Adding upstream version 15.5.upstream/15.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 781 insertions, 0 deletions

diff --git a/src/include/fmgr.h b/src/include/fmgr.h
new file mode 100644
index 0000000..5314b73
--- /dev/null
+++ b/src/include/fmgr.h
@@ -0,0 +1,781 @@
+/*-------------------------------------------------------------------------
+ *
+ * fmgr.h
+ *	  Definitions for the Postgres function manager and function-call
+ *	  interface.
+ *
+ * This file must be included by all Postgres modules that either define
+ * or call fmgr-callable functions.
+ *
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/fmgr.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FMGR_H
+#define FMGR_H
+
+/* We don't want to include primnodes.h here, so make some stub references */
+typedef struct Node *fmNodePtr;
+typedef struct Aggref *fmAggrefPtr;
+
+/* Likewise, avoid including execnodes.h here */
+typedef void (*fmExprContextCallbackFunction) (Datum arg);
+
+/* Likewise, avoid including stringinfo.h here */
+typedef struct StringInfoData *fmStringInfo;
+
+
+/*
+ * All functions that can be called directly by fmgr must have this signature.
+ * (Other functions can be called by using a handler that does have this
+ * signature.)
+ */
+
+typedef struct FunctionCallInfoBaseData *FunctionCallInfo;
+
+typedef Datum (*PGFunction) (FunctionCallInfo fcinfo);
+
+/*
+ * This struct holds the system-catalog information that must be looked up
+ * before a function can be called through fmgr.  If the same function is
+ * to be called multiple times, the lookup need be done only once and the
+ * info struct saved for re-use.
+ *
+ * Note that fn_expr really is parse-time-determined information about the
+ * arguments, rather than about the function itself.  But it's convenient to
+ * store it here rather than in FunctionCallInfoBaseData, where it might more
+ * logically belong.
+ *
+ * fn_extra is available for use by the called function; all other fields
+ * should be treated as read-only after the struct is created.
+ */
+typedef struct FmgrInfo
+{
+	PGFunction	fn_addr;		/* pointer to function or handler to be called */
+	Oid			fn_oid;			/* OID of function (NOT of handler, if any) */
+	short		fn_nargs;		/* number of input args (0..FUNC_MAX_ARGS) */
+	bool		fn_strict;		/* function is "strict" (NULL in => NULL out) */
+	bool		fn_retset;		/* function returns a set */
+	unsigned char fn_stats;		/* collect stats if track_functions > this */
+	void	   *fn_extra;		/* extra space for use by handler */
+	MemoryContext fn_mcxt;		/* memory context to store fn_extra in */
+	fmNodePtr	fn_expr;		/* expression parse tree for call, or NULL */
+} FmgrInfo;
+
+/*
+ * This struct is the data actually passed to an fmgr-called function.
+ *
+ * The called function is expected to set isnull, and possibly resultinfo or
+ * fields in whatever resultinfo points to.  It should not change any other
+ * fields.  (In particular, scribbling on the argument arrays is a bad idea,
+ * since some callers assume they can re-call with the same arguments.)
+ *
+ * Note that enough space for arguments needs to be provided, either by using
+ * SizeForFunctionCallInfo() in dynamic allocations, or by using
+ * LOCAL_FCINFO() for on-stack allocations.
+ *
+ * This struct is named *BaseData, rather than *Data, to break pre v12 code
+ * that allocated FunctionCallInfoData itself, as it'd often silently break
+ * old code due to no space for arguments being provided.
+ */
+typedef struct FunctionCallInfoBaseData
+{
+	FmgrInfo   *flinfo;			/* ptr to lookup info used for this call */
+	fmNodePtr	context;		/* pass info about context of call */
+	fmNodePtr	resultinfo;		/* pass or return extra info about result */
+	Oid			fncollation;	/* collation for function to use */
+#define FIELDNO_FUNCTIONCALLINFODATA_ISNULL 4
+	bool		isnull;			/* function must set true if result is NULL */
+	short		nargs;			/* # arguments actually passed */
+#define FIELDNO_FUNCTIONCALLINFODATA_ARGS 6
+	NullableDatum args[FLEXIBLE_ARRAY_MEMBER];
+} FunctionCallInfoBaseData;
+
+/*
+ * Space needed for a FunctionCallInfoBaseData struct with sufficient space
+ * for `nargs` arguments.
+ */
+#define SizeForFunctionCallInfo(nargs) \
+	(offsetof(FunctionCallInfoBaseData, args) + \
+	 sizeof(NullableDatum) * (nargs))
+
+/*
+ * This macro ensures that `name` points to a stack-allocated
+ * FunctionCallInfoBaseData struct with sufficient space for `nargs` arguments.
+ */
+#define LOCAL_FCINFO(name, nargs) \
+	/* use union with FunctionCallInfoBaseData to guarantee alignment */ \
+	union \
+	{ \
+		FunctionCallInfoBaseData fcinfo; \
+		/* ensure enough space for nargs args is available */ \
+		char fcinfo_data[SizeForFunctionCallInfo(nargs)]; \
+	} name##data; \
+	FunctionCallInfo name = &name##data.fcinfo
+
+/*
+ * This routine fills a FmgrInfo struct, given the OID
+ * of the function to be called.
+ */
+extern void fmgr_info(Oid functionId, FmgrInfo *finfo);
+
+/*
+ * Same, when the FmgrInfo struct is in a memory context longer-lived than
+ * CurrentMemoryContext.  The specified context will be set as fn_mcxt
+ * and used to hold all subsidiary data of finfo.
+ */
+extern void fmgr_info_cxt(Oid functionId, FmgrInfo *finfo,
+						  MemoryContext mcxt);
+
+/* Convenience macro for setting the fn_expr field */
+#define fmgr_info_set_expr(expr, finfo) \
+	((finfo)->fn_expr = (expr))
+
+/*
+ * Copy an FmgrInfo struct
+ */
+extern void fmgr_info_copy(FmgrInfo *dstinfo, FmgrInfo *srcinfo,
+						   MemoryContext destcxt);
+
+extern void fmgr_symbol(Oid functionId, char **mod, char **fn);
+
+/*
+ * This macro initializes all the fields of a FunctionCallInfoBaseData except
+ * for the args[] array.
+ */
+#define InitFunctionCallInfoData(Fcinfo, Flinfo, Nargs, Collation, Context, Resultinfo) \
+	do { \
+		(Fcinfo).flinfo = (Flinfo); \
+		(Fcinfo).context = (Context); \
+		(Fcinfo).resultinfo = (Resultinfo); \
+		(Fcinfo).fncollation = (Collation); \
+		(Fcinfo).isnull = false; \
+		(Fcinfo).nargs = (Nargs); \
+	} while (0)
+
+/*
+ * This macro invokes a function given a filled-in FunctionCallInfoBaseData
+ * struct.  The macro result is the returned Datum --- but note that
+ * caller must still check fcinfo->isnull!	Also, if function is strict,
+ * it is caller's responsibility to verify that no null arguments are present
+ * before calling.
+ *
+ * Some code performs multiple calls without redoing InitFunctionCallInfoData,
+ * possibly altering the argument values.  This is okay, but be sure to reset
+ * the fcinfo->isnull flag before each call, since callees are permitted to
+ * assume that starts out false.
+ */
+#define FunctionCallInvoke(fcinfo)	((* (fcinfo)->flinfo->fn_addr) (fcinfo))
+
+
+/*-------------------------------------------------------------------------
+ *		Support macros to ease writing fmgr-compatible functions
+ *
+ * A C-coded fmgr-compatible function should be declared as
+ *
+ *		Datum
+ *		function_name(PG_FUNCTION_ARGS)
+ *		{
+ *			...
+ *		}
+ *
+ * It should access its arguments using appropriate PG_GETARG_xxx macros
+ * and should return its result using PG_RETURN_xxx.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/* Standard parameter list for fmgr-compatible functions */
+#define PG_FUNCTION_ARGS	FunctionCallInfo fcinfo
+
+/*
+ * Get collation function should use.
+ */
+#define PG_GET_COLLATION()	(fcinfo->fncollation)
+
+/*
+ * Get number of arguments passed to function.
+ */
+#define PG_NARGS() (fcinfo->nargs)
+
+/*
+ * If function is not marked "proisstrict" in pg_proc, it must check for
+ * null arguments using this macro.  Do not try to GETARG a null argument!
+ */
+#define PG_ARGISNULL(n)  (fcinfo->args[n].isnull)
+
+/*
+ * Support for fetching detoasted copies of toastable datatypes (all of
+ * which are varlena types).  pg_detoast_datum() gives you either the input
+ * datum (if not toasted) or a detoasted copy allocated with palloc().
+ * pg_detoast_datum_copy() always gives you a palloc'd copy --- use it
+ * if you need a modifiable copy of the input.  Caller is expected to have
+ * checked for null inputs first, if necessary.
+ *
+ * pg_detoast_datum_packed() will return packed (1-byte header) datums
+ * unmodified.  It will still expand an externally toasted or compressed datum.
+ * The resulting datum can be accessed using VARSIZE_ANY() and VARDATA_ANY()
+ * (beware of multiple evaluations in those macros!)
+ *
+ * In consumers oblivious to data alignment, call PG_DETOAST_DATUM_PACKED(),
+ * VARDATA_ANY(), VARSIZE_ANY() and VARSIZE_ANY_EXHDR().  Elsewhere, call
+ * PG_DETOAST_DATUM(), VARDATA() and VARSIZE().  Directly fetching an int16,
+ * int32 or wider field in the struct representing the datum layout requires
+ * aligned data.  memcpy() is alignment-oblivious, as are most operations on
+ * datatypes, such as text, whose layout struct contains only char fields.
+ *
+ * Note: it'd be nice if these could be macros, but I see no way to do that
+ * without evaluating the arguments multiple times, which is NOT acceptable.
+ */
+extern struct varlena *pg_detoast_datum(struct varlena *datum);
+extern struct varlena *pg_detoast_datum_copy(struct varlena *datum);
+extern struct varlena *pg_detoast_datum_slice(struct varlena *datum,
+											  int32 first, int32 count);
+extern struct varlena *pg_detoast_datum_packed(struct varlena *datum);
+
+#define PG_DETOAST_DATUM(datum) \
+	pg_detoast_datum((struct varlena *) DatumGetPointer(datum))
+#define PG_DETOAST_DATUM_COPY(datum) \
+	pg_detoast_datum_copy((struct varlena *) DatumGetPointer(datum))
+#define PG_DETOAST_DATUM_SLICE(datum,f,c) \
+		pg_detoast_datum_slice((struct varlena *) DatumGetPointer(datum), \
+		(int32) (f), (int32) (c))
+/* WARNING -- unaligned pointer */
+#define PG_DETOAST_DATUM_PACKED(datum) \
+	pg_detoast_datum_packed((struct varlena *) DatumGetPointer(datum))
+
+/*
+ * Support for cleaning up detoasted copies of inputs.  This must only
+ * be used for pass-by-ref datatypes, and normally would only be used
+ * for toastable types.  If the given pointer is different from the
+ * original argument, assume it's a palloc'd detoasted copy, and pfree it.
+ * NOTE: most functions on toastable types do not have to worry about this,
+ * but we currently require that support functions for indexes not leak
+ * memory.
+ */
+#define PG_FREE_IF_COPY(ptr,n) \
+	do { \
+		if ((Pointer) (ptr) != PG_GETARG_POINTER(n)) \
+			pfree(ptr); \
+	} while (0)
+
+/* Macros for fetching arguments of standard types */
+
+#define PG_GETARG_DATUM(n)	 (fcinfo->args[n].value)
+#define PG_GETARG_INT32(n)	 DatumGetInt32(PG_GETARG_DATUM(n))
+#define PG_GETARG_UINT32(n)  DatumGetUInt32(PG_GETARG_DATUM(n))
+#define PG_GETARG_INT16(n)	 DatumGetInt16(PG_GETARG_DATUM(n))
+#define PG_GETARG_UINT16(n)  DatumGetUInt16(PG_GETARG_DATUM(n))
+#define PG_GETARG_CHAR(n)	 DatumGetChar(PG_GETARG_DATUM(n))
+#define PG_GETARG_BOOL(n)	 DatumGetBool(PG_GETARG_DATUM(n))
+#define PG_GETARG_OID(n)	 DatumGetObjectId(PG_GETARG_DATUM(n))
+#define PG_GETARG_POINTER(n) DatumGetPointer(PG_GETARG_DATUM(n))
+#define PG_GETARG_CSTRING(n) DatumGetCString(PG_GETARG_DATUM(n))
+#define PG_GETARG_NAME(n)	 DatumGetName(PG_GETARG_DATUM(n))
+#define PG_GETARG_TRANSACTIONID(n)	DatumGetTransactionId(PG_GETARG_DATUM(n))
+/* these macros hide the pass-by-reference-ness of the datatype: */
+#define PG_GETARG_FLOAT4(n)  DatumGetFloat4(PG_GETARG_DATUM(n))
+#define PG_GETARG_FLOAT8(n)  DatumGetFloat8(PG_GETARG_DATUM(n))
+#define PG_GETARG_INT64(n)	 DatumGetInt64(PG_GETARG_DATUM(n))
+/* use this if you want the raw, possibly-toasted input datum: */
+#define PG_GETARG_RAW_VARLENA_P(n)	((struct varlena *) PG_GETARG_POINTER(n))
+/* use this if you want the input datum de-toasted: */
+#define PG_GETARG_VARLENA_P(n) PG_DETOAST_DATUM(PG_GETARG_DATUM(n))
+/* and this if you can handle 1-byte-header datums: */
+#define PG_GETARG_VARLENA_PP(n) PG_DETOAST_DATUM_PACKED(PG_GETARG_DATUM(n))
+/* DatumGetFoo macros for varlena types will typically look like this: */
+#define DatumGetByteaPP(X)			((bytea *) PG_DETOAST_DATUM_PACKED(X))
+#define DatumGetTextPP(X)			((text *) PG_DETOAST_DATUM_PACKED(X))
+#define DatumGetBpCharPP(X)			((BpChar *) PG_DETOAST_DATUM_PACKED(X))
+#define DatumGetVarCharPP(X)		((VarChar *) PG_DETOAST_DATUM_PACKED(X))
+#define DatumGetHeapTupleHeader(X)	((HeapTupleHeader) PG_DETOAST_DATUM(X))
+/* And we also offer variants that return an OK-to-write copy */
+#define DatumGetByteaPCopy(X)		((bytea *) PG_DETOAST_DATUM_COPY(X))
+#define DatumGetTextPCopy(X)		((text *) PG_DETOAST_DATUM_COPY(X))
+#define DatumGetBpCharPCopy(X)		((BpChar *) PG_DETOAST_DATUM_COPY(X))
+#define DatumGetVarCharPCopy(X)		((VarChar *) PG_DETOAST_DATUM_COPY(X))
+#define DatumGetHeapTupleHeaderCopy(X)	((HeapTupleHeader) PG_DETOAST_DATUM_COPY(X))
+/* Variants which return n bytes starting at pos. m */
+#define DatumGetByteaPSlice(X,m,n)	((bytea *) PG_DETOAST_DATUM_SLICE(X,m,n))
+#define DatumGetTextPSlice(X,m,n)	((text *) PG_DETOAST_DATUM_SLICE(X,m,n))
+#define DatumGetBpCharPSlice(X,m,n) ((BpChar *) PG_DETOAST_DATUM_SLICE(X,m,n))
+#define DatumGetVarCharPSlice(X,m,n) ((VarChar *) PG_DETOAST_DATUM_SLICE(X,m,n))
+/* GETARG macros for varlena types will typically look like this: */
+#define PG_GETARG_BYTEA_PP(n)		DatumGetByteaPP(PG_GETARG_DATUM(n))
+#define PG_GETARG_TEXT_PP(n)		DatumGetTextPP(PG_GETARG_DATUM(n))
+#define PG_GETARG_BPCHAR_PP(n)		DatumGetBpCharPP(PG_GETARG_DATUM(n))
+#define PG_GETARG_VARCHAR_PP(n)		DatumGetVarCharPP(PG_GETARG_DATUM(n))
+#define PG_GETARG_HEAPTUPLEHEADER(n)	DatumGetHeapTupleHeader(PG_GETARG_DATUM(n))
+/* And we also offer variants that return an OK-to-write copy */
+#define PG_GETARG_BYTEA_P_COPY(n)	DatumGetByteaPCopy(PG_GETARG_DATUM(n))
+#define PG_GETARG_TEXT_P_COPY(n)	DatumGetTextPCopy(PG_GETARG_DATUM(n))
+#define PG_GETARG_BPCHAR_P_COPY(n)	DatumGetBpCharPCopy(PG_GETARG_DATUM(n))
+#define PG_GETARG_VARCHAR_P_COPY(n) DatumGetVarCharPCopy(PG_GETARG_DATUM(n))
+#define PG_GETARG_HEAPTUPLEHEADER_COPY(n)	DatumGetHeapTupleHeaderCopy(PG_GETARG_DATUM(n))
+/* And a b-byte slice from position a -also OK to write */
+#define PG_GETARG_BYTEA_P_SLICE(n,a,b) DatumGetByteaPSlice(PG_GETARG_DATUM(n),a,b)
+#define PG_GETARG_TEXT_P_SLICE(n,a,b)  DatumGetTextPSlice(PG_GETARG_DATUM(n),a,b)
+#define PG_GETARG_BPCHAR_P_SLICE(n,a,b) DatumGetBpCharPSlice(PG_GETARG_DATUM(n),a,b)
+#define PG_GETARG_VARCHAR_P_SLICE(n,a,b) DatumGetVarCharPSlice(PG_GETARG_DATUM(n),a,b)
+/*
+ * Obsolescent variants that guarantee INT alignment for the return value.
+ * Few operations on these particular types need alignment, mainly operations
+ * that cast the VARDATA pointer to a type like int16[].  Most code should use
+ * the ...PP(X) counterpart.  Nonetheless, these appear frequently in code
+ * predating the PostgreSQL 8.3 introduction of the ...PP(X) variants.
+ */
+#define DatumGetByteaP(X)			((bytea *) PG_DETOAST_DATUM(X))
+#define DatumGetTextP(X)			((text *) PG_DETOAST_DATUM(X))
+#define DatumGetBpCharP(X)			((BpChar *) PG_DETOAST_DATUM(X))
+#define DatumGetVarCharP(X)			((VarChar *) PG_DETOAST_DATUM(X))
+#define PG_GETARG_BYTEA_P(n)		DatumGetByteaP(PG_GETARG_DATUM(n))
+#define PG_GETARG_TEXT_P(n)			DatumGetTextP(PG_GETARG_DATUM(n))
+#define PG_GETARG_BPCHAR_P(n)		DatumGetBpCharP(PG_GETARG_DATUM(n))
+#define PG_GETARG_VARCHAR_P(n)		DatumGetVarCharP(PG_GETARG_DATUM(n))
+
+/* To access options from opclass support functions use this: */
+#define PG_HAS_OPCLASS_OPTIONS()	has_fn_opclass_options(fcinfo->flinfo)
+#define PG_GET_OPCLASS_OPTIONS()	get_fn_opclass_options(fcinfo->flinfo)
+
+/* To return a NULL do this: */
+#define PG_RETURN_NULL()  \
+	do { fcinfo->isnull = true; return (Datum) 0; } while (0)
+
+/* A few internal functions return void (which is not the same as NULL!) */
+#define PG_RETURN_VOID()	 return (Datum) 0
+
+/* Macros for returning results of standard types */
+
+#define PG_RETURN_DATUM(x)	 return (x)
+#define PG_RETURN_INT32(x)	 return Int32GetDatum(x)
+#define PG_RETURN_UINT32(x)  return UInt32GetDatum(x)
+#define PG_RETURN_INT16(x)	 return Int16GetDatum(x)
+#define PG_RETURN_UINT16(x)  return UInt16GetDatum(x)
+#define PG_RETURN_CHAR(x)	 return CharGetDatum(x)
+#define PG_RETURN_BOOL(x)	 return BoolGetDatum(x)
+#define PG_RETURN_OID(x)	 return ObjectIdGetDatum(x)
+#define PG_RETURN_POINTER(x) return PointerGetDatum(x)
+#define PG_RETURN_CSTRING(x) return CStringGetDatum(x)
+#define PG_RETURN_NAME(x)	 return NameGetDatum(x)
+#define PG_RETURN_TRANSACTIONID(x)	return TransactionIdGetDatum(x)
+/* these macros hide the pass-by-reference-ness of the datatype: */
+#define PG_RETURN_FLOAT4(x)  return Float4GetDatum(x)
+#define PG_RETURN_FLOAT8(x)  return Float8GetDatum(x)
+#define PG_RETURN_INT64(x)	 return Int64GetDatum(x)
+#define PG_RETURN_UINT64(x)  return UInt64GetDatum(x)
+/* RETURN macros for other pass-by-ref types will typically look like this: */
+#define PG_RETURN_BYTEA_P(x)   PG_RETURN_POINTER(x)
+#define PG_RETURN_TEXT_P(x)    PG_RETURN_POINTER(x)
+#define PG_RETURN_BPCHAR_P(x)  PG_RETURN_POINTER(x)
+#define PG_RETURN_VARCHAR_P(x) PG_RETURN_POINTER(x)
+#define PG_RETURN_HEAPTUPLEHEADER(x)  return HeapTupleHeaderGetDatum(x)
+
+
+/*-------------------------------------------------------------------------
+ *		Support for detecting call convention of dynamically-loaded functions
+ *
+ * Dynamically loaded functions currently can only use the version-1 ("new
+ * style") calling convention.  Version-0 ("old style") is not supported
+ * anymore.  Version 1 is the call convention defined in this header file, and
+ * must be accompanied by the macro call
+ *
+ *		PG_FUNCTION_INFO_V1(function_name);
+ *
+ * Note that internal functions do not need this decoration since they are
+ * assumed to be version-1.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+typedef struct
+{
+	int			api_version;	/* specifies call convention version number */
+	/* More fields may be added later, for version numbers > 1. */
+} Pg_finfo_record;
+
+/* Expected signature of an info function */
+typedef const Pg_finfo_record *(*PGFInfoFunction) (void);
+
+/*
+ *	Macro to build an info function associated with the given function name.
+ *
+ *	As a convenience, also provide an "extern" declaration for the given
+ *	function name, so that writers of C functions need not write that too.
+ *
+ *	On Windows, the function and info function must be exported.  Our normal
+ *	build processes take care of that via .DEF files or --export-all-symbols.
+ *	Module authors using a different build process might need to manually
+ *	declare the function PGDLLEXPORT.  We do that automatically here for the
+ *	info function, since authors shouldn't need to be explicitly aware of it.
+ */
+#define PG_FUNCTION_INFO_V1(funcname) \
+extern Datum funcname(PG_FUNCTION_ARGS); \
+extern PGDLLEXPORT const Pg_finfo_record * CppConcat(pg_finfo_,funcname)(void); \
+const Pg_finfo_record * \
+CppConcat(pg_finfo_,funcname) (void) \
+{ \
+	static const Pg_finfo_record my_finfo = { 1 }; \
+	return &my_finfo; \
+} \
+extern int no_such_variable
+
+
+/*-------------------------------------------------------------------------
+ *		Support for verifying backend compatibility of loaded modules
+ *
+ * We require dynamically-loaded modules to include the macro call
+ *		PG_MODULE_MAGIC;
+ * so that we can check for obvious incompatibility, such as being compiled
+ * for a different major PostgreSQL version.
+ *
+ * To compile with versions of PostgreSQL that do not support this,
+ * you may put an #ifdef/#endif test around it.  Note that in a multiple-
+ * source-file module, the macro call should only appear once.
+ *
+ * The specific items included in the magic block are intended to be ones that
+ * are custom-configurable and especially likely to break dynamically loaded
+ * modules if they were compiled with other values.  Also, the length field
+ * can be used to detect definition changes.
+ *
+ * Note: we compare magic blocks with memcmp(), so there had better not be
+ * any alignment pad bytes in them.
+ *
+ * Note: when changing the contents of magic blocks, be sure to adjust the
+ * incompatible_module_error() function in dfmgr.c.
+ *-------------------------------------------------------------------------
+ */
+
+/* Definition of the magic block structure */
+typedef struct
+{
+	int			len;			/* sizeof(this struct) */
+	int			version;		/* PostgreSQL major version */
+	int			funcmaxargs;	/* FUNC_MAX_ARGS */
+	int			indexmaxkeys;	/* INDEX_MAX_KEYS */
+	int			namedatalen;	/* NAMEDATALEN */
+	int			float8byval;	/* FLOAT8PASSBYVAL */
+	char		abi_extra[32];	/* see pg_config_manual.h */
+} Pg_magic_struct;
+
+/* The actual data block contents */
+#define PG_MODULE_MAGIC_DATA \
+{ \
+	sizeof(Pg_magic_struct), \
+	PG_VERSION_NUM / 100, \
+	FUNC_MAX_ARGS, \
+	INDEX_MAX_KEYS, \
+	NAMEDATALEN, \
+	FLOAT8PASSBYVAL, \
+	FMGR_ABI_EXTRA, \
+}
+
+StaticAssertDecl(sizeof(FMGR_ABI_EXTRA) <= sizeof(((Pg_magic_struct *) 0)->abi_extra),
+				 "FMGR_ABI_EXTRA too long");
+
+/*
+ * Declare the module magic function.  It needs to be a function as the dlsym
+ * in the backend is only guaranteed to work on functions, not data
+ */
+typedef const Pg_magic_struct *(*PGModuleMagicFunction) (void);
+
+#define PG_MAGIC_FUNCTION_NAME Pg_magic_func
+#define PG_MAGIC_FUNCTION_NAME_STRING "Pg_magic_func"
+
+#define PG_MODULE_MAGIC \
+extern PGDLLEXPORT const Pg_magic_struct *PG_MAGIC_FUNCTION_NAME(void); \
+const Pg_magic_struct * \
+PG_MAGIC_FUNCTION_NAME(void) \
+{ \
+	static const Pg_magic_struct Pg_magic_data = PG_MODULE_MAGIC_DATA; \
+	return &Pg_magic_data; \
+} \
+extern int no_such_variable
+
+
+/*-------------------------------------------------------------------------
+ *		Support routines and macros for callers of fmgr-compatible functions
+ *-------------------------------------------------------------------------
+ */
+
+/* These are for invocation of a specifically named function with a
+ * directly-computed parameter list.  Note that neither arguments nor result
+ * are allowed to be NULL.  Also, the function cannot be one that needs to
+ * look at FmgrInfo, since there won't be any.
+ */
+extern Datum DirectFunctionCall1Coll(PGFunction func, Oid collation,
+									 Datum arg1);
+extern Datum DirectFunctionCall2Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2);
+extern Datum DirectFunctionCall3Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2,
+									 Datum arg3);
+extern Datum DirectFunctionCall4Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2,
+									 Datum arg3, Datum arg4);
+extern Datum DirectFunctionCall5Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2,
+									 Datum arg3, Datum arg4, Datum arg5);
+extern Datum DirectFunctionCall6Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2,
+									 Datum arg3, Datum arg4, Datum arg5,
+									 Datum arg6);
+extern Datum DirectFunctionCall7Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2,
+									 Datum arg3, Datum arg4, Datum arg5,
+									 Datum arg6, Datum arg7);
+extern Datum DirectFunctionCall8Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2,
+									 Datum arg3, Datum arg4, Datum arg5,
+									 Datum arg6, Datum arg7, Datum arg8);
+extern Datum DirectFunctionCall9Coll(PGFunction func, Oid collation,
+									 Datum arg1, Datum arg2,
+									 Datum arg3, Datum arg4, Datum arg5,
+									 Datum arg6, Datum arg7, Datum arg8,
+									 Datum arg9);
+
+/*
+ * These functions work like the DirectFunctionCall functions except that
+ * they use the flinfo parameter to initialise the fcinfo for the call.
+ * It's recommended that the callee only use the fn_extra and fn_mcxt
+ * fields, as other fields will typically describe the calling function
+ * not the callee.  Conversely, the calling function should not have
+ * used fn_extra, unless its use is known to be compatible with the callee's.
+ */
+extern Datum CallerFInfoFunctionCall1(PGFunction func, FmgrInfo *flinfo,
+									  Oid collation, Datum arg1);
+extern Datum CallerFInfoFunctionCall2(PGFunction func, FmgrInfo *flinfo,
+									  Oid collation, Datum arg1, Datum arg2);
+
+/* These are for invocation of a previously-looked-up function with a
+ * directly-computed parameter list.  Note that neither arguments nor result
+ * are allowed to be NULL.
+ */
+extern Datum FunctionCall0Coll(FmgrInfo *flinfo, Oid collation);
+extern Datum FunctionCall1Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1);
+extern Datum FunctionCall2Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2);
+extern Datum FunctionCall3Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2,
+							   Datum arg3);
+extern Datum FunctionCall4Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2,
+							   Datum arg3, Datum arg4);
+extern Datum FunctionCall5Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2,
+							   Datum arg3, Datum arg4, Datum arg5);
+extern Datum FunctionCall6Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2,
+							   Datum arg3, Datum arg4, Datum arg5,
+							   Datum arg6);
+extern Datum FunctionCall7Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2,
+							   Datum arg3, Datum arg4, Datum arg5,
+							   Datum arg6, Datum arg7);
+extern Datum FunctionCall8Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2,
+							   Datum arg3, Datum arg4, Datum arg5,
+							   Datum arg6, Datum arg7, Datum arg8);
+extern Datum FunctionCall9Coll(FmgrInfo *flinfo, Oid collation,
+							   Datum arg1, Datum arg2,
+							   Datum arg3, Datum arg4, Datum arg5,
+							   Datum arg6, Datum arg7, Datum arg8,
+							   Datum arg9);
+
+/* These are for invocation of a function identified by OID with a
+ * directly-computed parameter list.  Note that neither arguments nor result
+ * are allowed to be NULL.  These are essentially fmgr_info() followed by
+ * FunctionCallN().  If the same function is to be invoked repeatedly, do the
+ * fmgr_info() once and then use FunctionCallN().
+ */
+extern Datum OidFunctionCall0Coll(Oid functionId, Oid collation);
+extern Datum OidFunctionCall1Coll(Oid functionId, Oid collation,
+								  Datum arg1);
+extern Datum OidFunctionCall2Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2);
+extern Datum OidFunctionCall3Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2,
+								  Datum arg3);
+extern Datum OidFunctionCall4Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2,
+								  Datum arg3, Datum arg4);
+extern Datum OidFunctionCall5Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2,
+								  Datum arg3, Datum arg4, Datum arg5);
+extern Datum OidFunctionCall6Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2,
+								  Datum arg3, Datum arg4, Datum arg5,
+								  Datum arg6);
+extern Datum OidFunctionCall7Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2,
+								  Datum arg3, Datum arg4, Datum arg5,
+								  Datum arg6, Datum arg7);
+extern Datum OidFunctionCall8Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2,
+								  Datum arg3, Datum arg4, Datum arg5,
+								  Datum arg6, Datum arg7, Datum arg8);
+extern Datum OidFunctionCall9Coll(Oid functionId, Oid collation,
+								  Datum arg1, Datum arg2,
+								  Datum arg3, Datum arg4, Datum arg5,
+								  Datum arg6, Datum arg7, Datum arg8,
+								  Datum arg9);
+
+/* These macros allow the collation argument to be omitted (with a default of
+ * InvalidOid, ie, no collation).  They exist mostly for backwards
+ * compatibility of source code.
+ */
+#define DirectFunctionCall1(func, arg1) \
+	DirectFunctionCall1Coll(func, InvalidOid, arg1)
+#define DirectFunctionCall2(func, arg1, arg2) \
+	DirectFunctionCall2Coll(func, InvalidOid, arg1, arg2)
+#define DirectFunctionCall3(func, arg1, arg2, arg3) \
+	DirectFunctionCall3Coll(func, InvalidOid, arg1, arg2, arg3)
+#define DirectFunctionCall4(func, arg1, arg2, arg3, arg4) \
+	DirectFunctionCall4Coll(func, InvalidOid, arg1, arg2, arg3, arg4)
+#define DirectFunctionCall5(func, arg1, arg2, arg3, arg4, arg5) \
+	DirectFunctionCall5Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5)
+#define DirectFunctionCall6(func, arg1, arg2, arg3, arg4, arg5, arg6) \
+	DirectFunctionCall6Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6)
+#define DirectFunctionCall7(func, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
+	DirectFunctionCall7Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7)
+#define DirectFunctionCall8(func, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
+	DirectFunctionCall8Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8)
+#define DirectFunctionCall9(func, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \
+	DirectFunctionCall9Coll(func, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9)
+#define FunctionCall1(flinfo, arg1) \
+	FunctionCall1Coll(flinfo, InvalidOid, arg1)
+#define FunctionCall2(flinfo, arg1, arg2) \
+	FunctionCall2Coll(flinfo, InvalidOid, arg1, arg2)
+#define FunctionCall3(flinfo, arg1, arg2, arg3) \
+	FunctionCall3Coll(flinfo, InvalidOid, arg1, arg2, arg3)
+#define FunctionCall4(flinfo, arg1, arg2, arg3, arg4) \
+	FunctionCall4Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4)
+#define FunctionCall5(flinfo, arg1, arg2, arg3, arg4, arg5) \
+	FunctionCall5Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5)
+#define FunctionCall6(flinfo, arg1, arg2, arg3, arg4, arg5, arg6) \
+	FunctionCall6Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6)
+#define FunctionCall7(flinfo, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
+	FunctionCall7Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7)
+#define FunctionCall8(flinfo, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
+	FunctionCall8Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8)
+#define FunctionCall9(flinfo, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \
+	FunctionCall9Coll(flinfo, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9)
+#define OidFunctionCall0(functionId) \
+	OidFunctionCall0Coll(functionId, InvalidOid)
+#define OidFunctionCall1(functionId, arg1) \
+	OidFunctionCall1Coll(functionId, InvalidOid, arg1)
+#define OidFunctionCall2(functionId, arg1, arg2) \
+	OidFunctionCall2Coll(functionId, InvalidOid, arg1, arg2)
+#define OidFunctionCall3(functionId, arg1, arg2, arg3) \
+	OidFunctionCall3Coll(functionId, InvalidOid, arg1, arg2, arg3)
+#define OidFunctionCall4(functionId, arg1, arg2, arg3, arg4) \
+	OidFunctionCall4Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4)
+#define OidFunctionCall5(functionId, arg1, arg2, arg3, arg4, arg5) \
+	OidFunctionCall5Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5)
+#define OidFunctionCall6(functionId, arg1, arg2, arg3, arg4, arg5, arg6) \
+	OidFunctionCall6Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6)
+#define OidFunctionCall7(functionId, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
+	OidFunctionCall7Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7)
+#define OidFunctionCall8(functionId, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
+	OidFunctionCall8Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8)
+#define OidFunctionCall9(functionId, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) \
+	OidFunctionCall9Coll(functionId, InvalidOid, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9)
+
+
+/* Special cases for convenient invocation of datatype I/O functions. */
+extern Datum InputFunctionCall(FmgrInfo *flinfo, char *str,
+							   Oid typioparam, int32 typmod);
+extern Datum OidInputFunctionCall(Oid functionId, char *str,
+								  Oid typioparam, int32 typmod);
+extern char *OutputFunctionCall(FmgrInfo *flinfo, Datum val);
+extern char *OidOutputFunctionCall(Oid functionId, Datum val);
+extern Datum ReceiveFunctionCall(FmgrInfo *flinfo, fmStringInfo buf,
+								 Oid typioparam, int32 typmod);
+extern Datum OidReceiveFunctionCall(Oid functionId, fmStringInfo buf,
+									Oid typioparam, int32 typmod);
+extern bytea *SendFunctionCall(FmgrInfo *flinfo, Datum val);
+extern bytea *OidSendFunctionCall(Oid functionId, Datum val);
+
+
+/*
+ * Routines in fmgr.c
+ */
+extern const Pg_finfo_record *fetch_finfo_record(void *filehandle, const char *funcname);
+extern Oid	fmgr_internal_function(const char *proname);
+extern Oid	get_fn_expr_rettype(FmgrInfo *flinfo);
+extern Oid	get_fn_expr_argtype(FmgrInfo *flinfo, int argnum);
+extern Oid	get_call_expr_argtype(fmNodePtr expr, int argnum);
+extern bool get_fn_expr_arg_stable(FmgrInfo *flinfo, int argnum);
+extern bool get_call_expr_arg_stable(fmNodePtr expr, int argnum);
+extern bool get_fn_expr_variadic(FmgrInfo *flinfo);
+extern bytea *get_fn_opclass_options(FmgrInfo *flinfo);
+extern bool has_fn_opclass_options(FmgrInfo *flinfo);
+extern void set_fn_opclass_options(FmgrInfo *flinfo, bytea *options);
+extern bool CheckFunctionValidatorAccess(Oid validatorOid, Oid functionOid);
+
+/*
+ * Routines in dfmgr.c
+ */
+extern PGDLLIMPORT char *Dynamic_library_path;
+
+extern void *load_external_function(const char *filename, const char *funcname,
+									bool signalNotFound, void **filehandle);
+extern void *lookup_external_function(void *filehandle, const char *funcname);
+extern void load_file(const char *filename, bool restricted);
+extern void **find_rendezvous_variable(const char *varName);
+extern Size EstimateLibraryStateSpace(void);
+extern void SerializeLibraryState(Size maxsize, char *start_address);
+extern void RestoreLibraryState(char *start_address);
+
+/*
+ * Support for aggregate functions
+ *
+ * These are actually in executor/nodeAgg.c, but we declare them here since
+ * the whole point is for callers to not be overly friendly with nodeAgg.
+ */
+
+/* AggCheckCallContext can return one of the following codes, or 0: */
+#define AGG_CONTEXT_AGGREGATE	1	/* regular aggregate */
+#define AGG_CONTEXT_WINDOW		2	/* window function */
+
+extern int	AggCheckCallContext(FunctionCallInfo fcinfo,
+								MemoryContext *aggcontext);
+extern fmAggrefPtr AggGetAggref(FunctionCallInfo fcinfo);
+extern MemoryContext AggGetTempMemoryContext(FunctionCallInfo fcinfo);
+extern bool AggStateIsShared(FunctionCallInfo fcinfo);
+extern void AggRegisterCallback(FunctionCallInfo fcinfo,
+								fmExprContextCallbackFunction func,
+								Datum arg);
+
+/*
+ * We allow plugin modules to hook function entry/exit.  This is intended
+ * as support for loadable security policy modules, which may want to
+ * perform additional privilege checks on function entry or exit, or to do
+ * other internal bookkeeping.  To make this possible, such modules must be
+ * able not only to support normal function entry and exit, but also to trap
+ * the case where we bail out due to an error; and they must also be able to
+ * prevent inlining.
+ */
+typedef enum FmgrHookEventType
+{
+	FHET_START,
+	FHET_END,
+	FHET_ABORT
+} FmgrHookEventType;
+
+typedef bool (*needs_fmgr_hook_type) (Oid fn_oid);
+
+typedef void (*fmgr_hook_type) (FmgrHookEventType event,
+								FmgrInfo *flinfo, Datum *arg);
+
+extern PGDLLIMPORT needs_fmgr_hook_type needs_fmgr_hook;
+extern PGDLLIMPORT fmgr_hook_type fmgr_hook;
+
+#define FmgrHookIsNeeded(fn_oid)							\
+	(!needs_fmgr_hook ? false : (*needs_fmgr_hook)(fn_oid))
+
+#endif							/* FMGR_H */