Changelog

All notable changes to this project will be documented in this file.

[0.5.0] — 2026-05-25

Circuits as static libraries (#16)

The central change in this release. Previously, witness generation required spawning a compiled executable per circuit.

Each circuit is now a linkable static archive (lib{circuit}.a) with a stable C FFI.

Two entry points per circuit:
- {circuit}_generate_witness(WitnessInput*, Bytes*): Generates a witness in memory from a JSON input string and an embedded .dat buffer; the caller owns the output buffer.
- {circuit}_generate_witness_from_files(dat, inputs, output): Generates a witness from a .dat file and a JSON input file, writing the witness to an output file.
The Rust crates (lbc-{circuit}-sys) wrap this FFI directly and can either link against a local build or download a prebuilt release automatically.

See rust/README.md for usage.
Bundled static GMP (#19)

libgmp is now compiled from source and statically linked, removing the runtime dependency on a system GMP installation, and standardizing the GMP version used across all platforms.
Older glibc compatibility (#21)

Linux builds now target an older glibc ABI for broader distribution support.
Dual MIT/Apache-2.0 license.

Symbol resolution conflicts (#22, #28, #29)

When multiple circuit libraries are linked into the same binary, the linker silently collapsed shared internal symbols to a single definition, corrupting witness parsing and causing SIGSEGV.

See CONTRIBUTING.md for a full explanation and maintenance notes.
macOS C++ library linkage (#27)

Fixed missing C++ standard library on macOS builds.
Circuit assert statements (#26)

Assert statements in the circuit source assumed standalone binary execution, causing disruptions when compiled as a library.
Comparator full less-than

Fixed incorrect output in the full less-than comparator circuit.

No changelog was kept prior to v0.5.0.