Simplification of the trigger code. (CVS 1976)

FossilOrigin-Name: 9fa904d94ec1787bc8b97ec06a5423248fcb67fb

manifest

@@ -1,5 +1,5 @@
-C Fix\sfor\stickets\s#912\sand\s#922.\s\sProblem\sintroduced\sby\scheck-in\s(1973).\s(CVS\s1975)
-D 2004-09-24T12:24:07
+C Simplification\sof\sthe\strigger\scode.\s(CVS\s1976)
+D 2004-09-24T12:24:36
 F Makefile.in abdeb5bd9d017822691884935c320037c33f6ee6
 F Makefile.linux-gcc a9e5a0d309fa7c38e7c14d3ecf7690879d3a5457
 F README f1de682fbbd94899d50aca13d387d1b3fd3be2dd
@@ -69,7 +69,7 @@ F src/test3.c 5b5b0f3d11b097399c1054fff73d8f3711092301
 F src/test4.c 7c6b9fc33dd1f3f93c7f1ee6e5e6d016afa6c1df
 F src/test5.c b001fa7f1b9e2dc5c2331de62fc641b5ab2bd7a1
 F src/tokenize.c 418ef7ba1149603a30dcf0057e04a3ea0e99edbe
-F src/trigger.c 3591b88baac4253c93733e34e4d1d74c549fe8a8
+F src/trigger.c d1f770ee37a80391dd6d0948ee821b0272f99ae7
 F src/update.c 7157084216c4b02a23cdb23eb6d246aa9034fa4d
 F src/utf.c 328890099db492dda5620ee5f924e244c6e57ff7
 F src/util.c f9b661a3b80a1469777771776a59a5f0e2f193fc
@@ -247,7 +247,7 @@ F www/tclsqlite.tcl 560ecd6a916b320e59f2917317398f3d59b7cc25
 F www/vdbe.tcl 59288db1ac5c0616296b26dce071c36cb611dfe9
 F www/version3.tcl 092a01f5ef430d2c4acc0ae558d74c4bb89638a0
 F www/whentouse.tcl a8335bce47cc2fddb07f19052cb0cb4d9129a8e4
-P a35e52276998f8db2407115b07f30bd490982944
-R 5792bfa085a00a00bd1d4a9801cd2ff0
+P 9001e2220d2e35b81a9b7dc70c012f94bb6db679
+R fcc40213cf4f43ad3198270005b0847c
 U drh
-Z d6e2d9c37d8b22b397c88a0920962493
+Z e0420e53be5e67880217af54cf3a9844

manifest.uuid

@@ -1 +1 @@
-9001e2220d2e35b81a9b7dc70c012f94bb6db679
+9fa904d94ec1787bc8b97ec06a5423248fcb67fb

src/trigger.c

@@ -650,6 +650,7 @@ static int codeTriggerProgram(
   assert( pTriggerStep!=0 );
   assert( v!=0 );
   sqlite3VdbeAddOp(v, OP_ContextPush, 0, 0);
+  VdbeComment((v, "# begin trigger %s", pStepList->pTrig->name));
   while( pTriggerStep ){
     orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
     pParse->trigStack->orconf = orconf;
@@ -697,6 +698,7 @@ static int codeTriggerProgram(
     pTriggerStep = pTriggerStep->pNext;
   }
   sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
+  VdbeComment((v, "# end trigger %s", pStepList->pTrig->name));
 
   return 0;
 }
@@ -733,7 +735,8 @@ int sqlite3CodeRowTrigger(
   int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */
 ){
   Trigger *pTrigger;
-  TriggerStack * pTriggerStack;
+  TriggerStack *pStack;
+  TriggerStack trigStackEntry;
 
   assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE);
   assert(tr_tm == TK_BEFORE || tr_tm == TK_AFTER );
@@ -748,12 +751,10 @@ int sqlite3CodeRowTrigger(
     if( pTrigger->op == op && pTrigger->tr_tm == tr_tm && 
         pTrigger->foreach == TK_ROW ){
       fire_this = 1;
-      pTriggerStack = pParse->trigStack;
-      while( pTriggerStack ){
-        if( pTriggerStack->pTrigger == pTrigger ){
+      for(pStack=pParse->trigStack; pStack; pStack=pStack->pNext){
+        if( pStack->pTrigger==pTrigger ){
 	  fire_this = 0;
 	}
-        pTriggerStack = pTriggerStack->pNext;
       }
       if( op == TK_UPDATE && pTrigger->pColumns &&
           !checkColumnOverLap(pTrigger->pColumns, pChanges) ){
@@ -761,10 +762,7 @@ int sqlite3CodeRowTrigger(
       }
     }
  
-    /* FIX ME:  Can we not omit the sqliteMalloc() and make pTriggerStack
-    ** point to a stack variable?
-    */
-    if( fire_this && (pTriggerStack = sqliteMalloc(sizeof(TriggerStack)))!=0 ){
+    if( fire_this ){
       int endTrigger;
       SrcList dummyTablist;
       Expr * whenExpr;
@@ -773,21 +771,20 @@ int sqlite3CodeRowTrigger(
       dummyTablist.nSrc = 0;
 
       /* Push an entry on to the trigger stack */
-      pTriggerStack->pTrigger = pTrigger;
-      pTriggerStack->newIdx = newIdx;
-      pTriggerStack->oldIdx = oldIdx;
-      pTriggerStack->pTab = pTab;
-      pTriggerStack->pNext = pParse->trigStack;
-      pTriggerStack->ignoreJump = ignoreJump;
-      pParse->trigStack = pTriggerStack;
+      trigStackEntry.pTrigger = pTrigger;
+      trigStackEntry.newIdx = newIdx;
+      trigStackEntry.oldIdx = oldIdx;
+      trigStackEntry.pTab = pTab;
+      trigStackEntry.pNext = pParse->trigStack;
+      trigStackEntry.ignoreJump = ignoreJump;
+      pParse->trigStack = &trigStackEntry;
       sqlite3AuthContextPush(pParse, &sContext, pTrigger->name);
 
       /* code the WHEN clause */
       endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe);
       whenExpr = sqlite3ExprDup(pTrigger->pWhen);
       if( sqlite3ExprResolveIds(pParse, &dummyTablist, 0, whenExpr) ){
-        pParse->trigStack = pParse->trigStack->pNext;
-        sqliteFree(pTriggerStack);
+        pParse->trigStack = trigStackEntry.pNext;
         sqlite3ExprDelete(whenExpr);
         return 1;
       }
@@ -797,9 +794,8 @@ int sqlite3CodeRowTrigger(
       codeTriggerProgram(pParse, pTrigger->step_list, orconf); 
 
       /* Pop the entry off the trigger stack */
-      pParse->trigStack = pParse->trigStack->pNext;
+      pParse->trigStack = trigStackEntry.pNext;
       sqlite3AuthContextPop(&sContext);
-      sqliteFree(pTriggerStack);
 
       sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger);
     }