building gcc against eclipse?

Thu Nov 12 16:53:00 GMT 2009

On Tue, Nov 10, 2009 at 10:00:29AM +0000, Andrew Haley wrote:
> Jack Howarth wrote:
>> In fink, we have been building the gcj ecj1 support by
>> copying the ecj-latest.jar file from ftp://sourceware.org/pub/java
>> into the top level of the gcc source directory. I would like to try
>> building gcc on darwin with the eclipse compiler instead. We have
>> a fink ecj package which provides...
>>>> /.
>> /sw
>> /sw/bin
>> /sw/bin/ecj
>> /sw/share
>> /sw/share/doc
>> /sw/share/doc/ecj
>> /sw/share/doc/ecj/about.html
>> /sw/share/java
>> /sw/share/java/ecj
>> /sw/share/java/ecj/ecj.jar
>>>> How exactly does one build the gcj against this ecj compiler? Would 
>> creating a symlink in the toplevel gcc directory to
>> /sw/share/java/ecj/ecj.jar be sufficient to cause the installed
>> eclipse compiler to be used for ecj1?
>> We configure for Fedora with --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
> You don't have to copy that jar into the toplev of srcdir.
>> Andrew.

Andrew,
 Would there be any possible differences in the code execution of gcj when built
with the stock ftp://sourceware.org/pub/java/ecj-latest.jar compared to the ecj.jar
from eclipse? My initial attempts at building a usable gcj with eclipse's ecj.jar
failed due to undefined symbols for org.eclipse.jdt.internal.compiler.batch.GCCMain
at runtime for ecj1. 
 I noticed that the fedora 12 gcc specfile at...
http://cvs.fedoraproject.org/viewvc/rpms/gcc/F-12/gcc.spec?revision=1.90&view=markup
has a section...
 %if %{build_java}
 %if !%{bootstrap_java}
 # If we don't have gjavah in $PATH, try to build it with the old gij
 mkdir java_hacks
 cd java_hacks
 cp -a ../../libjava/classpath/tools/external external
 mkdir -p gnu/classpath/tools
 cp -a ../../libjava/classpath/tools/gnu/classpath/tools/{common,javah,getopt} gnu/classpath/tools/
 cp -a ../../libjava/classpath/tools/resource/gnu/classpath/tools/common/Messages.properties gnu/classpath/tools/common
 cp -a ../../libjava/classpath/tools/resource/gnu/classpath/tools/getopt/Messages.properties gnu/classpath/tools/getopt
 cd external/asm; for i in `find . -name \*.java`; do gcj --encoding ISO-8859-1 -C $i -I.; done; cd ../..
 for i in `find gnu -name \*.java`; do gcj -C $i -I. -Iexternal/asm/; done
 gcj -findirect-dispatch -O2 -fmain=gnu.classpath.tools.javah.Main -I. -Iexternal/asm/ `find . -name \*.class` -o gjavah.r
eal
 cat > gjavah <<EOF
 #!/bin/sh
 export CLASSPATH=`pwd`${CLASSPATH:+:$CLASSPATH}
 exec `pwd`/gjavah.real "\$@"
 EOF
 chmod +x `pwd`/gjavah
 cat > ecj1 <<EOF
 #!/bin/sh
 exec gij -cp /usr/share/java/eclipse-ecj.jar org.eclipse.jdt.internal.compiler.batch.GCCMain "\$@"
 EOF
 chmod +x `pwd`/ecj1
 export PATH=`pwd`${PATH:+:$PATH}
 cd ..
 %endif
 %endif
This would be difficult to implement in fink for darwin since we don't have legacy gij/gcj compiler to
leverage from the system compilers. Is there another way to get around the issue of the undefined
org.eclipse.jdt.internal.compiler.batch.GCCMain symbol in ejc1 when using the ecj.jar from eclipse?
 Jack