cpython/Include/pyport.h

#ifndef Py_PYPORT_H
#define Py_PYPORT_H

#include "pyconfig.h" /* include for defines */

#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif

/**************************************************************************
Symbols and macros to supply platform-independent interfaces to basic
C language & library operations whose spellings vary across platforms.

Please try to make documentation here as clear as possible:  by definition,
the stuff here is trying to illuminate C's darkest corners.

Config #defines referenced here:

SIGNED_RIGHT_SHIFT_ZERO_FILLS
Meaning:  To be defined iff i>>j does not extend the sign bit when i is a
          signed integral type and i < 0.
Used in:  Py_ARITHMETIC_RIGHT_SHIFT

Py_DEBUG
Meaning:  Extra checks compiled in for debug mode.
Used in:  Py_SAFE_DOWNCAST

HAVE_UINTPTR_T
Meaning:  The C9X type uintptr_t is supported by the compiler
Used in:  Py_uintptr_t

HAVE_LONG_LONG
Meaning:  The compiler supports the C type "long long"
Used in:  PY_LONG_LONG

**************************************************************************/

/* typedefs for some C9X-defined synonyms for integral types.
 *
 * The names in Python are exactly the same as the C9X names, except with a
 * Py_ prefix.  Until C9X is universally implemented, this is the only way
 * to ensure that Python gets reliable names that don't conflict with names
 * in non-Python code that are playing their own tricks to define the C9X
 * names.
 *
 * NOTE: don't go nuts here!  Python has no use for *most* of the C9X
 * integral synonyms.  Only define the ones we actually need.
 */

#ifdef HAVE_LONG_LONG
#ifndef PY_LONG_LONG
#define PY_LONG_LONG long long
#if defined(LLONG_MAX)
/* If LLONG_MAX is defined in limits.h, use that. */
#define PY_LLONG_MIN LLONG_MIN
#define PY_LLONG_MAX LLONG_MAX
#define PY_ULLONG_MAX ULLONG_MAX
#elif defined(__LONG_LONG_MAX__)
/* Otherwise, if GCC has a builtin define, use that. */
#define PY_LLONG_MAX __LONG_LONG_MAX__
#define PY_LLONG_MIN (-PY_LLONG_MAX-1)
#define PY_ULLONG_MAX (__LONG_LONG_MAX__*2ULL + 1ULL)
#else
/* Otherwise, rely on two's complement. */
#define PY_ULLONG_MAX (~0ULL)
#define PY_LLONG_MAX  ((long long)(PY_ULLONG_MAX>>1))
#define PY_LLONG_MIN (-PY_LLONG_MAX-1)
#endif /* LLONG_MAX */
#endif
#endif /* HAVE_LONG_LONG */

/* uintptr_t is the C9X name for an unsigned integral type such that a
 * legitimate void* can be cast to uintptr_t and then back to void* again
 * without loss of information.  Similarly for intptr_t, wrt a signed
 * integral type.
 */
#ifdef HAVE_UINTPTR_T
typedef uintptr_t	Py_uintptr_t;
typedef intptr_t	Py_intptr_t;

#elif SIZEOF_VOID_P <= SIZEOF_INT
typedef unsigned int	Py_uintptr_t;
typedef int		Py_intptr_t;

#elif SIZEOF_VOID_P <= SIZEOF_LONG
typedef unsigned long	Py_uintptr_t;
typedef long		Py_intptr_t;

#elif defined(HAVE_LONG_LONG) && (SIZEOF_VOID_P <= SIZEOF_LONG_LONG)
typedef unsigned PY_LONG_LONG	Py_uintptr_t;
typedef PY_LONG_LONG		Py_intptr_t;

#else
#   error "Python needs a typedef for Py_uintptr_t in pyport.h."
#endif /* HAVE_UINTPTR_T */

/* Py_ssize_t is a signed integral type such that sizeof(Py_ssize_t) ==
 * sizeof(size_t).  C99 doesn't define such a thing directly (size_t is an
 * unsigned integral type).  See PEP 353 for details.
 */
#ifdef HAVE_SSIZE_T
typedef ssize_t		Py_ssize_t;
#elif SIZEOF_VOID_P == SIZEOF_SIZE_T
typedef Py_intptr_t	Py_ssize_t;
#else
#   error "Python needs a typedef for Py_ssize_t in pyport.h."
#endif

/* Largest possible value of size_t.
   SIZE_MAX is part of C99, so it might be defined on some
   platforms. If it is not defined, (size_t)-1 is a portable
   definition for C89, due to the way signed->unsigned 
   conversion is defined. */
#ifdef SIZE_MAX
#define PY_SIZE_MAX SIZE_MAX
#else
#define PY_SIZE_MAX ((size_t)-1)
#endif

/* Largest positive value of type Py_ssize_t. */
#define PY_SSIZE_T_MAX ((Py_ssize_t)(((size_t)-1)>>1))
/* Smallest negative value of type Py_ssize_t. */
#define PY_SSIZE_T_MIN (-PY_SSIZE_T_MAX-1)

#if SIZEOF_PID_T > SIZEOF_LONG
#   error "Python doesn't support sizeof(pid_t) > sizeof(long)"
#endif

/* PY_FORMAT_SIZE_T is a platform-specific modifier for use in a printf
 * format to convert an argument with the width of a size_t or Py_ssize_t.
 * C99 introduced "z" for this purpose, but not all platforms support that;
 * e.g., MS compilers use "I" instead.
 *
 * These "high level" Python format functions interpret "z" correctly on
 * all platforms (Python interprets the format string itself, and does whatever
 * the platform C requires to convert a size_t/Py_ssize_t argument):
 *
 *     PyBytes_FromFormat
 *     PyErr_Format
 *     PyBytes_FromFormatV
 *     PyUnicode_FromFormatV
 *
 * Lower-level uses require that you interpolate the correct format modifier
 * yourself (e.g., calling printf, fprintf, sprintf, PyOS_snprintf); for
 * example,
 *
 *     Py_ssize_t index;
 *     fprintf(stderr, "index %" PY_FORMAT_SIZE_T "d sucks\n", index);
 *
 * That will expand to %ld, or %Id, or to something else correct for a
 * Py_ssize_t on the platform.
 */
#ifndef PY_FORMAT_SIZE_T
#   if SIZEOF_SIZE_T == SIZEOF_INT && !defined(__APPLE__)
#       define PY_FORMAT_SIZE_T ""
#   elif SIZEOF_SIZE_T == SIZEOF_LONG
#       define PY_FORMAT_SIZE_T "l"
#   elif defined(MS_WINDOWS)
#       define PY_FORMAT_SIZE_T "I"
#   else
#       error "This platform's pyconfig.h needs to define PY_FORMAT_SIZE_T"
#   endif
#endif

/* Py_LOCAL can be used instead of static to get the fastest possible calling
 * convention for functions that are local to a given module.
 *
 * Py_LOCAL_INLINE does the same thing, and also explicitly requests inlining,
 * for platforms that support that.
 *
 * If PY_LOCAL_AGGRESSIVE is defined before python.h is included, more
 * "aggressive" inlining/optimizaion is enabled for the entire module.  This
 * may lead to code bloat, and may slow things down for those reasons.  It may
 * also lead to errors, if the code relies on pointer aliasing.  Use with
 * care.
 *
 * NOTE: You can only use this for functions that are entirely local to a
 * module; functions that are exported via method tables, callbacks, etc,
 * should keep using static.
 */

#undef USE_INLINE /* XXX - set via configure? */

#if defined(_MSC_VER)
#if defined(PY_LOCAL_AGGRESSIVE)
/* enable more aggressive optimization for visual studio */
#pragma optimize("agtw", on)
#endif
/* ignore warnings if the compiler decides not to inline a function */ 
#pragma warning(disable: 4710)
/* fastest possible local call under MSVC */
#define Py_LOCAL(type) static type __fastcall
#define Py_LOCAL_INLINE(type) static __inline type __fastcall
#elif defined(USE_INLINE)
#define Py_LOCAL(type) static type
#define Py_LOCAL_INLINE(type) static inline type
#else
#define Py_LOCAL(type) static type
#define Py_LOCAL_INLINE(type) static type
#endif

/* Py_MEMCPY can be used instead of memcpy in cases where the copied blocks
 * are often very short.  While most platforms have highly optimized code for
 * large transfers, the setup costs for memcpy are often quite high.  MEMCPY
 * solves this by doing short copies "in line".
 */

#if defined(_MSC_VER)
#define Py_MEMCPY(target, source, length) do {				\
		size_t i_, n_ = (length);				\
		char *t_ = (void*) (target);				\
		const char *s_ = (void*) (source);			\
		if (n_ >= 16)						\
			memcpy(t_, s_, n_);				\
		else							\
			for (i_ = 0; i_ < n_; i_++)			\
				t_[i_] = s_[i_];			\
	} while (0)
#else
#define Py_MEMCPY memcpy
#endif

#include <stdlib.h>

#include <math.h> /* Moved here from the math section, before extern "C" */

/********************************************
 * WRAPPER FOR <time.h> and/or <sys/time.h> *
 ********************************************/

#ifdef TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else /* !TIME_WITH_SYS_TIME */
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else /* !HAVE_SYS_TIME_H */
#include <time.h>
#endif /* !HAVE_SYS_TIME_H */
#endif /* !TIME_WITH_SYS_TIME */


/******************************
 * WRAPPER FOR <sys/select.h> *
 ******************************/

/* NB caller must include <sys/types.h> */

#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif /* !HAVE_SYS_SELECT_H */

/*******************************
 * stat() and fstat() fiddling *
 *******************************/

/* We expect that stat and fstat exist on most systems.
 *  It's confirmed on Unix, Mac and Windows.
 *  If you don't have them, add
 *      #define DONT_HAVE_STAT
 * and/or
 *      #define DONT_HAVE_FSTAT
 * to your pyconfig.h. Python code beyond this should check HAVE_STAT and
 * HAVE_FSTAT instead.
 * Also
 *      #define HAVE_SYS_STAT_H
 * if <sys/stat.h> exists on your platform, and
 *      #define HAVE_STAT_H
 * if <stat.h> does.
 */
#ifndef DONT_HAVE_STAT
#define HAVE_STAT
#endif

#ifndef DONT_HAVE_FSTAT
#define HAVE_FSTAT
#endif

#ifdef HAVE_SYS_STAT_H
#if defined(PYOS_OS2) && defined(PYCC_GCC)
#include <sys/types.h>
#endif
#include <sys/stat.h>
#elif defined(HAVE_STAT_H)
#include <stat.h>
#endif

#if defined(PYCC_VACPP)
/* VisualAge C/C++ Failed to Define MountType Field in sys/stat.h */
#define S_IFMT (S_IFDIR|S_IFCHR|S_IFREG)
#endif

#ifndef S_ISREG
#define S_ISREG(x) (((x) & S_IFMT) == S_IFREG)
#endif

#ifndef S_ISDIR
#define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR)
#endif


#ifdef __cplusplus
/* Move this down here since some C++ #include's don't like to be included
   inside an extern "C" */
extern "C" {
#endif


/* Py_ARITHMETIC_RIGHT_SHIFT
 * C doesn't define whether a right-shift of a signed integer sign-extends
 * or zero-fills.  Here a macro to force sign extension:
 * Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J)
 *    Return I >> J, forcing sign extension.
 * Requirements:
 *    I is of basic signed type TYPE (char, short, int, long, or long long).
 *    TYPE is one of char, short, int, long, or long long, although long long
 *    must not be used except on platforms that support it.
 *    J is an integer >= 0 and strictly less than the number of bits in TYPE
 *    (because C doesn't define what happens for J outside that range either).
 * Caution:
 *    I may be evaluated more than once.
 */
#ifdef SIGNED_RIGHT_SHIFT_ZERO_FILLS
#define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) \
	((I) < 0 ? ~((~(unsigned TYPE)(I)) >> (J)) : (I) >> (J))
#else
#define Py_ARITHMETIC_RIGHT_SHIFT(TYPE, I, J) ((I) >> (J))
#endif

/* Py_FORCE_EXPANSION(X)
 * "Simply" returns its argument.  However, macro expansions within the
 * argument are evaluated.  This unfortunate trickery is needed to get
 * token-pasting to work as desired in some cases.
 */
#define Py_FORCE_EXPANSION(X) X

/* Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW)
 * Cast VALUE to type NARROW from type WIDE.  In Py_DEBUG mode, this
 * assert-fails if any information is lost.
 * Caution:
 *    VALUE may be evaluated more than once.
 */
#ifdef Py_DEBUG
#define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) \
	(assert((WIDE)(NARROW)(VALUE) == (VALUE)), (NARROW)(VALUE))
#else
#define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) (NARROW)(VALUE)
#endif

/* Py_SET_ERRNO_ON_MATH_ERROR(x)
 * If a libm function did not set errno, but it looks like the result
 * overflowed or not-a-number, set errno to ERANGE or EDOM.  Set errno
 * to 0 before calling a libm function, and invoke this macro after,
 * passing the function result.
 * Caution:
 *    This isn't reliable.  See Py_OVERFLOWED comments.
 *    X is evaluated more than once.
 */
#if defined(__FreeBSD__) || defined(__OpenBSD__) || (defined(__hpux) && defined(__ia64))
#define _Py_SET_EDOM_FOR_NAN(X) if (isnan(X)) errno = EDOM;
#else
#define _Py_SET_EDOM_FOR_NAN(X) ;
#endif
#define Py_SET_ERRNO_ON_MATH_ERROR(X) \
	do { \
		if (errno == 0) { \
			if ((X) == Py_HUGE_VAL || (X) == -Py_HUGE_VAL) \
				errno = ERANGE; \
			else _Py_SET_EDOM_FOR_NAN(X) \
		} \
	} while(0)

/* Py_SET_ERANGE_ON_OVERFLOW(x)
 * An alias of Py_SET_ERRNO_ON_MATH_ERROR for backward-compatibility.
 */
#define Py_SET_ERANGE_IF_OVERFLOW(X) Py_SET_ERRNO_ON_MATH_ERROR(X)

/* Py_ADJUST_ERANGE1(x)
 * Py_ADJUST_ERANGE2(x, y)
 * Set errno to 0 before calling a libm function, and invoke one of these
 * macros after, passing the function result(s) (Py_ADJUST_ERANGE2 is useful
 * for functions returning complex results).  This makes two kinds of
 * adjustments to errno:  (A) If it looks like the platform libm set
 * errno=ERANGE due to underflow, clear errno. (B) If it looks like the
 * platform libm overflowed but didn't set errno, force errno to ERANGE.  In
 * effect, we're trying to force a useful implementation of C89 errno
 * behavior.
 * Caution:
 *    This isn't reliable.  See Py_OVERFLOWED comments.
 *    X and Y may be evaluated more than once.
 */
#define Py_ADJUST_ERANGE1(X)						\
	do {								\
		if (errno == 0) {					\
			if ((X) == Py_HUGE_VAL || (X) == -Py_HUGE_VAL)	\
				errno = ERANGE;				\
		}							\
		else if (errno == ERANGE && (X) == 0.0)			\
			errno = 0;					\
	} while(0)

#define Py_ADJUST_ERANGE2(X, Y)						\
	do {								\
		if ((X) == Py_HUGE_VAL || (X) == -Py_HUGE_VAL ||	\
		    (Y) == Py_HUGE_VAL || (Y) == -Py_HUGE_VAL) {	\
				if (errno == 0)				\
					errno = ERANGE;			\
		}							\
		else if (errno == ERANGE)				\
			errno = 0;					\
	} while(0)

/* Py_DEPRECATED(version)
 * Declare a variable, type, or function deprecated.
 * Usage:
 *    extern int old_var Py_DEPRECATED(2.3);
 *    typedef int T1 Py_DEPRECATED(2.4);
 *    extern int x() Py_DEPRECATED(2.5);
 */
#if defined(__GNUC__) && ((__GNUC__ >= 4) || \
			  (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1))
#define Py_DEPRECATED(VERSION_UNUSED) __attribute__((__deprecated__))
#else
#define Py_DEPRECATED(VERSION_UNUSED)
#endif

/**************************************************************************
Prototypes that are missing from the standard include files on some systems
(and possibly only some versions of such systems.)

Please be conservative with adding new ones, document them and enclose them
in platform-specific #ifdefs.
**************************************************************************/

#ifdef SOLARIS
/* Unchecked */
extern int gethostname(char *, int);
#endif

#ifdef HAVE__GETPTY
#include <sys/types.h>		/* we need to import mode_t */
extern char * _getpty(int *, int, mode_t, int);
#endif

/* On QNX 6, struct termio must be declared by including sys/termio.h
   if TCGETA, TCSETA, TCSETAW, or TCSETAF are used.  sys/termio.h must
   be included before termios.h or it will generate an error. */
#ifdef HAVE_SYS_TERMIO_H
#include <sys/termio.h>
#endif

#if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY)
#if !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H)
/* BSDI does not supply a prototype for the 'openpty' and 'forkpty'
   functions, even though they are included in libutil. */
#include <termios.h>
extern int openpty(int *, int *, char *, struct termios *, struct winsize *);
extern pid_t forkpty(int *, char *, struct termios *, struct winsize *);
#endif /* !defined(HAVE_PTY_H) && !defined(HAVE_LIBUTIL_H) */
#endif /* defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) */


/* On 4.4BSD-descendants, ctype functions serves the whole range of
 * wchar_t character set rather than single byte code points only.
 * This characteristic can break some operations of string object
 * including str.upper() and str.split() on UTF-8 locales.  This
 * workaround was provided by Tim Robbins of FreeBSD project.
 */

#ifdef __FreeBSD__
#include <osreldate.h>
#if __FreeBSD_version > 500039
#include <ctype.h>
#include <wctype.h>
#undef isalnum
#define isalnum(c) iswalnum(btowc(c))
#undef isalpha
#define isalpha(c) iswalpha(btowc(c))
#undef islower
#define islower(c) iswlower(btowc(c))
#undef isspace
#define isspace(c) iswspace(btowc(c))
#undef isupper
#define isupper(c) iswupper(btowc(c))
#undef tolower
#define tolower(c) towlower(btowc(c))
#undef toupper
#define toupper(c) towupper(btowc(c))
#endif
#endif


/* Declarations for symbol visibility.

  PyAPI_FUNC(type): Declares a public Python API function and return type
  PyAPI_DATA(type): Declares public Python data and its type
  PyMODINIT_FUNC:   A Python module init function.  If these functions are
                    inside the Python core, they are private to the core.
                    If in an extension module, it may be declared with
                    external linkage depending on the platform.

  As a number of platforms support/require "__declspec(dllimport/dllexport)",
  we support a HAVE_DECLSPEC_DLL macro to save duplication.
*/

/*
  All windows ports, except cygwin, are handled in PC/pyconfig.h.

  Cygwin is the only other autoconf platform requiring special
  linkage handling and it uses __declspec().
*/
#if defined(__CYGWIN__)
#	define HAVE_DECLSPEC_DLL
#endif

/* only get special linkage if built as shared or platform is Cygwin */
#if defined(Py_ENABLE_SHARED) || defined(__CYGWIN__)
#	if defined(HAVE_DECLSPEC_DLL)
#		ifdef Py_BUILD_CORE
#			define PyAPI_FUNC(RTYPE) __declspec(dllexport) RTYPE
#			define PyAPI_DATA(RTYPE) extern __declspec(dllexport) RTYPE
			/* module init functions inside the core need no external linkage */
			/* except for Cygwin to handle embedding */
#			if defined(__CYGWIN__)
#				define PyMODINIT_FUNC __declspec(dllexport) PyObject*
#			else /* __CYGWIN__ */
#				define PyMODINIT_FUNC PyObject*
#			endif /* __CYGWIN__ */
#		else /* Py_BUILD_CORE */
			/* Building an extension module, or an embedded situation */
			/* public Python functions and data are imported */
			/* Under Cygwin, auto-import functions to prevent compilation */
			/* failures similar to http://python.org/doc/FAQ.html#3.24 */
#			if !defined(__CYGWIN__)
#				define PyAPI_FUNC(RTYPE) __declspec(dllimport) RTYPE
#			endif /* !__CYGWIN__ */
#			define PyAPI_DATA(RTYPE) extern __declspec(dllimport) RTYPE
			/* module init functions outside the core must be exported */
#			if defined(__cplusplus)
#				define PyMODINIT_FUNC extern "C" __declspec(dllexport) PyObject*
#			else /* __cplusplus */
#				define PyMODINIT_FUNC __declspec(dllexport) PyObject*
#			endif /* __cplusplus */
#		endif /* Py_BUILD_CORE */
#	endif /* HAVE_DECLSPEC */
#endif /* Py_ENABLE_SHARED */

/* If no external linkage macros defined by now, create defaults */
#ifndef PyAPI_FUNC
#	define PyAPI_FUNC(RTYPE) RTYPE
#endif
#ifndef PyAPI_DATA
#	define PyAPI_DATA(RTYPE) extern RTYPE
#endif
#ifndef PyMODINIT_FUNC
#	if defined(__cplusplus)
#		define PyMODINIT_FUNC extern "C" PyObject*
#	else /* __cplusplus */
#		define PyMODINIT_FUNC PyObject*
#	endif /* __cplusplus */
#endif

/* limits.h constants that may be missing */

#ifndef INT_MAX
#define INT_MAX 2147483647
#endif

#ifndef LONG_MAX
#if SIZEOF_LONG == 4
#define LONG_MAX 0X7FFFFFFFL
#elif SIZEOF_LONG == 8
#define LONG_MAX 0X7FFFFFFFFFFFFFFFL
#else
#error "could not set LONG_MAX in pyport.h"
#endif
#endif

#ifndef LONG_MIN
#define LONG_MIN (-LONG_MAX-1)
#endif

#ifndef LONG_BIT
#define LONG_BIT (8 * SIZEOF_LONG)
#endif

#if LONG_BIT != 8 * SIZEOF_LONG
/* 04-Oct-2000 LONG_BIT is apparently (mis)defined as 64 on some recent
 * 32-bit platforms using gcc.  We try to catch that here at compile-time
 * rather than waiting for integer multiplication to trigger bogus
 * overflows.
 */
#error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
#endif

#ifdef __cplusplus
}
#endif

/*
 * Hide GCC attributes from compilers that don't support them.
 */
#if (!defined(__GNUC__) || __GNUC__ < 2 || \
     (__GNUC__ == 2 && __GNUC_MINOR__ < 7) )
#define Py_GCC_ATTRIBUTE(x)
#else
#define Py_GCC_ATTRIBUTE(x) __attribute__(x)
#endif

/*
 * Add PyArg_ParseTuple format where available.
 */
#ifdef HAVE_ATTRIBUTE_FORMAT_PARSETUPLE
#define Py_FORMAT_PARSETUPLE(func,p1,p2) __attribute__((format(func,p1,p2)))
#else
#define Py_FORMAT_PARSETUPLE(func,p1,p2)
#endif

/*
 * Specify alignment on compilers that support it.
 */
#if defined(__GNUC__) && __GNUC__ >= 3
#define Py_ALIGNED(x) __attribute__((aligned(x)))
#else
#define Py_ALIGNED(x)
#endif

/* Eliminate end-of-loop code not reached warnings from SunPro C
 * when using do{...}while(0) macros
 */
#ifdef __SUNPRO_C
#pragma error_messages (off,E_END_OF_LOOP_CODE_NOT_REACHED)
#endif

/*
 * Older Microsoft compilers don't support the C99 long long literal suffixes,
 * so these will be defined in PC/pyconfig.h for those compilers.
 */
#ifndef Py_LL
#define Py_LL(x) x##LL
#endif

#ifndef Py_ULL
#define Py_ULL(x) Py_LL(x##U)
#endif

#endif /* Py_PYPORT_H */