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00001 /*-------------------------------------------------------------------------
00002  *
00003  * c.h
00004  *    Fundamental C definitions.  This is included by every .c file in
00005  *    PostgreSQL (via either postgres.h or postgres_fe.h, as appropriate).
00006  *
00007  *    Note that the definitions here are not intended to be exposed to clients
00008  *    of the frontend interface libraries --- so we don't worry much about
00009  *    polluting the namespace with lots of stuff...
00010  *
00011  *
00012  * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
00013  * Portions Copyright (c) 1994, Regents of the University of California
00014  *
00015  * src/include/c.h
00016  *
00017  *-------------------------------------------------------------------------
00018  */
00019 /*
00020  *----------------------------------------------------------------
00021  *   TABLE OF CONTENTS
00022  *
00023  *      When adding stuff to this file, please try to put stuff
00024  *      into the relevant section, or add new sections as appropriate.
00025  *
00026  *    section   description
00027  *    -------   ------------------------------------------------
00028  *      0)      pg_config.h and standard system headers
00029  *      1)      hacks to cope with non-ANSI C compilers
00030  *      2)      bool, true, false, TRUE, FALSE, NULL
00031  *      3)      standard system types
00032  *      4)      IsValid macros for system types
00033  *      5)      offsetof, lengthof, endof, alignment
00034  *      6)      assertions
00035  *      7)      widely useful macros
00036  *      8)      random stuff
00037  *      9)      system-specific hacks
00038  *
00039  * NOTE: since this file is included by both frontend and backend modules, it's
00040  * almost certainly wrong to put an "extern" declaration here.  typedefs and
00041  * macros are the kind of thing that might go here.
00042  *
00043  *----------------------------------------------------------------
00044  */
00045 #ifndef C_H
00046 #define C_H
00047 
00048 #include "postgres_ext.h"
00049 
00050 /* Must undef pg_config_ext.h symbols before including pg_config.h */
00051 #undef PG_INT64_TYPE
00052 
00053 #include "pg_config.h"
00054 #include "pg_config_manual.h"   /* must be after pg_config.h */
00055 
00056 #if !defined(WIN32) && !defined(__CYGWIN__) /* win32 includes further down */
00057 #include "pg_config_os.h"       /* must be before any system header files */
00058 #endif
00059 
00060 #if _MSC_VER >= 1400 || defined(HAVE_CRTDEFS_H)
00061 #define errcode __msvc_errcode
00062 #include <crtdefs.h>
00063 #undef errcode
00064 #endif
00065 
00066 /*
00067  * We have to include stdlib.h here because it defines many of these macros
00068  * on some platforms, and we only want our definitions used if stdlib.h doesn't
00069  * have its own.  The same goes for stddef and stdarg if present.
00070  */
00071 
00072 #include <stdio.h>
00073 #include <stdlib.h>
00074 #include <string.h>
00075 #include <stddef.h>
00076 #include <stdarg.h>
00077 #ifdef HAVE_STRINGS_H
00078 #include <strings.h>
00079 #endif
00080 #ifdef HAVE_STDINT_H
00081 #include <stdint.h>
00082 #endif
00083 #include <sys/types.h>
00084 
00085 #include <errno.h>
00086 #if defined(WIN32) || defined(__CYGWIN__)
00087 #include <fcntl.h>              /* ensure O_BINARY is available */
00088 #endif
00089 
00090 #if defined(WIN32) || defined(__CYGWIN__)
00091 /* We have to redefine some system functions after they are included above. */
00092 #include "pg_config_os.h"
00093 #endif
00094 
00095 /* Must be before gettext() games below */
00096 #include <locale.h>
00097 
00098 #define _(x) gettext(x)
00099 
00100 #ifdef ENABLE_NLS
00101 #include <libintl.h>
00102 #else
00103 #define gettext(x) (x)
00104 #define dgettext(d,x) (x)
00105 #define ngettext(s,p,n) ((n) == 1 ? (s) : (p))
00106 #define dngettext(d,s,p,n) ((n) == 1 ? (s) : (p))
00107 #endif
00108 
00109 /*
00110  *  Use this to mark string constants as needing translation at some later
00111  *  time, rather than immediately.  This is useful for cases where you need
00112  *  access to the original string and translated string, and for cases where
00113  *  immediate translation is not possible, like when initializing global
00114  *  variables.
00115  *      http://www.gnu.org/software/autoconf/manual/gettext/Special-cases.html
00116  */
00117 #define gettext_noop(x) (x)
00118 
00119 
00120 /* ----------------------------------------------------------------
00121  *              Section 1: hacks to cope with non-ANSI C compilers
00122  *
00123  * type prefixes (const, signed, volatile, inline) are handled in pg_config.h.
00124  * ----------------------------------------------------------------
00125  */
00126 
00127 /*
00128  * CppAsString
00129  *      Convert the argument to a string, using the C preprocessor.
00130  * CppConcat
00131  *      Concatenate two arguments together, using the C preprocessor.
00132  *
00133  * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
00134  * whether #identifier works, but if we have that we likely have ## too.
00135  */
00136 #if defined(HAVE_STRINGIZE)
00137 
00138 #define CppAsString(identifier) #identifier
00139 #define CppConcat(x, y)         x##y
00140 #else                           /* !HAVE_STRINGIZE */
00141 
00142 #define CppAsString(identifier) "identifier"
00143 
00144 /*
00145  * CppIdentity -- On Reiser based cpp's this is used to concatenate
00146  *      two tokens.  That is
00147  *              CppIdentity(A)B ==> AB
00148  *      We renamed it to _private_CppIdentity because it should not
00149  *      be referenced outside this file.  On other cpp's it
00150  *      produces  A  B.
00151  */
00152 #define _priv_CppIdentity(x)x
00153 #define CppConcat(x, y)         _priv_CppIdentity(x)y
00154 #endif   /* !HAVE_STRINGIZE */
00155 
00156 /*
00157  * dummyret is used to set return values in macros that use ?: to make
00158  * assignments.  gcc wants these to be void, other compilers like char
00159  */
00160 #ifdef __GNUC__                 /* GNU cc */
00161 #define dummyret    void
00162 #else
00163 #define dummyret    char
00164 #endif
00165 
00166 #ifndef __GNUC__
00167 #define __attribute__(_arg_)
00168 #endif
00169 
00170 /* ----------------------------------------------------------------
00171  *              Section 2:  bool, true, false, TRUE, FALSE, NULL
00172  * ----------------------------------------------------------------
00173  */
00174 
00175 /*
00176  * bool
00177  *      Boolean value, either true or false.
00178  *
00179  * XXX for C++ compilers, we assume the compiler has a compatible
00180  * built-in definition of bool.
00181  */
00182 
00183 #ifndef __cplusplus
00184 
00185 #ifndef bool
00186 typedef char bool;
00187 #endif
00188 
00189 #ifndef true
00190 #define true    ((bool) 1)
00191 #endif
00192 
00193 #ifndef false
00194 #define false   ((bool) 0)
00195 #endif
00196 #endif   /* not C++ */
00197 
00198 typedef bool *BoolPtr;
00199 
00200 #ifndef TRUE
00201 #define TRUE    1
00202 #endif
00203 
00204 #ifndef FALSE
00205 #define FALSE   0
00206 #endif
00207 
00208 /*
00209  * NULL
00210  *      Null pointer.
00211  */
00212 #ifndef NULL
00213 #define NULL    ((void *) 0)
00214 #endif
00215 
00216 
00217 /* ----------------------------------------------------------------
00218  *              Section 3:  standard system types
00219  * ----------------------------------------------------------------
00220  */
00221 
00222 /*
00223  * Pointer
00224  *      Variable holding address of any memory resident object.
00225  *
00226  *      XXX Pointer arithmetic is done with this, so it can't be void *
00227  *      under "true" ANSI compilers.
00228  */
00229 typedef char *Pointer;
00230 
00231 /*
00232  * intN
00233  *      Signed integer, EXACTLY N BITS IN SIZE,
00234  *      used for numerical computations and the
00235  *      frontend/backend protocol.
00236  */
00237 #ifndef HAVE_INT8
00238 typedef signed char int8;       /* == 8 bits */
00239 typedef signed short int16;     /* == 16 bits */
00240 typedef signed int int32;       /* == 32 bits */
00241 #endif   /* not HAVE_INT8 */
00242 
00243 /*
00244  * uintN
00245  *      Unsigned integer, EXACTLY N BITS IN SIZE,
00246  *      used for numerical computations and the
00247  *      frontend/backend protocol.
00248  */
00249 #ifndef HAVE_UINT8
00250 typedef unsigned char uint8;    /* == 8 bits */
00251 typedef unsigned short uint16;  /* == 16 bits */
00252 typedef unsigned int uint32;    /* == 32 bits */
00253 #endif   /* not HAVE_UINT8 */
00254 
00255 /*
00256  * bitsN
00257  *      Unit of bitwise operation, AT LEAST N BITS IN SIZE.
00258  */
00259 typedef uint8 bits8;            /* >= 8 bits */
00260 typedef uint16 bits16;          /* >= 16 bits */
00261 typedef uint32 bits32;          /* >= 32 bits */
00262 
00263 /*
00264  * 64-bit integers
00265  */
00266 #ifdef HAVE_LONG_INT_64
00267 /* Plain "long int" fits, use it */
00268 
00269 #ifndef HAVE_INT64
00270 typedef long int int64;
00271 #endif
00272 #ifndef HAVE_UINT64
00273 typedef unsigned long int uint64;
00274 #endif
00275 #elif defined(HAVE_LONG_LONG_INT_64)
00276 /* We have working support for "long long int", use that */
00277 
00278 #ifndef HAVE_INT64
00279 typedef long long int int64;
00280 #endif
00281 #ifndef HAVE_UINT64
00282 typedef unsigned long long int uint64;
00283 #endif
00284 #else
00285 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
00286 #error must have a working 64-bit integer datatype
00287 #endif
00288 
00289 /* Decide if we need to decorate 64-bit constants */
00290 #ifdef HAVE_LL_CONSTANTS
00291 #define INT64CONST(x)  ((int64) x##LL)
00292 #define UINT64CONST(x) ((uint64) x##ULL)
00293 #else
00294 #define INT64CONST(x)  ((int64) x)
00295 #define UINT64CONST(x) ((uint64) x)
00296 #endif
00297 
00298 
00299 /* Select timestamp representation (float8 or int64) */
00300 #ifdef USE_INTEGER_DATETIMES
00301 #define HAVE_INT64_TIMESTAMP
00302 #endif
00303 
00304 /* sig_atomic_t is required by ANSI C, but may be missing on old platforms */
00305 #ifndef HAVE_SIG_ATOMIC_T
00306 typedef int sig_atomic_t;
00307 #endif
00308 
00309 /*
00310  * Size
00311  *      Size of any memory resident object, as returned by sizeof.
00312  */
00313 typedef size_t Size;
00314 
00315 /*
00316  * Index
00317  *      Index into any memory resident array.
00318  *
00319  * Note:
00320  *      Indices are non negative.
00321  */
00322 typedef unsigned int Index;
00323 
00324 /*
00325  * Offset
00326  *      Offset into any memory resident array.
00327  *
00328  * Note:
00329  *      This differs from an Index in that an Index is always
00330  *      non negative, whereas Offset may be negative.
00331  */
00332 typedef signed int Offset;
00333 
00334 /*
00335  * Common Postgres datatype names (as used in the catalogs)
00336  */
00337 typedef float float4;
00338 typedef double float8;
00339 
00340 /*
00341  * Oid, RegProcedure, TransactionId, SubTransactionId, MultiXactId,
00342  * CommandId
00343  */
00344 
00345 /* typedef Oid is in postgres_ext.h */
00346 
00347 /*
00348  * regproc is the type name used in the include/catalog headers, but
00349  * RegProcedure is the preferred name in C code.
00350  */
00351 typedef Oid regproc;
00352 typedef regproc RegProcedure;
00353 
00354 typedef uint32 TransactionId;
00355 
00356 typedef uint32 LocalTransactionId;
00357 
00358 typedef uint32 SubTransactionId;
00359 
00360 #define InvalidSubTransactionId     ((SubTransactionId) 0)
00361 #define TopSubTransactionId         ((SubTransactionId) 1)
00362 
00363 /* MultiXactId must be equivalent to TransactionId, to fit in t_xmax */
00364 typedef TransactionId MultiXactId;
00365 
00366 typedef uint32 MultiXactOffset;
00367 
00368 typedef uint32 CommandId;
00369 
00370 #define FirstCommandId  ((CommandId) 0)
00371 
00372 /*
00373  * Array indexing support
00374  */
00375 #define MAXDIM 6
00376 typedef struct
00377 {
00378     int         indx[MAXDIM];
00379 } IntArray;
00380 
00381 /* ----------------
00382  *      Variable-length datatypes all share the 'struct varlena' header.
00383  *
00384  * NOTE: for TOASTable types, this is an oversimplification, since the value
00385  * may be compressed or moved out-of-line.  However datatype-specific routines
00386  * are mostly content to deal with de-TOASTed values only, and of course
00387  * client-side routines should never see a TOASTed value.  But even in a
00388  * de-TOASTed value, beware of touching vl_len_ directly, as its representation
00389  * is no longer convenient.  It's recommended that code always use the VARDATA,
00390  * VARSIZE, and SET_VARSIZE macros instead of relying on direct mentions of
00391  * the struct fields.  See postgres.h for details of the TOASTed form.
00392  * ----------------
00393  */
00394 struct varlena
00395 {
00396     char        vl_len_[4];     /* Do not touch this field directly! */
00397     char        vl_dat[1];
00398 };
00399 
00400 #define VARHDRSZ        ((int32) sizeof(int32))
00401 
00402 /*
00403  * These widely-used datatypes are just a varlena header and the data bytes.
00404  * There is no terminating null or anything like that --- the data length is
00405  * always VARSIZE(ptr) - VARHDRSZ.
00406  */
00407 typedef struct varlena bytea;
00408 typedef struct varlena text;
00409 typedef struct varlena BpChar;  /* blank-padded char, ie SQL char(n) */
00410 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
00411 
00412 /*
00413  * Specialized array types.  These are physically laid out just the same
00414  * as regular arrays (so that the regular array subscripting code works
00415  * with them).  They exist as distinct types mostly for historical reasons:
00416  * they have nonstandard I/O behavior which we don't want to change for fear
00417  * of breaking applications that look at the system catalogs.  There is also
00418  * an implementation issue for oidvector: it's part of the primary key for
00419  * pg_proc, and we can't use the normal btree array support routines for that
00420  * without circularity.
00421  */
00422 typedef struct
00423 {
00424     int32       vl_len_;        /* these fields must match ArrayType! */
00425     int         ndim;           /* always 1 for int2vector */
00426     int32       dataoffset;     /* always 0 for int2vector */
00427     Oid         elemtype;
00428     int         dim1;
00429     int         lbound1;
00430     int16       values[1];      /* VARIABLE LENGTH ARRAY */
00431 } int2vector;                   /* VARIABLE LENGTH STRUCT */
00432 
00433 typedef struct
00434 {
00435     int32       vl_len_;        /* these fields must match ArrayType! */
00436     int         ndim;           /* always 1 for oidvector */
00437     int32       dataoffset;     /* always 0 for oidvector */
00438     Oid         elemtype;
00439     int         dim1;
00440     int         lbound1;
00441     Oid         values[1];      /* VARIABLE LENGTH ARRAY */
00442 } oidvector;                    /* VARIABLE LENGTH STRUCT */
00443 
00444 /*
00445  * Representation of a Name: effectively just a C string, but null-padded to
00446  * exactly NAMEDATALEN bytes.  The use of a struct is historical.
00447  */
00448 typedef struct nameData
00449 {
00450     char        data[NAMEDATALEN];
00451 } NameData;
00452 typedef NameData *Name;
00453 
00454 #define NameStr(name)   ((name).data)
00455 
00456 /*
00457  * Support macros for escaping strings.  escape_backslash should be TRUE
00458  * if generating a non-standard-conforming string.  Prefixing a string
00459  * with ESCAPE_STRING_SYNTAX guarantees it is non-standard-conforming.
00460  * Beware of multiple evaluation of the "ch" argument!
00461  */
00462 #define SQL_STR_DOUBLE(ch, escape_backslash)    \
00463     ((ch) == '\'' || ((ch) == '\\' && (escape_backslash)))
00464 
00465 #define ESCAPE_STRING_SYNTAX    'E'
00466 
00467 /* ----------------------------------------------------------------
00468  *              Section 4:  IsValid macros for system types
00469  * ----------------------------------------------------------------
00470  */
00471 /*
00472  * BoolIsValid
00473  *      True iff bool is valid.
00474  */
00475 #define BoolIsValid(boolean)    ((boolean) == false || (boolean) == true)
00476 
00477 /*
00478  * PointerIsValid
00479  *      True iff pointer is valid.
00480  */
00481 #define PointerIsValid(pointer) ((const void*)(pointer) != NULL)
00482 
00483 /*
00484  * PointerIsAligned
00485  *      True iff pointer is properly aligned to point to the given type.
00486  */
00487 #define PointerIsAligned(pointer, type) \
00488         (((intptr_t)(pointer) % (sizeof (type))) == 0)
00489 
00490 #define OidIsValid(objectId)  ((bool) ((objectId) != InvalidOid))
00491 
00492 #define RegProcedureIsValid(p)  OidIsValid(p)
00493 
00494 
00495 /* ----------------------------------------------------------------
00496  *              Section 5:  offsetof, lengthof, endof, alignment
00497  * ----------------------------------------------------------------
00498  */
00499 /*
00500  * offsetof
00501  *      Offset of a structure/union field within that structure/union.
00502  *
00503  *      XXX This is supposed to be part of stddef.h, but isn't on
00504  *      some systems (like SunOS 4).
00505  */
00506 #ifndef offsetof
00507 #define offsetof(type, field)   ((long) &((type *)0)->field)
00508 #endif   /* offsetof */
00509 
00510 /*
00511  * lengthof
00512  *      Number of elements in an array.
00513  */
00514 #define lengthof(array) (sizeof (array) / sizeof ((array)[0]))
00515 
00516 /*
00517  * endof
00518  *      Address of the element one past the last in an array.
00519  */
00520 #define endof(array)    (&(array)[lengthof(array)])
00521 
00522 /* ----------------
00523  * Alignment macros: align a length or address appropriately for a given type.
00524  * The fooALIGN() macros round up to a multiple of the required alignment,
00525  * while the fooALIGN_DOWN() macros round down.  The latter are more useful
00526  * for problems like "how many X-sized structures will fit in a page?".
00527  *
00528  * NOTE: TYPEALIGN[_DOWN] will not work if ALIGNVAL is not a power of 2.
00529  * That case seems extremely unlikely to be needed in practice, however.
00530  * ----------------
00531  */
00532 
00533 #define TYPEALIGN(ALIGNVAL,LEN)  \
00534     (((intptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((intptr_t) ((ALIGNVAL) - 1)))
00535 
00536 #define SHORTALIGN(LEN)         TYPEALIGN(ALIGNOF_SHORT, (LEN))
00537 #define INTALIGN(LEN)           TYPEALIGN(ALIGNOF_INT, (LEN))
00538 #define LONGALIGN(LEN)          TYPEALIGN(ALIGNOF_LONG, (LEN))
00539 #define DOUBLEALIGN(LEN)        TYPEALIGN(ALIGNOF_DOUBLE, (LEN))
00540 #define MAXALIGN(LEN)           TYPEALIGN(MAXIMUM_ALIGNOF, (LEN))
00541 /* MAXALIGN covers only built-in types, not buffers */
00542 #define BUFFERALIGN(LEN)        TYPEALIGN(ALIGNOF_BUFFER, (LEN))
00543 
00544 #define TYPEALIGN_DOWN(ALIGNVAL,LEN)  \
00545     (((intptr_t) (LEN)) & ~((intptr_t) ((ALIGNVAL) - 1)))
00546 
00547 #define SHORTALIGN_DOWN(LEN)    TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
00548 #define INTALIGN_DOWN(LEN)      TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
00549 #define LONGALIGN_DOWN(LEN)     TYPEALIGN_DOWN(ALIGNOF_LONG, (LEN))
00550 #define DOUBLEALIGN_DOWN(LEN)   TYPEALIGN_DOWN(ALIGNOF_DOUBLE, (LEN))
00551 #define MAXALIGN_DOWN(LEN)      TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
00552 
00553 /* ----------------------------------------------------------------
00554  *              Section 6:  assertions
00555  * ----------------------------------------------------------------
00556  */
00557 
00558 /*
00559  * USE_ASSERT_CHECKING, if defined, turns on all the assertions.
00560  * - plai  9/5/90
00561  *
00562  * It should _NOT_ be defined in releases or in benchmark copies
00563  */
00564 
00565 /*
00566  * Assert() can be used in both frontend and backend code. In frontend code it
00567  * just calls the standard assert, if it's available. If use of assertions is
00568  * not configured, it does nothing.
00569  */
00570 #ifndef USE_ASSERT_CHECKING
00571 
00572 #define Assert(condition)
00573 #define AssertMacro(condition)  ((void)true)
00574 #define AssertArg(condition)
00575 #define AssertState(condition)
00576 
00577 #elif defined(FRONTEND)
00578 
00579 #include <assert.h>
00580 #define Assert(p) assert(p)
00581 #define AssertMacro(p)  ((void) assert(p))
00582 #define AssertArg(condition) assert(condition)
00583 #define AssertState(condition) assert(condition)
00584 
00585 #else /* USE_ASSERT_CHECKING && !FRONTEND */
00586 
00587 /*
00588  * Trap
00589  *      Generates an exception if the given condition is true.
00590  */
00591 #define Trap(condition, errorType) \
00592     do { \
00593         if ((assert_enabled) && (condition)) \
00594             ExceptionalCondition(CppAsString(condition), (errorType), \
00595                                  __FILE__, __LINE__); \
00596     } while (0)
00597 
00598 /*
00599  *  TrapMacro is the same as Trap but it's intended for use in macros:
00600  *
00601  *      #define foo(x) (AssertMacro(x != 0), bar(x))
00602  *
00603  *  Isn't CPP fun?
00604  */
00605 #define TrapMacro(condition, errorType) \
00606     ((bool) ((! assert_enabled) || ! (condition) || \
00607              (ExceptionalCondition(CppAsString(condition), (errorType), \
00608                                    __FILE__, __LINE__), 0)))
00609 
00610 #define Assert(condition) \
00611         Trap(!(condition), "FailedAssertion")
00612 
00613 #define AssertMacro(condition) \
00614         ((void) TrapMacro(!(condition), "FailedAssertion"))
00615 
00616 #define AssertArg(condition) \
00617         Trap(!(condition), "BadArgument")
00618 
00619 #define AssertState(condition) \
00620         Trap(!(condition), "BadState")
00621 
00622 #endif /* USE_ASSERT_CHECKING && !FRONTEND */
00623 
00624 
00625 /*
00626  * Macros to support compile-time assertion checks.
00627  *
00628  * If the "condition" (a compile-time-constant expression) evaluates to false,
00629  * throw a compile error using the "errmessage" (a string literal).
00630  *
00631  * gcc 4.6 and up supports _Static_assert(), but there are bizarre syntactic
00632  * placement restrictions.  These macros make it safe to use as a statement
00633  * or in an expression, respectively.
00634  *
00635  * Otherwise we fall back on a kluge that assumes the compiler will complain
00636  * about a negative width for a struct bit-field.  This will not include a
00637  * helpful error message, but it beats not getting an error at all.
00638  */
00639 #ifdef HAVE__STATIC_ASSERT
00640 #define StaticAssertStmt(condition, errmessage) \
00641     do { _Static_assert(condition, errmessage); } while(0)
00642 #define StaticAssertExpr(condition, errmessage) \
00643     ({ StaticAssertStmt(condition, errmessage); true; })
00644 #else /* !HAVE__STATIC_ASSERT */
00645 #define StaticAssertStmt(condition, errmessage) \
00646     ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; }))
00647 #define StaticAssertExpr(condition, errmessage) \
00648     StaticAssertStmt(condition, errmessage)
00649 #endif /* HAVE__STATIC_ASSERT */
00650 
00651 
00652 /*
00653  * Compile-time checks that a variable (or expression) has the specified type.
00654  *
00655  * AssertVariableIsOfType() can be used as a statement.
00656  * AssertVariableIsOfTypeMacro() is intended for use in macros, eg
00657  *      #define foo(x) (AssertVariableIsOfTypeMacro(x, int), bar(x))
00658  *
00659  * If we don't have __builtin_types_compatible_p, we can still assert that
00660  * the types have the same size.  This is far from ideal (especially on 32-bit
00661  * platforms) but it provides at least some coverage.
00662  */
00663 #ifdef HAVE__BUILTIN_TYPES_COMPATIBLE_P
00664 #define AssertVariableIsOfType(varname, typename) \
00665     StaticAssertStmt(__builtin_types_compatible_p(__typeof__(varname), typename), \
00666     CppAsString(varname) " does not have type " CppAsString(typename))
00667 #define AssertVariableIsOfTypeMacro(varname, typename) \
00668     ((void) StaticAssertExpr(__builtin_types_compatible_p(__typeof__(varname), typename), \
00669      CppAsString(varname) " does not have type " CppAsString(typename)))
00670 #else /* !HAVE__BUILTIN_TYPES_COMPATIBLE_P */
00671 #define AssertVariableIsOfType(varname, typename) \
00672     StaticAssertStmt(sizeof(varname) == sizeof(typename), \
00673     CppAsString(varname) " does not have type " CppAsString(typename))
00674 #define AssertVariableIsOfTypeMacro(varname, typename) \
00675     ((void) StaticAssertExpr(sizeof(varname) == sizeof(typename),       \
00676      CppAsString(varname) " does not have type " CppAsString(typename)))
00677 #endif /* HAVE__BUILTIN_TYPES_COMPATIBLE_P */
00678 
00679 
00680 /* ----------------------------------------------------------------
00681  *              Section 7:  widely useful macros
00682  * ----------------------------------------------------------------
00683  */
00684 /*
00685  * Max
00686  *      Return the maximum of two numbers.
00687  */
00688 #define Max(x, y)       ((x) > (y) ? (x) : (y))
00689 
00690 /*
00691  * Min
00692  *      Return the minimum of two numbers.
00693  */
00694 #define Min(x, y)       ((x) < (y) ? (x) : (y))
00695 
00696 /*
00697  * Abs
00698  *      Return the absolute value of the argument.
00699  */
00700 #define Abs(x)          ((x) >= 0 ? (x) : -(x))
00701 
00702 /*
00703  * StrNCpy
00704  *  Like standard library function strncpy(), except that result string
00705  *  is guaranteed to be null-terminated --- that is, at most N-1 bytes
00706  *  of the source string will be kept.
00707  *  Also, the macro returns no result (too hard to do that without
00708  *  evaluating the arguments multiple times, which seems worse).
00709  *
00710  *  BTW: when you need to copy a non-null-terminated string (like a text
00711  *  datum) and add a null, do not do it with StrNCpy(..., len+1).  That
00712  *  might seem to work, but it fetches one byte more than there is in the
00713  *  text object.  One fine day you'll have a SIGSEGV because there isn't
00714  *  another byte before the end of memory.  Don't laugh, we've had real
00715  *  live bug reports from real live users over exactly this mistake.
00716  *  Do it honestly with "memcpy(dst,src,len); dst[len] = '\0';", instead.
00717  */
00718 #define StrNCpy(dst,src,len) \
00719     do \
00720     { \
00721         char * _dst = (dst); \
00722         Size _len = (len); \
00723 \
00724         if (_len > 0) \
00725         { \
00726             strncpy(_dst, (src), _len); \
00727             _dst[_len-1] = '\0'; \
00728         } \
00729     } while (0)
00730 
00731 
00732 /* Get a bit mask of the bits set in non-long aligned addresses */
00733 #define LONG_ALIGN_MASK (sizeof(long) - 1)
00734 
00735 /*
00736  * MemSet
00737  *  Exactly the same as standard library function memset(), but considerably
00738  *  faster for zeroing small word-aligned structures (such as parsetree nodes).
00739  *  This has to be a macro because the main point is to avoid function-call
00740  *  overhead.   However, we have also found that the loop is faster than
00741  *  native libc memset() on some platforms, even those with assembler
00742  *  memset() functions.  More research needs to be done, perhaps with
00743  *  MEMSET_LOOP_LIMIT tests in configure.
00744  */
00745 #define MemSet(start, val, len) \
00746     do \
00747     { \
00748         /* must be void* because we don't know if it is integer aligned yet */ \
00749         void   *_vstart = (void *) (start); \
00750         int     _val = (val); \
00751         Size    _len = (len); \
00752 \
00753         if ((((intptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
00754             (_len & LONG_ALIGN_MASK) == 0 && \
00755             _val == 0 && \
00756             _len <= MEMSET_LOOP_LIMIT && \
00757             /* \
00758              *  If MEMSET_LOOP_LIMIT == 0, optimizer should find \
00759              *  the whole "if" false at compile time. \
00760              */ \
00761             MEMSET_LOOP_LIMIT != 0) \
00762         { \
00763             long *_start = (long *) _vstart; \
00764             long *_stop = (long *) ((char *) _start + _len); \
00765             while (_start < _stop) \
00766                 *_start++ = 0; \
00767         } \
00768         else \
00769             memset(_vstart, _val, _len); \
00770     } while (0)
00771 
00772 /*
00773  * MemSetAligned is the same as MemSet except it omits the test to see if
00774  * "start" is word-aligned.  This is okay to use if the caller knows a-priori
00775  * that the pointer is suitably aligned (typically, because he just got it
00776  * from palloc(), which always delivers a max-aligned pointer).
00777  */
00778 #define MemSetAligned(start, val, len) \
00779     do \
00780     { \
00781         long   *_start = (long *) (start); \
00782         int     _val = (val); \
00783         Size    _len = (len); \
00784 \
00785         if ((_len & LONG_ALIGN_MASK) == 0 && \
00786             _val == 0 && \
00787             _len <= MEMSET_LOOP_LIMIT && \
00788             MEMSET_LOOP_LIMIT != 0) \
00789         { \
00790             long *_stop = (long *) ((char *) _start + _len); \
00791             while (_start < _stop) \
00792                 *_start++ = 0; \
00793         } \
00794         else \
00795             memset(_start, _val, _len); \
00796     } while (0)
00797 
00798 
00799 /*
00800  * MemSetTest/MemSetLoop are a variant version that allow all the tests in
00801  * MemSet to be done at compile time in cases where "val" and "len" are
00802  * constants *and* we know the "start" pointer must be word-aligned.
00803  * If MemSetTest succeeds, then it is okay to use MemSetLoop, otherwise use
00804  * MemSetAligned.  Beware of multiple evaluations of the arguments when using
00805  * this approach.
00806  */
00807 #define MemSetTest(val, len) \
00808     ( ((len) & LONG_ALIGN_MASK) == 0 && \
00809     (len) <= MEMSET_LOOP_LIMIT && \
00810     MEMSET_LOOP_LIMIT != 0 && \
00811     (val) == 0 )
00812 
00813 #define MemSetLoop(start, val, len) \
00814     do \
00815     { \
00816         long * _start = (long *) (start); \
00817         long * _stop = (long *) ((char *) _start + (Size) (len)); \
00818     \
00819         while (_start < _stop) \
00820             *_start++ = 0; \
00821     } while (0)
00822 
00823 
00824 /*
00825  * Mark a point as unreachable in a portable fashion.  This should preferably
00826  * be something that the compiler understands, to aid code generation.
00827  * In assert-enabled builds, we prefer abort() for debugging reasons.
00828  */
00829 #if defined(HAVE__BUILTIN_UNREACHABLE) && !defined(USE_ASSERT_CHECKING)
00830 #define pg_unreachable() __builtin_unreachable()
00831 #elif defined(_MSC_VER) && !defined(USE_ASSERT_CHECKING)
00832 #define pg_unreachable() __assume(0)
00833 #else
00834 #define pg_unreachable() abort()
00835 #endif
00836 
00837 
00838 /*
00839  * Function inlining support -- Allow modules to define functions that may be
00840  * inlined, if the compiler supports it.
00841  *
00842  * The function bodies must be defined in the module header prefixed by
00843  * STATIC_IF_INLINE, protected by a cpp symbol that the module's .c file must
00844  * define.  If the compiler doesn't support inline functions, the function
00845  * definitions are pulled in by the .c file as regular (not inline) symbols.
00846  *
00847  * The header must also declare the functions' prototypes, protected by
00848  * !PG_USE_INLINE.
00849  */
00850 #ifdef PG_USE_INLINE
00851 #define STATIC_IF_INLINE static inline
00852 #else
00853 #define STATIC_IF_INLINE
00854 #endif  /* PG_USE_INLINE */
00855 
00856 /* ----------------------------------------------------------------
00857  *              Section 8:  random stuff
00858  * ----------------------------------------------------------------
00859  */
00860 
00861 /* msb for char */
00862 #define HIGHBIT                 (0x80)
00863 #define IS_HIGHBIT_SET(ch)      ((unsigned char)(ch) & HIGHBIT)
00864 
00865 #define STATUS_OK               (0)
00866 #define STATUS_ERROR            (-1)
00867 #define STATUS_EOF              (-2)
00868 #define STATUS_FOUND            (1)
00869 #define STATUS_WAITING          (2)
00870 
00871 
00872 /*
00873  * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only
00874  * used in assert-enabled builds, to avoid compiler warnings about unused
00875  * variables in assert-disabled builds.
00876  */
00877 #ifdef USE_ASSERT_CHECKING
00878 #define PG_USED_FOR_ASSERTS_ONLY
00879 #else
00880 #define PG_USED_FOR_ASSERTS_ONLY __attribute__((unused))
00881 #endif
00882 
00883 
00884 /* gettext domain name mangling */
00885 
00886 /*
00887  * To better support parallel installations of major PostgeSQL
00888  * versions as well as parallel installations of major library soname
00889  * versions, we mangle the gettext domain name by appending those
00890  * version numbers.  The coding rule ought to be that whereever the
00891  * domain name is mentioned as a literal, it must be wrapped into
00892  * PG_TEXTDOMAIN().  The macros below do not work on non-literals; but
00893  * that is somewhat intentional because it avoids having to worry
00894  * about multiple states of premangling and postmangling as the values
00895  * are being passed around.
00896  *
00897  * Make sure this matches the installation rules in nls-global.mk.
00898  */
00899 
00900 /* need a second indirection because we want to stringize the macro value, not the name */
00901 #define CppAsString2(x) CppAsString(x)
00902 
00903 #ifdef SO_MAJOR_VERSION
00904 #define PG_TEXTDOMAIN(domain) (domain CppAsString2(SO_MAJOR_VERSION) "-" PG_MAJORVERSION)
00905 #else
00906 #define PG_TEXTDOMAIN(domain) (domain "-" PG_MAJORVERSION)
00907 #endif
00908 
00909 
00910 /* ----------------------------------------------------------------
00911  *              Section 9: system-specific hacks
00912  *
00913  *      This should be limited to things that absolutely have to be
00914  *      included in every source file.  The port-specific header file
00915  *      is usually a better place for this sort of thing.
00916  * ----------------------------------------------------------------
00917  */
00918 
00919 /*
00920  *  NOTE:  this is also used for opening text files.
00921  *  WIN32 treats Control-Z as EOF in files opened in text mode.
00922  *  Therefore, we open files in binary mode on Win32 so we can read
00923  *  literal control-Z.  The other affect is that we see CRLF, but
00924  *  that is OK because we can already handle those cleanly.
00925  */
00926 #if defined(WIN32) || defined(__CYGWIN__)
00927 #define PG_BINARY   O_BINARY
00928 #define PG_BINARY_A "ab"
00929 #define PG_BINARY_R "rb"
00930 #define PG_BINARY_W "wb"
00931 #else
00932 #define PG_BINARY   0
00933 #define PG_BINARY_A "a"
00934 #define PG_BINARY_R "r"
00935 #define PG_BINARY_W "w"
00936 #endif
00937 
00938 /*
00939  * Provide prototypes for routines not present in a particular machine's
00940  * standard C library.
00941  */
00942 
00943 #if !HAVE_DECL_SNPRINTF
00944 extern int
00945 snprintf(char *str, size_t count, const char *fmt,...)
00946 /* This extension allows gcc to check the format string */
00947 __attribute__((format(PG_PRINTF_ATTRIBUTE, 3, 4)));
00948 #endif
00949 
00950 #if !HAVE_DECL_VSNPRINTF
00951 extern int  vsnprintf(char *str, size_t count, const char *fmt, va_list args);
00952 #endif
00953 
00954 #if !defined(HAVE_MEMMOVE) && !defined(memmove)
00955 #define memmove(d, s, c)        bcopy(s, d, c)
00956 #endif
00957 
00958 /* no special DLL markers on most ports */
00959 #ifndef PGDLLIMPORT
00960 #define PGDLLIMPORT
00961 #endif
00962 #ifndef PGDLLEXPORT
00963 #define PGDLLEXPORT
00964 #endif
00965 
00966 /*
00967  * The following is used as the arg list for signal handlers.  Any ports
00968  * that take something other than an int argument should override this in
00969  * their pg_config_os.h file.  Note that variable names are required
00970  * because it is used in both the prototypes as well as the definitions.
00971  * Note also the long name.  We expect that this won't collide with
00972  * other names causing compiler warnings.
00973  */
00974 
00975 #ifndef SIGNAL_ARGS
00976 #define SIGNAL_ARGS  int postgres_signal_arg
00977 #endif
00978 
00979 /*
00980  * When there is no sigsetjmp, its functionality is provided by plain
00981  * setjmp. Incidentally, nothing provides setjmp's functionality in
00982  * that case.
00983  */
00984 #ifndef HAVE_SIGSETJMP
00985 #define sigjmp_buf jmp_buf
00986 #define sigsetjmp(x,y) setjmp(x)
00987 #define siglongjmp longjmp
00988 #endif
00989 
00990 #if defined(HAVE_FDATASYNC) && !HAVE_DECL_FDATASYNC
00991 extern int  fdatasync(int fildes);
00992 #endif
00993 
00994 /* If strtoq() exists, rename it to the more standard strtoll() */
00995 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOLL) && defined(HAVE_STRTOQ)
00996 #define strtoll strtoq
00997 #define HAVE_STRTOLL 1
00998 #endif
00999 
01000 /* If strtouq() exists, rename it to the more standard strtoull() */
01001 #if defined(HAVE_LONG_LONG_INT_64) && !defined(HAVE_STRTOULL) && defined(HAVE_STRTOUQ)
01002 #define strtoull strtouq
01003 #define HAVE_STRTOULL 1
01004 #endif
01005 
01006 /*
01007  * We assume if we have these two functions, we have their friends too, and
01008  * can use the wide-character functions.
01009  */
01010 #if defined(HAVE_WCSTOMBS) && defined(HAVE_TOWLOWER)
01011 #define USE_WIDE_UPPER_LOWER
01012 #endif
01013 
01014 /* EXEC_BACKEND defines */
01015 #ifdef EXEC_BACKEND
01016 #define NON_EXEC_STATIC
01017 #else
01018 #define NON_EXEC_STATIC static
01019 #endif
01020 
01021 /* /port compatibility functions */
01022 #include "port.h"
01023 
01024 #endif   /* C_H */