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 typedef struct SubrtnSig SubrtnSig;
  36
  37 /*
  38 ** A signature for a reusable subroutine that materializes the RHS of
  39 ** an IN operator.
  40 */
  41 struct SubrtnSig {
  42   int selId;          /* SELECT-id for the SELECT statement on the RHS */
  43   char *zAff;         /* Affinity of the overall IN expression */
  44   int iTable;         /* Ephemeral table generated by the subroutine */
  45   int iAddr;          /* Subroutine entry address */
  46   int regReturn;      /* Register used to hold return address */
  47 };
  48
  49 /*
  50 ** A single instruction of the virtual machine has an opcode
  51 ** and as many as three operands.  The instruction is recorded
  52 ** as an instance of the following structure:
  53 */
  54 struct VdbeOp {
  55   u8 opcode;          /* What operation to perform */
  56   signed char p4type; /* One of the P4_xxx constants for p4 */
  57   u16 p5;             /* Fifth parameter is an unsigned 16-bit integer */
  58   int p1;             /* First operand */
  59   int p2;             /* Second parameter (often the jump destination) */
  60   int p3;             /* The third parameter */
  61   union p4union {     /* fourth parameter */
  62     int i;                 /* Integer value if p4type==P4_INT32 */
  63     void *p;               /* Generic pointer */
  64     char *z;               /* Pointer to data for string (char array) types */
  65     i64 *pI64;             /* Used when p4type is P4_INT64 */
  66     double *pReal;         /* Used when p4type is P4_REAL */
  67     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
  68     sqlite3_context *pCtx; /* Used when p4type is P4_FUNCCTX */
  69     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
  70     Mem *pMem;             /* Used when p4type is P4_MEM */
  71     VTable *pVtab;         /* Used when p4type is P4_VTAB */
  72     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
  73     u32 *ai;               /* Used when p4type is P4_INTARRAY */
  74     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
  75     Table *pTab;           /* Used when p4type is P4_TABLE */
  76     SubrtnSig *pSubrtnSig; /* Used when p4type is P4_SUBRTNSIG */
  77 #ifdef SQLITE_ENABLE_CURSOR_HINTS
  78     Expr *pExpr;           /* Used when p4type is P4_EXPR */
  79 #endif
  80   } p4;
  81 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
  82   char *zComment;          /* Comment to improve readability */
  83 #endif
  84 #ifdef SQLITE_VDBE_COVERAGE
  85   u32 iSrcLine;            /* Source-code line that generated this opcode
  86                            ** with flags in the upper 8 bits */
  87 #endif
  88 #if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || defined(VDBE_PROFILE)
  89   u64 nExec;
  90   u64 nCycle;
  91 #endif
  92 };
  93 typedef struct VdbeOp VdbeOp;
  94
  95
  96 /*
  97 ** A sub-routine used to implement a trigger program.
  98 */
  99 struct SubProgram {
 100   VdbeOp *aOp;                  /* Array of opcodes for sub-program */
 101   int nOp;                      /* Elements in aOp[] */
 102   int nMem;                     /* Number of memory cells required */
 103   int nCsr;                     /* Number of cursors required */
 104   u8 *aOnce;                    /* Array of OP_Once flags */
 105   void *token;                  /* id that may be used to recursive triggers */
 106   SubProgram *pNext;            /* Next sub-program already visited */
 107 };
 108
 109 /*
 110 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because
 111 ** it takes up less space.
 112 */
 113 struct VdbeOpList {
 114   u8 opcode;          /* What operation to perform */
 115   signed char p1;     /* First operand */
 116   signed char p2;     /* Second parameter (often the jump destination) */
 117   signed char p3;     /* Third parameter */
 118 };
 119 typedef struct VdbeOpList VdbeOpList;
 120
 121 /*
 122 ** Allowed values of VdbeOp.p4type
 123 */
 124 #define P4_NOTUSED      0   /* The P4 parameter is not used */
 125 #define P4_TRANSIENT    0   /* P4 is a pointer to a transient string */
 126 #define P4_STATIC     (-1)  /* Pointer to a static string */
 127 #define P4_COLLSEQ    (-2)  /* P4 is a pointer to a CollSeq structure */
 128 #define P4_INT32      (-3)  /* P4 is a 32-bit signed integer */
 129 #define P4_SUBPROGRAM (-4)  /* P4 is a pointer to a SubProgram structure */
 130 #define P4_TABLE      (-5)  /* P4 is a pointer to a Table structure */
 131 /* Above do not own any resources.  Must free those below */
 132 #define P4_FREE_IF_LE (-6)
 133 #define P4_DYNAMIC    (-6)  /* Pointer to memory from sqliteMalloc() */
 134 #define P4_FUNCDEF    (-7)  /* P4 is a pointer to a FuncDef structure */
 135 #define P4_KEYINFO    (-8)  /* P4 is a pointer to a KeyInfo structure */
 136 #define P4_EXPR       (-9) /* P4 is a pointer to an Expr tree */
 137 #define P4_MEM        (-10) /* P4 is a pointer to a Mem*    structure */
 138 #define P4_VTAB       (-11) /* P4 is a pointer to an sqlite3_vtab structure */
 139 #define P4_REAL       (-12) /* P4 is a 64-bit floating point value */
 140 #define P4_INT64      (-13) /* P4 is a 64-bit signed integer */
 141 #define P4_INTARRAY   (-14) /* P4 is a vector of 32-bit integers */
 142 #define P4_FUNCCTX    (-15) /* P4 is a pointer to an sqlite3_context object */
 143 #define P4_TABLEREF   (-16) /* Like P4_TABLE, but reference counted */
 144 #define P4_SUBRTNSIG  (-17) /* P4 is a SubrtnSig pointer */
 145
 146 /* Error message codes for OP_Halt */
 147 #define P5_ConstraintNotNull 1
 148 #define P5_ConstraintUnique  2
 149 #define P5_ConstraintCheck   3
 150 #define P5_ConstraintFK      4
 151
 152 /*
 153 ** The Vdbe.aColName array contains 5n Mem structures, where n is the
 154 ** number of columns of data returned by the statement.
 155 */
 156 #define COLNAME_NAME     0
 157 #define COLNAME_DECLTYPE 1
 158 #define COLNAME_DATABASE 2
 159 #define COLNAME_TABLE    3
 160 #define COLNAME_COLUMN   4
 161 #ifdef SQLITE_ENABLE_COLUMN_METADATA
 162 # define COLNAME_N        5      /* Number of COLNAME_xxx symbols */
 163 #else
 164 # ifdef SQLITE_OMIT_DECLTYPE
 165 #   define COLNAME_N      1      /* Store only the name */
 166 # else
 167 #   define COLNAME_N      2      /* Store the name and decltype */
 168 # endif
 169 #endif
 170
 171 /*
 172 ** The following macro converts a label returned by sqlite3VdbeMakeLabel()
 173 ** into an index into the Parse.aLabel[] array that contains the resolved
 174 ** address of that label.
 175 */
 176 #define ADDR(X)  (~(X))
 177
 178 /*
 179 ** The makefile scans the vdbe.c source file and creates the "opcodes.h"
 180 ** header file that defines a number for each opcode used by the VDBE.
 181 */
 182 #include "opcodes.h"
 183
 184 /*
 185 ** Additional non-public SQLITE_PREPARE_* flags
 186 */
 187 #define SQLITE_PREPARE_SAVESQL  0x80  /* Preserve SQL text */
 188 #define SQLITE_PREPARE_MASK     0x0f  /* Mask of public flags */
 189
 190 /*
 191 ** Prototypes for the VDBE interface.  See comments on the implementation
 192 ** for a description of what each of these routines does.
 193 */
 194 Vdbe *sqlite3VdbeCreate(Parse*);
 195 Parse *sqlite3VdbeParser(Vdbe*);
 196 int sqlite3VdbeAddOp0(Vdbe*,int);
 197 int sqlite3VdbeAddOp1(Vdbe*,int,int);
 198 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
 199 int sqlite3VdbeGoto(Vdbe*,int);
 200 int sqlite3VdbeLoadString(Vdbe*,int,const char*);
 201 void sqlite3VdbeMultiLoad(Vdbe*,int,const char*,...);
 202 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 203 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
 204 int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
 205 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
 206 int sqlite3VdbeAddFunctionCall(Parse*,int,int,int,int,const FuncDef*,int);
 207 void sqlite3VdbeEndCoroutine(Vdbe*,int);
 208 #if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
 209   void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N);
 210   void sqlite3VdbeVerifyNoResultRow(Vdbe *p);
 211 #else
 212 # define sqlite3VdbeVerifyNoMallocRequired(A,B)
 213 # define sqlite3VdbeVerifyNoResultRow(A)
 214 #endif
 215 #if defined(SQLITE_DEBUG)
 216   void sqlite3VdbeVerifyAbortable(Vdbe *p, int);
 217   void sqlite3VdbeNoJumpsOutsideSubrtn(Vdbe*,int,int,int);
 218 #else
 219 # define sqlite3VdbeVerifyAbortable(A,B)
 220 # define sqlite3VdbeNoJumpsOutsideSubrtn(A,B,C,D)
 221 #endif
 222 VdbeOp *sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp,int iLineno);
 223 #ifndef SQLITE_OMIT_EXPLAIN
 224   int sqlite3VdbeExplain(Parse*,u8,const char*,...);
 225   void sqlite3VdbeExplainPop(Parse*);
 226   int sqlite3VdbeExplainParent(Parse*);
 227 # define ExplainQueryPlan(P)        sqlite3VdbeExplain P
 228 # ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 229 #  define ExplainQueryPlan2(V,P)     (V = sqlite3VdbeExplain P)
 230 # else
 231 #  define ExplainQueryPlan2(V,P)     ExplainQueryPlan(P)
 232 # endif
 233 # define ExplainQueryPlanPop(P)     sqlite3VdbeExplainPop(P)
 234 # define ExplainQueryPlanParent(P)  sqlite3VdbeExplainParent(P)
 235 #else
 236 # define ExplainQueryPlan(P)
 237 # define ExplainQueryPlan2(V,P)
 238 # define ExplainQueryPlanPop(P)
 239 # define ExplainQueryPlanParent(P) 0
 240 # define sqlite3ExplainBreakpoint(A,B) /*no-op*/
 241 #endif
 242 #if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_EXPLAIN)
 243   void sqlite3ExplainBreakpoint(const char*,const char*);
 244 #else
 245 # define sqlite3ExplainBreakpoint(A,B) /*no-op*/
 246 #endif
 247 void sqlite3VdbeAddParseSchemaOp(Vdbe*, int, char*, u16);
 248 void sqlite3VdbeChangeOpcode(Vdbe*, int addr, u8);
 249 void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
 250 void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
 251 void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3);
 252 void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
 253 void sqlite3VdbeTypeofColumn(Vdbe*, int);
 254 void sqlite3VdbeJumpHere(Vdbe*, int addr);
 255 void sqlite3VdbeJumpHereOrPopInst(Vdbe*, int addr);
 256 int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
 257 int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
 258 #ifdef SQLITE_DEBUG
 259   void sqlite3VdbeReleaseRegisters(Parse*,int addr, int n, u32 mask, int);
 260 #else
 261 # define sqlite3VdbeReleaseRegisters(P,A,N,M,F)
 262 #endif
 263 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
 264 void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
 265 void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
 266 void sqlite3VdbeUsesBtree(Vdbe*, int);
 267 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
 268 VdbeOp *sqlite3VdbeGetLastOp(Vdbe*);
 269 int sqlite3VdbeMakeLabel(Parse*);
 270 void sqlite3VdbeRunOnlyOnce(Vdbe*);
 271 void sqlite3VdbeReusable(Vdbe*);
 272 void sqlite3VdbeDelete(Vdbe*);
 273 void sqlite3VdbeMakeReady(Vdbe*,Parse*);
 274 int sqlite3VdbeFinalize(Vdbe*);
 275 void sqlite3VdbeResolveLabel(Vdbe*, int);
 276 int sqlite3VdbeCurrentAddr(Vdbe*);
 277 #ifdef SQLITE_DEBUG
 278   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
 279 #endif
 280 void sqlite3VdbeResetStepResult(Vdbe*);
 281 void sqlite3VdbeRewind(Vdbe*);
 282 int sqlite3VdbeReset(Vdbe*);
 283 void sqlite3VdbeSetNumCols(Vdbe*,int);
 284 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
 285 void sqlite3VdbeCountChanges(Vdbe*);
 286 sqlite3 *sqlite3VdbeDb(Vdbe*);
 287 u8 sqlite3VdbePrepareFlags(Vdbe*);
 288 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
 289 #ifdef SQLITE_ENABLE_NORMALIZE
 290 void sqlite3VdbeAddDblquoteStr(sqlite3*,Vdbe*,const char*);
 291 int sqlite3VdbeUsesDoubleQuotedString(Vdbe*,const char*);
 292 #endif
 293 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 294 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
 295 sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
 296 void sqlite3VdbeSetVarmask(Vdbe*, int);
 297 #ifndef SQLITE_OMIT_TRACE
 298   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
 299 #endif
 300 int sqlite3MemCompare(const Mem*, const Mem*, const CollSeq*);
 301 int sqlite3BlobCompare(const Mem*, const Mem*);
 302
 303 void sqlite3VdbeRecordUnpack(KeyInfo*,int,const void*,UnpackedRecord*);
 304 int sqlite3VdbeRecordCompare(int,const void*,UnpackedRecord*);
 305 int sqlite3VdbeRecordCompareWithSkip(int, const void *, UnpackedRecord *, int);
 306 UnpackedRecord *sqlite3VdbeAllocUnpackedRecord(KeyInfo*);
 307
 308 typedef int (*RecordCompare)(int,const void*,UnpackedRecord*);
 309 RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
 310
 311 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
 312 int sqlite3VdbeHasSubProgram(Vdbe*);
 313
 314 void sqlite3MemSetArrayInt64(sqlite3_value *aMem, int iIdx, i64 val);
 315
 316 int sqlite3NotPureFunc(sqlite3_context*);
 317 #ifdef SQLITE_ENABLE_BYTECODE_VTAB
 318 int sqlite3VdbeBytecodeVtabInit(sqlite3*);
 319 #endif
 320
 321 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
 322 ** each VDBE opcode.
 323 **
 324 ** Use the SQLITE_ENABLE_MODULE_COMMENTS macro to see some extra no-op
 325 ** comments in VDBE programs that show key decision points in the code
 326 ** generator.
 327 */
 328 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
 329   void sqlite3VdbeComment(Vdbe*, const char*, ...);
 330 # define VdbeComment(X)  sqlite3VdbeComment X
 331   void sqlite3VdbeNoopComment(Vdbe*, const char*, ...);
 332 # define VdbeNoopComment(X)  sqlite3VdbeNoopComment X
 333 # ifdef SQLITE_ENABLE_MODULE_COMMENTS
 334 #   define VdbeModuleComment(X)  sqlite3VdbeNoopComment X
 335 # else
 336 #   define VdbeModuleComment(X)
 337 # endif
 338 #else
 339 # define VdbeComment(X)
 340 # define VdbeNoopComment(X)
 341 # define VdbeModuleComment(X)
 342 #endif
 343
 344 /*
 345 ** The VdbeCoverage macros are used to set a coverage testing point
 346 ** for VDBE branch instructions.  The coverage testing points are line
 347 ** numbers in the sqlite3.c source file.  VDBE branch coverage testing
 348 ** only works with an amalgamation build.  That's ok since a VDBE branch
 349 ** coverage build designed for testing the test suite only.  No application
 350 ** should ever ship with VDBE branch coverage measuring turned on.
 351 **
 352 **    VdbeCoverage(v)                  // Mark the previously coded instruction
 353 **                                     // as a branch
 354 **
 355 **    VdbeCoverageIf(v, conditional)   // Mark previous if conditional true
 356 **
 357 **    VdbeCoverageAlwaysTaken(v)       // Previous branch is always taken
 358 **
 359 **    VdbeCoverageNeverTaken(v)        // Previous branch is never taken
 360 **
 361 **    VdbeCoverageNeverNull(v)         // Previous three-way branch is only
 362 **                                     // taken on the first two ways.  The
 363 **                                     // NULL option is not possible
 364 **
 365 **    VdbeCoverageEqNe(v)              // Previous OP_Jump is only interested
 366 **                                     // in distinguishing equal and not-equal.
 367 **
 368 ** Every VDBE branch operation must be tagged with one of the macros above.
 369 ** If not, then when "make test" is run with -DSQLITE_VDBE_COVERAGE and
 370 ** -DSQLITE_DEBUG then an ALWAYS() will fail in the vdbeTakeBranch()
 371 ** routine in vdbe.c, alerting the developer to the missed tag.
 372 **
 373 ** During testing, the test application will invoke
 374 ** sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE,...) to set a callback
 375 ** routine that is invoked as each bytecode branch is taken.  The callback
 376 ** contains the sqlite3.c source line number of the VdbeCoverage macro and
 377 ** flags to indicate whether or not the branch was taken.  The test application
 378 ** is responsible for keeping track of this and reporting byte-code branches
 379 ** that are never taken.
 380 **
 381 ** See the VdbeBranchTaken() macro and vdbeTakeBranch() function in the
 382 ** vdbe.c source file for additional information.
 383 */
 384 #ifdef SQLITE_VDBE_COVERAGE
 385   void sqlite3VdbeSetLineNumber(Vdbe*,int);
 386 # define VdbeCoverage(v) sqlite3VdbeSetLineNumber(v,__LINE__)
 387 # define VdbeCoverageIf(v,x) if(x)sqlite3VdbeSetLineNumber(v,__LINE__)
 388 # define VdbeCoverageAlwaysTaken(v) \
 389          sqlite3VdbeSetLineNumber(v,__LINE__|0x5000000);
 390 # define VdbeCoverageNeverTaken(v) \
 391          sqlite3VdbeSetLineNumber(v,__LINE__|0x6000000);
 392 # define VdbeCoverageNeverNull(v) \
 393          sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);
 394 # define VdbeCoverageNeverNullIf(v,x) \
 395          if(x)sqlite3VdbeSetLineNumber(v,__LINE__|0x4000000);
 396 # define VdbeCoverageEqNe(v) \
 397          sqlite3VdbeSetLineNumber(v,__LINE__|0x8000000);
 398 # define VDBE_OFFSET_LINENO(x) (__LINE__+x)
 399 #else
 400 # define VdbeCoverage(v)
 401 # define VdbeCoverageIf(v,x)
 402 # define VdbeCoverageAlwaysTaken(v)
 403 # define VdbeCoverageNeverTaken(v)
 404 # define VdbeCoverageNeverNull(v)
 405 # define VdbeCoverageNeverNullIf(v,x)
 406 # define VdbeCoverageEqNe(v)
 407 # define VDBE_OFFSET_LINENO(x) 0
 408 #endif
 409
 410 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 411 void sqlite3VdbeScanStatus(Vdbe*, int, int, int, LogEst, const char*);
 412 void sqlite3VdbeScanStatusRange(Vdbe*, int, int, int);
 413 void sqlite3VdbeScanStatusCounters(Vdbe*, int, int, int);
 414 #else
 415 # define sqlite3VdbeScanStatus(a,b,c,d,e,f)
 416 # define sqlite3VdbeScanStatusRange(a,b,c,d)
 417 # define sqlite3VdbeScanStatusCounters(a,b,c,d)
 418 #endif
 419
 420 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
 421 void sqlite3VdbePrintOp(FILE*, int, VdbeOp*);
 422 #endif
 423
 424 #if defined(SQLITE_ENABLE_CURSOR_HINTS) && defined(SQLITE_DEBUG)
 425 int sqlite3CursorRangeHintExprCheck(Walker *pWalker, Expr *pExpr);
 426 #endif
 427
 428 #endif /* SQLITE_VDBE_H */