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 "
  19 SUBDIRECTORY_OK=1
  20 . "$(git --exec-path)/git-sh-setup"
  21
  22 parallel=
  23 force=
  24 clean=
  25 while test $# -gt 0
  26 do
  27         case "$1" in
  28         -j)
  29                 parallel=$2; shift ;;
  30         -c|--clean)
  31                 clean=t ;;
  32         -f)
  33                 force=t ;;
  34         --)
  35                 shift; break ;;
  36         *)
  37                 usage ;;
  38         esac
  39         shift
  40 done
  41
  42 cd_to_toplevel
  43 tmp=Documentation/tmp-doc-diff
  44
  45 if test -n "$clean"
  46 then
  47         test $# -eq 0 || usage
  48         git worktree remove --force "$tmp/worktree" 2>/dev/null
  49         rm -rf "$tmp"
  50         exit 0
  51 fi
  52
  53 if test -z "$parallel"
  54 then
  55         parallel=$(getconf _NPROCESSORS_ONLN 2>/dev/null)
  56         if test $? != 0 || test -z "$parallel"
  57         then
  58                 parallel=1
  59         fi
  60 fi
  61
  62 test $# -gt 1 || usage
  63 from=$1; shift
  64 to=$1; shift
  65
  66 from_oid=$(git rev-parse --verify "$from") || exit 1
  67 to_oid=$(git rev-parse --verify "$to") || exit 1
  68
  69 if test -n "$force"
  70 then
  71         rm -rf "$tmp"
  72 fi
  73
  74 # We'll do both builds in a single worktree, which lets "make" reuse
  75 # results that don't differ between the two trees.
  76 if ! test -d "$tmp/worktree"
  77 then
  78         git worktree add -f --detach "$tmp/worktree" "$from" &&
  79         dots=$(echo "$tmp/worktree" | sed 's#[^/]*#..#g') &&
  80         ln -s "$dots/config.mak" "$tmp/worktree/config.mak"
  81 fi
  82
  83 # generate_render_makefile <srcdir> <dstdir>
  84 generate_render_makefile () {
  85         find "$1" -type f |
  86         while read src
  87         do
  88                 dst=$2/${src#$1/}
  89                 printf 'all:: %s\n' "$dst"
  90                 printf '%s: %s\n' "$dst" "$src"
  91                 printf '\t@echo >&2 "  RENDER $(notdir $@)" && \\\n'
  92                 printf '\tmkdir -p $(dir $@) && \\\n'
  93                 printf '\tMANWIDTH=80 man $< >$@+ && \\\n'
  94                 printf '\tmv $@+ $@\n'
  95         done
  96 }
  97
  98 # render_tree <committish_oid>
  99 render_tree () {
 100         # Skip install-man entirely if we already have an installed directory.
 101         # We can't rely on make here, since "install-man" unconditionally
 102         # copies the files (spending effort, but also updating timestamps that
 103         # we then can't rely on during the render step). We use "mv" to make
 104         # sure we don't get confused by a previous run that failed partway
 105         # through.
 106         if ! test -d "$tmp/installed/$1"
 107         then
 108                 git -C "$tmp/worktree" checkout --detach "$1" &&
 109                 make -j$parallel -C "$tmp/worktree" \
 110                         GIT_VERSION=omitted \
 111                         SOURCE_DATE_EPOCH=0 \
 112                         DESTDIR="$PWD/$tmp/installed/$1+" \
 113                         install-man &&
 114                 mv "$tmp/installed/$1+" "$tmp/installed/$1"
 115         fi &&
 116
 117         # As with "installed" above, we skip the render if it's already been
 118         # done.  So using make here is primarily just about running in
 119         # parallel.
 120         if ! test -d "$tmp/rendered/$1"
 121         then
 122                 generate_render_makefile "$tmp/installed/$1" "$tmp/rendered/$1+" |
 123                 make -j$parallel -f - &&
 124                 mv "$tmp/rendered/$1+" "$tmp/rendered/$1"
 125         fi
 126 }
 127
 128 render_tree $from_oid &&
 129 render_tree $to_oid &&
 130 git -C $tmp/rendered diff --no-index "$@" $from_oid $to_oid