--- /dev/null
+#!/bin/sh -e
+
+sed -i 's/!defined(_GCC_MAX_ALIGN_T)/& \&\& !defined(__DEFINED_max_align_t)/' libcxx/include/stddef.h
+sed -i 's/set(COMPILER_RT_HAS_SANITIZER_COMMON TRUE)/set(COMPILER_RT_HAS_SANITIZER_COMMON FALSE)/' compiler-rt/cmake/config-ix.cmake
+sed -i 's|\.lldb|.local/state/lldb|g' lldb/source/Host/common/Editline.cpp
+
+export DESTDIR="$1"
+cmake \
+ -G "Ninja" \
+ -B build \
+ -DCLANG_DEFAULT_CXX_STDLIB=libc++ \
+ -DCLANG_DEFAULT_RTLIB=compiler-rt \
+ -DCMAKE_BUILD_TYPE=Release \
+ -DCMAKE_C_COMPILER=clang \
+ -DCMAKE_INSTALL_PREFIX=/usr \
+ -DCOMPILER_RT_EXCLUDE_ATOMIC_BUILTIN=OFF \
+ -DCOMPILER_RT_USE_BUILTINS_LIBRARY=ON \
+ -DLIBCXXABI_USE_COMPILER_RT=ON \
+ -DLIBCXXABI_USE_LLVM_UNWINDER=ON \
+ -DLIBCXX_CXX_ABI=libcxxabi \
+ -DLIBCXX_HAS_ATOMIC_LIB=OFF \
+ -DLIBCXX_HAS_MUSL_LIBC=ON \
+ -DLIBCXX_USE_COMPILER_RT=ON \
+ -DLIBUNWIND_USE_COMPILER_RT=ON \
+ -DLLDB_ENABLE_CURSES=ON \
+ -DLLDB_ENABLE_LIBEDIT=ON \
+ -DLLVM_BUILD_DOCS=ON \
+ -DLLVM_BUILD_EXAMPLES=OFF \
+ -DLLVM_BUILD_LLVM_DYLIB=ON \
+ -DLLVM_BUILD_TESTS=OFF \
+ -DLLVM_ENABLE_EH=ON \
+ -DLLVM_ENABLE_LIBCXX=ON \
+ -DLLVM_ENABLE_LIBEDIT=ON \
+ -DLLVM_ENABLE_LIBXML2=OFF \
+ -DLLVM_ENABLE_PROJECTS="clang;compiler-rt;libunwind;libcxxabi;libcxx;lld;lldb" \
+ -DLLVM_ENABLE_RTTI=ON \
+ -DLLVM_ENABLE_SPHINX=ON \
+ -DLLVM_ENABLE_TERMINFO=OFF \
+ -DLLVM_HOST_TRIPLE="$(clang -dumpmachine)" \
+ -DLLVM_INCLUDE_DOCS=ON \
+ -DLLVM_INSTALL_BINUTILS_SYMLINKS=ON \
+ -DLLVM_LINK_LLVM_DYLIB=ON \
+ -DLLVM_TARGETS_TO_BUILD="host;AMDGPU" \
+ -DSPHINX_OUTPUT_MAN=ON \
+ -DSPHINX_WARNINGS_AS_ERRORS=OFF \
+ -Wno-dev \
+ llvm
+
+cmake --build build
+cmake --install build
+
+# libc++abi header files
+mkdir -p "$1/usr"
+cp -r libcxxabi/include "$1/usr"
+
+ln -s ld.lld "$1/usr/bin/ld"
+ln -s clang "$1/usr/bin/cc"
+ln -s clang++ "$1/usr/bin/c++"
+ln -s clang++ "$1/usr/bin/cpp"
+
+for i in \
+ llvm-addr2line \
+ llvm-ar \
+ llvm-as \
+ llvm-dlltool \
+ llvm-nm \
+ llvm-objdump \
+ llvm-ranlib \
+ llvm-readelf \
+ llvm-size \
+ llvm-strings \
+ llvm-strip
+ do
+ to="$1/usr/bin/$(printf %s "$i" | cut -d "-" -f 2)"
+ ln -sf "/usr/bin/$i" "$to"
+done
+
+install -m755 c99 "$1/usr/bin/c99"
+
+# Clang: Override libexec, the path is hardcoded, unfortunately.
+mv -f "$1/usr/libexec/ccc-analyzer" "$1/usr/lib/clang"
+mv -f "$1/usr/libexec/c++-analyzer" "$1/usr/lib/clang"
+rmdir "$1/usr/libexec"
+sed -i "s|libexec|lib/clang|" "$1/usr/bin/scan-build"