*
* funcapi.c
* Utility and convenience functions for fmgr functions that return
- * sets and/or composite types.
+ * sets and/or composite types, or deal with VARIADIC inputs.
*
- * Copyright (c) 2002-2011, PostgreSQL Global Development Group
+ * Copyright (c) 2002-2019, PostgreSQL Global Development Group
*
* IDENTIFICATION
* src/backend/utils/fmgr/funcapi.c
*/
#include "postgres.h"
-#include "access/heapam.h"
+#include "access/htup_details.h"
+#include "access/relation.h"
#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
+#include "utils/regproc.h"
+#include "utils/rel.h"
#include "utils/syscache.h"
#include "utils/typcache.h"
static void shutdown_MultiFuncCall(Datum arg);
static TypeFuncClass internal_get_result_type(Oid funcid,
- Node *call_expr,
- ReturnSetInfo *rsinfo,
- Oid *resultTypeId,
- TupleDesc *resultTupleDesc);
+ Node *call_expr,
+ ReturnSetInfo *rsinfo,
+ Oid *resultTypeId,
+ TupleDesc *resultTupleDesc);
static bool resolve_polymorphic_tupdesc(TupleDesc tupdesc,
- oidvector *declared_args,
- Node *call_expr);
-static TypeFuncClass get_type_func_class(Oid typid);
+ oidvector *declared_args,
+ Node *call_expr);
+static TypeFuncClass get_type_func_class(Oid typid, Oid *base_typeid);
/*
*/
multi_call_ctx = AllocSetContextCreate(fcinfo->flinfo->fn_mcxt,
"SRF multi-call context",
- ALLOCSET_SMALL_MINSIZE,
- ALLOCSET_SMALL_INITSIZE,
- ALLOCSET_SMALL_MAXSIZE);
+ ALLOCSET_SMALL_SIZES);
/*
* Allocate suitably long-lived space and zero it
*/
retval->call_cntr = 0;
retval->max_calls = 0;
- retval->slot = NULL;
retval->user_fctx = NULL;
retval->attinmeta = NULL;
retval->tuple_desc = NULL;
{
FuncCallContext *retval = (FuncCallContext *) fcinfo->flinfo->fn_extra;
- /*
- * Clear the TupleTableSlot, if present. This is for safety's sake: the
- * Slot will be in a long-lived context (it better be, if the
- * FuncCallContext is pointing to it), but in most usage patterns the
- * tuples stored in it will be in the function's per-tuple context. So at
- * the beginning of each call, the Slot will hold a dangling pointer to an
- * already-recycled tuple. We clear it out here.
- *
- * Note: use of retval->slot is obsolete as of 8.0, and we expect that it
- * will always be NULL. This is just here for backwards compatibility in
- * case someone creates a slot anyway.
- */
- if (retval->slot != NULL)
- ExecClearTuple(retval->slot);
-
return retval;
}
* Given a function's call info record, determine the kind of datatype
* it is supposed to return. If resultTypeId isn't NULL, *resultTypeId
* receives the actual datatype OID (this is mainly useful for scalar
- * result types). If resultTupleDesc isn't NULL, *resultTupleDesc
+ * result types). If resultTupleDesc isn't NULL, *resultTupleDesc
* receives a pointer to a TupleDesc when the result is of a composite
* type, or NULL when it's a scalar result.
*
* One hard case that this handles is resolution of actual rowtypes for
* functions returning RECORD (from either the function's OUT parameter
- * list, or a ReturnSetInfo context node). TYPEFUNC_RECORD is returned
+ * list, or a ReturnSetInfo context node). TYPEFUNC_RECORD is returned
* only when we couldn't resolve the actual rowtype for lack of information.
*
* The other hard case that this handles is resolution of polymorphism.
{
/* handle as a generic expression; no chance to resolve RECORD */
Oid typid = exprType(expr);
+ Oid base_typid;
if (resultTypeId)
*resultTypeId = typid;
if (resultTupleDesc)
*resultTupleDesc = NULL;
- result = get_type_func_class(typid);
- if (result == TYPEFUNC_COMPOSITE && resultTupleDesc)
- *resultTupleDesc = lookup_rowtype_tupdesc_copy(typid, -1);
+ result = get_type_func_class(typid, &base_typid);
+ if ((result == TYPEFUNC_COMPOSITE ||
+ result == TYPEFUNC_COMPOSITE_DOMAIN) &&
+ resultTupleDesc)
+ *resultTupleDesc = lookup_rowtype_tupdesc_copy(base_typid, -1);
}
return result;
/*
* internal_get_result_type -- workhorse code implementing all the above
*
- * funcid must always be supplied. call_expr and rsinfo can be NULL if not
+ * funcid must always be supplied. call_expr and rsinfo can be NULL if not
* available. We will return TYPEFUNC_RECORD, and store NULL into
* *resultTupleDesc, if we cannot deduce the complete result rowtype from
* the available information.
HeapTuple tp;
Form_pg_proc procform;
Oid rettype;
+ Oid base_rettype;
TupleDesc tupdesc;
/* First fetch the function's pg_proc row to inspect its rettype */
*resultTupleDesc = NULL; /* default result */
/* Classify the result type */
- result = get_type_func_class(rettype);
+ result = get_type_func_class(rettype, &base_rettype);
switch (result)
{
case TYPEFUNC_COMPOSITE:
+ case TYPEFUNC_COMPOSITE_DOMAIN:
if (resultTupleDesc)
- *resultTupleDesc = lookup_rowtype_tupdesc_copy(rettype, -1);
+ *resultTupleDesc = lookup_rowtype_tupdesc_copy(base_rettype, -1);
/* Named composite types can't have any polymorphic columns */
break;
case TYPEFUNC_SCALAR:
return result;
}
+/*
+ * get_expr_result_tupdesc
+ * Get a tupdesc describing the result of a composite-valued expression
+ *
+ * If expression is not composite or rowtype can't be determined, returns NULL
+ * if noError is true, else throws error.
+ *
+ * This is a simpler version of get_expr_result_type() for use when the caller
+ * is only interested in determinate rowtype results.
+ */
+TupleDesc
+get_expr_result_tupdesc(Node *expr, bool noError)
+{
+ TupleDesc tupleDesc;
+ TypeFuncClass functypclass;
+
+ functypclass = get_expr_result_type(expr, NULL, &tupleDesc);
+
+ if (functypclass == TYPEFUNC_COMPOSITE ||
+ functypclass == TYPEFUNC_COMPOSITE_DOMAIN)
+ return tupleDesc;
+
+ if (!noError)
+ {
+ Oid exprTypeId = exprType(expr);
+
+ if (exprTypeId != RECORDOID)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("type %s is not composite",
+ format_type_be(exprTypeId))));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("record type has not been registered")));
+ }
+
+ return NULL;
+}
+
/*
* Given the result tuple descriptor for a function with OUT parameters,
* replace any polymorphic columns (ANYELEMENT etc) with correct data types
- * deduced from the input arguments. Returns TRUE if able to deduce all types,
- * FALSE if not.
+ * deduced from the input arguments. Returns true if able to deduce all types,
+ * false if not.
*/
static bool
resolve_polymorphic_tupdesc(TupleDesc tupdesc, oidvector *declared_args,
int nargs = declared_args->dim1;
bool have_anyelement_result = false;
bool have_anyarray_result = false;
+ bool have_anyrange_result = false;
bool have_anynonarray = false;
bool have_anyenum = false;
Oid anyelement_type = InvalidOid;
Oid anyarray_type = InvalidOid;
+ Oid anyrange_type = InvalidOid;
+ Oid anycollation = InvalidOid;
int i;
/* See if there are any polymorphic outputs; quick out if not */
for (i = 0; i < natts; i++)
{
- switch (tupdesc->attrs[i]->atttypid)
+ switch (TupleDescAttr(tupdesc, i)->atttypid)
{
case ANYELEMENTOID:
have_anyelement_result = true;
have_anyelement_result = true;
have_anyenum = true;
break;
+ case ANYRANGEOID:
+ have_anyrange_result = true;
+ break;
default:
break;
}
}
- if (!have_anyelement_result && !have_anyarray_result)
+ if (!have_anyelement_result && !have_anyarray_result &&
+ !have_anyrange_result)
return true;
/*
- * Otherwise, extract actual datatype(s) from input arguments. (We assume
+ * Otherwise, extract actual datatype(s) from input arguments. (We assume
* the parser already validated consistency of the arguments.)
*/
if (!call_expr)
if (!OidIsValid(anyarray_type))
anyarray_type = get_call_expr_argtype(call_expr, i);
break;
+ case ANYRANGEOID:
+ if (!OidIsValid(anyrange_type))
+ anyrange_type = get_call_expr_argtype(call_expr, i);
+ break;
default:
break;
}
}
/* If nothing found, parser messed up */
- if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type))
+ if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
+ !OidIsValid(anyrange_type))
return false;
- /* If needed, deduce one polymorphic type from the other */
+
+ /* If needed, deduce one polymorphic type from others */
if (have_anyelement_result && !OidIsValid(anyelement_type))
- anyelement_type = resolve_generic_type(ANYELEMENTOID,
- anyarray_type,
- ANYARRAYOID);
+ {
+ if (OidIsValid(anyarray_type))
+ anyelement_type = resolve_generic_type(ANYELEMENTOID,
+ anyarray_type,
+ ANYARRAYOID);
+ if (OidIsValid(anyrange_type))
+ {
+ Oid subtype = resolve_generic_type(ANYELEMENTOID,
+ anyrange_type,
+ ANYRANGEOID);
+
+ /* check for inconsistent array and range results */
+ if (OidIsValid(anyelement_type) && anyelement_type != subtype)
+ return false;
+ anyelement_type = subtype;
+ }
+ }
+
if (have_anyarray_result && !OidIsValid(anyarray_type))
anyarray_type = resolve_generic_type(ANYARRAYOID,
anyelement_type,
ANYELEMENTOID);
+ /*
+ * We can't deduce a range type from other polymorphic inputs, because
+ * there may be multiple range types for the same subtype.
+ */
+ if (have_anyrange_result && !OidIsValid(anyrange_type))
+ return false;
+
/* Enforce ANYNONARRAY if needed */
if (have_anynonarray && type_is_array(anyelement_type))
return false;
if (have_anyenum && !type_is_enum(anyelement_type))
return false;
+ /*
+ * Identify the collation to use for polymorphic OUT parameters. (It'll
+ * necessarily be the same for both anyelement and anyarray.) Note that
+ * range types are not collatable, so any possible internal collation of a
+ * range type is not considered here.
+ */
+ if (OidIsValid(anyelement_type))
+ anycollation = get_typcollation(anyelement_type);
+ else if (OidIsValid(anyarray_type))
+ anycollation = get_typcollation(anyarray_type);
+
+ if (OidIsValid(anycollation))
+ {
+ /*
+ * The types are collatable, so consider whether to use a nondefault
+ * collation. We do so if we can identify the input collation used
+ * for the function.
+ */
+ Oid inputcollation = exprInputCollation(call_expr);
+
+ if (OidIsValid(inputcollation))
+ anycollation = inputcollation;
+ }
+
/* And finally replace the tuple column types as needed */
for (i = 0; i < natts; i++)
{
- switch (tupdesc->attrs[i]->atttypid)
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ switch (att->atttypid)
{
case ANYELEMENTOID:
case ANYNONARRAYOID:
case ANYENUMOID:
TupleDescInitEntry(tupdesc, i + 1,
- NameStr(tupdesc->attrs[i]->attname),
+ NameStr(att->attname),
anyelement_type,
-1,
0);
+ TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
break;
case ANYARRAYOID:
TupleDescInitEntry(tupdesc, i + 1,
- NameStr(tupdesc->attrs[i]->attname),
+ NameStr(att->attname),
anyarray_type,
-1,
0);
+ TupleDescInitEntryCollation(tupdesc, i + 1, anycollation);
+ break;
+ case ANYRANGEOID:
+ TupleDescInitEntry(tupdesc, i + 1,
+ NameStr(att->attname),
+ anyrange_type,
+ -1,
+ 0);
+ /* no collation should be attached to a range type */
break;
default:
break;
}
- /* Set collation based on actual argument types */
- TupleDescInitEntryCollation(tupdesc, i + 1,
- exprCollation(call_expr));
}
return true;
/*
* Given the declared argument types and modes for a function, replace any
* polymorphic types (ANYELEMENT etc) with correct data types deduced from the
- * input arguments. Returns TRUE if able to deduce all types, FALSE if not.
+ * input arguments. Returns true if able to deduce all types, false if not.
* This is the same logic as resolve_polymorphic_tupdesc, but with a different
* argument representation.
*
{
bool have_anyelement_result = false;
bool have_anyarray_result = false;
+ bool have_anyrange_result = false;
Oid anyelement_type = InvalidOid;
Oid anyarray_type = InvalidOid;
+ Oid anyrange_type = InvalidOid;
int inargno;
int i;
argtypes[i] = anyarray_type;
}
break;
+ case ANYRANGEOID:
+ if (argmode == PROARGMODE_OUT || argmode == PROARGMODE_TABLE)
+ have_anyrange_result = true;
+ else
+ {
+ if (!OidIsValid(anyrange_type))
+ {
+ anyrange_type = get_call_expr_argtype(call_expr,
+ inargno);
+ if (!OidIsValid(anyrange_type))
+ return false;
+ }
+ argtypes[i] = anyrange_type;
+ }
+ break;
default:
break;
}
}
/* Done? */
- if (!have_anyelement_result && !have_anyarray_result)
+ if (!have_anyelement_result && !have_anyarray_result &&
+ !have_anyrange_result)
return true;
/* If no input polymorphics, parser messed up */
- if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type))
+ if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type) &&
+ !OidIsValid(anyrange_type))
return false;
- /* If needed, deduce one polymorphic type from the other */
+ /* If needed, deduce one polymorphic type from others */
if (have_anyelement_result && !OidIsValid(anyelement_type))
- anyelement_type = resolve_generic_type(ANYELEMENTOID,
- anyarray_type,
- ANYARRAYOID);
+ {
+ if (OidIsValid(anyarray_type))
+ anyelement_type = resolve_generic_type(ANYELEMENTOID,
+ anyarray_type,
+ ANYARRAYOID);
+ if (OidIsValid(anyrange_type))
+ {
+ Oid subtype = resolve_generic_type(ANYELEMENTOID,
+ anyrange_type,
+ ANYRANGEOID);
+
+ /* check for inconsistent array and range results */
+ if (OidIsValid(anyelement_type) && anyelement_type != subtype)
+ return false;
+ anyelement_type = subtype;
+ }
+ }
+
if (have_anyarray_result && !OidIsValid(anyarray_type))
anyarray_type = resolve_generic_type(ANYARRAYOID,
anyelement_type,
ANYELEMENTOID);
+ /*
+ * We can't deduce a range type from other polymorphic inputs, because
+ * there may be multiple range types for the same subtype.
+ */
+ if (have_anyrange_result && !OidIsValid(anyrange_type))
+ return false;
+
/* XXX do we need to enforce ANYNONARRAY or ANYENUM here? I think not */
/* And finally replace the output column types as needed */
case ANYARRAYOID:
argtypes[i] = anyarray_type;
break;
+ case ANYRANGEOID:
+ argtypes[i] = anyrange_type;
+ break;
default:
break;
}
/*
* get_type_func_class
* Given the type OID, obtain its TYPEFUNC classification.
+ * Also, if it's a domain, return the base type OID.
*
* This is intended to centralize a bunch of formerly ad-hoc code for
* classifying types. The categories used here are useful for deciding
* how to handle functions returning the datatype.
*/
static TypeFuncClass
-get_type_func_class(Oid typid)
+get_type_func_class(Oid typid, Oid *base_typeid)
{
+ *base_typeid = typid;
+
switch (get_typtype(typid))
{
case TYPTYPE_COMPOSITE:
return TYPEFUNC_COMPOSITE;
case TYPTYPE_BASE:
- case TYPTYPE_DOMAIN:
case TYPTYPE_ENUM:
+ case TYPTYPE_RANGE:
return TYPEFUNC_SCALAR;
+ case TYPTYPE_DOMAIN:
+ *base_typeid = typid = getBaseType(typid);
+ if (get_typtype(typid) == TYPTYPE_COMPOSITE)
+ return TYPEFUNC_COMPOSITE_DOMAIN;
+ else /* domain base type can't be a pseudotype */
+ return TYPEFUNC_SCALAR;
case TYPTYPE_PSEUDO:
if (typid == RECORDOID)
return TYPEFUNC_RECORD;
* deconstruct_array() since the array data is just going to look like
* a C array of values.
*/
- arr = DatumGetArrayTypeP(proallargtypes); /* ensure not toasted */
+ arr = DatumGetArrayTypeP(proallargtypes); /* ensure not toasted */
numargs = ARR_DIMS(arr)[0];
if (ARR_NDIM(arr) != 1 ||
numargs < 0 ||
return numargs;
}
+/*
+ * get_func_trftypes
+ *
+ * Returns the number of transformed types used by function.
+ */
+int
+get_func_trftypes(HeapTuple procTup,
+ Oid **p_trftypes)
+{
+ Datum protrftypes;
+ ArrayType *arr;
+ int nelems;
+ bool isNull;
+
+ protrftypes = SysCacheGetAttr(PROCOID, procTup,
+ Anum_pg_proc_protrftypes,
+ &isNull);
+ if (!isNull)
+ {
+ /*
+ * We expect the arrays to be 1-D arrays of the right types; verify
+ * that. For the OID and char arrays, we don't need to use
+ * deconstruct_array() since the array data is just going to look like
+ * a C array of values.
+ */
+ arr = DatumGetArrayTypeP(protrftypes); /* ensure not toasted */
+ nelems = ARR_DIMS(arr)[0];
+ if (ARR_NDIM(arr) != 1 ||
+ nelems < 0 ||
+ ARR_HASNULL(arr) ||
+ ARR_ELEMTYPE(arr) != OIDOID)
+ elog(ERROR, "protrftypes is not a 1-D Oid array");
+ Assert(nelems >= ((Form_pg_proc) GETSTRUCT(procTup))->pronargs);
+ *p_trftypes = (Oid *) palloc(nelems * sizeof(Oid));
+ memcpy(*p_trftypes, ARR_DATA_PTR(arr),
+ nelems * sizeof(Oid));
+
+ return nelems;
+ }
+ else
+ return 0;
+}
/*
* get_func_input_arg_names
* For proargmodes, we don't need to use deconstruct_array() since the
* array data is just going to look like a C array of values.
*/
- arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
+ arr = DatumGetArrayTypeP(proargnames); /* ensure not toasted */
if (ARR_NDIM(arr) != 1 ||
ARR_HASNULL(arr) ||
ARR_ELEMTYPE(arr) != TEXTOID)
elog(ERROR, "cache lookup failed for function %u", functionId);
/* If there are no named OUT parameters, return NULL */
- if (heap_attisnull(procTuple, Anum_pg_proc_proargmodes) ||
- heap_attisnull(procTuple, Anum_pg_proc_proargnames))
+ if (heap_attisnull(procTuple, Anum_pg_proc_proargmodes, NULL) ||
+ heap_attisnull(procTuple, Anum_pg_proc_proargnames, NULL))
result = NULL;
else
{
return NULL;
/* If there are no OUT parameters, return NULL */
- if (heap_attisnull(procTuple, Anum_pg_proc_proallargtypes) ||
- heap_attisnull(procTuple, Anum_pg_proc_proargmodes))
+ if (heap_attisnull(procTuple, Anum_pg_proc_proallargtypes, NULL) ||
+ heap_attisnull(procTuple, Anum_pg_proc_proargmodes, NULL))
return NULL;
/* Get the data out of the tuple */
if (isnull)
proargnames = PointerGetDatum(NULL); /* just to be sure */
- return build_function_result_tupdesc_d(proallargtypes,
+ return build_function_result_tupdesc_d(procform->prokind,
+ proallargtypes,
proargmodes,
proargnames);
}
* convenience of ProcedureCreate, which needs to be able to compute the
* tupledesc before actually creating the function.
*
- * Returns NULL if there are not at least two OUT or INOUT arguments.
+ * For functions (but not for procedures), returns NULL if there are not at
+ * least two OUT or INOUT arguments.
*/
TupleDesc
-build_function_result_tupdesc_d(Datum proallargtypes,
+build_function_result_tupdesc_d(char prokind,
+ Datum proallargtypes,
Datum proargmodes,
Datum proargnames)
{
ARR_ELEMTYPE(arr) != OIDOID)
elog(ERROR, "proallargtypes is not a 1-D Oid array");
argtypes = (Oid *) ARR_DATA_PTR(arr);
- arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
+ arr = DatumGetArrayTypeP(proargmodes); /* ensure not toasted */
if (ARR_NDIM(arr) != 1 ||
ARR_DIMS(arr)[0] != numargs ||
ARR_HASNULL(arr) ||
if (pname == NULL || pname[0] == '\0')
{
/* Parameter is not named, so gin up a column name */
- pname = (char *) palloc(32);
- snprintf(pname, 32, "column%d", numoutargs + 1);
+ pname = psprintf("column%d", numoutargs + 1);
}
outargnames[numoutargs] = pname;
numoutargs++;
* If there is no output argument, or only one, the function does not
* return tuples.
*/
- if (numoutargs < 2)
+ if (numoutargs < 2 && prokind != PROKIND_PROCEDURE)
return NULL;
- desc = CreateTemplateTupleDesc(numoutargs, false);
+ desc = CreateTemplateTupleDesc(numoutargs);
for (i = 0; i < numoutargs; i++)
{
TupleDescInitEntry(desc, i + 1,
TupleDesc
TypeGetTupleDesc(Oid typeoid, List *colaliases)
{
- TypeFuncClass functypclass = get_type_func_class(typeoid);
+ Oid base_typeoid;
+ TypeFuncClass functypclass = get_type_func_class(typeoid, &base_typeoid);
TupleDesc tupdesc = NULL;
/*
- * Build a suitable tupledesc representing the output rows
+ * Build a suitable tupledesc representing the output rows. We
+ * intentionally do not support TYPEFUNC_COMPOSITE_DOMAIN here, as it's
+ * unlikely that legacy callers of this obsolete function would be
+ * prepared to apply domain constraints.
*/
if (functypclass == TYPEFUNC_COMPOSITE)
{
/* Composite data type, e.g. a table's row type */
- tupdesc = lookup_rowtype_tupdesc_copy(typeoid, -1);
+ tupdesc = lookup_rowtype_tupdesc_copy(base_typeoid, -1);
if (colaliases != NIL)
{
for (varattno = 0; varattno < natts; varattno++)
{
char *label = strVal(list_nth(colaliases, varattno));
+ Form_pg_attribute attr = TupleDescAttr(tupdesc, varattno);
if (label != NULL)
- namestrcpy(&(tupdesc->attrs[varattno]->attname), label);
+ namestrcpy(&(attr->attname), label);
}
/* The tuple type is now an anonymous record type */
if (list_length(colaliases) != 1)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("number of aliases does not match number of columns")));
+ errmsg("number of aliases does not match number of columns")));
/* OK, get the column alias */
attname = strVal(linitial(colaliases));
- tupdesc = CreateTemplateTupleDesc(1, false);
+ tupdesc = CreateTemplateTupleDesc(1);
TupleDescInitEntry(tupdesc,
(AttrNumber) 1,
attname,
return tupdesc;
}
+
+/*
+ * extract_variadic_args
+ *
+ * Extract a set of argument values, types and NULL markers for a given
+ * input function which makes use of a VARIADIC input whose argument list
+ * depends on the caller context. When doing a VARIADIC call, the caller
+ * has provided one argument made of an array of values, so deconstruct the
+ * array data before using it for the next processing. If no VARIADIC call
+ * is used, just fill in the status data based on all the arguments given
+ * by the caller.
+ *
+ * This function returns the number of arguments generated, or -1 in the
+ * case of "VARIADIC NULL".
+ */
+int
+extract_variadic_args(FunctionCallInfo fcinfo, int variadic_start,
+ bool convert_unknown, Datum **args, Oid **types,
+ bool **nulls)
+{
+ bool variadic = get_fn_expr_variadic(fcinfo->flinfo);
+ Datum *args_res;
+ bool *nulls_res;
+ Oid *types_res;
+ int nargs,
+ i;
+
+ *args = NULL;
+ *types = NULL;
+ *nulls = NULL;
+
+ if (variadic)
+ {
+ ArrayType *array_in;
+ Oid element_type;
+ bool typbyval;
+ char typalign;
+ int16 typlen;
+
+ Assert(PG_NARGS() == variadic_start + 1);
+
+ if (PG_ARGISNULL(variadic_start))
+ return -1;
+
+ array_in = PG_GETARG_ARRAYTYPE_P(variadic_start);
+ element_type = ARR_ELEMTYPE(array_in);
+
+ get_typlenbyvalalign(element_type,
+ &typlen, &typbyval, &typalign);
+ deconstruct_array(array_in, element_type, typlen, typbyval,
+ typalign, &args_res, &nulls_res,
+ &nargs);
+
+ /* All the elements of the array have the same type */
+ types_res = (Oid *) palloc0(nargs * sizeof(Oid));
+ for (i = 0; i < nargs; i++)
+ types_res[i] = element_type;
+ }
+ else
+ {
+ nargs = PG_NARGS() - variadic_start;
+ Assert(nargs > 0);
+ nulls_res = (bool *) palloc0(nargs * sizeof(bool));
+ args_res = (Datum *) palloc0(nargs * sizeof(Datum));
+ types_res = (Oid *) palloc0(nargs * sizeof(Oid));
+
+ for (i = 0; i < nargs; i++)
+ {
+ nulls_res[i] = PG_ARGISNULL(i + variadic_start);
+ types_res[i] = get_fn_expr_argtype(fcinfo->flinfo,
+ i + variadic_start);
+
+ /*
+ * Turn a constant (more or less literal) value that's of unknown
+ * type into text if required. Unknowns come in as a cstring
+ * pointer. Note: for functions declared as taking type "any", the
+ * parser will not do any type conversion on unknown-type literals
+ * (that is, undecorated strings or NULLs).
+ */
+ if (convert_unknown &&
+ types_res[i] == UNKNOWNOID &&
+ get_fn_expr_arg_stable(fcinfo->flinfo, i + variadic_start))
+ {
+ types_res[i] = TEXTOID;
+
+ if (PG_ARGISNULL(i + variadic_start))
+ args_res[i] = (Datum) 0;
+ else
+ args_res[i] =
+ CStringGetTextDatum(PG_GETARG_POINTER(i + variadic_start));
+ }
+ else
+ {
+ /* no conversion needed, just take the datum as given */
+ args_res[i] = PG_GETARG_DATUM(i + variadic_start);
+ }
+
+ if (!OidIsValid(types_res[i]) ||
+ (convert_unknown && types_res[i] == UNKNOWNOID))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not determine data type for argument %d",
+ i + 1)));
+ }
+ }
+
+ /* Fill in results */
+ *args = args_res;
+ *nulls = nulls_res;
+ *types = types_res;
+
+ return nargs;
+}