GNUstep under Ubuntu Linux

Objective-C under Ubuntu Linux

Compiling Everything from Scratch

The following script compiles and installs everything needed for Objective-C 2.0 from scratch. The script uses clang and libobjc2 for all the awesome new features like ARC, blocks, etc.

Reference manuals for GNUStep, including available APIs, etc, are available at http://www.gnustep.org/developers/documentation.html

NOTE: Unless you have a need for the above features, its recommended to install from the default repos as often the scripts below have issues.

sudo apt install gnustep

Ubuntu 19.04

In addition to building everything, this script also provides the ability to build the most recent version of four apps: Project Center, Gorm, GWorkspace, and System Preferences.

#!/bin/bash

# Show prompt function
function showPrompt()
{
  if [ "$PROMPT" = true ] ; then
    echo -e "\n\n"
    read -p "${GREEN}Press enter to continue...${NC}"
  fi
}

# Set colors
GREEN=`tput setaf 2`
NC=`tput sgr0` # No Color

# Set to true to also build and install apps
APPS=true

# Set to true to pause after each build to verify successful build and installation
PROMPT=false

# Install Requirements
sudo apt update

echo -e "\n\n${GREEN}Installing dependencies...${NC}"

sudo dpkg --add-architecture i386  # Enable 32-bit repos for libx11-dev:i386
sudo apt-get update
sudo apt -y install clang git cmake libffi-dev libxml2-dev \
libgnutls28-dev libicu-dev libblocksruntime-dev libkqueue-dev libpthread-workqueue-dev autoconf libtool \
libjpeg-dev libtiff-dev libffi-dev libcairo-dev libx11-dev:i386 libxt-dev libxft-dev

if [ "$APPS" = true ] ; then
  sudo apt -y install curl
fi

# Create build directory
mkdir GNUstep-build
cd GNUstep-build

# Set clang as compiler
export CC=clang
export CXX=clang++

# Checkout sources
echo -e "\n\n${GREEN}Checking out sources...${NC}"
#git clone https://github.com/nickhutchinson/libdispatch.git
git clone https://github.com/plaurent/libdispatch.git
cd libdispatch
  git checkout fix_major_missing_symbol_for_ubuntu1904
cd ..
git clone https://github.com/gnustep/libobjc2.git
git clone https://github.com/gnustep/tools-make.git
git clone https://github.com/gnustep/libs-base.git
git clone https://github.com/gnustep/libs-gui.git
git clone https://github.com/gnustep/libs-back.git

if [ "$APPS" = true ] ; then
  git clone https://github.com/gnustep/apps-projectcenter.git
  git clone https://github.com/gnustep/apps-gorm.git
  git clone https://github.com/gnustep/apps-gworkspace.git
  git clone https://github.com/gnustep/apps-systempreferences.git
fi

showPrompt

# Build GNUstep make first time
echo -e "\n\n"
echo -e "${GREEN}Building GNUstep-make for the first time...${NC}"
cd tools-make
# git checkout `git rev-list -1 --first-parent --before=2017-04-06 master` # fixes segfault, should probably be looked at.
./configure --enable-debug-by-default --with-layout=gnustep  --enable-objc-arc  --with-library-combo=ng-gnu-gnu
make -j8
sudo -E make install

. /usr/GNUstep/System/Library/Makefiles/GNUstep.sh
echo ". /usr/GNUstep/System/Library/Makefiles/GNUstep.sh" >> ~/.bashrc

showPrompt

# Build libdispatch
echo -e "\n\n"
echo -e "${GREEN}Building libdispatch...${NC}"
cd ../libdispatch
rm -Rf build
mkdir build && cd build
../configure  --prefix=/usr
make
sudo make install
sudo ldconfig

showPrompt

# Build libobjc2
echo -e "\n\n"
echo -e "${GREEN}Building libobjc2...${NC}"
cd ../../libobjc2
rm -Rf build
mkdir build && cd build
cmake ../ -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang -DCMAKE_ASM_COMPILER=clang -DTESTS=OFF
cmake --build .
sudo -E make install
sudo ldconfig

export LDFLAGS=-ldispatch

showPrompt

OBJCFLAGS="-fblocks -fobjc-runtime=gnustep-2.0"

# Build GNUstep make second time
echo -e "\n\n"
echo -e "${GREEN}Building GNUstep-make for the second time...${NC}"
cd ../../tools-make
./configure --enable-debug-by-default --with-layout=gnustep --enable-objc-arc --with-library-combo=ng-gnu-gnu
make -j8
sudo -E make install

. /usr/GNUstep/System/Library/Makefiles/GNUstep.sh

showPrompt

# Build GNUstep base
echo -e "\n\n"
echo -e "${GREEN}Building GNUstep-base...${NC}"
cd ../libs-base/
./configure
make -j8
sudo -E make install

showPrompt

# Build GNUstep GUI
echo -e "\n\n"
echo -e "${GREEN} Building GNUstep-gui...${NC}"
cd ../libs-gui
./configure
make -j8
sudo -E make install

showPrompt

# Build GNUstep back
echo -e "\n\n"
echo -e "${GREEN}Building GNUstep-back...${NC}"
cd ../libs-back
./configure
make -j8
sudo -E make install

showPrompt

. /usr/GNUstep/System/Library/Makefiles/GNUstep.sh

if [ "$APPS" = true ] ; then
  echo -e "${GREEN}Building ProjectCenter...${NC}"
  cd ../apps-projectcenter/
  make -j8
  sudo -E make install

  showPrompt

  echo -e "${GREEN}Building Gorm...${NC}"
  cd ../apps-gorm/
  make -j8
  sudo -E make install

  showPrompt

  echo -e "\n\n"
  echo -e "${GREEN}Building GWorkspace...${NC}"
  cd ../apps-gworkspace/
  ./configure
  make -j8
  sudo -E make install

  showPrompt

  echo -e "\n\n"
  echo -e "${GREEN}Building SystemPreferences...${NC}"
  cd ../apps-systempreferences/
  make -j8
  sudo -E make install

fi

echo -e "\n\n"
echo -e "${GREEN}Install is done. Open a new terminal to start using.${NC}"

Older versions of Ubuntu (18.04 or earlier)

On older versions of Ubuntu (including 18.04) you won't have a recent enough clang. If you want to build on an older Ubuntu (like 18.04) you should:

(1) Set OBJCFLAGS="-fblocks -fobjc-runtime=gnustep-1.9" in the script above

(2) git checkout 1.9 on libobjc2

(3) Build a new clang manually (instead of apt install clang):

svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm
cd llvm/tools
svn co http://llvm.org/svn/llvm-project/cfe/trunk clang
svn co http://llvm.org/svn/llvm-project/lldb/trunk lldb
cd ~/llvm
rm -rf build
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE:STRING=Release ..    # If you don't choose Release, it defaults to Debug which takes lots more space
make -j8   # 8=your number of build CPUs
echo "export PATH=\$PATH:~/llvm/build/bin" >> ~/.bashrc
echo "export CC=clang"  >> ~/.bashrc
echo "export CXX=clang++" >> ~/.bashrc
export PATH=$PATH:~/llvm/build/bin
. ~/.bashrc

export CC=clang
export CXX=clang++

Test Code

The following is some Objective-C source code from the internet. It demonstrates blocks, Grand Central Dispatch, and the use of GNUStep GUI.

#!/bin/bash

cat > blocktest.m << EOF
#include <stdio.h>

int main() {
    void (^hello)(void) = ^(void) {
        printf("Hello, block!\n");
    };
    hello();
    return 0;
}
EOF

cat > helloGCD_objc.m << EOF

#include <dispatch/dispatch.h>
#import <stdio.h>
#import "Fraction.h"

int main( int argc, const char *argv[] ) {
   dispatch_queue_t queue = dispatch_queue_create(NULL, NULL);
   Fraction *frac = [[Fraction alloc] init];

   [frac setNumerator: 1];
   [frac setDenominator: 3];

   // print it
   dispatch_sync(queue, ^{
     printf( "The fraction is: " );
     [frac print];
     printf( "\n" );
   });
   dispatch_release(queue);

   return 0;
}

EOF

cat > Fraction.h << EOF

#import <Foundation/NSObject.h>

@interface Fraction: NSObject {
   int numerator;
   int denominator;
}

-(void) print;
-(void) setNumerator: (int) n;
-(void) setDenominator: (int) d;
-(int) numerator;
-(int) denominator;
@end

EOF


cat > Fraction.m << EOF
#import "Fraction.h"
#import <stdio.h>

@implementation Fraction
-(void) print {
   printf( "%i/%i", numerator, denominator );
}

-(void) setNumerator: (int) n {
   numerator = n;
}

-(void) setDenominator: (int) d {
   denominator = d;
}

-(int) denominator {
   return denominator;
}

-(int) numerator {
   return numerator;
}
@end

EOF



cat > guitest.m << EOF
#import <AppKit/AppKit.h>

int main()
{
  NSApplication *app;  // Without these 2 lines, seg fault may occur
  app = [NSApplication sharedApplication];

  NSAlert * alert = [[NSAlert alloc] init];
  [alert setMessageText:@"Hello alert"];
  [alert addButtonWithTitle:@"All done"];
  int result = [alert runModal];
  if (result == NSAlertFirstButtonReturn) {
    NSLog(@"First button pressed");
  }
}
EOF

# ======================================================================
# COMPILE USING THE FOLLOWING COMMAND LINES, OR CREATE A MAKEFILE
# ======================================================================

# Using COMMAND LINE

clang `gnustep-config --objc-flags` `gnustep-config --objc-libs` -lobjc  blocktest.m
./a.out

clang `gnustep-config --objc-flags` `gnustep-config --objc-libs` -lobjc -ldispatch -lgnustep-base  Fraction.m helloGCD_objc.m
./a.out

clang `gnustep-config --objc-flags` `gnustep-config --objc-libs` -lobjc -fobjc-arc -ldispatch -lgnustep-base -lgnustep-gui  guitest.m
./a.out

# Using MAKEFILE

cat > GNUmakefile << EOF
include \$(GNUSTEP_MAKEFILES)/common.make

APP_NAME = GUITest
GUITest_OBJC_FILES = guitest.m

include \$(GNUSTEP_MAKEFILES)/application.make
EOF

make
openapp ./GUITest.app

General Note: When compiling your own code, it is generally good to tell clang both the family and version of the runtime: -fobjc-runtime=gnustep-2.0 (The current version number can be had by looking at the latest ANNOUNCE filename in https://github.com/gnustep/libobjc2 (e.g., ANNOUNCE.1.8.1))