Bash script to demonstrate the difference in size when stripping symbols and using -Os

reduced_size.sh

#!/bin/bash

set -eo pipefail

function env_exists() {
    conda env list | cut -d ' ' -f 1 | grep -v '#' | grep "${1}" 1> /dev/null
}

envname="skimage-test-opt"

# if our env exists, blow it away
if [ $(env_exists "${envname}") ]; then
    conda env remove -n "${envname}" -y
fi

# create an env to test with
conda create -n "${envname}" scikit-image cython nomkl -y -c conda-forge

cloneloc="/tmp/"${envname}""
rm -rf "${cloneloc}"

# shallow-ish clone of scikit image
git clone --depth=20 https://github.com/scikit-image/scikit-image "${cloneloc}"

skimage_hash=49f964e6babdb6fd48bd94d49c63049d7b58a432

# go to the clone
pushd "${cloneloc}"

# reset to a hash we know we can patch
git reset --hard "${skimage_hash}"

# activate the environment
source activate "${envname}"

# export the env in case someone wants to look at what's installed
conda env export > "${envname}.yml"

echo "Building WITHOUT size optimization and stripping ..."
python setup.py develop > /dev/null 2>&1

# compute the total size of dynamic shared objects built before optimization
before_total=$(du -hc $(find "$PWD" -name '*.so') | grep total)

# apply the patch to setup.py that strips all unnecessary symbols, builds for
# size and does not include debug symbols
cat <<EOF | git apply
diff --git a/setup.py b/setup.py
index 74115d5d..033b5e5a 100644
--- a/setup.py
+++ b/setup.py
@@ -81,6 +81,11 @@ def configuration(parent_package='', top_path=None):
     config.add_subpackage('skimage')
     config.add_data_dir('skimage/data')
 
+    for ext in config.ext_modules:
+        ext.extra_link_args.append('-Wl,--strip-all')
+        ext.extra_compile_args.append('-Os')
+        ext.extra_compile_args.append('-g0')
+
     return config
 
 
EOF

echo "Cleaning ..."
python setup.py clean
find . -name '*.so' -delete

echo "Building WITH size optimization and stripping ..."
python setup.py develop > /dev/null 2>&1

# compute the total size of dynamic shared objects built after optimization
after_total=$(du -hc $(find "$PWD" -name '*.so') | grep total)

echo "WITHOUT optimization: "${before_total}""
echo "WITH    optimization: "${after_total}""