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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 HAVE_XLOCALE_H
75 #include <xlocale.h>
76 #endif
77 #ifdef ENABLE_NLS
78 #include <libintl.h>
79 #endif
80 
81 /* Define before including zlib.h to add const decorations to zlib API. */
82 #ifdef HAVE_LIBZ
83 #define ZLIB_CONST
84 #endif
85 
86 
87 /* ----------------------------------------------------------------
88  * Section 1: compiler characteristics
89  *
90  * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
91  * ----------------------------------------------------------------
92  */
93 
94 /*
95  * Disable "inline" if PG_FORCE_DISABLE_INLINE is defined.
96  * This is used to work around compiler bugs and might also be useful for
97  * investigatory purposes.
98  */
99 #ifdef PG_FORCE_DISABLE_INLINE
100 #undef inline
101 #define inline
102 #endif
103 
104 /*
105  * Attribute macros
106  *
107  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
108  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html
109  * Clang: https://clang.llvm.org/docs/AttributeReference.html
110  * Sunpro: https://docs.oracle.com/cd/E18659_01/html/821-1384/gjzke.html
111  */
112 
113 /*
114  * For compilers which don't support __has_attribute, we just define
115  * __has_attribute(x) to 0 so that we can define macros for various
116  * __attribute__s more easily below.
117  */
118 #ifndef __has_attribute
119 #define __has_attribute(attribute) 0
120 #endif
121 
122 /* only GCC supports the unused attribute */
123 #ifdef __GNUC__
124 #define pg_attribute_unused() __attribute__((unused))
125 #else
126 #define pg_attribute_unused()
127 #endif
128 
129 /*
130  * pg_nodiscard means the compiler should warn if the result of a function
131  * call is ignored. The name "nodiscard" is chosen in alignment with
132  * (possibly future) C and C++ standards. For maximum compatibility, use it
133  * as a function declaration specifier, so it goes before the return type.
134  */
135 #ifdef __GNUC__
136 #define pg_nodiscard __attribute__((warn_unused_result))
137 #else
138 #define pg_nodiscard
139 #endif
140 
141 /*
142  * This macro will disable address safety instrumentation for a function
143  * when running with "-fsanitize=address". Think twice before using this!
144  */
145 #if defined(__clang__) || __GNUC__ >= 8
146 #define pg_attribute_no_sanitize_address() __attribute__((no_sanitize("address")))
147 #elif __has_attribute(no_sanitize_address)
148 /* This would work for clang, but it's deprecated. */
149 #define pg_attribute_no_sanitize_address() __attribute__((no_sanitize_address))
150 #else
151 #define pg_attribute_no_sanitize_address()
152 #endif
153 
154 /*
155  * Place this macro before functions that should be allowed to make misaligned
156  * accesses. Think twice before using it on non-x86-specific code!
157  * Testing can be done with "-fsanitize=alignment -fsanitize-trap=alignment"
158  * on clang, or "-fsanitize=alignment -fno-sanitize-recover=alignment" on gcc.
159  */
160 #if __clang_major__ >= 7 || __GNUC__ >= 8
161 #define pg_attribute_no_sanitize_alignment() __attribute__((no_sanitize("alignment")))
162 #else
163 #define pg_attribute_no_sanitize_alignment()
164 #endif
165 
166 /*
167  * pg_attribute_nonnull means the compiler should warn if the function is
168  * called with the listed arguments set to NULL. If no arguments are
169  * listed, the compiler should warn if any pointer arguments are set to NULL.
170  */
171 #if __has_attribute (nonnull)
172 #define pg_attribute_nonnull(...) __attribute__((nonnull(__VA_ARGS__)))
173 #else
174 #define pg_attribute_nonnull(...)
175 #endif
176 
177 /*
178  * pg_attribute_target allows specifying different target options that the
179  * function should be compiled with (e.g., for using special CPU instructions).
180  * Note that there still needs to be a configure-time check to verify that a
181  * specific target is understood by the compiler.
182  */
183 #if __has_attribute (target)
184 #define pg_attribute_target(...) __attribute__((target(__VA_ARGS__)))
185 #else
186 #define pg_attribute_target(...)
187 #endif
188 
189 /*
190  * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
191  * used in assert-enabled builds, to avoid compiler warnings about unused
192  * variables in assert-disabled builds.
193  */
194 #ifdef USE_ASSERT_CHECKING
195 #define PG_USED_FOR_ASSERTS_ONLY
196 #else
197 #define PG_USED_FOR_ASSERTS_ONLY pg_attribute_unused()
198 #endif
199 
200 /* GCC supports format attributes */
201 #if defined(__GNUC__)
202 #define pg_attribute_format_arg(a) __attribute__((format_arg(a)))
203 #define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
204 #else
205 #define pg_attribute_format_arg(a)
206 #define pg_attribute_printf(f,a)
207 #endif
208 
209 /* GCC and Sunpro support aligned, packed and noreturn */
210 #if defined(__GNUC__) || defined(__SUNPRO_C)
211 #define pg_attribute_aligned(a) __attribute__((aligned(a)))
212 #define pg_attribute_noreturn() __attribute__((noreturn))
213 #define pg_attribute_packed() __attribute__((packed))
214 #define HAVE_PG_ATTRIBUTE_NORETURN 1
215 #elif defined(_MSC_VER)
216 /*
217  * MSVC supports aligned. noreturn is also possible but in MSVC it is
218  * declared before the definition while pg_attribute_noreturn() macro
219  * is currently used after the definition.
220  *
221  * Packing is also possible but only by wrapping the entire struct definition
222  * which doesn't fit into our current macro declarations.
223  */
224 #define pg_attribute_aligned(a) __declspec(align(a))
225 #define pg_attribute_noreturn()
226 #else
227 /*
228  * NB: aligned and packed are not given default definitions because they
229  * affect code functionality; they *must* be implemented by the compiler
230  * if they are to be used.
231  */
232 #define pg_attribute_noreturn()
233 #endif
234 
235 /*
236  * Use "pg_attribute_always_inline" in place of "inline" for functions that
237  * we wish to force inlining of, even when the compiler's heuristics would
238  * choose not to. But, if possible, don't force inlining in unoptimized
239  * debug builds.
240  */
241 #if (defined(__GNUC__) && __GNUC__ > 3 && defined(__OPTIMIZE__)) || defined(__SUNPRO_C)
242 /* GCC > 3 and Sunpro support always_inline via __attribute__ */
243 #define pg_attribute_always_inline __attribute__((always_inline)) inline
244 #elif defined(_MSC_VER)
245 /* MSVC has a special keyword for this */
246 #define pg_attribute_always_inline __forceinline
247 #else
248 /* Otherwise, the best we can do is to say "inline" */
249 #define pg_attribute_always_inline inline
250 #endif
251 
252 /*
253  * Forcing a function not to be inlined can be useful if it's the slow path of
254  * a performance-critical function, or should be visible in profiles to allow
255  * for proper cost attribution. Note that unlike the pg_attribute_XXX macros
256  * above, this should be placed before the function's return type and name.
257  */
258 /* GCC and Sunpro support noinline via __attribute__ */
259 #if (defined(__GNUC__) && __GNUC__ > 2) || defined(__SUNPRO_C)
260 #define pg_noinline __attribute__((noinline))
261 /* msvc via declspec */
262 #elif defined(_MSC_VER)
263 #define pg_noinline __declspec(noinline)
264 #else
265 #define pg_noinline
266 #endif
267 
268 /*
269  * For now, just define pg_attribute_cold and pg_attribute_hot to be empty
270  * macros on minGW 8.1. There appears to be a compiler bug that results in
271  * compilation failure. At this time, we still have at least one buildfarm
272  * animal running that compiler, so this should make that green again. It's
273  * likely this compiler is not popular enough to warrant keeping this code
274  * around forever, so let's just remove it once the last buildfarm animal
275  * upgrades.
276  */
277 #if defined(__MINGW64__) && __GNUC__ == 8 && __GNUC_MINOR__ == 1
278 
279 #define pg_attribute_cold
280 #define pg_attribute_hot
281 
282 #else
283 /*
284  * Marking certain functions as "hot" or "cold" can be useful to assist the
285  * compiler in arranging the assembly code in a more efficient way.
286  */
287 #if __has_attribute (cold)
288 #define pg_attribute_cold __attribute__((cold))
289 #else
290 #define pg_attribute_cold
291 #endif
292 
293 #if __has_attribute (hot)
294 #define pg_attribute_hot __attribute__((hot))
295 #else
296 #define pg_attribute_hot
297 #endif
298 
299 #endif /* defined(__MINGW64__) && __GNUC__ == 8 &&
300  * __GNUC_MINOR__ == 1 */
301 /*
302  * Mark a point as unreachable in a portable fashion. This should preferably
303  * be something that the compiler understands, to aid code generation.
304  * In assert-enabled builds, we prefer abort() for debugging reasons.
305  */
306 #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
307 #define pg_unreachable() __builtin_unreachable()
308 #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
309 #define pg_unreachable() __assume(0)
310 #else
311 #define pg_unreachable() abort()
312 #endif
313 
314 /*
315  * Hints to the compiler about the likelihood of a branch. Both likely() and
316  * unlikely() return the boolean value of the contained expression.
317  *
318  * These should only be used sparingly, in very hot code paths. It's very easy
319  * to mis-estimate likelihoods.
320  */
321 #if __GNUC__ >= 3
322 #define likely(x) __builtin_expect((x) != 0, 1)
323 #define unlikely(x) __builtin_expect((x) != 0, 0)
324 #else
325 #define likely(x) ((x) != 0)
326 #define unlikely(x) ((x) != 0)
327 #endif
328 
329 /*
330  * CppAsString
331  * Convert the argument to a string, using the C preprocessor.
332  * CppAsString2
333  * Convert the argument to a string, after one round of macro expansion.
334  * CppConcat
335  * Concatenate two arguments together, using the C preprocessor.
336  *
337  * Note: There used to be support here for pre-ANSI C compilers that didn't
338  * support # and ##. Nowadays, these macros are just for clarity and/or
339  * backward compatibility with existing PostgreSQL code.
340  */
341 #define CppAsString(identifier) #identifier
342 #define CppAsString2(x) CppAsString(x)
343 #define CppConcat(x, y) x##y
344 
345 /*
346  * VA_ARGS_NARGS
347  * Returns the number of macro arguments it is passed.
348  *
349  * An empty argument still counts as an argument, so effectively, this is
350  * "one more than the number of commas in the argument list".
351  *
352  * This works for up to 63 arguments. Internally, VA_ARGS_NARGS_() is passed
353  * 64+N arguments, and the C99 standard only requires macros to allow up to
354  * 127 arguments, so we can't portably go higher. The implementation is
355  * pretty trivial: VA_ARGS_NARGS_() returns its 64th argument, and we set up
356  * the call so that that is the appropriate one of the list of constants.
357  * This idea is due to Laurent Deniau.
358  *
359  * MSVC has an implementation of __VA_ARGS__ that doesn't conform to the
360  * standard unless you use the /Zc:preprocessor compiler flag, but that
361  * isn't available before Visual Studio 2019. For now, use a different
362  * definition that also works on older compilers.
363  */
364 #ifdef _MSC_VER
365 #define EXPAND(args) args
366 #define VA_ARGS_NARGS(...) \
367  VA_ARGS_NARGS_ EXPAND((__VA_ARGS__, \
368  63,62,61,60, \
369  59,58,57,56,55,54,53,52,51,50, \
370  49,48,47,46,45,44,43,42,41,40, \
371  39,38,37,36,35,34,33,32,31,30, \
372  29,28,27,26,25,24,23,22,21,20, \
373  19,18,17,16,15,14,13,12,11,10, \
374  9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
375 #else
376 
377 #define VA_ARGS_NARGS(...) \
378  VA_ARGS_NARGS_(__VA_ARGS__, \
379  63,62,61,60, \
380  59,58,57,56,55,54,53,52,51,50, \
381  49,48,47,46,45,44,43,42,41,40, \
382  39,38,37,36,35,34,33,32,31,30, \
383  29,28,27,26,25,24,23,22,21,20, \
384  19,18,17,16,15,14,13,12,11,10, \
385  9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
386 #endif
387 
388 #define VA_ARGS_NARGS_( \
389  _01,_02,_03,_04,_05,_06,_07,_08,_09,_10, \
390  _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \
391  _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \
392  _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \
393  _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \
394  _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \
395  _61,_62,_63, N, ...) \
396  (N)
397 
398 /*
399  * Generic function pointer. This can be used in the rare cases where it's
400  * necessary to cast a function pointer to a seemingly incompatible function
401  * pointer type while avoiding gcc's -Wcast-function-type warnings.
402  */
403 typedef void (*pg_funcptr_t) (void);
404 
405 /*
406  * We require C99, hence the compiler should understand flexible array
407  * members. However, for documentation purposes we still consider it to be
408  * project style to write "field[FLEXIBLE_ARRAY_MEMBER]" not just "field[]".
409  * When computing the size of such an object, use "offsetof(struct s, f)"
410  * for portability. Don't use "offsetof(struct s, f[0])", as this doesn't
411  * work with MSVC and with C++ compilers.
412  */
413 #define FLEXIBLE_ARRAY_MEMBER /* empty */
414 
415 /*
416  * Does the compiler support #pragma GCC system_header? We optionally use it
417  * to avoid warnings that we can't fix (e.g. in the perl headers).
418  * See https://gcc.gnu.org/onlinedocs/cpp/System-Headers.html
419  *
420  * Headers for which we do not want to show compiler warnings can,
421  * conditionally, use #pragma GCC system_header to avoid warnings. Obviously
422  * this should only be used for external headers over which we do not have
423  * control.
424  *
425  * Support for the pragma is tested here, instead of during configure, as gcc
426  * also warns about the pragma being used in a .c file. It's surprisingly hard
427  * to get autoconf to use .h as the file-ending. Looks like gcc has
428  * implemented the pragma since the 2000, so this test should suffice.
429  *
430  *
431  * Alternatively, we could add the include paths for problematic headers with
432  * -isystem, but that is a larger hammer and is harder to search for.
433  *
434  * A more granular alternative would be to use #pragma GCC diagnostic
435  * push/ignored/pop, but gcc warns about unknown warnings being ignored, so
436  * every to-be-ignored-temporarily compiler warning would require its own
437  * pg_config.h symbol and #ifdef.
438  */
439 #ifdef __GNUC__
440 #define HAVE_PRAGMA_GCC_SYSTEM_HEADER 1
441 #endif
442 
443 
444 /* ----------------------------------------------------------------
445  * Section 2: bool, true, false
446  * ----------------------------------------------------------------
447  */
448 
449 /*
450  * bool
451  * Boolean value, either true or false.
452  *
453  * We use stdbool.h if available and its bool has size 1. That's useful for
454  * better compiler and debugger output and for compatibility with third-party
455  * libraries. But PostgreSQL currently cannot deal with bool of other sizes;
456  * there are static assertions around the code to prevent that.
457  *
458  * For C++ compilers, we assume the compiler has a compatible built-in
459  * definition of bool.
460  *
461  * See also the version of this code in src/interfaces/ecpg/include/ecpglib.h.
462  */
463 
464 #ifndef __cplusplus
465 
466 #ifdef PG_USE_STDBOOL
467 #include <stdbool.h>
468 #else
469 
470 #ifndef bool
471 typedef unsigned char bool;
472 #endif
473 
474 #ifndef true
475 #define true ((bool) 1)
476 #endif
477 
478 #ifndef false
479 #define false ((bool) 0)
480 #endif
481 
482 #endif /* not PG_USE_STDBOOL */
483 #endif /* not C++ */
484 
485 
486 /* ----------------------------------------------------------------
487  * Section 3: standard system types
488  * ----------------------------------------------------------------
489  */
490 
491 /*
492  * Pointer
493  * Variable holding address of any memory resident object.
494  *
495  * XXX Pointer arithmetic is done with this, so it can't be void *
496  * under "true" ANSI compilers.
497  */
498 typedef char *Pointer;
499 
500 /*
501  * intN
502  * Signed integer, EXACTLY N BITS IN SIZE,
503  * used for numerical computations and the
504  * frontend/backend protocol.
505  */
506 typedef signed char int8; /* == 8 bits */
507 typedef signed short int16; /* == 16 bits */
508 typedef signed int int32; /* == 32 bits */
509 
510 /*
511  * uintN
512  * Unsigned integer, EXACTLY N BITS IN SIZE,
513  * used for numerical computations and the
514  * frontend/backend protocol.
515  */
516 typedef unsigned char uint8; /* == 8 bits */
517 typedef unsigned short uint16; /* == 16 bits */
518 typedef unsigned int uint32; /* == 32 bits */
519 
520 /*
521  * bitsN
522  * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
523  */
524 typedef uint8 bits8; /* >= 8 bits */
525 typedef uint16 bits16; /* >= 16 bits */
526 typedef uint32 bits32; /* >= 32 bits */
527 
528 /*
529  * 64-bit integers
530  */
531 #ifdef HAVE_LONG_INT_64
532 /* Plain "long int" fits, use it */
533 
534 typedef long int int64;
535 typedef unsigned long int uint64;
536 #define INT64CONST(x) (x##L)
537 #define UINT64CONST(x) (x##UL)
538 #elif defined(HAVE_LONG_LONG_INT_64)
539 /* We have working support for "long long int", use that */
540 
541 typedef long long int int64;
542 typedef unsigned long long int uint64;
543 #define INT64CONST(x) (x##LL)
544 #define UINT64CONST(x) (x##ULL)
545 #else
546 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
547 #error must have a working 64-bit integer datatype
548 #endif
549 
550 /* snprintf format strings to use for 64-bit integers */
551 #define INT64_FORMAT "%" INT64_MODIFIER "d"
552 #define UINT64_FORMAT "%" INT64_MODIFIER "u"
553 
554 /*
555  * 128-bit signed and unsigned integers
556  * There currently is only limited support for such types.
557  * E.g. 128bit literals and snprintf are not supported; but math is.
558  * Also, because we exclude such types when choosing MAXIMUM_ALIGNOF,
559  * it must be possible to coerce the compiler to allocate them on no
560  * more than MAXALIGN boundaries.
561  */
562 #if defined(PG_INT128_TYPE)
563 #if defined(pg_attribute_aligned) || ALIGNOF_PG_INT128_TYPE <= MAXIMUM_ALIGNOF
564 #define HAVE_INT128 1
565 
566 typedef PG_INT128_TYPE int128
567 #if defined(pg_attribute_aligned)
568  pg_attribute_aligned(MAXIMUM_ALIGNOF)
569 #endif
570  ;
571 
572 typedef unsigned PG_INT128_TYPE uint128
573 #if defined(pg_attribute_aligned)
574  pg_attribute_aligned(MAXIMUM_ALIGNOF)
575 #endif
576  ;
577 
578 #endif
579 #endif
580 
581 /*
582  * stdint.h limits aren't guaranteed to have compatible types with our fixed
583  * width types. So just define our own.
584  */
585 #define PG_INT8_MIN (-0x7F-1)
586 #define PG_INT8_MAX (0x7F)
587 #define PG_UINT8_MAX (0xFF)
588 #define PG_INT16_MIN (-0x7FFF-1)
589 #define PG_INT16_MAX (0x7FFF)
590 #define PG_UINT16_MAX (0xFFFF)
591 #define PG_INT32_MIN (-0x7FFFFFFF-1)
592 #define PG_INT32_MAX (0x7FFFFFFF)
593 #define PG_UINT32_MAX (0xFFFFFFFFU)
594 #define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
595 #define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF)
596 #define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
597 
598 /*
599  * We now always use int64 timestamps, but keep this symbol defined for the
600  * benefit of external code that might test it.
601  */
602 #define HAVE_INT64_TIMESTAMP
603 
604 /*
605  * Size
606  * Size of any memory resident object, as returned by sizeof.
607  */
608 typedef size_t Size;
609 
610 /*
611  * Index
612  * Index into any memory resident array.
613  *
614  * Note:
615  * Indices are non negative.
616  */
617 typedef unsigned int Index;
618 
619 /*
620  * Offset
621  * Offset into any memory resident array.
622  *
623  * Note:
624  * This differs from an Index in that an Index is always
625  * non negative, whereas Offset may be negative.
626  */
627 typedef signed int Offset;
628 
629 /*
630  * Common Postgres datatype names (as used in the catalogs)
631  */
632 typedef float float4;
633 typedef double float8;
634 
635 #ifdef USE_FLOAT8_BYVAL
636 #define FLOAT8PASSBYVAL true
637 #else
638 #define FLOAT8PASSBYVAL false
639 #endif
640 
641 /*
642  * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
643  * CommandId
644  */
645 
646 /* typedef Oid is in postgres_ext.h */
647 
648 /*
649  * regproc is the type name used in the include/catalog headers, but
650  * RegProcedure is the preferred name in C code.
651  */
652 typedef Oid regproc;
654 
656 
658 
660 
661 #define InvalidSubTransactionId ((SubTransactionId) 0)
662 #define TopSubTransactionId ((SubTransactionId) 1)
663 
664 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
666 
668 
670 
671 #define FirstCommandId ((CommandId) 0)
672 #define InvalidCommandId (~(CommandId)0)
673 
674 
675 /* ----------------
676  * Variable-length datatypes all share the 'struct varlena' header.
677  *
678  * NOTE: for TOASTable types, this is an oversimplification, since the value
679  * may be compressed or moved out-of-line. However datatype-specific routines
680  * are mostly content to deal with de-TOASTed values only, and of course
681  * client-side routines should never see a TOASTed value. But even in a
682  * de-TOASTed value, beware of touching vl_len_ directly, as its
683  * representation is no longer convenient. It's recommended that code always
684  * use macros VARDATA_ANY, VARSIZE_ANY, VARSIZE_ANY_EXHDR, VARDATA, VARSIZE,
685  * and SET_VARSIZE instead of relying on direct mentions of the struct fields.
686  * See postgres.h for details of the TOASTed form.
687  * ----------------
688  */
689 struct varlena
690 {
691  char vl_len_[4]; /* Do not touch this field directly! */
692  char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */
693 };
694 
695 #define VARHDRSZ ((int32) sizeof(int32))
696 
697 /*
698  * These widely-used datatypes are just a varlena header and the data bytes.
699  * There is no terminating null or anything like that --- the data length is
700  * always VARSIZE_ANY_EXHDR(ptr).
701  */
702 typedef struct varlena bytea;
703 typedef struct varlena text;
704 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
705 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
706 
707 /*
708  * Specialized array types. These are physically laid out just the same
709  * as regular arrays (so that the regular array subscripting code works
710  * with them). They exist as distinct types mostly for historical reasons:
711  * they have nonstandard I/O behavior which we don't want to change for fear
712  * of breaking applications that look at the system catalogs. There is also
713  * an implementation issue for oidvector: it's part of the primary key for
714  * pg_proc, and we can't use the normal btree array support routines for that
715  * without circularity.
716  */
717 typedef struct
718 {
719  int32 vl_len_; /* these fields must match ArrayType! */
720  int ndim; /* always 1 for int2vector */
721  int32 dataoffset; /* always 0 for int2vector */
723  int dim1;
724  int lbound1;
726 } int2vector;
727 
728 typedef struct
729 {
730  int32 vl_len_; /* these fields must match ArrayType! */
731  int ndim; /* always 1 for oidvector */
732  int32 dataoffset; /* always 0 for oidvector */
734  int dim1;
735  int lbound1;
737 } oidvector;
738 
739 /*
740  * Representation of a Name: effectively just a C string, but null-padded to
741  * exactly NAMEDATALEN bytes. The use of a struct is historical.
742  */
743 typedef struct nameData
744 {
747 typedef NameData *Name;
748 
749 #define NameStr(name) ((name).data)
750 
751 
752 /* ----------------------------------------------------------------
753  * Section 4: IsValid macros for system types
754  * ----------------------------------------------------------------
755  */
756 /*
757  * BoolIsValid
758  * True iff bool is valid.
759  */
760 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
761 
762 /*
763  * PointerIsValid
764  * True iff pointer is valid.
765  */
766 #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
767 
768 /*
769  * PointerIsAligned
770  * True iff pointer is properly aligned to point to the given type.
771  */
772 #define PointerIsAligned(pointer, type) \
773  (((uintptr_t)(pointer) % (sizeof (type))) == 0)
774 
775 #define OffsetToPointer(base, offset) \
776  ((void *)((char *) base + offset))
777 
778 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
779 
780 #define RegProcedureIsValid(p) OidIsValid(p)
781 
782 
783 /* ----------------------------------------------------------------
784  * Section 5: lengthof, alignment
785  * ----------------------------------------------------------------
786  */
787 /*
788  * lengthof
789  * Number of elements in an array.
790  */
791 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
792 
793 /* ----------------
794  * Alignment macros: align a length or address appropriately for a given type.
795  * The fooALIGN() macros round up to a multiple of the required alignment,
796  * while the fooALIGN_DOWN() macros round down. The latter are more useful
797  * for problems like "how many X-sized structures will fit in a page?".
798  *
799  * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
800  * That case seems extremely unlikely to be needed in practice, however.
801  *
802  * NOTE: MAXIMUM_ALIGNOF, and hence MAXALIGN(), intentionally exclude any
803  * larger-than-8-byte types the compiler might have.
804  * ----------------
805  */
806 
807 #define TYPEALIGN(ALIGNVAL,LEN) \
808  (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
809 
810 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
811 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
812 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
813 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
814 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
815 /* MAXALIGN covers only built-in types, not buffers */
816 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
817 #define CACHELINEALIGN(LEN) TYPEALIGN(PG_CACHE_LINE_SIZE, (LEN))
818 
819 #define TYPEALIGN_DOWN(ALIGNVAL,LEN) \
820  (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
821 
822 #define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
823 #define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
824 #define LONGALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
825 #define DOUBLEALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
826 #define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
827 #define BUFFERALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_BUFFER, (LEN))
828 
829 /*
830  * The above macros will not work with types wider than uintptr_t, like with
831  * uint64 on 32-bit platforms. That's not problem for the usual use where a
832  * pointer or a length is aligned, but for the odd case that you need to
833  * align something (potentially) wider, use TYPEALIGN64.
834  */
835 #define TYPEALIGN64(ALIGNVAL,LEN) \
836  (((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1)))
837 
838 /* we don't currently need wider versions of the other ALIGN macros */
839 #define MAXALIGN64(LEN) TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN))
840 
841 
842 /* ----------------------------------------------------------------
843  * Section 6: assertions
844  * ----------------------------------------------------------------
845  */
846 
847 /*
848  * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
849  * - plai 9/5/90
850  *
851  * It should _NOT_ be defined in releases or in benchmark copies
852  */
853 
854 /*
855  * Assert() can be used in both frontend and backend code. In frontend code it
856  * just calls the standard assert, if it's available. If use of assertions is
857  * not configured, it does nothing.
858  */
859 #ifndef USE_ASSERT_CHECKING
860 
861 #define Assert(condition) ((void)true)
862 #define AssertMacro(condition) ((void)true)
863 
864 #elif defined(FRONTEND)
865 
866 #include <assert.h>
867 #define Assert(p) assert(p)
868 #define AssertMacro(p) ((void) assert(p))
869 
870 #else /* USE_ASSERT_CHECKING && !FRONTEND */
871 
872 /*
873  * Assert
874  * Generates a fatal exception if the given condition is false.
875  */
876 #define Assert(condition) \
877  do { \
878  if (!(condition)) \
879  ExceptionalCondition(#condition, __FILE__, __LINE__); \
880  } while (0)
881 
882 /*
883  * AssertMacro is the same as Assert but it's suitable for use in
884  * expression-like macros, for example:
885  *
886  * #define foo(x) (AssertMacro(x != 0), bar(x))
887  */
888 #define AssertMacro(condition) \
889  ((void) ((condition) || \
890  (ExceptionalCondition(#condition, __FILE__, __LINE__), 0)))
891 
892 #endif /* USE_ASSERT_CHECKING && !FRONTEND */
893 
894 /*
895  * Check that `ptr' is `bndr' aligned.
896  */
897 #define AssertPointerAlignment(ptr, bndr) \
898  Assert(TYPEALIGN(bndr, (uintptr_t)(ptr)) == (uintptr_t)(ptr))
899 
900 /*
901  * ExceptionalCondition is compiled into the backend whether or not
902  * USE_ASSERT_CHECKING is defined, so as to support use of extensions
903  * that are built with that #define with a backend that isn't. Hence,
904  * we should declare it as long as !FRONTEND.
905  */
906 #ifndef FRONTEND
907 extern void ExceptionalCondition(const char *conditionName,
908  const char *fileName, int lineNumber) pg_attribute_noreturn();
909 #endif
910 
911 /*
912  * Macros to support compile-time assertion checks.
913  *
914  * If the "condition" (a compile-time-constant expression) evaluates to false,
915  * throw a compile error using the "errmessage" (a string literal).
916  *
917  * C11 has _Static_assert(), and most C99 compilers already support that. For
918  * portability, we wrap it into StaticAssertDecl(). _Static_assert() is a
919  * "declaration", and so it must be placed where for example a variable
920  * declaration would be valid. As long as we compile with
921  * -Wno-declaration-after-statement, that also means it cannot be placed after
922  * statements in a function. Macros StaticAssertStmt() and StaticAssertExpr()
923  * make it safe to use as a statement or in an expression, respectively.
924  *
925  * For compilers without _Static_assert(), we fall back on a kluge that
926  * assumes the compiler will complain about a negative width for a struct
927  * bit-field. This will not include a helpful error message, but it beats not
928  * getting an error at all.
929  */
930 #ifndef __cplusplus
931 #ifdef HAVE__STATIC_ASSERT
932 #define StaticAssertDecl(condition, errmessage) \
933  _Static_assert(condition, errmessage)
934 #define StaticAssertStmt(condition, errmessage) \
935  do { _Static_assert(condition, errmessage); } while(0)
936 #define StaticAssertExpr(condition, errmessage) \
937  ((void) ({ StaticAssertStmt(condition, errmessage); true; }))
938 #else /* !HAVE__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  ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
943 #define StaticAssertExpr(condition, errmessage) \
944  StaticAssertStmt(condition, errmessage)
945 #endif /* HAVE__STATIC_ASSERT */
946 #else /* C++ */
947 #if defined(__cpp_static_assert) && __cpp_static_assert >= 200410
948 #define StaticAssertDecl(condition, errmessage) \
949  static_assert(condition, errmessage)
950 #define StaticAssertStmt(condition, errmessage) \
951  static_assert(condition, errmessage)
952 #define StaticAssertExpr(condition, errmessage) \
953  ({ static_assert(condition, errmessage); })
954 #else /* !__cpp_static_assert */
955 #define StaticAssertDecl(condition, errmessage) \
956  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
957 #define StaticAssertStmt(condition, errmessage) \
958  do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0)
959 #define StaticAssertExpr(condition, errmessage) \
960  ((void) ({ StaticAssertStmt(condition, errmessage); }))
961 #endif /* __cpp_static_assert */
962 #endif /* C++ */
963 
964 
965 /*
966  * Compile-time checks that a variable (or expression) has the specified type.
967  *
968  * AssertVariableIsOfType() can be used as a statement.
969  * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
970  * #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
971  *
972  * If we don't have __builtin_types_compatible_p, we can still assert that
973  * the types have the same size. This is far from ideal (especially on 32-bit
974  * platforms) but it provides at least some coverage.
975  */
976 #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
977 #define AssertVariableIsOfType(varname, typename) \
978  StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
979  CppAsString(varname) " does not have type " CppAsString(typename))
980 #define AssertVariableIsOfTypeMacro(varname, typename) \
981  (StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
982  CppAsString(varname) " does not have type " CppAsString(typename)))
983 #else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
984 #define AssertVariableIsOfType(varname, typename) \
985  StaticAssertStmt(sizeof(varname) == sizeof(typename), \
986  CppAsString(varname) " does not have type " CppAsString(typename))
987 #define AssertVariableIsOfTypeMacro(varname, typename) \
988  (StaticAssertExpr(sizeof(varname) == sizeof(typename), \
989  CppAsString(varname) " does not have type " CppAsString(typename)))
990 #endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
991 
992 
993 /* ----------------------------------------------------------------
994  * Section 7: widely useful macros
995  * ----------------------------------------------------------------
996  */
997 /*
998  * Max
999  * Return the maximum of two numbers.
1000  */
1001 #define Max(x, y) ((x) > (y) ? (x) : (y))
1002 
1003 /*
1004  * Min
1005  * Return the minimum of two numbers.
1006  */
1007 #define Min(x, y) ((x) < (y) ? (x) : (y))
1008 
1009 
1010 /* Get a bit mask of the bits set in non-long aligned addresses */
1011 #define LONG_ALIGN_MASK (sizeof(long) - 1)
1012 
1013 /*
1014  * MemSet
1015  * Exactly the same as standard library function memset(), but considerably
1016  * faster for zeroing small word-aligned structures (such as parsetree nodes).
1017  * This has to be a macro because the main point is to avoid function-call
1018  * overhead. However, we have also found that the loop is faster than
1019  * native libc memset() on some platforms, even those with assembler
1020  * memset() functions. More research needs to be done, perhaps with
1021  * MEMSET_LOOP_LIMIT tests in configure.
1022  */
1023 #define MemSet(start, val, len) \
1024  do \
1025  { \
1026  /* must be void* because we don't know if it is integer aligned yet */ \
1027  void *_vstart = (void *) (start); \
1028  int _val = (val); \
1029  Size _len = (len); \
1030 \
1031  if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
1032  (_len & LONG_ALIGN_MASK) == 0 && \
1033  _val == 0 && \
1034  _len <= MEMSET_LOOP_LIMIT && \
1035  /* \
1036  * If MEMSET_LOOP_LIMIT == 0, optimizer should find \
1037  * the whole "if" false at compile time. \
1038  */ \
1039  MEMSET_LOOP_LIMIT != 0) \
1040  { \
1041  long *_start = (long *) _vstart; \
1042  long *_stop = (long *) ((char *) _start + _len); \
1043  while (_start < _stop) \
1044  *_start++ = 0; \
1045  } \
1046  else \
1047  memset(_vstart, _val, _len); \
1048  } while (0)
1049 
1050 /*
1051  * MemSetAligned is the same as MemSet except it omits the test to see if
1052  * "start" is word-aligned. This is okay to use if the caller knows a-priori
1053  * that the pointer is suitably aligned (typically, because he just got it
1054  * from palloc(), which always delivers a max-aligned pointer).
1055  */
1056 #define MemSetAligned(start, val, len) \
1057  do \
1058  { \
1059  long *_start = (long *) (start); \
1060  int _val = (val); \
1061  Size _len = (len); \
1062 \
1063  if ((_len & LONG_ALIGN_MASK) == 0 && \
1064  _val == 0 && \
1065  _len <= MEMSET_LOOP_LIMIT && \
1066  MEMSET_LOOP_LIMIT != 0) \
1067  { \
1068  long *_stop = (long *) ((char *) _start + _len); \
1069  while (_start < _stop) \
1070  *_start++ = 0; \
1071  } \
1072  else \
1073  memset(_start, _val, _len); \
1074  } while (0)
1075 
1076 
1077 /*
1078  * Macros for range-checking float values before converting to integer.
1079  * We must be careful here that the boundary values are expressed exactly
1080  * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will
1081  * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded
1082  * off, so avoid using that.
1083  * The input must be rounded to an integer beforehand, typically with rint(),
1084  * else we might draw the wrong conclusion about close-to-the-limit values.
1085  * These macros will do the right thing for Inf, but not necessarily for NaN,
1086  * so check isnan(num) first if that's a possibility.
1087  */
1088 #define FLOAT4_FITS_IN_INT16(num) \
1089  ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN))
1090 #define FLOAT4_FITS_IN_INT32(num) \
1091  ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN))
1092 #define FLOAT4_FITS_IN_INT64(num) \
1093  ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN))
1094 #define FLOAT8_FITS_IN_INT16(num) \
1095  ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN))
1096 #define FLOAT8_FITS_IN_INT32(num) \
1097  ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN))
1098 #define FLOAT8_FITS_IN_INT64(num) \
1099  ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN))
1100 
1101 
1102 /* ----------------------------------------------------------------
1103  * Section 8: random stuff
1104  * ----------------------------------------------------------------
1105  */
1106 
1107 /*
1108  * Invert the sign of a qsort-style comparison result, ie, exchange negative
1109  * and positive integer values, being careful not to get the wrong answer
1110  * for INT_MIN. The argument should be an integral variable.
1111  */
1112 #define INVERT_COMPARE_RESULT(var) \
1113  ((var) = ((var) < 0) ? 1 : -(var))
1114 
1115 /*
1116  * Use this, not "char buf[BLCKSZ]", to declare a field or local variable
1117  * holding a page buffer, if that page might be accessed as a page. Otherwise
1118  * the variable might be under-aligned, causing problems on alignment-picky
1119  * hardware. We include both "double" and "int64" in the union to ensure that
1120  * the compiler knows the value must be MAXALIGN'ed (cf. configure's
1121  * computation of MAXIMUM_ALIGNOF).
1122  */
1123 typedef union PGAlignedBlock
1125  char data[BLCKSZ];
1126  double force_align_d;
1127  int64 force_align_i64;
1128 } PGAlignedBlock;
1129 
1130 /*
1131  * Use this to declare a field or local variable holding a page buffer, if that
1132  * page might be accessed as a page or passed to an SMgr I/O function. If
1133  * allocating using the MemoryContext API, the aligned allocation functions
1134  * should be used with PG_IO_ALIGN_SIZE. This alignment may be more efficient
1135  * for I/O in general, but may be strictly required on some platforms when
1136  * using direct I/O.
1137  */
1138 typedef union PGIOAlignedBlock
1139 {
1140 #ifdef pg_attribute_aligned
1142 #endif
1143  char data[BLCKSZ];
1144  double force_align_d;
1145  int64 force_align_i64;
1147 
1148 /* Same, but for an XLOG_BLCKSZ-sized buffer */
1149 typedef union PGAlignedXLogBlock
1150 {
1151 #ifdef pg_attribute_aligned
1153 #endif
1154  char data[XLOG_BLCKSZ];
1155  double force_align_d;
1156  int64 force_align_i64;
1159 /* msb for char */
1160 #define HIGHBIT (0x80)
1161 #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
1162 
1163 /*
1164  * Support macros for escaping strings. escape_backslash should be true
1165  * if generating a non-standard-conforming string. Prefixing a string
1166  * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
1167  * Beware of multiple evaluation of the "ch" argument!
1168  */
1169 #define SQL_STR_DOUBLE(ch, escape_backslash) \
1170  ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
1171 
1172 #define ESCAPE_STRING_SYNTAX 'E'
1175 #define STATUS_OK (0)
1176 #define STATUS_ERROR (-1)
1177 #define STATUS_EOF (-2)
1178 
1179 /*
1180  * gettext support
1181  */
1183 #ifndef ENABLE_NLS
1184 /* stuff we'd otherwise get from <libintl.h> */
1185 #define gettext(x) (x)
1186 #define dgettext(d,x) (x)
1187 #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
1188 #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
1189 #endif
1190 
1191 #define _(x) gettext(x)
1192 
1193 /*
1194  * Use this to mark string constants as needing translation at some later
1195  * time, rather than immediately. This is useful for cases where you need
1196  * access to the original string and translated string, and for cases where
1197  * immediate translation is not possible, like when initializing global
1198  * variables.
1199  *
1200  * https://www.gnu.org/software/gettext/manual/html_node/Special-cases.html
1201  */
1202 #define gettext_noop(x) (x)
1203 
1204 /*
1205  * To better support parallel installations of major PostgreSQL
1206  * versions as well as parallel installations of major library soname
1207  * versions, we mangle the gettext domain name by appending those
1208  * version numbers. The coding rule ought to be that wherever the
1209  * domain name is mentioned as a literal, it must be wrapped into
1210  * PG_TEXTDOMAIN(). The macros below do not work on non-literals; but
1211  * that is somewhat intentional because it avoids having to worry
1212  * about multiple states of premangling and postmangling as the values
1213  * are being passed around.
1214  *
1215  * Make sure this matches the installation rules in nls-global.mk.
1216  */
1217 #ifdef SO_MAJOR_VERSION
1218 #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
1219 #else
1220 #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
1221 #endif
1222 
1223 /*
1224  * Macro that allows to cast constness and volatile away from an expression, but doesn't
1225  * allow changing the underlying type. Enforcement of the latter
1226  * currently only works for gcc like compilers.
1227  *
1228  * Please note IT IS NOT SAFE to cast constness away if the result will ever
1229  * be modified (it would be undefined behaviour). Doing so anyway can cause
1230  * compiler misoptimizations or runtime crashes (modifying readonly memory).
1231  * It is only safe to use when the result will not be modified, but API
1232  * design or language restrictions prevent you from declaring that
1233  * (e.g. because a function returns both const and non-const variables).
1234  *
1235  * Note that this only works in function scope, not for global variables (it'd
1236  * be nice, but not trivial, to improve that).
1237  */
1238 #if defined(__cplusplus)
1239 #define unconstify(underlying_type, expr) const_cast<underlying_type>(expr)
1240 #define unvolatize(underlying_type, expr) const_cast<underlying_type>(expr)
1241 #elif defined(HAVE__BUILTIN_TYPES_COMPATIBLE_P)
1242 #define unconstify(underlying_type, expr) \
1243  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), const underlying_type), \
1244  "wrong cast"), \
1245  (underlying_type) (expr))
1246 #define unvolatize(underlying_type, expr) \
1247  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), volatile underlying_type), \
1248  "wrong cast"), \
1249  (underlying_type) (expr))
1250 #else
1251 #define unconstify(underlying_type, expr) \
1252  ((underlying_type) (expr))
1253 #define unvolatize(underlying_type, expr) \
1254  ((underlying_type) (expr))
1255 #endif
1256 
1257 /* ----------------------------------------------------------------
1258  * Section 9: system-specific hacks
1259  *
1260  * This should be limited to things that absolutely have to be
1261  * included in every source file. The port-specific header file
1262  * is usually a better place for this sort of thing.
1263  * ----------------------------------------------------------------
1264  */
1265 
1266 /*
1267  * NOTE: this is also used for opening text files.
1268  * WIN32 treats Control-Z as EOF in files opened in text mode.
1269  * Therefore, we open files in binary mode on Win32 so we can read
1270  * literal control-Z. The other affect is that we see CRLF, but
1271  * that is OK because we can already handle those cleanly.
1272  */
1273 #if defined(WIN32) || defined(__CYGWIN__)
1274 #define PG_BINARY O_BINARY
1275 #define PG_BINARY_A "ab"
1276 #define PG_BINARY_R "rb"
1277 #define PG_BINARY_W "wb"
1278 #else
1279 #define PG_BINARY 0
1280 #define PG_BINARY_A "a"
1281 #define PG_BINARY_R "r"
1282 #define PG_BINARY_W "w"
1283 #endif
1284 
1285 /*
1286  * Provide prototypes for routines not present in a particular machine's
1287  * standard C library.
1288  */
1289 
1290 #if !HAVE_DECL_FDATASYNC
1291 extern int fdatasync(int fildes);
1292 #endif
1293 
1294 /*
1295  * Thin wrappers that convert strings to exactly 64-bit integers, matching our
1296  * definition of int64. (For the naming, compare that POSIX has
1297  * strtoimax()/strtoumax() which return intmax_t/uintmax_t.)
1298  */
1299 #ifdef HAVE_LONG_INT_64
1300 #define strtoi64(str, endptr, base) ((int64) strtol(str, endptr, base))
1301 #define strtou64(str, endptr, base) ((uint64) strtoul(str, endptr, base))
1302 #else
1303 #define strtoi64(str, endptr, base) ((int64) strtoll(str, endptr, base))
1304 #define strtou64(str, endptr, base) ((uint64) strtoull(str, endptr, base))
1305 #endif
1306 
1307 /*
1308  * Similarly, wrappers around labs()/llabs() matching our int64.
1309  */
1310 #ifdef HAVE_LONG_INT_64
1311 #define i64abs(i) labs(i)
1312 #else
1313 #define i64abs(i) llabs(i)
1314 #endif
1315 
1316 /*
1317  * Use "extern PGDLLIMPORT ..." to declare variables that are defined
1318  * in the core backend and need to be accessible by loadable modules.
1319  * No special marking is required on most ports.
1320  */
1321 #ifndef PGDLLIMPORT
1322 #define PGDLLIMPORT
1323 #endif
1324 
1325 /*
1326  * Use "extern PGDLLEXPORT ..." to declare functions that are defined in
1327  * loadable modules and need to be callable by the core backend or other
1328  * loadable modules.
1329  * If the compiler knows __attribute__((visibility("*"))), we use that,
1330  * unless we already have a platform-specific definition. Otherwise,
1331  * no special marking is required.
1332  */
1333 #ifndef PGDLLEXPORT
1334 #ifdef HAVE_VISIBILITY_ATTRIBUTE
1335 #define PGDLLEXPORT __attribute__((visibility("default")))
1336 #else
1337 #define PGDLLEXPORT
1338 #endif
1339 #endif
1340 
1341 /*
1342  * The following is used as the arg list for signal handlers. Any ports
1343  * that take something other than an int argument should override this in
1344  * their pg_config_os.h file. Note that variable names are required
1345  * because it is used in both the prototypes as well as the definitions.
1346  * Note also the long name. We expect that this won't collide with
1347  * other names causing compiler warnings.
1348  */
1349 
1350 #ifndef SIGNAL_ARGS
1351 #define SIGNAL_ARGS int postgres_signal_arg
1352 #endif
1353 
1354 /*
1355  * When there is no sigsetjmp, its functionality is provided by plain
1356  * setjmp. We now support the case only on Windows. However, it seems
1357  * that MinGW-64 has some longstanding issues in its setjmp support,
1358  * so on that toolchain we cheat and use gcc's builtins.
1359  */
1360 #ifdef WIN32
1361 #ifdef __MINGW64__
1362 typedef intptr_t sigjmp_buf[5];
1363 #define sigsetjmp(x,y) __builtin_setjmp(x)
1364 #define siglongjmp __builtin_longjmp
1365 #else /* !__MINGW64__ */
1366 #define sigjmp_buf jmp_buf
1367 #define sigsetjmp(x,y) setjmp(x)
1368 #define siglongjmp longjmp
1369 #endif /* __MINGW64__ */
1370 #endif /* WIN32 */
1371 
1372 /* /port compatibility functions */
1373 #include "port.h"
1374 
1375 #endif /* C_H */
static Datum values[MAXATTR]
Definition: bootstrap.c:151
unsigned short uint16
Definition: c.h:517
unsigned int uint32
Definition: c.h:518
uint16 bits16
Definition: c.h:525
NameData * Name
Definition: c.h:747
signed char int8
Definition: c.h:506
union PGAlignedBlock PGAlignedBlock
signed short int16
Definition: c.h:507
union PGAlignedXLogBlock PGAlignedXLogBlock
uint32 SubTransactionId
Definition: c.h:659
signed int int32
Definition: c.h:508
char * Pointer
Definition: c.h:498
Oid regproc
Definition: c.h:652
uint32 MultiXactOffset
Definition: c.h:667
#define pg_attribute_noreturn()
Definition: c.h:232
double float8
Definition: c.h:633
TransactionId MultiXactId
Definition: c.h:665
#define FLEXIBLE_ARRAY_MEMBER
Definition: c.h:413
unsigned char bool
Definition: c.h:471
regproc RegProcedure
Definition: c.h:653
uint8 bits8
Definition: c.h:524
uint32 bits32
Definition: c.h:526
unsigned int Index
Definition: c.h:617
float float4
Definition: c.h:632
uint32 LocalTransactionId
Definition: c.h:657
unsigned char uint8
Definition: c.h:516
union PGIOAlignedBlock PGIOAlignedBlock
uint32 CommandId
Definition: c.h:669
uint32 TransactionId
Definition: c.h:655
signed int Offset
Definition: c.h:627
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:403
size_t Size
Definition: c.h:608
struct nameData NameData
struct pg_attribute_aligned(8) pg_atomic_uint64
Definition: generic-msvc.h:40
#define NAMEDATALEN
#define PG_IO_ALIGN_SIZE
unsigned int Oid
Definition: postgres_ext.h:31
Definition: c.h:718
int32 vl_len_
Definition: c.h:719
int ndim
Definition: c.h:720
int dim1
Definition: c.h:723
Oid elemtype
Definition: c.h:722
int32 dataoffset
Definition: c.h:721
int lbound1
Definition: c.h:724
Definition: c.h:744
char data[NAMEDATALEN]
Definition: c.h:745
Definition: c.h:729
int dim1
Definition: c.h:734
int32 dataoffset
Definition: c.h:732
Oid elemtype
Definition: c.h:733
int lbound1
Definition: c.h:735
int ndim
Definition: c.h:731
int32 vl_len_
Definition: c.h:730
Definition: c.h:690
char vl_len_[4]
Definition: c.h:691
char vl_dat[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:692
double force_align_d
Definition: c.h:1123
int64 force_align_i64
Definition: c.h:1124
char data[BLCKSZ]
Definition: c.h:1122
char data[XLOG_BLCKSZ]
Definition: c.h:1151
double force_align_d
Definition: c.h:1152
int64 force_align_i64
Definition: c.h:1153
double force_align_d
Definition: c.h:1141
int64 force_align_i64
Definition: c.h:1142
char data[BLCKSZ]
Definition: c.h:1140