outfuncs.c

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/*-------------------------------------------------------------------------
 *
 * outfuncs.c
 *    Output functions for Postgres tree nodes.
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/nodes/outfuncs.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
 
#include <ctype.h>
 
#include "access/attnum.h"
#include "common/shortest_dec.h"
#include "lib/stringinfo.h"
#include "miscadmin.h"
#include "nodes/bitmapset.h"
#include "nodes/nodes.h"
#include "nodes/pg_list.h"
#include "utils/datum.h"
 
/* State flag that determines how nodeToStringInternal() should treat location fields */
static bool write_location_fields = false;
 
static void outChar(StringInfo str, char c);
static void outDouble(StringInfo str, double d);
 
 
/*
 * Macros to simplify output of different kinds of fields.  Use these
 * wherever possible to reduce the chance for silly typos.  Note that these
 * hard-wire conventions about the names of the local variables in an Out
 * routine.
 */
 
/* Write the label for the node type */
#define WRITE_NODE_TYPE(nodelabel) \
    appendStringInfoString(str, nodelabel)
 
/* Write an integer field (anything written as ":fldname %d") */
#define WRITE_INT_FIELD(fldname) \
    appendStringInfo(str, " :" CppAsString(fldname) " %d", node->fldname)
 
/* Write an unsigned integer field (anything written as ":fldname %u") */
#define WRITE_UINT_FIELD(fldname) \
    appendStringInfo(str, " :" CppAsString(fldname) " %u", node->fldname)
 
/* Write an unsigned integer field (anything written with UINT64_FORMAT) */
#define WRITE_UINT64_FIELD(fldname) \
    appendStringInfo(str, " :" CppAsString(fldname) " " UINT64_FORMAT, \
                     node->fldname)
 
/* Write an OID field (don't hard-wire assumption that OID is same as uint) */
#define WRITE_OID_FIELD(fldname) \
    appendStringInfo(str, " :" CppAsString(fldname) " %u", node->fldname)
 
/* Write a long-integer field */
#define WRITE_LONG_FIELD(fldname) \
    appendStringInfo(str, " :" CppAsString(fldname) " %ld", node->fldname)
 
/* Write a char field (ie, one ascii character) */
#define WRITE_CHAR_FIELD(fldname) \
    (appendStringInfo(str, " :" CppAsString(fldname) " "), \
     outChar(str, node->fldname))
 
/* Write an enumerated-type field as an integer code */
#define WRITE_ENUM_FIELD(fldname, enumtype) \
    appendStringInfo(str, " :" CppAsString(fldname) " %d", \
                     (int) node->fldname)
 
/* Write a float field (actually, they're double) */
#define WRITE_FLOAT_FIELD(fldname) \
    (appendStringInfo(str, " :" CppAsString(fldname) " "), \
     outDouble(str, node->fldname))
 
/* Write a boolean field */
#define WRITE_BOOL_FIELD(fldname) \
    appendStringInfo(str, " :" CppAsString(fldname) " %s", \
                     booltostr(node->fldname))
 
/* Write a character-string (possibly NULL) field */
#define WRITE_STRING_FIELD(fldname) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     outToken(str, node->fldname))
 
/* Write a parse location field (actually same as INT case) */
#define WRITE_LOCATION_FIELD(fldname) \
    appendStringInfo(str, " :" CppAsString(fldname) " %d", write_location_fields ? node->fldname : -1)
 
/* Write a Node field */
#define WRITE_NODE_FIELD(fldname) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     outNode(str, node->fldname))
 
/* Write a bitmapset field */
#define WRITE_BITMAPSET_FIELD(fldname) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     outBitmapset(str, node->fldname))
 
/* Write a variable-length array (not a List) of Node pointers */
#define WRITE_NODE_ARRAY(fldname, len) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     writeNodeArray(str, (const Node * const *) node->fldname, len))
 
/* Write a variable-length array of AttrNumber */
#define WRITE_ATTRNUMBER_ARRAY(fldname, len) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     writeAttrNumberCols(str, node->fldname, len))
 
/* Write a variable-length array of Oid */
#define WRITE_OID_ARRAY(fldname, len) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     writeOidCols(str, node->fldname, len))
 
/* Write a variable-length array of Index */
#define WRITE_INDEX_ARRAY(fldname, len) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     writeIndexCols(str, node->fldname, len))
 
/* Write a variable-length array of int */
#define WRITE_INT_ARRAY(fldname, len) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     writeIntCols(str, node->fldname, len))
 
/* Write a variable-length array of bool */
#define WRITE_BOOL_ARRAY(fldname, len) \
    (appendStringInfoString(str, " :" CppAsString(fldname) " "), \
     writeBoolCols(str, node->fldname, len))
 
#define booltostr(x)  ((x) ? "true" : "false")
 
 
/*
 * outToken
 *    Convert an ordinary string (eg, an identifier) into a form that
 *    will be decoded back to a plain token by read.c's functions.
 *
 *    If a null string pointer is given, it is encoded as '<>'.
 *    An empty string is encoded as '""'.  To avoid ambiguity, input
 *    strings beginning with '<' or '"' receive a leading backslash.
 */
void
outToken(StringInfo str, const char *s)
{
    if (s == NULL)
    {
        appendStringInfoString(str, "<>");
        return;
    }
    if (*s == '\0')
    {
        appendStringInfoString(str, "\"\"");
        return;
    }
 
    /*
     * Look for characters or patterns that are treated specially by read.c
     * (either in pg_strtok() or in nodeRead()), and therefore need a
     * protective backslash.
     */
    /* These characters only need to be quoted at the start of the string */
    if (*s == '<' ||
        *s == '"' ||
        isdigit((unsigned char) *s) ||
        ((*s == '+' || *s == '-') &&
         (isdigit((unsigned char) s[1]) || s[1] == '.')))
        appendStringInfoChar(str, '\\');
    while (*s)
    {
        /* These chars must be backslashed anywhere in the string */
        if (*s == ' ' || *s == '\n' || *s == '\t' ||
            *s == '(' || *s == ')' || *s == '{' || *s == '}' ||
            *s == '\\')
            appendStringInfoChar(str, '\\');
        appendStringInfoChar(str, *s++);
    }
}
 
/*
 * Convert one char.  Goes through outToken() so that special characters are
 * escaped.
 */
static void
outChar(StringInfo str, char c)
{
    char        in[2];
 
    /* Traditionally, we've represented \0 as <>, so keep doing that */
    if (c == '\0')
    {
        appendStringInfoString(str, "<>");
        return;
    }
 
    in[0] = c;
    in[1] = '\0';
 
    outToken(str, in);
}
 
/*
 * Convert a double value, attempting to ensure the value is preserved exactly.
 */
static void
outDouble(StringInfo str, double d)
{
    char        buf[DOUBLE_SHORTEST_DECIMAL_LEN];
 
    double_to_shortest_decimal_buf(d, buf);
    appendStringInfoString(str, buf);
}
 
/*
 * common implementation for scalar-array-writing functions
 *
 * The data format is either "<>" for a NULL pointer or "(item item item)".
 * fmtstr must include a leading space, and the rest of it must produce
 * something that will be seen as a single simple token by pg_strtok().
 * convfunc can be empty, or the name of a conversion macro or function.
 */
#define WRITE_SCALAR_ARRAY(fnname, datatype, fmtstr, convfunc) \
static void \
fnname(StringInfo str, const datatype *arr, int len) \
{ \
    if (arr != NULL) \
    { \
        appendStringInfoChar(str, '('); \
        for (int i = 0; i < len; i++) \
            appendStringInfo(str, fmtstr, convfunc(arr[i])); \
        appendStringInfoChar(str, ')'); \
    } \
    else \
        appendStringInfoString(str, "<>"); \
}
 
WRITE_SCALAR_ARRAY(writeAttrNumberCols, AttrNumber, " %d",)
WRITE_SCALAR_ARRAY(writeOidCols, Oid, " %u",)
WRITE_SCALAR_ARRAY(writeIndexCols, Index, " %u",)
WRITE_SCALAR_ARRAY(writeIntCols, int, " %d",)
WRITE_SCALAR_ARRAY(writeBoolCols, bool, " %s", booltostr)
 
/*
 * Print an array (not a List) of Node pointers.
 *
 * The decoration is identical to that of scalar arrays, but we can't
 * quite use appendStringInfo() in the loop.
 */
static void
writeNodeArray(StringInfo str, const Node *const *arr, int len)
{
    if (arr != NULL)
    {
        appendStringInfoChar(str, '(');
        for (int i = 0; i < len; i++)
        {
            appendStringInfoChar(str, ' ');
            outNode(str, arr[i]);
        }
        appendStringInfoChar(str, ')');
    }
    else
        appendStringInfoString(str, "<>");
}
 
/*
 * Print a List.
 */
static void
_outList(StringInfo str, const List *node)
{
    const ListCell *lc;
 
    appendStringInfoChar(str, '(');
 
    if (IsA(node, IntList))
        appendStringInfoChar(str, 'i');
    else if (IsA(node, OidList))
        appendStringInfoChar(str, 'o');
    else if (IsA(node, XidList))
        appendStringInfoChar(str, 'x');
 
    foreach(lc, node)
    {
        /*
         * For the sake of backward compatibility, we emit a slightly
         * different whitespace format for lists of nodes vs. other types of
         * lists. XXX: is this necessary?
         */
        if (IsA(node, List))
        {
            outNode(str, lfirst(lc));
            if (lnext(node, lc))
                appendStringInfoChar(str, ' ');
        }
        else if (IsA(node, IntList))
            appendStringInfo(str, " %d", lfirst_int(lc));
        else if (IsA(node, OidList))
            appendStringInfo(str, " %u", lfirst_oid(lc));
        else if (IsA(node, XidList))
            appendStringInfo(str, " %u", lfirst_xid(lc));
        else
            elog(ERROR, "unrecognized list node type: %d",
                 (int) node->type);
    }
 
    appendStringInfoChar(str, ')');
}
 
/*
 * outBitmapset -
 *     converts a bitmap set of integers
 *
 * Note: the output format is "(b int int ...)", similar to an integer List.
 *
 * We export this function for use by extensions that define extensible nodes.
 * That's somewhat historical, though, because calling outNode() will work.
 */
void
outBitmapset(StringInfo str, const Bitmapset *bms)
{
    int         x;
 
    appendStringInfoChar(str, '(');
    appendStringInfoChar(str, 'b');
    x = -1;
    while ((x = bms_next_member(bms, x)) >= 0)
        appendStringInfo(str, " %d", x);
    appendStringInfoChar(str, ')');
}
 
/*
 * Print the value of a Datum given its type.
 */
void
outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
{
    Size        length,
                i;
    char       *s;
 
    length = datumGetSize(value, typbyval, typlen);
 
    if (typbyval)
    {
        s = (char *) (&value);
        appendStringInfo(str, "%u [ ", (unsigned int) length);
        for (i = 0; i < (Size) sizeof(Datum); i++)
            appendStringInfo(str, "%d ", (int) (s[i]));
        appendStringInfoChar(str, ']');
    }
    else
    {
        s = (char *) DatumGetPointer(value);
        if (!PointerIsValid(s))
            appendStringInfoString(str, "0 [ ]");
        else
        {
            appendStringInfo(str, "%u [ ", (unsigned int) length);
            for (i = 0; i < length; i++)
                appendStringInfo(str, "%d ", (int) (s[i]));
            appendStringInfoChar(str, ']');
        }
    }
}
 
 
#include "outfuncs.funcs.c"
 
 
/*
 * Support functions for nodes with custom_read_write attribute or
 * special_read_write attribute
 */
 
static void
_outConst(StringInfo str, const Const *node)
{
    WRITE_NODE_TYPE("CONST");
 
    WRITE_OID_FIELD(consttype);
    WRITE_INT_FIELD(consttypmod);
    WRITE_OID_FIELD(constcollid);
    WRITE_INT_FIELD(constlen);
    WRITE_BOOL_FIELD(constbyval);
    WRITE_BOOL_FIELD(constisnull);
    WRITE_LOCATION_FIELD(location);
 
    appendStringInfoString(str, " :constvalue ");
    if (node->constisnull)
        appendStringInfoString(str, "<>");
    else
        outDatum(str, node->constvalue, node->constlen, node->constbyval);
}
 
static void
_outBoolExpr(StringInfo str, const BoolExpr *node)
{
    char       *opstr = NULL;
 
    WRITE_NODE_TYPE("BOOLEXPR");
 
    /* do-it-yourself enum representation */
    switch (node->boolop)
    {
        case AND_EXPR:
            opstr = "and";
            break;
        case OR_EXPR:
            opstr = "or";
            break;
        case NOT_EXPR:
            opstr = "not";
            break;
    }
    appendStringInfoString(str, " :boolop ");
    outToken(str, opstr);
 
    WRITE_NODE_FIELD(args);
    WRITE_LOCATION_FIELD(location);
}
 
static void
_outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
{
    int         i;
 
    WRITE_NODE_TYPE("FOREIGNKEYOPTINFO");
 
    WRITE_UINT_FIELD(con_relid);
    WRITE_UINT_FIELD(ref_relid);
    WRITE_INT_FIELD(nkeys);
    WRITE_ATTRNUMBER_ARRAY(conkey, node->nkeys);
    WRITE_ATTRNUMBER_ARRAY(confkey, node->nkeys);
    WRITE_OID_ARRAY(conpfeqop, node->nkeys);
    WRITE_INT_FIELD(nmatched_ec);
    WRITE_INT_FIELD(nconst_ec);
    WRITE_INT_FIELD(nmatched_rcols);
    WRITE_INT_FIELD(nmatched_ri);
    /* for compactness, just print the number of matches per column: */
    appendStringInfoString(str, " :eclass");
    for (i = 0; i < node->nkeys; i++)
        appendStringInfo(str, " %d", (node->eclass[i] != NULL));
    appendStringInfoString(str, " :rinfos");
    for (i = 0; i < node->nkeys; i++)
        appendStringInfo(str, " %d", list_length(node->rinfos[i]));
}
 
static void
_outEquivalenceClass(StringInfo str, const EquivalenceClass *node)
{
    /*
     * To simplify reading, we just chase up to the topmost merged EC and
     * print that, without bothering to show the merge-ees separately.
     */
    while (node->ec_merged)
        node = node->ec_merged;
 
    WRITE_NODE_TYPE("EQUIVALENCECLASS");
 
    WRITE_NODE_FIELD(ec_opfamilies);
    WRITE_OID_FIELD(ec_collation);
    WRITE_NODE_FIELD(ec_members);
    WRITE_NODE_FIELD(ec_sources);
    WRITE_NODE_FIELD(ec_derives);
    WRITE_BITMAPSET_FIELD(ec_relids);
    WRITE_BOOL_FIELD(ec_has_const);
    WRITE_BOOL_FIELD(ec_has_volatile);
    WRITE_BOOL_FIELD(ec_broken);
    WRITE_UINT_FIELD(ec_sortref);
    WRITE_UINT_FIELD(ec_min_security);
    WRITE_UINT_FIELD(ec_max_security);
}
 
static void
_outExtensibleNode(StringInfo str, const ExtensibleNode *node)
{
    const ExtensibleNodeMethods *methods;
 
    methods = GetExtensibleNodeMethods(node->extnodename, false);
 
    WRITE_NODE_TYPE("EXTENSIBLENODE");
 
    WRITE_STRING_FIELD(extnodename);
 
    /* serialize the private fields */
    methods->nodeOut(str, node);
}
 
static void
_outRangeTblEntry(StringInfo str, const RangeTblEntry *node)
{
    WRITE_NODE_TYPE("RANGETBLENTRY");
 
    WRITE_NODE_FIELD(alias);
    WRITE_NODE_FIELD(eref);
    WRITE_ENUM_FIELD(rtekind, RTEKind);
 
    switch (node->rtekind)
    {
        case RTE_RELATION:
            WRITE_OID_FIELD(relid);
            WRITE_BOOL_FIELD(inh);
            WRITE_CHAR_FIELD(relkind);
            WRITE_INT_FIELD(rellockmode);
            WRITE_UINT_FIELD(perminfoindex);
            WRITE_NODE_FIELD(tablesample);
            break;
        case RTE_SUBQUERY:
            WRITE_NODE_FIELD(subquery);
            WRITE_BOOL_FIELD(security_barrier);
            /* we re-use these RELATION fields, too: */
            WRITE_OID_FIELD(relid);
            WRITE_BOOL_FIELD(inh);
            WRITE_CHAR_FIELD(relkind);
            WRITE_INT_FIELD(rellockmode);
            WRITE_UINT_FIELD(perminfoindex);
            break;
        case RTE_JOIN:
            WRITE_ENUM_FIELD(jointype, JoinType);
            WRITE_INT_FIELD(joinmergedcols);
            WRITE_NODE_FIELD(joinaliasvars);
            WRITE_NODE_FIELD(joinleftcols);
            WRITE_NODE_FIELD(joinrightcols);
            WRITE_NODE_FIELD(join_using_alias);
            break;
        case RTE_FUNCTION:
            WRITE_NODE_FIELD(functions);
            WRITE_BOOL_FIELD(funcordinality);
            break;
        case RTE_TABLEFUNC:
            WRITE_NODE_FIELD(tablefunc);
            break;
        case RTE_VALUES:
            WRITE_NODE_FIELD(values_lists);
            WRITE_NODE_FIELD(coltypes);
            WRITE_NODE_FIELD(coltypmods);
            WRITE_NODE_FIELD(colcollations);
            break;
        case RTE_CTE:
            WRITE_STRING_FIELD(ctename);
            WRITE_UINT_FIELD(ctelevelsup);
            WRITE_BOOL_FIELD(self_reference);
            WRITE_NODE_FIELD(coltypes);
            WRITE_NODE_FIELD(coltypmods);
            WRITE_NODE_FIELD(colcollations);
            break;
        case RTE_NAMEDTUPLESTORE:
            WRITE_STRING_FIELD(enrname);
            WRITE_FLOAT_FIELD(enrtuples);
            WRITE_NODE_FIELD(coltypes);
            WRITE_NODE_FIELD(coltypmods);
            WRITE_NODE_FIELD(colcollations);
            /* we re-use these RELATION fields, too: */
            WRITE_OID_FIELD(relid);
            break;
        case RTE_RESULT:
            /* no extra fields */
            break;
        case RTE_GROUP:
            WRITE_NODE_FIELD(groupexprs);
            break;
        default:
            elog(ERROR, "unrecognized RTE kind: %d", (int) node->rtekind);
            break;
    }
 
    WRITE_BOOL_FIELD(lateral);
    WRITE_BOOL_FIELD(inFromCl);
    WRITE_NODE_FIELD(securityQuals);
}
 
static void
_outA_Expr(StringInfo str, const A_Expr *node)
{
    WRITE_NODE_TYPE("A_EXPR");
 
    switch (node->kind)
    {
        case AEXPR_OP:
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_OP_ANY:
            appendStringInfoString(str, " ANY");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_OP_ALL:
            appendStringInfoString(str, " ALL");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_DISTINCT:
            appendStringInfoString(str, " DISTINCT");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_NOT_DISTINCT:
            appendStringInfoString(str, " NOT_DISTINCT");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_NULLIF:
            appendStringInfoString(str, " NULLIF");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_IN:
            appendStringInfoString(str, " IN");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_LIKE:
            appendStringInfoString(str, " LIKE");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_ILIKE:
            appendStringInfoString(str, " ILIKE");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_SIMILAR:
            appendStringInfoString(str, " SIMILAR");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_BETWEEN:
            appendStringInfoString(str, " BETWEEN");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_NOT_BETWEEN:
            appendStringInfoString(str, " NOT_BETWEEN");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_BETWEEN_SYM:
            appendStringInfoString(str, " BETWEEN_SYM");
            WRITE_NODE_FIELD(name);
            break;
        case AEXPR_NOT_BETWEEN_SYM:
            appendStringInfoString(str, " NOT_BETWEEN_SYM");
            WRITE_NODE_FIELD(name);
            break;
        default:
            elog(ERROR, "unrecognized A_Expr_Kind: %d", (int) node->kind);
            break;
    }
 
    WRITE_NODE_FIELD(lexpr);
    WRITE_NODE_FIELD(rexpr);
    WRITE_LOCATION_FIELD(location);
}
 
static void
_outInteger(StringInfo str, const Integer *node)
{
    appendStringInfo(str, "%d", node->ival);
}
 
static void
_outFloat(StringInfo str, const Float *node)
{
    /*
     * We assume the value is a valid numeric literal and so does not need
     * quoting.
     */
    appendStringInfoString(str, node->fval);
}
 
static void
_outBoolean(StringInfo str, const Boolean *node)
{
    appendStringInfoString(str, node->boolval ? "true" : "false");
}
 
static void
_outString(StringInfo str, const String *node)
{
    /*
     * We use outToken to provide escaping of the string's content, but we
     * don't want it to convert an empty string to '""', because we're putting
     * double quotes around the string already.
     */
    appendStringInfoChar(str, '"');
    if (node->sval[0] != '\0')
        outToken(str, node->sval);
    appendStringInfoChar(str, '"');
}
 
static void
_outBitString(StringInfo str, const BitString *node)
{
    /*
     * The lexer will always produce a string starting with 'b' or 'x'.  There
     * might be characters following that that need escaping, but outToken
     * won't escape the 'b' or 'x'.  This is relied on by nodeTokenType.
     */
    Assert(node->bsval[0] == 'b' || node->bsval[0] == 'x');
    outToken(str, node->bsval);
}
 
static void
_outA_Const(StringInfo str, const A_Const *node)
{
    WRITE_NODE_TYPE("A_CONST");
 
    if (node->isnull)
        appendStringInfoString(str, " NULL");
    else
    {
        appendStringInfoString(str, " :val ");
        outNode(str, &node->val);
    }
    WRITE_LOCATION_FIELD(location);
}
 
 
/*
 * outNode -
 *    converts a Node into ascii string and append it to 'str'
 */
void
outNode(StringInfo str, const void *obj)
{
    /* Guard against stack overflow due to overly complex expressions */
    check_stack_depth();
 
    if (obj == NULL)
        appendStringInfoString(str, "<>");
    else if (IsA(obj, List) || IsA(obj, IntList) || IsA(obj, OidList) ||
             IsA(obj, XidList))
        _outList(str, obj);
    /* nodeRead does not want to see { } around these! */
    else if (IsA(obj, Integer))
        _outInteger(str, (Integer *) obj);
    else if (IsA(obj, Float))
        _outFloat(str, (Float *) obj);
    else if (IsA(obj, Boolean))
        _outBoolean(str, (Boolean *) obj);
    else if (IsA(obj, String))
        _outString(str, (String *) obj);
    else if (IsA(obj, BitString))
        _outBitString(str, (BitString *) obj);
    else if (IsA(obj, Bitmapset))
        outBitmapset(str, (Bitmapset *) obj);
    else
    {
        appendStringInfoChar(str, '{');
        switch (nodeTag(obj))
        {
#include "outfuncs.switch.c"
 
            default:
 
                /*
                 * This should be an ERROR, but it's too useful to be able to
                 * dump structures that outNode only understands part of.
                 */
                elog(WARNING, "could not dump unrecognized node type: %d",
                     (int) nodeTag(obj));
                break;
        }
        appendStringInfoChar(str, '}');
    }
}
 
/*
 * nodeToString -
 *     returns the ascii representation of the Node as a palloc'd string
 *
 * write_loc_fields determines whether location fields are output with their
 * actual value rather than -1.  The actual value can be useful for debugging,
 * but for most uses, the actual value is not useful, since the original query
 * string is no longer available.
 */
static char *
nodeToStringInternal(const void *obj, bool write_loc_fields)
{
    StringInfoData str;
    bool        save_write_location_fields;
 
    save_write_location_fields = write_location_fields;
    write_location_fields = write_loc_fields;
 
    /* see stringinfo.h for an explanation of this maneuver */
    initStringInfo(&str);
    outNode(&str, obj);
 
    write_location_fields = save_write_location_fields;
 
    return str.data;
}
 
/*
 * Externally visible entry points
 */
char *
nodeToString(const void *obj)
{
    return nodeToStringInternal(obj, false);
}
 
char *
nodeToStringWithLocations(const void *obj)
{
    return nodeToStringInternal(obj, true);
}
 
 
/*
 * bmsToString -
 *     returns the ascii representation of the Bitmapset as a palloc'd string
 */
char *
bmsToString(const Bitmapset *bms)
{
    StringInfoData str;
 
    /* see stringinfo.h for an explanation of this maneuver */
    initStringInfo(&str);
    outBitmapset(&str, bms);
    return str.data;
}