Further reduction in the amount of memset() needed to initialize the Parse

object.

FossilOrigin-Name: 45e462c0060e51c3375a226d636148e3415ee6020e544ecc84861c7aef4ecf7b

6 files changed, 69 insertions, 33 deletions

diff --git a/src/analyze.c b/src/analyze.c
index 9213c202b..799d43924 100644
--- a/src/analyze.c
+++ b/src/analyze.c
@@ -215,7 +215,8 @@ static void openStatTable(
         sqlite3NestedParse(pParse,
             "CREATE TABLE %Q.%s(%s)", pDb->zDbSName, zTab, aTable[i].zCols
         );
-        aRoot[i] = (u32)pParse->regRoot;
+        assert( pParse->isCreate || pParse->nErr );
+        aRoot[i] = (u32)pParse->u1.cr.regRoot;
         aCreateTbl[i] = OPFLAG_P2ISREG;
       }
     }else{
diff --git a/src/build.c b/src/build.c
index cc29610e0..986107f48 100644
--- a/src/build.c
+++ b/src/build.c
@@ -168,10 +168,12 @@ void sqlite3FinishCoding(Parse *pParse){
        || sqlite3VdbeAssertMayAbort(v, pParse->mayAbort));
   if( v ){
     if( pParse->bReturning ){
-      Returning *pReturning = pParse->u1.pReturning;
+      Returning *pReturning;
       int addrRewind;
       int reg;
 
+      assert( !pParse->isCreate );
+      pReturning = pParse->u1.d.pReturning;
       if( pReturning->nRetCol ){
         sqlite3VdbeAddOp0(v, OP_FkCheck);
         addrRewind =
@@ -247,7 +249,9 @@ void sqlite3FinishCoding(Parse *pParse){
     }
 
     if( pParse->bReturning ){
-      Returning *pRet = pParse->u1.pReturning;
+      Returning *pRet;
+      assert( !pParse->isCreate );
+      pRet = pParse->u1.d.pReturning;
       if( pRet->nRetCol ){
         sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pRet->iRetCur, pRet->nRetCol);
       }
@@ -1319,8 +1323,9 @@ void sqlite3StartTable(
     /* If the file format and encoding in the database have not been set,
     ** set them now.
     */
-    reg1 = pParse->regRowid = ++pParse->nMem;
-    reg2 = pParse->regRoot = ++pParse->nMem;
+    assert( pParse->isCreate );
+    reg1 = pParse->u1.cr.regRowid = ++pParse->nMem;
+    reg2 = pParse->u1.cr.regRoot = ++pParse->nMem;
     reg3 = ++pParse->nMem;
     sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);
     sqlite3VdbeUsesBtree(v, iDb);
@@ -1335,8 +1340,8 @@ void sqlite3StartTable(
     ** The record created does not contain anything yet.  It will be replaced
     ** by the real entry in code generated at sqlite3EndTable().
     **
-    ** The rowid for the new entry is left in register pParse->regRowid.
-    ** The root page number of the new table is left in reg pParse->regRoot.
+    ** The rowid for the new entry is left in register pParse->u1.cr.regRowid.
+    ** The root page of the new table is left in reg pParse->u1.cr.regRoot.
     ** The rowid and root page number values are needed by the code that
     ** sqlite3EndTable will generate.
     */
@@ -1347,7 +1352,7 @@ void sqlite3StartTable(
 #endif
     {
       assert( !pParse->bReturning );
-      pParse->u1.addrCrTab =
+      pParse->u1.cr.addrCrTab =
          sqlite3VdbeAddOp3(v, OP_CreateBtree, iDb, reg2, BTREE_INTKEY);
     }
     sqlite3OpenSchemaTable(pParse, iDb);
@@ -1425,7 +1430,8 @@ void sqlite3AddReturning(Parse *pParse, ExprList *pList){
     sqlite3ExprListDelete(db, pList);
     return;
   }
-  pParse->u1.pReturning = pRet;
+  assert( !pParse->isCreate );
+  pParse->u1.d.pReturning = pRet;
   pRet->pParse = pParse;
   pRet->pReturnEL = pList;
   sqlite3ParserAddCleanup(pParse, sqlite3DeleteReturning, pRet);
@@ -1564,7 +1570,8 @@ void sqlite3AddColumn(Parse *pParse, Token sName, Token sType){
   }
   p->nCol++;
   p->nNVCol++;
-  pParse->constraintName.n = 0;
+  assert( pParse->isCreate );
+  pParse->u1.cr.constraintName.n = 0;
 }
 
 /*
@@ -1888,8 +1895,10 @@ void sqlite3AddCheckConstraint(
    && !sqlite3BtreeIsReadonly(db->aDb[db->init.iDb].pBt)
   ){
     pTab->pCheck = sqlite3ExprListAppend(pParse, pTab->pCheck, pCheckExpr);
-    if( pParse->constraintName.n ){
-      sqlite3ExprListSetName(pParse, pTab->pCheck, &pParse->constraintName, 1);
+    assert( pParse->isCreate );
+    if( pParse->u1.cr.constraintName.n ){
+      sqlite3ExprListSetName(pParse, pTab->pCheck,
+                             &pParse->u1.cr.constraintName, 1);
     }else{
       Token t;
       for(zStart++; sqlite3Isspace(zStart[0]); zStart++){}
@@ -2339,9 +2348,9 @@ static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
   ** into BTREE_BLOBKEY.
   */
   assert( !pParse->bReturning );
-  if( pParse->u1.addrCrTab ){
+  if( pParse->u1.cr.addrCrTab ){
     assert( v );
-    sqlite3VdbeChangeP3(v, pParse->u1.addrCrTab, BTREE_BLOBKEY);
+    sqlite3VdbeChangeP3(v, pParse->u1.cr.addrCrTab, BTREE_BLOBKEY);
   }
 
   /* Locate the PRIMARY KEY index.  Or, if this table was originally
@@ -2781,7 +2790,7 @@ void sqlite3EndTable(
 
     /* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT
     ** statement to populate the new table. The root-page number for the
-    ** new table is in register pParse->regRoot.
+    ** new table is in register pParse->u1.cr.regRoot.
     **
     ** Once the SELECT has been coded by sqlite3Select(), it is in a
     ** suitable state to query for the column names and types to be used
@@ -2812,7 +2821,8 @@ void sqlite3EndTable(
       regRec = ++pParse->nMem;
       regRowid = ++pParse->nMem;
       sqlite3MayAbort(pParse);
-      sqlite3VdbeAddOp3(v, OP_OpenWrite, iCsr, pParse->regRoot, iDb);
+      assert( pParse->isCreate );
+      sqlite3VdbeAddOp3(v, OP_OpenWrite, iCsr, pParse->u1.cr.regRoot, iDb);
       sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
       addrTop = sqlite3VdbeCurrentAddr(v) + 1;
       sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
@@ -2857,6 +2867,7 @@ void sqlite3EndTable(
     ** schema table.  We just need to update that slot with all
     ** the information we've collected.
     */
+    assert( pParse->isCreate );
     sqlite3NestedParse(pParse,
       "UPDATE %Q." LEGACY_SCHEMA_TABLE
       " SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q"
@@ -2865,9 +2876,9 @@ void sqlite3EndTable(
       zType,
       p->zName,
       p->zName,
-      pParse->regRoot,
+      pParse->u1.cr.regRoot,
       zStmt,
-      pParse->regRowid
+      pParse->u1.cr.regRowid
     );
     sqlite3DbFree(db, zStmt);
     sqlite3ChangeCookie(pParse, iDb);
diff --git a/src/parse.y b/src/parse.y
index e9e2c62e6..76c9a8e4e 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -63,6 +63,11 @@
 #include "sqliteInt.h"
 
 /*
+** Verify that the pParse->isCreate field is set
+*/
+#define ASSERT_IS_CREATE   assert(pParse->isCreate)
+
+/*
 ** Disable all error recovery processing in the parser push-down
 ** automaton.
 */
@@ -125,6 +130,10 @@ static void parserSyntaxError(Parse *pParse, Token *p){
 static void disableLookaside(Parse *pParse){
   sqlite3 *db = pParse->db;
   pParse->disableLookaside++;
+#ifdef SQLITE_DEBUG
+  pParse->isCreate = 1;
+#endif
+  memset(&pParse->u1.cr, 0, sizeof(pParse->u1.cr));
   DisableLookaside;
 }
 
@@ -197,7 +206,9 @@ cmd ::= create_table create_table_args.
 create_table ::= createkw temp(T) TABLE ifnotexists(E) nm(Y) dbnm(Z). {
    sqlite3StartTable(pParse,&Y,&Z,T,0,0,E);
 }
-createkw(A) ::= CREATE(A).  {disableLookaside(pParse);}
+createkw(A) ::= CREATE(A).  {
+  disableLookaside(pParse);
+}
 
 %type ifnotexists {int}
 ifnotexists(A) ::= .              {A = 0;}
@@ -373,7 +384,7 @@ scantok(A) ::= . {
 //
 carglist ::= carglist ccons.
 carglist ::= .
-ccons ::= CONSTRAINT nm(X).           {pParse->constraintName = X;}
+ccons ::= CONSTRAINT nm(X). {ASSERT_IS_CREATE; pParse->u1.cr.constraintName = X;}
 ccons ::= DEFAULT scantok(A) term(X).
                             {sqlite3AddDefaultValue(pParse,X,A.z,&A.z[A.n]);}
 ccons ::= DEFAULT LP(A) expr(X) RP(Z).
@@ -448,9 +459,9 @@ conslist_opt(A) ::= .                         {A.n = 0; A.z = 0;}
 conslist_opt(A) ::= COMMA(A) conslist.
 conslist ::= conslist tconscomma tcons.
 conslist ::= tcons.
-tconscomma ::= COMMA.            {pParse->constraintName.n = 0;}
+tconscomma ::= COMMA.          {ASSERT_IS_CREATE; pParse->u1.cr.constraintName.n = 0;}
 tconscomma ::= .
-tcons ::= CONSTRAINT nm(X).      {pParse->constraintName = X;}
+tcons ::= CONSTRAINT nm(X).    {ASSERT_IS_CREATE; pParse->u1.cr.constraintName = X;}
 tcons ::= PRIMARY KEY LP sortlist(X) autoinc(I) RP onconf(R).
                                  {sqlite3AddPrimaryKey(pParse,X,R,I,0);}
 tcons ::= UNIQUE LP sortlist(X) RP onconf(R).
@@ -1659,6 +1670,10 @@ trigger_decl(A) ::= temp(T) TRIGGER ifnotexists(NOERR) nm(B) dbnm(Z)
                     ON fullname(E) foreach_clause when_clause(G). {
   sqlite3BeginTrigger(pParse, &B, &Z, C, D.a, D.b, E, G, T, NOERR);
   A = (Z.n==0?B:Z); /*A-overwrites-T*/
+#ifdef SQLITE_DEBUG
+  assert( pParse->isCreate ); /* Set by createkw reduce action */
+  pParse->isCreate = 0;       /* But, should not be set for CREATE TRIGGER */
+#endif
 }
 
 %type trigger_time {int}
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index bbef593df..acc36f07c 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3841,6 +3841,8 @@ struct Parse {
 #endif
 #ifdef SQLITE_DEBUG
   u8 ifNotExists;      /* Might be true if IF NOT EXISTS.  Assert()s only */
+  u8 isCreate;         /* CREATE TABLE, INDEX, or VIEW (but not TRIGGER)
+                       ** and ALTER TABLE ADD COLUMN. */
 #endif
   int nRangeReg;       /* Size of the temporary register block */
   int iRangeReg;       /* First register in temporary register block */
@@ -3856,11 +3858,8 @@ struct Parse {
   ExprList *pConstExpr;/* Constant expressions */
   IndexedExpr *pIdxEpr;/* List of expressions used by active indexes */
   IndexedExpr *pIdxPartExpr; /* Exprs constrained by index WHERE clauses */
-  Token constraintName;/* Name of the constraint currently being parsed */
   yDbMask writeMask;   /* Start a write transaction on these databases */
   yDbMask cookieMask;  /* Bitmask of schema verified databases */
-  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
-  int regRoot;         /* Register holding root page number for new objects */
   int nMaxArg;         /* Max args passed to user function by sub-program */
   int nSelect;         /* Number of SELECT stmts. Counter for Select.selId */
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
@@ -3875,10 +3874,6 @@ struct Parse {
   Table *pTriggerTab;  /* Table triggers are being coded for */
   TriggerPrg *pTriggerPrg;  /* Linked list of coded triggers */
   ParseCleanup *pCleanup;   /* List of cleanup operations to run after parse */
-  union {
-    int addrCrTab;         /* Address of OP_CreateBtree on CREATE TABLE */
-    Returning *pReturning; /* The RETURNING clause */
-  } u1;
   LogEst nQueryLoop;   /* Est number of iterations of a query (10*log2(N)) */
   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
   u8 bReturning;       /* Coding a RETURNING trigger */
@@ -3897,6 +3892,17 @@ struct Parse {
   Token sNameToken;       /* Token with unqualified schema object name */
   u32 oldmask;            /* Mask of old.* columns referenced */
   u32 newmask;            /* Mask of new.* columns referenced */
+  union {
+    struct {  /* These fields available when isCreate is true */
+      int addrCrTab;        /* Address of OP_CreateBtree on CREATE TABLE */
+      int regRowid;         /* Register holding rowid of CREATE TABLE entry */
+      int regRoot;          /* Register holding root page for new objects */
+      Token constraintName; /* Name of the constraint currently being parsed */
+    } cr;
+    struct {  /* These fields available to all other statements */
+      Returning *pReturning; /* The RETURNING clause */
+    } d;
+  } u1;
 
   /************************************************************************
   ** Above is constant between recursions.  Below is reset before and after
diff --git a/src/trigger.c b/src/trigger.c
index e7b75d344..604c3ab42 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -70,7 +70,8 @@ Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
       assert( pParse->db->pVtabCtx==0 );
 #endif
       assert( pParse->bReturning );
-      assert( &(pParse->u1.pReturning->retTrig) == pTrig );
+      assert( !pParse->isCreate );
+      assert( &(pParse->u1.d.pReturning->retTrig) == pTrig );
       pTrig->table = pTab->zName;
       pTrig->pTabSchema = pTab->pSchema;
       pTrig->pNext = pList;
@@ -1047,7 +1048,8 @@ static void codeReturningTrigger(
     return;
   }
   assert( db->pParse==pParse );
-  pReturning = pParse->u1.pReturning;
+  assert( !pParse->isCreate );
+  pReturning = pParse->u1.d.pReturning;
   if( pTrigger != &(pReturning->retTrig) ){
     /* This RETURNING trigger is for a different statement */
     return;
diff --git a/src/vtab.c b/src/vtab.c
index 09f0c2d7f..e40f60873 100644
--- a/src/vtab.c
+++ b/src/vtab.c
@@ -479,11 +479,12 @@ void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
     ** schema table.  We just need to update that slot with all
     ** the information we've collected.
     **
-    ** The VM register number pParse->regRowid holds the rowid of an
+    ** The VM register number pParse->u1.cr.regRowid holds the rowid of an
     ** entry in the sqlite_schema table that was created for this vtab
     ** by sqlite3StartTable().
     */
     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    assert( pParse->isCreate );
     sqlite3NestedParse(pParse,
       "UPDATE %Q." LEGACY_SCHEMA_TABLE " "
          "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
@@ -492,7 +493,7 @@ void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
       pTab->zName,
       pTab->zName,
       zStmt,
-      pParse->regRowid
+      pParse->u1.cr.regRowid
     );
     v = sqlite3GetVdbe(pParse);
     sqlite3ChangeCookie(pParse, iDb);