Include/pyport.h

   1 /***********************************************************
   2 Copyright (c) 2000, BeOpen.com.
   3 All rights reserved.
   4
   5 See the file "Misc/COPYRIGHT" for information on usage and
   6 redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
   7 ******************************************************************/
   8
   9 #ifndef Py_PYPORT_H
  10 #define Py_PYPORT_H
  11
  12 #include "config.h" /* include for defines */
  13
  14 /**************************************************************************
  15 Symbols and macros to supply platform-independent interfaces to basic
  16 C language & library operations whose spellings vary across platforms.
  17
  18 Please try to make documentation here as clear as possible:  by definition,
  19 the stuff here is trying to illuminate C's darkest corners.
  20
  21 Config #defines referenced here:
  22
  23 SIGNED_RIGHT_SHIFT_ZERO_FILLS
  24 Meaning:  To be defined iff i>>j does not extend the sign bit when i is a
  25           signed integral type and i < 0.
  26 Used in:  Py_ARITHMETIC_RIGHT_SHIFT
  27
  28 Py_DEBUG
  29 Meaning:  Extra checks compiled in for debug mode.
  30 Used in:  Py_SAFE_DOWNCAST
  31 **************************************************************************/
  32
  33
  34 #define ANY void /* For API compatibility only. Obsolete, do not use. */
  35
  36 #ifdef HAVE_STDLIB_H
  37 #include <stdlib.h>
  38 #endif
  39
  40 #include <math.h> /* Moved here from the math section, before extern "C" */
  41
  42 /********************************************
  43  * WRAPPER FOR <time.h> and/or <sys/time.h> *
  44  ********************************************/
  45
  46 #ifdef TIME_WITH_SYS_TIME
  47 #include <sys/time.h>
  48 #include <time.h>
  49 #else /* !TIME_WITH_SYS_TIME */
  50 #ifdef HAVE_SYS_TIME_H
  51 #include <sys/time.h>
  52 #else /* !HAVE_SYS_TIME_H */
  53 #include <time.h>
  54 #endif /* !HAVE_SYS_TIME_H */
  55 #endif /* !TIME_WITH_SYS_TIME */
  56
  57
  58 /******************************
  59  * WRAPPER FOR <sys/select.h> *
  60  ******************************/
  61
  62 /* NB caller must include <sys/types.h> */
  63
  64 #ifdef HAVE_SYS_SELECT_H
  65
  66 #include <sys/select.h>
  67
  68 #else /* !HAVE_SYS_SELECT_H */
  69
  70 #ifdef USE_GUSI1
  71 /* If we don't have sys/select the definition may be in unistd.h */
  72 #include <GUSI.h>
  73 #endif
  74
  75 #endif /* !HAVE_SYS_SELECT_H */
  76
  77
  78 #ifdef __cplusplus
  79 /* Move this down here since some C++ #include's don't like to be included
  80    inside an extern "C" */
  81 extern "C" {
  82 #endif
  83
  84
  85 /* Py_ARITHMETIC_RIGHT_SHIFT
  86  * C doesn't define whether a right-shift of a signed integer sign-extends
  87  * or zero-fills.  Here a macro to force sign extension:
  88  * Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J)
  89  *    Return I >> J, forcing sign extension.
  90  * Requirements:
  91  *    I is of basic signed type TYPE (char, short, int, long, or long long).
  92  *    TYPE is one of char, short, int, long, or long long, although long long
  93  *    must not be used except on platforms that support it.
  94  *    J is an integer >= 0 and strictly less than the number of bits in TYPE
  95  *    (because C doesn't define what happens for J outside that range either).
  96  * Caution:
  97  *    I may be evaluated more than once.
  98  */
  99 #ifdef SIGNED_RIGHT_SHIFT_ZERO_FILLS
 100 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) \
 101         ((I) < 0 ? ~((~(unsigned TYPE)(I)) >> (J)) : (I) >> (J))
 102 #else
 103 #define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) ((I) >> (J))
 104 #endif
 105
 106 /* Py_FORCE_EXPANSION(X)
 107  * "Simply" returns its argument.  However, macro expansions within the
 108  * argument are evaluated.  This unfortunate trickery is needed to get
 109  * token-pasting to work as desired in some cases.
 110  */
 111 #define Py_FORCE_EXPANSION(X) X
 112
 113 /* Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW)
 114  * Cast VALUE to type NARROW from type WIDE.  In Py_DEBUG mode, this
 115  * assert-fails if any information is lost.
 116  * Caution:
 117  *    VALUE may be evaluated more than once.
 118  */
 119 #ifdef Py_DEBUG
 120 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) \
 121         (assert((WIDE)(NARROW)(VALUE) == (VALUE)), (NARROW)(VALUE))
 122 #else
 123 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) (NARROW)(VALUE)
 124 #endif
 125
 126 /* Py_IS_INFINITY(X)
 127  * Return 1 if float or double arg is an infinity, else 0.
 128  * Caution:
 129  *    X is evaluated more than once.
 130  *    This implementation may set the underflow flag if |X| is very small;
 131  *    it really can't be implemented correctly (& easily) before C99.
 132  */
 133  #define Py_IS_INFINITY(X) ((X) && (X)*0.5 == (X))
 134
 135 /**************************************************************************
 136 Prototypes that are missing from the standard include files on some systems
 137 (and possibly only some versions of such systems.)
 138
 139 Please be conservative with adding new ones, document them and enclose them
 140 in platform-specific #ifdefs.
 141 **************************************************************************/
 142
 143 #ifdef SOLARIS
 144 /* Unchecked */
 145 extern int gethostname(char *, int);
 146 #endif
 147
 148 #ifdef __BEOS__
 149 /* Unchecked */
 150 /* It's in the libs, but not the headers... - [cjh] */
 151 int shutdown( int, int );
 152 #endif
 153
 154 #ifdef HAVE__GETPTY
 155 #include <sys/types.h>          /* we need to import mode_t */
 156 extern char * _getpty(int *, int, mode_t, int);
 157 #endif
 158
 159 #if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY)
 160 #if !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H)
 161 /* BSDI does not supply a prototype for the 'openpty' and 'forkpty'
 162    functions, even though they are included in libutil. */
 163 #include <termios.h>
 164 extern int openpty(int *, int *, char *, struct termios *, struct winsize *);
 165 extern int forkpty(int *, char *, struct termios *, struct winsize *);
 166 #endif /* !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H) */
 167 #endif /* defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) */
 168
 169
 170 /* These are pulled from various places. It isn't obvious on what platforms
 171    they are necessary, nor what the exact prototype should look like (which
 172    is likely to vary between platforms!) If you find you need one of these
 173    declarations, please move them to a platform-specific block and include
 174    proper prototypes. */
 175 #if 0
 176
 177 /* From Modules/resource.c */
 178 extern int getrusage();
 179 extern int getpagesize();
 180
 181 /* From Python/sysmodule.c and Modules/posixmodule.c */
 182 extern int fclose(FILE *);
 183
 184 /* From Modules/posixmodule.c */
 185 extern int fdatasync(int);
 186 /* XXX These are supposedly for SunOS4.1.3 but "shouldn't hurt elsewhere" */
 187 extern int rename(const char *, const char *);
 188 extern int pclose(FILE *);
 189 extern int lstat(const char *, struct stat *);
 190 extern int symlink(const char *, const char *);
 191 extern int fsync(int fd);
 192
 193 #endif /* 0 */
 194
 195
 196 /************************
 197  * WRAPPER FOR <math.h> *
 198  ************************/
 199
 200 /* On the 68K Mac, when using CFM (Code Fragment Manager),
 201    <math.h> requires special treatment -- we need to surround it with
 202    #pragma lib_export off / on...
 203    This is because MathLib.o is a static library, and exporting its
 204    symbols doesn't quite work...
 205    XXX Not sure now...  Seems to be something else going on as well... */
 206
 207 #ifndef HAVE_HYPOT
 208 extern double hypot(double, double);
 209 #ifdef MWERKS_BEFORE_PRO4
 210 #define hypot we_dont_want_faulty_hypot_decl
 211 #endif
 212 #endif
 213
 214 #ifndef HAVE_HYPOT
 215 #ifdef __MWERKS__
 216 #undef hypot
 217 #endif
 218 #endif
 219
 220 #if defined(USE_MSL) && defined(__MC68K__)
 221 /* CodeWarrior MSL 2.1.1 has weird define overrides that don't work
 222 ** when you take the address of math functions. If I interpret the
 223 ** ANSI C standard correctly this is illegal, but I haven't been able
 224 ** to convince the MetroWerks folks of this...
 225 */
 226 #undef acos
 227 #undef asin
 228 #undef atan
 229 #undef atan2
 230 #undef ceil
 231 #undef cos
 232 #undef cosh
 233 #undef exp
 234 #undef fabs
 235 #undef floor
 236 #undef fmod
 237 #undef log
 238 #undef log10
 239 #undef pow
 240 #undef sin
 241 #undef sinh
 242 #undef sqrt
 243 #undef tan
 244 #undef tanh
 245 #define acos acosd
 246 #define asin asind
 247 #define atan atand
 248 #define atan2 atan2d
 249 #define ceil ceild
 250 #define cos cosd
 251 #define cosh coshd
 252 #define exp expd
 253 #define fabs fabsd
 254 #define floor floord
 255 #define fmod fmodd
 256 #define log logd
 257 #define log10 log10d
 258 #define pow powd
 259 #define sin sind
 260 #define sinh sinhd
 261 #define sqrt sqrtd
 262 #define tan tand
 263 #define tanh tanhd
 264 #endif
 265
 266
 267 /************************************
 268  * MALLOC COMPATIBILITY FOR pymem.h *
 269  ************************************/
 270
 271 #ifndef DL_IMPORT       /* declarations for DLL import */
 272 #define DL_IMPORT(RTYPE) RTYPE
 273 #endif
 274
 275 #ifndef NULL
 276 #define NULL ((void *)0)
 277 #endif
 278
 279 #ifdef MALLOC_ZERO_RETURNS_NULL
 280 /* XXX Always allocate one extra byte, since some malloc's return NULL
 281    XXX for malloc(0) or realloc(p, 0). */
 282 #define _PyMem_EXTRA 1
 283 #else
 284 #define _PyMem_EXTRA 0
 285 #endif
 286
 287
 288 /* If the fd manipulation macros aren't defined,
 289    here is a set that should do the job */
 290
 291 #if 0 /* disabled and probably obsolete */
 292
 293 #ifndef FD_SETSIZE
 294 #define FD_SETSIZE      256
 295 #endif
 296
 297 #ifndef FD_SET
 298
 299 typedef long fd_mask;
 300
 301 #define NFDBITS (sizeof(fd_mask) * NBBY)        /* bits per mask */
 302 #ifndef howmany
 303 #define howmany(x, y)   (((x)+((y)-1))/(y))
 304 #endif /* howmany */
 305
 306 typedef struct fd_set {
 307         fd_mask fds_bits[howmany(FD_SETSIZE, NFDBITS)];
 308 } fd_set;
 309
 310 #define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
 311 #define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
 312 #define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
 313 #define FD_ZERO(p)      memset((char *)(p), '\0', sizeof(*(p)))
 314
 315 #endif /* FD_SET */
 316
 317 #endif /* fd manipulation macros */
 318
 319
 320 #ifdef __cplusplus
 321 }
 322 #endif
 323
 324 #endif /* Py_PYPORT_H */