webengine/webkitutils/SqliteSymbian/func.c
changeset 0 dd21522fd290
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/webengine/webkitutils/SqliteSymbian/func.c	Mon Mar 30 12:54:55 2009 +0300
@@ -0,0 +1,1192 @@
+/*
+** 2002 February 23
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement various SQL
+** functions of SQLite.  
+**
+** There is only one exported symbol in this file - the function
+** sqliteRegisterBuildinFunctions() found at the bottom of the file.
+** All other code has file scope.
+**
+** $Id: func.c,v 1.133 2006/08/19 11:34:01 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+/* #include <math.h> */
+#include <stdlib.h>
+#include <assert.h>
+#include "vdbeInt.h"
+#include "os.h"
+
+/*
+** Return the collating function associated with a function.
+*/
+static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
+  return context->pColl;
+}
+
+/*
+** Implementation of the non-aggregate min() and max() functions
+*/
+static void minmaxFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  int mask;    /* 0 for min() or 0xffffffff for max() */
+  int iBest;
+  CollSeq *pColl;
+
+  if( argc==0 ) return;
+  mask = sqlite3_user_data(context)==0 ? 0 : -1;
+  pColl = sqlite3GetFuncCollSeq(context);
+  assert( pColl );
+  assert( mask==-1 || mask==0 );
+  iBest = 0;
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  for(i=1; i<argc; i++){
+    if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;
+    if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){
+      iBest = i;
+    }
+  }
+  sqlite3_result_value(context, argv[iBest]);
+}
+
+/*
+** Return the type of the argument.
+*/
+static void typeofFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const char *z = 0;
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_NULL:    z = "null";    break;
+    case SQLITE_INTEGER: z = "integer"; break;
+    case SQLITE_TEXT:    z = "text";    break;
+    case SQLITE_FLOAT:   z = "real";    break;
+    case SQLITE_BLOB:    z = "blob";    break;
+  }
+  sqlite3_result_text(context, z, -1, SQLITE_STATIC);
+}
+
+
+/*
+** Implementation of the length() function
+*/
+static void lengthFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int len;
+
+  assert( argc==1 );
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_BLOB:
+    case SQLITE_INTEGER:
+    case SQLITE_FLOAT: {
+      sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));
+      break;
+    }
+    case SQLITE_TEXT: {
+      const unsigned char *z = sqlite3_value_text(argv[0]);
+      for(len=0; *z; z++){ if( (0xc0&*z)!=0x80 ) len++; }
+      sqlite3_result_int(context, len);
+      break;
+    }
+    default: {
+      sqlite3_result_null(context);
+      break;
+    }
+  }
+}
+
+/*
+** Implementation of the abs() function
+*/
+static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  assert( argc==1 );
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_INTEGER: {
+      i64 iVal = sqlite3_value_int64(argv[0]);
+      if( iVal<0 ){
+        if( (iVal<<1)==0 ){
+          sqlite3_result_error(context, "integer overflow", -1);
+          return;
+        }
+        iVal = -iVal;
+      } 
+      sqlite3_result_int64(context, iVal);
+      break;
+    }
+    case SQLITE_NULL: {
+      sqlite3_result_null(context);
+      break;
+    }
+    default: {
+      double rVal = sqlite3_value_double(argv[0]);
+      if( rVal<0 ) rVal = -rVal;
+      sqlite3_result_double(context, rVal);
+      break;
+    }
+  }
+}
+
+/*
+** Implementation of the substr() function
+*/
+static void substrFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *z;
+  const unsigned char *z2;
+  int i;
+  int p1, p2, len;
+
+  assert( argc==3 );
+  z = sqlite3_value_text(argv[0]);
+  if( z==0 ) return;
+  p1 = sqlite3_value_int(argv[1]);
+  p2 = sqlite3_value_int(argv[2]);
+  for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z2)!=0x80 ) len++; }
+  if( p1<0 ){
+    p1 += len;
+    if( p1<0 ){
+      p2 += p1;
+      p1 = 0;
+    }
+  }else if( p1>0 ){
+    p1--;
+  }
+  if( p1+p2>len ){
+    p2 = len-p1;
+  }
+  for(i=0; i<p1 && z[i]; i++){
+    if( (z[i]&0xc0)==0x80 ) p1++;
+  }
+  while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p1++; }
+  for(; i<p1+p2 && z[i]; i++){
+    if( (z[i]&0xc0)==0x80 ) p2++;
+  }
+  while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p2++; }
+  if( p2<0 ) p2 = 0;
+  sqlite3_result_text(context, (char*)&z[p1], p2, SQLITE_TRANSIENT);
+}
+
+/*
+** Implementation of the round() function
+*/
+static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  int n = 0;
+  double r;
+  char zBuf[500];  /* larger than the %f representation of the largest double */
+  assert( argc==1 || argc==2 );
+  if( argc==2 ){
+    if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
+    n = sqlite3_value_int(argv[1]);
+    if( n>30 ) n = 30;
+    if( n<0 ) n = 0;
+  }
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  r = sqlite3_value_double(argv[0]);
+  sqlite3_snprintf(sizeof(zBuf),zBuf,"%.*f",n,r);
+  sqlite3AtoF(zBuf, &r);
+  sqlite3_result_double(context, r);
+}
+
+/*
+** Implementation of the upper() and lower() SQL functions.
+*/
+static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  unsigned char *z;
+  int i;
+  if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
+  z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
+  if( z==0 ) return;
+  strcpy((char*)z, (char*)sqlite3_value_text(argv[0]));
+  for(i=0; z[i]; i++){
+    z[i] = toupper(z[i]);
+  }
+  sqlite3_result_text(context, (char*)z, -1, SQLITE_TRANSIENT);
+  sqliteFree(z);
+}
+static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  unsigned char *z;
+  int i;
+  if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
+  z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
+  if( z==0 ) return;
+  strcpy((char*)z, (char*)sqlite3_value_text(argv[0]));
+  for(i=0; z[i]; i++){
+    z[i] = tolower(z[i]);
+  }
+  sqlite3_result_text(context, (char*)z, -1, SQLITE_TRANSIENT);
+  sqliteFree(z);
+}
+
+/*
+** Implementation of the IFNULL(), NVL(), and COALESCE() functions.  
+** All three do the same thing.  They return the first non-NULL
+** argument.
+*/
+static void ifnullFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int i;
+  for(i=0; i<argc; i++){
+    if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
+      sqlite3_result_value(context, argv[i]);
+      break;
+    }
+  }
+}
+
+/*
+** Implementation of random().  Return a random integer.  
+*/
+static void randomFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite_int64 r;
+  sqlite3Randomness(sizeof(r), &r);
+  if( (r<<1)==0 ) r = 0;  /* Prevent 0x8000.... as the result so that we */
+                          /* can always do abs() of the result */
+  sqlite3_result_int64(context, r);
+}
+
+/*
+** Implementation of the last_insert_rowid() SQL function.  The return
+** value is the same as the sqlite3_last_insert_rowid() API function.
+*/
+static void last_insert_rowid(
+  sqlite3_context *context, 
+  int arg, 
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_user_data(context);
+  sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));
+}
+
+/*
+** Implementation of the changes() SQL function.  The return value is the
+** same as the sqlite3_changes() API function.
+*/
+static void changes(
+  sqlite3_context *context,
+  int arg,
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_user_data(context);
+  sqlite3_result_int(context, sqlite3_changes(db));
+}
+
+/*
+** Implementation of the total_changes() SQL function.  The return value is
+** the same as the sqlite3_total_changes() API function.
+*/
+static void total_changes(
+  sqlite3_context *context,
+  int arg,
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_user_data(context);
+  sqlite3_result_int(context, sqlite3_total_changes(db));
+}
+
+/*
+** A structure defining how to do GLOB-style comparisons.
+*/
+struct compareInfo {
+  u8 matchAll;
+  u8 matchOne;
+  u8 matchSet;
+  u8 noCase;
+};
+
+static const struct compareInfo globInfo = { '*', '?', '[', 0 };
+/* The correct SQL-92 behavior is for the LIKE operator to ignore
+** case.  Thus  'a' LIKE 'A' would be true. */
+static const struct compareInfo likeInfoNorm = { '%', '_',   0, 1 };
+/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator
+** is case sensitive causing 'a' LIKE 'A' to be false */
+static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
+
+/*
+** X is a pointer to the first byte of a UTF-8 character.  Increment
+** X so that it points to the next character.  This only works right
+** if X points to a well-formed UTF-8 string.
+*/
+#define sqliteNextChar(X)  while( (0xc0&*++(X))==0x80 ){}
+#define sqliteCharVal(X)   sqlite3ReadUtf8(X)
+
+
+/*
+** Compare two UTF-8 strings for equality where the first string can
+** potentially be a "glob" expression.  Return true (1) if they
+** are the same and false (0) if they are different.
+**
+** Globbing rules:
+**
+**      '*'       Matches any sequence of zero or more characters.
+**
+**      '?'       Matches exactly one character.
+**
+**     [...]      Matches one character from the enclosed list of
+**                characters.
+**
+**     [^...]     Matches one character not in the enclosed list.
+**
+** With the [...] and [^...] matching, a ']' character can be included
+** in the list by making it the first character after '[' or '^'.  A
+** range of characters can be specified using '-'.  Example:
+** "[a-z]" matches any single lower-case letter.  To match a '-', make
+** it the last character in the list.
+**
+** This routine is usually quick, but can be N**2 in the worst case.
+**
+** Hints: to match '*' or '?', put them in "[]".  Like this:
+**
+**         abc[*]xyz        Matches "abc*xyz" only
+*/
+static int patternCompare(
+  const u8 *zPattern,              /* The glob pattern */
+  const u8 *zString,               /* The string to compare against the glob */
+  const struct compareInfo *pInfo, /* Information about how to do the compare */
+  const int esc                    /* The escape character */
+){
+  register int c;
+  int invert;
+  int seen;
+  int c2;
+  u8 matchOne = pInfo->matchOne;
+  u8 matchAll = pInfo->matchAll;
+  u8 matchSet = pInfo->matchSet;
+  u8 noCase = pInfo->noCase; 
+  int prevEscape = 0;     /* True if the previous character was 'escape' */
+
+  while( (c = *zPattern)!=0 ){
+    if( !prevEscape && c==matchAll ){
+      while( (c=zPattern[1]) == matchAll || c == matchOne ){
+        if( c==matchOne ){
+          if( *zString==0 ) return 0;
+          sqliteNextChar(zString);
+        }
+        zPattern++;
+      }
+      if( c && esc && sqlite3ReadUtf8(&zPattern[1])==esc ){
+        u8 const *zTemp = &zPattern[1];
+        sqliteNextChar(zTemp);
+        c = *zTemp;
+      }
+      if( c==0 ) return 1;
+      if( c==matchSet ){
+        assert( esc==0 );   /* This is GLOB, not LIKE */
+        while( *zString && patternCompare(&zPattern[1],zString,pInfo,esc)==0 ){
+          sqliteNextChar(zString);
+        }
+        return *zString!=0;
+      }else{
+        while( (c2 = *zString)!=0 ){
+          if( noCase ){
+            c2 = sqlite3UpperToLower[c2];
+            c = sqlite3UpperToLower[c];
+            while( c2 != 0 && c2 != c ){ c2 = sqlite3UpperToLower[*++zString]; }
+          }else{
+            while( c2 != 0 && c2 != c ){ c2 = *++zString; }
+          }
+          if( c2==0 ) return 0;
+          if( patternCompare(&zPattern[1],zString,pInfo,esc) ) return 1;
+          sqliteNextChar(zString);
+        }
+        return 0;
+      }
+    }else if( !prevEscape && c==matchOne ){
+      if( *zString==0 ) return 0;
+      sqliteNextChar(zString);
+      zPattern++;
+    }else if( c==matchSet ){
+      int prior_c = 0;
+      assert( esc==0 );    /* This only occurs for GLOB, not LIKE */
+      seen = 0;
+      invert = 0;
+      c = sqliteCharVal(zString);
+      if( c==0 ) return 0;
+      c2 = *++zPattern;
+      if( c2=='^' ){ invert = 1; c2 = *++zPattern; }
+      if( c2==']' ){
+        if( c==']' ) seen = 1;
+        c2 = *++zPattern;
+      }
+      while( (c2 = sqliteCharVal(zPattern))!=0 && c2!=']' ){
+        if( c2=='-' && zPattern[1]!=']' && zPattern[1]!=0 && prior_c>0 ){
+          zPattern++;
+          c2 = sqliteCharVal(zPattern);
+          if( c>=prior_c && c<=c2 ) seen = 1;
+          prior_c = 0;
+        }else if( c==c2 ){
+          seen = 1;
+          prior_c = c2;
+        }else{
+          prior_c = c2;
+        }
+        sqliteNextChar(zPattern);
+      }
+      if( c2==0 || (seen ^ invert)==0 ) return 0;
+      sqliteNextChar(zString);
+      zPattern++;
+    }else if( esc && !prevEscape && sqlite3ReadUtf8(zPattern)==esc){
+      prevEscape = 1;
+      sqliteNextChar(zPattern);
+    }else{
+      if( noCase ){
+        if( sqlite3UpperToLower[c] != sqlite3UpperToLower[*zString] ) return 0;
+      }else{
+        if( c != *zString ) return 0;
+      }
+      zPattern++;
+      zString++;
+      prevEscape = 0;
+    }
+  }
+  return *zString==0;
+}
+
+/*
+** Count the number of times that the LIKE operator (or GLOB which is
+** just a variation of LIKE) gets called.  This is used for testing
+** only.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_like_count = 0;
+#endif
+
+
+/*
+** Implementation of the like() SQL function.  This function implements
+** the build-in LIKE operator.  The first argument to the function is the
+** pattern and the second argument is the string.  So, the SQL statements:
+**
+**       A LIKE B
+**
+** is implemented as like(B,A).
+**
+** This same function (with a different compareInfo structure) computes
+** the GLOB operator.
+*/
+static void likeFunc(
+  sqlite3_context *context, 
+  int argc, 
+  sqlite3_value **argv
+){
+  const unsigned char *zA = sqlite3_value_text(argv[0]);
+  const unsigned char *zB = sqlite3_value_text(argv[1]);
+  int escape = 0;
+  if( argc==3 ){
+    /* The escape character string must consist of a single UTF-8 character.
+    ** Otherwise, return an error.
+    */
+    const unsigned char *zEsc = sqlite3_value_text(argv[2]);
+    if( sqlite3utf8CharLen((char*)zEsc, -1)!=1 ){
+      sqlite3_result_error(context, 
+          "ESCAPE expression must be a single character", -1);
+      return;
+    }
+    escape = sqlite3ReadUtf8(zEsc);
+  }
+  if( zA && zB ){
+    struct compareInfo *pInfo = sqlite3_user_data(context);
+#ifdef SQLITE_TEST
+    sqlite3_like_count++;
+#endif
+    sqlite3_result_int(context, patternCompare(zA, zB, pInfo, escape));
+  }
+}
+
+/*
+** Implementation of the NULLIF(x,y) function.  The result is the first
+** argument if the arguments are different.  The result is NULL if the
+** arguments are equal to each other.
+*/
+static void nullifFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  CollSeq *pColl = sqlite3GetFuncCollSeq(context);
+  if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
+    sqlite3_result_value(context, argv[0]);
+  }
+}
+
+/*
+** Implementation of the VERSION(*) function.  The result is the version
+** of the SQLite library that is running.
+*/
+static void versionFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  sqlite3_result_text(context, sqlite3_version, -1, SQLITE_STATIC);
+}
+
+/*
+** The MATCH() function is unimplemented.  If anybody tries to use it,
+** return an error.
+*/
+static void matchStub(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  static const char zErr[] = "MATCH is not implemented";
+  sqlite3_result_error(context, zErr, sizeof(zErr)-1);
+}
+
+
+/*
+** EXPERIMENTAL - This is not an official function.  The interface may
+** change.  This function may disappear.  Do not write code that depends
+** on this function.
+**
+** Implementation of the QUOTE() function.  This function takes a single
+** argument.  If the argument is numeric, the return value is the same as
+** the argument.  If the argument is NULL, the return value is the string
+** "NULL".  Otherwise, the argument is enclosed in single quotes with
+** single-quote escapes.
+*/
+static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  if( argc<1 ) return;
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_NULL: {
+      sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);
+      break;
+    }
+    case SQLITE_INTEGER:
+    case SQLITE_FLOAT: {
+      sqlite3_result_value(context, argv[0]);
+      break;
+    }
+    case SQLITE_BLOB: {
+      static const char hexdigits[] = { 
+        '0', '1', '2', '3', '4', '5', '6', '7',
+        '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' 
+      };
+      char *zText = 0;
+      int nBlob = sqlite3_value_bytes(argv[0]);
+      char const *zBlob = sqlite3_value_blob(argv[0]);
+
+      zText = (char *)sqliteMalloc((2*nBlob)+4); 
+      if( !zText ){
+        sqlite3_result_error(context, "out of memory", -1);
+      }else{
+        int i;
+        for(i=0; i<nBlob; i++){
+          zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
+          zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
+        }
+        zText[(nBlob*2)+2] = '\'';
+        zText[(nBlob*2)+3] = '\0';
+        zText[0] = 'X';
+        zText[1] = '\'';
+        sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
+        sqliteFree(zText);
+      }
+      break;
+    }
+    case SQLITE_TEXT: {
+      int i,j,n;
+      const unsigned char *zArg = sqlite3_value_text(argv[0]);
+      char *z;
+
+      for(i=n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
+      z = sqliteMalloc( i+n+3 );
+      if( z==0 ) return;
+      z[0] = '\'';
+      for(i=0, j=1; zArg[i]; i++){
+        z[j++] = zArg[i];
+        if( zArg[i]=='\'' ){
+          z[j++] = '\'';
+        }
+      }
+      z[j++] = '\'';
+      z[j] = 0;
+      sqlite3_result_text(context, z, j, SQLITE_TRANSIENT);
+      sqliteFree(z);
+    }
+  }
+}
+
+#ifdef SQLITE_SOUNDEX
+/*
+** Compute the soundex encoding of a word.
+*/
+static void soundexFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+  char zResult[8];
+  const u8 *zIn;
+  int i, j;
+  static const unsigned char iCode[] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
+    1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
+    0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
+    1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
+  };
+  assert( argc==1 );
+  zIn = (u8*)sqlite3_value_text(argv[0]);
+  if( zIn==0 ) zIn = (u8*)"";
+  for(i=0; zIn[i] && !isalpha(zIn[i]); i++){}
+  if( zIn[i] ){
+    u8 prevcode = iCode[zIn[i]&0x7f];
+    zResult[0] = toupper(zIn[i]);
+    for(j=1; j<4 && zIn[i]; i++){
+      int code = iCode[zIn[i]&0x7f];
+      if( code>0 ){
+        if( code!=prevcode ){
+          prevcode = code;
+          zResult[j++] = code + '0';
+        }
+      }else{
+        prevcode = 0;
+      }
+    }
+    while( j<4 ){
+      zResult[j++] = '0';
+    }
+    zResult[j] = 0;
+    sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
+  }else{
+    sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
+  }
+}
+#endif
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** A function that loads a shared-library extension then returns NULL.
+*/
+static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
+  const char *zFile = (const char *)sqlite3_value_text(argv[0]);
+  const char *zProc = 0;
+  sqlite3 *db = sqlite3_user_data(context);
+  char *zErrMsg = 0;
+
+  if( argc==2 ){
+    zProc = (const char *)sqlite3_value_text(argv[1]);
+  }
+  if( sqlite3_load_extension(db, zFile, zProc, &zErrMsg) ){
+    sqlite3_result_error(context, zErrMsg, -1);
+    sqlite3_free(zErrMsg);
+  }
+}
+#endif
+
+#ifdef SQLITE_TEST
+/*
+** This function generates a string of random characters.  Used for
+** generating test data.
+*/
+static void randStr(sqlite3_context *context, int argc, sqlite3_value **argv){
+  static const unsigned char zSrc[] = 
+     "abcdefghijklmnopqrstuvwxyz"
+     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+     "0123456789"
+     ".-!,:*^+=_|?/<> ";
+  int iMin, iMax, n, r, i;
+  unsigned char zBuf[1000];
+  if( argc>=1 ){
+    iMin = sqlite3_value_int(argv[0]);
+    if( iMin<0 ) iMin = 0;
+    if( iMin>=sizeof(zBuf) ) iMin = sizeof(zBuf)-1;
+  }else{
+    iMin = 1;
+  }
+  if( argc>=2 ){
+    iMax = sqlite3_value_int(argv[1]);
+    if( iMax<iMin ) iMax = iMin;
+    if( iMax>=sizeof(zBuf) ) iMax = sizeof(zBuf)-1;
+  }else{
+    iMax = 50;
+  }
+  n = iMin;
+  if( iMax>iMin ){
+    sqlite3Randomness(sizeof(r), &r);
+    r &= 0x7fffffff;
+    n += r%(iMax + 1 - iMin);
+  }
+  assert( n<sizeof(zBuf) );
+  sqlite3Randomness(n, zBuf);
+  for(i=0; i<n; i++){
+    zBuf[i] = zSrc[zBuf[i]%(sizeof(zSrc)-1)];
+  }
+  zBuf[n] = 0;
+  sqlite3_result_text(context, (char*)zBuf, n, SQLITE_TRANSIENT);
+}
+#endif /* SQLITE_TEST */
+
+#ifdef SQLITE_TEST
+/*
+** The following two SQL functions are used to test returning a text
+** result with a destructor. Function 'test_destructor' takes one argument
+** and returns the same argument interpreted as TEXT. A destructor is
+** passed with the sqlite3_result_text() call.
+**
+** SQL function 'test_destructor_count' returns the number of outstanding 
+** allocations made by 'test_destructor';
+**
+** WARNING: Not threadsafe.
+*/
+static int test_destructor_count_var = 0;
+static void destructor(void *p){
+  char *zVal = (char *)p;
+  assert(zVal);
+  zVal--;
+  sqliteFree(zVal);
+  test_destructor_count_var--;
+}
+static void test_destructor(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  char *zVal;
+  int len;
+  sqlite3 *db = sqlite3_user_data(pCtx);
+ 
+  test_destructor_count_var++;
+  assert( nArg==1 );
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  len = sqlite3ValueBytes(argv[0], ENC(db)); 
+  zVal = sqliteMalloc(len+3);
+  zVal[len] = 0;
+  zVal[len-1] = 0;
+  assert( zVal );
+  zVal++;
+  memcpy(zVal, sqlite3ValueText(argv[0], ENC(db)), len);
+  if( ENC(db)==SQLITE_UTF8 ){
+    sqlite3_result_text(pCtx, zVal, -1, destructor);
+#ifndef SQLITE_OMIT_UTF16
+  }else if( ENC(db)==SQLITE_UTF16LE ){
+    sqlite3_result_text16le(pCtx, zVal, -1, destructor);
+  }else{
+    sqlite3_result_text16be(pCtx, zVal, -1, destructor);
+#endif /* SQLITE_OMIT_UTF16 */
+  }
+}
+static void test_destructor_count(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  sqlite3_result_int(pCtx, test_destructor_count_var);
+}
+#endif /* SQLITE_TEST */
+
+#ifdef SQLITE_TEST
+/*
+** Routines for testing the sqlite3_get_auxdata() and sqlite3_set_auxdata()
+** interface.
+**
+** The test_auxdata() SQL function attempts to register each of its arguments
+** as auxiliary data.  If there are no prior registrations of aux data for
+** that argument (meaning the argument is not a constant or this is its first
+** call) then the result for that argument is 0.  If there is a prior
+** registration, the result for that argument is 1.  The overall result
+** is the individual argument results separated by spaces.
+*/
+static void free_test_auxdata(void *p) {sqliteFree(p);}
+static void test_auxdata(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  int i;
+  char *zRet = sqliteMalloc(nArg*2);
+  if( !zRet ) return;
+  for(i=0; i<nArg; i++){
+    char const *z = (char*)sqlite3_value_text(argv[i]);
+    if( z ){
+      char *zAux = sqlite3_get_auxdata(pCtx, i);
+      if( zAux ){
+        zRet[i*2] = '1';
+        if( strcmp(zAux, z) ){
+          sqlite3_result_error(pCtx, "Auxilary data corruption", -1);
+          return;
+        }
+      }else{
+        zRet[i*2] = '0';
+        zAux = sqliteStrDup(z);
+        sqlite3_set_auxdata(pCtx, i, zAux, free_test_auxdata);
+      }
+      zRet[i*2+1] = ' ';
+    }
+  }
+  sqlite3_result_text(pCtx, zRet, 2*nArg-1, free_test_auxdata);
+}
+#endif /* SQLITE_TEST */
+
+#ifdef SQLITE_TEST
+/*
+** A function to test error reporting from user functions. This function
+** returns a copy of it's first argument as an error.
+*/
+static void test_error(
+  sqlite3_context *pCtx, 
+  int nArg,
+  sqlite3_value **argv
+){
+  sqlite3_result_error(pCtx, (char*)sqlite3_value_text(argv[0]), 0);
+}
+#endif /* SQLITE_TEST */
+
+/*
+** An instance of the following structure holds the context of a
+** sum() or avg() aggregate computation.
+*/
+typedef struct SumCtx SumCtx;
+struct SumCtx {
+  double rSum;      /* Floating point sum */
+  i64 iSum;         /* Integer sum */   
+  i64 cnt;          /* Number of elements summed */
+  u8 overflow;      /* True if integer overflow seen */
+  u8 approx;        /* True if non-integer value was input to the sum */
+};
+
+/*
+** Routines used to compute the sum, average, and total.
+**
+** The SUM() function follows the (broken) SQL standard which means
+** that it returns NULL if it sums over no inputs.  TOTAL returns
+** 0.0 in that case.  In addition, TOTAL always returns a float where
+** SUM might return an integer if it never encounters a floating point
+** value.  TOTAL never fails, but SUM might through an exception if
+** it overflows an integer.
+*/
+static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+  SumCtx *p;
+  int type;
+  assert( argc==1 );
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  type = sqlite3_value_numeric_type(argv[0]);
+  if( p && type!=SQLITE_NULL ){
+    p->cnt++;
+    if( type==SQLITE_INTEGER ){
+      i64 v = sqlite3_value_int64(argv[0]);
+      p->rSum += v;
+      if( (p->approx|p->overflow)==0 ){
+        i64 iNewSum = p->iSum + v;
+        int s1 = p->iSum >> (sizeof(i64)*8-1);
+        int s2 = v       >> (sizeof(i64)*8-1);
+        int s3 = iNewSum >> (sizeof(i64)*8-1);
+        p->overflow = (s1&s2&~s3) | (~s1&~s2&s3);
+        p->iSum = iNewSum;
+      }
+    }else{
+      p->rSum += sqlite3_value_double(argv[0]);
+      p->approx = 1;
+    }
+  }
+}
+static void sumFinalize(sqlite3_context *context){
+  SumCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  if( p && p->cnt>0 ){
+    if( p->overflow ){
+      sqlite3_result_error(context,"integer overflow",-1);
+    }else if( p->approx ){
+      sqlite3_result_double(context, p->rSum);
+    }else{
+      sqlite3_result_int64(context, p->iSum);
+    }
+  }
+}
+static void avgFinalize(sqlite3_context *context){
+  SumCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  if( p && p->cnt>0 ){
+    sqlite3_result_double(context, p->rSum/(double)p->cnt);
+  }
+}
+static void totalFinalize(sqlite3_context *context){
+  SumCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  sqlite3_result_double(context, p ? p->rSum : 0.0);
+}
+
+/*
+** The following structure keeps track of state information for the
+** count() aggregate function.
+*/
+typedef struct CountCtx CountCtx;
+struct CountCtx {
+  i64 n;
+};
+
+/*
+** Routines to implement the count() aggregate function.
+*/
+static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+  CountCtx *p;
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
+    p->n++;
+  }
+}   
+static void countFinalize(sqlite3_context *context){
+  CountCtx *p;
+  p = sqlite3_aggregate_context(context, 0);
+  sqlite3_result_int64(context, p ? p->n : 0);
+}
+
+/*
+** Routines to implement min() and max() aggregate functions.
+*/
+static void minmaxStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+  Mem *pArg  = (Mem *)argv[0];
+  Mem *pBest;
+
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
+  if( !pBest ) return;
+
+  if( pBest->flags ){
+    int max;
+    int cmp;
+    CollSeq *pColl = sqlite3GetFuncCollSeq(context);
+    /* This step function is used for both the min() and max() aggregates,
+    ** the only difference between the two being that the sense of the
+    ** comparison is inverted. For the max() aggregate, the
+    ** sqlite3_user_data() function returns (void *)-1. For min() it
+    ** returns (void *)db, where db is the sqlite3* database pointer.
+    ** Therefore the next statement sets variable 'max' to 1 for the max()
+    ** aggregate, or 0 for min().
+    */
+    max = ((sqlite3_user_data(context)==(void *)-1)?1:0);
+    cmp = sqlite3MemCompare(pBest, pArg, pColl);
+    if( (max && cmp<0) || (!max && cmp>0) ){
+      sqlite3VdbeMemCopy(pBest, pArg);
+    }
+  }else{
+    sqlite3VdbeMemCopy(pBest, pArg);
+  }
+}
+static void minMaxFinalize(sqlite3_context *context){
+  sqlite3_value *pRes;
+  pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
+  if( pRes ){
+    if( pRes->flags ){
+      sqlite3_result_value(context, pRes);
+    }
+    sqlite3VdbeMemRelease(pRes);
+  }
+}
+
+
+/*
+** This function registered all of the above C functions as SQL
+** functions.  This should be the only routine in this file with
+** external linkage.
+*/
+void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
+  static const struct {
+     char *zName;
+     signed char nArg;
+     u8 argType;           /* 0: none.  1: db  2: (-1) */
+     u8 eTextRep;          /* 1: UTF-16.  0: UTF-8 */
+     u8 needCollSeq;
+     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
+  } aFuncs[] = {
+    { "min",               -1, 0, SQLITE_UTF8,    1, minmaxFunc },
+    { "min",                0, 0, SQLITE_UTF8,    1, 0          },
+    { "max",               -1, 2, SQLITE_UTF8,    1, minmaxFunc },
+    { "max",                0, 2, SQLITE_UTF8,    1, 0          },
+    { "typeof",             1, 0, SQLITE_UTF8,    0, typeofFunc },
+    { "length",             1, 0, SQLITE_UTF8,    0, lengthFunc },
+    { "substr",             3, 0, SQLITE_UTF8,    0, substrFunc },
+#ifndef SQLITE_OMIT_UTF16
+    { "substr",             3, 0, SQLITE_UTF16LE, 0, sqlite3utf16Substr },
+#endif
+    { "abs",                1, 0, SQLITE_UTF8,    0, absFunc    },
+    { "round",              1, 0, SQLITE_UTF8,    0, roundFunc  },
+    { "round",              2, 0, SQLITE_UTF8,    0, roundFunc  },
+    { "upper",              1, 0, SQLITE_UTF8,    0, upperFunc  },
+    { "lower",              1, 0, SQLITE_UTF8,    0, lowerFunc  },
+    { "coalesce",          -1, 0, SQLITE_UTF8,    0, ifnullFunc },
+    { "coalesce",           0, 0, SQLITE_UTF8,    0, 0          },
+    { "coalesce",           1, 0, SQLITE_UTF8,    0, 0          },
+    { "ifnull",             2, 0, SQLITE_UTF8,    1, ifnullFunc },
+    { "random",            -1, 0, SQLITE_UTF8,    0, randomFunc },
+    { "nullif",             2, 0, SQLITE_UTF8,    1, nullifFunc },
+    { "sqlite_version",     0, 0, SQLITE_UTF8,    0, versionFunc},
+    { "quote",              1, 0, SQLITE_UTF8,    0, quoteFunc  },
+    { "last_insert_rowid",  0, 1, SQLITE_UTF8,    0, last_insert_rowid },
+    { "changes",            0, 1, SQLITE_UTF8,    0, changes    },
+    { "total_changes",      0, 1, SQLITE_UTF8,    0, total_changes },
+    { "match",              2, 0, SQLITE_UTF8,    0, matchStub },
+#ifdef SQLITE_SOUNDEX
+    { "soundex",            1, 0, SQLITE_UTF8, 0, soundexFunc},
+#endif
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+    { "load_extension",     1, 1, SQLITE_UTF8,    0, loadExt },
+    { "load_extension",     2, 1, SQLITE_UTF8,    0, loadExt },
+#endif
+#ifdef SQLITE_TEST
+    { "randstr",               2, 0, SQLITE_UTF8, 0, randStr    },
+    { "test_destructor",       1, 1, SQLITE_UTF8, 0, test_destructor},
+    { "test_destructor_count", 0, 0, SQLITE_UTF8, 0, test_destructor_count},
+    { "test_auxdata",         -1, 0, SQLITE_UTF8, 0, test_auxdata},
+    { "test_error",            1, 0, SQLITE_UTF8, 0, test_error},
+#endif
+  };
+  static const struct {
+    char *zName;
+    signed char nArg;
+    u8 argType;
+    u8 needCollSeq;
+    void (*xStep)(sqlite3_context*,int,sqlite3_value**);
+    void (*xFinalize)(sqlite3_context*);
+  } aAggs[] = {
+    { "min",    1, 0, 1, minmaxStep,   minMaxFinalize },
+    { "max",    1, 2, 1, minmaxStep,   minMaxFinalize },
+    { "sum",    1, 0, 0, sumStep,      sumFinalize    },
+    { "total",  1, 0, 0, sumStep,      totalFinalize    },
+    { "avg",    1, 0, 0, sumStep,      avgFinalize    },
+    { "count",  0, 0, 0, countStep,    countFinalize  },
+    { "count",  1, 0, 0, countStep,    countFinalize  },
+  };
+  int i;
+
+  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
+    void *pArg = 0;
+    switch( aFuncs[i].argType ){
+      case 1: pArg = db; break;
+      case 2: pArg = (void *)(-1); break;
+    }
+    sqlite3CreateFunc(db, aFuncs[i].zName, aFuncs[i].nArg,
+        aFuncs[i].eTextRep, pArg, aFuncs[i].xFunc, 0, 0);
+    if( aFuncs[i].needCollSeq ){
+      FuncDef *pFunc = sqlite3FindFunction(db, aFuncs[i].zName, 
+          strlen(aFuncs[i].zName), aFuncs[i].nArg, aFuncs[i].eTextRep, 0);
+      if( pFunc && aFuncs[i].needCollSeq ){
+        pFunc->needCollSeq = 1;
+      }
+    }
+  }
+#ifndef SQLITE_OMIT_ALTERTABLE
+  sqlite3AlterFunctions(db);
+#endif
+#ifndef SQLITE_OMIT_PARSER
+  sqlite3AttachFunctions(db);
+#endif
+  for(i=0; i<sizeof(aAggs)/sizeof(aAggs[0]); i++){
+    void *pArg = 0;
+    switch( aAggs[i].argType ){
+      case 1: pArg = db; break;
+      case 2: pArg = (void *)(-1); break;
+    }
+    sqlite3CreateFunc(db, aAggs[i].zName, aAggs[i].nArg, SQLITE_UTF8, 
+        pArg, 0, aAggs[i].xStep, aAggs[i].xFinalize);
+    if( aAggs[i].needCollSeq ){
+      FuncDef *pFunc = sqlite3FindFunction( db, aAggs[i].zName,
+          strlen(aAggs[i].zName), aAggs[i].nArg, SQLITE_UTF8, 0);
+      if( pFunc && aAggs[i].needCollSeq ){
+        pFunc->needCollSeq = 1;
+      }
+    }
+  }
+  sqlite3RegisterDateTimeFunctions(db);
+#ifdef SQLITE_SSE
+  (void)sqlite3SseFunctions(db);
+#endif
+#ifdef SQLITE_CASE_SENSITIVE_LIKE
+  sqlite3RegisterLikeFunctions(db, 1);
+#else
+  sqlite3RegisterLikeFunctions(db, 0);
+#endif
+}
+
+/*
+** Set the LIKEOPT flag on the 2-argument function with the given name.
+*/
+static void setLikeOptFlag(sqlite3 *db, const char *zName, int flagVal){
+  FuncDef *pDef;
+  pDef = sqlite3FindFunction(db, zName, strlen(zName), 2, SQLITE_UTF8, 0);
+  if( pDef ){
+    pDef->flags = flagVal;
+  }
+}
+
+/*
+** Register the built-in LIKE and GLOB functions.  The caseSensitive
+** parameter determines whether or not the LIKE operator is case
+** sensitive.  GLOB is always case sensitive.
+*/
+void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
+  struct compareInfo *pInfo;
+  if( caseSensitive ){
+    pInfo = (struct compareInfo*)&likeInfoAlt;
+  }else{
+    pInfo = (struct compareInfo*)&likeInfoNorm;
+  }
+  sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
+  sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
+  sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8, 
+      (struct compareInfo*)&globInfo, likeFunc, 0,0);
+  setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE);
+  setLikeOptFlag(db, "like", 
+      caseSensitive ? (SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
+}
+
+/*
+** pExpr points to an expression which implements a function.  If
+** it is appropriate to apply the LIKE optimization to that function
+** then set aWc[0] through aWc[2] to the wildcard characters and
+** return TRUE.  If the function is not a LIKE-style function then
+** return FALSE.
+*/
+int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
+  FuncDef *pDef;
+  if( pExpr->op!=TK_FUNCTION ){
+    return 0;
+  }
+  if( pExpr->pList->nExpr!=2 ){
+    return 0;
+  }
+  pDef = sqlite3FindFunction(db, (char*)pExpr->token.z, pExpr->token.n, 2,
+                             SQLITE_UTF8, 0);
+  if( pDef==0 || (pDef->flags & SQLITE_FUNC_LIKE)==0 ){
+    return 0;
+  }
+
+  /* The memcpy() statement assumes that the wildcard characters are
+  ** the first three statements in the compareInfo structure.  The
+  ** asserts() that follow verify that assumption
+  */
+  memcpy(aWc, pDef->pUserData, 3);
+  assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
+  assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
+  assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
+  *pIsNocase = (pDef->flags & SQLITE_FUNC_CASE)==0;
+  return 1;
+}