[chore] add github workflow

.github/reqs.sh

@@ -0,0 +1,154 @@
+#!/usr/bin/env bash
+
+set -e
+set -x
+
+# input environment variables:
+# CXX_: the compiler version. eg, g++-9 or clang++-6.0
+# VG: whether to install valgrind
+
+#-------------------------------------------------------------------------------
+
+# add a gcc compiler
+function addgcc()
+{
+    version=$1
+    addpkg g++-$version
+    addpkg g++-$version-multilib
+}
+
+# add a clang compiler
+function addclang()
+{
+    version=$1
+    case $version in
+        # in 18.04, clang9 and later require PPAs
+        9 | 10 ) addpkg clang-$version "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-$version main" ;;
+        *      ) addpkg clang-$version ;;
+    esac
+    addpkg g++-multilib  # this is required for 32 bit https://askubuntu.com/questions/1057341/unable-to-find-stl-headers-in-ubuntu-18-04
+    addpkg clang-tidy-$version
+    wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key 2>/dev/null | sudo apt-key add -
+}
+
+# add a debian package to the list
+function addpkg()
+{
+    pkgs=$1
+    sourceslist=$2
+    DPKG="$DPKG $pkgs"
+    echo "adding to packages: $pkgs"
+    #echo "DPKG=$DPKG"
+    addsrc "$sourceslist" "# for packages: $pkgs"
+}
+
+# add an apt source
+function addsrc()
+{
+    sourceslist=$1
+    comment=$2
+    if [ ! -z "$sourceslist" ] ; then
+        echo "adding source: $sourceslist"
+        sudo bash -c "cat >> /etc/apt/sources.list <<EOF
+$comment
+$sourceslist
+EOF"
+        #cat /etc/apt/sources.list
+    fi
+}
+
+
+#-------------------------------------------------------------------------------
+
+function c4_gather_compilers()
+{
+    cxx=$1
+    case $cxx in
+        g++-10     ) addgcc 10 ;;
+        g++-9      ) addgcc 9  ;;
+        g++-8      ) addgcc 8  ;;
+        g++-7      ) addgcc 7  ;;
+        g++-6      ) addgcc 6  ;;
+        g++-5      ) addgcc 5  ;;
+        g++-4.9    ) addgcc 4.9 ;;
+        clang++-10 ) addclang 10  ;;
+        clang++-9  ) addclang 9   ;;
+        clang++-8  ) addclang 8   ;;
+        clang++-7  ) addclang 7   ;;
+        clang++-6.0) addclang 6.0 ;;
+        clang++-5.0) addclang 5.0 ;;
+        clang++-4.0) addclang 4.0 ;;
+        clang++-3.9) addclang 3.9 ;;
+        *)
+            all="g++-10 g++-9 g++-8 g++-7 g++-6 g++-5 g++-4.9 clang++-10 clang++-9 clang++-8 clang++-7 clang++-6.0 clang++-5.0 clang++-4.0 clang++-3.9"
+            echo "installing all compilers: $all"
+            for cxx in $all ; do
+                c4_gather_compilers $cxx
+            done
+            ;;
+    esac
+}
+
+function c4_gather_packages()
+{
+    # travis requires build-essential + cmake
+    if [ "$GITHUB_WORKFLOW" == "" ] ; then
+        addpkg build-essential
+        addpkg cmake
+    else
+        sudo dpkg --add-architecture i386
+    fi
+
+    c4_gather_compilers "$CXX_"
+
+    if [ "$VG" == "ON" ] ; then
+        addpkg valgrind
+    fi
+
+    echo "additional packages: $DPKG"
+
+    wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null | sudo apt-key add -
+    sudo -E apt-add-repository --yes 'deb https://apt.kitware.com/ubuntu/ bionic main'
+    sudo -E add-apt-repository --yes ppa:ubuntu-toolchain-r/test
+}
+
+function c4_install_everything()
+{
+    #sudo -E apt-get clean
+    sudo -E apt-get update
+
+    sudo -E apt-get install -y --force-yes \
+         linux-libc-dev:i386 \
+         libc6:i386 \
+         libc6-dev:i386 \
+         libc6-dbg:i386 \
+         $DPKG
+
+    if [ "$BT" == "Coverage" ]; then
+        sudo -E apt-get install -y --force-yes \
+             lcov \
+             libffi-dev \
+             libssl-dev \
+             python3-pip \
+             python3-setuptools
+        sudo pip3 install \
+             requests[security] \
+             pyopenssl \
+             ndg-httpsclient \
+             pyasn1 \
+             cpp-coveralls
+    fi
+
+    which cmake
+    cmake --version
+    $CXX_ --version
+    which $CXX_
+}
+
+#-------------------------------------------------------------------------------
+
+c4_gather_packages
+c4_install_everything
+
+
+echo "INSTALL COMPLETE: current directory: $(pwd)"