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) 1996-2004, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
15 * $PostgreSQL: pgsql/src/include/c.h,v 1.174 2004/09/26 15:13:42 tgl 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 */
55 #if !defined(WIN32) && !defined(__CYGWIN__)
56 #include "pg_config_os.h" /* must be before any system header files */
58 #include "postgres_ext.h"
68 #include <sys/types.h>
71 #if defined(WIN32) || defined(__CYGWIN__)
72 #include <fcntl.h> /* ensure O_BINARY is available */
74 #ifdef HAVE_SUPPORTDEFS_H
75 #include <SupportDefs.h>
78 #if defined(WIN32) || defined(__CYGWIN__)
79 #if !defined(_MSC_VER) && !defined(__BORLANDC__)
80 /* We have to redefine some system functions after they are included above */
81 #include "pg_config_os.h"
83 #include <windows.h> /* We don't have a port file for MSC/BCC */
87 /* Must be before gettext() games below */
93 #define gettext(x) (x)
95 #define gettext_noop(x) (x)
98 /* ----------------------------------------------------------------
99 * Section 1: hacks to cope with non-ANSI C compilers
101 * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
102 * ----------------------------------------------------------------
107 * Convert the argument to a string, using the C preprocessor.
109 * Concatenate two arguments together, using the C preprocessor.
111 * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
112 * whether #identifier works, but if we have that we likely have ## too.
114 #if defined(HAVE_STRINGIZE)
116 #define CppAsString(identifier) #identifier
117 #define CppConcat(x, y) x##y
119 #else /* !HAVE_STRINGIZE */
121 #define CppAsString(identifier) "identifier"
124 * CppIdentity -- On Reiser based cpp's this is used to concatenate
125 * two tokens. That is
126 * CppIdentity(A)B ==> AB
127 * We renamed it to _private_CppIdentity because it should not
128 * be referenced outside this file. On other cpp's it
131 #define _priv_CppIdentity(x)x
132 #define CppConcat(x, y) _priv_CppIdentity(x)y
133 #endif /* !HAVE_STRINGIZE */
136 * dummyret is used to set return values in macros that use ?: to make
137 * assignments. gcc wants these to be void, other compilers like char
139 #ifdef __GNUC__ /* GNU cc */
140 #define dummyret void
142 #define dummyret char
146 #define __attribute__(_arg_)
149 /* ----------------------------------------------------------------
150 * Section 2: bool, true, false, TRUE, FALSE, NULL
151 * ----------------------------------------------------------------
156 * Boolean value, either true or false.
158 * XXX for C++ compilers, we assume the compiler has a compatible
159 * built-in definition of bool.
162 /* BeOS defines bool already, but the compiler chokes on the
163 * #ifndef unless we wrap it in this check.
174 #define true ((bool) 1)
178 #define false ((bool) 0)
181 #endif /* __BEOS__ */
183 typedef bool *BoolPtr;
198 #define NULL ((void *) 0)
202 /* ----------------------------------------------------------------
203 * Section 3: standard system types
204 * ----------------------------------------------------------------
209 * Variable holding address of any memory resident object.
211 * XXX Pointer arithmetic is done with this, so it can't be void *
212 * under "true" ANSI compilers.
214 typedef char *Pointer;
218 * Signed integer, EXACTLY N BITS IN SIZE,
219 * used for numerical computations and the
220 * frontend/backend protocol.
223 typedef signed char int8; /* == 8 bits */
224 typedef signed short int16; /* == 16 bits */
225 typedef signed int int32; /* == 32 bits */
226 #endif /* not HAVE_INT8 */
230 * Unsigned integer, EXACTLY N BITS IN SIZE,
231 * used for numerical computations and the
232 * frontend/backend protocol.
234 /* Also defined in interfaces/odbc/md5.h */
236 typedef unsigned char uint8; /* == 8 bits */
237 typedef unsigned short uint16; /* == 16 bits */
238 typedef unsigned int uint32; /* == 32 bits */
239 #endif /* not HAVE_UINT8 */
243 * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
245 typedef uint8 bits8; /* >= 8 bits */
246 typedef uint16 bits16; /* >= 16 bits */
247 typedef uint32 bits32; /* >= 32 bits */
251 * Floating point number, AT LEAST N BITS IN SIZE,
252 * used for numerical computations.
254 * Since sizeof(floatN) may be > sizeof(char *), always pass
255 * floatN by reference.
257 * XXX: these typedefs are now deprecated in favor of float4 and float8.
258 * They will eventually go away.
260 typedef float float32data;
261 typedef double float64data;
262 typedef float *float32;
263 typedef double *float64;
268 #ifdef HAVE_LONG_INT_64
269 /* Plain "long int" fits, use it */
272 typedef long int int64;
275 typedef unsigned long int uint64;
278 #elif defined(HAVE_LONG_LONG_INT_64)
279 /* We have working support for "long long int", use that */
282 typedef long long int int64;
285 typedef unsigned long long int uint64;
288 #else /* not HAVE_LONG_INT_64 and not
289 * HAVE_LONG_LONG_INT_64 */
291 /* Won't actually work, but fall back to long int so that code compiles */
293 typedef long int int64;
296 typedef unsigned long int uint64;
299 #define INT64_IS_BUSTED
300 #endif /* not HAVE_LONG_INT_64 and not
301 * HAVE_LONG_LONG_INT_64 */
303 /* Decide if we need to decorate 64-bit constants */
304 #ifdef HAVE_LL_CONSTANTS
305 #define INT64CONST(x) ((int64) x##LL)
306 #define UINT64CONST(x) ((uint64) x##ULL)
308 #define INT64CONST(x) ((int64) x)
309 #define UINT64CONST(x) ((uint64) x)
313 /* Select timestamp representation (float8 or int64) */
314 #if defined(USE_INTEGER_DATETIMES) && !defined(INT64_IS_BUSTED)
315 #define HAVE_INT64_TIMESTAMP
318 /* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
319 #ifndef HAVE_SIG_ATOMIC_T
320 typedef int sig_atomic_t;
325 * Size of any memory resident object, as returned by sizeof.
331 * Index into any memory resident array.
334 * Indices are non negative.
336 typedef unsigned int Index;
340 * Offset into any memory resident array.
343 * This differs from an Index in that an Index is always
344 * non negative, whereas Offset may be negative.
346 typedef signed int Offset;
349 * Common Postgres datatype names (as used in the catalogs)
353 typedef float float4;
354 typedef double float8;
357 * Oid, RegProcedure, TransactionId, SubTransactionId, CommandId, AclId
360 /* typedef Oid is in postgres_ext.h */
363 * regproc is the type name used in the include/catalog headers, but
364 * RegProcedure is the preferred name in C code.
367 typedef regproc RegProcedure;
369 typedef uint32 TransactionId;
371 typedef uint32 SubTransactionId;
373 #define InvalidSubTransactionId ((SubTransactionId) 0)
374 #define TopSubTransactionId ((SubTransactionId) 1)
376 typedef uint32 CommandId;
378 #define FirstCommandId ((CommandId) 0)
380 typedef int32 AclId; /* user and group identifiers */
383 * Array indexing support
392 * Variable-length datatypes all share the 'struct varlena' header.
394 * NOTE: for TOASTable types, this is an oversimplification, since the value
395 * may be compressed or moved out-of-line. However datatype-specific routines
396 * are mostly content to deal with de-TOASTed values only, and of course
397 * client-side routines should never see a TOASTed value. See postgres.h for
398 * details of the TOASTed form.
407 #define VARHDRSZ ((int32) sizeof(int32))
410 * These widely-used datatypes are just a varlena header and the data bytes.
411 * There is no terminating null or anything like that --- the data length is
412 * always VARSIZE(ptr) - VARHDRSZ.
414 typedef struct varlena bytea;
415 typedef struct varlena text;
416 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
417 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
420 * Fixed-length array types (these are not varlena's!)
423 typedef int2 int2vector[INDEX_MAX_KEYS];
424 typedef Oid oidvector[INDEX_MAX_KEYS];
427 * We want NameData to have length NAMEDATALEN and int alignment,
428 * because that's how the data type 'name' is defined in pg_type.
429 * Use a union to make sure the compiler agrees. Note that NAMEDATALEN
430 * must be a multiple of sizeof(int), else sizeof(NameData) will probably
431 * not come out equal to NAMEDATALEN.
433 typedef union nameData
435 char data[NAMEDATALEN];
438 typedef NameData *Name;
440 #define NameStr(name) ((name).data)
443 /* ----------------------------------------------------------------
444 * Section 4: IsValid macros for system types
445 * ----------------------------------------------------------------
449 * True iff bool is valid.
451 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
455 * True iff pointer is valid.
457 #define PointerIsValid(pointer) ((void*)(pointer) != NULL)
461 * True iff pointer is properly aligned to point to the given type.
463 #define PointerIsAligned(pointer, type) \
464 (((long)(pointer) % (sizeof (type))) == 0)
466 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
468 #define AclIdIsValid(aclId) ((bool) ((aclId) != 0))
470 #define RegProcedureIsValid(p) OidIsValid(p)
473 /* ----------------------------------------------------------------
474 * Section 5: offsetof, lengthof, endof, alignment
475 * ----------------------------------------------------------------
479 * Offset of a structure/union field within that structure/union.
481 * XXX This is supposed to be part of stddef.h, but isn't on
482 * some systems (like SunOS 4).
485 #define offsetof(type, field) ((long) &((type *)0)->field)
486 #endif /* offsetof */
490 * Number of elements in an array.
492 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
496 * Address of the element one past the last in an array.
498 #define endof(array) (&array[lengthof(array)])
501 * Alignment macros: align a length or address appropriately for a given type.
503 * There used to be some incredibly crufty platform-dependent hackery here,
504 * but now we rely on the configure script to get the info for us. Much nicer.
506 * NOTE: TYPEALIGN will not work if ALIGNVAL is not a power of 2.
507 * That case seems extremely unlikely to occur in practice, however.
511 #define TYPEALIGN(ALIGNVAL,LEN) \
512 (((long) (LEN) + (ALIGNVAL-1)) & ~((long) (ALIGNVAL-1)))
514 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
515 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
516 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
517 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
518 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
519 /* MAXALIGN covers only built-in types, not buffers */
520 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
523 /* ----------------------------------------------------------------
524 * Section 6: widely useful macros
525 * ----------------------------------------------------------------
529 * Return the maximum of two numbers.
531 #define Max(x, y) ((x) > (y) ? (x) : (y))
535 * Return the minimum of two numbers.
537 #define Min(x, y) ((x) < (y) ? (x) : (y))
541 * Return the absolute value of the argument.
543 #define Abs(x) ((x) >= 0 ? (x) : -(x))
547 * Like standard library function strncpy(), except that result string
548 * is guaranteed to be null-terminated --- that is, at most N-1 bytes
549 * of the source string will be kept.
550 * Also, the macro returns no result (too hard to do that without
551 * evaluating the arguments multiple times, which seems worse).
553 * BTW: when you need to copy a non-null-terminated string (like a text
554 * datum) and add a null, do not do it with StrNCpy(..., len+1). That
555 * might seem to work, but it fetches one byte more than there is in the
556 * text object. One fine day you'll have a SIGSEGV because there isn't
557 * another byte before the end of memory. Don't laugh, we've had real
558 * live bug reports from real live users over exactly this mistake.
559 * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
561 #define StrNCpy(dst,src,len) \
564 char * _dst = (dst); \
569 strncpy(_dst, (src), _len); \
570 _dst[_len-1] = '\0'; \
575 /* Get a bit mask of the bits set in non-int32 aligned addresses */
576 #define INT_ALIGN_MASK (sizeof(int32) - 1)
580 * Exactly the same as standard library function memset(), but considerably
581 * faster for zeroing small word-aligned structures (such as parsetree nodes).
582 * This has to be a macro because the main point is to avoid function-call
583 * overhead. However, we have also found that the loop is faster than
584 * native libc memset() on some platforms, even those with assembler
585 * memset() functions. More research needs to be done, perhaps with
586 * platform-specific MEMSET_LOOP_LIMIT values or tests in configure.
590 #define MemSet(start, val, len) \
593 int32 * _start = (int32 *) (start); \
597 if ((((long) _start) & INT_ALIGN_MASK) == 0 && \
598 (_len & INT_ALIGN_MASK) == 0 && \
600 _len <= MEMSET_LOOP_LIMIT) \
602 int32 * _stop = (int32 *) ((char *) _start + _len); \
603 while (_start < _stop) \
607 memset((char *) _start, _val, _len); \
610 #define MEMSET_LOOP_LIMIT 1024
613 * MemSetAligned is the same as MemSet except it omits the test to see if
614 * "start" is word-aligned. This is okay to use if the caller knows a-priori
615 * that the pointer is suitably aligned (typically, because he just got it
616 * from palloc(), which always delivers a max-aligned pointer).
618 #define MemSetAligned(start, val, len) \
621 int32 * _start = (int32 *) (start); \
625 if ((_len & INT_ALIGN_MASK) == 0 && \
627 _len <= MEMSET_LOOP_LIMIT) \
629 int32 * _stop = (int32 *) ((char *) _start + _len); \
630 while (_start < _stop) \
634 memset((char *) _start, _val, _len); \
639 * MemSetTest/MemSetLoop are a variant version that allow all the tests in
640 * MemSet to be done at compile time in cases where "val" and "len" are
641 * constants *and* we know the "start" pointer must be word-aligned.
642 * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
643 * MemSetAligned. Beware of multiple evaluations of the arguments when using
646 #define MemSetTest(val, len) \
647 ( ((len) & INT_ALIGN_MASK) == 0 && \
648 (len) <= MEMSET_LOOP_LIMIT && \
651 #define MemSetLoop(start, val, len) \
654 int32 * _start = (int32 *) (start); \
655 int32 * _stop = (int32 *) ((char *) _start + (Size) (len)); \
657 while (_start < _stop) \
662 /* ----------------------------------------------------------------
663 * Section 7: random stuff
664 * ----------------------------------------------------------------
668 #define CSIGNBIT (0x80)
670 #define STATUS_OK (0)
671 #define STATUS_ERROR (-1)
672 #define STATUS_EOF (-2)
673 #define STATUS_FOUND (1)
676 /* ----------------------------------------------------------------
677 * Section 8: system-specific hacks
679 * This should be limited to things that absolutely have to be
680 * included in every source file. The port-specific header file
681 * is usually a better place for this sort of thing.
682 * ----------------------------------------------------------------
686 * NOTE: this is also used for opening text files.
687 * WIN32 treats Control-Z as EOF in files opened in text mode.
688 * Therefore, we open files in binary mode on Win32 so we can read
689 * literal control-Z. The other affect is that we see CRLF, but
690 * that is OK because we can already handle those cleanly.
692 #if defined(WIN32) || defined(__CYGWIN__)
693 #define PG_BINARY O_BINARY
694 #define PG_BINARY_R "rb"
695 #define PG_BINARY_W "wb"
698 #define PG_BINARY_R "r"
699 #define PG_BINARY_W "w"
702 #if defined(sun) && defined(__sparc__) && !defined(__SVR4)
706 /* These are for things that are one way on Unix and another on NT */
707 #define NULL_DEV "/dev/null"
710 * Provide prototypes for routines not present in a particular machine's
711 * standard C library.
714 #if !HAVE_DECL_SNPRINTF
716 snprintf(char *str, size_t count, const char *fmt,...)
717 /* This extension allows gcc to check the format string */
718 __attribute__((format(printf, 3, 4)));
721 #if !HAVE_DECL_VSNPRINTF
722 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
725 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
726 #define memmove(d, s, c) bcopy(s, d, c)
730 #define DLLIMPORT /* no special DLL markers on most ports */
734 * The following is used as the arg list for signal handlers. Any ports
735 * that take something other than an int argument should override this in
736 * their pg_config_os.h file. Note that variable names are required
737 * because it is used in both the prototypes as well as the definitions.
738 * Note also the long name. We expect that this won't collide with
739 * other names causing compiler warnings.
743 #define SIGNAL_ARGS int postgres_signal_arg
747 * When there is no sigsetjmp, its functionality is provided by plain
748 * setjmp. Incidentally, nothing provides setjmp's functionality in
751 #ifndef HAVE_SIGSETJMP
752 #define sigjmp_buf jmp_buf
753 #define sigsetjmp(x,y) setjmp(x)
754 #define siglongjmp longjmp
757 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
758 extern int fdatasync(int fildes);
761 /* If strtoq() exists, rename it to the more standard strtoll() */
762 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
763 #define strtoll strtoq
764 #define HAVE_STRTOLL 1
767 /* If strtouq() exists, rename it to the more standard strtoull() */
768 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
769 #define strtoull strtouq
770 #define HAVE_STRTOULL 1
773 /* EXEC_BACKEND defines */
775 #define NON_EXEC_STATIC
777 #define NON_EXEC_STATIC static
780 /* /port compatibility functions */