pre-commit

#!/bin/bash

# This commit hook will automatically update the files that have been staged for
# a commit. It will update the copyright date to indicate the correct year. It
# will also apply include-what-you-use to the files, this feature is meant to
# remove extraneous includes and include the headers relevant to each
# particular file, however it is in its alpha stage of development and does
# still contain bugs. Finally, the hook will apply git-format rules to the files
# that are being staged. 
#
# Defaults for using each of the features are shown below:
# License Update:       ON
# Include what you use: OFF
# Clang formatting:     ON
# Clang tidy:           ON
# MARKDOWN_FORMAT_ON:   ON 
# PYTHON_FORMAT_ON:     ON
#
# The default settings can be toggled by defining the following environment 
# variables
#
# export DATE_ON=1 - turns on 
# export DATE_ON=0 - turns off 
#
# export IWYU_ON=1 - turns on 
# export IWYU_ON=0 - turns off
#
# export CLANG_FORMAT_ON=1 - turns on
# export CLANG_FORMAT_ON=0 - turns off
#
# export CLANG_TIDY_ON=1 - turns on
# export CLANG_TIDY_ON=0 - turns off
#
# export HEADER_GUARD_ON=1 - turns on
# export HEADER_GUARD_ON=0 - turns off
#
# export MARKDOWN_FORMAT_ON=1 - turns on
# export MARKDOWN_FORMAT_ON=0 - turns off
#
# export PYTHON_FORMAT_ON=1 - turns on
# export PYTHON_FORMAT_ON=0 - turns off
#
# To use the hook, it must be placed in the .gith/hooks folder of whatever 
# repository is being used. It must also be made executable. 
#
# Assuming I am going to be using repo votca/csg
#
# cp pre-commit votca/csg/.git/hooks/pre-commit
# chmod 777 votca/csg/.git/hooks/pre-commit
#
# Then you should be good to go

################################################################################
# Updating License Date
################################################################################
# Default is on 
if [ -z ${DATE_ON} ] # If not defined turn on
then
  environement_variable_update_license=1
else
  if [ "${DATE_ON}" -eq "1" ]
  then
    environement_variable_update_license=1
  else 
    environement_variable_update_license=0
  fi
fi

update_license_dates_of_altered_files(){
  echo "Updating Copyright date in "$file
  new_date=$(date +%Y)
  sed -i 's/Copyright \(.*\)-.* The/Copyright \1-'"$new_date"' The/g' $file
}

################################################################################
# Checking Header Guard
################################################################################
# Default is on 
if [ -z ${HEADER_GUARD_ON} ] # If not defined turn on
then
  environement_variable_header_guard=1
else
  if [ "${HEADER_GUARD_ON}" -eq "1" ]
  then
    environement_variable_header_guard=1
  else 
    environement_variable_header_guard=0
  fi
fi

check_header_guard_of_altered_files(){
  # Only applies to header files
  if [[ $file == *".h" ]] 
  then
    # Only fixes if already included 
    count=$(grep -c "#ifndef" $file)
    if [ "$count" -ne "0" ] 
    then 
      echo "Updating Header Guard for file $file"
      repo_base=$(basename `git rev-parse --show-toplevel`)
      repo_base=$(echo ${repo_base^^})
      file_base=$(basename -s .h $file)
      file_base=$(echo ${file_base^^})
      sed -i "0,/#ifndef/ s/#ifndef .*/#ifndef VOTCA_${repo_base}_${file_base}_H/" $file
      sed -i "0,/#define/ s/#define .*/#define VOTCA_${repo_base}_${file_base}_H/" $file

      # Find last matching endif
      line_num=$(grep -n "#endif" $file  | tail -n1 | sed 's/:.*//')
      sed -i "${line_num}s/#endif.*/#endif \/\/ VOTCA_${repo_base}_${file_base}_H/" $file
    fi
  fi
}

################################################################################
# Updating Includes
################################################################################
# Default is off
if [ -z ${IWYU_ON} ] # If not defined turn off 
then
  echo "Include what you use is not set" 
  environement_variable_apply_include_what_you_use=0
else
    if [ "1" -eq "${IWYU_ON}" ]
    then
      environement_variable_apply_include_what_you_use=1
    else
      environement_variable_apply_include_what_you_use=0
    fi
fi
# This variable will ignore any includes proposed by include-what-you-use 
# that are from the boost library, this was included as IWYU is in the alpha
# phase of development and tends to screw up with third party libraries. 
ignore_includes=()

apply_include_what_you_use(){
  echo "Applying IWYU to file "$file
  data=$(include-what-you-use $file 2>&1 )
  echo "$data" | fix_includes.py $file
  extra_includes=$(echo "$data" | awk '/should add these lines/,/should remove these lines/ { print $2}' )

  # Filter includes
  filtered_includes=()
  for ignore in ${ignore_includes[@]}
  do
    filtered_includes+=$(echo "$extra_includes" | grep $ignore )
  done
  
  # Remove includes from file if the match 
  for item in ${filtered_includes[@]}
  do
    item=$(echo $item | sed 's/\//\\\//g')
    echo $item
    sed -i "/#include ${item}/d" $file
  done
}

################################################################################
# Formatting Files .cc and .h
################################################################################
# Default is on 
if [ -z ${CLANG_FORMAT_ON} ] # if not defined turn it on  
then
  environement_variable_apply_clang_formatting=1
else
  if [ "${CLANG_FORMAT_ON}" -eq "1" ]
  then
    environement_variable_apply_clang_formatting=1
  else 
    environement_variable_apply_clang_formatting=0
  fi
fi

# Exclude .h.in files controlled by CMake
apply_clang_formating_to_altered_files(){
  if [[ $file == *".h" ]] || [[ $file == *".cc" ]]
  then
    echo "Applying clang style formatting to file "$file
    clang-format -i -style=file $file
  fi
}

################################################################################
# Formatting Files .cc 
################################################################################
# Default is on 
if [ -z ${CLANG_TIDY_ON} ] # if not defined turn it on  
then
  environement_variable_apply_clang_tidy=1
else
  if [ "${CLANG_TIDY_ON}" -eq "1" ]
  then
    environement_variable_apply_clang_tidy=1
  else 
    environement_variable_apply_clang_tidy=0
  fi
fi

# Exclude .h.in files controlled by CMake
apply_clang_tidy_to_altered_files(){
  if [[ $file == *".h" ]] || [[ $file == *".cc" ]]
  then
    echo "Applying clang tidy to file "$file
    clang-tidy $file -checks=* -- -I${GIT_DIR}/include/votca
  fi
}
################################################################################
# Formatting Files .md 
################################################################################
# Default is on 
if [ -z ${MARKDOWN_FORMAT_ON} ] # if not defined turn it on  
then
  environement_variable_apply_markdown_formatting=1
else
  if [ "${MARKDOWN_FORMAT_ON}" -eq "1" ]
  then
    environement_variable_apply_markdown_formatting=1
  else 
    environement_variable_apply_markdown_formatting=0
  fi
fi

apply_markdown_formating_to_altered_files(){
  if [[ $file == *".md" ]]
  then
    echo "Applying markdown formatting to file "$file
    remark --setting '"listItemIndent":"1"' --setting '"bullet":"*"' $file -o $file
  fi
}

################################################################################
# Formatting Files .py 
################################################################################
# Default is on 
if [ -z ${PYTHON_FORMAT_ON} ] # if not defined turn it on  
then
  environement_variable_apply_python_formatting=1
else
  if [ "${PYTHON_FORMAT_ON}" -eq "1" ]
  then
    environement_variable_apply_python_formatting=1
  else 
    environement_variable_apply_python_formatting=0
  fi
fi

apply_python_formating_to_altered_files(){
  if [[ $file == *".py" ]]
  then
    echo "Applying python formatting to file "$file
    autopep8 -i $file
  fi
}

################################################################################
# Main
################################################################################

commit_hash=$(git log -1 | grep commit | awk '{print $2}')

list_of_changed_header_and_source_files=$(git diff --diff-filter=d --cached --name-only $commit_hash | grep '\(\.cc\|\.h\)$')

year=$(date +"%Y")
for file in ${list_of_changed_header_and_source_files[@]}
do

  if [ "1" -eq "${environement_variable_header_guard}" ] 
  then
    check_header_guard_of_altered_files
  fi

  if [ "1" -eq "${environement_variable_update_license}" ] 
  then
    update_license_dates_of_altered_files
  fi

  if [ "1" -eq "${environement_variable_apply_include_what_you_use}" ] 
  then
    apply_include_what_you_use
  fi
  
  if [ "1" -eq "${environement_variable_apply_clang_formatting}" ] 
  then
    apply_clang_formating_to_altered_files
  fi

  if [ "1" -eq "${environement_variable_apply_clang_tidy}" ] 
  then
    apply_clang_tidy_to_altered_files
  fi

  git add $file
done

list_of_changed_markdown_files=$(git diff --diff-filter=d --cached --name-only $commit_hash | grep '\(\.md\|\.MD|\.Md\)$')
for file in ${list_of_changed_markdown_files[@]}
do
  if [ "1" -eq "{environement_variable_apply_markdown_formatting}" ]
  then
    apply_markdown_formating_to_altered_files
  fi
   git add $file
done

list_of_changed_python_files=$(git diff --diff-filter=d --cached --name-only $commit_hash | grep '\.py$')
for file in ${list_of_changed_python_files[@]}
do
  if [ "1" -eq "{environement_variable_apply_python_formatting}" ]
  then
    apply_python_formating_to_altered_files
  fi
  git add $file
done