objcopy_perf.sh

#!/bin/bash

set -euo pipefail

echo creating init file
echo <<EOF > input.S
.section .text
EOF
echo '' > keep_syms.txt
for i in $(seq 0 100000)
do
    echo -e "sym_${i}:\nnop\n" >> input.S
    if [[ ${i} -lt 30000 ]]; then
        echo "sym_${i}" >> keep_syms.txt
    fi
done
echo <<EOF >> input.S
.section .ballast
nop
EOF
echo creating obj file
llvm-mc -triple arm-linux-androideabi -filetype=obj input.S -o out.o
echo creating shared obj file
ld.lld  -shared out.o -o libtestcase.so

echo performing llvm objcopy
\time llvm-objcopy -S --remove-section .ballast  \
    --keep-symbols=keep_syms.txt \
    libtestcase.so libtestcase_smaller.so

echo performing GNU objcopy
\time arm-linux-androideabi-objcopy -S --remove-section .ballast  \
    --keep-symbols=keep_syms.txt \
    libtestcase.so libtestcase_smaller.so