Function build 

pub fn build(
    entries: &[DataEntry],
    files: &[(&[DataEntry], Option<u32>)],
    shared: &[usize],
    linkage: &[DataEntry],
    local: &[DataEntry],
    notation: Notation<'_>,
    qualify: Qualify,
    parmcheck: Option<(usize, u32)>,
) -> Result<Layout, Error>

Lays out WORKING-STORAGE, then each file’s record area, which all its 01 records share and which is at least record_max bytes. Files whose shared entry names the same file share one area, as large as the largest of them (see record_area_owners). notation is what SPECIAL-NAMES changes in the PICTUREs; qualify how RENAMES and later references resolve. Under PARMCHECK, parmcheck is how many of entries the program declares itself, the special registers the compiler adds following them, and the bytes of the buffer that goes between (Programming Guide SC27-8714-03, p. 397).