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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) 1996-2023, 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 
79 /* ----------------------------------------------------------------
80  * Section 1: compiler characteristics
81  *
82  * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
83  * ----------------------------------------------------------------
84  */
85 
86 /*
87  * Disable "inline" if PG_FORCE_DISABLE_INLINE is defined.
88  * This is used to work around compiler bugs and might also be useful for
89  * investigatory purposes.
90  */
91 #ifdef PG_FORCE_DISABLE_INLINE
92 #undef inline
93 #define inline
94 #endif
95 
96 /*
97  * Attribute macros
98  *
99  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
100  * GCC: https://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html
101  * Clang: https://clang.llvm.org/docs/AttributeReference.html
102  * Sunpro: https://docs.oracle.com/cd/E18659_01/html/821-1384/gjzke.html
103  * XLC: https://www.ibm.com/support/knowledgecenter/SSGH2K_13.1.2/com.ibm.xlc131.aix.doc/language_ref/function_attributes.html
104  * XLC: https://www.ibm.com/support/knowledgecenter/SSGH2K_13.1.2/com.ibm.xlc131.aix.doc/language_ref/type_attrib.html
105  */
106 
107 /*
108  * For compilers which don't support __has_attribute, we just define
109  * __has_attribute(x) to 0 so that we can define macros for various
110  * __attribute__s more easily below.
111  */
112 #ifndef __has_attribute
113 #define __has_attribute(attribute) 0
114 #endif
115 
116 /* only GCC supports the unused attribute */
117 #ifdef __GNUC__
118 #define pg_attribute_unused() __attribute__((unused))
119 #else
120 #define pg_attribute_unused()
121 #endif
122 
123 /*
124  * pg_nodiscard means the compiler should warn if the result of a function
125  * call is ignored. The name "nodiscard" is chosen in alignment with
126  * (possibly future) C and C++ standards. For maximum compatibility, use it
127  * as a function declaration specifier, so it goes before the return type.
128  */
129 #ifdef __GNUC__
130 #define pg_nodiscard __attribute__((warn_unused_result))
131 #else
132 #define pg_nodiscard
133 #endif
134 
135 /*
136  * Place this macro before functions that should be allowed to make misaligned
137  * accesses. Think twice before using it on non-x86-specific code!
138  * Testing can be done with "-fsanitize=alignment -fsanitize-trap=alignment"
139  * on clang, or "-fsanitize=alignment -fno-sanitize-recover=alignment" on gcc.
140  */
141 #if __clang_major__ >= 7 || __GNUC__ >= 8
142 #define pg_attribute_no_sanitize_alignment() __attribute__((no_sanitize("alignment")))
143 #else
144 #define pg_attribute_no_sanitize_alignment()
145 #endif
146 
147 /*
148  * pg_attribute_nonnull means the compiler should warn if the function is
149  * called with the listed arguments set to NULL. If no arguments are
150  * listed, the compiler should warn if any pointer arguments are set to NULL.
151  */
152 #if __has_attribute (nonnull)
153 #define pg_attribute_nonnull(...) __attribute__((nonnull(__VA_ARGS__)))
154 #else
155 #define pg_attribute_nonnull(...)
156 #endif
157 
158 /*
159  * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
160  * used in assert-enabled builds, to avoid compiler warnings about unused
161  * variables in assert-disabled builds.
162  */
163 #ifdef USE_ASSERT_CHECKING
164 #define PG_USED_FOR_ASSERTS_ONLY
165 #else
166 #define PG_USED_FOR_ASSERTS_ONLY pg_attribute_unused()
167 #endif
168 
169 /* GCC and XLC support format attributes */
170 #if defined(__GNUC__) || defined(__IBMC__)
171 #define pg_attribute_format_arg(a) __attribute__((format_arg(a)))
172 #define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a)))
173 #else
174 #define pg_attribute_format_arg(a)
175 #define pg_attribute_printf(f,a)
176 #endif
177 
178 /* GCC, Sunpro and XLC support aligned, packed and noreturn */
179 #if defined(__GNUC__) || defined(__SUNPRO_C) || defined(__IBMC__)
180 #define pg_attribute_aligned(a) __attribute__((aligned(a)))
181 #define pg_attribute_noreturn() __attribute__((noreturn))
182 #define pg_attribute_packed() __attribute__((packed))
183 #define HAVE_PG_ATTRIBUTE_NORETURN 1
184 #elif defined(_MSC_VER)
185 /*
186  * MSVC supports aligned. noreturn is also possible but in MSVC it is
187  * declared before the definition while pg_attribute_noreturn() macro
188  * is currently used after the definition.
189  *
190  * Packing is also possible but only by wrapping the entire struct definition
191  * which doesn't fit into our current macro declarations.
192  */
193 #define pg_attribute_aligned(a) __declspec(align(a))
194 #define pg_attribute_noreturn()
195 #else
196 /*
197  * NB: aligned and packed are not given default definitions because they
198  * affect code functionality; they *must* be implemented by the compiler
199  * if they are to be used.
200  */
201 #define pg_attribute_noreturn()
202 #endif
203 
204 /*
205  * Use "pg_attribute_always_inline" in place of "inline" for functions that
206  * we wish to force inlining of, even when the compiler's heuristics would
207  * choose not to. But, if possible, don't force inlining in unoptimized
208  * debug builds.
209  */
210 #if (defined(__GNUC__) && __GNUC__ > 3 && defined(__OPTIMIZE__)) || defined(__SUNPRO_C) || defined(__IBMC__)
211 /* GCC > 3, Sunpro and XLC support always_inline via __attribute__ */
212 #define pg_attribute_always_inline __attribute__((always_inline)) inline
213 #elif defined(_MSC_VER)
214 /* MSVC has a special keyword for this */
215 #define pg_attribute_always_inline __forceinline
216 #else
217 /* Otherwise, the best we can do is to say "inline" */
218 #define pg_attribute_always_inline inline
219 #endif
220 
221 /*
222  * Forcing a function not to be inlined can be useful if it's the slow path of
223  * a performance-critical function, or should be visible in profiles to allow
224  * for proper cost attribution. Note that unlike the pg_attribute_XXX macros
225  * above, this should be placed before the function's return type and name.
226  */
227 /* GCC, Sunpro and XLC support noinline via __attribute__ */
228 #if (defined(__GNUC__) && __GNUC__ > 2) || defined(__SUNPRO_C) || defined(__IBMC__)
229 #define pg_noinline __attribute__((noinline))
230 /* msvc via declspec */
231 #elif defined(_MSC_VER)
232 #define pg_noinline __declspec(noinline)
233 #else
234 #define pg_noinline
235 #endif
236 
237 /*
238  * For now, just define pg_attribute_cold and pg_attribute_hot to be empty
239  * macros on minGW 8.1. There appears to be a compiler bug that results in
240  * compilation failure. At this time, we still have at least one buildfarm
241  * animal running that compiler, so this should make that green again. It's
242  * likely this compiler is not popular enough to warrant keeping this code
243  * around forever, so let's just remove it once the last buildfarm animal
244  * upgrades.
245  */
246 #if defined(__MINGW64__) && __GNUC__ == 8 && __GNUC_MINOR__ == 1
247 
248 #define pg_attribute_cold
249 #define pg_attribute_hot
250 
251 #else
252 /*
253  * Marking certain functions as "hot" or "cold" can be useful to assist the
254  * compiler in arranging the assembly code in a more efficient way.
255  */
256 #if __has_attribute (cold)
257 #define pg_attribute_cold __attribute__((cold))
258 #else
259 #define pg_attribute_cold
260 #endif
261 
262 #if __has_attribute (hot)
263 #define pg_attribute_hot __attribute__((hot))
264 #else
265 #define pg_attribute_hot
266 #endif
267 
268 #endif /* defined(__MINGW64__) && __GNUC__ == 8 &&
269  * __GNUC_MINOR__ == 1 */
270 /*
271  * Mark a point as unreachable in a portable fashion. This should preferably
272  * be something that the compiler understands, to aid code generation.
273  * In assert-enabled builds, we prefer abort() for debugging reasons.
274  */
275 #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
276 #define pg_unreachable() __builtin_unreachable()
277 #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
278 #define pg_unreachable() __assume(0)
279 #else
280 #define pg_unreachable() abort()
281 #endif
282 
283 /*
284  * Hints to the compiler about the likelihood of a branch. Both likely() and
285  * unlikely() return the boolean value of the contained expression.
286  *
287  * These should only be used sparingly, in very hot code paths. It's very easy
288  * to mis-estimate likelihoods.
289  */
290 #if __GNUC__ >= 3
291 #define likely(x) __builtin_expect((x) != 0, 1)
292 #define unlikely(x) __builtin_expect((x) != 0, 0)
293 #else
294 #define likely(x) ((x) != 0)
295 #define unlikely(x) ((x) != 0)
296 #endif
297 
298 /*
299  * CppAsString
300  * Convert the argument to a string, using the C preprocessor.
301  * CppAsString2
302  * Convert the argument to a string, after one round of macro expansion.
303  * CppConcat
304  * Concatenate two arguments together, using the C preprocessor.
305  *
306  * Note: There used to be support here for pre-ANSI C compilers that didn't
307  * support # and ##. Nowadays, these macros are just for clarity and/or
308  * backward compatibility with existing PostgreSQL code.
309  */
310 #define CppAsString(identifier) #identifier
311 #define CppAsString2(x) CppAsString(x)
312 #define CppConcat(x, y) x##y
313 
314 /*
315  * VA_ARGS_NARGS
316  * Returns the number of macro arguments it is passed.
317  *
318  * An empty argument still counts as an argument, so effectively, this is
319  * "one more than the number of commas in the argument list".
320  *
321  * This works for up to 63 arguments. Internally, VA_ARGS_NARGS_() is passed
322  * 64+N arguments, and the C99 standard only requires macros to allow up to
323  * 127 arguments, so we can't portably go higher. The implementation is
324  * pretty trivial: VA_ARGS_NARGS_() returns its 64th argument, and we set up
325  * the call so that that is the appropriate one of the list of constants.
326  * This idea is due to Laurent Deniau.
327  *
328  * MSVC has an implementation of __VA_ARGS__ that doesn't conform to the
329  * standard unless you use the /Zc:preprocessor compiler flag, but that
330  * isn't available before Visual Studio 2019. For now, use a different
331  * definition that also works on older compilers.
332  */
333 #ifdef _MSC_VER
334 #define EXPAND(args) args
335 #define VA_ARGS_NARGS(...) \
336  VA_ARGS_NARGS_ EXPAND((__VA_ARGS__, \
337  63,62,61,60, \
338  59,58,57,56,55,54,53,52,51,50, \
339  49,48,47,46,45,44,43,42,41,40, \
340  39,38,37,36,35,34,33,32,31,30, \
341  29,28,27,26,25,24,23,22,21,20, \
342  19,18,17,16,15,14,13,12,11,10, \
343  9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
344 #else
345 
346 #define VA_ARGS_NARGS(...) \
347  VA_ARGS_NARGS_(__VA_ARGS__, \
348  63,62,61,60, \
349  59,58,57,56,55,54,53,52,51,50, \
350  49,48,47,46,45,44,43,42,41,40, \
351  39,38,37,36,35,34,33,32,31,30, \
352  29,28,27,26,25,24,23,22,21,20, \
353  19,18,17,16,15,14,13,12,11,10, \
354  9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
355 #endif
356 
357 #define VA_ARGS_NARGS_( \
358  _01,_02,_03,_04,_05,_06,_07,_08,_09,_10, \
359  _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \
360  _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \
361  _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \
362  _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \
363  _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \
364  _61,_62,_63, N, ...) \
365  (N)
366 
367 /*
368  * Generic function pointer. This can be used in the rare cases where it's
369  * necessary to cast a function pointer to a seemingly incompatible function
370  * pointer type while avoiding gcc's -Wcast-function-type warnings.
371  */
372 typedef void (*pg_funcptr_t) (void);
373 
374 /*
375  * We require C99, hence the compiler should understand flexible array
376  * members. However, for documentation purposes we still consider it to be
377  * project style to write "field[FLEXIBLE_ARRAY_MEMBER]" not just "field[]".
378  * When computing the size of such an object, use "offsetof(struct s, f)"
379  * for portability. Don't use "offsetof(struct s, f[0])", as this doesn't
380  * work with MSVC and with C++ compilers.
381  */
382 #define FLEXIBLE_ARRAY_MEMBER /* empty */
383 
384 /*
385  * Does the compiler support #pragma GCC system_header? We optionally use it
386  * to avoid warnings that we can't fix (e.g. in the perl headers).
387  * See https://gcc.gnu.org/onlinedocs/cpp/System-Headers.html
388  *
389  * Headers for which we do not want to show compiler warnings can,
390  * conditionally, use #pragma GCC system_header to avoid warnings. Obviously
391  * this should only be used for external headers over which we do not have
392  * control.
393  *
394  * Support for the pragma is tested here, instead of during configure, as gcc
395  * also warns about the pragma being used in a .c file. It's surprisingly hard
396  * to get autoconf to use .h as the file-ending. Looks like gcc has
397  * implemented the pragma since the 2000, so this test should suffice.
398  *
399  *
400  * Alternatively, we could add the include paths for problematic headers with
401  * -isystem, but that is a larger hammer and is harder to search for.
402  *
403  * A more granular alternative would be to use #pragma GCC diagnostic
404  * push/ignored/pop, but gcc warns about unknown warnings being ignored, so
405  * every to-be-ignored-temporarily compiler warning would require its own
406  * pg_config.h symbol and #ifdef.
407  */
408 #ifdef __GNUC__
409 #define HAVE_PRAGMA_GCC_SYSTEM_HEADER 1
410 #endif
411 
412 
413 /* ----------------------------------------------------------------
414  * Section 2: bool, true, false
415  * ----------------------------------------------------------------
416  */
417 
418 /*
419  * bool
420  * Boolean value, either true or false.
421  *
422  * We use stdbool.h if available and its bool has size 1. That's useful for
423  * better compiler and debugger output and for compatibility with third-party
424  * libraries. But PostgreSQL currently cannot deal with bool of other sizes;
425  * there are static assertions around the code to prevent that.
426  *
427  * For C++ compilers, we assume the compiler has a compatible built-in
428  * definition of bool.
429  *
430  * See also the version of this code in src/interfaces/ecpg/include/ecpglib.h.
431  */
432 
433 #ifndef __cplusplus
434 
435 #ifdef PG_USE_STDBOOL
436 #include <stdbool.h>
437 #else
438 
439 #ifndef bool
440 typedef unsigned char bool;
441 #endif
442 
443 #ifndef true
444 #define true ((bool) 1)
445 #endif
446 
447 #ifndef false
448 #define false ((bool) 0)
449 #endif
450 
451 #endif /* not PG_USE_STDBOOL */
452 #endif /* not C++ */
453 
454 
455 /* ----------------------------------------------------------------
456  * Section 3: standard system types
457  * ----------------------------------------------------------------
458  */
459 
460 /*
461  * Pointer
462  * Variable holding address of any memory resident object.
463  *
464  * XXX Pointer arithmetic is done with this, so it can't be void *
465  * under "true" ANSI compilers.
466  */
467 typedef char *Pointer;
468 
469 /*
470  * intN
471  * Signed integer, EXACTLY N BITS IN SIZE,
472  * used for numerical computations and the
473  * frontend/backend protocol.
474  */
475 #ifndef HAVE_INT8
476 typedef signed char int8; /* == 8 bits */
477 typedef signed short int16; /* == 16 bits */
478 typedef signed int int32; /* == 32 bits */
479 #endif /* not HAVE_INT8 */
480 
481 /*
482  * uintN
483  * Unsigned integer, EXACTLY N BITS IN SIZE,
484  * used for numerical computations and the
485  * frontend/backend protocol.
486  */
487 #ifndef HAVE_UINT8
488 typedef unsigned char uint8; /* == 8 bits */
489 typedef unsigned short uint16; /* == 16 bits */
490 typedef unsigned int uint32; /* == 32 bits */
491 #endif /* not HAVE_UINT8 */
492 
493 /*
494  * bitsN
495  * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
496  */
497 typedef uint8 bits8; /* >= 8 bits */
498 typedef uint16 bits16; /* >= 16 bits */
499 typedef uint32 bits32; /* >= 32 bits */
500 
501 /*
502  * 64-bit integers
503  */
504 #ifdef HAVE_LONG_INT_64
505 /* Plain "long int" fits, use it */
506 
507 #ifndef HAVE_INT64
508 typedef long int int64;
509 #endif
510 #ifndef HAVE_UINT64
511 typedef unsigned long int uint64;
512 #endif
513 #define INT64CONST(x) (x##L)
514 #define UINT64CONST(x) (x##UL)
515 #elif defined(HAVE_LONG_LONG_INT_64)
516 /* We have working support for "long long int", use that */
517 
518 #ifndef HAVE_INT64
519 typedef long long int int64;
520 #endif
521 #ifndef HAVE_UINT64
522 typedef unsigned long long int uint64;
523 #endif
524 #define INT64CONST(x) (x##LL)
525 #define UINT64CONST(x) (x##ULL)
526 #else
527 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
528 #error must have a working 64-bit integer datatype
529 #endif
530 
531 /* snprintf format strings to use for 64-bit integers */
532 #define INT64_FORMAT "%" INT64_MODIFIER "d"
533 #define UINT64_FORMAT "%" INT64_MODIFIER "u"
534 
535 /*
536  * 128-bit signed and unsigned integers
537  * There currently is only limited support for such types.
538  * E.g. 128bit literals and snprintf are not supported; but math is.
539  * Also, because we exclude such types when choosing MAXIMUM_ALIGNOF,
540  * it must be possible to coerce the compiler to allocate them on no
541  * more than MAXALIGN boundaries.
542  */
543 #if defined(PG_INT128_TYPE)
544 #if defined(pg_attribute_aligned) || ALIGNOF_PG_INT128_TYPE <= MAXIMUM_ALIGNOF
545 #define HAVE_INT128 1
546 
547 typedef PG_INT128_TYPE int128
548 #if defined(pg_attribute_aligned)
549  pg_attribute_aligned(MAXIMUM_ALIGNOF)
550 #endif
551  ;
552 
553 typedef unsigned PG_INT128_TYPE uint128
554 #if defined(pg_attribute_aligned)
555  pg_attribute_aligned(MAXIMUM_ALIGNOF)
556 #endif
557  ;
558 
559 #endif
560 #endif
561 
562 /*
563  * stdint.h limits aren't guaranteed to have compatible types with our fixed
564  * width types. So just define our own.
565  */
566 #define PG_INT8_MIN (-0x7F-1)
567 #define PG_INT8_MAX (0x7F)
568 #define PG_UINT8_MAX (0xFF)
569 #define PG_INT16_MIN (-0x7FFF-1)
570 #define PG_INT16_MAX (0x7FFF)
571 #define PG_UINT16_MAX (0xFFFF)
572 #define PG_INT32_MIN (-0x7FFFFFFF-1)
573 #define PG_INT32_MAX (0x7FFFFFFF)
574 #define PG_UINT32_MAX (0xFFFFFFFFU)
575 #define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
576 #define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF)
577 #define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
578 
579 /*
580  * We now always use int64 timestamps, but keep this symbol defined for the
581  * benefit of external code that might test it.
582  */
583 #define HAVE_INT64_TIMESTAMP
584 
585 /*
586  * Size
587  * Size of any memory resident object, as returned by sizeof.
588  */
589 typedef size_t Size;
590 
591 /*
592  * Index
593  * Index into any memory resident array.
594  *
595  * Note:
596  * Indices are non negative.
597  */
598 typedef unsigned int Index;
599 
600 /*
601  * Offset
602  * Offset into any memory resident array.
603  *
604  * Note:
605  * This differs from an Index in that an Index is always
606  * non negative, whereas Offset may be negative.
607  */
608 typedef signed int Offset;
609 
610 /*
611  * Common Postgres datatype names (as used in the catalogs)
612  */
613 typedef float float4;
614 typedef double float8;
615 
616 #ifdef USE_FLOAT8_BYVAL
617 #define FLOAT8PASSBYVAL true
618 #else
619 #define FLOAT8PASSBYVAL false
620 #endif
621 
622 /*
623  * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
624  * CommandId
625  */
626 
627 /* typedef Oid is in postgres_ext.h */
628 
629 /*
630  * regproc is the type name used in the include/catalog headers, but
631  * RegProcedure is the preferred name in C code.
632  */
633 typedef Oid regproc;
635 
637 
639 
641 
642 #define InvalidSubTransactionId ((SubTransactionId) 0)
643 #define TopSubTransactionId ((SubTransactionId) 1)
644 
645 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
647 
649 
651 
652 #define FirstCommandId ((CommandId) 0)
653 #define InvalidCommandId (~(CommandId)0)
654 
655 
656 /* ----------------
657  * Variable-length datatypes all share the 'struct varlena' header.
658  *
659  * NOTE: for TOASTable types, this is an oversimplification, since the value
660  * may be compressed or moved out-of-line. However datatype-specific routines
661  * are mostly content to deal with de-TOASTed values only, and of course
662  * client-side routines should never see a TOASTed value. But even in a
663  * de-TOASTed value, beware of touching vl_len_ directly, as its
664  * representation is no longer convenient. It's recommended that code always
665  * use macros VARDATA_ANY, VARSIZE_ANY, VARSIZE_ANY_EXHDR, VARDATA, VARSIZE,
666  * and SET_VARSIZE instead of relying on direct mentions of the struct fields.
667  * See postgres.h for details of the TOASTed form.
668  * ----------------
669  */
670 struct varlena
671 {
672  char vl_len_[4]; /* Do not touch this field directly! */
673  char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */
674 };
675 
676 #define VARHDRSZ ((int32) sizeof(int32))
677 
678 /*
679  * These widely-used datatypes are just a varlena header and the data bytes.
680  * There is no terminating null or anything like that --- the data length is
681  * always VARSIZE_ANY_EXHDR(ptr).
682  */
683 typedef struct varlena bytea;
684 typedef struct varlena text;
685 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
686 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
687 
688 /*
689  * Specialized array types. These are physically laid out just the same
690  * as regular arrays (so that the regular array subscripting code works
691  * with them). They exist as distinct types mostly for historical reasons:
692  * they have nonstandard I/O behavior which we don't want to change for fear
693  * of breaking applications that look at the system catalogs. There is also
694  * an implementation issue for oidvector: it's part of the primary key for
695  * pg_proc, and we can't use the normal btree array support routines for that
696  * without circularity.
697  */
698 typedef struct
699 {
700  int32 vl_len_; /* these fields must match ArrayType! */
701  int ndim; /* always 1 for int2vector */
702  int32 dataoffset; /* always 0 for int2vector */
704  int dim1;
705  int lbound1;
707 } int2vector;
708 
709 typedef struct
710 {
711  int32 vl_len_; /* these fields must match ArrayType! */
712  int ndim; /* always 1 for oidvector */
713  int32 dataoffset; /* always 0 for oidvector */
715  int dim1;
716  int lbound1;
718 } oidvector;
719 
720 /*
721  * Representation of a Name: effectively just a C string, but null-padded to
722  * exactly NAMEDATALEN bytes. The use of a struct is historical.
723  */
724 typedef struct nameData
725 {
728 typedef NameData *Name;
729 
730 #define NameStr(name) ((name).data)
731 
732 
733 /* ----------------------------------------------------------------
734  * Section 4: IsValid macros for system types
735  * ----------------------------------------------------------------
736  */
737 /*
738  * BoolIsValid
739  * True iff bool is valid.
740  */
741 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
742 
743 /*
744  * PointerIsValid
745  * True iff pointer is valid.
746  */
747 #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
748 
749 /*
750  * PointerIsAligned
751  * True iff pointer is properly aligned to point to the given type.
752  */
753 #define PointerIsAligned(pointer, type) \
754  (((uintptr_t)(pointer) % (sizeof (type))) == 0)
755 
756 #define OffsetToPointer(base, offset) \
757  ((void *)((char *) base + offset))
758 
759 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
760 
761 #define RegProcedureIsValid(p) OidIsValid(p)
762 
763 
764 /* ----------------------------------------------------------------
765  * Section 5: lengthof, alignment
766  * ----------------------------------------------------------------
767  */
768 /*
769  * lengthof
770  * Number of elements in an array.
771  */
772 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
773 
774 /* ----------------
775  * Alignment macros: align a length or address appropriately for a given type.
776  * The fooALIGN() macros round up to a multiple of the required alignment,
777  * while the fooALIGN_DOWN() macros round down. The latter are more useful
778  * for problems like "how many X-sized structures will fit in a page?".
779  *
780  * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
781  * That case seems extremely unlikely to be needed in practice, however.
782  *
783  * NOTE: MAXIMUM_ALIGNOF, and hence MAXALIGN(), intentionally exclude any
784  * larger-than-8-byte types the compiler might have.
785  * ----------------
786  */
787 
788 #define TYPEALIGN(ALIGNVAL,LEN) \
789  (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
790 
791 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
792 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
793 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
794 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
795 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
796 /* MAXALIGN covers only built-in types, not buffers */
797 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
798 #define CACHELINEALIGN(LEN) TYPEALIGN(PG_CACHE_LINE_SIZE, (LEN))
799 
800 #define TYPEALIGN_DOWN(ALIGNVAL,LEN) \
801  (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
802 
803 #define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
804 #define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
805 #define LONGALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
806 #define DOUBLEALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
807 #define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
808 #define BUFFERALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_BUFFER, (LEN))
809 
810 /*
811  * The above macros will not work with types wider than uintptr_t, like with
812  * uint64 on 32-bit platforms. That's not problem for the usual use where a
813  * pointer or a length is aligned, but for the odd case that you need to
814  * align something (potentially) wider, use TYPEALIGN64.
815  */
816 #define TYPEALIGN64(ALIGNVAL,LEN) \
817  (((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1)))
818 
819 /* we don't currently need wider versions of the other ALIGN macros */
820 #define MAXALIGN64(LEN) TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN))
821 
822 
823 /* ----------------------------------------------------------------
824  * Section 6: assertions
825  * ----------------------------------------------------------------
826  */
827 
828 /*
829  * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
830  * - plai 9/5/90
831  *
832  * It should _NOT_ be defined in releases or in benchmark copies
833  */
834 
835 /*
836  * Assert() can be used in both frontend and backend code. In frontend code it
837  * just calls the standard assert, if it's available. If use of assertions is
838  * not configured, it does nothing.
839  */
840 #ifndef USE_ASSERT_CHECKING
841 
842 #define Assert(condition) ((void)true)
843 #define AssertMacro(condition) ((void)true)
844 
845 #elif defined(FRONTEND)
846 
847 #include <assert.h>
848 #define Assert(p) assert(p)
849 #define AssertMacro(p) ((void) assert(p))
850 
851 #else /* USE_ASSERT_CHECKING && !FRONTEND */
852 
853 /*
854  * Assert
855  * Generates a fatal exception if the given condition is false.
856  */
857 #define Assert(condition) \
858  do { \
859  if (!(condition)) \
860  ExceptionalCondition(#condition, __FILE__, __LINE__); \
861  } while (0)
862 
863 /*
864  * AssertMacro is the same as Assert but it's suitable for use in
865  * expression-like macros, for example:
866  *
867  * #define foo(x) (AssertMacro(x != 0), bar(x))
868  */
869 #define AssertMacro(condition) \
870  ((void) ((condition) || \
871  (ExceptionalCondition(#condition, __FILE__, __LINE__), 0)))
872 
873 #endif /* USE_ASSERT_CHECKING && !FRONTEND */
874 
875 /*
876  * Check that `ptr' is `bndr' aligned.
877  */
878 #define AssertPointerAlignment(ptr, bndr) \
879  Assert(TYPEALIGN(bndr, (uintptr_t)(ptr)) == (uintptr_t)(ptr))
880 
881 /*
882  * ExceptionalCondition is compiled into the backend whether or not
883  * USE_ASSERT_CHECKING is defined, so as to support use of extensions
884  * that are built with that #define with a backend that isn't. Hence,
885  * we should declare it as long as !FRONTEND.
886  */
887 #ifndef FRONTEND
888 extern void ExceptionalCondition(const char *conditionName,
889  const char *fileName, int lineNumber) pg_attribute_noreturn();
890 #endif
891 
892 /*
893  * Macros to support compile-time assertion checks.
894  *
895  * If the "condition" (a compile-time-constant expression) evaluates to false,
896  * throw a compile error using the "errmessage" (a string literal).
897  *
898  * C11 has _Static_assert(), and most C99 compilers already support that. For
899  * portability, we wrap it into StaticAssertDecl(). _Static_assert() is a
900  * "declaration", and so it must be placed where for example a variable
901  * declaration would be valid. As long as we compile with
902  * -Wno-declaration-after-statement, that also means it cannot be placed after
903  * statements in a function. Macros StaticAssertStmt() and StaticAssertExpr()
904  * make it safe to use as a statement or in an expression, respectively.
905  *
906  * For compilers without _Static_assert(), we fall back on a kluge that
907  * assumes the compiler will complain about a negative width for a struct
908  * bit-field. This will not include a helpful error message, but it beats not
909  * getting an error at all.
910  */
911 #ifndef __cplusplus
912 #ifdef HAVE__STATIC_ASSERT
913 #define StaticAssertDecl(condition, errmessage) \
914  _Static_assert(condition, errmessage)
915 #define StaticAssertStmt(condition, errmessage) \
916  do { _Static_assert(condition, errmessage); } while(0)
917 #define StaticAssertExpr(condition, errmessage) \
918  ((void) ({ StaticAssertStmt(condition, errmessage); true; }))
919 #else /* !HAVE__STATIC_ASSERT */
920 #define StaticAssertDecl(condition, errmessage) \
921  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
922 #define StaticAssertStmt(condition, errmessage) \
923  ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
924 #define StaticAssertExpr(condition, errmessage) \
925  StaticAssertStmt(condition, errmessage)
926 #endif /* HAVE__STATIC_ASSERT */
927 #else /* C++ */
928 #if defined(__cpp_static_assert) && __cpp_static_assert >= 200410
929 #define StaticAssertDecl(condition, errmessage) \
930  static_assert(condition, errmessage)
931 #define StaticAssertStmt(condition, errmessage) \
932  static_assert(condition, errmessage)
933 #define StaticAssertExpr(condition, errmessage) \
934  ({ static_assert(condition, errmessage); })
935 #else /* !__cpp_static_assert */
936 #define StaticAssertDecl(condition, errmessage) \
937  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
938 #define StaticAssertStmt(condition, errmessage) \
939  do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0)
940 #define StaticAssertExpr(condition, errmessage) \
941  ((void) ({ StaticAssertStmt(condition, errmessage); }))
942 #endif /* __cpp_static_assert */
943 #endif /* C++ */
944 
945 
946 /*
947  * Compile-time checks that a variable (or expression) has the specified type.
948  *
949  * AssertVariableIsOfType() can be used as a statement.
950  * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
951  * #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
952  *
953  * If we don't have __builtin_types_compatible_p, we can still assert that
954  * the types have the same size. This is far from ideal (especially on 32-bit
955  * platforms) but it provides at least some coverage.
956  */
957 #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
958 #define AssertVariableIsOfType(varname, typename) \
959  StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
960  CppAsString(varname) " does not have type " CppAsString(typename))
961 #define AssertVariableIsOfTypeMacro(varname, typename) \
962  (StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
963  CppAsString(varname) " does not have type " CppAsString(typename)))
964 #else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
965 #define AssertVariableIsOfType(varname, typename) \
966  StaticAssertStmt(sizeof(varname) == sizeof(typename), \
967  CppAsString(varname) " does not have type " CppAsString(typename))
968 #define AssertVariableIsOfTypeMacro(varname, typename) \
969  (StaticAssertExpr(sizeof(varname) == sizeof(typename), \
970  CppAsString(varname) " does not have type " CppAsString(typename)))
971 #endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
972 
973 
974 /* ----------------------------------------------------------------
975  * Section 7: widely useful macros
976  * ----------------------------------------------------------------
977  */
978 /*
979  * Max
980  * Return the maximum of two numbers.
981  */
982 #define Max(x, y) ((x) > (y) ? (x) : (y))
983 
984 /*
985  * Min
986  * Return the minimum of two numbers.
987  */
988 #define Min(x, y) ((x) < (y) ? (x) : (y))
989 
990 
991 /* Get a bit mask of the bits set in non-long aligned addresses */
992 #define LONG_ALIGN_MASK (sizeof(long) - 1)
993 
994 /*
995  * MemSet
996  * Exactly the same as standard library function memset(), but considerably
997  * faster for zeroing small word-aligned structures (such as parsetree nodes).
998  * This has to be a macro because the main point is to avoid function-call
999  * overhead. However, we have also found that the loop is faster than
1000  * native libc memset() on some platforms, even those with assembler
1001  * memset() functions. More research needs to be done, perhaps with
1002  * MEMSET_LOOP_LIMIT tests in configure.
1003  */
1004 #define MemSet(start, val, len) \
1005  do \
1006  { \
1007  /* must be void* because we don't know if it is integer aligned yet */ \
1008  void *_vstart = (void *) (start); \
1009  int _val = (val); \
1010  Size _len = (len); \
1011 \
1012  if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
1013  (_len & LONG_ALIGN_MASK) == 0 && \
1014  _val == 0 && \
1015  _len <= MEMSET_LOOP_LIMIT && \
1016  /* \
1017  * If MEMSET_LOOP_LIMIT == 0, optimizer should find \
1018  * the whole "if" false at compile time. \
1019  */ \
1020  MEMSET_LOOP_LIMIT != 0) \
1021  { \
1022  long *_start = (long *) _vstart; \
1023  long *_stop = (long *) ((char *) _start + _len); \
1024  while (_start < _stop) \
1025  *_start++ = 0; \
1026  } \
1027  else \
1028  memset(_vstart, _val, _len); \
1029  } while (0)
1030 
1031 /*
1032  * MemSetAligned is the same as MemSet except it omits the test to see if
1033  * "start" is word-aligned. This is okay to use if the caller knows a-priori
1034  * that the pointer is suitably aligned (typically, because he just got it
1035  * from palloc(), which always delivers a max-aligned pointer).
1036  */
1037 #define MemSetAligned(start, val, len) \
1038  do \
1039  { \
1040  long *_start = (long *) (start); \
1041  int _val = (val); \
1042  Size _len = (len); \
1043 \
1044  if ((_len & LONG_ALIGN_MASK) == 0 && \
1045  _val == 0 && \
1046  _len <= MEMSET_LOOP_LIMIT && \
1047  MEMSET_LOOP_LIMIT != 0) \
1048  { \
1049  long *_stop = (long *) ((char *) _start + _len); \
1050  while (_start < _stop) \
1051  *_start++ = 0; \
1052  } \
1053  else \
1054  memset(_start, _val, _len); \
1055  } while (0)
1056 
1057 
1058 /*
1059  * MemSetTest/MemSetLoop are a variant version that allow all the tests in
1060  * MemSet to be done at compile time in cases where "val" and "len" are
1061  * constants *and* we know the "start" pointer must be word-aligned.
1062  * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
1063  * MemSetAligned. Beware of multiple evaluations of the arguments when using
1064  * this approach.
1065  */
1066 #define MemSetTest(val, len) \
1067  ( ((len) & LONG_ALIGN_MASK) == 0 && \
1068  (len) <= MEMSET_LOOP_LIMIT && \
1069  MEMSET_LOOP_LIMIT != 0 && \
1070  (val) == 0 )
1071 
1072 #define MemSetLoop(start, val, len) \
1073  do \
1074  { \
1075  long * _start = (long *) (start); \
1076  long * _stop = (long *) ((char *) _start + (Size) (len)); \
1077  \
1078  while (_start < _stop) \
1079  *_start++ = 0; \
1080  } while (0)
1081 
1082 /*
1083  * Macros for range-checking float values before converting to integer.
1084  * We must be careful here that the boundary values are expressed exactly
1085  * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will
1086  * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded
1087  * off, so avoid using that.
1088  * The input must be rounded to an integer beforehand, typically with rint(),
1089  * else we might draw the wrong conclusion about close-to-the-limit values.
1090  * These macros will do the right thing for Inf, but not necessarily for NaN,
1091  * so check isnan(num) first if that's a possibility.
1092  */
1093 #define FLOAT4_FITS_IN_INT16(num) \
1094  ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN))
1095 #define FLOAT4_FITS_IN_INT32(num) \
1096  ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN))
1097 #define FLOAT4_FITS_IN_INT64(num) \
1098  ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN))
1099 #define FLOAT8_FITS_IN_INT16(num) \
1100  ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN))
1101 #define FLOAT8_FITS_IN_INT32(num) \
1102  ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN))
1103 #define FLOAT8_FITS_IN_INT64(num) \
1104  ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN))
1105 
1106 
1107 /* ----------------------------------------------------------------
1108  * Section 8: random stuff
1109  * ----------------------------------------------------------------
1110  */
1111 
1112 /*
1113  * Invert the sign of a qsort-style comparison result, ie, exchange negative
1114  * and positive integer values, being careful not to get the wrong answer
1115  * for INT_MIN. The argument should be an integral variable.
1116  */
1117 #define INVERT_COMPARE_RESULT(var) \
1118  ((var) = ((var) < 0) ? 1 : -(var))
1119 
1120 /*
1121  * Use this, not "char buf[BLCKSZ]", to declare a field or local variable
1122  * holding a page buffer, if that page might be accessed as a page and not
1123  * just a string of bytes. Otherwise the variable might be under-aligned,
1124  * causing problems on alignment-picky hardware. (In some places, we use
1125  * this to declare buffers even though we only pass them to read() and
1126  * write(), because copying to/from aligned buffers is usually faster than
1127  * using unaligned buffers.) We include both "double" and "int64" in the
1128  * union to ensure that the compiler knows the value must be MAXALIGN'ed
1129  * (cf. configure's computation of MAXIMUM_ALIGNOF).
1130  */
1131 typedef union PGAlignedBlock
1133  char data[BLCKSZ];
1134  double force_align_d;
1135  int64 force_align_i64;
1137 
1138 /* Same, but for an XLOG_BLCKSZ-sized buffer */
1139 typedef union PGAlignedXLogBlock
1141  char data[XLOG_BLCKSZ];
1142  double force_align_d;
1143  int64 force_align_i64;
1146 /* msb for char */
1147 #define HIGHBIT (0x80)
1148 #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
1149 
1150 /*
1151  * Support macros for escaping strings. escape_backslash should be true
1152  * if generating a non-standard-conforming string. Prefixing a string
1153  * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
1154  * Beware of multiple evaluation of the "ch" argument!
1155  */
1156 #define SQL_STR_DOUBLE(ch, escape_backslash) \
1157  ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
1158 
1159 #define ESCAPE_STRING_SYNTAX 'E'
1162 #define STATUS_OK (0)
1163 #define STATUS_ERROR (-1)
1164 #define STATUS_EOF (-2)
1165 
1166 /*
1167  * gettext support
1168  */
1170 #ifndef ENABLE_NLS
1171 /* stuff we'd otherwise get from <libintl.h> */
1172 #define gettext(x) (x)
1173 #define dgettext(d,x) (x)
1174 #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
1175 #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
1176 #endif
1177 
1178 #define _(x) gettext(x)
1179 
1180 /*
1181  * Use this to mark string constants as needing translation at some later
1182  * time, rather than immediately. This is useful for cases where you need
1183  * access to the original string and translated string, and for cases where
1184  * immediate translation is not possible, like when initializing global
1185  * variables.
1186  *
1187  * https://www.gnu.org/software/gettext/manual/html_node/Special-cases.html
1188  */
1189 #define gettext_noop(x) (x)
1190 
1191 /*
1192  * To better support parallel installations of major PostgreSQL
1193  * versions as well as parallel installations of major library soname
1194  * versions, we mangle the gettext domain name by appending those
1195  * version numbers. The coding rule ought to be that wherever the
1196  * domain name is mentioned as a literal, it must be wrapped into
1197  * PG_TEXTDOMAIN(). The macros below do not work on non-literals; but
1198  * that is somewhat intentional because it avoids having to worry
1199  * about multiple states of premangling and postmangling as the values
1200  * are being passed around.
1201  *
1202  * Make sure this matches the installation rules in nls-global.mk.
1203  */
1204 #ifdef SO_MAJOR_VERSION
1205 #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
1206 #else
1207 #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
1208 #endif
1209 
1210 /*
1211  * Macro that allows to cast constness and volatile away from an expression, but doesn't
1212  * allow changing the underlying type. Enforcement of the latter
1213  * currently only works for gcc like compilers.
1214  *
1215  * Please note IT IS NOT SAFE to cast constness away if the result will ever
1216  * be modified (it would be undefined behaviour). Doing so anyway can cause
1217  * compiler misoptimizations or runtime crashes (modifying readonly memory).
1218  * It is only safe to use when the result will not be modified, but API
1219  * design or language restrictions prevent you from declaring that
1220  * (e.g. because a function returns both const and non-const variables).
1221  *
1222  * Note that this only works in function scope, not for global variables (it'd
1223  * be nice, but not trivial, to improve that).
1224  */
1225 #if 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:156
unsigned short uint16
Definition: c.h:489
unsigned int uint32
Definition: c.h:490
uint16 bits16
Definition: c.h:498
NameData * Name
Definition: c.h:728
signed char int8
Definition: c.h:476
union PGAlignedBlock PGAlignedBlock
signed short int16
Definition: c.h:477
union PGAlignedXLogBlock PGAlignedXLogBlock
uint32 SubTransactionId
Definition: c.h:640
signed int int32
Definition: c.h:478
char * Pointer
Definition: c.h:467
Oid regproc
Definition: c.h:633
uint32 MultiXactOffset
Definition: c.h:648
#define pg_attribute_noreturn()
Definition: c.h:201
double float8
Definition: c.h:614
TransactionId MultiXactId
Definition: c.h:646
#define FLEXIBLE_ARRAY_MEMBER
Definition: c.h:382
unsigned char bool
Definition: c.h:440
regproc RegProcedure
Definition: c.h:634
uint8 bits8
Definition: c.h:497
uint32 bits32
Definition: c.h:499
unsigned int Index
Definition: c.h:598
float float4
Definition: c.h:613
uint32 LocalTransactionId
Definition: c.h:638
unsigned char uint8
Definition: c.h:488
uint32 CommandId
Definition: c.h:650
uint32 TransactionId
Definition: c.h:636
signed int Offset
Definition: c.h:608
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:372
size_t Size
Definition: c.h:589
struct nameData NameData
#define NAMEDATALEN
unsigned int Oid
Definition: postgres_ext.h:31
Definition: c.h:699
int32 vl_len_
Definition: c.h:700
int ndim
Definition: c.h:701
int dim1
Definition: c.h:704
Oid elemtype
Definition: c.h:703
int32 dataoffset
Definition: c.h:702
int lbound1
Definition: c.h:705
Definition: c.h:725
char data[NAMEDATALEN]
Definition: c.h:726
Definition: c.h:710
int dim1
Definition: c.h:715
int32 dataoffset
Definition: c.h:713
Oid elemtype
Definition: c.h:714
int lbound1
Definition: c.h:716
int ndim
Definition: c.h:712
int32 vl_len_
Definition: c.h:711
Definition: c.h:671
char vl_len_[4]
Definition: c.h:672
char vl_dat[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:673
double force_align_d
Definition: c.h:1131
int64 force_align_i64
Definition: c.h:1132
char data[BLCKSZ]
Definition: c.h:1130
char data[XLOG_BLCKSZ]
Definition: c.h:1138
double force_align_d
Definition: c.h:1139
int64 force_align_i64
Definition: c.h:1140