CaDiCaL SAT solver

==================

This is a stand alone crate that contains both the C++ source code of the CaDiCaL incremental SAT solver together with its Rust binding. The C++ files are compiled and statically linked during the build process. This crate works on Linux, Apple OSX, Windows, Android, iOS, Raspberry Pi, NetBSD and FreeBSD.

CaDiCaL won first place in the SAT track of the SAT Race 2019 and second overall place. It was written by Armin Biere, and it is available under the MIT license.

The literals are unwrapped positive and negative integers, exactly as in the DIMACS format. The common IPASIR operations are presented in a safe Rust interface.

let mut sat: cadical::Solver = Default::default();
sat.add_clause([1, 2]);
sat.add_clause([-1, 2]);
assert_eq!(sat.solve(), Some(true));
assert_eq!(sat.value(2), Some(true));

The C++ library is build with assertions disabled and with optimization level 3 by default. C++ assertions are enabled only when cargo is building a debug version and the cpp-debug feature of the library is enabled.

Information for developers

To update cadical version, simply download a new version from:

https://github.com/sirandreww/cadical.git

This is a fork of cadical that fixes a small issue with the C API of cadical. Then paste the downloaded to replace /cadical with the new version using the same directory name.

Using different C++ compilers and linkers

To compile the project you need to have a C++ compiler in order to compile CaDiCal. To set the compiler certain environment variables must be set before trying to compile.

The C++ standard library may be linked to the crate target. By default it's:

1. libc++ for macOS, FreeBSD, and OpenBSD
2. libc++_shared for Android, nothing for MSVC
3. libstdc++ for anything else. It can be changed by setting the CXXSTDLIB environment variable.

Using c++

Run these commands in order.

cargo clean
unset CRATE_CC_NO_DEFAULTS
unset CXXFLAGS
unset CXXSTDLIB
unset RUSTFLAGS
export CXX=/usr/bin/g++
cargo test

Using Clang

First you should get the C++ library that works with Clang using one of these commands (not sure which specific one, but the first should work):

sudo apt install libc++-dev
sudo apt install libc++abi-dev
sudo apt install libstdc++-dev

Then run these commands in order:

cargo clean
unset CRATE_CC_NO_DEFAULTS
unset CXXFLAGS
unset CXXSTDLIB
unset RUSTFLAGS
export CXX=clang++
cargo test

Using LLD

First get the linker using:

sudo apt install lld

Then run these commands in order:

cargo clean
unset CRATE_CC_NO_DEFAULTS
unset CXXFLAGS
unset CXXSTDLIB
export RUSTFLAGS="-C link-arg=-fuse-ld=lld"
export CXX=g++
cargo test

Using g++ for linking

There are situations, when running with a different g++ compiler than the one that PATH points to where the C++ standard library would not be found. To fix this, you need to tell rust compiler to link with the same version directly.

Run these commands in order:

cargo clean
unset CRATE_CC_NO_DEFAULTS
unset CXXFLAGS
unset CXXSTDLIB
export RUSTFLAGS="-C linker=g++"
export CXX=g++
cargo test