xref: /sqlite-3.40.0/src/vdbeInt.h (revision a3fdec71)
1 /*
2 ** 2003 September 6
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This is the header file for information that is private to the
13 ** VDBE.  This information used to all be at the top of the single
14 ** source code file "vdbe.c".  When that file became too big (over
15 ** 6000 lines long) it was split up into several smaller files and
16 ** this header information was factored out.
17 */
18 #ifndef _VDBEINT_H_
19 #define _VDBEINT_H_
20 
21 /*
22 ** The maximum number of times that a statement will try to reparse
23 ** itself before giving up and returning SQLITE_SCHEMA.
24 */
25 #ifndef SQLITE_MAX_SCHEMA_RETRY
26 # define SQLITE_MAX_SCHEMA_RETRY 50
27 #endif
28 
29 /*
30 ** SQL is translated into a sequence of instructions to be
31 ** executed by a virtual machine.  Each instruction is an instance
32 ** of the following structure.
33 */
34 typedef struct VdbeOp Op;
35 
36 /*
37 ** Boolean values
38 */
39 typedef unsigned Bool;
40 
41 /* Opaque type used by code in vdbesort.c */
42 typedef struct VdbeSorter VdbeSorter;
43 
44 /* Opaque type used by the explainer */
45 typedef struct Explain Explain;
46 
47 /* Elements of the linked list at Vdbe.pAuxData */
48 typedef struct AuxData AuxData;
49 
50 /*
51 ** A cursor is a pointer into a single BTree within a database file.
52 ** The cursor can seek to a BTree entry with a particular key, or
53 ** loop over all entries of the Btree.  You can also insert new BTree
54 ** entries or retrieve the key or data from the entry that the cursor
55 ** is currently pointing to.
56 **
57 ** Cursors can also point to virtual tables, sorters, or "pseudo-tables".
58 ** A pseudo-table is a single-row table implemented by registers.
59 **
60 ** Every cursor that the virtual machine has open is represented by an
61 ** instance of the following structure.
62 */
63 struct VdbeCursor {
64   BtCursor *pCursor;    /* The cursor structure of the backend */
65   Btree *pBt;           /* Separate file holding temporary table */
66   KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
67   int seekResult;       /* Result of previous sqlite3BtreeMoveto() */
68   int pseudoTableReg;   /* Register holding pseudotable content. */
69   i16 nField;           /* Number of fields in the header */
70   u16 nHdrParsed;       /* Number of header fields parsed so far */
71   i8 iDb;               /* Index of cursor database in db->aDb[] (or -1) */
72   u8 nullRow;           /* True if pointing to a row with no data */
73   u8 rowidIsValid;      /* True if lastRowid is valid */
74   u8 deferredMoveto;    /* A call to sqlite3BtreeMoveto() is needed */
75   Bool useRandomRowid:1;/* Generate new record numbers semi-randomly */
76   Bool isTable:1;       /* True if a table requiring integer keys */
77   Bool isOrdered:1;     /* True if the underlying table is BTREE_UNORDERED */
78   Bool multiPseudo:1;   /* Multi-register pseudo-cursor */
79   sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
80   i64 seqCount;         /* Sequence counter */
81   i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
82   i64 lastRowid;        /* Rowid being deleted by OP_Delete */
83   VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
84 
85   /* Cached information about the header for the data record that the
86   ** cursor is currently pointing to.  Only valid if cacheStatus matches
87   ** Vdbe.cacheCtr.  Vdbe.cacheCtr will never take on the value of
88   ** CACHE_STALE and so setting cacheStatus=CACHE_STALE guarantees that
89   ** the cache is out of date.
90   **
91   ** aRow might point to (ephemeral) data for the current row, or it might
92   ** be NULL.
93   */
94   u32 cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
95   u32 payloadSize;      /* Total number of bytes in the record */
96   u32 szRow;            /* Byte available in aRow */
97   u32 iHdrOffset;       /* Offset to next unparsed byte of the header */
98   const u8 *aRow;       /* Data for the current row, if all on one page */
99   u32 aType[1];         /* Type values for all entries in the record */
100   /* 2*nField extra array elements allocated for aType[], beyond the one
101   ** static element declared in the structure.  nField total array slots for
102   ** aType[] and nField+1 array slots for aOffset[] */
103 };
104 typedef struct VdbeCursor VdbeCursor;
105 
106 /*
107 ** When a sub-program is executed (OP_Program), a structure of this type
108 ** is allocated to store the current value of the program counter, as
109 ** well as the current memory cell array and various other frame specific
110 ** values stored in the Vdbe struct. When the sub-program is finished,
111 ** these values are copied back to the Vdbe from the VdbeFrame structure,
112 ** restoring the state of the VM to as it was before the sub-program
113 ** began executing.
114 **
115 ** The memory for a VdbeFrame object is allocated and managed by a memory
116 ** cell in the parent (calling) frame. When the memory cell is deleted or
117 ** overwritten, the VdbeFrame object is not freed immediately. Instead, it
118 ** is linked into the Vdbe.pDelFrame list. The contents of the Vdbe.pDelFrame
119 ** list is deleted when the VM is reset in VdbeHalt(). The reason for doing
120 ** this instead of deleting the VdbeFrame immediately is to avoid recursive
121 ** calls to sqlite3VdbeMemRelease() when the memory cells belonging to the
122 ** child frame are released.
123 **
124 ** The currently executing frame is stored in Vdbe.pFrame. Vdbe.pFrame is
125 ** set to NULL if the currently executing frame is the main program.
126 */
127 typedef struct VdbeFrame VdbeFrame;
128 struct VdbeFrame {
129   Vdbe *v;                /* VM this frame belongs to */
130   VdbeFrame *pParent;     /* Parent of this frame, or NULL if parent is main */
131   Op *aOp;                /* Program instructions for parent frame */
132   Mem *aMem;              /* Array of memory cells for parent frame */
133   u8 *aOnceFlag;          /* Array of OP_Once flags for parent frame */
134   VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
135   void *token;            /* Copy of SubProgram.token */
136   i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
137   int nCursor;            /* Number of entries in apCsr */
138   int pc;                 /* Program Counter in parent (calling) frame */
139   int nOp;                /* Size of aOp array */
140   int nMem;               /* Number of entries in aMem */
141   int nOnceFlag;          /* Number of entries in aOnceFlag */
142   int nChildMem;          /* Number of memory cells for child frame */
143   int nChildCsr;          /* Number of cursors for child frame */
144   int nChange;            /* Statement changes (Vdbe.nChanges)     */
145 };
146 
147 #define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])
148 
149 /*
150 ** A value for VdbeCursor.cacheValid that means the cache is always invalid.
151 */
152 #define CACHE_STALE 0
153 
154 /*
155 ** Internally, the vdbe manipulates nearly all SQL values as Mem
156 ** structures. Each Mem struct may cache multiple representations (string,
157 ** integer etc.) of the same value.
158 */
159 struct Mem {
160   sqlite3 *db;        /* The associated database connection */
161   char *z;            /* String or BLOB value */
162   double r;           /* Real value */
163   union {
164     i64 i;              /* Integer value used when MEM_Int is set in flags */
165     int nZero;          /* Used when bit MEM_Zero is set in flags */
166     FuncDef *pDef;      /* Used only when flags==MEM_Agg */
167     RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
168     VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
169   } u;
170   int n;              /* Number of characters in string value, excluding '\0' */
171   u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
172   u8  type;           /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */
173   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
174 #ifdef SQLITE_DEBUG
175   Mem *pScopyFrom;    /* This Mem is a shallow copy of pScopyFrom */
176   void *pFiller;      /* So that sizeof(Mem) is a multiple of 8 */
177 #endif
178   void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
179   char *zMalloc;      /* Dynamic buffer allocated by sqlite3_malloc() */
180 };
181 
182 /* One or more of the following flags are set to indicate the validOK
183 ** representations of the value stored in the Mem struct.
184 **
185 ** If the MEM_Null flag is set, then the value is an SQL NULL value.
186 ** No other flags may be set in this case.
187 **
188 ** If the MEM_Str flag is set then Mem.z points at a string representation.
189 ** Usually this is encoded in the same unicode encoding as the main
190 ** database (see below for exceptions). If the MEM_Term flag is also
191 ** set, then the string is nul terminated. The MEM_Int and MEM_Real
192 ** flags may coexist with the MEM_Str flag.
193 */
194 #define MEM_Null      0x0001   /* Value is NULL */
195 #define MEM_Str       0x0002   /* Value is a string */
196 #define MEM_Int       0x0004   /* Value is an integer */
197 #define MEM_Real      0x0008   /* Value is a real number */
198 #define MEM_Blob      0x0010   /* Value is a BLOB */
199 #define MEM_RowSet    0x0020   /* Value is a RowSet object */
200 #define MEM_Frame     0x0040   /* Value is a VdbeFrame object */
201 #define MEM_Invalid   0x0080   /* Value is undefined */
202 #define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
203 #define MEM_TypeMask  0x01ff   /* Mask of type bits */
204 
205 
206 /* Whenever Mem contains a valid string or blob representation, one of
207 ** the following flags must be set to determine the memory management
208 ** policy for Mem.z.  The MEM_Term flag tells us whether or not the
209 ** string is \000 or \u0000 terminated
210 */
211 #define MEM_Term      0x0200   /* String rep is nul terminated */
212 #define MEM_Dyn       0x0400   /* Need to call sqliteFree() on Mem.z */
213 #define MEM_Static    0x0800   /* Mem.z points to a static string */
214 #define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */
215 #define MEM_Agg       0x2000   /* Mem.z points to an agg function context */
216 #define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */
217 #ifdef SQLITE_OMIT_INCRBLOB
218   #undef MEM_Zero
219   #define MEM_Zero 0x0000
220 #endif
221 
222 /*
223 ** Clear any existing type flags from a Mem and replace them with f
224 */
225 #define MemSetTypeFlag(p, f) \
226    ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)
227 
228 /*
229 ** Return true if a memory cell is not marked as invalid.  This macro
230 ** is for use inside assert() statements only.
231 */
232 #ifdef SQLITE_DEBUG
233 #define memIsValid(M)  ((M)->flags & MEM_Invalid)==0
234 #endif
235 
236 /*
237 ** Each auxilliary data pointer stored by a user defined function
238 ** implementation calling sqlite3_set_auxdata() is stored in an instance
239 ** of this structure. All such structures associated with a single VM
240 ** are stored in a linked list headed at Vdbe.pAuxData. All are destroyed
241 ** when the VM is halted (if not before).
242 */
243 struct AuxData {
244   int iOp;                        /* Instruction number of OP_Function opcode */
245   int iArg;                       /* Index of function argument. */
246   void *pAux;                     /* Aux data pointer */
247   void (*xDelete)(void *);        /* Destructor for the aux data */
248   AuxData *pNext;                 /* Next element in list */
249 };
250 
251 /*
252 ** The "context" argument for a installable function.  A pointer to an
253 ** instance of this structure is the first argument to the routines used
254 ** implement the SQL functions.
255 **
256 ** There is a typedef for this structure in sqlite.h.  So all routines,
257 ** even the public interface to SQLite, can use a pointer to this structure.
258 ** But this file is the only place where the internal details of this
259 ** structure are known.
260 **
261 ** This structure is defined inside of vdbeInt.h because it uses substructures
262 ** (Mem) which are only defined there.
263 */
264 struct sqlite3_context {
265   FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
266   Mem s;                /* The return value is stored here */
267   Mem *pMem;            /* Memory cell used to store aggregate context */
268   CollSeq *pColl;       /* Collating sequence */
269   Vdbe *pVdbe;          /* The VM that owns this context */
270   int iOp;              /* Instruction number of OP_Function */
271   int isError;          /* Error code returned by the function. */
272   u8 skipFlag;          /* Skip skip accumulator loading if true */
273   u8 fErrorOrAux;       /* isError!=0 or pVdbe->pAuxData modified */
274 };
275 
276 /*
277 ** An Explain object accumulates indented output which is helpful
278 ** in describing recursive data structures.
279 */
280 struct Explain {
281   Vdbe *pVdbe;       /* Attach the explanation to this Vdbe */
282   StrAccum str;      /* The string being accumulated */
283   int nIndent;       /* Number of elements in aIndent */
284   u16 aIndent[100];  /* Levels of indentation */
285   char zBase[100];   /* Initial space */
286 };
287 
288 /* A bitfield type for use inside of structures.  Always follow with :N where
289 ** N is the number of bits.
290 */
291 typedef unsigned bft;  /* Bit Field Type */
292 
293 /*
294 ** An instance of the virtual machine.  This structure contains the complete
295 ** state of the virtual machine.
296 **
297 ** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
298 ** is really a pointer to an instance of this structure.
299 **
300 ** The Vdbe.inVtabMethod variable is set to non-zero for the duration of
301 ** any virtual table method invocations made by the vdbe program. It is
302 ** set to 2 for xDestroy method calls and 1 for all other methods. This
303 ** variable is used for two purposes: to allow xDestroy methods to execute
304 ** "DROP TABLE" statements and to prevent some nasty side effects of
305 ** malloc failure when SQLite is invoked recursively by a virtual table
306 ** method function.
307 */
308 struct Vdbe {
309   sqlite3 *db;            /* The database connection that owns this statement */
310   Op *aOp;                /* Space to hold the virtual machine's program */
311   Mem *aMem;              /* The memory locations */
312   Mem **apArg;            /* Arguments to currently executing user function */
313   Mem *aColName;          /* Column names to return */
314   Mem *pResultSet;        /* Pointer to an array of results */
315   Parse *pParse;          /* Parsing context used to create this Vdbe */
316   int nMem;               /* Number of memory locations currently allocated */
317   int nOp;                /* Number of instructions in the program */
318   int nCursor;            /* Number of slots in apCsr[] */
319   u32 magic;              /* Magic number for sanity checking */
320   char *zErrMsg;          /* Error message written here */
321   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
322   VdbeCursor **apCsr;     /* One element of this array for each open cursor */
323   Mem *aVar;              /* Values for the OP_Variable opcode. */
324   char **azVar;           /* Name of variables */
325   ynVar nVar;             /* Number of entries in aVar[] */
326   ynVar nzVar;            /* Number of entries in azVar[] */
327   u32 cacheCtr;           /* VdbeCursor row cache generation counter */
328   int pc;                 /* The program counter */
329   int rc;                 /* Value to return */
330   u16 nResColumn;         /* Number of columns in one row of the result set */
331   u8 errorAction;         /* Recovery action to do in case of an error */
332   u8 minWriteFileFormat;  /* Minimum file format for writable database files */
333   bft explain:2;          /* True if EXPLAIN present on SQL command */
334   bft inVtabMethod:2;     /* See comments above */
335   bft changeCntOn:1;      /* True to update the change-counter */
336   bft expired:1;          /* True if the VM needs to be recompiled */
337   bft runOnlyOnce:1;      /* Automatically expire on reset */
338   bft usesStmtJournal:1;  /* True if uses a statement journal */
339   bft readOnly:1;         /* True for statements that do not write */
340   bft bIsReader:1;        /* True for statements that read */
341   bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
342   bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
343   int nChange;            /* Number of db changes made since last reset */
344   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
345   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
346   int iStatement;         /* Statement number (or 0 if has not opened stmt) */
347   u32 aCounter[5];        /* Counters used by sqlite3_stmt_status() */
348 #ifndef SQLITE_OMIT_TRACE
349   i64 startTime;          /* Time when query started - used for profiling */
350 #endif
351   i64 iCurrentTime;       /* Value of julianday('now') for this statement */
352   i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
353   i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
354   i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
355   char *zSql;             /* Text of the SQL statement that generated this */
356   void *pFree;            /* Free this when deleting the vdbe */
357 #ifdef SQLITE_ENABLE_TREE_EXPLAIN
358   Explain *pExplain;      /* The explainer */
359   char *zExplain;         /* Explanation of data structures */
360 #endif
361   VdbeFrame *pFrame;      /* Parent frame */
362   VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
363   int nFrame;             /* Number of frames in pFrame list */
364   u32 expmask;            /* Binding to these vars invalidates VM */
365   SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
366   int nOnceFlag;          /* Size of array aOnceFlag[] */
367   u8 *aOnceFlag;          /* Flags for OP_Once */
368   AuxData *pAuxData;      /* Linked list of auxdata allocations */
369 };
370 
371 /*
372 ** The following are allowed values for Vdbe.magic
373 */
374 #define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
375 #define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
376 #define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
377 #define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
378 
379 /*
380 ** Function prototypes
381 */
382 void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
383 void sqliteVdbePopStack(Vdbe*,int);
384 int sqlite3VdbeCursorMoveto(VdbeCursor*);
385 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
386 void sqlite3VdbePrintOp(FILE*, int, Op*);
387 #endif
388 u32 sqlite3VdbeSerialTypeLen(u32);
389 u32 sqlite3VdbeSerialType(Mem*, int);
390 u32 sqlite3VdbeSerialPut(unsigned char*, Mem*, u32);
391 u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
392 void sqlite3VdbeDeleteAuxData(Vdbe*, int, int);
393 
394 int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
395 int sqlite3VdbeIdxKeyCompare(VdbeCursor*,UnpackedRecord*,int*);
396 int sqlite3VdbeIdxRowid(sqlite3*, BtCursor *, i64 *);
397 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
398 int sqlite3VdbeExec(Vdbe*);
399 int sqlite3VdbeList(Vdbe*);
400 int sqlite3VdbeHalt(Vdbe*);
401 int sqlite3VdbeChangeEncoding(Mem *, int);
402 int sqlite3VdbeMemTooBig(Mem*);
403 int sqlite3VdbeMemCopy(Mem*, const Mem*);
404 void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);
405 void sqlite3VdbeMemMove(Mem*, Mem*);
406 int sqlite3VdbeMemNulTerminate(Mem*);
407 int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));
408 void sqlite3VdbeMemSetInt64(Mem*, i64);
409 #ifdef SQLITE_OMIT_FLOATING_POINT
410 # define sqlite3VdbeMemSetDouble sqlite3VdbeMemSetInt64
411 #else
412   void sqlite3VdbeMemSetDouble(Mem*, double);
413 #endif
414 void sqlite3VdbeMemSetNull(Mem*);
415 void sqlite3VdbeMemSetZeroBlob(Mem*,int);
416 void sqlite3VdbeMemSetRowSet(Mem*);
417 int sqlite3VdbeMemMakeWriteable(Mem*);
418 int sqlite3VdbeMemStringify(Mem*, int);
419 i64 sqlite3VdbeIntValue(Mem*);
420 int sqlite3VdbeMemIntegerify(Mem*);
421 double sqlite3VdbeRealValue(Mem*);
422 void sqlite3VdbeIntegerAffinity(Mem*);
423 int sqlite3VdbeMemRealify(Mem*);
424 int sqlite3VdbeMemNumerify(Mem*);
425 int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,int,Mem*);
426 void sqlite3VdbeMemRelease(Mem *p);
427 void sqlite3VdbeMemReleaseExternal(Mem *p);
428 #define VdbeMemRelease(X)  \
429   if((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame)) \
430     sqlite3VdbeMemReleaseExternal(X);
431 int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
432 const char *sqlite3OpcodeName(int);
433 int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
434 int sqlite3VdbeCloseStatement(Vdbe *, int);
435 void sqlite3VdbeFrameDelete(VdbeFrame*);
436 int sqlite3VdbeFrameRestore(VdbeFrame *);
437 void sqlite3VdbeMemStoreType(Mem *pMem);
438 int sqlite3VdbeTransferError(Vdbe *p);
439 
440 int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
441 void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
442 int sqlite3VdbeSorterRowkey(const VdbeCursor *, Mem *);
443 int sqlite3VdbeSorterNext(sqlite3 *, const VdbeCursor *, int *);
444 int sqlite3VdbeSorterRewind(sqlite3 *, const VdbeCursor *, int *);
445 int sqlite3VdbeSorterWrite(sqlite3 *, const VdbeCursor *, Mem *);
446 int sqlite3VdbeSorterCompare(const VdbeCursor *, Mem *, int, int *);
447 
448 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
449   void sqlite3VdbeEnter(Vdbe*);
450   void sqlite3VdbeLeave(Vdbe*);
451 #else
452 # define sqlite3VdbeEnter(X)
453 # define sqlite3VdbeLeave(X)
454 #endif
455 
456 #ifdef SQLITE_DEBUG
457 void sqlite3VdbeMemAboutToChange(Vdbe*,Mem*);
458 #endif
459 
460 #ifndef SQLITE_OMIT_FOREIGN_KEY
461 int sqlite3VdbeCheckFk(Vdbe *, int);
462 #else
463 # define sqlite3VdbeCheckFk(p,i) 0
464 #endif
465 
466 int sqlite3VdbeMemTranslate(Mem*, u8);
467 #ifdef SQLITE_DEBUG
468   void sqlite3VdbePrintSql(Vdbe*);
469   void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
470 #endif
471 int sqlite3VdbeMemHandleBom(Mem *pMem);
472 
473 #ifndef SQLITE_OMIT_INCRBLOB
474   int sqlite3VdbeMemExpandBlob(Mem *);
475   #define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
476 #else
477   #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK
478   #define ExpandBlob(P) SQLITE_OK
479 #endif
480 
481 #endif /* !defined(_VDBEINT_H_) */
482