xref: /sqlite-3.40.0/src/vdbe.h (revision e99cb2da)
1 /*
2 ** 2001 September 15
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 ** Header file for the Virtual DataBase Engine (VDBE)
13 **
14 ** This header defines the interface to the virtual database engine
15 ** or VDBE.  The VDBE implements an abstract machine that runs a
16 ** simple program to access and modify the underlying database.
17 */
18 #ifndef SQLITE_VDBE_H
19 #define SQLITE_VDBE_H
20 #include <stdio.h>
21 
22 /*
23 ** A single VDBE is an opaque structure named "Vdbe".  Only routines
24 ** in the source file sqliteVdbe.c are allowed to see the insides
25 ** of this structure.
26 */
27 typedef struct Vdbe Vdbe;
28 
29 /*
30 ** The names of the following types declared in vdbeInt.h are required
31 ** for the VdbeOp definition.
32 */
33 typedef struct sqlite3_value Mem;
34 typedef struct SubProgram SubProgram;
35 
36 /*
37 ** A single instruction of the virtual machine has an opcode
38 ** and as many as three operands.  The instruction is recorded
39 ** as an instance of the following structure:
40 */
41 struct VdbeOp {
42   u8 opcode;          /* What operation to perform */
43   signed char p4type; /* One of the P4_xxx constants for p4 */
44   u16 p5;             /* Fifth parameter is an unsigned 16-bit integer */
45   int p1;             /* First operand */
46   int p2;             /* Second parameter (often the jump destination) */
47   int p3;             /* The third parameter */
48   union p4union {     /* fourth parameter */
49     int i;                 /* Integer value if p4type==P4_INT32 */
50     void *p;               /* Generic pointer */
51     char *z;               /* Pointer to data for string (char array) types */
52     i64 *pI64;             /* Used when p4type is P4_INT64 */
53     double *pReal;         /* Used when p4type is P4_REAL */
54     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
55     sqlite3_context *pCtx; /* Used when p4type is P4_FUNCCTX */
56     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
57     Mem *pMem;             /* Used when p4type is P4_MEM */
58     VTable *pVtab;         /* Used when p4type is P4_VTAB */
59     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
60     int *ai;               /* Used when p4type is P4_INTARRAY */
61     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
62     Table *pTab;           /* Used when p4type is P4_TABLE */
63 #ifdef SQLITE_ENABLE_CURSOR_HINTS
64     Expr *pExpr;           /* Used when p4type is P4_EXPR */
65 #endif
66     int (*xAdvance)(BtCursor *, int);
67   } p4;
68 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
69   char *zComment;          /* Comment to improve readability */
70 #endif
71 #ifdef VDBE_PROFILE
72   u32 cnt;                 /* Number of times this instruction was executed */
73   u64 cycles;              /* Total time spent executing this instruction */
74 #endif
75 #ifdef SQLITE_VDBE_COVERAGE
76   u32 iSrcLine;            /* Source-code line that generated this opcode
77                            ** with flags in the upper 8 bits */
78 #endif
79 };
80 typedef struct VdbeOp VdbeOp;
81 
82 
83 /*
84 ** A sub-routine used to implement a trigger program.
85 */
86 struct SubProgram {
87   VdbeOp *aOp;                  /* Array of opcodes for sub-program */
88   int nOp;                      /* Elements in aOp[] */
89   int nMem;                     /* Number of memory cells required */
90   int nCsr;                     /* Number of cursors required */
91   u8 *aOnce;                    /* Array of OP_Once flags */
92   void *token;                  /* id that may be used to recursive triggers */
93   SubProgram *pNext;            /* Next sub-program already visited */
94 };
95 
96 /*
97 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because
98 ** it takes up less space.
99 */
100 struct VdbeOpList {
101   u8 opcode;          /* What operation to perform */
102   signed char p1;     /* First operand */
103   signed char p2;     /* Second parameter (often the jump destination) */
104   signed char p3;     /* Third parameter */
105 };
106 typedef struct VdbeOpList VdbeOpList;
107 
108 /*
109 ** Allowed values of VdbeOp.p4type
110 */
111 #define P4_NOTUSED      0   /* The P4 parameter is not used */
112 #define P4_TRANSIENT    0   /* P4 is a pointer to a transient string */
113 #define P4_STATIC     (-1)  /* Pointer to a static string */
114 #define P4_COLLSEQ    (-2)  /* P4 is a pointer to a CollSeq structure */
115 #define P4_INT32      (-3)  /* P4 is a 32-bit signed integer */
116 #define P4_SUBPROGRAM (-4)  /* P4 is a pointer to a SubProgram structure */
117 #define P4_ADVANCE    (-5)  /* P4 is a pointer to BtreeNext() or BtreePrev() */
118 #define P4_TABLE      (-6)  /* P4 is a pointer to a Table structure */
119 /* Above do not own any resources.  Must free those below */
120 #define P4_FREE_IF_LE (-7)
121 #define P4_DYNAMIC    (-7)  /* Pointer to memory from sqliteMalloc() */
122 #define P4_FUNCDEF    (-8)  /* P4 is a pointer to a FuncDef structure */
123 #define P4_KEYINFO    (-9)  /* P4 is a pointer to a KeyInfo structure */
124 #define P4_EXPR       (-10) /* P4 is a pointer to an Expr tree */
125 #define P4_MEM        (-11) /* P4 is a pointer to a Mem*    structure */
126 #define P4_VTAB       (-12) /* P4 is a pointer to an sqlite3_vtab structure */
127 #define P4_REAL       (-13) /* P4 is a 64-bit floating point value */
128 #define P4_INT64      (-14) /* P4 is a 64-bit signed integer */
129 #define P4_INTARRAY   (-15) /* P4 is a vector of 32-bit integers */
130 #define P4_FUNCCTX    (-16) /* P4 is a pointer to an sqlite3_context object */
131 #define P4_DYNBLOB    (-17) /* Pointer to memory from sqliteMalloc() */
132 
133 /* Error message codes for OP_Halt */
134 #define P5_ConstraintNotNull 1
135 #define P5_ConstraintUnique  2
136 #define P5_ConstraintCheck   3
137 #define P5_ConstraintFK      4
138 
139 /*
140 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
141 ** number of columns of data returned by the statement.
142 */
143 #define COLNAME_NAME     0
144 #define COLNAME_DECLTYPE 1
145 #define COLNAME_DATABASE 2
146 #define COLNAME_TABLE    3
147 #define COLNAME_COLUMN   4
148 #ifdef SQLITE_ENABLE_COLUMN_METADATA
149 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
150 #else
151 # ifdef SQLITE_OMIT_DECLTYPE
152 #   define COLNAME_N      1      /* Store only the name */
153 # else
154 #   define COLNAME_N      2      /* Store the name and decltype */
155 # endif
156 #endif
157 
158 /*
159 ** The following macro converts a label returned by sqlite3VdbeMakeLabel()
160 ** into an index into the Parse.aLabel[] array that contains the resolved
161 ** address of that label.
162 */
163 #define ADDR(X)  (~(X))
164 
165 /*
166 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
167 ** header file that defines a number for each opcode used by the VDBE.
168 */
169 #include "opcodes.h"
170 
171 /*
172 ** Additional non-public SQLITE_PREPARE_* flags
173 */
174 #define SQLITE_PREPARE_SAVESQL  0x80  /* Preserve SQL text */
175 #define SQLITE_PREPARE_MASK     0x0f  /* Mask of public flags */
176 
177 /*
178 ** Prototypes for the VDBE interface.  See comments on the implementation
179 ** for a description of what each of these routines does.
180 */
181 Vdbe *sqlite3VdbeCreate(Parse*);
182 Parse *sqlite3VdbeParser(Vdbe*);
183 int sqlite3VdbeAddOp0(Vdbe*,int);
184 int sqlite3VdbeAddOp1(Vdbe*,int,int);
185 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
186 int sqlite3VdbeGoto(Vdbe*,int);
187 int sqlite3VdbeLoadString(Vdbe*,int,const char*);
188 void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
189 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
190 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
191 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
192 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
193 int sqlite3VdbeAddFunctionCall(Parse*,int,int,int,int,const FuncDef*,int);
194 void sqlite3VdbeEndCoroutine(Vdbe*,int);
195 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
196   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
197   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);
198 #else
199 # define sqlite3VdbeVerifyNoMallocRequired(A,B)
200 # define sqlite3VdbeVerifyNoResultRow(A)
201 #endif
202 #if defined(SQLITE_DEBUG)
203   void sqlite3VdbeVerifyAbortable(Vdbe *p, int);
204 #else
205 # define sqlite3VdbeVerifyAbortable(A,B)
206 #endif
207 VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp,int iLineno);
208 #ifndef SQLITE_OMIT_EXPLAIN
209   void sqlite3VdbeExplain(Parse*,u8,const char*,...);
210   void sqlite3VdbeExplainPop(Parse*);
211   int sqlite3VdbeExplainParent(Parse*);
212 # define ExplainQueryPlan(P)        sqlite3VdbeExplain P
213 # define ExplainQueryPlanPop(P)     sqlite3VdbeExplainPop(P)
214 # define ExplainQueryPlanParent(P)  sqlite3VdbeExplainParent(P)
215 #else
216 # define ExplainQueryPlan(P)
217 # define ExplainQueryPlanPop(P)
218 # define ExplainQueryPlanParent(P) 0
219 # define sqlite3ExplainBreakpoint(A,B) /*no-op*/
220 #endif
221 #if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_EXPLAIN)
222   void sqlite3ExplainBreakpoint(const char*,const char*);
223 #else
224 # define sqlite3ExplainBreakpoint(A,B) /*no-op*/
225 #endif
226 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
227 void sqlite3VdbeChangeOpcode(Vdbe*, int addr, u8);
228 void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
229 void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
230 void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3);
231 void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
232 void sqlite3VdbeJumpHere(Vdbe*, int addr);
233 int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
234 int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
235 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
236 void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
237 void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
238 void sqlite3VdbeUsesBtree(Vdbe*, int);
239 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
240 int sqlite3VdbeMakeLabel(Parse*);
241 void sqlite3VdbeRunOnlyOnce(Vdbe*);
242 void sqlite3VdbeReusable(Vdbe*);
243 void sqlite3VdbeDelete(Vdbe*);
244 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
245 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
246 int sqlite3VdbeFinalize(Vdbe*);
247 void sqlite3VdbeResolveLabel(Vdbe*, int);
248 int sqlite3VdbeCurrentAddr(Vdbe*);
249 #ifdef SQLITE_DEBUG
250   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
251 #endif
252 void sqlite3VdbeResetStepResult(Vdbe*);
253 void sqlite3VdbeRewind(Vdbe*);
254 int sqlite3VdbeReset(Vdbe*);
255 void sqlite3VdbeSetNumCols(Vdbe*,int);
256 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
257 void sqlite3VdbeCountChanges(Vdbe*);
258 sqlite3 *sqlite3VdbeDb(Vdbe*);
259 u8 sqlite3VdbePrepareFlags(Vdbe*);
260 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
261 #ifdef SQLITE_ENABLE_NORMALIZE
262 void sqlite3VdbeAddDblquoteStr(sqlite3*,Vdbe*,const char*);
263 int sqlite3VdbeUsesDoubleQuotedString(Vdbe*,const char*);
264 #endif
265 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
266 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
267 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
268 void sqlite3VdbeSetVarmask(Vdbe*, int);
269 #ifndef SQLITE_OMIT_TRACE
270   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
271 #endif
272 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
273 int sqlite3BlobCompare(const Mem*, const Mem*);
274 
275 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
276 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
277 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
278 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);
279 
280 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
281 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
282 
283 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
284 int sqlite3VdbeHasSubProgram(Vdbe*);
285 
286 int sqlite3NotPureFunc(sqlite3_context*);
287 
288 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
289 ** each VDBE opcode.
290 **
291 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
292 ** comments in VDBE programs that show key decision points in the code
293 ** generator.
294 */
295 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
296   void sqlite3VdbeComment(Vdbe*, const char*, ...);
297 # define VdbeComment(X)  sqlite3VdbeComment X
298   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
299 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
300 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
301 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
302 # else
303 #   define VdbeModuleComment(X)
304 # endif
305 #else
306 # define VdbeComment(X)
307 # define VdbeNoopComment(X)
308 # define VdbeModuleComment(X)
309 #endif
310 
311 /*
312 ** The VdbeCoverage macros are used to set a coverage testing point
313 ** for VDBE branch instructions.  The coverage testing points are line
314 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
315 ** only works with an amalagmation build.  That's ok since a VDBE branch
316 ** coverage build designed for testing the test suite only.  No application
317 ** should ever ship with VDBE branch coverage measuring turned on.
318 **
319 **    VdbeCoverage(v)                  // Mark the previously coded instruction
320 **                                     // as a branch
321 **
322 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
323 **
324 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
325 **
326 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
327 **
328 **    VdbeCoverageNeverNull(v)         // Previous three-way branch is only
329 **                                     // taken on the first two ways.  The
330 **                                     // NULL option is not possible
331 **
332 **    VdbeCoverageEqNe(v)              // Previous OP_Jump is only interested
333 **                                     // in distingishing equal and not-equal.
334 **
335 ** Every VDBE branch operation must be tagged with one of the macros above.
336 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
337 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
338 ** routine in vdbe.c, alerting the developer to the missed tag.
339 **
340 ** During testing, the test application will invoke
341 ** sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE,...) to set a callback
342 ** routine that is invoked as each bytecode branch is taken.  The callback
343 ** contains the sqlite3.c source line number ov the VdbeCoverage macro and
344 ** flags to indicate whether or not the branch was taken.  The test application
345 ** is responsible for keeping track of this and reporting byte-code branches
346 ** that are never taken.
347 **
348 ** See the VdbeBranchTaken() macro and vdbeTakeBranch() function in the
349 ** vdbe.c source file for additional information.
350 */
351 #ifdef SQLITE_VDBE_COVERAGE
352   void sqlite3VdbeSetLineNumber(Vdbe*,int);
353 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
354 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
355 # define VdbeCoverageAlwaysTaken(v) \
356          sqlite3VdbeSetLineNumber(v,__LINE__|0x5000000);
357 # define VdbeCoverageNeverTaken(v) \
358          sqlite3VdbeSetLineNumber(v,__LINE__|0x6000000);
359 # define VdbeCoverageNeverNull(v) \
360          sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);
361 # define VdbeCoverageNeverNullIf(v,x) \
362          if(x)sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);
363 # define VdbeCoverageEqNe(v) \
364          sqlite3VdbeSetLineNumber(v,__LINE__|0x8000000);
365 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
366 #else
367 # define VdbeCoverage(v)
368 # define VdbeCoverageIf(v,x)
369 # define VdbeCoverageAlwaysTaken(v)
370 # define VdbeCoverageNeverTaken(v)
371 # define VdbeCoverageNeverNull(v)
372 # define VdbeCoverageNeverNullIf(v,x)
373 # define VdbeCoverageEqNe(v)
374 # define VDBE_OFFSET_LINENO(x) 0
375 #endif
376 
377 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
378 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
379 #else
380 # define sqlite3VdbeScanStatus(a,b,c,d,e)
381 #endif
382 
383 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
384 void sqlite3VdbePrintOp(FILE*, int, VdbeOp*);
385 #endif
386 
387 #endif /* SQLITE_VDBE_H */
388