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Sourcecode: firebird3.0 version File versions  Download package

cmd.cpp

//____________________________________________________________
//
//          PROGRAM:    C preprocessor
//          MODULE:           cmd.cpp
//          DESCRIPTION:      Data definition compiler
//
//  The contents of this file are subject to the Interbase Public
//  License Version 1.0 (the "License"); you may not use this file
//  except in compliance with the License. You may obtain a copy
//  of the License at http://www.Inprise.com/IPL.html
//
//  Software distributed under the License is distributed on an
//  "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
//  or implied. See the License for the specific language governing
//  rights and limitations under the License.
//
//  The Original Code was created by Inprise Corporation
//  and its predecessors. Portions created by Inprise Corporation are
//  Copyright (C) Inprise Corporation.
//
//  All Rights Reserved.
//  Contributor(s): ______________________________________.
//  TMN (Mike Nordell) 11.APR.2001 - Reduce compiler warnings
//
//
//____________________________________________________________
//
//

#include "firebird.h"
#include <string.h>
#include "../gpre/gpre.h"
#include "../jrd/ibase.h"
#include "../jrd/flags.h"
#include "../gpre/cmd_proto.h"
#include "../gpre/cme_proto.h"
#include "../gpre/cmp_proto.h"
#include "../gpre/gpre_proto.h"
#include "../gpre/msc_proto.h"
#include "../gpre/gpre_meta.h"

typedef void (*pfn_local_trigger_cb) (gpre_nod*, gpre_req*);

//static void add_cache(gpre_req*, const act*, gpre_dbb*);
static void alter_database(gpre_req*, act*);
static void alter_domain(gpre_req*, const act*);
static void alter_index(gpre_req*, const act*);
static void alter_table(gpre_req*, const act*);
static void create_check_constraint(gpre_req*, const act*, cnstrt*);
static void create_constraint(gpre_req*, const act*, cnstrt*);
static void create_database(gpre_req*, const act*);
static void create_database_modify_dyn(gpre_req*, act*);
static void create_default_blr(gpre_req*, const TEXT*, const USHORT);
static void create_del_cascade_trg(gpre_req*, const act*, cnstrt*);
static void create_domain(gpre_req*, const act*);
static void create_domain_constraint(gpre_req*, const cnstrt*);
static void create_generator(gpre_req*, const act*);
static void create_index(gpre_req*, const gpre_index*);
static void create_matching_blr(gpre_req*, const cnstrt*);
static void create_set_default_trg(gpre_req*, const act*, cnstrt*, bool);
static void create_set_null_trg(gpre_req*, const act*, cnstrt*, bool);
static void create_shadow(gpre_req*, act*);
static void create_table(gpre_req*, const act*);
static void create_trg_firing_cond(gpre_req*, const cnstrt*);
static void create_trigger(gpre_req*, const act*, gpre_trg*, pfn_local_trigger_cb);
static void create_upd_cascade_trg(gpre_req*, const act*, cnstrt*);
static bool create_view(gpre_req*, act*);
static void create_view_trigger(gpre_req*, const act*, gpre_trg*, gpre_nod*, gpre_ctx**);
static void declare_filter(gpre_req*, const act*);
static void declare_udf(gpre_req*, const act*);
static void get_referred_fields(const act*, cnstrt*);
static void grant_revoke_privileges(gpre_req*, const act*);
static void init_field_struct(gpre_fld*);
static void put_array_info(gpre_req*, const gpre_fld*);
static void put_blr(gpre_req*, USHORT, gpre_nod*, pfn_local_trigger_cb);
static void put_computed_blr(gpre_req*, const gpre_fld*);
static void put_computed_source(gpre_req*, const gpre_fld*);
static void put_cstring(gpre_req*, USHORT, const TEXT*);
static void put_dtype(gpre_req*, const gpre_fld*);
static void put_field_attributes(gpre_req*, const gpre_fld*);
static void put_numeric(gpre_req*, USHORT, SSHORT);
static void put_short_cstring(gpre_req*, USHORT, const TEXT*);
static void put_string(gpre_req*, USHORT, const TEXT*, USHORT);
static void put_symbol(gpre_req*, int, const gpre_sym*);
static void put_trigger_blr(gpre_req*, USHORT, gpre_nod*, pfn_local_trigger_cb);
static void put_view_trigger_blr(gpre_req*, const gpre_rel*, USHORT, gpre_trg*,
                                                 gpre_nod*, gpre_ctx**);
static void replace_field_names(gpre_nod* const, const gpre_nod* const,
                                                gpre_fld* const, bool, gpre_ctx**);
static void set_statistics(gpre_req*, const act*);

static inline void STUFF_CHECK(gpre_req* request, int n)
{
      if (request->req_base - request->req_blr + request->req_length <= n + 50)
            CMP_check(request, n);
}


const int BLOB_BUFFER_SIZE = 4096;  // to read in blr blob for default values


//____________________________________________________________
//
//          Compile a single request, but do not generate any text.
//          Generate port blocks, assign parameter numbers, message
//          numbers, and internal idents.  Compute length of request.
//

int CMD_compile_ddl(gpre_req* request)
{
      // Initialize the blr string

      act* action = request->req_actions;
      request->req_blr = request->req_base = MSC_alloc(250);
      request->req_length = 250;
      request->req_flags |= REQ_exp_hand;
      request->add_byte(isc_dyn_version_1);
      request->add_byte(isc_dyn_begin);

      switch (action->act_type)
      {
      case ACT_alter_table:
            alter_table(request, action);
            break;

      case ACT_alter_database:
            alter_database(request, action);
            break;

      case ACT_alter_domain:
            alter_domain(request, action);
            break;

      case ACT_alter_index:
            alter_index(request, action);
            break;

      case ACT_create_database:
            if (!(request->req_flags & REQ_sql_database_dyn))
            {
                  request->req_blr = request->req_base;
                  create_database(request, action);
                  return 0;
            }
            create_database_modify_dyn(request, action);
            break;

      case ACT_create_domain:
            create_domain(request, action);
            break;

      case ACT_create_generator:
            create_generator(request, action);
            break;

      case ACT_create_index:
            {
                  const gpre_index* index = (gpre_index*) action->act_object;
                  create_index(request, index);
            }
            break;

      case ACT_create_shadow:
            create_shadow(request, action);
            break;

      case ACT_create_table:
            create_table(request, action);
            break;

      case ACT_create_view:
            if (!create_view(request, action))
                  return -1;
            break;

      case ACT_drop_database:
            break;

      case ACT_drop_domain:
            put_cstring(request, isc_dyn_delete_global_fld, (TEXT *) action->act_object);
            request->add_end();
            break;

      case ACT_drop_filter:
            put_cstring(request, isc_dyn_delete_filter, (TEXT *) action->act_object);
            request->add_end();
            break;

      case ACT_drop_index:
            {
                  const gpre_index* index = (gpre_index*) action->act_object;
                  put_symbol(request, isc_dyn_delete_idx, index->ind_symbol);
                  request->add_end();
            }
            break;

      case ACT_drop_shadow:
            put_numeric(request, isc_dyn_delete_shadow, (SSHORT) (IPTR) action->act_object);
            request->add_end();
            break;

      case ACT_drop_table:
      case ACT_drop_view:
            {
                  const gpre_rel* relation = (gpre_rel*) action->act_object;
                  put_symbol(request, isc_dyn_delete_rel, relation->rel_symbol);
                  request->add_end();
            }
            break;

      case ACT_drop_udf:
            put_cstring(request, isc_dyn_delete_function, (TEXT *) action->act_object);
            request->add_end();
            break;

      case ACT_dyn_grant:
            grant_revoke_privileges(request, action);
            break;

      case ACT_dyn_revoke:
            grant_revoke_privileges(request, action);
            break;

      case ACT_declare_filter:
            declare_filter(request, action);
            break;

      case ACT_declare_udf:
            declare_udf(request, action);
            break;

      case ACT_statistics:
            set_statistics(request, action);
            break;

      default:
            CPR_error("*** unknown request type node ***");
            return -1;
      }

      request->add_end();
      request->add_byte(isc_dyn_eoc);
      request->req_length = request->req_blr - request->req_base;
      request->req_blr = request->req_base;

      return 0;
}


//____________________________________________________________
//
//          Add cache file to a database.
//
/*
static void add_cache( gpre_req* request, const act* action, gpre_dbb* database)
{
      TEXT file_name[254]; // CVC: Maybe MAXPATHLEN?

      const gpre_file* file = database->dbb_cache_file;
      const SSHORT l = MIN((strlen(file->fil_name)), (sizeof(file_name) - 1));

      strncpy(file_name, file->fil_name, l);
      file_name[l] = '\0';
      put_cstring(request, isc_dyn_def_cache_file, file_name);
      request->add_byte(isc_dyn_file_length);
      request->add_word(4);
      request->add_long(file->fil_length);
      request->add_end();
}
*/

//____________________________________________________________
//
//          Generate dynamic DDL for modifying database.
//

static void alter_database( gpre_req* request, act* action)
{
      gpre_dbb* db = (gpre_dbb*) action->act_object;

      request->add_byte(isc_dyn_mod_database);

      // Reverse the order of files (parser left them backwards)

      gpre_file* next;
      gpre_file* files = NULL;
      for (gpre_file* file = db->dbb_files; file; file = next)
      {
            next = file->fil_next;
            file->fil_next = files;
            files = file;
      }

      for (const gpre_file* file = files; file != NULL; file = file->fil_next)
      {
            put_cstring(request, isc_dyn_def_file, file->fil_name);
            request->add_byte(isc_dyn_file_start);
            request->add_word(4);
            const SLONG start = file->fil_start;
            request->add_long(start);
            request->add_byte(isc_dyn_file_length);
            request->add_word(4);
            request->add_long(file->fil_length);
            request->add_end();
      }

      // Drop cache
/*
      if (db->dbb_flags & DBB_drop_cache)
            request->add_byte(isc_dyn_drop_cache);

      if (db->dbb_cache_file)
            add_cache(request, action, db);
*/

      if (db->dbb_def_charset)
            put_cstring(request, isc_dyn_fld_character_set_name, db->dbb_def_charset);

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for CREATE DOMAIN action.
//

static void alter_domain( gpre_req* request, const act* action)
{
      const gpre_fld* field = (gpre_fld*) action->act_object;

      // modify field info

      put_symbol(request, isc_dyn_mod_global_fld, field->fld_symbol);

      const gpre_nod* default_node = field->fld_default_value;
      if (default_node)
      {
            if (default_node->nod_type == nod_erase) {
                  request->add_byte(isc_dyn_del_default);
            }
            else
            {
                  put_blr(request, isc_dyn_fld_default_value, field->fld_default_value, CME_expr);
                  TEXT* default_source = (TEXT *) MSC_alloc(field->fld_default_source->txt_length + 1);
                  CPR_get_text(default_source, field->fld_default_source);
                  put_cstring(request, isc_dyn_fld_default_source, default_source);
            }
      }

      if (field->fld_constraints)
      {
            request->add_byte(isc_dyn_single_validation);
            for (const cnstrt* constraint = field->fld_constraints;
                   constraint;
                   constraint = constraint->cnstrt_next)
            {
                  if (constraint->cnstrt_flags & CNSTRT_delete)
                        request->add_byte(isc_dyn_del_validation);
            }
            create_domain_constraint(request, field->fld_constraints);
      }

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for ALTER INDEX statement
//

static void alter_index( gpre_req* request, const act* action)
{
      const gpre_index* index = (gpre_index*) action->act_object;
      put_symbol(request, isc_dyn_mod_idx, index->ind_symbol);

      const SSHORT value = (index->ind_flags & IND_active) ? 0 : 1;
      put_numeric(request, isc_dyn_idx_inactive, value);

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for ALTER TABLE action.
//

static void alter_table( gpre_req* request, const act* action)
{
      // add relation name

      const gpre_rel* relation = (gpre_rel*) action->act_object;
      put_symbol(request, isc_dyn_mod_rel, relation->rel_symbol);

      // add field info

      for (const gpre_fld* field = relation->rel_fields; field; field = field->fld_next)
      {
            if (field->fld_flags & FLD_delete)
            {
                  put_symbol(request, isc_dyn_delete_local_fld, field->fld_symbol);
                  request->add_end();
            }
            else if (field->fld_flags & FLD_meta)
            {
                  if (field->fld_global)
                  {
                        put_symbol(request, isc_dyn_def_local_fld, field->fld_symbol);
                        put_symbol(request, isc_dyn_fld_source, field->fld_global);
                  }
                  else
                        put_symbol(request, isc_dyn_def_sql_fld, field->fld_symbol);

                  put_field_attributes(request, field);

                  if (field->fld_default_value)
                  {
                        put_blr(request, isc_dyn_fld_default_value, field->fld_default_value, CME_expr);
                        TEXT* default_source = (TEXT*) MSC_alloc(field->fld_default_source->txt_length + 1);
                        CPR_get_text(default_source, field->fld_default_source);
                        put_cstring(request, isc_dyn_fld_default_source, default_source);
                  }

                  request->add_end();

                  // Any constraints defined for field being added?

                  if (field->fld_constraints)
                        create_constraint(request, action, field->fld_constraints);
            }
      }

      // Check for any relation level ADD/DROP of constraints

      if (relation->rel_constraints)
      {
            for (const cnstrt* constraint = relation->rel_constraints;
                   constraint;
                   constraint = constraint->cnstrt_next)
            {
                  if (constraint->cnstrt_flags & CNSTRT_delete)
                        put_cstring(request, isc_dyn_delete_rel_constraint,
                                          constraint->cnstrt_name->str_string);
            }
            create_constraint(request, action, relation->rel_constraints);
      }

      request->add_end();
}


//____________________________________________________________
//
//          Generate dyn for creating a CHECK constraint.
//

static void create_check_constraint( gpre_req* request, const act* action,
      cnstrt* constraint)
{
      gpre_trg* trigger = (gpre_trg*) MSC_alloc(TRG_LEN);

      // create the INSERT trigger

      trigger->trg_type = PRE_STORE_TRIGGER;

      // "insert violates CHECK constraint on table"

      trigger->trg_message = NULL;
      trigger->trg_boolean = constraint->cnstrt_boolean;
      trigger->trg_source = (STR) MSC_alloc(constraint->cnstrt_text->txt_length + 1);
      CPR_get_text(trigger->trg_source->str_string, constraint->cnstrt_text);
      create_trigger(request, action, trigger, CME_expr);

      // create the UPDATE trigger

      trigger->trg_type = PRE_MODIFY_TRIGGER;

      // "update violates CHECK constraint on table"

      create_trigger(request, action, trigger, CME_expr);
}


//____________________________________________________________
//
//  Function
//          Generate blr to express: if (old.primary_key != new.primary_key).
//          do a column by column comparison.
//

static void create_trg_firing_cond( gpre_req* request, const cnstrt* constraint)
{
      // count primary key columns
      const gpre_lls* prim_key_fld = constraint->cnstrt_referred_fields;
      const gpre_lls* field = prim_key_fld;

      fb_assert(field != NULL);

      USHORT prim_key_num_flds = 0;
      while (field)
      {
            prim_key_num_flds++;
            field = field->lls_next;
      }

      fb_assert(prim_key_num_flds > 0);

      // generate blr
      request->add_byte(blr_if);
      if (prim_key_num_flds > 1)
            request->add_byte(blr_or);

      USHORT num_flds = 0;
      for (; prim_key_fld; prim_key_fld = prim_key_fld->lls_next)
      {
            request->add_byte(blr_neq);

            const str* prim_key_fld_name = (STR) prim_key_fld->lls_object;

            request->add_byte(blr_field);
            request->add_byte((SSHORT) 0);
            put_cstring(request, 0, prim_key_fld_name->str_string);
            request->add_byte(blr_field);
            request->add_byte((SSHORT) 1);
            put_cstring(request, 0, prim_key_fld_name->str_string);

            ++num_flds;

            if (prim_key_num_flds - num_flds >= 2)
                  request->add_byte(blr_or);
      }
}


//____________________________________________________________
//
//  Function
//          Generate blr to express: foreign_key == primary_key
//          ie.,  for_key.column_1 = prim_key.column_1 and
//          for_key.column_2 = prim_key.column_2 and ....  so on..
//

static void create_matching_blr(gpre_req* request, const cnstrt* constraint)
{
      // count primary key columns
      const gpre_lls*  prim_key_fld = constraint->cnstrt_referred_fields;
      const gpre_lls* field = prim_key_fld;

      fb_assert(field != NULL);

      USHORT prim_key_num_flds = 0;
      while (field)
      {
            prim_key_num_flds++;
            field = field->lls_next;
      }

      fb_assert(prim_key_num_flds > 0);

      // count of foreign key columns
      const gpre_lls* for_key_fld = constraint->cnstrt_fields;
      field = for_key_fld;

      fb_assert(field != NULL);

      USHORT for_key_num_flds = 0;
      while (field)
      {
            for_key_num_flds++;
            field = field->lls_next;
      }

      fb_assert(for_key_num_flds > 0);
      fb_assert(prim_key_num_flds == for_key_num_flds);

      request->add_byte(blr_boolean);
      if (prim_key_num_flds > 1)
            request->add_byte(blr_and);

      USHORT num_flds = 0;

      do {
            request->add_byte(blr_eql);

            const str* for_key_fld_name = (STR) for_key_fld->lls_object;
            const str* prim_key_fld_name = (STR) prim_key_fld->lls_object;

            request->add_byte(blr_field);
            request->add_byte((SSHORT) 2);
            put_cstring(request, 0, for_key_fld_name->str_string);
            request->add_byte(blr_field);
            request->add_byte((SSHORT) 0);
            put_cstring(request, 0, prim_key_fld_name->str_string);

            ++num_flds;

            if (prim_key_num_flds - num_flds >= 2)
                  request->add_byte(blr_and);

            for_key_fld = for_key_fld->lls_next;
            prim_key_fld = prim_key_fld->lls_next;
      } while (num_flds < for_key_num_flds);

      request->add_byte(blr_end);
}


//____________________________________________________________
//  Function:
//          The default_blr is passed in default_buffer. It is of the form:
//          blr_version4 blr_literal ..... blr_eoc.
//          strip the blr_version4/blr_version5 and blr_eoc verbs and stuff the remaining
//          blr in the blr stream in the request.
//

static void create_default_blr(gpre_req* request,
                                             const TEXT* default_buff, const USHORT buff_size)
{
      int i;

      fb_assert(*default_buff == blr_version4 || *default_buff == blr_version5);

      for (i = 1; ((i < buff_size) && (default_buff[i] != blr_eoc)); i++)
            request->add_byte(default_buff[i]);

      fb_assert(default_buff[i] == blr_eoc);

}


//____________________________________________________________
//
//          Generate dyn for "on update cascade" trigger (for referential
//          integrity) along with the trigger blr.
//

static void create_upd_cascade_trg( gpre_req* request, const act* action,
                                                   cnstrt* constraint)
{
      gpre_lls* for_key_fld = constraint->cnstrt_fields;
      gpre_lls* prim_key_fld = constraint->cnstrt_referred_fields;
      gpre_rel* relation = (gpre_rel*) action->act_object;

      // no trigger name is generated here. Let the engine make one up
      put_string(request, isc_dyn_def_trigger, "", (USHORT) 0);

      put_numeric(request, isc_dyn_trg_type, (SSHORT) POST_MODIFY_TRIGGER);

      request->add_byte(isc_dyn_sql_object);
      put_numeric(request, isc_dyn_trg_sequence, (SSHORT) 1);
      put_numeric(request, isc_dyn_trg_inactive, (SSHORT) 0);
      put_cstring(request, isc_dyn_rel_name, constraint->cnstrt_referred_rel->str_string);

      // the trigger blr

      request->add_byte(isc_dyn_trg_blr);
      const USHORT offset = request->req_blr - request->req_base;

      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);

      create_trg_firing_cond(request, constraint);

      request->add_byte(blr_begin);
      request->add_byte(blr_begin);

      request->add_byte(blr_for);
      request->add_byte(blr_rse);

      // the new context for the prim. key relation
      request->add_byte(1);

      request->add_byte(blr_relation);
      put_cstring(request, 0, relation->rel_symbol->sym_string);
      // the context for the foreign key relation
      request->add_byte(2);

      // generate the blr for: foreign_key == primary_key
      create_matching_blr(request, constraint);

      request->add_byte(blr_modify);
      request->add_byte((SSHORT) 2);
      request->add_byte((SSHORT) 2);
      request->add_byte(blr_begin);

      for (; for_key_fld && prim_key_fld;
             for_key_fld = for_key_fld->lls_next, prim_key_fld = prim_key_fld->lls_next)
      {
            const str* for_key_fld_name = (STR) for_key_fld->lls_object;
            const str* prim_key_fld_name = (STR) prim_key_fld->lls_object;

            request->add_byte(blr_assignment);
            request->add_byte(blr_field);
            request->add_byte((SSHORT) 1);
            put_cstring(request, 0, prim_key_fld_name->str_string);
            request->add_byte(blr_field);
            request->add_byte((SSHORT) 2);
            put_cstring(request, 0, for_key_fld_name->str_string);
      }

      request->add_byte(blr_end);
      request->add_byte(blr_end);
      request->add_byte(blr_end);
      request->add_byte(blr_end);

      request->add_byte(blr_eoc);
      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
      // end of the blr

      // no trg_source and no trg_description
      request->add_byte(isc_dyn_end);
}


//____________________________________________________________
//
//          Generate dyn for "on delete cascade" trigger (for referential
//          integrity) along with the trigger blr.
//

static void create_del_cascade_trg( gpre_req* request, const act* action,
                                                   cnstrt* constraint)
{
      const gpre_rel* relation = (gpre_rel*) action->act_object;

      // stuff a trigger_name of size 0. So the dyn-parser will make one up.
      put_string(request, isc_dyn_def_trigger, "", (USHORT) 0);

      put_numeric(request, isc_dyn_trg_type, (SSHORT) POST_ERASE_TRIGGER);

      request->add_byte(isc_dyn_sql_object);
      put_numeric(request, isc_dyn_trg_sequence, (SSHORT) 1);
      put_numeric(request, isc_dyn_trg_inactive, (SSHORT) 0);
      put_cstring(request, isc_dyn_rel_name, constraint->cnstrt_referred_rel->str_string);

      // the trigger blr
      request->add_byte(isc_dyn_trg_blr);
      const USHORT offset = request->req_blr - request->req_base;

      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);

      request->add_byte(blr_for);
      request->add_byte(blr_rse);

      // the context for the prim. key relation
      request->add_byte(1);

      request->add_byte(blr_relation);
      put_cstring(request, 0, relation->rel_symbol->sym_string);
      // the context for the foreign key relation
      request->add_byte(2);

      create_matching_blr(request, constraint);

      request->add_byte(blr_erase);
      request->add_byte((SSHORT) 2);
      request->add_byte(blr_eoc);
      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
      // end of the blr

      // no trg_source and no trg_description
      request->add_byte(isc_dyn_end);
}


//____________________________________________________________
//
//          Generate dyn for "on delete|update set default" trigger (for
//          referential integrity) along with the trigger blr.
//          The non_upd_trg parameter == true is an update trigger.
//

static void create_set_default_trg(gpre_req* request,
                                                   const act* action,
                                                   cnstrt* constraint,
                                                   bool on_upd_trg)
{
      TEXT s[512];
      TEXT default_val[BLOB_BUFFER_SIZE];

      fb_assert(request->req_actions->act_type == ACT_create_table ||
               request->req_actions->act_type == ACT_alter_table);

      gpre_lls* for_key_fld = constraint->cnstrt_fields;
      const gpre_rel* relation = (gpre_rel*) action->act_object;

      // no trigger name. It is generated by the engine
      put_string(request, isc_dyn_def_trigger, "", (USHORT) 0);

      put_numeric(request, isc_dyn_trg_type,
                        (SSHORT) (on_upd_trg ? POST_MODIFY_TRIGGER : POST_ERASE_TRIGGER));

      request->add_byte(isc_dyn_sql_object);
      put_numeric(request, isc_dyn_trg_sequence, (SSHORT) 1);
      put_numeric(request, isc_dyn_trg_inactive, (SSHORT) 0);
      put_cstring(request, isc_dyn_rel_name, constraint->cnstrt_referred_rel->str_string);

      // the trigger blr

      request->add_byte(isc_dyn_trg_blr);
      const USHORT offset = request->req_blr - request->req_base;

      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);

      // for ON UPDATE TRIGGER only: generate the trigger firing condition:
      // if prim_key.old_value != prim_key.new value.
      // Note that the key could consist of multiple columns

      if (on_upd_trg)
      {
            create_trg_firing_cond(request, constraint);
            request->add_byte(blr_begin);
            request->add_byte(blr_begin);
      }

      request->add_byte(blr_for);
      request->add_byte(blr_rse);

      // the context for the prim. key relation
      request->add_byte(1);

      request->add_byte(blr_relation);
      put_cstring(request, 0, relation->rel_symbol->sym_string);
      // the context for the foreign key relation
      request->add_byte(2);

      create_matching_blr(request, constraint);

      request->add_byte(blr_modify);
      request->add_byte((SSHORT) 2);
      request->add_byte((SSHORT) 2);
      request->add_byte(blr_begin);

      for (; for_key_fld; for_key_fld = for_key_fld->lls_next)
      {
            // for every column in the foreign key ....
            const str* for_key_fld_name = (STR) for_key_fld->lls_object;

            request->add_byte(blr_assignment);

            // here stuff the default value as blr_literal .... or blr_null
            // if this column does not have an applicable default

            // the default is determined in many cases:
            // (1) The default-info for the column is in memory. (This is because
            // the column is being created in this application)
            // (1-a) the table has a column level default. We get this by
            // searching both current ddl statement and requests
            // linked list.
            // (1-b) the table does not have a column level default, but
            // has a domain default. We get this by searching
            // requests linked list.
            // (2) The default-info for the column is not in memory.
            // We get the column and/or domain default value from the system
            // tables by calling MET_get_column_default/MET_get_domain_default

            bool search_for_default = true;
            bool search_for_column = false;
            const TEXT* search_for_domain = NULL;

            // Is the column being created in this ddl statement?
            gpre_fld* field;
            for (field = relation->rel_fields; field; field = field->fld_next)
            {
                  if (strcmp(field->fld_symbol->sym_string, for_key_fld_name->str_string) == 0)
                  {
                        break;
                  }
            }

            if (field)
            {
                  // Yes. The column is being created in this ddl statement
                  if (field->fld_default_value) {
                        // (1-a)
                        CME_expr(field->fld_default_value, request);
                        search_for_default = false;
                  }
                  else
                  {
                        // check for domain default
                        if (field->fld_global)
                        {
                              // could be either (1-b) or (2)
                              search_for_domain = field->fld_global->sym_string;
                        }
                        else
                        {
                              request->add_byte(blr_null);
                              search_for_default = false;
                        }
                  }
            }
            else
            {
                  // Nop. The column is not being created in this ddl statement
                  if (request->req_actions->act_type == ACT_create_table)
                  {
                        sprintf(s, "field \"%s\" does not exist in relation \"%s\"",
                                    for_key_fld_name->str_string, relation->rel_symbol->sym_string);
                        CPR_error(s);
                  }

                  // Thus we have an ALTER TABLE statement.

                  // If somebody is 'clever' enough to create table and then to alter it
                  // within the same application ...
                  gpre_req* req = gpreGlob.requests;
                  for (; req; req = req->req_next)
                  {
                        act* request_action;
                        gpre_rel* rel;
                        if (req->req_type == REQ_ddl && (request_action = req->req_actions) &&
                              (request_action->act_type == ACT_create_table ||
                                    request_action->act_type == ACT_alter_table) &&
                              (rel = (gpre_rel*) request_action->act_object) &&
                              strcmp(rel->rel_symbol->sym_string, relation->rel_symbol->sym_string) == 0)
                        {
                              // ... then try to check for the default in memory
                              gpre_fld* fld;
                              for (fld = (gpre_fld*) rel->rel_fields; fld; fld = fld->fld_next)
                              {
                                    if (strcmp(fld->fld_symbol->sym_string, for_key_fld_name->str_string) != 0)
                                          continue;
                                    if (fld->fld_default_value)
                                    {
                                          // case (1-a):
                                          CME_expr(fld->fld_default_value, request);
                                          search_for_default = false;
                                    }
                                    else
                                    {
                                          if (fld->fld_global) {
                                                search_for_domain = fld->fld_global->sym_string;
                                          }
                                          else
                                          {
                                                // default not found
                                                request->add_byte(blr_null);
                                                search_for_default = false;
                                          }
                                    }
                                    break;
                              }
                              if (fld)
                                    break;
                        }
                  }
                  if (!req)
                        search_for_column = true;
            }

            if (search_for_default && search_for_domain != NULL)
            {
                  // search for domain level default
                  fb_assert(search_for_column == false);
                  // search for domain in memory
                  for (gpre_req* req = gpreGlob.requests; req; req = req->req_next)
                  {
                        act* request_action;
                        gpre_fld* domain;
                        if (req->req_type == REQ_ddl &&
                              (request_action = req->req_actions) &&
                              (request_action->act_type == ACT_create_domain ||
                                    request_action->act_type == ACT_alter_domain) &&
                              (domain = (gpre_fld*) request_action->act_object) &&
                              strcmp(search_for_domain, domain->fld_symbol->sym_string) == 0 &&
                              domain->fld_default_value->nod_type != nod_erase)
                        {
                              // domain found in memory
                              if (domain->fld_default_value)
                              {
                                    // case (1-b)
                                    CME_expr(domain->fld_default_value, request);
                              }
                              else
                              {
                                    // default not found
                                    request->add_byte(blr_null);
                              }
                              search_for_default = false;
                              break;
                        }
                  }

                  if (search_for_default)
                  {
                        // search for domain in db system tables
                        if (MET_get_domain_default(relation->rel_database, search_for_domain,
                                                               default_val, sizeof(default_val)))
                        {
                              create_default_blr(request, default_val, sizeof(default_val));
                        }
                        else {
                              request->add_byte(blr_null);
                        }
                        search_for_default = false;
                  }
            }                                   // end of search for domain level default

            if (search_for_default && search_for_column)
            {
                  // nothing is found in memory, try to check db system tables
                  fb_assert(search_for_domain == NULL);
                  if (MET_get_column_default(relation, for_key_fld_name->str_string,
                                                         default_val, sizeof(default_val)))
                  {
                        create_default_blr(request, default_val, sizeof(default_val));
                  }
                  else {
                        request->add_byte(blr_null);
                  }
            }

            // the context for the foreign key relation
            request->add_byte(blr_field);
            request->add_byte((SSHORT) 2);
            put_cstring(request, 0, for_key_fld_name->str_string);

      }
      request->add_byte(blr_end);

      if (on_upd_trg)
      {
            request->add_byte(blr_end);
            request->add_byte(blr_end);
            request->add_byte(blr_end);
      }

      request->add_byte(blr_eoc);
      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
      // end of the blr

      // no trg_source and no trg_description
      request->add_byte(isc_dyn_end);

}


//____________________________________________________________
//
//          Generate dyn for "on delete|update set null" trigger (for
//          referential integrity). The trigger blr is the same for
//          both the delete and update cases. Only differences is its
//          TRIGGER_TYPE (ON DELETE or ON UPDATE).
//          The non_upd_trg parameter == true is an update trigger.
//

static void create_set_null_trg(gpre_req* request,
                                                const act* action,
                                                cnstrt* constraint,
                                                bool on_upd_trg)
{
      gpre_lls* for_key_fld = constraint->cnstrt_fields;
      const gpre_rel* relation = (gpre_rel*) action->act_object;

      // no trigger name. It is generated by the engine
      put_string(request, isc_dyn_def_trigger, "", (USHORT) 0);

      put_numeric(request, isc_dyn_trg_type,
                        (SSHORT) (on_upd_trg ? POST_MODIFY_TRIGGER : POST_ERASE_TRIGGER));

      request->add_byte(isc_dyn_sql_object);
      put_numeric(request, isc_dyn_trg_sequence, (SSHORT) 1);
      put_numeric(request, isc_dyn_trg_inactive, (SSHORT) 0);
      put_cstring(request, isc_dyn_rel_name, constraint->cnstrt_referred_rel->str_string);

      // the trigger blr

      request->add_byte(isc_dyn_trg_blr);
      const USHORT offset = request->req_blr - request->req_base;

      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);

      // for ON UPDATE TRIGGER only: generate the trigger firing condition:
      // if prim_key.old_value != prim_key.new value.
      // Note that the key could consist of multiple columns

      if (on_upd_trg)
      {
            create_trg_firing_cond(request, constraint);
            request->add_byte(blr_begin);
            request->add_byte(blr_begin);
      }

      request->add_byte(blr_for);
      request->add_byte(blr_rse);

      // the context for the prim. key relation
      request->add_byte(1);

      request->add_byte(blr_relation);
      put_cstring(request, 0, relation->rel_symbol->sym_string);
      // the context for the foreign key relation
      request->add_byte(2);

      create_matching_blr(request, constraint);

      request->add_byte(blr_modify);
      request->add_byte((SSHORT) 2);
      request->add_byte((SSHORT) 2);
      request->add_byte(blr_begin);

      for (; for_key_fld; for_key_fld = for_key_fld->lls_next)
      {
            const str* for_key_fld_name = (STR) for_key_fld->lls_object;

            request->add_byte(blr_assignment);
            request->add_byte(blr_null);
            request->add_byte(blr_field);
            request->add_byte((SSHORT) 2);
            put_cstring(request, 0, for_key_fld_name->str_string);
      }
      request->add_byte(blr_end);

      if (on_upd_trg)
      {
            request->add_byte(blr_end);
            request->add_byte(blr_end);
            request->add_byte(blr_end);
      }

      request->add_byte(blr_eoc);
      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
      // end of the blr

      // no trg_source and no trg_description
      request->add_byte(isc_dyn_end);
}


//____________________________________________________________
//
//          Get referred fields from memory/system tables
//

static void get_referred_fields(const act* action, cnstrt* constraint)
{
      TEXT s[512];
      const gpre_rel* relation = (gpre_rel*) action->act_object;

      for (gpre_req* req = gpreGlob.requests; req; req = req->req_next)
      {
            const act* request_action;
            const gpre_rel* rel;
            if (req->req_type == REQ_ddl && (request_action = req->req_actions) &&
                  (request_action->act_type == ACT_create_table ||
                        request_action->act_type == ACT_alter_table) &&
                  (rel = (gpre_rel*) request_action->act_object) &&
                  strcmp(rel->rel_symbol->sym_string, constraint->cnstrt_referred_rel->str_string) == 0)
            {
                  for (const cnstrt* cns = rel->rel_constraints; cns; cns = cns->cnstrt_next)
                  {
                        if (cns->cnstrt_type == CNSTRT_PRIMARY_KEY)
                        {
                              constraint->cnstrt_referred_fields = cns->cnstrt_fields;
                              break;
                        }
                  }
                  if (!constraint->cnstrt_referred_fields && rel->rel_fields)
                        for (const cnstrt* cns = rel->rel_fields->fld_constraints; cns; cns = cns->cnstrt_next)
                        {
                              if (cns->cnstrt_type == CNSTRT_PRIMARY_KEY)
                              {
                                    constraint->cnstrt_referred_fields = cns->cnstrt_fields;
                                    break;
                              }
                        }
                  if (constraint->cnstrt_referred_fields)
                        break;
            }
      }

      if (constraint->cnstrt_referred_fields == NULL)
            // Nothing is in memory. Try to find in system tables
            constraint->cnstrt_referred_fields =
                  MET_get_primary_key(relation->rel_database, constraint->cnstrt_referred_rel->str_string);

      if (constraint->cnstrt_referred_fields == NULL)
      {
            // Nothing is in system tables.
            sprintf(s,
                        "\"REFERENCES %s\" without \"(column list)\" requires PRIMARY KEY on referenced table",
                        constraint->cnstrt_referred_rel->str_string);
            CPR_error(s);
      }
      else
      {
            // count both primary key and foreign key columns
            USHORT prim_key_num_flds = 0, for_key_num_flds = 0;
            const gpre_lls* field = constraint->cnstrt_referred_fields;
            while (field)
            {
                  prim_key_num_flds++;
                  field = field->lls_next;
            }
            field = constraint->cnstrt_fields;
            while (field)
            {
                  for_key_num_flds++;
                  field = field->lls_next;
            }
            if (prim_key_num_flds != for_key_num_flds)
            {
                  sprintf(s,
                              "PRIMARY KEY column count in relation \"%s\" does not match FOREIGN KEY in relation \"%s\"",
                              constraint->cnstrt_referred_rel->str_string,
                              relation->rel_symbol->sym_string);
                  CPR_error(s);
            }
      }
}


//____________________________________________________________
//
//          Generate dyn for creating a constraint.
//

static void create_constraint( gpre_req* request, const act* action, cnstrt* constraint)
{
      for (; constraint; constraint = constraint->cnstrt_next)
      {
            if (constraint->cnstrt_flags & CNSTRT_delete)
                  continue;
            put_cstring(request, isc_dyn_rel_constraint, constraint->cnstrt_name->str_string);

        switch (constraint->cnstrt_type)
        {
            case CNSTRT_PRIMARY_KEY:
                  request->add_byte(isc_dyn_def_primary_key);
                  break;
            case CNSTRT_UNIQUE:
                  request->add_byte(isc_dyn_def_unique);
                  break;
            case CNSTRT_FOREIGN_KEY:
                  request->add_byte(isc_dyn_def_foreign_key);
                  break;
            case CNSTRT_NOT_NULL:
                  request->add_byte(isc_dyn_fld_not_null);
                  request->add_end();
                  continue;
            case CNSTRT_CHECK:
                  create_check_constraint(request, action, constraint);
                  request->add_end();
                  continue;
            default:
                fb_assert(false);
            }

            // stuff a zero-length name, indicating that an index
            // name should be generated

            request->add_word(0);

            if (constraint->cnstrt_type == CNSTRT_FOREIGN_KEY)
            {
                  // If <referenced column list> is not specified try to catch
                  // them right here
                  if (constraint->cnstrt_referred_fields == NULL)
                        get_referred_fields(action, constraint);

                  if (constraint->cnstrt_fkey_def_type & REF_UPDATE_ACTION)
                  {
                        request->add_byte(isc_dyn_foreign_key_update);
                        switch (constraint->cnstrt_fkey_def_type & REF_UPDATE_MASK)
                        {
                        case REF_UPD_NONE:
                              request->add_byte(isc_dyn_foreign_key_none);
                              break;
                        case REF_UPD_CASCADE:
                              request->add_byte(isc_dyn_foreign_key_cascade);
                              create_upd_cascade_trg(request, action, constraint);
                              break;
                        case REF_UPD_SET_DEFAULT:
                              request->add_byte(isc_dyn_foreign_key_default);
                              create_set_default_trg(request, action, constraint, true);
                              break;
                        case REF_UPD_SET_NULL:
                              request->add_byte(isc_dyn_foreign_key_null);
                              create_set_null_trg(request, action, constraint, true);
                              break;
                        default:
                              // just in case
                              fb_assert(0);
                              request->add_byte(isc_dyn_foreign_key_none);
                              break;
                        }
                  }
                  if (constraint->cnstrt_fkey_def_type & REF_DELETE_ACTION)
                  {
                        request->add_byte(isc_dyn_foreign_key_delete);
                        switch (constraint->cnstrt_fkey_def_type & REF_DELETE_MASK)
                        {
                        case REF_DEL_NONE:
                              request->add_byte(isc_dyn_foreign_key_none);
                              break;
                        case REF_DEL_CASCADE:
                              request->add_byte(isc_dyn_foreign_key_cascade);
                              create_del_cascade_trg(request, action, constraint);
                              break;
                        case REF_DEL_SET_DEFAULT:
                              request->add_byte(isc_dyn_foreign_key_default);
                              create_set_default_trg(request, action, constraint, false);
                              break;
                        case REF_DEL_SET_NULL:
                              request->add_byte(isc_dyn_foreign_key_null);
                              create_set_null_trg(request, action, constraint, false);
                              break;
                        default:
                              // just in case
                              fb_assert(0);
                              request->add_byte(isc_dyn_foreign_key_none);
                              break;
                        }
                  }
            }
            else
                  put_numeric(request, isc_dyn_idx_unique, 1);

            for (const gpre_lls* field = constraint->cnstrt_fields; field; field = field->lls_next)
            {
                  const str* string = (STR) field->lls_object;
                  put_cstring(request, isc_dyn_fld_name, string->str_string);
            }
            if (constraint->cnstrt_type == CNSTRT_FOREIGN_KEY)
            {
                  put_cstring(request, isc_dyn_idx_foreign_key, constraint->cnstrt_referred_rel->str_string);
                  for (const gpre_lls* field = constraint->cnstrt_referred_fields; field;
                        field = field->lls_next)
                  {
                        const str* string = (STR) field->lls_object;
                        put_cstring(request, isc_dyn_idx_ref_column, string->str_string);
                  }
            }
            request->add_end();
      }
}


//____________________________________________________________
//
//          Generate parameter buffer for CREATE DATABASE action.
//

static void create_database( gpre_req* request, const act* action)
{
      const gpre_dbb* db = ((mdbb*) action->act_object)->mdbb_database;
      request->add_byte(isc_dpb_version1);
      request->add_byte(isc_dpb_overwrite);
      request->add_byte(1);
      request->add_byte(0);

      request->add_byte(isc_dpb_sql_dialect);
      request->add_byte(sizeof(int));
      int def_db_dial = 3;
      if (gpreGlob.dialect_specified && (gpreGlob.sw_sql_dialect == 1 || gpreGlob.sw_sql_dialect == 3))
            def_db_dial = gpreGlob.sw_sql_dialect;
      request->add_long(def_db_dial);

#ifdef NOT_USED_OR_REPLACED
      if (db->dbb_allocation)
      {
            request->add_byte(isc_dpb_allocation);
            request->add_byte(4);
            request->add_long(db->dbb_allocation);
      }
#endif

      if (db->dbb_pagesize)
      {
            request->add_byte(isc_dpb_page_size);
            request->add_byte(4);
            request->add_long(db->dbb_pagesize);
      }

      if (db->dbb_buffercount)
      {
            request->add_byte(isc_dpb_num_buffers);
            request->add_byte(4);
            request->add_long(db->dbb_buffercount);
      }

      SSHORT l;

      if (db->dbb_c_user && !db->dbb_r_user)
      {
            request->add_byte(isc_dpb_user_name);
            l = strlen(db->dbb_c_user);
            request->add_byte(l);
            const char* ch = db->dbb_c_user;
            while (*ch)
                  request->add_byte(*ch++);
      }

      if (db->dbb_c_password && !db->dbb_r_password)
      {
            request->add_byte(isc_dpb_password);
            l = strlen(db->dbb_c_password);
            request->add_byte(l);
            const char* ch = db->dbb_c_password;
            while (*ch)
                  request->add_byte(*ch++);
      }

      *request->req_blr = 0;
      request->req_length = request->req_blr - request->req_base;
      if (request->req_length == 1)
            request->req_length = 0;
      request->req_blr = request->req_base;
}


//____________________________________________________________
//
//          Generate dynamic DDL for second stage of create database
//

static void create_database_modify_dyn( gpre_req* request, act* action)
{
      gpre_dbb* db = ((mdbb*) action->act_object)->mdbb_database;

      request->add_byte(isc_dyn_mod_database);

      // Reverse the order of files (parser left them backwards)

      gpre_file* next;
      gpre_file* files = NULL;
      for (gpre_file* file = db->dbb_files; file; file = next)
      {
            next = file->fil_next;
            file->fil_next = files;
            files = file;
      }

      SLONG start = db->dbb_length;

      for (const gpre_file* file = files; file != NULL; file = file->fil_next)
      {
            put_cstring(request, isc_dyn_def_file, file->fil_name);
            request->add_byte(isc_dyn_file_start);
            request->add_word(4);
            start = MAX(start, file->fil_start);
            request->add_long(start);
            request->add_byte(isc_dyn_file_length);
            request->add_word(4);
            request->add_long(file->fil_length);
            request->add_end();
            start += file->fil_length;
      }

/*
      if (db->dbb_cache_file)
            add_cache(request, action, db);
*/

      if (db->dbb_def_charset)
            put_cstring(request, isc_dyn_fld_character_set_name, db->dbb_def_charset);

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for CREATE DOMAIN action.
//

static void create_domain( gpre_req* request, const act* action)
{
      const gpre_fld* field = (gpre_fld*) action->act_object;

      // add field info

      put_symbol(request, isc_dyn_def_global_fld, field->fld_symbol);
      put_field_attributes(request, field);

      if (field->fld_default_value)
      {
            put_blr(request, isc_dyn_fld_default_value, field->fld_default_value, CME_expr);
            TEXT* default_source = (TEXT*) MSC_alloc(field->fld_default_source->txt_length + 1);
            CPR_get_text(default_source, field->fld_default_source);
            put_cstring(request, isc_dyn_fld_default_source, default_source);
      }

      if (field->fld_constraints)
            create_domain_constraint(request, field->fld_constraints);

      request->add_end();
}


//____________________________________________________________
//
//          Generate dyn for creating a constraints for domains.
//

static void create_domain_constraint(gpre_req* request, const cnstrt* constraint)
{
      for (; constraint; constraint = constraint->cnstrt_next)
      {
            if (constraint->cnstrt_flags & CNSTRT_delete)
                  continue;

            // this will be used later
            // put_cstring (request, isc_dyn_rel_constraint, constraint->cnstrt_name->str_string);

            if (constraint->cnstrt_type == CNSTRT_CHECK)
            {
                  TEXT* source = (TEXT*) MSC_alloc(constraint->cnstrt_text->txt_length + 1);
                  CPR_get_text(source, constraint->cnstrt_text);
                  if (source != NULL)
                        put_cstring(request, isc_dyn_fld_validation_source, source);
                  put_blr(request, isc_dyn_fld_validation_blr, constraint->cnstrt_boolean, CME_expr);
            }
      }
}


//____________________________________________________________
//
//          Generate dynamic DDL for creating a generator.
//

static void create_generator( gpre_req* request, const act* action)
{
      const TEXT* generator_name = (TEXT*) action->act_object;
      put_cstring(request, isc_dyn_def_generator, generator_name);
      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for CREATE INDEX action.
//

static void create_index( gpre_req* request, const gpre_index* index)
{
      if (index->ind_symbol)
            put_symbol(request, isc_dyn_def_idx, index->ind_symbol);
      else
      {
            // An index created because of the UNIQUE constraint on this field.
            put_cstring(request, isc_dyn_def_idx, "");
      }

      put_symbol(request, isc_dyn_rel_name, index->ind_relation->rel_symbol);

      if (index->ind_flags & IND_dup_flag)
            put_numeric(request, isc_dyn_idx_unique, 1);

      if (index->ind_flags & IND_descend)
            put_numeric(request, isc_dyn_idx_type, 1);

      if (index->ind_symbol)
      {
            for (const gpre_fld* field = index->ind_fields; field; field = field->fld_next)
            {
                  put_symbol(request, isc_dyn_fld_name, field->fld_symbol);
            }
      }
      else
      {
            // An index created on this one field because of the UNIQUE constraint on this field.
            put_symbol(request, isc_dyn_fld_name, index->ind_fields->fld_symbol);
      }

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for creating a shadow
//

static void create_shadow( gpre_req* request, act* action)
{
      gpre_file* files = (gpre_file*) action->act_object;
      gpre_file* file;

      // Reverse the order of files (parser left them backwards)
      gpre_file* next;
      for (file = files, files = NULL; file; file = next)
      {
            next = file->fil_next;
            file->fil_next = files;
            files = file;
      }
      put_numeric(request, isc_dyn_def_shadow, (SSHORT) files->fil_shadow_number);

      for (file = files; file != NULL; file = file->fil_next)
      {
            put_cstring(request, isc_dyn_def_file, file->fil_name);
            request->add_byte(isc_dyn_file_start);
            request->add_word(4);
            const SLONG start = file->fil_start;
            request->add_long(start);
            request->add_byte(isc_dyn_file_length);
            request->add_word(4);
            request->add_long(file->fil_length);
            if (file->fil_flags & FIL_manual)
                  put_numeric(request, isc_dyn_shadow_man_auto, 1);
            if (file->fil_flags & FIL_conditional)
                  put_numeric(request, isc_dyn_shadow_conditional, 1);
            request->add_end();
      }
      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for CREATE TABLE action.
//

static void create_table( gpre_req* request, const act* action)
{
      // add relation name

      const gpre_rel* relation = (gpre_rel*) action->act_object;
      put_symbol(request, isc_dyn_def_rel, relation->rel_symbol);

      // If the relation is defined as an external file, add dyn for that

      if (relation->rel_ext_file)
            put_cstring(request, isc_dyn_rel_ext_file, relation->rel_ext_file);

      put_numeric(request, isc_dyn_rel_sql_protection, 1);

      // add field info
      USHORT position = 0;
      for (const gpre_fld* field = relation->rel_fields; field; field = field->fld_next)
      {
            if (field->fld_global)
            {
                  put_symbol(request, isc_dyn_def_local_fld, field->fld_symbol);
                  put_symbol(request, isc_dyn_fld_source, field->fld_global);
            }
            else
                  put_symbol(request, isc_dyn_def_sql_fld, field->fld_symbol);

            put_field_attributes(request, field);
            put_numeric(request, isc_dyn_fld_position, position++);

            if (field->fld_default_value)
            {
                  put_blr(request, isc_dyn_fld_default_value, field->fld_default_value, CME_expr);
                  TEXT* default_source = (TEXT*) MSC_alloc(field->fld_default_source->txt_length + 1);
                  CPR_get_text(default_source, field->fld_default_source);
                  put_cstring(request, isc_dyn_fld_default_source, default_source);
            }

            request->add_end();
            if (field->fld_constraints)
                  create_constraint(request, action, field->fld_constraints);
      }


      if (relation->rel_constraints)
            create_constraint(request, action, relation->rel_constraints);

      request->add_end();

      // Need to create an index for any fields (columns) declared with the UNIQUE constraint.

      for (const gpre_fld* field = relation->rel_fields; field; field = field->fld_next)
      {
            if (field->fld_index)
                  create_index(request, field->fld_index);
      }
}


//____________________________________________________________
//
//          Generate dynamic DDL for a trigger.
//

static void create_trigger(gpre_req* request,
                                       const act* action,
                                       gpre_trg* trigger, pfn_local_trigger_cb routine)
{
      const gpre_rel* relation = (gpre_rel*) action->act_object;

      // Name of trigger to be generated

      put_cstring(request, isc_dyn_def_trigger, "");

      put_symbol(request, isc_dyn_rel_name, relation->rel_symbol);
      put_numeric(request, isc_dyn_trg_type, trigger->trg_type);
      put_numeric(request, isc_dyn_trg_sequence, 0);
      put_numeric(request, isc_dyn_trg_inactive, 0);
      request->add_byte(isc_dyn_sql_object);

      if (trigger->trg_source != NULL)
            put_cstring(request, isc_dyn_trg_source, trigger->trg_source->str_string);

      if (trigger->trg_message != NULL)
      {
            put_numeric(request, isc_dyn_def_trigger_msg, 1);
            put_cstring(request, isc_dyn_trg_msg, trigger->trg_message->str_string);
            request->add_byte(isc_dyn_end);
      }

      // Generate the BLR for firing the trigger

      put_trigger_blr(request, isc_dyn_trg_blr, trigger->trg_boolean, routine);

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for CREATE VIEW action.
//

static bool create_view(gpre_req* request, act* action)
{
      // add relation name

      gpre_rel* relation = (gpre_rel*) action->act_object;
      put_symbol(request, isc_dyn_def_view, relation->rel_symbol);
      put_numeric(request, isc_dyn_rel_sql_protection, 1);

      // write out blr

      put_blr(request, isc_dyn_view_blr, (gpre_nod*) relation->rel_view_rse, CME_rse);

      // write out view source

      TEXT* view_source = (TEXT *) MSC_alloc(relation->rel_view_text->txt_length + 1);
      CPR_get_text(view_source, relation->rel_view_text);
      put_cstring(request, isc_dyn_view_source, view_source);

      // Write out view context info
      gpre_rel* sub_relation = 0;
      for (gpre_ctx* context = request->req_contexts; context; context = context->ctx_next)
      {
            sub_relation = context->ctx_relation;
            if (!sub_relation)
                  continue;
            put_symbol(request, isc_dyn_view_relation, sub_relation->rel_symbol);
            put_numeric(request, isc_dyn_view_context, context->ctx_internal);
            if (context->ctx_symbol)
                  put_symbol(request, isc_dyn_view_context_name, context->ctx_symbol);
            //if (context->ctx_type)
            //    put_numeric(request, isc_dyn_view_context_type, context->ctx_type);
            //if (context->ctx_package)
            //    put_symbol(request, isc_dyn_pkg_name, context->ctx_package);
            request->add_end();
      }

      // add the mapping from the rse to the view fields

      gpre_fld* field = relation->rel_fields;
      gpre_nod* fields = relation->rel_view_rse->rse_fields;
      SSHORT position = 0;
      bool non_updateable = false;

      gpre_nod** ptr;
      const gpre_nod* const* end;

      for (ptr = fields->nod_arg, end = ptr + fields->nod_count; ptr < end;
             ptr++, (field = field ? field->fld_next : NULL))
      {
            const gpre_fld* fld = NULL;
            const gpre_ctx* context = NULL;
            gpre_nod* value = *ptr;
            if (value->nod_type == nod_field)
            {
                  const ref* reference = (ref*) value->nod_arg[0];
                  fld = reference->ref_field;
                  const gpre_req* slice_req;
                  const slc* slice;
                  if ((value->nod_count >= 2) && (slice_req = (gpre_req*) value->nod_arg[2]) &&
                        (slice = slice_req->req_slice))
                  {
                              CPR_error("Array slices not supported in views");
                  }
                  context = reference->ref_context;
            }
            const gpre_sym* symbol;
            if (field)
                  symbol = field->fld_symbol;
            else if (fld)
                  symbol = fld->fld_symbol;
            else
            {
                  request->req_length = 0;
                  CPR_error("view expression requires field name");
                  return false;
            }
            if (fld)
            {
                  put_symbol(request, isc_dyn_def_local_fld, symbol);
                  put_symbol(request, isc_dyn_fld_base_fld, fld->fld_symbol);
                  put_numeric(request, isc_dyn_view_context, context->ctx_internal);
                  // ??? context_type, package???
            }
            else
            {
                  non_updateable = true;
                  put_symbol(request, isc_dyn_def_sql_fld, symbol);
                  put_blr(request, isc_dyn_fld_computed_blr, value, CME_expr);
                  gpre_fld tmp_field;
                  init_field_struct(&tmp_field);
                  CME_get_dtype(value, &tmp_field);
                  put_dtype(request, &tmp_field);
            }
            put_numeric(request, isc_dyn_fld_position, position++);
            request->add_end();
      }

      if (relation->rel_flags & REL_view_check)
      {
            // VIEW WITH CHECK OPTION
            // Make sure VIEW is updateable
            gpre_rse* select = relation->rel_view_rse;
            if (select->rse_aggregate || non_updateable || select->rse_count != 1)
            {
                  CPR_error("Invalid view WITH CHECK OPTION - non-updateable view");
                  return false;
            }

            if (!select->rse_boolean)
            {
                  CPR_error("Invalid view WITH CHECK OPTION - no WHERE clause");
                  return false;
            }

            // For the triggers, the OLD, NEW contexts are reserved

            request->req_internal = 0;
            request->req_contexts = 0;

            gpre_ctx* contexts[3];

            // Make the OLD context for the trigger
            gpre_ctx* context;

            contexts[0] = request->req_contexts = context = MSC_context(request);
            context->ctx_relation = relation;

            // Make the NEW context for the trigger

            contexts[1] = request->req_contexts = context = MSC_context(request);
            context->ctx_relation = relation;

            // Make the context for the  base relation

            contexts[2] = select->rse_context[0] = request->req_contexts =
                  context = MSC_context(request);
            context->ctx_relation = sub_relation;

            // Make lists to assign from NEW fields to fields in the base relation.
            // Also make sure rows in base relation correspond to rows in VIEW by
            // making sure values in fields inherited by the VIEW are same as
            // values in base relation.

            field = relation->rel_fields;
            fields = relation->rel_view_rse->rse_fields;
            gpre_nod* and_nod = 0;
            gpre_nod* or_node = 0;
            SSHORT count = 0;
            gpre_lls* stack = NULL;
            for (ptr = fields->nod_arg, end = ptr + fields->nod_count; ptr < end;
                   ptr++, (field = field ? field->fld_next : NULL))
            {
                  gpre_fld* fld = NULL;
                  gpre_nod* value = *ptr;
                  if (value->nod_type == nod_field)
                  {
                        ref* reference = (ref*) value->nod_arg[0];
                        reference->ref_context = contexts[2];
                        fld = reference->ref_field;
                  }
                  ref* view_ref = MSC_reference(0);
                  view_ref->ref_context = contexts[0];
                  ref* new_view_ref = MSC_reference(0);
                  new_view_ref->ref_context = contexts[1];
                  new_view_ref->ref_field = view_ref->ref_field = field ? field : fld;
                  gpre_nod* view_field = MSC_unary(nod_field, (gpre_nod*) view_ref);
                  gpre_nod* new_view_field = MSC_unary(nod_field, (gpre_nod*) new_view_ref);

                  gpre_nod* anull_node = MSC_unary(nod_missing, view_field);
                  gpre_nod* bnull_node = MSC_unary(nod_missing, value);
                  gpre_nod* iand_node = MSC_binary(nod_and, anull_node, bnull_node);

                  gpre_nod* eq_nod = MSC_binary(nod_eq, view_field, value);

                  or_node = MSC_binary(nod_or, eq_nod, iand_node);

                  gpre_nod* set_item = MSC_node(nod_assignment, 2);
                  set_item->nod_arg[1] = value;
                  set_item->nod_arg[0] = new_view_field;
                  MSC_push(set_item, &stack);
                  count++;

                  if (!or_node)
                        or_node = MSC_binary(nod_or, eq_nod, iand_node);
                  else if (!and_nod)
                        and_nod = MSC_binary(nod_and, or_node, MSC_binary(nod_or, eq_nod, iand_node));
                  else
                        and_nod = MSC_binary(nod_and, and_nod, MSC_binary(nod_or, eq_nod, iand_node));
            }

            gpre_nod* set_list = MSC_node(nod_list, count);
            ptr = set_list->nod_arg + count;
            while (stack)
                  *--ptr = (gpre_nod*) MSC_pop(&stack);

            // Modify the context of fields in boolean to be that of the
            // sub-relation.

            replace_field_names(select->rse_boolean, 0, 0, false, contexts);

            gpre_nod* view_boolean = select->rse_boolean;
            select->rse_boolean = MSC_binary(nod_and, and_nod ? and_nod : or_node, select->rse_boolean);

            // create the UPDATE trigger

            gpre_trg* trigger = (gpre_trg*) MSC_alloc(TRG_LEN);
            trigger->trg_type = PRE_MODIFY_TRIGGER;

            // "update violates CHECK constraint on view"

            trigger->trg_message = NULL;
            trigger->trg_boolean = (gpre_nod*) select;
            create_view_trigger(request, action, trigger, view_boolean, contexts);

            // create the Pre-store trigger

            trigger->trg_type = PRE_STORE_TRIGGER;

            // "insert violates CHECK constraint on view"

            create_view_trigger(request, action, trigger, view_boolean, contexts);
      }

      request->add_end();

      return true;
}


//____________________________________________________________
//
//          Generate dynamic DDL for a trigger.
//

static void create_view_trigger(gpre_req* request,
                                                const act* action,
                                                gpre_trg* trigger,
                                                gpre_nod* view_boolean,
                                                gpre_ctx** contexts)
{
      const gpre_rel* relation = (gpre_rel*) action->act_object;

      // Name of trigger to be generated

      put_cstring(request, isc_dyn_def_trigger, "");

      put_symbol(request, isc_dyn_rel_name, relation->rel_symbol);
      put_numeric(request, isc_dyn_trg_type, trigger->trg_type);
      put_numeric(request, isc_dyn_trg_sequence, 0);
      request->add_byte(isc_dyn_sql_object);

      if (trigger->trg_source != NULL)
            put_cstring(request, isc_dyn_trg_source, trigger->trg_source->str_string);

      if (trigger->trg_message != NULL)
      {
            put_numeric(request, isc_dyn_def_trigger_msg, 1);
            put_cstring(request, isc_dyn_trg_msg, trigger->trg_message->str_string);
            request->add_byte(isc_dyn_end);
      }

      // Generate the BLR for firing the trigger

      put_view_trigger_blr(request, relation, isc_dyn_trg_blr, trigger, view_boolean, contexts);

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for DECLARE FILTER action.
//

static void declare_filter( gpre_req* request, const act* action)
{
      const gpre_filter* filter = (gpre_filter*) action->act_object;
      put_cstring(request, isc_dyn_def_filter, filter->fltr_name);
      put_numeric(request, isc_dyn_filter_in_subtype, filter->fltr_input_type);
      put_numeric(request, isc_dyn_filter_out_subtype,
                        filter->fltr_output_type);
      put_cstring(request, isc_dyn_func_entry_point, filter->fltr_entry_point);

      put_cstring(request, isc_dyn_func_module_name, filter->fltr_module_name);
      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for DECLARE EXTERNAL
//

static void declare_udf( gpre_req* request, const act* action)
{
      const decl_udf* udf_declaration = (decl_udf*) action->act_object;
      const TEXT* udf_name = udf_declaration->decl_udf_name;
      put_cstring(request, isc_dyn_def_function, udf_name);
      put_cstring(request, isc_dyn_func_entry_point, udf_declaration->decl_udf_entry_point);
      put_cstring(request, isc_dyn_func_module_name, udf_declaration->decl_udf_module_name);

      // Reverse the order of arguments which parse left backwords.

      //for (field = udf_declaration->decl_udf_arg_list, udf_declaration->decl_udf_arg_list = NULL; field; field = next)
      //{
      //    next = field->fld_next;
      //    field->fld_next = udf_declaration->decl_udf_arg_list;
      //    udf_declaration->decl_udf_arg_list = field;
      //}

      SSHORT position, blob_position = 0;
      const gpre_fld* field = udf_declaration->decl_udf_return_type;
      if (field)
      {
            // Function returns a value

            // Some data types can not be returned as value
            if (udf_declaration->decl_udf_return_mode == FUN_value)
            {
                  switch (field->fld_dtype)
                  {
                  case dtype_text:
                  case dtype_varying:
                  case dtype_cstring:
                  case dtype_blob:
                  case dtype_timestamp:
                        CPR_error("return mode by value not allowed for this data type");
                  }
            }

            // For functions returning a blob, coerce return argument position to
            // be the last parameter.

            if (field->fld_dtype == dtype_blob)
            {
                  blob_position = 1;
                  for (const gpre_fld* next = udf_declaration->decl_udf_arg_list; next; next = next->fld_next)
                  {
                        ++blob_position;
                  }
                  put_numeric(request, isc_dyn_func_return_argument, blob_position);
            }
            else
                  put_numeric(request, isc_dyn_func_return_argument, 0);

            position = 0;
      }
      else {
            position = 1;

            // Function modifies an argument whose value is the function return value

            put_numeric(request, isc_dyn_func_return_argument, udf_declaration->decl_udf_return_parameter);
      }

      // Now define all the arguments

      if (!position)
      {
            if (field->fld_dtype == dtype_blob)
            {
                  put_numeric(request, isc_dyn_def_function_arg, blob_position);
                  put_numeric(request, isc_dyn_func_mechanism, FUN_blob_struct);
            }
            else
            {
                  put_numeric(request, isc_dyn_def_function_arg, 0);
                  put_numeric(request, isc_dyn_func_mechanism, udf_declaration->decl_udf_return_mode);
            }

            put_cstring(request, isc_dyn_function_name, udf_name);
            put_dtype(request, field);
            request->add_byte(isc_dyn_end);
            position = 1;
      }

      for (field = udf_declaration->decl_udf_arg_list; field; field = field->fld_next)
      {
            if (position > 10)
                  CPR_error("External functions can not have more than 10 parameters");
            put_numeric(request, isc_dyn_def_function_arg, position++);

            if (field->fld_dtype == dtype_blob)
                  put_numeric(request, isc_dyn_func_mechanism, FUN_blob_struct);
            else
                  put_numeric(request, isc_dyn_func_mechanism, FUN_reference);

            put_cstring(request, isc_dyn_function_name, udf_name);
            put_dtype(request, field);
            request->add_byte(isc_dyn_end);
      }

      request->add_end();
}


//____________________________________________________________
//
//          Generate dynamic DDL for GRANT or
//          REVOKE privileges action.
//

static void grant_revoke_privileges( gpre_req* request, const act* action)
{
      TEXT privileges[7];
      TEXT* p = privileges;
      const prv* priv_block = (PRV) action->act_object;

      if (priv_block->prv_privileges & PRV_select)
            *p++ = 'S';

      if (priv_block->prv_privileges & PRV_insert)
            *p++ = 'I';

      if (priv_block->prv_privileges & PRV_delete)
            *p++ = 'D';

      if (priv_block->prv_privileges & PRV_execute)
            *p++ = 'X';

      if (priv_block->prv_privileges & PRV_all)
            *p++ = 'A';

      if (priv_block->prv_privileges & PRV_references)
            *p++ = 'R';

      *p = 0;

      // If there are any select, insert, or delete privileges to be granted
      // or revoked output the necessary DYN strings

      if (p != privileges)
      {
            for (priv_block = (PRV) action->act_object; priv_block; priv_block = priv_block->prv_next)
            {
                  if (action->act_type == ACT_dyn_grant)
                        put_cstring(request, isc_dyn_grant, privileges);
                  else                    // action = ACT_dyn_revoke
                        put_cstring(request, isc_dyn_revoke, privileges);

                  put_cstring(request, priv_block->prv_object_dyn, priv_block->prv_relation->str_string);
                  put_cstring(request, priv_block->prv_user_dyn, priv_block->prv_username);

                  if (priv_block->prv_privileges & PRV_grant_option)
                  {
                        put_numeric(request, isc_dyn_grant_options, 1);
                  }

                  request->add_end();
            }
      }

      // If there are no UPDATE privileges to be granted or revoked, we've finished

      if (!(((PRV) action->act_object)->prv_privileges & PRV_update))
            return;

      p = privileges;
      *p++ = 'U';
      *p = 0;

      for (priv_block = (PRV) action->act_object; priv_block; priv_block = priv_block->prv_next)
      {
            if (priv_block->prv_fields)
            {
                  for (const gpre_lls* field = priv_block->prv_fields; field; field = field->lls_next)
                  {
                        if (action->act_type == ACT_dyn_grant)
                              put_cstring(request, isc_dyn_grant, privileges);
                        else              // action->act_type == ACT_dyn_revoke
                              put_cstring(request, isc_dyn_revoke, privileges);

                        put_cstring(request, priv_block->prv_object_dyn, priv_block->prv_relation->str_string);
                        const str* string = (STR) field->lls_object;
                        put_cstring(request, isc_dyn_fld_name, string->str_string);
                        put_cstring(request, priv_block->prv_user_dyn, priv_block->prv_username);

                        if (priv_block->prv_privileges & PRV_grant_option)
                        {
                              put_numeric(request, isc_dyn_grant_options, 1);
                        }

                        request->add_end();
                  }
            }
            else
            {
                  // No specific fields mentioned;
                  // UPDATE privilege granted or revoked on all fields
                  if (action->act_type == ACT_dyn_grant)
                        put_cstring(request, isc_dyn_grant, privileges);
                  else                    // action->act_type == ACT_dyn_revoke
                        put_cstring(request, isc_dyn_revoke, privileges);

                  put_cstring(request, priv_block->prv_object_dyn, priv_block->prv_relation->str_string);
                  put_cstring(request, priv_block->prv_user_dyn, priv_block->prv_username);

                  if (priv_block->prv_privileges & PRV_grant_option)
                  {
                        put_numeric(request, isc_dyn_grant_options, 1);
                  }

                  request->add_end();
            }
      }
}


//____________________________________________________________
//
//
//

static void init_field_struct( gpre_fld* field)
{
      field->fld_dtype = 0;
      field->fld_length = 0;
      field->fld_scale = 0;
      field->fld_id = 0;
      field->fld_flags = 0;
      field->fld_seg_length = 0;
      field->fld_position = 0;
      field->fld_sub_type = 0;
      field->fld_next = 0;
      field->fld_array = 0;
      field->fld_relation = 0;
      field->fld_procedure = 0;
      field->fld_symbol = 0;
      field->fld_global = 0;
      field->fld_array_info = 0;
      field->fld_default_value = 0;
      field->fld_default_source = 0;
      field->fld_index = 0;
      field->fld_constraints = 0;
      field->fld_character_set = 0;
      field->fld_collate = 0;
      field->fld_computed = 0;
      field->fld_char_length = 0;
      field->fld_charset_id = 0;
      field->fld_collate_id = 0;
}


//____________________________________________________________
//
//          Put dimensions for the array field.
//

static void put_array_info( gpre_req* request, const gpre_fld* field)
{
      const ary* array_info = field->fld_array_info;
      const SSHORT dims = (SSHORT) array_info->ary_dimension_count;
      put_numeric(request, isc_dyn_fld_dimensions, dims);
      for (SSHORT i = 0; i < dims; ++i)
      {
            put_numeric(request, isc_dyn_def_dimension, i);
            request->add_byte(isc_dyn_dim_lower);
            const SLONG lrange = (SLONG) (array_info->ary_rpt[i].ary_lower);
            request->add_word(4);
            request->add_long(lrange);
            request->add_byte(isc_dyn_dim_upper);
            const SLONG urange = (SLONG) (array_info->ary_rpt[i].ary_upper);
            request->add_word(4);
            request->add_long(urange);
            request->add_byte(isc_dyn_end);
      }
}


//____________________________________________________________
//
//          Put an expression expressed in BLR.
//

static void put_blr(gpre_req* request,
                              USHORT blr_operator, gpre_nod* node, pfn_local_trigger_cb routine)
{
      request->add_byte(blr_operator);
      const USHORT offset = request->req_blr - request->req_base;
      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);
      (*routine) (node, request);
      request->add_byte(blr_eoc);
      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
}


//____________________________________________________________
//
//          Generate dynamic DDL for a computed field.
//

static void put_computed_blr( gpre_req* request, const gpre_fld* field)
{
      //const act* action = request->req_actions;
      //const gpre_rel* relation = (gpre_rel*) action->act_object;

      // Computed field context has to be 0 - so force it

      gpre_ctx* context = request->req_contexts;
      const USHORT save_ctx_int = context->ctx_internal;
      context->ctx_internal = 0;
      request->add_byte(isc_dyn_fld_computed_blr);

      const USHORT offset = request->req_blr - request->req_base;
      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);
      CME_expr(field->fld_computed->cmpf_boolean, request);
      request->add_byte(blr_eoc);

      context->ctx_internal = save_ctx_int;

      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
}


//____________________________________________________________
//
//          Generate dynamic DDL for a computed field.
//

static void put_computed_source( gpre_req* request, const gpre_fld* field)
{
      //const act* action = request->req_actions;
      //const gpre_rel* relation = (gpre_rel*) action->act_object;

      if (field->fld_computed->cmpf_text != NULL)
      {
            TEXT* computed_source = (TEXT*) MSC_alloc(field->fld_computed->cmpf_text->txt_length + 1);
            CPR_get_text(computed_source, field->fld_computed->cmpf_text);
            put_cstring(request, isc_dyn_fld_computed_source, computed_source);
      }
}


//____________________________________________________________
//
//          Put a null-terminated string valued attributed to the output string.
//

static void put_cstring(gpre_req* request, USHORT ddl_operator,
                                    const TEXT* string)
{
      USHORT length = 0;
      if (string != NULL)
            length = strlen(string);

      put_string(request, ddl_operator, string, length);
}


//____________________________________________________________
//
//          Generate dynamic DDL to create a field for CREATE
//          or ALTER TABLE action.
//

static void put_dtype( gpre_req* request, const gpre_fld* field)
{
      USHORT dtype = 0;

      USHORT length = field->fld_length;
      //const USHORT precision = field->fld_precision;
      //const USHORT sub_type = field->fld_sub_type;
      switch (field->fld_dtype)
      {
      case dtype_cstring:

            // If the user is defining a field as cstring then generate
            // blr_cstring. Currently being used only for defining udf's

            if (field->fld_flags & FLD_meta_cstring)
                  dtype = blr_cstring;
            else
            {

                  // Correct the length of C string for meta data operations

                  if (gpreGlob.sw_cstring && field->fld_sub_type != dsc_text_type_fixed)
                        length--;
                  dtype = blr_text;
            }

      case dtype_text:
            if (field->fld_dtype == dtype_text)
                  dtype = blr_text;
            // Fall into

      case dtype_varying:
            fb_assert(length);
            if (field->fld_dtype == dtype_varying)
                  dtype = blr_varying;

            put_numeric(request, isc_dyn_fld_type, dtype);
            put_numeric(request, isc_dyn_fld_length, length);
            put_numeric(request, isc_dyn_fld_scale, 0);

            if (field->fld_sub_type)
                  put_numeric(request, isc_dyn_fld_sub_type, field->fld_sub_type);

            if (field->fld_char_length)
                  put_numeric(request, isc_dyn_fld_char_length, field->fld_char_length);
            if (field->fld_collate_id)
                  put_numeric(request, isc_dyn_fld_collation, field->fld_collate_id);

            if (field->fld_charset_id)
                  put_numeric(request, isc_dyn_fld_character_set, field->fld_charset_id);
            return;

      case dtype_short:
            dtype = blr_short;
            length = sizeof(SSHORT);
            if (gpreGlob.sw_server_version >= 6)
            {
                  put_numeric(request, isc_dyn_fld_type, dtype);
                  put_numeric(request, isc_dyn_fld_length, length);
                  put_numeric(request, isc_dyn_fld_scale, field->fld_scale);
                  put_numeric(request, isc_dyn_fld_precision, field->fld_precision);
                  put_numeric(request, isc_dyn_fld_sub_type, field->fld_sub_type);
                  return;
            }
            break;

      case dtype_long:
            dtype = blr_long;
            length = sizeof(SLONG);
            if (gpreGlob.sw_server_version >= 6)
            {
                  put_numeric(request, isc_dyn_fld_type, dtype);
                  put_numeric(request, isc_dyn_fld_length, length);
                  put_numeric(request, isc_dyn_fld_scale, field->fld_scale);
                  put_numeric(request, isc_dyn_fld_precision, field->fld_precision);
                  put_numeric(request, isc_dyn_fld_sub_type, field->fld_sub_type);
                  return;
            }
            break;

      case dtype_blob:
            dtype = blr_blob;
            length = 8;
            put_numeric(request, isc_dyn_fld_type, dtype);
            put_numeric(request, isc_dyn_fld_length, length);
            put_numeric(request, isc_dyn_fld_scale, 0);
            put_numeric(request, isc_dyn_fld_sub_type, field->fld_sub_type);
            put_numeric(request, isc_dyn_fld_segment_length, field->fld_seg_length);
            if (field->fld_sub_type == isc_blob_text && field->fld_charset_id)
                  put_numeric(request, isc_dyn_fld_character_set, field->fld_charset_id);
            return;

      case dtype_quad:
            dtype = blr_quad;
            length = 8;
            break;

      case dtype_real:
            dtype = blr_float;
            length = sizeof(float);
            break;

      case dtype_double:
            dtype = blr_double;
            length = sizeof(double);
            break;

      // Begin sql date/time/timestamp
      case dtype_sql_date:
            dtype = blr_sql_date;
            length = sizeof(ISC_DATE);
            break;

      case dtype_sql_time:
            dtype = blr_sql_time;
            length = sizeof(ISC_TIME);
            break;

      case dtype_timestamp:
            dtype = blr_timestamp;
            length = sizeof(ISC_TIMESTAMP);
            break;
      // End sql date/time/timestamp

      case dtype_int64:
            dtype = blr_int64;
            length = sizeof(ISC_INT64);
            put_numeric(request, isc_dyn_fld_type, dtype);
            put_numeric(request, isc_dyn_fld_length, length);
            put_numeric(request, isc_dyn_fld_scale, field->fld_scale);
            put_numeric(request, isc_dyn_fld_precision, field->fld_precision);
            put_numeric(request, isc_dyn_fld_sub_type, field->fld_sub_type);
            return;

      default:
            CPR_bugcheck(" *** Unknown datatype in put_dtype *** ");
            break;
      }

      put_numeric(request, isc_dyn_fld_type, dtype);
      put_numeric(request, isc_dyn_fld_length, length);
      put_numeric(request, isc_dyn_fld_scale, field->fld_scale);

}


//____________________________________________________________
//
//          Generate dynamic DDL to create a field for CREATE
//          or ALTER TABLE action.
//
//          Emit the DDL that is appopriate for a local instance
//          of a field.  eg: that can vary from the local fields
//          global field (DOMAIN in SQL).
//

static void put_field_attributes( gpre_req* request, const gpre_fld* field)
{

      if (field->fld_flags & FLD_computed)
            put_computed_blr(request, field);

      if (!field->fld_global)
            put_dtype(request, field);

      // Put the DDL for local field instances

      if (field->fld_array_info)
            put_array_info(request, field);

      if (field->fld_collate && field->fld_global) {
            put_numeric(request, isc_dyn_fld_collation, field->fld_collate->intlsym_collate_id);
      }

      if (field->fld_flags & FLD_not_null) {
            request->add_byte(isc_dyn_fld_not_null);
      }

      if (field->fld_flags & FLD_computed)
            put_computed_source(request, field);
}


//____________________________________________________________
//
//          Put a numeric valued attributed to the output string.
//

static void put_numeric( gpre_req* request, USHORT blr_operator, SSHORT number)
{

      request->add_byte(blr_operator);
      request->add_word(2);
      request->add_word(number);
}


//____________________________________________________________
//
//          Put a counted string valued attributed to the output string.
//          Count value is BYTE instead of WORD like put_cstring & put_string
//

static void put_short_cstring(gpre_req* request, USHORT ddl_operator, const TEXT* string)
{
      SSHORT length = 0;
      if (string != NULL)
            length = strlen(string);

      STUFF_CHECK(request, length);

      request->add_byte(ddl_operator);
      request->add_byte(length);

      if (string != NULL)
      {
            while (length--)
                  request->add_byte(*string++);
      }
}


//____________________________________________________________
//
//          Put a counted string valued attributed to the output string.
//

static void put_string(gpre_req* request, USHORT ddl_operator, const TEXT* string, USHORT length)
{

      STUFF_CHECK(request, length);

      if (ddl_operator)
      {
            request->add_byte(ddl_operator);
            request->add_word(length);
      }
      else
            request->add_byte(length);


      if (string != NULL)
      {
            while (length--)
                  request->add_byte(*string++);
      }
}


//____________________________________________________________
//
//          Put a symbol valued attribute.
//

static void put_symbol(gpre_req* request, int ddl_operator, const gpre_sym* symbol)
{
      put_cstring(request, (USHORT) ddl_operator, symbol->sym_string);
}


//____________________________________________________________
//
//          Generate BLR for a trigger whose action is to abort.
//          Abort with a gds_error code error.
//

static void put_trigger_blr(gpre_req* request,
                                          USHORT blr_operator,
                                          gpre_nod* node, pfn_local_trigger_cb routine)
{
      request->add_byte(blr_operator);
      const USHORT offset = request->req_blr - request->req_base;
      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);
      request->add_byte(blr_begin);
      request->add_byte(blr_if);
      (*routine) (node, request);
      request->add_byte(blr_begin);
      request->add_byte(blr_end);

      // Generate the action for the trigger to be abort

      request->add_byte(blr_abort);
      put_short_cstring(request, blr_gds_code, "check_constraint");
      request->add_byte(blr_end);                     // for if
      request->add_byte(blr_eoc);
      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
}


//____________________________________________________________
//
//          Generate BLR for a trigger for a VIEW WITH CHECK OPTION.
//          This is messy, the gpre_rse passed in is mutilated by the end.
//          Fields in the where clause and in the VIEW definition, are replaced
//          by the VIEW fields.
//          For fields in the where clause but not in the VIEW definition,
//          the fields are set to NULL node for the PRE STORE trigger.
//
//

static void put_view_trigger_blr(gpre_req* request,
                                                 const gpre_rel* relation,
                                                 USHORT blr_operator,
                                                 gpre_trg* trigger,
                                                 gpre_nod* view_boolean, gpre_ctx** contexts)
{
      gpre_rse* node = (gpre_rse*) trigger->trg_boolean;
      request->add_byte(blr_operator);
      const USHORT offset = request->req_blr - request->req_base;
      request->add_word(0);
      if (request->req_flags & REQ_blr_version4)
            request->add_byte(blr_version4);
      else
            request->add_byte(blr_version5);
      request->add_byte(blr_begin);

      if (trigger->trg_type == PRE_MODIFY_TRIGGER)
      {
            request->add_byte(blr_for);
            CME_rse(node, request);

            // For the boolean, replace all fields in the rse and the view, with the
            // equivalent view field_name, for remaining fields in rse, leave them
            // alone.

            replace_field_names(view_boolean, node->rse_fields, relation->rel_fields, false, contexts);

            request->add_byte(blr_begin);
            request->add_byte(blr_if);
            CME_expr(view_boolean, request);

            request->add_byte(blr_begin);
            request->add_byte(blr_end);

            // Generate the action for the trigger to be abort

            request->add_byte(blr_abort);
            put_short_cstring(request, blr_gds_code, "check_constraint");
            request->add_byte(blr_end);
            request->add_byte(blr_end);
            request->add_byte(blr_eoc);
      }                                         // end of PRE_MODIFY_TRIGGER trigger

      if (trigger->trg_type == PRE_STORE_TRIGGER)
      {
            replace_field_names(view_boolean, node->rse_fields, relation->rel_fields, true, contexts);

            request->add_byte(blr_if);
            CME_expr(view_boolean, request);

            request->add_byte(blr_begin);
            request->add_byte(blr_end);

            // Generate the action for the trigger to be abort

            request->add_byte(blr_abort);
            put_short_cstring(request, blr_gds_code, "check_constraint");
            request->add_byte(blr_end);
            request->add_byte(blr_eoc);
      }                                         // end of PRE_STORE_TRIGGER trigger

      const USHORT length = request->req_blr - request->req_base - offset - 2;
      request->req_base[offset] = (UCHAR) length;
      request->req_base[offset + 1] = (UCHAR) (length >> 8);
}


//____________________________________________________________
//
//          Replace fields in given rse by fields referenced in VIEW.
//          if fields in gpre_rse are not part of VIEW definition, then they
//          are not changed.
//          If search list is not specified, then only the context of the fields
//          in the rse is chaged to contexts[2].
//          If null_them is true, then fields in rse but not in VIEW definition
//          are converted to null nodes, this is used for PRE STORE trigger
//          verification.
//

static void replace_field_names(gpre_nod* const input,
                                                const gpre_nod* const search_list,
                                                gpre_fld* const replace_with,
                                                bool null_them,
                                                gpre_ctx** contexts)
{
      if (!input)
            return;

      if ((input->nod_type == nod_via || input->nod_type == nod_any || input->nod_type == nod_unique) &&
            search_list == 0 && replace_with == 0 && input->nod_count == 0)
      {
            CPR_error("Invalid view WITH CHECK OPTION - no subqueries permitted");
            return;
      }

      gpre_nod** ptr = input->nod_arg;
      for (const gpre_nod* const* const end = ptr + input->nod_count; ptr < end; ptr++)
      {
            if ((*ptr)->nod_type == nod_field)
            {
                  ref* reference = (ref*) (*ptr)->nod_arg[0];
                  gpre_fld* rse_field = reference->ref_field;
                  if (null_them)
                  {
                        if (reference->ref_context == contexts[2]) {
                              *ptr = MSC_node(nod_null, 0);
                        }
                        continue;
                  }
                  reference->ref_context = contexts[2];
                  if (!search_list)
                        continue;
                  gpre_fld* view_field = replace_with;
                  gpre_nod* const* ptrs = search_list->nod_arg;
                  for (gpre_nod* const* const ends = ptrs + search_list->nod_count;
                        ptrs < ends;
                        ptrs++, view_field = view_field ? view_field->fld_next : NULL)
                  {
                        const ref* references = (ref*) (*ptrs)->nod_arg[0];
                        gpre_fld* select_field = references->ref_field;
                        if (rse_field == select_field)
                        {
                              reference->ref_field = view_field ? view_field : select_field;
                              reference->ref_context = contexts[1];
                              break;
                        }
                  }
            }
            else
                  replace_field_names(*ptr, search_list, replace_with, null_them, contexts);
      }
}


//____________________________________________________________
//
//          Generate dynamic DDL for a set statistics
//

static void set_statistics( gpre_req* request, const act* action)
{
      const sts* stats = (STS) action->act_object;
      if (stats)
            if (stats->sts_flags & STS_index)
            {
                  put_cstring(request, isc_dyn_mod_idx, stats->sts_name->str_string);
                  request->add_byte(isc_dyn_idx_statistic);
            }

      request->add_end();
}


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