/ Check-in [ab2ba8e7]
Login
SQLite training in Houston TX on 2019-11-05 (details)
Part of the 2019 Tcl Conference

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Add the exprNodeCopy() routine that will safely memcpy() an Expr node that might be a size-reduced node.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | expr-node-copy-patch
Files: files | file ages | folders
SHA3-256: ab2ba8e732d4a813a336e37e06bbc98842d22d4896120b1b97e8577684e9ea53
User & Date: drh 2019-05-07 02:57:28
Context
2019-05-07
02:57
Add the exprNodeCopy() routine that will safely memcpy() an Expr node that might be a size-reduced node. Leaf check-in: ab2ba8e7 user: drh tags: expr-node-copy-patch
2019-01-05
21:56
Add the exprNodeCopy() routine that will safely memcpy() an Expr node that might be a size-reduced node. check-in: a874c649 user: drh tags: trunk
2018-06-04
14:10
Merge changes from trunk. check-in: 95fbac39 user: drh tags: apple-osx
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/expr.c.

1079
1080
1081
1082
1083
1084
1085










1086
1087
1088
1089
1090
1091
1092
....
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
....
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
*/
static int exprStructSize(Expr *p){
  if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
  if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
  return EXPR_FULLSIZE;
}











/*
** The dupedExpr*Size() routines each return the number of bytes required
** to store a copy of an expression or expression tree.  They differ in
** how much of the tree is measured.
**
**     dupedExprStructSize()     Size of only the Expr structure 
................................................................................
      assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
      assert(pExpr->x.pList->nExpr > 0);
      pEList = pExpr->x.pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      endLabel = sqlite3VdbeMakeLabel(v);
      if( (pX = pExpr->pLeft)!=0 ){
        tempX = *pX;
        testcase( pX->op==TK_COLUMN );
        exprToRegister(&tempX, exprCodeVector(pParse, &tempX, &regFree1));
        testcase( regFree1==0 );
        memset(&opCompare, 0, sizeof(opCompare));
        opCompare.op = TK_EQ;
        opCompare.pLeft = &tempX;
        pTest = &opCompare;
................................................................................
){
 Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
  Expr compLeft;    /* The  x>=y  term */
  Expr compRight;   /* The  x<=z  term */
  Expr exprX;       /* The  x  subexpression */
  int regFree1 = 0; /* Temporary use register */


  memset(&compLeft, 0, sizeof(Expr));
  memset(&compRight, 0, sizeof(Expr));
  memset(&exprAnd, 0, sizeof(Expr));

  assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
  exprX = *pExpr->pLeft;
  exprAnd.op = TK_AND;
  exprAnd.pLeft = &compLeft;
  exprAnd.pRight = &compRight;
  compLeft.op = TK_GE;
  compLeft.pLeft = &exprX;
  compLeft.pRight = pExpr->x.pList->a[0].pExpr;
  compRight.op = TK_LE;







>
>
>
>
>
>
>
>
>
>







 







|







 







<





|







1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
....
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
....
4438
4439
4440
4441
4442
4443
4444

4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
*/
static int exprStructSize(Expr *p){
  if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
  if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
  return EXPR_FULLSIZE;
}

/*
** Copy the complete content of an Expr node, taking care not to read
** past the end of the structure for a reduced-size version of the source
** Expr.
*/
static void exprNodeCopy(Expr *pDest, Expr *pSrc){
  memset(pDest, 0, sizeof(Expr));
  memcpy(pDest, pSrc, exprStructSize(pSrc));
}

/*
** The dupedExpr*Size() routines each return the number of bytes required
** to store a copy of an expression or expression tree.  They differ in
** how much of the tree is measured.
**
**     dupedExprStructSize()     Size of only the Expr structure 
................................................................................
      assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
      assert(pExpr->x.pList->nExpr > 0);
      pEList = pExpr->x.pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      endLabel = sqlite3VdbeMakeLabel(v);
      if( (pX = pExpr->pLeft)!=0 ){
        exprNodeCopy(&tempX, pX);
        testcase( pX->op==TK_COLUMN );
        exprToRegister(&tempX, exprCodeVector(pParse, &tempX, &regFree1));
        testcase( regFree1==0 );
        memset(&opCompare, 0, sizeof(opCompare));
        opCompare.op = TK_EQ;
        opCompare.pLeft = &tempX;
        pTest = &opCompare;
................................................................................
){
 Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
  Expr compLeft;    /* The  x>=y  term */
  Expr compRight;   /* The  x<=z  term */
  Expr exprX;       /* The  x  subexpression */
  int regFree1 = 0; /* Temporary use register */


  memset(&compLeft, 0, sizeof(Expr));
  memset(&compRight, 0, sizeof(Expr));
  memset(&exprAnd, 0, sizeof(Expr));

  assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
  exprNodeCopy(&exprX, pExpr->pLeft);
  exprAnd.op = TK_AND;
  exprAnd.pLeft = &compLeft;
  exprAnd.pRight = &compRight;
  compLeft.op = TK_GE;
  compLeft.pLeft = &exprX;
  compLeft.pRight = pExpr->x.pList->a[0].pExpr;
  compRight.op = TK_LE;