Building Clang on Linux

GCC is not the only open source C++ compiler that’s available out there on the interwebs — there’s also Clang, which is part of the LLVM Compiler Infrastructure. Each has its strengths and weaknesses, and both are excellent compilers for a wide variety of platforms. Whenever possible, I try to compile the Linux code I write with both compilers, for the simple reason that sometimes one will catch an error or emit a warning that the other one missed. I find that having my code build cleanly with at least two compilers and all warnings enabled is a useful best practice for improving code quality.

As it turns out, Clang on Linux has a very interesting capability: it can use GCC’s version of the standard C++ library (libstdc++), or its own version (libc++). The choice of standard library may be specified using a command-line argument (-stdlib=libstdc++ or -stdlib=libc++, respectively). Furthermore, if you have multiple versions of GCC installed on your Linux system, you can provide an optional command-line argument to Clang that specifies the GCC version whose libstdc++ you want to use (--gcc-toolchain=<path>).

This post is a followup to Building GCC on Linux, and in it I’m going to describe a set of scripts I wrote for building Clang on Linux. I call this collection clang-builder and it is available on GitLab. (continue…)