SQLite

  return match;
}

/*
** Search a FuncDefHash for a function with the given name.  Return
** a pointer to the matching FuncDef if found, or 0 if there is no match.
*/
static FuncDef *functionSearch(
  int h,               /* Hash of the name */
  const char *zFunc    /* Name of function */
){
  FuncDef *p;
  for(p=sqlite3BuiltinFunctions.a[h]; p; p=p->u.pHash){
    if( sqlite3StrICmp(p->zName, zFunc)==0 ){
      return p;
    }
  }
  return 0;
}
#ifdef SQLITE_ENABLE_NORMALIZE
FuncDef *sqlite3FunctionSearchN(
  int h,               /* Hash of the name */
  const char *zFunc,   /* Name of function */
  int nFunc            /* Length of the name */
){
  FuncDef *p;
  for(p=sqlite3BuiltinFunctions.a[h]; p; p=p->u.pHash){
    if( sqlite3StrNICmp(p->zName, zFunc, nFunc)==0 ){
      return p;
    }
  }
  return 0;
}
#endif /* SQLITE_ENABLE_NORMALIZE */

/*
** Insert a new FuncDef into a FuncDefHash hash table.
*/
void sqlite3InsertBuiltinFuncs(
  FuncDef *aDef,      /* List of global functions to be inserted */
  int nDef            /* Length of the apDef[] list */
){
  int i;
  for(i=0; i<nDef; i++){
    FuncDef *pOther;
    const char *zName = aDef[i].zName;
    int nName = sqlite3Strlen30(zName);
    int h = SQLITE_FUNC_HASH(zName[0], nName);
    assert( zName[0]>='a' && zName[0]<='z' );
    pOther = functionSearch(h, zName);
    if( pOther ){
      assert( pOther!=&aDef[i] && pOther->pNext!=&aDef[i] );
      aDef[i].pNext = pOther->pNext;
      pOther->pNext = &aDef[i];
    }else{
      aDef[i].pNext = 0;
      aDef[i].u.pHash = sqlite3BuiltinFunctions.a[h];

  ** have fields overwritten with new information appropriate for the
  ** new function.  But the FuncDefs for built-in functions are read-only.
  ** So we must not search for built-ins when creating a new function.
  */ 
  if( !createFlag && (pBest==0 || (db->mDbFlags & DBFLAG_PreferBuiltin)!=0) ){
    bestScore = 0;
    h = SQLITE_FUNC_HASH(sqlite3UpperToLower[(u8)zName[0]], nName);
    p = functionSearch(h, zName);
    while( p ){
      int score = matchQuality(p, nArg, enc);
      if( score>bestScore ){
        pBest = p;
        bestScore = score;
      }
      p = p->pNext;

    ** 0x9e3779b1 is 2654435761 which is the closest prime number to
    ** (2**32)*golden_ratio, where golden_ratio = (sqrt(5) - 1)/2. */
    h += sqlite3UpperToLower[c];
    h *= 0x9e3779b1;
  }
  return h;
}
#ifdef SQLITE_ENABLE_NORMALIZE
static unsigned int strHashN(const char *z, int n){
  unsigned int h = 0;
  int i;
  for(i=0; i<n; i++){
    /* Knuth multiplicative hashing.  (Sorting & Searching, p. 510).
    ** 0x9e3779b1 is 2654435761 which is the closest prime number to
    ** (2**32)*golden_ratio, where golden_ratio = (sqrt(5) - 1)/2. */
    h += sqlite3UpperToLower[(unsigned char)z[i]];
    h *= 0x9e3779b1;
  }
  return h;
}
#endif /* SQLITE_ENABLE_NORMALIZE */


/* Link pNew element into the hash table pH.  If pEntry!=0 then also
** insert pNew into the pEntry hash bucket.
*/
static void insertElement(
  Hash *pH,              /* The complete hash table */

    if( sqlite3StrICmp(elem->pKey,pKey)==0 ){ 
      return elem;
    }
    elem = elem->next;
  }
  return &nullElement;
}
#ifdef SQLITE_ENABLE_NORMALIZE
static HashElem *findElementWithHashN(
  const Hash *pH,     /* The pH to be searched */
  const char *pKey,   /* The key we are searching for */
  int nKey,           /* Number of key bytes to use */
  unsigned int *pHash /* Write the hash value here */
){
  HashElem *elem;                /* Used to loop thru the element list */
  int count;                     /* Number of elements left to test */
  unsigned int h;                /* The computed hash */
  static HashElem nullElement = { 0, 0, 0, 0 };

  if( pH->ht ){   /*OPTIMIZATION-IF-TRUE*/
    struct _ht *pEntry;
    h = strHashN(pKey, nKey) % pH->htsize;
    pEntry = &pH->ht[h];
    elem = pEntry->chain;
    count = pEntry->count;
  }else{
    h = 0;
    elem = pH->first;
    count = pH->count;
  }
  if( pHash ) *pHash = h;
  while( count-- ){
    assert( elem!=0 );
    if( sqlite3StrNICmp(elem->pKey,pKey,nKey)==0 ){ 
      return elem;
    }
    elem = elem->next;
  }
  return &nullElement;
}
#endif /* SQLITE_ENABLE_NORMALIZE */

/* Remove a single entry from the hash table given a pointer to that
** element and a hash on the element's key.
*/
static void removeElementGivenHash(
  Hash *pH,         /* The pH containing "elem" */
  HashElem* elem,   /* The element to be removed from the pH */

** found, or NULL if there is no match.
*/
void *sqlite3HashFind(const Hash *pH, const char *pKey){
  assert( pH!=0 );
  assert( pKey!=0 );
  return findElementWithHash(pH, pKey, 0)->data;
}
#ifdef SQLITE_ENABLE_NORMALIZE
void *sqlite3HashFindN(const Hash *pH, const char *pKey, int nKey){
  assert( pH!=0 );
  assert( pKey!=0 );
  assert( nKey>=0 );
  return findElementWithHashN(pH, pKey, nKey, 0)->data;
}
#endif /* SQLITE_ENABLE_NORMALIZE */

/* Insert an element into the hash table pH.  The key is pKey
** and the data is "data".
**
** If no element exists with a matching key, then a new
** element is created and NULL is returned.
**

/*
** Access routines.  To delete, insert a NULL pointer.
*/
void sqlite3HashInit(Hash*);
void *sqlite3HashInsert(Hash*, const char *pKey, void *pData);
void *sqlite3HashFind(const Hash*, const char *pKey);
#ifdef SQLITE_ENABLE_NORMALIZE
void *sqlite3HashFindN(const Hash *pH, const char *pKey, int nKey);
#endif
void sqlite3HashClear(Hash*);

/*
** Macros for looping over all elements of a hash table.  The idiom is
** like this:
**
**   Hash h;

){
  int bFound = 0;     /* Non-zero if token is an identifier name. */
  int i, j;           /* Database and column loop indexes. */
  Schema *pSchema;    /* Schema for current database. */
  Hash *pHash;        /* Hash table of tables for current database. */
  HashElem *e;        /* Hash element for hash table iteration. */
  Table *pTab;        /* Database table for columns being checked. */











  if( sqlite3IsRowidN(zToken, nToken) ){
    return 1;

  }
  if( nToken>0 ){
    int hash = SQLITE_FUNC_HASH(sqlite3UpperToLower[(u8)zToken[0]], nToken);
    if( sqlite3FunctionSearchN(hash, zToken, nToken) ) return 1;



  }
  assert( db!=0 );
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  for(i=0; i<db->nDb; i++){
    pHash = &db->aFunc;
    if( sqlite3HashFindN(pHash, zToken, nToken) ){
      bFound = 1;
      break;
    }
    pSchema = db->aDb[i].pSchema;
    if( pSchema==0 ) continue;
    pHash = &pSchema->tblHash;
    if( sqlite3HashFindN(pHash, zToken, nToken) ){
      bFound = 1;
      break;
    }
    for(e=sqliteHashFirst(pHash); e; e=sqliteHashNext(e)){
      pTab = sqliteHashData(e);
      if( pTab==0 ) continue;
      pHash = pTab->pColHash;

          }
        }else{
          *pRc = SQLITE_NOMEM_BKPT;
          bFound = 0;
          goto done;
        }
      }
      if( pHash && sqlite3HashFindN(pHash, zToken, nToken) ){
        bFound = 1;
        goto done;
      }
    }
  }
done:
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);

  return bFound;
}

/*
** Attempt to estimate the final output buffer size needed for the fully
** normalized version of the specified SQL string.  This should take into
** account any potential expansion that could occur (e.g. via IN clauses

void sqlite3UniqueConstraint(Parse*, int, Index*);
void sqlite3RowidConstraint(Parse*, int, Table*);
Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
IdList *sqlite3IdListDup(sqlite3*,IdList*);
Select *sqlite3SelectDup(sqlite3*,Select*,int);
#ifdef SQLITE_ENABLE_NORMALIZE
FuncDef *sqlite3FunctionSearchN(int,const char*,int);
#endif
void sqlite3InsertBuiltinFuncs(FuncDef*,int);
FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,u8,u8);
void sqlite3RegisterBuiltinFunctions(void);
void sqlite3RegisterDateTimeFunctions(void);
void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3*);
int sqlite3SafetyCheckOk(sqlite3*);
int sqlite3SafetyCheckSickOrOk(sqlite3*);