Documentation: extract script to generate a list of mergetools

We include the list of available mergetools into our manpages. Extract
the script that performs this logic such that we can reuse it in other
build systems.

While at it, refactor the Makefile targets such that we don't create
"mergetools-list.made" anymore. It shouldn't be necessary, as we can
instead have other targets depend on "mergetools-{diff,merge}.txt"
directly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/Makefile b/Documentation/Makefile
index e853d89eb5d6c89eb7e7bf10c5b75e5ad0db531b..f0e5bc9c0c64ddf83b2d9fde0bf877a4f4b847f3 100644 (file)
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -282,11 +282,13 @@ ifneq ($(filter-out lint-docs clean,$(MAKECMDGOALS)),)
 -include ../GIT-VERSION-FILE
 endif
 
+mergetools_txt = mergetools-diff.txt mergetools-merge.txt
+
 #
 # Determine "include::" file references in asciidoc files.
 #
 docdep_prereqs = \
-       mergetools-list.made $(mergetools_txt) \
+       $(mergetools_txt) \
        cmd-list.made $(cmds_txt)
 
 doc.dep : $(docdep_prereqs) $(DOC_DEP_TXT) build-docdep.perl
@@ -315,19 +317,11 @@ cmd-list.made: cmd-list.perl ../command-list.txt $(MAN1_TXT)
        $(QUIET_GEN)$(PERL_PATH) ./cmd-list.perl .. . $(cmds_txt) && \
        date >$@
 
-mergetools_txt = mergetools-diff.txt mergetools-merge.txt
-
-$(mergetools_txt): mergetools-list.made
-
-mergetools-list.made: ../git-mergetool--lib.sh $(wildcard ../mergetools/*)
-       $(QUIET_GEN) \
-       $(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && TOOL_MODE=diff && \
-               . ../git-mergetool--lib.sh && \
-               show_tool_names can_diff' | sed -e "s/\([a-z0-9]*\)/\`\1\`;;/" >mergetools-diff.txt && \
-       $(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && TOOL_MODE=merge && \
-               . ../git-mergetool--lib.sh && \
-               show_tool_names can_merge' | sed -e "s/\([a-z0-9]*\)/\`\1\`;;/" >mergetools-merge.txt && \
-       date >$@
+mergetools-%.txt: generate-mergetool-list.sh ../git-mergetool--lib.sh $(wildcard ../mergetools/*)
+mergetools-diff.txt:
+       $(QUIET_GEN)$(SHELL_PATH) ./generate-mergetool-list.sh .. diff $@
+mergetools-merge.txt:
+       $(QUIET_GEN)$(SHELL_PATH) ./generate-mergetool-list.sh .. merge $@
 
 TRACK_ASCIIDOCFLAGS = $(subst ','\'',$(ASCIIDOC_COMMON):$(ASCIIDOC_HTML):$(ASCIIDOC_DOCBOOK))
 

diff --git a/Documentation/generate-mergetool-list.sh b/Documentation/generate-mergetool-list.sh
new file mode 100755 (executable)
index 0000000..6700498
--- /dev/null
+++ b/Documentation/generate-mergetool-list.sh
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+if test "$#" -ne 3
+then
+       echo >&2 "USAGE: $0 <SOURCE_DIR> <MODE> <OUTPUT>"
+       exit 1
+fi
+
+SOURCE_DIR="$1"
+TOOL_MODE="$2"
+OUTPUT="$3"
+MERGE_TOOLS_DIR="$SOURCE_DIR/mergetools"
+
+(
+       . "$SOURCE_DIR"/git-mergetool--lib.sh &&
+       show_tool_names can_$TOOL_MODE
+) | sed -e "s/\([a-z0-9]*\)/\`\1\`;;/" >"$OUTPUT"