Merge branch 'nd/submodule-helper-incomplete-line-fix'
[git] / 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-header-footer       cut away header and 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_header_footer=
35 while test $# -gt 0
36 do
37         case "$1" in
38         -j)
39                 parallel=$2; shift ;;
40         -c|--clean)
41                 clean=t ;;
42         -f)
43                 force=t ;;
44         --from-asciidoctor)
45                 from_program=-asciidoctor ;;
46         --to-asciidoctor)
47                 to_program=-asciidoctor ;;
48         --asciidoctor)
49                 from_program=-asciidoctor
50                 to_program=-asciidoctor ;;
51         --from-asciidoc)
52                 from_program=-asciidoc ;;
53         --to-asciidoc)
54                 to_program=-asciidoc ;;
55         --asciidoc)
56                 from_program=-asciidoc
57                 to_program=-asciidoc ;;
58         --cut-header-footer)
59                 cut_header_footer=-cut-header-footer ;;
60         --)
61                 shift; break ;;
62         *)
63                 usage ;;
64         esac
65         shift
66 done
67
68 tmp="$(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_header_footer &&
122 to_dir=$to_oid$to_program$cut_header_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_header_footer" = "-cut-header-footer"
173                 then
174                         for f in $(find "$tmp/rendered/$dname" -type f)
175                         do
176                                 tail -n +3 "$f" | head -n -2 |
177                                 sed -e '1{/^$/d}' -e '${/^$/d}' >"$f+" &&
178                                 mv "$f+" "$f" ||
179                                 return 1
180                         done
181                 fi
182         fi
183 }
184
185 render_tree $from_oid $from_dir $from_makemanflags &&
186 render_tree $to_oid $to_dir $to_makemanflags &&
187 git -C $tmp/rendered diff --no-index "$@" $from_dir $to_dir