#!/store/1-stage1/protobusybox/bin/ash

#> FETCH b0e42aafc01ece2ca2b42e3526f54bebc4b1f1dc8de6e34f46a0446a13e882b9
#>  FROM https://github.com/llvm/llvm-project/releases/download/llvmorg-17.0.1/llvm-project-17.0.1.src.tar.xz

set -uex

export PATH='/store/1-stage1/protobusybox/bin/'
export PATH="$PATH:/store/2a0-static-gnumake/wrappers"
export PATH="$PATH:/store/2a7-cmake/bin"
export PATH="$PATH:/store/2a8-python/bin"
# 2a9-intermediate-clang intentionally not added to $PATH to prevent confusion

export SHELL=/store/1-stage1/protobusybox/bin/ash
PREV_CLANG=/store/2a9-intermediate-clang

mkdir -p /tmp/2b1-clang; cd /tmp/2b1-clang
# clang's cmake configuration should pick up ccache automatically from PATH
#if [ -e /ccache/setup ]; then . /ccache/setup; fi
export PATH="$PATH:/ccache/bin"
command -v ccache && USE_CCACHE=YES || USE_CCACHE=NO

echo "### $0: preparing future sysroot..."
OUT=/store/2b1-clang
SYSROOT=$OUT/sysroot
mkdir -p $SYSROOT/lib $SYSROOT/include
ln -s /store/2b0-musl/lib/* $SYSROOT/lib/
ln -s /store/2b0-musl/include/* $SYSROOT/include/

echo "### $0: unpacking LLVM/Clang sources..."
tar --strip-components=1 -xf /downloads/llvm-project-17.0.1.src.tar.xz

echo "### $0: fixing up LLVM/Clang sources..."
sed -i "s|COMMAND sh|COMMAND $SHELL|" \
	llvm/cmake/modules/GetHostTriple.cmake clang/CMakeLists.txt
echo 'echo x86_64-unknown-linux-musl' > llvm/cmake/config.guess
LOADER=/store/2b0-musl/lib/libc.so
sed -i "s|/lib/ld-musl-\" + ArchName + \".so.1|$LOADER|" \
	clang/lib/Driver/ToolChains/Linux.cpp
BEGINEND='const bool HasCRTBeginEndFiles'
sed -i "s|${BEGINEND} =|${BEGINEND} = false; ${BEGINEND}_unused =|" \
	clang/lib/Driver/ToolChains/Gnu.cpp
REL_ORIGIN='_install_rpath \"\$ORIGIN/../lib${LLVM_LIBDIR_SUFFIX}\"'
sed -i "s|_install_rpath \"\\\\\$ORIGIN/..|_install_rpath \"$OUT|" \
	llvm/cmake/modules/AddLLVM.cmake
sed -i 's|numShards = 32;|numShards = 1;|' lld/*/SyntheticSections.*
sed -i 's|numShards = 256;|numShards = 1;|' lld/*/ICF.cpp
sed -i 's|__FILE__|__FILE_NAME__|' compiler-rt/lib/builtins/int_util.h
sed -i 's|"@LLVM_SRC_ROOT@"|"REDACTED"|' \
	llvm/tools/llvm-config/BuildVariables.inc.in
sed -i 's|"@LLVM_OBJ_ROOT@"|"REDACTED"|' \
	llvm/tools/llvm-config/BuildVariables.inc.in

echo "### $0: building LLVM/Clang..."
export LD_LIBRARY_PATH="/store/2b0-musl/lib:$PREV_CLANG/lib"
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/tmp/2b1-clang/build/lib" # libLLVM

EXTRA_INCL='/tmp/2b1-clang/extra_includes'
mkdir -p $EXTRA_INCL
cp clang/lib/Headers/*intrin*.h $EXTRA_INCL/
cp clang/lib/Headers/mm_malloc.h $EXTRA_INCL/
[ -e $EXTRA_INCL/immintrin.h ]

OPTS=''
add_opt() {
	OPTS="$OPTS -D$1"
}
add_opt CMAKE_BUILD_TYPE=Release
add_opt LLVM_OPTIMIZED_TABLEGEN=YES
add_opt LLVM_CCACHE_BUILD=$USE_CCACHE
add_opt DEFAULT_SYSROOT=$SYSROOT
add_opt CMAKE_INSTALL_PREFIX=$OUT
add_opt LLVM_INSTALL_BINUTILS_SYMLINKS=YES
add_opt LLVM_INSTALL_CCTOOLS_SYMLINKS=YES
add_opt CMAKE_INSTALL_DO_STRIP=YES
add_opt LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=YES
add_opt LLVM_TARGET_ARCH=X86
add_opt LLVM_TARGETS_TO_BUILD=Native
add_opt LLVM_BUILTIN_TARGETS=x86_64-unknown-linux-musl
add_opt LLVM_DEFAULT_TARGET_TRIPLE=x86_64-unknown-linux-musl
add_opt LLVM_HOST_TRIPLE=x86_64-unknown-linux-musl
add_opt COMPILER_RT_DEFAULT_TARGET_TRIPLE=x86_64-unknown-linux-musl
add_opt LLVM_APPEND_VC_REV=NO
add_opt LLVM_INCLUDE_TESTS=NO
add_opt LLVM_INCLUDE_EXAMPLES=NO
add_opt LLVM_INCLUDE_BENCHMARKS=NO
add_opt LLVM_ENABLE_BACKTRACES=NO
add_opt LLVM_ENABLE_EH=YES
add_opt LLVM_ENABLE_RTTI=YES
add_opt CLANG_ENABLE_ARCMT=NO
add_opt CLANG_ENABLE_STATIC_ANALYZER=NO
add_opt COMPILER_RT_BUILD_SANITIZERS=NO
add_opt COMPILER_RT_BUILD_XRAY=NO
add_opt COMPILER_RT_BUILD_LIBFUZZER=NO
add_opt COMPILER_RT_BUILD_PROFILE=NO
add_opt COMPILER_RT_BUILD_MEMPROF=NO
add_opt COMPILER_RT_BUILD_ORC=NO
add_opt COMPILER_RT_USE_BUILTINS_LIBRARY=YES
add_opt CLANG_DEFAULT_CXX_STDLIB=libc++
add_opt CLANG_DEFAULT_LINKER=lld
add_opt CLANG_DEFAULT_RTLIB=compiler-rt
add_opt LIBCXX_HAS_MUSL_LIBC=YES
add_opt LIBCXX_USE_COMPILER_RT=YES
add_opt LIBCXX_INCLUDE_BENCHMARKS=NO
add_opt LIBCXX_CXX_ABI=libcxxabi
add_opt LIBCXXABI_USE_COMPILER_RT=YES
add_opt LIBCXXABI_USE_LLVM_UNWINDER=YES
add_opt LIBCXX_ADDITIONAL_COMPILE_FLAGS=-I/store/2a6-linux-headers/include
add_opt LLVM_INSTALL_TOOLCHAIN_ONLY=YES
add_opt LIBUNWIND_USE_COMPILER_RT=YES
add_opt LLVM_ENABLE_THREADS=NO

REWRITE="-ffile-prefix-map=$(pwd)=/builddir/"
CFLAGS="--sysroot=$SYSROOT -I$EXTRA_INCL $REWRITE"
LDFLAGS="-Wl,--dynamic-linker=$LOADER"
cmake -S llvm -B build -G 'Unix Makefiles' \
	-DCMAKE_ASM_COMPILER=$PREV_CLANG/bin/clang \
	-DCMAKE_C_COMPILER=$PREV_CLANG/bin/clang \
	-DCMAKE_CXX_COMPILER=$PREV_CLANG/bin/clang++ \
	-DLLVM_ENABLE_PROJECTS='clang;lld' \
	-DLLVM_ENABLE_RUNTIMES='compiler-rt;libcxx;libcxxabi;libunwind' \
        -DCMAKE_C_FLAGS="$CFLAGS" \
        -DCMAKE_CXX_FLAGS="$CFLAGS" \
        -DCMAKE_C_LINK_FLAGS="$LDFLAGS" \
        -DCMAKE_CXX_LINK_FLAGS="$LDFLAGS" \
	-DLLVM_BUILD_LLVM_DYLIB=YES \
	-DLLVM_LINK_LLVM_DYLIB=YES \
	-DCLANG_LINK_LLVM_DYLIB=YES \
	$OPTS

make -C build -j $NPROC clang lld runtimes

echo "### $0: installing LLVM/Clang..."
make -C build -j $NPROC install/strip
ln -s $OUT/lib/x86_64-unknown-linux-musl/* $OUT/lib/

echo "### $0: setting up generic names..."
ln -s $OUT/bin/clang $OUT/bin/cc
ln -s $OUT/bin/clang++ $OUT/bin/c++
ln -s $OUT/bin/clang-cpp $OUT/bin/cpp
ln -s $OUT/bin/lld $OUT/bin/ld

echo "### $0: HACK making linux target work..."
# FIXME boost wants it at lib/clang/17/lib/linux/libclang_rt.builtins-x86_64.a
OUTLIB=$OUT/lib/clang/17/lib
ln -s $OUTLIB/x86_64-unknown-linux-musl $OUTLIB/linux
ln -s $OUTLIB/x86_64-unknown-linux-musl/libclang_rt.builtins.a \
	$OUTLIB/x86_64-unknown-linux-musl/libclang_rt.builtins-x86_64.a

echo "### $0: mixing new stuff into sysroot..."
ln -s $OUT/lib/* $OUT/sysroot/lib/

echo "### $0: NOT checking for build path leaks - see _2b1.test.sh"