Crate qld 

qld is a fast, parallel linker that accepts GNU ld, gold, lld and mold command lines, and can also be driven as a library.

Status

Pre-alpha. The pipeline is being implemented milestone by milestone; see ROADMAP.md. Nothing outside this crate’s root re-exports should be considered stable, and the root API will not be stable until 1.0.

Library use

Build LinkOptions by hand or from a command line (parse_gnu), and call link. Diagnostics go to a DiagnosticSink of your choice. Inputs can be byte buffers (InputKind::bytes, MemoryFiles), the output can come back as bytes (link_to_memory, OutputBuffer), a link can be cancelled from another thread (CancelToken), and it runs in the caller’s rayon pool, as it is, when called inside rayon::ThreadPool::install.

A link built with LinkOptions::new is hermetic and silent: the process never exits, nothing is written to its standard output or standard error, and no environment variable is read. LinkOptions::use_process_defaults opts into all three, and parse_gnu applies it, because it describes the link the qld binary runs.

use qld::{InputAttrs, InputKind, LinkOptions, OutputKind};
use qld::diag::Collect;

let mut options = LinkOptions::new();
options.kind = OutputKind::StaticExecutable;
options.push_input(InputKind::bytes("main.o", object), InputAttrs::default());
let diagnostics = Collect::new();
let image: Vec<u8> = qld::link_to_memory(&options, &diagnostics)?;

The examples/ directory has complete programs: link_argv, in_memory, custom_sink, rayon_pool and cancel.

Layout

Modules follow the link pipeline described in docs/architecture.md:

Module	Role
args	Option model and the argv front ends
[input]	Mapping input files, identifying formats, archives
[symbols]	String interning and the global symbol table
[passes]	Format-neutral passes: GC, ICF, section merging
[script]	GNU linker script parser and evaluator
[output]	Output file writer and post-write steps
[elf], [coff], [macho], [hunk]	Format backends
[arch]	Instruction-level helpers shared across formats
[debug]	DWARF handling: compression, indexes, line lookup
[demangle]	Itanium C++ and Rust symbol demangling for diagnostics
[hints]	Suggestions for undefined symbols: missing -l, versions, near misses
[plugin]	LTO plugin host (feature plugin)

Format backends own their own symbol precedence and layout rules. The shared modules must not depend on a backend.

Only args, diag, error and target are documented; the other modules are public for qld’s own tests and tools, and are not covered by semantic versioning.

Re-exports

pub use args::CancelToken;

pub use args::InputAttrs;

pub use args::InputKind;

pub use args::InputSpec;

pub use args::LinkOptions;

pub use args::OutputBuffer;

pub use args::OutputKind;

pub use args::ParseOutcome;

pub use args::TextOutput;

pub use args::parse_gnu;

pub use args::parse_gnu_with;

pub use diag::Diagnostic;

pub use diag::DiagnosticSink;

pub use diag::Severity;

pub use error::Error;

pub use error::Result;

pub use target::Architecture;

pub use target::BinaryFormat;

pub use target::Endianness;

pub use target::OperatingSystem;

pub use target::PointerWidth;

pub use target::Target;

Modules

args

Command-line option model and the argv front ends that fill it in.

diag

Diagnostics: warnings, errors and notes reported during a link.

error

Fatal error type.

target

Target description: the format, architecture and ABI being linked for.

Structs

MemoryFiles

An InputProvider holding files in memory, keyed by path.

ScriptError

A fatal problem in a linker script, with the position it was found at.

Constants

PROGRAM_NAME

Program name used to prefix diagnostics.

Traits

InputProvider

Answers for paths before the file system does; see the module documentation.

Functions

link

Runs a link described by options.

link_to_memory

Runs a link described by options and returns the output image instead of writing LinkOptions::output, which then only names the output.

version_line

Version string, printed by --version and -v.