WordPress at a glance
function is not described

uninstall_plugin() WP 2.7.0

Uninstall a single plugin.

Calls the uninstall hook, if it is available.

Return

true. True if a plugin's uninstall.php file has been found and included.

Usage

uninstall_plugin( $plugin );
$plugin(string) (required)
Path to the plugin file relative to the plugins directory.

Code of uninstall plugin: wp-admin/includes/plugin.php WP 5.2.2

<?php
function uninstall_plugin( $plugin ) {
	$file = plugin_basename( $plugin );

	$uninstallable_plugins = (array) get_option( 'uninstall_plugins' );

	/**
	 * Fires in uninstall_plugin() immediately before the plugin is uninstalled.
	 *
	 * @since 4.5.0
	 *
	 * @param string $plugin                Path to the plugin file relative to the plugins directory.
	 * @param array  $uninstallable_plugins Uninstallable plugins.
	 */
	do_action( 'pre_uninstall_plugin', $plugin, $uninstallable_plugins );

	if ( file_exists( WP_PLUGIN_DIR . '/' . dirname( $file ) . '/uninstall.php' ) ) {
		if ( isset( $uninstallable_plugins[ $file ] ) ) {
			unset( $uninstallable_plugins[ $file ] );
			update_option( 'uninstall_plugins', $uninstallable_plugins );
		}
		unset( $uninstallable_plugins );

		define( 'WP_UNINSTALL_PLUGIN', $file );
		wp_register_plugin_realpath( WP_PLUGIN_DIR . '/' . $file );
		include( WP_PLUGIN_DIR . '/' . dirname( $file ) . '/uninstall.php' );

		return true;
	}

	if ( isset( $uninstallable_plugins[ $file ] ) ) {
		$callable = $uninstallable_plugins[ $file ];
		unset( $uninstallable_plugins[ $file ] );
		update_option( 'uninstall_plugins', $uninstallable_plugins );
		unset( $uninstallable_plugins );

		wp_register_plugin_realpath( WP_PLUGIN_DIR . '/' . $file );
		include( WP_PLUGIN_DIR . '/' . $file );

		add_action( "uninstall_{$file}", $callable );

		/**
		 * Fires in uninstall_plugin() once the plugin has been uninstalled.
		 *
		 * The action concatenates the 'uninstall_' prefix with the basename of the
		 * plugin passed to uninstall_plugin() to create a dynamically-named action.
		 *
		 * @since 2.7.0
		 */
		do_action( "uninstall_{$file}" );
	}
}