nbtree: fix read page recheck typo.

[pgsql.git] / src / backend / bootstrap / bootstrap.c

/*-------------------------------------------------------------------------
 *
 * bootstrap.c
 *        routines to support running postgres in 'bootstrap' mode
 *      bootstrap mode is used to create the initial template database
 *
 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *        src/backend/bootstrap/bootstrap.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include <unistd.h>
#include <signal.h>

#include "access/genam.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/tableam.h"
#include "access/toast_compression.h"
#include "access/xact.h"
#include "bootstrap/bootstrap.h"
#include "catalog/index.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
#include "common/link-canary.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "pg_getopt.h"
#include "storage/bufpage.h"
#include "storage/ipc.h"
#include "storage/proc.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/relmapper.h"


static void CheckerModeMain(void);
static void bootstrap_signals(void);
static Form_pg_attribute AllocateAttribute(void);
static void populate_typ_list(void);
static Oid      gettype(char *type);
static void cleanup(void);

/* ----------------
 *              global variables
 * ----------------
 */

Relation        boot_reldesc;           /* current relation descriptor */

Form_pg_attribute attrtypes[MAXATTR];   /* points to attribute info */
int                     numattr;                        /* number of attributes for cur. rel */


/*
 * Basic information associated with each type.  This is used before
 * pg_type is filled, so it has to cover the datatypes used as column types
 * in the core "bootstrapped" catalogs.
 *
 *              XXX several of these input/output functions do catalog scans
 *                      (e.g., F_REGPROCIN scans pg_proc).  this obviously creates some
 *                      order dependencies in the catalog creation process.
 */
struct typinfo
{
        char            name[NAMEDATALEN];
        Oid                     oid;
        Oid                     elem;
        int16           len;
        bool            byval;
        char            align;
        char            storage;
        Oid                     collation;
        Oid                     inproc;
        Oid                     outproc;
};

static const struct typinfo TypInfo[] = {
        {"bool", BOOLOID, 0, 1, true, TYPALIGN_CHAR, TYPSTORAGE_PLAIN, InvalidOid,
        F_BOOLIN, F_BOOLOUT},
        {"bytea", BYTEAOID, 0, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, InvalidOid,
        F_BYTEAIN, F_BYTEAOUT},
        {"char", CHAROID, 0, 1, true, TYPALIGN_CHAR, TYPSTORAGE_PLAIN, InvalidOid,
        F_CHARIN, F_CHAROUT},
        {"int2", INT2OID, 0, 2, true, TYPALIGN_SHORT, TYPSTORAGE_PLAIN, InvalidOid,
        F_INT2IN, F_INT2OUT},
        {"int4", INT4OID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_INT4IN, F_INT4OUT},
        {"float4", FLOAT4OID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_FLOAT4IN, F_FLOAT4OUT},
        {"name", NAMEOID, CHAROID, NAMEDATALEN, false, TYPALIGN_CHAR, TYPSTORAGE_PLAIN, C_COLLATION_OID,
        F_NAMEIN, F_NAMEOUT},
        {"regclass", REGCLASSOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_REGCLASSIN, F_REGCLASSOUT},
        {"regproc", REGPROCOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_REGPROCIN, F_REGPROCOUT},
        {"regtype", REGTYPEOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_REGTYPEIN, F_REGTYPEOUT},
        {"regrole", REGROLEOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_REGROLEIN, F_REGROLEOUT},
        {"regnamespace", REGNAMESPACEOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_REGNAMESPACEIN, F_REGNAMESPACEOUT},
        {"text", TEXTOID, 0, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, DEFAULT_COLLATION_OID,
        F_TEXTIN, F_TEXTOUT},
        {"oid", OIDOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_OIDIN, F_OIDOUT},
        {"tid", TIDOID, 0, 6, false, TYPALIGN_SHORT, TYPSTORAGE_PLAIN, InvalidOid,
        F_TIDIN, F_TIDOUT},
        {"xid", XIDOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_XIDIN, F_XIDOUT},
        {"cid", CIDOID, 0, 4, true, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_CIDIN, F_CIDOUT},
        {"pg_node_tree", PG_NODE_TREEOID, 0, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, DEFAULT_COLLATION_OID,
        F_PG_NODE_TREE_IN, F_PG_NODE_TREE_OUT},
        {"int2vector", INT2VECTOROID, INT2OID, -1, false, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_INT2VECTORIN, F_INT2VECTOROUT},
        {"oidvector", OIDVECTOROID, OIDOID, -1, false, TYPALIGN_INT, TYPSTORAGE_PLAIN, InvalidOid,
        F_OIDVECTORIN, F_OIDVECTOROUT},
        {"_int4", INT4ARRAYOID, INT4OID, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, InvalidOid,
        F_ARRAY_IN, F_ARRAY_OUT},
        {"_text", 1009, TEXTOID, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, DEFAULT_COLLATION_OID,
        F_ARRAY_IN, F_ARRAY_OUT},
        {"_oid", 1028, OIDOID, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, InvalidOid,
        F_ARRAY_IN, F_ARRAY_OUT},
        {"_char", 1002, CHAROID, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, InvalidOid,
        F_ARRAY_IN, F_ARRAY_OUT},
        {"_aclitem", 1034, ACLITEMOID, -1, false, TYPALIGN_INT, TYPSTORAGE_EXTENDED, InvalidOid,
        F_ARRAY_IN, F_ARRAY_OUT}
};

static const int n_types = sizeof(TypInfo) / sizeof(struct typinfo);

struct typmap
{                                                               /* a hack */
        Oid                     am_oid;
        FormData_pg_type am_typ;
};

static List *Typ = NIL;                 /* List of struct typmap* */
static struct typmap *Ap = NULL;

static Datum values[MAXATTR];   /* current row's attribute values */
static bool Nulls[MAXATTR];

static MemoryContext nogc = NULL;       /* special no-gc mem context */

/*
 *      At bootstrap time, we first declare all the indices to be built, and
 *      then build them.  The IndexList structure stores enough information
 *      to allow us to build the indices after they've been declared.
 */

typedef struct _IndexList
{
        Oid                     il_heap;
        Oid                     il_ind;
        IndexInfo  *il_info;
        struct _IndexList *il_next;
} IndexList;

static IndexList *ILHead = NULL;


/*
 * In shared memory checker mode, all we really want to do is create shared
 * memory and semaphores (just to prove we can do it with the current GUC
 * settings).  Since, in fact, that was already done by
 * CreateSharedMemoryAndSemaphores(), we have nothing more to do here.
 */
static void
CheckerModeMain(void)
{
        proc_exit(0);
}

/*
 *       The main entry point for running the backend in bootstrap mode
 *
 *       The bootstrap mode is used to initialize the template database.
 *       The bootstrap backend doesn't speak SQL, but instead expects
 *       commands in a special bootstrap language.
 *
 *       When check_only is true, startup is done only far enough to verify that
 *       the current configuration, particularly the passed in options pertaining
 *       to shared memory sizing, options work (or at least do not cause an error
 *       up to shared memory creation).
 */
void
BootstrapModeMain(int argc, char *argv[], bool check_only)
{
        int                     i;
        char       *progname = argv[0];
        int                     flag;
        char       *userDoption = NULL;
        uint32          bootstrap_data_checksum_version = 0;    /* No checksum */

        Assert(!IsUnderPostmaster);

        InitStandaloneProcess(argv[0]);

        /* Set defaults, to be overridden by explicit options below */
        InitializeGUCOptions();

        /* an initial --boot or --check should be present */
        Assert(argc > 1
                   && (strcmp(argv[1], "--boot") == 0
                           || strcmp(argv[1], "--check") == 0));
        argv++;
        argc--;

        while ((flag = getopt(argc, argv, "B:c:d:D:Fkr:X:-:")) != -1)
        {
                switch (flag)
                {
                        case 'B':
                                SetConfigOption("shared_buffers", optarg, PGC_POSTMASTER, PGC_S_ARGV);
                                break;
                        case 'c':
                        case '-':
                                {
                                        char       *name,
                                                           *value;

                                        ParseLongOption(optarg, &name, &value);
                                        if (!value)
                                        {
                                                if (flag == '-')
                                                        ereport(ERROR,
                                                                        (errcode(ERRCODE_SYNTAX_ERROR),
                                                                         errmsg("--%s requires a value",
                                                                                        optarg)));
                                                else
                                                        ereport(ERROR,
                                                                        (errcode(ERRCODE_SYNTAX_ERROR),
                                                                         errmsg("-c %s requires a value",
                                                                                        optarg)));
                                        }

                                        SetConfigOption(name, value, PGC_POSTMASTER, PGC_S_ARGV);
                                        pfree(name);
                                        pfree(value);
                                        break;
                                }
                        case 'D':
                                userDoption = pstrdup(optarg);
                                break;
                        case 'd':
                                {
                                        /* Turn on debugging for the bootstrap process. */
                                        char       *debugstr;

                                        debugstr = psprintf("debug%s", optarg);
                                        SetConfigOption("log_min_messages", debugstr,
                                                                        PGC_POSTMASTER, PGC_S_ARGV);
                                        SetConfigOption("client_min_messages", debugstr,
                                                                        PGC_POSTMASTER, PGC_S_ARGV);
                                        pfree(debugstr);
                                }
                                break;
                        case 'F':
                                SetConfigOption("fsync", "false", PGC_POSTMASTER, PGC_S_ARGV);
                                break;
                        case 'k':
                                bootstrap_data_checksum_version = PG_DATA_CHECKSUM_VERSION;
                                break;
                        case 'r':
                                strlcpy(OutputFileName, optarg, MAXPGPATH);
                                break;
                        case 'X':
                                SetConfigOption("wal_segment_size", optarg, PGC_INTERNAL, PGC_S_DYNAMIC_DEFAULT);
                                break;
                        default:
                                write_stderr("Try \"%s --help\" for more information.\n",
                                                         progname);
                                proc_exit(1);
                                break;
                }
        }

        if (argc != optind)
        {
                write_stderr("%s: invalid command-line arguments\n", progname);
                proc_exit(1);
        }

        /* Acquire configuration parameters */
        if (!SelectConfigFiles(userDoption, progname))
                proc_exit(1);

        /*
         * Validate we have been given a reasonable-looking DataDir and change
         * into it
         */
        checkDataDir();
        ChangeToDataDir();

        CreateDataDirLockFile(false);

        SetProcessingMode(BootstrapProcessing);
        IgnoreSystemIndexes = true;

        InitializeMaxBackends();

        InitializeFastPathLocks();

        CreateSharedMemoryAndSemaphores();

        /*
         * XXX: It might make sense to move this into its own function at some
         * point. Right now it seems like it'd cause more code duplication than
         * it's worth.
         */
        if (check_only)
        {
                SetProcessingMode(NormalProcessing);
                CheckerModeMain();
                abort();
        }

        /*
         * Do backend-like initialization for bootstrap mode
         */
        InitProcess();

        BaseInit();

        bootstrap_signals();
        BootStrapXLOG(bootstrap_data_checksum_version);

        /*
         * To ensure that src/common/link-canary.c is linked into the backend, we
         * must call it from somewhere.  Here is as good as anywhere.
         */
        if (pg_link_canary_is_frontend())
                elog(ERROR, "backend is incorrectly linked to frontend functions");

        InitPostgres(NULL, InvalidOid, NULL, InvalidOid, 0, NULL);

        /* Initialize stuff for bootstrap-file processing */
        for (i = 0; i < MAXATTR; i++)
        {
                attrtypes[i] = NULL;
                Nulls[i] = false;
        }

        /*
         * Process bootstrap input.
         */
        StartTransactionCommand();
        boot_yyparse();
        CommitTransactionCommand();

        /*
         * We should now know about all mapped relations, so it's okay to write
         * out the initial relation mapping files.
         */
        RelationMapFinishBootstrap();

        /* Clean up and exit */
        cleanup();
        proc_exit(0);
}


/* ----------------------------------------------------------------
 *                                              misc functions
 * ----------------------------------------------------------------
 */

/*
 * Set up signal handling for a bootstrap process
 */
static void
bootstrap_signals(void)
{
        Assert(!IsUnderPostmaster);

        /*
         * We don't actually need any non-default signal handling in bootstrap
         * mode; "curl up and die" is a sufficient response for all these cases.
         * Let's set that handling explicitly, as documentation if nothing else.
         */
        pqsignal(SIGHUP, SIG_DFL);
        pqsignal(SIGINT, SIG_DFL);
        pqsignal(SIGTERM, SIG_DFL);
        pqsignal(SIGQUIT, SIG_DFL);
}

/* ----------------------------------------------------------------
 *                              MANUAL BACKEND INTERACTIVE INTERFACE COMMANDS
 * ----------------------------------------------------------------
 */

/* ----------------
 *              boot_openrel
 *
 * Execute BKI OPEN command.
 * ----------------
 */
void
boot_openrel(char *relname)
{
        int                     i;

        if (strlen(relname) >= NAMEDATALEN)
                relname[NAMEDATALEN - 1] = '\0';

        /*
         * pg_type must be filled before any OPEN command is executed, hence we
         * can now populate Typ if we haven't yet.
         */
        if (Typ == NIL)
                populate_typ_list();

        if (boot_reldesc != NULL)
                closerel(NULL);

        elog(DEBUG4, "open relation %s, attrsize %d",
                 relname, (int) ATTRIBUTE_FIXED_PART_SIZE);

        boot_reldesc = table_openrv(makeRangeVar(NULL, relname, -1), NoLock);
        numattr = RelationGetNumberOfAttributes(boot_reldesc);
        for (i = 0; i < numattr; i++)
        {
                if (attrtypes[i] == NULL)
                        attrtypes[i] = AllocateAttribute();
                memmove((char *) attrtypes[i],
                                (char *) TupleDescAttr(boot_reldesc->rd_att, i),
                                ATTRIBUTE_FIXED_PART_SIZE);

                {
                        Form_pg_attribute at = attrtypes[i];

                        elog(DEBUG4, "create attribute %d name %s len %d num %d type %u",
                                 i, NameStr(at->attname), at->attlen, at->attnum,
                                 at->atttypid);
                }
        }
}

/* ----------------
 *              closerel
 * ----------------
 */
void
closerel(char *relname)
{
        if (relname)
        {
                if (boot_reldesc)
                {
                        if (strcmp(RelationGetRelationName(boot_reldesc), relname) != 0)
                                elog(ERROR, "close of %s when %s was expected",
                                         relname, RelationGetRelationName(boot_reldesc));
                }
                else
                        elog(ERROR, "close of %s before any relation was opened",
                                 relname);
        }

        if (boot_reldesc == NULL)
                elog(ERROR, "no open relation to close");
        else
        {
                elog(DEBUG4, "close relation %s",
                         RelationGetRelationName(boot_reldesc));
                table_close(boot_reldesc, NoLock);
                boot_reldesc = NULL;
        }
}



/* ----------------
 * DEFINEATTR()
 *
 * define a <field,type> pair
 * if there are n fields in a relation to be created, this routine
 * will be called n times
 * ----------------
 */
void
DefineAttr(char *name, char *type, int attnum, int nullness)
{
        Oid                     typeoid;

        if (boot_reldesc != NULL)
        {
                elog(WARNING, "no open relations allowed with CREATE command");
                closerel(NULL);
        }

        if (attrtypes[attnum] == NULL)
                attrtypes[attnum] = AllocateAttribute();
        MemSet(attrtypes[attnum], 0, ATTRIBUTE_FIXED_PART_SIZE);

        namestrcpy(&attrtypes[attnum]->attname, name);
        elog(DEBUG4, "column %s %s", NameStr(attrtypes[attnum]->attname), type);
        attrtypes[attnum]->attnum = attnum + 1;

        typeoid = gettype(type);

        if (Typ != NIL)
        {
                attrtypes[attnum]->atttypid = Ap->am_oid;
                attrtypes[attnum]->attlen = Ap->am_typ.typlen;
                attrtypes[attnum]->attbyval = Ap->am_typ.typbyval;
                attrtypes[attnum]->attalign = Ap->am_typ.typalign;
                attrtypes[attnum]->attstorage = Ap->am_typ.typstorage;
                attrtypes[attnum]->attcompression = InvalidCompressionMethod;
                attrtypes[attnum]->attcollation = Ap->am_typ.typcollation;
                /* if an array type, assume 1-dimensional attribute */
                if (Ap->am_typ.typelem != InvalidOid && Ap->am_typ.typlen < 0)
                        attrtypes[attnum]->attndims = 1;
                else
                        attrtypes[attnum]->attndims = 0;
        }
        else
        {
                attrtypes[attnum]->atttypid = TypInfo[typeoid].oid;
                attrtypes[attnum]->attlen = TypInfo[typeoid].len;
                attrtypes[attnum]->attbyval = TypInfo[typeoid].byval;
                attrtypes[attnum]->attalign = TypInfo[typeoid].align;
                attrtypes[attnum]->attstorage = TypInfo[typeoid].storage;
                attrtypes[attnum]->attcompression = InvalidCompressionMethod;
                attrtypes[attnum]->attcollation = TypInfo[typeoid].collation;
                /* if an array type, assume 1-dimensional attribute */
                if (TypInfo[typeoid].elem != InvalidOid &&
                        attrtypes[attnum]->attlen < 0)
                        attrtypes[attnum]->attndims = 1;
                else
                        attrtypes[attnum]->attndims = 0;
        }

        /*
         * If a system catalog column is collation-aware, force it to use C
         * collation, so that its behavior is independent of the database's
         * collation.  This is essential to allow template0 to be cloned with a
         * different database collation.
         */
        if (OidIsValid(attrtypes[attnum]->attcollation))
                attrtypes[attnum]->attcollation = C_COLLATION_OID;

        attrtypes[attnum]->attcacheoff = -1;
        attrtypes[attnum]->atttypmod = -1;
        attrtypes[attnum]->attislocal = true;

        if (nullness == BOOTCOL_NULL_FORCE_NOT_NULL)
        {
                attrtypes[attnum]->attnotnull = true;
        }
        else if (nullness == BOOTCOL_NULL_FORCE_NULL)
        {
                attrtypes[attnum]->attnotnull = false;
        }
        else
        {
                Assert(nullness == BOOTCOL_NULL_AUTO);

                /*
                 * Mark as "not null" if type is fixed-width and prior columns are
                 * likewise fixed-width and not-null.  This corresponds to case where
                 * column can be accessed directly via C struct declaration.
                 */
                if (attrtypes[attnum]->attlen > 0)
                {
                        int                     i;

                        /* check earlier attributes */
                        for (i = 0; i < attnum; i++)
                        {
                                if (attrtypes[i]->attlen <= 0 ||
                                        !attrtypes[i]->attnotnull)
                                        break;
                        }
                        if (i == attnum)
                                attrtypes[attnum]->attnotnull = true;
                }
        }
}


/* ----------------
 *              InsertOneTuple
 *
 * If objectid is not zero, it is a specific OID to assign to the tuple.
 * Otherwise, an OID will be assigned (if necessary) by heap_insert.
 * ----------------
 */
void
InsertOneTuple(void)
{
        HeapTuple       tuple;
        TupleDesc       tupDesc;
        int                     i;

        elog(DEBUG4, "inserting row with %d columns", numattr);

        tupDesc = CreateTupleDesc(numattr, attrtypes);
        tuple = heap_form_tuple(tupDesc, values, Nulls);
        pfree(tupDesc);                         /* just free's tupDesc, not the attrtypes */

        simple_heap_insert(boot_reldesc, tuple);
        heap_freetuple(tuple);
        elog(DEBUG4, "row inserted");

        /*
         * Reset null markers for next tuple
         */
        for (i = 0; i < numattr; i++)
                Nulls[i] = false;
}

/* ----------------
 *              InsertOneValue
 * ----------------
 */
void
InsertOneValue(char *value, int i)
{
        Oid                     typoid;
        int16           typlen;
        bool            typbyval;
        char            typalign;
        char            typdelim;
        Oid                     typioparam;
        Oid                     typinput;
        Oid                     typoutput;

        Assert(i >= 0 && i < MAXATTR);

        elog(DEBUG4, "inserting column %d value \"%s\"", i, value);

        typoid = TupleDescAttr(boot_reldesc->rd_att, i)->atttypid;

        boot_get_type_io_data(typoid,
                                                  &typlen, &typbyval, &typalign,
                                                  &typdelim, &typioparam,
                                                  &typinput, &typoutput);

        values[i] = OidInputFunctionCall(typinput, value, typioparam, -1);

        /*
         * We use ereport not elog here so that parameters aren't evaluated unless
         * the message is going to be printed, which generally it isn't
         */
        ereport(DEBUG4,
                        (errmsg_internal("inserted -> %s",
                                                         OidOutputFunctionCall(typoutput, values[i]))));
}

/* ----------------
 *              InsertOneNull
 * ----------------
 */
void
InsertOneNull(int i)
{
        elog(DEBUG4, "inserting column %d NULL", i);
        Assert(i >= 0 && i < MAXATTR);
        if (TupleDescAttr(boot_reldesc->rd_att, i)->attnotnull)
                elog(ERROR,
                         "NULL value specified for not-null column \"%s\" of relation \"%s\"",
                         NameStr(TupleDescAttr(boot_reldesc->rd_att, i)->attname),
                         RelationGetRelationName(boot_reldesc));
        values[i] = PointerGetDatum(NULL);
        Nulls[i] = true;
}

/* ----------------
 *              cleanup
 * ----------------
 */
static void
cleanup(void)
{
        if (boot_reldesc != NULL)
                closerel(NULL);
}

/* ----------------
 *              populate_typ_list
 *
 * Load the Typ list by reading pg_type.
 * ----------------
 */
static void
populate_typ_list(void)
{
        Relation        rel;
        TableScanDesc scan;
        HeapTuple       tup;
        MemoryContext old;

        Assert(Typ == NIL);

        rel = table_open(TypeRelationId, NoLock);
        scan = table_beginscan_catalog(rel, 0, NULL);
        old = MemoryContextSwitchTo(TopMemoryContext);
        while ((tup = heap_getnext(scan, ForwardScanDirection)) != NULL)
        {
                Form_pg_type typForm = (Form_pg_type) GETSTRUCT(tup);
                struct typmap *newtyp;

                newtyp = (struct typmap *) palloc(sizeof(struct typmap));
                Typ = lappend(Typ, newtyp);

                newtyp->am_oid = typForm->oid;
                memcpy(&newtyp->am_typ, typForm, sizeof(newtyp->am_typ));
        }
        MemoryContextSwitchTo(old);
        table_endscan(scan);
        table_close(rel, NoLock);
}

/* ----------------
 *              gettype
 *
 * NB: this is really ugly; it will return an integer index into TypInfo[],
 * and not an OID at all, until the first reference to a type not known in
 * TypInfo[].  At that point it will read and cache pg_type in Typ,
 * and subsequently return a real OID (and set the global pointer Ap to
 * point at the found row in Typ).  So caller must check whether Typ is
 * still NIL to determine what the return value is!
 * ----------------
 */
static Oid
gettype(char *type)
{
        if (Typ != NIL)
        {
                ListCell   *lc;

                foreach(lc, Typ)
                {
                        struct typmap *app = lfirst(lc);

                        if (strncmp(NameStr(app->am_typ.typname), type, NAMEDATALEN) == 0)
                        {
                                Ap = app;
                                return app->am_oid;
                        }
                }

                /*
                 * The type wasn't known; reload the pg_type contents and check again
                 * to handle composite types, added since last populating the list.
                 */

                list_free_deep(Typ);
                Typ = NIL;
                populate_typ_list();

                /*
                 * Calling gettype would result in infinite recursion for types
                 * missing in pg_type, so just repeat the lookup.
                 */
                foreach(lc, Typ)
                {
                        struct typmap *app = lfirst(lc);

                        if (strncmp(NameStr(app->am_typ.typname), type, NAMEDATALEN) == 0)
                        {
                                Ap = app;
                                return app->am_oid;
                        }
                }
        }
        else
        {
                int                     i;

                for (i = 0; i < n_types; i++)
                {
                        if (strncmp(type, TypInfo[i].name, NAMEDATALEN) == 0)
                                return i;
                }
                /* Not in TypInfo, so we'd better be able to read pg_type now */
                elog(DEBUG4, "external type: %s", type);
                populate_typ_list();
                return gettype(type);
        }
        elog(ERROR, "unrecognized type \"%s\"", type);
        /* not reached, here to make compiler happy */
        return 0;
}

/* ----------------
 *              boot_get_type_io_data
 *
 * Obtain type I/O information at bootstrap time.  This intentionally has
 * almost the same API as lsyscache.c's get_type_io_data, except that
 * we only support obtaining the typinput and typoutput routines, not
 * the binary I/O routines.  It is exported so that array_in and array_out
 * can be made to work during early bootstrap.
 * ----------------
 */
void
boot_get_type_io_data(Oid typid,
                                          int16 *typlen,
                                          bool *typbyval,
                                          char *typalign,
                                          char *typdelim,
                                          Oid *typioparam,
                                          Oid *typinput,
                                          Oid *typoutput)
{
        if (Typ != NIL)
        {
                /* We have the boot-time contents of pg_type, so use it */
                struct typmap *ap = NULL;
                ListCell   *lc;

                foreach(lc, Typ)
                {
                        ap = lfirst(lc);
                        if (ap->am_oid == typid)
                                break;
                }

                if (!ap || ap->am_oid != typid)
                        elog(ERROR, "type OID %u not found in Typ list", typid);

                *typlen = ap->am_typ.typlen;
                *typbyval = ap->am_typ.typbyval;
                *typalign = ap->am_typ.typalign;
                *typdelim = ap->am_typ.typdelim;

                /* XXX this logic must match getTypeIOParam() */
                if (OidIsValid(ap->am_typ.typelem))
                        *typioparam = ap->am_typ.typelem;
                else
                        *typioparam = typid;

                *typinput = ap->am_typ.typinput;
                *typoutput = ap->am_typ.typoutput;
        }
        else
        {
                /* We don't have pg_type yet, so use the hard-wired TypInfo array */
                int                     typeindex;

                for (typeindex = 0; typeindex < n_types; typeindex++)
                {
                        if (TypInfo[typeindex].oid == typid)
                                break;
                }
                if (typeindex >= n_types)
                        elog(ERROR, "type OID %u not found in TypInfo", typid);

                *typlen = TypInfo[typeindex].len;
                *typbyval = TypInfo[typeindex].byval;
                *typalign = TypInfo[typeindex].align;
                /* We assume typdelim is ',' for all boot-time types */
                *typdelim = ',';

                /* XXX this logic must match getTypeIOParam() */
                if (OidIsValid(TypInfo[typeindex].elem))
                        *typioparam = TypInfo[typeindex].elem;
                else
                        *typioparam = typid;

                *typinput = TypInfo[typeindex].inproc;
                *typoutput = TypInfo[typeindex].outproc;
        }
}

/* ----------------
 *              AllocateAttribute
 *
 * Note: bootstrap never sets any per-column ACLs, so we only need
 * ATTRIBUTE_FIXED_PART_SIZE space per attribute.
 * ----------------
 */
static Form_pg_attribute
AllocateAttribute(void)
{
        return (Form_pg_attribute)
                MemoryContextAllocZero(TopMemoryContext, ATTRIBUTE_FIXED_PART_SIZE);
}

/*
 *      index_register() -- record an index that has been set up for building
 *                                              later.
 *
 *              At bootstrap time, we define a bunch of indexes on system catalogs.
 *              We postpone actually building the indexes until just before we're
 *              finished with initialization, however.  This is because the indexes
 *              themselves have catalog entries, and those have to be included in the
 *              indexes on those catalogs.  Doing it in two phases is the simplest
 *              way of making sure the indexes have the right contents at the end.
 */
void
index_register(Oid heap,
                           Oid ind,
                           const IndexInfo *indexInfo)
{
        IndexList  *newind;
        MemoryContext oldcxt;

        /*
         * XXX mao 10/31/92 -- don't gc index reldescs, associated info at
         * bootstrap time.  we'll declare the indexes now, but want to create them
         * later.
         */

        if (nogc == NULL)
                nogc = AllocSetContextCreate(NULL,
                                                                         "BootstrapNoGC",
                                                                         ALLOCSET_DEFAULT_SIZES);

        oldcxt = MemoryContextSwitchTo(nogc);

        newind = (IndexList *) palloc(sizeof(IndexList));
        newind->il_heap = heap;
        newind->il_ind = ind;
        newind->il_info = (IndexInfo *) palloc(sizeof(IndexInfo));

        memcpy(newind->il_info, indexInfo, sizeof(IndexInfo));
        /* expressions will likely be null, but may as well copy it */
        newind->il_info->ii_Expressions =
                copyObject(indexInfo->ii_Expressions);
        newind->il_info->ii_ExpressionsState = NIL;
        /* predicate will likely be null, but may as well copy it */
        newind->il_info->ii_Predicate =
                copyObject(indexInfo->ii_Predicate);
        newind->il_info->ii_PredicateState = NULL;
        /* no exclusion constraints at bootstrap time, so no need to copy */
        Assert(indexInfo->ii_ExclusionOps == NULL);
        Assert(indexInfo->ii_ExclusionProcs == NULL);
        Assert(indexInfo->ii_ExclusionStrats == NULL);

        newind->il_next = ILHead;
        ILHead = newind;

        MemoryContextSwitchTo(oldcxt);
}


/*
 * build_indices -- fill in all the indexes registered earlier
 */
void
build_indices(void)
{
        for (; ILHead != NULL; ILHead = ILHead->il_next)
        {
                Relation        heap;
                Relation        ind;

                /* need not bother with locks during bootstrap */
                heap = table_open(ILHead->il_heap, NoLock);
                ind = index_open(ILHead->il_ind, NoLock);

                index_build(heap, ind, ILHead->il_info, false, false);

                index_close(ind, NoLock);
                table_close(heap, NoLock);
        }
}