webcomp: Very simple WebAssembly compiler based on LLVM 8+

webcomp.sh

#!/bin/bash

if [[ "$(curl https://gist.github.com/Codezigineer/501c09f8a3114ce7bb32c7d27301650b/raw/webcomp.sh)" != "$(cat $0)" ]]; then
    cd "$(dirname $0)"
    curl https://gist.github.com/Codezigineer/501c09f8a3114ce7bb32c7d27301650b/raw/webcomp.sh -o webcomp
fi

usage() {
   echo "Usage: webcomp [ -f infile ] [ -o outfile ] [ -O0 ] [ -O1 ] [ -O2 ] [ -O3 ] [ -t target {default is wasm32} ] [ -O ]"
}

set -e
target=wasm32
optlevel=
while getopts ":f:o:O0:O1:O2:O3:t:O:" o; do
    case "${o}" in
        f)
            in="$in ${OPTARG}"
            ;;
        o)
            out=${OPTARG}
            ;;
        O0)
            ;;
        O1)
            optlevel=-01
            ;;
        O2)
            optlevel=-02
            ;;
        O3)
            optlevel=-03
            ;;
        t)
            target=${OPTARG}
            ;;
        *)
            if [[ -z "${in}" ]] || [[ -z "${out}" ]]; then
                usage
                exit 1
            fi
            ;;
    esac
done 

if [[ -z "$in" ]]; then 
    usage
    exit 1;
elif [[ -z "$out" ]]; then
    usage
    exit 1;
fi

if [[ "$target" != "wasm32" ]] && [[ "$target" != "wasm64" ]]; then
    target=wasm32
fi

oldpwd=$PWD

folder=$(mktemp -d)
cd $folder
wget https://github.com/PicsumProjects/wclibc/releases/download/latest/wclibc-${target}.wasm -o wclibc.wasm

clang \
  --target=$target \
  -nostdlib \
  -Wl,--no-entry \
  -Wl,--export-all \
  ./wclibc.wasm
  $in
  -o $oldpwd/$out
  
cd $oldpwd
rm -rf $folder