c.h

从一个开源软件中摘取的正则表达式模块

{
	char		vl_len_[4];		/* Do not touch this field directly! */
	char		vl_dat[1];
};

#define VARHDRSZ		((int32) sizeof(int32))

/*
 * These widely-used datatypes are just a varlena header and the data bytes.
 * There is no terminating null or anything like that --- the data length is
 * always VARSIZE(ptr) - VARHDRSZ.
 */
typedef struct varlena bytea;
typedef struct varlena text;
typedef struct varlena BpChar;	/* blank-padded char, ie SQL char(n) */
typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */

/*
 * Specialized array types.  These are physically laid out just the same
 * as regular arrays (so that the regular array subscripting code works
 * with them).	They exist as distinct types mostly for historical reasons:
 * they have nonstandard I/O behavior which we don't want to change for fear
 * of breaking applications that look at the system catalogs.  There is also
 * an implementation issue for oidvector: it's part of the primary key for
 * pg_proc, and we can't use the normal btree array support routines for that
 * without circularity.
 */



/*
 * We want NameData to have length NAMEDATALEN and int alignment,
 * because that's how the data type 'name' is defined in pg_type.
 * Use a union to make sure the compiler agrees.  Note that NAMEDATALEN
 * must be a multiple of sizeof(int), else sizeof(NameData) will probably
 * not come out equal to NAMEDATALEN.
 */

/*
typedef union nameData
{
	char		data[NAMEDATALEN];
	int			alignmentDummy;
} NameData;
typedef NameData *Name;
#define NameStr(name)	((name).data)
*/

/*
 * Support macros for escaping strings.  escape_backslash should be TRUE
 * if generating a non-standard-conforming string.	Prefixing a string
 * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
 * Beware of multiple evaluation of the "ch" argument!
 */
#define SQL_STR_DOUBLE(ch, escape_backslash)	\
	((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))

#define ESCAPE_STRING_SYNTAX	'E'

/* ----------------------------------------------------------------
 *				Section 4:	IsValid macros for system types
 * ----------------------------------------------------------------
 */
/*
 * BoolIsValid
 *		True iff bool is valid.
 */
#define BoolIsValid(boolean)	((boolean) == false || (boolean) == true)

/*
 * PointerIsValid
 *		True iff pointer is valid.
 */
#define PointerIsValid(pointer) ((void*)(pointer) != NULL)

/*
 * PointerIsAligned
 *		True iff pointer is properly aligned to point to the given type.
 */
#define PointerIsAligned(pointer, type) \
		(((long)(pointer) % (sizeof (type))) == 0)

#define OidIsValid(objectId)  ((bool) ((objectId) != InvalidOid))

#define RegProcedureIsValid(p)	OidIsValid(p)


/* ----------------------------------------------------------------
 *				Section 5:	offsetof, lengthof, endof, alignment
 * ----------------------------------------------------------------
 */
/*
 * offsetof
 *		Offset of a structure/union field within that structure/union.
 *
 *		XXX This is supposed to be part of stddef.h, but isn't on
 *		some systems (like SunOS 4).
 */
#ifndef offsetof
#define offsetof(type, field)	((long) &((type *)0)->field)
#endif   /* offsetof */

/*
 * lengthof
 *		Number of elements in an array.
 */
#define lengthof(array) (sizeof (array) / sizeof ((array)[0]))

/*
 * endof
 *		Address of the element one past the last in an array.
 */
#define endof(array)	(&(array)[lengthof(array)])

/* ----------------
 * Alignment macros: align a length or address appropriately for a given type.
 * The fooALIGN() macros round up to a multiple of the required alignment,
 * while the fooALIGN_DOWN() macros round down.  The latter are more useful
 * for problems like "how many X-sized structures will fit in a page?".
 *
 * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
 * That case seems extremely unlikely to be needed in practice, however.
 * ----------------
 */

#define TYPEALIGN(ALIGNVAL,LEN)  \
	(((long) (LEN) + ((ALIGNVAL) - 1)) & ~((long) ((ALIGNVAL) - 1)))

#define SHORTALIGN(LEN)			TYPEALIGN(ALIGNOF_SHORT, (LEN))
#define INTALIGN(LEN)			TYPEALIGN(ALIGNOF_INT, (LEN))
#define LONGALIGN(LEN)			TYPEALIGN(ALIGNOF_LONG, (LEN))
#define DOUBLEALIGN(LEN)		TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
#define MAXALIGN(LEN)			TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
/* MAXALIGN covers only built-in types, not buffers */
#define BUFFERALIGN(LEN)		TYPEALIGN(ALIGNOF_BUFFER, (LEN))

#define TYPEALIGN_DOWN(ALIGNVAL,LEN)  \
	(((long) (LEN)) & ~((long) ((ALIGNVAL) - 1)))

#define SHORTALIGN_DOWN(LEN)	TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
#define INTALIGN_DOWN(LEN)		TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
#define LONGALIGN_DOWN(LEN)		TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
#define DOUBLEALIGN_DOWN(LEN)	TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
#define MAXALIGN_DOWN(LEN)		TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))

/* ----------------------------------------------------------------
 *				Section 6:	widely useful macros
 * ----------------------------------------------------------------
 */
/*
 * Max
 *		Return the maximum of two numbers.
 */
#define Max(x, y)		((x) > (y) ? (x) : (y))

/*
 * Min
 *		Return the minimum of two numbers.
 */
#define Min(x, y)		((x) < (y) ? (x) : (y))

/*
 * Abs
 *		Return the absolute value of the argument.
 */
#define Abs(x)			((x) >= 0 ? (x) : -(x))

/*
 * StrNCpy
 *	Like standard library function strncpy(), except that result string
 *	is guaranteed to be null-terminated --- that is, at most N-1 bytes
 *	of the source string will be kept.
 *	Also, the macro returns no result (too hard to do that without
 *	evaluating the arguments multiple times, which seems worse).
 *
 *	BTW: when you need to copy a non-null-terminated string (like a text
 *	datum) and add a null, do not do it with StrNCpy(..., len+1).  That
 *	might seem to work, but it fetches one byte more than there is in the
 *	text object.  One fine day you'll have a SIGSEGV because there isn't
 *	another byte before the end of memory.	Don't laugh, we've had real
 *	live bug reports from real live users over exactly this mistake.
 *	Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
 */
#define StrNCpy(dst,src,len) \
	do \
	{ \
		char * _dst = (dst); \
		Size _len = (len); \
\
		if (_len > 0) \
		{ \
			strncpy(_dst, (src), _len); \
			_dst[_len-1] = '\0'; \
		} \
	} while (0)


/* Get a bit mask of the bits set in non-long aligned addresses */
#define LONG_ALIGN_MASK (sizeof(long) - 1)

/*
 * MemSet
 *	Exactly the same as standard library function memset(), but considerably
 *	faster for zeroing small word-aligned structures (such as parsetree nodes).
 *	This has to be a macro because the main point is to avoid function-call
 *	overhead.	However, we have also found that the loop is faster than
 *	native libc memset() on some platforms, even those with assembler
 *	memset() functions.  More research needs to be done, perhaps with
 *	MEMSET_LOOP_LIMIT tests in configure.
 */
#define MemSet(start, val, len) \
	do \
	{ \
		/* must be void* because we don't know if it is integer aligned yet */ \
		void   *_vstart = (void *) (start); \
		int		_val = (val); \
		Size	_len = (len); \
\
		if ((((long) _vstart) & LONG_ALIGN_MASK) == 0 && \
			(_len & LONG_ALIGN_MASK) == 0 && \
			_val == 0 && \
			_len <= MEMSET_LOOP_LIMIT && \
			/* \
			 *	If MEMSET_LOOP_LIMIT == 0, optimizer should find \
			 *	the whole "if" false at compile time. \
			 */ \
			MEMSET_LOOP_LIMIT != 0) \
		{ \
			long *_start = (long *) _vstart; \
			long *_stop = (long *) ((char *) _start + _len); \
			while (_start < _stop) \
				*_start++ = 0; \
		} \
		else \
			memset(_vstart, _val, _len); \
	} while (0)

/*
 * MemSetAligned is the same as MemSet except it omits the test to see if
 * "start" is word-aligned.  This is okay to use if the caller knows a-priori
 * that the pointer is suitably aligned (typically, because he just got it
 * from palloc(), which always delivers a max-aligned pointer).
 */
#define MemSetAligned(start, val, len) \
	do \
	{ \
		long   *_start = (long *) (start); \
		int		_val = (val); \
		Size	_len = (len); \
\
		if ((_len & LONG_ALIGN_MASK) == 0 && \
			_val == 0 && \
			_len <= MEMSET_LOOP_LIMIT && \
			MEMSET_LOOP_LIMIT != 0) \
		{ \
			long *_stop = (long *) ((char *) _start + _len); \
			while (_start < _stop) \
				*_start++ = 0; \
		} \
		else \
			memset(_start, _val, _len); \
	} while (0)


/*
 * MemSetTest/MemSetLoop are a variant version that allow all the tests in
 * MemSet to be done at compile time in cases where "val" and "len" are
 * constants *and* we know the "start" pointer must be word-aligned.
 * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
 * MemSetAligned.  Beware of multiple evaluations of the arguments when using
 * this approach.
 */
#define MemSetTest(val, len) \
	( ((len) & LONG_ALIGN_MASK) == 0 && \
	(len) <= MEMSET_LOOP_LIMIT && \
	MEMSET_LOOP_LIMIT != 0 && \
	(val) == 0 )

#define MemSetLoop(start, val, len) \
	do \
	{ \
		long * _start = (long *) (start); \
		long * _stop = (long *) ((char *) _start + (Size) (len)); \
	\
		while (_start < _stop) \
			*_start++ = 0; \
	} while (0)


/* ----------------------------------------------------------------
 *				Section 7:	random stuff
 * ----------------------------------------------------------------
 */

/* msb for char */
#define HIGHBIT					(0x80)
#define IS_HIGHBIT_SET(ch)		((unsigned char)(ch) & HIGHBIT)

#define STATUS_OK				(0)
#define STATUS_ERROR			(-1)
#define STATUS_EOF				(-2)
#define STATUS_FOUND			(1)
#define STATUS_WAITING			(2)


/* ----------------------------------------------------------------
 *				Section 8: system-specific hacks
 *
 *		This should be limited to things that absolutely have to be
 *		included in every source file.	The port-specific header file
 *		is usually a better place for this sort of thing.
 * ----------------------------------------------------------------
 */

/*
 *	NOTE:  this is also used for opening text files.
 *	WIN32 treats Control-Z as EOF in files opened in text mode.
 *	Therefore, we open files in binary mode on Win32 so we can read
 *	literal control-Z.	The other affect is that we see CRLF, but
 *	that is OK because we can already handle those cleanly.
 */
#if defined(WIN32) || defined(__CYGWIN__)
#define PG_BINARY	O_BINARY
#define PG_BINARY_A "ab"
#define PG_BINARY_R "rb"
#define PG_BINARY_W "wb"
#else
#define PG_BINARY	0
#define PG_BINARY_A "a"
#define PG_BINARY_R "r"
#define PG_BINARY_W "w"
#endif

#if defined(sun) && defined(__sparc__) && !defined(__SVR4)
#include <unistd.h>
#endif

/* These are for things that are one way on Unix and another on NT */
#define NULL_DEV		"/dev/null"

/*
 * Provide prototypes for routines not present in a particular machine's
 * standard C library.
 */

#if !HAVE_DECL_SNPRINTF
extern int
snprintf(char *str, size_t count, const char *fmt,...)
/* This extension allows gcc to check the format string */
__attribute__((format(printf, 3, 4)));
#endif

#if !HAVE_DECL_VSNPRINTF
extern int	vsnprintf(char *str, size_t count, const char *fmt, va_list args);
#endif

#if !defined(HAVE_MEMMOVE) && !defined(memmove)
#define memmove(d, s, c)		bcopy(s, d, c)
#endif

#ifndef PGDLLIMPORT
#define PGDLLIMPORT				/* no special DLL markers on most ports */
#endif

/*
 * The following is used as the arg list for signal handlers.  Any ports
 * that take something other than an int argument should override this in
 * their pg_config_os.h file.  Note that variable names are required
 * because it is used in both the prototypes as well as the definitions.
 * Note also the long name.  We expect that this won't collide with
 * other names causing compiler warnings.
 */

#ifndef SIGNAL_ARGS
#define SIGNAL_ARGS  int postgres_signal_arg
#endif

/*
 * When there is no sigsetjmp, its functionality is provided by plain
 * setjmp. Incidentally, nothing provides setjmp's functionality in
 * that case.
 */
#ifndef HAVE_SIGSETJMP
#define sigjmp_buf jmp_buf
#define sigsetjmp(x,y) setjmp(x)
#define siglongjmp longjmp
#endif

#if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
extern int	fdatasync(int fildes);
#endif

/* If strtoq() exists, rename it to the more standard strtoll() */
#if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
#define strtoll strtoq
#define HAVE_STRTOLL 1
#endif

/* If strtouq() exists, rename it to the more standard strtoull() */
#if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
#define strtoull strtouq
#define HAVE_STRTOULL 1
#endif

/* EXEC_BACKEND defines */
#ifdef EXEC_BACKEND
#define NON_EXEC_STATIC
#else
#define NON_EXEC_STATIC static
#endif

/* /port compatibility functions */
/*#include "port.h"*/

#endif   /* C_H */