https://www.sqlite.org/cgi/src/info/374b5108087a2eae

--- ext/fts3/fts3_tokenizer.c
+++ ext/fts3/fts3_tokenizer.c
@@ -30,6 +30,18 @@
 #include <string.h>
 
 /*
+** Return true if the two-argument version of fts3_tokenizer()
+** has been activated via a prior call to sqlite3_db_config(db,
+** SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, 1, 0);
+*/
+static int fts3TokenizerEnabled(sqlite3_context *context){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  int isEnabled = 0;
+  sqlite3_db_config(db,SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER,-1,&isEnabled);
+  return isEnabled;
+}
+
+/*
 ** Implementation of the SQL scalar function for accessing the underlying 
 ** hash table. This function may be called as follows:
 **
@@ -49,7 +61,7 @@
 ** is a blob containing the pointer stored as the hash data corresponding
 ** to string <key-name> (after the hash-table is updated, if applicable).
 */
-static void scalarFunc(
+static void fts3TokenizerFunc(
   sqlite3_context *context,
   int argc,
   sqlite3_value **argv
@@ -67,27 +79,23 @@
   nName = sqlite3_value_bytes(argv[0])+1;
 
   if( argc==2 ){
-#ifdef SQLITE_ENABLE_FTS3_TOKENIZER
-    void *pOld;
-    int n = sqlite3_value_bytes(argv[1]);
-    if( zName==0 || n!=sizeof(pPtr) ){
-      sqlite3_result_error(context, "argument type mismatch", -1);
-      return;
-    }
-    pPtr = *(void **)sqlite3_value_blob(argv[1]);
-    pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);
-    if( pOld==pPtr ){
-      sqlite3_result_error(context, "out of memory", -1);
+    if( fts3TokenizerEnabled(context) ){
+      void *pOld;
+      int n = sqlite3_value_bytes(argv[1]);
+      if( zName==0 || n!=sizeof(pPtr) ){
+        sqlite3_result_error(context, "argument type mismatch", -1);
+        return;
+      }
+      pPtr = *(void **)sqlite3_value_blob(argv[1]);
+      pOld = sqlite3Fts3HashInsert(pHash, (void *)zName, nName, pPtr);
+      if( pOld==pPtr ){
+        sqlite3_result_error(context, "out of memory", -1);
+      }
+    }else{
+      sqlite3_result_error(context, "fts3tokenize disabled", -1);
       return;
     }
-#else
-    sqlite3_result_error(context, "fts3tokenize: " 
-        "disabled - rebuild with -DSQLITE_ENABLE_FTS3_TOKENIZER", -1
-    );
-    return;
-#endif /* SQLITE_ENABLE_FTS3_TOKENIZER */
-  }else
-  {
+  }else{
     if( zName ){
       pPtr = sqlite3Fts3HashFind(pHash, zName, nName);
     }
@@ -98,7 +106,6 @@
       return;
     }
   }
-
   sqlite3_result_blob(context, (void *)&pPtr, sizeof(pPtr), SQLITE_TRANSIENT);
 }
 
@@ -336,7 +343,6 @@
   Tcl_DecrRefCount(pRet);
 }
 
-#ifdef SQLITE_ENABLE_FTS3_TOKENIZER
 static
 int registerTokenizer(
   sqlite3 *db, 
@@ -358,7 +364,6 @@
 
   return sqlite3_finalize(pStmt);
 }
-#endif /* SQLITE_ENABLE_FTS3_TOKENIZER */
 
 
 static
@@ -431,13 +436,13 @@
   assert( 0==strcmp(sqlite3_errmsg(db), "unknown tokenizer: nosuchtokenizer") );
 
   /* Test the storage function */
-#ifdef SQLITE_ENABLE_FTS3_TOKENIZER
-  rc = registerTokenizer(db, "nosuchtokenizer", p1);
-  assert( rc==SQLITE_OK );
-  rc = queryTokenizer(db, "nosuchtokenizer", &p2);
-  assert( rc==SQLITE_OK );
-  assert( p2==p1 );
-#endif
+  if( fts3TokenizerEnabled(context) ){
+    rc = registerTokenizer(db, "nosuchtokenizer", p1);
+    assert( rc==SQLITE_OK );
+    rc = queryTokenizer(db, "nosuchtokenizer", &p2);
+    assert( rc==SQLITE_OK );
+    assert( p2==p1 );
+  }
 
   sqlite3_result_text(context, "ok", -1, SQLITE_STATIC);
 }
@@ -453,7 +458,7 @@
 **    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
 **
 ** This function adds a scalar function (see header comment above
-** scalarFunc() in this file for details) and, if ENABLE_TABLE is
+** fts3TokenizerFunc() in this file for details) and, if ENABLE_TABLE is
 ** defined at compilation time, a temporary virtual table (see header 
 ** comment above struct HashTableVtab) to the database schema. Both 
 ** provide read/write access to the contents of *pHash.
@@ -482,10 +487,10 @@
 #endif
 
   if( SQLITE_OK==rc ){
-    rc = sqlite3_create_function(db, zName, 1, any, p, scalarFunc, 0, 0);
+    rc = sqlite3_create_function(db, zName, 1, any, p, fts3TokenizerFunc, 0, 0);
   }
   if( SQLITE_OK==rc ){
-    rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0);
+    rc = sqlite3_create_function(db, zName, 2, any, p, fts3TokenizerFunc, 0, 0);
   }
 #ifdef SQLITE_TEST
   if( SQLITE_OK==rc ){
--- src/main.c
+++ src/main.c
@@ -797,8 +797,9 @@
         int op;      /* The opcode */
         u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
       } aFlagOp[] = {
-        { SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    },
-        { SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  },
+        { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
+        { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
+        { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
       };
       unsigned int i;
       rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
@@ -2815,6 +2816,9 @@
 #if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
                  | SQLITE_CellSizeCk
 #endif
+#if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
+                 | SQLITE_Fts3Tokenizer
+#endif
       ;
   sqlite3HashInit(&db->aCollSeq);
 #ifndef SQLITE_OMIT_VIRTUALTABLE
--- src/sqlite.h.in
+++ src/sqlite.h.in
@@ -1904,11 +1904,25 @@
 ** following this call.  The second parameter may be a NULL pointer, in
 ** which case the trigger setting is not reported back. </dd>
 **
+** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
+** <dd> ^This option is used to enable or disable the two-argument
+** version of the [fts3_tokenizer()] function which is part of the
+** [FTS3] full-text search engine extension.
+** There should be two additional arguments.
+** The first argument is an integer which is 0 to disable fts3_tokenizer() or
+** positive to enable fts3_tokenizer() or negative to leave the setting
+** unchanged.
+** The second parameter is a pointer to an integer into which
+** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
+** following this call.  The second parameter may be a NULL pointer, in
+** which case the new setting is not reported back. </dd>
+**
 ** </dl>
 */
-#define SQLITE_DBCONFIG_LOOKASIDE       1001  /* void* int int */
-#define SQLITE_DBCONFIG_ENABLE_FKEY     1002  /* int int* */
-#define SQLITE_DBCONFIG_ENABLE_TRIGGER  1003  /* int int* */
+#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
+#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
+#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
 
 
 /*
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -1317,6 +1317,7 @@
 #define SQLITE_VdbeEQP        0x04000000  /* Debug EXPLAIN QUERY PLAN */
 #define SQLITE_Vacuum         0x08000000  /* Currently in a VACUUM */
 #define SQLITE_CellSizeCk     0x10000000  /* Check btree cell sizes on load */
+#define SQLITE_Fts3Tokenizer  0x20000000  /* Enable fts3_tokenizer(2) */
 
 
 /*
--- src/test1.c
+++ src/test1.c
@@ -6921,6 +6921,53 @@
 }
 
 /*
+** tclcmd:   sqlite3_db_config DB SETTING VALUE
+**
+** Invoke sqlite3_db_config() for one of the setting values.
+*/
+static int test_sqlite3_db_config(
+  void *clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  static const struct {
+    const char *zName;
+    int eVal;
+  } aSetting[] = {
+    { "FKEY",            SQLITE_DBCONFIG_ENABLE_FKEY },
+    { "TRIGGER",         SQLITE_DBCONFIG_ENABLE_TRIGGER },
+    { "FTS3_TOKENIZER",  SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER },
+  };
+  int i;
+  int v;
+  const char *zSetting;
+  sqlite3 *db;
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB SETTING VALUE");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zSetting = Tcl_GetString(objv[2]);
+  if( sqlite3_strglob("SQLITE_*", zSetting)==0 ) zSetting += 7;
+  if( sqlite3_strglob("DBCONFIG_*", zSetting)==0 ) zSetting += 9;
+  if( sqlite3_strglob("ENABLE_*", zSetting)==0 ) zSetting += 7;
+  for(i=0; i<ArraySize(aSetting); i++){
+    if( strcmp(zSetting, aSetting[i].zName)==0 ) break;
+  }
+  if( i>=ArraySize(aSetting) ){
+    Tcl_SetObjResult(interp,
+      Tcl_NewStringObj("unknown sqlite3_db_config setting", -1));
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[3], &v) ) return TCL_ERROR;
+  sqlite3_db_config(db, aSetting[i].eVal, v, &v);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(v));
+  return TCL_OK;
+}
+
+/*
 ** Register commands with the TCL interpreter.
 */
 int Sqlitetest1_Init(Tcl_Interp *interp){
@@ -6989,6 +7036,7 @@
      Tcl_ObjCmdProc *xProc;
      void *clientData;
   } aObjCmd[] = {
+     { "sqlite3_db_config",             test_sqlite3_db_config, 0 },
      { "bad_behavior",                  test_bad_behavior,  (void*)&iZero },
      { "register_dbstat_vtab",          test_register_dbstat_vtab  },
      { "sqlite3_connection_pointer",    get_sqlite_pointer, 0 },
--- src/test_config.c
+++ src/test_config.c
@@ -370,12 +370,6 @@
   Tcl_SetVar2(interp, "sqlite_options", "fts3", "0", TCL_GLOBAL_ONLY);
 #endif
 
-#ifdef SQLITE_ENABLE_FTS3_TOKENIZER
-  Tcl_SetVar2(interp, "sqlite_options", "fts3_tokenizer", "1", TCL_GLOBAL_ONLY);
-#else
-  Tcl_SetVar2(interp, "sqlite_options", "fts3_tokenizer", "0", TCL_GLOBAL_ONLY);
-#endif
-
 #ifdef SQLITE_ENABLE_FTS5
   Tcl_SetVar2(interp, "sqlite_options", "fts5", "1", TCL_GLOBAL_ONLY);
 #else
--- test/fts3atoken.test
+++ test/fts3atoken.test
@@ -56,40 +56,41 @@
 #
 #   5: Test that the table created to use tokenizer 'blah' is usable.
 #
-ifcapable fts3_tokenizer {
-  do_test fts3atoken-1.1 {
-    catchsql {
-      CREATE VIRTUAL TABLE t1 USING fts3(content, tokenize blah);
-    }
-  } {1 {unknown tokenizer: blah}}
-  do_test fts3atoken-1.2 {
-    execsql {
-      SELECT fts3_tokenizer('blah', fts3_tokenizer('simple')) IS NULL;
-    }
-  } {0}
-  do_test fts3atoken-1.3 {
-    execsql {
-      SELECT fts3_tokenizer('blah') == fts3_tokenizer('simple');
-    }
-  } {1}
-  do_test fts3atoken-1.4 {
-    catchsql {
-      CREATE VIRTUAL TABLE t1 USING fts3(content, tokenize blah);
-    }
-  } {0 {}}
-  do_test fts3atoken-1.5 {
-    execsql {
-      INSERT INTO t1(content) VALUES('There was movement at the station');
-      INSERT INTO t1(content) VALUES('For the word has passed around');
-      INSERT INTO t1(content) VALUES('That the colt from ol regret had got');
-      SELECT content FROM t1 WHERE content MATCH 'movement'
-    }
-  } {{There was movement at the station}}
-} else {
-  do_catchsql_test 1.6 {
+sqlite3_db_config db SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1
+do_test fts3atoken-1.1 {
+  catchsql {
+    CREATE VIRTUAL TABLE t1 USING fts3(content, tokenize blah);
+  }
+} {1 {unknown tokenizer: blah}}
+do_test fts3atoken-1.2 {
+  execsql {
     SELECT fts3_tokenizer('blah', fts3_tokenizer('simple')) IS NULL;
-  } {1 {fts3tokenize: disabled - rebuild with -DSQLITE_ENABLE_FTS3_TOKENIZER}}
-}
+  }
+} {0}
+do_test fts3atoken-1.3 {
+  execsql {
+    SELECT fts3_tokenizer('blah') == fts3_tokenizer('simple');
+  }
+} {1}
+do_test fts3atoken-1.4 {
+  catchsql {
+    CREATE VIRTUAL TABLE t1 USING fts3(content, tokenize blah);
+  }
+} {0 {}}
+do_test fts3atoken-1.5 {
+  execsql {
+    INSERT INTO t1(content) VALUES('There was movement at the station');
+    INSERT INTO t1(content) VALUES('For the word has passed around');
+    INSERT INTO t1(content) VALUES('That the colt from ol regret had got');
+    SELECT content FROM t1 WHERE content MATCH 'movement'
+  }
+} {{There was movement at the station}}
+
+sqlite3_db_config db SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 0
+do_catchsql_test 1.6 {
+  SELECT fts3_tokenizer('blah', fts3_tokenizer('simple')) IS NULL;
+} {1 {fts3tokenize disabled}}
+
 
 #--------------------------------------------------------------------------
 # Test cases fts3atoken-2.* test error cases in the scalar function based
@@ -212,14 +213,14 @@
 do_catchsql_test 6.2.1 {
   SELECT fts3_tokenizer(NULL);
 } {1 {unknown tokenizer: }}
-ifcapable fts3_tokenizer {
-  do_catchsql_test 6.2.2 {
-    SELECT fts3_tokenizer(NULL, X'1234567812345678');
-  } {1 {argument type mismatch}}
-  do_catchsql_test 6.2.3 {
-    SELECT fts3_tokenizer(NULL, X'12345678');
-  } {1 {argument type mismatch}}
-}
+
+sqlite3_db_config db SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1
+do_catchsql_test 6.2.2 {
+  SELECT fts3_tokenizer(NULL, X'1234567812345678');
+} {1 {argument type mismatch}}
+do_catchsql_test 6.2.3 {
+  SELECT fts3_tokenizer(NULL, X'12345678');
+} {1 {argument type mismatch}}
 
 
 finish_test
--- test/fts4langid.test
+++ test/fts4langid.test
@@ -358,31 +358,30 @@
   }
 }
 
-ifcapable fts3_tokenizer {
-  do_test 4.1.0 {
-    reset_db
-    set ptr [fts3_test_tokenizer]
-    execsql { SELECT fts3_tokenizer('testtokenizer', $ptr) }
-    build_multilingual_db_2 db
-  } {}
-  do_execsql_test 4.1.1 {
-    SELECT docid FROM t4 WHERE t4 MATCH 'quick';
-  } {0}
-  do_execsql_test 4.1.2 {
-    SELECT docid FROM t4 WHERE t4 MATCH 'quick' AND lid=1;
-  } {}
-  do_execsql_test 4.1.3 {
-    SELECT docid FROM t4 WHERE t4 MATCH 'Quick' AND lid=1;
-  } {1}
-  for {set i 0} {$i < 50} {incr i} {
-    do_execsql_test 4.1.4.$i {
-      SELECT count(*) FROM t4 WHERE t4 MATCH 'fox' AND lid=$i;
-    } [expr 0==($i%2)]
-  }
-  do_catchsql_test 4.1.5 {
-    INSERT INTO t4(content, lid) VALUES('hello world', 101)
-  } {1 {SQL logic error or missing database}}
+do_test 4.1.0 {
+  reset_db
+  set ptr [fts3_test_tokenizer]
+  sqlite3_db_config db SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1
+  execsql { SELECT fts3_tokenizer('testtokenizer', $ptr) }
+  build_multilingual_db_2 db
+} {}
+do_execsql_test 4.1.1 {
+  SELECT docid FROM t4 WHERE t4 MATCH 'quick';
+} {0}
+do_execsql_test 4.1.2 {
+  SELECT docid FROM t4 WHERE t4 MATCH 'quick' AND lid=1;
+} {}
+do_execsql_test 4.1.3 {
+  SELECT docid FROM t4 WHERE t4 MATCH 'Quick' AND lid=1;
+} {1}
+for {set i 0} {$i < 50} {incr i} {
+  do_execsql_test 4.1.4.$i {
+    SELECT count(*) FROM t4 WHERE t4 MATCH 'fox' AND lid=$i;
+  } [expr 0==($i%2)]
 }
+do_catchsql_test 4.1.5 {
+  INSERT INTO t4(content, lid) VALUES('hello world', 101)
+} {1 {SQL logic error or missing database}}
 
 #-------------------------------------------------------------------------
 # Test cases 5.*