Protected visibility is available with the ELF object format

[VoxSciurorum]

No description provided.

[neboat]

Just a thought, should we add a CI test that only the expected symbols are exported from the runtime library? I think that should be easy to do.

[VoxSciurorum]

Here is a script to check exports. I don't know how to add it to CI. The runtime fails the check as written because of the Cilk_ symbols.
We could also use a linker map on ELF systems to control exports.

#!/bin/sh
case `uname` in
    Darwin)
        cmd="nm -gU"
        prefix="_"
        ;;
    Linux|*BSD)
        cmd="nm --dynamic --defined-only"
        prefix=""
        ;;
    *)
        echo "Unsupported platform" 1>&2
        exit 1 ;;
esac
${cmd:?} "${1:?}" |
  awk '$3 ~ /^'"${prefix}"'__(cilk|pedigree)/ { next } \
       $3 ~ /^_(init|fini)/ { next } \
       { print "Unexpected exported symbol " $3; exit 1 }'