parseFormValue

fn parseFormValue(
    r: *Reader,
    form_id: u64,
    format: Format,
    endian: Endian,
    addr_size_bytes: u8,
    implicit_const: ?i64,
    version: u16,
) ScanError!FormValue {
    return switch (form_id) {
        // DWARF5.pdf page 213: the size of this value is encoded in the
        // compilation unit header as address size.
        FORM.addr => .{ .addr = try readAddress(r, endian, addr_size_bytes) },
        FORM.addrx1 => .{ .addrx = try r.takeByte() },
        FORM.addrx2 => .{ .addrx = try r.takeInt(u16, endian) },
        FORM.addrx3 => .{ .addrx = try r.takeInt(u24, endian) },
        FORM.addrx4 => .{ .addrx = try r.takeInt(u32, endian) },
        FORM.addrx => .{ .addrx = try r.takeLeb128(u64) },

        FORM.block1 => .{ .block = try r.take(try r.takeByte()) },
        FORM.block2 => .{ .block = try r.take(try r.takeInt(u16, endian)) },
        FORM.block4 => .{ .block = try r.take(try r.takeInt(u32, endian)) },
        FORM.block => .{ .block = try r.take(try r.takeLeb128(usize)) },

        FORM.data1 => .{ .udata = try r.takeByte() },
        FORM.data2 => .{ .udata = try r.takeInt(u16, endian) },
        FORM.data4 => .{ .udata = try r.takeInt(u32, endian) },
        FORM.data8 => .{ .udata = try r.takeInt(u64, endian) },
        FORM.data16 => .{ .data16 = try r.takeArray(16) },
        FORM.udata => .{ .udata = try r.takeLeb128(u64) },
        FORM.sdata => .{ .sdata = try r.takeLeb128(i64) },
        FORM.exprloc => .{ .exprloc = try r.take(try r.takeLeb128(usize)) },
        FORM.flag => .{ .flag = (try r.takeByte()) != 0 },
        FORM.flag_present => .{ .flag = true },
        FORM.sec_offset => .{ .sec_offset = try readFormatSizedInt(r, format, endian) },

        FORM.ref1 => .{ .ref = try r.takeByte() },
        FORM.ref2 => .{ .ref = try r.takeInt(u16, endian) },
        FORM.ref4 => .{ .ref = try r.takeInt(u32, endian) },
        FORM.ref8 => .{ .ref = try r.takeInt(u64, endian) },
        FORM.ref_udata => .{ .ref = try r.takeLeb128(u64) },

        FORM.ref_addr => .{
            .ref_addr = switch (version) {
                2 => try readAddress(r, endian, addr_size_bytes),
                else => try readFormatSizedInt(r, format, endian),
            },
        },
        FORM.ref_sig8 => .{ .ref = try r.takeInt(u64, endian) },

        FORM.string => .{ .string = try r.takeSentinel(0) },
        FORM.strp => .{ .strp = try readFormatSizedInt(r, format, endian) },
        FORM.strx1 => .{ .strx = try r.takeByte() },
        FORM.strx2 => .{ .strx = try r.takeInt(u16, endian) },
        FORM.strx3 => .{ .strx = try r.takeInt(u24, endian) },
        FORM.strx4 => .{ .strx = try r.takeInt(u32, endian) },
        FORM.strx => .{ .strx = try r.takeLeb128(usize) },
        FORM.line_strp => .{ .line_strp = try readFormatSizedInt(r, format, endian) },
        FORM.indirect => parseFormValue(r, try r.takeLeb128(u64), format, endian, addr_size_bytes, implicit_const, version),
        FORM.implicit_const => .{ .sdata = implicit_const orelse return bad() },
        FORM.loclistx => .{ .loclistx = try r.takeLeb128(u64) },
        FORM.rnglistx => .{ .rnglistx = try r.takeLeb128(u64) },
        else => {
            //debug.print("unrecognized form id: {x}\n", .{form_id});
            return bad();
        },
    };
}