SQLite

**
**    *  Recursive calls to this routine from thread X return immediately
**       without blocking.
*/
int sqlite3_initialize(void){
  MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
  int rc;                                      /* Result code */
#ifdef SQLITE_EXTRA_INIT
  int bRunExtraInit = 0;                       /* Extra initialization needed */
#endif

#ifdef SQLITE_OMIT_WSD
  rc = sqlite3_wsd_init(4096, 24);
  if( rc!=SQLITE_OK ){
    return rc;
  }
#endif

      sqlite3GlobalConfig.isPCacheInit = 1;
      rc = sqlite3OsInit();
    }
    if( rc==SQLITE_OK ){
      sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
          sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
      sqlite3GlobalConfig.isInit = 1;
#ifdef SQLITE_EXTRA_INIT
      bRunExtraInit = 1;
#endif
    }
    sqlite3GlobalConfig.inProgress = 0;
  }
  sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);

  /* Go back under the static mutex and clean up the recursive
  ** mutex to prevent a resource leak.

#endif
#endif

  /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
  ** compile-time option.
  */
#ifdef SQLITE_EXTRA_INIT
  if( bRunExtraInit ){
    int SQLITE_EXTRA_INIT(const char*);
    rc = SQLITE_EXTRA_INIT(0);
  }
#endif

  return rc;
}

        ** back to NULL pointers too.  This will cause the malloc to go
        ** back to its default implementation when sqlite3_initialize() is
        ** run.
        */
        memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
      }else{
        /* The heap pointer is not NULL, then install one of the
        ** mem5.c/mem3.c methods.  The enclosing #if guarantees at
        ** least one of these methods is currently enabled.
        */
#ifdef SQLITE_ENABLE_MEMSYS3
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
#endif
#ifdef SQLITE_ENABLE_MEMSYS5
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
#endif
      }
      break;
    }
#endif

    case SQLITE_CONFIG_LOOKASIDE: {
      sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
      sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
      break;
    }
    
    /* Record a pointer to the logger function and its first argument.
    ** The default is NULL.  Logging is disabled if the function pointer is
    ** NULL.
    */
    case SQLITE_CONFIG_LOG: {
      /* MSVC is picky about pulling func ptrs from va lists.
      ** http://support.microsoft.com/kb/47961
      ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));

    ** method that there may be extra parameters following the file-name.  */
    flags |= SQLITE_OPEN_URI;

    for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
    zFile = sqlite3_malloc(nByte);
    if( !zFile ) return SQLITE_NOMEM;

    iIn = 5;
#ifndef SQLITE_ALLOW_URI_AUTHORITY
    /* Discard the scheme and authority segments of the URI. */
    if( zUri[5]=='/' && zUri[6]=='/' ){
      iIn = 7;
      while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;

      if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
        *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s", 
            iIn-7, &zUri[7]);
        rc = SQLITE_ERROR;
        goto parse_uri_out;
      }


    }
#endif

    /* Copy the filename and any query parameters into the zFile buffer. 
    ** Decode %HH escape codes along the way. 
    **
    ** Within this loop, variable eState may be set to 0, 1 or 2, depending
    ** on the parsing context. As follows:
    **

  ** of each block.  One byte per block.
  */
  u8 *aCtrl;

} mem5;

/*
** Access the static variable through a macro for SQLITE_OMIT_WSD.
*/
#define mem5 GLOBAL(struct Mem5Global, mem5)

/*
** Assuming mem5.zPool is divided up into an array of Mem5Link
** structures, return a pointer to the idx-th such link.
*/
#define MEM5LINK(idx) ((Mem5Link *)(&mem5.zPool[(idx)*mem5.szAtom]))

/*
** Unlink the chunk at mem5.aPool[i] from list it is currently
** on.  It should be found on mem5.aiFreelist[iLogsize].
*/

  return iFirst;
}

/*
** Return a block of memory of at least nBytes in size.
** Return NULL if unable.  Return NULL if nBytes==0.
**
** The caller guarantees that nByte is positive.
**
** The caller has obtained a mutex prior to invoking this
** routine so there is never any chance that two or more
** threads can be in this routine at the same time.
*/
static void *memsys5MallocUnsafe(int nByte){
  int i;           /* Index of a mem5.aPool[] slot */

    }
    size *= 2;
  }
  memsys5Link(iBlock, iLogsize);
}

/*
** Allocate nBytes of memory.
*/
static void *memsys5Malloc(int nBytes){
  sqlite3_int64 *p = 0;
  if( nBytes>0 ){
    memsys5Enter();
    p = memsys5MallocUnsafe(nBytes);
    memsys5Leave();

** TK_AS operator.  The TK_AS operator causes the expression to be
** evaluated just once and then reused for each alias.
**
** The reason for suppressing the TK_AS term when the expression is a simple
** column reference is so that the column reference will be recognized as
** usable by indices within the WHERE clause processing logic. 
**
** The TK_AS operator is inhibited if zType[0]=='G'.  This means
** that in a GROUP BY clause, the expression is evaluated twice.  Hence:
**
**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY x
**
** Is equivalent to:
**
**     SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
**
** The result of random()%5 in the GROUP BY clause is probably different
** from the result in the result-set.  On the other hand Standard SQL does
** not allow the GROUP BY clause to contain references to result-set columns.
** So this should never come up in well-formed queries.
**
** If the reference is followed by a COLLATE operator, then make sure
** the COLLATE operator is preserved.  For example:
**
**     SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase;
**
** Should be transformed into:

    **
    **     SELECT a+b AS x FROM table WHERE x<10;
    **
    ** In cases like this, replace pExpr with a copy of the expression that
    ** forms the result set entry ("a+b" in the example) and return immediately.
    ** Note that the expression in the result set should have already been
    ** resolved by the time the WHERE clause is resolved.
    **
    ** The ability to use an output result-set column in the WHERE, GROUP BY,
    ** or HAVING clauses, or as part of a larger expression in the ORDRE BY
    ** clause is not standard SQL.  This is a (goofy) SQLite extension, that
    ** is supported for backwards compatibility only.  TO DO: Issue a warning
    ** on sqlite3_log() whenever the capability is used.
    */
    if( (pEList = pNC->pEList)!=0
     && zTab==0
     && cnt==0
    ){
      for(j=0; j<pEList->nExpr; j++){
        char *zAs = pEList->a[j].zName;
        if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
          Expr *pOrig;
          assert( pExpr->pLeft==0 && pExpr->pRight==0 );
          assert( pExpr->x.pList==0 );

  }
  return 0;
}

/*
** Check every term in the ORDER BY or GROUP BY clause pOrderBy of
** the SELECT statement pSelect.  If any term is reference to a
** result set expression (as determined by the ExprList.a.iOrderByCol field)
** then convert that term into a copy of the corresponding result set
** column.
**
** If any errors are detected, add an error message to pParse and
** return non-zero.  Return zero if no errors are seen.
*/
int sqlite3ResolveOrderGroupBy(

** The Name context of the SELECT statement is pNC.  zType is either
** "ORDER" or "GROUP" depending on which type of clause pOrderBy is.
**
** This routine resolves each term of the clause into an expression.
** If the order-by term is an integer I between 1 and N (where N is the
** number of columns in the result set of the SELECT) then the expression
** in the resolution is a copy of the I-th result-set expression.  If
** the order-by term is an identifier that corresponds to the AS-name of
** a result-set expression, then the term resolves to a copy of the
** result-set expression.  Otherwise, the expression is resolved in
** the usual way - using sqlite3ResolveExprNames().
**
** This routine returns the number of errors.  If errors occur, then
** an appropriate error message might be left in pParse.  (OOM errors
** excepted.)

  int nResult;                   /* Number of terms in the result set */

  if( pOrderBy==0 ) return 0;
  nResult = pSelect->pEList->nExpr;
  pParse = pNC->pParse;
  for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
    Expr *pE = pItem->pExpr;
    Expr *pE2 = sqlite3ExprSkipCollate(pE);
    if( zType[0]!='G' ){
      iCol = resolveAsName(pParse, pSelect->pEList, pE2);
      if( iCol>0 ){
        /* If an AS-name match is found, mark this ORDER BY column as being
        ** a copy of the iCol-th result-set column.  The subsequent call to
        ** sqlite3ResolveOrderGroupBy() will convert the expression to a
        ** copy of the iCol-th result-set expression. */
        pItem->iOrderByCol = (u16)iCol;
        continue;
      }
    }
    if( sqlite3ExprIsInteger(pE2, &iCol) ){
      /* The ORDER BY term is an integer constant.  Again, set the column
      ** number so that sqlite3ResolveOrderGroupBy() will convert the
      ** order-by term to a copy of the result-set expression */
      if( iCol<1 || iCol>0xffff ){
        resolveOutOfRangeError(pParse, zType, i+1, nResult);
        return 1;
      }

    /* If a HAVING clause is present, then there must be a GROUP BY clause.
    */
    if( p->pHaving && !pGroupBy ){
      sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
      return WRC_Abort;
    }
  
    /* Add the output column list to the name-context before parsing the
    ** other expressions in the SELECT statement. This is so that
    ** expressions in the WHERE clause (etc.) can refer to expressions by
    ** aliases in the result set.
    **
    ** Minor point: If this is the case, then the expression will be
    ** re-evaluated for each reference to it.
    */
    sNC.pEList = p->pEList;

    if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;
    if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;


    /* The ORDER BY and GROUP BY clauses may not refer to terms in
    ** outer queries 
    */
    sNC.pNext = 0;
    sNC.ncFlags |= NC_AllowAgg;

** NameContext in the parent query.  Thus the process of scanning the
** NameContext list corresponds to searching through successively outer
** subqueries looking for a match.
*/
struct NameContext {
  Parse *pParse;       /* The parser */
  SrcList *pSrcList;   /* One or more tables used to resolve names */
  ExprList *pEList;    /* Optional list of result-set columns */
  AggInfo *pAggInfo;   /* Information about aggregates at this level */
  NameContext *pNext;  /* Next outer name context.  NULL for outermost */
  int nRef;            /* Number of names resolved by this context */
  int nErr;            /* Number of errors encountered while resolving names */
  u8 ncFlags;          /* Zero or more NC_* flags defined below */
};

/*
** Allowed values for the NameContext, ncFlags field.
*/
#define NC_AllowAgg  0x01    /* Aggregate functions are allowed here */
#define NC_HasAgg    0x02    /* One or more aggregate functions seen */
#define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
#define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */


#define NC_PartIdx   0x10    /* True if resolving a partial index WHERE */

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**
** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
** If there is a LIMIT clause, the parser sets nLimit to the value of the

# include <stdlib.h>
# include <string.h>
# include <assert.h>
  typedef unsigned char u8;
#endif
#include <ctype.h>

/* Used to get the current process ID */
#if !defined(_WIN32)
# include <unistd.h>
# define GETPID getpid
#elif !defined(_WIN32_WCE)
# ifndef SQLITE_AMALGAMATION
#  define WIN32_LEAN_AND_MEAN
#  include <windows.h>
# endif
# define GETPID (int)GetCurrentProcessId
#endif

/*
 * Windows needs to know which symbols to export.  Unix does not.
 * BUILD_sqlite should be undefined for Unix.
 */
#ifdef BUILD_sqlite
#undef TCL_STORAGE_CLASS
#define TCL_STORAGE_CLASS DLLEXPORT

  }
#endif
}

#define TCLSH_MAIN main   /* Needed to fake out mktclapp */
int TCLSH_MAIN(int argc, char **argv){
  Tcl_Interp *interp;

#if !defined(_WIN32_WCE)
  if( getenv("BREAK") ){
    fprintf(stderr,
        "attach debugger to process %d and press any key to continue.\n",
        GETPID());
    fgetc(stdin);
  }
#endif

  /* Call sqlite3_shutdown() once before doing anything else. This is to
  ** test that sqlite3_shutdown() can be safely called by a process before
  ** sqlite3_initialize() is. */
  sqlite3_shutdown();

  Tcl_FindExecutable(argv[0]);
  interp = Tcl_CreateInterp();

#
#***********************************************************************
#
# This file tests features of the name resolver (the component that
# figures out what identifiers in the SQL statement refer to) that
# were fixed by ticket [2500cdb9be]
#
# See also tickets [1c69be2daf] and [f617ea3125] from 2013-08-14.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# "ORDER BY y" binds to the output result-set column named "y"
# if available.  If no output column is named "y", then try to
# bind against an input column named "y".
#
# This is classical SQL92 behavior.
#
do_test resolver01-1.1 {
  catchsql {
    CREATE TABLE t1(x, y); INSERT INTO t1 VALUES(11,22);
    CREATE TABLE t2(y, z); INSERT INTO t2 VALUES(33,44);
    SELECT 1 AS y FROM t1, t2 ORDER BY y;
  }
} {0 1}
do_test resolver01-1.2 {
  catchsql {
    SELECT 1 AS yy FROM t1, t2 ORDER BY y;
  }
} {1 {ambiguous column name: y}}
do_test resolver01-1.3 {
  catchsql {
    CREATE TABLE t3(x,y); INSERT INTO t3 VALUES(11,44),(33,22);
    SELECT x AS y FROM t3 ORDER BY y;
  }
} {0 {11 33}}
do_test resolver01-1.4 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY y;
  }
} {0 {33 11}}

# SQLite allows the WHERE clause to reference output columns if there is
# no other way to resolve the name.
#
do_test resolver01-1.5 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY yy;
  }
} {0 {11 33}}
do_test resolver01-1.6 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY 1;
  }
} {0 {11 33}}

# The "ORDER BY y COLLATE nocase" form works the same as "ORDER BY y".
# The "y" binds more tightly to output columns than to input columns.
#
# This is for compatibility with SQL92 and with historical SQLite behavior.
# Note that PostgreSQL considers "y COLLATE nocase" to be an expression
# and thus PostgreSQL treats this case as if it where the 3.x case below.
#
do_test resolver01-2.1 {
  catchsql {
    SELECT 2 AS y FROM t1, t2 ORDER BY y COLLATE nocase;
  }
} {0 2}
do_test resolver01-2.2 {
  catchsql {
    SELECT 2 AS yy FROM t1, t2 ORDER BY y COLLATE nocase;
  }
} {1 {ambiguous column name: y}}
do_test resolver01-2.3 {
  catchsql {
    SELECT x AS y FROM t3 ORDER BY y COLLATE nocase;
  }
} {0 {11 33}}
do_test resolver01-2.4 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY y COLLATE nocase;
  }
} {0 {33 11}}
do_test resolver01-2.5 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY yy COLLATE nocase;
  }
} {0 {11 33}}
do_test resolver01-2.6 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY 1 COLLATE nocase;
  }
} {0 {11 33}}

# But if the form is "ORDER BY expr" then bind more tightly to the
# the input column names and only use the output column names if no
# input column name matches.
#
# This is SQL99 behavior, as implemented by PostgreSQL and MS-SQL.
# Note that Oracle works differently.
#
do_test resolver01-3.1 {
  catchsql {
    SELECT 3 AS y FROM t1, t2 ORDER BY +y;
  }
} {1 {ambiguous column name: y}}
do_test resolver01-3.2 {
  catchsql {
    SELECT 2 AS yy FROM t1, t2 ORDER BY +y;
  }
} {1 {ambiguous column name: y}}
do_test resolver01-3.3 {
  catchsql {
    SELECT x AS y FROM t3 ORDER BY +y;
  }
} {0 {33 11}}
do_test resolver01-3.4 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY +y;
  }
} {0 {33 11}}
do_test resolver01-3.5 {
  catchsql {
    SELECT x AS yy FROM t3 ORDER BY +yy
  }
} {0 {11 33}}

# This is the test case given in ticket [f617ea3125e9] (with table name
# changed from "t1" to "t4".  The behavior of (1) and (3) match with
# PostgreSQL, but we intentionally break with PostgreSQL to provide
# SQL92 behavior for case (2).
#
do_execsql_test resolver01-4.1 {
  CREATE TABLE t4(m CHAR(2));
  INSERT INTO t4 VALUES('az');
  INSERT INTO t4 VALUES('by');
  INSERT INTO t4 VALUES('cx');
  SELECT '1', substr(m,2) AS m FROM t4 ORDER BY m;
  SELECT '2', substr(m,2) AS m FROM t4 ORDER BY m COLLATE binary;
  SELECT '3', substr(m,2) AS m FROM t4 ORDER BY lower(m);
} {1 x 1 y 1 z 2 x 2 y 2 z 3 z 3 y 3 x}

##########################################################################
# Test cases for ticket [1c69be2dafc28]:  Make sure the GROUP BY binds
# more tightly to the input tables in all cases.
#
# This first case case has been wrong in SQLite for time out of mind.
# For SQLite version 3.7.17 the answer was two rows, which is wrong.
#
do_execsql_test resolver01-5.1 {
  CREATE TABLE t5(m CHAR(2));
  INSERT INTO t5 VALUES('ax');
  INSERT INTO t5 VALUES('bx');
  INSERT INTO t5 VALUES('cy');
  SELECT count(*), substr(m,2,1) AS m FROM t5 GROUP BY m ORDER BY 1, 2;
} {1 x 1 x 1 y}

# This case is unambiguous and has always been correct.
#
do_execsql_test resolver01-5.2 {
  SELECT count(*), substr(m,2,1) AS mx FROM t5 GROUP BY m ORDER BY 1, 2;
} {1 x 1 x 1 y}

# This case is not allowed in standard SQL, but SQLite allows and does
# the sensible thing.
#
do_execsql_test resolver01-5.3 {
  SELECT count(*), substr(m,2,1) AS mx FROM t5 GROUP BY mx ORDER BY 1, 2;
} {1 y 2 x}
do_execsql_test resolver01-5.4 {
  SELECT count(*), substr(m,2,1) AS mx FROM t5
   GROUP BY substr(m,2,1) ORDER BY 1, 2;
} {1 y 2 x}

# These test case weere provided in the 2013-08-14 email from Rob Golsteijn
# that originally reported the problem of ticket [1c69be2dafc28].
#
do_execsql_test resolver01-6.1 {
  CREATE TABLE t61(name);
  SELECT min(name) FROM t61 GROUP BY lower(name);
} {}
do_execsql_test resolver01-6.2 {
  SELECT min(name) AS name FROM t61 GROUP BY lower(name); 
} {}
do_execsql_test resolver01-6.3 {
  CREATE TABLE t63(name);
  INSERT INTO t63 VALUES (NULL);
  INSERT INTO t63 VALUES ('abc');
  SELECT count(),
       NULLIF(name,'abc') AS name
    FROM t63
   GROUP BY lower(name);
} {1 {} 1 {}}





finish_test

  execsql {
    SELECT a AS "b" FROM t3 ORDER BY [B];
  }
} {1 9}

# In "ORDER BY +b" the term is now an expression rather than
# a label.  It therefore matches by rule (3) instead of rule (2).



# 
do_test tkt2822-5.5 {
  execsql {
    SELECT a AS b FROM t3 ORDER BY +b;
  }
} {9 1}

# Tests for rule 2 in compound queries
#
do_test tkt2822-6.1 {
  execsql {
    CREATE TABLE t6a(p,q);
    INSERT INTO t6a VALUES(1,8);