#!/bin/sh
# file: mkshlib.lnx	G. Moody	26 January 1995
#			Last revised:	15 April 1997 (comments only)
# Generate an a.out-format shared DB library under Linux
#
# If you are simply installing the DB Software Package under Linux, you do not
# need to recompile the shared DB library;  the normal installation procedure
# installs precompiled versions of it.
#
# You might wish to recompile the shared DB library if you have added support
# for other signal or annotation file formats to the library sources.  By
# recompiling and reinstalling the shared DB library, you can enable existing
# DB applications to support your formats without recompiling the applications
# themselves.
#
# Rather than using this shell script, you should compile an ELF-format shared
# library (using `make slib') if your Linux system supports it (and you should
# consider upgrading your Linux system if it does not yet support ELF).  ELF is
# the format used by all new versions of Linux, and a.out format is rapidly
# becoming obsolete.
#
# Keep in mind that the shared DB library is not *necessary* in any case;  you
# can always link your programs with libdb.a (the static library) if you can't
# rebuild the shared library.
#
# If, despite the above, you still wish to recompile the shared DB library in
# a.out format, run this shell script from within the directory that contains
# the DB library sources.  The programs `getvars', `getfuncs', `getsize',
# `mkimage', `mkstubs', and `verify-shlib', if not installed on your system,
# can be obtained by anonymous ftp from tsx-11.mit.edu;  get
#    pub/linux/packages/GCC/src/tools-2.16.tar.gz
# (or a later version if available).   The `tools' package also includes
# `jumpas', installed as /usr/bin/jumpas and used by gcc within this script as
# a replacement for the standard `as' assembler.
#
# Making an a.out-format shared library work under Linux is a bit tricky.
# Before you consider changing anything in this script, read the documentation
# that comes with `tools' and study the example included with `tools'
# carefully.  Note that (at least as of version 2.16) the documentation omits
# several crucial details, so you MUST study the example if you hope to
# understand how this process works!
#
# A particularly thorny problem is that all a.out-format shared libraries must
# contain unique load addresses between 0x60000000 and 0xc0000000.  The
# standard Linux and X11 libraries have been assigned addresses at the lower
# end of this range (from 0x60000000 through 0x665fffff, as of version 2.16).
# I have arbitrarily selected 0x9f000000 for the DB library load address.
# Although the documentation for `tools' suggests that distributors of shared
# libraries may wish to register their libraries' load addresses to avoid
# conflicts, I have not done so, suspecting that the DB library will be of
# interest to a rather small subset of Linux users.  I have simply chosen an
# address that I hope will be well clear of conflicts, at least for a while.
# If you need to change it, do so, but you will need in this case to re-link
# your programs as well.
#
# At the end of this script, `verify-shlib' should report that libdb.so.* and
# libdb.sa have identical addresses.  If it reports *any* discrepancies, these
# must be resolved before continuing, or your DB applications will crash.
#
# Please let me know if you encounter problems using this script.  Thanks!
# -- george@hstbme.mit.edu

case `uname -s` in
   Linux) ;;
   *) exit 1 ;;
esac

# The library version number must be passed in to this script as the first
# and only argument.
case $# in
   1) VERSION=$1 ;;
   *) echo "usage: $0 version-number"
      exit 1 ;;
esac

# Note that JUMP_DIR must be an absolute pathname of a directory.
JUMP_DIR=`pwd`/jump
export JUMP_DIR
JUMP_LIB=libdb
export JUMP_LIB
LOAD_ADDR=0x9f000000
LIB_NAME=libdb
JUMP_SIZE=0x4000
GOT_SIZE=0x2000
OBJS='dbinit.o annot.o signal.o calib.o dbio.o'

# It shouldn't be necessary to delete the previous JUMP_DIR, but if we don't,
# and we are running as root, getvars and getfuncs complain that they can't
# read jump.log.
rm -rf $JUMP_DIR
mkdir -p $JUMP_DIR
make clean
make "CC=gcc -B/usr/bin/jump -I/usr/local/include" lib
ranlib $LIB_NAME.a
cd jump
getvars
getfuncs
rm jump.log
cd ..
make clean
make "CC=gcc -B/usr/bin/jump -I/usr/local/include" lib
cd jump
getsize >jump.vars-new
cd ..
mkimage -l $LIB_NAME -v $VERSION -a $LOAD_ADDR -j $JUMP_SIZE -g $GOT_SIZE -- \
 $OBJS -lc `gcc --print-libgcc-file-name` -lc
mkstubs -l $LIB_NAME -v $VERSION -a $LOAD_ADDR -j $JUMP_SIZE -g $GOT_SIZE -- \
 $LIB_NAME
if
 verify-shlib -l $LIB_NAME.so.$VERSION $LIB_NAME.sa | grep -q "identical"
then
 echo The shared DB library was built successfully.
 exit 0
else
 echo The shared DB library was not built successfully.
 echo Review `pwd`/verify.out and correct the errors before continuing.
 exit 1
fi