build-clang.sh

#!/usr/bin/env bash

set -ex

source shared.sh

LLVM=llvmorg-9.0.0

mkdir llvm-project
cd llvm-project

curl -L https://github.com/llvm/llvm-project/archive/$LLVM.tar.gz | \
  tar xzf - --strip-components=1

mkdir clang-build
cd clang-build

# For whatever reason the default set of include paths for clang is different
# than that of gcc. As a result we need to manually include our sysroot's
# include path, /rustroot/include, to clang's default include path.
INC="/rustroot/include:/usr/include"

hide_output \
    cmake ../llvm \
      -DCMAKE_C_COMPILER=/rustroot/bin/gcc \
      -DCMAKE_CXX_COMPILER=/rustroot/bin/g++ \
      -DCMAKE_BUILD_TYPE=Release \
      -DCMAKE_INSTALL_PREFIX=/rustroot \
      -DLLVM_TARGETS_TO_BUILD=X86 \
      -DLLVM_ENABLE_PROJECTS="clang;lld" \
      -DC_INCLUDE_DIRS="$INC"

hide_output make -j10
hide_output make install

cd ../..
rm -rf llvm-project