Getting started with FLEX:
installing GNU Classpath

The FLEX compiler uses the GNU Project's free implementation of the Java standard class libraries, called GNU Classpath. If you are only interested in analyzing Java bytecode you will not (necessarily) need to install GNU Classpath, but if you will if you want to use FLEX to generate executable code.

There are several different ways to install GNU Classpath:

• If you are running a debian system:

  Simply use the command (as root):

  apt-get install classpath jikes-classpath

  FLEX will now find the classpath installation in its standard location. However, you will also want to make sure you are using FLEX properties files which match the version of classpath you have installed. Since debian currently packages Classpath version 0.05 in unstable and 0.04 in testing/stable (check here for the latest package status), you will need to execute something like the following:

  cd ~/Harpoon/Code && make cvs-update-classpath-0.05

  Configure the Runtime with: --with-classpath

• If you wish to use our implementation of Real Time Java:

  Assuming you've checked our FLEX into the ~/Harpoon directory, as recommended:

  cd ~/Harpoon
cvs -d `cat Code/CVS/Root` checkout Classpath
cd Classpath
./build

  and, if you are cross-compiling for StrongARM, you also need:

  cd ~/Harpoon/Classpath && ./build-arm

  Presumably you will also need to set the CLASSPATH_HOME variable in your environment.

  Configure the Runtime with: --with-classpath=$HOME/Harpoon/Classpath/install/lib/classpath

• Otherwise:
  

  It's not too hard to build GNU Classpath direct from GNU's source distribution.

  1. Download classpath-0.05.tar.gz via FTP from alpha.gnu.org/gnu/classpath.
  2. Unpack it in ~/Harpoon:

     cd ~/Harpoon && tar -xzf classpath-0.05.tar.gz

  3. Configure the sources as follows:

     cd ~/Harpoon/classpath-0.05
./configure --with-jikes --enable-jni --prefix=$HOME/Harpoon/classpath-install

  4. Build the sources!

     cd ~/Harpoon/classpath-0.05
make && make install

  5. Finally, point FLEX to the classpath installation by adding this to your ~/.bash_profile:

     export CLASSPATH_HOME=$HOME/Harpoon/classpath-0.05
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$HOME/Harpoon/classpath-install/lib/classpath

     (If you are using csh, some slight changes will be required.)
  6. Make sure FLEX is using appropriate properties files for this version of Classpath:

     cd ~/Harpoon/Code && make cvs-update-classpath-0.05

  7. That's it! You're done!

  Configure the Runtime with: --with-classpath=$HOME/Harpoon/classpath-install/lib/classpath

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cananian Last updated: 21 July 2003