Rust low-level bindings for GMP, MPFR and MPC

The gmp-mpfr-sys crate provides Rust FFI bindings to the following [GNU] arbitrary-precision libraries:

• [GMP] for integers and rational numbers,
• [MPFR] for floating-point numbers, and
• [MPC] for complex numbers.

The source of the three libraries is included in the package.

The gmp-mpfr-sys crate is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. See the full text of the [GNU LGPL] and [GNU GPL] for details.

What’s new

Version 1.1.9 (2018-10-05)

• [MPFR] was updated from version 4.0.1-p11 to version 4.0.1-p13.
• Function parameters that should be [intmax_t] or [uintmax_t] were fixed.

Other releases

Details on other releases can be found in [RELEASES.md].

Basic features

This crate contains three modules:

• [gmp] provides external FFI bindings to [GMP].
• [mpfr] provides external FFI bindings to [MPFR].
• [mpc] provides external FFI bindings to [MPC].

If you want a high-level API, consider using Rug, a crate which provides integers and floating-point with arbitrary precision and correct rounding:

• [Integer] is a bignum integer with arbitrary precision,
• [Rational] is a bignum rational number with arbitrary precision,
• [Float] is a multi-precision floating-point number with correct rounding, and
• [Complex] is a multi-precision complex number with correct rounding.

Name prefixes

Since modules and enumerated types provide namespacing, most prefixes in the C names are removed. However, when the prefix is not a whole word it is not removed. For example [mp_set_memory_functions] becomes [gmp::set_memory_functions], but [mpz_init] becomes [gmp::mpz_init] not gmp::z_init, and [MPFR_RNDN] in [enum MPFR_RND_T] becomes [mpfr::rnd_t::RNDN] not mpfr::rnd_t::N. Also, the types [mpfr::mpfr_t] and [mpc::mpc_t] are not shortened to mpfr::t or mpc::t.

Types

Unlike in the C libraries, the types [gmp::mpz_t], [gmp::mpq_t], [gmp::mpf_t], [gmp::randstate_t], [mpfr::mpfr_t] and [mpc::mpc_t] are defined directly as structs, not as single-element arrays.

Undocumented or obsolete functions

The bindings do not cover undocumented or obsolete functions and macros.

Using gmp-mpfr-sys

The gmp-mpfr-sys crate is available on crates.io. To use gmp-mpfr-sys in your crate, add it as a dependency inside [Cargo.toml]:

toml [dependencies] gmp-mpfr-sys = "1.1"

You also need to declare it by adding this to your crate root (usually lib.rs or main.rs):

rust extern crate gmp_mpfr_sys;

This crate required rustc version 1.13.0 or later.

If the C libraries have a major version bump with some deprecated functions removed, but no features are removed in the Rust bindings, then gmp-mpfr-sys will have a minor version bump rather than a major version bump. This allows more compatiblity across crates that use the Rust bindings but do not use the C libraries directly.

If on the other hand a dependent crate makes use of internal implementation details, or includes a C library that directly uses the header (.h) and library (.a) files built using C, it can be a good idea to depend on version "~1.1" instead of version "1.1" in order to ensure backwards compatibility at the C level as well.

Optional features

The gmp-mpfr-sys crate has two optional features:

1. mpfr, enabled by default. Required to include the [MPFR] library.
2. mpc, enabled by default. Required to include the [MPC] library. This feature requires the mpfr feature.

The [GMP] library is always included.

The two optional features are enabled by default; to use features selectively, you can add the dependency like this to [Cargo.toml]:

toml [dependencies.gmp-mpfr-sys] version = "1.1" default-features = false features = ["mpfr"]

Here only the mpfr feature is selected.

Metadata

The gmp-mpfr-sys crate passes some metadata to its dependents:

1. DEP_GMP_LIMB_BITS contains the number of bits per limb, which is 32 or 64.
2. DEP_GMP_OUT_DIR contains the path of a directory that contains two subdirectories: the first subdirectory is named lib and contains the generated library (.a) files, and the second subdirectory is named include and contains the corresponding header (.h) files.
3. DEP_GMP_LIB_DIR contains the path of the lib subdirectory of the DEP_GMP_OUT_DIR directory.
4. DEP_GMP_INCLUDE_DIR contains the path of the include subdirectory of the DEP_GMP_OUT_DIR directory.

A dependent crate can use these environment variables in its build script.

Building on GNU/Linux

To build on GNU/Linux, simply make sure you have diffutils, gcc, make and m4 installed on your system. For example on Fedora:

sh sudo dnf install diffutils gcc make m4

Building on macOS

To build on macOS, you need the command-line developer tools. To install them, run the following command in a terminal:

sh xcode-select --install

Building on Windows

You can build on Windows with the Rust GNU toolchain and an up-to-date MSYS2 installation. Some steps for a 64-bit environment are listed below. (32-bit: Changes for a 32-bit environment are written in brackets like this comment.)

To install MSYS2:

1. Install MSYS2 using the installer.

2. Launch the MSYS2 MinGW 64-bit terminal from the start menu. (32-bit: Launch the MSYS2 MinGW 32-bit terminal instead.)

3. Install the required tools.

   sh pacman -S pacman-mirrors pacman -S diffutils make mingw-w64-x86_64-gcc

   (32-bit: Install mingw-w64-i686-gcc instead of mingw-w64-x86_64-gcc.)

Then, to build a crate with a dependency on this crate:

1. Launch the MSYS MinGW 64-bit terminal from the start menu. (32-bit: Launch the MSYS2 MinGW 32-bit terminal instead.)

2. Change to the crate directory.

3. Build the crate using cargo.