#! /bin/bash

# libunwind-llvm 
# Source: https://github.com/llvm/llvm-project/releases/download/llvmorg-12.0.0/libunwind-12.0.0.src.tar.xz
# Source: https://github.com/llvm/llvm-project/releases/download/llvmorg-12.0.0/libcxx-12.0.0.src.tar.xz
# Source: https://github.com/llvm/llvm-project/releases/download/llvmorg-12.0.0/llvm-12.0.0.src.tar.xz
#
# $BUILD = Directory to temporarily install
# $PKGS  = Directory to store built packages
#
# DEPS
# Required:     CMake
# Recommended:  NONE
# Optional:     NONE


# if optimizing with GCC:
export  CFLAGS="-march=native -pipe "
export CFLAGS+="-O3 -ffat-lto-objects -flto=4 "
export LDFLAGS="-flto=4 -Wl,-O2 -Wl,--as-needed "

# libunwind from LLVM requires main mono LLVM source tree
# with libcxx extracted in projects directory.
tar xf pkgs/llvm-12.0.0.src.tar.xz      && \
tar xf pkgs/libunwind-12.0.0.src.tar.xz && \
tar xf pkgs/libcxx-12.0.0.src.tar.xz    && \
cd llvm-12.0.0.src && export LLVMSRC=$PWD && cd projects && \
mv -v ../../libunwind-12.0.0.src libunwind && \
mv -v ../../libcxx-12.0.0.src    libcxx    && \
cd libunwind && \

sed -i 's,^# Setup flags.$,add_library_flags(ssp_nonshared),' src/CMakeLists.txt &&

cmake -B BUILD \
      -DCMAKE_INSTALL_PREFIX=/usr \
      -DCMAKE_BUILD_TYPE=Release \
      -DLLVM_PATH=$LLVMSRC  && \

read -p "Compile?" && make -C BUILD -j2 && \

sudo -S make DESTDIR=$BUILD -C BUILD install &&

cd $BUILD && sudo -S mkdir -v ${BUILD}/install &&
cat > /tmp/slack-desc << "EOF"
# HOW TO EDIT THIS FILE:
# The "handy ruler" below makes it easier to edit a package description.  Line
# up the first '|' above the ':' following the base package name, and the '|'
# on the right side marks the last column you can put a character in.  You must
# make exactly 11 lines for the formatting to be correct.  It's also
# customary to leave one space after the ':' except on otherwise blank lines.

              |-----handy-ruler------------------------------------------------------|
libunwind-llvm: llvm's libunwind
libunwind-llvm:
libunwind-llvm: libunwind is an implementation of the interface defined by the HP 
libunwind-llvm: libunwind project. It was contributed by Apple as a way to enable 
libunwind-llvm: clang++ to port to platforms that do not have a system unwinder. It 
libunwind-llvm: is intended to be a small and fast implementation of the ABI, leaving
libunwind-llvm: off some features of HP’s libunwind that never materialized (e.g. 
libunwind-llvm: remote unwinding)
libunwind-llvm:
libunwind-llvm:
EOF
sudo -S mv -v /tmp/slack-desc install/ &&
sudo -S makepkg -l y -c n $PKGS/libunwind-llvm-12.0.0-$(uname -m)-mlfs.txz &&
sudo -S rm -rf ${BUILD}/*