Fix the application-defined function logic so that functions with a variable

number of parameters can be replaced or deleted correctly.  Also refactor
some of the function-finder code for clarity of presentation.

FossilOrigin-Name: 09d5581c81fb6a9bf6a369d0abf5ef6b54637576

manifest

@@ -1,5 +1,5 @@
-C Update\ssqlite3_analyzer\sto\scorrectly\sfind\sall\sdatabase\sfiles\swhen\sthe\nmultiplexor\sis\sbeing\sused.
+C Fix\sthe\sapplication-defined\sfunction\slogic\sso\sthat\sfunctions\swith\sa\svariable\nnumber\sof\sparameters\scan\sbe\sreplaced\sor\sdeleted\scorrectly.\s\sAlso\srefactor\nsome\sof\sthe\sfunction-finder\scode\sfor\sclarity\sof\spresentation.
-D 2012-04-06T00:09:27.071
+D 2012-04-07T00:09:21.842
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 2f37e468503dbe79d35c9f6dffcf3fae1ae9ec20
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -130,7 +130,7 @@ F src/btree.c df800f10896bc2ddaa1125c532d6e7a7b9efc532
 F src/btree.h 48a013f8964f12d944d90e4700df47b72dd6d923
 F src/btreeInt.h 38a639c0542c29fe8331a221c4aed0cb8686249e
 F src/build.c 987c6933ea170e443dc6a79d52f8d2506206b12b
-F src/callback.c 0425c6320730e6d3981acfb9202c1bed9016ad1a
+F src/callback.c 0cb4228cdcd827dcc5def98fb099edcc9142dbcd
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c a9c26822515f81ec21588cbb482ca6724be02e33
 F src/date.c 067a81c9942c497aafd2c260e13add8a7d0c7dd4
@@ -179,13 +179,13 @@ F src/pragma.c e708b3bb5704605816f617e0b1d63a5488060715
 F src/prepare.c ec4989f7f480544bdc4192fe663470d2a2d7d61e
 F src/printf.c 7ffb4ebb8b341f67e049695ba031da717b3d2699
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
-F src/resolve.c 3d3e80a98f203ac6b9329e9621e29eda85ddfd40
+F src/resolve.c 969ec2bc52db1b068054ecf5ddc74f244102a71d
 F src/rowset.c f6a49f3e9579428024662f6e2931832511f831a1
 F src/select.c 5e0e481c7d215d3c7ca8ccae1e688aa30163c6c1
 F src/shell.c ce4d41582182b8fad3be364e2fa295b70bc342ab
 F src/sqlite.h.in 11a883919b0baf4ffaa7550cfeef99be613ec2bf
 F src/sqlite3ext.h 6904f4aadf976f95241311fbffb00823075d9477
-F src/sqliteInt.h d701123ab4c8774ee2837cd4ade84e370d665f87
+F src/sqliteInt.h ce7d8404f15db6cbe73cf196d3d6198aaa4e3924
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 35939e7e03abf1b7577ce311f48f682c40de3208
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -1000,7 +1000,7 @@ F tool/tostr.awk e75472c2f98dd76e06b8c9c1367f4ab07e122d06
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings-clang.sh 9f406d66e750e8ac031c63a9ef3248aaa347ef2a
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
-P 1b08fef9451f4d59148548faed115d1a5d0bcd98
+P 1bfc30cb0fdc4b9def989eea2d78f6ac851633fa
-R 220148404893713f89fb8c5c7ad54b6d
+R 7617876a091e2e4cf9376c46017f187f
 U drh
-Z 737b7c44e8ad27216e6474b5a72beb32
+Z 1d4ad19c22a54f0c05282a803680a670

manifest.uuid

@@ -1 +1 @@
-1bfc30cb0fdc4b9def989eea2d78f6ac851633fa
+09d5581c81fb6a9bf6a369d0abf5ef6b54637576

src/callback.c

@@ -223,38 +223,57 @@ CollSeq *sqlite3FindCollSeq(
 ** that uses encoding enc. The value returned indicates how well the
 ** request is matched. A higher value indicates a better match.
 **
+** If nArg is -1 that means to only return a match (non-zero) if p->nArg
+** is also -1.  In other words, we are searching for a function that
+** takes a variable number of arguments.
+**
+** If nArg is -2 that means that we are searching for any function 
+** regardless of the number of arguments it uses, so return a positive
+** match score for any
+**
 ** The returned value is always between 0 and 6, as follows:
 **
-** 0: Not a match, or if nArg<0 and the function is has no implementation.
+** 0: Not a match.
-** 1: A variable arguments function that prefers UTF-8 when a UTF-16
+** 1: UTF8/16 conversion required and function takes any number of arguments.
-**    encoding is requested, or vice versa.
+** 2: UTF16 byte order change required and function takes any number of args.
-** 2: A variable arguments function that uses UTF-16BE when UTF-16LE is
+** 3: encoding matches and function takes any number of arguments
-**    requested, or vice versa.
+** 4: UTF8/16 conversion required - argument count matches exactly
-** 3: A variable arguments function using the same text encoding.
+** 5: UTF16 byte order conversion required - argument count matches exactly
-** 4: A function with the exact number of arguments requested that
+** 6: Perfect match:  encoding and argument count match exactly.
-**    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.
 **
+** If nArg==(-2) then any function with a non-null xStep or xFunc is
+** a perfect match and any function with both xStep and xFunc NULL is
+** a non-match.
 */
-static int matchQuality(FuncDef *p, int nArg, u8 enc){
+#define FUNC_PERFECT_MATCH 6  /* The score for a perfect match */
-  int match = 0;
+static int matchQuality(
-  if( p->nArg==-1 || p->nArg==nArg 
+  FuncDef *p,     /* The function we are evaluating for match quality */
-   || (nArg==-1 && (p->xFunc!=0 || p->xStep!=0))
+  int nArg,       /* Desired number of arguments.  (-1)==any */
+  u8 enc          /* Desired text encoding */
 ){
-    match = 1;
+  int match;
-    if( p->nArg==nArg || nArg==-1 ){
+
+  /* nArg of -2 is a special case */
+  if( nArg==(-2) ) return (p->xFunc==0 && p->xStep==0) ? 0 : FUNC_PERFECT_MATCH;
+
+  /* Wrong number of arguments means "no match" */
+  if( p->nArg!=nArg && p->nArg>=0 ) return 0;
+
+  /* Give a better score to a function with a specific number of arguments
+  ** than to function that accepts any number of arguments. */
+  if( p->nArg==nArg ){
     match = 4;
+  }else{
+    match = 1;
   }
+
+  /* Bonus points if the text encoding matches */
   if( enc==p->iPrefEnc ){
-      match += 2;
+    match += 2;  /* Exact encoding match */
-    }
+  }else if( (enc & p->iPrefEnc & 2)!=0 ){
-    else if( (enc==SQLITE_UTF16LE && p->iPrefEnc==SQLITE_UTF16BE) ||
+    match += 1;  /* Both are UTF16, but with different byte orders */
-             (enc==SQLITE_UTF16BE && p->iPrefEnc==SQLITE_UTF16LE) ){
-      match += 1;
-    }
   }
+
   return match;
 }
 
@@ -310,13 +329,12 @@ void sqlite3FuncDefInsert(
 **
 ** If the createFlag argument is true, then a new (blank) FuncDef
 ** structure is created and liked into the "db" structure if a
-** no matching function previously existed.  When createFlag is true
+** no matching function previously existed.
-** and the nArg parameter is -1, then only a function that accepts
-** any number of arguments will be returned.
 **
-** If createFlag is false and nArg is -1, then the first valid
+** If nArg is -2, then the first valid function found is returned.  A
-** function found is returned.  A function is valid if either xFunc
+** function is valid if either xFunc or xStep is non-zero.  The nArg==(-2)
-** or xStep is non-zero.
+** case is used to see if zName is a valid function name for some number
+** of arguments.  If nArg is -2, then createFlag must be 0.
 **
 ** If createFlag is false, then a function with the required name and
 ** number of arguments may be returned even if the eTextRep flag does not
@@ -328,14 +346,15 @@ FuncDef *sqlite3FindFunction(
   int nName,         /* Number of characters in the name */
   int nArg,          /* Number of arguments.  -1 means any number */
   u8 enc,            /* Preferred text encoding */
-  int createFlag     /* Create new entry if true and does not otherwise exist */
+  u8 createFlag      /* Create new entry if true and does not otherwise exist */
 ){
   FuncDef *p;         /* Iterator variable */
   FuncDef *pBest = 0; /* Best match found so far */
   int bestScore = 0;  /* Score of best match */
   int h;              /* Hash value */
 
-
+  assert( nArg>=(-2) );
+  assert( nArg>=(-1) || createFlag==0 );
   assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
   h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % ArraySize(db->aFunc.a);
 
@@ -381,7 +400,7 @@ FuncDef *sqlite3FindFunction(
   ** exact match for the name, number of arguments and encoding, then add a
   ** new entry to the hash table and return it.
   */
-  if( createFlag && (bestScore<6 || pBest->nArg!=nArg) && 
+  if( createFlag && bestScore<FUNC_PERFECT_MATCH && 
       (pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName+1))!=0 ){
     pBest->zName = (char *)&pBest[1];
     pBest->nArg = (u16)nArg;

src/resolve.c

@@ -533,7 +533,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       nId = sqlite3Strlen30(zId);
       pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
       if( pDef==0 ){
-        pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
+        pDef = sqlite3FindFunction(pParse->db, zId, nId, -2, enc, 0);
         if( pDef==0 ){
           no_such_func = 1;
         }else{

src/sqliteInt.h

@@ -2845,7 +2845,7 @@ SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
 IdList *sqlite3IdListDup(sqlite3*,IdList*);
 Select *sqlite3SelectDup(sqlite3*,Select*,int);
 void sqlite3FuncDefInsert(FuncDefHash*, FuncDef*);
-FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,int);
+FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,int,u8,u8);
 void sqlite3RegisterBuiltinFunctions(sqlite3*);
 void sqlite3RegisterDateTimeFunctions(void);
 void sqlite3RegisterGlobalFunctions(void);