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Change the way token memory is allocated in an effort to fix ticket #136.

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There is now a memory leak when using views of views. (CVS 725)

FossilOrigin-Name: 22d8726e61eec0e53893f492cb2163824b87a23e
This commit is contained in:
drh
2002-08-24 18:24:51 +00:00
parent 79983d03e8
commit 4b59ab5e64
18 changed files with 515 additions and 343 deletions
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234
src/expr.c
View File

@@ -12,7 +12,7 @@
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.79 2002/07/18 00:34:12 drh Exp $
** $Id: expr.c,v 1.80 2002/08/24 18:24:54 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -34,16 +34,17 @@ Expr *sqliteExpr(int op, Expr *pLeft, Expr *pRight, Token *pToken){
pNew->pLeft = pLeft;
pNew->pRight = pRight;
if( pToken ){
assert( pToken->dyn==0 );
pNew->token = *pToken;
pNew->token.base = 1;
}else if( pLeft && pRight ){
sqliteExprSpan(pNew, &pLeft->token, &pRight->token);
}else{
pNew->token.dyn = 0;
pNew->token.base = 1;
pNew->token.z = 0;
pNew->token.n = 0;
}
if( pLeft && pRight ){
sqliteExprSpan(pNew, &pLeft->span, &pRight->span);
}else{
pNew->span = pNew->token;
}
return pNew;
}
@@ -53,8 +54,17 @@ Expr *sqliteExpr(int op, Expr *pLeft, Expr *pRight, Token *pToken){
*/
void sqliteExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
if( pExpr ){
pExpr->span.z = pLeft->z;
pExpr->span.n = pRight->n + Addr(pRight->z) - Addr(pLeft->z);
assert( pExpr->token.dyn==0 );
if( pLeft->dyn==0 && pRight->dyn==0 ){
pExpr->token.z = pLeft->z;
pExpr->token.n = pRight->n + Addr(pRight->z) - Addr(pLeft->z);
pExpr->token.base = 0;
}else{
pExpr->token.z = 0;
pExpr->token.n = 0;
pExpr->token.dyn = 0;
pExpr->token.base = 0;
}
}
}
@@ -71,8 +81,18 @@ Expr *sqliteExprFunction(ExprList *pList, Token *pToken){
}
pNew->op = TK_FUNCTION;
pNew->pList = pList;
/* Expr.token.n is the length of the entire function
** call, including the function arguments. The parser
** will extend token.n to cover the either length of the string.
** Expr.nFuncName is the length of just the function name.
*/
pNew->token.dyn = 0;
pNew->token.base = 1;
if( pToken ){
assert( pToken->dyn==0 );
pNew->token = *pToken;
pNew->nFuncName = pToken->n>255 ? 255 : pToken->n;
}else{
pNew->token.z = 0;
pNew->token.n = 0;
@@ -85,6 +105,7 @@ Expr *sqliteExprFunction(ExprList *pList, Token *pToken){
*/
void sqliteExprDelete(Expr *p){
if( p==0 ) return;
if( p->token.dyn && p->token.z ) sqliteFree((char*)p->token.z);
if( p->pLeft ) sqliteExprDelete(p->pLeft);
if( p->pRight ) sqliteExprDelete(p->pRight);
if( p->pList ) sqliteExprListDelete(p->pList);
@@ -92,69 +113,6 @@ void sqliteExprDelete(Expr *p){
sqliteFree(p);
}
/*
** The following group of functions are used to translate the string
** pointers of tokens in expression from one buffer to another.
**
** Normally, the Expr.token.z and Expr.span.z fields point into the
** original input buffer of an SQL statement. This is usually OK
** since the SQL statement is executed and the expression is deleted
** before the input buffer is freed. Making the tokens point to the
** original input buffer saves many calls to malloc() and thus helps
** the library to run faster.
**
** But sometimes we need an expression to persist past the time when
** the input buffer is freed. (Example: The SELECT clause of a
** CREATE VIEW statement contains expressions that must persist for
** the life of the view.) When that happens we have to make a
** persistent copy of the input buffer and translate the Expr.token.z
** and Expr.span.z fields to point to the copy rather than the
** original input buffer. The following group of routines handle that
** translation.
**
** The "offset" parameter is the distance from the original input buffer
** to the persistent copy. These routines recursively walk the entire
** expression tree and shift all tokens by "offset" amount.
**
** The work of figuring out the appropriate "offset" and making the
** presistent copy of the input buffer is done by the calling routine.
*/
void sqliteExprMoveStrings(Expr *p, int offset){
if( p==0 ) return;
if( !p->staticToken ){
if( p->token.z ) p->token.z += offset;
if( p->span.z ) p->span.z += offset;
}
if( p->pLeft ) sqliteExprMoveStrings(p->pLeft, offset);
if( p->pRight ) sqliteExprMoveStrings(p->pRight, offset);
if( p->pList ) sqliteExprListMoveStrings(p->pList, offset);
if( p->pSelect ) sqliteSelectMoveStrings(p->pSelect, offset);
}
void sqliteExprListMoveStrings(ExprList *pList, int offset){
int i;
if( pList==0 ) return;
for(i=0; i<pList->nExpr; i++){
sqliteExprMoveStrings(pList->a[i].pExpr, offset);
}
}
static void sqliteSrcListMoveStrings(SrcList *pSrc, int offset){
int i;
if( pSrc==0 ) return;
for(i=0; i<pSrc->nSrc; i++){
sqliteSelectMoveStrings(pSrc->a[i].pSelect, offset);
sqliteExprMoveStrings(pSrc->a[i].pOn, offset);
}
}
void sqliteSelectMoveStrings(Select *pSelect, int offset){
if( pSelect==0 ) return;
sqliteExprListMoveStrings(pSelect->pEList, offset);
sqliteSrcListMoveStrings(pSelect->pSrc, offset);
sqliteExprMoveStrings(pSelect->pWhere, offset);
sqliteExprListMoveStrings(pSelect->pGroupBy, offset);
sqliteExprMoveStrings(pSelect->pHaving, offset);
sqliteExprListMoveStrings(pSelect->pOrderBy, offset);
sqliteSelectMoveStrings(pSelect->pPrior, offset);
}
/*
** The following group of routines make deep copies of expressions,
@@ -162,10 +120,6 @@ void sqliteSelectMoveStrings(Select *pSelect, int offset){
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**
** Note, however, that the Expr.token.z and Expr.span.z fields point to
** string space that is allocated separately from the expression tree
** itself. These routines do NOT duplicate that string space.
**
** The expression list, ID, and source lists return by sqliteExprListDup(),
** sqliteIdListDup(), and sqliteSrcListDup() can not be further expanded
** by subsequent calls to sqlite*ListAppend() routines.
@@ -178,12 +132,38 @@ Expr *sqliteExprDup(Expr *p){
pNew = sqliteMalloc( sizeof(*p) );
if( pNew==0 ) return 0;
memcpy(pNew, p, sizeof(*pNew));
/* Only make a copy of the token if it is a base token (meaning that
** it covers a single term of an expression - not two or more terms)
** or if it is already dynamically allocated. So, for example, in
** a complex expression like "a+b+c", the token "b" would be duplicated
** but "a+b" would not be. */
if( p->token.z!=0 && (p->token.base || p->token.dyn) ){
pNew->token.z = sqliteStrDup(p->token.z);
pNew->token.dyn = 1;
}else{
pNew->token.z = 0;
pNew->token.n = 0;
pNew->token.dyn = 0;
}
pNew->pLeft = sqliteExprDup(p->pLeft);
pNew->pRight = sqliteExprDup(p->pRight);
pNew->pList = sqliteExprListDup(p->pList);
pNew->pSelect = sqliteSelectDup(p->pSelect);
return pNew;
}
void sqliteTokenCopy(Token *pTo, Token *pFrom){
if( pTo->dyn ) sqliteFree((char*)pTo->z);
pTo->base = pFrom->base;
if( pFrom->z ){
pTo->n = pFrom->n;
pTo->z = sqliteStrNDup(pFrom->z, pFrom->n);
pTo->dyn = 1;
}else{
pTo->n = 0;
pTo->z = 0;
pTo->dyn = 0;
}
}
ExprList *sqliteExprListDup(ExprList *p){
ExprList *pNew;
int i;
@@ -194,7 +174,14 @@ ExprList *sqliteExprListDup(ExprList *p){
pNew->a = sqliteMalloc( p->nExpr*sizeof(p->a[0]) );
if( pNew->a==0 ) return 0;
for(i=0; i<p->nExpr; i++){
pNew->a[i].pExpr = sqliteExprDup(p->a[i].pExpr);
Expr *pNewExpr, *pOldExpr;
pNew->a[i].pExpr = pNewExpr = sqliteExprDup(pOldExpr = p->a[i].pExpr);
if( pOldExpr->token.z!=0 && pNewExpr && pNewExpr->token.z==0 ){
/* Always make a copy of the token for top-level expressions in the
** expression list. The logic in SELECT processing that determines
** the names of columns in the result set needs this information */
sqliteTokenCopy(&pNew->a[i].pExpr->token, &p->a[i].pExpr->token);
}
pNew->a[i].zName = sqliteStrDup(p->a[i].zName);
pNew->a[i].sortOrder = p->a[i].sortOrder;
pNew->a[i].isAgg = p->a[i].isAgg;
@@ -363,6 +350,9 @@ int sqliteExprIsInteger(Expr *p, int *pValue){
}
break;
}
case TK_UPLUS: {
return sqliteExprIsInteger(p->pLeft, pValue);
}
case TK_UMINUS: {
int v;
if( sqliteExprIsInteger(p->pLeft, &v) ){
@@ -712,6 +702,39 @@ int sqliteExprResolveIds(
return 0;
}
/*
** pExpr is a node that defines a function of some kind. It might
** be a syntactic function like "count(x)" or it might be a function
** that implements an operator, like "a LIKE b".
**
** This routine makes *pzName point to the name of the function and
** *pnName hold the number of characters in the function name.
*/
static void getFunctionName(Expr *pExpr, const char **pzName, int *pnName){
switch( pExpr->op ){
case TK_FUNCTION: {
*pzName = pExpr->token.z;
*pnName = pExpr->nFuncName;
break;
}
case TK_LIKE: {
*pzName = "like";
*pnName = 4;
break;
}
case TK_GLOB: {
*pzName = "glob";
*pnName = 4;
break;
}
default: {
*pzName = "can't happen";
*pnName = 12;
break;
}
}
}
/*
** Error check the functions in an expression. Make sure all
** function names are recognized and all functions have the correct
@@ -725,6 +748,8 @@ int sqliteExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
int nErr = 0;
if( pExpr==0 ) return 0;
switch( pExpr->op ){
case TK_GLOB:
case TK_LIKE:
case TK_FUNCTION: {
int n = pExpr->pList ? pExpr->pList->nExpr : 0; /* Number of arguments */
int no_such_func = 0; /* True if no such function exists */
@@ -732,16 +757,16 @@ int sqliteExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
int wrong_num_args = 0; /* True if wrong number of arguments */
int is_agg = 0; /* True if is an aggregate function */
int i;
int nId; /* Number of characters in function name */
const char *zId; /* The function name. */
FuncDef *pDef;
pDef = sqliteFindFunction(pParse->db,
pExpr->token.z, pExpr->token.n, n, 0);
getFunctionName(pExpr, &zId, &nId);
pDef = sqliteFindFunction(pParse->db, zId, nId, n, 0);
if( pDef==0 ){
pDef = sqliteFindFunction(pParse->db,
pExpr->token.z, pExpr->token.n, -1, 0);
pDef = sqliteFindFunction(pParse->db, zId, nId, -1, 0);
if( pDef==0 ){
if( n==1 && pExpr->token.n==6
&& sqliteStrNICmp(pExpr->token.z, "typeof", 6)==0 ){
if( n==1 && nId==6 && sqliteStrNICmp(zId, "typeof", 6)==0 ){
is_type_of = 1;
}else {
no_such_func = 1;
@@ -754,19 +779,17 @@ int sqliteExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
}
if( is_agg && !allowAgg ){
sqliteSetNString(&pParse->zErrMsg, "misuse of aggregate function ", -1,
pExpr->token.z, pExpr->token.n, "()", 2, 0);
zId, nId, "()", 2, 0);
pParse->nErr++;
nErr++;
is_agg = 0;
}else if( no_such_func ){
sqliteSetNString(&pParse->zErrMsg, "no such function: ", -1,
pExpr->token.z, pExpr->token.n, 0);
sqliteSetNString(&pParse->zErrMsg, "no such function: ", -1, zId,nId,0);
pParse->nErr++;
nErr++;
}else if( wrong_num_args ){
sqliteSetNString(&pParse->zErrMsg,
"wrong number of arguments to function ",-1,
pExpr->token.z, pExpr->token.n, "()", 2, 0);
"wrong number of arguments to function ", -1, zId, nId, "()", 2, 0);
pParse->nErr++;
nErr++;
}
@@ -849,6 +872,7 @@ int sqliteExprType(Expr *p){
case TK_NOTNULL:
case TK_NOT:
case TK_UMINUS:
case TK_UPLUS:
case TK_BITAND:
case TK_BITOR:
case TK_BITNOT:
@@ -859,6 +883,8 @@ int sqliteExprType(Expr *p){
case TK_FLOAT:
case TK_IN:
case TK_BETWEEN:
case TK_GLOB:
case TK_LIKE:
return SQLITE_SO_NUM;
case TK_STRING:
@@ -1031,6 +1057,19 @@ void sqliteExprCode(Parse *pParse, Expr *pExpr){
sqliteVdbeAddOp(v, OP_Concat, 2, 0);
break;
}
case TK_UPLUS: {
Expr *pLeft = pExpr->pLeft;
if( pLeft && pLeft->op==TK_INTEGER ){
sqliteVdbeAddOp(v, OP_Integer, atoi(pLeft->token.z), 0);
sqliteVdbeChangeP3(v, -1, pLeft->token.z, pLeft->token.n);
}else if( pLeft && pLeft->op==TK_FLOAT ){
sqliteVdbeAddOp(v, OP_String, 0, 0);
sqliteVdbeChangeP3(v, -1, pLeft->token.z, pLeft->token.n);
}else{
sqliteExprCode(pParse, pExpr->pLeft);
}
break;
}
case TK_UMINUS: {
assert( pExpr->pLeft );
if( pExpr->pLeft->op==TK_FLOAT || pExpr->pLeft->op==TK_INTEGER ){
@@ -1068,13 +1107,17 @@ void sqliteExprCode(Parse *pParse, Expr *pExpr){
sqliteVdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
break;
}
case TK_GLOB:
case TK_LIKE:
case TK_FUNCTION: {
int i;
ExprList *pList = pExpr->pList;
int nExpr = pList ? pList->nExpr : 0;
FuncDef *pDef;
pDef = sqliteFindFunction(pParse->db,
pExpr->token.z, pExpr->token.n, nExpr, 0);
int nId;
const char *zId;
getFunctionName(pExpr, &zId, &nId);
pDef = sqliteFindFunction(pParse->db, zId, nId, nExpr, 0);
assert( pDef!=0 );
for(i=0; i<nExpr; i++){
sqliteExprCode(pParse, pList->a[i].pExpr);
@@ -1402,9 +1445,16 @@ int sqliteExprCompare(Expr *pA, Expr *pB){
if( pA->pSelect || pB->pSelect ) return 0;
if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
if( pA->token.z ){
int n;
if( pB->token.z==0 ) return 0;
if( pB->token.n!=pA->token.n ) return 0;
if( sqliteStrNICmp(pA->token.z, pB->token.z, pA->token.n)!=0 ) return 0;
if( pA->op==TK_FUNCTION || pA->op==TK_AGG_FUNCTION ){
n = pA->nFuncName;
if( pB->nFuncName!=n ) return 0;
}else{
n = pA->token.n;
if( pB->token.n!=n ) return 0;
}
if( sqliteStrNICmp(pA->token.z, pB->token.z, n)!=0 ) return 0;
}
return 1;
}
@@ -1475,7 +1525,7 @@ int sqliteExprAnalyzeAggregates(Parse *pParse, Expr *pExpr){
pParse->aAgg[i].isAgg = 1;
pParse->aAgg[i].pExpr = pExpr;
pParse->aAgg[i].pFunc = sqliteFindFunction(pParse->db,
pExpr->token.z, pExpr->token.n,
pExpr->token.z, pExpr->nFuncName,
pExpr->pList ? pExpr->pList->nExpr : 0, 0);
}
pExpr->iAgg = i;