Enum Fragment 

pub enum Fragment {
    Fixed {
        bytes: FragmentBytes,
        relocation: Option<Relocation>,
        span: Span,
    },
    Align {
        alignment: u32,
        fill: u8,
        max_skip: Option<u32>,
        use_nop: bool,
        span: Span,
    },
    Relaxable {
        short_bytes: InstrBytes,
        short_reloc_offset: usize,
        short_relocation: Option<Relocation>,
        long_bytes: InstrBytes,
        long_relocation: Relocation,
        is_long: bool,
        span: Span,
    },
    Org {
        target: u64,
        fill: u8,
        span: Span,
    },
}

A fragment of assembled output.

The linker operates on an ordered list of fragments. During branch relaxation the sizes of Fragment::Relaxable and Fragment::Align fragments may change, but they only ever grow (monotonic), which guarantees convergence.

Variants

Fixed

Fixed-size bytes with optional relocation.

Fields

bytes: FragmentBytes

The raw assembled bytes (inline for instructions, heap for large data).

relocation: Option<Relocation>

Optional relocation to apply to these bytes.

span: Span

Source span of the originating instruction or directive.

Align

Alignment padding — size depends on preceding layout.

When use_nop is true (x86/x86-64 code alignment with no explicit fill byte), pad with Intel-recommended multi-byte NOP sequences instead of repeating a single fill byte.

Fields

alignment: u32

Required byte alignment (must be a power of two).

fill: u8

Byte value used for padding when use_nop is false.

max_skip: Option<u32>

If set, skip this alignment entirely when the required padding exceeds this many bytes.

use_nop: bool

Use multi-byte NOP sequences instead of repeating fill.

span: Span

Source span of the alignment directive.

Relaxable

A relaxable branch instruction.

Starts in short form (rel8). If the linker determines the target is beyond ±127 bytes it promotes to the long form (rel32) and re-lays out. Promotion is irreversible (Szymanski monotonic growth).

Fields

short_bytes: InstrBytes

Short-form bytes (e.g. [0xEB, 0x00] for JMP rel8).

short_reloc_offset: usize

Offset of the rel8 displacement within short_bytes.

short_relocation: Option<Relocation>

Optional relocation for the short form. When Some, the linker applies this relocation to short_bytes instead of raw byte-patching. Used for RISC-V B-type branches.

long_bytes: InstrBytes

Long-form bytes (e.g. [0xE9, 0,0,0,0] for JMP rel32).

long_relocation: Relocation

Relocation for the long form (contains label, offset, etc.).

is_long: bool

Whether this fragment has been promoted to long form.

span: Span

Source span.

Org

Advance the location counter to an absolute address, padding with fill bytes. If the target is behind the current position, an error is raised during emission.

Fields

target: u64

Absolute target address for the location counter.

fill: u8

Byte value used to fill the gap.

span: Span

Source span of the .org directive.

Trait Implementations

impl Clone for Fragment

fn clone(&self) -> Fragment

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Fragment

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.