git-gui: extract script to generate "tclIndex"

Extract script to generate "tclIndex". This change allows us to reuse
the build logic with the Meson build system.

Signed-off-by: Patrick Steinhardt <ps@pks.im>

Author: pks-t

Makefile

@@ -75,7 +75,6 @@ ifndef V
 	QUIET_INDEX    = $(QUIET)echo '   ' INDEX $(dir $@) &&
 	QUIET_MSGFMT0  = $(QUIET)printf '    MSGFMT %12s ' $@ && v=`
 	QUIET_MSGFMT1  = 2>&1` && echo "$$v" | sed -e 's/fuzzy translations/fuzzy/' | sed -e 's/ messages*//g'
-	QUIET_2DEVNULL = 2>/dev/null
 
 	INSTALL_D0 = dir=
 	INSTALL_D1 = && echo ' ' DEST $$dir && $(INSTALL) -d -m 755 "$$dir"
@@ -226,19 +225,8 @@ update-po:: $(PO_TEMPLATE)
 $(ALL_MSGFILES): %.msg : %.po
 	$(QUIET_MSGFMT0)$(MSGFMT) --statistics --tcl -l $(basename $(notdir $<)) -d $(dir $@) $< $(QUIET_MSGFMT1)
 
-lib/tclIndex: $(ALL_LIBFILES) GIT-GUI-BUILD-OPTIONS
-	$(QUIET_INDEX)if echo \
-	  $(foreach p,$(PRELOAD_FILES),source $p\;) \
-	  auto_mkindex lib $(patsubst lib/%,%,$(sort $(ALL_LIBFILES))) \
-	| $(TCL_PATH) $(QUIET_2DEVNULL); then : ok; \
-	else \
-	 echo >&2 "    * $(TCL_PATH) failed; using unoptimized loading"; \
-	 rm -f $@ ; \
-	 echo '# Autogenerated by git-gui Makefile' >$@ && \
-	 echo >>$@ && \
-	 $(foreach p,$(PRELOAD_FILES) $(sort $(ALL_LIBFILES)),echo '$(subst lib/,,$p)' >>$@ &&) \
-	 echo >>$@ ; \
-	fi
+lib/tclIndex: $(ALL_LIBFILES) generate-tclindex.sh GIT-GUI-BUILD-OPTIONS
+	$(QUIET_INDEX)$(SHELL_PATH) generate-tclindex.sh . ./GIT-GUI-BUILD-OPTIONS $(ALL_LIBFILES)
 
 GIT-GUI-BUILD-OPTIONS: FORCE
 	@sed \

generate-tclindex.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+if test "$#" -lt 3
+then
+	echo >&2 "usage: $0 <BUILD_DIR> <BUILD_OPTIONS> <LIBFILE> [<LIBFILE>...]"
+	exit 1
+fi
+
+BUILD_DIR="$1"
+BUILD_OPTIONS="$2"
+shift 2
+LIBFILES="$(echo "$@" | sort | sed 's|lib/||g')"
+
+. "$BUILD_OPTIONS"
+
+cd "$BUILD_DIR"
+
+if {
+	echo "source lib/class.tcl;"
+	echo "auto_mkindex lib $LIBFILES"
+} | "$TCL_PATH"
+then
+	: ok
+else
+	 echo >&2 "    * $TCL_PATH failed; using unoptimized loading"
+	 rm -f $@
+	 echo '# Autogenerated by git-gui Makefile' >lib/tclIndex
+	 echo >>lib/tclIndex
+	 echo "class.tcl" >>lib/tclIndex
+	 printf "%s\n" $LIBFILES >>lib/tclIndex
+	 echo >>lib/tclIndex
+fi