Cross-compiling on Linux for iOS - ios

Question

I am trying to cross-compile Ruby for iOS devices. I have a rather lengthy script that downloads the latest source code for Ruby, unzips it, and compiles it.
The script is as follows:
#!/bin/bash
rm -rf ~/built/ruby
AR=~/toolchain/armv7-apple-darwin11-ar
AS=~/toolchain/armv7-apple-darwin11-as
CC=~/toolchain/armv7-apple-darwin11-clang
CXX=~/toolchain/armv7-apple-darwin11-clang++
LD=~/toolchain/armv7-apple-darwin11-ld
NM=~/toolchain/armv7-apple-darwin11-nm
OBJDUMP=~/toolchain/armv7-apple-darwin11-objdump
RANLIB=~/toolchain/armv7-apple-darwin11-ranlib
STRIP=~/toolchain/armv7-apple-darwin11-strip
SDK=/home/citrusui/sdks/iPhoneOS9.3.sdk
CFLAGS="-arch armv7 -arch arm64 -isysroot $SDK"
LDFLAGS="-Wl,-segalign,4000"
DESTDIR=~/built/ruby/var/stash
apt install autoconf bison clang jq xutils-dev
curl https://api.github.com/repos/ruby/ruby/tags -o ruby.json
URL=`jq -r 'map(select(.name != "yarv_migration_base"))[0].tarball_url' ruby.json`
TAG=`jq -r 'map(select(.name != "yarv_migration_base"))[0].name' ruby.json`
echo "Downloading from $URL"...
if [ -f ruby_$TAG.tar.gz ] && [ -d ruby-ruby* ]; then
echo "Already downloaded."
cd ruby-ruby*
autoconf
./configure --host=armv7-apple-darwin11 -target=armv7-apple-darwin11 CC="$CC" CXX="$CXX" CXXFLAGS="$CFLAGS" CFLAGS="$CFLAGS" STRIP=$STRIP RANLIB=$RANLIB NM=$NM AR=$AR AS=$AS LD=$LD OBJDUMP=$OBJDUMP LDFLAGS="$LDFLAGS" DESTDIR="$DESTDIR"
make install -j4
cd ~/built/ruby
lndir var/stash
exit 0
fi
curl -L $URL -o ruby_$TAG.tar.gz
tar -xvzf ruby_$TAG.tar.gz
cd ruby-ruby*
autoconf
./configure --host=armv7-apple-darwin11 -target=armv7-apple-darwin11 CC="$CC" CXX="$CXX" CXXFLAGS="$CFLAGS" CFLAGS="$CFLAGS" STRIP=$STRIP RANLIB=$RANLIB NM=$NM AR=$AR AS=$AS LD=$LD OBJDUMP=$OBJDUMP LDFLAGS="$LDFLAGS" DESTDIR="$DESTDIR"
make install -j4
cd ~/built/ruby
lndir var/stash
Now, I have also downloaded the iOS 9.3 SDK from Xcode and dropped it into my ~/sdks/ folder. However, the compiling process still results in ELF format binaries.
I also have a toolchain (in ~/toolchain/) downloaded from here. I assume this will allow LLVM/Clang to produce arm(64) binaries, but I don't know how I would tell clang to process this toolchain. Specifying $TOOLCHAIN in ./configure doesn't help, either.