xref: /sqlite-3.40.0/src/vdbe.h (revision dfe4e6bb)
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   u8 notUsed1;
45   u8 p5;              /* Fifth parameter is an unsigned character */
46   int p1;             /* First operand */
47   int p2;             /* Second parameter (often the jump destination) */
48   int p3;             /* The third parameter */
49   union p4union {     /* fourth parameter */
50     int i;                 /* Integer value if p4type==P4_INT32 */
51     void *p;               /* Generic pointer */
52     char *z;               /* Pointer to data for string (char array) types */
53     i64 *pI64;             /* Used when p4type is P4_INT64 */
54     double *pReal;         /* Used when p4type is P4_REAL */
55     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
56     sqlite3_context *pCtx; /* Used when p4type is P4_FUNCCTX */
57     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
58     Mem *pMem;             /* Used when p4type is P4_MEM */
59     VTable *pVtab;         /* Used when p4type is P4_VTAB */
60     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
61     int *ai;               /* Used when p4type is P4_INTARRAY */
62     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
63     Table *pTab;           /* Used when p4type is P4_TABLE */
64 #ifdef SQLITE_ENABLE_CURSOR_HINTS
65     Expr *pExpr;           /* Used when p4type is P4_EXPR */
66 #endif
67     int (*xAdvance)(BtCursor *, int *);
68   } p4;
69 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
70   char *zComment;          /* Comment to improve readability */
71 #endif
72 #ifdef VDBE_PROFILE
73   u32 cnt;                 /* Number of times this instruction was executed */
74   u64 cycles;              /* Total time spent executing this instruction */
75 #endif
76 #ifdef SQLITE_VDBE_COVERAGE
77   int iSrcLine;            /* Source-code line that generated this opcode */
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   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  (-4)  /* P4 is a pointer to a CollSeq structure */
114 #define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
115 #define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
116 #define P4_EXPR     (-7)  /* P4 is a pointer to an Expr tree */
117 #define P4_MEM      (-8)  /* 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     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
120 #define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
121 #define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
122 #define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
123 #define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
124 #define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
125 #define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
126 #define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */
127 #define P4_TABLE    (-20) /* P4 is a pointer to a Table structure */
128 #define P4_FUNCCTX  (-21) /* P4 is a pointer to an sqlite3_context object */
129 
130 /* Error message codes for OP_Halt */
131 #define P5_ConstraintNotNull 1
132 #define P5_ConstraintUnique  2
133 #define P5_ConstraintCheck   3
134 #define P5_ConstraintFK      4
135 
136 /*
137 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
138 ** number of columns of data returned by the statement.
139 */
140 #define COLNAME_NAME     0
141 #define COLNAME_DECLTYPE 1
142 #define COLNAME_DATABASE 2
143 #define COLNAME_TABLE    3
144 #define COLNAME_COLUMN   4
145 #ifdef SQLITE_ENABLE_COLUMN_METADATA
146 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
147 #else
148 # ifdef SQLITE_OMIT_DECLTYPE
149 #   define COLNAME_N      1      /* Store only the name */
150 # else
151 #   define COLNAME_N      2      /* Store the name and decltype */
152 # endif
153 #endif
154 
155 /*
156 ** The following macro converts a relative address in the p2 field
157 ** of a VdbeOp structure into a negative number so that
158 ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
159 ** the macro again restores the address.
160 */
161 #define ADDR(X)  (-1-(X))
162 
163 /*
164 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
165 ** header file that defines a number for each opcode used by the VDBE.
166 */
167 #include "opcodes.h"
168 
169 /*
170 ** Prototypes for the VDBE interface.  See comments on the implementation
171 ** for a description of what each of these routines does.
172 */
173 Vdbe *sqlite3VdbeCreate(Parse*);
174 int sqlite3VdbeAddOp0(Vdbe*,int);
175 int sqlite3VdbeAddOp1(Vdbe*,int,int);
176 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
177 int sqlite3VdbeGoto(Vdbe*,int);
178 int sqlite3VdbeLoadString(Vdbe*,int,const char*);
179 void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
180 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
181 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
182 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
183 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
184 void sqlite3VdbeEndCoroutine(Vdbe*,int);
185 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
186   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
187 #else
188 # define sqlite3VdbeVerifyNoMallocRequired(A,B)
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*, u8 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 sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
202 void sqlite3VdbeUsesBtree(Vdbe*, int);
203 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
204 int sqlite3VdbeMakeLabel(Vdbe*);
205 void sqlite3VdbeRunOnlyOnce(Vdbe*);
206 void sqlite3VdbeReusable(Vdbe*);
207 void sqlite3VdbeDelete(Vdbe*);
208 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
209 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
210 int sqlite3VdbeFinalize(Vdbe*);
211 void sqlite3VdbeResolveLabel(Vdbe*, int);
212 int sqlite3VdbeCurrentAddr(Vdbe*);
213 #ifdef SQLITE_DEBUG
214   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
215 #endif
216 void sqlite3VdbeResetStepResult(Vdbe*);
217 void sqlite3VdbeRewind(Vdbe*);
218 int sqlite3VdbeReset(Vdbe*);
219 void sqlite3VdbeSetNumCols(Vdbe*,int);
220 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
221 void sqlite3VdbeCountChanges(Vdbe*);
222 sqlite3 *sqlite3VdbeDb(Vdbe*);
223 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int);
224 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
225 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
226 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
227 void sqlite3VdbeSetVarmask(Vdbe*, int);
228 #ifndef SQLITE_OMIT_TRACE
229   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
230 #endif
231 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
232 
233 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
234 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
235 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
236 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo *, char *, int, char **);
237 
238 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
239 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
240 
241 #ifndef SQLITE_OMIT_TRIGGER
242 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
243 #endif
244 
245 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
246 ** each VDBE opcode.
247 **
248 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
249 ** comments in VDBE programs that show key decision points in the code
250 ** generator.
251 */
252 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
253   void sqlite3VdbeComment(Vdbe*, const char*, ...);
254 # define VdbeComment(X)  sqlite3VdbeComment X
255   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
256 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
257 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
258 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
259 # else
260 #   define VdbeModuleComment(X)
261 # endif
262 #else
263 # define VdbeComment(X)
264 # define VdbeNoopComment(X)
265 # define VdbeModuleComment(X)
266 #endif
267 
268 /*
269 ** The VdbeCoverage macros are used to set a coverage testing point
270 ** for VDBE branch instructions.  The coverage testing points are line
271 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
272 ** only works with an amalagmation build.  That's ok since a VDBE branch
273 ** coverage build designed for testing the test suite only.  No application
274 ** should ever ship with VDBE branch coverage measuring turned on.
275 **
276 **    VdbeCoverage(v)                  // Mark the previously coded instruction
277 **                                     // as a branch
278 **
279 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
280 **
281 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
282 **
283 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
284 **
285 ** Every VDBE branch operation must be tagged with one of the macros above.
286 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
287 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
288 ** routine in vdbe.c, alerting the developer to the missed tag.
289 */
290 #ifdef SQLITE_VDBE_COVERAGE
291   void sqlite3VdbeSetLineNumber(Vdbe*,int);
292 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
293 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
294 # define VdbeCoverageAlwaysTaken(v) sqlite3VdbeSetLineNumber(v,2);
295 # define VdbeCoverageNeverTaken(v) sqlite3VdbeSetLineNumber(v,1);
296 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
297 #else
298 # define VdbeCoverage(v)
299 # define VdbeCoverageIf(v,x)
300 # define VdbeCoverageAlwaysTaken(v)
301 # define VdbeCoverageNeverTaken(v)
302 # define VDBE_OFFSET_LINENO(x) 0
303 #endif
304 
305 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
306 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
307 #else
308 # define sqlite3VdbeScanStatus(a,b,c,d,e)
309 #endif
310 
311 #endif /* SQLITE_VDBE_H */
312