xref: /sqlite-3.40.0/src/vdbe.h (revision 3f09beda)
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 opflags;         /* Mask of the OPFLG_* flags in opcodes.h */
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     int (*xAdvance)(BtCursor *, int *);
64   } p4;
65 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
66   char *zComment;          /* Comment to improve readability */
67 #endif
68 #ifdef VDBE_PROFILE
69   u32 cnt;                 /* Number of times this instruction was executed */
70   u64 cycles;              /* Total time spent executing this instruction */
71 #endif
72 #ifdef SQLITE_VDBE_COVERAGE
73   int iSrcLine;            /* Source-code line that generated this opcode */
74 #endif
75 };
76 typedef struct VdbeOp VdbeOp;
77 
78 
79 /*
80 ** A sub-routine used to implement a trigger program.
81 */
82 struct SubProgram {
83   VdbeOp *aOp;                  /* Array of opcodes for sub-program */
84   int nOp;                      /* Elements in aOp[] */
85   int nMem;                     /* Number of memory cells required */
86   int nCsr;                     /* Number of cursors required */
87   int nOnce;                    /* Number of OP_Once instructions */
88   void *token;                  /* id that may be used to recursive triggers */
89   SubProgram *pNext;            /* Next sub-program already visited */
90 };
91 
92 /*
93 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because
94 ** it takes up less space.
95 */
96 struct VdbeOpList {
97   u8 opcode;          /* What operation to perform */
98   signed char p1;     /* First operand */
99   signed char p2;     /* Second parameter (often the jump destination) */
100   signed char p3;     /* Third parameter */
101 };
102 typedef struct VdbeOpList VdbeOpList;
103 
104 /*
105 ** Allowed values of VdbeOp.p4type
106 */
107 #define P4_NOTUSED    0   /* The P4 parameter is not used */
108 #define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
109 #define P4_STATIC   (-2)  /* Pointer to a static string */
110 #define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
111 #define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
112 #define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
113 #define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
114 #define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
115 #define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
116 #define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
117 #define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
118 #define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
119 #define P4_INT32    (-14) /* P4 is a 32-bit signed integer */
120 #define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
121 #define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
122 #define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */
123 #define P4_FUNCCTX  (-20) /* P4 is a pointer to an sqlite3_context object */
124 
125 /* Error message codes for OP_Halt */
126 #define P5_ConstraintNotNull 1
127 #define P5_ConstraintUnique  2
128 #define P5_ConstraintCheck   3
129 #define P5_ConstraintFK      4
130 
131 /*
132 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
133 ** number of columns of data returned by the statement.
134 */
135 #define COLNAME_NAME     0
136 #define COLNAME_DECLTYPE 1
137 #define COLNAME_DATABASE 2
138 #define COLNAME_TABLE    3
139 #define COLNAME_COLUMN   4
140 #ifdef SQLITE_ENABLE_COLUMN_METADATA
141 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
142 #else
143 # ifdef SQLITE_OMIT_DECLTYPE
144 #   define COLNAME_N      1      /* Store only the name */
145 # else
146 #   define COLNAME_N      2      /* Store the name and decltype */
147 # endif
148 #endif
149 
150 /*
151 ** The following macro converts a relative address in the p2 field
152 ** of a VdbeOp structure into a negative number so that
153 ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
154 ** the macro again restores the address.
155 */
156 #define ADDR(X)  (-1-(X))
157 
158 /*
159 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
160 ** header file that defines a number for each opcode used by the VDBE.
161 */
162 #include "opcodes.h"
163 
164 /*
165 ** Prototypes for the VDBE interface.  See comments on the implementation
166 ** for a description of what each of these routines does.
167 */
168 Vdbe *sqlite3VdbeCreate(Parse*);
169 int sqlite3VdbeAddOp0(Vdbe*,int);
170 int sqlite3VdbeAddOp1(Vdbe*,int,int);
171 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
172 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
173 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
174 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
175 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
176 int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
177 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
178 void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
179 void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
180 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
181 void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
182 void sqlite3VdbeJumpHere(Vdbe*, int addr);
183 void sqlite3VdbeChangeToNoop(Vdbe*, int addr);
184 int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
185 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
186 void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
187 void sqlite3VdbeUsesBtree(Vdbe*, int);
188 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
189 int sqlite3VdbeMakeLabel(Vdbe*);
190 void sqlite3VdbeRunOnlyOnce(Vdbe*);
191 void sqlite3VdbeDelete(Vdbe*);
192 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
193 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
194 int sqlite3VdbeFinalize(Vdbe*);
195 void sqlite3VdbeResolveLabel(Vdbe*, int);
196 int sqlite3VdbeCurrentAddr(Vdbe*);
197 #ifdef SQLITE_DEBUG
198   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
199 #endif
200 void sqlite3VdbeResetStepResult(Vdbe*);
201 void sqlite3VdbeRewind(Vdbe*);
202 int sqlite3VdbeReset(Vdbe*);
203 void sqlite3VdbeSetNumCols(Vdbe*,int);
204 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
205 void sqlite3VdbeCountChanges(Vdbe*);
206 sqlite3 *sqlite3VdbeDb(Vdbe*);
207 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int);
208 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
209 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
210 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
211 void sqlite3VdbeSetVarmask(Vdbe*, int);
212 #ifndef SQLITE_OMIT_TRACE
213   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
214 #endif
215 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
216 
217 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
218 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
219 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
220 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo *, char *, int, char **);
221 
222 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
223 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
224 
225 #ifndef SQLITE_OMIT_TRIGGER
226 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
227 #endif
228 
229 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
230 ** each VDBE opcode.
231 **
232 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
233 ** comments in VDBE programs that show key decision points in the code
234 ** generator.
235 */
236 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
237   void sqlite3VdbeComment(Vdbe*, const char*, ...);
238 # define VdbeComment(X)  sqlite3VdbeComment X
239   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
240 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
241 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
242 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
243 # else
244 #   define VdbeModuleComment(X)
245 # endif
246 #else
247 # define VdbeComment(X)
248 # define VdbeNoopComment(X)
249 # define VdbeModuleComment(X)
250 #endif
251 
252 /*
253 ** The VdbeCoverage macros are used to set a coverage testing point
254 ** for VDBE branch instructions.  The coverage testing points are line
255 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
256 ** only works with an amalagmation build.  That's ok since a VDBE branch
257 ** coverage build designed for testing the test suite only.  No application
258 ** should ever ship with VDBE branch coverage measuring turned on.
259 **
260 **    VdbeCoverage(v)                  // Mark the previously coded instruction
261 **                                     // as a branch
262 **
263 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
264 **
265 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
266 **
267 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
268 **
269 ** Every VDBE branch operation must be tagged with one of the macros above.
270 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
271 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
272 ** routine in vdbe.c, alerting the developer to the missed tag.
273 */
274 #ifdef SQLITE_VDBE_COVERAGE
275   void sqlite3VdbeSetLineNumber(Vdbe*,int);
276 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
277 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
278 # define VdbeCoverageAlwaysTaken(v) sqlite3VdbeSetLineNumber(v,2);
279 # define VdbeCoverageNeverTaken(v) sqlite3VdbeSetLineNumber(v,1);
280 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
281 #else
282 # define VdbeCoverage(v)
283 # define VdbeCoverageIf(v,x)
284 # define VdbeCoverageAlwaysTaken(v)
285 # define VdbeCoverageNeverTaken(v)
286 # define VDBE_OFFSET_LINENO(x) 0
287 #endif
288 
289 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
290 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
291 #else
292 # define sqlite3VdbeScanStatus(a,b,c,d,e)
293 #endif
294 
295 #endif
296