Extension loading implemented

README.md

@@ -239,6 +239,23 @@ Additionally, a video tutorial by [Mitch McCollum (finepointcgi)](https://github
 
     Backup or restore the current database to/from a path, see [here](https://www.sqlite.org/backup.html). This feature is useful if you are using a database as your save file and you want to easily implement a saving/loading mechanic. Be warned that the original database will be overwritten entirely when restoring.
 
+- int enable_load_extension = **enable_load_extension(** Boolean success **)**
+
+    [Extension loading](https://www.sqlite.org/c3ref/load_extension.html) is disabled by default for security reasons. There are two ways to load an extension: C-API and SQL function. This method turns on both options.
+    SQL function `load_extension()` can only be used after enabling extension loading with this method. Preferably should be disabled after loading the extension to prevent SQL injections. Returns the SQLite return code.
+
+- int load_extension = **load_extension(** String extension_path, String extension_entry_point **)**
+
+    Loads the extension in the given path. Does not require [method SQLite.enable_load_extension], as it only enables C-API during the call and disables it right after, utilizing the recommended extension loading method declared by the SQLite documentation ([see](https://www.sqlite.org/c3ref/load_extension.html)). Returns the SQLite return code.
+    - **extension_path:** the path to the compiled binary of the extension
+    - **entrypoint:** the extension's entrypoint method (init function). It is defined in the .c file of the extension.
+
+   Example for loading the spellfix module:
+
+    ```gdscript
+    db.load_extension("res://addons/godot-sqlite/extensions/spellfix.dll", "sqlite3_spellfix_init")
+    ```
+
 ## Frequently Asked Questions (FAQ)
 
 ### 1. My query fails and returns syntax errors, what should I do?

doc_classes/SQLite.xml

@@ -197,6 +197,25 @@
 				[/codeblock]
 			</description>
 		</method>
+		<method name="enable_load_extension">
+			<return type="int" />
+			<description>
+				[url=https://www.sqlite.org/c3ref/load_extension.html]Extension loading[/url] is disabled by default for security reasons. There are two ways to load an extension: C-API and SQL function. This method turns on both options.
+				SQL function [code]load_extension()[/code] can only be used after enabling extension loading with this method. Preferably should be disabled after loading the extension to prevent SQL injections. Returns the SQLite return code.
+			</description>
+		</method>
+		<method name="load_extension">
+			<return type="int" />
+			<description>
+				Loads the extension in the given path. Does not require [method SQLite.enable_load_extension], as it only enables C-API during the call and disables it right after, utilizing the recommended extension loading method declared by the SQLite documentation ([url=https://www.sqlite.org/c3ref/load_extension.html]see[/url]). Returns the SQLite return code.
+				- [b]extension_path:[/b] the path to the compiled binary of the extension
+				- [b]entrypoint:[/b] the extension's entrypoint method (init function). It is defined in the .c file of the extension. 
+				Example for loading the spellfix module:
+				[codeblock]
+				db.load_extension("res://addons/godot-sqlite/extensions/spellfix.dll", "sqlite3_spellfix_init")
+				[/codeblock]
+			</description>
+		</method>
 	</methods>
 	<members>
 		<member name="path" type="String" default="default">

src/gdsqlite.cpp

@@ -30,6 +30,9 @@ void SQLite::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_autocommit"), &SQLite::get_autocommit);
 	ClassDB::bind_method(D_METHOD("compileoption_used", "option_name"), &SQLite::compileoption_used);
 
+	ClassDB::bind_method(D_METHOD("enable_load_extension", "onoff"), &SQLite::enable_load_extension);
+	ClassDB::bind_method(D_METHOD("load_extension", "extension_path", "entrypoint"), &SQLite::load_extension, DEFVAL("sqlite3_extension_init"));
+
 	// Properties.
 	ClassDB::bind_method(D_METHOD("set_last_insert_rowid", "last_insert_rowid"), &SQLite::set_last_insert_rowid);
 	ClassDB::bind_method(D_METHOD("get_last_insert_rowid"), &SQLite::get_last_insert_rowid);
@@ -1152,3 +1155,48 @@ int SQLite::compileoption_used(const String &option_name) const {
 	const char *char_name = dummy_name.get_data();
 	return sqlite3_compileoption_used(char_name);
 }
+
+int SQLite::enable_load_extension(const bool &p_onoff) {
+	int rc;
+	if (p_onoff == true) {
+		rc = sqlite3_enable_load_extension(db, 1);
+	}
+	else{
+		rc = sqlite3_enable_load_extension(db, 0);
+	}
+	if (rc != SQLITE_OK) {
+		UtilityFunctions::printerr("GDSQLite Error: Extension loading cannot be enabled/disabled.");
+	}	
+	return rc;
+}
+
+int SQLite::load_extension(const String &p_path, const String &entrypoint) {
+
+	int rc;
+
+	char *zErrMsg = 0;
+	String globalized_path = ProjectSettings::get_singleton()->globalize_path(p_path.strip_edges());
+	const CharString dummy_path = globalized_path.utf8();
+	const char *char_path = dummy_path.get_data();
+
+	const CharString dummy_func_name = entrypoint.utf8();
+	const char *func_name = dummy_func_name.get_data();
+
+	// Enable C-API only
+	sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, NULL);
+	// load extension
+	rc = sqlite3_load_extension(db, char_path, func_name, &zErrMsg);
+	// Disable C-API
+	sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 0, NULL);
+
+	if (rc != SQLITE_OK) {
+		UtilityFunctions::printerr("GDSQLite Error: Unable to load extension: " + String::utf8(zErrMsg));
+		sqlite3_free(zErrMsg);
+		return rc;
+	}
+	if (verbosity_level > VerbosityLevel::QUIET) {
+		UtilityFunctions::print("Loaded extension successfully (" + globalized_path + ")");
+	}
+
+	return rc;
+}

src/gdsqlite.h

@@ -92,6 +92,9 @@ class SQLite : public RefCounted {
 	int get_autocommit() const;
 	int compileoption_used(const String &option_name) const;
 
+	int load_extension(const String &p_path, const String &p_init_func_name);
+	int enable_load_extension(const bool &p_onoff);
+
 	// Properties.
 	void set_last_insert_rowid(const int64_t &p_last_insert_rowid);
 	int64_t get_last_insert_rowid() const;