#!/usr/bin/bash -eu

if [ -z "$RPM_BUILD_ROOT" ] || [ "$RPM_BUILD_ROOT" = "/" ]; then

	exit 0

fi

CLANG_FLAGS=$@

NCPUS=${RPM_BUILD_NCPUS:-1}

check_convert_bitcode () {

  local file_name=$(realpath ${1})

  local file_type=$(file ${file_name})

  shift

  CLANG_FLAGS="$@"

  if [[ "${file_type}" == *"LLVM IR bitcode"* ]]; then

    # Check the output of llvm-strings for the command line, which is in the LLVM bitcode because

    # we pass -frecord-gcc-switches.

    # Check for a line that has "-flto" after (or without) "-fno-lto".

    llvm-strings ${file_name} | while read line ; do

      flto=$(echo $line   | grep -o -b -e -flto     | tail -n 1 | cut -d : -f 1)

      fnolto=$(echo $line | grep -o -b -e -fno-lto  | tail -n 1 | cut -d : -f 1)

      if test -n "$flto" && { test -z "$fnolto" || test "$flto" -gt "$fnolto"; } ; then

        echo "Compiling LLVM bitcode file ${file_name}."

        clang ${CLANG_FLAGS} -fno-lto -Wno-unused-command-line-argument \

          -x ir ${file_name} -c -o ${file_name}

        break

      fi

      done

  elif [[ "${file_type}" == *"current ar archive"* ]]; then

    echo "Unpacking ar archive ${file_name} to check for LLVM bitcode components."

    # create archive stage for objects

    local archive_stage=$(mktemp -d)

    local archive=${file_name}

    pushd ${archive_stage}

    ar x ${archive}

    for archived_file in $(find -not -type d); do

      check_convert_bitcode ${archived_file} ${CLANG_FLAGS}

      echo "Repacking ${archived_file} into ${archive}."

      ar r ${archive} ${archived_file}

    done

    popd

  fi

}

echo "Checking for LLVM bitcode artifacts"

export -f check_convert_bitcode

# Deduplicate by device:inode to avoid processing hardlinks in parallel.

find "$RPM_BUILD_ROOT" -type f -name "*.[ao]" -printf "%D:%i %p\n" | \

  awk '!seen[$1]++' | cut -d" " -f2- | \

  xargs -d"\n" -r -n1 -P$NCPUS sh -c "check_convert_bitcode \$@ $CLANG_FLAGS" ARG0