Allow indexes to be created on date/time functions as long as the 'now'

date and the 'localtime' and 'utc' modifiers are not used. FossilOrigin-Name: 0a5e1c04d9d07bb7fd6546a9ddac1bf42b19ea19c2b79570aea6cd4226887a27
2025-08-07 02:42:48 +03:00 · 2017-07-19 19:48:40 +00:00
parent 885f410472
commit 3e34eabcdf
11 changed files with 189 additions and 145 deletions
--- a/33
+++ b/33
@@ -1,5 +1,5 @@
-C Remove\ssome\s'breakpoint'\scommands\sin\stest\sfiles.
-D 2017-07-19T18:01:42.362
+C Allow\sindexes\sto\sbe\screated\son\sdate/time\sfunctions\sas\slong\sas\sthe\s'now'\ndate\sand\sthe\s'localtime'\sand\s'utc'\smodifiers\sare\snot\sused.
+D 2017-07-19T19:48:40.351
 F Makefile.in d9873c9925917cca9990ee24be17eb9613a668012c85a343aef7e5536ae266e8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 02b469e9dcd5b7ee63fc1fb05babc174260ee4cfa4e0ef2e48c3c6801567a016
@@ -402,10 +402,10 @@ F src/build.c 74108007d286232fb4290464ee5452fa860c26215f8caa0e6c7cbf69a6fafe8f
 F src/callback.c 8e14b60d1ed1c87c02cb5f121ecda99224f2aea6524a77ee6f72c9b5c7110f84
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 928954802b1397d9fb1378c7eb702c94b4735bbab1d5793e21b6a77734f56a1b
-F src/date.c cc42a41c7422389860d40419a5e3bce5eaf6e7835c3ba2677751dc653550a5c7
+F src/date.c 921fb5957cacfb4e512d25efa13fbdf5f3ebade2077a0809fbe24105d2f33cff
 F src/dbstat.c 7a4ba8518b6369ef3600c49cf9c918ad979acba610b2aebef1b656d649b96720
-F src/delete.c 3213547e97b676c6fa79948b7a9ede4801ea04a01a2043241deafedf132ecf5d
-F src/expr.c 68552ca7f1238c9661e60a3adb4bd28c93d5373895bed5a0293b3977518dc980
+F src/delete.c 939bd15e6b54b82b951e1c0ffc2ff2b4ab579196780a1f6d394e47bd6f799b6c
+F src/expr.c 17fb28516a5fbfbabdade6b3401c797b0804de25e36b7b1becff2cf07921dc4c
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 5ff2c895fe087756d8085dc1a9bc229b5670e2a65c3929dd87c71e43649af333
 F src/func.c e2854b19386b93ad6b498a3f3b7d6baa98ec14cfe84530fb12fce4414263d871
@@ -445,7 +445,7 @@ F src/parse.y e384cb73f99e1b074085c974b37f4d830e885359e4b60837e30f7d67c16ba65b
 F src/pcache.c 62835bed959e2914edd26afadfecce29ece0e870
 F src/pcache.h 521bb9610d38ef17a3cc9b5ddafd4546c2ea67fa3d0e464823d73c2a28d50e11
 F src/pcache1.c 1195a21fe28e223e024f900b2011e80df53793f0356a24caace4188b098540dc
-F src/pragma.c d42b6b5af353bcd763f1901accb63e07855bb8d74c81d246be12488e424e6804
+F src/pragma.c 95672b7dc59930b4978d08baa8c357085767cc30e5d3ddac9b12592489d3ede2
 F src/pragma.h bb83728944b42f6d409c77f5838a8edbdb0fe83046c5496ffc9602b40340a324
 F src/prepare.c dd250f904739b1dc449c131ac527c35e3424d94082dd111321bd83f80c6bb0fe
 F src/printf.c 8757834f1b54dae512fb25eb1acc8e94a0d15dd2290b58f2563f65973265adb2
@@ -458,7 +458,7 @@ F src/shell.c.in b5725acacba95ccefa57b6d068f710e29ba8239c3aa704628a1902a1f729c17
 F src/sqlite.h.in dad804d4e1979a2ddec33cc8da6aa50c04e6ba0dcb4058e7b3609588d010e041
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 967154985ed2ae62f90d9029bb5b5071793d847f1696a2ebe9e8cc0b042ae60b
-F src/sqliteInt.h 0ba730cdc8afa723a5642380712f8bb33abd6a69218571c18b94acf3562de22a
+F src/sqliteInt.h 9b57e05822422268d5a20fa797afd23bf2b039c8401e87dff26700c0c39faf34
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c a9e66593dfb28a9e746cba7153f84d49c1ddc4b1
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -520,11 +520,11 @@ F src/update.c c443935c652af9365e033f756550b5032d02e1b06eb2cb890ed7511ae0c051dc
 F src/utf.c 810fbfebe12359f10bc2a011520a6e10879ab2a163bcb26c74768eab82ea62a5
 F src/util.c fc081ec6f63448dcd80d3dfad35baecfa104823254a815b081a4d9fe76e1db23
 F src/vacuum.c 874c0f2f15ab2908748297d587d22d485ea96d55aaec91d4775dddb2e24d2ecf
-F src/vdbe.c adc8a378710ec2376101483cc8a5f499539ee9bbebfb2a784f3370704d5d44ad
-F src/vdbe.h 7bf719031782823b915aff2c1f93d1944c1c6b300770a15339b7dbc9610b802e
+F src/vdbe.c 1e541ec7ff409bbabcc6b4f154957296fff5827c16c2ab0056348acae75685bf
+F src/vdbe.h c1fc5b3d31756eb12b7bf43595260388b01f2c85e65fdb6ac0c3f618bfcaf717
 F src/vdbeInt.h 19bd04a4211fe56c712ab35b48be77fd5a0579b851e9dea2cb8deade359b72b9
 F src/vdbeapi.c 52844a5a71712197be45f1c63d730c48a745c7457c959465cfb2b969af40a266
-F src/vdbeaux.c 518d1cf6728ecb591390541c58b14902e8d61735ef574426b9971624c54d2c4b
+F src/vdbeaux.c 23a02ba4195b5cc4d48a494d52a8cd5a194ce5f80e8a295c302bcbabccf39979
 F src/vdbeblob.c 359891617358deefc85bef7bcf787fa6b77facb9
 F src/vdbemem.c fe8fce1cdc258320b465934039fe4b1230d63f81d6b81b1eac775b6eec00af0d
 F src/vdbesort.c f512c68d0bf7e0105316a5594c4329358c8ee9cae3b25138df041d97516c0372
@@ -935,7 +935,7 @@ F test/index7.test 7feababe16f2091b229c22aff2bcc1d4d6b9d2bb
 F test/index8.test bc2e3db70e8e62459aaa1bd7e4a9b39664f8f9d7
 F test/index9.test 0aa3e509dddf81f93380396e40e9bb386904c1054924ba8fa9bcdfe85a8e7721
 F test/indexedby.test 9c4cd331224e57f79fbf411ae245e6272d415985
-F test/indexexpr1.test 038b3befa74e5a75126b6e9dd2ae5df61c1c7cf7
+F test/indexexpr1.test 1857373a97e4795ce4119caf05cbb148bdabe1c8738fc0b7e5e240abb6adbe4e
 F test/indexexpr2.test 3ddd7f23bc381b9f2b7a15f2d083b1a4078e7733dce8295602ecfa3c74a34cf9
 F test/indexfault.test 31d4ab9a7d2f6e9616933eb079722362a883eb1d
 F test/init.test 15c823093fdabbf7b531fe22cf037134d09587a7
@@ -1636,7 +1636,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P c93284cd65b6471bffc38696e14dc24a2170698faf566cf91b727ba272f88c25
-R 9a0e35c22d772f08ad350059e0e65c0d
-U mistachkin
-Z 3b6354332c6aa6dc358fe07c8de8d63d
+P d14fc621e918915bbf8e04597eb238ea78dff3d9c5eb4402cb88692d00dbdfee
+R 71a176dbaf167be1fc010ab41b45c196
+T *branch * index-on-date-func
+T *sym-index-on-date-func *
+T -sym-trunk *
+U drh
+Z 6174c3091e77280f162146b58b68a8ad
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d14fc621e918915bbf8e04597eb238ea78dff3d9c5eb4402cb88692d00dbdfee
+0a5e1c04d9d07bb7fd6546a9ddac1bf42b19ea19c2b79570aea6cd4226887a27
--- a/src/date.c
+++ b/src/date.c
@@ -386,7 +386,8 @@ static int parseDateOrTime(
    return 0;
  }else if( parseHhMmSs(zDate, p)==0 ){
    return 0;
-  }else if( sqlite3StrICmp(zDate,"now")==0){
+  }else if( sqlite3StrICmp(zDate,"now")==0 ){
+    sqlite3VdbePureFuncOnly(context);
    return setDateTimeToCurrent(context, p);
  }else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8) ){
    setRawDateNumber(p, r);
@@ -670,6 +671,7 @@ static int parseModifier(
      ** show local time.
      */
      if( sqlite3_stricmp(z, "localtime")==0 ){
+        sqlite3VdbePureFuncOnly(pCtx);
        computeJD(p);
        p->iJD += localtimeOffset(p, pCtx, &rc);
        clearYMD_HMS_TZ(p);
@@ -696,6 +698,7 @@ static int parseModifier(
      }
 #ifndef SQLITE_OMIT_LOCALTIME
      else if( sqlite3_stricmp(z, "utc")==0 ){
+        sqlite3VdbePureFuncOnly(pCtx);
        if( p->tzSet==0 ){
          sqlite3_int64 c1;
          computeJD(p);
@@ -1231,11 +1234,11 @@ static void currentTimeFunc(
 void sqlite3RegisterDateTimeFunctions(void){
  static FuncDef aDateTimeFuncs[] = {
 #ifndef SQLITE_OMIT_DATETIME_FUNCS
-    DFUNCTION(julianday,        -1, 0, 0, juliandayFunc ),
-    DFUNCTION(date,             -1, 0, 0, dateFunc      ),
-    DFUNCTION(time,             -1, 0, 0, timeFunc      ),
-    DFUNCTION(datetime,         -1, 0, 0, datetimeFunc  ),
-    DFUNCTION(strftime,         -1, 0, 0, strftimeFunc  ),
+    PURE_DATE(julianday,        -1, 0, 0, juliandayFunc ),
+    PURE_DATE(date,             -1, 0, 0, dateFunc      ),
+    PURE_DATE(time,             -1, 0, 0, timeFunc      ),
+    PURE_DATE(datetime,         -1, 0, 0, datetimeFunc  ),
+    PURE_DATE(strftime,         -1, 0, 0, strftimeFunc  ),
    DFUNCTION(current_time,      0, 0, 0, ctimeFunc     ),
    DFUNCTION(current_timestamp, 0, 0, 0, ctimestampFunc),
    DFUNCTION(current_date,      0, 0, 0, cdateFunc     ),
--- a/src/delete.c
+++ b/src/delete.c
@@ -852,10 +852,11 @@ int sqlite3GenerateIndexKey(
  if( piPartIdxLabel ){
    if( pIdx->pPartIdxWhere ){
      *piPartIdxLabel = sqlite3VdbeMakeLabel(v);
-      pParse->iSelfTab = iDataCur;
+      pParse->iSelfTab = iDataCur + 1;
      sqlite3ExprCachePush(pParse);
      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
                            SQLITE_JUMPIFNULL);
+      pParse->iSelfTab = 0;
    }else{
      *piPartIdxLabel = 0;
    }
--- a/src/expr.c
+++ b/src/expr.c
@@ -3238,8 +3238,9 @@ void sqlite3ExprCodeLoadIndexColumn(
  if( iTabCol==XN_EXPR ){
    assert( pIdx->aColExpr );
    assert( pIdx->aColExpr->nExpr>iIdxCol );
-    pParse->iSelfTab = iTabCur;
+    pParse->iSelfTab = iTabCur + 1;
    sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[iIdxCol].pExpr, regOut);
+    pParse->iSelfTab = 0;
  }else{
    sqlite3ExprCodeGetColumnOfTable(pParse->pVdbe, pIdx->pTable, iTabCur,
                                    iTabCol, regOut);
@@ -3489,7 +3490,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
        }else{
          /* Coding an expression that is part of an index where column names
          ** in the index refer to the table to which the index belongs */
-          iTab = pParse->iSelfTab;
+          iTab = pParse->iSelfTab - 1;
        }
      }
      return sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
@@ -3826,8 +3827,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
        if( !pColl ) pColl = db->pDfltColl; 
        sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
      }
-      sqlite3VdbeAddOp4(v, OP_Function0, constMask, r1, target,
-                        (char*)pDef, P4_FUNCDEF);
+      sqlite3VdbeAddOp4(v, pParse->iSelfTab ? OP_PureFunc0 : OP_Function0,
+                        constMask, r1, target, (char*)pDef, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, (u8)nFarg);
      if( nFarg && constMask==0 ){
        sqlite3ReleaseTempRange(pParse, r1, nFarg);
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -1594,7 +1594,7 @@ void sqlite3Pragma(
            int addrCkOk = sqlite3VdbeMakeLabel(v);
            char *zErr;
            int k;
-            pParse->iSelfTab = iDataCur;
+            pParse->iSelfTab = iDataCur+1;
            sqlite3ExprCachePush(pParse);
            for(k=pCheck->nExpr-1; k>0; k--){
              sqlite3ExprIfFalse(pParse, pCheck->a[k].pExpr, addrCkFault, 0);
@@ -1602,6 +1602,7 @@ void sqlite3Pragma(
            sqlite3ExprIfTrue(pParse, pCheck->a[0].pExpr, addrCkOk, 
                SQLITE_JUMPIFNULL);
            sqlite3VdbeResolveLabel(v, addrCkFault);
+            pParse->iSelfTab = 0;
            zErr = sqlite3MPrintf(db, "CHECK constraint failed in %s",
                pTab->zName);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1628,7 +1628,14 @@ struct FuncDestructor {
 **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
 **     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions
 **     and functions like sqlite_version() that can change, but not during
-**     a single query.
+**     a single query.  The iArg is ignored.  The user-data is always set
+**     to a NULL pointer.  The bNC parameter is not used.
+**
+**   PURE_DATE(zName, nArg, iArg, bNC, xFunc)
+**     Used for "pure" date/time functions, this macro is like DFUNCTION
+**     except that it does set the SQLITE_FUNC_CONSTANT flags.  iArg is
+**     ignored and the user-data for these functions is set to an 
+**     arbitrary non-NULL pointer.  The bNC parameter is not used.
 **
 **   AGGREGATE(zName, nArg, iArg, bNC, xStep, xFinal)
 **     Used to create an aggregate function definition implemented by
@@ -1651,8 +1658,11 @@ struct FuncDestructor {
  {nArg, SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
 #define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
-  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
-   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
+  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8, \
+   0, 0, xFunc, 0, #zName, {0} }
+#define PURE_DATE(zName, nArg, iArg, bNC, xFunc) \
+  {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8|SQLITE_FUNC_CONSTANT, \
+   (void*)xFunc, 0, xFunc, 0, #zName, {0} }
 #define FUNCTION2(zName, nArg, iArg, bNC, xFunc, extraFlags) \
  {nArg,SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL)|extraFlags,\
   SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, #zName, {0} }
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -1590,117 +1590,6 @@ case OP_CollSeq: {
  break;
 }

-/* Opcode: Function0 P1 P2 P3 P4 P5
-** Synopsis: r[P3]=func(r[P2@P5])
-**
-** Invoke a user function (P4 is a pointer to a FuncDef object that
-** defines the function) with P5 arguments taken from register P2 and
-** successors.  The result of the function is stored in register P3.
-** Register P3 must not be one of the function inputs.
-**
-** P1 is a 32-bit bitmask indicating whether or not each argument to the 
-** function was determined to be constant at compile time. If the first
-** argument was constant then bit 0 of P1 is set. This is used to determine
-** whether meta data associated with a user function argument using the
-** sqlite3_set_auxdata() API may be safely retained until the next
-** invocation of this opcode.
-**
-** See also: Function, AggStep, AggFinal
-*/
-/* Opcode: Function P1 P2 P3 P4 P5
-** Synopsis: r[P3]=func(r[P2@P5])
-**
-** Invoke a user function (P4 is a pointer to an sqlite3_context object that
-** contains a pointer to the function to be run) with P5 arguments taken
-** from register P2 and successors.  The result of the function is stored
-** in register P3.  Register P3 must not be one of the function inputs.
-**
-** P1 is a 32-bit bitmask indicating whether or not each argument to the 
-** function was determined to be constant at compile time. If the first
-** argument was constant then bit 0 of P1 is set. This is used to determine
-** whether meta data associated with a user function argument using the
-** sqlite3_set_auxdata() API may be safely retained until the next
-** invocation of this opcode.
-**
-** SQL functions are initially coded as OP_Function0 with P4 pointing
-** to a FuncDef object.  But on first evaluation, the P4 operand is
-** automatically converted into an sqlite3_context object and the operation
-** changed to this OP_Function opcode.  In this way, the initialization of
-** the sqlite3_context object occurs only once, rather than once for each
-** evaluation of the function.
-**
-** See also: Function0, AggStep, AggFinal
-*/
-case OP_Function0: {
-  int n;
-  sqlite3_context *pCtx;
-
-  assert( pOp->p4type==P4_FUNCDEF );
-  n = pOp->p5;
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
-  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
-  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
-  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
-  if( pCtx==0 ) goto no_mem;
-  pCtx->pOut = 0;
-  pCtx->pFunc = pOp->p4.pFunc;
-  pCtx->iOp = (int)(pOp - aOp);
-  pCtx->pVdbe = p;
-  pCtx->argc = n;
-  pOp->p4type = P4_FUNCCTX;
-  pOp->p4.pCtx = pCtx;
-  pOp->opcode = OP_Function;
-  /* Fall through into OP_Function */
-}
-case OP_Function: {
-  int i;
-  sqlite3_context *pCtx;
-
-  assert( pOp->p4type==P4_FUNCCTX );
-  pCtx = pOp->p4.pCtx;
-
-  /* If this function is inside of a trigger, the register array in aMem[]
-  ** might change from one evaluation to the next.  The next block of code
-  ** checks to see if the register array has changed, and if so it
-  ** reinitializes the relavant parts of the sqlite3_context object */
-  pOut = &aMem[pOp->p3];
-  if( pCtx->pOut != pOut ){
-    pCtx->pOut = pOut;
-    for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
-  }
-
-  memAboutToChange(p, pOut);
-#ifdef SQLITE_DEBUG
-  for(i=0; i<pCtx->argc; i++){
-    assert( memIsValid(pCtx->argv[i]) );
-    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
-  }
-#endif
-  MemSetTypeFlag(pOut, MEM_Null);
-  pCtx->fErrorOrAux = 0;
-  (*pCtx->pFunc->xSFunc)(pCtx, pCtx->argc, pCtx->argv);/* IMP: R-24505-23230 */
-
-  /* If the function returned an error, throw an exception */
-  if( pCtx->fErrorOrAux ){
-    if( pCtx->isError ){
-      sqlite3VdbeError(p, "%s", sqlite3_value_text(pOut));
-      rc = pCtx->isError;
-    }
-    sqlite3VdbeDeleteAuxData(db, &p->pAuxData, pCtx->iOp, pOp->p1);
-    if( rc ) goto abort_due_to_error;
-  }
-
-  /* Copy the result of the function into register P3 */
-  if( pOut->flags & (MEM_Str|MEM_Blob) ){
-    sqlite3VdbeChangeEncoding(pOut, encoding);
-    if( sqlite3VdbeMemTooBig(pOut) ) goto too_big;
-  }
-
-  REGISTER_TRACE(pOp->p3, pOut);
-  UPDATE_MAX_BLOBSIZE(pOut);
-  break;
-}
-
 /* Opcode: BitAnd P1 P2 P3 * *
 ** Synopsis: r[P3]=r[P1]&r[P2]
 **
@@ -7000,6 +6889,121 @@ case OP_MaxPgcnt: {            /* out2 */
 }
 #endif

+/* Opcode: Function0 P1 P2 P3 P4 P5
+** Synopsis: r[P3]=func(r[P2@P5])
+**
+** Invoke a user function (P4 is a pointer to a FuncDef object that
+** defines the function) with P5 arguments taken from register P2 and
+** successors.  The result of the function is stored in register P3.
+** Register P3 must not be one of the function inputs.
+**
+** P1 is a 32-bit bitmask indicating whether or not each argument to the 
+** function was determined to be constant at compile time. If the first
+** argument was constant then bit 0 of P1 is set. This is used to determine
+** whether meta data associated with a user function argument using the
+** sqlite3_set_auxdata() API may be safely retained until the next
+** invocation of this opcode.
+**
+** See also: Function, AggStep, AggFinal
+*/
+/* Opcode: Function P1 P2 P3 P4 P5
+** Synopsis: r[P3]=func(r[P2@P5])
+**
+** Invoke a user function (P4 is a pointer to an sqlite3_context object that
+** contains a pointer to the function to be run) with P5 arguments taken
+** from register P2 and successors.  The result of the function is stored
+** in register P3.  Register P3 must not be one of the function inputs.
+**
+** P1 is a 32-bit bitmask indicating whether or not each argument to the 
+** function was determined to be constant at compile time. If the first
+** argument was constant then bit 0 of P1 is set. This is used to determine
+** whether meta data associated with a user function argument using the
+** sqlite3_set_auxdata() API may be safely retained until the next
+** invocation of this opcode.
+**
+** SQL functions are initially coded as OP_Function0 with P4 pointing
+** to a FuncDef object.  But on first evaluation, the P4 operand is
+** automatically converted into an sqlite3_context object and the operation
+** changed to this OP_Function opcode.  In this way, the initialization of
+** the sqlite3_context object occurs only once, rather than once for each
+** evaluation of the function.
+**
+** See also: Function0, AggStep, AggFinal
+*/
+case OP_PureFunc0:
+case OP_Function0: {
+  int n;
+  sqlite3_context *pCtx;
+
+  assert( pOp->p4type==P4_FUNCDEF );
+  n = pOp->p5;
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
+  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
+  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
+  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
+  if( pCtx==0 ) goto no_mem;
+  pCtx->pOut = 0;
+  pCtx->pFunc = pOp->p4.pFunc;
+  pCtx->iOp = (int)(pOp - aOp);
+  pCtx->pVdbe = p;
+  pCtx->argc = n;
+  pOp->p4type = P4_FUNCCTX;
+  pOp->p4.pCtx = pCtx;
+  assert( OP_PureFunc == OP_PureFunc0+2 );
+  assert( OP_Function == OP_Function0+2 );
+  pOp->opcode += 2;
+  /* Fall through into OP_Function */
+}
+case OP_PureFunc:
+case OP_Function: {
+  int i;
+  sqlite3_context *pCtx;
+
+  assert( pOp->p4type==P4_FUNCCTX );
+  pCtx = pOp->p4.pCtx;
+
+  /* If this function is inside of a trigger, the register array in aMem[]
+  ** might change from one evaluation to the next.  The next block of code
+  ** checks to see if the register array has changed, and if so it
+  ** reinitializes the relavant parts of the sqlite3_context object */
+  pOut = &aMem[pOp->p3];
+  if( pCtx->pOut != pOut ){
+    pCtx->pOut = pOut;
+    for(i=pCtx->argc-1; i>=0; i--) pCtx->argv[i] = &aMem[pOp->p2+i];
+  }
+
+  memAboutToChange(p, pOut);
+#ifdef SQLITE_DEBUG
+  for(i=0; i<pCtx->argc; i++){
+    assert( memIsValid(pCtx->argv[i]) );
+    REGISTER_TRACE(pOp->p2+i, pCtx->argv[i]);
+  }
+#endif
+  MemSetTypeFlag(pOut, MEM_Null);
+  pCtx->fErrorOrAux = 0;
+  (*pCtx->pFunc->xSFunc)(pCtx, pCtx->argc, pCtx->argv);/* IMP: R-24505-23230 */
+
+  /* If the function returned an error, throw an exception */
+  if( pCtx->fErrorOrAux ){
+    if( pCtx->isError ){
+      sqlite3VdbeError(p, "%s", sqlite3_value_text(pOut));
+      rc = pCtx->isError;
+    }
+    sqlite3VdbeDeleteAuxData(db, &p->pAuxData, pCtx->iOp, pOp->p1);
+    if( rc ) goto abort_due_to_error;
+  }
+
+  /* Copy the result of the function into register P3 */
+  if( pOut->flags & (MEM_Str|MEM_Blob) ){
+    sqlite3VdbeChangeEncoding(pOut, encoding);
+    if( sqlite3VdbeMemTooBig(pOut) ) goto too_big;
+  }
+
+  REGISTER_TRACE(pOp->p3, pOut);
+  UPDATE_MAX_BLOBSIZE(pOut);
+  break;
+}
+

 /* Opcode: Init P1 P2 * P4 *
 ** Synopsis: Start at P2
--- a/src/vdbe.h
+++ b/src/vdbe.h
@@ -253,6 +253,8 @@ RecordCompare sqlite3VdbeFindCompare(UnpackedRecord*);
 void sqlite3VdbeLinkSubProgram(Vdbe *, SubProgram *);
 #endif

+void sqlite3VdbePureFuncOnly(sqlite3_context*);
+
 /* Use SQLITE_ENABLE_COMMENTS to enable generation of extra comments on
 ** each VDBE opcode.
 **
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -4583,6 +4583,22 @@ void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
  }
 }

+/*
+** Cause a function to throw an error if it was call from OP_PureFunc
+** rather than OP_Function.
+**
+** OP_PureFunc means that the function must be deterministic, and should
+** throw an error if it is given inputs that would make it non-deterministic.
+** This routine is invoked by date/time functions that use non-deterministic
+** features such as 'now'.
+*/
+void sqlite3VdbePureFuncOnly(sqlite3_context *pCtx){
+  if( pCtx->pVdbe->aOp[pCtx->iOp].opcode==OP_PureFunc ){
+    sqlite3_result_error(pCtx, 
+       "non-deterministic functions prohibited in index expressions", -1);
+  }
+}
+
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /*
 ** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
--- a/test/indexexpr1.test
+++ b/test/indexexpr1.test
@@ -181,12 +181,12 @@ do_execsql_test indexexpr1-260eqp {


 do_catchsql_test indexexpr1-300 {
-  CREATE TABLE t2(a,b,c);
+  CREATE TABLE t2(a,b,c); INSERT INTO t2 VALUES(1,2,3);
  CREATE INDEX t2x1 ON t2(a,b+random());
 } {1 {non-deterministic functions prohibited in index expressions}}
 do_catchsql_test indexexpr1-301 {
-  CREATE INDEX t2x1 ON t2(a+julianday('now'));
-} {1 {non-deterministic functions prohibited in index expressions}}
+  CREATE INDEX t2x1 ON t2(julianday('now',a));
+} {1 {non-deterministic function}}
 do_catchsql_test indexexpr1-310 {
  CREATE INDEX t2x2 ON t2(a,b+(SELECT 15));
 } {1 {subqueries prohibited in index expressions}}
@@ -380,4 +380,7 @@ do_execsql_test indexexpr1-1300.1 {
  SELECT a FROM t1300 WHERE substr(b,4)='ess' COLLATE nocase ORDER BY +a;
 } {3 4}

+# Date and time functions can participate in an index as long as they
+# do not contain
+
 finish_test