--
-A lot of the standard library files come from the GNU Classpath project.
-<http://www.gnu.org/software/classpath/>
-The libgcj and Classpath project have officially merged, but the merge
-is not yet complete. Our eventual goal is for Classpath to be an upstream
-source provider for libgcj, however it will be some time before this becomes
-reality: libgcj and Classpath have different implementations of many core
-java classes. In order to merge them, we need to select the best (most
-efficient, cleanest) implementation of each method/class/package, resolve
-any conflicts created by the merge, and test the final result.
-
-The merged files can be recognized by the standard Classpath copyright
-comments at the top of the file. If you make changes to these files
-then you should also check in the fix to Classpath. For small changes
-it may be easier to send a patch to the classpath mailinglist. For
-large changes, if you have direct write access to the libgcj tree,
-then you will also need to get a Classpath account and do the work
-yourself.
-<http://mail.gnu.org/mailman/listinfo/classpath/>
-<mailto:classpath@gnu.org>
-
-If you merge a libgcj class with a classpath class then you must update the
-copyright notice at the top of the file so others can see that this is a
-shared libgcj/classpath file.
+If you plan to modify a .java file, you will need to configure with
+--enable-java-maintainer-mode. In order to make this work properly,
+you will need to have 'ecj1' and 'gjavah' executables in your PATH at
+build time.
+
+One way to do this is to download ecj.jar (see contrib/download_ecj)
+and write a simple wrapper script like:
+
+ #! /bin/sh
+ gij -cp /home/tromey/gnu/Generics/trunk/ecj.jar \
+ org.eclipse.jdt.internal.compiler.batch.GCCMain \
+ ${1+"$@"}
+
+For gjavah, you can make a tools.zip from the classes in
+classpath/lib/tools/ and write a gjavah script like:
+
+ #! /bin/sh
+ dir=/home/tromey/gnu/Generics/Gcjh
+ gij -cp $dir/tools.zip \
+ gnu.classpath.tools.javah.Main \
+ ${1+"$@"}
+
+Another way to get a version of gjavah is to first do a
+non-maintainer-mode build and use the newly installed gjavah.
+
+--
+
+To regenerate libjava/configure, first run aclocal passing the flags
+found near the top of Makefile.am, then autoconf. H. J. Lu writes that
+this can be done using these commands:
+
+ cd libjava &&
+ rm -f aclocal.m4 &&
+ ACFLAGS=$(grep "^ACLOCAL_AMFLAGS" Makefile.in | sed -e "s/ACLOCAL_AMFLAGS[ \t ]*=//") &&
+ aclocal-1.9 $ACFLAGS &&
+ rm -f configure &&
+ autoconf-2.59 &&
+ rm -fr autom4te.cache
+
+See the GCC documentation which auto* versions to use.
+
+--
+
+libgcj uses GNU Classpath as an upstream provider. Snapshots of
+Classpath are imported into the libgcj source tree. Some classes are
+overridden by local versions; these files still appear in the libgcj
+tree.
+
+To import a new release:
+
+- Check out a classpath snapshot or take a release tar.gz file.
+ I use 'cvs export' for this. Make a tag to ensure future hackers
+ know exactly what revision was checked out; tags are of the form
+ 'libgcj-import-DATE' (when using a tagged checkout do:
+ - ./autogen.sh && ./configure && make dist
+ to get a proper .tar.gz for importing below).
+- Get a svn checkout of
+ svn+ssh://gcc.gnu.org/svn/gcc/branches/CLASSPATH/libjava/classpath
+ this contains "pure" GNU Classpath inside the GCC tree.
+- Clean it up and get the files from a new version:
+ - find classpath -type f | grep -v '/\.svn' | grep -v '/\.cvs' | xargs rm
+ - tar zxf classpath-x.tar.gz
+ - cp -r classpath-x/* classpath
+- Add/Remove files:
+ - svn status classpath | grep ^\! | cut -c8- | xargs svn remove
+ - svn status classpath | grep ^\? | cut -c8- | xargs svn add
+- If there are any empty directories now they can be removed. You can find
+ candidates (dirs with files removed) with:
+ - for i in `svn status classpath | grep ^D | cut -c8-`; \
+ do ls -d `dirname $i`; done | uniq
+- Update vendor branch
+ - svn commit classpath
+- Note the new revision number (Xrev)
+- Get a fresh svn trunk checkout and cd gcc/libjava
+- Merge the changes between classpath versions into the trunk.
+ svn merge -rXrev-1:Xrev \
+ svn+ssh://gcc.gnu.org/svn/gcc/branches/CLASSPATH/libjava/classpath \
+ classpath
+- Resolve any conflicts pointed out by svn status classpath | grep ^C
+ - Makefile.in files will be regenerated in the next step.
+ - Other files should have a "GCJ LOCAL" comment, and/or are mentioned
+ in the classpath/ChangeLog.gcj file.
+ (Don't forget to svn resolved files.)
+- Use auto* to create configure, Makefile.in, etc
+ Make sure you have Automake 1.9.6 installed. Exactly that version!
+ You have to make sure to use the gcc libtool.m4 and gcc lt* scripts
+ cd .../classpath
+ cp ../../lt* .
+ cp ../../config.sub ../../config.guess .
+ aclocal -I m4 -I ../.. -I ../../config
+ autoconf
+ autoheader
+ automake
+ rm -rf autom4te.cache
+ cd ..
+ scripts/makemake.tcl > sources.am
+ automake
+- Remove the generated class and header files:
+ find classpath -name '*.class' | xargs -r rm -f
+ find gnu java javax org sun -name '*.h' \
+ | xargs -r grep -Fl 'DO NOT EDIT THIS FILE - it is machine generated' \
+ | xargs -r rm -f
+- Build, fix, till everything works.
+ Be sure to build all peers (--enable-java-awt=gtk,xlib,qt
+ --enable-gconf-peer --enable-gstreamer-peer)
+ Be sure to update gnu/classpath/Configuration.java to reflect
+ the new version
+ Possibly update the gcj/javaprims.h file with scripts/classes.pl
+ (See below, it can only be done after the first source->bytecode
+ pass has finished.)
+ You will need to configure with --enable-java-maintainer-mode and you
+ will need to update the .class files and generated CNI header files in
+ your working tree
+- Add/Remove newly generated files:
+ - svn status classpath | grep '^!.*\.class$' | cut -c8- | xargs svn remove
+ - svn status classpath | grep '^?' | cut -c8- | xargs svn add
+ - svn status gnu java javax org sun | grep '^!.*\.h$' | cut -c8- | xargs svn remove
+ - svn status gnu java javax org sun | grep '^?' | cut -c8- | xargs svn add
+
+Over time we plan to remove as many of the remaining divergences as
+possible.
+
+File additions and deletions require running scripts/makemake.tcl
+before running automake.
+
+--
+
+In general you should not make any changes in the classpath/
+directory. Changes here should come via imports from upstream.
+However, there are three (known) exceptions to this rule:
+
+* In an emergency, such as a bootstrap breakage, it is ok to commit a
+ patch provided that the problem is resolved (by fixing a compiler
+ bug or fixing the Classpath bug upstream) somehow and the resolution
+ is later checked in (erasing the local diff).
+
+* On a release branch to fix a bug, where a full-scale import of
+ Classpath is not advisable.
+
+* We maintain a fair number of divergences in the build system.
+ This is a pain but they don't seem suitable for upstream.
--
-If you need to add new java files to libgcj then you have to edit the
-Makefile.am file in the top (libjava) directory. And run automake.
-But note the following (thanks to Bryce McKinlay):
+You can develop in a GCC tree using a CVS checkout of Classpath, most
+of the time. (The exceptions are when an incompatible change has been
+made in Classpath and some core part of libgcj has not yet been
+updated.)
+
+The way to set this up is very similar to importing a new version of
+Classpath into the libgcj tree. In your working tree:
+
+* cd gcc/libjava; rm -rf classpath
+* cvs co classpath
+* cd classpath
+ Now run the auto tools as specified in the import process; then
+ cd ..
+* Run 'scripts/makemake.tcl > sources.am' in the source tree
+* Run automake for libgcj
-> Do you know the magic dance I have to do when adding files to Makefile.am
-> so they will appear in Makefile.in and finally in the user generated
-> Makefile?
-Yup, you need the magic libgcj automake ;-)
+Now you should be ready to go.
-<ftp://sources.redhat.com/pub/java/automake-gcj-1.4.tar.gz>
+If you are working in a tree like this, you must remember to run
+makemake.tcl and automake whenever you update your embedded classpath
+tree.
-Install that (don't worry, it should still work for other projects), add your
-files to the Makefile.am, then just type "automake" and it will regenerate the
-Makefile.in. Easy!
+--
-Tom Tromey adds:
If you add a class to java.lang, java.io, or java.util
(including sub-packages, like java.lang.ref).
* Go to the `namespace java' line, and delete that entire block (the
entire contents of the namespace)
-* Then insert the output of `perl ../scripts/classes.pl' into the file
- at that point.
-
-If you're generating a patch there is a program you can get to do an
-offline `cvs add' (it will fake an `add' if you don't have write
-permission yet). Then you can use `cvs diff -N' to generate the
-patch. See http://www.red-bean.com/cvsutils/
-
+* Then insert the output of `perl scripts/classes.pl' into the file
+ at that point. This must be run from the source tree, in
+ libjava/classpath/lib; it uses the .class file name to determine
+ what to print.
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