Bash shell script to build libjpeg on macOS for the purpose of creating a universal binary

build_libjpeg.sh

#!/bin/bash
# Alex Bettarini - 28 Jul 2022

#-------------------------------------------------------------------------------
STEP_DOWNLOAD_LIB_JPEG=true
STEP_INFO_JPEG=true
STEP_CONFIGURE_LIB_JPEG=true
STEP_COMPILE_LIB_JPEG=true  # and install
STEP_PACKAGE_LIB_JPEG=true

#-------------------------------------------------------------------------------
#JPEG_VERSION=9d
JPEG_VERSION=9e

#-------------------------------------------------------------------------------
CONFIG_BIN_DIR=bin
JPEG=jpeg-$JPEG_VERSION

WD=$(pwd)

SRC=$WD/temp/src
BLD=$WD/temp/bld
BIN=$WD/temp/$CONFIG_BIN_DIR

SRC_JPEG=$SRC/$JPEG
BLD_JPEG=$BLD/$JPEG
BIN_JPEG=$BIN/$JPEG

mkdir -p $SRC

#----------------------------------------------------------------------------
if [ $STEP_DOWNLOAD_LIB_JPEG ] ; then
if [ -d $SRC_JPEG ] ; then
echo "=== Download $JPEG exists"
else
cd $SRC
echo "=== Download $JPEG"
curl -O http://www.ijg.org/files/jpegsrc.v$JPEG_VERSION.tar.gz
tar -zxf jpegsrc.v$JPEG_VERSION.tar.gz
rm jpegsrc.v$JPEG_VERSION.tar.gz
fi
fi

#----------------------------------------------------------------------------
if [ $STEP_INFO_JPEG ] ; then
cd $SRC_JPEG
echo -n "=== JPEG: " ;  grep "JVERSION" jversion.h | cut -d"\"" -f2
grep "define JPEG_LIB_VERSION" jpeglib.h
fi

#----------------------------------------------------------------------------
if [ $STEP_CONFIGURE_LIB_JPEG ] ; then
echo -e "\n=== Configure $JPEG in $BLD_JPEG"
mkdir -p "$BLD_JPEG" ; cd "$BLD_JPEG"
export CFLAGS="-arch x86_64 -arch arm64"
"$SRC_JPEG"/configure \
		--prefix="$BIN_JPEG"
fi

#----------------------------------------------------------------------------
if [ $STEP_COMPILE_LIB_JPEG ] ; then
cd $BLD_JPEG
echo -e "\n=== Build $JPEG"
make

echo -e "\n=== Install $JPEG"
make install
fi

#----------------------------------------------------------------------------
if [ $STEP_PACKAGE_LIB_JPEG ] ; then
cd $BIN
echo -e "\n=== Package $JPEG"
zip -rXq $WD/$JPEG.zip "$JPEG"
fi

At present I have to run this script on two different machines, one with an X86_64 CPU and another with an arm64 CPU, then combine the two libraries with lipo. How can the script be extended to allow building the universal binary only one one machine ? I have tried passing CXX="g++ -arch x86_64 -arch arm64" to the configure command, but it didn't work...

Doing this kind of stuff with CMake is a breeze, but the libjpeg project uses Autotools to configure the build, and I haven't been able to configure it correctly so far.

It finally worked after adding export CFLAGS="-arch x86_64 -arch arm64" before calling config