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 of
8 * the frontend interface libraries --- so we don't worry much about polluting
9 * the namespace with lots of stuff...
12 * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
15 * $Id: c.h,v 1.94 2001/06/02 18:25:18 petere 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) 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 macros
40 * are the kind of thing that might go here.
42 *----------------------------------------------------------------
47 /* We have to include stdlib.h here because it defines many of these macros
48 on some platforms, and we only want our definitions used if stdlib.h doesn't
49 have its own. The same goes for stddef and stdarg if present.
59 #ifdef STRING_H_WITH_STRINGS_H
65 #include <sys/fcntl.h> /* ensure O_BINARY is available */
67 #ifdef HAVE_SUPPORTDEFS_H
68 #include <SupportDefs.h>
74 #define gettext(x) (x)
77 /* ----------------------------------------------------------------
78 * Section 1: hacks to cope with non-ANSI C compilers
80 * type prefixes (const, signed, volatile, inline) are now handled in config.h.
81 * ----------------------------------------------------------------
86 * Convert the argument to a string, using the C preprocessor.
88 * Concatenate two arguments together, using the C preprocessor.
90 * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
91 * whether #identifier works, but if we have that we likely have ## too.
93 #if defined(HAVE_STRINGIZE)
95 #define CppAsString(identifier) #identifier
96 #define CppConcat(x, y) x##y
98 #else /* !HAVE_STRINGIZE */
100 #define CppAsString(identifier) "identifier"
103 * CppIdentity -- On Reiser based cpp's this is used to concatenate
104 * two tokens. That is
105 * CppIdentity(A)B ==> AB
106 * We renamed it to _private_CppIdentity because it should not
107 * be referenced outside this file. On other cpp's it
110 #define _priv_CppIdentity(x)x
111 #define CppConcat(x, y) _priv_CppIdentity(x)y
113 #endif /* !HAVE_STRINGIZE */
116 * dummyret is used to set return values in macros that use ?: to make
117 * assignments. gcc wants these to be void, other compilers like char
119 #ifdef __GNUC__ /* GNU cc */
120 #define dummyret void
122 #define dummyret char
126 /* ----------------------------------------------------------------
127 * Section 2: bool, true, false, TRUE, FALSE, NULL
128 * ----------------------------------------------------------------
132 * Boolean value, either true or false.
136 /* BeOS defines bool already, but the compiler chokes on the
137 * #ifndef unless we wrap it in this check.
145 #endif /* ndef bool */
149 #define true ((bool) 1)
153 #define false ((bool) 0)
156 #endif /* __BEOS__ */
158 typedef bool *BoolPtr;
173 #define NULL ((void *) 0)
177 /* ----------------------------------------------------------------
178 * Section 3: standard system types
179 * ----------------------------------------------------------------
184 * Variable holding address of any memory resident object.
186 * XXX Pointer arithmetic is done with this, so it can't be void *
187 * under "true" ANSI compilers.
189 typedef char *Pointer;
193 * Signed integer, EXACTLY N BITS IN SIZE,
194 * used for numerical computations and the
195 * frontend/backend protocol.
197 #ifndef __BEOS__ /* this shouldn't be required, but is is! */
198 typedef signed char int8; /* == 8 bits */
199 typedef signed short int16; /* == 16 bits */
200 typedef signed int int32; /* == 32 bits */
202 #endif /* __BEOS__ */
206 * Unsigned integer, EXACTLY N BITS IN SIZE,
207 * used for numerical computations and the
208 * frontend/backend protocol.
210 #ifndef __BEOS__ /* this shouldn't be required, but is is! */
211 typedef unsigned char uint8; /* == 8 bits */
212 typedef unsigned short uint16; /* == 16 bits */
213 typedef unsigned int uint32; /* == 32 bits */
215 #endif /* __BEOS__ */
219 * Boolean value, AT LEAST N BITS IN SIZE.
221 typedef uint8 bool8; /* >= 8 bits */
222 typedef uint16 bool16; /* >= 16 bits */
223 typedef uint32 bool32; /* >= 32 bits */
227 * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
229 typedef uint8 bits8; /* >= 8 bits */
230 typedef uint16 bits16; /* >= 16 bits */
231 typedef uint32 bits32; /* >= 32 bits */
235 * Unit of storage, AT LEAST N BITS IN SIZE,
236 * used to fetch/store data.
238 typedef uint8 word8; /* >= 8 bits */
239 typedef uint16 word16; /* >= 16 bits */
240 typedef uint32 word32; /* >= 32 bits */
244 * Floating point number, AT LEAST N BITS IN SIZE,
245 * used for numerical computations.
247 * Since sizeof(floatN) may be > sizeof(char *), always pass
248 * floatN by reference.
250 * XXX: these typedefs are now deprecated in favor of float4 and float8.
251 * They will eventually go away.
253 typedef float float32data;
254 typedef double float64data;
255 typedef float *float32;
256 typedef double *float64;
261 #ifndef __BEOS__ /* this is already defined on BeOS */
262 #ifdef HAVE_LONG_INT_64
263 /* Plain "long int" fits, use it */
264 typedef long int int64;
265 typedef unsigned long int uint64;
268 #ifdef HAVE_LONG_LONG_INT_64
269 /* We have working support for "long long int", use that */
270 typedef long long int int64;
271 typedef unsigned long long int uint64;
274 /* Won't actually work, but fall back to long int so that code compiles */
275 typedef long int int64;
276 typedef unsigned long int uint64;
278 #define INT64_IS_BUSTED
281 #endif /* __BEOS__ */
285 * Size of any memory resident object, as returned by sizeof.
291 * Index into any memory resident array.
294 * Indices are non negative.
296 typedef unsigned int Index;
300 * Offset into any memory resident array.
303 * This differs from an Index in that an Index is always
304 * non negative, whereas Offset may be negative.
306 typedef signed int Offset;
309 * Common Postgres datatype names (as used in the catalogs)
313 typedef float float4;
314 typedef double float8;
317 * Oid, RegProcedure, TransactionId, CommandId
320 /* typedef Oid is in postgres_ext.h */
322 /* unfortunately, both regproc and RegProcedure are used */
324 typedef Oid RegProcedure;
326 typedef uint32 TransactionId;
328 #define InvalidTransactionId 0
330 typedef uint32 CommandId;
332 #define FirstCommandId 0
335 * Array indexing support
344 * Variable-length datatypes all share the 'struct varlena' header.
346 * NOTE: for TOASTable types, this is an oversimplification, since the value may be
347 * compressed or moved out-of-line. However datatype-specific routines are mostly
348 * content to deal with de-TOASTed values only, and of course client-side routines
349 * should never see a TOASTed value. See postgres.h for details of the TOASTed form.
358 #define VARHDRSZ ((int32) sizeof(int32))
361 * These widely-used datatypes are just a varlena header and the data bytes.
362 * There is no terminating null or anything like that --- the data length is
363 * always VARSIZE(ptr) - VARHDRSZ.
365 typedef struct varlena bytea;
366 typedef struct varlena text;
367 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
368 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
371 * Fixed-length array types (these are not varlena's!)
374 typedef int2 int2vector[INDEX_MAX_KEYS];
375 typedef Oid oidvector[INDEX_MAX_KEYS];
378 * We want NameData to have length NAMEDATALEN and int alignment,
379 * because that's how the data type 'name' is defined in pg_type.
380 * Use a union to make sure the compiler agrees.
382 typedef union nameData
384 char data[NAMEDATALEN];
387 typedef NameData *Name;
389 #define NameStr(name) ((name).data)
392 /* ----------------------------------------------------------------
393 * Section 4: IsValid macros for system types
394 * ----------------------------------------------------------------
398 * True iff bool is valid.
400 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
404 * True iff pointer is valid.
406 #define PointerIsValid(pointer) ((void*)(pointer) != NULL)
410 * True iff pointer is properly aligned to point to the given type.
412 #define PointerIsAligned(pointer, type) \
413 (((long)(pointer) % (sizeof (type))) == 0)
415 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
417 #define RegProcedureIsValid(p) OidIsValid(p)
420 /* ----------------------------------------------------------------
421 * Section 5: offsetof, lengthof, endof, alignment
422 * ----------------------------------------------------------------
426 * Offset of a structure/union field within that structure/union.
428 * XXX This is supposed to be part of stddef.h, but isn't on
429 * some systems (like SunOS 4).
432 #define offsetof(type, field) ((long) &((type *)0)->field)
433 #endif /* offsetof */
437 * Number of elements in an array.
439 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
443 * Address of the element one past the last in an array.
445 #define endof(array) (&array[lengthof(array)])
448 * Alignment macros: align a length or address appropriately for a given type.
450 * There used to be some incredibly crufty platform-dependent hackery here,
451 * but now we rely on the configure script to get the info for us. Much nicer.
453 * NOTE: TYPEALIGN will not work if ALIGNVAL is not a power of 2.
454 * That case seems extremely unlikely to occur in practice, however.
458 #define TYPEALIGN(ALIGNVAL,LEN) (((long)(LEN) + (ALIGNVAL-1)) & ~(ALIGNVAL-1))
460 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
461 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
462 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
463 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
464 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
467 /* ----------------------------------------------------------------
468 * Section 6: widely useful macros
469 * ----------------------------------------------------------------
473 * Return the maximum of two numbers.
475 #define Max(x, y) ((x) > (y) ? (x) : (y))
479 * Return the minimum of two numbers.
481 #define Min(x, y) ((x) < (y) ? (x) : (y))
485 * Return the absolute value of the argument.
487 #define Abs(x) ((x) >= 0 ? (x) : -(x))
491 * Like standard library function strncpy(), except that result string
492 * is guaranteed to be null-terminated --- that is, at most N-1 bytes
493 * of the source string will be kept.
494 * Also, the macro returns no result (too hard to do that without
495 * evaluating the arguments multiple times, which seems worse).
497 * BTW: when you need to copy a non-null-terminated string (like a text
498 * datum) and add a null, do not do it with StrNCpy(..., len+1). That
499 * might seem to work, but it fetches one byte more than there is in the
500 * text object. One fine day you'll have a SIGSEGV because there isn't
501 * another byte before the end of memory. Don't laugh, we've had real
502 * live bug reports from real live users over exactly this mistake.
503 * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
505 #define StrNCpy(dst,src,len) \
508 char * _dst = (dst); \
513 strncpy(_dst, (src), _len); \
514 _dst[_len-1] = '\0'; \
519 /* Get a bit mask of the bits set in non-int32 aligned addresses */
520 #define INT_ALIGN_MASK (sizeof(int32) - 1)
524 * Exactly the same as standard library function memset(), but considerably
525 * faster for zeroing small word-aligned structures (such as parsetree nodes).
526 * This has to be a macro because the main point is to avoid function-call
529 * We got the 64 number by testing this against the stock memset() on
530 * BSD/OS 3.0. Larger values were slower. bjm 1997/09/11
532 * I think the crossover point could be a good deal higher for
533 * most platforms, actually. tgl 2000-03-19
535 #define MemSet(start, val, len) \
538 int32 * _start = (int32 *) (start); \
542 if ((((long) _start) & INT_ALIGN_MASK) == 0 && \
543 (_len & INT_ALIGN_MASK) == 0 && \
545 _len <= MEMSET_LOOP_LIMIT) \
547 int32 * _stop = (int32 *) ((char *) _start + _len); \
548 while (_start < _stop) \
552 memset((char *) _start, _val, _len); \
555 #define MEMSET_LOOP_LIMIT 64
558 /* ----------------------------------------------------------------
559 * Section 7: random stuff
560 * ----------------------------------------------------------------
564 #define CSIGNBIT (0x80)
566 #define STATUS_OK (0)
567 #define STATUS_ERROR (-1)
568 #define STATUS_NOT_FOUND (-2)
569 #define STATUS_INVALID (-3)
570 #define STATUS_UNCATALOGUED (-4)
571 #define STATUS_REPLACED (-5)
572 #define STATUS_NOT_DONE (-6)
573 #define STATUS_BAD_PACKET (-7)
574 #define STATUS_FOUND (1)
577 /* ----------------------------------------------------------------
578 * Section 8: system-specific hacks
580 * This should be limited to things that absolutely have to be
581 * included in every source file. The port-specific header file
582 * is usually a better place for this sort of thing.
583 * ----------------------------------------------------------------
587 #define PG_BINARY O_BINARY
588 #define PG_BINARY_R "rb"
589 #define PG_BINARY_W "wb"
592 #define PG_BINARY_R "r"
593 #define PG_BINARY_W "w"
596 #if defined(sun) && defined(__sparc__) && !defined(__SVR4)
600 /* These are for things that are one way on Unix and another on NT */
601 #define NULL_DEV "/dev/null"
603 /* defines for dynamic linking on Win32 platform */
605 #if __GNUC__ && ! defined (__declspec)
606 #error You need egcs 1.1 or newer for compiling!
609 #define DLLIMPORT __declspec (dllexport)
610 #else /* not BUILDING_DLL */
611 #define DLLIMPORT __declspec (dllimport)
613 #else /* not CYGWIN */
617 /* Provide prototypes for routines not present in a particular machine's
618 * standard C library. It'd be better to put these in config.h, but
619 * in config.h we haven't yet included anything that defines size_t...
622 #ifndef HAVE_SNPRINTF_DECL
623 extern int snprintf(char *str, size_t count, const char *fmt,...);
627 #ifndef HAVE_VSNPRINTF_DECL
628 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
632 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
633 #define memmove(d, s, c) bcopy(s, d, c)