About

This CMake module finds the ccache executable on the system and routes compilation and linking calls via ccache executable to speed up recompilation. More about ccache.

Following CMake generators are supported:

• Xcode;
• Ninja and Unix Makefiles;
• Visual Studio (MSVC and MSBuild), requires ccache version 4.6 or newer, use of CMAKE_MSVC_DEBUG_INFORMATION_FORMAT required CMake version 3.25 or newer.

By default this module will look only for ccache program, to try alternative compiler cache programs (not tested), force override CCACHE_PROGRAMS cache variable. For example, to look for cache programs in the following order of preference sccache, buildcache, ccache, add to CMakeLists.txt:

set(CCACHE_PROGRAMS "sccache;buildcache;ccache" CACHE STRING _ FORCE)

Usage

Add path where Findccache.cmake is located to CMAKE_MODULE_PATH variable. For example, if Findccache.cmake is located next to CMakeLists.txt file, use:

list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR})

CMAKE_MODULE_PATH should be set before calling find_package().

For more information on find package modules see: https://cmake.org/cmake/help/latest/command/find_package.html

Adding following line after project() will try to enable use of compiler cache:

find_package(ccache)

As of time of writing ccache does not yet support MSVC /Zi flag and requires /Z7 instead. If possible, it is advised to switch CMP0141 to NEW and set CMAKE_MSVC_DEBUG_INFORMATION_FORMAT to Embedded in the root CMakeLists.txt before first project() or enable_language() call. If CMP0141 is set to OLD, this script will try the old way of switching debug information format by manipulating CMAKE_<lang>_FLAGS_<config>, which is known to be unreliable in some cases.

set(CMAKE_MSVC_DEBUG_INFORMATION_FORMAT Embedded)
cmake_policy(SET CMP0141 NEW)

project(...)

list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR})
find_package(ccache REQUIRED)

For the complete example see CMakeLists.txt

ccache Setup

On Windows

• Download and install ccache
• Add ccache installation directory to PATH

On MacOS

• brew install ccache

On Ubuntu

• sudo apt install ccache

Other Resources

Alternative Compile Cache Tools

• sccache
• buildcache
• Nuitka/clcache
• frerich/clcache (no longer maintained)

Useful Links

• https://github.com/frerich/clcache/wiki/Caveats
• https://gitlab.com/bits-n-bites/buildcache/-/blob/master/doc/usage.md?ref_type=heads#using-with-visual-studio--msbuild
• https://prismlauncher.org/wiki/development/build-instructions/
• https://github.com/TheLartians/Ccache.cmake