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   u32 iSrcLine;            /* Source-code line that generated this opcode
  77                            ** with flags in the upper 8 bits */
  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   u8 *aOnce;                    /* Array of OP_Once flags */
  92   void *token;                  /* id that may be used to recursive triggers */
  93   SubProgram *pNext;            /* Next sub-program already visited */
  94 };
  95
  96 /*
  97 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because
  98 ** it takes up less space.
  99 */
 100 struct VdbeOpList {
 101   u8 opcode;          /* What operation to perform */
 102   signed char p1;     /* First operand */
 103   signed char p2;     /* Second parameter (often the jump destination) */
 104   signed char p3;     /* Third parameter */
 105 };
 106 typedef struct VdbeOpList VdbeOpList;
 107
 108 /*
 109 ** Allowed values of VdbeOp.p4type
 110 */
 111 #define P4_NOTUSED      0   /* The P4 parameter is not used */
 112 #define P4_TRANSIENT    0   /* P4 is a pointer to a transient string */
 113 #define P4_STATIC     (-1)  /* Pointer to a static string */
 114 #define P4_COLLSEQ    (-2)  /* P4 is a pointer to a CollSeq structure */
 115 #define P4_INT32      (-3)  /* P4 is a 32-bit signed integer */
 116 #define P4_SUBPROGRAM (-4)  /* P4 is a pointer to a SubProgram structure */
 117 #define P4_ADVANCE    (-5)  /* P4 is a pointer to BtreeNext() or BtreePrev() */
 118 #define P4_TABLE      (-6)  /* P4 is a pointer to a Table structure */
 119 /* Above do not own any resources.  Must free those below */
 120 #define P4_FREE_IF_LE (-7)
 121 #define P4_DYNAMIC    (-7)  /* Pointer to memory from sqliteMalloc() */
 122 #define P4_FUNCDEF    (-8)  /* P4 is a pointer to a FuncDef structure */
 123 #define P4_KEYINFO    (-9)  /* P4 is a pointer to a KeyInfo structure */
 124 #define P4_EXPR       (-10) /* P4 is a pointer to an Expr tree */
 125 #define P4_MEM        (-11) /* P4 is a pointer to a Mem*    structure */
 126 #define P4_VTAB       (-12) /* P4 is a pointer to an sqlite3_vtab structure */
 127 #define P4_REAL       (-13) /* P4 is a 64-bit floating point value */
 128 #define P4_INT64      (-14) /* P4 is a 64-bit signed integer */
 129 #define P4_INTARRAY   (-15) /* P4 is a vector of 32-bit integers */
 130 #define P4_FUNCCTX    (-16) /* P4 is a pointer to an sqlite3_context object */
 131 #define P4_DYNBLOB    (-17) /* Pointer to memory from sqliteMalloc() */
 132
 133 /* Error message codes for OP_Halt */
 134 #define P5_ConstraintNotNull 1
 135 #define P5_ConstraintUnique  2
 136 #define P5_ConstraintCheck   3
 137 #define P5_ConstraintFK      4
 138
 139 /*
 140 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
 141 ** number of columns of data returned by the statement.
 142 */
 143 #define COLNAME_NAME     0
 144 #define COLNAME_DECLTYPE 1
 145 #define COLNAME_DATABASE 2
 146 #define COLNAME_TABLE    3
 147 #define COLNAME_COLUMN   4
 148 #ifdef SQLITE_ENABLE_COLUMN_METADATA
 149 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
 150 #else
 151 # ifdef SQLITE_OMIT_DECLTYPE
 152 #   define COLNAME_N      1      /* Store only the name */
 153 # else
 154 #   define COLNAME_N      2      /* Store the name and decltype */
 155 # endif
 156 #endif
 157
 158 /*
 159 ** The following macro converts a relative address in the p2 field
 160 ** of a VdbeOp structure into a negative number so that
 161 ** sqlite3VdbeAddOpList() knows that the address is relative.  Calling
 162 ** the macro again restores the address.
 163 */
 164 #define ADDR(X)  (-1-(X))
 165
 166 /*
 167 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
 168 ** header file that defines a number for each opcode used by the VDBE.
 169 */
 170 #include "opcodes.h"
 171
 172 /*
 173 ** Additional non-public SQLITE_PREPARE_* flags
 174 */
 175 #define SQLITE_PREPARE_SAVESQL  0x80  /* Preserve SQL text */
 176 #define SQLITE_PREPARE_MASK     0x0f  /* Mask of public flags */
 177
 178 /*
 179 ** Prototypes for the VDBE interface.  See comments on the implementation
 180 ** for a description of what each of these routines does.
 181 */
 182 Vdbe *sqlite3VdbeCreate(Parse*);
 183 int sqlite3VdbeAddOp0(Vdbe*,int);
 184 int sqlite3VdbeAddOp1(Vdbe*,int,int);
 185 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
 186 int sqlite3VdbeGoto(Vdbe*,int);
 187 int sqlite3VdbeLoadString(Vdbe*,int,const char*);
 188 void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
 189 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 190 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
 191 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
 192 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
 193 void sqlite3VdbeEndCoroutine(Vdbe*,int);
 194 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
 195   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
 196   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);
 197 #else
 198 # define sqlite3VdbeVerifyNoMallocRequired(A,B)
 199 # define sqlite3VdbeVerifyNoResultRow(A)
 200 #endif
 201 #if defined(SQLITE_DEBUG)
 202   void sqlite3VdbeVerifyAbortable(Vdbe *p, int);
 203 #else
 204 # define sqlite3VdbeVerifyAbortable(A,B)
 205 #endif
 206 VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp,int iLineno);
 207 #ifndef SQLITE_OMIT_EXPLAIN
 208   void sqlite3VdbeExplain(Parse*,u8,const char*,...);
 209   void sqlite3VdbeExplainPop(Parse*);
 210   int sqlite3VdbeExplainParent(Parse*);
 211 # define ExplainQueryPlan(P)        sqlite3VdbeExplain P
 212 # define ExplainQueryPlanPop(P)     sqlite3VdbeExplainPop(P)
 213 # define ExplainQueryPlanParent(P)  sqlite3VdbeExplainParent(P)
 214 #else
 215 # define ExplainQueryPlan(P)
 216 # define ExplainQueryPlanPop(P)
 217 # define ExplainQueryPlanParent(P) 0
 218 #endif
 219 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
 220 void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
 221 void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
 222 void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
 223 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
 224 void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
 225 void sqlite3VdbeJumpHere(Vdbe*, int addr);
 226 int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
 227 int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
 228 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
 229 void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
 230 void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
 231 void sqlite3VdbeUsesBtree(Vdbe*, int);
 232 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
 233 int sqlite3VdbeMakeLabel(Vdbe*);
 234 void sqlite3VdbeRunOnlyOnce(Vdbe*);
 235 void sqlite3VdbeReusable(Vdbe*);
 236 void sqlite3VdbeDelete(Vdbe*);
 237 void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
 238 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
 239 int sqlite3VdbeFinalize(Vdbe*);
 240 void sqlite3VdbeResolveLabel(Vdbe*, int);
 241 #ifdef SQLITE_COVERAGE_TEST
 242   int sqlite3VdbeLabelHasBeenResolved(Vdbe*,int);
 243 #endif
 244 int sqlite3VdbeCurrentAddr(Vdbe*);
 245 #ifdef SQLITE_DEBUG
 246   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
 247 #endif
 248 void sqlite3VdbeResetStepResult(Vdbe*);
 249 void sqlite3VdbeRewind(Vdbe*);
 250 int sqlite3VdbeReset(Vdbe*);
 251 void sqlite3VdbeSetNumCols(Vdbe*,int);
 252 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
 253 void sqlite3VdbeCountChanges(Vdbe*);
 254 sqlite3 *sqlite3VdbeDb(Vdbe*);
 255 u8 sqlite3VdbePrepareFlags(Vdbe*);
 256 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
 257 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 258 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
 259 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
 260 void sqlite3VdbeSetVarmask(Vdbe*, int);
 261 #ifndef SQLITE_OMIT_TRACE
 262   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
 263 #endif
 264 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
 265 int sqlite3BlobCompare(const Mem*, const Mem*);
 266
 267 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
 268 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
 269 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
 270 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);
 271
 272 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
 273 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
 274
 275 #ifndef SQLITE_OMIT_TRIGGER
 276 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
 277 #endif
 278
 279 int sqlite3NotPureFunc(sqlite3_context*);
 280
 281 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
 282 ** each VDBE opcode.
 283 **
 284 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
 285 ** comments in VDBE programs that show key decision points in the code
 286 ** generator.
 287 */
 288 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
 289   void sqlite3VdbeComment(Vdbe*, const char*, ...);
 290 # define VdbeComment(X)  sqlite3VdbeComment X
 291   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
 292 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
 293 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
 294 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
 295 # else
 296 #   define VdbeModuleComment(X)
 297 # endif
 298 #else
 299 # define VdbeComment(X)
 300 # define VdbeNoopComment(X)
 301 # define VdbeModuleComment(X)
 302 #endif
 303
 304 /*
 305 ** The VdbeCoverage macros are used to set a coverage testing point
 306 ** for VDBE branch instructions.  The coverage testing points are line
 307 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
 308 ** only works with an amalagmation build.  That's ok since a VDBE branch
 309 ** coverage build designed for testing the test suite only.  No application
 310 ** should ever ship with VDBE branch coverage measuring turned on.
 311 **
 312 **    VdbeCoverage(v)                  // Mark the previously coded instruction
 313 **                                     // as a branch
 314 **
 315 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
 316 **
 317 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
 318 **
 319 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
 320 **
 321 **    VdbeCoverageNeverNull(v)         // Previous three-way branch is only
 322 **                                     // taken on the first two ways.  The
 323 **                                     // NULL option is not possible
 324 **
 325 **    VdbeCoverageEqNe(v)              // Previous OP_Jump is only interested
 326 **                                     // in distingishing equal and not-equal.
 327 **
 328 ** Every VDBE branch operation must be tagged with one of the macros above.
 329 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
 330 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
 331 ** routine in vdbe.c, alerting the developer to the missed tag.
 332 **
 333 ** During testing, the test application will invoke
 334 ** sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE,...) to set a callback
 335 ** routine that is invoked as each bytecode branch is taken.  The callback
 336 ** contains the sqlite3.c source line number ov the VdbeCoverage macro and
 337 ** flags to indicate whether or not the branch was taken.  The test application
 338 ** is responsible for keeping track of this and reporting byte-code branches
 339 ** that are never taken.
 340 **
 341 ** See the VdbeBranchTaken() macro and vdbeTakeBranch() function in the
 342 ** vdbe.c source file for additional information.
 343 */
 344 #ifdef SQLITE_VDBE_COVERAGE
 345   void sqlite3VdbeSetLineNumber(Vdbe*,int);
 346 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
 347 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
 348 # define VdbeCoverageAlwaysTaken(v) \
 349          sqlite3VdbeSetLineNumber(v,__LINE__|0x5000000);
 350 # define VdbeCoverageNeverTaken(v) \
 351          sqlite3VdbeSetLineNumber(v,__LINE__|0x6000000);
 352 # define VdbeCoverageNeverNull(v) \
 353          sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);
 354 # define VdbeCoverageNeverNullIf(v,x) \
 355          if(x)sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);
 356 # define VdbeCoverageEqNe(v) \
 357          sqlite3VdbeSetLineNumber(v,__LINE__|0x8000000);
 358 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
 359 #else
 360 # define VdbeCoverage(v)
 361 # define VdbeCoverageIf(v,x)
 362 # define VdbeCoverageAlwaysTaken(v)
 363 # define VdbeCoverageNeverTaken(v)
 364 # define VdbeCoverageNeverNull(v)
 365 # define VdbeCoverageNeverNullIf(v,x)
 366 # define VdbeCoverageEqNe(v)
 367 # define VDBE_OFFSET_LINENO(x) 0
 368 #endif
 369
 370 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 371 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
 372 #else
 373 # define sqlite3VdbeScanStatus(a,b,c,d,e)
 374 #endif
 375
 376 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
 377 void sqlite3VdbePrintOp(FILE*, int, VdbeOp*);
 378 #endif
 379
 380 #endif /* SQLITE_VDBE_H */