GNUstep under Ubuntu Linux

From GNUstepWiki

Objective-C under Ubuntu Linux

Compiling Everything from Scratch (Ubuntu 14.04, 15.04)

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.

(See below for Ubuntu 12.04 help.)

Reference manuals for GNUStep, including available APIs, etc, are available at


sudo dpkg --add-architecture i386
sudo apt-get update
sudo apt-get -y install build-essential git subversion ninja cmake libffi-dev libxml2-dev \
libgnutls-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

sudo apt-get -y install python-dev libncurses5-dev doxygen swig libedit-dev

cd ~
git clone git://
svn co
git clone

# OBTAIN, COMPILE, INSTALL THE LATEST LLVM/clang. (Doing apt-get install clang instead may or may not work.)
svn co llvm
cd llvm/tools
svn co clang
svn co 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++

clang -v
clang++ -v

cd ~/libobjc2
rm -rf build
mkdir build
cd build
cmake ..
make -j8
sudo -E make install

cd ~/core/make
./configure --enable-debug-by-default --with-layout=gnustep --enable-objc-nonfragile-abi
make && sudo -E make install
echo ". /usr/GNUstep/System/Library/Makefiles/" >> ~/.bashrc

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

sudo /sbin/ldconfig

cd ~/core/base/
make -j8
sudo -E make install

cd ~/libdispatch
rm -rf libdispatch-build
mkdir libdispatch-build && cd libdispatch-build
sudo make install
sudo ldconfig

cd ~/core/gui
make -j8
sudo -E make install

cd ~/core/back
make -j8
sudo -E make install

echo "Install is done. Open a new terminal or type source ~/.bashrc"

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.

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

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

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" );

   return 0;


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;


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;


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");

# ======================================================================
# ======================================================================


clang `gnustep-config --objc-flags` `gnustep-config --objc-libs` -fobjc-runtime=gnustep -fblocks -fobjc-arc -lobjc  blocktest.m

clang `gnustep-config --objc-flags` `gnustep-config --objc-libs` -fobjc-runtime=gnustep -fblocks -lobjc -ldispatch -lgnustep-base  Fraction.m helloGCD_objc.m

clang `gnustep-config --objc-flags` `gnustep-config --objc-libs`  -fobjc-runtime=gnustep -fblocks -lobjc -fobjc-arc -ldispatch -lgnustep-base -lgnustep-gui  guitest.m


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

GUITest_OBJC_FILES = guitest.m

include \$(GNUSTEP_MAKEFILES)/application.make

openapp ./

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-1.8.1 (The current version number can be had by looking at the latest ANNOUNCE filename in (e.g., ANNOUNCE.1.8.1))

Ubuntu 12.04 Help

On Ubuntu 12.04, the default installed version of CMake is 2.8.7 but you need 2.8.8 or later to compile LLVM. And the default installed version of GCC and G++ is 4.6 but you need 4.8 or later to compile LLVM.

For CMake, the solution is to download and compile CMake yourself. Use the existing CMake 2.8.7 and then replace it:

  1. Download the latest CMake version from the CMake web site (, and uncompress it in a folder.
  2. Create a _build directory in the CMake sources folder.
  3. From the _build directory, run the following commands to build and install CMake from sources:
cpack -G DEB
sudo apt-get remove cmake cmake-data
sudo dpkg -i cmake*.deb

To get GCC and G++ 4.8, do the following:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-4.8 g++-4.8
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 50
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 50

You should be good to go.