In the VDBE, allocate space to hold column names when the VDBE first starts.

The ColumnCount opcode now just writes the null terminator into this space. (CVS 818)

FossilOrigin-Name: 46d8f5e377bf790c18a7acdd1f3bc20b538d69eb

manifest

@@ -1,5 +1,5 @@
-C When\sconstructing\srecords\sand\sindex\skeys,\suse\sstatic\sstring\sspace\srather\sthan\nmallocing\s(when\spossible)\sfor\sa\ssmall\sspeed\simprovement.\s(CVS\s817)
-D 2003-01-07T13:43:46
+C In\sthe\sVDBE,\sallocate\sspace\sto\shold\scolumn\snames\swhen\sthe\sVDBE\sfirst\sstarts.\nThe\sColumnCount\sopcode\snow\sjust\swrites\sthe\snull\sterminator\sinto\sthis\sspace.\s(CVS\s818)
+D 2003-01-07T13:55:23
 F Makefile.in 868c17a1ae1c07603d491274cc8f86c04acf2a1e
 F Makefile.linux-gcc b86a99c493a5bfb402d1d9178dcdc4bd4b32f906
 F README f1de682fbbd94899d50aca13d387d1b3fd3be2dd
@@ -52,7 +52,7 @@ F src/tokenize.c 7ac1c33e0149647c9eb5959c48992df6906d4809
 F src/trigger.c 5ba917fc226b96065108da28186c2efaec53e481
 F src/update.c 881e4c8e7c786545da4fd2d95da19252b2e31137
 F src/util.c e2d108842e02810d3d3242cac0e024b09cdb3c4a
-F src/vdbe.c 07570003d3378b668408d8e54f4b137a12ca4df6
+F src/vdbe.c 42577c260b0bba8ff8dce60a0ffd8c71f413ef35
 F src/vdbe.h 754eba497cfe0c3e352b9c101ab2f811f10d0a55
 F src/where.c af235636b7bc7f7f42ee1c7162d1958ad0102cab
 F test/all.test 873d30e25a41b3aa48fec5633a7ec1816e107029
@@ -152,7 +152,7 @@ F www/speed.tcl a20a792738475b68756ea7a19321600f23d1d803
 F www/sqlite.tcl ae3dcfb077e53833b59d4fcc94d8a12c50a44098
 F www/tclsqlite.tcl 1db15abeb446aad0caf0b95b8b9579720e4ea331
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P a362981b20fd33254ad498619eedf75b576682e3
-R 167f2117e4d0226460f1cb7008234b4d
+P 657c9fb5133aef93e4edd433912e6942ad9674ec
+R 30af34abe888623d0ad22c90d02b73df
 U drh
-Z 09ee972659cfc232fea37abfb187e33e
+Z 10b12f5b3cbab70eee4329daa1b839b8

manifest.uuid

@@ -1 +1 @@
-657c9fb5133aef93e4edd433912e6942ad9674ec
+46d8f5e377bf790c18a7acdd1f3bc20b538d69eb

src/vdbe.c

@@ -36,7 +36,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.193 2003/01/07 13:43:46 drh Exp $
+** $Id: vdbe.c,v 1.194 2003/01/07 13:55:23 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -247,7 +247,6 @@ struct Vdbe {
   int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
   int *aLabel;        /* Space to hold the labels */
   int tos;            /* Index of top of stack */
-  int nStackAlloc;    /* Size of the stack */
   Stack *aStack;      /* The operand stack, except string values */
   char **zStack;      /* Text or binary values of the stack */
   char **azColName;   /* Becomes the 4th parameter to callbacks */
@@ -1034,8 +1033,6 @@ static void SorterReset(Vdbe *p){
 static void Cleanup(Vdbe *p){
   int i;
   PopStack(p, p->tos+1);
-  sqliteFree(p->azColName);
-  p->azColName = 0;
   closeAllCursors(p);
   if( p->aMem ){
     for(i=0; i<p->nMem; i++){
@@ -1105,7 +1102,6 @@ void sqliteVdbeDelete(Vdbe *p){
   sqliteFree(p->aOp);
   sqliteFree(p->aLabel);
   sqliteFree(p->aStack);
-  sqliteFree(p->zStack);
   sqliteFree(p);
 }
 
@@ -1410,8 +1406,10 @@ int sqliteVdbeExec(
   ** Allocation all the stack space we will ever need.
   */
   sqliteVdbeAddOp(p, OP_Halt, 0, 0);
-  zStack = p->zStack = sqliteMalloc( p->nOp*sizeof(zStack[0]) );
-  aStack = p->aStack = sqliteMalloc( p->nOp*sizeof(aStack[0]) );
+  aStack = sqliteMalloc( p->nOp*(sizeof(aStack[0]) + 2*sizeof(char*)) );
+  p->aStack = aStack;
+  zStack = p->zStack = (char**)&aStack[p->nOp];
+  p->azColName = (char**)&zStack[p->nOp];
   p->tos = -1;
 #ifdef VDBE_PROFILE
   {
@@ -1721,13 +1719,9 @@ case OP_Push: {
 /* Opcode: ColumnCount P1 * *
 **
 ** Specify the number of column values that will appear in the
-** array passed as the 4th parameter to the callback.  No checking
-** is done.  If this value is wrong, a coredump can result.
+** array passed as the 4th parameter to the callback. 
 */
 case OP_ColumnCount: {
-  char **az = sqliteRealloc(p->azColName, (pOp->p1+1)*sizeof(char*));
-  if( az==0 ){ goto no_mem; }
-  p->azColName = az;
   p->azColName[pOp->p1] = 0;
   p->nCallback = 0;
   break;
@@ -1737,9 +1731,6 @@ case OP_ColumnCount: {
 **
 ** P3 becomes the P1-th column name (first is 0).  An array of pointers
 ** to all column names is passed as the 4th parameter to the callback.
-** The ColumnCount opcode must be executed first to allocate space to
-** hold the column names.  Failure to do this will likely result in
-** a coredump.
 */
 case OP_ColumnName: {
   p->azColName[pOp->p1] = pOp->p3;