src/vdbe.h

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