cg-diff

   1 #!/usr/bin/env bash
   2 #
   3 # Show changes in the diff format
   4 # Copyright (c) Petr Baudis, 2005
   5 #
   6 # Outputs a diff for converting the first tree to the second one.
   7 # By default compares the current working tree to the state at the
   8 # last commit. The output will automatically be displayed in a pager
   9 # unless it is piped to a program.
  10 #
  11 # OPTIONS
  12 # -------
  13 # -c:: Colorize
  14 #       Colorize the output. You can customize the colors using the
  15 #       $CG_COLORS environment variable (see below).
  16 #
  17 # --diffcore ARGS:: Diffcore arguments to pass the Git diff command
  18 #       Pass the given diffcore arguments the called Git diff command.
  19 #       See e.g. git-diff-tree(1) documentation for the list of possible
  20 #       arguments; '-R', '-B', and '-C' might be of particular interest
  21 #       ('-M' is already passed by default).
  22 #
  23 # --no-renames:: Do not detect renames
  24 #       By default, `cg-diff` will automatically detect file renames.
  25 #       Diff produced by the rename-aware `cg-diff` will be unappliable
  26 #       using patch(1) (you need to use `cg-patch`) and the renames
  27 #       detection can add slight extra performance penalty. This switch
  28 #       will turn the rename detection off.
  29 #
  30 # -p:: Diff against commit parent
  31 #       Show diff to the parent of the current commit (or the commit
  32 #       specified by the -r parameter).
  33 #
  34 # -s:: Summarize and show diff stat
  35 #       Summarize the diff by showing a histogram for removed and added
  36 #       lines (similar to the output of diffstat(1)) and information
  37 #       about added and renamed files and mode changes.
  38 #
  39 # -r FROM_ID[..TO_ID]:: Limit to revision range
  40 #       Specify the revisions to diff using either '-r rev1..rev2' or
  41 #       '-r rev1 -r rev2'. If no revision is specified, the current
  42 #       working tree is implied. Note that no revision is different from
  43 #       empty revision which means '-r rev..' compares between 'rev' and
  44 #       'HEAD', while '-r rev' compares between 'rev' and working tree.
  45 #
  46 # -m:: Base the diff at the merge base
  47 #       Base the diff at the merge base of the -r arguments (defaulting
  48 #       to HEAD and 'origin' or the current branch's default remote
  49 #       branch, see `cg-fetch` for details).
  50 #
  51 # ENVIRONMENT VARIABLES
  52 # ---------------------
  53 # PAGER::
  54 #       The pager to display log information in, defaults to `less`.
  55 #
  56 # PAGER_FLAGS::
  57 #       Flags to pass to the pager.
  58 #
  59 # CG_COLORS::
  60 #       Colon-separated list of 'name=color' pairs, where name is
  61 #       one of diffhdr, diffhdradd, diffhdrmod, diffhdrrem, diffadd,
  62 #       diffmod, diffrem, diffhunk, diffctx, default, and value is
  63 #       an ECMA-48 SGR sequence (see e.g. console_codes(4)).
  64 #
  65 # CG_COLORS_AUTO::
  66 #       Even if -c was passed or specified in ~/.cgrc, if this option
  67 #       is set, use colors only when the output is a terminal and it
  68 #       supports colors.
  69 #
  70 # CG_LESS::
  71 #       This is what the $LESS environment variable value will be set
  72 #       to before invoking $PAGER. It defaults to $LESS concatenated
  73 #       with the `R` flag to allow displaying of colorized output.
  74 #
  75 # CONFIGURATION VARIABLES
  76 # -----------------------
  77 # The following GIT configuration file variables are recognized:
  78 #
  79 # diff.usecolor::
  80 #       If enabled, colorify the output like with -c if the output
  81 #       is a terminal.
  82 #
  83 # NOTES
  84 # -----
  85 # The ':' is equivalent to '..' in revisions range specification (to make
  86 # things more comfortable to SVN users). See cogito(7) for more details
  87 # about revision specification.
  88
  89 # Testsuite: TODO
  90
  91 USAGE="cg-diff [-c] [-m] [-s] [-p] [-r FROM_ID[..TO_ID]] [FILE]..."
  92 _git_wc_unneeded=1
  93
  94 . "${COGITO_LIB}"cg-Xlib || exit 1
  95
  96
  97 setup_colors()
  98 {
  99         colorify_setup "$colorify_diffcolors"
 100         # It could've been turned on by diff.usecolor
 101         opt_color=1
 102 }
 103
 104 colorize()
 105 {
 106         if [ "$opt_color" ]; then
 107                 sed -e '
 108                         s/^diff --git.*/'$coldiffhdr'&'$coldefault'/
 109                         s/^+++.*/'$coldiffhdradd'&'$coldefault'/
 110                         s/^---.*/'$coldiffhdrrem'&'$coldefault'/
 111                         s/^[+].*/'$coldiffadd'&'$coldefault'/
 112                         s/^[-].*/'$coldiffrem'&'$coldefault'/
 113                         s/^new\( file\)\{0,1\} mode .*/'$coldiffadd'&'$coldefault'/
 114                         s/^\(deleted file\|old\) mode .*/'$coldiffrem'&'$coldefault'/
 115                         s/^rename to .*/'$coldiffadd'&'$coldefault'/
 116                         s/^rename from .*/'$coldiffrem'&'$coldefault'/
 117                         s/^\(@@ -.* +.* @@\)\(.*\)/'$coldiffhunk'\1'$coldiffctx'\2'$coldefault'/
 118                 '
 119         else
 120                 cat
 121         fi
 122 }
 123
 124
 125 id1=" " # means HEAD
 126 id2=" " # means working copy
 127 diffcore=
 128 parent=
 129 opt_color=
 130 mergebase=
 131 style=-p
 132 renames=-M
 133
 134 while optparse; do
 135         if optparse -c; then
 136                 opt_color=1
 137         elif optparse --diffcore=; then
 138                 diffcore="$OPTARG"
 139         elif optparse -p; then
 140                 [ "$mergebase" ] && optconflict -m
 141                 parent=1
 142         elif optparse -R || optparse --no-renames; then
 143                 renames=
 144         elif optparse -s; then
 145                 style="--stat"
 146         elif optparse -r=; then
 147                 if echo "$OPTARG" | fgrep -q '..'; then
 148                         id2="${OPTARG#*..}"
 149                         id1="${OPTARG%..*}"
 150                 elif echo "$OPTARG" | grep -q ':'; then
 151                         id2="${OPTARG#*:}"
 152                         id1="${OPTARG%:*}"
 153                 elif [ "$id1" = " " ]; then
 154                         id1="$OPTARG"
 155                 elif [ "$id2" = " " ]; then
 156                         id2="$OPTARG"
 157                 else
 158                         die "too many revisions"
 159                 fi
 160         elif optparse -m; then
 161                 [ "$parent" ] && optconflict -p
 162                 mergebase=1
 163         else
 164                 optfail
 165         fi
 166 done
 167
 168
 169 colorify_detect "$opt_color" diff && setup_colors
 170
 171 [ "$id1" = " " ] && id1=HEAD
 172
 173 if [ "$parent" ]; then
 174         [ "$id2" = " " ] || die "too many revisions"
 175         id2="$id1"
 176
 177         ids="$(cg-object-id -p "$id2")" || exit 1
 178         [ "$(echo "$ids" | wc -l)" -gt 1 ] && \
 179                 warn "choosing the first parent of a merge commit. This may not be what you want."
 180         id1="$(echo "$ids" | head -n 1)" || exit 1
 181
 182 elif [ "$mergebase" ]; then
 183         [ "$id2" = " " ] && { id2="$(choose_origin refs/heads "what to diff against?")" || exit 1; }
 184
 185         id1="$(cg-object-id -c "$id1")" || exit 1
 186         id2="$(cg-object-id -c "$id2")" || exit 1
 187
 188         conservative_merge_base "$id1" "$id2" || exit 1
 189         [ "$_cg_base_conservative" ] &&
 190                 warn -b "multiple merge bases, picking the most conservative one"
 191         id1="$_cg_baselist"
 192
 193 else
 194         id1="$(cg-object-id -t "$id1")" || exit 1
 195 fi
 196
 197
 198 if [ "$id2" = " " ]; then
 199         [ "$_git_no_wc" ] && die "only cg-diff between two revisions allowed outside a working copy"
 200
 201         # Make sure we only diff modified files
 202         git-update-index --refresh >/dev/null
 203
 204         diffprog=git-diff-index
 205         diffargs=(-m "$id1")
 206
 207 else
 208         id2="$(cg-object-id -t "$id2")" || exit 1
 209         [ "$id1" = "$id2" ] && exit 0
 210
 211         diffprog=git-diff-tree
 212         diffargs=("$id1" "$id2")
 213 fi
 214
 215
 216 diffargs[${#diffargs[@]}]="--"
 217 if [ ! "$ARGS" ]; then
 218         diffargs[${#diffargs[@]}]="${_git_relpath:-.}"
 219 else
 220         for file in "${ARGS[@]}"; do
 221                 diffargs[${#diffargs[@]}]="$_git_relpath$file"
 222         done
 223 fi
 224
 225 # FIXME: Update ret based on what did we match. And take "$@"
 226 # to account after all.
 227 #ret=
 228 $diffprog -r $renames $diffcore $style "${diffargs[@]}" | colorize | pager
 229 #[ "$ret" ] && die "no files matched"
 230 #exit $ret
 231 exit 0