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) 1996-2006, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
15 * $PostgreSQL: pgsql/src/include/c.h,v 1.212 2006/10/03 03:59:22 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 */
55 #if !defined(WIN32) && !defined(__CYGWIN__) /* win32 will include further down */
56 #include "pg_config_os.h" /* must be before any system header files */
58 #include "postgres_ext.h"
61 #if defined(__BORLANDC__) || (_MSC_VER > 1400)
73 #include <sys/types.h>
76 #if defined(WIN32) || defined(__CYGWIN__)
77 #include <fcntl.h> /* ensure O_BINARY is available */
79 #ifdef HAVE_SUPPORTDEFS_H
80 #include <SupportDefs.h>
83 #if defined(WIN32) || defined(__CYGWIN__)
84 /* We have to redefine some system functions after they are included above. */
85 #include "pg_config_os.h"
88 /* Must be before gettext() games below */
91 #define _(x) gettext((x))
96 #define gettext(x) (x)
100 * Use this to mark strings to be translated by gettext, in places where
101 * you don't want an actual function call to occur (eg, constant tables).
103 #define gettext_noop(x) (x)
106 /* ----------------------------------------------------------------
107 * Section 1: hacks to cope with non-ANSI C compilers
109 * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
110 * ----------------------------------------------------------------
115 * Convert the argument to a string, using the C preprocessor.
117 * Concatenate two arguments together, using the C preprocessor.
119 * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
120 * whether #identifier works, but if we have that we likely have ## too.
122 #if defined(HAVE_STRINGIZE)
124 #define CppAsString(identifier) #identifier
125 #define CppConcat(x, y) x##y
126 #else /* !HAVE_STRINGIZE */
128 #define CppAsString(identifier) "identifier"
131 * CppIdentity -- On Reiser based cpp's this is used to concatenate
132 * two tokens. That is
133 * CppIdentity(A)B ==> AB
134 * We renamed it to _private_CppIdentity because it should not
135 * be referenced outside this file. On other cpp's it
138 #define _priv_CppIdentity(x)x
139 #define CppConcat(x, y) _priv_CppIdentity(x)y
140 #endif /* !HAVE_STRINGIZE */
143 * dummyret is used to set return values in macros that use ?: to make
144 * assignments. gcc wants these to be void, other compilers like char
146 #ifdef __GNUC__ /* GNU cc */
147 #define dummyret void
149 #define dummyret char
153 #define __attribute__(_arg_)
156 /* ----------------------------------------------------------------
157 * Section 2: bool, true, false, TRUE, FALSE, NULL
158 * ----------------------------------------------------------------
163 * Boolean value, either true or false.
165 * XXX for C++ compilers, we assume the compiler has a compatible
166 * built-in definition of bool.
176 #define true ((bool) 1)
180 #define false ((bool) 0)
184 typedef bool *BoolPtr;
199 #define NULL ((void *) 0)
203 /* ----------------------------------------------------------------
204 * Section 3: standard system types
205 * ----------------------------------------------------------------
210 * Variable holding address of any memory resident object.
212 * XXX Pointer arithmetic is done with this, so it can't be void *
213 * under "true" ANSI compilers.
215 typedef char *Pointer;
219 * Signed integer, EXACTLY N BITS IN SIZE,
220 * used for numerical computations and the
221 * frontend/backend protocol.
224 typedef signed char int8; /* == 8 bits */
225 typedef signed short int16; /* == 16 bits */
226 typedef signed int int32; /* == 32 bits */
227 #endif /* not HAVE_INT8 */
231 * Unsigned integer, EXACTLY N BITS IN SIZE,
232 * used for numerical computations and the
233 * frontend/backend protocol.
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;
277 #elif defined(HAVE_LONG_LONG_INT_64)
278 /* We have working support for "long long int", use that */
281 typedef long long int int64;
284 typedef unsigned long long int uint64;
286 #else /* not HAVE_LONG_INT_64 and not
287 * HAVE_LONG_LONG_INT_64 */
289 /* Won't actually work, but fall back to long int so that code compiles */
291 typedef long int int64;
294 typedef unsigned long int uint64;
297 #define INT64_IS_BUSTED
298 #endif /* not HAVE_LONG_INT_64 and not
299 * HAVE_LONG_LONG_INT_64 */
301 /* Decide if we need to decorate 64-bit constants */
302 #ifdef HAVE_LL_CONSTANTS
303 #define INT64CONST(x) ((int64) x##LL)
304 #define UINT64CONST(x) ((uint64) x##ULL)
306 #define INT64CONST(x) ((int64) x)
307 #define UINT64CONST(x) ((uint64) x)
311 /* Select timestamp representation (float8 or int64) */
312 #if defined(USE_INTEGER_DATETIMES) && !defined(INT64_IS_BUSTED)
313 #define HAVE_INT64_TIMESTAMP
316 /* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
317 #ifndef HAVE_SIG_ATOMIC_T
318 typedef int sig_atomic_t;
323 * Size of any memory resident object, as returned by sizeof.
329 * Index into any memory resident array.
332 * Indices are non negative.
334 typedef unsigned int Index;
338 * Offset into any memory resident array.
341 * This differs from an Index in that an Index is always
342 * non negative, whereas Offset may be negative.
344 typedef signed int Offset;
347 * Common Postgres datatype names (as used in the catalogs)
351 typedef float float4;
352 typedef double float8;
355 * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
359 /* typedef Oid is in postgres_ext.h */
362 * regproc is the type name used in the include/catalog headers, but
363 * RegProcedure is the preferred name in C code.
366 typedef regproc RegProcedure;
368 typedef uint32 TransactionId;
370 typedef uint32 SubTransactionId;
372 #define InvalidSubTransactionId ((SubTransactionId) 0)
373 #define TopSubTransactionId ((SubTransactionId) 1)
375 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
376 typedef TransactionId MultiXactId;
378 typedef uint32 MultiXactOffset;
380 typedef uint32 CommandId;
382 #define FirstCommandId ((CommandId) 0)
385 * Array indexing support
394 * Variable-length datatypes all share the 'struct varlena' header.
396 * NOTE: for TOASTable types, this is an oversimplification, since the value
397 * may be compressed or moved out-of-line. However datatype-specific routines
398 * are mostly content to deal with de-TOASTed values only, and of course
399 * client-side routines should never see a TOASTed value. See postgres.h for
400 * details of the TOASTed form.
409 #define VARHDRSZ ((int32) sizeof(int32))
412 * These widely-used datatypes are just a varlena header and the data bytes.
413 * There is no terminating null or anything like that --- the data length is
414 * always VARSIZE(ptr) - VARHDRSZ.
416 typedef struct varlena bytea;
417 typedef struct varlena text;
418 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
419 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
422 * Specialized array types. These are physically laid out just the same
423 * as regular arrays (so that the regular array subscripting code works
424 * with them). They exist as distinct types mostly for historical reasons:
425 * they have nonstandard I/O behavior which we don't want to change for fear
426 * of breaking applications that look at the system catalogs. There is also
427 * an implementation issue for oidvector: it's part of the primary key for
428 * pg_proc, and we can't use the normal btree array support routines for that
429 * without circularity.
433 int32 size; /* these fields must match ArrayType! */
434 int ndim; /* always 1 for int2vector */
435 int32 dataoffset; /* always 0 for int2vector */
439 int2 values[1]; /* VARIABLE LENGTH ARRAY */
440 } int2vector; /* VARIABLE LENGTH STRUCT */
444 int32 size; /* these fields must match ArrayType! */
445 int ndim; /* always 1 for oidvector */
446 int32 dataoffset; /* always 0 for oidvector */
450 Oid values[1]; /* VARIABLE LENGTH ARRAY */
451 } oidvector; /* VARIABLE LENGTH STRUCT */
454 * We want NameData to have length NAMEDATALEN and int alignment,
455 * because that's how the data type 'name' is defined in pg_type.
456 * Use a union to make sure the compiler agrees. Note that NAMEDATALEN
457 * must be a multiple of sizeof(int), else sizeof(NameData) will probably
458 * not come out equal to NAMEDATALEN.
460 typedef union nameData
462 char data[NAMEDATALEN];
465 typedef NameData *Name;
467 #define NameStr(name) ((name).data)
470 * Support macros for escaping strings. escape_backslash should be TRUE
471 * if generating a non-standard-conforming string. Prefixing a string
472 * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
473 * Beware of multiple evaluation of the "ch" argument!
475 #define SQL_STR_DOUBLE(ch, escape_backslash) \
476 ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
478 #define ESCAPE_STRING_SYNTAX 'E'
480 /* ----------------------------------------------------------------
481 * Section 4: IsValid macros for system types
482 * ----------------------------------------------------------------
486 * True iff bool is valid.
488 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
492 * True iff pointer is valid.
494 #define PointerIsValid(pointer) ((void*)(pointer) != NULL)
498 * True iff pointer is properly aligned to point to the given type.
500 #define PointerIsAligned(pointer, type) \
501 (((long)(pointer) % (sizeof (type))) == 0)
503 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
505 #define RegProcedureIsValid(p) OidIsValid(p)
508 /* ----------------------------------------------------------------
509 * Section 5: offsetof, lengthof, endof, alignment
510 * ----------------------------------------------------------------
514 * Offset of a structure/union field within that structure/union.
516 * XXX This is supposed to be part of stddef.h, but isn't on
517 * some systems (like SunOS 4).
520 #define offsetof(type, field) ((long) &((type *)0)->field)
521 #endif /* offsetof */
525 * Number of elements in an array.
527 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
531 * Address of the element one past the last in an array.
533 #define endof(array) (&(array)[lengthof(array)])
536 * Alignment macros: align a length or address appropriately for a given type.
538 * There used to be some incredibly crufty platform-dependent hackery here,
539 * but now we rely on the configure script to get the info for us. Much nicer.
541 * NOTE: TYPEALIGN will not work if ALIGNVAL is not a power of 2.
542 * That case seems extremely unlikely to occur in practice, however.
546 #define TYPEALIGN(ALIGNVAL,LEN) \
547 (((long) (LEN) + ((ALIGNVAL) - 1)) & ~((long) ((ALIGNVAL) - 1)))
549 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
550 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
551 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
552 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
553 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
554 /* MAXALIGN covers only built-in types, not buffers */
555 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
558 /* ----------------------------------------------------------------
559 * Section 6: widely useful macros
560 * ----------------------------------------------------------------
564 * Return the maximum of two numbers.
566 #define Max(x, y) ((x) > (y) ? (x) : (y))
570 * Return the minimum of two numbers.
572 #define Min(x, y) ((x) < (y) ? (x) : (y))
576 * Return the absolute value of the argument.
578 #define Abs(x) ((x) >= 0 ? (x) : -(x))
582 * Like standard library function strncpy(), except that result string
583 * is guaranteed to be null-terminated --- that is, at most N-1 bytes
584 * of the source string will be kept.
585 * Also, the macro returns no result (too hard to do that without
586 * evaluating the arguments multiple times, which seems worse).
588 * BTW: when you need to copy a non-null-terminated string (like a text
589 * datum) and add a null, do not do it with StrNCpy(..., len+1). That
590 * might seem to work, but it fetches one byte more than there is in the
591 * text object. One fine day you'll have a SIGSEGV because there isn't
592 * another byte before the end of memory. Don't laugh, we've had real
593 * live bug reports from real live users over exactly this mistake.
594 * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
596 #define StrNCpy(dst,src,len) \
599 char * _dst = (dst); \
604 strncpy(_dst, (src), _len); \
605 _dst[_len-1] = '\0'; \
610 /* Get a bit mask of the bits set in non-long aligned addresses */
611 #define LONG_ALIGN_MASK (sizeof(long) - 1)
615 * Exactly the same as standard library function memset(), but considerably
616 * faster for zeroing small word-aligned structures (such as parsetree nodes).
617 * This has to be a macro because the main point is to avoid function-call
618 * overhead. However, we have also found that the loop is faster than
619 * native libc memset() on some platforms, even those with assembler
620 * memset() functions. More research needs to be done, perhaps with
621 * MEMSET_LOOP_LIMIT tests in configure.
623 #define MemSet(start, val, len) \
626 /* must be void* because we don't know if it is integer aligned yet */ \
627 void *_vstart = (void *) (start); \
631 if ((((long) _vstart) & LONG_ALIGN_MASK) == 0 && \
632 (_len & LONG_ALIGN_MASK) == 0 && \
634 _len <= MEMSET_LOOP_LIMIT && \
636 * If MEMSET_LOOP_LIMIT == 0, optimizer should find \
637 * the whole "if" false at compile time. \
639 MEMSET_LOOP_LIMIT != 0) \
641 long *_start = (long *) _vstart; \
642 long *_stop = (long *) ((char *) _start + _len); \
643 while (_start < _stop) \
647 memset(_vstart, _val, _len); \
651 * MemSetAligned is the same as MemSet except it omits the test to see if
652 * "start" is word-aligned. This is okay to use if the caller knows a-priori
653 * that the pointer is suitably aligned (typically, because he just got it
654 * from palloc(), which always delivers a max-aligned pointer).
656 #define MemSetAligned(start, val, len) \
659 long *_start = (long *) (start); \
663 if ((_len & LONG_ALIGN_MASK) == 0 && \
665 _len <= MEMSET_LOOP_LIMIT && \
666 MEMSET_LOOP_LIMIT != 0) \
668 long *_stop = (long *) ((char *) _start + _len); \
669 while (_start < _stop) \
673 memset(_start, _val, _len); \
678 * MemSetTest/MemSetLoop are a variant version that allow all the tests in
679 * MemSet to be done at compile time in cases where "val" and "len" are
680 * constants *and* we know the "start" pointer must be word-aligned.
681 * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
682 * MemSetAligned. Beware of multiple evaluations of the arguments when using
685 #define MemSetTest(val, len) \
686 ( ((len) & LONG_ALIGN_MASK) == 0 && \
687 (len) <= MEMSET_LOOP_LIMIT && \
688 MEMSET_LOOP_LIMIT != 0 && \
691 #define MemSetLoop(start, val, len) \
694 long * _start = (long *) (start); \
695 long * _stop = (long *) ((char *) _start + (Size) (len)); \
697 while (_start < _stop) \
702 /* ----------------------------------------------------------------
703 * Section 7: random stuff
704 * ----------------------------------------------------------------
708 #define HIGHBIT (0x80)
709 #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
711 #define STATUS_OK (0)
712 #define STATUS_ERROR (-1)
713 #define STATUS_EOF (-2)
714 #define STATUS_FOUND (1)
715 #define STATUS_WAITING (2)
718 /* ----------------------------------------------------------------
719 * Section 8: system-specific hacks
721 * This should be limited to things that absolutely have to be
722 * included in every source file. The port-specific header file
723 * is usually a better place for this sort of thing.
724 * ----------------------------------------------------------------
728 * NOTE: this is also used for opening text files.
729 * WIN32 treats Control-Z as EOF in files opened in text mode.
730 * Therefore, we open files in binary mode on Win32 so we can read
731 * literal control-Z. The other affect is that we see CRLF, but
732 * that is OK because we can already handle those cleanly.
734 #if defined(WIN32) || defined(__CYGWIN__)
735 #define PG_BINARY O_BINARY
736 #define PG_BINARY_R "rb"
737 #define PG_BINARY_W "wb"
740 #define PG_BINARY_R "r"
741 #define PG_BINARY_W "w"
744 #if defined(sun) && defined(__sparc__) && !defined(__SVR4)
748 /* These are for things that are one way on Unix and another on NT */
749 #define NULL_DEV "/dev/null"
752 * Provide prototypes for routines not present in a particular machine's
753 * standard C library.
756 #if !HAVE_DECL_SNPRINTF
758 snprintf(char *str, size_t count, const char *fmt,...)
759 /* This extension allows gcc to check the format string */
760 __attribute__((format(printf, 3, 4)));
763 #if !HAVE_DECL_VSNPRINTF
764 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
767 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
768 #define memmove(d, s, c) bcopy(s, d, c)
772 #define DLLIMPORT /* no special DLL markers on most ports */
776 * The following is used as the arg list for signal handlers. Any ports
777 * that take something other than an int argument should override this in
778 * their pg_config_os.h file. Note that variable names are required
779 * because it is used in both the prototypes as well as the definitions.
780 * Note also the long name. We expect that this won't collide with
781 * other names causing compiler warnings.
785 #define SIGNAL_ARGS int postgres_signal_arg
789 * When there is no sigsetjmp, its functionality is provided by plain
790 * setjmp. Incidentally, nothing provides setjmp's functionality in
793 #ifndef HAVE_SIGSETJMP
794 #define sigjmp_buf jmp_buf
795 #define sigsetjmp(x,y) setjmp(x)
796 #define siglongjmp longjmp
799 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
800 extern int fdatasync(int fildes);
803 /* If strtoq() exists, rename it to the more standard strtoll() */
804 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
805 #define strtoll strtoq
806 #define HAVE_STRTOLL 1
809 /* If strtouq() exists, rename it to the more standard strtoull() */
810 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
811 #define strtoull strtouq
812 #define HAVE_STRTOULL 1
815 /* EXEC_BACKEND defines */
817 #define NON_EXEC_STATIC
819 #define NON_EXEC_STATIC static
822 /* /port compatibility functions */