cc-wrapper: Utilize patched cctools ld for more robust macOS Sierra hack

set -eu -o pipefail

# For cmd | while read; do ...; done

shopt -s lastpipe

path_backup="$PATH"

if [ -n "@coreutils_bin@" ]; then

  PATH="@coreutils_bin@/bin"

fi

declare -r recurThreshold=300

declare -ri recurThreshold=200

declare -i overflowCount=0

declare overflowCount=0

for ((n=0; n < $#; ++n)); do

    case "${!n}" in

        -l*) let overflowCount+=1 ;;

        -reexport-l*) let overflowCount+=1 ;;

        *) ;;

    esac

done

declare -ar origArgs=("$@")

declare -a allArgs=()

if (( "$overflowCount" <= "$recurThreshold" )); then

    allArgs=("$@")

else

    declare -a childrenLookup=() childrenLink=()

# Throw away what we won't need

declare -a parentArgs=()

while (( $# )); do

    case "$1" in

            -L/*)

                childrenLookup+=("$1")

                allArgs+=("$1")

                ;;

            -L)

                echo "cctools LD does not support '-L foo' or '-l foo'" >&2

                exit 1

                ;;

        -l)

                echo "cctools LD does not support '-L foo' or '-l foo'" >&2

            echo "cctools LD does not support '-l foo'" >&2

            exit 1

            ;;

            -lazy_library | -lazy_framework | -lto_library)

                # We aren't linking any "azy_library", "to_library", etc.

                allArgs+=("$1")

                ;;

            -lazy-l | -weak-l)    allArgs+=("$1") ;;

                # We can't so easily prevent header issues from these.

            -lSystem)             allArgs+=("$1") ;;

                # Special case as indirection seems like a bad idea for something

                # so fundamental. Can be removed for simplicity.

            -l?* | -reexport-l?*) childrenLink+=("$1") ;;

            *)                    allArgs+=("$1") ;;

        -lazy_library | -reexport_library | -upward_library | -weak_library)

            overflowCount+=1

            shift 2

            ;;

        -l* | *.so.* | *.dylib | -lazy-l* | -reexport-l* | -upward-l* | -weak-l*)

            overflowCount+=1

            shift 1

            ;;

        *.a | *.o)

            shift 1

            ;;

        -L | -F)

            # Evidentally ld doesn't like using the child's RPATH, so it still

            # needs these.

            parentArgs+=("$1" "$2")

            shift 2

            ;;

        -L?* | -F?*)

            parentArgs+=("$1")

            shift 1

            ;;

        -o)

            outputName="$2"

            parentArgs+=("$1" "$2")

            shift 2

            ;;

        -install_name | -dylib_install_name | -dynamic-linker | -plugin)

            parentArgs+=("$1" "$2")

            shift 2

            ;;

        -rpath)

            # Only an rpath to the child is needed, which we will add

            shift 2

            ;;

        *)

            if [[ -f "$1" ]]; then

                # Propabably a non-standard object file like Haskell's

                # `.dyn_o`. Skip it like other inputs

                :

            else

                parentArgs+=("$1")

            fi

            shift 1

            ;;

    esac

done

        shift

if (( "$overflowCount" <= "$recurThreshold" )); then

    if [ -n "${NIX_DEBUG:-}" ]; then

        echo "ld-wrapper: Only ${overflowCount} inputs counted while ${recurThreshold} is the ceiling, linking normally. " >&2

    fi

    PATH="$path_backup"

    exec @prog@ "${origArgs[@]}"

fi

if [ -n "${NIX_DEBUG:-}" ]; then

    echo "ld-wrapper: ${overflowCount} inputs counted when ${recurThreshold} is the ceiling, inspecting further. " >&2

fi

# Collect the normalized linker input

declare -a norm=()

# Arguments are null-separated

@prog@ --dump-normalized-lib-args "${origArgs[@]}" |

    while IFS= read -r -d '' input; do

        norm+=("$input")

    done

    declare n=0

    while (( $n < "${#childrenLink[@]}" )); do

        if [[ "${childrenLink[n]}" = -l* ]]; then

            childrenLink[n]="-reexport${childrenLink[n]}"

declare -i leafCount=0

declare lastLeaf=''

declare -a childrenInputs=() trailingInputs=()

while (( "${#norm[@]}" )); do

    case "${norm[0]}" in

        -lazy_library | -upward_library)

            # TODO(@Ericson2314): Don't do that, but intersperse children

            # between such args.

            echo "ld-wrapper: Warning: Potentially changing link order" >&2

            trailingInputs+=("${norm[0]}" "${norm[1]}")

            norm=("${norm[@]:2}")

            ;;

        -reexport_library | -weak_library)

            childrenInputs+=("${norm[0]}" "${norm[1]}")

            if [[ "${norm[1]}" != "$lastLeaf" ]]; then

                leafCount+=1

                lastLeaf="${norm[1]}"

            fi

            norm=("${norm[@]:2}")

            ;;

        *.so | *.dylib)

            childrenInputs+=(-reexport_library "${norm[0]}")

            if [[ "${norm[0]}" != "$lastLeaf" ]]; then

                leafCount+=1

                lastLeaf="${norm[0]}"

            fi

            norm=("${norm[@]:1}")

            ;;

        *.o | *.a)

            # Don't delegate object files or static libs

            parentArgs+=("${norm[0]}")

            norm=("${norm[@]:1}")

            ;;

        *)

            if [[ -f "${norm[0]}" ]]; then

                # Propabably a non-standard object file. We'll let it by.

                parentArgs+=("${norm[0]}")

                norm=("${norm[@]:1}")

            else

                echo "ld-wrapper: Internal Error: Invalid normalized argument" >&2

                exit -1

            fi

        let ++n

            ;;

    esac

done

    unset n

    declare -r outputNameLibless=$(basename $( \

if (( "$leafCount" <= "$recurThreshold" )); then

    if [ -n "${NIX_DEBUG:-}" ]; then

        echo "ld-wrapper: Only ${leafCount} *dynamic* inputs counted while ${recurThreshold} is the ceiling, linking normally. " >&2

    fi

    PATH="$path_backup"

    exec @prog@ "${origArgs[@]}"

fi

if [ -n "${NIX_DEBUG:-}" ]; then

    echo "ld-wrapper: ${leafCount} *dynamic* inputs counted when ${recurThreshold} is the ceiling, delegating to children. " >&2

fi

declare -r outputNameLibless=$( \

    if [[ -z "${outputName:+isUndefined}" ]]; then

        echo unnamed

        elif [[ "${outputName:0:3}" = lib ]]; then

            echo "${outputName:3}"

        else

            echo "${outputName}"

        fi))

    declare -ra children=("$outputNameLibless-reexport-delegate-0" \

                          "$outputNameLibless-reexport-delegate-1")

        return 0;

    fi

    baseName=$(basename ${outputName})

    if [[ "$baseName" = lib* ]]; then

        baseName="${baseName:3}"

    fi

    echo "$baseName")

    mkdir -p "$out/lib"

declare -ra children=(

    "$outputNameLibless-reexport-delegate-0"

    "$outputNameLibless-reexport-delegate-1"

)

    PATH="$PATH:@out@/bin"

mkdir -p "$out/lib"

symbolBloatObject=$outputNameLibless-symbol-hack.o

    if [[ ! -e $symbolBloatObject ]]; then

if [[ ! -f $symbolBloatObject ]]; then

    # `-Q` means use GNU Assembler rather than Clang, avoiding an awkward

    # dependency cycle.

        printf '.private_extern _______child_hack_foo\nchild_hack_foo:\n' \

            | @targetPrefix@as -Q -- -o $symbolBloatObject

    printf '.private_extern _______child_hack_foo\nchild_hack_foo:\n' |

        PATH="$PATH:@out@/bin" @targetPrefix@as -Q -- -o $symbolBloatObject

fi

    # first half of libs

    @targetPrefix@ld -macosx_version_min $MACOSX_DEPLOYMENT_TARGET -arch x86_64 -dylib \

# Split inputs between children

declare -a child0Inputs=() child1Inputs=("${childrenInputs[@]}")

let "countFirstChild = $leafCount / 2" || true

lastLeaf=''

while (( "$countFirstChild" )); do

    case "${child1Inputs[0]}" in

        -reexport_library | -weak_library)

            child0Inputs+=("${child1Inputs[0]}" "${child1Inputs[1]}")

            if [[ "${child1Inputs[1]}" != "$lastLeaf" ]]; then

                let countFirstChild-=1 || true

                lastLeaf="${child1Inputs[1]}"

            fi

            child1Inputs=("${child1Inputs[@]:2}")

            ;;

        *.so | *.dylib)

            child0Inputs+=(-reexport_library "${child1Inputs[0]}")

            if [[ "${child1Inputs[0]}" != "$lastLeaf" ]]; then

                let countFirstChild-=1 || true

                lastLeaf="${child1Inputs[1]}"

            fi

            child1Inputs=("${child1Inputs[@]:2}")

            ;;

        *)

            echo "ld-wrapper: Internal Error: Invalid delegated input" >&2

            exit -1

            ;;

    esac

done

# First half of libs

@out@/bin/@targetPrefix@ld \

  -macosx_version_min $MACOSX_DEPLOYMENT_TARGET -arch x86_64 -dylib \

  -o "$out/lib/lib${children[0]}.dylib" \

  -install_name "$out/lib/lib${children[0]}.dylib" \

      "${childrenLookup[@]}" "$symbolBloatObject" \

      "${childrenLink[@]:0:$((${#childrenLink[@]} / 2 ))}"

  "$symbolBloatObject" "${child0Inputs[@]}" "${trailingInputs[@]}"

    # second half of libs

    @targetPrefix@ld -macosx_version_min $MACOSX_DEPLOYMENT_TARGET -arch x86_64 -dylib \

# Second half of libs

@out@/bin/@targetPrefix@ld \

  -macosx_version_min $MACOSX_DEPLOYMENT_TARGET -arch x86_64 -dylib \

  -o "$out/lib/lib${children[1]}.dylib" \

  -install_name "$out/lib/lib${children[1]}.dylib" \

      "${childrenLookup[@]}" "$symbolBloatObject" \

      "${childrenLink[@]:$((${#childrenLink[@]} / 2 ))}"

  "$symbolBloatObject" "${child1Inputs[@]}" "${trailingInputs[@]}"

parentArgs+=("-L$out/lib" -rpath "$out/lib")

if [[ $outputName != *reexport-delegate* ]]; then

	parentArgs+=("-l${children[0]}" "-l${children[1]}")

else

    parentArgs+=("-reexport-l${children[0]}" "-reexport-l${children[1]}")

fi

parentArgs+=("${trailingInputs[@]}")

    allArgs+=("-L$out/lib" "-l${children[0]}" "-l${children[1]}")

if [ -n "${NIX_DEBUG:-}" ]; then

    echo "flags using delegated children to @prog@:" >&2

    printf "  %q\n" "${parentArgs[@]}" >&2

fi

PATH="$path_backup"

exec @prog@ "${allArgs[@]}"

exec @prog@ "${parentArgs[@]}"