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CMake

This guide explains how to use the declarative build system, cmake, when packaging software for openRuyi.

When you build the software you are packaging using commands such as %cmake, %cmake --build, and %cmake --install, we recommend using BuildSystem: cmake to take advantage of its standardized build workflow and macro support.

Dependencies​

To use the cmake build system, add the following BuildRequires. Since the build environment preinstalls gcc, you do not need to declare gcc explicitly.

BuildRequires:  cmake

Examples​

Assume the original build configuration in %build looks like the following snippet:

%build
export CC=clang CXX=clang++
cmake -S . -B build \
    -DCMAKE_C_FLAGS_RELEASE:STRING=-DNDEBUG \
    -DCMAKE_CXX_FLAGS_RELEASE:STRING=-DNDEBUG \
    -DCMAKE_Fortran_FLAGS_RELEASE:STRING=-DNDEBUG \
    -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON \
    -DCMAKE_INSTALL_DO_STRIP:BOOL=OFF \
    -DCMAKE_INSTALL_PREFIX:PATH=%{_prefix} \
    -DCMAKE_INSTALL_FULL_SBINDIR:PATH=%{_bindir} \
    -DCMAKE_INSTALL_SBINDIR:PATH=bin \
    -DINCLUDE_INSTALL_DIR:PATH=%{_includedir} \
    -DLIB_INSTALL_DIR:PATH=%{_libdir} \
    -DSYSCONF_INSTALL_DIR:PATH=%{_sysconfdir} \
    -DSHARE_INSTALL_PREFIX:PATH=%{_datadir} \
    -DLIB_SUFFIX=64 \
    -DENABLE_CCACHE=1 \
    -DINSTALL_GTEST:BOOL=OFF

cmake --build build --verbose -- all doc

After converting the build section to the cmake build system, you need to adjust the commands to reflect their proper locations. Since we are also adding an explicit configuration section (%conf), the final result becomes:

BuildOption(conf):  -DENABLE_CCACHE=1
BuildOption(conf):  -DINSTALL_GTEST:BOOL=OFF
BuildOption(build):  -- all doc

%build -p
export CC=clang CXX=clang++

Assume the original installation configuration in %install is as follows:

%install
cmake --install build
rm -v %{buildroot}%{_libdir}/*.a

The updated configuration is:

%install -a
rm -v %{buildroot}%{_libdir}/*.a

Build System Notes​

The file /usr/lib/rpm/macros.d/macros.cmake defines macros for the cmake build system.

For the configuration phase (%conf), the system presets the following values by default:

  • The system sets the default source directory (%_vpath_srcdir) to . and the default build directory (%__cmake_builddir) to %_target_platform. This setting ensures the system performs an out-of-source build by default.

  • CMAKE_BUILD_TYPE: RelWithDebInfo: The system builds an optimized binary with debug information by default.

  • CMAKE_VERBOSE_MAKEFILE:BOOL=ON: This flag enables verbose build output.

  • CMAKE_INSTALL_DO_STRIP:BOOL=OFF: This setting prevents CMake from stripping binaries during installation, which allows RPM to handle stripping in a unified way.

  • BUILD_SHARED_LIBS:BOOL=ON: The system enables shared library builds by default.

  • CMAKE_INSTALL_PREFIX:PATH=%{_prefix}

  • CMAKE_INSTALL_LIBDIR:PATH=%{_lib}

  • CMAKE_INSTALL_FULL_LIBDIR:PATH=%{_libdir}

  • CMAKE_INSTALL_SBINDIR:PATH=...

  • CMAKE_INSTALL_FULL_SBINDIR:PATH=%{_sbindir}

  • CMAKE_INSTALL_LIBEXECDIR:PATH=...

  • CMAKE_INSTALL_FULL_LIBEXECDIR:PATH=%{_libexecdir}

  • INCLUDE_INSTALL_DIR:PATH=%{_includedir}

  • LIB_INSTALL_DIR:PATH=%{_libdir}

  • SYSCONF_INSTALL_DIR:PATH=%{_sysconfdir}

  • SHARE_INSTALL_PREFIX:PATH=%{_datadir}

    • These settings align upstream project installation paths with the appropriate system locations.

  • LIB_SUFFIX=64: For upstream projects that recognize LIB_SUFFIX, this value indicates that the directory suffix for 64-bit libraries is 64.