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) 1996-2002, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
15 * $Id: c.h,v 1.122 2002/08/21 17:20:58 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) 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 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.
52 #include "pg_config.h"
53 #include "postgres_ext.h"
63 #include <sys/types.h>
67 #include <sys/fcntl.h> /* ensure O_BINARY is available */
69 #ifdef HAVE_SUPPORTDEFS_H
70 #include <SupportDefs.h>
73 /* Must be before gettext() games below */
79 #define gettext(x) (x)
81 #define gettext_noop(x) (x)
84 /* ----------------------------------------------------------------
85 * Section 1: hacks to cope with non-ANSI C compilers
87 * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
88 * ----------------------------------------------------------------
93 * Convert the argument to a string, using the C preprocessor.
95 * Concatenate two arguments together, using the C preprocessor.
97 * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
98 * whether #identifier works, but if we have that we likely have ## too.
100 #if defined(HAVE_STRINGIZE)
102 #define CppAsString(identifier) #identifier
103 #define CppConcat(x, y) x##y
105 #else /* !HAVE_STRINGIZE */
107 #define CppAsString(identifier) "identifier"
110 * CppIdentity -- On Reiser based cpp's this is used to concatenate
111 * two tokens. That is
112 * CppIdentity(A)B ==> AB
113 * We renamed it to _private_CppIdentity because it should not
114 * be referenced outside this file. On other cpp's it
117 #define _priv_CppIdentity(x)x
118 #define CppConcat(x, y) _priv_CppIdentity(x)y
119 #endif /* !HAVE_STRINGIZE */
122 * dummyret is used to set return values in macros that use ?: to make
123 * assignments. gcc wants these to be void, other compilers like char
125 #ifdef __GNUC__ /* GNU cc */
126 #define dummyret void
128 #define dummyret char
132 #define __attribute__(_arg_)
135 /* ----------------------------------------------------------------
136 * Section 2: bool, true, false, TRUE, FALSE, NULL
137 * ----------------------------------------------------------------
142 * Boolean value, either true or false.
144 * XXX for C++ compilers, we assume the compiler has a compatible
145 * built-in definition of bool.
148 /* BeOS defines bool already, but the compiler chokes on the
149 * #ifndef unless we wrap it in this check.
151 /* Also defined in interfaces/odbc/md5.h */
161 #define true ((bool) 1)
165 #define false ((bool) 0)
168 #endif /* __BEOS__ */
170 typedef bool *BoolPtr;
185 #define NULL ((void *) 0)
189 /* ----------------------------------------------------------------
190 * Section 3: standard system types
191 * ----------------------------------------------------------------
196 * Variable holding address of any memory resident object.
198 * XXX Pointer arithmetic is done with this, so it can't be void *
199 * under "true" ANSI compilers.
201 typedef char *Pointer;
205 * Signed integer, EXACTLY N BITS IN SIZE,
206 * used for numerical computations and the
207 * frontend/backend protocol.
210 typedef signed char int8; /* == 8 bits */
211 typedef signed short int16; /* == 16 bits */
212 typedef signed int int32; /* == 32 bits */
213 #endif /* not HAVE_INT8 */
217 * Unsigned integer, EXACTLY N BITS IN SIZE,
218 * used for numerical computations and the
219 * frontend/backend protocol.
221 /* Also defined in interfaces/odbc/md5.h */
223 typedef unsigned char uint8; /* == 8 bits */
224 typedef unsigned short uint16; /* == 16 bits */
225 typedef unsigned int uint32; /* == 32 bits */
226 #endif /* not HAVE_UINT8 */
230 * Boolean value, AT LEAST N BITS IN SIZE.
232 typedef uint8 bool8; /* >= 8 bits */
233 typedef uint16 bool16; /* >= 16 bits */
234 typedef uint32 bool32; /* >= 32 bits */
238 * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
240 typedef uint8 bits8; /* >= 8 bits */
241 typedef uint16 bits16; /* >= 16 bits */
242 typedef uint32 bits32; /* >= 32 bits */
246 * Unit of storage, AT LEAST N BITS IN SIZE,
247 * used to fetch/store data.
249 typedef uint8 word8; /* >= 8 bits */
250 typedef uint16 word16; /* >= 16 bits */
251 typedef uint32 word32; /* >= 32 bits */
255 * Floating point number, AT LEAST N BITS IN SIZE,
256 * used for numerical computations.
258 * Since sizeof(floatN) may be > sizeof(char *), always pass
259 * floatN by reference.
261 * XXX: these typedefs are now deprecated in favor of float4 and float8.
262 * They will eventually go away.
264 typedef float float32data;
265 typedef double float64data;
266 typedef float *float32;
267 typedef double *float64;
272 #ifdef HAVE_LONG_INT_64
273 /* Plain "long int" fits, use it */
276 typedef long int int64;
279 typedef unsigned long int uint64;
282 #elif defined(HAVE_LONG_LONG_INT_64)
283 /* We have working support for "long long int", use that */
286 typedef long long int int64;
289 typedef unsigned long long int uint64;
292 #else /* not HAVE_LONG_INT_64 and not HAVE_LONG_LONG_INT_64 */
294 /* Won't actually work, but fall back to long int so that code compiles */
296 typedef long int int64;
299 typedef unsigned long int uint64;
302 #define INT64_IS_BUSTED
304 #endif /* not HAVE_LONG_INT_64 and not HAVE_LONG_LONG_INT_64 */
306 /* Decide if we need to decorate 64-bit constants */
307 #ifdef HAVE_LL_CONSTANTS
308 #define INT64CONST(x) ((int64) x##LL)
309 #define UINT64CONST(x) ((uint64) x##LL)
311 #define INT64CONST(x) ((int64) x)
312 #define UINT64CONST(x) ((uint64) x)
316 /* Select timestamp representation (float8 or int64) */
317 #if defined(USE_INTEGER_DATETIMES) && !defined(INT64_IS_BUSTED)
318 #define HAVE_INT64_TIMESTAMP
321 /* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
322 #ifndef HAVE_SIG_ATOMIC_T
323 typedef int sig_atomic_t;
328 * Size of any memory resident object, as returned by sizeof.
334 * Index into any memory resident array.
337 * Indices are non negative.
339 typedef unsigned int Index;
343 * Offset into any memory resident array.
346 * This differs from an Index in that an Index is always
347 * non negative, whereas Offset may be negative.
349 typedef signed int Offset;
352 * Common Postgres datatype names (as used in the catalogs)
356 typedef float float4;
357 typedef double float8;
360 * Oid, RegProcedure, TransactionId, CommandId
363 /* typedef Oid is in postgres_ext.h */
366 * regproc is the type name used in the include/catalog headers, but
367 * RegProcedure is the preferred name in C code.
370 typedef regproc RegProcedure;
372 typedef uint32 TransactionId;
374 typedef uint32 CommandId;
376 #define FirstCommandId ((CommandId) 0)
379 * Array indexing support
388 * Variable-length datatypes all share the 'struct varlena' header.
390 * NOTE: for TOASTable types, this is an oversimplification, since the value may be
391 * compressed or moved out-of-line. However datatype-specific routines are mostly
392 * content to deal with de-TOASTed values only, and of course client-side routines
393 * should never see a TOASTed value. See postgres.h for details of the TOASTed form.
402 #define VARHDRSZ ((int32) sizeof(int32))
405 * These widely-used datatypes are just a varlena header and the data bytes.
406 * There is no terminating null or anything like that --- the data length is
407 * always VARSIZE(ptr) - VARHDRSZ.
409 typedef struct varlena bytea;
410 typedef struct varlena text;
411 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
412 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
415 * Fixed-length array types (these are not varlena's!)
418 typedef int2 int2vector[INDEX_MAX_KEYS];
419 typedef Oid oidvector[INDEX_MAX_KEYS];
422 * We want NameData to have length NAMEDATALEN and int alignment,
423 * because that's how the data type 'name' is defined in pg_type.
424 * Use a union to make sure the compiler agrees. Note that NAMEDATALEN
425 * must be a multiple of sizeof(int), else sizeof(NameData) will probably
426 * not come out equal to NAMEDATALEN.
428 typedef union nameData
430 char data[NAMEDATALEN];
433 typedef NameData *Name;
435 #define NameStr(name) ((name).data)
438 /* ----------------------------------------------------------------
439 * Section 4: IsValid macros for system types
440 * ----------------------------------------------------------------
444 * True iff bool is valid.
446 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
450 * True iff pointer is valid.
452 #define PointerIsValid(pointer) ((void*)(pointer) != NULL)
456 * True iff pointer is properly aligned to point to the given type.
458 #define PointerIsAligned(pointer, type) \
459 (((long)(pointer) % (sizeof (type))) == 0)
461 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
463 #define RegProcedureIsValid(p) OidIsValid(p)
466 /* ----------------------------------------------------------------
467 * Section 5: offsetof, lengthof, endof, alignment
468 * ----------------------------------------------------------------
472 * Offset of a structure/union field within that structure/union.
474 * XXX This is supposed to be part of stddef.h, but isn't on
475 * some systems (like SunOS 4).
478 #define offsetof(type, field) ((long) &((type *)0)->field)
479 #endif /* offsetof */
483 * Number of elements in an array.
485 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
489 * Address of the element one past the last in an array.
491 #define endof(array) (&array[lengthof(array)])
494 * Alignment macros: align a length or address appropriately for a given type.
496 * There used to be some incredibly crufty platform-dependent hackery here,
497 * but now we rely on the configure script to get the info for us. Much nicer.
499 * NOTE: TYPEALIGN will not work if ALIGNVAL is not a power of 2.
500 * That case seems extremely unlikely to occur in practice, however.
504 #define TYPEALIGN(ALIGNVAL,LEN) (((long)(LEN) + (ALIGNVAL-1)) & ~(ALIGNVAL-1))
506 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
507 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
508 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
509 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
510 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
513 /* ----------------------------------------------------------------
514 * Section 6: widely useful macros
515 * ----------------------------------------------------------------
519 * Return the maximum of two numbers.
521 #define Max(x, y) ((x) > (y) ? (x) : (y))
525 * Return the minimum of two numbers.
527 #define Min(x, y) ((x) < (y) ? (x) : (y))
531 * Return the absolute value of the argument.
533 #define Abs(x) ((x) >= 0 ? (x) : -(x))
537 * Like standard library function strncpy(), except that result string
538 * is guaranteed to be null-terminated --- that is, at most N-1 bytes
539 * of the source string will be kept.
540 * Also, the macro returns no result (too hard to do that without
541 * evaluating the arguments multiple times, which seems worse).
543 * BTW: when you need to copy a non-null-terminated string (like a text
544 * datum) and add a null, do not do it with StrNCpy(..., len+1). That
545 * might seem to work, but it fetches one byte more than there is in the
546 * text object. One fine day you'll have a SIGSEGV because there isn't
547 * another byte before the end of memory. Don't laugh, we've had real
548 * live bug reports from real live users over exactly this mistake.
549 * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
551 #define StrNCpy(dst,src,len) \
554 char * _dst = (dst); \
559 strncpy(_dst, (src), _len); \
560 _dst[_len-1] = '\0'; \
565 /* Get a bit mask of the bits set in non-int32 aligned addresses */
566 #define INT_ALIGN_MASK (sizeof(int32) - 1)
570 * Exactly the same as standard library function memset(), but considerably
571 * faster for zeroing small word-aligned structures (such as parsetree nodes).
572 * This has to be a macro because the main point is to avoid function-call
575 * We got the 64 number by testing this against the stock memset() on
576 * BSD/OS 3.0. Larger values were slower. bjm 1997/09/11
578 * I think the crossover point could be a good deal higher for
579 * most platforms, actually. tgl 2000-03-19
581 #define MemSet(start, val, len) \
584 int32 * _start = (int32 *) (start); \
588 if ((((long) _start) & INT_ALIGN_MASK) == 0 && \
589 (_len & INT_ALIGN_MASK) == 0 && \
591 _len <= MEMSET_LOOP_LIMIT) \
593 int32 * _stop = (int32 *) ((char *) _start + _len); \
594 while (_start < _stop) \
598 memset((char *) _start, _val, _len); \
601 #define MEMSET_LOOP_LIMIT 64
604 /* ----------------------------------------------------------------
605 * Section 7: random stuff
606 * ----------------------------------------------------------------
610 #define CSIGNBIT (0x80)
612 #define STATUS_OK (0)
613 #define STATUS_ERROR (-1)
614 #define STATUS_EOF (-2)
615 #define STATUS_FOUND (1)
618 /* ----------------------------------------------------------------
619 * Section 8: system-specific hacks
621 * This should be limited to things that absolutely have to be
622 * included in every source file. The port-specific header file
623 * is usually a better place for this sort of thing.
624 * ----------------------------------------------------------------
628 #define PG_BINARY O_BINARY
629 #define PG_BINARY_R "rb"
630 #define PG_BINARY_W "wb"
633 #define PG_BINARY_R "r"
634 #define PG_BINARY_W "w"
637 #if defined(sun) && defined(__sparc__) && !defined(__SVR4)
641 /* These are for things that are one way on Unix and another on NT */
642 #define NULL_DEV "/dev/null"
645 * Provide prototypes for routines not present in a particular machine's
646 * standard C library. It'd be better to put these in pg_config.h, but
647 * in pg_config.h we haven't yet included anything that defines size_t...
650 #if !HAVE_DECL_SNPRINTF
652 snprintf(char *str, size_t count, const char *fmt,...)
653 /* This extension allows gcc to check the format string */
654 __attribute__((format(printf, 3, 4)));
657 #if !HAVE_DECL_VSNPRINTF
658 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
661 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
662 #define memmove(d, s, c) bcopy(s, d, c)