#!/bin/bash
# Given a list of header files, compute the bss index that results from
# including them. (See prevent_bss_reordering.h for more information.)

TEMPC=$(mktemp -t bss.XXXXXXX.c)
TEMPO=$(mktemp -t bss.XXXXXXX.o)
trap "rm -f $TEMPC $TEMPO" EXIT

set -e

if [[ $# = 0 ]]; then
    echo "Usage: ./tools/calc_bss.sh file1.h file2.h ..." >&2
    exit 1
fi

if [ -z "$CROSS" ]; then
    CROSS=mips-linux-gnu-
fi

# bss indexing starts at 3
for I in {3..255}; do
    echo "char bss$I;" >> $TEMPC
done
for I in {0..2}; do
    echo "char bss$I;" >> $TEMPC
done

while [[ $# -gt 0 ]]; do
    echo "#include \"$1\"" >> $TEMPC
    shift
done

echo "char measurement;" >> $TEMPC

$(pwd)/tools/ido_recomp/linux/7.1/cc -G 0 -non_shared \
    -Xfullwarn -Xcpluscomm -O2 -g3 -Xcpluscomm -mips2 \
    -I $(pwd)/include/ -I $(pwd)/src/ -I $(pwd)/assets/ -I $(pwd)/build/ \
    -Wab,-r4300_mul -woff 624,649,838,712 -c $TEMPC -o $TEMPO

LINE=$(${CROSS}objdump -t $TEMPO | grep measurement | cut -d' ' -f1)
NUM=$((0x$LINE - 1))
echo "bss index: $NUM"