#! /bin/bash
#
# For testing commits on a branch.
#
# The script loops through all commits in a branch (or between two given commits),
# checks out each, builds INET, and launches a script that runs some simulations.
# The output of the simulations MUST NOT change for commits that are just refactoring,
# fix an unrelated bug, or introduce an unrelated new feature.
#
# The commits that change the output of the simulations are tagged in git, so they
# can be viewed using "gitk --all".
#
# The script run by default is a "print-fingerprints" script that runs a series of
# simulations, and greps the error messages and fingerprint messages from them.
# So, effectively the script checks which commits change the fingerprint. The
# fingerprint change then must be justified by the changes in the commit.
#

# range of commits to test; edit to your needs
ENDREV=topic/etherfixes
STARTREV=integration

# the command to run on each commit
COMMAND=./print-fingerprints

# the label (actually, branch) names added to commits where command output changes
LABEL=fingerprint-change

INET_ROOT=../../..

# get the list of commits
commits=`git rev-list --reverse $STARTREV..$ENDREV || exit 1`

# make clean
(cd .. && make cleanall)
rm -rf work
mkdir work

echo > work/.lastoutput

i=0
for commit in $commits; do
    (( i += 1 ))

    echo
    echo ---------------------------------------------------
    echo -n $i ": "
    git log -n 1 --pretty=oneline $commit | cat || exit 1
    git checkout -q $commit || exit 1

    git branch -d "$LABEL-$i" 2>/dev/null

    echo "Building..."
    (cd $INET_ROOT && make makefiles)
    (cd $INET_ROOT && make -j2) > work/build.$i.$commit 2>&1 || continue  # skip checks on build error

    echo "Collecting fingerprints..."
    $COMMAND > work/output.$i.$commit || exit 1

    if diff work/output.$i.$commit work/.lastoutput > /dev/null; then
        echo "script output unchanged"
    else
        echo "CHANGE DETECTED! Tagging with '$LABEL-$i'"
        git branch -f "$LABEL-$i"
    fi

    cp work/output.$i.$commit work/.lastoutput
done