nixpkgs/pkgs/build-support/cc-wrapper/macos-sierra-reexport-hack.bash
John Ericson 1cd74ac70a cc-wrapper: Make sure symbol tables of child delegators is not empty
As described in https://github.com/NixOS/nixpkgs/issues/18461, MacOS no
longer accepts dylibs which only reexport other dylibs, because their
symbol tables are empty. To get around this, we define an object file
with a single "private extern" symbol, which hopefully won't clobber
anything.
2017-07-31 17:02:56 -04:00

104 lines
3.0 KiB
Bash

#! @shell@
set -eu -o pipefail
path_backup="$PATH"
if [ -n "@coreutils_bin@" ]; then
PATH="@coreutils_bin@/bin"
fi
declare -r recurThreshold=300
declare overflowCount=0
for ((n=0; n < $#; ++n)); do
case "${!n}" in
-l*) let overflowCount+=1 ;;
-reexport-l*) let overflowCount+=1 ;;
*) ;;
esac
done
declare -a allArgs=()
if (( "$overflowCount" <= "$recurThreshold" )); then
allArgs=("$@")
else
declare -a childrenLookup=() childrenLink=()
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
exit 1
;;
-lto_library) allArgs+=("$1") ;;
# We aren't linking any "to_library"
-lSystem) allArgs+=("$1") ;;
# Special case as indirection seems like a bad idea for something
# so fundamental. Can be removed for simplicity.
-l?*) childrenLink+=("$1") ;;
-reexport-l?*) childrenLink+=("$1") ;;
*) allArgs+=("$1") ;;
esac
shift
done
declare n=0
while (( $n < "${#childrenLink[@]}" )); do
if [[ "${childrenLink[n]}" = -l* ]]; then
childrenLink[n]="-reexport${childrenLink[n]}"
fi
let ++n
done
unset n
declare -r outputNameLibless=$(basename $( \
if [[ -z "${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" \
"$outputNameLibless-reexport-delegate-1")
mkdir -p "$out/lib"
PATH="$PATH:@out@/bin"
symbolBloatObject=$outputNameLibless-symbol-hack.o
if [[ ! -e $symbolBloatObject ]]; then
printf '.private_extern _______child_hack_foo\nchild_hack_foo:\n' \
| @binPrefix@as -- -o $symbolBloatObject
fi
# first half of libs
@binPrefix@ld -macosx_version_min 10.10 -arch x86_64 -dylib \
-o "$out/lib/lib${children[0]}.dylib" \
-install_name "$out/lib/lib${children[0]}.dylib" \
"${childrenLookup[@]}" "$symbolBloatObject" \
"${childrenLink[@]:0:$((${#childrenLink[@]} / 2 ))}"
# second half of libs
@binPrefix@ld -macosx_version_min 10.10 -arch x86_64 -dylib \
-o "$out/lib/lib${children[1]}.dylib" \
-install_name "$out/lib/lib${children[1]}.dylib" \
"${childrenLookup[@]}" "$symbolBloatObject" \
"${childrenLink[@]:$((${#childrenLink[@]} / 2 ))}"
allArgs+=("-L$out/lib" "-l${children[0]}" "-l${children[1]}")
fi
PATH="$path_backup"
exec @prog@ "${allArgs[@]}"