gitrev.sh

#!/bin/bash
#
# Copyright (c) 2020 - 2021, ETH Zurich, Computer Engineering Group (TEC)
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#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
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# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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# OF THE POSSIBILITY OF SUCH DAMAGE.
#
#
# writes the GIT hash and compile date into the file gitrev.h
#

OUTFILE="../Inc/gitrev.h"
GITSHA=$(git rev-parse HEAD | head -c 8)
GITSHA_INT32=$(echo $(( 16#$GITSHA)))

# get the current timestamp, with hourly granularity (to prevent frequent recompilation of the code due to changing timestamp)
CURRTIME=$(date +%s -d "$(date +'%F %H:00:00')")

# only update the file if the content has changed
NEWCONTENT="\n#ifndef __GITREV_H\n#define __GITREV_H\n\n#define GIT_REV       \"${GITSHA}\"\n#define GIT_REV_INT   ${GITSHA_INT32}\n#define BUILD_TIME    ${CURRTIME}\n\n#endif /* __GITREV_H */"

grep "${GITSHA}" $OUTFILE > /dev/null && grep "${CURRTIME}" $OUTFILE > /dev/null
if [ $? -ne 0 ]; then
  printf "$NEWCONTENT" > $OUTFILE
  echo "file $OUTFILE updated"
else
  echo "file content unchanged"
fi