sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in
	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

sqlite3_analyzer$(TEXE): sqlite3_analyzer.c
	$(LTLINK) sqlite3_analyzer.c -o $@ $(LIBTCL) $(TLIBS)

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \
  $(TOP)/ext/repair/checkfreelist.c \
  $(TOP)/ext/misc/btreeinfo.c \
  $(TOP)/ext/repair/sqlite3_checker.c.in

sqlite3_checker.c:	$(CHECKER_DEPS)
	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/ext/repair/sqlite3_checker.c.in >$@

sqlite3_checker$(TEXE):	sqlite3_checker.c
	$(LTLINK) sqlite3_checker.c -o $@ $(LIBTCL) $(TLIBS)

dbdump$(TEXE): $(TOP)/ext/misc/dbdump.c sqlite3.lo
	$(LTLINK) -DDBDUMP_STANDALONE -o $@ \
           $(TOP)/ext/misc/dbdump.c sqlite3.lo $(TLIBS)

showdb$(TEXE):	$(TOP)/tool/showdb.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showdb.c sqlite3.lo $(TLIBS)

# executables needed for testing
#
TESTPROGS = \
  testfixture.exe \
  $(SQLITE3EXE) \
  sqlite3_analyzer.exe \
  sqlite3_checker.exe \
  sqldiff.exe \
  dbhash.exe

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)\test\fuzzdata1.db \

sqlite3_analyzer.c:	$(SQLITE3C) $(SQLITE3H) $(TOP)\src\tclsqlite.c $(TOP)\tool\spaceanal.tcl $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in $(SQLITE_TCL_DEP)
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in > $@

sqlite3_analyzer.exe:	sqlite3_analyzer.c $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqlite3_analyzer.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS) $(TLIBS)

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \
  $(TOP)/ext/repair/checkfreelist.c \
  $(TOP)/ext/misc/btreeinfo.c \
  $(TOP)/ext/repair/sqlite3_checker.c.in

sqlite3_checker.c:	$(CHECKER_DEPS)
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\ext\repair\sqlite3_checker.c.in > $@

sqlite3_checker.exe:	sqlite3_checker.c $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqlite3_checker.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS) $(TLIBS)

dbdump.exe:	$(TOP)\ext\misc\dbdump.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DDBDUMP_STANDALONE $(TOP)\ext\misc\dbdump.c $(SQLITE3C) \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS)

testloadext.lo:	$(TOP)\src\test_loadext.c
	$(LTCOMPILE) $(NO_WARN) -c $(TOP)\src\test_loadext.c

**       ORDER BY nEntry DESC, name;
**
** Show the names of all WITHOUT ROWID tables: 
**
**      SELECT name FROM sqlite_btreeinfo
**       WHERE type='table' AND NOT hasRowid;
*/
#if !defined(SQLITEINT_H)
#include "sqlite3ext.h"
#endif
SQLITE_EXTENSION_INIT1
#include <string.h>
#include <assert.h>

/* Columns available in this virtual table */
#define BINFO_COLUMN_TYPE         0
#define BINFO_COLUMN_NAME         1

*/
static int editDist3Install(sqlite3 *db){
  int rc;
  EditDist3Config *pConfig = sqlite3_malloc64( sizeof(*pConfig) );
  if( pConfig==0 ) return SQLITE_NOMEM;
  memset(pConfig, 0, sizeof(*pConfig));
  rc = sqlite3_create_function_v2(db, "editdist3",
              2, SQLITE_UTF8|SQLITE_DETERMINISTIC, pConfig,
              editDist3SqlFunc, 0, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function_v2(db, "editdist3",
                3, SQLITE_UTF8|SQLITE_DETERMINISTIC, pConfig,
                editDist3SqlFunc, 0, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function_v2(db, "editdist3",
                1, SQLITE_UTF8|SQLITE_DETERMINISTIC, pConfig,
                editDist3SqlFunc, 0, 0, editDist3ConfigDelete);
  }else{
    sqlite3_free(pConfig);
  }
  return rc;
}
/* End configurable cost unicode edit distance routines
******************************************************************************

/*
** Register the various functions and the virtual table.
*/
static int spellfix1Register(sqlite3 *db){
  int rc = SQLITE_OK;
  int i;
  rc = sqlite3_create_function(db, "spellfix1_translit", 1,
                               SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                transliterateSqlFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_editdist", 2,
                                 SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                  editdistSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_phonehash", 1,
                                 SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                  phoneticHashSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_scriptcode", 1,
                                  SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                  scriptCodeSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "spellfix1", &spellfix1Module, 0);
  }
  if( rc==SQLITE_OK ){
    rc = editDist3Install(db);

  rc = sqlite3_prepare_v2(db, zTrunk, -1, &pTrunk, 0);
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_bind_text(pTrunk, 1, zDb, -1, SQLITE_STATIC);
  while( rc==SQLITE_OK && sqlite3_step(pTrunk)==SQLITE_ROW ){
    u32 i;
    u32 iTrunk = (u32)sqlite3_column_int(pTrunk, 0);
    const u8 *aData = (const u8*)sqlite3_column_blob(pTrunk, 1);
    u32 nData = (u32)sqlite3_column_bytes(pTrunk, 1);
    u32 iNext = get4byte(&aData[0]);
    u32 nLeaf = get4byte(&aData[4]);

    if( nLeaf>((nData/4)-2-6) ){
      rc = checkFreelistError(pzOut, 
          "leaf count out of range (%d) on trunk page %d", 
          (int)nLeaf, (int)iTrunk

/*
** 2017 October 27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1

#ifndef SQLITE_AMALGAMATION
# include <string.h>
# include <stdio.h>
# include <stdlib.h>
# include <assert.h>
# define ALWAYS(X)  1
# define NEVER(X)   0
  typedef unsigned char u8;
  typedef unsigned short u16;
  typedef unsigned int u32;
#define get4byte(x) (        \
    ((u32)((x)[0])<<24) +    \
    ((u32)((x)[1])<<16) +    \
    ((u32)((x)[2])<<8) +     \
    ((u32)((x)[3]))          \
)
#endif

typedef struct CidxTable CidxTable;
typedef struct CidxCursor CidxCursor;

struct CidxTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;
};

struct CidxCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  sqlite3_int64 iRowid;
  sqlite3_stmt *pStmt;
};

typedef struct CidxColumn CidxColumn;
struct CidxColumn {
  char *zExpr;                    /* Text for indexed expression */
  int bDesc;                      /* True for DESC columns, otherwise false */
  int bKey;                       /* Part of index, not PK */
};

typedef struct CidxIndex CidxIndex;
struct CidxIndex {
  int nCol;                       /* Elements in aCol[] array */
  CidxColumn aCol[1];             /* Array of indexed columns */
};

static void *cidxMalloc(int *pRc, int n){
  void *pRet = 0;
  assert( n!=0 );
  if( *pRc==SQLITE_OK ){
    pRet = sqlite3_malloc(n);
    if( pRet ){
      memset(pRet, 0, n);
    }else{
      *pRc = SQLITE_NOMEM;
    }
  }
  return pRet;
}

static void cidxCursorError(CidxCursor *pCsr, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  assert( pCsr->base.pVtab->zErrMsg==0 );
  pCsr->base.pVtab->zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}

/*
** Connect to then incremental_index_check virtual table.
*/
static int cidxConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  int rc = SQLITE_OK;
  CidxTable *pRet;

#define IIC_ERRMSG        0
#define IIC_CURRENT_KEY   1
#define IIC_INDEX_NAME    2
#define IIC_AFTER_KEY     3
  rc = sqlite3_declare_vtab(db,
      "CREATE TABLE xyz("
      " errmsg TEXT, current_key TEXT,"
      " index_name HIDDEN, after_key HIDDEN"
      ")"
  );
  pRet = cidxMalloc(&rc, sizeof(CidxTable));
  if( pRet ){
    pRet->db = db;
  }

  *ppVtab = (sqlite3_vtab*)pRet;
  return rc;
}

/*
** Disconnect from or destroy an incremental_index_check virtual table.
*/
static int cidxDisconnect(sqlite3_vtab *pVtab){
  CidxTable *pTab = (CidxTable*)pVtab;
  sqlite3_free(pTab);
  return SQLITE_OK;
}

/*
** xBestIndex method.
*/
static int cidxBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pInfo){
  int iIdxName = -1;
  int iAfterKey = -1;
  int i;

  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];
    if( p->usable==0 ) continue;
    if( p->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;

    if( p->iColumn==IIC_INDEX_NAME ){
      iIdxName = i;
    }
    if( p->iColumn==IIC_AFTER_KEY ){
      iAfterKey = i;
    }
  }

  if( iIdxName<0 ){
    pInfo->estimatedCost = 1000000000.0;
  }else{
    pInfo->aConstraintUsage[iIdxName].argvIndex = 1;
    pInfo->aConstraintUsage[iIdxName].omit = 1;
    if( iAfterKey<0 ){
      pInfo->estimatedCost = 1000000.0;
    }else{
      pInfo->aConstraintUsage[iAfterKey].argvIndex = 2;
      pInfo->aConstraintUsage[iAfterKey].omit = 1;
      pInfo->estimatedCost = 1000.0;
    }
  }

  return SQLITE_OK;
}

/*
** Open a new btreeinfo cursor.
*/
static int cidxOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  CidxCursor *pRet;
  int rc = SQLITE_OK;

  pRet = cidxMalloc(&rc, sizeof(CidxCursor));

  *ppCursor = (sqlite3_vtab_cursor*)pRet;
  return rc;
}

/*
** Close a btreeinfo cursor.
*/
static int cidxClose(sqlite3_vtab_cursor *pCursor){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  sqlite3_finalize(pCsr->pStmt);
  pCsr->pStmt = 0;
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Move a btreeinfo cursor to the next entry in the file.
*/
static int cidxNext(sqlite3_vtab_cursor *pCursor){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  int rc = sqlite3_step(pCsr->pStmt);
  if( rc!=SQLITE_ROW ){
    rc = sqlite3_finalize(pCsr->pStmt);
    pCsr->pStmt = 0;
    if( rc!=SQLITE_OK ){
      sqlite3 *db = ((CidxTable*)pCsr->base.pVtab)->db;
      cidxCursorError(pCsr, "Cursor error: %s", sqlite3_errmsg(db));
    }
  }else{
    pCsr->iRowid++;
    rc = SQLITE_OK;
  }
  return rc;
}

/* We have reached EOF if previous sqlite3_step() returned
** anything other than SQLITE_ROW;
*/
static int cidxEof(sqlite3_vtab_cursor *pCursor){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  return pCsr->pStmt==0;
}

static char *cidxMprintf(int *pRc, const char *zFmt, ...){
  char *zRet = 0;
  va_list ap;
  va_start(ap, zFmt);
  zRet = sqlite3_vmprintf(zFmt, ap);
  if( *pRc==SQLITE_OK ){
    if( zRet==0 ){
      *pRc = SQLITE_NOMEM;
    }
  }else{
    sqlite3_free(zRet);
    zRet = 0;
  }
  va_end(ap);
  return zRet;
}

static sqlite3_stmt *cidxPrepare(
  int *pRc, CidxCursor *pCsr, const char *zFmt, ...
){
  sqlite3_stmt *pRet = 0;
  char *zSql;
  va_list ap;                     /* ... printf arguments */
  va_start(ap, zFmt);

  zSql = sqlite3_vmprintf(zFmt, ap);
  if( *pRc==SQLITE_OK ){
    if( zSql==0 ){
      *pRc = SQLITE_NOMEM;
    }else{
      sqlite3 *db = ((CidxTable*)pCsr->base.pVtab)->db;
      *pRc = sqlite3_prepare_v2(db, zSql, -1, &pRet, 0);
      if( *pRc!=SQLITE_OK ){
        cidxCursorError(pCsr, "SQL error: %s", sqlite3_errmsg(db));
      }
    }
  }
  sqlite3_free(zSql);
  va_end(ap);

  return pRet;
}

static void cidxFinalize(int *pRc, sqlite3_stmt *pStmt){
  int rc = sqlite3_finalize(pStmt);
  if( *pRc==SQLITE_OK ) *pRc = rc;
}

char *cidxStrdup(int *pRc, const char *zStr){
  char *zRet = 0;
  if( *pRc==SQLITE_OK ){
    int n = (int)strlen(zStr);
    zRet = cidxMalloc(pRc, n+1);
    if( zRet ) memcpy(zRet, zStr, n+1);
  }
  return zRet;
}

static void cidxFreeIndex(CidxIndex *pIdx){
  if( pIdx ){
    int i;
    for(i=0; i<pIdx->nCol; i++){
      sqlite3_free(pIdx->aCol[i].zExpr);
    }
    sqlite3_free(pIdx);
  }
}

static int cidx_isspace(char c){
  return c==' ' || c=='\t' || c=='\r' || c=='\n';
}

static int cidx_isident(char c){
  return c<0 
    || (c>='0' && c<='9') || (c>='a' && c<='z') 
    || (c>='A' && c<='Z') || c=='_';
}

#define CIDX_PARSE_EOF   0
#define CIDX_PARSE_COMMA 1      /*  "," */
#define CIDX_PARSE_OPEN  2      /*  "(" */
#define CIDX_PARSE_CLOSE 3      /*  ")" */

static int cidxFindNext(
  const char *zIn, 
  const char **pzOut,
  int *pbDoNotTrim                /* OUT: True if prev is -- comment */
){
  const char *z = zIn;

  while( 1 ){
    if( z[0]=='-' && z[1]=='-' ){
      z += 2;
      while( z[0]!='\n' ){
        if( z[0]=='\0' ) return CIDX_PARSE_EOF;
        z++;
      }
      while( cidx_isspace(*z) ) z++;
      *pbDoNotTrim = 1;
    }else{
      *pzOut = z;
      switch( *z ){
        case '\0':
          return CIDX_PARSE_EOF;
        case '(':
          return CIDX_PARSE_OPEN;
        case ')':
          return CIDX_PARSE_CLOSE;
        case ',':
          return CIDX_PARSE_COMMA;
  
        case '"': 
        case '\'': 
        case '`': {
          char q = *z;
          z++;
          while( *z ){
            if( *z==q ){
              z++;
              if( *z!=q ) break;
            }
            z++;
          }
          break;
        }
  
        case '[':
          while( *z++!=']' );
          break;
  
        case '/':
          if( z[1]=='*' ){
            z += 2;
            while( z[0]!='*' || z[1]!='/' ){
              if( z[1]=='\0' ) return CIDX_PARSE_EOF;
              z++;
            }
            z += 2;
            break;
          }
  
        default:
          z++;
          break;
      }
      *pbDoNotTrim = 0;
    }
  }

  assert( 0 );
  return -1;
}

static int cidxParseSQL(CidxCursor *pCsr, CidxIndex *pIdx, const char *zSql){
  const char *z = zSql;
  const char *z1;
  int e;
  int rc = SQLITE_OK;
  int nParen = 1;
  int bDoNotTrim = 0;
  CidxColumn *pCol = pIdx->aCol;

  e = cidxFindNext(z, &z, &bDoNotTrim);
  if( e!=CIDX_PARSE_OPEN ) goto parse_error;
  z1 = z+1;
  z++;
  while( nParen>0 ){
    e = cidxFindNext(z, &z, &bDoNotTrim);
    if( e==CIDX_PARSE_EOF ) goto parse_error;
    if( (e==CIDX_PARSE_COMMA || e==CIDX_PARSE_CLOSE) && nParen==1 ){
      const char *z2 = z;
      if( pCol->zExpr ) goto parse_error;

      if( bDoNotTrim==0 ){
        while( cidx_isspace(z[-1]) ) z--;
        if( !sqlite3_strnicmp(&z[-3], "asc", 3) && 0==cidx_isident(z[-4]) ){
          z -= 3;
          while( cidx_isspace(z[-1]) ) z--;
        }else
          if( !sqlite3_strnicmp(&z[-4], "desc", 4) && 0==cidx_isident(z[-5]) ){
            z -= 4;
            while( cidx_isspace(z[-1]) ) z--;
          }
        while( cidx_isspace(z1[0]) ) z1++;
      }

      pCol->zExpr = cidxMprintf(&rc, "%.*s", z-z1, z1);
      pCol++;
      z = z1 = z2+1;
    }
    if( e==CIDX_PARSE_OPEN ) nParen++;
    if( e==CIDX_PARSE_CLOSE ) nParen--;
    z++;
  }

  return rc;

 parse_error:
  cidxCursorError(pCsr, "Parse error in: %s", zSql);
  return SQLITE_ERROR;
}

static int cidxLookupIndex(
  CidxCursor *pCsr,               /* Cursor object */
  const char *zIdx,               /* Name of index to look up */
  CidxIndex **ppIdx,              /* OUT: Description of columns */
  char **pzTab                    /* OUT: Table name */
){
  int rc = SQLITE_OK;
  char *zTab = 0;
  CidxIndex *pIdx = 0;

  sqlite3_stmt *pFindTab = 0;
  sqlite3_stmt *pInfo = 0;
    
  /* Find the table for this index. */
  pFindTab = cidxPrepare(&rc, pCsr, 
      "SELECT tbl_name, sql FROM sqlite_master WHERE name=%Q AND type='index'",
      zIdx
  );
  if( rc==SQLITE_OK && sqlite3_step(pFindTab)==SQLITE_ROW ){
    const char *zSql = (const char*)sqlite3_column_text(pFindTab, 1);
    zTab = cidxStrdup(&rc, (const char*)sqlite3_column_text(pFindTab, 0));

    pInfo = cidxPrepare(&rc, pCsr, "PRAGMA index_xinfo(%Q)", zIdx);
    if( rc==SQLITE_OK ){
      int nAlloc = 0;
      int iCol = 0;

      while( sqlite3_step(pInfo)==SQLITE_ROW ){
        const char *zName = (const char*)sqlite3_column_text(pInfo, 2);
        const char *zColl = (const char*)sqlite3_column_text(pInfo, 4);
        CidxColumn *p;
        if( zName==0 ) zName = "rowid";
        if( iCol==nAlloc ){
          int nByte = sizeof(CidxIndex) + sizeof(CidxColumn)*(nAlloc+8);
          pIdx = (CidxIndex*)sqlite3_realloc(pIdx, nByte);
          nAlloc += 8;
        }
        p = &pIdx->aCol[iCol++];
        p->bDesc = sqlite3_column_int(pInfo, 3);
        p->bKey = sqlite3_column_int(pInfo, 5);
        if( zSql==0 || p->bKey==0 ){
          p->zExpr = cidxMprintf(&rc, "\"%w\" COLLATE %s",zName,zColl);
        }else{
          p->zExpr = 0;
        }
        pIdx->nCol = iCol;
      }
      cidxFinalize(&rc, pInfo);
    }

    if( rc==SQLITE_OK && zSql ){
      rc = cidxParseSQL(pCsr, pIdx, zSql);
    }
  }

  cidxFinalize(&rc, pFindTab);
  if( rc==SQLITE_OK && zTab==0 ){
    rc = SQLITE_ERROR;
  }
  
  if( rc!=SQLITE_OK ){
    sqlite3_free(zTab);
    cidxFreeIndex(pIdx);
  }else{
    *pzTab = zTab;
    *ppIdx = pIdx;
  }

  return rc;
}

static int cidxDecodeAfter(
  CidxCursor *pCsr, 
  int nCol, 
  const char *zAfterKey, 
  char ***pazAfter
){
  char **azAfter;
  int rc = SQLITE_OK;
  int nAfterKey = (int)strlen(zAfterKey);

  azAfter = cidxMalloc(&rc, sizeof(char*)*nCol + nAfterKey+1);
  if( rc==SQLITE_OK ){
    int i;
    char *zCopy = (char*)&azAfter[nCol];
    char *p = zCopy;
    memcpy(zCopy, zAfterKey, nAfterKey+1);
    for(i=0; i<nCol; i++){
      while( *p==' ' ) p++;

      /* Check NULL values */
      if( *p=='N' ){
        if( memcmp(p, "NULL", 4) ) goto parse_error;
        p += 4;
      }

      /* Check strings and blob literals */
      else if( *p=='X' || *p=='\'' ){
        azAfter[i] = p;
        if( *p=='X' ) p++;
        if( *p!='\'' ) goto parse_error;
        p++;
        while( 1 ){
          if( *p=='\0' ) goto parse_error;
          if( *p=='\'' ){
            p++;
            if( *p!='\'' ) break;
          }
          p++;
        }
      }

      /* Check numbers */
      else{
        azAfter[i] = p;
        while( (*p>='0' && *p<='9') 
            || *p=='.' || *p=='+' || *p=='-' || *p=='e' || *p=='E'
        ){
          p++;
        }
      }

      while( *p==' ' ) p++;
      if( *p!=(i==(nCol-1) ? '\0' : ',') ){
        goto parse_error;
      }
      *p++ = '\0';
    }
  }

  *pazAfter = azAfter;
  return rc;

 parse_error:
  sqlite3_free(azAfter);
  *pazAfter = 0;
  cidxCursorError(pCsr, "%s", "error parsing after value");
  return SQLITE_ERROR;
}

static char *cidxWhere(
  int *pRc, CidxColumn *aCol, char **azAfter, int iGt, int bLastIsNull
){
  char *zRet = 0;
  const char *zSep = "";
  int i;

  for(i=0; i<iGt; i++){
    zRet = cidxMprintf(pRc, "%z%s(%s) IS %s", zRet, 
        zSep, aCol[i].zExpr, (azAfter[i] ? azAfter[i] : "NULL")
    );
    zSep = " AND ";
  }

  if( bLastIsNull ){
    zRet = cidxMprintf(pRc, "%z%s(%s) IS NULL", zRet, zSep, aCol[iGt].zExpr);
  }
  else if( azAfter[iGt] ){
    zRet = cidxMprintf(pRc, "%z%s(%s) %s %s", zRet, 
        zSep, aCol[iGt].zExpr, (aCol[iGt].bDesc ? "<" : ">"), 
        azAfter[iGt]
    );
  }else{
    zRet = cidxMprintf(pRc, "%z%s(%s) IS NOT NULL", zRet, zSep,aCol[iGt].zExpr);
  }

  return zRet;
}

#define CIDX_CLIST_ALL         0
#define CIDX_CLIST_ORDERBY     1
#define CIDX_CLIST_CURRENT_KEY 2
#define CIDX_CLIST_SUBWHERE    3
#define CIDX_CLIST_SUBEXPR     4

/*
** This function returns various strings based on the contents of the
** CidxIndex structure and the eType parameter.
*/
static char *cidxColumnList(
  int *pRc,                       /* IN/OUT: Error code */
  const char *zIdx,
  CidxIndex *pIdx,                /* Indexed columns */
  int eType                       /* True to include ASC/DESC */
){
  char *zRet = 0;
  if( *pRc==SQLITE_OK ){
    const char *aDir[2] = {"", " DESC"};
    int i;
    const char *zSep = "";

    for(i=0; i<pIdx->nCol; i++){
      CidxColumn *p = &pIdx->aCol[i];
      assert( pIdx->aCol[i].bDesc==0 || pIdx->aCol[i].bDesc==1 );
      switch( eType ){

        case CIDX_CLIST_ORDERBY:
          zRet = cidxMprintf(pRc, "%z%s%d%s", zRet, zSep, i+1, aDir[p->bDesc]);
          zSep = ",";
          break;

        case CIDX_CLIST_CURRENT_KEY:
          zRet = cidxMprintf(pRc, "%z%squote(i%d)", zRet, zSep, i);
          zSep = "||','||";
          break;

        case CIDX_CLIST_SUBWHERE:
          if( p->bKey==0 ){
            zRet = cidxMprintf(pRc, "%z%s%s IS i.i%d", zRet, 
                zSep, p->zExpr, i
            );
            zSep = " AND ";
          }
          break;

        case CIDX_CLIST_SUBEXPR:
          if( p->bKey==1 ){
            zRet = cidxMprintf(pRc, "%z%s%s IS i.i%d", zRet, 
                zSep, p->zExpr, i
            );
            zSep = " AND ";
          }
          break;

        default:
          assert( eType==CIDX_CLIST_ALL );
          zRet = cidxMprintf(pRc, "%z%s(%s) AS i%d", zRet, zSep, p->zExpr, i);
          zSep = ", ";
          break;
      }
    }
  }

  return zRet;
}

/* 
** Position a cursor back to the beginning.
*/
static int cidxFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  int rc = SQLITE_OK;
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  const char *zIdxName = 0;
  const char *zAfterKey = 0;

  if( argc>0 ){
    zIdxName = (const char*)sqlite3_value_text(argv[0]);
    if( argc>1 ){
      zAfterKey = (const char*)sqlite3_value_text(argv[1]);
    }
  }

  if( zIdxName ){
    char *zTab = 0;
    char *zCurrentKey = 0;
    char *zOrderBy = 0;
    char *zSubWhere = 0;
    char *zSubExpr = 0;
    char *zSrcList = 0;

    char **azAfter = 0;
    CidxIndex *pIdx = 0;

    rc = cidxLookupIndex(pCsr, zIdxName, &pIdx, &zTab);

    zOrderBy = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_ORDERBY);
    zCurrentKey = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_CURRENT_KEY);
    zSubWhere = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_SUBWHERE);
    zSubExpr = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_SUBEXPR);
    zSrcList = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_ALL);

    if( rc==SQLITE_OK && zAfterKey ){
      rc = cidxDecodeAfter(pCsr, pIdx->nCol, zAfterKey, &azAfter);
    }

    if( rc || zAfterKey==0 ){
      pCsr->pStmt = cidxPrepare(&rc, pCsr, 
          "SELECT (SELECT %s FROM %Q AS t WHERE %s), %s "
          "FROM (SELECT %s FROM %Q ORDER BY %s) AS i",
          zSubExpr, zTab, zSubWhere, zCurrentKey, 
          zSrcList, zTab, zOrderBy
      );
      /* printf("SQL: %s\n", sqlite3_sql(pCsr->pStmt)); */
    }else{
      const char *zSep = "";
      char *zSql;
      int i;

      zSql = cidxMprintf(&rc, 
          "SELECT (SELECT %s FROM %Q WHERE %s), %s FROM (",
          zSubExpr, zTab, zSubWhere, zCurrentKey
      );
      for(i=pIdx->nCol-1; i>=0; i--){
        int j;
        if( pIdx->aCol[i].bDesc && azAfter[i]==0 ) continue;
        for(j=0; j<2; j++){
          char *zWhere = cidxWhere(&rc, pIdx->aCol, azAfter, i, j);
          zSql = cidxMprintf(&rc, "%z"
              "%sSELECT * FROM (SELECT %s FROM %Q WHERE %z ORDER BY %s)",
              zSql, zSep, zSrcList, zTab, zWhere, zOrderBy
          );
          zSep = " UNION ALL ";
          if( pIdx->aCol[i].bDesc==0 ) break;
        }
      }
      zSql = cidxMprintf(&rc, "%z) AS i", zSql);

      /* printf("SQL: %s\n", zSql); */
      pCsr->pStmt = cidxPrepare(&rc, pCsr, "%z", zSql);
    }

    sqlite3_free(zTab);
    sqlite3_free(zCurrentKey);
    sqlite3_free(zOrderBy);
    sqlite3_free(zSubWhere);
    sqlite3_free(zSubExpr);
    sqlite3_free(zSrcList);
    cidxFreeIndex(pIdx);
    sqlite3_free(azAfter);
  }

  if( pCsr->pStmt ){
    assert( rc==SQLITE_OK );
    rc = cidxNext(pCursor);
  }
  pCsr->iRowid = 1;
  return rc;
}

/* 
** Return a column value.
*/
static int cidxColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int iCol
){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  assert( iCol>=IIC_ERRMSG && iCol<=IIC_AFTER_KEY );
  if( iCol==IIC_ERRMSG ){
    const char *zVal = 0;
    if( sqlite3_column_type(pCsr->pStmt, 0)==SQLITE_INTEGER ){
      if( sqlite3_column_int(pCsr->pStmt, 0)==0 ){
        zVal = "row data mismatch";
      }
    }else{
      zVal = "row missing";
    }
    sqlite3_result_text(ctx, zVal, -1, SQLITE_STATIC);
  }else if( iCol==IIC_CURRENT_KEY ){
    sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pStmt, 1));
  }
  return SQLITE_OK;
}

/* Return the ROWID for the sqlite_btreeinfo table */
static int cidxRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  *pRowid = 0;
  return SQLITE_OK;
}

/*
** Register the virtual table modules with the database handle passed
** as the only argument.
*/
static int ciInit(sqlite3 *db){
  static sqlite3_module cidx_module = {
    0,                            /* iVersion */
    0,                            /* xCreate */
    cidxConnect,                  /* xConnect */
    cidxBestIndex,                /* xBestIndex */
    cidxDisconnect,               /* xDisconnect */
    0,                            /* xDestroy */
    cidxOpen,                     /* xOpen - open a cursor */
    cidxClose,                    /* xClose - close a cursor */
    cidxFilter,                   /* xFilter - configure scan constraints */
    cidxNext,                     /* xNext - advance a cursor */
    cidxEof,                      /* xEof - check for end of scan */
    cidxColumn,                   /* xColumn - read data */
    cidxRowid,                    /* xRowid - read data */
    0,                            /* xUpdate */
    0,                            /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
  };
  return sqlite3_create_module(db, "incremental_index_check", &cidx_module, 0);
}

/*
** Extension load function.
*/
#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_checkindex_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  return ciInit(db);
}

/*
** Read an SQLite database file and analyze its space utilization.  Generate
** text on standard output.
*/
#define TCLSH_INIT_PROC sqlite3_checker_init_proc
#define SQLITE_ENABLE_DBPAGE_VTAB 1
#define SQLITE_ENABLE_JSON1 1
#undef SQLITE_THREADSAFE
#define SQLITE_THREADSAFE 0
#undef SQLITE_ENABLE_COLUMN_METADATA
#define SQLITE_OMIT_DECLTYPE 1
#define SQLITE_OMIT_DEPRECATED 1
#define SQLITE_OMIT_PROGRESS_CALLBACK 1
#define SQLITE_OMIT_SHARED_CACHE 1
#define SQLITE_DEFAULT_MEMSTATUS 0
#define SQLITE_MAX_EXPR_DEPTH 0
INCLUDE sqlite3.c
INCLUDE $ROOT/src/tclsqlite.c
INCLUDE $ROOT/ext/misc/btreeinfo.c
INCLUDE $ROOT/ext/repair/checkindex.c
INCLUDE $ROOT/ext/repair/checkfreelist.c

/*
** Decode a pointer to an sqlite3 object.
*/
int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){
  struct SqliteDb *p;
  Tcl_CmdInfo cmdInfo;
  if( Tcl_GetCommandInfo(interp, zA, &cmdInfo) ){
    p = (struct SqliteDb*)cmdInfo.objClientData;
    *ppDb = p->db;
    return TCL_OK;
  }else{
    *ppDb = 0;
    return TCL_ERROR;
  }
  return TCL_OK;
}

/*
**   sqlite3_imposter db main rootpage {CREATE TABLE...}  ;# setup an imposter
**   sqlite3_imposter db main                             ;# rm all imposters
*/
static int sqlite3_imposter(
  void *clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3 *db;
  const char *zSchema;
  int iRoot;
  const char *zSql;

  if( objc!=3 && objc!=5 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB SCHEMA [ROOTPAGE SQL]");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  zSchema = Tcl_GetString(objv[2]);
  if( objc==3 ){
    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, zSchema, 0, 1);
  }else{
    if( Tcl_GetIntFromObj(interp, objv[3], &iRoot) ) return TCL_ERROR;
    zSql = Tcl_GetString(objv[4]);
    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, zSchema, 1, iRoot);
    sqlite3_exec(db, zSql, 0, 0, 0);
    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, zSchema, 0, 0);
  }
  return TCL_OK;
}

#include <stdio.h>

const char *sqlite3_checker_init_proc(Tcl_Interp *interp){
  Tcl_CreateObjCommand(interp, "sqlite3_imposter", 
                       (Tcl_ObjCmdProc*)sqlite3_imposter, 0, 0);
  sqlite3_auto_extension((void(*)(void))sqlite3_btreeinfo_init);
  sqlite3_auto_extension((void(*)(void))sqlite3_checkindex_init);
  sqlite3_auto_extension((void(*)(void))sqlite3_checkfreelist_init);
  return
BEGIN_STRING
INCLUDE $ROOT/ext/repair/sqlite3_checker.tcl
END_STRING
;
}

# This TCL script is the main driver script for the sqlite3_checker utility
# program.
#

# Special case:
#
#      sqlite3_checker --test FILENAME ARGS
#
# uses FILENAME in place of this script.
#
if {[lindex $argv 0]=="--test" && [llength $argv]>1} {
  set ::argv0 [lindex $argv 1]
  set argv [lrange $argv 2 end]
  source $argv0
  exit 0
}

# Emulate a TCL shell
#
proc tclsh {} {
  set line {}
  while {![eof stdin]} {
    if {$line!=""} {
      puts -nonewline "> "
    } else {
      puts -nonewline "% "
    }
    flush stdout
    append line [gets stdin]
    if {[info complete $line]} {
      if {[catch {uplevel #0 $line} result]} {
        puts stderr "Error: $result"
      } elseif {$result!=""} {
        puts $result
      }
      set line {}
    } else {
      append line \n
    }
  }
}

# Do an incremental integrity check of a single index
#
proc check_index {idxname batchsize} {
  set i 0
  set more 1
  set nerr 0
  set pct 00.0
  set max [db one {SELECT nEntry FROM sqlite_btreeinfo('main')
                    WHERE name=$idxname}]
  puts -nonewline "$idxname: $i of $max rows ($pct%)\r"
  flush stdout
  while {$more} {
    set more 0
    db eval {SELECT errmsg, current_key AS key
               FROM incremental_index_check($idxname)
              WHERE after_key=$key
              LIMIT $batchsize} {
      set more 1
      if {$errmsg!=""} {
        incr nerr
        puts "$idxname: key($key): $errmsg"
      }
      incr i
    }
    set x [format {%.1f} [expr {($i*100.0)/$max}]]
    if {$x!=$pct} {
      puts -nonewline "$idxname: $i of $max rows ($pct%)\r"
      flush stdout
      set pct $x
    }
  }
  puts "$idxname: $nerr errors out of $i entries"
}

# Print a usage message on standard error, then quit.
#
proc usage {} {
  set argv0 [file rootname [file tail [info nameofexecutable]]]
  puts stderr "Usage: $argv0 OPTIONS database-filename"
  puts stderr {
Do sanity checking on a live SQLite3 database file specified by the
"database-filename" argument.

Options:

   --batchsize N     Number of rows to check per transaction

   --freelist        Perform a freelist check

   --index NAME      Run a check of the index NAME

   --summary         Print summary information about the database

   --table NAME      Run a check of all indexes for table NAME

   --tclsh           Run the built-in TCL interpreter (for debugging)

   --version         Show the version number of SQLite
}
  exit 1
}

set file_to_analyze {}
append argv {}
set bFreelistCheck 0
set bSummary 0
set zIndex {}
set zTable {}
set batchsize 1000
set bAll 1
set argc [llength $argv]
for {set i 0} {$i<$argc} {incr i} {
  set arg [lindex $argv $i]
  if {[regexp {^-+tclsh$} $arg]} {
    tclsh
    exit 0
  }
  if {[regexp {^-+version$} $arg]} {
    sqlite3 mem :memory:
    puts [mem one {SELECT sqlite_version()||' '||sqlite_source_id()}]
    mem close
    exit 0
  }
  if {[regexp {^-+freelist$} $arg]} {
    set bFreelistCheck 1
    set bAll 0
    continue
  }
  if {[regexp {^-+summary$} $arg]} {
    set bSummary 1
    set bAll 0
    continue
  }
  if {[regexp {^-+batchsize$} $arg]} {
    incr i
    if {$i>=$argc} {
      puts stderr "missing argument on $arg"
      exit 1
    }
    set batchsize [lindex $argv $i]
    continue
  }
  if {[regexp {^-+index$} $arg]} {
    incr i
    if {$i>=$argc} {
      puts stderr "missing argument on $arg"
      exit 1
    }
    set zIndex [lindex $argv $i]
    set bAll 0
    continue
  }
  if {[regexp {^-+table$} $arg]} {
    incr i
    if {$i>=$argc} {
      puts stderr "missing argument on $arg"
      exit 1
    }
    set zTable [lindex $argv $i]
    set bAll 0
    continue
  }
  if {[regexp {^-} $arg]} {
    puts stderr "Unknown option: $arg"
    usage
  }
  if {$file_to_analyze!=""} {
    usage
  } else {
    set file_to_analyze $arg
  }
}
if {$file_to_analyze==""} usage

# If a TCL script is specified on the command-line, then run that
# script.
#
if {[file extension $file_to_analyze]==".tcl"} {
  source $file_to_analyze
  exit 0
}

set root_filename $file_to_analyze
regexp {^file:(//)?([^?]*)} $file_to_analyze all x1 root_filename
if {![file exists $root_filename]} {
  puts stderr "No such file: $root_filename"
  exit 1
}
if {![file readable $root_filename]} {
  puts stderr "File is not readable: $root_filename"
  exit 1
}

if {[catch {sqlite3 db $file_to_analyze} res]} {
  puts stderr "Cannot open datababase $root_filename: $res"
  exit 1
}

if {$bFreelistCheck || $bAll} {
  puts -nonewline "freelist-check: "
  flush stdout
  puts [db one {SELECT checkfreelist('main')}]
}
if {$bSummary} {
  set scale 0
  set pgsz [db one {PRAGMA page_size}]
  db eval {SELECT nPage*$pgsz AS sz, name, tbl_name
             FROM sqlite_btreeinfo
            WHERE type='index'
            ORDER BY 1 DESC, name} {
    if {$scale==0} {
      if {$sz>10000000} {
        set scale 1000000.0
        set unit MB
      } else {
        set scale 1000.0
        set unit KB
      }
    }
    puts [format {%7.1f %s index %s of table %s} \
            [expr {$sz/$scale}] $unit $name $tbl_name]
  }
}
if {$zIndex!=""} {
  check_index $zIndex $batchsize
}
if {$zTable!=""} {
  foreach idx [db eval {SELECT name FROM sqlite_master
                         WHERE type='index' AND rootpage>0
                           AND tbl_name=$zTable}] {
    check_index $idx $batchsize
  }
}
if {$bAll} {
  set allidx [db eval {SELECT name FROM sqlite_btreeinfo('main')
                        WHERE type='index' AND rootpage>0
                        ORDER BY nEntry}]
  foreach idx $allidx {
    check_index $idx $batchsize
  }
}

To run these tests, first build sqlite3_checker:


>     make sqlite3_checker


Then run the "test.tcl" script using:


>     ./sqlite3_checker --test $path/test.tcl


Optionally add the full pathnames of individual *.test modules

# 2017-10-11

set testprefix checkfreelist

do_execsql_test 1.0 {
  PRAGMA page_size=1024;
  CREATE TABLE t1(a, b);
}

do_execsql_test 1.2 { SELECT checkfreelist('main') } {ok}
do_execsql_test 1.3 {
  WITH s(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<10000
  )
  INSERT INTO t1 SELECT randomblob(400), randomblob(400) FROM s;
  DELETE FROM t1 WHERE rowid%3;
  PRAGMA freelist_count;
} {6726}

do_execsql_test 1.4 { SELECT checkfreelist('main') } {ok}
do_execsql_test 1.5 {
  WITH freelist_trunk(i, d, n) AS (
    SELECT 1, NULL, sqlite_readint32(data, 32) FROM sqlite_dbpage WHERE pgno=1
      UNION ALL
    SELECT n, data, sqlite_readint32(data) 
    FROM freelist_trunk, sqlite_dbpage WHERE pgno=n
  )
  SELECT i FROM freelist_trunk WHERE i!=1;
} {
  10009 9715 9343 8969 8595 8222 7847 7474 7102 6727 6354 5982 5608 5234
  4860 4487 4112 3740 3367 2992 2619 2247 1872 1499 1125 752 377 5
}

do_execsql_test 1.6 { SELECT checkfreelist('main') } {ok}

proc set_int {blob idx newval} {
  binary scan $blob I* ints
  lset ints $idx $newval
  binary format I* $ints
}
db func set_int set_int

proc get_int {blob idx} {
  binary scan $blob I* ints
  lindex $ints $idx
}
db func get_int get_int

do_execsql_test 1.7 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 1, get_int(data, 1)-1) 
      WHERE pgno=4860;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{free-list count mismatch: actual=6725 header=6726}}

do_execsql_test 1.8 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 5, (SELECT * FROM pragma_page_count)+1)
      WHERE pgno=4860;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 10092 is out of range (child 3 of trunk page 4860)}}

do_execsql_test 1.9 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 5, 0)
      WHERE pgno=4860;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 0 is out of range (child 3 of trunk page 4860)}}

do_execsql_test 1.10 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, get_int(data, 1)+1, 0)
      WHERE pgno=5;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 0 is out of range (child 247 of trunk page 5)}}

do_execsql_test 1.11 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 1, 249)
      WHERE pgno=5;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf count out of range (249) on trunk page 5}}

# 2017-10-11
#
set testprefix checkindex

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a);
  INSERT INTO t1 VALUES('one', 2);
  INSERT INTO t1 VALUES('two', 4);
  INSERT INTO t1 VALUES('three', 6);
  INSERT INTO t1 VALUES('four', 8);
  INSERT INTO t1 VALUES('five', 10);

  CREATE INDEX i2 ON t1(a DESC);
} {}

proc incr_index_check {idx nStep} {
  set Q {
    SELECT errmsg, current_key FROM incremental_index_check($idx, $after)
    LIMIT $nStep
  }

  set res [list]
  while {1} {
    unset -nocomplain current_key
    set res1 [db eval $Q]
    if {[llength $res1]==0} break
    set res [concat $res $res1]
    set after [lindex $res end]
  }

  return $res
}

proc do_index_check_test {tn idx res} {
  uplevel [list do_execsql_test $tn.1 "
    SELECT errmsg, current_key FROM incremental_index_check('$idx');
  " $res]

  uplevel [list do_test $tn.2 "incr_index_check $idx 1" [list {*}$res]]
  uplevel [list do_test $tn.3 "incr_index_check $idx 2" [list {*}$res]]
  uplevel [list do_test $tn.4 "incr_index_check $idx 5" [list {*}$res]]
}


do_execsql_test 1.2 {
  SELECT errmsg IS NULL, current_key FROM incremental_index_check('i1');
} {
  1 'five',5
  1 'four',4
  1 'one',1
  1 'three',3
  1 'two',2
}

do_index_check_test 1.3 i1 {
  {} 'five',5
  {} 'four',4
  {} 'one',1
  {} 'three',3
  {} 'two',2
}

do_index_check_test 1.4 i2 {
  {} 'two',2
  {} 'three',3
  {} 'one',1
  {} 'four',4
  {} 'five',5
}

do_test 1.5 {
  set tblroot [db one { SELECT rootpage FROM sqlite_master WHERE name='t1' }]
  sqlite3_imposter db main $tblroot {CREATE TABLE xt1(a,b)}
  db eval {
    UPDATE xt1 SET a='six' WHERE rowid=3;
    DELETE FROM xt1 WHERE rowid = 5;
  }
  sqlite3_imposter db main
} {}

do_index_check_test 1.6 i1 {
  {row missing} 'five',5
  {} 'four',4
  {} 'one',1
  {row data mismatch} 'three',3
  {} 'two',2
}

do_index_check_test 1.7 i2 {
  {} 'two',2
  {row data mismatch} 'three',3
  {} 'one',1
  {} 'four',4
  {row missing} 'five',5
}

#--------------------------------------------------------------------------
do_execsql_test 2.0 {

  CREATE TABLE t2(a INTEGER PRIMARY KEY, b, c, d);

  INSERT INTO t2 VALUES(1, NULL, 1, 1);
  INSERT INTO t2 VALUES(2, 1, NULL, 1);
  INSERT INTO t2 VALUES(3, 1, 1, NULL);

  INSERT INTO t2 VALUES(4, 2, 2, 1);
  INSERT INTO t2 VALUES(5, 2, 2, 2);
  INSERT INTO t2 VALUES(6, 2, 2, 3);

  INSERT INTO t2 VALUES(7, 2, 2, 1);
  INSERT INTO t2 VALUES(8, 2, 2, 2);
  INSERT INTO t2 VALUES(9, 2, 2, 3);

  CREATE INDEX i3 ON t2(b, c, d);
  CREATE INDEX i4 ON t2(b DESC, c DESC, d DESC);
  CREATE INDEX i5 ON t2(d, c DESC, b);
} {}

do_index_check_test 2.1 i3 {
  {} NULL,1,1,1 
  {} 1,NULL,1,2 
  {} 1,1,NULL,3 
  {} 2,2,1,4 
  {} 2,2,1,7 
  {} 2,2,2,5
  {} 2,2,2,8 
  {} 2,2,3,6 
  {} 2,2,3,9
}

do_index_check_test 2.2 i4 {
  {} 2,2,3,6 
  {} 2,2,3,9
  {} 2,2,2,5
  {} 2,2,2,8 
  {} 2,2,1,4 
  {} 2,2,1,7 
  {} 1,1,NULL,3 
  {} 1,NULL,1,2 
  {} NULL,1,1,1 
}

do_index_check_test 2.3 i5 {
  {} NULL,1,1,3 
  {} 1,2,2,4 
  {} 1,2,2,7 
  {} 1,1,NULL,1 
  {} 1,NULL,1,2 
  {} 2,2,2,5 
  {} 2,2,2,8 
  {} 3,2,2,6 
  {} 3,2,2,9
}

#--------------------------------------------------------------------------
do_execsql_test 3.0 {

  CREATE TABLE t3(w, x, y, z PRIMARY KEY) WITHOUT ROWID;
  CREATE INDEX t3wxy ON t3(w, x, y);
  CREATE INDEX t3wxy2 ON t3(w DESC, x DESC, y DESC);

  INSERT INTO t3 VALUES(NULL, NULL, NULL, 1);
  INSERT INTO t3 VALUES(NULL, NULL, NULL, 2);
  INSERT INTO t3 VALUES(NULL, NULL, NULL, 3);

  INSERT INTO t3 VALUES('a', NULL, NULL, 4);
  INSERT INTO t3 VALUES('a', NULL, NULL, 5);
  INSERT INTO t3 VALUES('a', NULL, NULL, 6);

  INSERT INTO t3 VALUES('a', 'b', NULL, 7);
  INSERT INTO t3 VALUES('a', 'b', NULL, 8);
  INSERT INTO t3 VALUES('a', 'b', NULL, 9);

} {}

do_index_check_test 3.1 t3wxy {
  {} NULL,NULL,NULL,1 {} NULL,NULL,NULL,2 {} NULL,NULL,NULL,3 
  {} 'a',NULL,NULL,4  {} 'a',NULL,NULL,5  {} 'a',NULL,NULL,6 
  {} 'a','b',NULL,7   {} 'a','b',NULL,8   {} 'a','b',NULL,9 
}
do_index_check_test 3.2 t3wxy2 {
  {} 'a','b',NULL,7   {} 'a','b',NULL,8   {} 'a','b',NULL,9 
  {} 'a',NULL,NULL,4  {} 'a',NULL,NULL,5  {} 'a',NULL,NULL,6 
  {} NULL,NULL,NULL,1 {} NULL,NULL,NULL,2 {} NULL,NULL,NULL,3 
}

#--------------------------------------------------------------------------
# Test with an index that uses non-default collation sequences.
#
do_execsql_test 4.0 {
  CREATE TABLE t4(a INTEGER PRIMARY KEY, c1 TEXT, c2 TEXT);
  INSERT INTO t4 VALUES(1, 'aaa', 'bbb');
  INSERT INTO t4 VALUES(2, 'AAA', 'CCC');
  INSERT INTO t4 VALUES(3, 'aab', 'ddd');
  INSERT INTO t4 VALUES(4, 'AAB', 'EEE');

  CREATE INDEX t4cc ON t4(c1 COLLATE nocase, c2 COLLATE nocase);
}

do_index_check_test 4.1 t4cc {
  {} 'aaa','bbb',1 
  {} 'AAA','CCC',2 
  {} 'aab','ddd',3 
  {} 'AAB','EEE',4
}

do_test 4.2 {
  set tblroot [db one { SELECT rootpage FROM sqlite_master WHERE name='t4' }]
  sqlite3_imposter db main $tblroot \
     {CREATE TABLE xt4(a INTEGER PRIMARY KEY, c1 TEXT, c2 TEXT)}

  db eval {
    UPDATE xt4 SET c1='hello' WHERE rowid=2;
    DELETE FROM xt4 WHERE rowid = 3;
  }
  sqlite3_imposter db main
} {}

do_index_check_test 4.3 t4cc {
  {} 'aaa','bbb',1 
  {row data mismatch} 'AAA','CCC',2 
  {row missing} 'aab','ddd',3 
  {} 'AAB','EEE',4
}

#--------------------------------------------------------------------------
# Test an index on an expression.
#
do_execsql_test 5.0 {
  CREATE TABLE t5(x INTEGER PRIMARY KEY, y TEXT, UNIQUE(y));
  INSERT INTO t5 VALUES(1, '{"x":1, "y":1}');
  INSERT INTO t5 VALUES(2, '{"x":2, "y":2}');
  INSERT INTO t5 VALUES(3, '{"x":3, "y":3}');
  INSERT INTO t5 VALUES(4, '{"w":4, "z":4}');
  INSERT INTO t5 VALUES(5, '{"x":5, "y":5}');

  CREATE INDEX t5x ON t5( json_extract(y, '$.x') );
  CREATE INDEX t5y ON t5( json_extract(y, '$.y') DESC );
}

do_index_check_test 5.1.1 t5x {
  {} NULL,4 {} 1,1 {} 2,2 {} 3,3 {} 5,5
}

do_index_check_test 5.1.2 t5y {
  {} 5,5 {} 3,3 {} 2,2 {} 1,1 {} NULL,4
}

do_index_check_test 5.1.3 sqlite_autoindex_t5_1 {
  {} {'{"w":4, "z":4}',4} 
  {} {'{"x":1, "y":1}',1} 
  {} {'{"x":2, "y":2}',2} 
  {} {'{"x":3, "y":3}',3} 
  {} {'{"x":5, "y":5}',5}
}

do_test 5.2 {
  set tblroot [db one { SELECT rootpage FROM sqlite_master WHERE name='t5' }]
  sqlite3_imposter db main $tblroot \
      {CREATE TABLE xt5(a INTEGER PRIMARY KEY, c1 TEXT);}
  db eval {
    UPDATE xt5 SET c1='{"x":22, "y":11}' WHERE rowid=1;
    DELETE FROM xt5 WHERE rowid = 4;
  }
  sqlite3_imposter db main
} {}

do_index_check_test 5.3.1 t5x {
  {row missing} NULL,4 
  {row data mismatch} 1,1 
  {} 2,2 
  {} 3,3 
  {} 5,5
}

do_index_check_test 5.3.2 sqlite_autoindex_t5_1 {
  {row missing} {'{"w":4, "z":4}',4} 
  {row data mismatch} {'{"x":1, "y":1}',1} 
  {} {'{"x":2, "y":2}',2} 
  {} {'{"x":3, "y":3}',3} 
  {} {'{"x":5, "y":5}',5}
}

#-------------------------------------------------------------------------
#
do_execsql_test 6.0 {
  CREATE TABLE t6(x INTEGER PRIMARY KEY, y, z);
  CREATE INDEX t6x1 ON t6(y, /* one,two,three */ z);
  CREATE INDEX t6x2 ON t6(z, -- hello,world,
  y);

  CREATE INDEX t6x3 ON t6(z -- hello,world
  , y);

  INSERT INTO t6 VALUES(1, 2, 3);
  INSERT INTO t6 VALUES(4, 5, 6);
}

do_index_check_test 6.1 t6x1 {
  {} 2,3,1 
  {} 5,6,4
}
do_index_check_test 6.2 t6x2 {
  {} 3,2,1 
  {} 6,5,4
}
do_index_check_test 6.2 t6x3 {
  {} 3,2,1 
  {} 6,5,4
}

# Run this script using
#
#       sqlite3_checker --test $thisscript $testscripts
#
# The $testscripts argument is optional.  If omitted, all *.test files
# in the same directory as $thisscript are run.
#
set NTEST 0
set NERR  0


# Invoke the do_test procedure to run a single test
#
# The $expected parameter is the expected result.  The result is the return
# value from the last TCL command in $cmd.
#
# Normally, $expected must match exactly.  But if $expected is of the form
# "/regexp/" then regular expression matching is used.  If $expected is
# "~/regexp/" then the regular expression must NOT match.  If $expected is
# of the form "#/value-list/" then each term in value-list must be numeric
# and must approximately match the corresponding numeric term in $result.
# Values must match within 10%.  Or if the $expected term is A..B then the
# $result term must be in between A and B.
#
proc do_test {name cmd expected} {
  if {[info exists ::testprefix]} {
    set name "$::testprefix$name"
  }

  incr ::NTEST
  puts -nonewline $name...
  flush stdout

  if {[catch {uplevel #0 "$cmd;\n"} result]} {
    puts -nonewline $name...
    puts "\nError: $result"
    incr ::NERR
  } else {
    set ok [expr {[string compare $result $expected]==0}]
    if {!$ok} {
      puts "\n!  $name expected: \[$expected\]\n! $name got:      \[$result\]"
      incr ::NERR
    } else {
      puts " Ok"
    }
  }
  flush stdout
}

#
#   do_execsql_test TESTNAME SQL RES
#
proc do_execsql_test {testname sql {result {}}} {
  uplevel [list do_test $testname [list db eval $sql] [list {*}$result]]
}

if {[llength $argv]==0} {
  set dir [file dirname $argv0]
  set argv [glob -nocomplain $dir/*.test]
}
foreach testfile $argv {
  file delete -force test.db
  sqlite3 db test.db
  source $testfile
  catch {db close}
}
puts "$NERR errors out of $NTEST tests"

# executables needed for testing
#
TESTPROGS = \
  testfixture$(EXE) \
  sqlite3$(EXE) \
  sqlite3_analyzer$(EXE) \
  sqlite3_checker$(EXE) \
  sqldiff$(EXE) \
  dbhash$(EXE)

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)/test/fuzzdata1.db \

sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/sqlite3_analyzer.c.in $(TOP)/tool/mkccode.tcl
	tclsh $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

sqlite3_analyzer$(EXE): sqlite3_analyzer.c
	$(TCCX) $(TCL_FLAGS) sqlite3_analyzer.c -o $@ $(LIBTCL) $(THREADLIB) 

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \
  $(TOP)/ext/repair/checkfreelist.c \
  $(TOP)/ext/misc/btreeinfo.c \
  $(TOP)/ext/repair/sqlite3_checker.c.in

sqlite3_checker.c:	$(CHECKER_DEPS)
	tclsh $(TOP)/tool/mkccode.tcl $(TOP)/ext/repair/sqlite3_checker.c.in >$@

sqlite3_checker$(TEXE):	sqlite3_checker.c
	$(TCCX) $(TCL_FLAGS) sqlite3_checker.c -o $@ $(LIBTCL) $(THREADLIB)

dbdump$(EXE):	$(TOP)/ext/misc/dbdump.c sqlite3.o
	$(TCCX) -DDBDUMP_STANDALONE -o dbdump$(EXE) \
            $(TOP)/ext/misc/dbdump.c sqlite3.o $(THREADLIB)

# Rules to build the 'testfixture' application.
#
TESTFIXTURE_FLAGS  = -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1

  zSchema = (const char*)sqlite3_value_text(argv[4]);
  iDb = zSchema ? sqlite3FindDbName(pTab->db, zSchema) : -1;
  if( iDb<0 ){
    zErr = "no such schema";
    goto update_fail;
  }
  pBt = pTab->db->aDb[iDb].pBt;
  if( pgno<1 || pBt==0 || pgno>(int)sqlite3BtreeLastPage(pBt) ){
    zErr = "bad page number";
    goto update_fail;
  }
  szPage = sqlite3BtreeGetPageSize(pBt);
  if( sqlite3_value_type(argv[3])!=SQLITE_BLOB 
   || sqlite3_value_bytes(argv[3])!=szPage
  ){

  }else{
    pFile->ctrlFlags |= mask;
  }
}

/* Forward declaration */
static int unixGetTempname(int nBuf, char *zBuf);
static int fcntlReadShm(unixFile*,void*);

/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){
  unixFile *pFile = (unixFile*)id;
  switch( op ){

      return rc ? SQLITE_IOERR_COMMIT_ATOMIC : SQLITE_OK;
    }
    case SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE: {
      int rc = osIoctl(pFile->h, F2FS_IOC_ABORT_VOLATILE_WRITE);
      return rc ? SQLITE_IOERR_ROLLBACK_ATOMIC : SQLITE_OK;
    }
#endif /* __linux__ && SQLITE_ENABLE_BATCH_ATOMIC_WRITE */

    case SQLITE_FCNTL_READ_SHM: {
      return fcntlReadShm(pFile, pArg);
    }

    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = pFile->eFileLock;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_LAST_ERRNO: {
      *(int*)pArg = pFile->lastErrno;

};

/*
** Constants used for locking
*/
#define UNIX_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)         /* first lock byte */
#define UNIX_SHM_DMS    (UNIX_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */

/*
** Implementation of file-control SQLITE_FCNTL_READ_SHM.
*/
static int fcntlReadShm(unixFile *pFile, void *pArg){
  struct ReadShmParam {
    void *pBuf;
    int nBuf;
  } *pParam = (struct ReadShmParam*)pArg;
  unixShmNode *pShmNode = pFile->pShm->pShmNode;
  int rc = SQLITE_OK;
  sqlite3_mutex_enter( pShmNode->mutex );
  if( pShmNode->isUnlocked==1 ){
    struct stat buf;          /* Used to hold return values of fstat() */
    if( osFstat(pShmNode->h, &buf) ){
      rc = SQLITE_IOERR_FSTAT;
    }else if( 0!=lseek(pShmNode->h, 0, SEEK_SET) ){
      rc = SQLITE_IOERR_READ;
    }else{
      int nRead = buf.st_size;
      if( nRead==0 ){
        pParam->nBuf = 0;
        pParam->pBuf = 0;
      }else{    
        pParam->pBuf = sqlite3_malloc(nRead);
        if( pParam->pBuf ){
          int res = osRead(pShmNode->h, pParam->pBuf, nRead);
          if( res!=nRead ){
            sqlite3_free(pParam->pBuf);
            pParam->pBuf = 0;
            rc = SQLITE_IOERR_READ;
          }else{
            pParam->nBuf = nRead;
          }
        }else{
          rc = SQLITE_NOMEM_BKPT;
        }
      }
    }
  }else{
    rc = SQLITE_BUSY;
  }
  sqlite3_mutex_leave( pShmNode->mutex );
  return rc;
}

/*
** Apply posix advisory locks for all bytes from ofst through ofst+n-1.
**
** Locks block if the mask is exactly UNIX_SHM_C and are non-blocking
** otherwise.
*/

#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))

#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))

** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
** operations since the previous successful call to 
** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
** ^This file control takes the file descriptor out of batch write mode
** so that all subsequent write operations are independent.
** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
**
** <li>[[SQLITE_FCNTL_READ_SHM]]
** The [SQLITE_FCNTL_READ_SHM] opcode may be used to read data from 
** the shared-memory region used by wal mode if the previous call
** to the xShmMap method returned SQLITE_READONLY_CANTLOCK. The argument
** must point to an instance of a structure declared as:
** <blockquote><pre>
**   struct ReadShmArg { void *pBuf; int nBuf };
** </pre></blockquote>)^
** Before returning, this operation allocates a buffer large enough for
** the entire shared-memory using sqlite3_malloc() and populates it with
** a copy thereof. ReadShmArg.pBuf is set to point to the buffer, and
** ReadShmArg to its size in bytes. It is the responsibility of the caller
** to eventually free the buffer using sqlite3_free().
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_FCNTL_GET_LOCKPROXYFILE       2
#define SQLITE_FCNTL_SET_LOCKPROXYFILE       3
#define SQLITE_FCNTL_LAST_ERRNO              4
#define SQLITE_FCNTL_SIZE_HINT               5

#define SQLITE_FCNTL_VFS_POINTER            27
#define SQLITE_FCNTL_JOURNAL_POINTER        28
#define SQLITE_FCNTL_WIN32_GET_HANDLE       29
#define SQLITE_FCNTL_PDB                    30
#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE     31
#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
#define SQLITE_FCNTL_READ_SHM               34

/* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO

  u8 exclusiveMode;          /* Non-zero if connection is in exclusive mode */
  u8 writeLock;              /* True if in a write transaction */
  u8 ckptLock;               /* True if holding a checkpoint lock */
  u8 readOnly;               /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */
  u8 truncateOnCommit;       /* True to truncate WAL file on commit */
  u8 syncHeader;             /* Fsync the WAL header if true */
  u8 padToSectorBoundary;    /* Pad transactions out to the next sector */
  u8 bUnlocked;              /* A readonly_shm connection without DMS lock */
  WalIndexHdr hdr;           /* Wal-index header for current transaction */
  u32 minFrame;              /* Ignore wal frames before this one */
  u32 iReCksum;              /* On commit, recalculate checksums from here */
  const char *zWalName;      /* Name of WAL file */
  u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
#ifdef SQLITE_DEBUG
  u8 lockError;              /* True if a locking error has occurred */

*/
#define HASHTABLE_NPAGE_ONE  (HASHTABLE_NPAGE - (WALINDEX_HDR_SIZE/sizeof(u32)))

/* The wal-index is divided into pages of WALINDEX_PGSZ bytes each. */
#define WALINDEX_PGSZ   (                                         \
    sizeof(ht_slot)*HASHTABLE_NSLOT + HASHTABLE_NPAGE*sizeof(u32) \
)

/*
** Grow the pWal->apWiData[] array so that it is at least nPage entries
** in size. Return SQLITE_NOMEM if an OOM error occurs, or SQLITE_OK 
** otherwise.
*/
static int walIndexGrowArray(Wal *pWal, int nPage){
  if( nPage>pWal->nWiData ){
    int nByte = sizeof(u32*)*nPage;
    volatile u32 **apNew;
    apNew = (volatile u32 **)sqlite3_realloc64((void *)pWal->apWiData, nByte);
    if( !apNew ){
      return SQLITE_NOMEM_BKPT;
    }
    memset((void*)&apNew[pWal->nWiData], 0,
           sizeof(u32*)*(nPage-pWal->nWiData));
    pWal->apWiData = apNew;
    pWal->nWiData = nPage;
  }
  return SQLITE_OK;
}

/*
** Obtain a pointer to the iPage'th page of the wal-index. The wal-index
** is broken into pages of WALINDEX_PGSZ bytes. Wal-index pages are
** numbered from zero.
**
** If this call is successful, *ppPage is set to point to the wal-index
** page and SQLITE_OK is returned. If an error (an OOM or VFS error) occurs,
** then an SQLite error code is returned and *ppPage is set to 0.
*/
static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
  int rc = SQLITE_OK;

  /* Enlarge the pWal->apWiData[] array if required */

  if( walIndexGrowArray(pWal, iPage+1) ){



    *ppPage = 0;
    return SQLITE_NOMEM;





  }

  /* Request a pointer to the required page from the VFS */
  if( pWal->apWiData[iPage]==0 ){
    if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE ){
      pWal->apWiData[iPage] = (u32 volatile *)sqlite3MallocZero(WALINDEX_PGSZ);
      if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM_BKPT;

*/
static int walIndexRecover(Wal *pWal){
  int rc;                         /* Return Code */
  i64 nSize;                      /* Size of log file */
  u32 aFrameCksum[2] = {0, 0};
  int iLock;                      /* Lock offset to lock for checkpoint */

  /* Obtain an exclusive lock on all bytes in the locking range except
  ** WAL_READ_LOCK(0) not already locked by the caller. The caller is
  ** guaranteed to have locked the WAL_WRITE_LOCK byte, and may have also
  ** locked the WAL_CKPT_LOCK byte. If successful, the same bytes that are
  ** locked here are unlocked before this function returns.  */

  assert( pWal->ckptLock==1 || pWal->ckptLock==0 );
  assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 );
  assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE );
  assert( pWal->writeLock );
  iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock;
  rc = walLockExclusive(pWal, iLock, WAL_READ_LOCK(0)-iLock);
  if( rc==SQLITE_OK ){

  int badHdr;                     /* True if a header read failed */
  volatile u32 *page0;            /* Chunk of wal-index containing header */

  /* Ensure that page 0 of the wal-index (the page that contains the 
  ** wal-index header) is mapped. Return early if an error occurs here.
  */
  assert( pChanged );
  assert( pWal->bUnlocked==0 );
  rc = walIndexPage(pWal, 0, &page0);
  if( rc!=SQLITE_OK ){








    return rc;
  };
  assert( page0 || pWal->writeLock==0 );

  /* If the first page of the wal-index has been mapped, try to read the
  ** wal-index header immediately, without holding any lock. This usually
  ** works, but may fail if the wal-index header is corrupt or currently 
  ** being modified by another thread or process.
  */
  badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);

  /* If the first attempt failed, it might have been due to a race
  ** with a writer.  So get a WRITE lock and try again.
  */
  assert( badHdr==0 || pWal->writeLock==0 );
  if( badHdr ){
    if( pWal->readOnly & WAL_SHM_RDONLY ){
      if( pWal->bUnlocked ){
        rc = SQLITE_READONLY_RECOVERY;
      }
      else if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){
        walUnlockShared(pWal, WAL_WRITE_LOCK);
        rc = SQLITE_READONLY_RECOVERY;
      }
    }else if( SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){
      pWal->writeLock = 1;
      if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){
        badHdr = walIndexTryHdr(pWal, pChanged);

}

/*
** This is the value that walTryBeginRead returns when it needs to
** be retried.
*/
#define WAL_RETRY  (-1)

/*
** When this function is called, a call to xShmMap has just returned
** SQLITE_READONLY_CANTLOCK, indicating that the *-shm file was opened
** read-only and that there were no other connections to the database 
** at that point.
*/
static int walBeginUnlocked(Wal *pWal, int *pChanged){
  struct ReadShmParam {
    void *pBuf;
    int nBuf;
  } buf = {0, 0};
  i64 nSize;
  int rc;
  volatile void *pDummy;

  assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );
  assert( pWal->readOnly & WAL_SHM_RDONLY );
  
  /* Take WAL_READ_LOCK(0). This has the effect of preventing any
  ** live clients from running a checkpoint, but does not stop them
  ** from running recovery.  */
  rc = walLockShared(pWal, WAL_READ_LOCK(0));
  if( rc!=SQLITE_OK ){
    return (rc==SQLITE_BUSY ? WAL_RETRY : rc);
  }

  /* Try to map the *-shm file again. If it succeeds this time, then 
  ** a non-readonly_shm connection has already connected to the database.
  ** In this case, start over with opening the transaction.
  **
  ** The WAL_READ_LOCK(0) lock held by this client prevents a checkpoint
  ** from taking place. But it does not prevent the wal from being wrapped
  ** if a checkpoint has already taken place. This means that if another
  ** client is connected at this point, it may have already checkpointed 
  ** the entire wal. In that case it would not be safe to continue with
  ** the unlocked transaction, as the other client may overwrite wal 
  ** frames that this client is still using.  */
  rc = sqlite3OsShmMap(pWal->pDbFd, 0, WALINDEX_PGSZ, 0, &pDummy);
  if( rc!=SQLITE_READONLY_CANTLOCK ){
    rc = (rc==SQLITE_OK ? WAL_RETRY : rc);
    goto begin_unlocked_out;
  }
  pWal->readLock = 0;

  /* Figure out how large the wal file is. If it is zero bytes in size,
  ** do not bother loading the *-shm file. Just read from the db file
  ** exclusively like any other Wal.readLock==0 client. Otherwise,
  ** use SQLITE_FCNTL_READ_SHM to load the contents of the *-shm file 
  ** into heap memory. */
  rc = sqlite3OsFileSize(pWal->pWalFd, &nSize);
  if( rc!=SQLITE_OK ) return rc;

  memset(&pWal->hdr, 0, sizeof(WalIndexHdr));
  if( nSize>0 ){
    rc = sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_READ_SHM, (void*)&buf);
    if( rc!=SQLITE_OK ){
      return rc==SQLITE_BUSY ? WAL_RETRY : rc;
    }
    if( buf.nBuf<WALINDEX_PGSZ ){
      rc = SQLITE_READONLY_RECOVERY;
    }else{
      int i;
      int nChunk = buf.nBuf/WALINDEX_PGSZ;
      if( walIndexGrowArray(pWal, nChunk) ){
        rc = SQLITE_NOMEM;
      }else{
        u8 *aBuf = (u8*)buf.pBuf;
        for(i=0; i<nChunk; i++){
          pWal->apWiData[i] = (volatile u32*)&aBuf[i*WALINDEX_PGSZ];
        }
        if( walIndexTryHdr(pWal, pChanged) ){
          rc = SQLITE_READONLY_RECOVERY;
        }
      }
    }
  }

 begin_unlocked_out:
  if( rc!=SQLITE_OK ){
    sqlite3_free(buf.pBuf);
    memset(pWal->apWiData, 0, pWal->nWiData*sizeof(u32*));
    walUnlockShared(pWal, WAL_READ_LOCK(0));
  }else{
    pWal->bUnlocked = 1;
    *pChanged = 1;
  }
  return rc;
}

/*
** Attempt to start a read transaction.  This might fail due to a race or
** other transient condition.  When that happens, it returns WAL_RETRY to
** indicate to the caller that it is safe to retry immediately.
**
** On success return SQLITE_OK.  On a permanent failure (such an

    }
    if( cnt>=10 ) nDelay = (cnt-9)*(cnt-9)*39;
    sqlite3OsSleep(pWal->pVfs, nDelay);
  }

  if( !useWal ){
    rc = walIndexReadHdr(pWal, pChanged);
    if( rc==SQLITE_READONLY_CANTLOCK ){
      /* This is a readonly_shm connection and there are no other connections
      ** to the database. So the *-shm file may not be accessed using mmap.
      ** Try to open an "unlocked" transaction - one that loads the *-shm
      ** file into memory using read() - instead.  */
      assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );
      assert( pWal->readOnly & WAL_SHM_RDONLY );
      return walBeginUnlocked(pWal, pChanged);
    }
    if( rc==SQLITE_BUSY ){
      /* If there is not a recovery running in another thread or process
      ** then convert BUSY errors to WAL_RETRY.  If recovery is known to
      ** be running, convert BUSY to BUSY_RECOVERY.  There is a race here
      ** which might cause WAL_RETRY to be returned even if BUSY_RECOVERY
      ** would be technically correct.  But the race is benign since with
      ** WAL_RETRY this routine will be called again and will probably be

** read-lock.
*/
void sqlite3WalEndReadTransaction(Wal *pWal){
  sqlite3WalEndWriteTransaction(pWal);
  if( pWal->readLock>=0 ){
    walUnlockShared(pWal, WAL_READ_LOCK(pWal->readLock));
    pWal->readLock = -1;
    if( pWal->bUnlocked ){
      sqlite3_free((void*)pWal->apWiData[0]);
      memset(pWal->apWiData, 0, sizeof(u32*)*pWal->nWiData);
      pWal->bUnlocked = 0;
    }
  }
}

/*
** Search the wal file for page pgno. If found, set *piRead to the frame that
** contains the page. Otherwise, if pgno is not in the wal file, set *piRead
** to zero.

  /* If the "last page" field of the wal-index header snapshot is 0, then
  ** no data will be read from the wal under any circumstances. Return early
  ** in this case as an optimization.  Likewise, if pWal->readLock==0, 
  ** then the WAL is ignored by the reader so return early, as if the 
  ** WAL were empty.
  */
  if( iLast==0 || (pWal->readLock==0 && !pWal->bUnlocked) ){
    *piRead = 0;
    return SQLITE_OK;
  }

  /* Search the hash table or tables for an entry matching page number
  ** pgno. Each iteration of the following for() loop searches one
  ** hash table (each hash table indexes up to HASHTABLE_NPAGE frames).

  Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
  int noCase = 0;                  /* uppercase equivalent to lowercase */
  int op;                          /* Top-level operator.  pExpr->op */
  Parse *pParse = pWInfo->pParse;  /* Parsing context */
  sqlite3 *db = pParse->db;        /* Database connection */
  unsigned char eOp2 = 0;          /* op2 value for LIKE/REGEXP/GLOB */
  int nLeft;                       /* Number of elements on left side vector */

  if( db->mallocFailed ){
    return;
  }
  pTerm = &pWC->a[idxTerm];
  pMaskSet = &pWInfo->sMaskSet;

  ** not normally optimized for ordinary tables.  In other words, OP
  ** is one of MATCH, LIKE, GLOB, REGEXP, !=, IS, IS NOT, or NOT NULL.
  ** This information is used by the xBestIndex methods of
  ** virtual tables.  The native query optimizer does not attempt
  ** to do anything with MATCH functions.
  */
  if( pWC->op==TK_AND ){
    Expr *pRight = 0, *pLeft = 0;
    int res = isAuxiliaryVtabOperator(pExpr, &eOp2, &pLeft, &pRight);
    while( res-- > 0 ){
      int idxNew;
      WhereTerm *pNewTerm;
      Bitmask prereqColumn, prereqExpr;

      prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);

  do_test 1.1.13  { sql2 "INSERT INTO t1 VALUES('i', 'j')" } {}

  do_test 1.2.1 {
    code2 { db2 close }
    code1 { db close }
    list [file exists test.db-wal] [file exists test.db-shm]
  } {1 1}

  do_test 1.2.2 {
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    sql1 { SELECT * FROM t1 }
  } {a b c d e f g h i j}

  do_test 1.2.3 {
    code1 { db close }
    file attributes test.db-shm -permissions rw-r--r--
    hexio_write test.db-shm 0 01020304 
    file attributes test.db-shm -permissions r--r--r--
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    csql1 { SELECT * FROM t1 }
  } {1 {attempt to write a readonly database}}
  do_test 1.2.4 {
    code1 { sqlite3_extended_errcode db } 
  } {SQLITE_READONLY_RECOVERY}

  do_test 1.2.5 {
    file attributes test.db-shm -permissions rw-r--r--
    code2 { sqlite3 db2 test.db }
    sql2 "SELECT * FROM t1" 
  } {a b c d e f g h i j}
  file attributes test.db-shm -permissions r--r--r--

    code2 { db2 close }
    file exists test.db-shm
  } {0}
  do_test 1.3.2.2 {
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    csql1 { SELECT * FROM sqlite_master }
  } {1 {unable to open database file}}

  # Update: This test used to fail (because a 0 byte *-shm file does not
  # contain a valid shm-header) but now succeeds (because a readonly_shm
  # connection ignores the *-shm file completely if the wal file is also
  # zero bytes in size).
  do_test 1.3.2.3 {
    code1 { db close }
    close [open test.db-shm w]
    file attributes test.db-shm -permissions r--r--r--
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    csql1 { SELECT * FROM t1 }
  } {0 {a b c d e f g h i j k l}}
  do_test 1.3.2.4 {
    code1 { sqlite3_extended_errcode db } 
  } {SQLITE_OK}

  #-----------------------------------------------------------------------
  # Test cases 1.4.* check that checkpoints and log wraps don't prevent
  # read-only connections from reading the database.
  do_test 1.4.1 {
    code1 { db close }
    forcedelete test.db-shm

      PRAGMA journal_mode = WAL;
      INSERT INTO t1 VALUES('a', 'b');
      INSERT INTO t1 VALUES('c', 'd');
    }
    file exists test.db-shm
  } {1}

  do_test 1.2.1 {
    forcecopy test.db test.db2
    forcecopy test.db-wal test.db2-wal
    forcecopy test.db-shm test.db2-shm
    code1 {
      sqlite3 db file:test.db2?readonly_shm=1
    }
  } {}
  do_test 1.2.2 {
    sql1 { SELECT * FROM t1 }
  } {a b c d}

  do_test 1.3.1 {
    code3 { sqlite3 db3 test.db2 }
    sql3 { SELECT * FROM t1 }
  } {a b c d}

  do_test 1.3.2 {

    code1 {
      sqlite3 db file:test.db2?readonly_shm=1
    }
    sql1 { 
      BEGIN;
      SELECT * FROM t1;
    }
  } {a b c d e f g h}

  do_test 2.3.1 {
    code3 { sqlite3 db3 test.db2 }
    sql3 { SELECT * FROM t1 }
  } {a b c d e f g h}

}

finish_test