regproc.c

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/*-------------------------------------------------------------------------
 *
 * regproc.c
 *    Functions for the built-in types regproc, regclass, regtype, etc.
 *
 * These types are all binary-compatible with type Oid, and rely on Oid
 * for comparison and so forth.  Their only interesting behavior is in
 * special I/O conversion routines.
 *
 *
 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/utils/adt/regproc.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
 
#include <ctype.h>
 
#include "access/htup_details.h"
#include "catalog/namespace.h"
#include "catalog/pg_class.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_ts_config.h"
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "lib/stringinfo.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "nodes/miscnodes.h"
#include "parser/parse_type.h"
#include "parser/scansup.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/regproc.h"
#include "utils/syscache.h"
#include "utils/varlena.h"
 
static bool parseNumericOid(char *string, Oid *result, Node *escontext);
static bool parseDashOrOid(char *string, Oid *result, Node *escontext);
static bool parseNameAndArgTypes(const char *string, bool allowNone,
                                 List **names, int *nargs, Oid *argtypes,
                                 Node *escontext);
 
 
/*****************************************************************************
 *   USER I/O ROUTINES                                                       *
 *****************************************************************************/
 
/*
 * regprocin        - converts "proname" to proc OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_proc entry.
 */
Datum
regprocin(PG_FUNCTION_ARGS)
{
    char       *pro_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    RegProcedure result;
    List       *names;
    FuncCandidateList clist;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(pro_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* Else it's a name, possibly schema-qualified */
 
    /*
     * We should never get here in bootstrap mode, as all references should
     * have been resolved by genbki.pl.
     */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regproc values must be OIDs in bootstrap mode");
 
    /*
     * Normal case: parse the name into components and see if it matches any
     * pg_proc entries in the current search path.
     */
    names = stringToQualifiedNameList(pro_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    clist = FuncnameGetCandidates(names, -1, NIL, false, false, false, true);
 
    if (clist == NULL)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_FUNCTION),
                 errmsg("function \"%s\" does not exist", pro_name_or_oid)));
    else if (clist->next != NULL)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_AMBIGUOUS_FUNCTION),
                 errmsg("more than one function named \"%s\"",
                        pro_name_or_oid)));
 
    result = clist->oid;
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regproc   - converts "proname" to proc OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regproc(PG_FUNCTION_ARGS)
{
    char       *pro_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regprocin, pro_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * regprocout       - converts proc OID to "pro_name"
 */
Datum
regprocout(PG_FUNCTION_ARGS)
{
    RegProcedure proid = PG_GETARG_OID(0);
    char       *result;
    HeapTuple   proctup;
 
    if (proid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(proid));
 
    if (HeapTupleIsValid(proctup))
    {
        Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup);
        char       *proname = NameStr(procform->proname);
 
        /*
         * In bootstrap mode, skip the fancy namespace stuff and just return
         * the proc name.  (This path is only needed for debugging output
         * anyway.)
         */
        if (IsBootstrapProcessingMode())
            result = pstrdup(proname);
        else
        {
            char       *nspname;
            FuncCandidateList clist;
 
            /*
             * Would this proc be found (uniquely!) by regprocin? If not,
             * qualify it.
             */
            clist = FuncnameGetCandidates(list_make1(makeString(proname)),
                                          -1, NIL, false, false, false, false);
            if (clist != NULL && clist->next == NULL &&
                clist->oid == proid)
                nspname = NULL;
            else
                nspname = get_namespace_name(procform->pronamespace);
 
            result = quote_qualified_identifier(nspname, proname);
        }
 
        ReleaseSysCache(proctup);
    }
    else
    {
        /* If OID doesn't match any pg_proc entry, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", proid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regprocrecv         - converts external binary format to regproc
 */
Datum
regprocrecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regprocsend         - converts regproc to binary format
 */
Datum
regprocsend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regprocedurein       - converts "proname(args)" to proc OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_proc entry.
 */
Datum
regprocedurein(PG_FUNCTION_ARGS)
{
    char       *pro_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    RegProcedure result;
    List       *names;
    int         nargs;
    Oid         argtypes[FUNC_MAX_ARGS];
    FuncCandidateList clist;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(pro_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regprocedure values must be OIDs in bootstrap mode");
 
    /*
     * Else it's a name and arguments.  Parse the name and arguments, look up
     * potential matches in the current namespace search list, and scan to see
     * which one exactly matches the given argument types.  (There will not be
     * more than one match.)
     */
    if (!parseNameAndArgTypes(pro_name_or_oid, false,
                              &names, &nargs, argtypes,
                              escontext))
        PG_RETURN_NULL();
 
    clist = FuncnameGetCandidates(names, nargs, NIL, false, false,
                                  false, true);
 
    for (; clist; clist = clist->next)
    {
        if (memcmp(clist->args, argtypes, nargs * sizeof(Oid)) == 0)
            break;
    }
 
    if (clist == NULL)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_FUNCTION),
                 errmsg("function \"%s\" does not exist", pro_name_or_oid)));
 
    result = clist->oid;
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regprocedure  - converts "proname(args)" to proc OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regprocedure(PG_FUNCTION_ARGS)
{
    char       *pro_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regprocedurein, pro_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * format_procedure     - converts proc OID to "pro_name(args)"
 *
 * This exports the useful functionality of regprocedureout for use
 * in other backend modules.  The result is a palloc'd string.
 */
char *
format_procedure(Oid procedure_oid)
{
    return format_procedure_extended(procedure_oid, 0);
}
 
char *
format_procedure_qualified(Oid procedure_oid)
{
    return format_procedure_extended(procedure_oid, FORMAT_PROC_FORCE_QUALIFY);
}
 
/*
 * format_procedure_extended - converts procedure OID to "pro_name(args)"
 *
 * This exports the useful functionality of regprocedureout for use
 * in other backend modules.  The result is a palloc'd string, or NULL.
 *
 * Routine to produce regprocedure names; see format_procedure above.
 *
 * The following bits in 'flags' modify the behavior:
 * - FORMAT_PROC_INVALID_AS_NULL
 *          if the procedure OID is invalid or unknown, return NULL instead
 *          of the numeric OID.
 * - FORMAT_PROC_FORCE_QUALIFY
 *          always schema-qualify procedure names, regardless of search_path
 */
char *
format_procedure_extended(Oid procedure_oid, bits16 flags)
{
    char       *result;
    HeapTuple   proctup;
 
    proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(procedure_oid));
 
    if (HeapTupleIsValid(proctup))
    {
        Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup);
        char       *proname = NameStr(procform->proname);
        int         nargs = procform->pronargs;
        int         i;
        char       *nspname;
        StringInfoData buf;
 
        /* XXX no support here for bootstrap mode */
        Assert(!IsBootstrapProcessingMode());
 
        initStringInfo(&buf);
 
        /*
         * Would this proc be found (given the right args) by regprocedurein?
         * If not, or if caller requests it, we need to qualify it.
         */
        if ((flags & FORMAT_PROC_FORCE_QUALIFY) == 0 &&
            FunctionIsVisible(procedure_oid))
            nspname = NULL;
        else
            nspname = get_namespace_name(procform->pronamespace);
 
        appendStringInfo(&buf, "%s(",
                         quote_qualified_identifier(nspname, proname));
        for (i = 0; i < nargs; i++)
        {
            Oid         thisargtype = procform->proargtypes.values[i];
 
            if (i > 0)
                appendStringInfoChar(&buf, ',');
            appendStringInfoString(&buf,
                                   (flags & FORMAT_PROC_FORCE_QUALIFY) != 0 ?
                                   format_type_be_qualified(thisargtype) :
                                   format_type_be(thisargtype));
        }
        appendStringInfoChar(&buf, ')');
 
        result = buf.data;
 
        ReleaseSysCache(proctup);
    }
    else if ((flags & FORMAT_PROC_INVALID_AS_NULL) != 0)
    {
        /* If object is undefined, return NULL as wanted by caller */
        result = NULL;
    }
    else
    {
        /* If OID doesn't match any pg_proc entry, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", procedure_oid);
    }
 
    return result;
}
 
/*
 * Output an objname/objargs representation for the procedure with the
 * given OID.  If it doesn't exist, an error is thrown.
 *
 * This can be used to feed get_object_address.
 */
void
format_procedure_parts(Oid procedure_oid, List **objnames, List **objargs,
                       bool missing_ok)
{
    HeapTuple   proctup;
    Form_pg_proc procform;
    int         nargs;
    int         i;
 
    proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(procedure_oid));
 
    if (!HeapTupleIsValid(proctup))
    {
        if (!missing_ok)
            elog(ERROR, "cache lookup failed for procedure with OID %u", procedure_oid);
        return;
    }
 
    procform = (Form_pg_proc) GETSTRUCT(proctup);
    nargs = procform->pronargs;
 
    *objnames = list_make2(get_namespace_name_or_temp(procform->pronamespace),
                           pstrdup(NameStr(procform->proname)));
    *objargs = NIL;
    for (i = 0; i < nargs; i++)
    {
        Oid         thisargtype = procform->proargtypes.values[i];
 
        *objargs = lappend(*objargs, format_type_be_qualified(thisargtype));
    }
 
    ReleaseSysCache(proctup);
}
 
/*
 * regprocedureout      - converts proc OID to "pro_name(args)"
 */
Datum
regprocedureout(PG_FUNCTION_ARGS)
{
    RegProcedure proid = PG_GETARG_OID(0);
    char       *result;
 
    if (proid == InvalidOid)
        result = pstrdup("-");
    else
        result = format_procedure(proid);
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regprocedurerecv            - converts external binary format to regprocedure
 */
Datum
regprocedurerecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regproceduresend            - converts regprocedure to binary format
 */
Datum
regproceduresend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regoperin        - converts "oprname" to operator OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '0' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_operator entry.
 */
Datum
regoperin(PG_FUNCTION_ARGS)
{
    char       *opr_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
    FuncCandidateList clist;
 
    /* Handle "0" or numeric OID */
    if (parseNumericOid(opr_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* Else it's a name, possibly schema-qualified */
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regoper values must be OIDs in bootstrap mode");
 
    /*
     * Normal case: parse the name into components and see if it matches any
     * pg_operator entries in the current search path.
     */
    names = stringToQualifiedNameList(opr_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    clist = OpernameGetCandidates(names, '\0', true);
 
    if (clist == NULL)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_FUNCTION),
                 errmsg("operator does not exist: %s", opr_name_or_oid)));
    else if (clist->next != NULL)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_AMBIGUOUS_FUNCTION),
                 errmsg("more than one operator named %s",
                        opr_name_or_oid)));
 
    result = clist->oid;
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regoper       - converts "oprname" to operator OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regoper(PG_FUNCTION_ARGS)
{
    char       *opr_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regoperin, opr_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * regoperout       - converts operator OID to "opr_name"
 */
Datum
regoperout(PG_FUNCTION_ARGS)
{
    Oid         oprid = PG_GETARG_OID(0);
    char       *result;
    HeapTuple   opertup;
 
    if (oprid == InvalidOid)
    {
        result = pstrdup("0");
        PG_RETURN_CSTRING(result);
    }
 
    opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(oprid));
 
    if (HeapTupleIsValid(opertup))
    {
        Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup);
        char       *oprname = NameStr(operform->oprname);
 
        /*
         * In bootstrap mode, skip the fancy namespace stuff and just return
         * the oper name.  (This path is only needed for debugging output
         * anyway.)
         */
        if (IsBootstrapProcessingMode())
            result = pstrdup(oprname);
        else
        {
            FuncCandidateList clist;
 
            /*
             * Would this oper be found (uniquely!) by regoperin? If not,
             * qualify it.
             */
            clist = OpernameGetCandidates(list_make1(makeString(oprname)),
                                          '\0', false);
            if (clist != NULL && clist->next == NULL &&
                clist->oid == oprid)
                result = pstrdup(oprname);
            else
            {
                const char *nspname;
 
                nspname = get_namespace_name(operform->oprnamespace);
                nspname = quote_identifier(nspname);
                result = (char *) palloc(strlen(nspname) + strlen(oprname) + 2);
                sprintf(result, "%s.%s", nspname, oprname);
            }
        }
 
        ReleaseSysCache(opertup);
    }
    else
    {
        /*
         * If OID doesn't match any pg_operator entry, return it numerically
         */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", oprid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regoperrecv         - converts external binary format to regoper
 */
Datum
regoperrecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regopersend         - converts regoper to binary format
 */
Datum
regopersend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regoperatorin        - converts "oprname(args)" to operator OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '0' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_operator entry.
 */
Datum
regoperatorin(PG_FUNCTION_ARGS)
{
    char       *opr_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
    int         nargs;
    Oid         argtypes[FUNC_MAX_ARGS];
 
    /* Handle "0" or numeric OID */
    if (parseNumericOid(opr_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regoperator values must be OIDs in bootstrap mode");
 
    /*
     * Else it's a name and arguments.  Parse the name and arguments, look up
     * potential matches in the current namespace search list, and scan to see
     * which one exactly matches the given argument types.  (There will not be
     * more than one match.)
     */
    if (!parseNameAndArgTypes(opr_name_or_oid, true,
                              &names, &nargs, argtypes,
                              escontext))
        PG_RETURN_NULL();
 
    if (nargs == 1)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_PARAMETER),
                 errmsg("missing argument"),
                 errhint("Use NONE to denote the missing argument of a unary operator.")));
    if (nargs != 2)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
                 errmsg("too many arguments"),
                 errhint("Provide two argument types for operator.")));
 
    result = OpernameGetOprid(names, argtypes[0], argtypes[1]);
 
    if (!OidIsValid(result))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_FUNCTION),
                 errmsg("operator does not exist: %s", opr_name_or_oid)));
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regoperator   - converts "oprname(args)" to operator OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regoperator(PG_FUNCTION_ARGS)
{
    char       *opr_name_or_oid = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regoperatorin, opr_name_or_oid,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * format_operator_extended - converts operator OID to "opr_name(args)"
 *
 * This exports the useful functionality of regoperatorout for use
 * in other backend modules.  The result is a palloc'd string, or NULL.
 *
 * The following bits in 'flags' modify the behavior:
 * - FORMAT_OPERATOR_INVALID_AS_NULL
 *          if the operator OID is invalid or unknown, return NULL instead
 *          of the numeric OID.
 * - FORMAT_OPERATOR_FORCE_QUALIFY
 *          always schema-qualify operator names, regardless of search_path
 */
char *
format_operator_extended(Oid operator_oid, bits16 flags)
{
    char       *result;
    HeapTuple   opertup;
 
    opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(operator_oid));
 
    if (HeapTupleIsValid(opertup))
    {
        Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup);
        char       *oprname = NameStr(operform->oprname);
        char       *nspname;
        StringInfoData buf;
 
        /* XXX no support here for bootstrap mode */
        Assert(!IsBootstrapProcessingMode());
 
        initStringInfo(&buf);
 
        /*
         * Would this oper be found (given the right args) by regoperatorin?
         * If not, or if caller explicitly requests it, we need to qualify it.
         */
        if ((flags & FORMAT_OPERATOR_FORCE_QUALIFY) != 0 ||
            !OperatorIsVisible(operator_oid))
        {
            nspname = get_namespace_name(operform->oprnamespace);
            appendStringInfo(&buf, "%s.",
                             quote_identifier(nspname));
        }
 
        appendStringInfo(&buf, "%s(", oprname);
 
        if (operform->oprleft)
            appendStringInfo(&buf, "%s,",
                             (flags & FORMAT_OPERATOR_FORCE_QUALIFY) != 0 ?
                             format_type_be_qualified(operform->oprleft) :
                             format_type_be(operform->oprleft));
        else
            appendStringInfoString(&buf, "NONE,");
 
        if (operform->oprright)
            appendStringInfo(&buf, "%s)",
                             (flags & FORMAT_OPERATOR_FORCE_QUALIFY) != 0 ?
                             format_type_be_qualified(operform->oprright) :
                             format_type_be(operform->oprright));
        else
            appendStringInfoString(&buf, "NONE)");
 
        result = buf.data;
 
        ReleaseSysCache(opertup);
    }
    else if ((flags & FORMAT_OPERATOR_INVALID_AS_NULL) != 0)
    {
        /* If object is undefined, return NULL as wanted by caller */
        result = NULL;
    }
    else
    {
        /*
         * If OID doesn't match any pg_operator entry, return it numerically
         */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", operator_oid);
    }
 
    return result;
}
 
char *
format_operator(Oid operator_oid)
{
    return format_operator_extended(operator_oid, 0);
}
 
char *
format_operator_qualified(Oid operator_oid)
{
    return format_operator_extended(operator_oid,
                                    FORMAT_OPERATOR_FORCE_QUALIFY);
}
 
void
format_operator_parts(Oid operator_oid, List **objnames, List **objargs,
                      bool missing_ok)
{
    HeapTuple   opertup;
    Form_pg_operator oprForm;
 
    opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(operator_oid));
    if (!HeapTupleIsValid(opertup))
    {
        if (!missing_ok)
            elog(ERROR, "cache lookup failed for operator with OID %u",
                 operator_oid);
        return;
    }
 
    oprForm = (Form_pg_operator) GETSTRUCT(opertup);
    *objnames = list_make2(get_namespace_name_or_temp(oprForm->oprnamespace),
                           pstrdup(NameStr(oprForm->oprname)));
    *objargs = NIL;
    if (oprForm->oprleft)
        *objargs = lappend(*objargs,
                           format_type_be_qualified(oprForm->oprleft));
    if (oprForm->oprright)
        *objargs = lappend(*objargs,
                           format_type_be_qualified(oprForm->oprright));
 
    ReleaseSysCache(opertup);
}
 
/*
 * regoperatorout       - converts operator OID to "opr_name(args)"
 */
Datum
regoperatorout(PG_FUNCTION_ARGS)
{
    Oid         oprid = PG_GETARG_OID(0);
    char       *result;
 
    if (oprid == InvalidOid)
        result = pstrdup("0");
    else
        result = format_operator(oprid);
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regoperatorrecv         - converts external binary format to regoperator
 */
Datum
regoperatorrecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regoperatorsend         - converts regoperator to binary format
 */
Datum
regoperatorsend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regclassin       - converts "classname" to class OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_class entry.
 */
Datum
regclassin(PG_FUNCTION_ARGS)
{
    char       *class_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(class_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* Else it's a name, possibly schema-qualified */
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regclass values must be OIDs in bootstrap mode");
 
    /*
     * Normal case: parse the name into components and see if it matches any
     * pg_class entries in the current search path.
     */
    names = stringToQualifiedNameList(class_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    /* We might not even have permissions on this relation; don't lock it. */
    result = RangeVarGetRelid(makeRangeVarFromNameList(names), NoLock, true);
 
    if (!OidIsValid(result))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_TABLE),
                 errmsg("relation \"%s\" does not exist",
                        NameListToString(names))));
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regclass      - converts "classname" to class OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regclass(PG_FUNCTION_ARGS)
{
    char       *class_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regclassin, class_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * regclassout      - converts class OID to "class_name"
 */
Datum
regclassout(PG_FUNCTION_ARGS)
{
    Oid         classid = PG_GETARG_OID(0);
    char       *result;
    HeapTuple   classtup;
 
    if (classid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    classtup = SearchSysCache1(RELOID, ObjectIdGetDatum(classid));
 
    if (HeapTupleIsValid(classtup))
    {
        Form_pg_class classform = (Form_pg_class) GETSTRUCT(classtup);
        char       *classname = NameStr(classform->relname);
 
        /*
         * In bootstrap mode, skip the fancy namespace stuff and just return
         * the class name.  (This path is only needed for debugging output
         * anyway.)
         */
        if (IsBootstrapProcessingMode())
            result = pstrdup(classname);
        else
        {
            char       *nspname;
 
            /*
             * Would this class be found by regclassin? If not, qualify it.
             */
            if (RelationIsVisible(classid))
                nspname = NULL;
            else
                nspname = get_namespace_name(classform->relnamespace);
 
            result = quote_qualified_identifier(nspname, classname);
        }
 
        ReleaseSysCache(classtup);
    }
    else
    {
        /* If OID doesn't match any pg_class entry, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", classid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regclassrecv            - converts external binary format to regclass
 */
Datum
regclassrecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regclasssend            - converts regclass to binary format
 */
Datum
regclasssend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regcollationin       - converts "collationname" to collation OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_collation entry.
 */
Datum
regcollationin(PG_FUNCTION_ARGS)
{
    char       *collation_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(collation_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* Else it's a name, possibly schema-qualified */
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regcollation values must be OIDs in bootstrap mode");
 
    /*
     * Normal case: parse the name into components and see if it matches any
     * pg_collation entries in the current search path.
     */
    names = stringToQualifiedNameList(collation_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    result = get_collation_oid(names, true);
 
    if (!OidIsValid(result))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("collation \"%s\" for encoding \"%s\" does not exist",
                        NameListToString(names), GetDatabaseEncodingName())));
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regcollation      - converts "collationname" to collation OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regcollation(PG_FUNCTION_ARGS)
{
    char       *collation_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regcollationin, collation_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * regcollationout      - converts collation OID to "collation_name"
 */
Datum
regcollationout(PG_FUNCTION_ARGS)
{
    Oid         collationid = PG_GETARG_OID(0);
    char       *result;
    HeapTuple   collationtup;
 
    if (collationid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    collationtup = SearchSysCache1(COLLOID, ObjectIdGetDatum(collationid));
 
    if (HeapTupleIsValid(collationtup))
    {
        Form_pg_collation collationform = (Form_pg_collation) GETSTRUCT(collationtup);
        char       *collationname = NameStr(collationform->collname);
 
        /*
         * In bootstrap mode, skip the fancy namespace stuff and just return
         * the collation name.  (This path is only needed for debugging output
         * anyway.)
         */
        if (IsBootstrapProcessingMode())
            result = pstrdup(collationname);
        else
        {
            char       *nspname;
 
            /*
             * Would this collation be found by regcollationin? If not,
             * qualify it.
             */
            if (CollationIsVisible(collationid))
                nspname = NULL;
            else
                nspname = get_namespace_name(collationform->collnamespace);
 
            result = quote_qualified_identifier(nspname, collationname);
        }
 
        ReleaseSysCache(collationtup);
    }
    else
    {
        /* If OID doesn't match any pg_collation entry, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", collationid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regcollationrecv            - converts external binary format to regcollation
 */
Datum
regcollationrecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regcollationsend            - converts regcollation to binary format
 */
Datum
regcollationsend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regtypein        - converts "typename" to type OID
 *
 * The type name can be specified using the full type syntax recognized by
 * the parser; for example, DOUBLE PRECISION and INTEGER[] will work and be
 * translated to the correct type names.  (We ignore any typmod info
 * generated by the parser, however.)
 *
 * We also accept a numeric OID, for symmetry with the output routine,
 * and for possible use in bootstrap mode.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_type entry.
 */
Datum
regtypein(PG_FUNCTION_ARGS)
{
    char       *typ_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    int32       typmod;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(typ_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* Else it's a type name, possibly schema-qualified or decorated */
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regtype values must be OIDs in bootstrap mode");
 
    /*
     * Normal case: invoke the full parser to deal with special cases such as
     * array syntax.  We don't need to check for parseTypeString failure,
     * since we'll just return anyway.
     */
    (void) parseTypeString(typ_name_or_oid, &result, &typmod, escontext);
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regtype       - converts "typename" to type OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regtype(PG_FUNCTION_ARGS)
{
    char       *typ_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regtypein, typ_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * regtypeout       - converts type OID to "typ_name"
 */
Datum
regtypeout(PG_FUNCTION_ARGS)
{
    Oid         typid = PG_GETARG_OID(0);
    char       *result;
    HeapTuple   typetup;
 
    if (typid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    typetup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
 
    if (HeapTupleIsValid(typetup))
    {
        Form_pg_type typeform = (Form_pg_type) GETSTRUCT(typetup);
 
        /*
         * In bootstrap mode, skip the fancy namespace stuff and just return
         * the type name.  (This path is only needed for debugging output
         * anyway.)
         */
        if (IsBootstrapProcessingMode())
        {
            char       *typname = NameStr(typeform->typname);
 
            result = pstrdup(typname);
        }
        else
            result = format_type_be(typid);
 
        ReleaseSysCache(typetup);
    }
    else
    {
        /* If OID doesn't match any pg_type entry, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", typid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regtyperecv         - converts external binary format to regtype
 */
Datum
regtyperecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regtypesend         - converts regtype to binary format
 */
Datum
regtypesend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regconfigin      - converts "tsconfigname" to tsconfig OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_ts_config entry.
 */
Datum
regconfigin(PG_FUNCTION_ARGS)
{
    char       *cfg_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(cfg_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regconfig values must be OIDs in bootstrap mode");
 
    /*
     * Normal case: parse the name into components and see if it matches any
     * pg_ts_config entries in the current search path.
     */
    names = stringToQualifiedNameList(cfg_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    result = get_ts_config_oid(names, true);
 
    if (!OidIsValid(result))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("text search configuration \"%s\" does not exist",
                        NameListToString(names))));
 
    PG_RETURN_OID(result);
}
 
/*
 * regconfigout     - converts tsconfig OID to "tsconfigname"
 */
Datum
regconfigout(PG_FUNCTION_ARGS)
{
    Oid         cfgid = PG_GETARG_OID(0);
    char       *result;
    HeapTuple   cfgtup;
 
    if (cfgid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    cfgtup = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfgid));
 
    if (HeapTupleIsValid(cfgtup))
    {
        Form_pg_ts_config cfgform = (Form_pg_ts_config) GETSTRUCT(cfgtup);
        char       *cfgname = NameStr(cfgform->cfgname);
        char       *nspname;
 
        /*
         * Would this config be found by regconfigin? If not, qualify it.
         */
        if (TSConfigIsVisible(cfgid))
            nspname = NULL;
        else
            nspname = get_namespace_name(cfgform->cfgnamespace);
 
        result = quote_qualified_identifier(nspname, cfgname);
 
        ReleaseSysCache(cfgtup);
    }
    else
    {
        /* If OID doesn't match any pg_ts_config row, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", cfgid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regconfigrecv           - converts external binary format to regconfig
 */
Datum
regconfigrecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regconfigsend           - converts regconfig to binary format
 */
Datum
regconfigsend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
 
/*
 * regdictionaryin      - converts "tsdictionaryname" to tsdictionary OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_ts_dict entry.
 */
Datum
regdictionaryin(PG_FUNCTION_ARGS)
{
    char       *dict_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(dict_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regdictionary values must be OIDs in bootstrap mode");
 
    /*
     * Normal case: parse the name into components and see if it matches any
     * pg_ts_dict entries in the current search path.
     */
    names = stringToQualifiedNameList(dict_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    result = get_ts_dict_oid(names, true);
 
    if (!OidIsValid(result))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("text search dictionary \"%s\" does not exist",
                        NameListToString(names))));
 
    PG_RETURN_OID(result);
}
 
/*
 * regdictionaryout     - converts tsdictionary OID to "tsdictionaryname"
 */
Datum
regdictionaryout(PG_FUNCTION_ARGS)
{
    Oid         dictid = PG_GETARG_OID(0);
    char       *result;
    HeapTuple   dicttup;
 
    if (dictid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    dicttup = SearchSysCache1(TSDICTOID, ObjectIdGetDatum(dictid));
 
    if (HeapTupleIsValid(dicttup))
    {
        Form_pg_ts_dict dictform = (Form_pg_ts_dict) GETSTRUCT(dicttup);
        char       *dictname = NameStr(dictform->dictname);
        char       *nspname;
 
        /*
         * Would this dictionary be found by regdictionaryin? If not, qualify
         * it.
         */
        if (TSDictionaryIsVisible(dictid))
            nspname = NULL;
        else
            nspname = get_namespace_name(dictform->dictnamespace);
 
        result = quote_qualified_identifier(nspname, dictname);
 
        ReleaseSysCache(dicttup);
    }
    else
    {
        /* If OID doesn't match any pg_ts_dict row, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", dictid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regdictionaryrecv   - converts external binary format to regdictionary
 */
Datum
regdictionaryrecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regdictionarysend   - converts regdictionary to binary format
 */
Datum
regdictionarysend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
/*
 * regrolein    - converts "rolename" to role OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_authid entry.
 */
Datum
regrolein(PG_FUNCTION_ARGS)
{
    char       *role_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(role_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regrole values must be OIDs in bootstrap mode");
 
    /* Normal case: see if the name matches any pg_authid entry. */
    names = stringToQualifiedNameList(role_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    if (list_length(names) != 1)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_INVALID_NAME),
                 errmsg("invalid name syntax")));
 
    result = get_role_oid(strVal(linitial(names)), true);
 
    if (!OidIsValid(result))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("role \"%s\" does not exist",
                        strVal(linitial(names)))));
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regrole       - converts "rolename" to role OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regrole(PG_FUNCTION_ARGS)
{
    char       *role_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regrolein, role_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * regroleout       - converts role OID to "role_name"
 */
Datum
regroleout(PG_FUNCTION_ARGS)
{
    Oid         roleoid = PG_GETARG_OID(0);
    char       *result;
 
    if (roleoid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    result = GetUserNameFromId(roleoid, true);
 
    if (result)
    {
        /* pstrdup is not really necessary, but it avoids a compiler warning */
        result = pstrdup(quote_identifier(result));
    }
    else
    {
        /* If OID doesn't match any role, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", roleoid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regrolerecv - converts external binary format to regrole
 */
Datum
regrolerecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regrolesend - converts regrole to binary format
 */
Datum
regrolesend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
/*
 * regnamespacein       - converts "nspname" to namespace OID
 *
 * We also accept a numeric OID, for symmetry with the output routine.
 *
 * '-' signifies unknown (OID 0).  In all other cases, the input must
 * match an existing pg_namespace entry.
 */
Datum
regnamespacein(PG_FUNCTION_ARGS)
{
    char       *nsp_name_or_oid = PG_GETARG_CSTRING(0);
    Node       *escontext = fcinfo->context;
    Oid         result;
    List       *names;
 
    /* Handle "-" or numeric OID */
    if (parseDashOrOid(nsp_name_or_oid, &result, escontext))
        PG_RETURN_OID(result);
 
    /* The rest of this wouldn't work in bootstrap mode */
    if (IsBootstrapProcessingMode())
        elog(ERROR, "regnamespace values must be OIDs in bootstrap mode");
 
    /* Normal case: see if the name matches any pg_namespace entry. */
    names = stringToQualifiedNameList(nsp_name_or_oid, escontext);
    if (names == NIL)
        PG_RETURN_NULL();
 
    if (list_length(names) != 1)
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_INVALID_NAME),
                 errmsg("invalid name syntax")));
 
    result = get_namespace_oid(strVal(linitial(names)), true);
 
    if (!OidIsValid(result))
        ereturn(escontext, (Datum) 0,
                (errcode(ERRCODE_UNDEFINED_SCHEMA),
                 errmsg("schema \"%s\" does not exist",
                        strVal(linitial(names)))));
 
    PG_RETURN_OID(result);
}
 
/*
 * to_regnamespace      - converts "nspname" to namespace OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regnamespace(PG_FUNCTION_ARGS)
{
    char       *nsp_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
    Datum       result;
    ErrorSaveContext escontext = {T_ErrorSaveContext};
 
    if (!DirectInputFunctionCallSafe(regnamespacein, nsp_name,
                                     InvalidOid, -1,
                                     (Node *) &escontext,
                                     &result))
        PG_RETURN_NULL();
    PG_RETURN_DATUM(result);
}
 
/*
 * regnamespaceout      - converts namespace OID to "nsp_name"
 */
Datum
regnamespaceout(PG_FUNCTION_ARGS)
{
    Oid         nspid = PG_GETARG_OID(0);
    char       *result;
 
    if (nspid == InvalidOid)
    {
        result = pstrdup("-");
        PG_RETURN_CSTRING(result);
    }
 
    result = get_namespace_name(nspid);
 
    if (result)
    {
        /* pstrdup is not really necessary, but it avoids a compiler warning */
        result = pstrdup(quote_identifier(result));
    }
    else
    {
        /* If OID doesn't match any namespace, return it numerically */
        result = (char *) palloc(NAMEDATALEN);
        snprintf(result, NAMEDATALEN, "%u", nspid);
    }
 
    PG_RETURN_CSTRING(result);
}
 
/*
 *      regnamespacerecv    - converts external binary format to regnamespace
 */
Datum
regnamespacerecv(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidrecv, so share code */
    return oidrecv(fcinfo);
}
 
/*
 *      regnamespacesend        - converts regnamespace to binary format
 */
Datum
regnamespacesend(PG_FUNCTION_ARGS)
{
    /* Exactly the same as oidsend, so share code */
    return oidsend(fcinfo);
}
 
/*
 * text_regclass: convert text to regclass
 *
 * This could be replaced by CoerceViaIO, except that we need to treat
 * text-to-regclass as an implicit cast to support legacy forms of nextval()
 * and related functions.
 */
Datum
text_regclass(PG_FUNCTION_ARGS)
{
    text       *relname = PG_GETARG_TEXT_PP(0);
    Oid         result;
    RangeVar   *rv;
 
    rv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
 
    /* We might not even have permissions on this relation; don't lock it. */
    result = RangeVarGetRelid(rv, NoLock, false);
 
    PG_RETURN_OID(result);
}
 
 
/*
 * Given a C string, parse it into a qualified-name list.
 *
 * If escontext is an ErrorSaveContext node, invalid input will be
 * reported there instead of being thrown, and we return NIL.
 * (NIL is not possible as a success return, since empty-input is an error.)
 */
List *
stringToQualifiedNameList(const char *string, Node *escontext)
{
    char       *rawname;
    List       *result = NIL;
    List       *namelist;
    ListCell   *l;
 
    /* We need a modifiable copy of the input string. */
    rawname = pstrdup(string);
 
    if (!SplitIdentifierString(rawname, '.', &namelist))
        ereturn(escontext, NIL,
                (errcode(ERRCODE_INVALID_NAME),
                 errmsg("invalid name syntax")));
 
    if (namelist == NIL)
        ereturn(escontext, NIL,
                (errcode(ERRCODE_INVALID_NAME),
                 errmsg("invalid name syntax")));
 
    foreach(l, namelist)
    {
        char       *curname = (char *) lfirst(l);
 
        result = lappend(result, makeString(pstrdup(curname)));
    }
 
    pfree(rawname);
    list_free(namelist);
 
    return result;
}
 
/*****************************************************************************
 *   SUPPORT ROUTINES                                                        *
 *****************************************************************************/
 
/*
 * Given a C string, see if it is all-digits (and not empty).
 * If so, convert directly to OID and return true.
 * If it is not all-digits, return false.
 *
 * If escontext is an ErrorSaveContext node, any error in oidin() will be
 * reported there instead of being thrown (but we still return true).
 */
static bool
parseNumericOid(char *string, Oid *result, Node *escontext)
{
    if (string[0] >= '0' && string[0] <= '9' &&
        strspn(string, "0123456789") == strlen(string))
    {
        Datum       oid_datum;
 
        /* We need not care here whether oidin() fails or not. */
        (void) DirectInputFunctionCallSafe(oidin, string,
                                           InvalidOid, -1,
                                           escontext,
                                           &oid_datum);
        *result = DatumGetObjectId(oid_datum);
        return true;
    }
 
    /* Prevent uninitialized-variable warnings from stupider compilers. */
    *result = InvalidOid;
    return false;
}
 
/*
 * As above, but also accept "-" as meaning 0 (InvalidOid).
 */
static bool
parseDashOrOid(char *string, Oid *result, Node *escontext)
{
    /* '-' ? */
    if (strcmp(string, "-") == 0)
    {
        *result = InvalidOid;
        return true;
    }
 
    /* Numeric OID? */
    return parseNumericOid(string, result, escontext);
}
 
/*
 * Given a C string, parse it into a qualified function or operator name
 * followed by a parenthesized list of type names.  Reduce the
 * type names to an array of OIDs (returned into *nargs and *argtypes;
 * the argtypes array should be of size FUNC_MAX_ARGS).  The function or
 * operator name is returned to *names as a List of Strings.
 *
 * If allowNone is true, accept "NONE" and return it as InvalidOid (this is
 * for unary operators).
 *
 * Returns true on success, false on failure (the latter only possible
 * if escontext is an ErrorSaveContext node).
 */
static bool
parseNameAndArgTypes(const char *string, bool allowNone, List **names,
                     int *nargs, Oid *argtypes,
                     Node *escontext)
{
    char       *rawname;
    char       *ptr;
    char       *ptr2;
    char       *typename;
    bool        in_quote;
    bool        had_comma;
    int         paren_count;
    Oid         typeid;
    int32       typmod;
 
    /* We need a modifiable copy of the input string. */
    rawname = pstrdup(string);
 
    /* Scan to find the expected left paren; mustn't be quoted */
    in_quote = false;
    for (ptr = rawname; *ptr; ptr++)
    {
        if (*ptr == '"')
            in_quote = !in_quote;
        else if (*ptr == '(' && !in_quote)
            break;
    }
    if (*ptr == '\0')
        ereturn(escontext, false,
                (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
                 errmsg("expected a left parenthesis")));
 
    /* Separate the name and parse it into a list */
    *ptr++ = '\0';
    *names = stringToQualifiedNameList(rawname, escontext);
    if (*names == NIL)
        return false;
 
    /* Check for the trailing right parenthesis and remove it */
    ptr2 = ptr + strlen(ptr);
    while (--ptr2 > ptr)
    {
        if (!scanner_isspace(*ptr2))
            break;
    }
    if (*ptr2 != ')')
        ereturn(escontext, false,
                (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
                 errmsg("expected a right parenthesis")));
 
    *ptr2 = '\0';
 
    /* Separate the remaining string into comma-separated type names */
    *nargs = 0;
    had_comma = false;
 
    for (;;)
    {
        /* allow leading whitespace */
        while (scanner_isspace(*ptr))
            ptr++;
        if (*ptr == '\0')
        {
            /* End of string.  Okay unless we had a comma before. */
            if (had_comma)
                ereturn(escontext, false,
                        (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
                         errmsg("expected a type name")));
            break;
        }
        typename = ptr;
        /* Find end of type name --- end of string or comma */
        /* ... but not a quoted or parenthesized comma */
        in_quote = false;
        paren_count = 0;
        for (; *ptr; ptr++)
        {
            if (*ptr == '"')
                in_quote = !in_quote;
            else if (*ptr == ',' && !in_quote && paren_count == 0)
                break;
            else if (!in_quote)
            {
                switch (*ptr)
                {
                    case '(':
                    case '[':
                        paren_count++;
                        break;
                    case ')':
                    case ']':
                        paren_count--;
                        break;
                }
            }
        }
        if (in_quote || paren_count != 0)
            ereturn(escontext, false,
                    (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
                     errmsg("improper type name")));
 
        ptr2 = ptr;
        if (*ptr == ',')
        {
            had_comma = true;
            *ptr++ = '\0';
        }
        else
        {
            had_comma = false;
            Assert(*ptr == '\0');
        }
        /* Lop off trailing whitespace */
        while (--ptr2 >= typename)
        {
            if (!scanner_isspace(*ptr2))
                break;
            *ptr2 = '\0';
        }
 
        if (allowNone && pg_strcasecmp(typename, "none") == 0)
        {
            /* Special case for NONE */
            typeid = InvalidOid;
            typmod = -1;
        }
        else
        {
            /* Use full parser to resolve the type name */
            if (!parseTypeString(typename, &typeid, &typmod, escontext))
                return false;
        }
        if (*nargs >= FUNC_MAX_ARGS)
            ereturn(escontext, false,
                    (errcode(ERRCODE_TOO_MANY_ARGUMENTS),
                     errmsg("too many arguments")));
 
        argtypes[*nargs] = typeid;
        (*nargs)++;
    }
 
    pfree(rawname);
 
    return true;
}