xref: /sqlite-3.40.0/src/vdbeInt.h (revision 50f79f56)
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_TypeMask  0x00ff   /* Mask of type bits */
191 
192 /* Whenever Mem contains a valid string or blob representation, one of
193 ** the following flags must be set to determine the memory management
194 ** policy for Mem.z.  The MEM_Term flag tells us whether or not the
195 ** string is \000 or \u0000 terminated
196 */
197 #define MEM_Term      0x0200   /* String rep is nul terminated */
198 #define MEM_Dyn       0x0400   /* Need to call sqliteFree() on Mem.z */
199 #define MEM_Static    0x0800   /* Mem.z points to a static string */
200 #define MEM_Ephem     0x1000   /* Mem.z points to an ephemeral string */
201 #define MEM_Agg       0x2000   /* Mem.z points to an agg function context */
202 #define MEM_Zero      0x4000   /* Mem.i contains count of 0s appended to blob */
203 #ifdef SQLITE_OMIT_INCRBLOB
204   #undef MEM_Zero
205   #define MEM_Zero 0x0000
206 #endif
207 
208 /*
209 ** Clear any existing type flags from a Mem and replace them with f
210 */
211 #define MemSetTypeFlag(p, f) \
212    ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)
213 
214 /*
215 ** Return true if a memory cell is not marked as invalid.  This macro
216 ** is for use inside assert() statements only.
217 */
218 #ifdef SQLITE_DEBUG
219 #define memIsValid(M)  ((M)->flags & MEM_Invalid)==0
220 #endif
221 
222 
223 /* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains
224 ** additional information about auxiliary information bound to arguments
225 ** of the function.  This is used to implement the sqlite3_get_auxdata()
226 ** and sqlite3_set_auxdata() APIs.  The "auxdata" is some auxiliary data
227 ** that can be associated with a constant argument to a function.  This
228 ** allows functions such as "regexp" to compile their constant regular
229 ** expression argument once and reused the compiled code for multiple
230 ** invocations.
231 */
232 struct VdbeFunc {
233   FuncDef *pFunc;               /* The definition of the function */
234   int nAux;                     /* Number of entries allocated for apAux[] */
235   struct AuxData {
236     void *pAux;                   /* Aux data for the i-th argument */
237     void (*xDelete)(void *);      /* Destructor for the aux data */
238   } apAux[1];                   /* One slot for each function argument */
239 };
240 
241 /*
242 ** The "context" argument for a installable function.  A pointer to an
243 ** instance of this structure is the first argument to the routines used
244 ** implement the SQL functions.
245 **
246 ** There is a typedef for this structure in sqlite.h.  So all routines,
247 ** even the public interface to SQLite, can use a pointer to this structure.
248 ** But this file is the only place where the internal details of this
249 ** structure are known.
250 **
251 ** This structure is defined inside of vdbeInt.h because it uses substructures
252 ** (Mem) which are only defined there.
253 */
254 struct sqlite3_context {
255   FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
256   VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
257   Mem s;                /* The return value is stored here */
258   Mem *pMem;            /* Memory cell used to store aggregate context */
259   CollSeq *pColl;       /* Collating sequence */
260   int isError;          /* Error code returned by the function. */
261   int skipFlag;         /* Skip skip accumulator loading if true */
262 };
263 
264 /*
265 ** An Explain object accumulates indented output which is helpful
266 ** in describing recursive data structures.
267 */
268 struct Explain {
269   Vdbe *pVdbe;       /* Attach the explanation to this Vdbe */
270   StrAccum str;      /* The string being accumulated */
271   int nIndent;       /* Number of elements in aIndent */
272   u16 aIndent[100];  /* Levels of indentation */
273   char zBase[100];   /* Initial space */
274 };
275 
276 /*
277 ** An instance of the virtual machine.  This structure contains the complete
278 ** state of the virtual machine.
279 **
280 ** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
281 ** is really a pointer to an instance of this structure.
282 **
283 ** The Vdbe.inVtabMethod variable is set to non-zero for the duration of
284 ** any virtual table method invocations made by the vdbe program. It is
285 ** set to 2 for xDestroy method calls and 1 for all other methods. This
286 ** variable is used for two purposes: to allow xDestroy methods to execute
287 ** "DROP TABLE" statements and to prevent some nasty side effects of
288 ** malloc failure when SQLite is invoked recursively by a virtual table
289 ** method function.
290 */
291 struct Vdbe {
292   sqlite3 *db;            /* The database connection that owns this statement */
293   Op *aOp;                /* Space to hold the virtual machine's program */
294   Mem *aMem;              /* The memory locations */
295   Mem **apArg;            /* Arguments to currently executing user function */
296   Mem *aColName;          /* Column names to return */
297   Mem *pResultSet;        /* Pointer to an array of results */
298   int nMem;               /* Number of memory locations currently allocated */
299   int nOp;                /* Number of instructions in the program */
300   int nOpAlloc;           /* Number of slots allocated for aOp[] */
301   int nLabel;             /* Number of labels used */
302   int *aLabel;            /* Space to hold the labels */
303   u16 nResColumn;         /* Number of columns in one row of the result set */
304   u16 nCursor;            /* Number of slots in apCsr[] */
305   u32 magic;              /* Magic number for sanity checking */
306   char *zErrMsg;          /* Error message written here */
307   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
308   VdbeCursor **apCsr;     /* One element of this array for each open cursor */
309   Mem *aVar;              /* Values for the OP_Variable opcode. */
310   char **azVar;           /* Name of variables */
311   ynVar nVar;             /* Number of entries in aVar[] */
312   ynVar nzVar;            /* Number of entries in azVar[] */
313   u32 cacheCtr;           /* VdbeCursor row cache generation counter */
314   int pc;                 /* The program counter */
315   int rc;                 /* Value to return */
316   u8 errorAction;         /* Recovery action to do in case of an error */
317   u8 explain;             /* True if EXPLAIN present on SQL command */
318   u8 changeCntOn;         /* True to update the change-counter */
319   u8 expired;             /* True if the VM needs to be recompiled */
320   u8 runOnlyOnce;         /* Automatically expire on reset */
321   u8 minWriteFileFormat;  /* Minimum file format for writable database files */
322   u8 inVtabMethod;        /* See comments above */
323   u8 usesStmtJournal;     /* True if uses a statement journal */
324   u8 readOnly;            /* True for read-only statements */
325   u8 isPrepareV2;         /* True if prepared with prepare_v2() */
326   int nChange;            /* Number of db changes made since last reset */
327   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
328   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
329   int iStatement;         /* Statement number (or 0 if has not opened stmt) */
330   int aCounter[3];        /* Counters used by sqlite3_stmt_status() */
331 #ifndef SQLITE_OMIT_TRACE
332   i64 startTime;          /* Time when query started - used for profiling */
333 #endif
334   i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
335   i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
336   char *zSql;             /* Text of the SQL statement that generated this */
337   void *pFree;            /* Free this when deleting the vdbe */
338 #ifdef SQLITE_DEBUG
339   FILE *trace;            /* Write an execution trace here, if not NULL */
340 #endif
341 #ifdef SQLITE_ENABLE_TREE_EXPLAIN
342   Explain *pExplain;      /* The explainer */
343   char *zExplain;         /* Explanation of data structures */
344 #endif
345   VdbeFrame *pFrame;      /* Parent frame */
346   VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
347   int nFrame;             /* Number of frames in pFrame list */
348   u32 expmask;            /* Binding to these vars invalidates VM */
349   SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
350   int nOnceFlag;          /* Size of array aOnceFlag[] */
351   u8 *aOnceFlag;          /* Flags for OP_Once */
352 };
353 
354 /*
355 ** The following are allowed values for Vdbe.magic
356 */
357 #define VDBE_MAGIC_INIT     0x26bceaa5    /* Building a VDBE program */
358 #define VDBE_MAGIC_RUN      0xbdf20da3    /* VDBE is ready to execute */
359 #define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
360 #define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
361 
362 /*
363 ** Function prototypes
364 */
365 void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
366 void sqliteVdbePopStack(Vdbe*,int);
367 int sqlite3VdbeCursorMoveto(VdbeCursor*);
368 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
369 void sqlite3VdbePrintOp(FILE*, int, Op*);
370 #endif
371 u32 sqlite3VdbeSerialTypeLen(u32);
372 u32 sqlite3VdbeSerialType(Mem*, int);
373 u32 sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
374 u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
375 void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);
376 
377 int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
378 int sqlite3VdbeIdxKeyCompare(VdbeCursor*,UnpackedRecord*,int*);
379 int sqlite3VdbeIdxRowid(sqlite3*, BtCursor *, i64 *);
380 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
381 int sqlite3VdbeExec(Vdbe*);
382 int sqlite3VdbeList(Vdbe*);
383 int sqlite3VdbeHalt(Vdbe*);
384 int sqlite3VdbeChangeEncoding(Mem *, int);
385 int sqlite3VdbeMemTooBig(Mem*);
386 int sqlite3VdbeMemCopy(Mem*, const Mem*);
387 void sqlite3VdbeMemShallowCopy(Mem*, const Mem*, int);
388 void sqlite3VdbeMemMove(Mem*, Mem*);
389 int sqlite3VdbeMemNulTerminate(Mem*);
390 int sqlite3VdbeMemSetStr(Mem*, const char*, int, u8, void(*)(void*));
391 void sqlite3VdbeMemSetInt64(Mem*, i64);
392 #ifdef SQLITE_OMIT_FLOATING_POINT
393 # define sqlite3VdbeMemSetDouble sqlite3VdbeMemSetInt64
394 #else
395   void sqlite3VdbeMemSetDouble(Mem*, double);
396 #endif
397 void sqlite3VdbeMemSetNull(Mem*);
398 void sqlite3VdbeMemSetZeroBlob(Mem*,int);
399 void sqlite3VdbeMemSetRowSet(Mem*);
400 int sqlite3VdbeMemMakeWriteable(Mem*);
401 int sqlite3VdbeMemStringify(Mem*, int);
402 i64 sqlite3VdbeIntValue(Mem*);
403 int sqlite3VdbeMemIntegerify(Mem*);
404 double sqlite3VdbeRealValue(Mem*);
405 void sqlite3VdbeIntegerAffinity(Mem*);
406 int sqlite3VdbeMemRealify(Mem*);
407 int sqlite3VdbeMemNumerify(Mem*);
408 int sqlite3VdbeMemFromBtree(BtCursor*,int,int,int,Mem*);
409 void sqlite3VdbeMemRelease(Mem *p);
410 void sqlite3VdbeMemReleaseExternal(Mem *p);
411 #define VdbeMemRelease(X)  \
412   if((X)->flags&(MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame)) \
413     sqlite3VdbeMemReleaseExternal(X);
414 int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
415 const char *sqlite3OpcodeName(int);
416 int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
417 int sqlite3VdbeCloseStatement(Vdbe *, int);
418 void sqlite3VdbeFrameDelete(VdbeFrame*);
419 int sqlite3VdbeFrameRestore(VdbeFrame *);
420 void sqlite3VdbeMemStoreType(Mem *pMem);
421 int sqlite3VdbeTransferError(Vdbe *p);
422 
423 #ifdef SQLITE_OMIT_MERGE_SORT
424 # define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
425 # define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
426 # define sqlite3VdbeSorterClose(Y,Z)
427 # define sqlite3VdbeSorterRowkey(Y,Z)    SQLITE_OK
428 # define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
429 # define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK
430 # define sqlite3VdbeSorterCompare(X,Y,Z) SQLITE_OK
431 #else
432 int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
433 void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
434 int sqlite3VdbeSorterRowkey(VdbeCursor *, Mem *);
435 int sqlite3VdbeSorterNext(sqlite3 *, VdbeCursor *, int *);
436 int sqlite3VdbeSorterRewind(sqlite3 *, VdbeCursor *, int *);
437 int sqlite3VdbeSorterWrite(sqlite3 *, VdbeCursor *, Mem *);
438 int sqlite3VdbeSorterCompare(VdbeCursor *, Mem *, int *);
439 #endif
440 
441 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
442   void sqlite3VdbeEnter(Vdbe*);
443   void sqlite3VdbeLeave(Vdbe*);
444 #else
445 # define sqlite3VdbeEnter(X)
446 # define sqlite3VdbeLeave(X)
447 #endif
448 
449 #ifdef SQLITE_DEBUG
450 void sqlite3VdbeMemAboutToChange(Vdbe*,Mem*);
451 #endif
452 
453 #ifndef SQLITE_OMIT_FOREIGN_KEY
454 int sqlite3VdbeCheckFk(Vdbe *, int);
455 #else
456 # define sqlite3VdbeCheckFk(p,i) 0
457 #endif
458 
459 int sqlite3VdbeMemTranslate(Mem*, u8);
460 #ifdef SQLITE_DEBUG
461   void sqlite3VdbePrintSql(Vdbe*);
462   void sqlite3VdbeMemPrettyPrint(Mem *pMem, char *zBuf);
463 #endif
464 int sqlite3VdbeMemHandleBom(Mem *pMem);
465 
466 #ifndef SQLITE_OMIT_INCRBLOB
467   int sqlite3VdbeMemExpandBlob(Mem *);
468   #define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
469 #else
470   #define sqlite3VdbeMemExpandBlob(x) SQLITE_OK
471   #define ExpandBlob(P) SQLITE_OK
472 #endif
473 
474 #endif /* !defined(_VDBEINT_H_) */
475