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/*------------------------------------------------------------------------- * * 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) 1996-2020, 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 * 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 */ /* only GCC supports the unused attribute */ #ifdef __GNUC__ #define pg_attribute_unused() __attribute__((unused)) #else #define pg_attribute_unused() #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 /* * 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 /* * 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 /* * Does the compiler support #pragma GCC system_header? We optionally use it * to avoid warnings that we can't fix (e.g. in the perl headers). * See https://gcc.gnu.org/onlinedocs/cpp/System-Headers.html * * Headers for which we do not want to show compiler warnings can, * conditionally, use #pragma GCC system_header to avoid warnings. Obviously * this should only be used for external headers over which we do not have * control. * * Support for the pragma is tested here, instead of during configure, as gcc * also warns about the pragma being used in a .c file. It's surprisingly hard * to get autoconf to use .h as the file-ending. Looks like gcc has * implemented the pragma since the 2000, so this test should suffice. * * * Alternatively, we could add the include paths for problematic headers with * -isystem, but that is a larger hammer and is harder to search for. * * A more granular alternative would be to use #pragma GCC diagnostic * push/ignored/pop, but gcc warns about unknown warnings being ignored, so * every to-be-ignored-temporarily compiler warning would require its own * pg_config.h symbol and #ifdef. */ #ifdef __GNUC__ #define HAVE_PRAGMA_GCC_SYSTEM_HEADER 1 #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) /* * Array indexing support */ #define MAXDIM 6 typedef struct { int indx[MAXDIM]; } IntArray; /* ---------------- * 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)) /* * StrNCpy * Like standard library function strncpy(), except that result string * is guaranteed to be null-terminated --- that is, at most N-1 bytes * of the source string will be kept. * Also, the macro returns no result (too hard to do that without * evaluating the arguments multiple times, which seems worse). * * BTW: when you need to copy a non-null-terminated string (like a text * datum) and add a null, do not do it with StrNCpy(..., len+1). That * might seem to work, but it fetches one byte more than there is in the * text object. One fine day you'll have a SIGSEGV because there isn't * another byte before the end of memory. Don't laugh, we've had real * live bug reports from real live users over exactly this mistake. * Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead. */ #define StrNCpy(dst,src,len) \ do \ { \ char * _dst = (dst); \ Size _len = (len); \ \ if (_len > 0) \ { \ strncpy(_dst, (src), _len); \ _dst[_len-1] = '\0'; \ } \ } while (0) /* 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) #define STATUS_WAITING (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. * http://www.gnu.org/software/autoconf/manual/gettext/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. Incidentally, nothing provides setjmp's functionality in * that case. We now support the case only on Windows. */ #ifdef WIN32 #define sigjmp_buf jmp_buf #define sigsetjmp(x,y) setjmp(x) #define siglongjmp longjmp #endif /* 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 */