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