where should the .o files end up?

[Jeff Sturm]

Per Bothner wrote:
> > For compatibility with JDK, I recommend a shell script... you can even
> > call it `javac'.  If I can still find the one I used, I'll post it to
> > the list.
> 
> My plan was that 'gcj -C' would be more-or-less compatible with javac.
> 
> I.e. a javac shell-script should be nothing more than:
>         #!/bin/sh
>         exec gcj -C "$@"

That's fine for bytecode, but sometimes it would be convenient to have
native compilation mimic bytecode compilation, i.e. instead of

  javac f1.java f2.java
  jar -cf classes.jar f1.class f2.class

I want:

  gcj -c f1.java f2.java
  ar -r classes.a f1.o f2.o

Having a command like javac that produces .o files helps a little.  I've
attached my javac-like script (warning: I am an infrequent shell
programmer, and it almost certainly has bugs).  Note that it cannot
compile from bytecode, since it must extract the package name from the
source.

#!/bin/bash

# Read environment vars
: ${GCJDIR:=/usr/local}
: ${CLASSPATH:=.}

# Set defaults
gcj=$GCJDIR/bin/gcj
gcjargs=
objdir=.
classpath=$GCJDIR/share/libgcj.zip:$CLASSPATH
sources=

# Process command args
while [ $# -gt 0 ]; do
    case $1 in
        -g*|-O*)
            gcjargs="$gcjargs $1" ;;
        -classpath)
            classpath=$2
            shift ;;
        -d)
            objdir=$2
            if [ ! -d "$objdir" ]; then
                echo "error: $objdir is not a directory" >&2
                exit 1
            fi
            shift ;;
        -*)
            echo "warning: unrecognized option: $1" >&2 ;;
        *.java)
            sources="$sources $1" ;;
    esac
    shift
done

# Compile each source file in turn, exiting on error
for src in $sources; do
    obj=`basename $src .java`.o
    pkg=`grep '^package' $src | sed 's/package[ \t]*\(.*\);/\1/'`
    if [ "$pkg" ]; then
        pkgdir=`echo $pkg | sed 's,\.,/,'`
    else
        pkgdir=.
    fi
    # FIXME: don't create target directory if gcj doesn't complete
    mkdir -p $objdir/$pkgdir
    err=$?
    if [ $err -ne 0 ]; then exit $err; fi
    $gcj -c $gcjargs --classpath=$classpath $src -o $objdir/$pkgdir/$obj
    err=$?
    if [ $err -ne 0 ]; then exit $err; fi
done


--
Jeff Sturm
jeff.sturm@appnet.com