#!/bin/sh
set -e

llvm_rev=929d9ef111cc0053e245d04464c5ba9fba7727b2
clang_rev=56312023bf62cb40d2e33ea5e14d55c1e42303a7
lldb_lldb=f05a54ef760f7c71161e262197db38a2ee4e491e

missing=
pyinc="-I/usr/local/include/python2.7"
stdlib=
if [ -f /usr/lib/libc++.so ]; then
    CC=clang
    CXX=clang++
    stdlib="-stdlib=libc++"
else
    if [ -f /usr/local/bin/g++ ]; then
        CC=/usr/local/bin/gcc
        CC=/usr/local/bin/g++
    else
        CC=gcc
        CXX=g++
    fi
    case $($CC --version | egrep -o '[0-9]*\.[0-9]*\.[0-9]*') in
        4.6.[23456789]) ;;
        4.[789]*) ;;
        [56789]*) ;;
        *)
            missing="gcc(4.6.2 or later)"
            ;;
    esac
fi
for tool in cmake git ninja python swig $compiler; do
    if ! which $tool >/dev/null 2>&1; then
        missing="$missing $tool"
    fi
done
if [ -n "$missing" ]; then
    echo "error: the following ports or packages must be installed:" >&2
    echo $missing >&2
    exit 1
fi

do_fetch()
{
    if [ ! -d llvm ]; then
        echo "llvm directory does not exist -- cloning from github"
        git clone https://github.com/llvm-mirror/llvm.git
        cd llvm/tools
        git clone https://github.com/llvm-mirror/clang
        git clone https://github.com/fbsd/lldb.git
        cd ../..
    else
        echo "updating existing git clones"
        for dir in llvm llvm/tools/clang llvm/tools/lldb; do
            cd $dir
            git fetch --all
            cd -
        done
    fi
}

do_checkout()
{
    echo "checking out required versions"
    git checkout $llvm_rev
    cd tools/clang
    git checkout $clang_rev
    cd ../lldb
    git checkout $lldb_rev
    cd ../..
}

do_cmake()
{
    echo "Configuring build"
    # assume we have clang
    CC=$CC CXX=$CXX cmake ../ -G Ninja -DCMAKE_CXX_FLAGS="$stdlib $pyinc -g"
}

do_build()
{
    echo "Building lldb"
    cd build
    ninja lldb
    cd ..
}

do_fetch
cd llvm
do_checkout
if [ ! -d build ]; then
    mkdir build
    cd build
    do_cmake
    cd ..
fi
do_build
cd ..

echo "lldb should now be built as: ./llvm/build/bin/lldb"