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c.h
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1 /*-------------------------------------------------------------------------
2  *
3  * c.h
4  * Fundamental C definitions. This is included by every .c file in
5  * PostgreSQL (via either postgres.h or postgres_fe.h, as appropriate).
6  *
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...
10  *
11  *
12  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
13  * Portions Copyright (c) 1994, Regents of the University of California
14  *
15  * src/include/c.h
16  *
17  *-------------------------------------------------------------------------
18  */
19 /*
20  *----------------------------------------------------------------
21  * TABLE OF CONTENTS
22  *
23  * When adding stuff to this file, please try to put stuff
24  * into the relevant section, or add new sections as appropriate.
25  *
26  * section description
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) assertions
35  * 7) widely useful macros
36  * 8) random stuff
37  * 9) system-specific hacks
38  *
39  * NOTE: since this file is included by both frontend and backend modules, it's
40  * almost certainly wrong to put an "extern" declaration here. typedefs and
41  * macros are the kind of thing that might go here.
42  *
43  *----------------------------------------------------------------
44  */
45 #ifndef C_H
46 #define C_H
47 
48 #include "postgres_ext.h"
49 
50 /* Must undef pg_config_ext.h symbols before including pg_config.h */
51 #undef PG_INT64_TYPE
52 
53 #include "pg_config.h"
54 #include "pg_config_manual.h" /* must be after pg_config.h */
55 
56 /*
57  * We always rely on the WIN32 macro being set by our build system,
58  * but _WIN32 is the compiler pre-defined macro. So make sure we define
59  * WIN32 whenever _WIN32 is set, to facilitate standalone building.
60  */
61 #if defined(_WIN32) && !defined(WIN32)
62 #define WIN32
63 #endif
64 
65 #if !defined(WIN32) && !defined(__CYGWIN__) /* win32 includes further down */
66 #include "pg_config_os.h" /* must be before any system header files */
67 #endif
68 
69 #if _MSC_VER >= 1400 || defined(HAVE_CRTDEFS_H)
70 #define errcode __msvc_errcode
71 #include <crtdefs.h>
72 #undef errcode
73 #endif
74 
75 /*
76  * We have to include stdlib.h here because it defines many of these macros
77  * on some platforms, and we only want our definitions used if stdlib.h doesn't
78  * have its own. The same goes for stddef and stdarg if present.
79  */
80 
81 #include <stdio.h>
82 #include <stdlib.h>
83 #include <string.h>
84 #include <stddef.h>
85 #include <stdarg.h>
86 #ifdef HAVE_STRINGS_H
87 #include <strings.h>
88 #endif
89 #ifdef HAVE_STDINT_H
90 #include <stdint.h>
91 #endif
92 #include <sys/types.h>
93 
94 #include <errno.h>
95 #if defined(WIN32) || defined(__CYGWIN__)
96 #include <fcntl.h> /* ensure O_BINARY is available */
97 #endif
98 
99 #if defined(WIN32) || defined(__CYGWIN__)
100 /* We have to redefine some system functions after they are included above. */
101 #include "pg_config_os.h"
102 #endif
103 
104 /*
105  * Force disable inlining if PG_FORCE_DISABLE_INLINE is defined. This is used
106  * to work around compiler bugs and might also be useful for investigatory
107  * purposes by defining the symbol in the platform's header..
108  *
109  * This is done early (in slightly the wrong section) as functionality later
110  * in this file might want to rely on inline functions.
111  */
112 #ifdef PG_FORCE_DISABLE_INLINE
113 #undef inline
114 #define inline
115 #endif
116 
117 /* Must be before gettext() games below */
118 #include <locale.h>
119 
120 #define _(x) gettext(x)
121 
122 #ifdef ENABLE_NLS
123 #include <libintl.h>
124 #else
125 #define gettext(x) (x)
126 #define dgettext(d,x) (x)
127 #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
128 #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
129 #endif
130 
131 /*
132  * Use this to mark string constants as needing translation at some later
133  * time, rather than immediately. This is useful for cases where you need
134  * access to the original string and translated string, and for cases where
135  * immediate translation is not possible, like when initializing global
136  * variables.
137  * http://www.gnu.org/software/autoconf/manual/gettext/Special-cases.html
138  */
139 #define gettext_noop(x) (x)
140 
141 
142 /* ----------------------------------------------------------------
143  * Section 1: hacks to cope with non-ANSI C compilers
144  *
145  * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
146  * ----------------------------------------------------------------
147  */
148 
149 /*
150  * CppAsString
151  * Convert the argument to a string, using the C preprocessor.
152  * CppConcat
153  * Concatenate two arguments together, using the C preprocessor.
154  *
155  * Note: There used to be support here for pre-ANSI C compilers that didn't
156  * support # and ##. Nowadays, these macros are just for clarity and/or
157  * backward compatibility with existing PostgreSQL code.
158  */
159 #define CppAsString(identifier) #identifier
160 #define CppConcat(x, y) x##y
161 
162 /*
163  * dummyret is used to set return values in macros that use ?: to make
164  * assignments. gcc wants these to be void, other compilers like char
165  */
166 #ifdef __GNUC__ /* GNU cc */
167 #define dummyret void
168 #else
169 #define dummyret char
170 #endif
171 
172 /* Which __func__ symbol do we have, if any? */
173 #ifdef HAVE_FUNCNAME__FUNC
174 #define PG_FUNCNAME_MACRO __func__
175 #else
176 #ifdef HAVE_FUNCNAME__FUNCTION
177 #define PG_FUNCNAME_MACRO __FUNCTION__
178 #else
179 #define PG_FUNCNAME_MACRO NULL
180 #endif
181 #endif
182 
183 /* ----------------------------------------------------------------
184  * Section 2: bool, true, false, TRUE, FALSE, NULL
185  * ----------------------------------------------------------------
186  */
187 
188 /*
189  * bool
190  * Boolean value, either true or false.
191  *
192  * XXX for C++ compilers, we assume the compiler has a compatible
193  * built-in definition of bool.
194  */
195 
196 #ifndef __cplusplus
197 
198 #ifndef bool
199 typedef char bool;
200 #endif
201 
202 #ifndef true
203 #define true ((bool) 1)
204 #endif
205 
206 #ifndef false
207 #define false ((bool) 0)
208 #endif
209 #endif /* not C++ */
210 
211 typedef bool *BoolPtr;
212 
213 #ifndef TRUE
214 #define TRUE 1
215 #endif
216 
217 #ifndef FALSE
218 #define FALSE 0
219 #endif
220 
221 /*
222  * NULL
223  * Null pointer.
224  */
225 #ifndef NULL
226 #define NULL ((void *) 0)
227 #endif
228 
229 
230 /* ----------------------------------------------------------------
231  * Section 3: standard system types
232  * ----------------------------------------------------------------
233  */
234 
235 /*
236  * Pointer
237  * Variable holding address of any memory resident object.
238  *
239  * XXX Pointer arithmetic is done with this, so it can't be void *
240  * under "true" ANSI compilers.
241  */
242 typedef char *Pointer;
243 
244 /*
245  * intN
246  * Signed integer, EXACTLY N BITS IN SIZE,
247  * used for numerical computations and the
248  * frontend/backend protocol.
249  */
250 #ifndef HAVE_INT8
251 typedef signed char int8; /* == 8 bits */
252 typedef signed short int16; /* == 16 bits */
253 typedef signed int int32; /* == 32 bits */
254 #endif /* not HAVE_INT8 */
255 
256 /*
257  * uintN
258  * Unsigned integer, EXACTLY N BITS IN SIZE,
259  * used for numerical computations and the
260  * frontend/backend protocol.
261  */
262 #ifndef HAVE_UINT8
263 typedef unsigned char uint8; /* == 8 bits */
264 typedef unsigned short uint16; /* == 16 bits */
265 typedef unsigned int uint32; /* == 32 bits */
266 #endif /* not HAVE_UINT8 */
267 
268 /*
269  * bitsN
270  * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
271  */
272 typedef uint8 bits8; /* >= 8 bits */
273 typedef uint16 bits16; /* >= 16 bits */
274 typedef uint32 bits32; /* >= 32 bits */
275 
276 /*
277  * 64-bit integers
278  */
279 #ifdef HAVE_LONG_INT_64
280 /* Plain "long int" fits, use it */
281 
282 #ifndef HAVE_INT64
283 typedef long int int64;
284 #endif
285 #ifndef HAVE_UINT64
286 typedef unsigned long int uint64;
287 #endif
288 #elif defined(HAVE_LONG_LONG_INT_64)
289 /* We have working support for "long long int", use that */
290 
291 #ifndef HAVE_INT64
292 typedef long long int int64;
293 #endif
294 #ifndef HAVE_UINT64
295 typedef unsigned long long int uint64;
296 #endif
297 #else
298 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
299 #error must have a working 64-bit integer datatype
300 #endif
301 
302 /* Decide if we need to decorate 64-bit constants */
303 #ifdef HAVE_LL_CONSTANTS
304 #define INT64CONST(x) ((int64) x##LL)
305 #define UINT64CONST(x) ((uint64) x##ULL)
306 #else
307 #define INT64CONST(x) ((int64) x)
308 #define UINT64CONST(x) ((uint64) x)
309 #endif
310 
311 /* snprintf format strings to use for 64-bit integers */
312 #define INT64_FORMAT "%" INT64_MODIFIER "d"
313 #define UINT64_FORMAT "%" INT64_MODIFIER "u"
314 
315 /*
316  * 128-bit signed and unsigned integers
317  * There currently is only a limited support for the type. E.g. 128bit
318  * literals and snprintf are not supported; but math is.
319  */
320 #if defined(PG_INT128_TYPE)
321 #define HAVE_INT128
322 typedef PG_INT128_TYPE int128;
323 typedef unsigned PG_INT128_TYPE uint128;
324 #endif
325 
326 /*
327  * stdint.h limits aren't guaranteed to be present and aren't guaranteed to
328  * have compatible types with our fixed width types. So just define our own.
329  */
330 #define PG_INT8_MIN (-0x7F-1)
331 #define PG_INT8_MAX (0x7F)
332 #define PG_UINT8_MAX (0xFF)
333 #define PG_INT16_MIN (-0x7FFF-1)
334 #define PG_INT16_MAX (0x7FFF)
335 #define PG_UINT16_MAX (0xFFFF)
336 #define PG_INT32_MIN (-0x7FFFFFFF-1)
337 #define PG_INT32_MAX (0x7FFFFFFF)
338 #define PG_UINT32_MAX (0xFFFFFFFF)
339 #define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
340 #define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF)
341 #define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
342 
343 /*
344  * We now always use int64 timestamps, but keep this symbol defined for the
345  * benefit of external code that might test it.
346  */
347 #define HAVE_INT64_TIMESTAMP
348 
349 /*
350  * Size
351  * Size of any memory resident object, as returned by sizeof.
352  */
353 typedef size_t Size;
354 
355 /*
356  * Index
357  * Index into any memory resident array.
358  *
359  * Note:
360  * Indices are non negative.
361  */
362 typedef unsigned int Index;
363 
364 /*
365  * Offset
366  * Offset into any memory resident array.
367  *
368  * Note:
369  * This differs from an Index in that an Index is always
370  * non negative, whereas Offset may be negative.
371  */
372 typedef signed int Offset;
373 
374 /*
375  * Common Postgres datatype names (as used in the catalogs)
376  */
377 typedef float float4;
378 typedef double float8;
379 
380 /*
381  * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
382  * CommandId
383  */
384 
385 /* typedef Oid is in postgres_ext.h */
386 
387 /*
388  * regproc is the type name used in the include/catalog headers, but
389  * RegProcedure is the preferred name in C code.
390  */
391 typedef Oid regproc;
393 
395 
397 
399 
400 #define InvalidSubTransactionId ((SubTransactionId) 0)
401 #define TopSubTransactionId ((SubTransactionId) 1)
402 
403 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
405 
407 
409 
410 #define FirstCommandId ((CommandId) 0)
411 #define InvalidCommandId (~(CommandId)0)
412 
413 /*
414  * Array indexing support
415  */
416 #define MAXDIM 6
417 typedef struct
418 {
419  int indx[MAXDIM];
420 } IntArray;
421 
422 /* ----------------
423  * Variable-length datatypes all share the 'struct varlena' header.
424  *
425  * NOTE: for TOASTable types, this is an oversimplification, since the value
426  * may be compressed or moved out-of-line. However datatype-specific routines
427  * are mostly content to deal with de-TOASTed values only, and of course
428  * client-side routines should never see a TOASTed value. But even in a
429  * de-TOASTed value, beware of touching vl_len_ directly, as its representation
430  * is no longer convenient. It's recommended that code always use the VARDATA,
431  * VARSIZE, and SET_VARSIZE macros instead of relying on direct mentions of
432  * the struct fields. See postgres.h for details of the TOASTed form.
433  * ----------------
434  */
435 struct varlena
436 {
437  char vl_len_[4]; /* Do not touch this field directly! */
438  char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */
439 };
440 
441 #define VARHDRSZ ((int32) sizeof(int32))
442 
443 /*
444  * These widely-used datatypes are just a varlena header and the data bytes.
445  * There is no terminating null or anything like that --- the data length is
446  * always VARSIZE(ptr) - VARHDRSZ.
447  */
448 typedef struct varlena bytea;
449 typedef struct varlena text;
450 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
451 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
452 
453 /*
454  * Specialized array types. These are physically laid out just the same
455  * as regular arrays (so that the regular array subscripting code works
456  * with them). They exist as distinct types mostly for historical reasons:
457  * they have nonstandard I/O behavior which we don't want to change for fear
458  * of breaking applications that look at the system catalogs. There is also
459  * an implementation issue for oidvector: it's part of the primary key for
460  * pg_proc, and we can't use the normal btree array support routines for that
461  * without circularity.
462  */
463 typedef struct
464 {
465  int32 vl_len_; /* these fields must match ArrayType! */
466  int ndim; /* always 1 for int2vector */
467  int32 dataoffset; /* always 0 for int2vector */
469  int dim1;
470  int lbound1;
471  int16 values[FLEXIBLE_ARRAY_MEMBER];
472 } int2vector;
473 
474 typedef struct
475 {
476  int32 vl_len_; /* these fields must match ArrayType! */
477  int ndim; /* always 1 for oidvector */
478  int32 dataoffset; /* always 0 for oidvector */
480  int dim1;
481  int lbound1;
482  Oid values[FLEXIBLE_ARRAY_MEMBER];
483 } oidvector;
484 
485 /*
486  * Representation of a Name: effectively just a C string, but null-padded to
487  * exactly NAMEDATALEN bytes. The use of a struct is historical.
488  */
489 typedef struct nameData
490 {
492 } NameData;
493 typedef NameData *Name;
494 
495 #define NameStr(name) ((name).data)
496 
497 /*
498  * Support macros for escaping strings. escape_backslash should be TRUE
499  * if generating a non-standard-conforming string. Prefixing a string
500  * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
501  * Beware of multiple evaluation of the "ch" argument!
502  */
503 #define SQL_STR_DOUBLE(ch, escape_backslash) \
504  ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
505 
506 #define ESCAPE_STRING_SYNTAX 'E'
507 
508 /* ----------------------------------------------------------------
509  * Section 4: IsValid macros for system types
510  * ----------------------------------------------------------------
511  */
512 /*
513  * BoolIsValid
514  * True iff bool is valid.
515  */
516 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
517 
518 /*
519  * PointerIsValid
520  * True iff pointer is valid.
521  */
522 #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
523 
524 /*
525  * PointerIsAligned
526  * True iff pointer is properly aligned to point to the given type.
527  */
528 #define PointerIsAligned(pointer, type) \
529  (((uintptr_t)(pointer) % (sizeof (type))) == 0)
530 
531 #define OffsetToPointer(base, offset) \
532  ((void *)((char *) base + offset))
533 
534 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
535 
536 #define RegProcedureIsValid(p) OidIsValid(p)
537 
538 
539 /* ----------------------------------------------------------------
540  * Section 5: offsetof, lengthof, endof, alignment
541  * ----------------------------------------------------------------
542  */
543 /*
544  * offsetof
545  * Offset of a structure/union field within that structure/union.
546  *
547  * XXX This is supposed to be part of stddef.h, but isn't on
548  * some systems (like SunOS 4).
549  */
550 #ifndef offsetof
551 #define offsetof(type, field) ((long) &((type *)0)->field)
552 #endif /* offsetof */
553 
554 /*
555  * lengthof
556  * Number of elements in an array.
557  */
558 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
559 
560 /*
561  * endof
562  * Address of the element one past the last in an array.
563  */
564 #define endof(array) (&(array)[lengthof(array)])
565 
566 /* ----------------
567  * Alignment macros: align a length or address appropriately for a given type.
568  * The fooALIGN() macros round up to a multiple of the required alignment,
569  * while the fooALIGN_DOWN() macros round down. The latter are more useful
570  * for problems like "how many X-sized structures will fit in a page?".
571  *
572  * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
573  * That case seems extremely unlikely to be needed in practice, however.
574  * ----------------
575  */
576 
577 #define TYPEALIGN(ALIGNVAL,LEN) \
578  (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
579 
580 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
581 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
582 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
583 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
584 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
585 /* MAXALIGN covers only built-in types, not buffers */
586 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
587 #define CACHELINEALIGN(LEN) TYPEALIGN(PG_CACHE_LINE_SIZE, (LEN))
588 
589 #define TYPEALIGN_DOWN(ALIGNVAL,LEN) \
590  (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
591 
592 #define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
593 #define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
594 #define LONGALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
595 #define DOUBLEALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
596 #define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
597 
598 /*
599  * The above macros will not work with types wider than uintptr_t, like with
600  * uint64 on 32-bit platforms. That's not problem for the usual use where a
601  * pointer or a length is aligned, but for the odd case that you need to
602  * align something (potentially) wider, use TYPEALIGN64.
603  */
604 #define TYPEALIGN64(ALIGNVAL,LEN) \
605  (((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1)))
606 
607 /* we don't currently need wider versions of the other ALIGN macros */
608 #define MAXALIGN64(LEN) TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN))
609 
610 /* ----------------
611  * Attribute macros
612  *
613  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
614  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html
615  * Sunpro: https://docs.oracle.com/cd/E18659_01/html/821-1384/gjzke.html
616  * XLC: http://www-01.ibm.com/support/knowledgecenter/SSGH2K_11.1.0/com.ibm.xlc111.aix.doc/language_ref/function_attributes.html
617  * XLC: http://www-01.ibm.com/support/knowledgecenter/SSGH2K_11.1.0/com.ibm.xlc111.aix.doc/language_ref/type_attrib.html
618  * ----------------
619  */
620 
621 /* only GCC supports the unused attribute */
622 #ifdef __GNUC__
623 #define pg_attribute_unused() __attribute__((unused))
624 #else
625 #define pg_attribute_unused()
626 #endif
627 
628 /* GCC and XLC support format attributes */
629 #if defined(__GNUC__) || defined(__IBMC__)
630 #define pg_attribute_format_arg(a) __attribute__((format_arg(a)))
631 #define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
632 #else
633 #define pg_attribute_format_arg(a)
634 #define pg_attribute_printf(f,a)
635 #endif
636 
637 /* GCC, Sunpro and XLC support aligned, packed and noreturn */
638 #if defined(__GNUC__) || defined(__SUNPRO_C) || defined(__IBMC__)
639 #define pg_attribute_aligned(a) __attribute__((aligned(a)))
640 #define pg_attribute_noreturn() __attribute__((noreturn))
641 #define pg_attribute_packed() __attribute__((packed))
642 #define HAVE_PG_ATTRIBUTE_NORETURN 1
643 #else
644 /*
645  * NB: aligned and packed are not given default definitions because they
646  * affect code functionality; they *must* be implemented by the compiler
647  * if they are to be used.
648  */
649 #define pg_attribute_noreturn()
650 #endif
651 
652 /* ----------------------------------------------------------------
653  * Section 6: assertions
654  * ----------------------------------------------------------------
655  */
656 
657 /*
658  * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
659  * - plai 9/5/90
660  *
661  * It should _NOT_ be defined in releases or in benchmark copies
662  */
663 
664 /*
665  * Assert() can be used in both frontend and backend code. In frontend code it
666  * just calls the standard assert, if it's available. If use of assertions is
667  * not configured, it does nothing.
668  */
669 #ifndef USE_ASSERT_CHECKING
670 
671 #define Assert(condition) ((void)true)
672 #define AssertMacro(condition) ((void)true)
673 #define AssertArg(condition) ((void)true)
674 #define AssertState(condition) ((void)true)
675 #define AssertPointerAlignment(ptr, bndr) ((void)true)
676 #define Trap(condition, errorType) ((void)true)
677 #define TrapMacro(condition, errorType) (true)
678 
679 #elif defined(FRONTEND)
680 
681 #include <assert.h>
682 #define Assert(p) assert(p)
683 #define AssertMacro(p) ((void) assert(p))
684 #define AssertArg(condition) assert(condition)
685 #define AssertState(condition) assert(condition)
686 #define AssertPointerAlignment(ptr, bndr) ((void)true)
687 #else /* USE_ASSERT_CHECKING && !FRONTEND */
688 
689 /*
690  * Trap
691  * Generates an exception if the given condition is true.
692  */
693 #define Trap(condition, errorType) \
694  do { \
695  if (condition) \
696  ExceptionalCondition(CppAsString(condition), (errorType), \
697  __FILE__, __LINE__); \
698  } while (0)
699 
700 /*
701  * TrapMacro is the same as Trap but it's intended for use in macros:
702  *
703  * #define foo(x) (AssertMacro(x != 0), bar(x))
704  *
705  * Isn't CPP fun?
706  */
707 #define TrapMacro(condition, errorType) \
708  ((bool) (! (condition) || \
709  (ExceptionalCondition(CppAsString(condition), (errorType), \
710  __FILE__, __LINE__), 0)))
711 
712 #define Assert(condition) \
713  Trap(!(condition), "FailedAssertion")
714 
715 #define AssertMacro(condition) \
716  ((void) TrapMacro(!(condition), "FailedAssertion"))
717 
718 #define AssertArg(condition) \
719  Trap(!(condition), "BadArgument")
720 
721 #define AssertState(condition) \
722  Trap(!(condition), "BadState")
723 
724 /*
725  * Check that `ptr' is `bndr' aligned.
726  */
727 #define AssertPointerAlignment(ptr, bndr) \
728  Trap(TYPEALIGN(bndr, (uintptr_t)(ptr)) != (uintptr_t)(ptr), \
729  "UnalignedPointer")
730 
731 #endif /* USE_ASSERT_CHECKING && !FRONTEND */
732 
733 /*
734  * Macros to support compile-time assertion checks.
735  *
736  * If the "condition" (a compile-time-constant expression) evaluates to false,
737  * throw a compile error using the "errmessage" (a string literal).
738  *
739  * gcc 4.6 and up supports _Static_assert(), but there are bizarre syntactic
740  * placement restrictions. These macros make it safe to use as a statement
741  * or in an expression, respectively.
742  *
743  * Otherwise we fall back on a kluge that assumes the compiler will complain
744  * about a negative width for a struct bit-field. This will not include a
745  * helpful error message, but it beats not getting an error at all.
746  */
747 #ifdef HAVE__STATIC_ASSERT
748 #define StaticAssertStmt(condition, errmessage) \
749  do { _Static_assert(condition, errmessage); } while(0)
750 #define StaticAssertExpr(condition, errmessage) \
751  ({ StaticAssertStmt(condition, errmessage); true; })
752 #else /* !HAVE__STATIC_ASSERT */
753 #define StaticAssertStmt(condition, errmessage) \
754  ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
755 #define StaticAssertExpr(condition, errmessage) \
756  StaticAssertStmt(condition, errmessage)
757 #endif /* HAVE__STATIC_ASSERT */
758 
759 
760 /*
761  * Compile-time checks that a variable (or expression) has the specified type.
762  *
763  * AssertVariableIsOfType() can be used as a statement.
764  * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
765  * #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
766  *
767  * If we don't have __builtin_types_compatible_p, we can still assert that
768  * the types have the same size. This is far from ideal (especially on 32-bit
769  * platforms) but it provides at least some coverage.
770  */
771 #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
772 #define AssertVariableIsOfType(varname, typename) \
773  StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
774  CppAsString(varname) " does not have type " CppAsString(typename))
775 #define AssertVariableIsOfTypeMacro(varname, typename) \
776  ((void) StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
777  CppAsString(varname) " does not have type " CppAsString(typename)))
778 #else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
779 #define AssertVariableIsOfType(varname, typename) \
780  StaticAssertStmt(sizeof(varname) == sizeof(typename), \
781  CppAsString(varname) " does not have type " CppAsString(typename))
782 #define AssertVariableIsOfTypeMacro(varname, typename) \
783  ((void) StaticAssertExpr(sizeof(varname) == sizeof(typename), \
784  CppAsString(varname) " does not have type " CppAsString(typename)))
785 #endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
786 
787 
788 /* ----------------------------------------------------------------
789  * Section 7: widely useful macros
790  * ----------------------------------------------------------------
791  */
792 /*
793  * Max
794  * Return the maximum of two numbers.
795  */
796 #define Max(x, y) ((x) > (y) ? (x) : (y))
797 
798 /*
799  * Min
800  * Return the minimum of two numbers.
801  */
802 #define Min(x, y) ((x) < (y) ? (x) : (y))
803 
804 /*
805  * Abs
806  * Return the absolute value of the argument.
807  */
808 #define Abs(x) ((x) >= 0 ? (x) : -(x))
809 
810 /*
811  * StrNCpy
812  * Like standard library function strncpy(), except that result string
813  * is guaranteed to be null-terminated --- that is, at most N-1 bytes
814  * of the source string will be kept.
815  * Also, the macro returns no result (too hard to do that without
816  * evaluating the arguments multiple times, which seems worse).
817  *
818  * BTW: when you need to copy a non-null-terminated string (like a text
819  * datum) and add a null, do not do it with StrNCpy(..., len+1). That
820  * might seem to work, but it fetches one byte more than there is in the
821  * text object. One fine day you'll have a SIGSEGV because there isn't
822  * another byte before the end of memory. Don't laugh, we've had real
823  * live bug reports from real live users over exactly this mistake.
824  * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
825  */
826 #define StrNCpy(dst,src,len) \
827  do \
828  { \
829  char * _dst = (dst); \
830  Size _len = (len); \
831 \
832  if (_len > 0) \
833  { \
834  strncpy(_dst, (src), _len); \
835  _dst[_len-1] = '\0'; \
836  } \
837  } while (0)
838 
839 
840 /* Get a bit mask of the bits set in non-long aligned addresses */
841 #define LONG_ALIGN_MASK (sizeof(long) - 1)
842 
843 /*
844  * MemSet
845  * Exactly the same as standard library function memset(), but considerably
846  * faster for zeroing small word-aligned structures (such as parsetree nodes).
847  * This has to be a macro because the main point is to avoid function-call
848  * overhead. However, we have also found that the loop is faster than
849  * native libc memset() on some platforms, even those with assembler
850  * memset() functions. More research needs to be done, perhaps with
851  * MEMSET_LOOP_LIMIT tests in configure.
852  */
853 #define MemSet(start, val, len) \
854  do \
855  { \
856  /* must be void* because we don't know if it is integer aligned yet */ \
857  void *_vstart = (void *) (start); \
858  int _val = (val); \
859  Size _len = (len); \
860 \
861  if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
862  (_len & LONG_ALIGN_MASK) == 0 && \
863  _val == 0 && \
864  _len <= MEMSET_LOOP_LIMIT && \
865  /* \
866  * If MEMSET_LOOP_LIMIT == 0, optimizer should find \
867  * the whole "if" false at compile time. \
868  */ \
869  MEMSET_LOOP_LIMIT != 0) \
870  { \
871  long *_start = (long *) _vstart; \
872  long *_stop = (long *) ((char *) _start + _len); \
873  while (_start < _stop) \
874  *_start++ = 0; \
875  } \
876  else \
877  memset(_vstart, _val, _len); \
878  } while (0)
879 
880 /*
881  * MemSetAligned is the same as MemSet except it omits the test to see if
882  * "start" is word-aligned. This is okay to use if the caller knows a-priori
883  * that the pointer is suitably aligned (typically, because he just got it
884  * from palloc(), which always delivers a max-aligned pointer).
885  */
886 #define MemSetAligned(start, val, len) \
887  do \
888  { \
889  long *_start = (long *) (start); \
890  int _val = (val); \
891  Size _len = (len); \
892 \
893  if ((_len & LONG_ALIGN_MASK) == 0 && \
894  _val == 0 && \
895  _len <= MEMSET_LOOP_LIMIT && \
896  MEMSET_LOOP_LIMIT != 0) \
897  { \
898  long *_stop = (long *) ((char *) _start + _len); \
899  while (_start < _stop) \
900  *_start++ = 0; \
901  } \
902  else \
903  memset(_start, _val, _len); \
904  } while (0)
905 
906 
907 /*
908  * MemSetTest/MemSetLoop are a variant version that allow all the tests in
909  * MemSet to be done at compile time in cases where "val" and "len" are
910  * constants *and* we know the "start" pointer must be word-aligned.
911  * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
912  * MemSetAligned. Beware of multiple evaluations of the arguments when using
913  * this approach.
914  */
915 #define MemSetTest(val, len) \
916  ( ((len) & LONG_ALIGN_MASK) == 0 && \
917  (len) <= MEMSET_LOOP_LIMIT && \
918  MEMSET_LOOP_LIMIT != 0 && \
919  (val) == 0 )
920 
921 #define MemSetLoop(start, val, len) \
922  do \
923  { \
924  long * _start = (long *) (start); \
925  long * _stop = (long *) ((char *) _start + (Size) (len)); \
926  \
927  while (_start < _stop) \
928  *_start++ = 0; \
929  } while (0)
930 
931 
932 /*
933  * Mark a point as unreachable in a portable fashion. This should preferably
934  * be something that the compiler understands, to aid code generation.
935  * In assert-enabled builds, we prefer abort() for debugging reasons.
936  */
937 #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
938 #define pg_unreachable() __builtin_unreachable()
939 #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
940 #define pg_unreachable() __assume(0)
941 #else
942 #define pg_unreachable() abort()
943 #endif
944 
945 
946 /*
947  * Hints to the compiler about the likelihood of a branch. Both likely() and
948  * unlikely() return the boolean value of the contained expression.
949  *
950  * These should only be used sparingly, in very hot code paths. It's very easy
951  * to mis-estimate likelihoods.
952  */
953 #if __GNUC__ >= 3
954 #define likely(x) __builtin_expect((x) != 0, 1)
955 #define unlikely(x) __builtin_expect((x) != 0, 0)
956 #else
957 #define likely(x) ((x) != 0)
958 #define unlikely(x) ((x) != 0)
959 #endif
960 
961 
962 /* ----------------------------------------------------------------
963  * Section 8: random stuff
964  * ----------------------------------------------------------------
965  */
966 
967 /* msb for char */
968 #define HIGHBIT (0x80)
969 #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
970 
971 #define STATUS_OK (0)
972 #define STATUS_ERROR (-1)
973 #define STATUS_EOF (-2)
974 #define STATUS_FOUND (1)
975 #define STATUS_WAITING (2)
976 
977 
978 /*
979  * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
980  * used in assert-enabled builds, to avoid compiler warnings about unused
981  * variables in assert-disabled builds.
982  */
983 #ifdef USE_ASSERT_CHECKING
984 #define PG_USED_FOR_ASSERTS_ONLY
985 #else
986 #define PG_USED_FOR_ASSERTS_ONLY pg_attribute_unused()
987 #endif
988 
989 
990 /* gettext domain name mangling */
991 
992 /*
993  * To better support parallel installations of major PostgreSQL
994  * versions as well as parallel installations of major library soname
995  * versions, we mangle the gettext domain name by appending those
996  * version numbers. The coding rule ought to be that wherever the
997  * domain name is mentioned as a literal, it must be wrapped into
998  * PG_TEXTDOMAIN(). The macros below do not work on non-literals; but
999  * that is somewhat intentional because it avoids having to worry
1000  * about multiple states of premangling and postmangling as the values
1001  * are being passed around.
1002  *
1003  * Make sure this matches the installation rules in nls-global.mk.
1004  */
1005 
1006 /* need a second indirection because we want to stringize the macro value, not the name */
1007 #define CppAsString2(x) CppAsString(x)
1008 
1009 #ifdef SO_MAJOR_VERSION
1010 #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
1011 #else
1012 #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
1013 #endif
1014 
1015 
1016 /* ----------------------------------------------------------------
1017  * Section 9: system-specific hacks
1018  *
1019  * This should be limited to things that absolutely have to be
1020  * included in every source file. The port-specific header file
1021  * is usually a better place for this sort of thing.
1022  * ----------------------------------------------------------------
1023  */
1024 
1025 /*
1026  * NOTE: this is also used for opening text files.
1027  * WIN32 treats Control-Z as EOF in files opened in text mode.
1028  * Therefore, we open files in binary mode on Win32 so we can read
1029  * literal control-Z. The other affect is that we see CRLF, but
1030  * that is OK because we can already handle those cleanly.
1031  */
1032 #if defined(WIN32) || defined(__CYGWIN__)
1033 #define PG_BINARY O_BINARY
1034 #define PG_BINARY_A "ab"
1035 #define PG_BINARY_R "rb"
1036 #define PG_BINARY_W "wb"
1037 #else
1038 #define PG_BINARY 0
1039 #define PG_BINARY_A "a"
1040 #define PG_BINARY_R "r"
1041 #define PG_BINARY_W "w"
1042 #endif
1043 
1044 /*
1045  * Provide prototypes for routines not present in a particular machine's
1046  * standard C library.
1047  */
1048 
1049 #if !HAVE_DECL_SNPRINTF
1050 extern int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3, 4);
1051 #endif
1052 
1053 #if !HAVE_DECL_VSNPRINTF
1054 extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
1055 #endif
1056 
1057 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
1058 #define memmove(d, s, c) bcopy(s, d, c)
1059 #endif
1060 
1061 /* no special DLL markers on most ports */
1062 #ifndef PGDLLIMPORT
1063 #define PGDLLIMPORT
1064 #endif
1065 #ifndef PGDLLEXPORT
1066 #define PGDLLEXPORT
1067 #endif
1068 
1069 /*
1070  * The following is used as the arg list for signal handlers. Any ports
1071  * that take something other than an int argument should override this in
1072  * their pg_config_os.h file. Note that variable names are required
1073  * because it is used in both the prototypes as well as the definitions.
1074  * Note also the long name. We expect that this won't collide with
1075  * other names causing compiler warnings.
1076  */
1077 
1078 #ifndef SIGNAL_ARGS
1079 #define SIGNAL_ARGS int postgres_signal_arg
1080 #endif
1081 
1082 /*
1083  * When there is no sigsetjmp, its functionality is provided by plain
1084  * setjmp. Incidentally, nothing provides setjmp's functionality in
1085  * that case. We now support the case only on Windows.
1086  */
1087 #ifdef WIN32
1088 #define sigjmp_buf jmp_buf
1089 #define sigsetjmp(x,y) setjmp(x)
1090 #define siglongjmp longjmp
1091 #endif
1092 
1093 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
1094 extern int fdatasync(int fildes);
1095 #endif
1096 
1097 /* If strtoq() exists, rename it to the more standard strtoll() */
1098 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
1099 #define strtoll strtoq
1100 #define HAVE_STRTOLL 1
1101 #endif
1102 
1103 /* If strtouq() exists, rename it to the more standard strtoull() */
1104 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
1105 #define strtoull strtouq
1106 #define HAVE_STRTOULL 1
1107 #endif
1108 
1109 /*
1110  * We assume if we have these two functions, we have their friends too, and
1111  * can use the wide-character functions.
1112  */
1113 #if defined(HAVE_WCSTOMBS) && defined(HAVE_TOWLOWER)
1114 #define USE_WIDE_UPPER_LOWER
1115 #endif
1116 
1117 /* EXEC_BACKEND defines */
1118 #ifdef EXEC_BACKEND
1119 #define NON_EXEC_STATIC
1120 #else
1121 #define NON_EXEC_STATIC static
1122 #endif
1123 
1124 /* /port compatibility functions */
1125 #include "port.h"
1126 
1127 #endif /* C_H */
signed short int16
Definition: c.h:252
uint32 CommandId
Definition: c.h:408
int lbound1
Definition: c.h:470
Definition: c.h:474
char data[NAMEDATALEN]
Definition: c.h:491
uint32 MultiXactOffset
Definition: c.h:406
uint32 TransactionId
Definition: c.h:394
#define MAXDIM
Definition: c.h:416
uint16 bits16
Definition: c.h:273
regproc RegProcedure
Definition: c.h:392
unsigned char uint8
Definition: c.h:263
int32 dataoffset
Definition: c.h:478
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
Oid elemtype
Definition: c.h:468
uint32 SubTransactionId
Definition: c.h:398
unsigned int Oid
Definition: postgres_ext.h:31
char bool
Definition: c.h:199
signed int int32
Definition: c.h:253
#define pg_attribute_printf(f, a)
Definition: c.h:634
char vl_len_[4]
Definition: c.h:437
int int vsnprintf(char *str, size_t count, const char *fmt, va_list args)
#define NAMEDATALEN
unsigned short uint16
Definition: c.h:264
char * Pointer
Definition: c.h:242
int32 dataoffset
Definition: c.h:467
double float8
Definition: c.h:378
int32 vl_len_
Definition: c.h:476
Definition: c.h:489
int dim1
Definition: c.h:480
int ndim
Definition: c.h:466
unsigned int uint32
Definition: c.h:265
uint32 LocalTransactionId
Definition: c.h:396
char vl_dat[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:438
signed char int8
Definition: c.h:251
float float4
Definition: c.h:377
uint8 bits8
Definition: c.h:272
Definition: c.h:463
int dim1
Definition: c.h:469
unsigned int Index
Definition: c.h:362
TransactionId MultiXactId
Definition: c.h:404
uint32 bits32
Definition: c.h:274
int32 vl_len_
Definition: c.h:465
signed int Offset
Definition: c.h:372
size_t Size
Definition: c.h:353
int lbound1
Definition: c.h:481
Oid regproc
Definition: c.h:391
static Datum values[MAXATTR]
Definition: bootstrap.c:162
Definition: c.h:417
Oid elemtype
Definition: c.h:479
bool * BoolPtr
Definition: c.h:211
struct nameData NameData
Definition: c.h:435
NameData * Name
Definition: c.h:493
int ndim
Definition: c.h:477