bzip2/COMPILING.md

Compiling bzip2

The following build systems are available for Bzip2:

• Meson: This is our preferred build system for Unix-like systems.
• CMake: Build tool for Unix and Windows.
• nmake: Unsupported; used only for Windows and Microsoft Visual Studio 2013 or later.

Meson works for Unix-like OSes and Windows; nmake is only for Windows.

Using Meson

Meson provides a large number of built-in options to control compilation. A few important ones are listed below:

• -Ddefault_library=[static|shared|both], defaults to shared, if you wish to statically link libbz2 into the binaries set this to static
• --backend : defaults to ninja, use vs if you want to use msbuild
• --unity : This enables a unity build (sometimes called a jumbo build), makes a single build faster but rebuilds slower
• -Dbuildtype=[debug|debugoptmized|release|minsize|plain] : Controls default optimization/debug generation args, defaults to debug, use plain if you wish to pass your own cflags.

Meson recognizes environment variables like $CFLAGS and $CC, it is recommended that you do not use $CFLAGS, and instead use -Dc_args and -DC_link_args, as Meson will remember these even if you need to reconfigure from scratch (such as when you update Meson), it will not remember $CFLAGS.

Meson will never change compilers once configured, so $CC is perfectly safe.

Unix-like (Linux, *BSD, Cygwin, macOS)

You will need

• Python 3.5 or newer (for Meson)
• meson (Verison 0.48 or newer)
• ninja
• pkg-config
• A C compiler such as GCC or Clang

Some linux distros package managers refer to ninja as ninja-build, fedora and debian/ubuntu both do this. Your OS probably provides meson, although it may be too old, in that case you can use python3's pip to install meson:

sudo pip3 install meson

or, for a user local install:

pip3 install --user meson

Once you have installed the dependencies, the following should work to use the standard Meson configuration, a builddir for compilation, and a /usr prefix for installation:

meson --prefix /usr builddir/
ninja -C builddir
meson test -C builddir --print-errorlogs
[sudo] ninja -C builddir install

You can use meson configure builddir to check configuration options. Currently bzip only has one project specific option, which is to force the generation of documentation on or off.

Ninja acepts many of the same arguments as make, although it will automatically detect the number of CPU cores available and use an appropriate number of threads.

Windows

You will need to either download python 3.5 or newer and install with pip:

py -m pip install meson

or you can download pre-bundled installers of meson directly from meson's github.

Either should work fine for the purposes of building bzip2

You will also need pkg-config. There are many sources of pkg-config, I recommend installing from chocolatey because it's easy. chocolatey can also provide ninja, though ninja is not required on windows if you want to use msbuild.

If you want to use MSVC or a compatible compiler launch the associated environment cmd to run meson from; the environments required to make those compilers work is quite complex otherwise.

Once you have all of that installed you can invoke meson to configure the build. By default meson will generate a ninja backend, if you would prefer to use msbuild pass the backend flag --backend=vs. MSVC (and compatible compilers like clang-cl and ICL) work with ninja as well.

meson $builddir
ninja -C $builddir
meson test -C builddir --print-errorlogs

or:

meson $builddir --backend=vs
cd $builddir
msbuild bzip2.sln /m

Using CMake

Build instructions for Unix & Windows (CMake)

Bzip2 can be compiled with the CMake build system. You can use these commands to build Bzip2 in a certain build directory.

Basic Release build

mkdir build && cd build
cmake ..
cmake --build . --config Release

Basic Debug build

mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE="Debug"
cmake --build . --config Debug

Build and install to a specific install location (prefix)

mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX:PATH=`pwd`/install ..
cmake --build . --target install --config Release

Build with example application (dlltest)

mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX:PATH=`pwd`/install .. -DENABLE_EXAMPLES=ON
cmake --build . --target install --config Release

Build and run tests

• -V: Verbose
• -C: Required for Windows builds

mkdir build && cd build
cmake ..
cmake --build . --config Release
ctest -C Release -V

Using nmake on Windows

Bzip2 can be built with Microsoft Visual Studio 2013 or later. From a Visual Studio Tools Command Prompt run:

nmake -f makefile.msc

The build will produce bzip2.exe and bzip2recover.exe files that are dependent on bz2-1.dll and the Microsoft C Runtime library. Dynamic import and static libraries are also built: bz2-1.lib and bz2-static.lib.