clang-redirect

# cat rh-toolset-redirect
#!/bin/bash -
#===============================================================================
#
#          FILE: rh-toolset-redirect.sh
#
#   DESCRIPTION: Redirect command to devtoolset command. This script is designed
#                to be the target of symlinks of the form:
#
#                <RedHatToolsetName>-redirect
#
#               e.g. 'devtoolset-redirect', or 'llvm-toolset-redirect'
#
#                And that symlink should in turn be the target of a versioned
#                tool name such as 'clang7' or 'g++6'
#
#                E.g. g++6. It will strip the toolset_version, and redirect
#                the arguments to the toolset version of <binary_name>
#
#                Additionally, an unversioned symlink to a versioned symlink 
#                will use the versioned symlink to determine the version.
#
#                E.g., if we have symlinks:
#
#                   clang --> clang7 --> llvm-toolset-redirect -> <this-script>
#
#                Invoking 'clang' will mean the version will be taken from
#                'clang7', and the toolset name will be 'llvm-toolset'.
#                This allows you to set a default version by
#                creating an unversioned symlink to the desired versioned
#                symlink.
#
#                The toolset to redirect to is taken from the penultimate
#                symlink (in the example 'llvm-toolset')
#
#       CREATED: 2017-07-18
#
#        AUTHOR: Anthony Dervish
#
#===============================================================================

set -o nounset                              # Treat unset variables as an error

Script="${BASH_SOURCE[0]}"
ScriptDir="$( cd "$( dirname "${Script}"  )" && pwd -P )"

function GetVersion() {
    local bname=$(basename $Script)
    local version=$(echo "${bname}" | sed -E 's/^.*([0-9]+)$/\1/')
    if [[ "${version}" != "${bname}" ]]; then
        echo "$version"
    fi
}

ToolsetVersion=$(GetVersion "${Script}")
if [[ -z "$ToolsetVersion" ]]; then
    if [[ -h "${Script}" ]]; then
        Script="${ScriptDir}/$(basename $(readlink "${Script}"))"
        ToolsetVersion=$(GetVersion "${Script}")
        if [[ -z "${ToolsetVersion}" ]]; then
            echo "Symlink name to this script should end in an integer toolset version!" >&2
            exit 1
        fi
    fi
fi

if [[ ! -h "${Script}" ]]; then
    echo "${Script} should be a symlink to <toolset>-redirect, which in turn should be a"
    echo "symlink to this script."
    exit 1
fi


ToolsetSymlink=$(readlink "${Script}")
UnversionedToolset="${ToolsetSymlink%-redirect}"

OrigName=$(basename "${Script}")
ToolsetName=${UnversionedToolset}-${ToolsetVersion}
ToolsetDir="/opt/rh/${ToolsetName}"

if [[ ! -d "${ToolsetDir}" ]]; then
    echo "Unknown ${UnversionedToolset} version '${ToolsetVersion}'" >&2
    exit 1
fi

RedirectBaseDir="${ToolsetDir}/root/bin"
ToolName=${OrigName%${ToolsetVersion}}
ToolBinary="${RedirectBaseDir}/${ToolName}"

cat <<EOF | sed 's/\"/\\"/g' |
${ToolBinary} $@
EOF
exec scl enable "${ToolsetName}" -

# vim: filetype=sh: