SQLite

    /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
    **
    ** Set the VDBE coverage callback function to xCallback with context 
    ** pointer ptr.
    */
    case SQLITE_TESTCTRL_VDBE_COVERAGE: {
#ifdef SQLITE_VDBE_COVERAGE
      typedef void (*branch_callback)(void*,unsigned int,
                                      unsigned char,unsigned char);
      sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
      sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
#endif
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */

  void(*xSqllog)(void*,sqlite3*,const char*, int);
  void *pSqllogArg;
#endif
#ifdef SQLITE_VDBE_COVERAGE
  /* The following callback (if not NULL) is invoked on every VDBE branch
  ** operation.  Set the callback using SQLITE_TESTCTRL_VDBE_COVERAGE.
  */
  void (*xVdbeBranch)(void*,unsigned iSrcLine,u8 eThis,u8 eMx);  /* Callback */
  void *pVdbeBranchArg;                                     /* 1st argument */
#endif
#ifndef SQLITE_UNTESTABLE
  int (*xTestCallback)(int);        /* Invoked by sqlite3FaultSim() */
#endif
  int bLocaltimeFault;              /* True to fail localtime() calls */
  int iOnceResetThreshold;          /* When to reset OP_Once counters */

#endif

/*
** Invoke the VDBE coverage callback, if that callback is defined.  This
** feature is used for test suite validation only and does not appear an
** production builds.
**
** M is an integer between 2 and 4.  2 indicates a ordinary two-way
** branch (I=0 means fall through and I=1 means taken).  3 indicates
** a 3-way branch where the third way is when one of the operands is
** NULL.  4 indicates the OP_Jump instruction which has three destinations
** depending on whether the first operand is less than, equal to, or greater
** than the second. 
**
** iSrcLine is the source code line (from the __LINE__ macro) that
** generated the VDBE instruction combined with flag bits.  The source

** code line number is in the lower 24 bits of iSrcLine and the upper
** 8 bytes are flags.  The lower three bits of the flags indicate
** values for I that should never occur.  For example, if the branch is
** always taken, the flags should be 0x05 since the fall-through and
** alternate branch are never taken.  If a branch is never taken then
** flags should be 0x06 since only the fall-through approach is allowed.
**
** Bit 0x04 of the flags indicates an OP_Jump opcode that is only
** interested in equal or not-equal.  In other words, I==0 and I==2
** should be treated the same.
**
** Since only a line number is retained, not the filename, this macro
** only works for amalgamation builds.  But that is ok, since these macros
** should be no-ops except for special builds used to measure test coverage.
*/
#if !defined(SQLITE_VDBE_COVERAGE)
# define VdbeBranchTaken(I,M)
#else
# define VdbeBranchTaken(I,M) vdbeTakeBranch(pOp->iSrcLine,I,M)
  static void vdbeTakeBranch(u32 iSrcLine, u8 I, u8 M){
    u8 mNever;
    assert( I<=2 );  /* 0: fall through,  1: taken,  2: alternate taken */
    assert( M<=4 );  /* 2: two-way branch, 3: three-way branch, 4: OP_Jump */
    assert( I<M );   /* I can only be 2 if M is 3 or 4 */
    /* Transform I from a integer [0,1,2] into a bitmask of [1,2,4] */
    I = 1<<I;
    /* The upper 8 bits of iSrcLine are flags.  The lower three bits of
    ** the flags indicate directions that the branch can never go.  If
    ** a branch really does go in one of those directions, assert right
    ** away. */
    mNever = iSrcLine >> 24;


    assert( (I & mNever)==0 );

    if( sqlite3GlobalConfig.xVdbeBranch==0 ) return;  /*NO_TEST*/
    I |= mNever;
    if( M==2 ) I |= 0x04;
    if( M==4 ){
      I |= 0x08;
      if( (I&0x05)!=0 ) I |= 0x05;
    }
    sqlite3GlobalConfig.xVdbeBranch(sqlite3GlobalConfig.pVdbeBranchArg,
                                    iSrcLine&0xffffff, I, M);

  }
#endif

/*
** Convert the given register into a string if it isn't one
** already. Return non-zero if a malloc() fails.
*/

**
** Jump to the instruction at address P1, P2, or P3 depending on whether
** in the most recent OP_Compare instruction the P1 vector was less than
** equal to, or greater than the P2 vector, respectively.
*/
case OP_Jump: {             /* jump */
  if( iCompare<0 ){
    VdbeBranchTaken(0,4); pOp = &aOp[pOp->p1 - 1];
  }else if( iCompare==0 ){
    VdbeBranchTaken(1,4); pOp = &aOp[pOp->p2 - 1];
  }else{
    VdbeBranchTaken(2,4); pOp = &aOp[pOp->p3 - 1];
  }
  break;
}

/* Opcode: And P1 P2 P3 * *
** Synopsis: r[P3]=(r[P1] && r[P2])
**

  char *zComment;          /* Comment to improve readability */
#endif
#ifdef VDBE_PROFILE
  u32 cnt;                 /* Number of times this instruction was executed */
  u64 cycles;              /* Total time spent executing this instruction */
#endif
#ifdef SQLITE_VDBE_COVERAGE
  u32 iSrcLine;            /* Source-code line that generated this opcode
                           ** with flags in the upper 8 bits */
#endif
};
typedef struct VdbeOp VdbeOp;


/*
** A sub-routine used to implement a trigger program.

**
**    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
**
**    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
**
**    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
**
**    VdbeCoverageNeverNull(v)         // Previous three-way branch is only
**                                     // taken on the first two ways.  The
**                                     // NULL option is not possible
**
**    VdbeCoverageEqNe(v)              // Previous OP_Jump is only interested
**                                     // in distingishing equal and not-equal.
**
** Every VDBE branch operation must be tagged with one of the macros above.
** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
** routine in vdbe.c, alerting the developer to the missed tag.
**
** During testing, the test application will invoke
** sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE,...) to set a callback
** routine that is invoked as each bytecode branch is taken.  The callback
** contains the sqlite3.c source line number ov the VdbeCoverage macro and
** flags to indicate whether or not the branch was taken.  The test application
** is responsible for keeping track of this and reporting byte-code branches
** that are never taken.
**
** See the VdbeBranchTaken() macro and vdbeTakeBranch() function in the
** vdbe.c source file for additional information.
*/
#ifdef SQLITE_VDBE_COVERAGE
  void sqlite3VdbeSetLineNumber(Vdbe*,int);
# define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
# define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
# define VdbeCoverageAlwaysTaken(v) \
         sqlite3VdbeSetLineNumber(v,__LINE__|0x5000000);
# define VdbeCoverageNeverTaken(v) \
         sqlite3VdbeSetLineNumber(v,__LINE__|0x6000000);
# define VdbeCoverageNeverNull(v) \
         sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);
# define VdbeCoverageEqNe(v) \
         sqlite3VdbeSetLineNumber(v,__LINE__|0x8000000);
# define VDBE_OFFSET_LINENO(x) (__LINE__+x)
#else
# define VdbeCoverage(v)
# define VdbeCoverageIf(v,x)
# define VdbeCoverageAlwaysTaken(v)
# define VdbeCoverageNeverTaken(v)
# define VdbeCoverageNeverNull(v)
# define VdbeCoverageEqNe(v)
# define VDBE_OFFSET_LINENO(x) 0
#endif

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
#else
# define sqlite3VdbeScanStatus(a,b,c,d,e)