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"
43 tmp=Documentation/tmp-doc-diff
47 test $# -eq 0 || usage
48 git worktree remove --force "$tmp/worktree" 2>/dev/null
53 if test -z "$parallel"
55 parallel=$(getconf _NPROCESSORS_ONLN 2>/dev/null)
56 if test $? != 0 || test -z "$parallel"
62 test $# -gt 1 || usage
66 from_oid=$(git rev-parse --verify "$from") || exit 1
67 to_oid=$(git rev-parse --verify "$to") || exit 1
74 # We'll do both builds in a single worktree, which lets "make" reuse
75 # results that don't differ between the two trees.
76 if ! test -d "$tmp/worktree"
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"
83 # generate_render_makefile <srcdir> <dstdir>
84 generate_render_makefile () {
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 $@+ $@\n'
98 # render_tree <committish_oid>
100 # Skip install-man entirely if we already have an installed directory.
101 # We can't rely on make here, since "install-man" unconditionally
102 # copies the files (spending effort, but also updating timestamps that
103 # we then can't rely on during the render step). We use "mv" to make
104 # sure we don't get confused by a previous run that failed partway
106 if ! test -d "$tmp/installed/$1"
108 git -C "$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/$1+" \
114 mv "$tmp/installed/$1+" "$tmp/installed/$1"
117 # As with "installed" above, we skip the render if it's already been
118 # done. So using make here is primarily just about running in
120 if ! test -d "$tmp/rendered/$1"
122 generate_render_makefile "$tmp/installed/$1" "$tmp/rendered/$1+" |
123 make -j$parallel -f - &&
124 mv "$tmp/rendered/$1+" "$tmp/rendered/$1"
128 render_tree $from_oid &&
129 render_tree $to_oid &&
130 git -C $tmp/rendered diff --no-index "$@" $from_oid $to_oid