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) 1996-2005, PostgreSQL Global Development Group
13 * Portions Copyright (c) 1994, Regents of the University of California
15 * $PostgreSQL: pgsql/src/include/c.h,v 1.187 2005/07/02 17:01:52 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__)
56 #include "pg_config_os.h" /* must be before any system header files */
58 #if defined(_MSC_VER) || defined(__BORLANDC__)
59 #define WIN32_CLIENT_ONLY
62 #include "postgres_ext.h"
72 #include <sys/types.h>
75 #if defined(WIN32) || defined(__CYGWIN__)
76 #include <fcntl.h> /* ensure O_BINARY is available */
78 #ifdef HAVE_SUPPORTDEFS_H
79 #include <SupportDefs.h>
82 #if defined(WIN32) || defined(__CYGWIN__)
83 #ifndef WIN32_CLIENT_ONLY
84 /* We have to redefine some system functions after they are included above */
85 #include "pg_config_os.h"
87 #include "port/win32.h" /* We didn't run configure, but this is our port file */
91 /* Must be before gettext() games below */
94 #define _(x) gettext((x))
99 #define gettext(x) (x)
103 * These strings are to be translation via xgettext. We can't
104 * call gettext() because it is located in variable initialization and
105 * a function call can not be used.
107 #define gettext_noop(x) (x)
110 /* ----------------------------------------------------------------
111 * Section 1: hacks to cope with non-ANSI C compilers
113 * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
114 * ----------------------------------------------------------------
119 * Convert the argument to a string, using the C preprocessor.
121 * Concatenate two arguments together, using the C preprocessor.
123 * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
124 * whether #identifier works, but if we have that we likely have ## too.
126 #if defined(HAVE_STRINGIZE)
128 #define CppAsString(identifier) #identifier
129 #define CppConcat(x, y) x##y
131 #else /* !HAVE_STRINGIZE */
133 #define CppAsString(identifier) "identifier"
136 * CppIdentity -- On Reiser based cpp's this is used to concatenate
137 * two tokens. That is
138 * CppIdentity(A)B ==> AB
139 * We renamed it to _private_CppIdentity because it should not
140 * be referenced outside this file. On other cpp's it
143 #define _priv_CppIdentity(x)x
144 #define CppConcat(x, y) _priv_CppIdentity(x)y
145 #endif /* !HAVE_STRINGIZE */
148 * dummyret is used to set return values in macros that use ?: to make
149 * assignments. gcc wants these to be void, other compilers like char
151 #ifdef __GNUC__ /* GNU cc */
152 #define dummyret void
154 #define dummyret char
158 #define __attribute__(_arg_)
161 /* ----------------------------------------------------------------
162 * Section 2: bool, true, false, TRUE, FALSE, NULL
163 * ----------------------------------------------------------------
168 * Boolean value, either true or false.
170 * XXX for C++ compilers, we assume the compiler has a compatible
171 * built-in definition of bool.
174 /* BeOS defines bool already, but the compiler chokes on the
175 * #ifndef unless we wrap it in this check.
186 #define true ((bool) 1)
190 #define false ((bool) 0)
193 #endif /* __BEOS__ */
195 typedef bool *BoolPtr;
210 #define NULL ((void *) 0)
214 /* ----------------------------------------------------------------
215 * Section 3: standard system types
216 * ----------------------------------------------------------------
221 * Variable holding address of any memory resident object.
223 * XXX Pointer arithmetic is done with this, so it can't be void *
224 * under "true" ANSI compilers.
226 typedef char *Pointer;
230 * Signed integer, EXACTLY N BITS IN SIZE,
231 * used for numerical computations and the
232 * frontend/backend protocol.
235 typedef signed char int8; /* == 8 bits */
236 typedef signed short int16; /* == 16 bits */
237 typedef signed int int32; /* == 32 bits */
238 #endif /* not HAVE_INT8 */
242 * Unsigned integer, EXACTLY N BITS IN SIZE,
243 * used for numerical computations and the
244 * frontend/backend protocol.
247 typedef unsigned char uint8; /* == 8 bits */
248 typedef unsigned short uint16; /* == 16 bits */
249 typedef unsigned int uint32; /* == 32 bits */
250 #endif /* not HAVE_UINT8 */
254 * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
256 typedef uint8 bits8; /* >= 8 bits */
257 typedef uint16 bits16; /* >= 16 bits */
258 typedef uint32 bits32; /* >= 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##ULL)
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 /* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
330 #ifndef HAVE_SIG_ATOMIC_T
331 typedef int sig_atomic_t;
336 * Size of any memory resident object, as returned by sizeof.
342 * Index into any memory resident array.
345 * Indices are non negative.
347 typedef unsigned int Index;
351 * Offset into any memory resident array.
354 * This differs from an Index in that an Index is always
355 * non negative, whereas Offset may be negative.
357 typedef signed int Offset;
360 * Common Postgres datatype names (as used in the catalogs)
364 typedef float float4;
365 typedef double float8;
368 * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
372 /* typedef Oid is in postgres_ext.h */
375 * regproc is the type name used in the include/catalog headers, but
376 * RegProcedure is the preferred name in C code.
379 typedef regproc RegProcedure;
381 typedef uint32 TransactionId;
383 typedef uint32 SubTransactionId;
385 #define InvalidSubTransactionId ((SubTransactionId) 0)
386 #define TopSubTransactionId ((SubTransactionId) 1)
388 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
389 typedef TransactionId MultiXactId;
391 typedef uint32 MultiXactOffset;
393 typedef uint32 CommandId;
395 #define FirstCommandId ((CommandId) 0)
398 * Array indexing support
407 * Variable-length datatypes all share the 'struct varlena' header.
409 * NOTE: for TOASTable types, this is an oversimplification, since the value
410 * may be compressed or moved out-of-line. However datatype-specific routines
411 * are mostly content to deal with de-TOASTed values only, and of course
412 * client-side routines should never see a TOASTed value. See postgres.h for
413 * details of the TOASTed form.
422 #define VARHDRSZ ((int32) sizeof(int32))
425 * These widely-used datatypes are just a varlena header and the data bytes.
426 * There is no terminating null or anything like that --- the data length is
427 * always VARSIZE(ptr) - VARHDRSZ.
429 typedef struct varlena bytea;
430 typedef struct varlena text;
431 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
432 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
435 * Specialized array types. These are physically laid out just the same
436 * as regular arrays (so that the regular array subscripting code works
437 * with them). They exist as distinct types mostly for historical reasons:
438 * they have nonstandard I/O behavior which we don't want to change for fear
439 * of breaking applications that look at the system catalogs. There is also
440 * an implementation issue for oidvector: it's part of the primary key for
441 * pg_proc, and we can't use the normal btree array support routines for that
442 * without circularity.
446 int32 size; /* these fields must match ArrayType! */
452 int2 values[1]; /* VARIABLE LENGTH ARRAY */
453 } int2vector; /* VARIABLE LENGTH STRUCT */
457 int32 size; /* these fields must match ArrayType! */
463 Oid values[1]; /* VARIABLE LENGTH ARRAY */
464 } oidvector; /* VARIABLE LENGTH STRUCT */
467 * We want NameData to have length NAMEDATALEN and int alignment,
468 * because that's how the data type 'name' is defined in pg_type.
469 * Use a union to make sure the compiler agrees. Note that NAMEDATALEN
470 * must be a multiple of sizeof(int), else sizeof(NameData) will probably
471 * not come out equal to NAMEDATALEN.
473 typedef union nameData
475 char data[NAMEDATALEN];
478 typedef NameData *Name;
480 #define NameStr(name) ((name).data)
482 #define SQL_STR_DOUBLE(ch) ((ch) == '\'' || (ch) == '\\')
483 #define ESCAPE_STRING_SYNTAX 'E'
485 /* ----------------------------------------------------------------
486 * Section 4: IsValid macros for system types
487 * ----------------------------------------------------------------
491 * True iff bool is valid.
493 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
497 * True iff pointer is valid.
499 #define PointerIsValid(pointer) ((void*)(pointer) != NULL)
503 * True iff pointer is properly aligned to point to the given type.
505 #define PointerIsAligned(pointer, type) \
506 (((long)(pointer) % (sizeof (type))) == 0)
508 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
510 #define RegProcedureIsValid(p) OidIsValid(p)
513 /* ----------------------------------------------------------------
514 * Section 5: offsetof, lengthof, endof, alignment
515 * ----------------------------------------------------------------
519 * Offset of a structure/union field within that structure/union.
521 * XXX This is supposed to be part of stddef.h, but isn't on
522 * some systems (like SunOS 4).
525 #define offsetof(type, field) ((long) &((type *)0)->field)
526 #endif /* offsetof */
530 * Number of elements in an array.
532 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
536 * Address of the element one past the last in an array.
538 #define endof(array) (&(array)[lengthof(array)])
541 * Alignment macros: align a length or address appropriately for a given type.
543 * There used to be some incredibly crufty platform-dependent hackery here,
544 * but now we rely on the configure script to get the info for us. Much nicer.
546 * NOTE: TYPEALIGN will not work if ALIGNVAL is not a power of 2.
547 * That case seems extremely unlikely to occur in practice, however.
551 #define TYPEALIGN(ALIGNVAL,LEN) \
552 (((long) (LEN) + ((ALIGNVAL) - 1)) & ~((long) ((ALIGNVAL) - 1)))
554 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
555 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
556 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
557 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
558 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
559 /* MAXALIGN covers only built-in types, not buffers */
560 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
563 /* ----------------------------------------------------------------
564 * Section 6: widely useful macros
565 * ----------------------------------------------------------------
569 * Return the maximum of two numbers.
571 #define Max(x, y) ((x) > (y) ? (x) : (y))
575 * Return the minimum of two numbers.
577 #define Min(x, y) ((x) < (y) ? (x) : (y))
581 * Return the absolute value of the argument.
583 #define Abs(x) ((x) >= 0 ? (x) : -(x))
587 * Like standard library function strncpy(), except that result string
588 * is guaranteed to be null-terminated --- that is, at most N-1 bytes
589 * of the source string will be kept.
590 * Also, the macro returns no result (too hard to do that without
591 * evaluating the arguments multiple times, which seems worse).
593 * BTW: when you need to copy a non-null-terminated string (like a text
594 * datum) and add a null, do not do it with StrNCpy(..., len+1). That
595 * might seem to work, but it fetches one byte more than there is in the
596 * text object. One fine day you'll have a SIGSEGV because there isn't
597 * another byte before the end of memory. Don't laugh, we've had real
598 * live bug reports from real live users over exactly this mistake.
599 * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
601 #define StrNCpy(dst,src,len) \
604 char * _dst = (dst); \
609 strncpy(_dst, (src), _len); \
610 _dst[_len-1] = '\0'; \
615 /* Get a bit mask of the bits set in non-int32 aligned addresses */
616 #define INT_ALIGN_MASK (sizeof(int32) - 1)
620 * Exactly the same as standard library function memset(), but considerably
621 * faster for zeroing small word-aligned structures (such as parsetree nodes).
622 * This has to be a macro because the main point is to avoid function-call
623 * overhead. However, we have also found that the loop is faster than
624 * native libc memset() on some platforms, even those with assembler
625 * memset() functions. More research needs to be done, perhaps with
626 * platform-specific MEMSET_LOOP_LIMIT values or tests in configure.
630 #define MemSet(start, val, len) \
633 int32 *_start = (int32 *) (start); \
637 if ((((long) _start) & INT_ALIGN_MASK) == 0 && \
638 (_len & INT_ALIGN_MASK) == 0 && \
640 _len <= MEMSET_LOOP_LIMIT) \
642 int32 *_stop = (int32 *) ((char *) _start + _len); \
643 while (_start < _stop) \
647 memset(_start, _val, _len); \
650 #define MEMSET_LOOP_LIMIT 1024
653 * MemSetAligned is the same as MemSet except it omits the test to see if
654 * "start" is word-aligned. This is okay to use if the caller knows a-priori
655 * that the pointer is suitably aligned (typically, because he just got it
656 * from palloc(), which always delivers a max-aligned pointer).
658 #define MemSetAligned(start, val, len) \
661 int32 *_start = (int32 *) (start); \
665 if ((_len & INT_ALIGN_MASK) == 0 && \
667 _len <= MEMSET_LOOP_LIMIT) \
669 int32 *_stop = (int32 *) ((char *) _start + _len); \
670 while (_start < _stop) \
674 memset(_start, _val, _len); \
679 * MemSetTest/MemSetLoop are a variant version that allow all the tests in
680 * MemSet to be done at compile time in cases where "val" and "len" are
681 * constants *and* we know the "start" pointer must be word-aligned.
682 * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
683 * MemSetAligned. Beware of multiple evaluations of the arguments when using
686 #define MemSetTest(val, len) \
687 ( ((len) & INT_ALIGN_MASK) == 0 && \
688 (len) <= MEMSET_LOOP_LIMIT && \
691 #define MemSetLoop(start, val, len) \
694 int32 * _start = (int32 *) (start); \
695 int32 * _stop = (int32 *) ((char *) _start + (Size) (len)); \
697 while (_start < _stop) \
702 /* ----------------------------------------------------------------
703 * Section 7: random stuff
704 * ----------------------------------------------------------------
708 #define CSIGNBIT (0x80)
710 #define STATUS_OK (0)
711 #define STATUS_ERROR (-1)
712 #define STATUS_EOF (-2)
713 #define STATUS_FOUND (1)
716 /* ----------------------------------------------------------------
717 * Section 8: system-specific hacks
719 * This should be limited to things that absolutely have to be
720 * included in every source file. The port-specific header file
721 * is usually a better place for this sort of thing.
722 * ----------------------------------------------------------------
726 * NOTE: this is also used for opening text files.
727 * WIN32 treats Control-Z as EOF in files opened in text mode.
728 * Therefore, we open files in binary mode on Win32 so we can read
729 * literal control-Z. The other affect is that we see CRLF, but
730 * that is OK because we can already handle those cleanly.
732 #if defined(WIN32) || defined(__CYGWIN__)
733 #define PG_BINARY O_BINARY
734 #define PG_BINARY_R "rb"
735 #define PG_BINARY_W "wb"
738 #define PG_BINARY_R "r"
739 #define PG_BINARY_W "w"
742 #if defined(sun) && defined(__sparc__) && !defined(__SVR4)
746 /* These are for things that are one way on Unix and another on NT */
747 #define NULL_DEV "/dev/null"
750 * Provide prototypes for routines not present in a particular machine's
751 * standard C library.
754 #if !HAVE_DECL_SNPRINTF
756 snprintf(char *str, size_t count, const char *fmt,...)
757 /* This extension allows gcc to check the format string */
758 __attribute__((format(printf, 3, 4)));
761 #if !HAVE_DECL_VSNPRINTF
762 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
765 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
766 #define memmove(d, s, c) bcopy(s, d, c)
770 #define DLLIMPORT /* no special DLL markers on most ports */
774 * The following is used as the arg list for signal handlers. Any ports
775 * that take something other than an int argument should override this in
776 * their pg_config_os.h file. Note that variable names are required
777 * because it is used in both the prototypes as well as the definitions.
778 * Note also the long name. We expect that this won't collide with
779 * other names causing compiler warnings.
783 #define SIGNAL_ARGS int postgres_signal_arg
787 * When there is no sigsetjmp, its functionality is provided by plain
788 * setjmp. Incidentally, nothing provides setjmp's functionality in
791 #ifndef HAVE_SIGSETJMP
792 #define sigjmp_buf jmp_buf
793 #define sigsetjmp(x,y) setjmp(x)
794 #define siglongjmp longjmp
797 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
798 extern int fdatasync(int fildes);
801 /* If strtoq() exists, rename it to the more standard strtoll() */
802 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
803 #define strtoll strtoq
804 #define HAVE_STRTOLL 1
807 /* If strtouq() exists, rename it to the more standard strtoull() */
808 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
809 #define strtoull strtouq
810 #define HAVE_STRTOULL 1
813 /* EXEC_BACKEND defines */
815 #define NON_EXEC_STATIC
817 #define NON_EXEC_STATIC static
820 /* /port compatibility functions */