util/lint/check-style

   1 #!/usr/bin/env bash
   2 # git pre-commit hook that runs an clang-format stylecheck.
   3 # Features:
   4 #  - abort commit when commit does not comply with the style guidelines
   5 #  - create a patch of the proposed style changes
   6 #
   7 # modifications for clang-format by rene.milk@wwu.de
   8 # Link:    https://github.com/githubbrowser/Pre-commit-hooks
   9 # Contact: David Martin, david.martin.mailbox@googlemail.com
  10
  11 # DESCR: Checking that VCS 'staged' source conforms to coding style
  12
  13 ##################################################################
  14 # SETTINGS
  15 # set path to clang-format binary
  16 CLANG_FORMAT="$(command -v clang-format)"
  17
  18 # remove any older patches from previous commits. Set to true or false.
  19 # DELETE_OLD_PATCHES=false
  20 DELETE_OLD_PATCHES=false
  21
  22 # only parse files with the extensions in FILE_EXTS. Set to true or false.
  23 # if false every changed file in the commit will be parsed with clang-format.
  24 # if true only files matching one of the extensions are parsed with clang-format.
  25 # PARSE_EXTS=true
  26 PARSE_EXTS=true
  27
  28 # file types to parse. Only effective when PARSE_EXTS is true.
  29 # FILE_EXTS=".c .h .cpp .hpp"
  30 FILE_EXTS=".c .h .cpp .hpp .cc .hh .cxx"
  31
  32 ##################################################################
  33 # There should be no need to change anything below this line.
  34
  35 # Reference: http://stackoverflow.com/questions/1055671/how-can-i-get-the-behavior-of-gnus-readlink-f-on-a-mac
  36 canonicalize_filename () {
  37     local target_file=$1
  38     local physical_directory=""
  39     local result=""
  40
  41     # Need to restore the working directory after work.
  42     pushd `pwd` > /dev/null
  43
  44     cd "$(dirname "$target_file")"
  45     target_file=`basename $target_file`
  46
  47     # Iterate down a (possible) chain of symlinks
  48     while [ -L "$target_file" ]
  49     do
  50         target_file=$(readlink "$target_file")
  51         cd "$(dirname "$target_file")"
  52         target_file=$(basename "$target_file")
  53     done
  54
  55     # Compute the canonicalized name by finding the physical path
  56     # for the directory we're in and appending the target file.
  57     physical_directory=`pwd -P`
  58     result="$physical_directory"/"$target_file"
  59
  60     # restore the working directory after work.
  61     popd > /dev/null
  62
  63     echo "$result"
  64 }
  65
  66 # exit on error
  67 set -e
  68
  69 # check whether the given file matches any of the set extensions
  70 matches_extension() {
  71     local filename=$(basename "$1")
  72     local extension=".${filename##*.}"
  73     local ext
  74
  75     for ext in $FILE_EXTS; do [[ "$ext" == "$extension" ]] && return 0; done
  76
  77     return 1
  78 }
  79
  80 # necessary check for initial commit
  81 if git rev-parse --verify HEAD >/dev/null 2>&1 ; then
  82     against=HEAD
  83 else
  84     # Initial commit: diff against an empty tree object
  85     against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
  86 fi
  87
  88 if [ ! -x "$CLANG_FORMAT" ] ; then
  89     printf "Warning: clang-format executable not found.\n"
  90     printf "Set the correct path in $(canonicalize_filename "$0").\n"
  91     printf "Skipping clang-format style check test.\n"
  92 #    exit 1
  93     exit 0
  94 fi
  95
  96 # create a random filename to store our generated patch
  97 prefix="pre-commit-clang-format"
  98 suffix="$(date +%s)"
  99 patch="/tmp/$prefix-$suffix.patch"
 100
 101 # clean up any older clang-format patches
 102 $DELETE_OLD_PATCHES && rm -f /tmp/$prefix*.patch
 103
 104 # create one patch containing all changes to the files
 105 git diff-index --cached --diff-filter=ACMR --name-only $against -- | while read file;
 106 do
 107     # ignore file if we do check for file extensions and the file
 108     # does not match any of the extensions specified in $FILE_EXTS
 109     if $PARSE_EXTS && ! matches_extension "$file"; then
 110         continue;
 111     fi
 112
 113     # clang-format our sourcefile, create a patch with diff and append it to our $patch
 114     # The sed call is necessary to transform the patch from
 115     #    --- $file timestamp
 116     #    +++ - timestamp
 117     # to both lines working on the same file and having a a/ and b/ prefix.
 118     # Else it can not be applied with 'git apply'.
 119     "$CLANG_FORMAT" -style=file "$file" | \
 120         diff -u "$file" - | \
 121         sed -e "1s|--- |--- a/|" -e "2s|+++ -|+++ b/$file|" >> "$patch"
 122 done
 123
 124 # if no patch has been generated all is ok, clean up the file stub and exit
 125 if [ ! -s "$patch" ] ; then
 126     printf "Files in this commit comply with the clang-format rules.\n"
 127     rm -f "$patch"
 128     exit 0
 129 fi
 130
 131 # a patch has been created, notify the user and exit
 132 printf "\nThe following differences were found between the code to commit "
 133 printf "and the clang-format rules:\n\n"
 134 cat "$patch"
 135
 136 printf "\nYou can apply these changes with:\n git apply $patch\n"
 137 printf "(may need to be called from the root directory of your repository)\n"
 138
 139 # FIXME: clang-format is currently unusable, so don't abort the commit.
 140 # printf "Aborting commit. Apply changes and commit again or skip checking with"
 141 # printf " --no-verify (not recommended).\n"
 142 # exit 1
 143
 144 exit 0