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Diffstat (limited to 'src/include/c.h')
| -rw-r--r-- | src/include/c.h | 1364 |
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diff --git a/src/include/c.h b/src/include/c.h new file mode 100644 index 0000000..c8ede08 --- /dev/null +++ b/src/include/c.h @@ -0,0 +1,1364 @@ +/*------------------------------------------------------------------------- + * + * c.h + * Fundamental C definitions. This is included by every .c file in + * PostgreSQL (via either postgres.h or postgres_fe.h, as appropriate). + * + * Note that the definitions here are not intended to be exposed to clients + * of the frontend interface libraries --- so we don't worry much about + * polluting the namespace with lots of stuff... + * + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/c.h + * + *------------------------------------------------------------------------- + */ +/* + *---------------------------------------------------------------- + * TABLE OF CONTENTS + * + * When adding stuff to this file, please try to put stuff + * into the relevant section, or add new sections as appropriate. + * + * section description + * ------- ------------------------------------------------ + * 0) pg_config.h and standard system headers + * 1) compiler characteristics + * 2) bool, true, false + * 3) standard system types + * 4) IsValid macros for system types + * 5) offsetof, lengthof, alignment + * 6) assertions + * 7) widely useful macros + * 8) random stuff + * 9) system-specific hacks + * + * NOTE: since this file is included by both frontend and backend modules, + * it's usually wrong to put an "extern" declaration here, unless it's + * ifdef'd so that it's seen in only one case or the other. + * typedefs and macros are the kind of thing that might go here. + * + *---------------------------------------------------------------- + */ +#ifndef C_H +#define C_H + +#include "postgres_ext.h" + +/* Must undef pg_config_ext.h symbols before including pg_config.h */ +#undef PG_INT64_TYPE + +#include "pg_config.h" +#include "pg_config_manual.h" /* must be after pg_config.h */ +#include "pg_config_os.h" /* must be before any system header files */ + +/* System header files that should be available everywhere in Postgres */ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stddef.h> +#include <stdarg.h> +#ifdef HAVE_STRINGS_H +#include <strings.h> +#endif +#include <stdint.h> +#include <sys/types.h> +#include <errno.h> +#if defined(WIN32) || defined(__CYGWIN__) +#include <fcntl.h> /* ensure O_BINARY is available */ +#endif +#include <locale.h> +#ifdef ENABLE_NLS +#include <libintl.h> +#endif + + +/* ---------------------------------------------------------------- + * Section 1: compiler characteristics + * + * type prefixes (const, signed, volatile, inline) are handled in pg_config.h. + * ---------------------------------------------------------------- + */ + +/* + * Disable "inline" if PG_FORCE_DISABLE_INLINE is defined. + * This is used to work around compiler bugs and might also be useful for + * investigatory purposes. + */ +#ifdef PG_FORCE_DISABLE_INLINE +#undef inline +#define inline +#endif + +/* + * Attribute macros + * + * GCC: https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html + * GCC: https://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html + * Clang: https://clang.llvm.org/docs/AttributeReference.html + * Sunpro: https://docs.oracle.com/cd/E18659_01/html/821-1384/gjzke.html + * XLC: https://www.ibm.com/support/knowledgecenter/SSGH2K_13.1.2/com.ibm.xlc131.aix.doc/language_ref/function_attributes.html + * XLC: https://www.ibm.com/support/knowledgecenter/SSGH2K_13.1.2/com.ibm.xlc131.aix.doc/language_ref/type_attrib.html + */ + +/* + * For compilers which don't support __has_attribute, we just define + * __has_attribute(x) to 0 so that we can define macros for various + * __attribute__s more easily below. + */ +#ifndef __has_attribute +#define __has_attribute(attribute) 0 +#endif + +/* only GCC supports the unused attribute */ +#ifdef __GNUC__ +#define pg_attribute_unused() __attribute__((unused)) +#else +#define pg_attribute_unused() +#endif + +/* + * pg_nodiscard means the compiler should warn if the result of a function + * call is ignored. The name "nodiscard" is chosen in alignment with + * (possibly future) C and C++ standards. For maximum compatibility, use it + * as a function declaration specifier, so it goes before the return type. + */ +#ifdef __GNUC__ +#define pg_nodiscard __attribute__((warn_unused_result)) +#else +#define pg_nodiscard +#endif + +/* + * Place this macro before functions that should be allowed to make misaligned + * accesses. Think twice before using it on non-x86-specific code! + * Testing can be done with "-fsanitize=alignment -fsanitize-trap=alignment" + * on clang, or "-fsanitize=alignment -fno-sanitize-recover=alignment" on gcc. + */ +#if __clang_major__ >= 7 || __GNUC__ >= 8 +#define pg_attribute_no_sanitize_alignment() __attribute__((no_sanitize("alignment"))) +#else +#define pg_attribute_no_sanitize_alignment() +#endif + +/* + * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only + * used in assert-enabled builds, to avoid compiler warnings about unused + * variables in assert-disabled builds. + */ +#ifdef USE_ASSERT_CHECKING +#define PG_USED_FOR_ASSERTS_ONLY +#else +#define PG_USED_FOR_ASSERTS_ONLY pg_attribute_unused() +#endif + +/* GCC and XLC support format attributes */ +#if defined(__GNUC__) || defined(__IBMC__) +#define pg_attribute_format_arg(a) __attribute__((format_arg(a))) +#define pg_attribute_printf(f,a) __attribute__((format(PG_PRINTF_ATTRIBUTE, f, a))) +#else +#define pg_attribute_format_arg(a) +#define pg_attribute_printf(f,a) +#endif + +/* GCC, Sunpro and XLC support aligned, packed and noreturn */ +#if defined(__GNUC__) || defined(__SUNPRO_C) || defined(__IBMC__) +#define pg_attribute_aligned(a) __attribute__((aligned(a))) +#define pg_attribute_noreturn() __attribute__((noreturn)) +#define pg_attribute_packed() __attribute__((packed)) +#define HAVE_PG_ATTRIBUTE_NORETURN 1 +#else +/* + * NB: aligned and packed are not given default definitions because they + * affect code functionality; they *must* be implemented by the compiler + * if they are to be used. + */ +#define pg_attribute_noreturn() +#endif + +/* + * Use "pg_attribute_always_inline" in place of "inline" for functions that + * we wish to force inlining of, even when the compiler's heuristics would + * choose not to. But, if possible, don't force inlining in unoptimized + * debug builds. + */ +#if (defined(__GNUC__) && __GNUC__ > 3 && defined(__OPTIMIZE__)) || defined(__SUNPRO_C) || defined(__IBMC__) +/* GCC > 3, Sunpro and XLC support always_inline via __attribute__ */ +#define pg_attribute_always_inline __attribute__((always_inline)) inline +#elif defined(_MSC_VER) +/* MSVC has a special keyword for this */ +#define pg_attribute_always_inline __forceinline +#else +/* Otherwise, the best we can do is to say "inline" */ +#define pg_attribute_always_inline inline +#endif + +/* + * Forcing a function not to be inlined can be useful if it's the slow path of + * a performance-critical function, or should be visible in profiles to allow + * for proper cost attribution. Note that unlike the pg_attribute_XXX macros + * above, this should be placed before the function's return type and name. + */ +/* GCC, Sunpro and XLC support noinline via __attribute__ */ +#if (defined(__GNUC__) && __GNUC__ > 2) || defined(__SUNPRO_C) || defined(__IBMC__) +#define pg_noinline __attribute__((noinline)) +/* msvc via declspec */ +#elif defined(_MSC_VER) +#define pg_noinline __declspec(noinline) +#else +#define pg_noinline +#endif + +/* + * For now, just define pg_attribute_cold and pg_attribute_hot to be empty + * macros on minGW 8.1. There appears to be a compiler bug that results in + * compilation failure. At this time, we still have at least one buildfarm + * animal running that compiler, so this should make that green again. It's + * likely this compiler is not popular enough to warrant keeping this code + * around forever, so let's just remove it once the last buildfarm animal + * upgrades. + */ +#if defined(__MINGW64__) && __GNUC__ == 8 && __GNUC_MINOR__ == 1 + +#define pg_attribute_cold +#define pg_attribute_hot + +#else +/* + * Marking certain functions as "hot" or "cold" can be useful to assist the + * compiler in arranging the assembly code in a more efficient way. + */ +#if __has_attribute (cold) +#define pg_attribute_cold __attribute__((cold)) +#else +#define pg_attribute_cold +#endif + +#if __has_attribute (hot) +#define pg_attribute_hot __attribute__((hot)) +#else +#define pg_attribute_hot +#endif + +#endif /* defined(__MINGW64__) && __GNUC__ == 8 && + * __GNUC_MINOR__ == 1 */ +/* + * Mark a point as unreachable in a portable fashion. This should preferably + * be something that the compiler understands, to aid code generation. + * In assert-enabled builds, we prefer abort() for debugging reasons. + */ +#if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING) +#define pg_unreachable() __builtin_unreachable() +#elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING) +#define pg_unreachable() __assume(0) +#else +#define pg_unreachable() abort() +#endif + +/* + * Hints to the compiler about the likelihood of a branch. Both likely() and + * unlikely() return the boolean value of the contained expression. + * + * These should only be used sparingly, in very hot code paths. It's very easy + * to mis-estimate likelihoods. + */ +#if __GNUC__ >= 3 +#define likely(x) __builtin_expect((x) != 0, 1) +#define unlikely(x) __builtin_expect((x) != 0, 0) +#else +#define likely(x) ((x) != 0) +#define unlikely(x) ((x) != 0) +#endif + +/* + * CppAsString + * Convert the argument to a string, using the C preprocessor. + * CppAsString2 + * Convert the argument to a string, after one round of macro expansion. + * CppConcat + * Concatenate two arguments together, using the C preprocessor. + * + * Note: There used to be support here for pre-ANSI C compilers that didn't + * support # and ##. Nowadays, these macros are just for clarity and/or + * backward compatibility with existing PostgreSQL code. + */ +#define CppAsString(identifier) #identifier +#define CppAsString2(x) CppAsString(x) +#define CppConcat(x, y) x##y + +/* + * VA_ARGS_NARGS + * Returns the number of macro arguments it is passed. + * + * An empty argument still counts as an argument, so effectively, this is + * "one more than the number of commas in the argument list". + * + * This works for up to 63 arguments. Internally, VA_ARGS_NARGS_() is passed + * 64+N arguments, and the C99 standard only requires macros to allow up to + * 127 arguments, so we can't portably go higher. The implementation is + * pretty trivial: VA_ARGS_NARGS_() returns its 64th argument, and we set up + * the call so that that is the appropriate one of the list of constants. + * This idea is due to Laurent Deniau. + */ +#define VA_ARGS_NARGS(...) \ + VA_ARGS_NARGS_(__VA_ARGS__, \ + 63,62,61,60, \ + 59,58,57,56,55,54,53,52,51,50, \ + 49,48,47,46,45,44,43,42,41,40, \ + 39,38,37,36,35,34,33,32,31,30, \ + 29,28,27,26,25,24,23,22,21,20, \ + 19,18,17,16,15,14,13,12,11,10, \ + 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) +#define VA_ARGS_NARGS_( \ + _01,_02,_03,_04,_05,_06,_07,_08,_09,_10, \ + _11,_12,_13,_14,_15,_16,_17,_18,_19,_20, \ + _21,_22,_23,_24,_25,_26,_27,_28,_29,_30, \ + _31,_32,_33,_34,_35,_36,_37,_38,_39,_40, \ + _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \ + _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \ + _61,_62,_63, N, ...) \ + (N) + +/* + * dummyret is used to set return values in macros that use ?: to make + * assignments. gcc wants these to be void, other compilers like char + */ +#ifdef __GNUC__ /* GNU cc */ +#define dummyret void +#else +#define dummyret char +#endif + +/* + * Generic function pointer. This can be used in the rare cases where it's + * necessary to cast a function pointer to a seemingly incompatible function + * pointer type while avoiding gcc's -Wcast-function-type warnings. + */ +typedef void (*pg_funcptr_t) (void); + +/* + * We require C99, hence the compiler should understand flexible array + * members. However, for documentation purposes we still consider it to be + * project style to write "field[FLEXIBLE_ARRAY_MEMBER]" not just "field[]". + * When computing the size of such an object, use "offsetof(struct s, f)" + * for portability. Don't use "offsetof(struct s, f[0])", as this doesn't + * work with MSVC and with C++ compilers. + */ +#define FLEXIBLE_ARRAY_MEMBER /* empty */ + +/* Which __func__ symbol do we have, if any? */ +#ifdef HAVE_FUNCNAME__FUNC +#define PG_FUNCNAME_MACRO __func__ +#else +#ifdef HAVE_FUNCNAME__FUNCTION +#define PG_FUNCNAME_MACRO __FUNCTION__ +#else +#define PG_FUNCNAME_MACRO NULL +#endif +#endif + + +/* ---------------------------------------------------------------- + * Section 2: bool, true, false + * ---------------------------------------------------------------- + */ + +/* + * bool + * Boolean value, either true or false. + * + * We use stdbool.h if available and its bool has size 1. That's useful for + * better compiler and debugger output and for compatibility with third-party + * libraries. But PostgreSQL currently cannot deal with bool of other sizes; + * there are static assertions around the code to prevent that. + * + * For C++ compilers, we assume the compiler has a compatible built-in + * definition of bool. + * + * See also the version of this code in src/interfaces/ecpg/include/ecpglib.h. + */ + +#ifndef __cplusplus + +#ifdef PG_USE_STDBOOL +#include <stdbool.h> +#else + +#ifndef bool +typedef unsigned char bool; +#endif + +#ifndef true +#define true ((bool) 1) +#endif + +#ifndef false +#define false ((bool) 0) +#endif + +#endif /* not PG_USE_STDBOOL */ +#endif /* not C++ */ + + +/* ---------------------------------------------------------------- + * Section 3: standard system types + * ---------------------------------------------------------------- + */ + +/* + * Pointer + * Variable holding address of any memory resident object. + * + * XXX Pointer arithmetic is done with this, so it can't be void * + * under "true" ANSI compilers. + */ +typedef char *Pointer; + +/* + * intN + * Signed integer, EXACTLY N BITS IN SIZE, + * used for numerical computations and the + * frontend/backend protocol. + */ +#ifndef HAVE_INT8 +typedef signed char int8; /* == 8 bits */ +typedef signed short int16; /* == 16 bits */ +typedef signed int int32; /* == 32 bits */ +#endif /* not HAVE_INT8 */ + +/* + * uintN + * Unsigned integer, EXACTLY N BITS IN SIZE, + * used for numerical computations and the + * frontend/backend protocol. + */ +#ifndef HAVE_UINT8 +typedef unsigned char uint8; /* == 8 bits */ +typedef unsigned short uint16; /* == 16 bits */ +typedef unsigned int uint32; /* == 32 bits */ +#endif /* not HAVE_UINT8 */ + +/* + * bitsN + * Unit of bitwise operation, AT LEAST N BITS IN SIZE. + */ +typedef uint8 bits8; /* >= 8 bits */ +typedef uint16 bits16; /* >= 16 bits */ +typedef uint32 bits32; /* >= 32 bits */ + +/* + * 64-bit integers + */ +#ifdef HAVE_LONG_INT_64 +/* Plain "long int" fits, use it */ + +#ifndef HAVE_INT64 +typedef long int int64; +#endif +#ifndef HAVE_UINT64 +typedef unsigned long int uint64; +#endif +#define INT64CONST(x) (x##L) +#define UINT64CONST(x) (x##UL) +#elif defined(HAVE_LONG_LONG_INT_64) +/* We have working support for "long long int", use that */ + +#ifndef HAVE_INT64 +typedef long long int int64; +#endif +#ifndef HAVE_UINT64 +typedef unsigned long long int uint64; +#endif +#define INT64CONST(x) (x##LL) +#define UINT64CONST(x) (x##ULL) +#else +/* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */ +#error must have a working 64-bit integer datatype +#endif + +/* snprintf format strings to use for 64-bit integers */ +#define INT64_FORMAT "%" INT64_MODIFIER "d" +#define UINT64_FORMAT "%" INT64_MODIFIER "u" + +/* + * 128-bit signed and unsigned integers + * There currently is only limited support for such types. + * E.g. 128bit literals and snprintf are not supported; but math is. + * Also, because we exclude such types when choosing MAXIMUM_ALIGNOF, + * it must be possible to coerce the compiler to allocate them on no + * more than MAXALIGN boundaries. + */ +#if defined(PG_INT128_TYPE) +#if defined(pg_attribute_aligned) || ALIGNOF_PG_INT128_TYPE <= MAXIMUM_ALIGNOF +#define HAVE_INT128 1 + +typedef PG_INT128_TYPE int128 +#if defined(pg_attribute_aligned) + pg_attribute_aligned(MAXIMUM_ALIGNOF) +#endif + ; + +typedef unsigned PG_INT128_TYPE uint128 +#if defined(pg_attribute_aligned) + pg_attribute_aligned(MAXIMUM_ALIGNOF) +#endif + ; + +#endif +#endif + +/* + * stdint.h limits aren't guaranteed to have compatible types with our fixed + * width types. So just define our own. + */ +#define PG_INT8_MIN (-0x7F-1) +#define PG_INT8_MAX (0x7F) +#define PG_UINT8_MAX (0xFF) +#define PG_INT16_MIN (-0x7FFF-1) +#define PG_INT16_MAX (0x7FFF) +#define PG_UINT16_MAX (0xFFFF) +#define PG_INT32_MIN (-0x7FFFFFFF-1) +#define PG_INT32_MAX (0x7FFFFFFF) +#define PG_UINT32_MAX (0xFFFFFFFFU) +#define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1) +#define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF) +#define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF) + +/* + * We now always use int64 timestamps, but keep this symbol defined for the + * benefit of external code that might test it. + */ +#define HAVE_INT64_TIMESTAMP + +/* + * Size + * Size of any memory resident object, as returned by sizeof. + */ +typedef size_t Size; + +/* + * Index + * Index into any memory resident array. + * + * Note: + * Indices are non negative. + */ +typedef unsigned int Index; + +/* + * Offset + * Offset into any memory resident array. + * + * Note: + * This differs from an Index in that an Index is always + * non negative, whereas Offset may be negative. + */ +typedef signed int Offset; + +/* + * Common Postgres datatype names (as used in the catalogs) + */ +typedef float float4; +typedef double float8; + +#ifdef USE_FLOAT8_BYVAL +#define FLOAT8PASSBYVAL true +#else +#define FLOAT8PASSBYVAL false +#endif + +/* + * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId, + * CommandId + */ + +/* typedef Oid is in postgres_ext.h */ + +/* + * regproc is the type name used in the include/catalog headers, but + * RegProcedure is the preferred name in C code. + */ +typedef Oid regproc; +typedef regproc RegProcedure; + +typedef uint32 TransactionId; + +typedef uint32 LocalTransactionId; + +typedef uint32 SubTransactionId; + +#define InvalidSubTransactionId ((SubTransactionId) 0) +#define TopSubTransactionId ((SubTransactionId) 1) + +/* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */ +typedef TransactionId MultiXactId; + +typedef uint32 MultiXactOffset; + +typedef uint32 CommandId; + +#define FirstCommandId ((CommandId) 0) +#define InvalidCommandId (~(CommandId)0) + + +/* ---------------- + * Variable-length datatypes all share the 'struct varlena' header. + * + * NOTE: for TOASTable types, this is an oversimplification, since the value + * may be compressed or moved out-of-line. However datatype-specific routines + * are mostly content to deal with de-TOASTed values only, and of course + * client-side routines should never see a TOASTed value. But even in a + * de-TOASTed value, beware of touching vl_len_ directly, as its + * representation is no longer convenient. It's recommended that code always + * use macros VARDATA_ANY, VARSIZE_ANY, VARSIZE_ANY_EXHDR, VARDATA, VARSIZE, + * and SET_VARSIZE instead of relying on direct mentions of the struct fields. + * See postgres.h for details of the TOASTed form. + * ---------------- + */ +struct varlena +{ + char vl_len_[4]; /* Do not touch this field directly! */ + char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */ +}; + +#define VARHDRSZ ((int32) sizeof(int32)) + +/* + * These widely-used datatypes are just a varlena header and the data bytes. + * There is no terminating null or anything like that --- the data length is + * always VARSIZE_ANY_EXHDR(ptr). + */ +typedef struct varlena bytea; +typedef struct varlena text; +typedef struct varlena BpChar; /* blank-padded char, ie SQL char(n) */ +typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */ + +/* + * Specialized array types. These are physically laid out just the same + * as regular arrays (so that the regular array subscripting code works + * with them). They exist as distinct types mostly for historical reasons: + * they have nonstandard I/O behavior which we don't want to change for fear + * of breaking applications that look at the system catalogs. There is also + * an implementation issue for oidvector: it's part of the primary key for + * pg_proc, and we can't use the normal btree array support routines for that + * without circularity. + */ +typedef struct +{ + int32 vl_len_; /* these fields must match ArrayType! */ + int ndim; /* always 1 for int2vector */ + int32 dataoffset; /* always 0 for int2vector */ + Oid elemtype; + int dim1; + int lbound1; + int16 values[FLEXIBLE_ARRAY_MEMBER]; +} int2vector; + +typedef struct +{ + int32 vl_len_; /* these fields must match ArrayType! */ + int ndim; /* always 1 for oidvector */ + int32 dataoffset; /* always 0 for oidvector */ + Oid elemtype; + int dim1; + int lbound1; + Oid values[FLEXIBLE_ARRAY_MEMBER]; +} oidvector; + +/* + * Representation of a Name: effectively just a C string, but null-padded to + * exactly NAMEDATALEN bytes. The use of a struct is historical. + */ +typedef struct nameData +{ + char data[NAMEDATALEN]; +} NameData; +typedef NameData *Name; + +#define NameStr(name) ((name).data) + + +/* ---------------------------------------------------------------- + * Section 4: IsValid macros for system types + * ---------------------------------------------------------------- + */ +/* + * BoolIsValid + * True iff bool is valid. + */ +#define BoolIsValid(boolean) ((boolean) == false || (boolean) == true) + +/* + * PointerIsValid + * True iff pointer is valid. + */ +#define PointerIsValid(pointer) ((const void*)(pointer) != NULL) + +/* + * PointerIsAligned + * True iff pointer is properly aligned to point to the given type. + */ +#define PointerIsAligned(pointer, type) \ + (((uintptr_t)(pointer) % (sizeof (type))) == 0) + +#define OffsetToPointer(base, offset) \ + ((void *)((char *) base + offset)) + +#define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid)) + +#define RegProcedureIsValid(p) OidIsValid(p) + + +/* ---------------------------------------------------------------- + * Section 5: offsetof, lengthof, alignment + * ---------------------------------------------------------------- + */ +/* + * offsetof + * Offset of a structure/union field within that structure/union. + * + * XXX This is supposed to be part of stddef.h, but isn't on + * some systems (like SunOS 4). + */ +#ifndef offsetof +#define offsetof(type, field) ((long) &((type *)0)->field) +#endif /* offsetof */ + +/* + * lengthof + * Number of elements in an array. + */ +#define lengthof(array) (sizeof (array) / sizeof ((array)[0])) + +/* ---------------- + * Alignment macros: align a length or address appropriately for a given type. + * The fooALIGN() macros round up to a multiple of the required alignment, + * while the fooALIGN_DOWN() macros round down. The latter are more useful + * for problems like "how many X-sized structures will fit in a page?". + * + * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2. + * That case seems extremely unlikely to be needed in practice, however. + * + * NOTE: MAXIMUM_ALIGNOF, and hence MAXALIGN(), intentionally exclude any + * larger-than-8-byte types the compiler might have. + * ---------------- + */ + +#define TYPEALIGN(ALIGNVAL,LEN) \ + (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1))) + +#define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN)) +#define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN)) +#define LONGALIGN(LEN) TYPEALIGN(ALIGNOF_LONG, (LEN)) +#define DOUBLEALIGN(LEN) TYPEALIGN(ALIGNOF_DOUBLE, (LEN)) +#define MAXALIGN(LEN) TYPEALIGN(MAXIMUM_ALIGNOF, (LEN)) +/* MAXALIGN covers only built-in types, not buffers */ +#define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN)) +#define CACHELINEALIGN(LEN) TYPEALIGN(PG_CACHE_LINE_SIZE, (LEN)) + +#define TYPEALIGN_DOWN(ALIGNVAL,LEN) \ + (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1))) + +#define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN)) +#define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN)) +#define LONGALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN)) +#define DOUBLEALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN)) +#define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN)) +#define BUFFERALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_BUFFER, (LEN)) + +/* + * The above macros will not work with types wider than uintptr_t, like with + * uint64 on 32-bit platforms. That's not problem for the usual use where a + * pointer or a length is aligned, but for the odd case that you need to + * align something (potentially) wider, use TYPEALIGN64. + */ +#define TYPEALIGN64(ALIGNVAL,LEN) \ + (((uint64) (LEN) + ((ALIGNVAL) - 1)) & ~((uint64) ((ALIGNVAL) - 1))) + +/* we don't currently need wider versions of the other ALIGN macros */ +#define MAXALIGN64(LEN) TYPEALIGN64(MAXIMUM_ALIGNOF, (LEN)) + + +/* ---------------------------------------------------------------- + * Section 6: assertions + * ---------------------------------------------------------------- + */ + +/* + * USE_ASSERT_CHECKING, if defined, turns on all the assertions. + * - plai 9/5/90 + * + * It should _NOT_ be defined in releases or in benchmark copies + */ + +/* + * Assert() can be used in both frontend and backend code. In frontend code it + * just calls the standard assert, if it's available. If use of assertions is + * not configured, it does nothing. + */ +#ifndef USE_ASSERT_CHECKING + +#define Assert(condition) ((void)true) +#define AssertMacro(condition) ((void)true) +#define AssertArg(condition) ((void)true) +#define AssertState(condition) ((void)true) +#define AssertPointerAlignment(ptr, bndr) ((void)true) +#define Trap(condition, errorType) ((void)true) +#define TrapMacro(condition, errorType) (true) + +#elif defined(FRONTEND) + +#include <assert.h> +#define Assert(p) assert(p) +#define AssertMacro(p) ((void) assert(p)) +#define AssertArg(condition) assert(condition) +#define AssertState(condition) assert(condition) +#define AssertPointerAlignment(ptr, bndr) ((void)true) + +#else /* USE_ASSERT_CHECKING && !FRONTEND */ + +/* + * Trap + * Generates an exception if the given condition is true. + */ +#define Trap(condition, errorType) \ + do { \ + if (condition) \ + ExceptionalCondition(#condition, (errorType), \ + __FILE__, __LINE__); \ + } while (0) + +/* + * TrapMacro is the same as Trap but it's intended for use in macros: + * + * #define foo(x) (AssertMacro(x != 0), bar(x)) + * + * Isn't CPP fun? + */ +#define TrapMacro(condition, errorType) \ + ((bool) (! (condition) || \ + (ExceptionalCondition(#condition, (errorType), \ + __FILE__, __LINE__), 0))) + +#define Assert(condition) \ + do { \ + if (!(condition)) \ + ExceptionalCondition(#condition, "FailedAssertion", \ + __FILE__, __LINE__); \ + } while (0) + +#define AssertMacro(condition) \ + ((void) ((condition) || \ + (ExceptionalCondition(#condition, "FailedAssertion", \ + __FILE__, __LINE__), 0))) + +#define AssertArg(condition) \ + do { \ + if (!(condition)) \ + ExceptionalCondition(#condition, "BadArgument", \ + __FILE__, __LINE__); \ + } while (0) + +#define AssertState(condition) \ + do { \ + if (!(condition)) \ + ExceptionalCondition(#condition, "BadState", \ + __FILE__, __LINE__); \ + } while (0) + +/* + * Check that `ptr' is `bndr' aligned. + */ +#define AssertPointerAlignment(ptr, bndr) \ + Trap(TYPEALIGN(bndr, (uintptr_t)(ptr)) != (uintptr_t)(ptr), \ + "UnalignedPointer") + +#endif /* USE_ASSERT_CHECKING && !FRONTEND */ + +/* + * ExceptionalCondition is compiled into the backend whether or not + * USE_ASSERT_CHECKING is defined, so as to support use of extensions + * that are built with that #define with a backend that isn't. Hence, + * we should declare it as long as !FRONTEND. + */ +#ifndef FRONTEND +extern void ExceptionalCondition(const char *conditionName, + const char *errorType, + const char *fileName, int lineNumber) pg_attribute_noreturn(); +#endif + +/* + * Macros to support compile-time assertion checks. + * + * If the "condition" (a compile-time-constant expression) evaluates to false, + * throw a compile error using the "errmessage" (a string literal). + * + * gcc 4.6 and up supports _Static_assert(), but there are bizarre syntactic + * placement restrictions. Macros StaticAssertStmt() and StaticAssertExpr() + * make it safe to use as a statement or in an expression, respectively. + * The macro StaticAssertDecl() is suitable for use at file scope (outside of + * any function). + * + * Otherwise we fall back on a kluge that assumes the compiler will complain + * about a negative width for a struct bit-field. This will not include a + * helpful error message, but it beats not getting an error at all. + */ +#ifndef __cplusplus +#ifdef HAVE__STATIC_ASSERT +#define StaticAssertStmt(condition, errmessage) \ + do { _Static_assert(condition, errmessage); } while(0) +#define StaticAssertExpr(condition, errmessage) \ + ((void) ({ StaticAssertStmt(condition, errmessage); true; })) +#define StaticAssertDecl(condition, errmessage) \ + _Static_assert(condition, errmessage) +#else /* !HAVE__STATIC_ASSERT */ +#define StaticAssertStmt(condition, errmessage) \ + ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; })) +#define StaticAssertExpr(condition, errmessage) \ + StaticAssertStmt(condition, errmessage) +#define StaticAssertDecl(condition, errmessage) \ + extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1]) +#endif /* HAVE__STATIC_ASSERT */ +#else /* C++ */ +#if defined(__cpp_static_assert) && __cpp_static_assert >= 200410 +#define StaticAssertStmt(condition, errmessage) \ + static_assert(condition, errmessage) +#define StaticAssertExpr(condition, errmessage) \ + ({ static_assert(condition, errmessage); }) +#define StaticAssertDecl(condition, errmessage) \ + static_assert(condition, errmessage) +#else /* !__cpp_static_assert */ +#define StaticAssertStmt(condition, errmessage) \ + do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0) +#define StaticAssertExpr(condition, errmessage) \ + ((void) ({ StaticAssertStmt(condition, errmessage); })) +#define StaticAssertDecl(condition, errmessage) \ + extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1]) +#endif /* __cpp_static_assert */ +#endif /* C++ */ + + +/* + * Compile-time checks that a variable (or expression) has the specified type. + * + * AssertVariableIsOfType() can be used as a statement. + * AssertVariableIsOfTypeMacro() is intended for use in macros, eg + * #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x)) + * + * If we don't have __builtin_types_compatible_p, we can still assert that + * the types have the same size. This is far from ideal (especially on 32-bit + * platforms) but it provides at least some coverage. + */ +#ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P +#define AssertVariableIsOfType(varname, typename) \ + StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \ + CppAsString(varname) " does not have type " CppAsString(typename)) +#define AssertVariableIsOfTypeMacro(varname, typename) \ + (StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \ + CppAsString(varname) " does not have type " CppAsString(typename))) +#else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */ +#define AssertVariableIsOfType(varname, typename) \ + StaticAssertStmt(sizeof(varname) == sizeof(typename), \ + CppAsString(varname) " does not have type " CppAsString(typename)) +#define AssertVariableIsOfTypeMacro(varname, typename) \ + (StaticAssertExpr(sizeof(varname) == sizeof(typename), \ + CppAsString(varname) " does not have type " CppAsString(typename))) +#endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */ + + +/* ---------------------------------------------------------------- + * Section 7: widely useful macros + * ---------------------------------------------------------------- + */ +/* + * Max + * Return the maximum of two numbers. + */ +#define Max(x, y) ((x) > (y) ? (x) : (y)) + +/* + * Min + * Return the minimum of two numbers. + */ +#define Min(x, y) ((x) < (y) ? (x) : (y)) + +/* + * Abs + * Return the absolute value of the argument. + */ +#define Abs(x) ((x) >= 0 ? (x) : -(x)) + + +/* Get a bit mask of the bits set in non-long aligned addresses */ +#define LONG_ALIGN_MASK (sizeof(long) - 1) + +/* + * MemSet + * Exactly the same as standard library function memset(), but considerably + * faster for zeroing small word-aligned structures (such as parsetree nodes). + * This has to be a macro because the main point is to avoid function-call + * overhead. However, we have also found that the loop is faster than + * native libc memset() on some platforms, even those with assembler + * memset() functions. More research needs to be done, perhaps with + * MEMSET_LOOP_LIMIT tests in configure. + */ +#define MemSet(start, val, len) \ + do \ + { \ + /* must be void* because we don't know if it is integer aligned yet */ \ + void *_vstart = (void *) (start); \ + int _val = (val); \ + Size _len = (len); \ +\ + if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \ + (_len & LONG_ALIGN_MASK) == 0 && \ + _val == 0 && \ + _len <= MEMSET_LOOP_LIMIT && \ + /* \ + * If MEMSET_LOOP_LIMIT == 0, optimizer should find \ + * the whole "if" false at compile time. \ + */ \ + MEMSET_LOOP_LIMIT != 0) \ + { \ + long *_start = (long *) _vstart; \ + long *_stop = (long *) ((char *) _start + _len); \ + while (_start < _stop) \ + *_start++ = 0; \ + } \ + else \ + memset(_vstart, _val, _len); \ + } while (0) + +/* + * MemSetAligned is the same as MemSet except it omits the test to see if + * "start" is word-aligned. This is okay to use if the caller knows a-priori + * that the pointer is suitably aligned (typically, because he just got it + * from palloc(), which always delivers a max-aligned pointer). + */ +#define MemSetAligned(start, val, len) \ + do \ + { \ + long *_start = (long *) (start); \ + int _val = (val); \ + Size _len = (len); \ +\ + if ((_len & LONG_ALIGN_MASK) == 0 && \ + _val == 0 && \ + _len <= MEMSET_LOOP_LIMIT && \ + MEMSET_LOOP_LIMIT != 0) \ + { \ + long *_stop = (long *) ((char *) _start + _len); \ + while (_start < _stop) \ + *_start++ = 0; \ + } \ + else \ + memset(_start, _val, _len); \ + } while (0) + + +/* + * MemSetTest/MemSetLoop are a variant version that allow all the tests in + * MemSet to be done at compile time in cases where "val" and "len" are + * constants *and* we know the "start" pointer must be word-aligned. + * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use + * MemSetAligned. Beware of multiple evaluations of the arguments when using + * this approach. + */ +#define MemSetTest(val, len) \ + ( ((len) & LONG_ALIGN_MASK) == 0 && \ + (len) <= MEMSET_LOOP_LIMIT && \ + MEMSET_LOOP_LIMIT != 0 && \ + (val) == 0 ) + +#define MemSetLoop(start, val, len) \ + do \ + { \ + long * _start = (long *) (start); \ + long * _stop = (long *) ((char *) _start + (Size) (len)); \ + \ + while (_start < _stop) \ + *_start++ = 0; \ + } while (0) + +/* + * Macros for range-checking float values before converting to integer. + * We must be careful here that the boundary values are expressed exactly + * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will + * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded + * off, so avoid using that. + * The input must be rounded to an integer beforehand, typically with rint(), + * else we might draw the wrong conclusion about close-to-the-limit values. + * These macros will do the right thing for Inf, but not necessarily for NaN, + * so check isnan(num) first if that's a possibility. + */ +#define FLOAT4_FITS_IN_INT16(num) \ + ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN)) +#define FLOAT4_FITS_IN_INT32(num) \ + ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN)) +#define FLOAT4_FITS_IN_INT64(num) \ + ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN)) +#define FLOAT8_FITS_IN_INT16(num) \ + ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN)) +#define FLOAT8_FITS_IN_INT32(num) \ + ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN)) +#define FLOAT8_FITS_IN_INT64(num) \ + ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN)) + + +/* ---------------------------------------------------------------- + * Section 8: random stuff + * ---------------------------------------------------------------- + */ + +#ifdef HAVE_STRUCT_SOCKADDR_UN +#define HAVE_UNIX_SOCKETS 1 +#endif + +/* + * Invert the sign of a qsort-style comparison result, ie, exchange negative + * and positive integer values, being careful not to get the wrong answer + * for INT_MIN. The argument should be an integral variable. + */ +#define INVERT_COMPARE_RESULT(var) \ + ((var) = ((var) < 0) ? 1 : -(var)) + +/* + * Use this, not "char buf[BLCKSZ]", to declare a field or local variable + * holding a page buffer, if that page might be accessed as a page and not + * just a string of bytes. Otherwise the variable might be under-aligned, + * causing problems on alignment-picky hardware. (In some places, we use + * this to declare buffers even though we only pass them to read() and + * write(), because copying to/from aligned buffers is usually faster than + * using unaligned buffers.) We include both "double" and "int64" in the + * union to ensure that the compiler knows the value must be MAXALIGN'ed + * (cf. configure's computation of MAXIMUM_ALIGNOF). + */ +typedef union PGAlignedBlock +{ + char data[BLCKSZ]; + double force_align_d; + int64 force_align_i64; +} PGAlignedBlock; + +/* Same, but for an XLOG_BLCKSZ-sized buffer */ +typedef union PGAlignedXLogBlock +{ + char data[XLOG_BLCKSZ]; + double force_align_d; + int64 force_align_i64; +} PGAlignedXLogBlock; + +/* msb for char */ +#define HIGHBIT (0x80) +#define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT) + +/* + * Support macros for escaping strings. escape_backslash should be true + * if generating a non-standard-conforming string. Prefixing a string + * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming. + * Beware of multiple evaluation of the "ch" argument! + */ +#define SQL_STR_DOUBLE(ch, escape_backslash) \ + ((ch) == '\'' || ((ch) == '\\' && (escape_backslash))) + +#define ESCAPE_STRING_SYNTAX 'E' + + +#define STATUS_OK (0) +#define STATUS_ERROR (-1) +#define STATUS_EOF (-2) + +/* + * gettext support + */ + +#ifndef ENABLE_NLS +/* stuff we'd otherwise get from <libintl.h> */ +#define gettext(x) (x) +#define dgettext(d,x) (x) +#define ngettext(s,p,n) ((n) == 1 ? (s) : (p)) +#define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p)) +#endif + +#define _(x) gettext(x) + +/* + * Use this to mark string constants as needing translation at some later + * time, rather than immediately. This is useful for cases where you need + * access to the original string and translated string, and for cases where + * immediate translation is not possible, like when initializing global + * variables. + * + * https://www.gnu.org/software/gettext/manual/html_node/Special-cases.html + */ +#define gettext_noop(x) (x) + +/* + * To better support parallel installations of major PostgreSQL + * versions as well as parallel installations of major library soname + * versions, we mangle the gettext domain name by appending those + * version numbers. The coding rule ought to be that wherever the + * domain name is mentioned as a literal, it must be wrapped into + * PG_TEXTDOMAIN(). The macros below do not work on non-literals; but + * that is somewhat intentional because it avoids having to worry + * about multiple states of premangling and postmangling as the values + * are being passed around. + * + * Make sure this matches the installation rules in nls-global.mk. + */ +#ifdef SO_MAJOR_VERSION +#define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION) +#else +#define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION) +#endif + +/* + * Macro that allows to cast constness and volatile away from an expression, but doesn't + * allow changing the underlying type. Enforcement of the latter + * currently only works for gcc like compilers. + * + * Please note IT IS NOT SAFE to cast constness away if the result will ever + * be modified (it would be undefined behaviour). Doing so anyway can cause + * compiler misoptimizations or runtime crashes (modifying readonly memory). + * It is only safe to use when the result will not be modified, but API + * design or language restrictions prevent you from declaring that + * (e.g. because a function returns both const and non-const variables). + * + * Note that this only works in function scope, not for global variables (it'd + * be nice, but not trivial, to improve that). + */ +#if defined(HAVE__BUILTIN_TYPES_COMPATIBLE_P) +#define unconstify(underlying_type, expr) \ + (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), const underlying_type), \ + "wrong cast"), \ + (underlying_type) (expr)) +#define unvolatize(underlying_type, expr) \ + (StaticAssertExpr(__builtin_types_compatible_p(__typeof(expr), volatile underlying_type), \ + "wrong cast"), \ + (underlying_type) (expr)) +#else +#define unconstify(underlying_type, expr) \ + ((underlying_type) (expr)) +#define unvolatize(underlying_type, expr) \ + ((underlying_type) (expr)) +#endif + +/* ---------------------------------------------------------------- + * Section 9: system-specific hacks + * + * This should be limited to things that absolutely have to be + * included in every source file. The port-specific header file + * is usually a better place for this sort of thing. + * ---------------------------------------------------------------- + */ + +/* + * NOTE: this is also used for opening text files. + * WIN32 treats Control-Z as EOF in files opened in text mode. + * Therefore, we open files in binary mode on Win32 so we can read + * literal control-Z. The other affect is that we see CRLF, but + * that is OK because we can already handle those cleanly. + */ +#if defined(WIN32) || defined(__CYGWIN__) +#define PG_BINARY O_BINARY +#define PG_BINARY_A "ab" +#define PG_BINARY_R "rb" +#define PG_BINARY_W "wb" +#else +#define PG_BINARY 0 +#define PG_BINARY_A "a" +#define PG_BINARY_R "r" +#define PG_BINARY_W "w" +#endif + +/* + * Provide prototypes for routines not present in a particular machine's + * standard C library. + */ + +#if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC +extern int fdatasync(int fildes); +#endif + +/* Older platforms may provide strto[u]ll functionality under other names */ +#if !defined(HAVE_STRTOLL) && defined(HAVE___STRTOLL) +#define strtoll __strtoll +#define HAVE_STRTOLL 1 +#endif + +#if !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ) +#define strtoll strtoq +#define HAVE_STRTOLL 1 +#endif + +#if !defined(HAVE_STRTOULL) && defined(HAVE___STRTOULL) +#define strtoull __strtoull +#define HAVE_STRTOULL 1 +#endif + +#if !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ) +#define strtoull strtouq +#define HAVE_STRTOULL 1 +#endif + +#if defined(HAVE_STRTOLL) && !HAVE_DECL_STRTOLL +extern long long strtoll(const char *str, char **endptr, int base); +#endif + +#if defined(HAVE_STRTOULL) && !HAVE_DECL_STRTOULL +extern unsigned long long strtoull(const char *str, char **endptr, int base); +#endif + +/* no special DLL markers on most ports */ +#ifndef PGDLLIMPORT +#define PGDLLIMPORT +#endif +#ifndef PGDLLEXPORT +#define PGDLLEXPORT +#endif + +/* + * The following is used as the arg list for signal handlers. Any ports + * that take something other than an int argument should override this in + * their pg_config_os.h file. Note that variable names are required + * because it is used in both the prototypes as well as the definitions. + * Note also the long name. We expect that this won't collide with + * other names causing compiler warnings. + */ + +#ifndef SIGNAL_ARGS +#define SIGNAL_ARGS int postgres_signal_arg +#endif + +/* + * When there is no sigsetjmp, its functionality is provided by plain + * setjmp. We now support the case only on Windows. However, it seems + * that MinGW-64 has some longstanding issues in its setjmp support, + * so on that toolchain we cheat and use gcc's builtins. + */ +#ifdef WIN32 +#ifdef __MINGW64__ +typedef intptr_t sigjmp_buf[5]; +#define sigsetjmp(x,y) __builtin_setjmp(x) +#define siglongjmp __builtin_longjmp +#else /* !__MINGW64__ */ +#define sigjmp_buf jmp_buf +#define sigsetjmp(x,y) setjmp(x) +#define siglongjmp longjmp +#endif /* __MINGW64__ */ +#endif /* WIN32 */ + +/* EXEC_BACKEND defines */ +#ifdef EXEC_BACKEND +#define NON_EXEC_STATIC +#else +#define NON_EXEC_STATIC static +#endif + +/* /port compatibility functions */ +#include "port.h" + +#endif /* C_H */ |