From 023c3370ac330760aaf399cf6f6d9dbd7350e8e5 Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Fri, 6 Dec 2024 14:24:55 +0100
Subject: [PATCH] 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>
---
 Documentation/Makefile                   | 22 ++++++++--------------
 Documentation/generate-mergetool-list.sh | 17 +++++++++++++++++
 2 files changed, 25 insertions(+), 14 deletions(-)
 create mode 100755 Documentation/generate-mergetool-list.sh

diff --git a/Documentation/Makefile b/Documentation/Makefile
index e853d89eb5..f0e5bc9c0c 100644
--- 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
index 0000000000..6700498b93
--- /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"