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 maxint -- the largest supported integer (the smallest is -maxint-1)\n\
1047 maxsize -- the largest supported length of containers.\n\
1048 maxunicode -- the largest supported character\n\
1049 builtin_module_names -- tuple of module names built into this interpreter\n\
1050 version -- the version of this interpreter as a string\n\
1051 version_info -- version information as a tuple\n\
1052 hexversion -- version information encoded as a single integer\n\
1053 copyright -- copyright notice pertaining to this interpreter\n\
1054 platform -- platform identifier\n\
1055 executable -- pathname of this Python interpreter\n\
1056 prefix -- prefix used to find the Python library\n\
1057 exec_prefix -- prefix used to find the machine-specific Python library\n\
1058 "
1059 )
1060 #ifdef MS_WINDOWS
1061 /* concatenating string here */
1062 PyDoc_STR(
1063 "dllhandle -- [Windows only] integer handle of the Python DLL\n\
1064 winver -- [Windows only] version number of the Python DLL\n\
1065 "
1066 )
1067 #endif /* MS_WINDOWS */
1068 PyDoc_STR(
1069 "__stdin__ -- the original stdin; don't touch!\n\
1070 __stdout__ -- the original stdout; don't touch!\n\
1071 __stderr__ -- the original stderr; don't touch!\n\
1072 __displayhook__ -- the original displayhook; don't touch!\n\
1073 __excepthook__ -- the original excepthook; don't touch!\n\
1074 \n\
1075 Functions:\n\
1076 \n\
1077 displayhook() -- print an object to the screen, and save it in __builtin__._\n\
1078 excepthook() -- print an exception and its traceback to sys.stderr\n\
1079 exc_info() -- return thread-safe information about the current exception\n\
1080 exc_clear() -- clear the exception state for the current thread\n\
1081 exit() -- exit the interpreter by raising SystemExit\n\
1082 getdlopenflags() -- returns flags to be used for dlopen() calls\n\
1083 getprofile() -- get the global profiling function\n\
1084 getrefcount() -- return the reference count for an object (plus one :-)\n\
1085 getrecursionlimit() -- return the max recursion depth for the interpreter\n\
1086 getsizeof() -- return the size of an object in bytes\n\
1087 gettrace() -- get the global debug tracing function\n\
1088 setcheckinterval() -- control how often the interpreter checks for events\n\
1089 setdlopenflags() -- set the flags to be used for dlopen() calls\n\
1090 setprofile() -- set the global profiling function\n\
1091 setrecursionlimit() -- set the max recursion depth for the interpreter\n\
1092 settrace() -- set the global debug tracing function\n\
1093 "
1094 )
1095 /* end of sys_doc */ ;
1096
1097 static int
1098 _check_and_flush (FILE *stream)
1099 {
1100   int prev_fail = ferror (stream);
1101   return fflush (stream) || prev_fail ? EOF : 0;
1102 }
1103
1104 /* Subversion branch and revision management */
1105 static const char _patchlevel_revision[] = PY_PATCHLEVEL_REVISION;
1106 static const char headurl[] = "$HeadURL$";
1107 static int svn_initialized;
1108 static char patchlevel_revision[50]; /* Just the number */
1109 static char branch[50];
1110 static char shortbranch[50];
1111 static const char *svn_revision;
1112
1113 static void
1114 svnversion_init(void)
1115 {
1116         const char *python, *br_start, *br_end, *br_end2, *svnversion;
1117         Py_ssize_t len;
1118         int istag;
1119
1120         if (svn_initialized)
1121                 return;
1122
1123         python = strstr(headurl, "/python/");
1124         if (!python) {
1125                 /* XXX quick hack to get bzr working */
1126                 *patchlevel_revision = '\0';
1127                 strcpy(branch, "");
1128                 strcpy(shortbranch, "unknown");
1129                 svn_revision = "";
1130                 return;
1131                 /* Py_FatalError("subversion keywords missing"); */
1132         }
1133
1134         br_start = python + 8;
1135         br_end = strchr(br_start, '/');
1136         assert(br_end);
1137
1138         /* Works even for trunk,
1139            as we are in trunk/Python/sysmodule.c */
1140         br_end2 = strchr(br_end+1, '/');
1141
1142         istag = strncmp(br_start, "tags", 4) == 0;
1143         if (strncmp(br_start, "trunk", 5) == 0) {
1144                 strcpy(branch, "trunk");
1145                 strcpy(shortbranch, "trunk");
1146
1147         }
1148         else if (istag || strncmp(br_start, "branches", 8) == 0) {
1149                 len = br_end2 - br_start;
1150                 strncpy(branch, br_start, len);
1151                 branch[len] = '\0';
1152
1153                 len = br_end2 - (br_end + 1);
1154                 strncpy(shortbranch, br_end + 1, len);
1155                 shortbranch[len] = '\0';
1156         }
1157         else {
1158                 Py_FatalError("bad HeadURL");
1159                 return;
1160         }
1161
1162
1163         svnversion = _Py_svnversion();
1164         if (strcmp(svnversion, "exported") != 0)
1165                 svn_revision = svnversion;
1166         else if (istag) {
1167                 len = strlen(_patchlevel_revision);
1168                 assert(len >= 13);
1169                 assert(len < (sizeof(patchlevel_revision) + 13));
1170                 strncpy(patchlevel_revision, _patchlevel_revision + 11,
1171                         len - 13);
1172                 patchlevel_revision[len - 13] = '\0';
1173                 svn_revision = patchlevel_revision;
1174         }
1175         else
1176                 svn_revision = "";
1177
1178         svn_initialized = 1;
1179 }
1180
1181 /* Return svnversion output if available.
1182    Else return Revision of patchlevel.h if on branch.
1183    Else return empty string */
1184 const char*
1185 Py_SubversionRevision()
1186 {
1187         svnversion_init();
1188         return svn_revision;
1189 }
1190
1191 const char*
1192 Py_SubversionShortBranch()
1193 {
1194         svnversion_init();
1195         return shortbranch;
1196 }
1197
1198
1199 PyDoc_STRVAR(flags__doc__,
1200 "sys.flags\n\
1201 \n\
1202 Flags provided through command line arguments or environment vars.");
1203
1204 static PyTypeObject FlagsType = {0, 0, 0, 0, 0, 0};
1205
1206 static PyStructSequence_Field flags_fields[] = {
1207         {"debug",               "-d"},
1208         {"py3k_warning",        "-3"},
1209         {"division_warning",    "-Q"},
1210         {"division_new",        "-Qnew"},
1211         {"inspect",             "-i"},
1212         {"interactive",         "-i"},
1213         {"optimize",            "-O or -OO"},
1214         {"dont_write_bytecode", "-B"},
1215         {"no_user_site",        "-s"},
1216         {"no_site",             "-S"},
1217         {"ignore_environment",  "-E"},
1218         {"tabcheck",            "-t or -tt"},
1219         {"verbose",             "-v"},
1220 #ifdef RISCOS
1221         {"riscos_wimp",         "???"},
1222 #endif
1223         /* {"unbuffered",               "-u"}, */
1224         {"unicode",             "-U"},
1225         /* {"skip_first",               "-x"}, */
1226         {"bytes_warning", "-b"},
1227         {0}
1228 };
1229
1230 static PyStructSequence_Desc flags_desc = {
1231         "sys.flags",    /* name */
1232         flags__doc__,   /* doc */
1233         flags_fields,   /* fields */
1234 #ifdef RISCOS
1235         16
1236 #else
1237         15
1238 #endif
1239 };
1240
1241 static PyObject*
1242 make_flags(void)
1243 {
1244         int pos = 0;
1245         PyObject *seq;
1246
1247         seq = PyStructSequence_New(&FlagsType);
1248         if (seq == NULL)
1249                 return NULL;
1250
1251 #define SetFlag(flag) \
1252         PyStructSequence_SET_ITEM(seq, pos++, PyInt_FromLong(flag))
1253
1254         SetFlag(Py_DebugFlag);
1255         SetFlag(Py_Py3kWarningFlag);
1256         SetFlag(Py_DivisionWarningFlag);
1257         SetFlag(_Py_QnewFlag);
1258         SetFlag(Py_InspectFlag);
1259         SetFlag(Py_InteractiveFlag);
1260         SetFlag(Py_OptimizeFlag);
1261         SetFlag(Py_DontWriteBytecodeFlag);
1262         SetFlag(Py_NoUserSiteDirectory);
1263         SetFlag(Py_NoSiteFlag);
1264         SetFlag(Py_IgnoreEnvironmentFlag);
1265         SetFlag(Py_TabcheckFlag);
1266         SetFlag(Py_VerboseFlag);
1267 #ifdef RISCOS
1268         SetFlag(Py_RISCOSWimpFlag);
1269 #endif
1270         /* SetFlag(saw_unbuffered_flag); */
1271         SetFlag(Py_UnicodeFlag);
1272         /* SetFlag(skipfirstline); */
1273     SetFlag(Py_BytesWarningFlag);
1274 #undef SetFlag
1275
1276         if (PyErr_Occurred()) {
1277                 return NULL;
1278         }
1279         return seq;
1280 }
1281
1282 PyObject *
1283 _PySys_Init(void)
1284 {
1285         PyObject *m, *v, *sysdict;
1286         PyObject *sysin, *sysout, *syserr;
1287         char *s;
1288
1289         m = Py_InitModule3("sys", sys_methods, sys_doc);
1290         if (m == NULL)
1291                 return NULL;
1292         sysdict = PyModule_GetDict(m);
1293 #define SET_SYS_FROM_STRING(key, value)                 \
1294         v = value;                                      \
1295         if (v != NULL)                                  \
1296                 PyDict_SetItemString(sysdict, key, v);  \
1297         Py_XDECREF(v)
1298
1299         {
1300                 /* XXX: does this work on Win/Win64? (see posix_fstat) */
1301                 struct stat sb;
1302                 if (fstat(fileno(stdin), &sb) == 0 &&
1303                     S_ISDIR(sb.st_mode)) {
1304                         /* There's nothing more we can do. */
1305                         /* Py_FatalError() will core dump, so just exit. */
1306                         PySys_WriteStderr("Python error: <stdin> is a directory, cannot continue\n");
1307                         exit(EXIT_FAILURE);
1308                 }
1309         }
1310
1311         /* Closing the standard FILE* if sys.std* goes aways causes problems
1312          * for embedded Python usages. Closing them when somebody explicitly
1313          * invokes .close() might be possible, but the FAQ promises they get
1314          * never closed. However, we still need to get write errors when
1315          * writing fails (e.g. because stdout is redirected), so we flush the
1316          * streams and check for errors before the file objects are deleted.
1317          * On OS X, fflush()ing stdin causes an error, so we exempt stdin
1318          * from that procedure.
1319          */
1320         sysin = PyFile_FromFile(stdin, "<stdin>", "r", NULL);
1321         sysout = PyFile_FromFile(stdout, "<stdout>", "w", _check_and_flush);
1322         syserr = PyFile_FromFile(stderr, "<stderr>", "w", _check_and_flush);
1323         if (PyErr_Occurred())
1324                 return NULL;
1325
1326         PyDict_SetItemString(sysdict, "stdin", sysin);
1327         PyDict_SetItemString(sysdict, "stdout", sysout);
1328         PyDict_SetItemString(sysdict, "stderr", syserr);
1329         /* Make backup copies for cleanup */
1330         PyDict_SetItemString(sysdict, "__stdin__", sysin);
1331         PyDict_SetItemString(sysdict, "__stdout__", sysout);
1332         PyDict_SetItemString(sysdict, "__stderr__", syserr);
1333         PyDict_SetItemString(sysdict, "__displayhook__",
1334                              PyDict_GetItemString(sysdict, "displayhook"));
1335         PyDict_SetItemString(sysdict, "__excepthook__",
1336                              PyDict_GetItemString(sysdict, "excepthook"));
1337         Py_XDECREF(sysin);
1338         Py_XDECREF(sysout);
1339         Py_XDECREF(syserr);
1340
1341         SET_SYS_FROM_STRING("version",
1342                              PyString_FromString(Py_GetVersion()));
1343         SET_SYS_FROM_STRING("hexversion",
1344                              PyInt_FromLong(PY_VERSION_HEX));
1345         svnversion_init();
1346         SET_SYS_FROM_STRING("subversion",
1347                              Py_BuildValue("(ssz)", "CPython", branch,
1348                                           svn_revision));
1349         SET_SYS_FROM_STRING("dont_write_bytecode",
1350                              PyBool_FromLong(Py_DontWriteBytecodeFlag));
1351         /*
1352          * These release level checks are mutually exclusive and cover
1353          * the field, so don't get too fancy with the pre-processor!
1354          */
1355 #if PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_ALPHA
1356         s = "alpha";
1357 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_BETA
1358         s = "beta";
1359 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_GAMMA
1360         s = "candidate";
1361 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_FINAL
1362         s = "final";
1363 #endif
1364
1365         SET_SYS_FROM_STRING("version_info",
1366                             Py_BuildValue("iiisi", PY_MAJOR_VERSION,
1367                                                PY_MINOR_VERSION,
1368                                                PY_MICRO_VERSION, s,
1369                                                PY_RELEASE_SERIAL));
1370         SET_SYS_FROM_STRING("api_version",
1371                             PyInt_FromLong(PYTHON_API_VERSION));
1372         SET_SYS_FROM_STRING("copyright",
1373                             PyString_FromString(Py_GetCopyright()));
1374         SET_SYS_FROM_STRING("platform",
1375                             PyString_FromString(Py_GetPlatform()));
1376         SET_SYS_FROM_STRING("executable",
1377                             PyString_FromString(Py_GetProgramFullPath()));
1378         SET_SYS_FROM_STRING("prefix",
1379                             PyString_FromString(Py_GetPrefix()));
1380         SET_SYS_FROM_STRING("exec_prefix",
1381                             PyString_FromString(Py_GetExecPrefix()));
1382         SET_SYS_FROM_STRING("maxsize",
1383                             PyInt_FromSsize_t(PY_SSIZE_T_MAX));
1384         SET_SYS_FROM_STRING("maxint",
1385                             PyInt_FromLong(PyInt_GetMax()));
1386         SET_SYS_FROM_STRING("py3kwarning",
1387                             PyBool_FromLong(Py_Py3kWarningFlag));
1388         SET_SYS_FROM_STRING("float_info",
1389                             PyFloat_GetInfo());
1390 #ifdef Py_USING_UNICODE
1391         SET_SYS_FROM_STRING("maxunicode",
1392                             PyInt_FromLong(PyUnicode_GetMax()));
1393 #endif
1394         SET_SYS_FROM_STRING("builtin_module_names",
1395                             list_builtin_module_names());
1396         {
1397                 /* Assumes that longs are at least 2 bytes long.
1398                    Should be safe! */
1399                 unsigned long number = 1;
1400                 char *value;
1401
1402                 s = (char *) &number;
1403                 if (s[0] == 0)
1404                         value = "big";
1405                 else
1406                         value = "little";
1407                 SET_SYS_FROM_STRING("byteorder",
1408                                     PyString_FromString(value));
1409         }
1410 #ifdef MS_COREDLL
1411         SET_SYS_FROM_STRING("dllhandle",
1412                             PyLong_FromVoidPtr(PyWin_DLLhModule));
1413         SET_SYS_FROM_STRING("winver",
1414                             PyString_FromString(PyWin_DLLVersionString));
1415 #endif
1416         if (warnoptions == NULL) {
1417                 warnoptions = PyList_New(0);
1418         }
1419         else {
1420                 Py_INCREF(warnoptions);
1421         }
1422         if (warnoptions != NULL) {
1423                 PyDict_SetItemString(sysdict, "warnoptions", warnoptions);
1424         }
1425
1426         if (FlagsType.tp_name == 0)
1427                 PyStructSequence_InitType(&FlagsType, &flags_desc);
1428         SET_SYS_FROM_STRING("flags", make_flags());
1429         /* prevent user from creating new instances */
1430         FlagsType.tp_init = NULL;
1431         FlagsType.tp_new = NULL;
1432
1433 #undef SET_SYS_FROM_STRING
1434         if (PyErr_Occurred())
1435                 return NULL;
1436         return m;
1437 }
1438
1439 static PyObject *
1440 makepathobject(char *path, int delim)
1441 {
1442         int i, n;
1443         char *p;
1444         PyObject *v, *w;
1445
1446         n = 1;
1447         p = path;
1448         while ((p = strchr(p, delim)) != NULL) {
1449                 n++;
1450                 p++;
1451         }
1452         v = PyList_New(n);
1453         if (v == NULL)
1454                 return NULL;
1455         for (i = 0; ; i++) {
1456                 p = strchr(path, delim);
1457                 if (p == NULL)
1458                         p = strchr(path, '\0'); /* End of string */
1459                 w = PyString_FromStringAndSize(path, (Py_ssize_t) (p - path));
1460                 if (w == NULL) {
1461                         Py_DECREF(v);
1462                         return NULL;
1463                 }
1464                 PyList_SetItem(v, i, w);
1465                 if (*p == '\0')
1466                         break;
1467                 path = p+1;
1468         }
1469         return v;
1470 }
1471
1472 void
1473 PySys_SetPath(char *path)
1474 {
1475         PyObject *v;
1476         if ((v = makepathobject(path, DELIM)) == NULL)
1477                 Py_FatalError("can't create sys.path");
1478         if (PySys_SetObject("path", v) != 0)
1479                 Py_FatalError("can't assign sys.path");
1480         Py_DECREF(v);
1481 }
1482
1483 static PyObject *
1484 makeargvobject(int argc, char **argv)
1485 {
1486         PyObject *av;
1487         if (argc <= 0 || argv == NULL) {
1488                 /* Ensure at least one (empty) argument is seen */
1489                 static char *empty_argv[1] = {""};
1490                 argv = empty_argv;
1491                 argc = 1;
1492         }
1493         av = PyList_New(argc);
1494         if (av != NULL) {
1495                 int i;
1496                 for (i = 0; i < argc; i++) {
1497 #ifdef __VMS
1498                         PyObject *v;
1499
1500                         /* argv[0] is the script pathname if known */
1501                         if (i == 0) {
1502                                 char* fn = decc$translate_vms(argv[0]);
1503                                 if ((fn == (char *)0) || fn == (char *)-1)
1504                                         v = PyString_FromString(argv[0]);
1505                                 else
1506                                         v = PyString_FromString(
1507                                                 decc$translate_vms(argv[0]));
1508                         } else
1509                                 v = PyString_FromString(argv[i]);
1510 #else
1511                         PyObject *v = PyString_FromString(argv[i]);
1512 #endif
1513                         if (v == NULL) {
1514                                 Py_DECREF(av);
1515                                 av = NULL;
1516                                 break;
1517                         }
1518                         PyList_SetItem(av, i, v);
1519                 }
1520         }
1521         return av;
1522 }
1523
1524 void
1525 PySys_SetArgv(int argc, char **argv)
1526 {
1527 #if defined(HAVE_REALPATH)
1528         char fullpath[MAXPATHLEN];
1529 #elif defined(MS_WINDOWS)
1530         char fullpath[MAX_PATH];
1531 #endif
1532         PyObject *av = makeargvobject(argc, argv);
1533         PyObject *path = PySys_GetObject("path");
1534         if (av == NULL)
1535                 Py_FatalError("no mem for sys.argv");
1536         if (PySys_SetObject("argv", av) != 0)
1537                 Py_FatalError("can't assign sys.argv");
1538         if (path != NULL) {
1539                 char *argv0 = argv[0];
1540                 char *p = NULL;
1541                 Py_ssize_t n = 0;
1542                 PyObject *a;
1543 #ifdef HAVE_READLINK
1544                 char link[MAXPATHLEN+1];
1545                 char argv0copy[2*MAXPATHLEN+1];
1546                 int nr = 0;
1547                 if (argc > 0 && argv0 != NULL && strcmp(argv0, "-c") != 0)
1548                         nr = readlink(argv0, link, MAXPATHLEN);
1549                 if (nr > 0) {
1550                         /* It's a symlink */
1551                         link[nr] = '\0';
1552                         if (link[0] == SEP)
1553                                 argv0 = link; /* Link to absolute path */
1554                         else if (strchr(link, SEP) == NULL)
1555                                 ; /* Link without path */
1556                         else {
1557                                 /* Must join(dirname(argv0), link) */
1558                                 char *q = strrchr(argv0, SEP);
1559                                 if (q == NULL)
1560                                         argv0 = link; /* argv0 without path */
1561                                 else {
1562                                         /* Must make a copy */
1563                                         strcpy(argv0copy, argv0);
1564                                         q = strrchr(argv0copy, SEP);
1565                                         strcpy(q+1, link);
1566                                         argv0 = argv0copy;
1567                                 }
1568                         }
1569                 }
1570 #endif /* HAVE_READLINK */
1571 #if SEP == '\\' /* Special case for MS filename syntax */
1572                 if (argc > 0 && argv0 != NULL && strcmp(argv0, "-c") != 0) {
1573                         char *q;
1574 #ifdef MS_WINDOWS
1575                         char *ptemp;
1576                         if (GetFullPathName(argv0,
1577                                            sizeof(fullpath),
1578                                            fullpath,
1579                                            &ptemp)) {
1580                                 argv0 = fullpath;
1581                         }
1582 #endif
1583                         p = strrchr(argv0, SEP);
1584                         /* Test for alternate separator */
1585                         q = strrchr(p ? p : argv0, '/');
1586                         if (q != NULL)
1587                                 p = q;
1588                         if (p != NULL) {
1589                                 n = p + 1 - argv0;
1590                                 if (n > 1 && p[-1] != ':')
1591                                         n--; /* Drop trailing separator */
1592                         }
1593                 }
1594 #else /* All other filename syntaxes */
1595                 if (argc > 0 && argv0 != NULL && strcmp(argv0, "-c") != 0) {
1596 #if defined(HAVE_REALPATH)
1597                         if (realpath(argv0, fullpath)) {
1598                                 argv0 = fullpath;
1599                         }
1600 #endif
1601                         p = strrchr(argv0, SEP);
1602                 }
1603                 if (p != NULL) {
1604 #ifndef RISCOS
1605                         n = p + 1 - argv0;
1606 #else /* don't include trailing separator */
1607                         n = p - argv0;
1608 #endif /* RISCOS */
1609 #if SEP == '/' /* Special case for Unix filename syntax */
1610                         if (n > 1)
1611                                 n--; /* Drop trailing separator */
1612 #endif /* Unix */
1613                 }
1614 #endif /* All others */
1615                 a = PyString_FromStringAndSize(argv0, n);
1616                 if (a == NULL)
1617                         Py_FatalError("no mem for sys.path insertion");
1618                 if (PyList_Insert(path, 0, a) < 0)
1619                         Py_FatalError("sys.path.insert(0) failed");
1620                 Py_DECREF(a);
1621         }
1622         Py_DECREF(av);
1623 }
1624
1625
1626 /* APIs to write to sys.stdout or sys.stderr using a printf-like interface.
1627    Adapted from code submitted by Just van Rossum.
1628
1629    PySys_WriteStdout(format, ...)
1630    PySys_WriteStderr(format, ...)
1631
1632       The first function writes to sys.stdout; the second to sys.stderr.  When
1633       there is a problem, they write to the real (C level) stdout or stderr;
1634       no exceptions are raised.
1635
1636       Both take a printf-style format string as their first argument followed
1637       by a variable length argument list determined by the format string.
1638
1639       *** WARNING ***
1640
1641       The format should limit the total size of the formatted output string to
1642       1000 bytes.  In particular, this means that no unrestricted "%s" formats
1643       should occur; these should be limited using "%.<N>s where <N> is a
1644       decimal number calculated so that <N> plus the maximum size of other
1645       formatted text does not exceed 1000 bytes.  Also watch out for "%f",
1646       which can print hundreds of digits for very large numbers.
1647
1648  */
1649
1650 static void
1651 mywrite(char *name, FILE *fp, const char *format, va_list va)
1652 {
1653         PyObject *file;
1654         PyObject *error_type, *error_value, *error_traceback;
1655
1656         PyErr_Fetch(&error_type, &error_value, &error_traceback);
1657         file = PySys_GetObject(name);
1658         if (file == NULL || PyFile_AsFile(file) == fp)
1659                 vfprintf(fp, format, va);
1660         else {
1661                 char buffer[1001];
1662                 const int written = PyOS_vsnprintf(buffer, sizeof(buffer),
1663                                                    format, va);
1664                 if (PyFile_WriteString(buffer, file) != 0) {
1665                         PyErr_Clear();
1666                         fputs(buffer, fp);
1667                 }
1668                 if (written < 0 || (size_t)written >= sizeof(buffer)) {
1669                         const char *truncated = "... truncated";
1670                         if (PyFile_WriteString(truncated, file) != 0) {
1671                                 PyErr_Clear();
1672                                 fputs(truncated, fp);
1673                         }
1674                 }
1675         }
1676         PyErr_Restore(error_type, error_value, error_traceback);
1677 }
1678
1679 void
1680 PySys_WriteStdout(const char *format, ...)
1681 {
1682         va_list va;
1683
1684         va_start(va, format);
1685         mywrite("stdout", stdout, format, va);
1686         va_end(va);
1687 }
1688
1689 void
1690 PySys_WriteStderr(const char *format, ...)
1691 {
1692         va_list va;
1693
1694         va_start(va, format);
1695         mywrite("stderr", stderr, format, va);
1696         va_end(va);
1697 }