X-Git-Url: https://granicus.if.org/sourcecode?a=blobdiff_plain;f=src%2Finclude%2Fc.h;h=9066e3c57835f97f8a0ee6cf1cf4bd8102979fcb;hb=c7b8998ebbf310a156aa38022555a24d98fdbfb4;hp=0686ad3d078a9b2ef8dbdc4a0b9740ff4bec24cf;hpb=9f2e211386931f7aee48ffbc2fcaef1632d8329f;p=postgresql diff --git a/src/include/c.h b/src/include/c.h index 0686ad3d07..9066e3c578 100644 --- a/src/include/c.h +++ b/src/include/c.h @@ -9,7 +9,7 @@ * polluting the namespace with lots of stuff... * * - * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group + * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * src/include/c.h @@ -31,12 +31,13 @@ * 3) standard system types * 4) IsValid macros for system types * 5) offsetof, lengthof, endof, alignment - * 6) widely useful macros - * 7) random stuff - * 8) system-specific hacks + * 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 + * almost certainly wrong to put an "extern" declaration here. typedefs and * macros are the kind of thing that might go here. * *---------------------------------------------------------------- @@ -44,26 +45,39 @@ #ifndef C_H #define C_H -/* - * 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 "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 */ -#if !defined(WIN32) && !defined(__CYGWIN__) /* win32 will include further - * down */ + +/* + * 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 -#include "postgres_ext.h" -#if _MSC_VER >= 1400 +#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 @@ -81,15 +95,25 @@ #if defined(WIN32) || defined(__CYGWIN__) #include /* ensure O_BINARY is available */ #endif -#ifdef HAVE_SUPPORTDEFS_H -#include -#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 @@ -106,7 +130,7 @@ /* * Use this to mark string constants as needing translation at some later - * time, rather than immediately. This is useful for cases where you need + * 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. @@ -125,31 +149,18 @@ /* * 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: the standard Autoconf macro AC_C_STRINGIZE actually only checks - * whether #identifier works, but if we have that we likely have ## too. + * 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. */ -#if defined(HAVE_STRINGIZE) - #define CppAsString(identifier) #identifier +#define CppAsString2(x) CppAsString(x) #define CppConcat(x, y) x##y -#else /* !HAVE_STRINGIZE */ - -#define CppAsString(identifier) "identifier" - -/* - * CppIdentity -- On Reiser based cpp's this is used to concatenate - * two tokens. That is - * CppIdentity(A)B ==> AB - * We renamed it to _private_CppIdentity because it should not - * be referenced outside this file. On other cpp's it - * produces A B. - */ -#define _priv_CppIdentity(x)x -#define CppConcat(x, y) _priv_CppIdentity(x)y -#endif /* !HAVE_STRINGIZE */ /* * dummyret is used to set return values in macros that use ?: to make @@ -161,8 +172,15 @@ #define dummyret char #endif -#ifndef __GNUC__ -#define __attribute__(_arg_) +/* 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 /* ---------------------------------------------------------------- @@ -191,7 +209,7 @@ typedef char bool; #ifndef false #define false ((bool) 0) #endif -#endif /* not C++ */ +#endif /* not C++ */ typedef bool *BoolPtr; @@ -236,7 +254,7 @@ typedef char *Pointer; typedef signed char int8; /* == 8 bits */ typedef signed short int16; /* == 16 bits */ typedef signed int int32; /* == 32 bits */ -#endif /* not HAVE_INT8 */ +#endif /* not HAVE_INT8 */ /* * uintN @@ -248,7 +266,7 @@ typedef signed int int32; /* == 32 bits */ typedef unsigned char uint8; /* == 8 bits */ typedef unsigned short uint16; /* == 16 bits */ typedef unsigned int uint32; /* == 32 bits */ -#endif /* not HAVE_UINT8 */ +#endif /* not HAVE_UINT8 */ /* * bitsN @@ -293,16 +311,43 @@ typedef unsigned long long int uint64; #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" -/* Select timestamp representation (float8 or int64) */ -#ifdef USE_INTEGER_DATETIMES -#define HAVE_INT64_TIMESTAMP +/* + * 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 -/* sig_atomic_t is required by ANSI C, but may be missing on old platforms */ -#ifndef HAVE_SIG_ATOMIC_T -typedef int sig_atomic_t; -#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) + +/* + * 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 @@ -332,8 +377,6 @@ typedef signed int Offset; /* * Common Postgres datatype names (as used in the catalogs) */ -typedef int16 int2; -typedef int32 int4; typedef float float4; typedef double float8; @@ -368,6 +411,7 @@ typedef uint32 MultiXactOffset; typedef uint32 CommandId; #define FirstCommandId ((CommandId) 0) +#define InvalidCommandId (~(CommandId)0) /* * Array indexing support @@ -376,25 +420,26 @@ typedef uint32 CommandId; typedef struct { int indx[MAXDIM]; -} IntArray; +} 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 + * 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. + * 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[1]; + char vl_dat[FLEXIBLE_ARRAY_MEMBER]; /* Data content is here */ }; #define VARHDRSZ ((int32) sizeof(int32)) @@ -402,7 +447,7 @@ struct varlena /* * 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. + * always VARSIZE_ANY_EXHDR(ptr). */ typedef struct varlena bytea; typedef struct varlena text; @@ -412,7 +457,7 @@ 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: + * 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 @@ -427,8 +472,8 @@ typedef struct Oid elemtype; int dim1; int lbound1; - int2 values[1]; /* VARIABLE LENGTH ARRAY */ -} int2vector; /* VARIABLE LENGTH STRUCT */ + int16 values[FLEXIBLE_ARRAY_MEMBER]; +} int2vector; typedef struct { @@ -438,8 +483,8 @@ typedef struct Oid elemtype; int dim1; int lbound1; - Oid values[1]; /* VARIABLE LENGTH ARRAY */ -} oidvector; /* VARIABLE LENGTH STRUCT */ + Oid values[FLEXIBLE_ARRAY_MEMBER]; +} oidvector; /* * Representation of a Name: effectively just a C string, but null-padded to @@ -455,7 +500,7 @@ typedef NameData *Name; /* * Support macros for escaping strings. escape_backslash should be TRUE - * if generating a non-standard-conforming string. Prefixing a string + * 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! */ @@ -478,14 +523,17 @@ typedef NameData *Name; * PointerIsValid * True iff pointer is valid. */ -#define PointerIsValid(pointer) ((void*)(pointer) != NULL) +#define PointerIsValid(pointer) ((const void*)(pointer) != NULL) /* * PointerIsAligned * True iff pointer is properly aligned to point to the given type. */ #define PointerIsAligned(pointer, type) \ - (((intptr_t)(pointer) % (sizeof (type))) == 0) + (((uintptr_t)(pointer) % (sizeof (type))) == 0) + +#define OffsetToPointer(base, offset) \ + ((void *)((char *) base + offset)) #define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid)) @@ -505,7 +553,7 @@ typedef NameData *Name; */ #ifndef offsetof #define offsetof(type, field) ((long) &((type *)0)->field) -#endif /* offsetof */ +#endif /* offsetof */ /* * lengthof @@ -531,7 +579,7 @@ typedef NameData *Name; */ #define TYPEALIGN(ALIGNVAL,LEN) \ - (((intptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((intptr_t) ((ALIGNVAL) - 1))) + (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1))) #define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN)) #define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN)) @@ -540,9 +588,10 @@ typedef NameData *Name; #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) \ - (((intptr_t) (LEN)) & ~((intptr_t) ((ALIGNVAL) - 1))) + (((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)) @@ -550,8 +599,198 @@ typedef NameData *Name; #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: widely useful macros + * 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 * ---------------------------------------------------------------- */ /* @@ -584,7 +823,7 @@ typedef NameData *Name; * 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 + * 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. */ @@ -610,7 +849,7 @@ typedef NameData *Name; * 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 + * 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. @@ -623,7 +862,7 @@ typedef NameData *Name; int _val = (val); \ Size _len = (len); \ \ - if ((((intptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \ + if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \ (_len & LONG_ALIGN_MASK) == 0 && \ _val == 0 && \ _len <= MEMSET_LOOP_LIMIT && \ @@ -694,8 +933,38 @@ typedef NameData *Name; } 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 + + +/* + * 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 + + /* ---------------------------------------------------------------- - * Section 7: random stuff + * Section 8: random stuff * ---------------------------------------------------------------- */ @@ -710,13 +979,25 @@ typedef NameData *Name; #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 PostgeSQL + * 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 whereever the + * 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 @@ -725,10 +1006,6 @@ typedef NameData *Name; * * 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 @@ -737,10 +1014,10 @@ typedef NameData *Name; /* ---------------------------------------------------------------- - * Section 8: system-specific hacks + * 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 + * included in every source file. The port-specific header file * is usually a better place for this sort of thing. * ---------------------------------------------------------------- */ @@ -749,7 +1026,7 @@ typedef NameData *Name; * 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 + * 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__) @@ -770,10 +1047,7 @@ typedef NameData *Name; */ #if !HAVE_DECL_SNPRINTF -extern int -snprintf(char *str, size_t count, const char *fmt,...) -/* This extension allows gcc to check the format string */ -__attribute__((format(printf, 3, 4))); +extern int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3, 4); #endif #if !HAVE_DECL_VSNPRINTF @@ -808,9 +1082,9 @@ extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args); /* * When there is no sigsetjmp, its functionality is provided by plain * setjmp. Incidentally, nothing provides setjmp's functionality in - * that case. + * that case. We now support the case only on Windows. */ -#ifndef HAVE_SIGSETJMP +#ifdef WIN32 #define sigjmp_buf jmp_buf #define sigsetjmp(x,y) setjmp(x) #define siglongjmp longjmp @@ -850,4 +1124,4 @@ extern int fdatasync(int fildes); /* /port compatibility functions */ #include "port.h" -#endif /* C_H */ +#endif /* C_H */