Documentation/doc-diff

   1 #!/bin/sh
   2 #
   3 # Build two documentation trees and diff the resulting formatted output.
   4 # Compared to a source diff, this can reveal mistakes in the formatting.
   5 # For example:
   6 #
   7 #   ./doc-diff origin/master HEAD
   8 #
   9 # would show the differences introduced by a branch based on master.
  10
  11 OPTIONS_SPEC="\
  12 doc-diff [options] <from> <to> [-- <diff-options>]
  13 doc-diff (-c|--clean)
  14 --
  15 j=n                     parallel argument to pass to make
  16 f                       force rebuild; do not rely on cached results
  17 c,clean                 cleanup temporary working files
  18 from-asciidoc           use asciidoc with the 'from'-commit
  19 from-asciidoctor        use asciidoctor with the 'from'-commit
  20 asciidoc                use asciidoc with both commits
  21 to-asciidoc             use asciidoc with the 'to'-commit
  22 to-asciidoctor          use asciidoctor with the 'to'-commit
  23 asciidoctor             use asciidoctor with both commits
  24 cut-footer              cut away footer
  25 "
  26 SUBDIRECTORY_OK=1
  27 . "$(git --exec-path)/git-sh-setup"
  28
  29 parallel=
  30 force=
  31 clean=
  32 from_program=
  33 to_program=
  34 cut_footer=
  35 while test $# -gt 0
  36 do
  37         case "$1" in
  38         -j)
  39                 parallel=$2; shift ;;
  40         -c|--clean)
  41                 clean=t ;;
  42         -f)
  43                 force=t ;;
  44         --from-asciidoctor)
  45                 from_program=-asciidoctor ;;
  46         --to-asciidoctor)
  47                 to_program=-asciidoctor ;;
  48         --asciidoctor)
  49                 from_program=-asciidoctor
  50                 to_program=-asciidoctor ;;
  51         --from-asciidoc)
  52                 from_program=-asciidoc ;;
  53         --to-asciidoc)
  54                 to_program=-asciidoc ;;
  55         --asciidoc)
  56                 from_program=-asciidoc
  57                 to_program=-asciidoc ;;
  58         --cut-footer)
  59                 cut_footer=-cut-footer ;;
  60         --)
  61                 shift; break ;;
  62         *)
  63                 usage ;;
  64         esac
  65         shift
  66 done
  67
  68 tmp="$(git rev-parse --show-toplevel)/Documentation/tmp-doc-diff" || exit 1
  69
  70 if test -n "$clean"
  71 then
  72         test $# -eq 0 || usage
  73         git worktree remove --force "$tmp/worktree" 2>/dev/null
  74         rm -rf "$tmp"
  75         exit 0
  76 fi
  77
  78 if test -z "$parallel"
  79 then
  80         parallel=$(getconf _NPROCESSORS_ONLN 2>/dev/null)
  81         if test $? != 0 || test -z "$parallel"
  82         then
  83                 parallel=1
  84         fi
  85 fi
  86
  87 test $# -gt 1 || usage
  88 from=$1; shift
  89 to=$1; shift
  90
  91 from_oid=$(git rev-parse --verify "$from") || exit 1
  92 to_oid=$(git rev-parse --verify "$to") || exit 1
  93
  94 if test -n "$force"
  95 then
  96         rm -rf "$tmp"
  97 fi
  98
  99 # We'll do both builds in a single worktree, which lets "make" reuse
 100 # results that don't differ between the two trees.
 101 if ! test -d "$tmp/worktree"
 102 then
 103         git worktree add -f --detach "$tmp/worktree" "$from" &&
 104         dots=$(echo "$tmp/worktree" | sed 's#[^/]*#..#g') &&
 105         ln -s "$dots/config.mak" "$tmp/worktree/config.mak"
 106 fi
 107
 108 construct_makemanflags () {
 109         if test "$1" = "-asciidoc"
 110         then
 111                 echo USE_ASCIIDOCTOR=
 112         elif test "$1" = "-asciidoctor"
 113         then
 114                 echo USE_ASCIIDOCTOR=YesPlease
 115         fi
 116 }
 117
 118 from_makemanflags=$(construct_makemanflags "$from_program") &&
 119 to_makemanflags=$(construct_makemanflags "$to_program") &&
 120
 121 from_dir=$from_oid$from_program$cut_footer &&
 122 to_dir=$to_oid$to_program$cut_footer &&
 123
 124 # generate_render_makefile <srcdir> <dstdir>
 125 generate_render_makefile () {
 126         find "$1" -type f |
 127         while read src
 128         do
 129                 dst=$2/${src#$1/}
 130                 printf 'all: %s\n' "$dst"
 131                 printf '%s: %s\n' "$dst" "$src"
 132                 printf '\t@echo >&2 "  RENDER $(notdir $@)" && \\\n'
 133                 printf '\tmkdir -p $(dir $@) && \\\n'
 134                 printf '\tMANWIDTH=80 man $< >$@+ && \\\n'
 135                 printf '\tmv $@+ $@\n'
 136         done
 137 }
 138
 139 # render_tree <committish_oid> <directory_name> <makemanflags>
 140 render_tree () {
 141         # Skip install-man entirely if we already have an installed directory.
 142         # We can't rely on make here, since "install-man" unconditionally
 143         # copies the files (spending effort, but also updating timestamps that
 144         # we then can't rely on during the render step). We use "mv" to make
 145         # sure we don't get confused by a previous run that failed partway
 146         # through.
 147         oid=$1 &&
 148         dname=$2 &&
 149         makemanflags=$3 &&
 150         if ! test -d "$tmp/installed/$dname"
 151         then
 152                 git -C "$tmp/worktree" checkout --detach "$oid" &&
 153                 make -j$parallel -C "$tmp/worktree" \
 154                         $makemanflags \
 155                         GIT_VERSION=omitted \
 156                         SOURCE_DATE_EPOCH=0 \
 157                         DESTDIR="$tmp/installed/$dname+" \
 158                         install-man &&
 159                 mv "$tmp/installed/$dname+" "$tmp/installed/$dname"
 160         fi &&
 161
 162         # As with "installed" above, we skip the render if it's already been
 163         # done.  So using make here is primarily just about running in
 164         # parallel.
 165         if ! test -d "$tmp/rendered/$dname"
 166         then
 167                 generate_render_makefile "$tmp/installed/$dname" \
 168                         "$tmp/rendered/$dname+" |
 169                 make -j$parallel -f - &&
 170                 mv "$tmp/rendered/$dname+" "$tmp/rendered/$dname"
 171
 172                 if test "$cut_footer" = "-cut-footer"
 173                 then
 174                         for f in $(find "$tmp/rendered/$dname" -type f)
 175                         do
 176                                 head -n -2 "$f" | sed -e '${/^$/d}' >"$f+" &&
 177                                 mv "$f+" "$f" ||
 178                                 return 1
 179                         done
 180                 fi
 181         fi
 182 }
 183
 184 render_tree $from_oid $from_dir $from_makemanflags &&
 185 render_tree $to_oid $to_dir $to_makemanflags &&
 186 git -C $tmp/rendered diff --no-index "$@" $from_dir $to_dir