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 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_TRANSIENT    0   /* P4 is a pointer to a transient string */
 112 #define P4_STATIC     (-1)  /* Pointer to a static string */
 113 #define P4_COLLSEQ    (-2)  /* P4 is a pointer to a CollSeq structure */
 114 #define P4_INT32      (-3)  /* P4 is a 32-bit signed integer */
 115 #define P4_SUBPROGRAM (-4)  /* P4 is a pointer to a SubProgram structure */
 116 #define P4_ADVANCE    (-5)  /* P4 is a pointer to BtreeNext() or BtreePrev() */
 117 #define P4_TABLE      (-6)  /* P4 is a pointer to a Table structure */
 118 /* Above do not own any resources.  Must free those below */
 119 #define P4_FREE_IF_LE (-7)
 120 #define P4_DYNAMIC    (-7)  /* Pointer to memory from sqliteMalloc() */
 121 #define P4_FUNCDEF    (-8)  /* P4 is a pointer to a FuncDef structure */
 122 #define P4_KEYINFO    (-9)  /* P4 is a pointer to a KeyInfo structure */
 123 #define P4_EXPR       (-10) /* P4 is a pointer to an Expr tree */
 124 #define P4_MEM        (-11) /* P4 is a pointer to a Mem*    structure */
 125 #define P4_VTAB       (-12) /* P4 is a pointer to an sqlite3_vtab structure */
 126 #define P4_REAL       (-13) /* P4 is a 64-bit floating point value */
 127 #define P4_INT64      (-14) /* P4 is a 64-bit signed integer */
 128 #define P4_INTARRAY   (-15) /* P4 is a vector of 32-bit integers */
 129 #define P4_FUNCCTX    (-16) /* P4 is a pointer to an sqlite3_context object */
 130
 131 /* Error message codes for OP_Halt */
 132 #define P5_ConstraintNotNull 1
 133 #define P5_ConstraintUnique  2
 134 #define P5_ConstraintCheck   3
 135 #define P5_ConstraintFK      4
 136
 137 /*
 138 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
 139 ** number of columns of data returned by the statement.
 140 */
 141 #define COLNAME_NAME     0
 142 #define COLNAME_DECLTYPE 1
 143 #define COLNAME_DATABASE 2
 144 #define COLNAME_TABLE    3
 145 #define COLNAME_COLUMN   4
 146 #ifdef SQLITE_ENABLE_COLUMN_METADATA
 147 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
 148 #else
 149 # ifdef SQLITE_OMIT_DECLTYPE
 150 #   define COLNAME_N      1      /* Store only the name */
 151 # else
 152 #   define COLNAME_N      2      /* Store the name and decltype */
 153 # endif
 154 #endif
 155
 156 /*
 157 ** The following macro converts a relative address in the p2 field
 158 ** of a VdbeOp structure into a negative number so that
 159 ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
 160 ** the macro again restores the address.
 161 */
 162 #define ADDR(X)  (-1-(X))
 163
 164 /*
 165 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
 166 ** header file that defines a number for each opcode used by the VDBE.
 167 */
 168 #include "opcodes.h"
 169
 170 /*
 171 ** Additional non-public SQLITE_PREPARE_* flags
 172 */
 173 #define SQLITE_PREPARE_SAVESQL  0x80  /* Preserve SQL text */
 174 #define SQLITE_PREPARE_MASK     0x0f  /* Mask of public flags */
 175
 176 /*
 177 ** Prototypes for the VDBE interface.  See comments on the implementation
 178 ** for a description of what each of these routines does.
 179 */
 180 Vdbe *sqlite3VdbeCreate(Parse*);
 181 int sqlite3VdbeAddOp0(Vdbe*,int);
 182 int sqlite3VdbeAddOp1(Vdbe*,int,int);
 183 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
 184 int sqlite3VdbeGoto(Vdbe*,int);
 185 int sqlite3VdbeLoadString(Vdbe*,int,const char*);
 186 void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
 187 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 188 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
 189 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
 190 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
 191 void sqlite3VdbeEndCoroutine(Vdbe*,int);
 192 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
 193   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
 194   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);
 195 #else
 196 # define sqlite3VdbeVerifyNoMallocRequired(A,B)
 197 # define sqlite3VdbeVerifyNoResultRow(A)
 198 #endif
 199 VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
 200 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
 201 void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
 202 void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
 203 void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
 204 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
 205 void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
 206 void sqlite3VdbeJumpHere(Vdbe*, int addr);
 207 int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
 208 int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
 209 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
 210 void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
 211 void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
 212 void sqlite3VdbeUsesBtree(Vdbe*, int);
 213 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
 214 int sqlite3VdbeMakeLabel(Vdbe*);
 215 void sqlite3VdbeRunOnlyOnce(Vdbe*);
 216 void sqlite3VdbeReusable(Vdbe*);
 217 void sqlite3VdbeDelete(Vdbe*);
 218 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
 219 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
 220 int sqlite3VdbeFinalize(Vdbe*);
 221 void sqlite3VdbeResolveLabel(Vdbe*, int);
 222 int sqlite3VdbeCurrentAddr(Vdbe*);
 223 #ifdef SQLITE_DEBUG
 224   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
 225 #endif
 226 void sqlite3VdbeResetStepResult(Vdbe*);
 227 void sqlite3VdbeRewind(Vdbe*);
 228 int sqlite3VdbeReset(Vdbe*);
 229 void sqlite3VdbeSetNumCols(Vdbe*,int);
 230 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
 231 void sqlite3VdbeCountChanges(Vdbe*);
 232 sqlite3 *sqlite3VdbeDb(Vdbe*);
 233 u8 sqlite3VdbePrepareFlags(Vdbe*);
 234 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
 235 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 236 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
 237 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
 238 void sqlite3VdbeSetVarmask(Vdbe*, int);
 239 #ifndef SQLITE_OMIT_TRACE
 240   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
 241 #endif
 242 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
 243
 244 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
 245 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
 246 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
 247 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);
 248
 249 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
 250 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
 251
 252 #ifndef SQLITE_OMIT_TRIGGER
 253 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
 254 #endif
 255
 256 int sqlite3NotPureFunc(sqlite3_context*);
 257
 258 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
 259 ** each VDBE opcode.
 260 **
 261 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
 262 ** comments in VDBE programs that show key decision points in the code
 263 ** generator.
 264 */
 265 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
 266   void sqlite3VdbeComment(Vdbe*, const char*, ...);
 267 # define VdbeComment(X)  sqlite3VdbeComment X
 268   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
 269 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
 270 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
 271 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
 272 # else
 273 #   define VdbeModuleComment(X)
 274 # endif
 275 #else
 276 # define VdbeComment(X)
 277 # define VdbeNoopComment(X)
 278 # define VdbeModuleComment(X)
 279 #endif
 280
 281 /*
 282 ** The VdbeCoverage macros are used to set a coverage testing point
 283 ** for VDBE branch instructions.  The coverage testing points are line
 284 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
 285 ** only works with an amalagmation build.  That's ok since a VDBE branch
 286 ** coverage build designed for testing the test suite only.  No application
 287 ** should ever ship with VDBE branch coverage measuring turned on.
 288 **
 289 **    VdbeCoverage(v)                  // Mark the previously coded instruction
 290 **                                     // as a branch
 291 **
 292 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
 293 **
 294 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
 295 **
 296 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
 297 **
 298 ** Every VDBE branch operation must be tagged with one of the macros above.
 299 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
 300 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
 301 ** routine in vdbe.c, alerting the developer to the missed tag.
 302 */
 303 #ifdef SQLITE_VDBE_COVERAGE
 304   void sqlite3VdbeSetLineNumber(Vdbe*,int);
 305 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
 306 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
 307 # define VdbeCoverageAlwaysTaken(v) sqlite3VdbeSetLineNumber(v,2);
 308 # define VdbeCoverageNeverTaken(v) sqlite3VdbeSetLineNumber(v,1);
 309 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
 310 #else
 311 # define VdbeCoverage(v)
 312 # define VdbeCoverageIf(v,x)
 313 # define VdbeCoverageAlwaysTaken(v)
 314 # define VdbeCoverageNeverTaken(v)
 315 # define VDBE_OFFSET_LINENO(x) 0
 316 #endif
 317
 318 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 319 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
 320 #else
 321 # define sqlite3VdbeScanStatus(a,b,c,d,e)
 322 #endif
 323
 324 #endif /* SQLITE_VDBE_H */