprintf(buffer, sizeof(buffer),
1735                                                    format, va);
1736                 if (PyFile_WriteString(buffer, file) != 0) {
1737                         PyErr_Clear();
1738                         fputs(buffer, fp);
1739                 }
1740                 if (written < 0 || (size_t)written >= sizeof(buffer)) {
1741                         const char *truncated = "... truncated";
1742                         if (PyFile_WriteString(truncated, file) != 0) {
1743                                 PyErr_Clear();
1744                                 fputs(truncated, fp);
1745                         }
1746                 }
1747         }
1748         PyErr_Restore(error_type, error_value, error_traceback);
1749 }
1750
1751 void
1752 PySys_WriteStdout(const char *format, ...)
1753 {
1754         va_list va;
1755
1756         va_start(va, format);
1757         mywrite("stdout", stdout, format, va);
1758         va_end(va);
1759 }
1760
1761 void
1762 PySys_WriteStderr(const char *format, ...)
1763 {
1764         va_list va;
1765
1766         va_start(va, format);
1767         mywrite("stderr", stderr, format, va);
1768         va_end(va);
1769 }