nixpkgs/pkgs/build-support/cc-wrapper/ld-wrapper.sh

#! @shell@
set -e -o pipefail
shopt -s nullglob

path_backup="$PATH"

# phase separation makes this look useless
# shellcheck disable=SC2157
if [ -n "@coreutils_bin@" ]; then
    PATH="@coreutils_bin@/bin"
fi

if [ -n "$NIX_LD_WRAPPER_START_HOOK" ]; then
    source "$NIX_LD_WRAPPER_START_HOOK"
fi

if [ -z "$NIX_CC_WRAPPER_FLAGS_SET" ]; then
    source @out@/nix-support/add-flags.sh
fi

source @out@/nix-support/utils.sh


# Optionally filter out paths not refering to the store.
expandResponseParams "$@"
if [[ "$NIX_ENFORCE_PURITY" = 1 && -n "$NIX_STORE"
        && ( -z "$NIX_IGNORE_LD_THROUGH_GCC" || -z "$NIX_LDFLAGS_SET" ) ]]; then
    rest=()
    nParams=${#params[@]}
    declare -i n=0
    while [ "$n" -lt "$nParams" ]; do
        p=${params[n]}
        p2=${params[n+1]}
        if [ "${p:0:3}" = -L/ ] && badPath "${p:2}"; then
            skip "${p:2}"
        elif [ "$p" = -L ] && badPath "$p2"; then
            n+=1; skip "$p2"
        elif [ "$p" = -rpath ] && badPath "$p2"; then
            n+=1; skip "$p2"
        elif [ "$p" = -dynamic-linker ] && badPath "$p2"; then
            n+=1; skip "$p2"
        elif [ "${p:0:1}" = / ] && badPath "$p"; then
            # We cannot skip this; barf.
            echo "impure path \`$p' used in link" >&2
            exit 1
        elif [ "${p:0:9}" = --sysroot ]; then
            # Our ld is not built with sysroot support (Can we fix that?)
            :
        else
            rest+=("$p")
        fi
        n+=1
    done
    params=("${rest[@]}")
fi

source @out@/nix-support/add-hardening.sh

extraAfter=("${hardeningLDFlags[@]}")
extraBefore=()

if [ -z "$NIX_LDFLAGS_SET" ]; then
    extraAfter+=($NIX_LDFLAGS)
    extraBefore+=($NIX_LDFLAGS_BEFORE)
fi

extraAfter+=($NIX_LDFLAGS_AFTER $NIX_LDFLAGS_HARDEN)

declare -a libDirs
declare -A libs
relocatable=

# Find all -L... switches for rpath, and relocatable flags for build id.
if [ "$NIX_DONT_SET_RPATH" != 1 ] || [ "$NIX_SET_BUILD_ID" = 1 ]; then
    prev=
    for p in "${extraBefore[@]}" "${params[@]}" "${extraAfter[@]}"; do
        case "$prev" in
            -L)
                libDirs+=("$p")
                ;;
            -l)
                libs["lib${p}.so"]=1
                ;;
            -dynamic-linker | -plugin)
                # Ignore this argument, or it will match *.so and be added to rpath.
                ;;
            *)
                case "$p" in
                    -L/*)
                        libDirs+=("${p:2}")
                        ;;
                    -l?*)
                        libs["lib${p:2}.so"]=1
                        ;;
                    "$NIX_STORE"/*.so | "$NIX_STORE"/*.so.*)
                        # This is a direct reference to a shared library.
                        libDirs+=("${p%/*}")
                        libs["${p##*/}"]=1
                        ;;
                    -r | --relocatable | -i)
                        relocatable=1
                esac
                ;;
        esac
        prev="$p"
    done
fi


# Add all used dynamic libraries to the rpath.
if [ "$NIX_DONT_SET_RPATH" != 1 ]; then
    # For each directory in the library search path (-L...),
    # see if it contains a dynamic library used by a -l... flag.  If
    # so, add the directory to the rpath.
    # It's important to add the rpath in the order of -L..., so
    # the link time chosen objects will be those of runtime linking.
    declare -A rpaths
    for dir in "${libDirs[@]}"; do
        if [[ "$dir" =~ [/.][/.] ]] && dir2=$(readlink -f "$dir"); then
            dir="$dir2"
        fi
        if [ "${rpaths[$dir]}" ] || [[ "$dir" != "$NIX_STORE"/* ]]; then
            # If the path is not in the store, don't add it to the rpath.
            # This typically happens for libraries in /tmp that are later
            # copied to $out/lib.  If not, we're screwed.
            continue
        fi
        for path in "$dir"/lib*.so; do
            file="${path##*/}"
            if [ "${libs[$file]}" ]; then
                libs["$file"]=
                if [ ! "${rpaths[$dir]}" ]; then
                    rpaths["$dir"]=1
                    extraAfter+=(-rpath "$dir")
                fi
            fi
        done
    done
fi


# Only add --build-id if this is a final link. FIXME: should build gcc
# with --enable-linker-build-id instead?
if [ "$NIX_SET_BUILD_ID" = 1 ] && [ ! "$relocatable" ]; then
    extraAfter+=(--build-id)
fi


# Optionally print debug info.
if [ -n "$NIX_DEBUG" ]; then
    echo "extra flags before to @prog@:" >&2
    printf "  %q\n" "${extraBefore[@]}"  >&2
    echo "original flags to @prog@:" >&2
    printf "  %q\n" "${params[@]}" >&2
    echo "extra flags after to @prog@:" >&2
    printf "  %q\n" "${extraAfter[@]}" >&2
fi

if [ -n "$NIX_LD_WRAPPER_EXEC_HOOK" ]; then
    source "$NIX_LD_WRAPPER_EXEC_HOOK"
fi

PATH="$path_backup"
exec @prog@ "${extraBefore[@]}" "${params[@]}" "${extraAfter[@]}"