1 /*------------------------------------------------------------------------- 2 * 3 * fmgr.h 4 * Definitions for the Postgres function manager and function-call 5 * interface. 6 * 7 * This file must be included by all Postgres modules that either define 8 * or call fmgr-callable functions. 9 * 10 * 11 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group 12 * Portions Copyright (c) 1994, Regents of the University of California 13 * 14 * src/include/fmgr.h 15 * 16 *------------------------------------------------------------------------- 17 */ 18 #ifndef FMGR_H 19 #define FMGR_H 20 21 /* We don't want to include primnodes.h here, so make some stub references */ 22 typedef struct Node *fmNodePtr; 23 typedef struct Aggref *fmAggrefPtr; 24 25 /* Likewise, avoid including execnodes.h here */ 26 typedef void (*fmExprContextCallbackFunction) (Datum arg); 27 28 /* Likewise, avoid including stringinfo.h here */ 29 typedef struct StringInfoData *fmStringInfo; 30 31 32 /* 33 * All functions that can be called directly by fmgr must have this signature. 34 * (Other functions can be called by using a handler that does have this 35 * signature.) 36 */ 37 38 typedef struct FunctionCallInfoBaseData *FunctionCallInfo; 39 40 typedef Datum (*PGFunction) (FunctionCallInfo fcinfo); 41 42 /* 43 * This struct holds the system-catalog information that must be looked up 44 * before a function can be called through fmgr. If the same function is 45 * to be called multiple times, the lookup need be done only once and the 46 * info struct saved for re-use. 47 * 48 * Note that fn_expr really is parse-time-determined information about the 49 * arguments, rather than about the function itself. But it's convenient to 50 * store it here rather than in FunctionCallInfoBaseData, where it might more 51 * logically belong. 52 * 53 * fn_extra is available for use by the called function; all other fields 54 * should be treated as read-only after the struct is created. 55 */ 56 typedef struct FmgrInfo 57 { 58 PGFunction fn_addr; /* pointer to function or handler to be called */ 59 Oid fn_oid; /* OID of function (NOT of handler, if any) */ 60 short fn_nargs; /* number of input args (0..FUNC_MAX_ARGS) */ 61 bool fn_strict; /* function is "strict" (NULL in => NULL out) */ 62 bool fn_retset; /* function returns a set */ 63 unsigned char fn_stats; /* collect stats if track_functions > this */ 64 void *fn_extra; /* extra space for use by handler */ 65 MemoryContext fn_mcxt; /* memory context to store fn_extra in */ 66 fmNodePtr fn_expr; /* expression parse tree for call, or NULL */ 67 } FmgrInfo; 68 69 /* 70 * This struct is the data actually passed to an fmgr-called function. 71 * 72 * The called function is expected to set isnull, and possibly resultinfo or 73 * fields in whatever resultinfo points to. It should not change any other 74 * fields. (In particular, scribbling on the argument arrays is a bad idea, 75 * since some callers assume they can re-call with the same arguments.) 76 * 77 * Note that enough space for arguments needs to be provided, either by using 78 * SizeForFunctionCallInfo() in dynamic allocations, or by using 79 * LOCAL_FCINFO() for on-stack allocations. 80 * 81 * This struct is named *BaseData, rather than *Data, to break pre v12 code 82 * that allocated FunctionCallInfoData itself, as it'd often silently break 83 * old code due to no space for arguments being provided. 84 */ 85 typedef struct FunctionCallInfoBaseData 86 { 87 FmgrInfo *flinfo; /* ptr to lookup info used for this call */ 88 fmNodePtr context; /* pass info about context of call */ 89 fmNodePtr resultinfo; /* pass or return extra info about result */ 90 Oid fncollation; /* collation for function to use */ 91 #define FIELDNO_FUNCTIONCALLINFODATA_ISNULL 4 92 bool isnull; /* function must set true if result is NULL */ 93 short nargs; /* # arguments actually passed */ 94 #define FIELDNO_FUNCTIONCALLINFODATA_ARGS 6 95 NullableDatum args[FLEXIBLE_ARRAY_MEMBER]; 96 } FunctionCallInfoBaseData; 97 98 /* 99 * Space needed for a FunctionCallInfoBaseData struct with sufficient space 100 * for `nargs` arguments. 101 */ 102 #define SizeForFunctionCallInfo(nargs) \ 103 (offsetof(FunctionCallInfoBaseData, args) + \ 104 sizeof(NullableDatum) * (nargs)) 105 106 /* 107 * This macro ensures that `name` points to a stack-allocated 108 * FunctionCallInfoBaseData struct with sufficient space for `nargs` arguments. 109 */ 110 #define LOCAL_FCINFO(name, nargs) \ 111 /* use union with FunctionCallInfoBaseData to guarantee alignment */ \ 112 union \ 113 { \ 114 FunctionCallInfoBaseData fcinfo; \ 115 /* ensure enough space for nargs args is available */ \ 116 char fcinfo_data[SizeForFunctionCallInfo(nargs)]; \ 117 } name##data; \ 118 FunctionCallInfo name = &name##data.fcinfo 119 120 /* 121 * This routine fills a FmgrInfo struct, given the OID 122 * of the function to be called. 123 */ 124 extern void fmgr_info(Oid functionId, FmgrInfo *finfo); 125 126 /* 127 * Same, when the FmgrInfo struct is in a memory context longer-lived than 128 * CurrentMemoryContext. The specified context will be set as fn_mcxt 129 * and used to hold all subsidiary data of finfo. 130 */ 131 extern void fmgr_info_cxt(Oid functionId, FmgrInfo *finfo, 132 MemoryContext mcxt); 133 134 /* Convenience macro for setting the fn_expr field */ 135 #define fmgr_info_set_expr(expr, finfo) \ 136 ((finfo)->fn_expr = (expr)) 137 138 /* 139 * Copy an FmgrInfo struct 140 */ 141 extern void fmgr_info_copy(FmgrInfo *dstinfo, FmgrInfo *srcinfo, 142 MemoryContext destcxt); 143 144 extern void fmgr_symbol(Oid functionId, char **mod, char **fn); 145 146 /* 147 * This macro initializes all the fields of a FunctionCallInfoBaseData except 148 * for the args[] array. 149 */ 150 #define InitFunctionCallInfoData(Fcinfo, Flinfo, Nargs, Collation, Context, Resultinfo) \ 151 do { \ 152 (Fcinfo).flinfo = (Flinfo); \ 153 (Fcinfo).context = (Context); \ 154 (Fcinfo).resultinfo = (Resultinfo); \ 155 (Fcinfo).fncollation = (Collation); \ 156 (Fcinfo).isnull = false; \ 157 (Fcinfo).nargs = (Nargs); \ 158 } while (0) 159 160 /* 161 * This macro invokes a function given a filled-in FunctionCallInfoBaseData 162 * struct. The macro result is the returned Datum --- but note that 163 * caller must still check fcinfo->isnull! Also, if function is strict, 164 * it is caller's responsibility to verify that no null arguments are present 165 * before calling. 166 * 167 * Some code performs multiple calls without redoing InitFunctionCallInfoData, 168 * possibly altering the argument values. This is okay, but be sure to reset 169 * the fcinfo->isnull flag before each call, since callees are permitted to 170 * assume that starts out false. 171 */ 172 #define FunctionCallInvoke(fcinfo) ((* (fcinfo)->flinfo->fn_addr) (fcinfo)) 173 174 175 /*------------------------------------------------------------------------- 176 * Support macros to ease writing fmgr-compatible functions 177 * 178 * A C-coded fmgr-compatible function should be declared as 179 * 180 * Datum 181 * function_name(PG_FUNCTION_ARGS) 182 * { 183 * ... 184 * } 185 * 186 * It should access its arguments using appropriate PG_GETARG_xxx macros 187 * and should return its result using PG_RETURN_xxx. 188 * 189 *------------------------------------------------------------------------- 190 */ 191 192 /* Standard parameter list for fmgr-compatible functions */ 193 #define PG_FUNCTION_ARGS FunctionCallInfo fcinfo 194 195 /* 196 * Get collation function should use. 197 */ 198 #define PG_GET_COLLATION() (fcinfo->fncollation) 199 200 /* 201 * Get number of arguments passed to function. 202 */ 203 #define PG_NARGS() (fcinfo->nargs) 204 205 /* 206 * If function is not marked "proisstrict" in pg_proc, it must check for 207 * null arguments using this macro. Do not try to GETARG a null argument! 208 */ 209 #define PG_ARGISNULL(n) (fcinfo->args[n].isnull) 210 211 /* 212 * Support for fetching detoasted copies of toastable datatypes (all of 213 * which are varlena types). pg_detoast_datum() gives you either the input 214 * datum (if not toasted) or a detoasted copy allocated with palloc(). 215 * pg_detoast_datum_copy() always gives you a palloc'd copy --- use it 216 * if you need a modifiable copy of the input. Caller is expected to have 217 * checked for null inputs first, if necessary. 218 * 219 * pg_detoast_datum_packed() will return packed (1-byte header) datums 220 * unmodified. It will still expand an externally toasted or compressed datum. 221 * The resulting datum can be accessed using VARSIZE_ANY() and VARDATA_ANY() 222 * (beware of multiple evaluations in those macros!) 223 * 224 * In consumers oblivious to data alignment, call PG_DETOAST_DATUM_PACKED(), 225 * VARDATA_ANY(), VARSIZE_ANY() and VARSIZE_ANY_EXHDR(). Elsewhere, call 226 * PG_DETOAST_DATUM(), VARDATA() and VARSIZE(). Directly fetching an int16, 227 * int32 or wider field in the struct representing the datum layout requires 228 * aligned data. memcpy() is alignment-oblivious, as are most operations on 229 * datatypes, such as text, whose layout struct contains only char fields. 230 * 231 * Note: it'd be nice if these could be macros, but I see no way to do that 232 * without evaluating the arguments multiple times, which is NOT acceptable. 233 */ 234 extern struct varlena *pg_detoast_datum(struct varlena *datum); 235 extern struct varlena *pg_detoast_datum_copy(struct varlena *datum); 236 extern struct varlena *pg_detoast_datum_slice(struct varlena *datum, 237 int32 first, int32 count); 238 extern struct varlena *pg_detoast_datum_packed(struct varlena *datum); 239 240 #define PG_DETOAST_DATUM(datum) \ 241 pg_detoast_datum((struct varlena *) DatumGetPointer(datum)) 242 #define PG_DETOAST_DATUM_COPY(datum) \ 243 pg_detoast_datum_copy((struct varlena *) DatumGetPointer(datum)) 244 #define PG_DETOAST_DATUM_SLICE(datum,f,c) \ 245 pg_detoast_datum_slice((struct varlena *) DatumGetPointer(datum), \ 246 (int32) (f), (int32) (c)) 247 /* WARNING -- unaligned pointer */ 248 #define PG_DETOAST_DATUM_PACKED(datum) \ 249 pg_detoast_datum_packed((struct varlena *) DatumGetPointer(datum)) 250 251 /* 252 * Support for cleaning up detoasted copies of inputs. This must only 253 * be used for pass-by-ref datatypes, and normally would only be used 254 * for toastable types. If the given pointer is different from the 255 * original argument, assume it's a palloc'd detoasted copy, and pfree it. 256 * NOTE: most functions on toastable types do not have to worry about this, 257 * but we currently require that support functions for indexes not leak 258 * memory. 259 */ 260 #define PG_FREE_IF_COPY(ptr,n) \ 261 do { \ 262 if ((Pointer) (ptr) != PG_GETARG_POINTER(n)) \ 263 pfree(ptr); \ 264 } while (0) 265 266 /* Macros for fetching arguments of standard types */ 267 268 #define PG_GETARG_DATUM(n) (fcinfo->args[n].value) 269 #define PG_GETARG_INT32(n) DatumGetInt32(PG_GETARG_DATUM(n)) 270 #define PG_GETARG_UINT32(n) DatumGetUInt32(PG_GETARG_DATUM(n)) 271 #define PG_GETARG_INT16(n) DatumGetInt16(PG_GETARG_DATUM(n)) 272 #define PG_GETARG_UINT16(n) DatumGetUInt16(PG_GETARG_DATUM(n)) 273 #define PG_GETARG_CHAR(n) DatumGetChar(PG_GETARG_DATUM(n)) 274 #define PG_GETARG_BOOL(n) DatumGetBool(PG_GETARG_DATUM(n)) 275 #define PG_GETARG_OID(n) DatumGetObjectId(PG_GETARG_DATUM(n)) 276 #define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n)) 277 #define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n)) 278 #define PG_GETARG_NAME(n) DatumGetName(PG_GETARG_DATUM(n)) 279 /* these macros hide the pass-by-reference-ness of the datatype: */ 280 #define PG_GETARG_FLOAT4(n) DatumGetFloat4(PG_GETARG_DATUM(n)) 281 #define PG_GETARG_FLOAT8(n) DatumGetFloat8(PG_GETARG_DATUM(n)) 282 #define PG_GETARG_INT64(n) DatumGetInt64(PG_GETARG_DATUM(n)) 283 /* use this if you want the raw, possibly-toasted input datum: */ 284 #define PG_GETARG_RAW_VARLENA_P(n) ((struct varlena *) PG_GETARG_POINTER(n)) 285 /* use this if you want the input datum de-toasted: */ 286 #define PG_GETARG_VARLENA_P(n) PG_DETOAST_DATUM(PG_GETARG_DATUM(n)) 287 /* and this if you can handle 1-byte-header datums: */ 288 #define PG_GETARG_VARLENA_PP(n) PG_DETOAST_DATUM_PACKED(PG_GETARG_DATUM(n)) 289 /* DatumGetFoo macros for varlena types will typically look like this: */ 290 #define DatumGetByteaPP(X) ((bytea *) PG_DETOAST_DATUM_PACKED(X)) 291 #define DatumGetTextPP(X) ((text *) PG_DETOAST_DATUM_PACKED(X)) 292 #define DatumGetBpCharPP(X) ((BpChar *) PG_DETOAST_DATUM_PACKED(X)) 293 #define DatumGetVarCharPP(X) ((VarChar *) PG_DETOAST_DATUM_PACKED(X)) 294 #define DatumGetHeapTupleHeader(X) ((HeapTupleHeader) PG_DETOAST_DATUM(X)) 295 /* And we also offer variants that return an OK-to-write copy */ 296 #define DatumGetByteaPCopy(X) ((bytea *) PG_DETOAST_DATUM_COPY(X)) 297 #define DatumGetTextPCopy(X) ((text *) PG_DETOAST_DATUM_COPY(X)) 298 #define DatumGetBpCharPCopy(X) ((BpChar *) PG_DETOAST_DATUM_COPY(X)) 299 #define DatumGetVarCharPCopy(X) ((VarChar *) PG_DETOAST_DATUM_COPY(X)) 300 #define DatumGetHeapTupleHeaderCopy(X) ((HeapTupleHeader) PG_DETOAST_DATUM_COPY(X)) 301 /* Variants which return n bytes starting at pos. m */ 302 #define DatumGetByteaPSlice(X,m,n) ((bytea *) PG_DETOAST_DATUM_SLICE(X,m,n)) 303 #define DatumGetTextPSlice(X,m,n) ((text *) PG_DETOAST_DATUM_SLICE(X,m,n)) 304 #define DatumGetBpCharPSlice(X,m,n) ((BpChar *) PG_DETOAST_DATUM_SLICE(X,m,n)) 305 #define DatumGetVarCharPSlice(X,m,n) ((VarChar *) PG_DETOAST_DATUM_SLICE(X,m,n)) 306 /* GETARG macros for varlena types will typically look like this: */ 307 #define PG_GETARG_BYTEA_PP(n) DatumGetByteaPP(PG_GETARG_DATUM(n)) 308 #define PG_GETARG_TEXT_PP(n) DatumGetTextPP(PG_GETARG_DATUM(n)) 309 #define PG_GETARG_BPCHAR_PP(n) DatumGetBpCharPP(PG_GETARG_DATUM(n)) 310 #define PG_GETARG_VARCHAR_PP(n) DatumGetVarCharPP(PG_GETARG_DATUM(n)) 311 #define PG_GETARG_HEAPTUPLEHEADER(n) DatumGetHeapTupleHeader(PG_GETARG_DATUM(n)) 312 /* And we also offer variants that return an OK-to-write copy */ 313 #define PG_GETARG_BYTEA_P_COPY(n) DatumGetByteaPCopy(PG_GETARG_DATUM(n)) 314 #define PG_GETARG_TEXT_P_COPY(n) DatumGetTextPCopy(PG_GETARG_DATUM(n)) 315 #define PG_GETARG_BPCHAR_P_COPY(n) DatumGetBpCharPCopy(PG_GETARG_DATUM(n)) 316 #define PG_GETARG_VARCHAR_P_COPY(n) DatumGetVarCharPCopy(PG_GETARG_DATUM(n)) 317 #define PG_GETARG_HEAPTUPLEHEADER_COPY(n) DatumGetHeapTupleHeaderCopy(PG_GETARG_DATUM(n)) 318 /* And a b-byte slice from position a -also OK to write */ 319 #define PG_GETARG_BYTEA_P_SLICE(n,a,b) DatumGetByteaPSlice(PG_GETARG_DATUM(n),a,b) 320 #define PG_GETARG_TEXT_P_SLICE(n,a,b) DatumGetTextPSlice(PG_GETARG_DATUM(n),a,b) 321 #define PG_GETARG_BPCHAR_P_SLICE(n,a,b) DatumGetBpCharPSlice(PG_GETARG_DATUM(n),a,b) 322 #define PG_GETARG_VARCHAR_P_SLICE(n,a,b) DatumGetVarCharPSlice(PG_GETARG_DATUM(n),a,b) 323 /* 324 * Obsolescent variants that guarantee INT alignment for the return value. 325 * Few operations on these particular types need alignment, mainly operations 326 * that cast the VARDATA pointer to a type like int16[]. Most code should use 327 * the ...PP(X) counterpart. Nonetheless, these appear frequently in code 328 * predating the PostgreSQL 8.3 introduction of the ...PP(X) variants. 329 */ 330 #define DatumGetByteaP(X) ((bytea *) PG_DETOAST_DATUM(X)) 331 #define DatumGetTextP(X) ((text *) PG_DETOAST_DATUM(X)) 332 #define DatumGetBpCharP(X) ((BpChar *) PG_DETOAST_DATUM(X)) 333 #define DatumGetVarCharP(X) ((VarChar *) PG_DETOAST_DATUM(X)) 334 #define PG_GETARG_BYTEA_P(n) DatumGetByteaP(PG_GETARG_DATUM(n)) 335 #define PG_GETARG_TEXT_P(n) DatumGetTextP(PG_GETARG_DATUM(n)) 336 #define PG_GETARG_BPCHAR_P(n) DatumGetBpCharP(PG_GETARG_DATUM(n)) 337 #define PG_GETARG_VARCHAR_P(n) DatumGetVarCharP(PG_GETARG_DATUM(n)) 338 339 /* To access options from opclass support functions use this: */ 340 #define PG_HAS_OPCLASS_OPTIONS() has_fn_opclass_options(fcinfo->flinfo) 341 #define PG_GET_OPCLASS_OPTIONS() get_fn_opclass_options(fcinfo->flinfo) 342 343 /* To return a NULL do this: */ 344 #define PG_RETURN_NULL() \ 345 do { fcinfo->isnull = true; return (Datum) 0; } while (0) 346 347 /* A few internal functions return void (which is not the same as NULL!) */ 348 #define PG_RETURN_VOID() return (Datum) 0 349 350 /* Macros for returning results of standard types */ 351 352 #define PG_RETURN_DATUM(x) return (x) 353 #define PG_RETURN_INT32(x) return Int32GetDatum(x) 354 #define PG_RETURN_UINT32(x) return UInt32GetDatum(x) 355 #define PG_RETURN_INT16(x) return Int16GetDatum(x) 356 #define PG_RETURN_UINT16(x) return UInt16GetDatum(x) 357 #define PG_RETURN_CHAR(x) return CharGetDatum(x) 358 #define PG_RETURN_BOOL(x) return BoolGetDatum(x) 359 #define PG_RETURN_OID(x) return ObjectIdGetDatum(x) 360 #define PG_RETURN_POINTER(x) return PointerGetDatum(x) 361 #define PG_RETURN_CSTRING(x) return CStringGetDatum(x) 362 #define PG_RETURN_NAME(x) return NameGetDatum(x) 363 /* these macros hide the pass-by-reference-ness of the datatype: */ 364 #define PG_RETURN_FLOAT4(x) return Float4GetDatum(x) 365 #define PG_RETURN_FLOAT8(x) return Float8GetDatum(x) 366 #define PG_RETURN_INT64(x) return Int64GetDatum(x) 367 #define PG_RETURN_UINT64(x) return UInt64GetDatum(x) 368 /* RETURN macros for other pass-by-ref types will typically look like this: */ 369 #define PG_RETURN_BYTEA_P(x) PG_RETURN_POINTER(x) 370 #define PG_RETURN_TEXT_P(x) PG_RETURN_POINTER(x) 371 #define PG_RETURN_BPCHAR_P(x) PG_RETURN_POINTER(x) 372 #define PG_RETURN_VARCHAR_P(x) PG_RETURN_POINTER(x) 373 #define PG_RETURN_HEAPTUPLEHEADER(x) return HeapTupleHeaderGetDatum(x) 374 375 376 /*------------------------------------------------------------------------- 377 * Support for detecting call convention of dynamically-loaded functions 378 * 379 * Dynamically loaded functions currently can only use the version-1 ("new 380 * style") calling convention. Version-0 ("old style") is not supported 381 * anymore. Version 1 is the call convention defined in this header file, and 382 * must be accompanied by the macro call 383 * 384 * PG_FUNCTION_INFO_V1(function_name); 385 * 386 * Note that internal functions do not need this decoration since they are 387 * assumed to be version-1. 388 * 389 *------------------------------------------------------------------------- 390 */ 391 392 typedef struct 393 { 394 int api_version; /* specifies call convention version number */ 395 /* More fields may be added later, for version numbers > 1. */ 396 } Pg_finfo_record; 397 398 /* Expected signature of an info function */ 399 typedef const Pg_finfo_record *(*PGFInfoFunction) (void); 400 401 /* 402 * Macro to build an info function associated with the given function name. 403 * 404 * As a convenience, also provide an "extern" declaration for the given 405 * function name, so that writers of C functions need not write that too. 406 * 407 * On Windows, the function and info function must be exported. Our normal 408 * build processes take care of that via .DEF files or --export-all-symbols. 409 * Module authors using a different build process might need to manually 410 * declare the function PGDLLEXPORT. We do that automatically here for the 411 * info function, since authors shouldn't need to be explicitly aware of it. 412 */ 413 #define PG_FUNCTION_INFO_V1(funcname) \ 414 extern Datum funcname(PG_FUNCTION_ARGS); \ 415 extern PGDLLEXPORT const Pg_finfo_record * CppConcat(pg_finfo_,funcname)(void); \ 416 const Pg_finfo_record * \ 417 CppConcat(pg_finfo_,funcname) (void) \ 418 { \ 419 static const Pg_finfo_record my_finfo = { 1 }; \ 420 return &my_finfo; \ 421 } \ 422 extern int no_such_variable 423 424 425 /*------------------------------------------------------------------------- 426 * Support for verifying backend compatibility of loaded modules 427 * 428 * We require dynamically-loaded modules to include the macro call 429 * PG_MODULE_MAGIC; 430 * so that we can check for obvious incompatibility, such as being compiled 431 * for a different major PostgreSQL version. 432 * 433 * To compile with versions of PostgreSQL that do not support this, 434 * you may put an #ifdef/#endif test around it. Note that in a multiple- 435 * source-file module, the macro call should only appear once. 436 * 437 * The specific items included in the magic block are intended to be ones that 438 * are custom-configurable and especially likely to break dynamically loaded 439 * modules if they were compiled with other values. Also, the length field 440 * can be used to detect definition changes. 441 * 442 * Note: we compare magic blocks with memcmp(), so there had better not be 443 * any alignment pad bytes in them. 444 * 445 * Note: when changing the contents of magic blocks, be sure to adjust the 446 * incompatible_module_error() function in dfmgr.c. 447 *------------------------------------------------------------------------- 448 */ 449 450 /* Definition of the magic block structure */ 451 typedef struct 452 { 453 int len; /* sizeof(this struct) */ 454 int version; /* PostgreSQL major version */ 455 int funcmaxargs; /* FUNC_MAX_ARGS */ 456 int indexmaxkeys; /* INDEX_MAX_KEYS */ 457 int namedatalen; /* NAMEDATALEN */ 458 int float8byval; /* FLOAT8PASSBYVAL */ 459 } Pg_magic_struct; 460 461 /* The actual data block contents */ 462 #define PG_MODULE_MAGIC_DATA \ 463 { \ 464 sizeof(Pg_magic_struct), \ 465 PG_VERSION_NUM / 100, \ 466 FUNC_MAX_ARGS, \ 467 INDEX_MAX_KEYS, \ 468 NAMEDATALEN, \ 469 FLOAT8PASSBYVAL \ 470 } 471 472 /* 473 * Declare the module magic function. It needs to be a function as the dlsym 474 * in the backend is only guaranteed to work on functions, not data 475 */ 476 typedef const Pg_magic_struct *(*PGModuleMagicFunction) (void); 477 478 #define PG_MAGIC_FUNCTION_NAME Pg_magic_func 479 #define PG_MAGIC_FUNCTION_NAME_STRING "Pg_magic_func" 480 481 #define PG_MODULE_MAGIC \ 482 extern PGDLLEXPORT const Pg_magic_struct *PG_MAGIC_FUNCTION_NAME(void); \ 483 const Pg_magic_struct * \ 484 PG_MAGIC_FUNCTION_NAME(void) \ 485 { \ 486 static const Pg_magic_struct Pg_magic_data = PG_MODULE_MAGIC_DATA; \ 487 return &Pg_magic_data; \ 488 } \ 489 extern int no_such_variable 490 491 492 /*------------------------------------------------------------------------- 493 * Support routines and macros for callers of fmgr-compatible functions 494 *------------------------------------------------------------------------- 495 */ 496 497 /* These are for invocation of a specifically named function with a 498 * directly-computed parameter list. Note that neither arguments nor result 499 * are allowed to be NULL. Also, the function cannot be one that needs to 500 * look at FmgrInfo, since there won't be any. 501 */ 502 extern Datum DirectFunctionCall1Coll(PGFunction func, Oid collation, 503 Datum arg1); 504 extern Datum DirectFunctionCall2Coll(PGFunction func, Oid collation, 505 Datum arg1, Datum arg2); 506 extern Datum DirectFunctionCall3Coll(PGFunction func, Oid collation, 507 Datum arg1, Datum arg2, 508 Datum arg3); 509 extern Datum DirectFunctionCall4Coll(PGFunction func, Oid collation, 510 Datum arg1, Datum arg2, 511 Datum arg3, Datum arg4); 512 extern Datum DirectFunctionCall5Coll(PGFunction func, Oid collation, 513 Datum arg1, Datum arg2, 514 Datum arg3, Datum arg4, Datum arg5); 515 extern Datum DirectFunctionCall6Coll(PGFunction func, Oid collation, 516 Datum arg1, Datum arg2, 517 Datum arg3, Datum arg4, Datum arg5, 518 Datum arg6); 519 extern Datum DirectFunctionCall7Coll(PGFunction func, Oid collation, 520 Datum arg1, Datum arg2, 521 Datum arg3, Datum arg4, Datum arg5, 522 Datum arg6, Datum arg7); 523 extern Datum DirectFunctionCall8Coll(PGFunction func, Oid collation, 524 Datum arg1, Datum arg2, 525 Datum arg3, Datum arg4, Datum arg5, 526 Datum arg6, Datum arg7, Datum arg8); 527 extern Datum DirectFunctionCall9Coll(PGFunction func, Oid collation, 528 Datum arg1, Datum arg2, 529 Datum arg3, Datum arg4, Datum arg5, 530 Datum arg6, Datum arg7, Datum arg8, 531 Datum arg9); 532 533 /* 534 * These functions work like the DirectFunctionCall functions except that 535 * they use the flinfo parameter to initialise the fcinfo for the call. 536 * It's recommended that the callee only use the fn_extra and fn_mcxt 537 * fields, as other fields will typically describe the calling function 538 * not the callee. Conversely, the calling function should not have 539 * used fn_extra, unless its use is known to be compatible with the callee's. 540 */ 541 extern Datum CallerFInfoFunctionCall1(PGFunction func, FmgrInfo *flinfo, 542 Oid collation, Datum arg1); 543 extern Datum CallerFInfoFunctionCall2(PGFunction func, FmgrInfo *flinfo, 544 Oid collation, Datum arg1, Datum arg2); 545 546 /* These are for invocation of a previously-looked-up function with a 547 * directly-computed parameter list. Note that neither arguments nor result 548 * are allowed to be NULL. 549 */ 550 extern Datum FunctionCall0Coll(FmgrInfo *flinfo, Oid collation); 551 extern Datum FunctionCall1Coll(FmgrInfo *flinfo, Oid collation, 552 Datum arg1); 553 extern Datum FunctionCall2Coll(FmgrInfo *flinfo, Oid collation, 554 Datum arg1, Datum arg2); 555 extern Datum FunctionCall3Coll(FmgrInfo *flinfo, Oid collation, 556 Datum arg1, Datum arg2, 557 Datum arg3); 558 extern Datum FunctionCall4Coll(FmgrInfo *flinfo, Oid collation, 559 Datum arg1, Datum arg2, 560 Datum arg3, Datum arg4); 561 extern Datum FunctionCall5Coll(FmgrInfo *flinfo, Oid collation, 562 Datum arg1, Datum arg2, 563 Datum arg3, Datum arg4, Datum arg5); 564 extern Datum FunctionCall6Coll(FmgrInfo *flinfo, Oid collation, 565 Datum arg1, Datum arg2, 566 Datum arg3, Datum arg4, Datum arg5, 567 Datum arg6); 568 extern Datum FunctionCall7Coll(FmgrInfo *flinfo, Oid collation, 569 Datum arg1, Datum arg2, 570 Datum arg3, Datum arg4, Datum arg5, 571 Datum arg6, Datum arg7); 572 extern Datum FunctionCall8Coll(FmgrInfo *flinfo, Oid collation, 573 Datum arg1, Datum arg2, 574 Datum arg3, Datum arg4, Datum arg5, 575 Datum arg6, Datum arg7, Datum arg8); 576 extern Datum FunctionCall9Coll(FmgrInfo *flinfo, Oid collation, 577 Datum arg1, Datum arg2, 578 Datum arg3, Datum arg4, Datum arg5, 579 Datum arg6, Datum arg7, Datum arg8, 580 Datum arg9); 581 582 /* These are for invocation of a function identified by OID with a 583 * directly-computed parameter list. Note that neither arguments nor result 584 * are allowed to be NULL. These are essentially fmgr_info() followed by 585 * FunctionCallN(). If the same function is to be invoked repeatedly, do the 586 * fmgr_info() once and then use FunctionCallN(). 587 */ 588 extern Datum OidFunctionCall0Coll(Oid functionId, Oid collation); 589 extern Datum OidFunctionCall1Coll(Oid functionId, Oid collation, 590 Datum arg1); 591 extern Datum OidFunctionCall2Coll(Oid functionId, Oid collation, 592 Datum arg1, Datum arg2); 593 extern Datum OidFunctionCall3Coll(Oid functionId, Oid collation, 594 Datum arg1, Datum arg2, 595 Datum arg3); 596 extern Datum OidFunctionCall4Coll(Oid functionId, Oid collation, 597 Datum arg1, Datum arg2, 598 Datum arg3, Datum arg4); 599 extern Datum OidFunctionCall5Coll(Oid functionId, Oid collation, 600 Datum arg1, Datum arg2, 601 Datum arg3, Datum arg4, Datum arg5); 602 extern Datum OidFunctionCall6Coll(Oid functionId, Oid collation, 603 Datum arg1, Datum arg2, 604 Datum arg3, Datum arg4, Datum arg5, 605 Datum arg6); 606 extern Datum OidFunctionCall7Coll(Oid functionId, Oid collation, 607 Datum arg1, Datum arg2, 608 Datum arg3, Datum arg4, Datum arg5, 609 Datum arg6, Datum arg7); 610 extern Datum OidFunctionCall8Coll(Oid functionId, Oid collation, 611 Datum arg1, Datum arg2, 612 Datum arg3, Datum arg4, Datum arg5, 613 Datum arg6, Datum arg7, Datum arg8); 614 extern Datum OidFunctionCall9Coll(Oid functionId, Oid collation, 615 Datum arg1, Datum arg2, 616 Datum arg3, Datum arg4, Datum arg5, 617 Datum arg6, Datum arg7, Datum arg8, 618 Datum arg9); 619 620 /* These macros allow the collation argument to be omitted (with a default of 621 * InvalidOid, ie, no collation). They exist mostly for backwards 622 * compatibility of source code. 623 */ 624 #define DirectFunctionCall1(func, arg1) \ 625 DirectFunctionCall1Coll(func, InvalidOid, arg1) 626 #define DirectFunctionCall2(func, arg1, arg2) \ 627 DirectFunctionCall2Coll(func, InvalidOid, arg1, arg2) 628 #define DirectFunctionCall3(func, arg1, arg2, arg3) \ 629 DirectFunctionCall3Coll(func, InvalidOid, arg1, arg2, arg3) 630 #define DirectFunctionCall4(func, arg1, arg2, arg3, arg4) \ 631 DirectFunctionCall4Coll(func, InvalidOid, arg1, arg2, arg3, arg4) 632 #define DirectFunctionCall5(func, arg1, arg2, arg3, arg4, arg5) \ 633 DirectFunctionCall5Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5) 634 #define DirectFunctionCall6(func, arg1, arg2, arg3, arg4, arg5, arg6) \ 635 DirectFunctionCall6Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6) 636 #define DirectFunctionCall7(func, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \ 637 DirectFunctionCall7Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7) 638 #define DirectFunctionCall8(func, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \ 639 DirectFunctionCall8Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) 640 #define DirectFunctionCall9(func, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \ 641 DirectFunctionCall9Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) 642 #define FunctionCall1(flinfo, arg1) \ 643 FunctionCall1Coll(flinfo, InvalidOid, arg1) 644 #define FunctionCall2(flinfo, arg1, arg2) \ 645 FunctionCall2Coll(flinfo, InvalidOid, arg1, arg2) 646 #define FunctionCall3(flinfo, arg1, arg2, arg3) \ 647 FunctionCall3Coll(flinfo, InvalidOid, arg1, arg2, arg3) 648 #define FunctionCall4(flinfo, arg1, arg2, arg3, arg4) \ 649 FunctionCall4Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4) 650 #define FunctionCall5(flinfo, arg1, arg2, arg3, arg4, arg5) \ 651 FunctionCall5Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5) 652 #define FunctionCall6(flinfo, arg1, arg2, arg3, arg4, arg5, arg6) \ 653 FunctionCall6Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6) 654 #define FunctionCall7(flinfo, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \ 655 FunctionCall7Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7) 656 #define FunctionCall8(flinfo, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \ 657 FunctionCall8Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) 658 #define FunctionCall9(flinfo, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \ 659 FunctionCall9Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) 660 #define OidFunctionCall0(functionId) \ 661 OidFunctionCall0Coll(functionId, InvalidOid) 662 #define OidFunctionCall1(functionId, arg1) \ 663 OidFunctionCall1Coll(functionId, InvalidOid, arg1) 664 #define OidFunctionCall2(functionId, arg1, arg2) \ 665 OidFunctionCall2Coll(functionId, InvalidOid, arg1, arg2) 666 #define OidFunctionCall3(functionId, arg1, arg2, arg3) \ 667 OidFunctionCall3Coll(functionId, InvalidOid, arg1, arg2, arg3) 668 #define OidFunctionCall4(functionId, arg1, arg2, arg3, arg4) \ 669 OidFunctionCall4Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4) 670 #define OidFunctionCall5(functionId, arg1, arg2, arg3, arg4, arg5) \ 671 OidFunctionCall5Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5) 672 #define OidFunctionCall6(functionId, arg1, arg2, arg3, arg4, arg5, arg6) \ 673 OidFunctionCall6Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6) 674 #define OidFunctionCall7(functionId, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \ 675 OidFunctionCall7Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7) 676 #define OidFunctionCall8(functionId, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \ 677 OidFunctionCall8Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) 678 #define OidFunctionCall9(functionId, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \ 679 OidFunctionCall9Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) 680 681 682 /* Special cases for convenient invocation of datatype I/O functions. */ 683 extern Datum InputFunctionCall(FmgrInfo *flinfo, char *str, 684 Oid typioparam, int32 typmod); 685 extern Datum OidInputFunctionCall(Oid functionId, char *str, 686 Oid typioparam, int32 typmod); 687 extern char *OutputFunctionCall(FmgrInfo *flinfo, Datum val); 688 extern char *OidOutputFunctionCall(Oid functionId, Datum val); 689 extern Datum ReceiveFunctionCall(FmgrInfo *flinfo, fmStringInfo buf, 690 Oid typioparam, int32 typmod); 691 extern Datum OidReceiveFunctionCall(Oid functionId, fmStringInfo buf, 692 Oid typioparam, int32 typmod); 693 extern bytea *SendFunctionCall(FmgrInfo *flinfo, Datum val); 694 extern bytea *OidSendFunctionCall(Oid functionId, Datum val); 695 696 697 /* 698 * Routines in fmgr.c 699 */ 700 extern const Pg_finfo_record *fetch_finfo_record(void *filehandle, const char *funcname); 701 extern void clear_external_function_hash(void *filehandle); 702 extern Oid fmgr_internal_function(const char *proname); 703 extern Oid get_fn_expr_rettype(FmgrInfo *flinfo); 704 extern Oid get_fn_expr_argtype(FmgrInfo *flinfo, int argnum); 705 extern Oid get_call_expr_argtype(fmNodePtr expr, int argnum); 706 extern bool get_fn_expr_arg_stable(FmgrInfo *flinfo, int argnum); 707 extern bool get_call_expr_arg_stable(fmNodePtr expr, int argnum); 708 extern bool get_fn_expr_variadic(FmgrInfo *flinfo); 709 extern bytea *get_fn_opclass_options(FmgrInfo *flinfo); 710 extern bool has_fn_opclass_options(FmgrInfo *flinfo); 711 extern void set_fn_opclass_options(FmgrInfo *flinfo, bytea *options); 712 extern bool CheckFunctionValidatorAccess(Oid validatorOid, Oid functionOid); 713 714 /* 715 * Routines in dfmgr.c 716 */ 717 extern char *Dynamic_library_path; 718 719 extern PGFunction load_external_function(const char *filename, const char *funcname, 720 bool signalNotFound, void **filehandle); 721 extern PGFunction lookup_external_function(void *filehandle, const char *funcname); 722 extern void load_file(const char *filename, bool restricted); 723 extern void **find_rendezvous_variable(const char *varName); 724 extern Size EstimateLibraryStateSpace(void); 725 extern void SerializeLibraryState(Size maxsize, char *start_address); 726 extern void RestoreLibraryState(char *start_address); 727 728 /* 729 * Support for aggregate functions 730 * 731 * These are actually in executor/nodeAgg.c, but we declare them here since 732 * the whole point is for callers to not be overly friendly with nodeAgg. 733 */ 734 735 /* AggCheckCallContext can return one of the following codes, or 0: */ 736 #define AGG_CONTEXT_AGGREGATE 1 /* regular aggregate */ 737 #define AGG_CONTEXT_WINDOW 2 /* window function */ 738 739 extern int AggCheckCallContext(FunctionCallInfo fcinfo, 740 MemoryContext *aggcontext); 741 extern fmAggrefPtr AggGetAggref(FunctionCallInfo fcinfo); 742 extern MemoryContext AggGetTempMemoryContext(FunctionCallInfo fcinfo); 743 extern bool AggStateIsShared(FunctionCallInfo fcinfo); 744 extern void AggRegisterCallback(FunctionCallInfo fcinfo, 745 fmExprContextCallbackFunction func, 746 Datum arg); 747 748 /* 749 * We allow plugin modules to hook function entry/exit. This is intended 750 * as support for loadable security policy modules, which may want to 751 * perform additional privilege checks on function entry or exit, or to do 752 * other internal bookkeeping. To make this possible, such modules must be 753 * able not only to support normal function entry and exit, but also to trap 754 * the case where we bail out due to an error; and they must also be able to 755 * prevent inlining. 756 */ 757 typedef enum FmgrHookEventType 758 { 759 FHET_START, 760 FHET_END, 761 FHET_ABORT 762 } FmgrHookEventType; 763 764 typedef bool (*needs_fmgr_hook_type) (Oid fn_oid); 765 766 typedef void (*fmgr_hook_type) (FmgrHookEventType event, 767 FmgrInfo *flinfo, Datum *arg); 768 769 extern PGDLLIMPORT needs_fmgr_hook_type needs_fmgr_hook; 770 extern PGDLLIMPORT fmgr_hook_type fmgr_hook; 771 772 #define FmgrHookIsNeeded(fn_oid) \ 773 (!needs_fmgr_hook ? false : (*needs_fmgr_hook)(fn_oid)) 774 775 #endif /* FMGR_H */ 776