1 /*-------------------------------------------------------------------------
4 * Fundamental C definitions. This is included by every .c file in
5 * PostgreSQL (via either postgres.h or postgres_fe.h, as appropriate).
7 * Note that the definitions here are not intended to be exposed to clients
8 * of the frontend interface libraries --- so we don't worry much about
9 * polluting the namespace with lots of stuff...
12 * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
15 * $Id: c.h,v 1.150 2003/06/12 08:15:29 momjian Exp $
17 *-------------------------------------------------------------------------
20 *----------------------------------------------------------------
23 * When adding stuff to this file, please try to put stuff
24 * into the relevant section, or add new sections as appropriate.
27 * ------- ------------------------------------------------
28 * 0) pg_config.h and standard system headers
29 * 1) hacks to cope with non-ANSI C compilers
30 * 2) bool, true, false, TRUE, FALSE, NULL
31 * 3) standard system types
32 * 4) IsValid macros for system types
33 * 5) offsetof, lengthof, endof, alignment
34 * 6) widely useful macros
36 * 8) system-specific hacks
38 * NOTE: since this file is included by both frontend and backend modules, it's
39 * almost certainly wrong to put an "extern" declaration here. typedefs and
40 * macros are the kind of thing that might go here.
42 *----------------------------------------------------------------
48 * We have to include stdlib.h here because it defines many of these macros
49 * on some platforms, and we only want our definitions used if stdlib.h doesn't
50 * have its own. The same goes for stddef and stdarg if present.
53 #include "pg_config.h"
54 #include "pg_config_manual.h" /* must be after pg_config.h */
56 #include "pg_config_os.h" /* must be before any system header files */
58 #include "postgres_ext.h"
68 #include <sys/types.h>
71 #include <fcntl.h> /* ensure O_BINARY is available */
72 #ifdef HAVE_SUPPORTDEFS_H
73 #include <SupportDefs.h>
76 #if defined(WIN32) && !defined(_MSC_VER) && !defined(__BORLANDC__)
77 /* We have to redefine some system functions after they are included above */
78 #include "pg_config_os.h"
81 /* Must be before gettext() games below */
87 #define gettext(x) (x)
89 #define gettext_noop(x) (x)
92 /* ----------------------------------------------------------------
93 * Section 1: hacks to cope with non-ANSI C compilers
95 * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
96 * ----------------------------------------------------------------
101 * Convert the argument to a string, using the C preprocessor.
103 * Concatenate two arguments together, using the C preprocessor.
105 * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
106 * whether #identifier works, but if we have that we likely have ## too.
108 #if defined(HAVE_STRINGIZE)
110 #define CppAsString(identifier) #identifier
111 #define CppConcat(x, y) x##y
113 #else /* !HAVE_STRINGIZE */
115 #define CppAsString(identifier) "identifier"
118 * CppIdentity -- On Reiser based cpp's this is used to concatenate
119 * two tokens. That is
120 * CppIdentity(A)B ==> AB
121 * We renamed it to _private_CppIdentity because it should not
122 * be referenced outside this file. On other cpp's it
125 #define _priv_CppIdentity(x)x
126 #define CppConcat(x, y) _priv_CppIdentity(x)y
127 #endif /* !HAVE_STRINGIZE */
130 * dummyret is used to set return values in macros that use ?: to make
131 * assignments. gcc wants these to be void, other compilers like char
133 #ifdef __GNUC__ /* GNU cc */
134 #define dummyret void
136 #define dummyret char
140 #define __attribute__(_arg_)
143 /* ----------------------------------------------------------------
144 * Section 2: bool, true, false, TRUE, FALSE, NULL
145 * ----------------------------------------------------------------
150 * Boolean value, either true or false.
152 * XXX for C++ compilers, we assume the compiler has a compatible
153 * built-in definition of bool.
156 /* BeOS defines bool already, but the compiler chokes on the
157 * #ifndef unless we wrap it in this check.
168 #define true ((bool) 1)
172 #define false ((bool) 0)
175 #endif /* __BEOS__ */
177 typedef bool *BoolPtr;
192 #define NULL ((void *) 0)
196 /* ----------------------------------------------------------------
197 * Section 3: standard system types
198 * ----------------------------------------------------------------
203 * Variable holding address of any memory resident object.
205 * XXX Pointer arithmetic is done with this, so it can't be void *
206 * under "true" ANSI compilers.
208 typedef char *Pointer;
212 * Signed integer, EXACTLY N BITS IN SIZE,
213 * used for numerical computations and the
214 * frontend/backend protocol.
217 typedef signed char int8; /* == 8 bits */
218 typedef signed short int16; /* == 16 bits */
219 typedef signed int int32; /* == 32 bits */
220 #endif /* not HAVE_INT8 */
224 * Unsigned integer, EXACTLY N BITS IN SIZE,
225 * used for numerical computations and the
226 * frontend/backend protocol.
228 /* Also defined in interfaces/odbc/md5.h */
230 typedef unsigned char uint8; /* == 8 bits */
231 typedef unsigned short uint16; /* == 16 bits */
232 typedef unsigned int uint32; /* == 32 bits */
233 #endif /* not HAVE_UINT8 */
237 * Boolean value, AT LEAST N BITS IN SIZE.
239 typedef uint8 bool8; /* >= 8 bits */
240 typedef uint16 bool16; /* >= 16 bits */
241 typedef uint32 bool32; /* >= 32 bits */
245 * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
247 typedef uint8 bits8; /* >= 8 bits */
248 typedef uint16 bits16; /* >= 16 bits */
249 typedef uint32 bits32; /* >= 32 bits */
253 * Unit of storage, AT LEAST N BITS IN SIZE,
254 * used to fetch/store data.
256 typedef uint8 word8; /* >= 8 bits */
257 typedef uint16 word16; /* >= 16 bits */
258 typedef uint32 word32; /* >= 32 bits */
262 * Floating point number, AT LEAST N BITS IN SIZE,
263 * used for numerical computations.
265 * Since sizeof(floatN) may be > sizeof(char *), always pass
266 * floatN by reference.
268 * XXX: these typedefs are now deprecated in favor of float4 and float8.
269 * They will eventually go away.
271 typedef float float32data;
272 typedef double float64data;
273 typedef float *float32;
274 typedef double *float64;
279 #ifdef HAVE_LONG_INT_64
280 /* Plain "long int" fits, use it */
283 typedef long int int64;
286 typedef unsigned long int uint64;
289 #elif defined(HAVE_LONG_LONG_INT_64)
290 /* We have working support for "long long int", use that */
293 typedef long long int int64;
296 typedef unsigned long long int uint64;
299 #else /* not HAVE_LONG_INT_64 and not
300 * HAVE_LONG_LONG_INT_64 */
302 /* Won't actually work, but fall back to long int so that code compiles */
304 typedef long int int64;
307 typedef unsigned long int uint64;
310 #define INT64_IS_BUSTED
311 #endif /* not HAVE_LONG_INT_64 and not
312 * HAVE_LONG_LONG_INT_64 */
314 /* Decide if we need to decorate 64-bit constants */
315 #ifdef HAVE_LL_CONSTANTS
316 #define INT64CONST(x) ((int64) x##LL)
317 #define UINT64CONST(x) ((uint64) x##LL)
319 #define INT64CONST(x) ((int64) x)
320 #define UINT64CONST(x) ((uint64) x)
324 /* Select timestamp representation (float8 or int64) */
325 #if defined(USE_INTEGER_DATETIMES) && !defined(INT64_IS_BUSTED)
326 #define HAVE_INT64_TIMESTAMP
329 /* Global variable holding time zone information. */
330 #ifndef HAVE_UNDERSCORE_TIMEZONE
331 #define TIMEZONE_GLOBAL timezone
333 #define TIMEZONE_GLOBAL _timezone
334 #define tzname _tzname /* should be in time.h? */
337 /* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
338 #ifndef HAVE_SIG_ATOMIC_T
339 typedef int sig_atomic_t;
344 * Size of any memory resident object, as returned by sizeof.
350 * Index into any memory resident array.
353 * Indices are non negative.
355 typedef unsigned int Index;
359 * Offset into any memory resident array.
362 * This differs from an Index in that an Index is always
363 * non negative, whereas Offset may be negative.
365 typedef signed int Offset;
368 * Common Postgres datatype names (as used in the catalogs)
372 typedef float float4;
373 typedef double float8;
376 * Oid, RegProcedure, TransactionId, CommandId, AclId
379 /* typedef Oid is in postgres_ext.h */
382 * regproc is the type name used in the include/catalog headers, but
383 * RegProcedure is the preferred name in C code.
386 typedef regproc RegProcedure;
388 typedef uint32 TransactionId;
390 typedef uint32 CommandId;
392 #define FirstCommandId ((CommandId) 0)
394 typedef int32 AclId; /* user and group identifiers */
397 * Array indexing support
406 * Variable-length datatypes all share the 'struct varlena' header.
408 * NOTE: for TOASTable types, this is an oversimplification, since the value
409 * may be compressed or moved out-of-line. However datatype-specific routines
410 * are mostly content to deal with de-TOASTed values only, and of course
411 * client-side routines should never see a TOASTed value. See postgres.h for
412 * details of the TOASTed form.
421 #define VARHDRSZ ((int32) sizeof(int32))
424 * These widely-used datatypes are just a varlena header and the data bytes.
425 * There is no terminating null or anything like that --- the data length is
426 * always VARSIZE(ptr) - VARHDRSZ.
428 typedef struct varlena bytea;
429 typedef struct varlena text;
430 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
431 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
434 * Fixed-length array types (these are not varlena's!)
437 typedef int2 int2vector[INDEX_MAX_KEYS];
438 typedef Oid oidvector[INDEX_MAX_KEYS];
441 * We want NameData to have length NAMEDATALEN and int alignment,
442 * because that's how the data type 'name' is defined in pg_type.
443 * Use a union to make sure the compiler agrees. Note that NAMEDATALEN
444 * must be a multiple of sizeof(int), else sizeof(NameData) will probably
445 * not come out equal to NAMEDATALEN.
447 typedef union nameData
449 char data[NAMEDATALEN];
452 typedef NameData *Name;
454 #define NameStr(name) ((name).data)
457 /* ----------------------------------------------------------------
458 * Section 4: IsValid macros for system types
459 * ----------------------------------------------------------------
463 * True iff bool is valid.
465 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
469 * True iff pointer is valid.
471 #define PointerIsValid(pointer) ((void*)(pointer) != NULL)
475 * True iff pointer is properly aligned to point to the given type.
477 #define PointerIsAligned(pointer, type) \
478 (((long)(pointer) % (sizeof (type))) == 0)
480 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
482 #define AclIdIsValid(aclId) ((bool) ((aclId) != 0))
484 #define RegProcedureIsValid(p) OidIsValid(p)
487 /* ----------------------------------------------------------------
488 * Section 5: offsetof, lengthof, endof, alignment
489 * ----------------------------------------------------------------
493 * Offset of a structure/union field within that structure/union.
495 * XXX This is supposed to be part of stddef.h, but isn't on
496 * some systems (like SunOS 4).
499 #define offsetof(type, field) ((long) &((type *)0)->field)
500 #endif /* offsetof */
504 * Number of elements in an array.
506 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
510 * Address of the element one past the last in an array.
512 #define endof(array) (&array[lengthof(array)])
515 * Alignment macros: align a length or address appropriately for a given type.
517 * There used to be some incredibly crufty platform-dependent hackery here,
518 * but now we rely on the configure script to get the info for us. Much nicer.
520 * NOTE: TYPEALIGN will not work if ALIGNVAL is not a power of 2.
521 * That case seems extremely unlikely to occur in practice, however.
525 #define TYPEALIGN(ALIGNVAL,LEN) (((long)(LEN) + (ALIGNVAL-1)) & ~(ALIGNVAL-1))
527 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
528 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
529 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
530 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
531 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
534 /* ----------------------------------------------------------------
535 * Section 6: widely useful macros
536 * ----------------------------------------------------------------
540 * Return the maximum of two numbers.
542 #define Max(x, y) ((x) > (y) ? (x) : (y))
546 * Return the minimum of two numbers.
548 #define Min(x, y) ((x) < (y) ? (x) : (y))
552 * Return the absolute value of the argument.
554 #define Abs(x) ((x) >= 0 ? (x) : -(x))
558 * Like standard library function strncpy(), except that result string
559 * is guaranteed to be null-terminated --- that is, at most N-1 bytes
560 * of the source string will be kept.
561 * Also, the macro returns no result (too hard to do that without
562 * evaluating the arguments multiple times, which seems worse).
564 * BTW: when you need to copy a non-null-terminated string (like a text
565 * datum) and add a null, do not do it with StrNCpy(..., len+1). That
566 * might seem to work, but it fetches one byte more than there is in the
567 * text object. One fine day you'll have a SIGSEGV because there isn't
568 * another byte before the end of memory. Don't laugh, we've had real
569 * live bug reports from real live users over exactly this mistake.
570 * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
572 #define StrNCpy(dst,src,len) \
575 char * _dst = (dst); \
580 strncpy(_dst, (src), _len); \
581 _dst[_len-1] = '\0'; \
586 /* Get a bit mask of the bits set in non-int32 aligned addresses */
587 #define INT_ALIGN_MASK (sizeof(int32) - 1)
591 * Exactly the same as standard library function memset(), but considerably
592 * faster for zeroing small word-aligned structures (such as parsetree nodes).
593 * This has to be a macro because the main point is to avoid function-call
594 * overhead. However, we have also found that the loop is faster than
595 * native libc memset() on some platforms, even those with assembler
596 * memset() functions. More research needs to be done, perhaps with
597 * platform-specific MEMSET_LOOP_LIMIT values or tests in configure.
601 #define MemSet(start, val, len) \
604 int32 * _start = (int32 *) (start); \
608 if ((((long) _start) & INT_ALIGN_MASK) == 0 && \
609 (_len & INT_ALIGN_MASK) == 0 && \
611 _len <= MEMSET_LOOP_LIMIT) \
613 int32 * _stop = (int32 *) ((char *) _start + _len); \
614 while (_start < _stop) \
618 memset((char *) _start, _val, _len); \
621 #define MEMSET_LOOP_LIMIT 1024
624 * MemSetAligned is the same as MemSet except it omits the test to see if
625 * "start" is word-aligned. This is okay to use if the caller knows a-priori
626 * that the pointer is suitably aligned (typically, because he just got it
627 * from palloc(), which always delivers a max-aligned pointer).
629 #define MemSetAligned(start, val, len) \
632 int32 * _start = (int32 *) (start); \
636 if ((_len & INT_ALIGN_MASK) == 0 && \
638 _len <= MEMSET_LOOP_LIMIT) \
640 int32 * _stop = (int32 *) ((char *) _start + _len); \
641 while (_start < _stop) \
645 memset((char *) _start, _val, _len); \
650 * MemSetTest/MemSetLoop are a variant version that allow all the tests in
651 * MemSet to be done at compile time in cases where "val" and "len" are
652 * constants *and* we know the "start" pointer must be word-aligned.
653 * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
654 * MemSetAligned. Beware of multiple evaluations of the arguments when using
657 #define MemSetTest(val, len) \
658 ( ((len) & INT_ALIGN_MASK) == 0 && \
659 (len) <= MEMSET_LOOP_LIMIT && \
662 #define MemSetLoop(start, val, len) \
665 int32 * _start = (int32 *) (start); \
666 int32 * _stop = (int32 *) ((char *) _start + (Size) (len)); \
668 while (_start < _stop) \
673 /* ----------------------------------------------------------------
674 * Section 7: random stuff
675 * ----------------------------------------------------------------
679 #define CSIGNBIT (0x80)
681 #define STATUS_OK (0)
682 #define STATUS_ERROR (-1)
683 #define STATUS_EOF (-2)
684 #define STATUS_FOUND (1)
687 /* ----------------------------------------------------------------
688 * Section 8: system-specific hacks
690 * This should be limited to things that absolutely have to be
691 * included in every source file. The port-specific header file
692 * is usually a better place for this sort of thing.
693 * ----------------------------------------------------------------
696 #if defined(__CYGWIN__) || defined(WIN32)
697 #define PG_BINARY O_BINARY
698 #define PG_BINARY_R "rb"
699 #define PG_BINARY_W "wb"
702 #define PG_BINARY_R "r"
703 #define PG_BINARY_W "w"
706 #if !defined(WIN32) && !defined(__BEOS__)
707 #define FCNTL_NONBLOCK(sock) fcntl(sock, F_SETFL, O_NONBLOCK)
709 extern long ioctlsocket_ret;
710 /* Returns non-0 on failure, while fcntl() returns -1 on failure */
712 #define FCNTL_NONBLOCK(sock) ((ioctlsocket(sock, FIONBIO, &ioctlsocket_ret) == 0) ? 0 : -1)
715 #define FCNTL_NONBLOCK(sock) ((ioctl(sock, FIONBIO, &ioctlsocket_ret) == 0) ? 0 : -1)
719 #if defined(sun) && defined(__sparc__) && !defined(__SVR4)
723 /* These are for things that are one way on Unix and another on NT */
724 #define NULL_DEV "/dev/null"
727 * Provide prototypes for routines not present in a particular machine's
728 * standard C library.
731 #if !HAVE_DECL_SNPRINTF
733 snprintf(char *str, size_t count, const char *fmt,...)
734 /* This extension allows gcc to check the format string */
735 __attribute__((format(printf, 3, 4)));
738 #if !HAVE_DECL_VSNPRINTF
739 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
742 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
743 #define memmove(d, s, c) bcopy(s, d, c)
747 #define DLLIMPORT /* no special DLL markers on most ports */
751 * The following is used as the arg list for signal handlers. Any ports
752 * that take something other than an int argument should override this in
753 * their pg_config_os.h file. Note that variable names are required
754 * because it is used in both the prototypes as well as the definitions.
755 * Note also the long name. We expect that this won't collide with
756 * other names causing compiler warnings.
760 #define SIGNAL_ARGS int postgres_signal_arg
764 * When there is no sigsetjmp, its functionality is provided by plain
765 * setjmp. Incidentally, nothing provides setjmp's functionality in
768 #ifndef HAVE_SIGSETJMP
769 # define sigjmp_buf jmp_buf
770 # define sigsetjmp(x,y) setjmp(x)
771 # define siglongjmp longjmp
774 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
775 extern int fdatasync(int fildes);
778 /* If strtoq() exists, rename it to the more standard strtoll() */
779 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
780 # define strtoll strtoq
781 # define HAVE_STRTOLL 1
784 /* If strtouq() exists, rename it to the more standard strtoull() */
785 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
786 # define strtoull strtouq
787 # define HAVE_STRTOULL 1
790 /* /port compatibility functions */