How to build and run libgcj/gcj snapshots or checkouts

1. Get a GCC snapshot or check out the sources.

2. Make a compile directory

  $ mkdir compile

3. Move the snapshot into the compile dir, e.g.

  $ cd compile
  $ mv ../gcc-20001211.tar.gz .
  $ gunzip *.gz
  $ tar xfv *.tar
  $ ln -s gcc-20001211 gcc

4. Tell the build system you want to build libgcj

  Have a look at the toplevel configure.in (gcc/configure.in) and
  make sure that the variable `noconfigdirs' isn't assigned to
  something (like target-libjava or ${libgcj}.)


  Also, check for platform-specific assignments of `noconfigdirs' with
  ${libgcj}; if ${libgcj} is listed for your platform, remove it before
  configuring.

5. Compile and install gcc/gcj/libgcj

  $ cd compile
  $ mkdir objdir
  $ cd objdir
  $ ../gcc/configure --enable-threads=posix --prefix=/home/joerg/gcc \
    --enable-shared --enable-languages=c++,java \
    --with-as=/opt/gnu/bin/as --with-ld=/opt/gnu/bin/ld
  $ make bootstrap
  $ make
  $ make install

The Boehm GC is the collector picked up by default.

If you compile under GNU/Linux you could omit the last two options. Under
Solaris you'll need them. If you omit '--prefix' the compiled source
will be installed under /usr/local. For more information about
installing gcc and/or configuration options see:

  http://gcc.gnu.org/install/

6. Adjust your environment

Reflect your choice of --prefix value to your environment. For csh
compatible shells, this would be something like the following:

setenv PATH /home/joerg/gcc/bin:$PATH
setenv LD_LIBRARY_PATH /home/joerg/gcc/lib

7. Edit a file HelloWorld.java

  public class HelloWorld {
    public static void main(String [] args) {
      System.out.println("Hello");
    }
  }

8. Compile and run HelloWorld

 $ gcj --main=HelloWorld -o HelloWorld HelloWorld.java
 $ ./HelloWorld