path: root/test/fuzzcheck.c

/*
** 2015-05-25
**
** 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.
**
*************************************************************************
**
** This is a utility program designed to aid running regressions tests on
** the SQLite library using data from external fuzzers.
**
** This program reads content from an SQLite database file with the following
** schema:
**
**     CREATE TABLE db(
**       dbid INTEGER PRIMARY KEY, -- database id
**       dbcontent BLOB            -- database disk file image
**     );
**     CREATE TABLE xsql(
**       sqlid INTEGER PRIMARY KEY,   -- SQL script id
**       sqltext TEXT                 -- Text of SQL statements to run
**     );
**     CREATE TABLE IF NOT EXISTS readme(
**       msg TEXT -- Human-readable description of this test collection
**     );
**
** For each database file in the DB table, the SQL text in the XSQL table
** is run against that database.  All README.MSG values are printed prior
** to the start of the test (unless the --quiet option is used).  If the
** DB table is empty, then all entries in XSQL are run against an empty
** in-memory database.
**
** This program is looking for crashes, assertion faults, and/or memory leaks.
** No attempt is made to verify the output.  The assumption is that either all
** of the database files or all of the SQL statements are malformed inputs,
** generated by a fuzzer, that need to be checked to make sure they do not
** present a security risk.
**
** This program also includes some command-line options to help with 
** creation and maintenance of the source content database.  The command
**
**     ./fuzzcheck database.db --load-sql FILE...
**
** Loads all FILE... arguments into the XSQL table.  The --load-db option
** works the same but loads the files into the DB table.  The -m option can
** be used to initialize the README table.  The "database.db" file is created
** if it does not previously exist.  Example:
**
**     ./fuzzcheck new.db --load-sql *.sql
**     ./fuzzcheck new.db --load-db *.db
**     ./fuzzcheck new.db -m 'New test cases'
**
** The three commands above will create the "new.db" file and initialize all
** tables.  Then do "./fuzzcheck new.db" to run the tests.
**
** DEBUGGING HINTS:
**
** If fuzzcheck does crash, it can be run in the debugger and the content
** of the global variable g.zTextName[] will identify the specific XSQL and
** DB values that were running when the crash occurred.
**
** DBSQLFUZZ: (Added 2020-02-25)
**
** The dbsqlfuzz fuzzer includes both a database file and SQL to run against
** that database in its input.  This utility can now process dbsqlfuzz
** input files.  Load such files using the "--load-dbsql FILE ..." command-line
** option.
**
** Dbsqlfuzz inputs are ordinary text.  The first part of the file is text
** that describes the content of the database (using a lot of hexadecimal),
** then there is a divider line followed by the SQL to run against the
** database.  Because they are ordinary text, dbsqlfuzz inputs are stored
** in the XSQL table, as if they were ordinary SQL inputs.  The isDbSql()
** function can look at a text string and determine whether or not it is
** a valid dbsqlfuzz input.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>
#include <assert.h>
#include "sqlite3.h"
#include "sqlite3recover.h"
#define ISSPACE(X) isspace((unsigned char)(X))
#define ISDIGIT(X) isdigit((unsigned char)(X))


#ifdef __unix__
# include <signal.h>
# include <unistd.h>
#endif

#include <stddef.h>
#if !defined(_MSC_VER)
# include <stdint.h>
#endif

#if defined(_MSC_VER)
typedef unsigned char uint8_t;
#endif

/*
** Files in the virtual file system.
*/
typedef struct VFile VFile;
struct VFile {
  char *zFilename;      /* Filename.  NULL for delete-on-close. From malloc() */
  int sz;               /* Size of the file in bytes */
  int nRef;             /* Number of references to this file */
  unsigned char *a;     /* Content of the file.  From malloc() */
};
typedef struct VHandle VHandle;
struct VHandle {
  sqlite3_file base;      /* Base class.  Must be first */
  VFile *pVFile;          /* The underlying file */
};

/*
** The value of a database file template, or of an SQL script
*/
typedef struct Blob Blob;
struct Blob {
  Blob *pNext;            /* Next in a list */
  int id;                 /* Id of this Blob */
  int seq;                /* Sequence number */
  int sz;                 /* Size of this Blob in bytes */
  unsigned char a[1];     /* Blob content.  Extra space allocated as needed. */
};

/*
** Maximum number of files in the in-memory virtual filesystem.
*/
#define MX_FILE  10

/*
** Maximum allowed file size
*/
#define MX_FILE_SZ 10000000

/*
** All global variables are gathered into the "g" singleton.
*/
static struct GlobalVars {
  const char *zArgv0;              /* Name of program */
  const char *zDbFile;             /* Name of database file */
  VFile aFile[MX_FILE];            /* The virtual filesystem */
  int nDb;                         /* Number of template databases */
  Blob *pFirstDb;                  /* Content of first template database */
  int nSql;                        /* Number of SQL scripts */
  Blob *pFirstSql;                 /* First SQL script */
  unsigned int uRandom;            /* Seed for the SQLite PRNG */
  unsigned int nInvariant;         /* Number of invariant checks run */
  char zTestName[100];             /* Name of current test */
} g;

/*
** Include the external vt02.c and randomjson.c modules.
*/
extern int sqlite3_vt02_init(sqlite3*,char***,void*);
extern int sqlite3_randomjson_init(sqlite3*,char***,void*);


/*
** Print an error message and quit.
*/
static void fatalError(const char *zFormat, ...){
  va_list ap;
  fprintf(stderr, "%s", g.zArgv0);
  if( g.zDbFile ) fprintf(stderr, " %s", g.zDbFile);
  if( g.zTestName[0] ) fprintf(stderr, " (%s)", g.zTestName);
  fprintf(stderr, ": ");
  va_start(ap, zFormat);
  vfprintf(stderr, zFormat, ap);
  va_end(ap);
  fprintf(stderr, "\n");
  exit(1);
}

/*
** signal handler
*/
#ifdef __unix__
static void signalHandler(int signum){
  const char *zSig;
  if( signum==SIGABRT ){
    zSig = "abort";
  }else if( signum==SIGALRM ){
    zSig = "timeout";
  }else if( signum==SIGSEGV ){
    zSig = "segfault";
  }else{
    zSig = "signal";
  }
  fatalError(zSig);
}
#endif

/*
** Set the an alarm to go off after N seconds.  Disable the alarm
** if N==0
*/
static void setAlarm(int N){
#ifdef __unix__
  alarm(N);
#else
  (void)N;
#endif
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/*
** This an SQL progress handler.  After an SQL statement has run for
** many steps, we want to interrupt it.  This guards against infinite
** loops from recursive common table expressions.
**
** *pVdbeLimitFlag is true if the --limit-vdbe command-line option is used.
** In that case, hitting the progress handler is a fatal error.
*/
static int progressHandler(void *pVdbeLimitFlag){
  if( *(int*)pVdbeLimitFlag ) fatalError("too many VDBE cycles");
  return 1;
}
#endif

/*
** Reallocate memory.  Show an error and quit if unable.
*/
static void *safe_realloc(void *pOld, int szNew){
  void *pNew = realloc(pOld, szNew<=0 ? 1 : szNew);
  if( pNew==0 ) fatalError("unable to realloc for %d bytes", szNew);
  return pNew;
}

/*
** Initialize the virtual file system.
*/
static void formatVfs(void){
  int i;
  for(i=0; i<MX_FILE; i++){
    g.aFile[i].sz = -1;
    g.aFile[i].zFilename = 0;
    g.aFile[i].a = 0;
    g.aFile[i].nRef = 0;
  }
}


/*
** Erase all information in the virtual file system.
*/
static void reformatVfs(void){
  int i;
  for(i=0; i<MX_FILE; i++){
    if( g.aFile[i].sz<0 ) continue;
    if( g.aFile[i].zFilename ){
      free(g.aFile[i].zFilename);
      g.aFile[i].zFilename = 0;
    }
    if( g.aFile[i].nRef>0 ){
      fatalError("file %d still open.  nRef=%d", i, g.aFile[i].nRef);
    }
    g.aFile[i].sz = -1;
    free(g.aFile[i].a);
    g.aFile[i].a = 0;
    g.aFile[i].nRef = 0;
  }
}

/*
** Find a VFile by name
*/
static VFile *findVFile(const char *zName){
  int i;
  if( zName==0 ) return 0;
  for(i=0; i<MX_FILE; i++){
    if( g.aFile[i].zFilename==0 ) continue;   
    if( strcmp(g.aFile[i].zFilename, zName)==0 ) return &g.aFile[i];
  }
  return 0;
}

/*
** Find a VFile by name.  Create it if it does not already exist and
** initialize it to the size and content given.
**
** Return NULL only if the filesystem is full.
*/
static VFile *createVFile(const char *zName, int sz, unsigned char *pData){
  VFile *pNew = findVFile(zName);
  int i;
  if( pNew ) return pNew;
  for(i=0; i<MX_FILE && g.aFile[i].sz>=0; i++){}
  if( i>=MX_FILE ) return 0;
  pNew = &g.aFile[i];
  if( zName ){
    int nName = (int)strlen(zName)+1;
    pNew->zFilename = safe_realloc(0, nName);
    memcpy(pNew->zFilename, zName, nName);
  }else{
    pNew->zFilename = 0;
  }
  pNew->nRef = 0;
  pNew->sz = sz;
  pNew->a = safe_realloc(0, sz);
  if( sz>0 ) memcpy(pNew->a, pData, sz);
  return pNew;
}

/* Return true if the line is all zeros */
static int allZero(unsigned char *aLine){
  int i;
  for(i=0; i<16 && aLine[i]==0; i++){}
  return i==16;
}

/*
** Render a database and query as text that can be input into
** the CLI.
*/
static void renderDbSqlForCLI(
  FILE *out,             /* Write to this file */
  const char *zFile,     /* Name of the database file */
  unsigned char *aDb,    /* Database content */
  int nDb,               /* Number of bytes in aDb[] */
  unsigned char *zSql,   /* SQL content */
  int nSql               /* Bytes of SQL */
){
  fprintf(out, ".print ******* %s *******\n", zFile);
  if( nDb>100 ){
    int i, j;                   /* Loop counters */
    int pgsz;                   /* Size of each page */
    int lastPage = 0;           /* Last page number shown */
    int iPage;                  /* Current page number */
    unsigned char *aLine;       /* Single line to display */
    unsigned char buf[16];      /* Fake line */
    unsigned char bShow[256];   /* Characters ok to display */

    memset(bShow, '.', sizeof(bShow));
    for(i=' '; i<='~'; i++){
      if( i!='{' && i!='}' && i!='"' && i!='\\' ) bShow[i] = i;
    }
    pgsz = (aDb[16]<<8) | aDb[17];
    if( pgsz==0 ) pgsz = 65536;
    if( pgsz<512 || (pgsz&(pgsz-1))!=0 ) pgsz = 4096;
    fprintf(out,".open --hexdb\n");
    fprintf(out,"| size %d pagesize %d filename %s\n",nDb,pgsz,zFile);
    for(i=0; i<nDb; i += 16){
      if( i+16>nDb ){
        memset(buf, 0, sizeof(buf));
        memcpy(buf, aDb+i, nDb-i);
        aLine = buf;
      }else{
        aLine = aDb + i;
      }
      if( allZero(aLine) ) continue;
      iPage = i/pgsz + 1;
      if( lastPage!=iPage ){
        fprintf(out,"| page %d offset %d\n", iPage, (iPage-1)*pgsz);
        lastPage = iPage;
      }
      fprintf(out,"|  %5d:", i-(iPage-1)*pgsz);
      for(j=0; j<16; j++) fprintf(out," %02x", aLine[j]);
      fprintf(out,"   ");
      for(j=0; j<16; j++){
        unsigned char c = (unsigned char)aLine[j];
        fputc( bShow[c], stdout);
      }
      fputc('\n', stdout);
    }
    fprintf(out,"| end %s\n", zFile);
  }else{
    fprintf(out,".open :memory:\n");
  }
  fprintf(out,".testctrl prng_seed 1 db\n");
  fprintf(out,".testctrl internal_functions\n");
  fprintf(out,"%.*s", nSql, zSql);
  if( nSql>0 && zSql[nSql-1]!='\n' ) fprintf(out, "\n");
}

/*
** Read the complete content of a file into memory.  Add a 0x00 terminator
** and return a pointer to the result.
**
** The file content is held in memory obtained from sqlite_malloc64() which
** should be freed by the caller.
*/
static char *readFile(const char *zFilename, long *sz){
  FILE *in;
  long nIn;
  unsigned char *pBuf;

  *sz = 0;
  if( zFilename==0 ) return 0;
  in = fopen(zFilename, "rb");
  if( in==0 ) return 0;
  fseek(in, 0, SEEK_END);
  *sz = nIn = ftell(in);
  rewind(in);
  pBuf = sqlite3_malloc64( nIn+1 );
  if( pBuf && 1==fread(pBuf, nIn, 1, in) ){
    pBuf[nIn] = 0;
    fclose(in);
    return (char*)pBuf;
  }  
  sqlite3_free(pBuf);
  *sz = 0;
  fclose(in);
  return 0;
}


/*
** Implementation of the "readfile(X)" SQL function.  The entire content
** of the file named X is read and returned as a BLOB.  NULL is returned
** if the file does not exist or is unreadable.
*/
static void readfileFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  long nIn;
  void *pBuf;
  const char *zName = (const char*)sqlite3_value_text(argv[0]);

  if( zName==0 ) return;
  pBuf = readFile(zName, &nIn);
  if( pBuf ){
    sqlite3_result_blob(context, pBuf, nIn, sqlite3_free);
  }
}

/*
** Implementation of the "readtextfile(X)" SQL function.  The text content
** of the file named X through the end of the file or to the first \000
** character, whichever comes first, is read and returned as TEXT.  NULL
** is returned if the file does not exist or is unreadable.
*/
static void readtextfileFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *zName;
  FILE *in;
  long nIn;
  char *pBuf;

  zName = (const char*)sqlite3_value_text(argv[0]);
  if( zName==0 ) return;
  in = fopen(zName, "rb");
  if( in==0 ) return;
  fseek(in, 0, SEEK_END);
  nIn = ftell(in);
  rewind(in);
  pBuf = sqlite3_malloc64( nIn+1 );
  if( pBuf && 1==fread(pBuf, nIn, 1, in) ){
    pBuf[nIn] = 0;
    sqlite3_result_text(context, pBuf, -1, sqlite3_free);
  }else{
    sqlite3_free(pBuf);
  }
  fclose(in);
}

/*
** Implementation of the "writefile(X,Y)" SQL function.  The argument Y
** is written into file X.  The number of bytes written is returned.  Or
** NULL is returned if something goes wrong, such as being unable to open
** file X for writing.
*/
static void writefileFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  FILE *out;
  const char *z;
  sqlite3_int64 rc;
  const char *zFile;

  (void)argc;
  zFile = (const char*)sqlite3_value_text(argv[0]);
  if( zFile==0 ) return;
  out = fopen(zFile, "wb");
  if( out==0 ) return;
  z = (const char*)sqlite3_value_blob(argv[1]);
  if( z==0 ){
    rc = 0;
  }else{
    rc = fwrite(z, 1, sqlite3_value_bytes(argv[1]), out);
  }
  fclose(out);
  sqlite3_result_int64(context, rc);
}


/*
** Load a list of Blob objects from the database
*/
static void blobListLoadFromDb(
  sqlite3 *db,             /* Read from this database */
  const char *zSql,        /* Query used to extract the blobs */
  int onlyId,              /* Only load where id is this value */
  int *pN,                 /* OUT: Write number of blobs loaded here */
  Blob **ppList            /* OUT: Write the head of the blob list here */
){
  Blob head;
  Blob *p;
  sqlite3_stmt *pStmt;
  int n = 0;
  int rc;
  char *z2;

  if( onlyId>0 ){
    z2 = sqlite3_mprintf("%s WHERE rowid=%d", zSql, onlyId);
  }else{
    z2 = sqlite3_mprintf("%s", zSql);
  }
  rc = sqlite3_prepare_v2(db, z2, -1, &pStmt, 0);
  sqlite3_free(z2);
  if( rc ) fatalError("%s", sqlite3_errmsg(db));
  head.pNext = 0;
  p = &head;
  while( SQLITE_ROW==sqlite3_step(pStmt) ){
    int sz = sqlite3_column_bytes(pStmt, 1);
    Blob *pNew = safe_realloc(0, sizeof(*pNew)+sz );
    pNew->id = sqlite3_column_int(pStmt, 0);
    pNew->sz = sz;
    pNew->seq = n++;
    pNew->pNext = 0;
    memcpy(pNew->a, sqlite3_column_blob(pStmt,1), sz);
    pNew->a[sz] = 0;
    p->pNext = pNew;
    p = pNew;
  }
  sqlite3_finalize(pStmt);
  *pN = n;
  *ppList = head.pNext;
}

/*
** Free a list of Blob objects
*/
static void blobListFree(Blob *p){
  Blob *pNext;
  while( p ){
    pNext = p->pNext;
    free(p);
    p = pNext;
  }
}

/* Return the current wall-clock time
**
** The number of milliseconds since the julian epoch.
** 1907-01-01 00:00:00  ->  210866716800000
** 2021-01-01 00:00:00  ->  212476176000000
*/
static sqlite3_int64 timeOfDay(void){
  static sqlite3_vfs *clockVfs = 0;
  sqlite3_int64 t;
  if( clockVfs==0 ){
    clockVfs = sqlite3_vfs_find(0);
    if( clockVfs==0 ) return 0;
  }
  if( clockVfs->iVersion>=1 && clockVfs->xCurrentTimeInt64!=0 ){
    clockVfs->xCurrentTimeInt64(clockVfs, &t);
  }else{
    double r;
    clockVfs->xCurrentTime(clockVfs, &r);
    t = (sqlite3_int64)(r*86400000.0);
  }
  return t;
}

/***************************************************************************
** Code to process combined database+SQL scripts generated by the
** dbsqlfuzz fuzzer.
*/

/* An instance of the following object is passed by pointer as the
** client data to various callbacks.
*/
typedef struct FuzzCtx {
  sqlite3 *db;               /* The database connection */
  sqlite3_int64 iCutoffTime; /* Stop processing at this time. */
  sqlite3_int64 iLastCb;     /* Time recorded for previous progress callback */
  sqlite3_int64 mxInterval;  /* Longest interval between two progress calls */
  unsigned nCb;              /* Number of progress callbacks */
  unsigned mxCb;             /* Maximum number of progress callbacks allowed */
  unsigned execCnt;          /* Number of calls to the sqlite3_exec callback */
  int timeoutHit;            /* True when reaching a timeout */
} FuzzCtx;

/* Verbosity level for the dbsqlfuzz test runner */
static int eVerbosity = 0;

/* True to activate PRAGMA vdbe_debug=on */
static int bVdbeDebug = 0;

/* Timeout for each fuzzing attempt, in milliseconds */
static int giTimeout = 10000;   /* Defaults to 10 seconds */

/* Maximum number of progress handler callbacks */
static unsigned int mxProgressCb = 2000;

/* Maximum string length in SQLite */
static int lengthLimit = 1000000;

/* Maximum expression depth */
static int depthLimit = 500;

/* Limit on the amount of heap memory that can be used */
static sqlite3_int64 heapLimit = 100000000;

/* Maximum byte-code program length in SQLite */
static int vdbeOpLimit = 25000;

/* Maximum size of the in-memory database */
static sqlite3_int64 maxDbSize = 104857600;
/* OOM simulation parameters */
static unsigned int oomCounter = 0;    /* Simulate OOM when equals 1 */
static unsigned int oomRepeat = 0;     /* Number of OOMs in a row */
static void*(*defaultMalloc)(int) = 0; /* The low-level malloc routine */

/* Enable recovery */
static int bNoRecover = 0;

/* This routine is called when a simulated OOM occurs.  It is broken
** out as a separate routine to make it easy to set a breakpoint on
** the OOM
*/
void oomFault(void){
  if( eVerbosity ){
    printf("Simulated OOM fault\n");
  }
  if( oomRepeat>0 ){
    oomRepeat--;
  }else{
    oomCounter--;
  }
}

/* This routine is a replacement malloc() that is used to simulate
** Out-Of-Memory (OOM) errors for testing purposes.
*/
static void *oomMalloc(int nByte){
  if( oomCounter ){
    if( oomCounter==1 ){
      oomFault();
      return 0;
    }else{
      oomCounter--;
    }
  }
  return defaultMalloc(nByte);
}

/* Register the OOM simulator.  This must occur before any memory
** allocations */
static void registerOomSimulator(void){
  sqlite3_mem_methods mem;
  sqlite3_shutdown();
  sqlite3_config(SQLITE_CONFIG_GETMALLOC, &mem);
  defaultMalloc = mem.xMalloc;
  mem.xMalloc = oomMalloc;
  sqlite3_config(SQLITE_CONFIG_MALLOC, &mem);
}

/* Turn off any pending OOM simulation */
static void disableOom(void){
  oomCounter = 0;
  oomRepeat = 0;
}

/*
** Translate a single byte of Hex into an integer.
** This routine only works if h really is a valid hexadecimal
** character:  0..9a..fA..F
*/
static unsigned char hexToInt(unsigned int h){
#ifdef SQLITE_EBCDIC
  h += 9*(1&~(h>>4));   /* EBCDIC */
#else
  h += 9*(1&(h>>6));    /* ASCII */
#endif
  return h & 0xf;
}

/*
** The first character of buffer zIn[0..nIn-1] is a '['.  This routine
** checked to see if the buffer holds "[NNNN]" or "[+NNNN]" and if it
** does it makes corresponding changes to the *pK value and *pI value
** and returns true.  If the input buffer does not match the patterns,
** no changes are made to either *pK or *pI and this routine returns false.
*/
static int isOffset(
  const unsigned char *zIn,  /* Text input */
  int nIn,                   /* Bytes of input */
  unsigned int *pK,          /* half-byte cursor to adjust */
  unsigned int *pI           /* Input index to adjust */
){
  int i;
  unsigned int k = 0;
  unsigned char c;
  for(i=1; i<nIn && (c = zIn[i])!=']'; i++){
    if( !isxdigit(c) ) return 0;
    k = k*16 + hexToInt(c);
  }
  if( i==nIn ) return 0;
  *pK = 2*k;
  *pI += i;
  return 1;
}

/*
** Decode the text starting at zIn into a binary database file.
** The maximum length of zIn is nIn bytes.  Store the binary database
** file in space obtained from sqlite3_malloc().
**
** Return the number of bytes of zIn consumed.  Or return -1 if there
** is an error.  One potential error is that the recipe specifies a
** database file larger than MX_FILE_SZ bytes.
**
** Abort on an OOM.
*/
static int decodeDatabase(
  const unsigned char *zIn,      /* Input text to be decoded */
  int nIn,                       /* Bytes of input text */
  unsigned char **paDecode,      /* OUT: decoded database file */
  int *pnDecode                  /* OUT: Size of decoded database */
){
  unsigned char *a, *aNew;       /* Database under construction */
  int mx = 0;                    /* Current size of the database */
  sqlite3_uint64 nAlloc = 4096;  /* Space allocated in a[] */
  unsigned int i;                /* Next byte of zIn[] to read */
  unsigned int j;                /* Temporary integer */
  unsigned int k;                /* half-byte cursor index for output */
  unsigned int n;                /* Number of bytes of input */
  unsigned char b = 0;
  if( nIn<4 ) return -1;
  n = (unsigned int)nIn;
  a = sqlite3_malloc64( nAlloc );
  if( a==0 ){
    fprintf(stderr, "Out of memory!\n");
    exit(1);
  }
  memset(a, 0, (size_t)nAlloc);
  for(i=k=0; i<n; i++){
    unsigned char c = (unsigned char)zIn[i];
    if( isxdigit(c) ){
      k++;
      if( k & 1 ){
        b = hexToInt(c)*16;
      }else{
        b += hexToInt(c);
        j = k/2 - 1;
        if( j>=nAlloc ){
          sqlite3_uint64 newSize;
          if( nAlloc==MX_FILE_SZ || j>=MX_FILE_SZ ){
            if( eVerbosity ){
              fprintf(stderr, "Input database too big: max %d bytes\n",
                      MX_FILE_SZ);
            }
            sqlite3_free(a);
            return -1;
          }
          newSize = nAlloc*2;
          if( newSize<=j ){
            newSize = (j+4096)&~4095;
          }
          if( newSize>MX_FILE_SZ ){
            if( j>=MX_FILE_SZ ){
              sqlite3_free(a);
              return -1;
            }
            newSize = MX_FILE_SZ;
          }
          aNew = sqlite3_realloc64( a, newSize );
          if( aNew==0 ){
            sqlite3_free(a);
            return -1;
          }
          a = aNew;
          assert( newSize > nAlloc );
          memset(a+nAlloc, 0, (size_t)(newSize - nAlloc));
          nAlloc = newSize;
        }
        if( j>=(unsigned)mx ){
          mx = (j + 4095)&~4095;
          if( mx>MX_FILE_SZ ) mx = MX_FILE_SZ;
        }
        assert( j<nAlloc );
        a[j] = b;
      }
    }else if( zIn[i]=='[' && i<n-3 && isOffset(zIn+i, nIn-i, &k, &i) ){
      continue;
   }else if( zIn[i]=='\n' && i<n-4 && memcmp(zIn+i,"\n--\n",4)==0 ){
      i += 4;
      break;
    }
  }
  *pnDecode = mx;
  *paDecode = a;
  return i;
}

/*
** Progress handler callback.
**
** The argument is the cutoff-time after which all processing should
** stop.  So return non-zero if the cut-off time is exceeded.
*/
static int progress_handler(void *pClientData) {
  FuzzCtx *p = (FuzzCtx*)pClientData;
  sqlite3_int64 iNow = timeOfDay();
  int rc = iNow>=p->iCutoffTime;
  sqlite3_int64 iDiff = iNow - p->iLastCb;
  /* printf("time-remaining: %lld\n", p->iCutoffTime - iNow); */
  if( iDiff > p->mxInterval ) p->mxInterval = iDiff;
  p->nCb++;
  if( rc==0 && p->mxCb>0 && p->mxCb<=p->nCb ) rc = 1;
  if( rc && !p->timeoutHit && eVerbosity>=2 ){
    printf("Timeout on progress callback %d\n", p->nCb);
    fflush(stdout);
    p->timeoutHit = 1;
  }
  return rc;
}

/*
** Flag bits set by block_troublesome_sql()
*/
#define BTS_SELECT      0x000001
#define BTS_NONSELECT   0x000002
#define BTS_BADFUNC     0x000004
#define BTS_BADPRAGMA   0x000008  /* Sticky for rest of the script */

/*
** Disallow debugging pragmas such as "PRAGMA vdbe_debug" and
** "PRAGMA parser_trace" since they can dramatically increase the
** amount of output without actually testing anything useful.
**
** Also block ATTACH if attaching a file from the filesystem.
*/
static int block_troublesome_sql(
  void *pClientData,
  int eCode,
  const char *zArg1,
  const char *zArg2,
  const char *zArg3,
  const char *zArg4
){
  unsigned int *pBtsFlags = (unsigned int*)pClientData;

  (void)zArg3;
  (void)zArg4;
  switch( eCode ){
    case SQLITE_PRAGMA: {
      if( sqlite3_stricmp("busy_timeout",zArg1)==0
       && (zArg2==0 || strtoll(zArg2,0,0)>100 || strtoll(zArg2,0,10)>100)
      ){
        return SQLITE_DENY;
      }else if( sqlite3_stricmp("hard_heap_limit", zArg1)==0
              || sqlite3_stricmp("reverse_unordered_selects", zArg1)==0
      ){
        /* BTS_BADPRAGMA is sticky.  A hard_heap_limit or
        ** revert_unordered_selects should inhibit all future attempts
        ** at verifying query invariants */
        *pBtsFlags |= BTS_BADPRAGMA;
      }else if( eVerbosity==0 ){
        if( sqlite3_strnicmp("vdbe_", zArg1, 5)==0
         || sqlite3_stricmp("parser_trace", zArg1)==0
         || sqlite3_stricmp("temp_store_directory", zArg1)==0
        ){
         return SQLITE_DENY;
        }
      }else if( sqlite3_stricmp("oom",zArg1)==0
              && zArg2!=0 && zArg2[0]!=0 ){
        oomCounter = atoi(zArg2);
      }
      *pBtsFlags |= BTS_NONSELECT;
      break;
    }
    case SQLITE_ATTACH: {
      /* Deny the ATTACH if it is attaching anything other than an in-memory
      ** database. */
      *pBtsFlags |= BTS_NONSELECT;
      if( zArg1==0 ) return SQLITE_DENY;
      if( strcmp(zArg1,":memory:")==0 ) return SQLITE_OK;
      if( sqlite3_strglob("file:*[?]vfs=memdb", zArg1)==0
       && sqlite3_strglob("file:*[^/a-zA-Z0-9_.]*[?]vfs=memdb", zArg1)!=0
      ){
        return SQLITE_OK;
      }
      return SQLITE_DENY;
    }
    case SQLITE_SELECT: {
      *pBtsFlags |= BTS_SELECT;
      break;
    }
    case SQLITE_FUNCTION: {
      static const char *azBadFuncs[] = {
        "avg",
        "count",
        "cume_dist",
        "current_date",
        "current_time",
        "current_timestamp",
        "date",
        "datetime",
        "decimal_sum",
        "dense_rank",
        "first_value",
        "geopoly_group_bbox",
        "group_concat",
        "implies_nonnull_row",
        "json_group_array",
        "json_group_object",
        "julianday",
        "lag",
        "last_value",
        "lead",
        "max",
        "min",
        "nth_value",
        "ntile",
        "percent_rank",
        "random",
        "randomblob",
        "rank",
        "row_number",
        "sqlite_offset",
        "strftime",
        "sum",
        "time",
        "total",
        "unixepoch",
      };
      int first, last;
      first = 0;
      last = sizeof(azBadFuncs)/sizeof(azBadFuncs[0]) - 1;
      do{
        int mid = (first+last)/2;
        int c = sqlite3_stricmp(azBadFuncs[mid], zArg2);
        if( c<0 ){
          first = mid+1;
        }else if( c>0 ){
          last = mid-1;
        }else{
          *pBtsFlags |= BTS_BADFUNC;
          break;
        }
      }while( first<=last );
      break;
    }
    case SQLITE_READ: {
      /* Benign */
      break;
    }
    default: {
      *pBtsFlags |= BTS_NONSELECT;
    }
  }
  return SQLITE_OK;
}

/* Implementation found in fuzzinvariant.c */
extern int fuzz_invariant(
  sqlite3 *db,            /* The database connection */
  sqlite3_stmt *pStmt,    /* Test statement stopped on an SQLITE_ROW */
  int iCnt,               /* Invariant sequence number, starting at 0 */
  int iRow,               /* The row number for pStmt */
  int nRow,               /* Total number of output rows */
  int *pbCorrupt,         /* IN/OUT: Flag indicating a corrupt database file */
  int eVerbosity          /* How much debugging output */
);

/* Implementation of sqlite_dbdata and sqlite_dbptr */
extern int sqlite3_dbdata_init(sqlite3*,const char**,void*);


/*
** This function is used as a callback by the recover extension. Simply
** print the supplied SQL statement to stdout.
*/
static int recoverSqlCb(void *pCtx, const char *zSql){
  if( eVerbosity>=2 ){
    printf("%s\n", zSql);
  }
  return SQLITE_OK;
}

/*
** This function is called to recover data from the database.
*/
static int recoverDatabase(sqlite3 *db){
  int rc;                                 /* Return code from this routine */
  const char *zRecoveryDb = "";           /* Name of "recovery" database */
  const char *zLAF = "lost_and_found";    /* Name of "lost_and_found" table */
  int bFreelist = 1;                      /* True to scan the freelist */
  int bRowids = 1;                        /* True to restore ROWID values */
  sqlite3_recover *p = 0;                 /* The recovery object */

  p = sqlite3_recover_init_sql(db, "main", recoverSqlCb, 0);
  sqlite3_recover_config(p, 789, (void*)zRecoveryDb);
  sqlite3_recover_config(p, SQLITE_RECOVER_LOST_AND_FOUND, (void*)zLAF);
  sqlite3_recover_config(p, SQLITE_RECOVER_ROWIDS, (void*)&bRowids);
  sqlite3_recover_config(p, SQLITE_RECOVER_FREELIST_CORRUPT,(void*)&bFreelist);
  sqlite3_recover_run(p);
  if( sqlite3_recover_errcode(p)!=SQLITE_OK ){
    const char *zErr = sqlite3_recover_errmsg(p);
    int errCode = sqlite3_recover_errcode(p);
    if( eVerbosity>0 ){
      printf("recovery error: %s (%d)\n", zErr, errCode);
    }
  }
  rc = sqlite3_recover_finish(p);
  if( eVerbosity>0 && rc ){
     printf("recovery returns error code %d\n", rc);
  }
  return rc;
}

/*
** Run the SQL text
*/
static int runDbSql(sqlite3 *db, const char *zSql, unsigned int *pBtsFlags){
  int rc;
  sqlite3_stmt *pStmt;
  int bCorrupt = 0;
  while( isspace(zSql[0]&0x7f) ) zSql++;
  if( zSql[0]==0 ) return SQLITE_OK;
  if( eVerbosity>=4 ){
    printf("RUNNING-SQL: [%s]\n", zSql);
    fflush(stdout);
  }
  (*pBtsFlags) &= BTS_BADPRAGMA;
  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  if( rc==SQLITE_OK ){
    int nRow = 0;
    while( (rc = sqlite3_step(pStmt))==SQLITE_ROW ){
      nRow++;
      if( eVerbosity>=4 ){
        int j;
        for(j=0; j<sqlite3_column_count(pStmt); j++){
          if( j ) printf(",");
          switch( sqlite3_column_type(pStmt, j) ){
            case SQLITE_NULL: {
              printf("NULL");
              break;
            }
            case SQLITE_INTEGER:
            case SQLITE_FLOAT: {
              printf("%s", sqlite3_column_text(pStmt, j));
              break;
            }
            case SQLITE_BLOB: {
              int n = sqlite3_column_bytes(pStmt, j);
              int i;
              const unsigned char *a;
              a = (const unsigned char*)sqlite3_column_blob(pStmt, j);
              printf("x'");
              for(i=0; i<n; i++){
                printf("%02x", a[i]);
              }
              printf("'");
              break;
            }
            case SQLITE_TEXT: {
              int n = sqlite3_column_bytes(pStmt, j);
              int i;
              const unsigned char *a;
              a = (const unsigned char*)sqlite3_column_blob(pStmt, j);
              printf("'");
              for(i=0; i<n; i++){
                if( a[i]=='\'' ){
                  printf("''");
                }else{
                  putchar(a[i]);
                }
              }
              printf("'");
              break;
            }
          } /* End switch() */
        } /* End for() */
        printf("\n");
        fflush(stdout);
      } /* End if( eVerbosity>=5 ) */
    } /* End while( SQLITE_ROW */
    if( rc==SQLITE_DONE ){
      if( (*pBtsFlags)==BTS_SELECT
       && !sqlite3_stmt_isexplain(pStmt)
       && nRow>0
      ){
        int iRow = 0;
        sqlite3_reset(pStmt);
        while( sqlite3_step(pStmt)==SQLITE_ROW ){
          int iCnt = 0;
          iRow++;
          for(iCnt=0; iCnt<99999; iCnt++){
            rc = fuzz_invariant(db, pStmt, iCnt, iRow, nRow,
                                &bCorrupt, eVerbosity);
            if( rc==SQLITE_DONE ) break;
            if( rc!=SQLITE_ERROR ) g.nInvariant++;
            if( eVerbosity>0 ){
              if( rc==SQLITE_OK ){
                printf("invariant-check: ok\n");
              }else if( rc==SQLITE_CORRUPT ){
                printf("invariant-check: failed due to database corruption\n");
              }
            }
          }
        }          
      }
    }else if( eVerbosity>=4 ){
      printf("SQL-ERROR: (%d) %s\n", rc, sqlite3_errmsg(db));
      fflush(stdout);
    }
  }else if( eVerbosity>=4 ){
    printf("SQL-ERROR (%d): %s\n", rc, sqlite3_errmsg(db));
    fflush(stdout);    
  } /* End if( SQLITE_OK ) */
  return sqlite3_finalize(pStmt);
}

/* Mappings into dbconfig settings for bits taken from bytes 72..75 of
** the input database.
**
** This should be the same as in dbsqlfuzz.c.  Make sure those codes stay
** in sync.
*/
static const struct {
  unsigned int mask;
  int iSetting;
  char *zName;
} aDbConfigSettings[] = {
  {  0x0001, SQLITE_DBCONFIG_ENABLE_FKEY,        "enable_fkey"        },
  {  0x0002, SQLITE_DBCONFIG_ENABLE_TRIGGER,     "enable_trigger"     },
  {  0x0004, SQLITE_DBCONFIG_ENABLE_VIEW,        "enable_view"        },
  {  0x0008, SQLITE_DBCONFIG_ENABLE_QPSG,        "enable_qpsg"        },
  {  0x0010, SQLITE_DBCONFIG_TRIGGER_EQP,        "trigger_eqp"        },
  {  0x0020, SQLITE_DBCONFIG_DEFENSIVE,          "defensive"          },
  {  0x0040, SQLITE_DBCONFIG_WRITABLE_SCHEMA,    "writable_schema"    },
  {  0x0080, SQLITE_DBCONFIG_LEGACY_ALTER_TABLE, "legacy_alter_table" },
  {  0x0100, SQLITE_DBCONFIG_STMT_SCANSTATUS,    "stmt_scanstatus"    },
  {  0x0200, SQLITE_DBCONFIG_REVERSE_SCANORDER,  "reverse_scanorder"  },
#ifdef SQLITE_DBCONFIG_STRICT_AGGREGATE
  {  0x0400, SQLITE_DBCONFIG_STRICT_AGGREGATE,   "strict_aggregate"   },
#endif
  {  0x0800, SQLITE_DBCONFIG_DQS_DML,            "dqs_dml"            },
  {  0x1000, SQLITE_DBCONFIG_DQS_DDL,            "dqs_ddl"            },
  {  0x2000, SQLITE_DBCONFIG_TRUSTED_SCHEMA,     "trusted_schema"     },
};

/* Toggle a dbconfig setting
*/
static void toggleDbConfig(sqlite3 *db, int iSetting){
  int v = 0;
  sqlite3_db_config(db, iSetting, -1, &v);
  v = !v;
  sqlite3_db_config(db, iSetting, v, 0);
}

/* Invoke this routine to run a single test case */
int runCombinedDbSqlInput(
  const uint8_t *aData,      /* Combined DB+SQL content */
  size_t nByte,              /* Size of aData in bytes */
  int iTimeout,              /* Use this timeout */
  int bScript,               /* If true, just render CLI output */
  int iSqlId                 /* SQL identifier */
){
  int rc;                    /* SQLite API return value */
  int iSql;                  /* Index in aData[] of start of SQL */
  unsigned char *aDb = 0;    /* Decoded database content */
  int nDb = 0;               /* Size of the decoded database */
  int i;                     /* Loop counter */
  int j;                     /* Start of current SQL statement */
  char *zSql = 0;            /* SQL text to run */
  int nSql;                  /* Bytes of SQL text */
  FuzzCtx cx;                /* Fuzzing context */
  unsigned int btsFlags = 0; /* Parsing flags */
  unsigned int dbFlags = 0;  /* Flag values from db offset 72..75 */
  unsigned int dbOpt = 0;    /* Flag values from db offset 76..79 */


  if( nByte<10 ) return 0;
  if( sqlite3_initialize() ) return 0;
  if( sqlite3_memory_used()!=0 ){
    int nAlloc = 0;
    int nNotUsed = 0;
    sqlite3_status(SQLITE_STATUS_MALLOC_COUNT, &nAlloc, &nNotUsed, 0);
    fprintf(stderr,"memory leak prior to test start:"
                   " %lld bytes in %d allocations\n",
            sqlite3_memory_used(), nAlloc);
    exit(1);
  }
  memset(&cx, 0, sizeof(cx));
  iSql = decodeDatabase((unsigned char*)aData, (int)nByte, &aDb, &nDb);
  if( iSql<0 ) return 0;
  if( nDb>=75 ){
    dbFlags = ((unsigned int)aDb[72]<<24) + ((unsigned int)aDb[73]<<16) +
              ((unsigned int)aDb[74]<<8) + (unsigned int)aDb[75];
  }
  if( nDb>=79 ){
    dbOpt = ((unsigned int)aDb[76]<<24) + ((unsigned int)aDb[77]<<16) +
            ((unsigned int)aDb[78]<<8) + (unsigned int)aDb[79];
  }
  nSql = (int)(nByte - iSql);
  if( bScript ){
    char zName[100];
    sqlite3_snprintf(sizeof(zName),zName,"dbsql%06d.db",iSqlId);
    renderDbSqlForCLI(stdout, zName, aDb, nDb,
                      (unsigned char*)(aData+iSql), nSql);
    sqlite3_free(aDb);
    return 0;
  }
  if( eVerbosity>=3 ){
    printf(
      "****** %d-byte input, %d-byte database, %d-byte script "
      "******\n", (int)nByte, nDb, nSql);
    fflush(stdout);
  }
  rc = sqlite3_open(0, &cx.db);
  if( rc ){
    sqlite3_free(aDb);
    return 1;
  }
  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, cx.db, dbOpt);
  for(i=0; i<sizeof(aDbConfigSettings)/sizeof(aDbConfigSettings[0]); i++){
    if( dbFlags & aDbConfigSettings[i].mask ){
      toggleDbConfig(cx.db, aDbConfigSettings[i].iSetting);
    }
  }
  if( bVdbeDebug ){
    sqlite3_exec(cx.db, "PRAGMA vdbe_debug=ON", 0, 0, 0);
  }

  /* Invoke the progress handler frequently to check to see if we
  ** are taking too long.  The progress handler will return true
  ** (which will block further processing) if more than giTimeout seconds have
  ** elapsed since the start of the test.
  */
  cx.iLastCb = timeOfDay();
  cx.iCutoffTime = cx.iLastCb + (iTimeout<giTimeout ? iTimeout : giTimeout);
  cx.mxCb = mxProgressCb;
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  sqlite3_progress_handler(cx.db, 10, progress_handler, (void*)&cx);
#endif

  /* Set a limit on the maximum size of a prepared statement, and the
  ** maximum length of a string or blob */
  if( vdbeOpLimit>0 ){
    sqlite3_limit(cx.db, SQLITE_LIMIT_VDBE_OP, vdbeOpLimit);
  }
  if( lengthLimit>0 ){
    sqlite3_limit(cx.db, SQLITE_LIMIT_LENGTH, lengthLimit);
  }
  if( depthLimit>0 ){
    sqlite3_limit(cx.db, SQLITE_LIMIT_EXPR_DEPTH, depthLimit);
  }
  sqlite3_limit(cx.db, SQLITE_LIMIT_LIKE_PATTERN_LENGTH, 100);
  sqlite3_hard_heap_limit64(heapLimit);
  rc = 1;
  sqlite3_test_control(SQLITE_TESTCTRL_JSON_SELFCHECK, &rc);

  if( nDb>=20 && aDb[18]==2 && aDb[19]==2 ){
    aDb[18] = aDb[19] = 1;
  }
  rc = sqlite3_deserialize(cx.db, "main", aDb, nDb, nDb,
          SQLITE_DESERIALIZE_RESIZEABLE |
          SQLITE_DESERIALIZE_FREEONCLOSE);
  if( rc ){
    fprintf(stderr, "sqlite3_deserialize() failed with %d\n", rc);
    goto testrun_finished;
  }
  if( maxDbSize>0 ){
    sqlite3_int64 x = maxDbSize;
    sqlite3_file_control(cx.db, "main", SQLITE_FCNTL_SIZE_LIMIT, &x);
  }

  /* For high debugging levels, turn on debug mode */
  if( eVerbosity>=5 ){
    sqlite3_exec(cx.db, "PRAGMA vdbe_debug=ON;", 0, 0, 0);
  }

  /* Block debug pragmas and ATTACH/DETACH.  But wait until after
  ** deserialize to do this because deserialize depends on ATTACH */
  sqlite3_set_authorizer(cx.db, block_troublesome_sql, &btsFlags);

  /* Add the vt02 virtual table */
  sqlite3_vt02_init(cx.db, 0, 0);

  /* Add the random_json() and random_json5() functions */
  sqlite3_randomjson_init(cx.db, 0, 0);

  /* Add support for sqlite_dbdata and sqlite_dbptr virtual tables used
  ** by the recovery API */
  sqlite3_dbdata_init(cx.db, 0, 0);

  /* Consistent PRNG seed */
#ifdef SQLITE_TESTCTRL_PRNG_SEED
  sqlite3_table_column_metadata(cx.db, 0, "x", 0, 0, 0, 0, 0, 0);
  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, 1, cx.db);
#else
  sqlite3_randomness(0,0);
#endif

  /* Run recovery on the initial database, just to make sure recovery
  ** works. */
  if( !bNoRecover ){
    recoverDatabase(cx.db);
  }

  zSql = sqlite3_malloc( nSql + 1 );
  if( zSql==0 ){
    fprintf(stderr, "Out of memory!\n");
  }else{
    memcpy(zSql, aData+iSql, nSql);
    zSql[nSql] = 0;
    for(i=j=0; zSql[i]; i++){
      if( zSql[i]==';' ){
        char cSaved = zSql[i+1];
        zSql[i+1] = 0;
        if( sqlite3_complete(zSql+j) ){
          rc = runDbSql(cx.db, zSql+j, &btsFlags);
          j = i+1;
        }
        zSql[i+1] = cSaved;
        if( rc==SQLITE_INTERRUPT || progress_handler(&cx) ){
          goto testrun_finished;
        }
      }
    }
    if( j<i ){
      runDbSql(cx.db, zSql+j, &btsFlags);
    }
  }
testrun_finished:
  sqlite3_free(zSql);
  rc = sqlite3_close(cx.db);
  if( rc!=SQLITE_OK ){
    fprintf(stdout, "sqlite3_close() returns %d\n", rc);
  }
  if( eVerbosity>=2 && !bScript ){
    fprintf(stdout, "Peak memory usages: %f MB\n",
       sqlite3_memory_highwater(1) / 1000000.0);
  }
  if( sqlite3_memory_used()!=0 ){
    int nAlloc = 0;
    int nNotUsed = 0;
    sqlite3_status(SQLITE_STATUS_MALLOC_COUNT, &nAlloc, &nNotUsed, 0);
    fprintf(stderr,"Memory leak: %lld bytes in %d allocations\n",
            sqlite3_memory_used(), nAlloc);
    exit(1);
  }
  sqlite3_hard_heap_limit64(0);
  sqlite3_soft_heap_limit64(0);
  return 0;
}

/*
** END of the dbsqlfuzz code
***************************************************************************/

/* Look at a SQL text and try to determine if it begins with a database
** description, such as would be found in a dbsqlfuzz test case.  Return
** true if this does appear to be a dbsqlfuzz test case and false otherwise.
*/
static int isDbSql(unsigned char *a, int n){
  unsigned char buf[12];
  int i;
  if( n>4 && memcmp(a,"\n--\n",4)==0 ) return 1;
  while( n>0 && isspace(a[0]) ){ a++; n--; }
  for(i=0; n>0 && i<8; n--, a++){
    if( isxdigit(a[0]) ) buf[i++] = a[0];
  }
  if( i==8 && memcmp(buf,"53514c69",8)==0 ) return 1;
  return 0;
}

/* Implementation of the isdbsql(TEXT) SQL function.
*/
static void isDbSqlFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int n = sqlite3_value_bytes(argv[0]);
  unsigned char *a = (unsigned char*)sqlite3_value_blob(argv[0]);
  sqlite3_result_int(context, a!=0 && n>0 && isDbSql(a,n));
}

/* Methods for the VHandle object
*/
static int inmemClose(sqlite3_file *pFile){
  VHandle *p = (VHandle*)pFile;
  VFile *pVFile = p->pVFile;
  pVFile->nRef--;
  if( pVFile->nRef==0 && pVFile->zFilename==0 ){
    pVFile->sz = -1;
    free(pVFile->a);
    pVFile->a = 0;
  }
  return SQLITE_OK;
}
static int inmemRead(
  sqlite3_file *pFile,   /* Read from this open file */
  void *pData,           /* Store content in this buffer */
  int iAmt,              /* Bytes of content */
  sqlite3_int64 iOfst    /* Start reading here */
){
  VHandle *pHandle = (VHandle*)pFile;
  VFile *pVFile = pHandle->pVFile;
  if( iOfst<0 || iOfst>=pVFile->sz ){
    memset(pData, 0, iAmt);
    return SQLITE_IOERR_SHORT_READ;
  }
  if( iOfst+iAmt>pVFile->sz ){
    memset(pData, 0, iAmt);
    iAmt = (int)(pVFile->sz - iOfst);
    memcpy(pData, pVFile->a + iOfst, iAmt);
    return SQLITE_IOERR_SHORT_READ;
  }
  memcpy(pData, pVFile->a + iOfst, iAmt);
  return SQLITE_OK;
}
static int inmemWrite(
  sqlite3_file *pFile,   /* Write to this file */
  const void *pData,     /* Content to write */
  int iAmt,              /* bytes to write */
  sqlite3_int64 iOfst    /* Start writing here */
){
  VHandle *pHandle = (VHandle*)pFile;
  VFile *pVFile = pHandle->pVFile;
  if( iOfst+iAmt > pVFile->sz ){
    if( iOfst+iAmt >= MX_FILE_SZ ){
      return SQLITE_FULL;
    }
    pVFile->a = safe_realloc(pVFile->a, (int)(iOfst+iAmt));
    if( iOfst > pVFile->sz ){
      memset(pVFile->a + pVFile->sz, 0, (int)(iOfst - pVFile->sz));
    }
    pVFile->sz = (int)(iOfst + iAmt);
  }
  memcpy(pVFile->a + iOfst, pData, iAmt);
  return SQLITE_OK;
}
static int inmemTruncate(sqlite3_file *pFile, sqlite3_int64 iSize){
  VHandle *pHandle = (VHandle*)pFile;
  VFile *pVFile = pHandle->pVFile;
  if( pVFile->sz>iSize && iSize>=0 ) pVFile->sz = (int)iSize;
  return SQLITE_OK;
}
static int inmemSync(sqlite3_file *pFile, int flags){
  return SQLITE_OK;
}
static int inmemFileSize(sqlite3_file *pFile, sqlite3_int64 *pSize){
  *pSize = ((VHandle*)pFile)->pVFile->sz;
  return SQLITE_OK;
}
static int inmemLock(sqlite3_file *pFile, int type){
  return SQLITE_OK;
}
static int inmemUnlock(sqlite3_file *pFile, int type){
  return SQLITE_OK;
}
static int inmemCheckReservedLock(sqlite3_file *pFile, int *pOut){
  *pOut = 0;
  return SQLITE_OK;
}
static int inmemFileControl(sqlite3_file *pFile, int op, void *pArg){
  return SQLITE_NOTFOUND;
}
static int inmemSectorSize(sqlite3_file *pFile){
  return 512;
}
static int inmemDeviceCharacteristics(sqlite3_file *pFile){
  return
      SQLITE_IOCAP_SAFE_APPEND |
      SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
      SQLITE_IOCAP_POWERSAFE_OVERWRITE;
}


/* Method table for VHandle
*/
static sqlite3_io_methods VHandleMethods = {
  /* iVersion  */    1,
  /* xClose    */    inmemClose,
  /* xRead     */    inmemRead,
  /* xWrite    */    inmemWrite,
  /* xTruncate */    inmemTruncate,
  /* xSync     */    inmemSync,
  /* xFileSize */    inmemFileSize,
  /* xLock     */    inmemLock,
  /* xUnlock   */    inmemUnlock,
  /* xCheck... */    inmemCheckReservedLock,
  /* xFileCtrl */    inmemFileControl,
  /* xSectorSz */    inmemSectorSize,
  /* xDevchar  */    inmemDeviceCharacteristics,
  /* xShmMap   */    0,
  /* xShmLock  */    0,
  /* xShmBarrier */  0,
  /* xShmUnmap */    0,
  /* xFetch    */    0,
  /* xUnfetch  */    0
};

/*
** Open a new file in the inmem VFS.  All files are anonymous and are
** delete-on-close.
*/
static int inmemOpen(
  sqlite3_vfs *pVfs,
  const char *zFilename,
  sqlite3_file *pFile,
  int openFlags,
  int *pOutFlags
){
  VFile *pVFile = createVFile(zFilename, 0, (unsigned char*)"");
  VHandle *pHandle = (VHandle*)pFile;
  if( pVFile==0 ){
    return SQLITE_FULL;
  }
  pHandle->pVFile = pVFile;
  pVFile->nRef++;
  pFile->pMethods = &VHandleMethods;
  if( pOutFlags ) *pOutFlags = openFlags;
  return SQLITE_OK;
}

/*
** Delete a file by name
*/
static int inmemDelete(
  sqlite3_vfs *pVfs,
  const char *zFilename,
  int syncdir
){
  VFile *pVFile = findVFile(zFilename);
  if( pVFile==0 ) return SQLITE_OK;
  if( pVFile->nRef==0 ){
    free(pVFile->zFilename);
    pVFile->zFilename = 0;
    pVFile->sz = -1;
    free(pVFile->a);
    pVFile->a = 0;
    return SQLITE_OK;
  }
  return SQLITE_IOERR_DELETE;
}

/* Check for the existance of a file
*/
static int inmemAccess(
  sqlite3_vfs *pVfs,
  const char *zFilename,
  int flags,
  int *pResOut
){
  VFile *pVFile = findVFile(zFilename);
  *pResOut =  pVFile!=0;
  return SQLITE_OK;
}

/* Get the canonical pathname for a file
*/
static int inmemFullPathname(
  sqlite3_vfs *pVfs,
  const char *zFilename,
  int nOut,
  char *zOut
){
  sqlite3_snprintf(nOut, zOut, "%s", zFilename);
  return SQLITE_OK;
}

/* Always use the same random see, for repeatability.
*/
static int inmemRandomness(sqlite3_vfs *NotUsed, int nBuf, char *zBuf){
  memset(zBuf, 0, nBuf);
  memcpy(zBuf, &g.uRandom, nBuf<sizeof(g.uRandom) ? nBuf : sizeof(g.uRandom));
  return nBuf;
}

/*
** Register the VFS that reads from the g.aFile[] set of files.
*/
static void inmemVfsRegister(int makeDefault){
  static sqlite3_vfs inmemVfs;
  sqlite3_vfs *pDefault = sqlite3_vfs_find(0);
  inmemVfs.iVersion = 3;
  inmemVfs.szOsFile = sizeof(VHandle);
  inmemVfs.mxPathname = 200;
  inmemVfs.zName = "inmem";
  inmemVfs.xOpen = inmemOpen;
  inmemVfs.xDelete = inmemDelete;
  inmemVfs.xAccess = inmemAccess;
  inmemVfs.xFullPathname = inmemFullPathname;
  inmemVfs.xRandomness = inmemRandomness;
  inmemVfs.xSleep = pDefault->xSleep;
  inmemVfs.xCurrentTimeInt64 = pDefault->xCurrentTimeInt64;
  sqlite3_vfs_register(&inmemVfs, makeDefault);
};

/*
** Allowed values for the runFlags parameter to runSql()
*/
#define SQL_TRACE  0x0001     /* Print each SQL statement as it is prepared */
#define SQL_OUTPUT 0x0002     /* Show the SQL output */

/*
** Run multiple commands of SQL.  Similar to sqlite3_exec(), but does not
** stop if an error is encountered.
*/
static void runSql(sqlite3 *db, const char *zSql, unsigned  runFlags){
  const char *zMore;
  sqlite3_stmt *pStmt;

  while( zSql && zSql[0] ){
    zMore = 0;
    pStmt = 0;
    sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zMore);
    if( zMore==zSql ) break;
    if( runFlags & SQL_TRACE ){
      const char *z = zSql;
      int n;
      while( z<zMore && ISSPACE(z[0]) ) z++;
      n = (int)(zMore - z);
      while( n>0 && ISSPACE(z[n-1]) ) n--;
      if( n==0 ) break;
      if( pStmt==0 ){
        printf("TRACE: %.*s (error: %s)\n", n, z, sqlite3_errmsg(db));
      }else{
        printf("TRACE: %.*s\n", n, z);
      }
    }
    zSql = zMore;
    if( pStmt ){
      if( (runFlags & SQL_OUTPUT)==0 ){
        while( SQLITE_ROW==sqlite3_step(pStmt) ){}
      }else{
        int nCol = -1;
        while( SQLITE_ROW==sqlite3_step(pStmt) ){
          int i;
          if( nCol<0 ){
            nCol = sqlite3_column_count(pStmt);
          }else if( nCol>0 ){
            printf("--------------------------------------------\n");
          }
          for(i=0; i<nCol; i++){
            int eType = sqlite3_column_type(pStmt,i);
            printf("%s = ", sqlite3_column_name(pStmt,i));
            switch( eType ){
              case SQLITE_NULL: {
                printf("NULL\n");
                break;
              }
              case SQLITE_INTEGER: {
                printf("INT %s\n", sqlite3_column_text(pStmt,i));
                break;
              }
              case SQLITE_FLOAT: {
                printf("FLOAT %s\n", sqlite3_column_text(pStmt,i));
                break;
              }
              case SQLITE_TEXT: {
                printf("TEXT [%s]\n", sqlite3_column_text(pStmt,i));
                break;
              }
              case SQLITE_BLOB: {
                printf("BLOB (%d bytes)\n", sqlite3_column_bytes(pStmt,i));
                break;
              }
            }
          }
        }
      }         
      sqlite3_finalize(pStmt);
    }
  }
}

/*
** Rebuild the database file.
**
**    (1)  Remove duplicate entries
**    (2)  Put all entries in order
**    (3)  Vacuum
*/
static void rebuild_database(sqlite3 *db, int dbSqlOnly){
  int rc;
  char *zSql;
  zSql = sqlite3_mprintf(
     "BEGIN;\n"
     "CREATE TEMP TABLE dbx AS SELECT DISTINCT dbcontent FROM db;\n"
     "DELETE FROM db;\n"
     "INSERT INTO db(dbid, dbcontent) "
        " SELECT NULL, dbcontent FROM dbx ORDER BY 2;\n"
     "DROP TABLE dbx;\n"
     "CREATE TEMP TABLE sx AS SELECT DISTINCT sqltext FROM xsql %s;\n"
     "DELETE FROM xsql;\n"
     "INSERT INTO xsql(sqlid,sqltext) "
        " SELECT NULL, sqltext FROM sx ORDER BY 2;\n"
     "DROP TABLE sx;\n"
     "COMMIT;\n"
     "PRAGMA page_size=1024;\n"
     "VACUUM;\n",
     dbSqlOnly ? " WHERE isdbsql(sqltext)" : ""
  );
  rc = sqlite3_exec(db, zSql, 0, 0, 0);
  sqlite3_free(zSql);
  if( rc ) fatalError("cannot rebuild: %s", sqlite3_errmsg(db));
}

/*
** Return the value of a hexadecimal digit.  Return -1 if the input
** is not a hex digit.
*/
static int hexDigitValue(char c){
  if( c>='0' && c<='9' ) return c - '0';
  if( c>='a' && c<='f' ) return c - 'a' + 10;
  if( c>='A' && c<='F' ) return c - 'A' + 10;
  return -1;
}

/*
** Interpret zArg as an integer value, possibly with suffixes.
*/
static int integerValue(const char *zArg){
  sqlite3_int64 v = 0;
  static const struct { char *zSuffix; int iMult; } aMult[] = {
    { "KiB", 1024 },
    { "MiB", 1024*1024 },
    { "GiB", 1024*1024*1024 },
    { "KB",  1000 },
    { "MB",  1000000 },
    { "GB",  1000000000 },
    { "K",   1000 },
    { "M",   1000000 },
    { "G",   1000000000 },
  };
  int i;
  int isNeg = 0;
  if( zArg[0]=='-' ){
    isNeg = 1;
    zArg++;
  }else if( zArg[0]=='+' ){
    zArg++;
  }
  if( zArg[0]=='0' && zArg[1]=='x' ){
    int x;
    zArg += 2;
    while( (x = hexDigitValue(zArg[0]))>=0 ){
      v = (v<<4) + x;
      zArg++;
    }
  }else{
    while( ISDIGIT(zArg[0]) ){
      v = v*10 + zArg[0] - '0';
      zArg++;
    }
  }
  for(i=0; i<sizeof(aMult)/sizeof(aMult[0]); i++){
    if( sqlite3_stricmp(aMult[i].zSuffix, zArg)==0 ){
      v *= aMult[i].iMult;
      break;
    }
  }
  if( v>0x7fffffff ) fatalError("parameter too large - max 2147483648");
  return (int)(isNeg? -v : v);
}

/*
** Return the number of "v" characters in a string.  Return 0 if there
** are any characters in the string other than "v".
*/
static int numberOfVChar(const char *z){
  int N = 0;
  while( z[0] && z[0]=='v' ){
    z++;
    N++;
  }
  return z[0]==0 ? N : 0;
}

/*
** Print sketchy documentation for this utility program
*/
static void showHelp(void){
  printf("Usage: %s [options] SOURCE-DB ?ARGS...?\n", g.zArgv0);
  printf(
"Read databases and SQL scripts from SOURCE-DB and execute each script against\n"
"each database, checking for crashes and memory leaks.\n"
"Options:\n"
"  --cell-size-check    Set the PRAGMA cell_size_check=ON\n"
"  --dbid N             Use only the database where dbid=N\n"
"  --export-db DIR      Write databases to files(s) in DIR. Works with --dbid\n"
"  --export-sql DIR     Write SQL to file(s) in DIR. Also works with --sqlid\n"
"  --help               Show this help text\n"
"  --info               Show information about SOURCE-DB w/o running tests\n"
"  --limit-depth N      Limit expression depth to N.  Default: 500\n"
"  --limit-heap N       Limit heap memory to N.  Default: 100M\n"
"  --limit-mem N        Limit memory used by test SQLite instance to N bytes\n"
"  --limit-vdbe         Panic if any test runs for more than 100,000 cycles\n"
"  --load-sql   FILE..  Load SQL scripts fron files into SOURCE-DB\n"
"  --load-db    FILE..  Load template databases from files into SOURCE_DB\n"
"  --load-dbsql FILE..  Load dbsqlfuzz outputs into the xsql table\n"
"               ^^^^------ Use \"-\" for FILE to read filenames from stdin\n"
"  -m TEXT              Add a description to the database\n"
"  --native-vfs         Use the native VFS for initially empty database files\n"
"  --native-malloc      Turn off MEMSYS3/5 and Lookaside\n"
"  --no-recover         Do not run recovery on dbsqlfuzz databases\n"
"  --oss-fuzz           Enable OSS-FUZZ testing\n"
"  --prng-seed N        Seed value for the PRGN inside of SQLite\n"
"  -q|--quiet           Reduced output\n"
"  --rebuild            Rebuild and vacuum the database file\n"
"  --result-trace       Show the results of each SQL command\n"
"  --script             Output CLI script instead of running tests\n"
"  --skip N             Skip the first N test cases\n"
"  --spinner            Use a spinner to show progress\n"
"  --sqlid N            Use only SQL where sqlid=N\n"
"  --timeout N          Maximum time for any one test in N millseconds\n"
"  -v|--verbose         Increased output.  Repeat for more output.\n"
"  --vdbe-debug         Activate VDBE debugging.\n"
"  --wait N             Wait N seconds before continuing - useful for\n"
"                          attaching an MSVC debugging.\n"
  );
}

int main(int argc, char **argv){
  sqlite3_int64 iBegin;        /* Start time of this program */
  int quietFlag = 0;           /* True if --quiet or -q */
  int verboseFlag = 0;         /* True if --verbose or -v */
  char *zInsSql = 0;           /* SQL statement for --load-db or --load-sql */
  int iFirstInsArg = 0;        /* First argv[] for --load-db or --load-sql */
  sqlite3 *db = 0;             /* The open database connection */
  sqlite3_stmt *pStmt;         /* A prepared statement */
  int rc;                      /* Result code from SQLite interface calls */
  Blob *pSql;                  /* For looping over SQL scripts */
  Blob *pDb;                   /* For looping over template databases */
  int i;                       /* Loop index for the argv[] loop */
  int dbSqlOnly = 0;           /* Only use scripts that are dbsqlfuzz */
  int onlySqlid = -1;          /* --sqlid */
  int onlyDbid = -1;           /* --dbid */
  int nativeFlag = 0;          /* --native-vfs */
  int rebuildFlag = 0;         /* --rebuild */
  int vdbeLimitFlag = 0;       /* --limit-vdbe */
  int infoFlag = 0;            /* --info */
  int nSkip = 0;               /* --skip */
  int bScript = 0;             /* --script */
  int bSpinner = 0;            /* True for --spinner */
  int timeoutTest = 0;         /* undocumented --timeout-test flag */
  int runFlags = 0;            /* Flags sent to runSql() */
  char *zMsg = 0;              /* Add this message */
  int nSrcDb = 0;              /* Number of source databases */
  char **azSrcDb = 0;          /* Array of source database names */
  int iSrcDb;                  /* Loop over all source databases */
  int nTest = 0;               /* Total number of tests performed */
  char *zDbName = "";          /* Appreviated name of a source database */
  const char *zFailCode = 0;   /* Value of the TEST_FAILURE env variable */
  int cellSzCkFlag = 0;        /* --cell-size-check */
  int sqlFuzz = 0;             /* True for SQL fuzz. False for DB fuzz */
  int iTimeout = 120000;       /* Default 120-second timeout */
  int nMem = 0;                /* Memory limit override */
  int nMemThisDb = 0;          /* Memory limit set by the CONFIG table */
  char *zExpDb = 0;            /* Write Databases to files in this directory */
  char *zExpSql = 0;           /* Write SQL to files in this directory */
  void *pHeap = 0;             /* Heap for use by SQLite */
  int ossFuzz = 0;             /* enable OSS-FUZZ testing */
  int ossFuzzThisDb = 0;       /* ossFuzz value for this particular database */
  int nativeMalloc = 0;        /* Turn off MEMSYS3/5 and lookaside if true */
  sqlite3_vfs *pDfltVfs;       /* The default VFS */
  int openFlags4Data;          /* Flags for sqlite3_open_v2() */
  int bTimer = 0;              /* Show elapse time for each test */
  int nV;                      /* How much to increase verbosity with -vvvv */
  sqlite3_int64 tmStart;       /* Start of each test */

  sqlite3_config(SQLITE_CONFIG_URI,1);
  registerOomSimulator();
  sqlite3_initialize();
  iBegin = timeOfDay();
#ifdef __unix__
  signal(SIGALRM, signalHandler);
  signal(SIGSEGV, signalHandler);
  signal(SIGABRT, signalHandler);
#endif
  g.zArgv0 = argv[0];
  openFlags4Data = SQLITE_OPEN_READONLY;
  zFailCode = getenv("TEST_FAILURE");
  pDfltVfs = sqlite3_vfs_find(0);
  inmemVfsRegister(1);
  for(i=1; i<argc; i++){
    const char *z = argv[i];
    if( z[0]=='-' ){
      z++;
      if( z[0]=='-' ) z++;
      if( strcmp(z,"cell-size-check")==0 ){
        cellSzCkFlag = 1;
      }else
      if( strcmp(z,"dbid")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        onlyDbid = integerValue(argv[++i]);
      }else
      if( strcmp(z,"export-db")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        zExpDb = argv[++i];
      }else
      if( strcmp(z,"export-sql")==0 || strcmp(z,"export-dbsql")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        zExpSql = argv[++i];
      }else
      if( strcmp(z,"help")==0 ){
        showHelp();
        return 0;
      }else
      if( strcmp(z,"info")==0 ){
        infoFlag = 1;
      }else
      if( strcmp(z,"limit-depth")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        depthLimit = integerValue(argv[++i]);
      }else
      if( strcmp(z,"limit-heap")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        heapLimit = integerValue(argv[++i]);
      }else
      if( strcmp(z,"limit-mem")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        nMem = integerValue(argv[++i]);
      }else
      if( strcmp(z,"limit-vdbe")==0 ){
        vdbeLimitFlag = 1;
      }else
      if( strcmp(z,"load-sql")==0 ){
        zInsSql = "INSERT INTO xsql(sqltext)"
                  "VALUES(CAST(readtextfile(?1) AS text))";
        iFirstInsArg = i+1;
        openFlags4Data = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
        break;
      }else
      if( strcmp(z,"load-db")==0 ){
        zInsSql = "INSERT INTO db(dbcontent) VALUES(readfile(?1))";
        iFirstInsArg = i+1;
        openFlags4Data = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
        break;
      }else
      if( strcmp(z,"load-dbsql")==0 ){
        zInsSql = "INSERT INTO xsql(sqltext)"
                  "VALUES(readfile(?1))";
        iFirstInsArg = i+1;
        openFlags4Data = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
        dbSqlOnly = 1;
        break;
      }else
      if( strcmp(z,"m")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        zMsg = argv[++i];
        openFlags4Data = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE;
      }else
      if( strcmp(z,"native-malloc")==0 ){
        nativeMalloc = 1;
      }else
      if( strcmp(z,"native-vfs")==0 ){
        nativeFlag = 1;
      }else
      if( strcmp(z,"no-recover")==0 ){
        bNoRecover = 1;
      }else
      if( strcmp(z,"oss-fuzz")==0 ){
        ossFuzz = 1;
      }else
      if( strcmp(z,"prng-seed")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        g.uRandom = atoi(argv[++i]);
      }else
      if( strcmp(z,"quiet")==0 || strcmp(z,"q")==0 ){
        quietFlag = 1;
        verboseFlag = 0;
        eVerbosity = 0;
      }else
      if( strcmp(z,"rebuild")==0 ){
        rebuildFlag = 1;
        openFlags4Data = SQLITE_OPEN_READWRITE;
      }else
      if( strcmp(z,"result-trace")==0 ){
        runFlags |= SQL_OUTPUT;
      }else
      if( strcmp(z,"script")==0 ){
        bScript = 1;
      }else
      if( strcmp(z,"skip")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        nSkip = atoi(argv[++i]);
      }else
      if( strcmp(z,"spinner")==0 ){
        bSpinner = 1;
      }else
      if( strcmp(z,"timer")==0 ){
        bTimer = 1;
      }else
      if( strcmp(z,"sqlid")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        onlySqlid = integerValue(argv[++i]);
      }else
      if( strcmp(z,"timeout")==0 ){
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        iTimeout = integerValue(argv[++i]);
      }else
      if( strcmp(z,"timeout-test")==0 ){
        timeoutTest = 1;
#ifndef __unix__
        fatalError("timeout is not available on non-unix systems");
#endif
      }else
      if( strcmp(z,"vdbe-debug")==0 ){
        bVdbeDebug = 1;
      }else
      if( strcmp(z,"verbose")==0 ){
        quietFlag = 0;
        verboseFlag++;
        eVerbosity++;
        if( verboseFlag>2 ) runFlags |= SQL_TRACE;
      }else
      if( (nV = numberOfVChar(z))>=1 ){
        quietFlag = 0;
        verboseFlag += nV;
        eVerbosity += nV;
        if( verboseFlag>2 ) runFlags |= SQL_TRACE;
      }else
      if( strcmp(z,"version")==0 ){
        int ii;
        const char *zz;
        printf("SQLite %s %s (%d-bit)\n",
            sqlite3_libversion(), sqlite3_sourceid(),
            8*(int)sizeof(char*));
        for(ii=0; (zz = sqlite3_compileoption_get(ii))!=0; ii++){
          printf("%s\n", zz);
        }
        return 0;
      }else
      if( strcmp(z,"wait")==0 ){
        int iDelay;
        if( i>=argc-1 ) fatalError("missing arguments on %s", argv[i]);
        iDelay = integerValue(argv[++i]);
        printf("Waiting %d seconds:", iDelay);
        fflush(stdout);
        while( 1 /*exit-by-break*/ ){
          sqlite3_sleep(1000);
          iDelay--;
          if( iDelay<=0 ) break;
          printf(" %d", iDelay);
          fflush(stdout);
        }
        printf("\n");
        fflush(stdout);
      }else
      if( strcmp(z,"is-dbsql")==0 ){
        i++;
        for(i++; i<argc; i++){
          long nData;
          char *aData = readFile(argv[i], &nData);
          printf("%d %s\n", isDbSql((unsigned char*)aData,nData), argv[i]);
          sqlite3_free(aData);
        }
        exit(0);
      }else
      {
        fatalError("unknown option: %s", argv[i]);
      }
    }else{
      nSrcDb++;
      azSrcDb = safe_realloc(azSrcDb, nSrcDb*sizeof(azSrcDb[0]));
      azSrcDb[nSrcDb-1] = argv[i];
    }
  }
  if( nSrcDb==0 ) fatalError("no source database specified");
  if( nSrcDb>1 ){
    if( zMsg ){
      fatalError("cannot change the description of more than one database");
    }
    if( zInsSql ){
      fatalError("cannot import into more than one database");
    }
  }

  /* Process each source database separately */
  for(iSrcDb=0; iSrcDb<nSrcDb; iSrcDb++){
    char *zRawData = 0;
    long nRawData = 0;
    g.zDbFile = azSrcDb[iSrcDb];
    rc = sqlite3_open_v2(azSrcDb[iSrcDb], &db,
                         openFlags4Data, pDfltVfs->zName);
    if( rc==SQLITE_OK ){
      rc = sqlite3_exec(db, "SELECT count(*) FROM sqlite_schema", 0, 0, 0);
    }
    if( rc ){
      sqlite3_close(db);
      zRawData = readFile(azSrcDb[iSrcDb], &nRawData);
      if( zRawData==0 ){
        fatalError("input file \"%s\" is not recognized\n", azSrcDb[iSrcDb]);
      }
      sqlite3_open(":memory:", &db);
    }

    /* Print the description, if there is one */
    if( infoFlag ){
      int n;
      zDbName = azSrcDb[iSrcDb];
      i = (int)strlen(zDbName) - 1;
      while( i>0 && zDbName[i-1]!='/' && zDbName[i-1]!='\\' ){ i--; }
      zDbName += i;
      sqlite3_prepare_v2(db, "SELECT msg FROM readme", -1, &pStmt, 0);
      if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
        printf("%s: %s", zDbName, sqlite3_column_text(pStmt,0));
      }else{
        printf("%s: (empty \"readme\")", zDbName);
      }
      sqlite3_finalize(pStmt);
      sqlite3_prepare_v2(db, "SELECT count(*) FROM db", -1, &pStmt, 0);
      if( pStmt
       && sqlite3_step(pStmt)==SQLITE_ROW
       && (n = sqlite3_column_int(pStmt,0))>0
      ){
        printf(" - %d DBs", n);
      }
      sqlite3_finalize(pStmt);
      sqlite3_prepare_v2(db, "SELECT count(*) FROM xsql", -1, &pStmt, 0);
      if( pStmt
       && sqlite3_step(pStmt)==SQLITE_ROW
       && (n = sqlite3_column_int(pStmt,0))>0
      ){
        printf(" - %d scripts", n);
      }
      sqlite3_finalize(pStmt);
      printf("\n");
      sqlite3_close(db);
      sqlite3_free(zRawData);
      continue;
    }

    rc = sqlite3_exec(db,
       "CREATE TABLE IF NOT EXISTS db(\n"
       "  dbid INTEGER PRIMARY KEY, -- database id\n"
       "  dbcontent BLOB            -- database disk file image\n"
       ");\n"
       "CREATE TABLE IF NOT EXISTS xsql(\n"
       "  sqlid INTEGER PRIMARY KEY,   -- SQL script id\n"
       "  sqltext TEXT                 -- Text of SQL statements to run\n"
       ");"
       "CREATE TABLE IF NOT EXISTS readme(\n"
       "  msg TEXT -- Human-readable description of this file\n"
       ");", 0, 0, 0);
    if( rc ) fatalError("cannot create schema: %s", sqlite3_errmsg(db));
    if( zMsg ){
      char *zSql;
      zSql = sqlite3_mprintf(
               "DELETE FROM readme; INSERT INTO readme(msg) VALUES(%Q)", zMsg);
      rc = sqlite3_exec(db, zSql, 0, 0, 0);
      sqlite3_free(zSql);
      if( rc ) fatalError("cannot change description: %s", sqlite3_errmsg(db));
    }
    if( zRawData ){
      zInsSql = "INSERT INTO xsql(sqltext) VALUES(?1)";
      rc = sqlite3_prepare_v2(db, zInsSql, -1, &pStmt, 0);
      if( rc ) fatalError("cannot prepare statement [%s]: %s",
                          zInsSql, sqlite3_errmsg(db));
      sqlite3_bind_text(pStmt, 1, zRawData, nRawData, SQLITE_STATIC);
      sqlite3_step(pStmt);
      rc = sqlite3_reset(pStmt);
      if( rc ) fatalError("insert failed for %s", argv[i]);
      sqlite3_finalize(pStmt);
      rebuild_database(db, dbSqlOnly);
      zInsSql = 0;
      sqlite3_free(zRawData);
      zRawData = 0;
    }
    ossFuzzThisDb = ossFuzz;

    /* If the CONFIG(name,value) table exists, read db-specific settings
    ** from that table */
    if( sqlite3_table_column_metadata(db,0,"config",0,0,0,0,0,0)==SQLITE_OK ){
      rc = sqlite3_prepare_v2(db, "SELECT name, value FROM config",
                                  -1, &pStmt, 0);
      if( rc ) fatalError("cannot prepare query of CONFIG table: %s",
                          sqlite3_errmsg(db));
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        const char *zName = (const char *)sqlite3_column_text(pStmt,0);
        if( zName==0 ) continue;
        if( strcmp(zName, "oss-fuzz")==0 ){
          ossFuzzThisDb = sqlite3_column_int(pStmt,1);
          if( verboseFlag>1 ) printf("Config: oss-fuzz=%d\n", ossFuzzThisDb);
        }
        if( strcmp(zName, "limit-mem")==0 ){
          nMemThisDb = sqlite3_column_int(pStmt,1);
          if( verboseFlag>1 ) printf("Config: limit-mem=%d\n", nMemThisDb);
        }
      }
      sqlite3_finalize(pStmt);
    }

    if( zInsSql ){
      sqlite3_create_function(db, "readfile", 1, SQLITE_UTF8, 0,
                              readfileFunc, 0, 0);
      sqlite3_create_function(db, "readtextfile", 1, SQLITE_UTF8, 0,
                              readtextfileFunc, 0, 0);
      sqlite3_create_function(db, "isdbsql", 1, SQLITE_UTF8, 0,
                              isDbSqlFunc, 0, 0);
      rc = sqlite3_prepare_v2(db, zInsSql, -1, &pStmt, 0);
      if( rc ) fatalError("cannot prepare statement [%s]: %s",
                          zInsSql, sqlite3_errmsg(db));
      rc = sqlite3_exec(db, "BEGIN", 0, 0, 0);
      if( rc ) fatalError("cannot start a transaction");
      for(i=iFirstInsArg; i<argc; i++){
        if( strcmp(argv[i],"-")==0 ){
          /* A filename of "-" means read multiple filenames from stdin */
          char zLine[2000];
          while( rc==0 && fgets(zLine,sizeof(zLine),stdin)!=0 ){
            size_t kk = strlen(zLine);
            while( kk>0 && zLine[kk-1]<=' ' ) kk--;
            sqlite3_bind_text(pStmt, 1, zLine, (int)kk, SQLITE_STATIC);
            if( verboseFlag>1 ) printf("loading %.*s\n", (int)kk, zLine);
            sqlite3_step(pStmt);
            rc = sqlite3_reset(pStmt);
            if( rc ) fatalError("insert failed for %s", zLine);
          }
        }else{
          sqlite3_bind_text(pStmt, 1, argv[i], -1, SQLITE_STATIC);
          if( verboseFlag>1 ) printf("loading %s\n", argv[i]);
          sqlite3_step(pStmt);
          rc = sqlite3_reset(pStmt);
          if( rc ) fatalError("insert failed for %s", argv[i]);
        }
      }
      sqlite3_finalize(pStmt);
      rc = sqlite3_exec(db, "COMMIT", 0, 0, 0);
      if( rc ) fatalError("cannot commit the transaction: %s",
                          sqlite3_errmsg(db));
      rebuild_database(db, dbSqlOnly);
      sqlite3_close(db);
      return 0;
    }
    rc = sqlite3_exec(db, "PRAGMA query_only=1;", 0, 0, 0);
    if( rc ) fatalError("cannot set database to query-only");
    if( zExpDb!=0 || zExpSql!=0 ){
      sqlite3_create_function(db, "writefile", 2, SQLITE_UTF8, 0,
                              writefileFunc, 0, 0);
      if( zExpDb!=0 ){
        const char *zExDb = 
          "SELECT writefile(printf('%s/db%06d.db',?1,dbid),dbcontent),"
          "       dbid, printf('%s/db%06d.db',?1,dbid), length(dbcontent)"
          "  FROM db WHERE ?2<0 OR dbid=?2;";
        rc = sqlite3_prepare_v2(db, zExDb, -1, &pStmt, 0);
        if( rc ) fatalError("cannot prepare statement [%s]: %s",
                            zExDb, sqlite3_errmsg(db));
        sqlite3_bind_text64(pStmt, 1, zExpDb, strlen(zExpDb),
                            SQLITE_STATIC, SQLITE_UTF8);
        sqlite3_bind_int(pStmt, 2, onlyDbid);
        while( sqlite3_step(pStmt)==SQLITE_ROW ){
          printf("write db-%d (%d bytes) into %s\n",
             sqlite3_column_int(pStmt,1),
             sqlite3_column_int(pStmt,3),
             sqlite3_column_text(pStmt,2));
        }
        sqlite3_finalize(pStmt);
      }
      if( zExpSql!=0 ){
        const char *zExSql = 
          "SELECT writefile(printf('%s/sql%06d.txt',?1,sqlid),sqltext),"
          "       sqlid, printf('%s/sql%06d.txt',?1,sqlid), length(sqltext)"
          "  FROM xsql WHERE ?2<0 OR sqlid=?2;";
        rc = sqlite3_prepare_v2(db, zExSql, -1, &pStmt, 0);
        if( rc ) fatalError("cannot prepare statement [%s]: %s",
                            zExSql, sqlite3_errmsg(db));
        sqlite3_bind_text64(pStmt, 1, zExpSql, strlen(zExpSql),
                            SQLITE_STATIC, SQLITE_UTF8);
        sqlite3_bind_int(pStmt, 2, onlySqlid);
        while( sqlite3_step(pStmt)==SQLITE_ROW ){
          printf("write sql-%d (%d bytes) into %s\n",
             sqlite3_column_int(pStmt,1),
             sqlite3_column_int(pStmt,3),
             sqlite3_column_text(pStmt,2));
        }
        sqlite3_finalize(pStmt);
      }
      sqlite3_close(db);
      return 0;
    }
  
    /* Load all SQL script content and all initial database images from the
    ** source db
    */
    blobListLoadFromDb(db, "SELECT sqlid, sqltext FROM xsql", onlySqlid,
                           &g.nSql, &g.pFirstSql);
    if( g.nSql==0 ) fatalError("need at least one SQL script");
    blobListLoadFromDb(db, "SELECT dbid, dbcontent FROM db", onlyDbid,
                       &g.nDb, &g.pFirstDb);
    if( g.nDb==0 ){
      g.pFirstDb = safe_realloc(0, sizeof(Blob));
      memset(g.pFirstDb, 0, sizeof(Blob));
      g.pFirstDb->id = 1;
      g.pFirstDb->seq = 0;
      g.nDb = 1;
      sqlFuzz = 1;
    }
  
    /* Print the description, if there is one */
    if( !quietFlag && !bScript ){
      zDbName = azSrcDb[iSrcDb];
      i = (int)strlen(zDbName) - 1;
      while( i>0 && zDbName[i-1]!='/' && zDbName[i-1]!='\\' ){ i--; }
      zDbName += i;
      if( verboseFlag ){
        sqlite3_prepare_v2(db, "SELECT msg FROM readme", -1, &pStmt, 0);
        if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
          printf("%s: %s\n", zDbName, sqlite3_column_text(pStmt,0));
        }
        sqlite3_finalize(pStmt);
      }
    }

    /* Rebuild the database, if requested */
    if( rebuildFlag ){
      if( !quietFlag ){
        printf("%s: rebuilding... ", zDbName);
        fflush(stdout);
      }
      rebuild_database(db, 0);
      if( !quietFlag ) printf("done\n");
    }
  
    /* Close the source database.  Verify that no SQLite memory allocations are
    ** outstanding.
    */
    sqlite3_close(db);
    if( sqlite3_memory_used()>0 ){
      fatalError("SQLite has memory in use before the start of testing");
    }

    /* Limit available memory, if requested */
    sqlite3_shutdown();

    if( nMemThisDb>0 && nMem==0 ){
      if( !nativeMalloc ){
        pHeap = realloc(pHeap, nMemThisDb);
        if( pHeap==0 ){
          fatalError("failed to allocate %d bytes of heap memory", nMem);
        }
        sqlite3_config(SQLITE_CONFIG_HEAP, pHeap, nMemThisDb, 128);
      }else{
        sqlite3_hard_heap_limit64((sqlite3_int64)nMemThisDb);
      }
    }else{
      sqlite3_hard_heap_limit64(0);
    }

    /* Disable lookaside with the --native-malloc option */
    if( nativeMalloc ){
      sqlite3_config(SQLITE_CONFIG_LOOKASIDE, 0, 0);
    }
  
    /* Reset the in-memory virtual filesystem */
    formatVfs();
    
    /* Run a test using each SQL script against each database.
    */
    if( verboseFlag<2 && !quietFlag && !bSpinner && !bScript ){
      printf("%s:", zDbName);
    }
    for(pSql=g.pFirstSql; pSql; pSql=pSql->pNext){
      tmStart = timeOfDay();
      if( isDbSql(pSql->a, pSql->sz) ){
        sqlite3_snprintf(sizeof(g.zTestName), g.zTestName, "sqlid=%d",pSql->id);
        if( bScript ){
          /* No progress output */
        }else if( bSpinner ){
          int nTotal =g.nSql;
          int idx = pSql->seq;
          printf("\r%s: %d/%d   ", zDbName, idx, nTotal);
          fflush(stdout);
        }else if( verboseFlag>1 ){
          printf("%s\n", g.zTestName);
          fflush(stdout);
        }else if( !quietFlag ){
          static int prevAmt = -1;
          int idx = pSql->seq;
          int amt = idx*10/(g.nSql);
          if( amt!=prevAmt ){
            printf(" %d%%", amt*10);
            fflush(stdout);
            prevAmt = amt;
          }
        }
        if( nSkip>0 ){
          nSkip--;
        }else{
          runCombinedDbSqlInput(pSql->a, pSql->sz, iTimeout, bScript, pSql->id);
        }
        nTest++;
        if( bTimer && !bScript ){
          sqlite3_int64 tmEnd = timeOfDay();
          printf("%lld %s\n", tmEnd - tmStart, g.zTestName);
        }
        g.zTestName[0] = 0;
        disableOom();
        continue;
      }
      for(pDb=g.pFirstDb; pDb; pDb=pDb->pNext){
        int openFlags;
        const char *zVfs = "inmem";
        sqlite3_snprintf(sizeof(g.zTestName), g.zTestName, "sqlid=%d,dbid=%d",
                         pSql->id, pDb->id);
        if( bScript ){
          /* No progress output */
        }else if( bSpinner ){
          int nTotal = g.nDb*g.nSql;
          int idx = pSql->seq*g.nDb + pDb->id - 1;
          printf("\r%s: %d/%d   ", zDbName, idx, nTotal);
          fflush(stdout);
        }else if( verboseFlag>1 ){
          printf("%s\n", g.zTestName);
          fflush(stdout);
        }else if( !quietFlag ){
          static int prevAmt = -1;
          int idx = pSql->seq*g.nDb + pDb->id - 1;
          int amt = idx*10/(g.nDb*g.nSql);
          if( amt!=prevAmt ){
            printf(" %d%%", amt*10);
            fflush(stdout);
            prevAmt = amt;
          }
        }
        if( nSkip>0 ){
          nSkip--;
          continue;
        }
        if( bScript ){
          char zName[100];
          sqlite3_snprintf(sizeof(zName), zName, "db%06d.db", 
                           pDb->id>1 ? pDb->id : pSql->id);
          renderDbSqlForCLI(stdout, zName,
             pDb->a, pDb->sz, pSql->a, pSql->sz);
          continue;
        }
        createVFile("main.db", pDb->sz, pDb->a);
        sqlite3_randomness(0,0);
        if( ossFuzzThisDb ){
#ifndef SQLITE_OSS_FUZZ
          fatalError("--oss-fuzz not supported: recompile"
                     " with -DSQLITE_OSS_FUZZ");
#else
          extern int LLVMFuzzerTestOneInput(const uint8_t*, size_t);
          LLVMFuzzerTestOneInput((const uint8_t*)pSql->a, (size_t)pSql->sz);
#endif
        }else{
          openFlags = SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE;
          if( nativeFlag && pDb->sz==0 ){
            openFlags |= SQLITE_OPEN_MEMORY;
            zVfs = 0;
          }
          rc = sqlite3_open_v2("main.db", &db, openFlags, zVfs);
          if( rc ) fatalError("cannot open inmem database");
          sqlite3_limit(db, SQLITE_LIMIT_LENGTH, 100000000);
          sqlite3_limit(db, SQLITE_LIMIT_LIKE_PATTERN_LENGTH, 50);
          if( cellSzCkFlag ) runSql(db, "PRAGMA cell_size_check=ON", runFlags);
          setAlarm((iTimeout+999)/1000);
          /* Enable test functions */
          sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, db);
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
          if( sqlFuzz || vdbeLimitFlag ){
            sqlite3_progress_handler(db, 100000, progressHandler,
                                     &vdbeLimitFlag);
          }
#endif
#ifdef SQLITE_TESTCTRL_PRNG_SEED
          sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, 1, db);
#endif
          if( bVdbeDebug ){
            sqlite3_exec(db, "PRAGMA vdbe_debug=ON", 0, 0, 0);
          }
          do{
            runSql(db, (char*)pSql->a, runFlags);
          }while( timeoutTest );
          setAlarm(0);
          sqlite3_exec(db, "PRAGMA temp_store_directory=''", 0, 0, 0);
          sqlite3_close(db);
        }
        if( sqlite3_memory_used()>0 ){
           fatalError("memory leak: %lld bytes outstanding",
                      sqlite3_memory_used());
        }
        reformatVfs();
        nTest++;
        if( bTimer ){
          sqlite3_int64 tmEnd = timeOfDay();
          printf("%lld %s\n", tmEnd - tmStart, g.zTestName);
        }
        g.zTestName[0] = 0;

        /* Simulate an error if the TEST_FAILURE environment variable is "5".
        ** This is used to verify that automated test script really do spot
        ** errors that occur in this test program.
        */
        if( zFailCode ){
          if( zFailCode[0]=='5' && zFailCode[1]==0 ){
            fatalError("simulated failure");
          }else if( zFailCode[0]!=0 ){
            /* If TEST_FAILURE is something other than 5, just exit the test
            ** early */
            printf("\nExit early due to TEST_FAILURE being set\n");
            iSrcDb = nSrcDb-1;
            goto sourcedb_cleanup;
          }
        }
      }
    }
    if( bScript ){
      /* No progress output */
    }else if( bSpinner ){
      int nTotal = g.nDb*g.nSql;
      printf("\r%s: %d/%d   \n", zDbName, nTotal, nTotal);
    }else if( !quietFlag && verboseFlag<2 ){
      printf(" 100%% - %d tests\n", g.nDb*g.nSql);
    }
  
    /* Clean up at the end of processing a single source database
    */
  sourcedb_cleanup:
    blobListFree(g.pFirstSql);
    blobListFree(g.pFirstDb);
    reformatVfs();
 
  } /* End loop over all source databases */

  if( !quietFlag && !bScript ){
    sqlite3_int64 iElapse = timeOfDay() - iBegin;
    if( g.nInvariant ){
      printf("fuzzcheck: %u query invariants checked\n", g.nInvariant);
    }
    printf("fuzzcheck: 0 errors out of %d tests in %d.%03d seconds\n"
           "SQLite %s %s (%d-bit)\n",
           nTest, (int)(iElapse/1000), (int)(iElapse%1000),
           sqlite3_libversion(), sqlite3_sourceid(),
           8*(int)sizeof(char*));
  }
  free(azSrcDb);
  free(pHeap);
  return 0;
}