xref: /sqlite-3.40.0/src/vdbeInt.h (revision 8749c183)
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 ** SQL is translated into a sequence of instructions to be
23 ** executed by a virtual machine.  Each instruction is an instance
24 ** of the following structure.
25 */
26 typedef struct VdbeOp Op;
27 
28 /*
29 ** Boolean values
30 */
31 typedef unsigned char Bool;
32 
33 /* Opaque type used by code in vdbesort.c */
34 typedef struct VdbeSorter VdbeSorter;
35 
36 /* Opaque type used by the explainer */
37 typedef struct Explain Explain;
38 
39 /*
40 ** A cursor is a pointer into a single BTree within a database file.
41 ** The cursor can seek to a BTree entry with a particular key, or
42 ** loop over all entries of the Btree.  You can also insert new BTree
43 ** entries or retrieve the key or data from the entry that the cursor
44 ** is currently pointing to.
45 **
46 ** Every cursor that the virtual machine has open is represented by an
47 ** instance of the following structure.
48 */
49 struct VdbeCursor {
50   BtCursor *pCursor;    /* The cursor structure of the backend */
51   Btree *pBt;           /* Separate file holding temporary table */
52   KeyInfo *pKeyInfo;    /* Info about index keys needed by index cursors */
53   int iDb;              /* Index of cursor database in db->aDb[] (or -1) */
54   int pseudoTableReg;   /* Register holding pseudotable content. */
55   int nField;           /* Number of fields in the header */
56   Bool zeroed;          /* True if zeroed out and ready for reuse */
57   Bool rowidIsValid;    /* True if lastRowid is valid */
58   Bool atFirst;         /* True if pointing to first entry */
59   Bool useRandomRowid;  /* Generate new record numbers semi-randomly */
60   Bool nullRow;         /* True if pointing to a row with no data */
61   Bool deferredMoveto;  /* A call to sqlite3BtreeMoveto() is needed */
62   Bool isTable;         /* True if a table requiring integer keys */
63   Bool isIndex;         /* True if an index containing keys only - no data */
64   Bool isOrdered;       /* True if the underlying table is BTREE_UNORDERED */
65   Bool isSorter;        /* True if a new-style sorter */
66   sqlite3_vtab_cursor *pVtabCursor;  /* The cursor for a virtual table */
67   const sqlite3_module *pModule;     /* Module for cursor pVtabCursor */
68   i64 seqCount;         /* Sequence counter */
69   i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
70   i64 lastRowid;        /* Last rowid from a Next or NextIdx operation */
71   VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
72 
73   /* Result of last sqlite3BtreeMoveto() done by an OP_NotExists or
74   ** OP_IsUnique opcode on this cursor. */
75   int seekResult;
76 
77   /* Cached information about the header for the data record that the
78   ** cursor is currently pointing to.  Only valid if cacheStatus matches
79   ** Vdbe.cacheCtr.  Vdbe.cacheCtr will never take on the value of
80   ** CACHE_STALE and so setting cacheStatus=CACHE_STALE guarantees that
81   ** the cache is out of date.
82   **
83   ** aRow might point to (ephemeral) data for the current row, or it might
84   ** be NULL.
85   */
86   u32 cacheStatus;      /* Cache is valid if this matches Vdbe.cacheCtr */
87   int payloadSize;      /* Total number of bytes in the record */
88   u32 *aType;           /* Type values for all entries in the record */
89   u32 *aOffset;         /* Cached offsets to the start of each columns data */
90   u8 *aRow;             /* Data for the current row, if all on one page */
91 };
92 typedef struct VdbeCursor VdbeCursor;
93 
94 /*
95 ** When a sub-program is executed (OP_Program), a structure of this type
96 ** is allocated to store the current value of the program counter, as
97 ** well as the current memory cell array and various other frame specific
98 ** values stored in the Vdbe struct. When the sub-program is finished,
99 ** these values are copied back to the Vdbe from the VdbeFrame structure,
100 ** restoring the state of the VM to as it was before the sub-program
101 ** began executing.
102 **
103 ** The memory for a VdbeFrame object is allocated and managed by a memory
104 ** cell in the parent (calling) frame. When the memory cell is deleted or
105 ** overwritten, the VdbeFrame object is not freed immediately. Instead, it
106 ** is linked into the Vdbe.pDelFrame list. The contents of the Vdbe.pDelFrame
107 ** list is deleted when the VM is reset in VdbeHalt(). The reason for doing
108 ** this instead of deleting the VdbeFrame immediately is to avoid recursive
109 ** calls to sqlite3VdbeMemRelease() when the memory cells belonging to the
110 ** child frame are released.
111 **
112 ** The currently executing frame is stored in Vdbe.pFrame. Vdbe.pFrame is
113 ** set to NULL if the currently executing frame is the main program.
114 */
115 typedef struct VdbeFrame VdbeFrame;
116 struct VdbeFrame {
117   Vdbe *v;                /* VM this frame belongs to */
118   VdbeFrame *pParent;     /* Parent of this frame, or NULL if parent is main */
119   Op *aOp;                /* Program instructions for parent frame */
120   Mem *aMem;              /* Array of memory cells for parent frame */
121   u8 *aOnceFlag;          /* Array of OP_Once flags for parent frame */
122   VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
123   void *token;            /* Copy of SubProgram.token */
124   i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
125   u16 nCursor;            /* Number of entries in apCsr */
126   int pc;                 /* Program Counter in parent (calling) frame */
127   int nOp;                /* Size of aOp array */
128   int nMem;               /* Number of entries in aMem */
129   int nOnceFlag;          /* Number of entries in aOnceFlag */
130   int nChildMem;          /* Number of memory cells for child frame */
131   int nChildCsr;          /* Number of cursors for child frame */
132   int nChange;            /* Statement changes (Vdbe.nChanges)     */
133 };
134 
135 #define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])
136 
137 /*
138 ** A value for VdbeCursor.cacheValid that means the cache is always invalid.
139 */
140 #define CACHE_STALE 0
141 
142 /*
143 ** Internally, the vdbe manipulates nearly all SQL values as Mem
144 ** structures. Each Mem struct may cache multiple representations (string,
145 ** integer etc.) of the same value.
146 */
147 struct Mem {
148   sqlite3 *db;        /* The associated database connection */
149   char *z;            /* String or BLOB value */
150   double r;           /* Real value */
151   union {
152     i64 i;              /* Integer value used when MEM_Int is set in flags */
153     int nZero;          /* Used when bit MEM_Zero is set in flags */
154     FuncDef *pDef;      /* Used only when flags==MEM_Agg */
155     RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
156     VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
157   } u;
158   int n;              /* Number of characters in string value, excluding '\0' */
159   u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
160   u8  type;           /* One of SQLITE_NULL, SQLITE_TEXT, SQLITE_INTEGER, etc */
161   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
162 #ifdef SQLITE_DEBUG
163   Mem *pScopyFrom;    /* This Mem is a shallow copy of pScopyFrom */
164   void *pFiller;      /* So that sizeof(Mem) is a multiple of 8 */
165 #endif
166   void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
167   char *zMalloc;      /* Dynamic buffer allocated by sqlite3_malloc() */
168 };
169 
170 /* One or more of the following flags are set to indicate the validOK
171 ** representations of the value stored in the Mem struct.
172 **
173 ** If the MEM_Null flag is set, then the value is an SQL NULL value.
174 ** No other flags may be set in this case.
175 **
176 ** If the MEM_Str flag is set then Mem.z points at a string representation.
177 ** Usually this is encoded in the same unicode encoding as the main
178 ** database (see below for exceptions). If the MEM_Term flag is also
179 ** set, then the string is nul terminated. The MEM_Int and MEM_Real
180 ** flags may coexist with the MEM_Str flag.
181 */
182 #define MEM_Null      0x0001   /* Value is NULL */
183 #define MEM_Str       0x0002   /* Value is a string */
184 #define MEM_Int       0x0004   /* Value is an integer */
185 #define MEM_Real      0x0008   /* Value is a real number */
186 #define MEM_Blob      0x0010   /* Value is a BLOB */
187 #define MEM_RowSet    0x0020   /* Value is a RowSet object */
188 #define MEM_Frame     0x0040   /* Value is a VdbeFrame object */
189 #define MEM_Invalid   0x0080   /* Value is undefined */
190 #define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
191 #define MEM_TypeMask  0x01ff   /* Mask of type bits */
192 
193 
194 /* Whenever Mem contains a valid string or blob representation, one of
195 ** the following flags must be set to determine the memory management
196 ** policy for Mem.z.  The MEM_Term flag tells us whether or not the
197 ** string is \000 or \u0000 terminated
198 */
199 #define MEM_Term      0x0200   /* String rep is nul terminated */
200 #define MEM_Dyn       0x0400   /* Need to call sqliteFree() on Mem.z */
201 #define MEM_Static    0x0800   /* Mem.z points to a static string */
202 #define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */
203 #define MEM_Agg       0x2000   /* Mem.z points to an agg function context */
204 #define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */
205 #ifdef SQLITE_OMIT_INCRBLOB
206   #undef MEM_Zero
207   #define MEM_Zero 0x0000
208 #endif
209 
210 /*
211 ** Clear any existing type flags from a Mem and replace them with f
212 */
213 #define MemSetTypeFlag(p, f) \
214    ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)
215 
216 /*
217 ** Return true if a memory cell is not marked as invalid.  This macro
218 ** is for use inside assert() statements only.
219 */
220 #ifdef SQLITE_DEBUG
221 #define memIsValid(M)  ((M)->flags & MEM_Invalid)==0
222 #endif
223 
224 
225 /* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains
226 ** additional information about auxiliary information bound to arguments
227 ** of the function.  This is used to implement the sqlite3_get_auxdata()
228 ** and sqlite3_set_auxdata() APIs.  The "auxdata" is some auxiliary data
229 ** that can be associated with a constant argument to a function.  This
230 ** allows functions such as "regexp" to compile their constant regular
231 ** expression argument once and reused the compiled code for multiple
232 ** invocations.
233 */
234 struct VdbeFunc {
235   FuncDef *pFunc;               /* The definition of the function */
236   int nAux;                     /* Number of entries allocated for apAux[] */
237   struct AuxData {
238     void *pAux;                   /* Aux data for the i-th argument */
239     void (*xDelete)(void *);      /* Destructor for the aux data */
240   } apAux[1];                   /* One slot for each function argument */
241 };
242 
243 /*
244 ** The "context" argument for a installable function.  A pointer to an
245 ** instance of this structure is the first argument to the routines used
246 ** implement the SQL functions.
247 **
248 ** There is a typedef for this structure in sqlite.h.  So all routines,
249 ** even the public interface to SQLite, can use a pointer to this structure.
250 ** But this file is the only place where the internal details of this
251 ** structure are known.
252 **
253 ** This structure is defined inside of vdbeInt.h because it uses substructures
254 ** (Mem) which are only defined there.
255 */
256 struct sqlite3_context {
257   FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
258   VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
259   Mem s;                /* The return value is stored here */
260   Mem *pMem;            /* Memory cell used to store aggregate context */
261   CollSeq *pColl;       /* Collating sequence */
262   int isError;          /* Error code returned by the function. */
263   int skipFlag;         /* Skip skip accumulator loading if true */
264 };
265 
266 /*
267 ** An Explain object accumulates indented output which is helpful
268 ** in describing recursive data structures.
269 */
270 struct Explain {
271   Vdbe *pVdbe;       /* Attach the explanation to this Vdbe */
272   StrAccum str;      /* The string being accumulated */
273   int nIndent;       /* Number of elements in aIndent */
274   u16 aIndent[100];  /* Levels of indentation */
275   char zBase[100];   /* Initial space */
276 };
277 
278 /* A bitfield type for use inside of structures.  Always follow with :N where
279 ** N is the number of bits.
280 */
281 typedef unsigned bft;  /* Bit Field Type */
282 
283 /*
284 ** An instance of the virtual machine.  This structure contains the complete
285 ** state of the virtual machine.
286 **
287 ** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
288 ** is really a pointer to an instance of this structure.
289 **
290 ** The Vdbe.inVtabMethod variable is set to non-zero for the duration of
291 ** any virtual table method invocations made by the vdbe program. It is
292 ** set to 2 for xDestroy method calls and 1 for all other methods. This
293 ** variable is used for two purposes: to allow xDestroy methods to execute
294 ** "DROP TABLE" statements and to prevent some nasty side effects of
295 ** malloc failure when SQLite is invoked recursively by a virtual table
296 ** method function.
297 */
298 struct Vdbe {
299   sqlite3 *db;            /* The database connection that owns this statement */
300   Op *aOp;                /* Space to hold the virtual machine's program */
301   Mem *aMem;              /* The memory locations */
302   Mem **apArg;            /* Arguments to currently executing user function */
303   Mem *aColName;          /* Column names to return */
304   Mem *pResultSet;        /* Pointer to an array of results */
305   int nMem;               /* Number of memory locations currently allocated */
306   int nOp;                /* Number of instructions in the program */
307   int nOpAlloc;           /* Number of slots allocated for aOp[] */
308   int nLabel;             /* Number of labels used */
309   int *aLabel;            /* Space to hold the labels */
310   u16 nResColumn;         /* Number of columns in one row of the result set */
311   u16 nCursor;            /* Number of slots in apCsr[] */
312   u32 magic;              /* Magic number for sanity checking */
313   char *zErrMsg;          /* Error message written here */
314   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
315   VdbeCursor **apCsr;     /* One element of this array for each open cursor */
316   Mem *aVar;              /* Values for the OP_Variable opcode. */
317   char **azVar;           /* Name of variables */
318   ynVar nVar;             /* Number of entries in aVar[] */
319   ynVar nzVar;            /* Number of entries in azVar[] */
320   u32 cacheCtr;           /* VdbeCursor row cache generation counter */
321   int pc;                 /* The program counter */
322   int rc;                 /* Value to return */
323   u8 errorAction;         /* Recovery action to do in case of an error */
324   u8 minWriteFileFormat;  /* Minimum file format for writable database files */
325   bft explain:2;          /* True if EXPLAIN present on SQL command */
326   bft inVtabMethod:2;     /* See comments above */
327   bft changeCntOn:1;      /* True to update the change-counter */
328   bft expired:1;          /* True if the VM needs to be recompiled */
329   bft runOnlyOnce:1;      /* Automatically expire on reset */
330   bft usesStmtJournal:1;  /* True if uses a statement journal */
331   bft readOnly:1;         /* True for read-only statements */
332   bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
333   bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
334   int nChange;            /* Number of db changes made since last reset */
335   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
336   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
337   int iStatement;         /* Statement number (or 0 if has not opened stmt) */
338   int aCounter[3];        /* Counters used by sqlite3_stmt_status() */
339 #ifndef SQLITE_OMIT_TRACE
340   i64 startTime;          /* Time when query started - used for profiling */
341 #endif
342   i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
343   i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
344   char *zSql;             /* Text of the SQL statement that generated this */
345   void *pFree;            /* Free this when deleting the vdbe */
346 #ifdef SQLITE_DEBUG
347   FILE *trace;            /* Write an execution trace here, if not NULL */
348 #endif
349 #ifdef SQLITE_ENABLE_TREE_EXPLAIN
350   Explain *pExplain;      /* The explainer */
351   char *zExplain;         /* Explanation of data structures */
352 #endif
353   VdbeFrame *pFrame;      /* Parent frame */
354   VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
355   int nFrame;             /* Number of frames in pFrame list */
356   u32 expmask;            /* Binding to these vars invalidates VM */
357   SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
358   int nOnceFlag;          /* Size of array aOnceFlag[] */
359   u8 *aOnceFlag;          /* Flags for OP_Once */
360 };
361 
362 /*
363 ** The following are allowed values for Vdbe.magic
364 */
365 #define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
366 #define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
367 #define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
368 #define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
369 
370 /*
371 ** Function prototypes
372 */
373 void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
374 void sqliteVdbePopStack(Vdbe*,int);
375 int sqlite3VdbeCursorMoveto(VdbeCursor*);
376 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
377 void sqlite3VdbePrintOp(FILE*, int, Op*);
378 #endif
379 u32 sqlite3VdbeSerialTypeLen(u32);
380 u32 sqlite3VdbeSerialType(Mem*, int);
381 u32 sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
382 u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
383 void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);
384 
385 int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
386 int sqlite3VdbeIdxKeyCompare(VdbeCursor*,UnpackedRecord*,int*);
387 int sqlite3VdbeIdxRowid(sqlite3*, BtCursor *, i64 *);
388 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
389 int sqlite3VdbeExec(Vdbe*);
390 int sqlite3VdbeList(Vdbe*);
391 int sqlite3VdbeHalt(Vdbe*);
392 int sqlite3VdbeChangeEncoding(Mem *, int);
393 int sqlite3VdbeMemTooBig(Mem*);
394 int sqlite3VdbeMemCopy(Mem*, const Mem*);
395 void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);
396 void sqlite3VdbeMemMove(Mem*, Mem*);
397 int sqlite3VdbeMemNulTerminate(Mem*);
398 int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));
399 void sqlite3VdbeMemSetInt64(Mem*, i64);
400 #ifdef SQLITE_OMIT_FLOATING_POINT
401 # define sqlite3VdbeMemSetDouble sqlite3VdbeMemSetInt64
402 #else
403   void sqlite3VdbeMemSetDouble(Mem*, double);
404 #endif
405 void sqlite3VdbeMemSetNull(Mem*);
406 void sqlite3VdbeMemSetZeroBlob(Mem*,int);
407 void sqlite3VdbeMemSetRowSet(Mem*);
408 int sqlite3VdbeMemMakeWriteable(Mem*);
409 int sqlite3VdbeMemStringify(Mem*, int);
410 i64 sqlite3VdbeIntValue(Mem*);
411 int sqlite3VdbeMemIntegerify(Mem*);
412 double sqlite3VdbeRealValue(Mem*);
413 void sqlite3VdbeIntegerAffinity(Mem*);
414 int sqlite3VdbeMemRealify(Mem*);
415 int sqlite3VdbeMemNumerify(Mem*);
416 int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
417 void sqlite3VdbeMemRelease(Mem *p);
418 void sqlite3VdbeMemReleaseExternal(Mem *p);
419 #define VdbeMemRelease(X)  \
420   if((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame)) \
421     sqlite3VdbeMemReleaseExternal(X);
422 int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
423 const char *sqlite3OpcodeName(int);
424 int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
425 int sqlite3VdbeCloseStatement(Vdbe *, int);
426 void sqlite3VdbeFrameDelete(VdbeFrame*);
427 int sqlite3VdbeFrameRestore(VdbeFrame *);
428 void sqlite3VdbeMemStoreType(Mem *pMem);
429 int sqlite3VdbeTransferError(Vdbe *p);
430 
431 #ifdef SQLITE_OMIT_MERGE_SORT
432 # define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
433 # define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
434 # define sqlite3VdbeSorterClose(Y,Z)
435 # define sqlite3VdbeSorterRowkey(Y,Z)    SQLITE_OK
436 # define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
437 # define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK
438 # define sqlite3VdbeSorterCompare(X,Y,Z) SQLITE_OK
439 #else
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 *);
447 #endif
448 
449 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
450   void sqlite3VdbeEnter(Vdbe*);
451   void sqlite3VdbeLeave(Vdbe*);
452 #else
453 # define sqlite3VdbeEnter(X)
454 # define sqlite3VdbeLeave(X)
455 #endif
456 
457 #ifdef SQLITE_DEBUG
458 void sqlite3VdbeMemAboutToChange(Vdbe*,Mem*);
459 #endif
460 
461 #ifndef SQLITE_OMIT_FOREIGN_KEY
462 int sqlite3VdbeCheckFk(Vdbe *, int);
463 #else
464 # define sqlite3VdbeCheckFk(p,i) 0
465 #endif
466 
467 int sqlite3VdbeMemTranslate(Mem*, u8);
468 #ifdef SQLITE_DEBUG
469   void sqlite3VdbePrintSql(Vdbe*);
470   void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
471 #endif
472 int sqlite3VdbeMemHandleBom(Mem *pMem);
473 
474 #ifndef SQLITE_OMIT_INCRBLOB
475   int sqlite3VdbeMemExpandBlob(Mem *);
476   #define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
477 #else
478   #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK
479   #define ExpandBlob(P) SQLITE_OK
480 #endif
481 
482 #endif /* !defined(_VDBEINT_H_) */
483