path: root/c.h

/*-------------------------------------------------------------------------
 *
 * c.h
 *	  Fundamental C definitions.  This is included by every .c file in
 *	  PostgreSQL (via either postgres.h or postgres_fe.h, as appropriate).
 *
 *	  Note that the definitions here are not intended to be exposed to clients
 *	  of the frontend interface libraries --- so we don't worry much about
 *	  polluting the namespace with lots of stuff...
 *
 *
 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $PostgreSQL: pgsql/src/include/c.h,v 1.214.2.1 2007/01/11 02:40:12 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
/*
 *----------------------------------------------------------------
 *	 TABLE OF CONTENTS
 *
 *		When adding stuff to this file, please try to put stuff
 *		into the relevant section, or add new sections as appropriate.
 *
 *	  section	description
 *	  -------	------------------------------------------------
 *		0)		pg_config.h and standard system headers
 *		1)		hacks to cope with non-ANSI C compilers
 *		2)		bool, true, false, TRUE, FALSE, NULL
 *		3)		standard system types
 *		4)		IsValid macros for system types
 *		5)		offsetof, lengthof, endof, alignment
 *		6)		widely useful macros
 *		7)		random stuff
 *		8)		system-specific hacks
 *
 * NOTE: since this file is included by both frontend and backend modules, it's
 * almost certainly wrong to put an "extern" declaration here.	typedefs and
 * macros are the kind of thing that might go here.
 *
 *----------------------------------------------------------------
 */
#ifndef C_H
#define C_H

/*
 * We have to include stdlib.h here because it defines many of these macros
 * on some platforms, and we only want our definitions used if stdlib.h doesn't
 * have its own.  The same goes for stddef and stdarg if present.
 */

#include "pg_config.h"
#include "pg_config_manual.h"	/* must be after pg_config.h */
#if !defined(WIN32) && !defined(__CYGWIN__)		/* win32 will include further
												 * down */
#include "pg_config_os.h"		/* must be before any system header files */
#endif
#include "postgres_ext.h"
#include "pg_trace.h"

#if _MSC_VER >= 1400
#define errcode __msvc_errcode
#include <crtdefs.h>
#undef errcode
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include <stdarg.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#include <sys/types.h>

#include <errno.h>
#if defined(WIN32) || defined(__CYGWIN__)
#include <fcntl.h>				/* ensure O_BINARY is available */
#endif
#ifdef HAVE_SUPPORTDEFS_H
#include <SupportDefs.h>
#endif

#if defined(WIN32) || defined(__CYGWIN__)
/* We have to redefine some system functions after they are included above. */
#include "pg_config_os.h"
#endif

/* Must be before gettext() games below */
#include <locale.h>

#define _(x) gettext((x))

#ifdef ENABLE_NLS
#include <libintl.h>
#else
#define gettext(x) (x)
#endif

/*
 *	Use this to mark strings to be translated by gettext, in places where
 *	you don't want an actual function call to occur (eg, constant tables).
 */
#define gettext_noop(x) (x)


/* ----------------------------------------------------------------
 *				Section 1: hacks to cope with non-ANSI C compilers
 *
 * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
 * ----------------------------------------------------------------
 */

/*
 * CppAsString
 *		Convert the argument to a string, using the C preprocessor.
 * CppConcat
 *		Concatenate two arguments together, using the C preprocessor.
 *
 * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
 * whether #identifier works, but if we have that we likely have ## too.
 */
#if defined(HAVE_STRINGIZE)

#define CppAsString(identifier) #identifier
#define CppConcat(x, y)			x##y
#else							/* !HAVE_STRINGIZE */

#define CppAsString(identifier) "identifier"

/*
 * CppIdentity -- On Reiser based cpp's this is used to concatenate
 *		two tokens.  That is
 *				CppIdentity(A)B ==> AB
 *		We renamed it to _private_CppIdentity because it should not
 *		be referenced outside this file.  On other cpp's it
 *		produces  A  B.
 */
#define _priv_CppIdentity(x)x
#define CppConcat(x, y)			_priv_CppIdentity(x)y
#endif   /* !HAVE_STRINGIZE */

/*
 * dummyret is used to set return values in macros that use ?: to make
 * assignments.  gcc wants these to be void, other compilers like char
 */
#ifdef __GNUC__					/* GNU cc */
#define dummyret	void
#else
#define dummyret	char
#endif

#ifndef __GNUC__
#define __attribute__(_arg_)
#endif

/* ----------------------------------------------------------------
 *				Section 2:	bool, true, false, TRUE, FALSE, NULL
 * ----------------------------------------------------------------
 */

/*
 * bool
 *		Boolean value, either true or false.
 *
 * XXX for C++ compilers, we assume the compiler has a compatible
 * built-in definition of bool.
 */

#ifndef __cplusplus

#ifndef bool
typedef char bool;
#endif

#ifndef true
#define true	((bool) 1)
#endif

#ifndef false
#define false	((bool) 0)
#endif
#endif   /* not C++ */

typedef bool *BoolPtr;

#ifndef TRUE
#define TRUE	1
#endif

#ifndef FALSE
#define FALSE	0
#endif

/*
 * NULL
 *		Null pointer.
 */
#ifndef NULL
#define NULL	((void *) 0)
#endif


/* ----------------------------------------------------------------
 *				Section 3:	standard system types
 * ----------------------------------------------------------------
 */

/*
 * Pointer
 *		Variable holding address of any memory resident object.
 *
 *		XXX Pointer arithmetic is done with this, so it can't be void *
 *		under "true" ANSI compilers.
 */
typedef char *Pointer;

/*
 * intN
 *		Signed integer, EXACTLY N BITS IN SIZE,
 *		used for numerical computations and the
 *		frontend/backend protocol.
 */
#ifndef HAVE_INT8
typedef signed char int8;		/* == 8 bits */
typedef signed short int16;		/* == 16 bits */
typedef signed int int32;		/* == 32 bits */
#endif   /* not HAVE_INT8 */

/*
 * uintN
 *		Unsigned integer, EXACTLY N BITS IN SIZE,
 *		used for numerical computations and the
 *		frontend/backend protocol.
 */
#ifndef HAVE_UINT8
typedef unsigned char uint8;	/* == 8 bits */
typedef unsigned short uint16;	/* == 16 bits */
typedef unsigned int uint32;	/* == 32 bits */
#endif   /* not HAVE_UINT8 */

/*
 * bitsN
 *		Unit of bitwise operation, AT LEAST N BITS IN SIZE.
 */
typedef uint8 bits8;			/* >= 8 bits */
typedef uint16 bits16;			/* >= 16 bits */
typedef uint32 bits32;			/* >= 32 bits */

/*
 * floatN
 *		Floating point number, AT LEAST N BITS IN SIZE,
 *		used for numerical computations.
 *
 *		Since sizeof(floatN) may be > sizeof(char *), always pass
 *		floatN by reference.
 *
 * XXX: these typedefs are now deprecated in favor of float4 and float8.
 * They will eventually go away.
 */
typedef float float32data;
typedef double float64data;
typedef float *float32;
typedef double *float64;

/*
 * 64-bit integers
 */
#ifdef HAVE_LONG_INT_64
/* Plain "long int" fits, use it */

#ifndef HAVE_INT64
typedef long int int64;
#endif
#ifndef HAVE_UINT64
typedef unsigned long int uint64;
#endif
#elif defined(HAVE_LONG_LONG_INT_64)
/* We have working support for "long long int", use that */

#ifndef HAVE_INT64
typedef long long int int64;
#endif
#ifndef HAVE_UINT64
typedef unsigned long long int uint64;
#endif
#else							/* not HAVE_LONG_INT_64 and not
								 * HAVE_LONG_LONG_INT_64 */

/* Won't actually work, but fall back to long int so that code compiles */
#ifndef HAVE_INT64
typedef long int int64;
#endif
#ifndef HAVE_UINT64
typedef unsigned long int uint64;
#endif

#define INT64_IS_BUSTED
#endif   /* not HAVE_LONG_INT_64 and not
								 * HAVE_LONG_LONG_INT_64 */

/* Decide if we need to decorate 64-bit constants */
#ifdef HAVE_LL_CONSTANTS
#define INT64CONST(x)  ((int64) x##LL)
#define UINT64CONST(x) ((uint64) x##ULL)
#else
#define INT64CONST(x)  ((int64) x)
#define UINT64CONST(x) ((uint64) x)
#endif


/* Select timestamp representation (float8 or int64) */
#if defined(USE_INTEGER_DATETIMES) && !defined(INT64_IS_BUSTED)
#define HAVE_INT64_TIMESTAMP
#endif

/* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
#ifndef HAVE_SIG_ATOMIC_T
typedef int sig_atomic_t;
#endif

/*
 * Size
 *		Size of any memory resident object, as returned by sizeof.
 */
typedef size_t Size;

/*
 * Index
 *		Index into any memory resident array.
 *
 * Note:
 *		Indices are non negative.
 */
typedef unsigned int Index;

/*
 * Offset
 *		Offset into any memory resident array.
 *
 * Note:
 *		This differs from an Index in that an Index is always
 *		non negative, whereas Offset may be negative.
 */
typedef signed int Offset;

/*
 * Common Postgres datatype names (as used in the catalogs)
 */
typedef int16 int2;
typedef int32 int4;
typedef float float4;
typedef double float8;

/*
 * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
 * CommandId
 */

/* typedef Oid is in postgres_ext.h */

/*
 * regproc is the type name used in the include/catalog headers, but
 * RegProcedure is the preferred name in C code.
 */
typedef Oid regproc;
typedef regproc RegProcedure;

typedef uint32 TransactionId;

typedef uint32 SubTransactionId;

#define InvalidSubTransactionId		((SubTransactionId) 0)
#define TopSubTransactionId			((SubTransactionId) 1)

/* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
typedef TransactionId MultiXactId;

typedef uint32 MultiXactOffset;

typedef uint32 CommandId;

#define FirstCommandId	((CommandId) 0)

/*
 * Array indexing support
 */
#define MAXDIM 6
typedef struct
{
	int			indx[MAXDIM];
}	IntArray;

/* ----------------
 *		Variable-length datatypes all share the 'struct varlena' header.
 *
 * NOTE: for TOASTable types, this is an oversimplification, since the value
 * may be compressed or moved out-of-line.	However datatype-specific routines
 * are mostly content to deal with de-TOASTed values only, and of course
 * client-side routines should never see a TOASTed value.  See postgres.h for
 * details of the TOASTed form.
 * ----------------
 */
struct varlena
{
	int32		vl_len;
	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.
 */
typedef struct
{
	int32		size;			/* these fields must match ArrayType! */
	int			ndim;			/* always 1 for int2vector */
	int32