Document support for external archive amalgamation

[gotson]

#464 #466

@michael-o i think we should document this somewhere. The current state of the README and README_BUILD is probably not the best, but seems like a feature for which we should have documentation.

I'm open to suggestions about the documentation.

[michael-o]

I can basically share what I do on HP-UX and FreeBSD. This works quite well and should work on any POSIX-like OS.

[gotson]

I can basically share what I do on HP-UX and FreeBSD. This works quite well and should work on any POSIX-like OS.

I think that would help, you can maybe share here in this issue, and we can figure out where to put that at a later stage.

[michael-o]

This is my example for HP-UX, since I build there everything from source:
Building SQLite:

CPPFLAGS="$CPPFLAGS -DSQLITE_HAVE_ISNAN -DSQLITE_ENABLE_COLUMN_METADATA" \
  LDFLAGS="$LDFLAGS -Wl,+concatrpath -Wl,+b -Wl,$LIBDIR -L$LIBDIR" \
  $CONFIGURE --enable-readline
make install

Note: I don't compile SQLite as part of the JDBC driver because other OSS uses SQLite as well.
Now compiling and linking to the JNI code:

gmake native SQLITE_OBJ=$LIBDIR/libsqlite3.a SQLITE_HEADER=$PREFIX/include/sqlite3.h
cp target/classes/org/sqlite/native/HPUX/ia64_32/libsqlitejdbc.so $LIBDIR

Note: I was not able to link dynamically on HP-UX, I don't know why, but static linking is good enough for me.

On FreeBSD it is a bit simpler, dynamic linking just works with SQLite from Ports:

gmake native SQLITE_OBJ=/usr/local/lib/libsqlite3.so SQLITE_HEADER=/usr/local/include/sqlite3.h JAVAC=javac JAVA=java CC=cc
$ ldd src/main/resources/org/sqlite/native/FreeBSD/x86_64/libsqlitejdbc.so
src/main/resources/org/sqlite/native/FreeBSD/x86_64/libsqlitejdbc.so:
        libsqlite3.so.0 => /usr/local/lib/libsqlite3.so.0 (0x800e00000)
        libc.so.7 => /lib/libc.so.7 (0x80024e000)
        libz.so.6 => /lib/libz.so.6 (0x800684000)
        libm.so.5 => /lib/libm.so.5 (0x8006a1000)
        libthr.so.3 => /lib/libthr.so.3 (0x8006d8000)

I would always prefer an external linked version of SQLite instead of the current amalagation because mostly people don't like to upgrade twice.

[michael-o]

@gotson Let me know whether this is acceptable for you.

[gotson]

@gotson Let me know whether this is acceptable for you.

I think it's a good start, i need to find some time to integrate this in the documentation. Thanks!