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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) 1996-2022, 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) offsetof, 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 #else
185 /*
186  * NB: aligned and packed are not given default definitions because they
187  * affect code functionality; they *must* be implemented by the compiler
188  * if they are to be used.
189  */
190 #define pg_attribute_noreturn()
191 #endif
192 
193 /*
194  * Use "pg_attribute_always_inline" in place of "inline" for functions that
195  * we wish to force inlining of, even when the compiler's heuristics would
196  * choose not to. But, if possible, don't force inlining in unoptimized
197  * debug builds.
198  */
199 #if (defined(__GNUC__) && __GNUC__ > 3 && defined(__OPTIMIZE__)) || defined(__SUNPRO_C) || defined(__IBMC__)
200 /* GCC > 3, Sunpro and XLC support always_inline via __attribute__ */
201 #define pg_attribute_always_inline __attribute__((always_inline)) inline
202 #elif defined(_MSC_VER)
203 /* MSVC has a special keyword for this */
204 #define pg_attribute_always_inline __forceinline
205 #else
206 /* Otherwise, the best we can do is to say "inline" */
207 #define pg_attribute_always_inline inline
208 #endif
209 
210 /*
211  * Forcing a function not to be inlined can be useful if it's the slow path of
212  * a performance-critical function, or should be visible in profiles to allow
213  * for proper cost attribution. Note that unlike the pg_attribute_XXX macros
214  * above, this should be placed before the function's return type and name.
215  */
216 /* GCC, Sunpro and XLC support noinline via __attribute__ */
217 #if (defined(__GNUC__) && __GNUC__ > 2) || defined(__SUNPRO_C) || defined(__IBMC__)
218 #define pg_noinline __attribute__((noinline))
219 /* msvc via declspec */
220 #elif defined(_MSC_VER)
221 #define pg_noinline __declspec(noinline)
222 #else
223 #define pg_noinline
224 #endif
225 
226 /*
227  * For now, just define pg_attribute_cold and pg_attribute_hot to be empty
228  * macros on minGW 8.1. There appears to be a compiler bug that results in
229  * compilation failure. At this time, we still have at least one buildfarm
230  * animal running that compiler, so this should make that green again. It's
231  * likely this compiler is not popular enough to warrant keeping this code
232  * around forever, so let's just remove it once the last buildfarm animal
233  * upgrades.
234  */
235 #if defined(__MINGW64__) && __GNUC__ == 8 && __GNUC_MINOR__ == 1
236 
237 #define pg_attribute_cold
238 #define pg_attribute_hot
239 
240 #else
241 /*
242  * Marking certain functions as "hot" or "cold" can be useful to assist the
243  * compiler in arranging the assembly code in a more efficient way.
244  */
245 #if __has_attribute (cold)
246 #define pg_attribute_cold __attribute__((cold))
247 #else
248 #define pg_attribute_cold
249 #endif
250 
251 #if __has_attribute (hot)
252 #define pg_attribute_hot __attribute__((hot))
253 #else
254 #define pg_attribute_hot
255 #endif
256 
257 #endif /* defined(__MINGW64__) && __GNUC__ == 8 &&
258  * __GNUC_MINOR__ == 1 */
259 /*
260  * Mark a point as unreachable in a portable fashion. This should preferably
261  * be something that the compiler understands, to aid code generation.
262  * In assert-enabled builds, we prefer abort() for debugging reasons.
263  */
264 #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
265 #define pg_unreachable() __builtin_unreachable()
266 #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
267 #define pg_unreachable() __assume(0)
268 #else
269 #define pg_unreachable() abort()
270 #endif
271 
272 /*
273  * Hints to the compiler about the likelihood of a branch. Both likely() and
274  * unlikely() return the boolean value of the contained expression.
275  *
276  * These should only be used sparingly, in very hot code paths. It's very easy
277  * to mis-estimate likelihoods.
278  */
279 #if __GNUC__ >= 3
280 #define likely(x) __builtin_expect((x) != 0, 1)
281 #define unlikely(x) __builtin_expect((x) != 0, 0)
282 #else
283 #define likely(x) ((x) != 0)
284 #define unlikely(x) ((x) != 0)
285 #endif
286 
287 /*
288  * CppAsString
289  * Convert the argument to a string, using the C preprocessor.
290  * CppAsString2
291  * Convert the argument to a string, after one round of macro expansion.
292  * CppConcat
293  * Concatenate two arguments together, using the C preprocessor.
294  *
295  * Note: There used to be support here for pre-ANSI C compilers that didn't
296  * support # and ##. Nowadays, these macros are just for clarity and/or
297  * backward compatibility with existing PostgreSQL code.
298  */
299 #define CppAsString(identifier) #identifier
300 #define CppAsString2(x) CppAsString(x)
301 #define CppConcat(x, y) x##y
302 
303 /*
304  * VA_ARGS_NARGS
305  * Returns the number of macro arguments it is passed.
306  *
307  * An empty argument still counts as an argument, so effectively, this is
308  * "one more than the number of commas in the argument list".
309  *
310  * This works for up to 63 arguments. Internally, VA_ARGS_NARGS_() is passed
311  * 64+N arguments, and the C99 standard only requires macros to allow up to
312  * 127 arguments, so we can't portably go higher. The implementation is
313  * pretty trivial: VA_ARGS_NARGS_() returns its 64th argument, and we set up
314  * the call so that that is the appropriate one of the list of constants.
315  * This idea is due to Laurent Deniau.
316  */
317 #define VA_ARGS_NARGS(...) \
318  VA_ARGS_NARGS_(__VA_ARGS__, \
319  63,62,61,60, \
320  59,58,57,56,55,54,53,52,51,50, \
321  49,48,47,46,45,44,43,42,41,40, \
322  39,38,37,36,35,34,33,32,31,30, \
323  29,28,27,26,25,24,23,22,21,20, \
324  19,18,17,16,15,14,13,12,11,10, \
325  9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
326 #define VA_ARGS_NARGS_( \
327  _01,_02,_03,_04,_05,_06,_07,_08,_09,_10, \
328  _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \
329  _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \
330  _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \
331  _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \
332  _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \
333  _61,_62,_63, N, ...) \
334  (N)
335 
336 /*
337  * dummyret is used to set return values in macros that use ?: to make
338  * assignments. gcc wants these to be void, other compilers like char
339  */
340 #ifdef __GNUC__ /* GNU cc */
341 #define dummyret void
342 #else
343 #define dummyret char
344 #endif
345 
346 /*
347  * Generic function pointer. This can be used in the rare cases where it's
348  * necessary to cast a function pointer to a seemingly incompatible function
349  * pointer type while avoiding gcc's -Wcast-function-type warnings.
350  */
351 typedef void (*pg_funcptr_t) (void);
352 
353 /*
354  * We require C99, hence the compiler should understand flexible array
355  * members. However, for documentation purposes we still consider it to be
356  * project style to write "field[FLEXIBLE_ARRAY_MEMBER]" not just "field[]".
357  * When computing the size of such an object, use "offsetof(struct s, f)"
358  * for portability. Don't use "offsetof(struct s, f[0])", as this doesn't
359  * work with MSVC and with C++ compilers.
360  */
361 #define FLEXIBLE_ARRAY_MEMBER /* empty */
362 
363 /* Which __func__ symbol do we have, if any? */
364 #ifdef HAVE_FUNCNAME__FUNC
365 #define PG_FUNCNAME_MACRO __func__
366 #else
367 #ifdef HAVE_FUNCNAME__FUNCTION
368 #define PG_FUNCNAME_MACRO __FUNCTION__
369 #else
370 #define PG_FUNCNAME_MACRO NULL
371 #endif
372 #endif
373 
374 
375 /* ----------------------------------------------------------------
376  * Section 2: bool, true, false
377  * ----------------------------------------------------------------
378  */
379 
380 /*
381  * bool
382  * Boolean value, either true or false.
383  *
384  * We use stdbool.h if available and its bool has size 1. That's useful for
385  * better compiler and debugger output and for compatibility with third-party
386  * libraries. But PostgreSQL currently cannot deal with bool of other sizes;
387  * there are static assertions around the code to prevent that.
388  *
389  * For C++ compilers, we assume the compiler has a compatible built-in
390  * definition of bool.
391  *
392  * See also the version of this code in src/interfaces/ecpg/include/ecpglib.h.
393  */
394 
395 #ifndef __cplusplus
396 
397 #ifdef PG_USE_STDBOOL
398 #include <stdbool.h>
399 #else
400 
401 #ifndef bool
402 typedef unsigned char bool;
403 #endif
404 
405 #ifndef true
406 #define true ((bool) 1)
407 #endif
408 
409 #ifndef false
410 #define false ((bool) 0)
411 #endif
412 
413 #endif /* not PG_USE_STDBOOL */
414 #endif /* not C++ */
415 
416 
417 /* ----------------------------------------------------------------
418  * Section 3: standard system types
419  * ----------------------------------------------------------------
420  */
421 
422 /*
423  * Pointer
424  * Variable holding address of any memory resident object.
425  *
426  * XXX Pointer arithmetic is done with this, so it can't be void *
427  * under "true" ANSI compilers.
428  */
429 typedef char *Pointer;
430 
431 /*
432  * intN
433  * Signed integer, EXACTLY N BITS IN SIZE,
434  * used for numerical computations and the
435  * frontend/backend protocol.
436  */
437 #ifndef HAVE_INT8
438 typedef signed char int8; /* == 8 bits */
439 typedef signed short int16; /* == 16 bits */
440 typedef signed int int32; /* == 32 bits */
441 #endif /* not HAVE_INT8 */
442 
443 /*
444  * uintN
445  * Unsigned integer, EXACTLY N BITS IN SIZE,
446  * used for numerical computations and the
447  * frontend/backend protocol.
448  */
449 #ifndef HAVE_UINT8
450 typedef unsigned char uint8; /* == 8 bits */
451 typedef unsigned short uint16; /* == 16 bits */
452 typedef unsigned int uint32; /* == 32 bits */
453 #endif /* not HAVE_UINT8 */
454 
455 /*
456  * bitsN
457  * Unit of bitwise operation, AT LEAST N BITS IN SIZE.
458  */
459 typedef uint8 bits8; /* >= 8 bits */
460 typedef uint16 bits16; /* >= 16 bits */
461 typedef uint32 bits32; /* >= 32 bits */
462 
463 /*
464  * 64-bit integers
465  */
466 #ifdef HAVE_LONG_INT_64
467 /* Plain "long int" fits, use it */
468 
469 #ifndef HAVE_INT64
470 typedef long int int64;
471 #endif
472 #ifndef HAVE_UINT64
473 typedef unsigned long int uint64;
474 #endif
475 #define INT64CONST(x) (x##L)
476 #define UINT64CONST(x) (x##UL)
477 #elif defined(HAVE_LONG_LONG_INT_64)
478 /* We have working support for "long long int", use that */
479 
480 #ifndef HAVE_INT64
481 typedef long long int int64;
482 #endif
483 #ifndef HAVE_UINT64
484 typedef unsigned long long int uint64;
485 #endif
486 #define INT64CONST(x) (x##LL)
487 #define UINT64CONST(x) (x##ULL)
488 #else
489 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
490 #error must have a working 64-bit integer datatype
491 #endif
492 
493 /* snprintf format strings to use for 64-bit integers */
494 #define INT64_FORMAT "%" INT64_MODIFIER "d"
495 #define UINT64_FORMAT "%" INT64_MODIFIER "u"
496 
497 /*
498  * 128-bit signed and unsigned integers
499  * There currently is only limited support for such types.
500  * E.g. 128bit literals and snprintf are not supported; but math is.
501  * Also, because we exclude such types when choosing MAXIMUM_ALIGNOF,
502  * it must be possible to coerce the compiler to allocate them on no
503  * more than MAXALIGN boundaries.
504  */
505 #if defined(PG_INT128_TYPE)
506 #if defined(pg_attribute_aligned) || ALIGNOF_PG_INT128_TYPE <= MAXIMUM_ALIGNOF
507 #define HAVE_INT128 1
508 
509 typedef PG_INT128_TYPE int128
510 #if defined(pg_attribute_aligned)
511  pg_attribute_aligned(MAXIMUM_ALIGNOF)
512 #endif
513  ;
514 
515 typedef unsigned PG_INT128_TYPE uint128
516 #if defined(pg_attribute_aligned)
517  pg_attribute_aligned(MAXIMUM_ALIGNOF)
518 #endif
519  ;
520 
521 #endif
522 #endif
523 
524 /*
525  * stdint.h limits aren't guaranteed to have compatible types with our fixed
526  * width types. So just define our own.
527  */
528 #define PG_INT8_MIN (-0x7F-1)
529 #define PG_INT8_MAX (0x7F)
530 #define PG_UINT8_MAX (0xFF)
531 #define PG_INT16_MIN (-0x7FFF-1)
532 #define PG_INT16_MAX (0x7FFF)
533 #define PG_UINT16_MAX (0xFFFF)
534 #define PG_INT32_MIN (-0x7FFFFFFF-1)
535 #define PG_INT32_MAX (0x7FFFFFFF)
536 #define PG_UINT32_MAX (0xFFFFFFFFU)
537 #define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1)
538 #define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF)
539 #define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
540 
541 /*
542  * We now always use int64 timestamps, but keep this symbol defined for the
543  * benefit of external code that might test it.
544  */
545 #define HAVE_INT64_TIMESTAMP
546 
547 /*
548  * Size
549  * Size of any memory resident object, as returned by sizeof.
550  */
551 typedef size_t Size;
552 
553 /*
554  * Index
555  * Index into any memory resident array.
556  *
557  * Note:
558  * Indices are non negative.
559  */
560 typedef unsigned int Index;
561 
562 /*
563  * Offset
564  * Offset into any memory resident array.
565  *
566  * Note:
567  * This differs from an Index in that an Index is always
568  * non negative, whereas Offset may be negative.
569  */
570 typedef signed int Offset;
571 
572 /*
573  * Common Postgres datatype names (as used in the catalogs)
574  */
575 typedef float float4;
576 typedef double float8;
577 
578 #ifdef USE_FLOAT8_BYVAL
579 #define FLOAT8PASSBYVAL true
580 #else
581 #define FLOAT8PASSBYVAL false
582 #endif
583 
584 /*
585  * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
586  * CommandId
587  */
588 
589 /* typedef Oid is in postgres_ext.h */
590 
591 /*
592  * regproc is the type name used in the include/catalog headers, but
593  * RegProcedure is the preferred name in C code.
594  */
595 typedef Oid regproc;
597 
599 
601 
603 
604 #define InvalidSubTransactionId ((SubTransactionId) 0)
605 #define TopSubTransactionId ((SubTransactionId) 1)
606 
607 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
609 
611 
613 
614 #define FirstCommandId ((CommandId) 0)
615 #define InvalidCommandId (~(CommandId)0)
616 
617 
618 /* ----------------
619  * Variable-length datatypes all share the 'struct varlena' header.
620  *
621  * NOTE: for TOASTable types, this is an oversimplification, since the value
622  * may be compressed or moved out-of-line. However datatype-specific routines
623  * are mostly content to deal with de-TOASTed values only, and of course
624  * client-side routines should never see a TOASTed value. But even in a
625  * de-TOASTed value, beware of touching vl_len_ directly, as its
626  * representation is no longer convenient. It's recommended that code always
627  * use macros VARDATA_ANY, VARSIZE_ANY, VARSIZE_ANY_EXHDR, VARDATA, VARSIZE,
628  * and SET_VARSIZE instead of relying on direct mentions of the struct fields.
629  * See postgres.h for details of the TOASTed form.
630  * ----------------
631  */
632 struct varlena
633 {
634  char vl_len_[4]; /* Do not touch this field directly! */
635  char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */
636 };
637 
638 #define VARHDRSZ ((int32) sizeof(int32))
639 
640 /*
641  * These widely-used datatypes are just a varlena header and the data bytes.
642  * There is no terminating null or anything like that --- the data length is
643  * always VARSIZE_ANY_EXHDR(ptr).
644  */
645 typedef struct varlena bytea;
646 typedef struct varlena text;
647 typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */
648 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
649 
650 /*
651  * Specialized array types. These are physically laid out just the same
652  * as regular arrays (so that the regular array subscripting code works
653  * with them). They exist as distinct types mostly for historical reasons:
654  * they have nonstandard I/O behavior which we don't want to change for fear
655  * of breaking applications that look at the system catalogs. There is also
656  * an implementation issue for oidvector: it's part of the primary key for
657  * pg_proc, and we can't use the normal btree array support routines for that
658  * without circularity.
659  */
660 typedef struct
661 {
662  int32 vl_len_; /* these fields must match ArrayType! */
663  int ndim; /* always 1 for int2vector */
664  int32 dataoffset; /* always 0 for int2vector */
666  int dim1;
667  int lbound1;
669 } int2vector;
670 
671 typedef struct
672 {
673  int32 vl_len_; /* these fields must match ArrayType! */
674  int ndim; /* always 1 for oidvector */
675  int32 dataoffset; /* always 0 for oidvector */
677  int dim1;
678  int lbound1;
680 } oidvector;
681 
682 /*
683  * Representation of a Name: effectively just a C string, but null-padded to
684  * exactly NAMEDATALEN bytes. The use of a struct is historical.
685  */
686 typedef struct nameData
687 {
690 typedef NameData *Name;
691 
692 #define NameStr(name) ((name).data)
693 
694 
695 /* ----------------------------------------------------------------
696  * Section 4: IsValid macros for system types
697  * ----------------------------------------------------------------
698  */
699 /*
700  * BoolIsValid
701  * True iff bool is valid.
702  */
703 #define BoolIsValid(boolean) ((boolean) == false || (boolean) == true)
704 
705 /*
706  * PointerIsValid
707  * True iff pointer is valid.
708  */
709 #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
710 
711 /*
712  * PointerIsAligned
713  * True iff pointer is properly aligned to point to the given type.
714  */
715 #define PointerIsAligned(pointer, type) \
716  (((uintptr_t)(pointer) % (sizeof (type))) == 0)
717 
718 #define OffsetToPointer(base, offset) \
719  ((void *)((char *) base + offset))
720 
721 #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
722 
723 #define RegProcedureIsValid(p) OidIsValid(p)
724 
725 
726 /* ----------------------------------------------------------------
727  * Section 5: offsetof, lengthof, alignment
728  * ----------------------------------------------------------------
729  */
730 /*
731  * offsetof
732  * Offset of a structure/union field within that structure/union.
733  *
734  * XXX This is supposed to be part of stddef.h, but isn't on
735  * some systems (like SunOS 4).
736  */
737 #ifndef offsetof
738 #define offsetof(type, field) ((long) &((type *)0)->field)
739 #endif /* offsetof */
740 
741 /*
742  * lengthof
743  * Number of elements in an array.
744  */
745 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
746 
747 /* ----------------
748  * Alignment macros: align a length or address appropriately for a given type.
749  * The fooALIGN() macros round up to a multiple of the required alignment,
750  * while the fooALIGN_DOWN() macros round down. The latter are more useful
751  * for problems like "how many X-sized structures will fit in a page?".
752  *
753  * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
754  * That case seems extremely unlikely to be needed in practice, however.
755  *
756  * NOTE: MAXIMUM_ALIGNOF, and hence MAXALIGN(), intentionally exclude any
757  * larger-than-8-byte types the compiler might have.
758  * ----------------
759  */
760 
761 #define TYPEALIGN(ALIGNVAL,LEN) \
762  (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
763 
764 #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
765 #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
766 #define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN))
767 #define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
768 #define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
769 /* MAXALIGN covers only built-in types, not buffers */
770 #define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
771 #define CACHELINEALIGN(LEN) TYPEALIGN(PG_CACHE_LINE_SIZE, (LEN))
772 
773 #define TYPEALIGN_DOWN(ALIGNVAL,LEN) \
774  (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
775 
776 #define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
777 #define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
778 #define LONGALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
779 #define DOUBLEALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
780 #define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
781 #define BUFFERALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_BUFFER, (LEN))
782 
783 /*
784  * The above macros will not work with types wider than uintptr_t, like with
785  * uint64 on 32-bit platforms. That's not problem for the usual use where a
786  * pointer or a length is aligned, but for the odd case that you need to
787  * align something (potentially) wider, use TYPEALIGN64.
788  */
789 #define TYPEALIGN64(ALIGNVAL,LEN) \
790  (((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1)))
791 
792 /* we don't currently need wider versions of the other ALIGN macros */
793 #define MAXALIGN64(LEN) TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN))
794 
795 
796 /* ----------------------------------------------------------------
797  * Section 6: assertions
798  * ----------------------------------------------------------------
799  */
800 
801 /*
802  * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
803  * - plai 9/5/90
804  *
805  * It should _NOT_ be defined in releases or in benchmark copies
806  */
807 
808 /*
809  * Assert() can be used in both frontend and backend code. In frontend code it
810  * just calls the standard assert, if it's available. If use of assertions is
811  * not configured, it does nothing.
812  */
813 #ifndef USE_ASSERT_CHECKING
814 
815 #define Assert(condition) ((void)true)
816 #define AssertMacro(condition) ((void)true)
817 #define AssertArg(condition) ((void)true)
818 #define AssertState(condition) ((void)true)
819 #define AssertPointerAlignment(ptr, bndr) ((void)true)
820 #define Trap(condition, errorType) ((void)true)
821 #define TrapMacro(condition, errorType) (true)
822 
823 #elif defined(FRONTEND)
824 
825 #include <assert.h>
826 #define Assert(p) assert(p)
827 #define AssertMacro(p) ((void) assert(p))
828 #define AssertArg(condition) assert(condition)
829 #define AssertState(condition) assert(condition)
830 #define AssertPointerAlignment(ptr, bndr) ((void)true)
831 
832 #else /* USE_ASSERT_CHECKING && !FRONTEND */
833 
834 /*
835  * Trap
836  * Generates an exception if the given condition is true.
837  */
838 #define Trap(condition, errorType) \
839  do { \
840  if (condition) \
841  ExceptionalCondition(#condition, (errorType), \
842  __FILE__, __LINE__); \
843  } while (0)
844 
845 /*
846  * TrapMacro is the same as Trap but it's intended for use in macros:
847  *
848  * #define foo(x) (AssertMacro(x != 0), bar(x))
849  *
850  * Isn't CPP fun?
851  */
852 #define TrapMacro(condition, errorType) \
853  ((bool) (! (condition) || \
854  (ExceptionalCondition(#condition, (errorType), \
855  __FILE__, __LINE__), 0)))
856 
857 #define Assert(condition) \
858  do { \
859  if (!(condition)) \
860  ExceptionalCondition(#condition, "FailedAssertion", \
861  __FILE__, __LINE__); \
862  } while (0)
863 
864 #define AssertMacro(condition) \
865  ((void) ((condition) || \
866  (ExceptionalCondition(#condition, "FailedAssertion", \
867  __FILE__, __LINE__), 0)))
868 
869 #define AssertArg(condition) \
870  do { \
871  if (!(condition)) \
872  ExceptionalCondition(#condition, "BadArgument", \
873  __FILE__, __LINE__); \
874  } while (0)
875 
876 #define AssertState(condition) \
877  do { \
878  if (!(condition)) \
879  ExceptionalCondition(#condition, "BadState", \
880  __FILE__, __LINE__); \
881  } while (0)
882 
883 /*
884  * Check that `ptr' is `bndr' aligned.
885  */
886 #define AssertPointerAlignment(ptr, bndr) \
887  Trap(TYPEALIGN(bndr, (uintptr_t)(ptr)) != (uintptr_t)(ptr), \
888  "UnalignedPointer")
889 
890 #endif /* USE_ASSERT_CHECKING && !FRONTEND */
891 
892 /*
893  * ExceptionalCondition is compiled into the backend whether or not
894  * USE_ASSERT_CHECKING is defined, so as to support use of extensions
895  * that are built with that #define with a backend that isn't. Hence,
896  * we should declare it as long as !FRONTEND.
897  */
898 #ifndef FRONTEND
899 extern void ExceptionalCondition(const char *conditionName,
900  const char *errorType,
901  const char *fileName, int lineNumber) pg_attribute_noreturn();
902 #endif
903 
904 /*
905  * Macros to support compile-time assertion checks.
906  *
907  * If the "condition" (a compile-time-constant expression) evaluates to false,
908  * throw a compile error using the "errmessage" (a string literal).
909  *
910  * gcc 4.6 and up supports _Static_assert(), but there are bizarre syntactic
911  * placement restrictions. Macros StaticAssertStmt() and StaticAssertExpr()
912  * make it safe to use as a statement or in an expression, respectively.
913  * The macro StaticAssertDecl() is suitable for use at file scope (outside of
914  * any function).
915  *
916  * Otherwise we fall back on a kluge that assumes the compiler will complain
917  * about a negative width for a struct bit-field. This will not include a
918  * helpful error message, but it beats not getting an error at all.
919  */
920 #ifndef __cplusplus
921 #ifdef HAVE__STATIC_ASSERT
922 #define StaticAssertStmt(condition, errmessage) \
923  do { _Static_assert(condition, errmessage); } while(0)
924 #define StaticAssertExpr(condition, errmessage) \
925  ((void) ({ StaticAssertStmt(condition, errmessage); true; }))
926 #define StaticAssertDecl(condition, errmessage) \
927  _Static_assert(condition, errmessage)
928 #else /* !HAVE__STATIC_ASSERT */
929 #define StaticAssertStmt(condition, errmessage) \
930  ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
931 #define StaticAssertExpr(condition, errmessage) \
932  StaticAssertStmt(condition, errmessage)
933 #define StaticAssertDecl(condition, errmessage) \
934  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
935 #endif /* HAVE__STATIC_ASSERT */
936 #else /* C++ */
937 #if defined(__cpp_static_assert) && __cpp_static_assert >= 200410
938 #define StaticAssertStmt(condition, errmessage) \
939  static_assert(condition, errmessage)
940 #define StaticAssertExpr(condition, errmessage) \
941  ({ static_assert(condition, errmessage); })
942 #define StaticAssertDecl(condition, errmessage) \
943  static_assert(condition, errmessage)
944 #else /* !__cpp_static_assert */
945 #define StaticAssertStmt(condition, errmessage) \
946  do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0)
947 #define StaticAssertExpr(condition, errmessage) \
948  ((void) ({ StaticAssertStmt(condition, errmessage); }))
949 #define StaticAssertDecl(condition, errmessage) \
950  extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1])
951 #endif /* __cpp_static_assert */
952 #endif /* C++ */
953 
954 
955 /*
956  * Compile-time checks that a variable (or expression) has the specified type.
957  *
958  * AssertVariableIsOfType() can be used as a statement.
959  * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
960  * #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
961  *
962  * If we don't have __builtin_types_compatible_p, we can still assert that
963  * the types have the same size. This is far from ideal (especially on 32-bit
964  * platforms) but it provides at least some coverage.
965  */
966 #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
967 #define AssertVariableIsOfType(varname, typename) \
968  StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
969  CppAsString(varname) " does not have type " CppAsString(typename))
970 #define AssertVariableIsOfTypeMacro(varname, typename) \
971  (StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
972  CppAsString(varname) " does not have type " CppAsString(typename)))
973 #else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
974 #define AssertVariableIsOfType(varname, typename) \
975  StaticAssertStmt(sizeof(varname) == sizeof(typename), \
976  CppAsString(varname) " does not have type " CppAsString(typename))
977 #define AssertVariableIsOfTypeMacro(varname, typename) \
978  (StaticAssertExpr(sizeof(varname) == sizeof(typename), \
979  CppAsString(varname) " does not have type " CppAsString(typename)))
980 #endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
981 
982 
983 /* ----------------------------------------------------------------
984  * Section 7: widely useful macros
985  * ----------------------------------------------------------------
986  */
987 /*
988  * Max
989  * Return the maximum of two numbers.
990  */
991 #define Max(x, y) ((x) > (y) ? (x) : (y))
992 
993 /*
994  * Min
995  * Return the minimum of two numbers.
996  */
997 #define Min(x, y) ((x) < (y) ? (x) : (y))
998 
999 /*
1000  * Abs
1001  * Return the absolute value of the argument.
1002  */
1003 #define Abs(x) ((x) >= 0 ? (x) : -(x))
1004 
1005 
1006 /* Get a bit mask of the bits set in non-long aligned addresses */
1007 #define LONG_ALIGN_MASK (sizeof(long) - 1)
1008 
1009 /*
1010  * MemSet
1011  * Exactly the same as standard library function memset(), but considerably
1012  * faster for zeroing small word-aligned structures (such as parsetree nodes).
1013  * This has to be a macro because the main point is to avoid function-call
1014  * overhead. However, we have also found that the loop is faster than
1015  * native libc memset() on some platforms, even those with assembler
1016  * memset() functions. More research needs to be done, perhaps with
1017  * MEMSET_LOOP_LIMIT tests in configure.
1018  */
1019 #define MemSet(start, val, len) \
1020  do \
1021  { \
1022  /* must be void* because we don't know if it is integer aligned yet */ \
1023  void *_vstart = (void *) (start); \
1024  int _val = (val); \
1025  Size _len = (len); \
1026 \
1027  if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
1028  (_len & LONG_ALIGN_MASK) == 0 && \
1029  _val == 0 && \
1030  _len <= MEMSET_LOOP_LIMIT && \
1031  /* \
1032  * If MEMSET_LOOP_LIMIT == 0, optimizer should find \
1033  * the whole "if" false at compile time. \
1034  */ \
1035  MEMSET_LOOP_LIMIT != 0) \
1036  { \
1037  long *_start = (long *) _vstart; \
1038  long *_stop = (long *) ((char *) _start + _len); \
1039  while (_start < _stop) \
1040  *_start++ = 0; \
1041  } \
1042  else \
1043  memset(_vstart, _val, _len); \
1044  } while (0)
1045 
1046 /*
1047  * MemSetAligned is the same as MemSet except it omits the test to see if
1048  * "start" is word-aligned. This is okay to use if the caller knows a-priori
1049  * that the pointer is suitably aligned (typically, because he just got it
1050  * from palloc(), which always delivers a max-aligned pointer).
1051  */
1052 #define MemSetAligned(start, val, len) \
1053  do \
1054  { \
1055  long *_start = (long *) (start); \
1056  int _val = (val); \
1057  Size _len = (len); \
1058 \
1059  if ((_len & LONG_ALIGN_MASK) == 0 && \
1060  _val == 0 && \
1061  _len <= MEMSET_LOOP_LIMIT && \
1062  MEMSET_LOOP_LIMIT != 0) \
1063  { \
1064  long *_stop = (long *) ((char *) _start + _len); \
1065  while (_start < _stop) \
1066  *_start++ = 0; \
1067  } \
1068  else \
1069  memset(_start, _val, _len); \
1070  } while (0)
1071 
1072 
1073 /*
1074  * MemSetTest/MemSetLoop are a variant version that allow all the tests in
1075  * MemSet to be done at compile time in cases where "val" and "len" are
1076  * constants *and* we know the "start" pointer must be word-aligned.
1077  * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
1078  * MemSetAligned. Beware of multiple evaluations of the arguments when using
1079  * this approach.
1080  */
1081 #define MemSetTest(val, len) \
1082  ( ((len) & LONG_ALIGN_MASK) == 0 && \
1083  (len) <= MEMSET_LOOP_LIMIT && \
1084  MEMSET_LOOP_LIMIT != 0 && \
1085  (val) == 0 )
1086 
1087 #define MemSetLoop(start, val, len) \
1088  do \
1089  { \
1090  long * _start = (long *) (start); \
1091  long * _stop = (long *) ((char *) _start + (Size) (len)); \
1092  \
1093  while (_start < _stop) \
1094  *_start++ = 0; \
1095  } while (0)
1096 
1097 /*
1098  * Macros for range-checking float values before converting to integer.
1099  * We must be careful here that the boundary values are expressed exactly
1100  * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will
1101  * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded
1102  * off, so avoid using that.
1103  * The input must be rounded to an integer beforehand, typically with rint(),
1104  * else we might draw the wrong conclusion about close-to-the-limit values.
1105  * These macros will do the right thing for Inf, but not necessarily for NaN,
1106  * so check isnan(num) first if that's a possibility.
1107  */
1108 #define FLOAT4_FITS_IN_INT16(num) \
1109  ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN))
1110 #define FLOAT4_FITS_IN_INT32(num) \
1111  ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN))
1112 #define FLOAT4_FITS_IN_INT64(num) \
1113  ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN))
1114 #define FLOAT8_FITS_IN_INT16(num) \
1115  ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN))
1116 #define FLOAT8_FITS_IN_INT32(num) \
1117  ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN))
1118 #define FLOAT8_FITS_IN_INT64(num) \
1119  ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN))
1120 
1121 
1122 /* ----------------------------------------------------------------
1123  * Section 8: random stuff
1124  * ----------------------------------------------------------------
1125  */
1126 
1127 #ifdef HAVE_STRUCT_SOCKADDR_UN
1128 #define HAVE_UNIX_SOCKETS 1
1129 #endif
1130 
1131 /*
1132  * Invert the sign of a qsort-style comparison result, ie, exchange negative
1133  * and positive integer values, being careful not to get the wrong answer
1134  * for INT_MIN. The argument should be an integral variable.
1135  */
1136 #define INVERT_COMPARE_RESULT(var) \
1137  ((var) = ((var) < 0) ? 1 : -(var))
1138 
1139 /*
1140  * Use this, not "char buf[BLCKSZ]", to declare a field or local variable
1141  * holding a page buffer, if that page might be accessed as a page and not
1142  * just a string of bytes. Otherwise the variable might be under-aligned,
1143  * causing problems on alignment-picky hardware. (In some places, we use
1144  * this to declare buffers even though we only pass them to read() and
1145  * write(), because copying to/from aligned buffers is usually faster than
1146  * using unaligned buffers.) We include both "double" and "int64" in the
1147  * union to ensure that the compiler knows the value must be MAXALIGN'ed
1148  * (cf. configure's computation of MAXIMUM_ALIGNOF).
1149  */
1150 typedef union PGAlignedBlock
1152  char data[BLCKSZ];
1153  double force_align_d;
1154  int64 force_align_i64;
1156 
1157 /* Same, but for an XLOG_BLCKSZ-sized buffer */
1158 typedef union PGAlignedXLogBlock
1160  char data[XLOG_BLCKSZ];
1161  double force_align_d;
1162  int64 force_align_i64;
1165 /* msb for char */
1166 #define HIGHBIT (0x80)
1167 #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT)
1168 
1169 /*
1170  * Support macros for escaping strings. escape_backslash should be true
1171  * if generating a non-standard-conforming string. Prefixing a string
1172  * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
1173  * Beware of multiple evaluation of the "ch" argument!
1174  */
1175 #define SQL_STR_DOUBLE(ch, escape_backslash) \
1176  ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
1177 
1178 #define ESCAPE_STRING_SYNTAX 'E'
1181 #define STATUS_OK (0)
1182 #define STATUS_ERROR (-1)
1183 #define STATUS_EOF (-2)
1184 
1185 /*
1186  * gettext support
1187  */
1189 #ifndef ENABLE_NLS
1190 /* stuff we'd otherwise get from <libintl.h> */
1191 #define gettext(x) (x)
1192 #define dgettext(d,x) (x)
1193 #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
1194 #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
1195 #endif
1196 
1197 #define _(x) gettext(x)
1198 
1199 /*
1200  * Use this to mark string constants as needing translation at some later
1201  * time, rather than immediately. This is useful for cases where you need
1202  * access to the original string and translated string, and for cases where
1203  * immediate translation is not possible, like when initializing global
1204  * variables.
1205  *
1206  * https://www.gnu.org/software/gettext/manual/html_node/Special-cases.html
1207  */
1208 #define gettext_noop(x) (x)
1209 
1210 /*
1211  * To better support parallel installations of major PostgreSQL
1212  * versions as well as parallel installations of major library soname
1213  * versions, we mangle the gettext domain name by appending those
1214  * version numbers. The coding rule ought to be that wherever the
1215  * domain name is mentioned as a literal, it must be wrapped into
1216  * PG_TEXTDOMAIN(). The macros below do not work on non-literals; but
1217  * that is somewhat intentional because it avoids having to worry
1218  * about multiple states of premangling and postmangling as the values
1219  * are being passed around.
1220  *
1221  * Make sure this matches the installation rules in nls-global.mk.
1222  */
1223 #ifdef SO_MAJOR_VERSION
1224 #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
1225 #else
1226 #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
1227 #endif
1228 
1229 /*
1230  * Macro that allows to cast constness and volatile away from an expression, but doesn't
1231  * allow changing the underlying type. Enforcement of the latter
1232  * currently only works for gcc like compilers.
1233  *
1234  * Please note IT IS NOT SAFE to cast constness away if the result will ever
1235  * be modified (it would be undefined behaviour). Doing so anyway can cause
1236  * compiler misoptimizations or runtime crashes (modifying readonly memory).
1237  * It is only safe to use when the result will not be modified, but API
1238  * design or language restrictions prevent you from declaring that
1239  * (e.g. because a function returns both const and non-const variables).
1240  *
1241  * Note that this only works in function scope, not for global variables (it'd
1242  * be nice, but not trivial, to improve that).
1243  */
1244 #if defined(HAVE__BUILTIN_TYPES_COMPATIBLE_P)
1245 #define unconstify(underlying_type, expr) \
1246  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), const underlying_type), \
1247  "wrong cast"), \
1248  (underlying_type) (expr))
1249 #define unvolatize(underlying_type, expr) \
1250  (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), volatile underlying_type), \
1251  "wrong cast"), \
1252  (underlying_type) (expr))
1253 #else
1254 #define unconstify(underlying_type, expr) \
1255  ((underlying_type) (expr))
1256 #define unvolatize(underlying_type, expr) \
1257  ((underlying_type) (expr))
1258 #endif
1259 
1260 /* ----------------------------------------------------------------
1261  * Section 9: system-specific hacks
1262  *
1263  * This should be limited to things that absolutely have to be
1264  * included in every source file. The port-specific header file
1265  * is usually a better place for this sort of thing.
1266  * ----------------------------------------------------------------
1267  */
1268 
1269 /*
1270  * NOTE: this is also used for opening text files.
1271  * WIN32 treats Control-Z as EOF in files opened in text mode.
1272  * Therefore, we open files in binary mode on Win32 so we can read
1273  * literal control-Z. The other affect is that we see CRLF, but
1274  * that is OK because we can already handle those cleanly.
1275  */
1276 #if defined(WIN32) || defined(__CYGWIN__)
1277 #define PG_BINARY O_BINARY
1278 #define PG_BINARY_A "ab"
1279 #define PG_BINARY_R "rb"
1280 #define PG_BINARY_W "wb"
1281 #else
1282 #define PG_BINARY 0
1283 #define PG_BINARY_A "a"
1284 #define PG_BINARY_R "r"
1285 #define PG_BINARY_W "w"
1286 #endif
1287 
1288 /*
1289  * Provide prototypes for routines not present in a particular machine's
1290  * standard C library.
1291  */
1292 
1293 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
1294 extern int fdatasync(int fildes);
1295 #endif
1296 
1297 /* Older platforms may provide strto[u]ll functionality under other names */
1298 #if !defined(HAVE_STRTOLL) && defined(HAVE___STRTOLL)
1299 #define strtoll __strtoll
1300 #define HAVE_STRTOLL 1
1301 #endif
1302 
1303 #if !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
1304 #define strtoll strtoq
1305 #define HAVE_STRTOLL 1
1306 #endif
1307 
1308 #if !defined(HAVE_STRTOULL) && defined(HAVE___STRTOULL)
1309 #define strtoull __strtoull
1310 #define HAVE_STRTOULL 1
1311 #endif
1312 
1313 #if !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
1314 #define strtoull strtouq
1315 #define HAVE_STRTOULL 1
1316 #endif
1317 
1318 #if defined(HAVE_STRTOLL) && !HAVE_DECL_STRTOLL
1319 extern long long strtoll(const char *str, char **endptr, int base);
1320 #endif
1321 
1322 #if defined(HAVE_STRTOULL) && !HAVE_DECL_STRTOULL
1323 extern unsigned long long strtoull(const char *str, char **endptr, int base);
1324 #endif
1325 
1326 /*
1327  * Thin wrappers that convert strings to exactly 64-bit integers, matching our
1328  * definition of int64. (For the naming, compare that POSIX has
1329  * strtoimax()/strtoumax() which return intmax_t/uintmax_t.)
1330  */
1331 #ifdef HAVE_LONG_INT_64
1332 #define strtoi64(str, endptr, base) ((int64) strtol(str, endptr, base))
1333 #define strtou64(str, endptr, base) ((uint64) strtoul(str, endptr, base))
1334 #else
1335 #define strtoi64(str, endptr, base) ((int64) strtoll(str, endptr, base))
1336 #define strtou64(str, endptr, base) ((uint64) strtoull(str, endptr, base))
1337 #endif
1338 
1339 /*
1340  * Use "extern PGDLLIMPORT ..." to declare variables that are defined
1341  * in the core backend and need to be accessible by loadable modules.
1342  * No special marking is required on most ports.
1343  */
1344 #ifndef PGDLLIMPORT
1345 #define PGDLLIMPORT
1346 #endif
1347 
1348 /*
1349  * Use "extern PGDLLEXPORT ..." to declare functions that are defined in
1350  * loadable modules and need to be callable by the core backend. (Usually,
1351  * this is not necessary because our build process automatically exports
1352  * such symbols, but sometimes manual marking is required.)
1353  * No special marking is required on most ports.
1354  */
1355 #ifndef PGDLLEXPORT
1356 #define PGDLLEXPORT
1357 #endif
1358 
1359 /*
1360  * The following is used as the arg list for signal handlers. Any ports
1361  * that take something other than an int argument should override this in
1362  * their pg_config_os.h file. Note that variable names are required
1363  * because it is used in both the prototypes as well as the definitions.
1364  * Note also the long name. We expect that this won't collide with
1365  * other names causing compiler warnings.
1366  */
1367 
1368 #ifndef SIGNAL_ARGS
1369 #define SIGNAL_ARGS int postgres_signal_arg
1370 #endif
1371 
1372 /*
1373  * When there is no sigsetjmp, its functionality is provided by plain
1374  * setjmp. We now support the case only on Windows. However, it seems
1375  * that MinGW-64 has some longstanding issues in its setjmp support,
1376  * so on that toolchain we cheat and use gcc's builtins.
1377  */
1378 #ifdef WIN32
1379 #ifdef __MINGW64__
1380 typedef intptr_t sigjmp_buf[5];
1381 #define sigsetjmp(x,y) __builtin_setjmp(x)
1382 #define siglongjmp __builtin_longjmp
1383 #else /* !__MINGW64__ */
1384 #define sigjmp_buf jmp_buf
1385 #define sigsetjmp(x,y) setjmp(x)
1386 #define siglongjmp longjmp
1387 #endif /* __MINGW64__ */
1388 #endif /* WIN32 */
1389 
1390 /* EXEC_BACKEND defines */
1391 #ifdef EXEC_BACKEND
1392 #define NON_EXEC_STATIC
1393 #else
1394 #define NON_EXEC_STATIC static
1395 #endif
1396 
1397 /* /port compatibility functions */
1398 #include "port.h"
1399 
1400 #endif /* C_H */
static Datum values[MAXATTR]
Definition: bootstrap.c:156
unsigned short uint16
Definition: c.h:451
unsigned int uint32
Definition: c.h:452
uint16 bits16
Definition: c.h:460
NameData * Name
Definition: c.h:690
signed char int8
Definition: c.h:438
union PGAlignedBlock PGAlignedBlock
signed short int16
Definition: c.h:439
union PGAlignedXLogBlock PGAlignedXLogBlock
void ExceptionalCondition(const char *conditionName, const char *errorType, const char *fileName, int lineNumber) pg_attribute_noreturn()
Definition: assert.c:30
uint32 SubTransactionId
Definition: c.h:602
signed int int32
Definition: c.h:440
char * Pointer
Definition: c.h:429
#define pg_attribute_noreturn()
Definition: c.h:190
Oid regproc
Definition: c.h:595
uint32 MultiXactOffset
Definition: c.h:610
double float8
Definition: c.h:576
TransactionId MultiXactId
Definition: c.h:608
#define FLEXIBLE_ARRAY_MEMBER
Definition: c.h:361
unsigned char bool
Definition: c.h:402
regproc RegProcedure
Definition: c.h:596
uint8 bits8
Definition: c.h:459
uint32 bits32
Definition: c.h:461
unsigned int Index
Definition: c.h:560
float float4
Definition: c.h:575
uint32 LocalTransactionId
Definition: c.h:600
unsigned char uint8
Definition: c.h:450
uint32 CommandId
Definition: c.h:612
uint32 TransactionId
Definition: c.h:598
signed int Offset
Definition: c.h:570
void(* pg_funcptr_t)(void)
Definition: c.h:351
size_t Size
Definition: c.h:551
struct nameData NameData
#define NAMEDATALEN
unsigned int Oid
Definition: postgres_ext.h:31
Definition: c.h:661
int32 vl_len_
Definition: c.h:662
int ndim
Definition: c.h:663
int dim1
Definition: c.h:666
Oid elemtype
Definition: c.h:665
int32 dataoffset
Definition: c.h:664
int lbound1
Definition: c.h:667
Definition: c.h:687
char data[NAMEDATALEN]
Definition: c.h:688
Definition: c.h:672
int dim1
Definition: c.h:677
int32 dataoffset
Definition: c.h:675
Oid elemtype
Definition: c.h:676
int lbound1
Definition: c.h:678
int ndim
Definition: c.h:674
int32 vl_len_
Definition: c.h:673
Definition: c.h:633
char vl_len_[4]
Definition: c.h:634
char vl_dat[FLEXIBLE_ARRAY_MEMBER]
Definition: c.h:635
double force_align_d
Definition: c.h:1150
int64 force_align_i64
Definition: c.h:1151
char data[BLCKSZ]
Definition: c.h:1149
char data[XLOG_BLCKSZ]
Definition: c.h:1157
double force_align_d
Definition: c.h:1158
int64 force_align_i64
Definition: c.h:1159