xref: /sqlite-3.40.0/src/vdbe.h (revision 88f769f9)
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   int iSrcLine;            /* Source-code line that generated this opcode */
77 #endif
78 };
79 typedef struct VdbeOp VdbeOp;
80 
81 
82 /*
83 ** A sub-routine used to implement a trigger program.
84 */
85 struct SubProgram {
86   VdbeOp *aOp;                  /* Array of opcodes for sub-program */
87   int nOp;                      /* Elements in aOp[] */
88   int nMem;                     /* Number of memory cells required */
89   int nCsr;                     /* Number of cursors required */
90   u8 *aOnce;                    /* Array of OP_Once flags */
91   void *token;                  /* id that may be used to recursive triggers */
92   SubProgram *pNext;            /* Next sub-program already visited */
93 };
94 
95 /*
96 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because
97 ** it takes up less space.
98 */
99 struct VdbeOpList {
100   u8 opcode;          /* What operation to perform */
101   signed char p1;     /* First operand */
102   signed char p2;     /* Second parameter (often the jump destination) */
103   signed char p3;     /* Third parameter */
104 };
105 typedef struct VdbeOpList VdbeOpList;
106 
107 /*
108 ** Allowed values of VdbeOp.p4type
109 */
110 #define P4_NOTUSED    0   /* The P4 parameter is not used */
111 #define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
112 #define P4_STATIC   (-2)  /* Pointer to a static string */
113 #define P4_COLLSEQ  (-3)  /* P4 is a pointer to a CollSeq structure */
114 #define P4_FUNCDEF  (-4)  /* P4 is a pointer to a FuncDef structure */
115 #define P4_KEYINFO  (-5)  /* P4 is a pointer to a KeyInfo structure */
116 #define P4_EXPR     (-6)  /* P4 is a pointer to an Expr tree */
117 #define P4_MEM      (-7)  /* P4 is a pointer to a Mem*    structure */
118 #define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
119 #define P4_VTAB     (-8) /* P4 is a pointer to an sqlite3_vtab structure */
120 #define P4_REAL     (-9) /* P4 is a 64-bit floating point value */
121 #define P4_INT64    (-10) /* P4 is a 64-bit signed integer */
122 #define P4_INT32    (-11) /* P4 is a 32-bit signed integer */
123 #define P4_INTARRAY (-12) /* P4 is a vector of 32-bit integers */
124 #define P4_SUBPROGRAM  (-13) /* P4 is a pointer to a SubProgram structure */
125 #define P4_ADVANCE  (-14) /* P4 is a pointer to BtreeNext() or BtreePrev() */
126 #define P4_TABLE    (-15) /* P4 is a pointer to a Table structure */
127 #define P4_FUNCCTX  (-16) /* P4 is a pointer to an sqlite3_context object */
128 
129 /* Error message codes for OP_Halt */
130 #define P5_ConstraintNotNull 1
131 #define P5_ConstraintUnique  2
132 #define P5_ConstraintCheck   3
133 #define P5_ConstraintFK      4
134 
135 /*
136 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
137 ** number of columns of data returned by the statement.
138 */
139 #define COLNAME_NAME     0
140 #define COLNAME_DECLTYPE 1
141 #define COLNAME_DATABASE 2
142 #define COLNAME_TABLE    3
143 #define COLNAME_COLUMN   4
144 #ifdef SQLITE_ENABLE_COLUMN_METADATA
145 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
146 #else
147 # ifdef SQLITE_OMIT_DECLTYPE
148 #   define COLNAME_N      1      /* Store only the name */
149 # else
150 #   define COLNAME_N      2      /* Store the name and decltype */
151 # endif
152 #endif
153 
154 /*
155 ** The following macro converts a relative address in the p2 field
156 ** of a VdbeOp structure into a negative number so that
157 ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
158 ** the macro again restores the address.
159 */
160 #define ADDR(X)  (-1-(X))
161 
162 /*
163 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
164 ** header file that defines a number for each opcode used by the VDBE.
165 */
166 #include "opcodes.h"
167 
168 /*
169 ** Additional non-public SQLITE_PREPARE_* flags
170 */
171 #define SQLITE_PREPARE_SAVESQL  0x80  /* Preserve SQL text */
172 #define SQLITE_PREPARE_MASK     0x0f  /* Mask of public flags */
173 
174 /*
175 ** Prototypes for the VDBE interface.  See comments on the implementation
176 ** for a description of what each of these routines does.
177 */
178 Vdbe *sqlite3VdbeCreate(Parse*);
179 int sqlite3VdbeAddOp0(Vdbe*,int);
180 int sqlite3VdbeAddOp1(Vdbe*,int,int);
181 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
182 int sqlite3VdbeGoto(Vdbe*,int);
183 int sqlite3VdbeLoadString(Vdbe*,int,const char*);
184 void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
185 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
186 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
187 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
188 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
189 void sqlite3VdbeEndCoroutine(Vdbe*,int);
190 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
191   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
192   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);
193 #else
194 # define sqlite3VdbeVerifyNoMallocRequired(A,B)
195 # define sqlite3VdbeVerifyNoResultRow(A)
196 #endif
197 VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
198 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
199 void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
200 void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
201 void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
202 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
203 void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
204 void sqlite3VdbeJumpHere(Vdbe*, int addr);
205 int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
206 int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
207 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
208 void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
209 void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
210 void sqlite3VdbeUsesBtree(Vdbe*, int);
211 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
212 int sqlite3VdbeMakeLabel(Vdbe*);
213 void sqlite3VdbeRunOnlyOnce(Vdbe*);
214 void sqlite3VdbeReusable(Vdbe*);
215 void sqlite3VdbeDelete(Vdbe*);
216 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
217 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
218 int sqlite3VdbeFinalize(Vdbe*);
219 void sqlite3VdbeResolveLabel(Vdbe*, int);
220 int sqlite3VdbeCurrentAddr(Vdbe*);
221 #ifdef SQLITE_DEBUG
222   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
223 #endif
224 void sqlite3VdbeResetStepResult(Vdbe*);
225 void sqlite3VdbeRewind(Vdbe*);
226 int sqlite3VdbeReset(Vdbe*);
227 void sqlite3VdbeSetNumCols(Vdbe*,int);
228 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
229 void sqlite3VdbeCountChanges(Vdbe*);
230 sqlite3 *sqlite3VdbeDb(Vdbe*);
231 u8 sqlite3VdbePrepareFlags(Vdbe*);
232 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
233 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
234 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
235 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
236 void sqlite3VdbeSetVarmask(Vdbe*, int);
237 #ifndef SQLITE_OMIT_TRACE
238   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
239 #endif
240 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
241 
242 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
243 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
244 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
245 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);
246 
247 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
248 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
249 
250 #ifndef SQLITE_OMIT_TRIGGER
251 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
252 #endif
253 
254 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
255 ** each VDBE opcode.
256 **
257 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
258 ** comments in VDBE programs that show key decision points in the code
259 ** generator.
260 */
261 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
262   void sqlite3VdbeComment(Vdbe*, const char*, ...);
263 # define VdbeComment(X)  sqlite3VdbeComment X
264   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
265 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
266 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
267 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
268 # else
269 #   define VdbeModuleComment(X)
270 # endif
271 #else
272 # define VdbeComment(X)
273 # define VdbeNoopComment(X)
274 # define VdbeModuleComment(X)
275 #endif
276 
277 /*
278 ** The VdbeCoverage macros are used to set a coverage testing point
279 ** for VDBE branch instructions.  The coverage testing points are line
280 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
281 ** only works with an amalagmation build.  That's ok since a VDBE branch
282 ** coverage build designed for testing the test suite only.  No application
283 ** should ever ship with VDBE branch coverage measuring turned on.
284 **
285 **    VdbeCoverage(v)                  // Mark the previously coded instruction
286 **                                     // as a branch
287 **
288 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
289 **
290 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
291 **
292 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
293 **
294 ** Every VDBE branch operation must be tagged with one of the macros above.
295 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
296 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
297 ** routine in vdbe.c, alerting the developer to the missed tag.
298 */
299 #ifdef SQLITE_VDBE_COVERAGE
300   void sqlite3VdbeSetLineNumber(Vdbe*,int);
301 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
302 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
303 # define VdbeCoverageAlwaysTaken(v) sqlite3VdbeSetLineNumber(v,2);
304 # define VdbeCoverageNeverTaken(v) sqlite3VdbeSetLineNumber(v,1);
305 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
306 #else
307 # define VdbeCoverage(v)
308 # define VdbeCoverageIf(v,x)
309 # define VdbeCoverageAlwaysTaken(v)
310 # define VdbeCoverageNeverTaken(v)
311 # define VDBE_OFFSET_LINENO(x) 0
312 #endif
313 
314 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
315 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
316 #else
317 # define sqlite3VdbeScanStatus(a,b,c,d,e)
318 #endif
319 
320 #endif /* SQLITE_VDBE_H */
321