Function make_text_label 

pub fn make_text_label(
    label: &str,
    ctx: &LabelSubstContext<'_>,
    font_name: &str,
    font_size: f64,
    cs: Charset,
) -> TextLabelLayout

Plain-text branch of make_label from lib/common/labels.c: object escape substitution, charset conversion (latin1ToUTF8 for charset=latin1, else htmlEntityUTF8) and make_simple_label.