define.c

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/*-------------------------------------------------------------------------
 *
 * define.c
 *    Support routines for various kinds of object creation.
 *
 *
 * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/commands/define.c
 *
 * DESCRIPTION
 *    The "DefineFoo" routines take the parse tree and pick out the
 *    appropriate arguments/flags, passing the results to the
 *    corresponding "FooDefine" routines (in src/catalog) that do
 *    the actual catalog-munging.  These routines also verify permission
 *    of the user to execute the command.
 *
 * NOTES
 *    These things must be defined and committed in the following order:
 *      "create function":
 *              input/output, recv/send procedures
 *      "create type":
 *              type
 *      "create operator":
 *              operators
 *
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include <ctype.h>
#include <math.h>

#include "catalog/namespace.h"
#include "commands/defrem.h"
#include "nodes/makefuncs.h"
#include "parser/parse_type.h"
#include "parser/scansup.h"
#include "utils/builtins.h"

/*
 * Extract a string value (otherwise uninterpreted) from a DefElem.
 */
char *
defGetString(DefElem *def)
{
    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires a parameter",
                        def->defname)));
    switch (nodeTag(def->arg))
    {
        case T_Integer:
            return psprintf("%ld", (long) intVal(def->arg));
        case T_Float:

            /*
             * T_Float values are kept in string form, so this type cheat
             * works (and doesn't risk losing precision)
             */
            return strVal(def->arg);
        case T_String:
            return strVal(def->arg);
        case T_TypeName:
            return TypeNameToString((TypeName *) def->arg);
        case T_List:
            return NameListToString((List *) def->arg);
        case T_A_Star:
            return pstrdup("*");
        default:
            elog(ERROR, "unrecognized node type: %d", (int) nodeTag(def->arg));
    }
    return NULL;                /* keep compiler quiet */
}

/*
 * Extract a numeric value (actually double) from a DefElem.
 */
double
defGetNumeric(DefElem *def)
{
    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires a numeric value",
                        def->defname)));
    switch (nodeTag(def->arg))
    {
        case T_Integer:
            return (double) intVal(def->arg);
        case T_Float:
            return floatVal(def->arg);
        default:
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("%s requires a numeric value",
                            def->defname)));
    }
    return 0;                   /* keep compiler quiet */
}

/*
 * Extract a boolean value from a DefElem.
 */
bool
defGetBoolean(DefElem *def)
{
    /*
     * If no parameter given, assume "true" is meant.
     */
    if (def->arg == NULL)
        return true;

    /*
     * Allow 0, 1, "true", "false", "on", "off"
     */
    switch (nodeTag(def->arg))
    {
        case T_Integer:
            switch (intVal(def->arg))
            {
                case 0:
                    return false;
                case 1:
                    return true;
                default:
                    /* otherwise, error out below */
                    break;
            }
            break;
        default:
            {
                char       *sval = defGetString(def);

                /*
                 * The set of strings accepted here should match up with the
                 * grammar's opt_boolean_or_string production.
                 */
                if (pg_strcasecmp(sval, "true") == 0)
                    return true;
                if (pg_strcasecmp(sval, "false") == 0)
                    return false;
                if (pg_strcasecmp(sval, "on") == 0)
                    return true;
                if (pg_strcasecmp(sval, "off") == 0)
                    return false;
            }
            break;
    }
    ereport(ERROR,
            (errcode(ERRCODE_SYNTAX_ERROR),
             errmsg("%s requires a Boolean value",
                    def->defname)));
    return false;               /* keep compiler quiet */
}

/*
 * Extract an int32 value from a DefElem.
 */
int32
defGetInt32(DefElem *def)
{
    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires an integer value",
                        def->defname)));
    switch (nodeTag(def->arg))
    {
        case T_Integer:
            return (int32) intVal(def->arg);
        default:
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("%s requires an integer value",
                            def->defname)));
    }
    return 0;                   /* keep compiler quiet */
}

/*
 * Extract an int64 value from a DefElem.
 */
int64
defGetInt64(DefElem *def)
{
    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires a numeric value",
                        def->defname)));
    switch (nodeTag(def->arg))
    {
        case T_Integer:
            return (int64) intVal(def->arg);
        case T_Float:

            /*
             * Values too large for int4 will be represented as Float
             * constants by the lexer.  Accept these if they are valid int8
             * strings.
             */
            return DatumGetInt64(DirectFunctionCall1(int8in,
                                                     CStringGetDatum(strVal(def->arg))));
        default:
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("%s requires a numeric value",
                            def->defname)));
    }
    return 0;                   /* keep compiler quiet */
}

/*
 * Extract a possibly-qualified name (as a List of Strings) from a DefElem.
 */
List *
defGetQualifiedName(DefElem *def)
{
    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires a parameter",
                        def->defname)));
    switch (nodeTag(def->arg))
    {
        case T_TypeName:
            return ((TypeName *) def->arg)->names;
        case T_List:
            return (List *) def->arg;
        case T_String:
            /* Allow quoted name for backwards compatibility */
            return list_make1(def->arg);
        default:
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("argument of %s must be a name",
                            def->defname)));
    }
    return NIL;                 /* keep compiler quiet */
}

/*
 * Extract a TypeName from a DefElem.
 *
 * Note: we do not accept a List arg here, because the parser will only
 * return a bare List when the name looks like an operator name.
 */
TypeName *
defGetTypeName(DefElem *def)
{
    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires a parameter",
                        def->defname)));
    switch (nodeTag(def->arg))
    {
        case T_TypeName:
            return (TypeName *) def->arg;
        case T_String:
            /* Allow quoted typename for backwards compatibility */
            return makeTypeNameFromNameList(list_make1(def->arg));
        default:
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("argument of %s must be a type name",
                            def->defname)));
    }
    return NULL;                /* keep compiler quiet */
}

/*
 * Extract a type length indicator (either absolute bytes, or
 * -1 for "variable") from a DefElem.
 */
int
defGetTypeLength(DefElem *def)
{
    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires a parameter",
                        def->defname)));
    switch (nodeTag(def->arg))
    {
        case T_Integer:
            return intVal(def->arg);
        case T_Float:
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("%s requires an integer value",
                            def->defname)));
            break;
        case T_String:
            if (pg_strcasecmp(strVal(def->arg), "variable") == 0)
                return -1;      /* variable length */
            break;
        case T_TypeName:
            /* cope if grammar chooses to believe "variable" is a typename */
            if (pg_strcasecmp(TypeNameToString((TypeName *) def->arg),
                              "variable") == 0)
                return -1;      /* variable length */
            break;
        case T_List:
            /* must be an operator name */
            break;
        default:
            elog(ERROR, "unrecognized node type: %d", (int) nodeTag(def->arg));
    }
    ereport(ERROR,
            (errcode(ERRCODE_SYNTAX_ERROR),
             errmsg("invalid argument for %s: \"%s\"",
                    def->defname, defGetString(def))));
    return 0;                   /* keep compiler quiet */
}

/*
 * Extract a list of string values (otherwise uninterpreted) from a DefElem.
 */
List *
defGetStringList(DefElem *def)
{
    ListCell   *cell;

    if (def->arg == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("%s requires a parameter",
                        def->defname)));
    if (nodeTag(def->arg) != T_List)
        elog(ERROR, "unrecognized node type: %d", (int) nodeTag(def->arg));

    foreach(cell, (List *) def->arg)
    {
        Node       *str = (Node *) lfirst(cell);

        if (!IsA(str, String))
            elog(ERROR, "unexpected node type in name list: %d",
                 (int) nodeTag(str));
    }

    return (List *) def->arg;
}