Include/pyport.h

   1 #ifndef Py_PYPORT_H
   2 #define Py_PYPORT_H
   3
   4 #include "config.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:  LONG_LONG
  31
  32 **************************************************************************/
  33
  34
  35 /* For backward compatibility only. Obsolete, do not use. */
  36 #define ANY void
  37 #ifdef HAVE_PROTOTYPES
  38 #define Py_PROTO(x) x
  39 #else
  40 #define Py_PROTO(x) ()
  41 #endif
  42 #ifndef Py_FPROTO
  43 #define Py_FPROTO(x) Py_PROTO(x)
  44 #endif
  45
  46 /* typedefs for some C9X-defined synonyms for integral types.
  47  *
  48  * The names in Python are exactly the same as the C9X names, except with a
  49  * Py_ prefix.  Until C9X is universally implemented, this is the only way
  50  * to ensure that Python gets reliable names that don't conflict with names
  51  * in non-Python code that are playing their own tricks to define the C9X
  52  * names.
  53  *
  54  * NOTE: don't go nuts here!  Python has no use for *most* of the C9X
  55  * integral synonyms.  Only define the ones we actually need.
  56  */
  57
  58 #ifdef HAVE_LONG_LONG
  59 #ifndef LONG_LONG
  60 #define LONG_LONG long long
  61 #endif
  62 #endif /* HAVE_LONG_LONG */
  63
  64 /* uintptr_t is the C9X name for an unsigned integral type such that a
  65  * legitimate void* can be cast to uintptr_t and then back to void* again
  66  * without loss of information.
  67  */
  68 #ifdef HAVE_UINTPTR_T
  69 typedef uintptr_t Py_uintptr_t;
  70 #elif SIZEOF_VOID_P <= SIZEOF_INT
  71 typedef unsigned int Py_uintptr_t;
  72 #elif SIZEOF_VOID_P <= SIZEOF_LONG
  73 typedef unsigned long Py_uintptr_t;
  74 #elif defined(HAVE_LONG_LONG) && (SIZEOF_VOID_P <= SIZEOF_LONG_LONG)
  75 typedef unsigned LONG_LONG Py_uintptr_t;
  76 #else
  77 #   error "Python needs a typedef for Py_uintptr_t in pyport.h."
  78 #endif /* HAVE_UINTPTR_T */
  79
  80 #ifdef HAVE_STDLIB_H
  81 #include <stdlib.h>
  82 #endif
  83
  84 #include <math.h> /* Moved here from the math section, before extern "C" */
  85
  86 /********************************************
  87  * WRAPPER FOR <time.h> and/or <sys/time.h> *
  88  ********************************************/
  89
  90 #ifdef TIME_WITH_SYS_TIME
  91 #include <sys/time.h>
  92 #include <time.h>
  93 #else /* !TIME_WITH_SYS_TIME */
  94 #ifdef HAVE_SYS_TIME_H
  95 #include <sys/time.h>
  96 #else /* !HAVE_SYS_TIME_H */
  97 #include <time.h>
  98 #endif /* !HAVE_SYS_TIME_H */
  99 #endif /* !TIME_WITH_SYS_TIME */
 100
 101
 102 /******************************
 103  * WRAPPER FOR <sys/select.h> *
 104  ******************************/
 105
 106 /* NB caller must include <sys/types.h> */
 107
 108 #ifdef HAVE_SYS_SELECT_H
 109
 110 #include <sys/select.h>
 111
 112 #else /* !HAVE_SYS_SELECT_H */
 113
 114 #ifdef USE_GUSI1
 115 /* If we don't have sys/select the definition may be in unistd.h */
 116 #include <GUSI.h>
 117 #endif
 118
 119 #endif /* !HAVE_SYS_SELECT_H */
 120
 121 /*******************************
 122  * stat() and fstat() fiddling *
 123  *******************************/
 124
 125 /* We expect that stat and fstat exist on most systems.
 126  *  It's confirmed on Unix, Mac and Windows.
 127  *  If you don't have them, add
 128  *      #define DONT_HAVE_STAT
 129  * and/or
 130  *      #define DONT_HAVE_FSTAT
 131  * to your config.h. Python code beyond this should check HAVE_STAT and
 132  * HAVE_FSTAT instead.
 133  * Also
 134  *      #define DONT_HAVE_SYS_STAT_H
 135  * if <sys/stat.h> doesn't exist on your platform, and
 136  *      #define HAVE_STAT_H
 137  * if <stat.h> does (don't look at me -- ths mess is inherited).
 138  */
 139 #ifndef DONT_HAVE_STAT
 140 #define HAVE_STAT
 141 #endif
 142
 143 #ifndef DONT_HAVE_FSTAT
 144 #define HAVE_FSTAT
 145 #endif
 146
 147 #ifndef DONT_HAVE_SYS_STAT_H
 148 #include <sys/stat.h>
 149 #elif defined(HAVE_STAT_H)
 150 #include <stat.h>
 151 #endif
 152
 153
 154 #ifdef __cplusplus
 155 /* Move this down here since some C++ #include's don't like to be included
 156    inside an extern "C" */
 157 extern "C" {
 158 #endif
 159
 160
 161 /* Py_ARITHMETIC_RIGHT_SHIFT
 162  * C doesn't define whether a right-shift of a signed integer sign-extends
 163  * or zero-fills.  Here a macro to force sign extension:
 164  * Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J)
 165  *    Return I >> J, forcing sign extension.
 166  * Requirements:
 167  *    I is of basic signed type TYPE (char, short, int, long, or long long).
 168  *    TYPE is one of char, short, int, long, or long long, although long long
 169  *    must not be used except on platforms that support it.
 170  *    J is an integer >= 0 and strictly less than the number of bits in TYPE
 171  *    (because C doesn't define what happens for J outside that range either).
 172  * Caution:
 173  *    I may be evaluated more than once.
 174  */
 175 #ifdef SIGNED_RIGHT_SHIFT_ZERO_FILLS
 176 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) \
 177         ((I) < 0 ? ~((~(unsigned TYPE)(I)) >> (J)) : (I) >> (J))
 178 #else
 179 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) ((I) >> (J))
 180 #endif
 181
 182 /* Py_FORCE_EXPANSION(X)
 183  * "Simply" returns its argument.  However, macro expansions within the
 184  * argument are evaluated.  This unfortunate trickery is needed to get
 185  * token-pasting to work as desired in some cases.
 186  */
 187 #define Py_FORCE_EXPANSION(X) X
 188
 189 /* Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW)
 190  * Cast VALUE to type NARROW from type WIDE.  In Py_DEBUG mode, this
 191  * assert-fails if any information is lost.
 192  * Caution:
 193  *    VALUE may be evaluated more than once.
 194  */
 195 #ifdef Py_DEBUG
 196 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) \
 197         (assert((WIDE)(NARROW)(VALUE) == (VALUE)), (NARROW)(VALUE))
 198 #else
 199 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) (NARROW)(VALUE)
 200 #endif
 201
 202 /* Py_IS_INFINITY(X)
 203  * Return 1 if float or double arg is an infinity, else 0.
 204  * Caution:
 205  *    X is evaluated more than once.
 206  *    This implementation may set the underflow flag if |X| is very small;
 207  *    it really can't be implemented correctly (& easily) before C99.
 208  */
 209 #define Py_IS_INFINITY(X) ((X) && (X)*0.5 == (X))
 210
 211 /**************************************************************************
 212 Prototypes that are missing from the standard include files on some systems
 213 (and possibly only some versions of such systems.)
 214
 215 Please be conservative with adding new ones, document them and enclose them
 216 in platform-specific #ifdefs.
 217 **************************************************************************/
 218
 219 #ifdef SOLARIS
 220 /* Unchecked */
 221 extern int gethostname(char *, int);
 222 #endif
 223
 224 #ifdef __BEOS__
 225 /* Unchecked */
 226 /* It's in the libs, but not the headers... - [cjh] */
 227 int shutdown( int, int );
 228 #endif
 229
 230 #ifdef HAVE__GETPTY
 231 #include <sys/types.h>          /* we need to import mode_t */
 232 extern char * _getpty(int *, int, mode_t, int);
 233 #endif
 234
 235 #if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY)
 236 #if !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H)
 237 /* BSDI does not supply a prototype for the 'openpty' and 'forkpty'
 238    functions, even though they are included in libutil. */
 239 #include <termios.h>
 240 extern int openpty(int *, int *, char *, struct termios *, struct winsize *);
 241 extern int forkpty(int *, char *, struct termios *, struct winsize *);
 242 #endif /* !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H) */
 243 #endif /* defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) */
 244
 245
 246 /* These are pulled from various places. It isn't obvious on what platforms
 247    they are necessary, nor what the exact prototype should look like (which
 248    is likely to vary between platforms!) If you find you need one of these
 249    declarations, please move them to a platform-specific block and include
 250    proper prototypes. */
 251 #if 0
 252
 253 /* From Modules/resource.c */
 254 extern int getrusage();
 255 extern int getpagesize();
 256
 257 /* From Python/sysmodule.c and Modules/posixmodule.c */
 258 extern int fclose(FILE *);
 259
 260 /* From Modules/posixmodule.c */
 261 extern int fdatasync(int);
 262 /* XXX These are supposedly for SunOS4.1.3 but "shouldn't hurt elsewhere" */
 263 extern int rename(const char *, const char *);
 264 extern int pclose(FILE *);
 265 extern int lstat(const char *, struct stat *);
 266 extern int symlink(const char *, const char *);
 267 extern int fsync(int fd);
 268
 269 #endif /* 0 */
 270
 271
 272 /************************
 273  * WRAPPER FOR <math.h> *
 274  ************************/
 275
 276 /* On the 68K Mac, when using CFM (Code Fragment Manager),
 277    <math.h> requires special treatment -- we need to surround it with
 278    #pragma lib_export off / on...
 279    This is because MathLib.o is a static library, and exporting its
 280    symbols doesn't quite work...
 281    XXX Not sure now...  Seems to be something else going on as well... */
 282
 283 #ifndef HAVE_HYPOT
 284 extern double hypot(double, double);
 285 #ifdef MWERKS_BEFORE_PRO4
 286 #define hypot we_dont_want_faulty_hypot_decl
 287 #endif
 288 #endif
 289
 290 #ifndef HAVE_HYPOT
 291 #ifdef __MWERKS__
 292 #undef hypot
 293 #endif
 294 #endif
 295
 296 #if defined(USE_MSL) && defined(__MC68K__)
 297 /* CodeWarrior MSL 2.1.1 has weird define overrides that don't work
 298 ** when you take the address of math functions. If I interpret the
 299 ** ANSI C standard correctly this is illegal, but I haven't been able
 300 ** to convince the MetroWerks folks of this...
 301 */
 302 #undef acos
 303 #undef asin
 304 #undef atan
 305 #undef atan2
 306 #undef ceil
 307 #undef cos
 308 #undef cosh
 309 #undef exp
 310 #undef fabs
 311 #undef floor
 312 #undef fmod
 313 #undef log
 314 #undef log10
 315 #undef pow
 316 #undef sin
 317 #undef sinh
 318 #undef sqrt
 319 #undef tan
 320 #undef tanh
 321 #define acos acosd
 322 #define asin asind
 323 #define atan atand
 324 #define atan2 atan2d
 325 #define ceil ceild
 326 #define cos cosd
 327 #define cosh coshd
 328 #define exp expd
 329 #define fabs fabsd
 330 #define floor floord
 331 #define fmod fmodd
 332 #define log logd
 333 #define log10 log10d
 334 #define pow powd
 335 #define sin sind
 336 #define sinh sinhd
 337 #define sqrt sqrtd
 338 #define tan tand
 339 #define tanh tanhd
 340 #endif
 341
 342
 343 /************************************
 344  * MALLOC COMPATIBILITY FOR pymem.h *
 345  ************************************/
 346
 347 #ifndef DL_IMPORT       /* declarations for DLL import */
 348 #define DL_IMPORT(RTYPE) RTYPE
 349 #endif
 350
 351 #ifdef MALLOC_ZERO_RETURNS_NULL
 352 /* XXX Always allocate one extra byte, since some malloc's return NULL
 353    XXX for malloc(0) or realloc(p, 0). */
 354 #define _PyMem_EXTRA 1
 355 #else
 356 #define _PyMem_EXTRA 0
 357 #endif
 358
 359
 360 /* If the fd manipulation macros aren't defined,
 361    here is a set that should do the job */
 362
 363 #if 0 /* disabled and probably obsolete */
 364
 365 #ifndef FD_SETSIZE
 366 #define FD_SETSIZE      256
 367 #endif
 368
 369 #ifndef FD_SET
 370
 371 typedef long fd_mask;
 372
 373 #define NFDBITS (sizeof(fd_mask) * NBBY)        /* bits per mask */
 374 #ifndef howmany
 375 #define howmany(x, y)   (((x)+((y)-1))/(y))
 376 #endif /* howmany */
 377
 378 typedef struct fd_set {
 379         fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
 380 } fd_set;
 381
 382 #define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
 383 #define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
 384 #define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
 385 #define FD_ZERO(p)      memset((char *)(p), '\0', sizeof(*(p)))
 386
 387 #endif /* FD_SET */
 388
 389 #endif /* fd manipulation macros */
 390
 391
 392 /* limits.h constants that may be missing */
 393
 394 #ifndef INT_MAX
 395 #define INT_MAX 2147483647
 396 #endif
 397
 398 #ifndef LONG_MAX
 399 #if SIZEOF_LONG == 4
 400 #define LONG_MAX 0X7FFFFFFFL
 401 #elif SIZEOF_LONG == 8
 402 #define LONG_MAX 0X7FFFFFFFFFFFFFFFL
 403 #else
 404 #error "could not set LONG_MAX in pyport.h"
 405 #endif
 406 #endif
 407
 408 #ifndef LONG_MIN
 409 #define LONG_MIN (-LONG_MAX-1)
 410 #endif
 411
 412 #ifndef LONG_BIT
 413 #define LONG_BIT (8 * SIZEOF_LONG)
 414 #endif
 415
 416 #if LONG_BIT != 8 * SIZEOF_LONG
 417 /* 04-Oct-2000 LONG_BIT is apparently (mis)defined as 64 on some recent
 418  * 32-bit platforms using gcc.  We try to catch that here at compile-time
 419  * rather than waiting for integer multiplication to trigger bogus
 420  * overflows.
 421  */
 422 #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
 423 #endif
 424
 425 #ifdef __NeXT__
 426 #ifdef __sparc__
 427 /*
 428  * This works around a bug in the NS/Sparc 3.3 pre-release
 429  * limits.h header file.
 430  * 10-Feb-1995 bwarsaw@cnri.reston.va.us
 431  */
 432 #undef LONG_MIN
 433 #define LONG_MIN (-LONG_MAX-1)
 434 #endif
 435 #endif
 436
 437 /*
 438  * Rename some functions for the Borland compiler
 439  */
 440 #ifdef __BORLANDC__
 441 #  include <io.h>
 442 #  define _chsize chsize
 443 #  define _setmode setmode
 444 #endif
 445
 446 #ifdef __cplusplus
 447 }
 448 #endif
 449
 450 #endif /* Py_PYPORT_H */