DistClang is the Clang compiler extension with a client-server infrastructure. It features the distributed cross-platform compilation and the intermediate result caching.
The project consists of 2 executables and a couple of configuration files.
clang is a client part and should reside on the machine where the compilation is invoked. It should replace the invocation of the original compiler.
clangd is a server that has 2 different roles: emitter and absorber.
First of all do clone with an argument --recurse-submodules and then configure the project:
./build/configure
To build You have to use a recent Clang compiler with C++14 support.
ninja -C out/Debug.gn All
cd out/Debug.gn
ln -s clang clang++
The resulting files clang, clang++ and clangd are located in the out/Debug.gn folder.
ninja -C out/Release.gn rpm_package deb_package
The resulting packages are:
out/Release.gn/dist-clang_<version>_amd64.deb
out/Release.gn/rpmbuild/RPMS/x86_64/dist-clang-<version>-1.x86_64.rpm
Don't use locally the clang and clangd from the out/Release.gn folder since they are hardcoded to use libraries from /usr/lib/dist-clang folder.
ninja -C out/Release.gn pkg_package
The resulting package is out/Release.gn/dist-clang-<version>.pkg
TODO!
TODO!
The basics is to make use of dist-clang's clang and clang++ as the compilers. Doing
export CC=/usr/bin/dist-clang/clang CXX=/usr/bin/dist-clang/clang++
possibly should work almost always.
To work properly the dist-clang should know about the real compiler's path and compiler's version.
One way to provide information about a real compiler is to put config file somewhere on the path to the folder where the build is performed. File must be named .distclang and should contain something like this:
path: "third_party/llvm-build/Release+Asserts/bin/clang"
version: "clang version 3.7.0 (trunk 231690)"
Another way - is to set some env. vars:
export DC_CLANG_PATH="/usr/bin/clang"
export DC_CLANG_VERSION="clang version 3.7.0 (trunk 231690)"
The last resort is to use dist-clang's auto-detect feature: it tries to find the next clang in the path, that differs from the current binary, i.e. /usr/bin/dist-clang/clang. It's a not recommended and error-prone way, since internally paths are compared as a raw strings - without link resolution, etc.
In any way, if the clang path is provided without version, then the version is carved out of the real clang's output.