/*
  Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.

  The MySQL Connector/ODBC is licensed under the terms of the GPLv2
  <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most
  MySQL Connectors. There are special exceptions to the terms and
  conditions of the GPLv2 as it is applied to this software, see the
  FLOSS License Exception
  <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
  
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published
  by the Free Software Foundation; version 2 of the License.
  
  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  for more details.
  
  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

/**
  @file  desc.c
  @brief Functions for handling descriptors.
*/

/***************************************************************************
 * The following ODBC APIs are implemented in this file:                   *
 *   SQLSetDescField     (ISO 92)                                          *
 *   SQLGetDescField     (ISO 92)                                          *
 *   SQLCopyDesc         (ISO 92)                                          *
 ****************************************************************************/

#include "driver.h"

/* Utility macros for defining descriptor fields */
#define HDR_FLD(field, perm, type) \
  static desc_field HDR_##field= \
    {(perm), (type), DESC_HDR, offsetof(DESC, field)}
    /* parens around field in offsetof() confuse GCC */

#define REC_FLD(field, perm, type) \
  static desc_field REC_##field= \
    {(perm), (type), DESC_REC, offsetof(DESCREC, field)}


/*
 * Allocate a new descriptor.
 * Should be used to allocate 'implicit' descriptors on the statement
 * or 'explicit' user-requested descriptors.
 */
DESC *desc_alloc(STMT *stmt, SQLSMALLINT alloc_type,
                 desc_ref_type ref_type, desc_desc_type desc_type)
{
  DESC *desc= (DESC *)my_malloc(sizeof(DESC), MYF(MY_ZEROFILL));
  if (!desc)
    return NULL;
  /*
     We let the dynamic array handle the memory for the whole DESCREC,
     but in desc_get_rec we manually get a pointer to it. This avoids
     having to call set_dynamic after modifying the DESCREC.
  */
  if (my_init_dynamic_array(&desc->records, sizeof(DESCREC), 0, 0))
  {
    x_free((char *)desc);
    return NULL;
  }
  desc->desc_type= desc_type;
  desc->alloc_type= alloc_type;
  desc->ref_type= ref_type;
  desc->stmt= stmt;
  /* spec-defined defaults/initialization */
  desc->array_size= 1;
  desc->array_status_ptr= NULL;
  desc->bind_offset_ptr= NULL;
  desc->bind_type= SQL_BIND_BY_COLUMN;
  desc->count= 0;
  desc->rows_processed_ptr= NULL;
  desc->exp.stmts= NULL;
  return desc;
}


/*
  Free a descriptor.
*/
void desc_free(DESC *desc)
{
  assert(desc);
  if (IS_APD(desc))
    desc_free_paramdata(desc);
  delete_dynamic(&desc->records);
  x_free(desc);
}


/*
  Free any memory allocated for SQLPutData(). This is only useful
  for APDs.
*/
void desc_free_paramdata(DESC *desc)
{
  SQLLEN i;
  for (i= 0; i < desc->count; ++i)
  {
    DESCREC *aprec= desc_get_rec(desc, i, FALSE);
    assert(aprec);
    if (aprec->par.alloced)
    {
      aprec->par.alloced= FALSE;
      x_free(aprec->par.value);
    }
  }
}


/*
 * Initialize APD
 */
void desc_rec_init_apd(DESCREC *rec)
{
  memset(rec, 0, sizeof(DESCREC));
  /* ODBC defaults */
  rec->concise_type= SQL_C_DEFAULT;
  rec->data_ptr= NULL;
  rec->indicator_ptr= NULL;
  rec->octet_length_ptr= NULL;
  rec->type= SQL_C_DEFAULT;

  /* internal */
  rec->par.alloced= FALSE;
  rec->par.value= NULL;
}


/*
 * Initialize IPD
 */
void desc_rec_init_ipd(DESCREC *rec)
{
  memset(rec, 0, sizeof(DESCREC));
  /* ODBC defaults */
  rec->fixed_prec_scale= SQL_TRUE;
  rec->local_type_name= (SQLCHAR *)"";
  rec->nullable= SQL_NULLABLE;
  rec->parameter_type= SQL_PARAM_INPUT;
  rec->type_name= (SQLCHAR *)"VARCHAR";
  rec->is_unsigned= SQL_FALSE;

  /* driver defaults */
  rec->name= (SQLCHAR *)"";
}


/*
 * Initialize ARD
 */
void desc_rec_init_ard(DESCREC *rec)
{
  memset(rec, 0, sizeof(DESCREC));
  /* ODBC defaults */
  rec->concise_type= SQL_C_DEFAULT;
  rec->data_ptr= NULL;
  rec->indicator_ptr= NULL;
  rec->octet_length_ptr= NULL;
  rec->type= SQL_C_DEFAULT;
}


/*
 * Initialize IRD
 */
void desc_rec_init_ird(DESCREC *rec)
{
  memset(rec, 0, sizeof(DESCREC));
  /* ODBC defaults */
  /* driver defaults */
  rec->auto_unique_value= SQL_FALSE;
  rec->case_sensitive= SQL_TRUE;
  rec->concise_type= SQL_VARCHAR;
  rec->display_size= 100;/*?*/
  rec->fixed_prec_scale= SQL_TRUE;
  rec->length= 100;/*?*/
  rec->nullable= SQL_NULLABLE_UNKNOWN;
  rec->type= SQL_VARCHAR;
  rec->type_name= (SQLCHAR *)"VARCHAR";
  rec->unnamed= SQL_UNNAMED;
  rec->is_unsigned= SQL_FALSE;
}


/*
 * Get a record from the descriptor.
 *
 * @param desc Descriptor
 * @param recnum 0-based record number
 * @param expand Whether to expand the descriptor to include the given
 *               recnum.
 * @return The requested record of NULL if it doesn't exist
 *         (and isn't created).
 */
DESCREC *desc_get_rec(DESC *desc, int recnum, my_bool expand)
{
  DESCREC *rec= NULL;
  int i;
  assert(recnum >= 0);
  /* expand if needed */
  if (expand)
  {
    for (i= desc->count; expand && i <= recnum; ++i)
    {
      /* we might have used records lying around from before if
       * SQLFreeStmt() was called with SQL_UNBIND or SQL_FREE_PARAMS
       */
      if (i < desc->records.elements)
      {
        rec= ((DESCREC *)desc->records.buffer) + recnum;
      }
      else
      {
        rec= (DESCREC *)alloc_dynamic(&desc->records);
        if (!rec)
          return NULL;
      }
      memset(rec, 0, sizeof(DESCREC));
      ++desc->count;

      /* record initialization */
      if (IS_APD(desc))
          desc_rec_init_apd(rec);
      else if (IS_IPD(desc))
          desc_rec_init_ipd(rec);
      else if (IS_ARD(desc))
          desc_rec_init_ard(rec);
      else if (IS_IRD(desc))
          desc_rec_init_ird(rec);
    }
  }
  if (recnum < desc->count)
    rec= ((DESCREC *)desc->records.buffer) + recnum;
  if (expand)
    assert(rec);
  return rec;
}


/*
 * Disassociate a statement from an explicitly allocated
 * descriptor.
 *
 * @param desc The descriptor
 * @param stmt The statement
 */
void desc_remove_stmt(DESC *desc, STMT *stmt)
{
  LIST *lstmt;

  if (desc->alloc_type != SQL_DESC_ALLOC_USER)
    return;

  for (lstmt= desc->exp.stmts; lstmt; lstmt= lstmt->next)
  {
    if (lstmt->data == stmt)
    {
      desc->exp.stmts= list_delete(desc->exp.stmts, lstmt);
      return;
    }
  }

  assert(!"Statement was not associated with descriptor");
}


/*
 * Check with the given descriptor contains any data-at-exec
 * records. Return the record number or -1 if none are found.
 */
int desc_find_dae_rec(DESC *desc)
{
  int i;
  DESCREC *rec;
  SQLLEN *octet_length_ptr;
  for (i= 0; i < desc->count; ++i)
  {
    rec= desc_get_rec(desc, i, FALSE);
    assert(rec);
    octet_length_ptr= ptr_offset_adjust(rec->octet_length_ptr,
                                        desc->bind_offset_ptr,
                                        desc->bind_type,
                                        sizeof(SQLLEN), /*row*/0);
    if (IS_DATA_AT_EXEC(octet_length_ptr))
      return i;
  }
  return -1;
}


/*
 * Apply the actual value to the descriptor field.
 *
 * @param dest Pointer to descriptor field to be set.
 * @param dest_type Type of descriptor field (same type constants as buflen).
 * @param src Value to be set.
 * @param buflen Length of value (as specified by SQLSetDescField).
 */
static void
apply_desc_val(void *dest, SQLSMALLINT dest_type, void *src, SQLINTEGER buflen)
{
  switch (buflen)
  {
  case SQL_IS_SMALLINT:
  case SQL_IS_INTEGER:
  case SQL_IS_LEN:
    if (dest_type == SQL_IS_SMALLINT)
      *(SQLSMALLINT *)dest= (SQLLEN)src;
    else if (dest_type == SQL_IS_USMALLINT)
      *(SQLUSMALLINT *)dest= (SQLLEN)src;
    else if (dest_type == SQL_IS_INTEGER)
      *(SQLINTEGER *)dest= (SQLLEN)src;
    else if (dest_type == SQL_IS_UINTEGER)
      *(SQLUINTEGER *)dest= (SQLLEN)src;
    else if (dest_type == SQL_IS_LEN)
      *(SQLLEN *)dest= (SQLLEN)src;
    else if (dest_type == SQL_IS_ULEN)
      *(SQLULEN *)dest= (SQLLEN)src;
    break;

  case SQL_IS_USMALLINT:
  case SQL_IS_UINTEGER:
  case SQL_IS_ULEN:
    if (dest_type == SQL_IS_SMALLINT)
      *(SQLSMALLINT *)dest= (SQLULEN)src;
    else if (dest_type == SQL_IS_USMALLINT)
      *(SQLUSMALLINT *)dest= (SQLULEN)src;
    else if (dest_type == SQL_IS_INTEGER)
      *(SQLINTEGER *)dest= (SQLULEN)src;
    else if (dest_type == SQL_IS_UINTEGER)
      *(SQLUINTEGER *)dest= (SQLULEN)src;
    else if (dest_type == SQL_IS_LEN)
      *(SQLLEN *)dest= (SQLULEN)src;
    else if (dest_type == SQL_IS_ULEN)
      *(SQLULEN *)dest= (SQLULEN)src;
    break;

  case SQL_IS_POINTER:
    *(SQLPOINTER *)dest= src;
    break;

  default:
    /* TODO it's an actual data length */
    /* free/malloc to the field and copy it */
    /* TODO .. check for 22001 - String data, right truncated
     * The FieldIdentifier argument was SQL_DESC_NAME,
     * and the BufferLength argument was a value larger
     * than SQL_MAX_IDENTIFIER_LEN.
     */
    break;
  }
}


/*
 * Get a descriptor field based on the constant.
 */
static desc_field *
getfield(SQLSMALLINT fldid)
{
  /* all field descriptions are immutable */
  /* See: SQLSetDescField() documentation
   * http://msdn2.microsoft.com/en-us/library/ms713560.aspx */
  HDR_FLD(alloc_type        , P_RI|P_RA          , SQL_IS_SMALLINT);
  HDR_FLD(array_size        , P_RA|P_WA          , SQL_IS_ULEN    );
  HDR_FLD(array_status_ptr  , P_RI|P_WI|P_RA|P_WA, SQL_IS_POINTER );
  HDR_FLD(bind_offset_ptr   , P_RA|P_WA          , SQL_IS_POINTER );
  HDR_FLD(bind_type         , P_RA|P_WA          , SQL_IS_INTEGER );
  HDR_FLD(count             , P_RI|P_WI|P_RA|P_WA, SQL_IS_LEN     );
  HDR_FLD(rows_processed_ptr, P_RI|P_WI          , SQL_IS_POINTER );

  REC_FLD(auto_unique_value, PR_RIR                     , SQL_IS_INTEGER);
  REC_FLD(base_column_name , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(base_table_name  , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(case_sensitive   , PR_RIR|PR_RIP              , SQL_IS_INTEGER);
  REC_FLD(catalog_name     , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(concise_type     , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_SMALLINT);
  REC_FLD(data_ptr         , PR_WAR|PR_WAP              , SQL_IS_POINTER);
  REC_FLD(display_size     , PR_RIR                     , SQL_IS_LEN);
  REC_FLD(fixed_prec_scale , PR_RIR|PR_RIP              , SQL_IS_SMALLINT);
  REC_FLD(indicator_ptr    , PR_WAR|PR_WAP              , SQL_IS_POINTER);
  REC_FLD(label            , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(length           , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_ULEN);
  REC_FLD(literal_prefix   , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(literal_suffix   , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(local_type_name  , PR_RIR|PR_RIP              , SQL_IS_POINTER);
  REC_FLD(name             , PR_RIR|PR_WIP              , SQL_IS_POINTER);
  REC_FLD(nullable         , PR_RIR|PR_RIP              , SQL_IS_SMALLINT);
  REC_FLD(num_prec_radix   , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_INTEGER);
  REC_FLD(octet_length     , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_LEN);
  REC_FLD(octet_length_ptr , PR_WAR|PR_WAP              , SQL_IS_POINTER);
  REC_FLD(parameter_type   , PR_WIP                     , SQL_IS_SMALLINT);
  REC_FLD(precision        , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_SMALLINT);
  REC_FLD(rowver           , PR_RIR|PR_RIP              , SQL_IS_SMALLINT);
  REC_FLD(scale            , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_SMALLINT);
  REC_FLD(schema_name      , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(searchable       , PR_RIR                     , SQL_IS_SMALLINT);
  REC_FLD(table_name       , PR_RIR                     , SQL_IS_POINTER);
  REC_FLD(type             , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_SMALLINT);
  REC_FLD(type_name        , PR_RIR|PR_RIP              , SQL_IS_POINTER);
  REC_FLD(unnamed          , PR_RIR|PR_WIP              , SQL_IS_SMALLINT);
  REC_FLD(is_unsigned      , PR_RIR|PR_RIP              , SQL_IS_SMALLINT);
  REC_FLD(updatable        , PR_RIR                     , SQL_IS_SMALLINT);
  REC_FLD(datetime_interval_code      , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_SMALLINT);
  REC_FLD(datetime_interval_precision , PR_WAR|PR_WAP|PR_RIR|PR_WIP, SQL_IS_INTEGER);

  /* match 'field' names above */
  switch(fldid)
  {
  case SQL_DESC_ALLOC_TYPE:
    return &HDR_alloc_type;
  case SQL_DESC_ARRAY_SIZE:
    return &HDR_array_size;
  case SQL_DESC_ARRAY_STATUS_PTR:
    return &HDR_array_status_ptr;
  case SQL_DESC_BIND_OFFSET_PTR:
    return &HDR_bind_offset_ptr;
  case SQL_DESC_BIND_TYPE:
    return &HDR_bind_type;
  case SQL_DESC_COUNT:
    return &HDR_count;
  case SQL_DESC_ROWS_PROCESSED_PTR:
    return &HDR_rows_processed_ptr;

  case SQL_DESC_AUTO_UNIQUE_VALUE:
    return &REC_auto_unique_value;
  case SQL_DESC_BASE_COLUMN_NAME:
    return &REC_base_column_name;
  case SQL_DESC_BASE_TABLE_NAME:
    return &REC_base_table_name;
  case SQL_DESC_CASE_SENSITIVE:
    return &REC_case_sensitive;
  case SQL_DESC_CATALOG_NAME:
    return &REC_catalog_name;
  case SQL_DESC_CONCISE_TYPE:
    return &REC_concise_type;
  case SQL_DESC_DATA_PTR:
    return &REC_data_ptr;
  case SQL_DESC_DISPLAY_SIZE:
    return &REC_display_size;
  case SQL_DESC_FIXED_PREC_SCALE:
    return &REC_fixed_prec_scale;
  case SQL_DESC_INDICATOR_PTR:
    return &REC_indicator_ptr;
  case SQL_DESC_LABEL:
    return &REC_label;
  case SQL_DESC_LENGTH:
    return &REC_length;
  case SQL_DESC_LITERAL_PREFIX:
    return &REC_literal_prefix;
  case SQL_DESC_LITERAL_SUFFIX:
    return &REC_literal_suffix;
  case SQL_DESC_LOCAL_TYPE_NAME:
    return &REC_local_type_name;
  case SQL_DESC_NAME:
    return &REC_name;
  case SQL_DESC_NULLABLE:
    return &REC_nullable;
  case SQL_DESC_NUM_PREC_RADIX:
    return &REC_num_prec_radix;
  case SQL_DESC_OCTET_LENGTH:
    return &REC_octet_length;
  case SQL_DESC_OCTET_LENGTH_PTR:
    return &REC_octet_length_ptr;
  case SQL_DESC_PARAMETER_TYPE:
    return &REC_parameter_type;
  case SQL_DESC_PRECISION:
    return &REC_precision;
  case SQL_DESC_ROWVER:
    return &REC_rowver;
  case SQL_DESC_SCALE:
    return &REC_scale;
  case SQL_DESC_SCHEMA_NAME:
    return &REC_schema_name;
  case SQL_DESC_SEARCHABLE:
    return &REC_searchable;
  case SQL_DESC_TABLE_NAME:
    return &REC_table_name;
  case SQL_DESC_TYPE:
    return &REC_type;
  case SQL_DESC_TYPE_NAME:
    return &REC_type_name;
  case SQL_DESC_UNNAMED:
    return &REC_unnamed;
  case SQL_DESC_UNSIGNED:
    return &REC_is_unsigned;
  case SQL_DESC_UPDATABLE:
    return &REC_updatable;
  case SQL_DESC_DATETIME_INTERVAL_CODE:
    return &REC_datetime_interval_code;
  case SQL_DESC_DATETIME_INTERVAL_PRECISION:
    return &REC_datetime_interval_precision;
  }
  return NULL;
}


/*
  @type    : ODBC 3.0 API
  @purpose : Get a field of a descriptor.
 */
SQLRETURN
MySQLGetDescField(SQLHDESC hdesc, SQLSMALLINT recnum, SQLSMALLINT fldid,
                  SQLPOINTER valptr, SQLINTEGER buflen, SQLINTEGER *outlen)
{
  desc_field *fld= getfield(fldid);
  DESC *desc= (DESC *)hdesc;
  void *src_struct;
  void *src;

  CLEAR_DESC_ERROR(desc);

  if (IS_IRD(desc) && desc->stmt->state < ST_PREPARED)
    /* TODO if it's prepared is the IRD still ok to access?
     * or must we pre-execute it */
    return set_desc_error(desc, "HY007",
              "Associated statement is not prepared",
              MYERR_S1007);

  if ((fld == NULL) ||
      /* header permissions check */
      (fld->loc == DESC_HDR &&
         (desc->ref_type == DESC_APP && (~fld->perms & P_RA)) ||
         (desc->ref_type == DESC_IMP && (~fld->perms & P_RI))))
  {
    return set_desc_error(desc, "HY091",
              "Invalid descriptor field identifier",
              MYERR_S1091);
  }
  else if (fld->loc == DESC_REC)
  {
    int perms= 0; /* needed perms to access */

    if (desc->ref_type == DESC_APP)
      perms= P_RA;
    else if (desc->ref_type == DESC_IMP)
      perms= P_RI;

    if (desc->desc_type == DESC_PARAM)
      perms= P_PAR(perms);
    else if (desc->desc_type == DESC_ROW)
      perms= P_ROW(perms);

    if ((~fld->perms & perms) == perms)
      return set_desc_error(desc, "HY091",
                "Invalid descriptor field identifier",
                MYERR_S1091);
  }

  /* get the src struct */
  if (fld->loc == DESC_HDR)
    src_struct= desc;
  else
  {
    if (recnum < 1 || recnum > desc->count)
      return set_desc_error(desc, "07009",
                "Invalid descriptor index",
                MYERR_07009);
    src_struct= desc_get_rec(desc, recnum - 1, FALSE);
    assert(src_struct);
  }

  src= ((char *)src_struct) + fld->offset;

  /* TODO checks when strings? */
  if ((fld->data_type == SQL_IS_POINTER && buflen != SQL_IS_POINTER) ||
      (fld->data_type != SQL_IS_POINTER && buflen == SQL_IS_POINTER))
    return set_desc_error(desc, "HY015",
                          "Invalid parameter type",
                          MYERR_S1015);

  switch (buflen)
  {
  case SQL_IS_SMALLINT:
    if (fld->data_type == SQL_IS_SMALLINT)
      *(SQLSMALLINT *)valptr= *(SQLSMALLINT *)src;
    else if (fld->data_type == SQL_IS_USMALLINT)
      *(SQLSMALLINT *)valptr= *(SQLUSMALLINT *)src;
    else if (fld->data_type == SQL_IS_INTEGER)
      *(SQLSMALLINT *)valptr= *(SQLINTEGER *)src;
    else if (fld->data_type == SQL_IS_UINTEGER)
      *(SQLSMALLINT *)valptr= *(SQLUINTEGER *)src;
    else if (fld->data_type == SQL_IS_LEN)
      *(SQLSMALLINT *)valptr= *(SQLLEN *)src;
    else if (fld->data_type == SQL_IS_ULEN)
      *(SQLSMALLINT *)valptr= *(SQLULEN *)src;
    break;

  case SQL_IS_USMALLINT:
    if (fld->data_type == SQL_IS_SMALLINT)
      *(SQLUSMALLINT *)valptr= *(SQLSMALLINT *)src;
    else if (fld->data_type == SQL_IS_USMALLINT)
      *(SQLUSMALLINT *)valptr= *(SQLUSMALLINT *)src;
    else if (fld->data_type == SQL_IS_INTEGER)
      *(SQLUSMALLINT *)valptr= *(SQLINTEGER *)src;
    else if (fld->data_type == SQL_IS_UINTEGER)
      *(SQLUSMALLINT *)valptr= *(SQLUINTEGER *)src;
    else if (fld->data_type == SQL_IS_LEN)
      *(SQLUSMALLINT *)valptr= *(SQLLEN *)src;
    else if (fld->data_type == SQL_IS_ULEN)
      *(SQLUSMALLINT *)valptr= *(SQLULEN *)src;
    break;

  case SQL_IS_INTEGER:
    if (fld->data_type == SQL_IS_SMALLINT)
      *(SQLINTEGER *)valptr= *(SQLSMALLINT *)src;
    else if (fld->data_type == SQL_IS_USMALLINT)
      *(SQLINTEGER *)valptr= *(SQLUSMALLINT *)src;
    else if (fld->data_type == SQL_IS_INTEGER)
      *(SQLINTEGER *)valptr= *(SQLINTEGER *)src;
    else if (fld->data_type == SQL_IS_UINTEGER)
      *(SQLINTEGER *)valptr= *(SQLUINTEGER *)src;
    else if (fld->data_type == SQL_IS_LEN)
      *(SQLINTEGER *)valptr= *(SQLLEN *)src;
    else if (fld->data_type == SQL_IS_ULEN)
      *(SQLINTEGER *)valptr= *(SQLULEN *)src;
    break;

  case SQL_IS_UINTEGER:
    if (fld->data_type == SQL_IS_SMALLINT)
      *(SQLUINTEGER *)valptr= *(SQLSMALLINT *)src;
    else if (fld->data_type == SQL_IS_USMALLINT)
      *(SQLUINTEGER *)valptr= *(SQLUSMALLINT *)src;
    else if (fld->data_type == SQL_IS_INTEGER)
      *(SQLUINTEGER *)valptr= *(SQLINTEGER *)src;
    else if (fld->data_type == SQL_IS_UINTEGER)
      *(SQLUINTEGER *)valptr= *(SQLUINTEGER *)src;
    else if (fld->data_type == SQL_IS_LEN)
      *(SQLUINTEGER *)valptr= *(SQLLEN *)src;
    else if (fld->data_type == SQL_IS_ULEN)
      *(SQLUINTEGER *)valptr= *(SQLULEN *)src;
    break;

  case SQL_IS_LEN:
    if (fld->data_type == SQL_IS_SMALLINT)
      *(SQLLEN *)valptr= *(SQLSMALLINT *)src;
    else if (fld->data_type == SQL_IS_USMALLINT)
      *(SQLLEN *)valptr= *(SQLUSMALLINT *)src;
    else if (fld->data_type == SQL_IS_INTEGER)
      *(SQLLEN *)valptr= *(SQLINTEGER *)src;
    else if (fld->data_type == SQL_IS_UINTEGER)
      *(SQLLEN *)valptr= *(SQLUINTEGER *)src;
    else if (fld->data_type == SQL_IS_LEN)
      *(SQLLEN *)valptr= *(SQLLEN *)src;
    else if (fld->data_type == SQL_IS_ULEN)
      *(SQLLEN *)valptr= *(SQLULEN *)src;
    break;

  case SQL_IS_ULEN:
    if (fld->data_type == SQL_IS_SMALLINT)
      *(SQLULEN *)valptr= *(SQLSMALLINT *)src;
    else if (fld->data_type == SQL_IS_USMALLINT)
      *(SQLULEN *)valptr= *(SQLUSMALLINT *)src;
    else if (fld->data_type == SQL_IS_INTEGER)
      *(SQLULEN *)valptr= *(SQLINTEGER *)src;
    else if (fld->data_type == SQL_IS_UINTEGER)
      *(SQLULEN *)valptr= *(SQLUINTEGER *)src;
    else if (fld->data_type == SQL_IS_LEN)
      *(SQLULEN *)valptr= *(SQLLEN *)src;
    else if (fld->data_type == SQL_IS_ULEN)
      *(SQLULEN *)valptr= *(SQLULEN *)src;
    break;

  case SQL_IS_POINTER:
    *(SQLPOINTER *)valptr= *(SQLPOINTER *)src;
    break;

  default:
    /* TODO it's an actual data length */
    /* free/malloc to the field and copy it, etc, etc */
    break;
  }

  return SQL_SUCCESS;
}


/*
  @type    : ODBC 3.0 API
  @purpose : Set a field of a descriptor.
 */
SQLRETURN
MySQLSetDescField(SQLHDESC hdesc, SQLSMALLINT recnum, SQLSMALLINT fldid,
                  SQLPOINTER val, SQLINTEGER buflen)
{
  desc_field *fld= getfield(fldid);
  DESC *desc= (DESC *)hdesc;
  void *dest_struct;
  void *dest;

  CLEAR_DESC_ERROR(desc);

  /* check for invalid IRD modification */
  if (IS_IRD(desc))
  {
    switch (fldid)
    {
    case SQL_DESC_ARRAY_STATUS_PTR:
    case SQL_DESC_ROWS_PROCESSED_PTR:
      break;
    default:
      return set_desc_error(desc, "HY016",
                            "Cannot modify an implementation row descriptor",
                            MYERR_S1016);
    }
  }

  if ((fld == NULL) ||
      /* header permissions check */
      (fld->loc == DESC_HDR &&
         ((desc->ref_type == DESC_APP && (~fld->perms & P_WA)) ||
          (desc->ref_type == DESC_IMP && (~fld->perms & P_WI)))))
  {
    return set_desc_error(desc, "HY091",
              "Invalid descriptor field identifier",
              MYERR_S1091);
  }
  else if (fld->loc == DESC_REC)
  {
    int perms= 0; /* needed perms to access */

    if (desc->ref_type == DESC_APP)
      perms= P_WA;
    else if (desc->ref_type == DESC_IMP)
      perms= P_WI;

    if (desc->desc_type == DESC_PARAM)
      perms= P_PAR(perms);
    else if (desc->desc_type == DESC_ROW)
      perms= P_ROW(perms);

    if ((~fld->perms & perms) == perms)
      return set_desc_error(desc, "HY091",
                "Invalid descriptor field identifier",
                MYERR_S1091);
  }

  /* get the dest struct */
  if (fld->loc == DESC_HDR)
    dest_struct= desc;
  else
  {
    if (recnum < 1)
      return set_desc_error(desc, "07009",
                "Invalid descriptor index",
                MYERR_07009);
    dest_struct= desc_get_rec(desc, recnum - 1, TRUE);
  }

  dest= ((char *)dest_struct) + fld->offset;

  /* some applications and even MSDN examples don't give a correct constant */
  if (buflen == 0)
    buflen= fld->data_type;

  /* TODO checks when strings? */
  if ((fld->data_type == SQL_IS_POINTER && buflen != SQL_IS_POINTER) ||
      (fld->data_type != SQL_IS_POINTER && buflen == SQL_IS_POINTER))
    return set_desc_error(desc, "HY015",
                          "Invalid parameter type",
                          MYERR_S1015);

  /* per-field checks/functionality */
  switch (fldid)
  {
  case SQL_DESC_COUNT:
    /* we just force the descriptor record count to expand */
    (void)desc_get_rec(desc, (SQLINTEGER)val - 1, TRUE);
    break;
  case SQL_DESC_NAME:
    /* We don't support named parameters, values stay as initialized */
    return set_desc_error(desc, "01S01",
                          "Option value changed",
                          MYERR_01S02);
  case SQL_DESC_UNNAMED:
    if (((SQLINTEGER)val) == SQL_NAMED)
      return set_desc_error(desc, "HY092",
                            "Invalid attribute/option identifier",
                            MYERR_S1092);
  }

  /* We have to unbind the value if not setting a buffer */
  switch (fldid)
  {
  case SQL_DESC_DATA_PTR:
  case SQL_DESC_OCTET_LENGTH_PTR:
  case SQL_DESC_INDICATOR_PTR:
    break;
  default:
    if (fld->loc == DESC_REC)
    {
      DESCREC *rec= (DESCREC *) dest_struct;
      rec->data_ptr= NULL;
    }
  }

  apply_desc_val(dest, fld->data_type, val, buflen);

  /* post-set responsibilities */
  if ((IS_ARD(desc) || IS_APD(desc)) && fld->loc == DESC_REC)
  {
    DESCREC *rec= (DESCREC *) dest_struct;
    switch (fldid)
    {
    case SQL_DESC_TYPE:
      rec->concise_type= rec->type;
      rec->datetime_interval_code= 0;
      break;
    case SQL_DESC_CONCISE_TYPE:
      rec->type= get_type_from_concise_type(rec->concise_type);
      rec->datetime_interval_code=
        get_dticode_from_concise_type(rec->concise_type);
      break;
    case SQL_DESC_DATETIME_INTERVAL_CODE: /* TODO validation for this value? */
      /* SQL_DESC_TYPE has to have already been set */
      if (rec->type == SQL_DATETIME)
        rec->concise_type=
          get_concise_type_from_datetime_code(rec->datetime_interval_code);
      else
        rec->concise_type=
          get_concise_type_from_interval_code(rec->datetime_interval_code);
      break;
    }

    switch (fldid)
    {
    case SQL_DESC_TYPE:
    case SQL_DESC_CONCISE_TYPE:
      /* setup type specific defaults (TODO others besides SQL_C_NUMERIC)? */
      if (IS_ARD(desc) && rec->type == SQL_C_NUMERIC)
      {
        rec->precision= 38;
        rec->scale= 0;
      }
    }
  }

  /*
    Set "real_param_done" for parameters if all fields needed to bind
    a parameter are set.
  */
  if (IS_APD(desc) && val != NULL && fld->loc == DESC_REC)
  {
    DESCREC *rec= (DESCREC *) dest_struct;
    switch (fldid)
    {
    case SQL_DESC_DATA_PTR:
    case SQL_DESC_OCTET_LENGTH_PTR:
    case SQL_DESC_INDICATOR_PTR:
      rec->par.real_param_done= TRUE;
      break;
    }
  }

  return SQL_SUCCESS;
}


/*
  @type    : ODBC 3.0 API
  @purpose : Copy descriptor information from one descriptor to another.
             Errors are placed in the TargetDescHandle.
 */
SQLRETURN MySQLCopyDesc(SQLHDESC SourceDescHandle, SQLHDESC TargetDescHandle)
{
  DESC *src= (DESC *)SourceDescHandle;
  DESC *dest= (DESC *)TargetDescHandle;

  CLEAR_DESC_ERROR(dest);

  if (IS_IRD(dest))
    return set_desc_error(dest, "HY016",
                          "Cannot modify an implementation row descriptor",
                          MYERR_S1016);

  if (IS_IRD(src) && src->stmt->state < ST_PREPARED)
    return set_desc_error(dest, "HY007",
              "Associated statement is not prepared",
              MYERR_S1007);

  /* copy the records */
  delete_dynamic(&dest->records);
  if (my_init_dynamic_array(&dest->records, sizeof(DESCREC),
                            src->records.max_element,
                            src->records.alloc_increment))
  {
    return set_desc_error(dest, "HY001",
              "Memory allocation error",
              MYERR_S1001);
  }
  memcpy(dest->records.buffer, src->records.buffer,
         src->records.max_element * src->records.size_of_element);

  /* copy all fields */
  dest->array_size= src->array_size;
  dest->array_status_ptr= src->array_status_ptr;
  dest->bind_offset_ptr= src->bind_offset_ptr;
  dest->bind_type= src->bind_type;
  dest->count= src->count;
  dest->rows_processed_ptr= src->rows_processed_ptr;
  memcpy(&dest->error, &src->error, sizeof(MYERROR));

  /* TODO consistency check on target, if needed (apd) */

  return SQL_SUCCESS;
}


/*
 * Call SQLGetDescField in the "context" of a statement. This will copy
 * any error from the descriptor to the statement.
 */
SQLRETURN
stmt_SQLGetDescField(STMT *stmt, DESC *desc, SQLSMALLINT recnum,
                     SQLSMALLINT fldid, SQLPOINTER valptr,
                     SQLINTEGER buflen, SQLINTEGER *outlen)
{
  SQLRETURN rc;
  if ((rc= MySQLGetDescField((SQLHANDLE)desc, recnum, fldid,
                             valptr, buflen, outlen)) != SQL_SUCCESS)
    memcpy(&stmt->error, &desc->error, sizeof(MYERROR));
  return rc;
}


/*
 * Call SQLSetDescField in the "context" of a statement. This will copy
 * any error from the descriptor to the statement.
 */
SQLRETURN
stmt_SQLSetDescField(STMT *stmt, DESC *desc, SQLSMALLINT recnum,
                     SQLSMALLINT fldid, SQLPOINTER val, SQLINTEGER buflen)
{
  SQLRETURN rc;
  if ((rc= MySQLSetDescField((SQLHANDLE)desc, recnum, fldid,
                             val, buflen)) != SQL_SUCCESS)
    memcpy(&stmt->error, &desc->error, sizeof(MYERROR));
  return rc;
}


/*
 * Call SQLCopyDesc in the "context" of a statement. This will copy
 * any error from the descriptor to the statement.
 */
SQLRETURN stmt_SQLCopyDesc(STMT *stmt, DESC *src, DESC *dest)
{
  SQLRETURN rc;
  if ((rc= MySQLCopyDesc((SQLHANDLE)src, (SQLHANDLE)dest)) != SQL_SUCCESS)
    memcpy(&stmt->error, &dest->error, sizeof(MYERROR));
  return rc;
}


SQLRETURN SQL_API
SQLCopyDesc(SQLHDESC SourceDescHandle, SQLHDESC TargetDescHandle)
{
  return MySQLCopyDesc(SourceDescHandle, TargetDescHandle);
}