xref: /sqlite-3.40.0/src/vdbe.h (revision 87f500ce)
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 Mem 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   void *token;                  /* id that may be used to recursive triggers */
91   SubProgram *pNext;            /* Next sub-program already visited */
92 };
93 
94 /*
95 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because
96 ** it takes up less space.
97 */
98 struct VdbeOpList {
99   u8 opcode;          /* What operation to perform */
100   signed char p1;     /* First operand */
101   signed char p2;     /* Second parameter (often the jump destination) */
102   signed char p3;     /* Third parameter */
103 };
104 typedef struct VdbeOpList VdbeOpList;
105 
106 /*
107 ** Allowed values of VdbeOp.p4type
108 */
109 #define P4_NOTUSED    0   /* The P4 parameter is not used */
110 #define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
111 #define P4_STATIC   (-2)  /* Pointer to a static string */
112 #define P4_COLLSEQ  (-3)  /* P4 is a pointer to a CollSeq structure */
113 #define P4_FUNCDEF  (-4)  /* P4 is a pointer to a FuncDef structure */
114 #define P4_KEYINFO  (-5)  /* P4 is a pointer to a KeyInfo structure */
115 #define P4_EXPR     (-6)  /* P4 is a pointer to an Expr tree */
116 #define P4_MEM      (-7)  /* P4 is a pointer to a Mem*    structure */
117 #define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
118 #define P4_VTAB     (-8) /* P4 is a pointer to an sqlite3_vtab structure */
119 #define P4_REAL     (-9) /* P4 is a 64-bit floating point value */
120 #define P4_INT64    (-10) /* P4 is a 64-bit signed integer */
121 #define P4_INT32    (-11) /* P4 is a 32-bit signed integer */
122 #define P4_INTARRAY (-12) /* P4 is a vector of 32-bit integers */
123 #define P4_SUBPROGRAM  (-13) /* P4 is a pointer to a SubProgram structure */
124 #define P4_ADVANCE  (-14) /* P4 is a pointer to BtreeNext() or BtreePrev() */
125 #define P4_TABLE    (-15) /* P4 is a pointer to a Table structure */
126 #define P4_FUNCCTX  (-16) /* P4 is a pointer to an sqlite3_context object */
127 
128 /* Error message codes for OP_Halt */
129 #define P5_ConstraintNotNull 1
130 #define P5_ConstraintUnique  2
131 #define P5_ConstraintCheck   3
132 #define P5_ConstraintFK      4
133 
134 /*
135 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
136 ** number of columns of data returned by the statement.
137 */
138 #define COLNAME_NAME     0
139 #define COLNAME_DECLTYPE 1
140 #define COLNAME_DATABASE 2
141 #define COLNAME_TABLE    3
142 #define COLNAME_COLUMN   4
143 #ifdef SQLITE_ENABLE_COLUMN_METADATA
144 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
145 #else
146 # ifdef SQLITE_OMIT_DECLTYPE
147 #   define COLNAME_N      1      /* Store only the name */
148 # else
149 #   define COLNAME_N      2      /* Store the name and decltype */
150 # endif
151 #endif
152 
153 /*
154 ** The following macro converts a relative address in the p2 field
155 ** of a VdbeOp structure into a negative number so that
156 ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
157 ** the macro again restores the address.
158 */
159 #define ADDR(X)  (-1-(X))
160 
161 /*
162 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
163 ** header file that defines a number for each opcode used by the VDBE.
164 */
165 #include "opcodes.h"
166 
167 /*
168 ** Prototypes for the VDBE interface.  See comments on the implementation
169 ** for a description of what each of these routines does.
170 */
171 Vdbe *sqlite3VdbeCreate(Parse*);
172 int sqlite3VdbeAddOp0(Vdbe*,int);
173 int sqlite3VdbeAddOp1(Vdbe*,int,int);
174 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
175 int sqlite3VdbeGoto(Vdbe*,int);
176 int sqlite3VdbeLoadString(Vdbe*,int,const char*);
177 void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
178 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
179 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
180 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
181 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
182 void sqlite3VdbeEndCoroutine(Vdbe*,int);
183 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
184   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
185   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);
186 #else
187 # define sqlite3VdbeVerifyNoMallocRequired(A,B)
188 # define sqlite3VdbeVerifyNoResultRow(A)
189 #endif
190 VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
191 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
192 void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
193 void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
194 void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
195 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
196 void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
197 void sqlite3VdbeJumpHere(Vdbe*, int addr);
198 int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
199 int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
200 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
201 void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
202 void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
203 void sqlite3VdbeUsesBtree(Vdbe*, int);
204 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
205 int sqlite3VdbeMakeLabel(Vdbe*);
206 void sqlite3VdbeRunOnlyOnce(Vdbe*);
207 void sqlite3VdbeReusable(Vdbe*);
208 void sqlite3VdbeDelete(Vdbe*);
209 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
210 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
211 int sqlite3VdbeFinalize(Vdbe*);
212 void sqlite3VdbeResolveLabel(Vdbe*, int);
213 int sqlite3VdbeCurrentAddr(Vdbe*);
214 #ifdef SQLITE_DEBUG
215   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
216 #endif
217 void sqlite3VdbeResetStepResult(Vdbe*);
218 void sqlite3VdbeRewind(Vdbe*);
219 int sqlite3VdbeReset(Vdbe*);
220 void sqlite3VdbeSetNumCols(Vdbe*,int);
221 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
222 void sqlite3VdbeCountChanges(Vdbe*);
223 sqlite3 *sqlite3VdbeDb(Vdbe*);
224 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int);
225 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
226 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
227 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
228 void sqlite3VdbeSetVarmask(Vdbe*, int);
229 #ifndef SQLITE_OMIT_TRACE
230   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
231 #endif
232 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
233 
234 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
235 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
236 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
237 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);
238 
239 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
240 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
241 
242 #ifndef SQLITE_OMIT_TRIGGER
243 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
244 #endif
245 
246 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
247 ** each VDBE opcode.
248 **
249 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
250 ** comments in VDBE programs that show key decision points in the code
251 ** generator.
252 */
253 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
254   void sqlite3VdbeComment(Vdbe*, const char*, ...);
255 # define VdbeComment(X)  sqlite3VdbeComment X
256   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
257 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
258 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
259 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
260 # else
261 #   define VdbeModuleComment(X)
262 # endif
263 #else
264 # define VdbeComment(X)
265 # define VdbeNoopComment(X)
266 # define VdbeModuleComment(X)
267 #endif
268 
269 /*
270 ** The VdbeCoverage macros are used to set a coverage testing point
271 ** for VDBE branch instructions.  The coverage testing points are line
272 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
273 ** only works with an amalagmation build.  That's ok since a VDBE branch
274 ** coverage build designed for testing the test suite only.  No application
275 ** should ever ship with VDBE branch coverage measuring turned on.
276 **
277 **    VdbeCoverage(v)                  // Mark the previously coded instruction
278 **                                     // as a branch
279 **
280 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
281 **
282 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
283 **
284 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
285 **
286 ** Every VDBE branch operation must be tagged with one of the macros above.
287 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
288 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
289 ** routine in vdbe.c, alerting the developer to the missed tag.
290 */
291 #ifdef SQLITE_VDBE_COVERAGE
292   void sqlite3VdbeSetLineNumber(Vdbe*,int);
293 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
294 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
295 # define VdbeCoverageAlwaysTaken(v) sqlite3VdbeSetLineNumber(v,2);
296 # define VdbeCoverageNeverTaken(v) sqlite3VdbeSetLineNumber(v,1);
297 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
298 #else
299 # define VdbeCoverage(v)
300 # define VdbeCoverageIf(v,x)
301 # define VdbeCoverageAlwaysTaken(v)
302 # define VdbeCoverageNeverTaken(v)
303 # define VDBE_OFFSET_LINENO(x) 0
304 #endif
305 
306 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
307 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
308 #else
309 # define sqlite3VdbeScanStatus(a,b,c,d,e)
310 #endif
311 
312 #endif /* SQLITE_VDBE_H */
313