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:  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 pyconfig.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 #if defined(PYCC_VACPP)
 154 /* VisualAge C/C++ Failed to Define MountType Field in sys/stat.h */
 155 #define S_IFMT (S_IFDIR|S_IFCHR|S_IFREG)
 156 #endif
 157
 158 #ifndef S_ISREG
 159 #define S_ISREG(x) (((x) & S_IFMT) == S_IFREG)
 160 #endif
 161
 162 #ifndef S_ISDIR
 163 #define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
 164 #endif
 165
 166
 167 #ifdef __cplusplus
 168 /* Move this down here since some C++ #include's don't like to be included
 169    inside an extern "C" */
 170 extern "C" {
 171 #endif
 172
 173
 174 /* Py_ARITHMETIC_RIGHT_SHIFT
 175  * C doesn't define whether a right-shift of a signed integer sign-extends
 176  * or zero-fills.  Here a macro to force sign extension:
 177  * Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J)
 178  *    Return I >> J, forcing sign extension.
 179  * Requirements:
 180  *    I is of basic signed type TYPE (char, short, int, long, or long long).
 181  *    TYPE is one of char, short, int, long, or long long, although long long
 182  *    must not be used except on platforms that support it.
 183  *    J is an integer >= 0 and strictly less than the number of bits in TYPE
 184  *    (because C doesn't define what happens for J outside that range either).
 185  * Caution:
 186  *    I may be evaluated more than once.
 187  */
 188 #ifdef SIGNED_RIGHT_SHIFT_ZERO_FILLS
 189 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) \
 190         ((I) < 0 ? ~((~(unsigned TYPE)(I)) >> (J)) : (I) >> (J))
 191 #else
 192 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) ((I) >> (J))
 193 #endif
 194
 195 /* Py_FORCE_EXPANSION(X)
 196  * "Simply" returns its argument.  However, macro expansions within the
 197  * argument are evaluated.  This unfortunate trickery is needed to get
 198  * token-pasting to work as desired in some cases.
 199  */
 200 #define Py_FORCE_EXPANSION(X) X
 201
 202 /* Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW)
 203  * Cast VALUE to type NARROW from type WIDE.  In Py_DEBUG mode, this
 204  * assert-fails if any information is lost.
 205  * Caution:
 206  *    VALUE may be evaluated more than once.
 207  */
 208 #ifdef Py_DEBUG
 209 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) \
 210         (assert((WIDE)(NARROW)(VALUE) == (VALUE)), (NARROW)(VALUE))
 211 #else
 212 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) (NARROW)(VALUE)
 213 #endif
 214
 215 /* Py_IS_INFINITY(X)
 216  * Return 1 if float or double arg is an infinity, else 0.
 217  * Caution:
 218  *    X is evaluated more than once.
 219  *    This implementation may set the underflow flag if |X| is very small;
 220  *    it really can't be implemented correctly (& easily) before C99.
 221  */
 222 #define Py_IS_INFINITY(X) ((X) && (X)*0.5 == (X))
 223
 224 /**************************************************************************
 225 Prototypes that are missing from the standard include files on some systems
 226 (and possibly only some versions of such systems.)
 227
 228 Please be conservative with adding new ones, document them and enclose them
 229 in platform-specific #ifdefs.
 230 **************************************************************************/
 231
 232 #ifdef SOLARIS
 233 /* Unchecked */
 234 extern int gethostname(char *, int);
 235 #endif
 236
 237 #ifdef __BEOS__
 238 /* Unchecked */
 239 /* It's in the libs, but not the headers... - [cjh] */
 240 int shutdown( int, int );
 241 #endif
 242
 243 #ifdef HAVE__GETPTY
 244 #include <sys/types.h>          /* we need to import mode_t */
 245 extern char * _getpty(int *, int, mode_t, int);
 246 #endif
 247
 248 #if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY)
 249 #if !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H)
 250 /* BSDI does not supply a prototype for the 'openpty' and 'forkpty'
 251    functions, even though they are included in libutil. */
 252 #include <termios.h>
 253 extern int openpty(int *, int *, char *, struct termios *, struct winsize *);
 254 extern int forkpty(int *, char *, struct termios *, struct winsize *);
 255 #endif /* !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H) */
 256 #endif /* defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) */
 257
 258
 259 /* These are pulled from various places. It isn't obvious on what platforms
 260    they are necessary, nor what the exact prototype should look like (which
 261    is likely to vary between platforms!) If you find you need one of these
 262    declarations, please move them to a platform-specific block and include
 263    proper prototypes. */
 264 #if 0
 265
 266 /* From Modules/resource.c */
 267 extern int getrusage();
 268 extern int getpagesize();
 269
 270 /* From Python/sysmodule.c and Modules/posixmodule.c */
 271 extern int fclose(FILE *);
 272
 273 /* From Modules/posixmodule.c */
 274 extern int fdatasync(int);
 275 /* XXX These are supposedly for SunOS4.1.3 but "shouldn't hurt elsewhere" */
 276 extern int rename(const char *, const char *);
 277 extern int pclose(FILE *);
 278 extern int lstat(const char *, struct stat *);
 279 extern int symlink(const char *, const char *);
 280 extern int fsync(int fd);
 281
 282 #endif /* 0 */
 283
 284
 285 /************************
 286  * WRAPPER FOR <math.h> *
 287  ************************/
 288
 289 #ifndef HAVE_HYPOT
 290 extern double hypot(double, double);
 291 #endif
 292
 293
 294 /************************************
 295  * MALLOC COMPATIBILITY FOR pymem.h *
 296  ************************************/
 297
 298 #ifndef DL_IMPORT       /* declarations for DLL import */
 299 #define DL_IMPORT(RTYPE) RTYPE
 300 #endif
 301
 302 #ifdef MALLOC_ZERO_RETURNS_NULL
 303 /* XXX Always allocate one extra byte, since some malloc's return NULL
 304    XXX for malloc(0) or realloc(p, 0). */
 305 #define _PyMem_EXTRA 1
 306 #else
 307 #define _PyMem_EXTRA 0
 308 #endif
 309
 310
 311 /* If the fd manipulation macros aren't defined,
 312    here is a set that should do the job */
 313
 314 #if 0 /* disabled and probably obsolete */
 315
 316 #ifndef FD_SETSIZE
 317 #define FD_SETSIZE      256
 318 #endif
 319
 320 #ifndef FD_SET
 321
 322 typedef long fd_mask;
 323
 324 #define NFDBITS (sizeof(fd_mask) * NBBY)        /* bits per mask */
 325 #ifndef howmany
 326 #define howmany(x, y)   (((x)+((y)-1))/(y))
 327 #endif /* howmany */
 328
 329 typedef struct fd_set {
 330         fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
 331 } fd_set;
 332
 333 #define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
 334 #define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
 335 #define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
 336 #define FD_ZERO(p)      memset((char *)(p), '\0', sizeof(*(p)))
 337
 338 #endif /* FD_SET */
 339
 340 #endif /* fd manipulation macros */
 341
 342
 343 /* limits.h constants that may be missing */
 344
 345 #ifndef INT_MAX
 346 #define INT_MAX 2147483647
 347 #endif
 348
 349 #ifndef LONG_MAX
 350 #if SIZEOF_LONG == 4
 351 #define LONG_MAX 0X7FFFFFFFL
 352 #elif SIZEOF_LONG == 8
 353 #define LONG_MAX 0X7FFFFFFFFFFFFFFFL
 354 #else
 355 #error "could not set LONG_MAX in pyport.h"
 356 #endif
 357 #endif
 358
 359 #ifndef LONG_MIN
 360 #define LONG_MIN (-LONG_MAX-1)
 361 #endif
 362
 363 #ifndef LONG_BIT
 364 #define LONG_BIT (8 * SIZEOF_LONG)
 365 #endif
 366
 367 #if LONG_BIT != 8 * SIZEOF_LONG
 368 /* 04-Oct-2000 LONG_BIT is apparently (mis)defined as 64 on some recent
 369  * 32-bit platforms using gcc.  We try to catch that here at compile-time
 370  * rather than waiting for integer multiplication to trigger bogus
 371  * overflows.
 372  */
 373 #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
 374 #endif
 375
 376 /*
 377  * Rename some functions for the Borland compiler
 378  */
 379 #ifdef __BORLANDC__
 380 #  include <io.h>
 381 #  define _chsize chsize
 382 #  define _setmode setmode
 383 #endif
 384
 385 #ifdef __cplusplus
 386 }
 387 #endif
 388
 389 #endif /* Py_PYPORT_H */