gcc-rs

Documentation

A simple library meant to be used as a build dependency with Cargo packages in order to build a set of C files into a static archive.

extern crate gcc;

fn main() {
    gcc::compile_library("libfoo.a", &["foo.c", "bar.c"]);
}

External configuration via environment variables

To control the programs and flags used for building, the builder can set a number of different enviroment variables.

• CFLAGS - a series of space seperated flags passed to "gcc". Note that individual flags cannot currently contain spaces, so doing something like: "-L=foo\ bar" is not possible.
• CC - the actual c compiler used. Note that this is used as an exact executable name, so (for example) no extra flags can be passed inside this variable, and the builder must ensure that there aren't any trailing spaces. This compiler must understand the -c flag. For certain TARGETs, it also is assumed to know about other flags (most common is -fPIC).
• AR - the ar (archiver) executable to use to build the static library.

Each of these variables can also be supplied with certain prefixes and suffixes, in the following prioritized order:

1. <var>_<target> - for example, CC_x86_64-unknown-linux-gnu
2. <var>_<target_with_underscores> - for example, CC_x86_64_unknown_linux_gnu
3. <build-kind>_<var> - for example, HOST_CC or TARGET_CFLAGS
4. <var> - a plain CC, AR as above.

If none of these varaibles exist, gcc-rs uses built-in defaults

In addition to the the above optional environment variables, gcc-rs has some functions with hard requirements on some variables supplied by cargo's build-script driver that it has the TARGET, OUT_DIR, OPT_LEVEL, and HOST variables

Windows notes

Currently use of this crate means that Windows users will require gcc to be installed at compile-time. This is typically acquired through the MinGW-w64, although we recommend installing through MSYS2 instead. Make sure to install the appropriate architecture corresponding to your installation of rustc.

Once gcc is installed, it also requires that the directory containing gcc is in the PATH environment variable.

C++ support

gcc-rs supports C++ libraries compilation by using the cpp method on Config:

extern crate gcc;

fn main() {
    gcc::Config::new()
        .cpp(true) // Switch to C++ library compilation.
        .file("foo.cpp")
        .compile("libfoo.a");
}

When using C++ library compilation switch, the CXX and CXXFLAGS env variables are used instead of CC and CFLAGS and the C++ standard library is linked to the crate target.

License

gcc-rs is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.

See LICENSE-APACHE, and LICENSE-MIT for details.