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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  */
109 
110 /*
111  * For compilers which don't support __has_attribute, we just define
112  * __has_attribute(x) to 0 so that we can define macros for various
113  * __attribute__s more easily below.
114  */
115 #ifndef __has_attribute
116 #define __has_attribute(attribute) 0
117 #endif
118 
119 /* only GCC supports the unused attribute */
120 #ifdef __GNUC__
121 #define pg_attribute_unused() __attribute__((unused))
122 #else
123 #define pg_attribute_unused()
124 #endif
125 
126 /*
127  * pg_nodiscard means the compiler should warn if the result of a function
128  * call is ignored. The name "nodiscard" is chosen in alignment with
129  * (possibly future) C and C++ standards. For maximum compatibility, use it
130  * as a function declaration specifier, so it goes before the return type.
131  */
132 #ifdef __GNUC__
133 #define pg_nodiscard __attribute__((warn_unused_result))
134 #else
135 #define pg_nodiscard
136 #endif
137 
138 /*
139  * Place this macro before functions that should be allowed to make misaligned
140  * accesses. Think twice before using it on non-x86-specific code!
141  * Testing can be done with "-fsanitize=alignment -fsanitize-trap=alignment"
142  * on clang, or "-fsanitize=alignment -fno-sanitize-recover=alignment" on gcc.
143  */
144 #if __clang_major__ >= 7 || __GNUC__ >= 8
145 #define pg_attribute_no_sanitize_alignment() __attribute__((no_sanitize("alignment")))
146 #else
147 #define pg_attribute_no_sanitize_alignment()
148 #endif
149 
150 /*
151  * pg_attribute_nonnull means the compiler should warn if the function is
152  * called with the listed arguments set to NULL. If no arguments are
153  * listed, the compiler should warn if any pointer arguments are set to NULL.
154  */
155 #if __has_attribute (nonnull)
156 #define pg_attribute_nonnull(...) __attribute__((nonnull(__VA_ARGS__)))
157 #else
158 #define pg_attribute_nonnull(...)
159 #endif
160 
161 /*
162  * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
163  * used in assert-enabled builds, to avoid compiler warnings about unused
164  * variables in assert-disabled builds.
165  */
166 #ifdef USE_ASSERT_CHECKING
167 #define PG_USED_FOR_ASSERTS_ONLY
168 #else
169 #define PG_USED_FOR_ASSERTS_ONLY pg_attribute_unused()
170 #endif
171 
172 /* GCC supports format attributes */
173 #if defined(__GNUC__)
174 #define pg_attribute_format_arg(a) __attribute__((format_arg(a)))
175 #define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
176 #else
177 #define pg_attribute_format_arg(a)
178 #define pg_attribute_printf(f,a)
179 #endif
180 
181 /* GCC and Sunpro support aligned, packed and noreturn */
182 #if defined(__GNUC__) || defined(__SUNPRO_C)
183 #define pg_attribute_aligned(a) __attribute__((aligned(a)))
184 #define pg_attribute_noreturn() __attribute__((noreturn))
185 #define pg_attribute_packed() __attribute__((packed))
186 #define HAVE_PG_ATTRIBUTE_NORETURN 1
187 #elif defined(_MSC_VER)
188 /*
189  * MSVC supports aligned. noreturn is also possible but in MSVC it is
190  * declared before the definition while pg_attribute_noreturn() macro
191  * is currently used after the definition.
192  *
193  * Packing is also possible but only by wrapping the entire struct definition
194  * which doesn't fit into our current macro declarations.
195  */
196 #define pg_attribute_aligned(a) __declspec(align(a))
197 #define pg_attribute_noreturn()
198 #else
199 /*
200  * NB: aligned and packed are not given default definitions because they
201  * affect code functionality; they *must* be implemented by the compiler
202  * if they are to be used.
203  */
204 #define pg_attribute_noreturn()
205 #endif
206 
207 /*
208  * Use "pg_attribute_always_inline" in place of "inline" for functions that
209  * we wish to force inlining of, even when the compiler's heuristics would
210  * choose not to. But, if possible, don't force inlining in unoptimized
211  * debug builds.
212  */
213 #if (defined(__GNUC__) && __GNUC__ > 3 && defined(__OPTIMIZE__)) || defined(__SUNPRO_C)
214 /* GCC > 3 and Sunpro support always_inline via __attribute__ */
215 #define pg_attribute_always_inline __attribute__((always_inline)) inline
216 #elif defined(_MSC_VER)
217 /* MSVC has a special keyword for this */
218 #define pg_attribute_always_inline __forceinline
219 #else
220 /* Otherwise, the best we can do is to say "inline" */
221 #define pg_attribute_always_inline inline
222 #endif
223 
224 /*
225  * Forcing a function not to be inlined can be useful if it's the slow path of
226  * a performance-critical function, or should be visible in profiles to allow
227  * for proper cost attribution. Note that unlike the pg_attribute_XXX macros
228  * above, this should be placed before the function's return type and name.
229  */
230 /* GCC and Sunpro support noinline via __attribute__ */
231 #if (defined(__GNUC__) && __GNUC__ > 2) || defined(__SUNPRO_C)
232 #define pg_noinline __attribute__((noinline))
233 /* msvc via declspec */
234 #elif defined(_MSC_VER)
235 #define pg_noinline __declspec(noinline)
236 #else
237 #define pg_noinline
238 #endif
239 
240 /*
241  * For now, just define pg_attribute_cold and pg_attribute_hot to be empty
242  * macros on minGW 8.1. There appears to be a compiler bug that results in
243  * compilation failure. At this time, we still have at least one buildfarm
244  * animal running that compiler, so this should make that green again. It's
245  * likely this compiler is not popular enough to warrant keeping this code
246  * around forever, so let's just remove it once the last buildfarm animal
247  * upgrades.
248  */
249 #if defined(__MINGW64__) && __GNUC__ == 8 && __GNUC_MINOR__ == 1
250 
251 #define pg_attribute_cold
252 #define pg_attribute_hot
253 
254 #else
255 /*
256  * Marking certain functions as "hot" or "cold" can be useful to assist the
257  * compiler in arranging the assembly code in a more efficient way.
258  */
259 #if __has_attribute (cold)
260 #define pg_attribute_cold __attribute__((cold))
261 #else
262 #define pg_attribute_cold
263 #endif
264 
265 #if __has_attribute (hot)
266 #define pg_attribute_hot __attribute__((hot))
267 #else
268 #define pg_attribute_hot
269 #endif
270 
271 #endif /* defined(__MINGW64__) && __GNUC__ == 8 &&
272  * __GNUC_MINOR__ == 1 */
273 /*
274  * Mark a point as unreachable in a portable fashion. This should preferably
275  * be something that the compiler understands, to aid code generation.
276  * In assert-enabled builds, we prefer abort() for debugging reasons.
277  */
278 #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
279 #define pg_unreachable() __builtin_unreachable()
280 #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
281 #define pg_unreachable() __assume(0)
282 #else
283 #define pg_unreachable() abort()
284 #endif
285 
286 /*
287  * Hints to the compiler about the likelihood of a branch. Both likely() and
288  * unlikely() return the boolean value of the contained expression.
289  *
290  * These should only be used sparingly, in very hot code paths. It's very easy
291  * to mis-estimate likelihoods.
292  */
293 #if __GNUC__ >= 3
294 #define likely(x) __builtin_expect((x) != 0, 1)
295 #define unlikely(x) __builtin_expect((x) != 0, 0)
296 #else
297 #define likely(x) ((x) != 0)
298 #define unlikely(x) ((x) != 0)
299 #endif
300 
301 /*
302  * CppAsString
303  * Convert the argument to a string, using the C preprocessor.
304  * CppAsString2
305  * Convert the argument to a string, after one round of macro expansion.
306  * CppConcat
307  * Concatenate two arguments together, using the C preprocessor.
308  *
309  * Note: There used to be support here for pre-ANSI C compilers that didn't
310  * support # and ##. Nowadays, these macros are just for clarity and/or
311  * backward compatibility with existing PostgreSQL code.
312  */
313 #define CppAsString(identifier) #identifier
314 #define CppAsString2(x) CppAsString(x)
315 #define CppConcat(x, y) x##y
316 
317 /*
318  * VA_ARGS_NARGS
319  * Returns the number of macro arguments it is passed.
320  *
321  * An empty argument still counts as an argument, so effectively, this is
322  * "one more than the number of commas in the argument list".
323  *
324  * This works for up to 63 arguments. Internally, VA_ARGS_NARGS_() is passed
325  * 64+N arguments, and the C99 standard only requires macros to allow up to
326  * 127 arguments, so we can't portably go higher. The implementation is
327  * pretty trivial: VA_ARGS_NARGS_() returns its 64th argument, and we set up
328  * the call so that that is the appropriate one of the list of constants.
329  * This idea is due to Laurent Deniau.
330  *
331  * MSVC has an implementation of __VA_ARGS__ that doesn't conform to the
332  * standard unless you use the /Zc:preprocessor compiler flag, but that
333  * isn't available before Visual Studio 2019. For now, use a different
334  * definition that also works on older compilers.
335  */
336 #ifdef _MSC_VER
337 #define EXPAND(args) args
338 #define VA_ARGS_NARGS(...) \
339  VA_ARGS_NARGS_ EXPAND((__VA_ARGS__, \
340  63,62,61,60, \
341  59,58,57,56,55,54,53,52,51,50, \
342  49,48,47,46,45,44,43,42,41,40, \
343  39,38,37,36,35,34,33,32,31,30, \
344  29,28,27,26,25,24,23,22,21,20, \
345  19,18,17,16,15,14,13,12,11,10, \
346  9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
347 #else
348 
349 #define VA_ARGS_NARGS(...) \
350  VA_ARGS_NARGS_(__VA_ARGS__, \
351  63,62,61,60, \
352  59,58,57,56,55,54,53,52,51,50, \
353  49,48,47,46,45,44,43,42,41,40, \
354  39,38,37,36,35,34,33,32,31,30, \
355  29,28,27,26,25,24,23,22,21,20, \
356  19,18,17,16,15,14,13,12,11,10, \
357  9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
358 #endif
359 
360 #define VA_ARGS_NARGS_( \
361  _01,_02,_03,_04,_05,_06,_07,_08,_09,_10, \
362  _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \
363  _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \
364  _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \
365  _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \
366  _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \
367  _61,_62,_63, N, ...) \
368  (N)
369 
370 /*
371  * Generic function pointer. This can be used in the rare cases where it's
372  * necessary to cast a function pointer to a seemingly incompatible function
373  * pointer type while avoiding gcc's -Wcast-function-type warnings.
374  */
375 typedef void (*pg_funcptr_t) (void);
376 
377 /*
378  * We require C99, hence the compiler should understand flexible array
379  * members. However, for documentation purposes we still consider it to be
380  * project style to write "field[FLEXIBLE_ARRAY_MEMBER]" not just "field[]".
381  * When computing the size of such an object, use "offsetof(struct s, f)"
382  * for portability. Don't use "offsetof(struct s, f[0])", as this doesn't
383  * work with MSVC and with C++ compilers.
384  */
385 #define FLEXIBLE_ARRAY_MEMBER /* empty */
386 
387 /*
388  * Does the compiler support #pragma GCC system_header? We optionally use it
389  * to avoid warnings that we can't fix (e.g. in the perl headers).
390  * See https://gcc.gnu.org/onlinedocs/cpp/System-Headers.html
391  *
392  * Headers for which we do not want to show compiler warnings can,
393  * conditionally, use #pragma GCC system_header to avoid warnings. Obviously
394  * this should only be used for external headers over which we do not have
395  * control.
396  *
397  * Support for the pragma is tested here, instead of during configure, as gcc
398  * also warns about the pragma being used in a .c file. It's surprisingly hard
399  * to get autoconf to use .h as the file-ending. Looks like gcc has
400  * implemented the pragma since the 2000, so this test should suffice.
401  *
402  *
403  * Alternatively, we could add the include paths for problematic headers with
404  * -isystem, but that is a larger hammer and is harder to search for.
405  *
406  * A more granular alternative would be to use #pragma GCC diagnostic
407  * push/ignored/pop, but gcc warns about unknown warnings being ignored, so
408  * every to-be-ignored-temporarily compiler warning would require its own
409  * pg_config.h symbol and #ifdef.
410  */
411 #ifdef __GNUC__
412 #define HAVE_PRAGMA_GCC_SYSTEM_HEADER 1
413 #endif
414 
415 
416 /* ----------------------------------------------------------------
417  * Section 2: bool, true, false
418  * ----------------------------------------------------------------
419  */
420 
421 /*
422  * bool
423  * Boolean value, either true or false.
424  *
425  * We use stdbool.h if available and its bool has size 1. That's useful for
426  * better compiler and debugger output and for compatibility with third-party
427  * libraries. But PostgreSQL currently cannot deal with bool of other sizes;
428  * there are static assertions around the code to prevent that.
429  *
430  * For C++ compilers, we assume the compiler has a compatible built-in
431  * definition of bool.
432  *
433  * See also the version of this code in src/interfaces/ecpg/include/ecpglib.h.
434  */
435 
436 #ifndef __cplusplus
437 
438 #ifdef PG_USE_STDBOOL
439 #include <stdbool.h>
440 #else
441 
442 #ifndef bool
443 typedef unsigned char bool;
444 #endif
445 
446 #ifndef true
447 #define true ((bool) 1)
448 #endif
449 
450 #ifndef false
451 #define false ((bool) 0)
452 #endif
453 
454 #endif /* not PG_USE_STDBOOL */
455 #endif /* not C++ */
456 
457 
458 /* ----------------------------------------------------------------
459  * Section 3: standard system types
460  * ----------------------------------------------------------------
461  */
462 
463 /*
464  * Pointer
465  * Variable holding address of any memory resident object.
466  *
467  * XXX Pointer arithmetic is done with this, so it can't be void *
468  * under "true" ANSI compilers.
469  */
470 typedef char *Pointer;
471 
472 /*
473  * intN
474  * Signed integer, EXACTLY N BITS IN SIZE,
475  * used for numerical computations and the
476  * frontend/backend protocol.
477  */
478 #ifndef HAVE_INT8
479 typedef signed char int8; /* == 8 bits */
480 typedef signed short int16; /* == 16 bits */
481 typedef signed int int32; /* == 32 bits */
482 #endif /* not HAVE_INT8 */
483 
484 /*
485  * uintN
486  * Unsigned integer, EXACTLY N BITS IN SIZE,
487  * used for numerical computations and the
488  * frontend/backend protocol.
489  */
490 #ifndef HAVE_UINT8
491 typedef unsigned char uint8; /* == 8 bits */
492 typedef unsigned short uint16; /* == 16 bits */
493 typedef unsigned int uint32; /* == 32 bits */
494 #endif /* not HAVE_UINT8 */
495 
496 /*
497  * bitsN
498  * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
499  */
500 typedef uint8 bits8; /* >= 8 bits */
501 typedef uint16 bits16; /* >= 16 bits */
502 typedef uint32 bits32; /* >= 32 bits */
503 
504 /*
505  * 64-bit integers
506  */
507 #ifdef HAVE_LONG_INT_64
508 /* Plain "long int" fits, use it */
509 
510 #ifndef HAVE_INT64
511 typedef long int int64;
512 #endif
513 #ifndef HAVE_UINT64
514 typedef unsigned long int uint64;
515 #endif
516 #define INT64CONST(x) (x##L)
517 #define UINT64CONST(x) (x##UL)
518 #elif defined(HAVE_LONG_LONG_INT_64)
519 /* We have working support for "long long int", use that */
520 
521 #ifndef HAVE_INT64
522 typedef long long int int64;
523 #endif
524 #ifndef HAVE_UINT64
525 typedef unsigned long long int uint64;
526 #endif
527 #define INT64CONST(x) (x##LL)
528 #define UINT64CONST(x) (x##ULL)
529 #else
530 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
531 #error must have a working 64-bit integer datatype
532 #endif
533 
534 /* snprintf format strings to use for 64-bit integers */
535 #define INT64_FORMAT "%" INT64_MODIFIER "d"
536 #define UINT64_FORMAT "%" INT64_MODIFIER "u"
537 
538 /*
539  * 128-bit signed and unsigned integers
540  * There currently is only limited support for such types.
541  * E.g. 128bit literals and snprintf are not supported; but math is.
542  * Also, because we exclude such types when choosing MAXIMUM_ALIGNOF,
543  * it must be possible to coerce the compiler to allocate them on no
544  * more than MAXALIGN boundaries.
545  */
546 #if defined(PG_INT128_TYPE)
547 #if defined(pg_attribute_aligned) || ALIGNOF_PG_INT128_TYPE <= MAXIMUM_ALIGNOF
548 #define HAVE_INT128 1
549 
550 typedef PG_INT128_TYPE int128
551 #if defined(pg_attribute_aligned)
552  pg_attribute_aligned(MAXIMUM_ALIGNOF)
553 #endif
554  ;
555 
556 typedef unsigned PG_INT128_TYPE uint128
557 #if defined(pg_attribute_aligned)
558  pg_attribute_aligned(MAXIMUM_ALIGNOF)
559 #endif
560  ;
561 
562 #endif
563 #endif
564 
565 /*
566  * stdint.h limits aren't guaranteed to have compatible types with our fixed
567  * width types. So just define our own.
568  */
569 #define PG_INT8_MIN (-0x7F-1)
570 #define PG_INT8_MAX (0x7F)
571 #define PG_UINT8_MAX (0xFF)
572 #define PG_INT16_MIN (-0x7FFF-1)
573 #define PG_INT16_MAX (0x7FFF)
574 #define PG_UINT16_MAX (0xFFFF)
575 #define PG_INT32_MIN (-0x7FFFFFFF-1)
576 #define PG_INT32_MAX (0x7FFFFFFF)
577 #define PG_UINT32_MAX (0xFFFFFFFFU)
578 #define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
579 #define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF)
580 #define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
581 
582 /*
583  * We now always use int64 timestamps, but keep this symbol defined for the
584  * benefit of external code that might test it.
585  */
586 #define HAVE_INT64_TIMESTAMP
587 
588 /*
589  * Size
590  * Size of any memory resident object, as returned by sizeof.
591  */
592 typedef size_t Size;
593 
594 /*
595  * Index
596  * Index into any memory resident array.
597  *
598  * Note:
599  * Indices are non negative.
600  */
601 typedef unsigned int Index;
602 
603 /*
604  * Offset
605  * Offset into any memory resident array.
606  *
607  * Note:
608  * This differs from an Index in that an Index is always
609  * non negative, whereas Offset may be negative.
610  */
611 typedef signed int Offset;
612 
613 /*
614  * Common Postgres datatype names (as used in the catalogs)
615  */
616 typedef float float4;
617 typedef double float8;
618 
619 #ifdef USE_FLOAT8_BYVAL
620 #define FLOAT8PASSBYVAL true
621 #else
622 #define FLOAT8PASSBYVAL false
623 #endif
624 
625 /*
626  * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
627  * CommandId
628  */
629 
630 /* typedef Oid is in postgres_ext.h */
631 
632 /*
633  * regproc is the type name used in the include/catalog headers, but
634  * RegProcedure is the preferred name in C code.
635  */
636 typedef Oid regproc;
638 
640 
642 
644 
645 #define InvalidSubTransactionId ((SubTransactionId) 0)
646 #define TopSubTransactionId ((SubTransactionId) 1)
647 
648 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
650 
652 
654 
655 #define FirstCommandId ((CommandId) 0)
656 #define InvalidCommandId (~(CommandId)0)
657 
658 
659 /* ----------------
660  * Variable-length datatypes all share the 'struct varlena' header.
661  *
662  * NOTE: for TOASTable types, this is an oversimplification, since the value
663  * may be compressed or moved out-of-line. However datatype-specific routines
664  * are mostly content to deal with de-TOASTed values only, and of course
665  * client-side routines should never see a TOASTed value. But even in a
666  * de-TOASTed value, beware of touching vl_len_ directly, as its
667  * representation is no longer convenient. It's recommended that code always
668  * use macros VARDATA_ANY, VARSIZE_ANY, VARSIZE_ANY_EXHDR, VARDATA, VARSIZE,
669  * and SET_VARSIZE instead of relying on direct mentions of the struct fields.
670  * See postgres.h for details of the TOASTed form.
671  * ----------------
672  */
673 struct varlena
674 {
675  char vl_len_[4]; /* Do not touch this field directly! */
676  char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */
677 };
678 
679 #define VARHDRSZ ((int32) sizeof(int32))
680 
681 /*
682  * These widely-used datatypes are just a varlena header and the data bytes.
683  * There is no terminating null or anything like that --- the data length is
684  * always VARSIZE_ANY_EXHDR(ptr).
685  */
686 typedef struct varlena bytea;
687 typedef struct varlena text;
688 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
689 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
690 
691 /*
692  * Specialized array types. These are physically laid out just the same
693  * as regular arrays (so that the regular array subscripting code works
694  * with them). They exist as distinct types mostly for historical reasons:
695  * they have nonstandard I/O behavior which we don't want to change for fear
696  * of breaking applications that look at the system catalogs. There is also
697  * an implementation issue for oidvector: it's part of the primary key for
698  * pg_proc, and we can't use the normal btree array support routines for that
699  * without circularity.
700  */
701 typedef struct
702 {
703  int32 vl_len_; /* these fields must match ArrayType! */
704  int ndim; /* always 1 for int2vector */
705  int32 dataoffset; /* always 0 for int2vector */
707  int dim1;
708  int lbound1;
710 } int2vector;
711 
712 typedef struct
713 {
714  int32 vl_len_; /* these fields must match ArrayType! */
715  int ndim; /* always 1 for oidvector */
716  int32 dataoffset; /* always 0 for oidvector */
718  int dim1;
719  int lbound1;
721 } oidvector;
722 
723 /*
724  * Representation of a Name: effectively just a C string, but null-padded to
725  * exactly NAMEDATALEN bytes. The use of a struct is historical.
726  */
727 typedef struct nameData
728 {
731 typedef NameData *Name;
732 
733 #define NameStr(name) ((name).data)
734 
735 
736 /* ----------------------------------------------------------------
737  * Section 4: IsValid macros for system types
738  * ----------------------------------------------------------------
739  */
740 /*
741  * BoolIsValid
742  * True iff bool is valid.
743  */
744 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
745 
746 /*
747  * PointerIsValid
748  * True iff pointer is valid.
749  */
750 #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
751 
752 /*
753  * PointerIsAligned
754  * True iff pointer is properly aligned to point to the given type.
755  */
756 #define PointerIsAligned(pointer, type) \
757  (((uintptr_t)(pointer) % (sizeof (type))) == 0)
758 
759 #define OffsetToPointer(base, offset) \
760  ((void *)((char *) base + offset))
761 
762 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
763 
764 #define RegProcedureIsValid(p) OidIsValid(p)
765 
766 
767 /* ----------------------------------------------------------------
768  * Section 5: lengthof, alignment
769  * ----------------------------------------------------------------
770  */
771 /*
772  * lengthof
773  * Number of elements in an array.
774  */
775 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
776 
777 /* ----------------
778  * Alignment macros: align a length or address appropriately for a given type.
779  * The fooALIGN() macros round up to a multiple of the required alignment,
780  * while the fooALIGN_DOWN() macros round down. The latter are more useful
781  * for problems like "how many X-sized structures will fit in a page?".
782  *
783  * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
784  * That case seems extremely unlikely to be needed in practice, however.
785  *
786  * NOTE: MAXIMUM_ALIGNOF, and hence MAXALIGN(), intentionally exclude any
787  * larger-than-8-byte types the compiler might have.
788  * ----------------
789  */
790 
791 #define TYPEALIGN(ALIGNVAL,LEN) \
792  (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
793 
794 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
795 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
796 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
797 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
798 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
799 /* MAXALIGN covers only built-in types, not buffers */
800 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
801 #define CACHELINEALIGN(LEN) TYPEALIGN(PG_CACHE_LINE_SIZE, (LEN))
802 
803 #define TYPEALIGN_DOWN(ALIGNVAL,LEN) \
804  (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
805 
806 #define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
807 #define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
808 #define LONGALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
809 #define DOUBLEALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
810 #define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
811 #define BUFFERALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_BUFFER, (LEN))
812 
813 /*
814  * The above macros will not work with types wider than uintptr_t, like with
815  * uint64 on 32-bit platforms. That's not problem for the usual use where a
816  * pointer or a length is aligned, but for the odd case that you need to
817  * align something (potentially) wider, use TYPEALIGN64.
818  */
819 #define TYPEALIGN64(ALIGNVAL,LEN) \
820  (((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1)))
821 
822 /* we don't currently need wider versions of the other ALIGN macros */
823 #define MAXALIGN64(LEN) TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN))
824 
825 
826 /* ----------------------------------------------------------------
827  * Section 6: assertions
828  * ----------------------------------------------------------------
829  */
830 
831 /*
832  * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
833  * - plai 9/5/90
834  *
835  * It should _NOT_ be defined in releases or in benchmark copies
836  */
837 
838 /*
839  * Assert() can be used in both frontend and backend code. In frontend code it
840  * just calls the standard assert, if it's available. If use of assertions is
841  * not configured, it does nothing.
842  */
843 #ifndef USE_ASSERT_CHECKING
844 
845 #define Assert(condition) ((void)true)
846 #define AssertMacro(condition) ((void)true)
847 
848 #elif defined(FRONTEND)
849 
850 #include <assert.h>
851 #define Assert(p) assert(p)
852 #define AssertMacro(p) ((void) assert(p))
853 
854 #else /* USE_ASSERT_CHECKING && !FRONTEND */
855 
856 /*
857  * Assert
858  * Generates a fatal exception if the given condition is false.
859  */
860 #define Assert(condition) \
861  do { \
862  if (!(condition)) \
863  ExceptionalCondition(#condition, __FILE__, __LINE__); \
864  } while (0)
865 
866 /*
867  * AssertMacro is the same as Assert but it's suitable for use in
868  * expression-like macros, for example:
869  *
870  * #define foo(x) (AssertMacro(x != 0), bar(x))
871  */
872 #define AssertMacro(condition) \
873  ((void) ((condition) || \
874  (ExceptionalCondition(#condition, __FILE__, __LINE__), 0)))
875 
876 #endif /* USE_ASSERT_CHECKING && !FRONTEND */
877 
878 /*
879  * Check that `ptr' is `bndr' aligned.
880  */
881 #define AssertPointerAlignment(ptr, bndr) \
882  Assert(TYPEALIGN(bndr, (uintptr_t)(ptr)) == (uintptr_t)(ptr))
883 
884 /*
885  * ExceptionalCondition is compiled into the backend whether or not
886  * USE_ASSERT_CHECKING is defined, so as to support use of extensions
887  * that are built with that #define with a backend that isn't. Hence,
888  * we should declare it as long as !FRONTEND.
889  */
890 #ifndef FRONTEND
891 extern void ExceptionalCondition(const char *conditionName,
892  const char *fileName, int lineNumber) pg_attribute_noreturn();
893 #endif
894 
895 /*
896  * Macros to support compile-time assertion checks.
897  *
898  * If the "condition" (a compile-time-constant expression) evaluates to false,
899  * throw a compile error using the "errmessage" (a string literal).
900  *
901  * C11 has _Static_assert(), and most C99 compilers already support that. For
902  * portability, we wrap it into StaticAssertDecl(). _Static_assert() is a
903  * "declaration", and so it must be placed where for example a variable
904  * declaration would be valid. As long as we compile with
905  * -Wno-declaration-after-statement, that also means it cannot be placed after
906  * statements in a function. Macros StaticAssertStmt() and StaticAssertExpr()
907  * make it safe to use as a statement or in an expression, respectively.
908  *
909  * For compilers without _Static_assert(), we fall back on a kluge that
910  * assumes the compiler will complain about a negative width for a struct
911  * bit-field. This will not include a helpful error message, but it beats not
912  * getting an error at all.
913  */
914 #ifndef __cplusplus
915 #ifdef HAVE__STATIC_ASSERT
916 #define StaticAssertDecl(condition, errmessage) \
917  _Static_assert(condition, errmessage)
918 #define StaticAssertStmt(condition, errmessage) \
919  do { _Static_assert(condition, errmessage); } while(0)
920 #define StaticAssertExpr(condition, errmessage) \
921  ((void) ({ StaticAssertStmt(condition, errmessage); true; }))
922 #else /* !HAVE__STATIC_ASSERT */
923 #define StaticAssertDecl(condition, errmessage) \
924  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
925 #define StaticAssertStmt(condition, errmessage) \
926  ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
927 #define StaticAssertExpr(condition, errmessage) \
928  StaticAssertStmt(condition, errmessage)
929 #endif /* HAVE__STATIC_ASSERT */
930 #else /* C++ */
931 #if defined(__cpp_static_assert) && __cpp_static_assert >= 200410
932 #define StaticAssertDecl(condition, errmessage) \
933  static_assert(condition, errmessage)
934 #define StaticAssertStmt(condition, errmessage) \
935  static_assert(condition, errmessage)
936 #define StaticAssertExpr(condition, errmessage) \
937  ({ static_assert(condition, errmessage); })
938 #else /* !__cpp_static_assert */
939 #define StaticAssertDecl(condition, errmessage) \
940  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
941 #define StaticAssertStmt(condition, errmessage) \
942  do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0)
943 #define StaticAssertExpr(condition, errmessage) \
944  ((void) ({ StaticAssertStmt(condition, errmessage); }))
945 #endif /* __cpp_static_assert */
946 #endif /* C++ */
947 
948 
949 /*
950  * Compile-time checks that a variable (or expression) has the specified type.
951  *
952  * AssertVariableIsOfType() can be used as a statement.
953  * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
954  * #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
955  *
956  * If we don't have __builtin_types_compatible_p, we can still assert that
957  * the types have the same size. This is far from ideal (especially on 32-bit
958  * platforms) but it provides at least some coverage.
959  */
960 #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
961 #define AssertVariableIsOfType(varname, typename) \
962  StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
963  CppAsString(varname) " does not have type " CppAsString(typename))
964 #define AssertVariableIsOfTypeMacro(varname, typename) \
965  (StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
966  CppAsString(varname) " does not have type " CppAsString(typename)))
967 #else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
968 #define AssertVariableIsOfType(varname, typename) \
969  StaticAssertStmt(sizeof(varname) == sizeof(typename), \
970  CppAsString(varname) " does not have type " CppAsString(typename))
971 #define AssertVariableIsOfTypeMacro(varname, typename) \
972  (StaticAssertExpr(sizeof(varname) == sizeof(typename), \
973  CppAsString(varname) " does not have type " CppAsString(typename)))
974 #endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
975 
976 
977 /* ----------------------------------------------------------------
978  * Section 7: widely useful macros
979  * ----------------------------------------------------------------
980  */
981 /*
982  * Max
983  * Return the maximum of two numbers.
984  */
985 #define Max(x, y) ((x) > (y) ? (x) : (y))
986 
987 /*
988  * Min
989  * Return the minimum of two numbers.
990  */
991 #define Min(x, y) ((x) < (y) ? (x) : (y))
992 
993 
994 /* Get a bit mask of the bits set in non-long aligned addresses */
995 #define LONG_ALIGN_MASK (sizeof(long) - 1)
996 
997 /*
998  * MemSet
999  * Exactly the same as standard library function memset(), but considerably
1000  * faster for zeroing small word-aligned structures (such as parsetree nodes).
1001  * This has to be a macro because the main point is to avoid function-call
1002  * overhead. However, we have also found that the loop is faster than
1003  * native libc memset() on some platforms, even those with assembler
1004  * memset() functions. More research needs to be done, perhaps with
1005  * MEMSET_LOOP_LIMIT tests in configure.
1006  */
1007 #define MemSet(start, val, len) \
1008  do \
1009  { \
1010  /* must be void* because we don't know if it is integer aligned yet */ \
1011  void *_vstart = (void *) (start); \
1012  int _val = (val); \
1013  Size _len = (len); \
1014 \
1015  if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
1016  (_len & LONG_ALIGN_MASK) == 0 && \
1017  _val == 0 && \
1018  _len <= MEMSET_LOOP_LIMIT && \
1019  /* \
1020  * If MEMSET_LOOP_LIMIT == 0, optimizer should find \
1021  * the whole "if" false at compile time. \
1022  */ \
1023  MEMSET_LOOP_LIMIT != 0) \
1024  { \
1025  long *_start = (long *) _vstart; \
1026  long *_stop = (long *) ((char *) _start + _len); \
1027  while (_start < _stop) \
1028  *_start++ = 0; \
1029  } \
1030  else \
1031  memset(_vstart, _val, _len); \
1032  } while (0)
1033 
1034 /*
1035  * MemSetAligned is the same as MemSet except it omits the test to see if
1036  * "start" is word-aligned. This is okay to use if the caller knows a-priori
1037  * that the pointer is suitably aligned (typically, because he just got it
1038  * from palloc(), which always delivers a max-aligned pointer).
1039  */
1040 #define MemSetAligned(start, val, len) \
1041  do \
1042  { \
1043  long *_start = (long *) (start); \
1044  int _val = (val); \
1045  Size _len = (len); \
1046 \
1047  if ((_len & LONG_ALIGN_MASK) == 0 && \
1048  _val == 0 && \
1049  _len <= MEMSET_LOOP_LIMIT && \
1050  MEMSET_LOOP_LIMIT != 0) \
1051  { \
1052  long *_stop = (long *) ((char *) _start + _len); \
1053  while (_start < _stop) \
1054  *_start++ = 0; \
1055  } \
1056  else \
1057  memset(_start, _val, _len); \
1058  } while (0)
1059 
1060 
1061 /*
1062  * Macros for range-checking float values before converting to integer.
1063  * We must be careful here that the boundary values are expressed exactly
1064  * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will
1065  * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded
1066  * off, so avoid using that.
1067  * The input must be rounded to an integer beforehand, typically with rint(),
1068  * else we might draw the wrong conclusion about close-to-the-limit values.
1069  * These macros will do the right thing for Inf, but not necessarily for NaN,
1070  * so check isnan(num) first if that's a possibility.
1071  */
1072 #define FLOAT4_FITS_IN_INT16(num) \
1073  ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN))
1074 #define FLOAT4_FITS_IN_INT32(num) \
1075  ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN))
1076 #define FLOAT4_FITS_IN_INT64(num) \
1077  ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN))
1078 #define FLOAT8_FITS_IN_INT16(num) \
1079  ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN))
1080 #define FLOAT8_FITS_IN_INT32(num) \
1081  ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN))
1082 #define FLOAT8_FITS_IN_INT64(num) \
1083  ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN))
1084 
1085 
1086 /* ----------------------------------------------------------------
1087  * Section 8: random stuff
1088  * ----------------------------------------------------------------
1089  */
1090 
1091 /*
1092  * Invert the sign of a qsort-style comparison result, ie, exchange negative
1093  * and positive integer values, being careful not to get the wrong answer
1094  * for INT_MIN. The argument should be an integral variable.
1095  */
1096 #define INVERT_COMPARE_RESULT(var) \
1097  ((var) = ((var) < 0) ? 1 : -(var))
1098 
1099 /*
1100  * Use this, not "char buf[BLCKSZ]", to declare a field or local variable
1101  * holding a page buffer, if that page might be accessed as a page. Otherwise
1102  * the variable might be under-aligned, causing problems on alignment-picky
1103  * hardware. We include both "double" and "int64" in the union to ensure that
1104  * the compiler knows the value must be MAXALIGN'ed (cf. configure's
1105  * computation of MAXIMUM_ALIGNOF).
1106  */
1107 typedef union PGAlignedBlock
1109  char data[BLCKSZ];
1110  double force_align_d;
1111  int64 force_align_i64;
1112 } PGAlignedBlock;
1113 
1114 /*
1115  * Use this to declare a field or local variable holding a page buffer, if that
1116  * page might be accessed as a page or passed to an SMgr I/O function. If
1117  * allocating using the MemoryContext API, the aligned allocation functions
1118  * should be used with PG_IO_ALIGN_SIZE. This alignment may be more efficient
1119  * for I/O in general, but may be strictly required on some platforms when
1120  * using direct I/O.
1121  */
1122 typedef union PGIOAlignedBlock
1123 {
1124 #ifdef pg_attribute_aligned
1125  pg_attribute_aligned(PG_IO_ALIGN_SIZE)
1126 #endif
1127  char data[BLCKSZ];
1128  double force_align_d;
1129  int64 force_align_i64;
1131 
1132 /* Same, but for an XLOG_BLCKSZ-sized buffer */
1133 typedef union PGAlignedXLogBlock
1134 {
1135 #ifdef pg_attribute_aligned
1136  pg_attribute_aligned(PG_IO_ALIGN_SIZE)
1137 #endif
1138  char data[XLOG_BLCKSZ];
1139  double force_align_d;
1140  int64 force_align_i64;
1143 /* msb for char */
1144 #define HIGHBIT (0x80)
1145 #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
1146 
1147 /*
1148  * Support macros for escaping strings. escape_backslash should be true
1149  * if generating a non-standard-conforming string. Prefixing a string
1150  * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
1151  * Beware of multiple evaluation of the "ch" argument!
1152  */
1153 #define SQL_STR_DOUBLE(ch, escape_backslash) \
1154  ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
1155 
1156 #define ESCAPE_STRING_SYNTAX 'E'
1159 #define STATUS_OK (0)
1160 #define STATUS_ERROR (-1)
1161 #define STATUS_EOF (-2)
1162 
1163 /*
1164  * gettext support
1165  */
1167 #ifndef ENABLE_NLS
1168 /* stuff we'd otherwise get from <libintl.h> */
1169 #define gettext(x) (x)
1170 #define dgettext(d,x) (x)
1171 #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
1172 #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
1173 #endif
1174 
1175 #define _(x) gettext(x)
1176 
1177 /*
1178  * Use this to mark string constants as needing translation at some later
1179  * time, rather than immediately. This is useful for cases where you need
1180  * access to the original string and translated string, and for cases where
1181  * immediate translation is not possible, like when initializing global
1182  * variables.
1183  *
1184  * https://www.gnu.org/software/gettext/manual/html_node/Special-cases.html
1185  */
1186 #define gettext_noop(x) (x)
1187 
1188 /*
1189  * To better support parallel installations of major PostgreSQL
1190  * versions as well as parallel installations of major library soname
1191  * versions, we mangle the gettext domain name by appending those
1192  * version numbers. The coding rule ought to be that wherever the
1193  * domain name is mentioned as a literal, it must be wrapped into
1194  * PG_TEXTDOMAIN(). The macros below do not work on non-literals; but
1195  * that is somewhat intentional because it avoids having to worry
1196  * about multiple states of premangling and postmangling as the values
1197  * are being passed around.
1198  *
1199  * Make sure this matches the installation rules in nls-global.mk.
1200  */
1201 #ifdef SO_MAJOR_VERSION
1202 #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
1203 #else
1204 #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
1205 #endif
1206 
1207 /*
1208  * Macro that allows to cast constness and volatile away from an expression, but doesn't
1209  * allow changing the underlying type. Enforcement of the latter
1210  * currently only works for gcc like compilers.
1211  *
1212  * Please note IT IS NOT SAFE to cast constness away if the result will ever
1213  * be modified (it would be undefined behaviour). Doing so anyway can cause
1214  * compiler misoptimizations or runtime crashes (modifying readonly memory).
1215  * It is only safe to use when the result will not be modified, but API
1216  * design or language restrictions prevent you from declaring that
1217  * (e.g. because a function returns both const and non-const variables).
1218  *
1219  * Note that this only works in function scope, not for global variables (it'd
1220  * be nice, but not trivial, to improve that).
1221  */
1222 #if defined(__cplusplus)
1223 #define unconstify(underlying_type, expr) const_cast<underlying_type>(expr)
1224 #define unvolatize(underlying_type, expr) const_cast<underlying_type>(expr)
1225 #elif defined(HAVE__BUILTIN_TYPES_COMPATIBLE_P)
1226 #define unconstify(underlying_type, expr) \
1227  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), const underlying_type), \
1228  "wrong cast"), \
1229  (underlying_type) (expr))
1230 #define unvolatize(underlying_type, expr) \
1231  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), volatile underlying_type), \
1232  "wrong cast"), \
1233  (underlying_type) (expr))
1234 #else
1235 #define unconstify(underlying_type, expr) \
1236  ((underlying_type) (expr))
1237 #define unvolatize(underlying_type, expr) \
1238  ((underlying_type) (expr))
1239 #endif
1240 
1241 /* ----------------------------------------------------------------
1242  * Section 9: system-specific hacks
1243  *
1244  * This should be limited to things that absolutely have to be
1245  * included in every source file. The port-specific header file
1246  * is usually a better place for this sort of thing.
1247  * ----------------------------------------------------------------
1248  */
1249 
1250 /*
1251  * NOTE: this is also used for opening text files.
1252  * WIN32 treats Control-Z as EOF in files opened in text mode.
1253  * Therefore, we open files in binary mode on Win32 so we can read
1254  * literal control-Z. The other affect is that we see CRLF, but
1255  * that is OK because we can already handle those cleanly.
1256  */
1257 #if defined(WIN32) || defined(__CYGWIN__)
1258 #define PG_BINARY O_BINARY
1259 #define PG_BINARY_A "ab"
1260 #define PG_BINARY_R "rb"
1261 #define PG_BINARY_W "wb"
1262 #else
1263 #define PG_BINARY 0
1264 #define PG_BINARY_A "a"
1265 #define PG_BINARY_R "r"
1266 #define PG_BINARY_W "w"
1267 #endif
1268 
1269 /*
1270  * Provide prototypes for routines not present in a particular machine's
1271  * standard C library.
1272  */
1273 
1274 #if !HAVE_DECL_FDATASYNC
1275 extern int fdatasync(int fildes);
1276 #endif
1277 
1278 /*
1279  * Thin wrappers that convert strings to exactly 64-bit integers, matching our
1280  * definition of int64. (For the naming, compare that POSIX has
1281  * strtoimax()/strtoumax() which return intmax_t/uintmax_t.)
1282  */
1283 #ifdef HAVE_LONG_INT_64
1284 #define strtoi64(str, endptr, base) ((int64) strtol(str, endptr, base))
1285 #define strtou64(str, endptr, base) ((uint64) strtoul(str, endptr, base))
1286 #else
1287 #define strtoi64(str, endptr, base) ((int64) strtoll(str, endptr, base))
1288 #define strtou64(str, endptr, base) ((uint64) strtoull(str, endptr, base))
1289 #endif
1290 
1291 /*
1292  * Similarly, wrappers around labs()/llabs() matching our int64.
1293  */
1294 #ifdef HAVE_LONG_INT_64
1295 #define i64abs(i) labs(i)
1296 #else
1297 #define i64abs(i) llabs(i)
1298 #endif
1299 
1300 /*
1301  * Use "extern PGDLLIMPORT ..." to declare variables that are defined
1302  * in the core backend and need to be accessible by loadable modules.
1303  * No special marking is required on most ports.
1304  */
1305 #ifndef PGDLLIMPORT
1306 #define PGDLLIMPORT
1307 #endif
1308 
1309 /*
1310  * Use "extern PGDLLEXPORT ..." to declare functions that are defined in
1311  * loadable modules and need to be callable by the core backend or other
1312  * loadable modules.
1313  * If the compiler knows __attribute__((visibility("*"))), we use that,
1314  * unless we already have a platform-specific definition. Otherwise,
1315  * no special marking is required.
1316  */
1317 #ifndef PGDLLEXPORT
1318 #ifdef HAVE_VISIBILITY_ATTRIBUTE
1319 #define PGDLLEXPORT __attribute__((visibility("default")))
1320 #else
1321 #define PGDLLEXPORT
1322 #endif
1323 #endif
1324 
1325 /*
1326  * The following is used as the arg list for signal handlers. Any ports
1327  * that take something other than an int argument should override this in
1328  * their pg_config_os.h file. Note that variable names are required
1329  * because it is used in both the prototypes as well as the definitions.
1330  * Note also the long name. We expect that this won't collide with
1331  * other names causing compiler warnings.
1332  */
1333 
1334 #ifndef SIGNAL_ARGS
1335 #define SIGNAL_ARGS int postgres_signal_arg
1336 #endif
1337 
1338 /*
1339  * When there is no sigsetjmp, its functionality is provided by plain
1340  * setjmp. We now support the case only on Windows. However, it seems
1341  * that MinGW-64 has some longstanding issues in its setjmp support,
1342  * so on that toolchain we cheat and use gcc's builtins.
1343  */
1344 #ifdef WIN32
1345 #ifdef __MINGW64__
1346 typedef intptr_t sigjmp_buf[5];
1347 #define sigsetjmp(x,y) __builtin_setjmp(x)
1348 #define siglongjmp __builtin_longjmp
1349 #else /* !__MINGW64__ */
1350 #define sigjmp_buf jmp_buf
1351 #define sigsetjmp(x,y) setjmp(x)
1352 #define siglongjmp longjmp
1353 #endif /* __MINGW64__ */
1354 #endif /* WIN32 */
1355 
1356 /* /port compatibility functions */
1357 #include "port.h"
1358 
1359 #endif /* C_H */
static Datum values[MAXATTR]
Definition: bootstrap.c:152
unsigned short uint16
Definition: c.h:492
unsigned int uint32
Definition: c.h:493
uint16 bits16
Definition: c.h:501
NameData * Name
Definition: c.h:731
signed char int8
Definition: c.h:479
union PGAlignedBlock PGAlignedBlock
signed short int16
Definition: c.h:480
union PGAlignedXLogBlock PGAlignedXLogBlock
uint32 SubTransactionId
Definition: c.h:643
signed int int32
Definition: c.h:481
char * Pointer
Definition: c.h:470
Oid regproc
Definition: c.h:636
uint32 MultiXactOffset
Definition: c.h:651
#define pg_attribute_noreturn()
Definition: c.h:204
double float8
Definition: c.h:617
TransactionId MultiXactId
Definition: c.h:649
#define FLEXIBLE_ARRAY_MEMBER
Definition: c.h:385
unsigned char bool
Definition: c.h:443
regproc RegProcedure
Definition: c.h:637
uint8 bits8
Definition: c.h:500
uint32 bits32
Definition: c.h:502
unsigned int Index
Definition: c.h:601
float float4
Definition: c.h:616
uint32 LocalTransactionId
Definition: c.h:641
unsigned char uint8
Definition: c.h:491
union PGIOAlignedBlock PGIOAlignedBlock
uint32 CommandId
Definition: c.h:653
uint32 TransactionId
Definition: c.h:639
signed int Offset
Definition: c.h:611
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:375
size_t Size
Definition: c.h:592
struct nameData NameData
#define NAMEDATALEN
#define PG_IO_ALIGN_SIZE
unsigned int Oid
Definition: postgres_ext.h:31
Definition: c.h:702
int32 vl_len_
Definition: c.h:703
int ndim
Definition: c.h:704
int dim1
Definition: c.h:707
Oid elemtype
Definition: c.h:706
int32 dataoffset
Definition: c.h:705
int lbound1
Definition: c.h:708
Definition: c.h:728
char data[NAMEDATALEN]
Definition: c.h:729
Definition: c.h:713
int dim1
Definition: c.h:718
int32 dataoffset
Definition: c.h:716
Oid elemtype
Definition: c.h:717
int lbound1
Definition: c.h:719
int ndim
Definition: c.h:715
int32 vl_len_
Definition: c.h:714
Definition: c.h:674
char vl_len_[4]
Definition: c.h:675
char vl_dat[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:676
double force_align_d
Definition: c.h:1107
int64 force_align_i64
Definition: c.h:1108
char data[BLCKSZ]
Definition: c.h:1106
char data[XLOG_BLCKSZ]
Definition: c.h:1135
double force_align_d
Definition: c.h:1136
int64 force_align_i64
Definition: c.h:1137
double force_align_d
Definition: c.h:1125
int64 force_align_i64
Definition: c.h:1126
char data[BLCKSZ]
Definition: c.h:1124