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-rw-r--r--src/expr.c87
1 files changed, 51 insertions, 36 deletions
diff --git a/src/expr.c b/src/expr.c
index 4c80f4400..45401649a 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -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 1.140 2004/06/12 00:42:35 danielk1977 Exp $
+** $Id: expr.c,v 1.141 2004/06/12 09:25:14 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -1012,12 +1012,12 @@ int sqlite3ExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
int nId; /* Number of characters in function name */
const char *zId; /* The function name. */
FuncDef *pDef;
- int iPrefEnc = (pParse->db->enc==SQLITE_UTF8)?0:1;
+ int enc = pParse->db->enc;
getFunctionName(pExpr, &zId, &nId);
- pDef = sqlite3FindFunction(pParse->db, zId, nId, n, iPrefEnc, 0);
+ pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
if( pDef==0 ){
- pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, iPrefEnc, 0);
+ pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
if( pDef==0 ){
no_such_func = 1;
}else{
@@ -1280,10 +1280,10 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
const char *zId;
int p2 = 0;
int i;
- int iPrefEnc = (pParse->db->enc==SQLITE_UTF8)?0:1;
+ u8 enc = pParse->db->enc;
CollSeq *pColl = 0;
getFunctionName(pExpr, &zId, &nId);
- pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, iPrefEnc, 0);
+ pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
assert( pDef!=0 );
nExpr = sqlite3ExprCodeExprList(pParse, pList);
for(i=0; i<nExpr && i<32; i++){
@@ -1296,7 +1296,7 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
}
if( pDef->needCollSeq ){
if( !pColl ) pColl = pParse->db->pDfltColl;
- sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, pColl, P3_COLLSEQ);
+ sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
}
sqlite3VdbeOp3(v, OP_Function, nExpr, p2, (char*)pDef, P3_FUNCDEF);
break;
@@ -1724,14 +1724,14 @@ int sqlite3ExprAnalyzeAggregates(Parse *pParse, Expr *pExpr){
}
}
if( i>=pParse->nAgg ){
- int iPrefEnc = (pParse->db->enc==SQLITE_UTF8)?0:1;
+ u8 enc = pParse->db->enc;
i = appendAggInfo(pParse);
if( i<0 ) return 1;
pParse->aAgg[i].isAgg = 1;
pParse->aAgg[i].pExpr = pExpr;
pParse->aAgg[i].pFunc = sqlite3FindFunction(pParse->db,
pExpr->token.z, pExpr->token.n,
- pExpr->pList ? pExpr->pList->nExpr : 0, iPrefEnc, 0);
+ pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0);
}
pExpr->iAgg = i;
break;
@@ -1781,53 +1781,68 @@ FuncDef *sqlite3FindFunction(
const char *zName, /* Name of the function. Not null-terminated */
int nName, /* Number of characters in the name */
int nArg, /* Number of arguments. -1 means any number */
- int eTextRep, /* True to retrieve UTF-16 versions. */
+ u8 enc, /* Preferred text encoding */
int createFlag /* Create new entry if true and does not otherwise exist */
){
FuncDef *p; /* Iterator variable */
FuncDef *pFirst; /* First function with this name */
FuncDef *pBest = 0; /* Best match found so far */
- int matchqual = 0;
+ int bestmatch = 0;
- /* Normalize argument values to simplify comparisons below. */
- if( eTextRep ) eTextRep = 1;
+
+ assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
if( nArg<-1 ) nArg = -1;
pFirst = (FuncDef*)sqlite3HashFind(&db->aFunc, zName, nName);
for(p=pFirst; p; p=p->pNext){
- if( 1 || p->xFunc || p->xStep ){
- if( p->nArg==nArg && p->iPrefEnc==eTextRep ){
- /* A perfect match. */
- pBest = p;
- matchqual = 4;
- break;
+ /* During the search for the best function definition, bestmatch is set
+ ** as follows to indicate the quality of the match with the definition
+ ** pointed to by pBest:
+ **
+ ** 0: pBest is NULL. No match has been found.
+ ** 1: A variable arguments function that prefers UTF-8 when a UTF-16
+ ** encoding is requested, or vice versa.
+ ** 2: A variable arguments function that uses UTF-16BE when UTF-16LE is
+ ** requested, or vice versa.
+ ** 3: A variable arguments function using the same text encoding.
+ ** 4: A function with the exact number of arguments requested that
+ ** prefers UTF-8 when a UTF-16 encoding is requested, or vice versa.
+ ** 5: A function with the exact number of arguments requested that
+ ** prefers UTF-16LE when UTF-16BE is requested, or vice versa.
+ ** 6: An exact match.
+ **
+ ** A larger value of 'matchqual' indicates a more desirable match.
+ */
+ if( p->nArg==-1 || p->nArg==nArg || nArg==-1 ){
+ int match = 1; /* Quality of this match */
+ if( p->nArg==nArg || nArg==-1 ){
+ match = 4;
}
- if( p->nArg==nArg ){
- /* Number of arguments matches, but not the text encoding */
- pBest = p;
- matchqual = 3;
+ if( enc==p->iPrefEnc ){
+ match += 2;
}
- else if( (p->nArg<0) || (nArg<0) ){
- if( matchqual<2 && p->iPrefEnc==eTextRep ){
- /* Matched a varargs function with correct text encoding */
- pBest = p;
- matchqual = 2;
- }
- if( matchqual<1 ){
- /* Matched a varargs function with incorrect text encoding */
- pBest = p;
- matchqual = 1;
- }
+ else if( (enc==SQLITE_UTF16LE && p->iPrefEnc==SQLITE_UTF16BE) ||
+ (enc==SQLITE_UTF16BE && p->iPrefEnc==SQLITE_UTF16LE) ){
+ match += 1;
+ }
+
+ if( match>bestmatch ){
+ pBest = p;
+ bestmatch = match;
}
}
}
- if( createFlag && matchqual<4 &&
+ /* If the createFlag parameter is true, and the seach did not reveal an
+ ** exact match for the name, number of arguments and encoding, then add a
+ ** new entry to the hash table and return it.
+ */
+ if( createFlag && bestmatch<6 &&
(pBest = sqliteMalloc(sizeof(*pBest)+nName+1)) ){
pBest->nArg = nArg;
pBest->pNext = pFirst;
pBest->zName = (char*)&pBest[1];
- pBest->iPrefEnc = eTextRep;
+ pBest->iPrefEnc = enc;
memcpy(pBest->zName, zName, nName);
pBest->zName[nName] = 0;
sqlite3HashInsert(&db->aFunc, pBest->zName, nName, (void*)pBest);
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-21 20:49:28 +0000