Function parse_line_info_dwarf2

objdiff-core/src/obj/dwarf2.rs:10–52

Parse line information from DWARF 2+ sections.

(
    obj_file: &object::File,
    sections: &mut [Section],
)

/// Parse line information from DWARF 2+ sections.
pub(crate) fn parse_line_info_dwarf2(
    obj_file: &object::File,
    sections: &mut [Section],
) -> Result<()> {
    let arena_data = Arena::new();
    let arena_relocations = Arena::new();
    let endian = match obj_file.endianness() {
        object::Endianness::Little => gimli::RunTimeEndian::Little,
        object::Endianness::Big => gimli::RunTimeEndian::Big,
    };
    let dwarf = gimli::Dwarf::load(|id: gimli::SectionId| -> Result<_> {
        load_file_section(id, obj_file, endian, &arena_data, &arena_relocations)
    })
    .context("loading DWARF sections")?;

    let mut iter = dwarf.units();
    if let Some(header) = iter.next().map_err(|e| gimli_error(e, "iterating over DWARF units"))? {
        let unit = dwarf.unit(header).map_err(|e| gimli_error(e, "loading DWARF unit"))?;
        if let Some(program) = unit.line_program.clone() {
            let mut text_sections = sections.iter_mut().filter(|s| s.kind == SectionKind::Code);
            let mut lines = text_sections.next().map(|section| &mut section.line_info);

            let mut rows = program.rows();
            while let Some((_header, row)) =
                rows.next_row().map_err(|e| gimli_error(e, "loading program row"))?
            {
                if let (Some(line), Some(lines)) = (row.line(), &mut lines) {
                    lines.insert(row.address(), line.get() as u32);
                }
                if row.end_sequence() {
                    // The next row is the start of a new sequence, which means we must
                    // advance to the next .text section.
                    lines = text_sections.next().map(|section| &mut section.line_info);
                }
            }
        }
    }
    if iter.next().map_err(|e| gimli_error(e, "checking for next unit"))?.is_some() {
        log::warn!("Multiple units found in DWARF data, only processing the first");
    }

    Ok(())
}

#[derive(Debug, Default)]
struct RelocationMap(object::read::RelocationMap);