Include/pyport.h

   1 #ifndef Py_PYPORT_H
   2 #define Py_PYPORT_H
   3
   4 #include "pyconfig.h" /* include for defines */
   5
   6 /**************************************************************************
   7 Symbols and macros to supply platform-independent interfaces to basic
   8 C language & library operations whose spellings vary across platforms.
   9
  10 Please try to make documentation here as clear as possible:  by definition,
  11 the stuff here is trying to illuminate C's darkest corners.
  12
  13 Config #defines referenced here:
  14
  15 SIGNED_RIGHT_SHIFT_ZERO_FILLS
  16 Meaning:  To be defined iff i>>j does not extend the sign bit when i is a
  17           signed integral type and i < 0.
  18 Used in:  Py_ARITHMETIC_RIGHT_SHIFT
  19
  20 Py_DEBUG
  21 Meaning:  Extra checks compiled in for debug mode.
  22 Used in:  Py_SAFE_DOWNCAST
  23
  24 HAVE_UINTPTR_T
  25 Meaning:  The C9X type uintptr_t is supported by the compiler
  26 Used in:  Py_uintptr_t
  27
  28 HAVE_LONG_LONG
  29 Meaning:  The compiler supports the C type "long long"
  30 Used in:  PY_LONG_LONG
  31
  32 **************************************************************************/
  33
  34
  35 /* For backward compatibility only. Obsolete, do not use. */
  36 #ifdef HAVE_PROTOTYPES
  37 #define Py_PROTO(x) x
  38 #else
  39 #define Py_PROTO(x) ()
  40 #endif
  41 #ifndef Py_FPROTO
  42 #define Py_FPROTO(x) Py_PROTO(x)
  43 #endif
  44
  45 /* typedefs for some C9X-defined synonyms for integral types.
  46  *
  47  * The names in Python are exactly the same as the C9X names, except with a
  48  * Py_ prefix.  Until C9X is universally implemented, this is the only way
  49  * to ensure that Python gets reliable names that don't conflict with names
  50  * in non-Python code that are playing their own tricks to define the C9X
  51  * names.
  52  *
  53  * NOTE: don't go nuts here!  Python has no use for *most* of the C9X
  54  * integral synonyms.  Only define the ones we actually need.
  55  */
  56
  57 #ifdef HAVE_LONG_LONG
  58 #ifndef PY_LONG_LONG
  59 #define PY_LONG_LONG long long
  60 #endif
  61 #endif /* HAVE_LONG_LONG */
  62
  63 /* uintptr_t is the C9X name for an unsigned integral type such that a
  64  * legitimate void* can be cast to uintptr_t and then back to void* again
  65  * without loss of information.  Similarly for intptr_t, wrt a signed
  66  * integral type.
  67  */
  68 #ifdef HAVE_UINTPTR_T
  69 typedef uintptr_t       Py_uintptr_t;
  70 typedef intptr_t        Py_intptr_t;
  71
  72 #elif SIZEOF_VOID_P <= SIZEOF_INT
  73 typedef unsigned int    Py_uintptr_t;
  74 typedef int             Py_intptr_t;
  75
  76 #elif SIZEOF_VOID_P <= SIZEOF_LONG
  77 typedef unsigned long   Py_uintptr_t;
  78 typedef long            Py_intptr_t;
  79
  80 #elif defined(HAVE_LONG_LONG) && (SIZEOF_VOID_P <= SIZEOF_LONG_LONG)
  81 typedef unsigned PY_LONG_LONG   Py_uintptr_t;
  82 typedef PY_LONG_LONG            Py_intptr_t;
  83
  84 #else
  85 #   error "Python needs a typedef for Py_uintptr_t in pyport.h."
  86 #endif /* HAVE_UINTPTR_T */
  87
  88 #ifdef HAVE_STDLIB_H
  89 #include <stdlib.h>
  90 #endif
  91
  92 #include <math.h> /* Moved here from the math section, before extern "C" */
  93
  94 /********************************************
  95  * WRAPPER FOR <time.h> and/or <sys/time.h> *
  96  ********************************************/
  97
  98 #ifdef TIME_WITH_SYS_TIME
  99 #include <sys/time.h>
 100 #include <time.h>
 101 #else /* !TIME_WITH_SYS_TIME */
 102 #ifdef HAVE_SYS_TIME_H
 103 #include <sys/time.h>
 104 #else /* !HAVE_SYS_TIME_H */
 105 #include <time.h>
 106 #endif /* !HAVE_SYS_TIME_H */
 107 #endif /* !TIME_WITH_SYS_TIME */
 108
 109
 110 /******************************
 111  * WRAPPER FOR <sys/select.h> *
 112  ******************************/
 113
 114 /* NB caller must include <sys/types.h> */
 115
 116 #ifdef HAVE_SYS_SELECT_H
 117
 118 #include <sys/select.h>
 119
 120 #endif /* !HAVE_SYS_SELECT_H */
 121
 122 /*******************************
 123  * stat() and fstat() fiddling *
 124  *******************************/
 125
 126 /* We expect that stat and fstat exist on most systems.
 127  *  It's confirmed on Unix, Mac and Windows.
 128  *  If you don't have them, add
 129  *      #define DONT_HAVE_STAT
 130  * and/or
 131  *      #define DONT_HAVE_FSTAT
 132  * to your pyconfig.h. Python code beyond this should check HAVE_STAT and
 133  * HAVE_FSTAT instead.
 134  * Also
 135  *      #define DONT_HAVE_SYS_STAT_H
 136  * if <sys/stat.h> doesn't exist on your platform, and
 137  *      #define HAVE_STAT_H
 138  * if <stat.h> does (don't look at me -- ths mess is inherited).
 139  */
 140 #ifndef DONT_HAVE_STAT
 141 #define HAVE_STAT
 142 #endif
 143
 144 #ifndef DONT_HAVE_FSTAT
 145 #define HAVE_FSTAT
 146 #endif
 147
 148 #ifdef RISCOS
 149 #include <sys/types.h>
 150 #include "unixstuff.h"
 151 #endif
 152
 153 #ifndef DONT_HAVE_SYS_STAT_H
 154 #if defined(PYOS_OS2) && defined(PYCC_GCC)
 155 #include <sys/types.h>
 156 #endif
 157 #include <sys/stat.h>
 158 #elif defined(HAVE_STAT_H)
 159 #include <stat.h>
 160 #endif
 161
 162 #if defined(PYCC_VACPP)
 163 /* VisualAge C/C++ Failed to Define MountType Field in sys/stat.h */
 164 #define S_IFMT (S_IFDIR|S_IFCHR|S_IFREG)
 165 #endif
 166
 167 #ifndef S_ISREG
 168 #define S_ISREG(x) (((x) & S_IFMT) == S_IFREG)
 169 #endif
 170
 171 #ifndef S_ISDIR
 172 #define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
 173 #endif
 174
 175
 176 #ifdef __cplusplus
 177 /* Move this down here since some C++ #include's don't like to be included
 178    inside an extern "C" */
 179 extern "C" {
 180 #endif
 181
 182
 183 /* Py_ARITHMETIC_RIGHT_SHIFT
 184  * C doesn't define whether a right-shift of a signed integer sign-extends
 185  * or zero-fills.  Here a macro to force sign extension:
 186  * Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J)
 187  *    Return I >> J, forcing sign extension.
 188  * Requirements:
 189  *    I is of basic signed type TYPE (char, short, int, long, or long long).
 190  *    TYPE is one of char, short, int, long, or long long, although long long
 191  *    must not be used except on platforms that support it.
 192  *    J is an integer >= 0 and strictly less than the number of bits in TYPE
 193  *    (because C doesn't define what happens for J outside that range either).
 194  * Caution:
 195  *    I may be evaluated more than once.
 196  */
 197 #ifdef SIGNED_RIGHT_SHIFT_ZERO_FILLS
 198 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) \
 199         ((I) < 0 ? ~((~(unsigned TYPE)(I)) >> (J)) : (I) >> (J))
 200 #else
 201 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) ((I) >> (J))
 202 #endif
 203
 204 /* Py_FORCE_EXPANSION(X)
 205  * "Simply" returns its argument.  However, macro expansions within the
 206  * argument are evaluated.  This unfortunate trickery is needed to get
 207  * token-pasting to work as desired in some cases.
 208  */
 209 #define Py_FORCE_EXPANSION(X) X
 210
 211 /* Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW)
 212  * Cast VALUE to type NARROW from type WIDE.  In Py_DEBUG mode, this
 213  * assert-fails if any information is lost.
 214  * Caution:
 215  *    VALUE may be evaluated more than once.
 216  */
 217 #ifdef Py_DEBUG
 218 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) \
 219         (assert((WIDE)(NARROW)(VALUE) == (VALUE)), (NARROW)(VALUE))
 220 #else
 221 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) (NARROW)(VALUE)
 222 #endif
 223
 224 /* Py_IS_INFINITY(X)
 225  * Return 1 if float or double arg is an infinity, else 0.
 226  * Caution:
 227  *    X is evaluated more than once.
 228  *    This implementation may set the underflow flag if |X| is very small;
 229  *    it really can't be implemented correctly (& easily) before C99.
 230  */
 231 #define Py_IS_INFINITY(X) ((X) && (X)*0.5 == (X))
 232
 233 /* HUGE_VAL is supposed to expand to a positive double infinity.  Python
 234  * uses Py_HUGE_VAL instead because some platforms are broken in this
 235  * respect.  We used to embed code in pyport.h to try to worm around that,
 236  * but different platforms are broken in conflicting ways.  If you're on
 237  * a platform where HUGE_VAL is defined incorrectly, fiddle your Python
 238  * config to #define Py_HUGE_VAL to something that works on your platform.
 239  */
 240 #ifndef Py_HUGE_VAL
 241 #define Py_HUGE_VAL HUGE_VAL
 242 #endif
 243
 244 /* Py_OVERFLOWED(X)
 245  * Return 1 iff a libm function overflowed.  Set errno to 0 before calling
 246  * a libm function, and invoke this macro after, passing the function
 247  * result.
 248  * Caution:
 249  *    This isn't reliable.  C99 no longer requires libm to set errno under
 250  *        any exceptional condition, but does require +- HUGE_VAL return
 251  *        values on overflow.  A 754 box *probably* maps HUGE_VAL to a
 252  *        double infinity, and we're cool if that's so, unless the input
 253  *        was an infinity and an infinity is the expected result.  A C89
 254  *        system sets errno to ERANGE, so we check for that too.  We're
 255  *        out of luck if a C99 754 box doesn't map HUGE_VAL to +Inf, or
 256  *        if the returned result is a NaN, or if a C89 box returns HUGE_VAL
 257  *        in non-overflow cases.
 258  *    X is evaluated more than once.
 259  * Some platforms have better way to spell this, so expect some #ifdef'ery.
 260  */
 261 #ifdef __FreeBSD__
 262 #define Py_OVERFLOWED(X) isinf(X)
 263 #else
 264 #define Py_OVERFLOWED(X) ((X) != 0.0 && (errno == ERANGE ||    \
 265                                          (X) == Py_HUGE_VAL || \
 266                                          (X) == -Py_HUGE_VAL))
 267 #endif
 268
 269 /* Py_SET_ERANGE_ON_OVERFLOW(x)
 270  * If a libm function did not set errno, but it looks like the result
 271  * overflowed, set errno to ERANGE.  Set errno to 0 before calling a libm
 272  * function, and invoke this macro after, passing the function result.
 273  * Caution:
 274  *    This isn't reliable.  See Py_OVERFLOWED comments.
 275  *    X is evaluated more than once.
 276  */
 277 #define Py_SET_ERANGE_IF_OVERFLOW(X) \
 278         do { \
 279                 if (errno == 0 && ((X) == Py_HUGE_VAL ||  \
 280                                    (X) == -Py_HUGE_VAL))  \
 281                         errno = ERANGE; \
 282         } while(0)
 283
 284 /* Py_ADJUST_ERANGE1(x)
 285  * Py_ADJUST_ERANGE2(x, y)
 286  * Set errno to 0 before calling a libm function, and invoke one of these
 287  * macros after, passing the function result(s) (Py_ADJUST_ERANGE2 is useful
 288  * for functions returning complex results).  This makes two kinds of
 289  * adjustments to errno:  (A) If it looks like the platform libm set
 290  * errno=ERANGE due to underflow, clear errno. (B) If it looks like the
 291  * platform libm overflowed but didn't set errno, force errno to ERANGE.  In
 292  * effect, we're trying to force a useful implementation of C89 errno
 293  * behavior.
 294  * Caution:
 295  *    This isn't reliable.  See Py_OVERFLOWED comments.
 296  *    X and Y may be evaluated more than once.
 297  */
 298 #define Py_ADJUST_ERANGE1(X)                                            \
 299         do {                                                            \
 300                 if (errno == 0) {                                       \
 301                         if ((X) == Py_HUGE_VAL || (X) == -Py_HUGE_VAL)  \
 302                                 errno = ERANGE;                         \
 303                 }                                                       \
 304                 else if (errno == ERANGE && (X) == 0.0)                 \
 305                         errno = 0;                                      \
 306         } while(0)
 307
 308 #define Py_ADJUST_ERANGE2(X, Y)                                         \
 309         do {                                                            \
 310                 if ((X) == Py_HUGE_VAL || (X) == -Py_HUGE_VAL ||        \
 311                     (Y) == Py_HUGE_VAL || (Y) == -Py_HUGE_VAL) {        \
 312                                 if (errno == 0)                         \
 313                                         errno = ERANGE;                 \
 314                 }                                                       \
 315                 else if (errno == ERANGE)                               \
 316                         errno = 0;                                      \
 317         } while(0)
 318
 319 /* Py_DEPRECATED(version)
 320  * Declare a variable, type, or function deprecated.
 321  * Usage:
 322  *    extern int old_var Py_DEPRECATED(2.3);
 323  *    typedef int T1 Py_DEPRECATED(2.4);
 324  *    extern int x() Py_DEPRECATED(2.5);
 325  */
 326 #if defined(__GNUC__) && (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1)
 327 #define Py_DEPRECATED(VERSION_UNUSED) __attribute__((__deprecated__))
 328 #else
 329 #define Py_DEPRECATED(VERSION_UNUSED)
 330 #endif
 331
 332 /**************************************************************************
 333 Prototypes that are missing from the standard include files on some systems
 334 (and possibly only some versions of such systems.)
 335
 336 Please be conservative with adding new ones, document them and enclose them
 337 in platform-specific #ifdefs.
 338 **************************************************************************/
 339
 340 #ifdef SOLARIS
 341 /* Unchecked */
 342 extern int gethostname(char *, int);
 343 #endif
 344
 345 #ifdef __BEOS__
 346 /* Unchecked */
 347 /* It's in the libs, but not the headers... - [cjh] */
 348 int shutdown( int, int );
 349 #endif
 350
 351 #ifdef HAVE__GETPTY
 352 #include <sys/types.h>          /* we need to import mode_t */
 353 extern char * _getpty(int *, int, mode_t, int);
 354 #endif
 355
 356 #if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY)
 357 #if !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H)
 358 /* BSDI does not supply a prototype for the 'openpty' and 'forkpty'
 359    functions, even though they are included in libutil. */
 360 #include <termios.h>
 361 extern int openpty(int *, int *, char *, struct termios *, struct winsize *);
 362 extern int forkpty(int *, char *, struct termios *, struct winsize *);
 363 #endif /* !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H) */
 364 #endif /* defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) */
 365
 366
 367 /* These are pulled from various places. It isn't obvious on what platforms
 368    they are necessary, nor what the exact prototype should look like (which
 369    is likely to vary between platforms!) If you find you need one of these
 370    declarations, please move them to a platform-specific block and include
 371    proper prototypes. */
 372 #if 0
 373
 374 /* From Modules/resource.c */
 375 extern int getrusage();
 376 extern int getpagesize();
 377
 378 /* From Python/sysmodule.c and Modules/posixmodule.c */
 379 extern int fclose(FILE *);
 380
 381 /* From Modules/posixmodule.c */
 382 extern int fdatasync(int);
 383 /* XXX These are supposedly for SunOS4.1.3 but "shouldn't hurt elsewhere" */
 384 extern int rename(const char *, const char *);
 385 extern int pclose(FILE *);
 386 extern int lstat(const char *, struct stat *);
 387 extern int symlink(const char *, const char *);
 388 extern int fsync(int fd);
 389
 390 #endif /* 0 */
 391
 392
 393 /************************
 394  * WRAPPER FOR <math.h> *
 395  ************************/
 396
 397 #ifndef HAVE_HYPOT
 398 extern double hypot(double, double);
 399 #endif
 400
 401 /* Declarations for symbol visibility.
 402
 403   PyAPI_FUNC(type): Declares a public Python API function and return type
 404   PyAPI_DATA(type): Declares public Python data and its type
 405   PyMODINIT_FUNC:   A Python module init function.  If these functions are
 406                     inside the Python core, they are private to the core.
 407                     If in an extension module, it may be declared with
 408                     external linkage depending on the platform.
 409
 410   As a number of platforms support/require "__declspec(dllimport/dllexport)",
 411   we support a HAVE_DECLSPEC_DLL macro to save duplication.
 412 */
 413
 414 /*
 415   All windows ports, except cygwin, are handled in PC/pyconfig.h.
 416
 417   BeOS and cygwin are the only other autoconf platform requiring special
 418   linkage handling and both of these use __declspec().
 419 */
 420 #if defined(__CYGWIN__) || defined(__BEOS__)
 421 #       define HAVE_DECLSPEC_DLL
 422 #endif
 423
 424 #if defined(Py_ENABLE_SHARED) /* only get special linkage if built as shared */
 425 #       if defined(HAVE_DECLSPEC_DLL)
 426 #               ifdef Py_BUILD_CORE
 427 #                       define PyAPI_FUNC(RTYPE) __declspec(dllexport) RTYPE
 428 #                       define PyAPI_DATA(RTYPE) extern __declspec(dllexport) RTYPE
 429                         /* module init functions inside the core need no external linkage */
 430 #                       define PyMODINIT_FUNC void
 431 #               else /* Py_BUILD_CORE */
 432                         /* Building an extension module, or an embedded situation */
 433                         /* public Python functions and data are imported */
 434                         /* Under Cygwin, auto-import functions to prevent compilation */
 435                         /* failures similar to http://python.org/doc/FAQ.html#3.24 */
 436 #                       if !defined(__CYGWIN__)
 437 #                               define PyAPI_FUNC(RTYPE) __declspec(dllimport) RTYPE
 438 #                       endif /* !__CYGWIN__ */
 439 #                       define PyAPI_DATA(RTYPE) extern __declspec(dllimport) RTYPE
 440                         /* module init functions outside the core must be exported */
 441 #                       if defined(__cplusplus)
 442 #                               define PyMODINIT_FUNC extern "C" __declspec(dllexport) void
 443 #                       else /* __cplusplus */
 444 #                               define PyMODINIT_FUNC __declspec(dllexport) void
 445 #                       endif /* __cplusplus */
 446 #               endif /* Py_BUILD_CORE */
 447 #       endif /* HAVE_DECLSPEC */
 448 #endif /* Py_ENABLE_SHARED */
 449
 450 /* If no external linkage macros defined by now, create defaults */
 451 #ifndef PyAPI_FUNC
 452 #       define PyAPI_FUNC(RTYPE) RTYPE
 453 #endif
 454 #ifndef PyAPI_DATA
 455 #       define PyAPI_DATA(RTYPE) extern RTYPE
 456 #endif
 457 #ifndef PyMODINIT_FUNC
 458 #       if defined(__cplusplus)
 459 #               define PyMODINIT_FUNC extern "C" void
 460 #       else /* __cplusplus */
 461 #               define PyMODINIT_FUNC void
 462 #       endif /* __cplusplus */
 463 #endif
 464
 465 /* Deprecated DL_IMPORT and DL_EXPORT macros */
 466 #if defined(Py_ENABLE_SHARED) && defined (HAVE_DECLSPEC_DLL)
 467 #       if defined(Py_BUILD_CORE)
 468 #               define DL_IMPORT(RTYPE) __declspec(dllexport) RTYPE
 469 #               define DL_EXPORT(RTYPE) __declspec(dllexport) RTYPE
 470 #       else
 471 #               define DL_IMPORT(RTYPE) __declspec(dllimport) RTYPE
 472 #               define DL_EXPORT(RTYPE) __declspec(dllexport) RTYPE
 473 #       endif
 474 #endif
 475 #ifndef DL_EXPORT
 476 #       define DL_EXPORT(RTYPE) RTYPE
 477 #endif
 478 #ifndef DL_IMPORT
 479 #       define DL_IMPORT(RTYPE) RTYPE
 480 #endif
 481 /* End of deprecated DL_* macros */
 482
 483 /* If the fd manipulation macros aren't defined,
 484    here is a set that should do the job */
 485
 486 #if 0 /* disabled and probably obsolete */
 487
 488 #ifndef FD_SETSIZE
 489 #define FD_SETSIZE      256
 490 #endif
 491
 492 #ifndef FD_SET
 493
 494 typedef long fd_mask;
 495
 496 #define NFDBITS (sizeof(fd_mask) * NBBY)        /* bits per mask */
 497 #ifndef howmany
 498 #define howmany(x, y)   (((x)+((y)-1))/(y))
 499 #endif /* howmany */
 500
 501 typedef struct fd_set {
 502         fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
 503 } fd_set;
 504
 505 #define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
 506 #define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
 507 #define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
 508 #define FD_ZERO(p)      memset((char *)(p), '\0', sizeof(*(p)))
 509
 510 #endif /* FD_SET */
 511
 512 #endif /* fd manipulation macros */
 513
 514
 515 /* limits.h constants that may be missing */
 516
 517 #ifndef INT_MAX
 518 #define INT_MAX 2147483647
 519 #endif
 520
 521 #ifndef LONG_MAX
 522 #if SIZEOF_LONG == 4
 523 #define LONG_MAX 0X7FFFFFFFL
 524 #elif SIZEOF_LONG == 8
 525 #define LONG_MAX 0X7FFFFFFFFFFFFFFFL
 526 #else
 527 #error "could not set LONG_MAX in pyport.h"
 528 #endif
 529 #endif
 530
 531 #ifndef LONG_MIN
 532 #define LONG_MIN (-LONG_MAX-1)
 533 #endif
 534
 535 #ifndef LONG_BIT
 536 #define LONG_BIT (8 * SIZEOF_LONG)
 537 #endif
 538
 539 #if LONG_BIT != 8 * SIZEOF_LONG
 540 /* 04-Oct-2000 LONG_BIT is apparently (mis)defined as 64 on some recent
 541  * 32-bit platforms using gcc.  We try to catch that here at compile-time
 542  * rather than waiting for integer multiplication to trigger bogus
 543  * overflows.
 544  */
 545 #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
 546 #endif
 547
 548 #ifdef __cplusplus
 549 }
 550 #endif
 551
 552 /*
 553  * Hide GCC attributes from compilers that don't support them.
 554  */
 555 #if (!defined(__GNUC__) || __GNUC__ < 2 || \
 556      (__GNUC__ == 2 && __GNUC_MINOR__ < 7) ) && \
 557     !defined(RISCOS)
 558 #define Py_GCC_ATTRIBUTE(x)
 559 #else
 560 #define Py_GCC_ATTRIBUTE(x) __attribute__(x)
 561 #endif
 562
 563 #endif /* Py_PYPORT_H */