/*------------------------------------------------------------------------- * * 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) 1996-2016, 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) hacks to cope with non-ANSI C compilers * 2) bool, true, false, TRUE, FALSE, NULL * 3) standard system types * 4) IsValid macros for system types * 5) offsetof, lengthof, endof, 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 * almost certainly wrong to put an "extern" declaration here. 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 */ /* * We always rely on the WIN32 macro being set by our build system, * but _WIN32 is the compiler pre-defined macro. So make sure we define * WIN32 whenever _WIN32 is set, to facilitate standalone building. */ #if defined(_WIN32) && !defined(WIN32) #define WIN32 #endif #if !defined(WIN32) && !defined(__CYGWIN__) /* win32 includes further down */ #include "pg_config_os.h" /* must be before any system header files */ #endif #if _MSC_VER >= 1400 || defined(HAVE_CRTDEFS_H) #define errcode __msvc_errcode #include #undef errcode #endif /* * We have to include stdlib.h here because it defines many of these macros * on some platforms, and we only want our definitions used if stdlib.h doesn't * have its own. The same goes for stddef and stdarg if present. */ #include #include #include #include #include #ifdef HAVE_STRINGS_H #include #endif #ifdef HAVE_STDINT_H #include #endif #include #include #if defined(WIN32) || defined(__CYGWIN__) #include /* ensure O_BINARY is available */ #endif #if defined(WIN32) || defined(__CYGWIN__) /* We have to redefine some system functions after they are included above. */ #include "pg_config_os.h" #endif /* * Force disable inlining if PG_FORCE_DISABLE_INLINE is defined. This is used * to work around compiler bugs and might also be useful for investigatory * purposes by defining the symbol in the platform's header.. * * This is done early (in slightly the wrong section) as functionality later * in this file might want to rely on inline functions. */ #ifdef PG_FORCE_DISABLE_INLINE #undef inline #define inline #endif /* Must be before gettext() games below */ #include #define _(x) gettext(x) #ifdef ENABLE_NLS #include #else #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 /* * 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) /* ---------------------------------------------------------------- * Section 1: hacks to cope with non-ANSI C compilers * * type prefixes (const, signed, volatile, inline) are handled in pg_config.h. * ---------------------------------------------------------------- */ /* * CppAsString * Convert the argument to a string, using the C preprocessor. * 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 CppConcat(x, y) x##y /* * 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 /* 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, TRUE, FALSE, NULL * ---------------------------------------------------------------- */ /* * bool * Boolean value, either true or false. * * XXX for C++ compilers, we assume the compiler has a compatible * built-in definition of bool. */ #ifndef __cplusplus #ifndef bool typedef char bool; #endif #ifndef true #define true ((bool) 1) #endif #ifndef false #define false ((bool) 0) #endif #endif /* not C++ */ typedef bool *BoolPtr; #ifndef TRUE #define TRUE 1 #endif #ifndef FALSE #define FALSE 0 #endif /* * NULL * Null pointer. */ #ifndef NULL #define NULL ((void *) 0) #endif /* ---------------------------------------------------------------- * 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 #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 #else /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */ #error must have a working 64-bit integer datatype #endif /* Decide if we need to decorate 64-bit constants */ #ifdef HAVE_LL_CONSTANTS #define INT64CONST(x) ((int64) x##LL) #define UINT64CONST(x) ((uint64) x##ULL) #else #define INT64CONST(x) ((int64) x) #define UINT64CONST(x) ((uint64) x) #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 a limited support for the type. E.g. 128bit * literals and snprintf are not supported; but math is. */ #if defined(PG_INT128_TYPE) #define HAVE_INT128 typedef PG_INT128_TYPE int128; typedef unsigned PG_INT128_TYPE uint128; #endif /* * stdint.h limits aren't guaranteed to be present and 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 (0xFFFFFFFF) #define PG_INT64_MIN (-INT64CONST(0x7FFFFFFFFFFFFFFF) - 1) #define PG_INT64_MAX INT64CONST(0x7FFFFFFFFFFFFFFF) #define PG_UINT64_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF) /* Select timestamp representation (float8 or int64) */ #ifdef USE_INTEGER_DATETIMES #define HAVE_INT64_TIMESTAMP #endif /* * 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; /* * 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 the VARDATA, * VARSIZE, and SET_VARSIZE macros 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(ptr) - VARHDRSZ. */ 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) /* * 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' /* ---------------------------------------------------------------- * 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 OidIsValid(objectId) ((bool) ((objectId) != InvalidOid)) #define RegProcedureIsValid(p) OidIsValid(p) /* ---------------------------------------------------------------- * Section 5: offsetof, lengthof, endof, 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])) /* * endof * Address of the element one past the last in an array. */ #define endof(array) (&(array)[lengthof(array)]) /* ---------------- * 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. * ---------------- */ #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)) /* * 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)) /* ---------------- * 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: http://www-01.ibm.com/support/knowledgecenter/SSGH2K_11.1.0/com.ibm.xlc111.aix.doc/language_ref/function_attributes.html * XLC: http://www-01.ibm.com/support/knowledgecenter/SSGH2K_11.1.0/com.ibm.xlc111.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 /* 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 /* ---------------------------------------------------------------- * 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 #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(CppAsString(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(CppAsString(condition), (errorType), \ __FILE__, __LINE__), 0))) #define Assert(condition) \ Trap(!(condition), "FailedAssertion") #define AssertMacro(condition) \ ((void) TrapMacro(!(condition), "FailedAssertion")) #define AssertArg(condition) \ Trap(!(condition), "BadArgument") #define AssertState(condition) \ Trap(!(condition), "BadState") /* * 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 */ /* * 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. These macros make it safe to use as a statement * or in an expression, respectively. * * 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. */ #ifdef HAVE__STATIC_ASSERT #define StaticAssertStmt(condition, errmessage) \ do { _Static_assert(condition, errmessage); } while(0) #define StaticAssertExpr(condition, errmessage) \ ({ StaticAssertStmt(condition, errmessage); true; }) #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) #endif /* HAVE__STATIC_ASSERT */ /* * 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) \ ((void) 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) \ ((void) 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) /* * 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 /* ---------------------------------------------------------------- * Section 8: random stuff * ---------------------------------------------------------------- */ /* msb for char */ #define HIGHBIT (0x80) #define IS_HIGHBIT_SET(ch) ((unsigned char)(ch) & HIGHBIT) #define STATUS_OK (0) #define STATUS_ERROR (-1) #define STATUS_EOF (-2) #define STATUS_FOUND (1) #define STATUS_WAITING (2) /* * 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 /* gettext domain name mangling */ /* * 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. */ /* need a second indirection because we want to stringize the macro value, not the name */ #define CppAsString2(x) CppAsString(x) #ifdef SO_MAJOR_VERSION #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION) #else #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION) #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 !HAVE_DECL_SNPRINTF extern int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3, 4); #endif #if !HAVE_DECL_VSNPRINTF extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args); #endif #if !defined(HAVE_MEMMOVE) && !defined(memmove) #define memmove(d, s, c) bcopy(s, d, c) #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 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC extern int fdatasync(int fildes); #endif /* If strtoq() exists, rename it to the more standard strtoll() */ #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ) #define strtoll strtoq #define HAVE_STRTOLL 1 #endif /* If strtouq() exists, rename it to the more standard strtoull() */ #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ) #define strtoull strtouq #define HAVE_STRTOULL 1 #endif /* * We assume if we have these two functions, we have their friends too, and * can use the wide-character functions. */ #if defined(HAVE_WCSTOMBS) && defined(HAVE_TOWLOWER) #define USE_WIDE_UPPER_LOWER #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 */