#!/bin/bash

############################################################################
#
# Script for converting the SCST source tree as it exists in the Subversion
# repository to a Linux kernel patch.
#
# Copyright (C) 2008 Bart Van Assche <bart.vanassche@gmail.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation, version 2
# of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
############################################################################

########################
# Function definitions #
########################

# Convert an existing patch.
# $1: path of patch to be added.
# $2: path in kernel tree of file to be patched.
function add_patch {
  if [ ! -e "$1" ]; then
    echo "Error: could not find $1." >&2
    exit 1
  fi

  sed -e "s:^--- [^ ]*:--- orig/$2:" -e "s:^+++ [^ ]*:+++ $2:" < "$1"
}

# Generate a patch for a file to be added to the kernel source tree, and strip
# trailing whitespace from C source files while converting the file to patch
# format.
# $1: path of file to be added.
# $2: path in kernel tree where file should be added.
function add_file {
  local a b

  if [ ! -e "$1" ]; then
    echo "Error: could not find $1." >&2
    exit 1
  fi

  # Skip any files generated by the kernel build process (*.mod.c).
  if [ "${1%.mod.c}" != "$1" ]; then
    return 0;
  fi

  cat <<EOF
diff -uprN orig/$2 $2
--- orig/$2
+++ $2
@@ -0,0 +1,$(wc -l "$1" | { read a b; echo $a; }) @@
EOF
  if [ "${2%.[ch]}" != "$2" ]; then
    sed -e 's/^/+/' -e 's/[ 	]*$//g' < "$1"
  else
    sed -e 's/^/+/' < "$1"
  fi
}


#########################
# Argument verification #
#########################

if [ ! -e scst -o ! -e iscsi-scst -o ! -e srpt ]; then
  echo "Please run this script from inside the SCST subversion source tree."
  exit 1
fi

if [ $# != 1 ]; then
  echo "Usage: $0 <kernel version>."
  exit 1
fi


####################
# Patch Generation #
####################

kernel_version="$1"
kpatch=(                                                                \
  "scst/kernel/scst_exec_req_fifo-${kernel_version}.patch"              \
  "iscsi-scst/kernel/patches/put_page_callback-${kernel_version}.patch" \
)

for p in "${kpatch[@]}"
do
  if [ ! -e "$p" ]; then
    echo "Error: kernel version ${kernel_version} is not supported by SCST."
    echo "(could not find file $p)."
    exit 1
  fi >&2
done


# General kernel patches.

for p in "${kpatch[@]}"
do
  cat "$p"
  echo ''
  echo ''
done


# Directory include/scst/

for f in scst/include/*h
do
  add_file "${f}" "linux-${kernel_version}/include/scst/${f#scst/include/}"
done

for f in iscsi-scst/include/*h
do
add_file "${f}" "linux-${kernel_version}/include/scst/${f#iscsi-scst/include/}"
done


# Directory drivers/

add_patch "scst/kernel/in-tree/Kconfig.drivers.Linux-${kernel_version}.patch" \
          "linux-${kernel_version}/drivers/Kconfig"

add_patch "scst/kernel/in-tree/Makefile.drivers.Linux-${kernel_version}.patch"\
          "linux-${kernel_version}/drivers/Makefile"


# Directory drivers/scst/

add_file "scst/kernel/in-tree/Kconfig.scst" \
         "linux-${kernel_version}/drivers/scst/Kconfig"
add_file "scst/kernel/in-tree/Makefile.scst" \
         "linux-${kernel_version}/drivers/scst/Makefile"


for f in scst/src/*.[ch]
do
  add_file ${f} linux-${kernel_version}/drivers/scst/${f#scst/src/}
  echo ''
  echo ''
done


# Directory drivers/scst/dev_handlers/

add_file "scst/kernel/in-tree/Makefile.dev_handlers" \
         "linux-${kernel_version}/drivers/scst/dev_handlers/Makefile"

for f in scst/src/dev_handlers/*.[ch]
do
  add_file ${f} linux-${kernel_version}/drivers/scst/dev_handlers/${f#scst/src/dev_handlers/}
  echo ''
  echo ''
done


# Directory drivers/scst/iscsi-scst/

add_file "iscsi-scst/kernel/Makefile.in-kernel" \
         "linux-${kernel_version}/drivers/scst/iscsi-scst/Makefile"

add_file "iscsi-scst/kernel/Kconfig" \
         "linux-${kernel_version}/drivers/scst/iscsi-scst/Kconfig"

for f in iscsi-scst/kernel/*.[ch]
do
  add_file "${f}" \
      "linux-${kernel_version}/drivers/scst/iscsi-scst/${f#iscsi-scst/kernel/}"
  echo ''
  echo ''
done


# Directory drivers/scst/qla2x00-target/

if false; then

add_file "qla2x00t/qla2x00-target/Makefile.in-kernel" \
         "linux-${kernel_version}/drivers/scst/qla2x00-target/Makefile"

add_file "qla2x00t/qla2x00-target/Kconfig" \
         "linux-${kernel_version}/drivers/scst/qla2x00-target/Kconfig"

add_file "qla2x00t/qla2x_tgt_def.h" \
         "linux-${kernel_version}/drivers/scst/qla2x00-target/qla2x_tgt_def.h"

for f in qla2x00t/qla2x00-target/*.[ch]
do
  add_file "${f}" \
      "linux-${kernel_version}/drivers/scst/qla2x00-target/${f#qla2x00t/qla2x00-target/}"
  echo ''
  echo ''
done

fi


# Directory drivers/infiniband/ulp/srpt/

add_patch "srpt/src/Kconfig.infiniband.Linux-${kernel_version}.patch" \
          "linux-${kernel_version}/drivers/infiniband/Kconfig"

add_patch "srpt/src/Makefile.infiniband.Linux-${kernel_version}.patch" \
          "linux-${kernel_version}/drivers/infiniband/Makefile"

add_file "srpt/src/Kconfig" "drivers/infiniband/ulp/srpt/Kconfig"

add_file "srpt/src/Makefile.in_kernel" "drivers/infiniband/ulp/srpt/Makefile"

for f in srpt/src/*.[ch]
do
  add_file ${f} linux-${kernel_version}/drivers/infiniband/ulp/srpt/${f#srpt/src/}
  echo ''
  echo ''
done