doc-diff: support diffing from/to AsciiDoc(tor)

Provide `--from-asciidoctor` and `--to-asciidoctor` to select that the
"from" resp. "to" commit should be built with Asciidoctor, and provide
an `--asciidoctor` shortcut for giving both. Similarly, provide
--{from-,to-,}asciidoc for explicitly selecting AsciiDoc.

Implement this using the USE_ASCIIDOCTOR flag. Let's not enforce a
default here, but instead just let the Makefile fall back on whatever is
in config.mak, so that `./doc-diff foo bar` without any of of these new
options behaves exactly like it did before this commit.

Encode the choice into the directory names of our "installed" and
"rendered" files, so that we can run `./doc-diff --from-asciidoc
--to-asciidoctor HEAD HEAD` without our two runs stomping on each other.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/doc-diff b/Documentation/doc-diff
index 3e975d3c5d8b9cf8c5b2b1581bb2a2d11270dd03..36fc2307a795ccac4f107fe3fb556ade1af9e2fa 100755 (executable)
--- a/Documentation/doc-diff
+++ b/Documentation/doc-diff
@@ -12,9 +12,15 @@ OPTIONS_SPEC="\
 doc-diff [options] <from> <to> [-- <diff-options>]
 doc-diff (-c|--clean)
 --
-j=n    parallel argument to pass to make
-f      force rebuild; do not rely on cached results
-c,clean        cleanup temporary working files
+j=n                    parallel argument to pass to make
+f                      force rebuild; do not rely on cached results
+c,clean                        cleanup temporary working files
+from-asciidoc          use asciidoc with the 'from'-commit
+from-asciidoctor       use asciidoctor with the 'from'-commit
+asciidoc               use asciidoc with both commits
+to-asciidoc            use asciidoc with the 'to'-commit
+to-asciidoctor         use asciidoctor with the 'to'-commit
+asciidoctor            use asciidoctor with both commits
 "
 SUBDIRECTORY_OK=1
 . "$(git --exec-path)/git-sh-setup"
@@ -22,6 +28,8 @@ SUBDIRECTORY_OK=1
 parallel=
 force=
 clean=
+from_program=
+to_program=
 while test $# -gt 0
 do
        case "$1" in
@@ -31,6 +39,20 @@ do
                clean=t ;;
        -f)
                force=t ;;
+       --from-asciidoctor)
+               from_program=-asciidoctor ;;
+       --to-asciidoctor)
+               to_program=-asciidoctor ;;
+       --asciidoctor)
+               from_program=-asciidoctor
+               to_program=-asciidoctor ;;
+       --from-asciidoc)
+               from_program=-asciidoc ;;
+       --to-asciidoc)
+               to_program=-asciidoc ;;
+       --asciidoc)
+               from_program=-asciidoc
+               to_program=-asciidoc ;;
        --)
                shift; break ;;
        *)
@@ -79,8 +101,21 @@ then
        ln -s "$dots/config.mak" "$tmp/worktree/config.mak"
 fi
 
-from_dir=$from_oid &&
-to_dir=$to_oid &&
+construct_makemanflags () {
+       if test "$1" = "-asciidoc"
+       then
+               echo USE_ASCIIDOCTOR=
+       elif test "$1" = "-asciidoctor"
+       then
+               echo USE_ASCIIDOCTOR=YesPlease
+       fi
+}
+
+from_makemanflags=$(construct_makemanflags "$from_program") &&
+to_makemanflags=$(construct_makemanflags "$to_program") &&
+
+from_dir=$from_oid$from_program &&
+to_dir=$to_oid$to_program &&
 
 # generate_render_makefile <srcdir> <dstdir>
 generate_render_makefile () {
@@ -97,7 +132,7 @@ generate_render_makefile () {
        done
 }
 
-# render_tree <committish_oid> <directory_name>
+# render_tree <committish_oid> <directory_name> <makemanflags>
 render_tree () {
        # Skip install-man entirely if we already have an installed directory.
        # We can't rely on make here, since "install-man" unconditionally
@@ -107,10 +142,12 @@ render_tree () {
        # through.
        oid=$1 &&
        dname=$2 &&
+       makemanflags=$3 &&
        if ! test -d "$tmp/installed/$dname"
        then
                git -C "$tmp/worktree" checkout --detach "$oid" &&
                make -j$parallel -C "$tmp/worktree" \
+                       $makemanflags \
                        GIT_VERSION=omitted \
                        SOURCE_DATE_EPOCH=0 \
                        DESTDIR="$tmp/installed/$dname+" \
@@ -130,6 +167,6 @@ render_tree () {
        fi
 }
 
-render_tree $from_oid $from_dir &&
-render_tree $to_oid $to_dir &&
+render_tree $from_oid $from_dir $from_makemanflags &&
+render_tree $to_oid $to_dir $to_makemanflags &&
 git -C $tmp/rendered diff --no-index "$@" $from_dir $to_dir