3 # Build two documentation trees and diff the resulting formatted output.
4 # Compared to a source diff, this can reveal mistakes in the formatting.
7 # ./doc-diff origin/master HEAD
9 # would show the differences introduced by a branch based on master.
12 doc-diff [options] <from> <to> [-- <diff-options>]
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
20 . "$(git --exec-path)/git-sh-setup"
42 tmp="$(git rev-parse --show-toplevel)/Documentation/tmp-doc-diff" || exit 1
46 test $# -eq 0 || usage
47 git worktree remove --force "$tmp/worktree" 2>/dev/null
52 if test -z "$parallel"
54 parallel=$(getconf _NPROCESSORS_ONLN 2>/dev/null)
55 if test $? != 0 || test -z "$parallel"
61 test $# -gt 1 || usage
65 from_oid=$(git rev-parse --verify "$from") || exit 1
66 to_oid=$(git rev-parse --verify "$to") || exit 1
73 # We'll do both builds in a single worktree, which lets "make" reuse
74 # results that don't differ between the two trees.
75 if ! test -d "$tmp/worktree"
77 git worktree add -f --detach "$tmp/worktree" "$from" &&
78 dots=$(echo "$tmp/worktree" | sed 's#[^/]*#..#g') &&
79 ln -s "$dots/config.mak" "$tmp/worktree/config.mak"
82 # generate_render_makefile <srcdir> <dstdir>
83 generate_render_makefile () {
88 printf 'all:: %s\n' "$dst"
89 printf '%s: %s\n' "$dst" "$src"
90 printf '\t@echo >&2 " RENDER $(notdir $@)" && \\\n'
91 printf '\tmkdir -p $(dir $@) && \\\n'
92 printf '\tMANWIDTH=80 man $< >$@+ && \\\n'
93 printf '\tmv $@+ $@\n'
97 # render_tree <committish_oid>
99 # Skip install-man entirely if we already have an installed directory.
100 # We can't rely on make here, since "install-man" unconditionally
101 # copies the files (spending effort, but also updating timestamps that
102 # we then can't rely on during the render step). We use "mv" to make
103 # sure we don't get confused by a previous run that failed partway
105 if ! test -d "$tmp/installed/$1"
107 git -C "$tmp/worktree" checkout --detach "$1" &&
108 make -j$parallel -C "$tmp/worktree" \
109 GIT_VERSION=omitted \
110 SOURCE_DATE_EPOCH=0 \
111 DESTDIR="$tmp/installed/$1+" \
113 mv "$tmp/installed/$1+" "$tmp/installed/$1"
116 # As with "installed" above, we skip the render if it's already been
117 # done. So using make here is primarily just about running in
119 if ! test -d "$tmp/rendered/$1"
121 generate_render_makefile "$tmp/installed/$1" "$tmp/rendered/$1+" |
122 make -j$parallel -f - &&
123 mv "$tmp/rendered/$1+" "$tmp/rendered/$1"
127 render_tree $from_oid &&
128 render_tree $to_oid &&
129 git -C $tmp/rendered diff --no-index "$@" $from_oid $to_oid