Documentation/doc-diff

   1 #!/bin/sh
   2
   3 OPTIONS_SPEC="\
   4 doc-diff [options] <from> <to> [-- <diff-options>]
   5 --
   6 j=n     parallel argument to pass to make
   7 f       force rebuild; do not rely on cached results
   8 "
   9 SUBDIRECTORY_OK=1
  10 . "$(git --exec-path)/git-sh-setup"
  11
  12 parallel=
  13 force=
  14 while test $# -gt 0
  15 do
  16         case "$1" in
  17         -j)
  18                 parallel=$2; shift ;;
  19         -f)
  20                 force=t ;;
  21         --)
  22                 shift; break ;;
  23         *)
  24                 usage ;;
  25         esac
  26         shift
  27 done
  28
  29 if test -z "$parallel"
  30 then
  31         parallel=$(getconf _NPROCESSORS_ONLN 2>/dev/null)
  32         if test $? != 0 || test -z "$parallel"
  33         then
  34                 parallel=1
  35         fi
  36 fi
  37
  38 test $# -gt 1 || usage
  39 from=$1; shift
  40 to=$1; shift
  41
  42 from_oid=$(git rev-parse --verify "$from") || exit 1
  43 to_oid=$(git rev-parse --verify "$to") || exit 1
  44
  45 cd_to_toplevel
  46 tmp=Documentation/tmp-doc-diff
  47
  48 if test -n "$force"
  49 then
  50         rm -rf "$tmp"
  51 fi
  52
  53 # We'll do both builds in a single worktree, which lets "make" reuse
  54 # results that don't differ between the two trees.
  55 if ! test -d "$tmp/worktree"
  56 then
  57         git worktree add --detach "$tmp/worktree" "$from" &&
  58         dots=$(echo "$tmp/worktree" | sed 's#[^/]*#..#g') &&
  59         ln -s "$dots/config.mak" "$tmp/worktree/config.mak"
  60 fi
  61
  62 # generate_render_makefile <srcdir> <dstdir>
  63 generate_render_makefile () {
  64         find "$1" -type f |
  65         while read src
  66         do
  67                 dst=$2/${src#$1/}
  68                 printf 'all:: %s\n' "$dst"
  69                 printf '%s: %s\n' "$dst" "$src"
  70                 printf '\t@echo >&2 "  RENDER $(notdir $@)" && \\\n'
  71                 printf '\tmkdir -p $(dir $@) && \\\n'
  72                 printf '\tMANWIDTH=80 man -l $< >$@+ && \\\n'
  73                 printf '\tmv $@+ $@\n'
  74         done
  75 }
  76
  77 # render_tree <dirname> <committish>
  78 render_tree () {
  79         # Skip install-man entirely if we already have an installed directory.
  80         # We can't rely on make here, since "install-man" unconditionally
  81         # copies the files (spending effort, but also updating timestamps that
  82         # we then can't rely on during the render step). We use "mv" to make
  83         # sure we don't get confused by a previous run that failed partway
  84         # through.
  85         if ! test -d "$tmp/installed/$1"
  86         then
  87                 git -C "$tmp/worktree" checkout "$2" &&
  88                 make -j$parallel -C "$tmp/worktree" \
  89                         GIT_VERSION=omitted \
  90                         SOURCE_DATE_EPOCH=0 \
  91                         DESTDIR="$PWD/$tmp/installed/$1+" \
  92                         install-man &&
  93                 mv "$tmp/installed/$1+" "$tmp/installed/$1"
  94         fi &&
  95
  96         # As with "installed" above, we skip the render if it's already been
  97         # done.  So using make here is primarily just about running in
  98         # parallel.
  99         if ! test -d "$tmp/rendered/$1"
 100         then
 101                 generate_render_makefile "$tmp/installed/$1" "$tmp/rendered/$1+" |
 102                 make -j$parallel -f - &&
 103                 mv "$tmp/rendered/$1+" "$tmp/rendered/$1"
 104         fi
 105 }
 106
 107 render_tree $from_oid "$from" &&
 108 render_tree $to_oid "$to" &&
 109 git -C $tmp/rendered diff --no-index "$@" $from_oid $to_oid