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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) 1996-2024, 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) compiler characteristics
30  * 2) bool, true, false
31  * 3) standard system types
32  * 4) IsValid macros for system types
33  * 5) lengthof, 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,
40  * it's usually wrong to put an "extern" declaration here, unless it's
41  * ifdef'd so that it's seen in only one case or the other.
42  * typedefs and macros are the kind of thing that might go here.
43  *
44  *----------------------------------------------------------------
45  */
46 #ifndef C_H
47 #define C_H
48 
49 #include "postgres_ext.h"
50 
51 /* Must undef pg_config_ext.h symbols before including pg_config.h */
52 #undef PG_INT64_TYPE
53 
54 #include "pg_config.h"
55 #include "pg_config_manual.h" /* must be after pg_config.h */
56 #include "pg_config_os.h" /* must be before any system header files */
57 
58 /* System header files that should be available everywhere in Postgres */
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <stddef.h>
63 #include <stdarg.h>
64 #ifdef HAVE_STRINGS_H
65 #include <strings.h>
66 #endif
67 #include <stdint.h>
68 #include <sys/types.h>
69 #include <errno.h>
70 #if defined(WIN32) || defined(__CYGWIN__)
71 #include <fcntl.h> /* ensure O_BINARY is available */
72 #endif
73 #include <locale.h>
74 #ifdef ENABLE_NLS
75 #include <libintl.h>
76 #endif
77 
78 /* Define before including zlib.h to add const decorations to zlib API. */
79 #ifdef HAVE_LIBZ
80 #define ZLIB_CONST
81 #endif
82 
83 
84 /* ----------------------------------------------------------------
85  * Section 1: compiler characteristics
86  *
87  * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
88  * ----------------------------------------------------------------
89  */
90 
91 /*
92  * Disable "inline" if PG_FORCE_DISABLE_INLINE is defined.
93  * This is used to work around compiler bugs and might also be useful for
94  * investigatory purposes.
95  */
96 #ifdef PG_FORCE_DISABLE_INLINE
97 #undef inline
98 #define inline
99 #endif
100 
101 /*
102  * Attribute macros
103  *
104  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
105  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html
106  * Clang: https://clang.llvm.org/docs/AttributeReference.html
107  * Sunpro: https://docs.oracle.com/cd/E18659_01/html/821-1384/gjzke.html
108  * XLC: https://www.ibm.com/support/knowledgecenter/SSGH2K_13.1.2/com.ibm.xlc131.aix.doc/language_ref/function_attributes.html
109  * XLC: https://www.ibm.com/support/knowledgecenter/SSGH2K_13.1.2/com.ibm.xlc131.aix.doc/language_ref/type_attrib.html
110  */
111 
112 /*
113  * For compilers which don't support __has_attribute, we just define
114  * __has_attribute(x) to 0 so that we can define macros for various
115  * __attribute__s more easily below.
116  */
117 #ifndef __has_attribute
118 #define __has_attribute(attribute) 0
119 #endif
120 
121 /* only GCC supports the unused attribute */
122 #ifdef __GNUC__
123 #define pg_attribute_unused() __attribute__((unused))
124 #else
125 #define pg_attribute_unused()
126 #endif
127 
128 /*
129  * pg_nodiscard means the compiler should warn if the result of a function
130  * call is ignored. The name "nodiscard" is chosen in alignment with
131  * (possibly future) C and C++ standards. For maximum compatibility, use it
132  * as a function declaration specifier, so it goes before the return type.
133  */
134 #ifdef __GNUC__
135 #define pg_nodiscard __attribute__((warn_unused_result))
136 #else
137 #define pg_nodiscard
138 #endif
139 
140 /*
141  * Place this macro before functions that should be allowed to make misaligned
142  * accesses. Think twice before using it on non-x86-specific code!
143  * Testing can be done with "-fsanitize=alignment -fsanitize-trap=alignment"
144  * on clang, or "-fsanitize=alignment -fno-sanitize-recover=alignment" on gcc.
145  */
146 #if __clang_major__ >= 7 || __GNUC__ >= 8
147 #define pg_attribute_no_sanitize_alignment() __attribute__((no_sanitize("alignment")))
148 #else
149 #define pg_attribute_no_sanitize_alignment()
150 #endif
151 
152 /*
153  * pg_attribute_nonnull means the compiler should warn if the function is
154  * called with the listed arguments set to NULL. If no arguments are
155  * listed, the compiler should warn if any pointer arguments are set to NULL.
156  */
157 #if __has_attribute (nonnull)
158 #define pg_attribute_nonnull(...) __attribute__((nonnull(__VA_ARGS__)))
159 #else
160 #define pg_attribute_nonnull(...)
161 #endif
162 
163 /*
164  * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
165  * used in assert-enabled builds, to avoid compiler warnings about unused
166  * variables in assert-disabled builds.
167  */
168 #ifdef USE_ASSERT_CHECKING
169 #define PG_USED_FOR_ASSERTS_ONLY
170 #else
171 #define PG_USED_FOR_ASSERTS_ONLY pg_attribute_unused()
172 #endif
173 
174 /* GCC and XLC support format attributes */
175 #if defined(__GNUC__) || defined(__IBMC__)
176 #define pg_attribute_format_arg(a) __attribute__((format_arg(a)))
177 #define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
178 #else
179 #define pg_attribute_format_arg(a)
180 #define pg_attribute_printf(f,a)
181 #endif
182 
183 /* GCC, Sunpro and XLC support aligned, packed and noreturn */
184 #if defined(__GNUC__) || defined(__SUNPRO_C) || defined(__IBMC__)
185 #define pg_attribute_aligned(a) __attribute__((aligned(a)))
186 #define pg_attribute_noreturn() __attribute__((noreturn))
187 #define pg_attribute_packed() __attribute__((packed))
188 #define HAVE_PG_ATTRIBUTE_NORETURN 1
189 #elif defined(_MSC_VER)
190 /*
191  * MSVC supports aligned. noreturn is also possible but in MSVC it is
192  * declared before the definition while pg_attribute_noreturn() macro
193  * is currently used after the definition.
194  *
195  * Packing is also possible but only by wrapping the entire struct definition
196  * which doesn't fit into our current macro declarations.
197  */
198 #define pg_attribute_aligned(a) __declspec(align(a))
199 #define pg_attribute_noreturn()
200 #else
201 /*
202  * NB: aligned and packed are not given default definitions because they
203  * affect code functionality; they *must* be implemented by the compiler
204  * if they are to be used.
205  */
206 #define pg_attribute_noreturn()
207 #endif
208 
209 /*
210  * Use "pg_attribute_always_inline" in place of "inline" for functions that
211  * we wish to force inlining of, even when the compiler's heuristics would
212  * choose not to. But, if possible, don't force inlining in unoptimized
213  * debug builds.
214  */
215 #if (defined(__GNUC__) && __GNUC__ > 3 && defined(__OPTIMIZE__)) || defined(__SUNPRO_C) || defined(__IBMC__)
216 /* GCC > 3, Sunpro and XLC support always_inline via __attribute__ */
217 #define pg_attribute_always_inline __attribute__((always_inline)) inline
218 #elif defined(_MSC_VER)
219 /* MSVC has a special keyword for this */
220 #define pg_attribute_always_inline __forceinline
221 #else
222 /* Otherwise, the best we can do is to say "inline" */
223 #define pg_attribute_always_inline inline
224 #endif
225 
226 /*
227  * Forcing a function not to be inlined can be useful if it's the slow path of
228  * a performance-critical function, or should be visible in profiles to allow
229  * for proper cost attribution. Note that unlike the pg_attribute_XXX macros
230  * above, this should be placed before the function's return type and name.
231  */
232 /* GCC, Sunpro and XLC support noinline via __attribute__ */
233 #if (defined(__GNUC__) && __GNUC__ > 2) || defined(__SUNPRO_C) || defined(__IBMC__)
234 #define pg_noinline __attribute__((noinline))
235 /* msvc via declspec */
236 #elif defined(_MSC_VER)
237 #define pg_noinline __declspec(noinline)
238 #else
239 #define pg_noinline
240 #endif
241 
242 /*
243  * For now, just define pg_attribute_cold and pg_attribute_hot to be empty
244  * macros on minGW 8.1. There appears to be a compiler bug that results in
245  * compilation failure. At this time, we still have at least one buildfarm
246  * animal running that compiler, so this should make that green again. It's
247  * likely this compiler is not popular enough to warrant keeping this code
248  * around forever, so let's just remove it once the last buildfarm animal
249  * upgrades.
250  */
251 #if defined(__MINGW64__) && __GNUC__ == 8 && __GNUC_MINOR__ == 1
252 
253 #define pg_attribute_cold
254 #define pg_attribute_hot
255 
256 #else
257 /*
258  * Marking certain functions as "hot" or "cold" can be useful to assist the
259  * compiler in arranging the assembly code in a more efficient way.
260  */
261 #if __has_attribute (cold)
262 #define pg_attribute_cold __attribute__((cold))
263 #else
264 #define pg_attribute_cold
265 #endif
266 
267 #if __has_attribute (hot)
268 #define pg_attribute_hot __attribute__((hot))
269 #else
270 #define pg_attribute_hot
271 #endif
272 
273 #endif /* defined(__MINGW64__) && __GNUC__ == 8 &&
274  * __GNUC_MINOR__ == 1 */
275 /*
276  * Mark a point as unreachable in a portable fashion. This should preferably
277  * be something that the compiler understands, to aid code generation.
278  * In assert-enabled builds, we prefer abort() for debugging reasons.
279  */
280 #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
281 #define pg_unreachable() __builtin_unreachable()
282 #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
283 #define pg_unreachable() __assume(0)
284 #else
285 #define pg_unreachable() abort()
286 #endif
287 
288 /*
289  * Hints to the compiler about the likelihood of a branch. Both likely() and
290  * unlikely() return the boolean value of the contained expression.
291  *
292  * These should only be used sparingly, in very hot code paths. It's very easy
293  * to mis-estimate likelihoods.
294  */
295 #if __GNUC__ >= 3
296 #define likely(x) __builtin_expect((x) != 0, 1)
297 #define unlikely(x) __builtin_expect((x) != 0, 0)
298 #else
299 #define likely(x) ((x) != 0)
300 #define unlikely(x) ((x) != 0)
301 #endif
302 
303 /*
304  * CppAsString
305  * Convert the argument to a string, using the C preprocessor.
306  * CppAsString2
307  * Convert the argument to a string, after one round of macro expansion.
308  * CppConcat
309  * Concatenate two arguments together, using the C preprocessor.
310  *
311  * Note: There used to be support here for pre-ANSI C compilers that didn't
312  * support # and ##. Nowadays, these macros are just for clarity and/or
313  * backward compatibility with existing PostgreSQL code.
314  */
315 #define CppAsString(identifier) #identifier
316 #define CppAsString2(x) CppAsString(x)
317 #define CppConcat(x, y) x##y
318 
319 /*
320  * VA_ARGS_NARGS
321  * Returns the number of macro arguments it is passed.
322  *
323  * An empty argument still counts as an argument, so effectively, this is
324  * "one more than the number of commas in the argument list".
325  *
326  * This works for up to 63 arguments. Internally, VA_ARGS_NARGS_() is passed
327  * 64+N arguments, and the C99 standard only requires macros to allow up to
328  * 127 arguments, so we can't portably go higher. The implementation is
329  * pretty trivial: VA_ARGS_NARGS_() returns its 64th argument, and we set up
330  * the call so that that is the appropriate one of the list of constants.
331  * This idea is due to Laurent Deniau.
332  *
333  * MSVC has an implementation of __VA_ARGS__ that doesn't conform to the
334  * standard unless you use the /Zc:preprocessor compiler flag, but that
335  * isn't available before Visual Studio 2019. For now, use a different
336  * definition that also works on older compilers.
337  */
338 #ifdef _MSC_VER
339 #define EXPAND(args) args
340 #define VA_ARGS_NARGS(...) \
341  VA_ARGS_NARGS_ EXPAND((__VA_ARGS__, \
342  63,62,61,60, \
343  59,58,57,56,55,54,53,52,51,50, \
344  49,48,47,46,45,44,43,42,41,40, \
345  39,38,37,36,35,34,33,32,31,30, \
346  29,28,27,26,25,24,23,22,21,20, \
347  19,18,17,16,15,14,13,12,11,10, \
348  9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
349 #else
350 
351 #define VA_ARGS_NARGS(...) \
352  VA_ARGS_NARGS_(__VA_ARGS__, \
353  63,62,61,60, \
354  59,58,57,56,55,54,53,52,51,50, \
355  49,48,47,46,45,44,43,42,41,40, \
356  39,38,37,36,35,34,33,32,31,30, \
357  29,28,27,26,25,24,23,22,21,20, \
358  19,18,17,16,15,14,13,12,11,10, \
359  9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
360 #endif
361 
362 #define VA_ARGS_NARGS_( \
363  _01,_02,_03,_04,_05,_06,_07,_08,_09,_10, \
364  _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \
365  _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \
366  _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \
367  _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \
368  _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \
369  _61,_62,_63, N, ...) \
370  (N)
371 
372 /*
373  * Generic function pointer. This can be used in the rare cases where it's
374  * necessary to cast a function pointer to a seemingly incompatible function
375  * pointer type while avoiding gcc's -Wcast-function-type warnings.
376  */
377 typedef void (*pg_funcptr_t) (void);
378 
379 /*
380  * We require C99, hence the compiler should understand flexible array
381  * members. However, for documentation purposes we still consider it to be
382  * project style to write "field[FLEXIBLE_ARRAY_MEMBER]" not just "field[]".
383  * When computing the size of such an object, use "offsetof(struct s, f)"
384  * for portability. Don't use "offsetof(struct s, f[0])", as this doesn't
385  * work with MSVC and with C++ compilers.
386  */
387 #define FLEXIBLE_ARRAY_MEMBER /* empty */
388 
389 /*
390  * Does the compiler support #pragma GCC system_header? We optionally use it
391  * to avoid warnings that we can't fix (e.g. in the perl headers).
392  * See https://gcc.gnu.org/onlinedocs/cpp/System-Headers.html
393  *
394  * Headers for which we do not want to show compiler warnings can,
395  * conditionally, use #pragma GCC system_header to avoid warnings. Obviously
396  * this should only be used for external headers over which we do not have
397  * control.
398  *
399  * Support for the pragma is tested here, instead of during configure, as gcc
400  * also warns about the pragma being used in a .c file. It's surprisingly hard
401  * to get autoconf to use .h as the file-ending. Looks like gcc has
402  * implemented the pragma since the 2000, so this test should suffice.
403  *
404  *
405  * Alternatively, we could add the include paths for problematic headers with
406  * -isystem, but that is a larger hammer and is harder to search for.
407  *
408  * A more granular alternative would be to use #pragma GCC diagnostic
409  * push/ignored/pop, but gcc warns about unknown warnings being ignored, so
410  * every to-be-ignored-temporarily compiler warning would require its own
411  * pg_config.h symbol and #ifdef.
412  */
413 #ifdef __GNUC__
414 #define HAVE_PRAGMA_GCC_SYSTEM_HEADER 1
415 #endif
416 
417 
418 /* ----------------------------------------------------------------
419  * Section 2: bool, true, false
420  * ----------------------------------------------------------------
421  */
422 
423 /*
424  * bool
425  * Boolean value, either true or false.
426  *
427  * We use stdbool.h if available and its bool has size 1. That's useful for
428  * better compiler and debugger output and for compatibility with third-party
429  * libraries. But PostgreSQL currently cannot deal with bool of other sizes;
430  * there are static assertions around the code to prevent that.
431  *
432  * For C++ compilers, we assume the compiler has a compatible built-in
433  * definition of bool.
434  *
435  * See also the version of this code in src/interfaces/ecpg/include/ecpglib.h.
436  */
437 
438 #ifndef __cplusplus
439 
440 #ifdef PG_USE_STDBOOL
441 #include <stdbool.h>
442 #else
443 
444 #ifndef bool
445 typedef unsigned char bool;
446 #endif
447 
448 #ifndef true
449 #define true ((bool) 1)
450 #endif
451 
452 #ifndef false
453 #define false ((bool) 0)
454 #endif
455 
456 #endif /* not PG_USE_STDBOOL */
457 #endif /* not C++ */
458 
459 
460 /* ----------------------------------------------------------------
461  * Section 3: standard system types
462  * ----------------------------------------------------------------
463  */
464 
465 /*
466  * Pointer
467  * Variable holding address of any memory resident object.
468  *
469  * XXX Pointer arithmetic is done with this, so it can't be void *
470  * under "true" ANSI compilers.
471  */
472 typedef char *Pointer;
473 
474 /*
475  * intN
476  * Signed integer, EXACTLY N BITS IN SIZE,
477  * used for numerical computations and the
478  * frontend/backend protocol.
479  */
480 #ifndef HAVE_INT8
481 typedef signed char int8; /* == 8 bits */
482 typedef signed short int16; /* == 16 bits */
483 typedef signed int int32; /* == 32 bits */
484 #endif /* not HAVE_INT8 */
485 
486 /*
487  * uintN
488  * Unsigned integer, EXACTLY N BITS IN SIZE,
489  * used for numerical computations and the
490  * frontend/backend protocol.
491  */
492 #ifndef HAVE_UINT8
493 typedef unsigned char uint8; /* == 8 bits */
494 typedef unsigned short uint16; /* == 16 bits */
495 typedef unsigned int uint32; /* == 32 bits */
496 #endif /* not HAVE_UINT8 */
497 
498 /*
499  * bitsN
500  * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
501  */
502 typedef uint8 bits8; /* >= 8 bits */
503 typedef uint16 bits16; /* >= 16 bits */
504 typedef uint32 bits32; /* >= 32 bits */
505 
506 /*
507  * 64-bit integers
508  */
509 #ifdef HAVE_LONG_INT_64
510 /* Plain "long int" fits, use it */
511 
512 #ifndef HAVE_INT64
513 typedef long int int64;
514 #endif
515 #ifndef HAVE_UINT64
516 typedef unsigned long int uint64;
517 #endif
518 #define INT64CONST(x) (x##L)
519 #define UINT64CONST(x) (x##UL)
520 #elif defined(HAVE_LONG_LONG_INT_64)
521 /* We have working support for "long long int", use that */
522 
523 #ifndef HAVE_INT64
524 typedef long long int int64;
525 #endif
526 #ifndef HAVE_UINT64
527 typedef unsigned long long int uint64;
528 #endif
529 #define INT64CONST(x) (x##LL)
530 #define UINT64CONST(x) (x##ULL)
531 #else
532 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
533 #error must have a working 64-bit integer datatype
534 #endif
535 
536 /* snprintf format strings to use for 64-bit integers */
537 #define INT64_FORMAT "%" INT64_MODIFIER "d"
538 #define UINT64_FORMAT "%" INT64_MODIFIER "u"
539 
540 /*
541  * 128-bit signed and unsigned integers
542  * There currently is only limited support for such types.
543  * E.g. 128bit literals and snprintf are not supported; but math is.
544  * Also, because we exclude such types when choosing MAXIMUM_ALIGNOF,
545  * it must be possible to coerce the compiler to allocate them on no
546  * more than MAXALIGN boundaries.
547  */
548 #if defined(PG_INT128_TYPE)
549 #if defined(pg_attribute_aligned) || ALIGNOF_PG_INT128_TYPE <= MAXIMUM_ALIGNOF
550 #define HAVE_INT128 1
551 
552 typedef PG_INT128_TYPE int128
553 #if defined(pg_attribute_aligned)
554  pg_attribute_aligned(MAXIMUM_ALIGNOF)
555 #endif
556  ;
557 
558 typedef unsigned PG_INT128_TYPE uint128
559 #if defined(pg_attribute_aligned)
560  pg_attribute_aligned(MAXIMUM_ALIGNOF)
561 #endif
562  ;
563 
564 #endif
565 #endif
566 
567 /*
568  * stdint.h limits aren't guaranteed to have compatible types with our fixed
569  * width types. So just define our own.
570  */
571 #define PG_INT8_MIN (-0x7F-1)
572 #define PG_INT8_MAX (0x7F)
573 #define PG_UINT8_MAX (0xFF)
574 #define PG_INT16_MIN (-0x7FFF-1)
575 #define PG_INT16_MAX (0x7FFF)
576 #define PG_UINT16_MAX (0xFFFF)
577 #define PG_INT32_MIN (-0x7FFFFFFF-1)
578 #define PG_INT32_MAX (0x7FFFFFFF)
579 #define PG_UINT32_MAX (0xFFFFFFFFU)
580 #define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
581 #define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF)
582 #define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
583 
584 /*
585  * We now always use int64 timestamps, but keep this symbol defined for the
586  * benefit of external code that might test it.
587  */
588 #define HAVE_INT64_TIMESTAMP
589 
590 /*
591  * Size
592  * Size of any memory resident object, as returned by sizeof.
593  */
594 typedef size_t Size;
595 
596 /*
597  * Index
598  * Index into any memory resident array.
599  *
600  * Note:
601  * Indices are non negative.
602  */
603 typedef unsigned int Index;
604 
605 /*
606  * Offset
607  * Offset into any memory resident array.
608  *
609  * Note:
610  * This differs from an Index in that an Index is always
611  * non negative, whereas Offset may be negative.
612  */
613 typedef signed int Offset;
614 
615 /*
616  * Common Postgres datatype names (as used in the catalogs)
617  */
618 typedef float float4;
619 typedef double float8;
620 
621 #ifdef USE_FLOAT8_BYVAL
622 #define FLOAT8PASSBYVAL true
623 #else
624 #define FLOAT8PASSBYVAL false
625 #endif
626 
627 /*
628  * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
629  * CommandId
630  */
631 
632 /* typedef Oid is in postgres_ext.h */
633 
634 /*
635  * regproc is the type name used in the include/catalog headers, but
636  * RegProcedure is the preferred name in C code.
637  */
638 typedef Oid regproc;
640 
642 
644 
646 
647 #define InvalidSubTransactionId ((SubTransactionId) 0)
648 #define TopSubTransactionId ((SubTransactionId) 1)
649 
650 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
652 
654 
656 
657 #define FirstCommandId ((CommandId) 0)
658 #define InvalidCommandId (~(CommandId)0)
659 
660 
661 /* ----------------
662  * Variable-length datatypes all share the 'struct varlena' header.
663  *
664  * NOTE: for TOASTable types, this is an oversimplification, since the value
665  * may be compressed or moved out-of-line. However datatype-specific routines
666  * are mostly content to deal with de-TOASTed values only, and of course
667  * client-side routines should never see a TOASTed value. But even in a
668  * de-TOASTed value, beware of touching vl_len_ directly, as its
669  * representation is no longer convenient. It's recommended that code always
670  * use macros VARDATA_ANY, VARSIZE_ANY, VARSIZE_ANY_EXHDR, VARDATA, VARSIZE,
671  * and SET_VARSIZE instead of relying on direct mentions of the struct fields.
672  * See postgres.h for details of the TOASTed form.
673  * ----------------
674  */
675 struct varlena
676 {
677  char vl_len_[4]; /* Do not touch this field directly! */
678  char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */
679 };
680 
681 #define VARHDRSZ ((int32) sizeof(int32))
682 
683 /*
684  * These widely-used datatypes are just a varlena header and the data bytes.
685  * There is no terminating null or anything like that --- the data length is
686  * always VARSIZE_ANY_EXHDR(ptr).
687  */
688 typedef struct varlena bytea;
689 typedef struct varlena text;
690 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
691 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
692 
693 /*
694  * Specialized array types. These are physically laid out just the same
695  * as regular arrays (so that the regular array subscripting code works
696  * with them). They exist as distinct types mostly for historical reasons:
697  * they have nonstandard I/O behavior which we don't want to change for fear
698  * of breaking applications that look at the system catalogs. There is also
699  * an implementation issue for oidvector: it's part of the primary key for
700  * pg_proc, and we can't use the normal btree array support routines for that
701  * without circularity.
702  */
703 typedef struct
704 {
705  int32 vl_len_; /* these fields must match ArrayType! */
706  int ndim; /* always 1 for int2vector */
707  int32 dataoffset; /* always 0 for int2vector */
709  int dim1;
710  int lbound1;
712 } int2vector;
713 
714 typedef struct
715 {
716  int32 vl_len_; /* these fields must match ArrayType! */
717  int ndim; /* always 1 for oidvector */
718  int32 dataoffset; /* always 0 for oidvector */
720  int dim1;
721  int lbound1;
723 } oidvector;
724 
725 /*
726  * Representation of a Name: effectively just a C string, but null-padded to
727  * exactly NAMEDATALEN bytes. The use of a struct is historical.
728  */
729 typedef struct nameData
730 {
733 typedef NameData *Name;
734 
735 #define NameStr(name) ((name).data)
736 
737 
738 /* ----------------------------------------------------------------
739  * Section 4: IsValid macros for system types
740  * ----------------------------------------------------------------
741  */
742 /*
743  * BoolIsValid
744  * True iff bool is valid.
745  */
746 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
747 
748 /*
749  * PointerIsValid
750  * True iff pointer is valid.
751  */
752 #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
753 
754 /*
755  * PointerIsAligned
756  * True iff pointer is properly aligned to point to the given type.
757  */
758 #define PointerIsAligned(pointer, type) \
759  (((uintptr_t)(pointer) % (sizeof (type))) == 0)
760 
761 #define OffsetToPointer(base, offset) \
762  ((void *)((char *) base + offset))
763 
764 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
765 
766 #define RegProcedureIsValid(p) OidIsValid(p)
767 
768 
769 /* ----------------------------------------------------------------
770  * Section 5: lengthof, alignment
771  * ----------------------------------------------------------------
772  */
773 /*
774  * lengthof
775  * Number of elements in an array.
776  */
777 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
778 
779 /* ----------------
780  * Alignment macros: align a length or address appropriately for a given type.
781  * The fooALIGN() macros round up to a multiple of the required alignment,
782  * while the fooALIGN_DOWN() macros round down. The latter are more useful
783  * for problems like "how many X-sized structures will fit in a page?".
784  *
785  * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
786  * That case seems extremely unlikely to be needed in practice, however.
787  *
788  * NOTE: MAXIMUM_ALIGNOF, and hence MAXALIGN(), intentionally exclude any
789  * larger-than-8-byte types the compiler might have.
790  * ----------------
791  */
792 
793 #define TYPEALIGN(ALIGNVAL,LEN) \
794  (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
795 
796 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
797 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
798 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
799 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
800 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
801 /* MAXALIGN covers only built-in types, not buffers */
802 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
803 #define CACHELINEALIGN(LEN) TYPEALIGN(PG_CACHE_LINE_SIZE, (LEN))
804 
805 #define TYPEALIGN_DOWN(ALIGNVAL,LEN) \
806  (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
807 
808 #define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
809 #define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
810 #define LONGALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
811 #define DOUBLEALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
812 #define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
813 #define BUFFERALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_BUFFER, (LEN))
814 
815 /*
816  * The above macros will not work with types wider than uintptr_t, like with
817  * uint64 on 32-bit platforms. That's not problem for the usual use where a
818  * pointer or a length is aligned, but for the odd case that you need to
819  * align something (potentially) wider, use TYPEALIGN64.
820  */
821 #define TYPEALIGN64(ALIGNVAL,LEN) \
822  (((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1)))
823 
824 /* we don't currently need wider versions of the other ALIGN macros */
825 #define MAXALIGN64(LEN) TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN))
826 
827 
828 /* ----------------------------------------------------------------
829  * Section 6: assertions
830  * ----------------------------------------------------------------
831  */
832 
833 /*
834  * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
835  * - plai 9/5/90
836  *
837  * It should _NOT_ be defined in releases or in benchmark copies
838  */
839 
840 /*
841  * Assert() can be used in both frontend and backend code. In frontend code it
842  * just calls the standard assert, if it's available. If use of assertions is
843  * not configured, it does nothing.
844  */
845 #ifndef USE_ASSERT_CHECKING
846 
847 #define Assert(condition) ((void)true)
848 #define AssertMacro(condition) ((void)true)
849 
850 #elif defined(FRONTEND)
851 
852 #include <assert.h>
853 #define Assert(p) assert(p)
854 #define AssertMacro(p) ((void) assert(p))
855 
856 #else /* USE_ASSERT_CHECKING && !FRONTEND */
857 
858 /*
859  * Assert
860  * Generates a fatal exception if the given condition is false.
861  */
862 #define Assert(condition) \
863  do { \
864  if (!(condition)) \
865  ExceptionalCondition(#condition, __FILE__, __LINE__); \
866  } while (0)
867 
868 /*
869  * AssertMacro is the same as Assert but it's suitable for use in
870  * expression-like macros, for example:
871  *
872  * #define foo(x) (AssertMacro(x != 0), bar(x))
873  */
874 #define AssertMacro(condition) \
875  ((void) ((condition) || \
876  (ExceptionalCondition(#condition, __FILE__, __LINE__), 0)))
877 
878 #endif /* USE_ASSERT_CHECKING && !FRONTEND */
879 
880 /*
881  * Check that `ptr' is `bndr' aligned.
882  */
883 #define AssertPointerAlignment(ptr, bndr) \
884  Assert(TYPEALIGN(bndr, (uintptr_t)(ptr)) == (uintptr_t)(ptr))
885 
886 /*
887  * ExceptionalCondition is compiled into the backend whether or not
888  * USE_ASSERT_CHECKING is defined, so as to support use of extensions
889  * that are built with that #define with a backend that isn't. Hence,
890  * we should declare it as long as !FRONTEND.
891  */
892 #ifndef FRONTEND
893 extern void ExceptionalCondition(const char *conditionName,
894  const char *fileName, int lineNumber) pg_attribute_noreturn();
895 #endif
896 
897 /*
898  * Macros to support compile-time assertion checks.
899  *
900  * If the "condition" (a compile-time-constant expression) evaluates to false,
901  * throw a compile error using the "errmessage" (a string literal).
902  *
903  * C11 has _Static_assert(), and most C99 compilers already support that. For
904  * portability, we wrap it into StaticAssertDecl(). _Static_assert() is a
905  * "declaration", and so it must be placed where for example a variable
906  * declaration would be valid. As long as we compile with
907  * -Wno-declaration-after-statement, that also means it cannot be placed after
908  * statements in a function. Macros StaticAssertStmt() and StaticAssertExpr()
909  * make it safe to use as a statement or in an expression, respectively.
910  *
911  * For compilers without _Static_assert(), we fall back on a kluge that
912  * assumes the compiler will complain about a negative width for a struct
913  * bit-field. This will not include a helpful error message, but it beats not
914  * getting an error at all.
915  */
916 #ifndef __cplusplus
917 #ifdef HAVE__STATIC_ASSERT
918 #define StaticAssertDecl(condition, errmessage) \
919  _Static_assert(condition, errmessage)
920 #define StaticAssertStmt(condition, errmessage) \
921  do { _Static_assert(condition, errmessage); } while(0)
922 #define StaticAssertExpr(condition, errmessage) \
923  ((void) ({ StaticAssertStmt(condition, errmessage); true; }))
924 #else /* !HAVE__STATIC_ASSERT */
925 #define StaticAssertDecl(condition, errmessage) \
926  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
927 #define StaticAssertStmt(condition, errmessage) \
928  ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
929 #define StaticAssertExpr(condition, errmessage) \
930  StaticAssertStmt(condition, errmessage)
931 #endif /* HAVE__STATIC_ASSERT */
932 #else /* C++ */
933 #if defined(__cpp_static_assert) && __cpp_static_assert >= 200410
934 #define StaticAssertDecl(condition, errmessage) \
935  static_assert(condition, errmessage)
936 #define StaticAssertStmt(condition, errmessage) \
937  static_assert(condition, errmessage)
938 #define StaticAssertExpr(condition, errmessage) \
939  ({ static_assert(condition, errmessage); })
940 #else /* !__cpp_static_assert */
941 #define StaticAssertDecl(condition, errmessage) \
942  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
943 #define StaticAssertStmt(condition, errmessage) \
944  do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0)
945 #define StaticAssertExpr(condition, errmessage) \
946  ((void) ({ StaticAssertStmt(condition, errmessage); }))
947 #endif /* __cpp_static_assert */
948 #endif /* C++ */
949 
950 
951 /*
952  * Compile-time checks that a variable (or expression) has the specified type.
953  *
954  * AssertVariableIsOfType() can be used as a statement.
955  * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
956  * #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
957  *
958  * If we don't have __builtin_types_compatible_p, we can still assert that
959  * the types have the same size. This is far from ideal (especially on 32-bit
960  * platforms) but it provides at least some coverage.
961  */
962 #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
963 #define AssertVariableIsOfType(varname, typename) \
964  StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
965  CppAsString(varname) " does not have type " CppAsString(typename))
966 #define AssertVariableIsOfTypeMacro(varname, typename) \
967  (StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
968  CppAsString(varname) " does not have type " CppAsString(typename)))
969 #else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
970 #define AssertVariableIsOfType(varname, typename) \
971  StaticAssertStmt(sizeof(varname) == sizeof(typename), \
972  CppAsString(varname) " does not have type " CppAsString(typename))
973 #define AssertVariableIsOfTypeMacro(varname, typename) \
974  (StaticAssertExpr(sizeof(varname) == sizeof(typename), \
975  CppAsString(varname) " does not have type " CppAsString(typename)))
976 #endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
977 
978 
979 /* ----------------------------------------------------------------
980  * Section 7: widely useful macros
981  * ----------------------------------------------------------------
982  */
983 /*
984  * Max
985  * Return the maximum of two numbers.
986  */
987 #define Max(x, y) ((x) > (y) ? (x) : (y))
988 
989 /*
990  * Min
991  * Return the minimum of two numbers.
992  */
993 #define Min(x, y) ((x) < (y) ? (x) : (y))
994 
995 
996 /* Get a bit mask of the bits set in non-long aligned addresses */
997 #define LONG_ALIGN_MASK (sizeof(long) - 1)
998 
999 /*
1000  * MemSet
1001  * Exactly the same as standard library function memset(), but considerably
1002  * faster for zeroing small word-aligned structures (such as parsetree nodes).
1003  * This has to be a macro because the main point is to avoid function-call
1004  * overhead. However, we have also found that the loop is faster than
1005  * native libc memset() on some platforms, even those with assembler
1006  * memset() functions. More research needs to be done, perhaps with
1007  * MEMSET_LOOP_LIMIT tests in configure.
1008  */
1009 #define MemSet(start, val, len) \
1010  do \
1011  { \
1012  /* must be void* because we don't know if it is integer aligned yet */ \
1013  void *_vstart = (void *) (start); \
1014  int _val = (val); \
1015  Size _len = (len); \
1016 \
1017  if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
1018  (_len & LONG_ALIGN_MASK) == 0 && \
1019  _val == 0 && \
1020  _len <= MEMSET_LOOP_LIMIT && \
1021  /* \
1022  * If MEMSET_LOOP_LIMIT == 0, optimizer should find \
1023  * the whole "if" false at compile time. \
1024  */ \
1025  MEMSET_LOOP_LIMIT != 0) \
1026  { \
1027  long *_start = (long *) _vstart; \
1028  long *_stop = (long *) ((char *) _start + _len); \
1029  while (_start < _stop) \
1030  *_start++ = 0; \
1031  } \
1032  else \
1033  memset(_vstart, _val, _len); \
1034  } while (0)
1035 
1036 /*
1037  * MemSetAligned is the same as MemSet except it omits the test to see if
1038  * "start" is word-aligned. This is okay to use if the caller knows a-priori
1039  * that the pointer is suitably aligned (typically, because he just got it
1040  * from palloc(), which always delivers a max-aligned pointer).
1041  */
1042 #define MemSetAligned(start, val, len) \
1043  do \
1044  { \
1045  long *_start = (long *) (start); \
1046  int _val = (val); \
1047  Size _len = (len); \
1048 \
1049  if ((_len & LONG_ALIGN_MASK) == 0 && \
1050  _val == 0 && \
1051  _len <= MEMSET_LOOP_LIMIT && \
1052  MEMSET_LOOP_LIMIT != 0) \
1053  { \
1054  long *_stop = (long *) ((char *) _start + _len); \
1055  while (_start < _stop) \
1056  *_start++ = 0; \
1057  } \
1058  else \
1059  memset(_start, _val, _len); \
1060  } while (0)
1061 
1062 
1063 /*
1064  * Macros for range-checking float values before converting to integer.
1065  * We must be careful here that the boundary values are expressed exactly
1066  * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will
1067  * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded
1068  * off, so avoid using that.
1069  * The input must be rounded to an integer beforehand, typically with rint(),
1070  * else we might draw the wrong conclusion about close-to-the-limit values.
1071  * These macros will do the right thing for Inf, but not necessarily for NaN,
1072  * so check isnan(num) first if that's a possibility.
1073  */
1074 #define FLOAT4_FITS_IN_INT16(num) \
1075  ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN))
1076 #define FLOAT4_FITS_IN_INT32(num) \
1077  ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN))
1078 #define FLOAT4_FITS_IN_INT64(num) \
1079  ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN))
1080 #define FLOAT8_FITS_IN_INT16(num) \
1081  ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN))
1082 #define FLOAT8_FITS_IN_INT32(num) \
1083  ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN))
1084 #define FLOAT8_FITS_IN_INT64(num) \
1085  ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN))
1086 
1087 
1088 /* ----------------------------------------------------------------
1089  * Section 8: random stuff
1090  * ----------------------------------------------------------------
1091  */
1092 
1093 /*
1094  * Invert the sign of a qsort-style comparison result, ie, exchange negative
1095  * and positive integer values, being careful not to get the wrong answer
1096  * for INT_MIN. The argument should be an integral variable.
1097  */
1098 #define INVERT_COMPARE_RESULT(var) \
1099  ((var) = ((var) < 0) ? 1 : -(var))
1100 
1101 /*
1102  * Use this, not "char buf[BLCKSZ]", to declare a field or local variable
1103  * holding a page buffer, if that page might be accessed as a page. Otherwise
1104  * the variable might be under-aligned, causing problems on alignment-picky
1105  * hardware. We include both "double" and "int64" in the union to ensure that
1106  * the compiler knows the value must be MAXALIGN'ed (cf. configure's
1107  * computation of MAXIMUM_ALIGNOF).
1108  */
1109 typedef union PGAlignedBlock
1111  char data[BLCKSZ];
1112  double force_align_d;
1113  int64 force_align_i64;
1114 } PGAlignedBlock;
1115 
1116 /*
1117  * Use this to declare a field or local variable holding a page buffer, if that
1118  * page might be accessed as a page or passed to an SMgr I/O function. If
1119  * allocating using the MemoryContext API, the aligned allocation functions
1120  * should be used with PG_IO_ALIGN_SIZE. This alignment may be more efficient
1121  * for I/O in general, but may be strictly required on some platforms when
1122  * using direct I/O.
1123  */
1124 typedef union PGIOAlignedBlock
1125 {
1126 #ifdef pg_attribute_aligned
1127  pg_attribute_aligned(PG_IO_ALIGN_SIZE)
1128 #endif
1129  char data[BLCKSZ];
1130  double force_align_d;
1131  int64 force_align_i64;
1133 
1134 /* Same, but for an XLOG_BLCKSZ-sized buffer */
1135 typedef union PGAlignedXLogBlock
1136 {
1137 #ifdef pg_attribute_aligned
1138  pg_attribute_aligned(PG_IO_ALIGN_SIZE)
1139 #endif
1140  char data[XLOG_BLCKSZ];
1141  double force_align_d;
1142  int64 force_align_i64;
1145 /* msb for char */
1146 #define HIGHBIT (0x80)
1147 #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
1148 
1149 /*
1150  * Support macros for escaping strings. escape_backslash should be true
1151  * if generating a non-standard-conforming string. Prefixing a string
1152  * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
1153  * Beware of multiple evaluation of the "ch" argument!
1154  */
1155 #define SQL_STR_DOUBLE(ch, escape_backslash) \
1156  ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
1157 
1158 #define ESCAPE_STRING_SYNTAX 'E'
1161 #define STATUS_OK (0)
1162 #define STATUS_ERROR (-1)
1163 #define STATUS_EOF (-2)
1164 
1165 /*
1166  * gettext support
1167  */
1169 #ifndef ENABLE_NLS
1170 /* stuff we'd otherwise get from <libintl.h> */
1171 #define gettext(x) (x)
1172 #define dgettext(d,x) (x)
1173 #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
1174 #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
1175 #endif
1176 
1177 #define _(x) gettext(x)
1178 
1179 /*
1180  * Use this to mark string constants as needing translation at some later
1181  * time, rather than immediately. This is useful for cases where you need
1182  * access to the original string and translated string, and for cases where
1183  * immediate translation is not possible, like when initializing global
1184  * variables.
1185  *
1186  * https://www.gnu.org/software/gettext/manual/html_node/Special-cases.html
1187  */
1188 #define gettext_noop(x) (x)
1189 
1190 /*
1191  * To better support parallel installations of major PostgreSQL
1192  * versions as well as parallel installations of major library soname
1193  * versions, we mangle the gettext domain name by appending those
1194  * version numbers. The coding rule ought to be that wherever the
1195  * domain name is mentioned as a literal, it must be wrapped into
1196  * PG_TEXTDOMAIN(). The macros below do not work on non-literals; but
1197  * that is somewhat intentional because it avoids having to worry
1198  * about multiple states of premangling and postmangling as the values
1199  * are being passed around.
1200  *
1201  * Make sure this matches the installation rules in nls-global.mk.
1202  */
1203 #ifdef SO_MAJOR_VERSION
1204 #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
1205 #else
1206 #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
1207 #endif
1208 
1209 /*
1210  * Macro that allows to cast constness and volatile away from an expression, but doesn't
1211  * allow changing the underlying type. Enforcement of the latter
1212  * currently only works for gcc like compilers.
1213  *
1214  * Please note IT IS NOT SAFE to cast constness away if the result will ever
1215  * be modified (it would be undefined behaviour). Doing so anyway can cause
1216  * compiler misoptimizations or runtime crashes (modifying readonly memory).
1217  * It is only safe to use when the result will not be modified, but API
1218  * design or language restrictions prevent you from declaring that
1219  * (e.g. because a function returns both const and non-const variables).
1220  *
1221  * Note that this only works in function scope, not for global variables (it'd
1222  * be nice, but not trivial, to improve that).
1223  */
1224 #if defined(__cplusplus)
1225 #define unconstify(underlying_type, expr) const_cast<underlying_type>(expr)
1226 #define unvolatize(underlying_type, expr) const_cast<underlying_type>(expr)
1227 #elif defined(HAVE__BUILTIN_TYPES_COMPATIBLE_P)
1228 #define unconstify(underlying_type, expr) \
1229  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), const underlying_type), \
1230  "wrong cast"), \
1231  (underlying_type) (expr))
1232 #define unvolatize(underlying_type, expr) \
1233  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), volatile underlying_type), \
1234  "wrong cast"), \
1235  (underlying_type) (expr))
1236 #else
1237 #define unconstify(underlying_type, expr) \
1238  ((underlying_type) (expr))
1239 #define unvolatize(underlying_type, expr) \
1240  ((underlying_type) (expr))
1241 #endif
1242 
1243 /* ----------------------------------------------------------------
1244  * Section 9: system-specific hacks
1245  *
1246  * This should be limited to things that absolutely have to be
1247  * included in every source file. The port-specific header file
1248  * is usually a better place for this sort of thing.
1249  * ----------------------------------------------------------------
1250  */
1251 
1252 /*
1253  * NOTE: this is also used for opening text files.
1254  * WIN32 treats Control-Z as EOF in files opened in text mode.
1255  * Therefore, we open files in binary mode on Win32 so we can read
1256  * literal control-Z. The other affect is that we see CRLF, but
1257  * that is OK because we can already handle those cleanly.
1258  */
1259 #if defined(WIN32) || defined(__CYGWIN__)
1260 #define PG_BINARY O_BINARY
1261 #define PG_BINARY_A "ab"
1262 #define PG_BINARY_R "rb"
1263 #define PG_BINARY_W "wb"
1264 #else
1265 #define PG_BINARY 0
1266 #define PG_BINARY_A "a"
1267 #define PG_BINARY_R "r"
1268 #define PG_BINARY_W "w"
1269 #endif
1270 
1271 /*
1272  * Provide prototypes for routines not present in a particular machine's
1273  * standard C library.
1274  */
1275 
1276 #if !HAVE_DECL_FDATASYNC
1277 extern int fdatasync(int fildes);
1278 #endif
1279 
1280 /*
1281  * Thin wrappers that convert strings to exactly 64-bit integers, matching our
1282  * definition of int64. (For the naming, compare that POSIX has
1283  * strtoimax()/strtoumax() which return intmax_t/uintmax_t.)
1284  */
1285 #ifdef HAVE_LONG_INT_64
1286 #define strtoi64(str, endptr, base) ((int64) strtol(str, endptr, base))
1287 #define strtou64(str, endptr, base) ((uint64) strtoul(str, endptr, base))
1288 #else
1289 #define strtoi64(str, endptr, base) ((int64) strtoll(str, endptr, base))
1290 #define strtou64(str, endptr, base) ((uint64) strtoull(str, endptr, base))
1291 #endif
1292 
1293 /*
1294  * Similarly, wrappers around labs()/llabs() matching our int64.
1295  */
1296 #ifdef HAVE_LONG_INT_64
1297 #define i64abs(i) labs(i)
1298 #else
1299 #define i64abs(i) llabs(i)
1300 #endif
1301 
1302 /*
1303  * Use "extern PGDLLIMPORT ..." to declare variables that are defined
1304  * in the core backend and need to be accessible by loadable modules.
1305  * No special marking is required on most ports.
1306  */
1307 #ifndef PGDLLIMPORT
1308 #define PGDLLIMPORT
1309 #endif
1310 
1311 /*
1312  * Use "extern PGDLLEXPORT ..." to declare functions that are defined in
1313  * loadable modules and need to be callable by the core backend or other
1314  * loadable modules.
1315  * If the compiler knows __attribute__((visibility("*"))), we use that,
1316  * unless we already have a platform-specific definition. Otherwise,
1317  * no special marking is required.
1318  */
1319 #ifndef PGDLLEXPORT
1320 #ifdef HAVE_VISIBILITY_ATTRIBUTE
1321 #define PGDLLEXPORT __attribute__((visibility("default")))
1322 #else
1323 #define PGDLLEXPORT
1324 #endif
1325 #endif
1326 
1327 /*
1328  * The following is used as the arg list for signal handlers. Any ports
1329  * that take something other than an int argument should override this in
1330  * their pg_config_os.h file. Note that variable names are required
1331  * because it is used in both the prototypes as well as the definitions.
1332  * Note also the long name. We expect that this won't collide with
1333  * other names causing compiler warnings.
1334  */
1335 
1336 #ifndef SIGNAL_ARGS
1337 #define SIGNAL_ARGS int postgres_signal_arg
1338 #endif
1339 
1340 /*
1341  * When there is no sigsetjmp, its functionality is provided by plain
1342  * setjmp. We now support the case only on Windows. However, it seems
1343  * that MinGW-64 has some longstanding issues in its setjmp support,
1344  * so on that toolchain we cheat and use gcc's builtins.
1345  */
1346 #ifdef WIN32
1347 #ifdef __MINGW64__
1348 typedef intptr_t sigjmp_buf[5];
1349 #define sigsetjmp(x,y) __builtin_setjmp(x)
1350 #define siglongjmp __builtin_longjmp
1351 #else /* !__MINGW64__ */
1352 #define sigjmp_buf jmp_buf
1353 #define sigsetjmp(x,y) setjmp(x)
1354 #define siglongjmp longjmp
1355 #endif /* __MINGW64__ */
1356 #endif /* WIN32 */
1357 
1358 /* /port compatibility functions */
1359 #include "port.h"
1360 
1361 #endif /* C_H */
static Datum values[MAXATTR]
Definition: bootstrap.c:156
unsigned short uint16
Definition: c.h:494
unsigned int uint32
Definition: c.h:495
uint16 bits16
Definition: c.h:503
NameData * Name
Definition: c.h:733
signed char int8
Definition: c.h:481
union PGAlignedBlock PGAlignedBlock
signed short int16
Definition: c.h:482
union PGAlignedXLogBlock PGAlignedXLogBlock
uint32 SubTransactionId
Definition: c.h:645
signed int int32
Definition: c.h:483
char * Pointer
Definition: c.h:472
Oid regproc
Definition: c.h:638
uint32 MultiXactOffset
Definition: c.h:653
#define pg_attribute_noreturn()
Definition: c.h:206
double float8
Definition: c.h:619
TransactionId MultiXactId
Definition: c.h:651
#define FLEXIBLE_ARRAY_MEMBER
Definition: c.h:387
unsigned char bool
Definition: c.h:445
regproc RegProcedure
Definition: c.h:639
uint8 bits8
Definition: c.h:502
uint32 bits32
Definition: c.h:504
unsigned int Index
Definition: c.h:603
float float4
Definition: c.h:618
uint32 LocalTransactionId
Definition: c.h:643
unsigned char uint8
Definition: c.h:493
union PGIOAlignedBlock PGIOAlignedBlock
uint32 CommandId
Definition: c.h:655
uint32 TransactionId
Definition: c.h:641
signed int Offset
Definition: c.h:613
int fdatasync(int fildes)
void ExceptionalCondition(const char *conditionName, const char *fileName, int lineNumber) pg_attribute_noreturn()
Definition: assert.c:30
void(* pg_funcptr_t)(void)
Definition: c.h:377
size_t Size
Definition: c.h:594
struct nameData NameData
#define NAMEDATALEN
#define PG_IO_ALIGN_SIZE
unsigned int Oid
Definition: postgres_ext.h:31
Definition: c.h:704
int32 vl_len_
Definition: c.h:705
int ndim
Definition: c.h:706
int dim1
Definition: c.h:709
Oid elemtype
Definition: c.h:708
int32 dataoffset
Definition: c.h:707
int lbound1
Definition: c.h:710
Definition: c.h:730
char data[NAMEDATALEN]
Definition: c.h:731
Definition: c.h:715
int dim1
Definition: c.h:720
int32 dataoffset
Definition: c.h:718
Oid elemtype
Definition: c.h:719
int lbound1
Definition: c.h:721
int ndim
Definition: c.h:717
int32 vl_len_
Definition: c.h:716
Definition: c.h:676
char vl_len_[4]
Definition: c.h:677
char vl_dat[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:678
double force_align_d
Definition: c.h:1109
int64 force_align_i64
Definition: c.h:1110
char data[BLCKSZ]
Definition: c.h:1108
char data[XLOG_BLCKSZ]
Definition: c.h:1137
double force_align_d
Definition: c.h:1138
int64 force_align_i64
Definition: c.h:1139
double force_align_d
Definition: c.h:1127
int64 force_align_i64
Definition: c.h:1128
char data[BLCKSZ]
Definition: c.h:1126