Building Clang From the Source

To build Clang from the source, you need following.

• Hardware as per the system requirements:

  • Linux, Solaries, BSD, Macos or Windows on x86, amd64, ARM, mips, PowerPC or SystemZ with GCC or Clang installed.
  • 15-20 GB of disk space.
  • And a lot of RAM 😅

• Software:

  • Python: >= 3.6
  • Cmake: >= 3.13.4
  • GCC: >= 5.1.0
  • zlib: >=1.2.3.4
  • GNU Make: 3.79
  • Git

Steps to build llvm are as follows:

• Get the source:

  $ git clone https://github.com/llvm/llvm-project.git
  

• Generate build files:

  $ cd llvm-project
  $ mkdir build
  $ cd build
  $ cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLLVM_ENABLE_PROJECTS=clang -G "Unix Makefiles" ../llvm
  

  One thing to note here, without -DCMAKE_BUILD_TYPE=RelWithDebInfo this build will take much more time (the build didn’t even finish on my machine).

• Build clang:

  $ make clang
  

  After this you will have clang built under llvm-project/build/bin.

• Try it out:

  $ bin/clang <some.c file> -o <some-binery-file>