support use of git submodules with the Makefiles

git=1 when invoking make will use the submodule submodules/lua.

On windows, it will also use the submodule submodules/pdcurses.

sys/unix/Makefile.top

@@ -104,7 +104,13 @@ DATNODLB = $(VARDATND) license symbols
 DATDLB = $(DATHELP) dungeon.lua tribute $(SPEC_LEVS) $(QUEST_LEVS) $(VARDATD)
 DAT = $(DATNODLB) $(DATDLB)
 
+LUAHEADERS = lib/lua-$(LUA_VERSION)/src
+LUATESTTARGET = $(LUAHEADERS)/lua.h
+LUATOP = $(LUAHEADERS)
+LUAMAKEFLAGS = CC='$(CC)' SYSCFLAGS='$(SYSCFLAGS)'
+LUA2NHTOP = ../../..
 TOPLUALIB = lib/lua/liblua.a
+
 ALLDEP = $(GAME) recover Guidebook $(VARDAT) spec_levs check-dlb
 
 # first target is also the default target for 'make' without any arguments
@@ -117,23 +123,28 @@ $(GAME): lua_support
 
 lua_support: $(TOPLUALIB) include/nhlua.h
 	@true
-lib/lua-$(LUA_VERSION)/src/liblua.a: lib/lua-$(LUA_VERSION)/src/lua.h
-	( cd lib/lua-$(LUA_VERSION)/src \
-	  && make CC='$(CC)' SYSCFLAGS='$(SYSCFLAGS)' a && cd ../../.. )
-lib/lua/liblua.a: lib/lua-$(LUA_VERSION)/src/liblua.a
+$(LUATOP)/liblua.a: $(LUAHEADERS)/lua.h
+	( cd $(LUATOP) \
+	  && make $(LUAMAKEFLAGS) a && cd $(LUA2NHTOP) )
+lib/lua/liblua.a: $(LUATOP)/liblua.a
 	@( if test -d lib/lua ; then true ; else mkdir -p lib/lua ; fi )
-	cp lib/lua-$(LUA_VERSION)/src/liblua.a $@
+	cp $(LUATOP)/liblua.a $@
 include/nhlua.h: $(TOPLUALIB)
 	echo '/* nhlua.h - generated by top Makefile */' > $@
-	@echo '#include "../lib/lua-$(LUA_VERSION)/src/lua.h"' >> $@
+	@echo '#include "../$(LUAHEADERS)/lua.h"' >> $@
 	@sed -e '/(lua_error)/!d' -e '/(lua_error)/s/;/ NORETURN;/1' \
-		< lib/lua-$(LUA_VERSION)/src/lua.h >> $@
-	@echo '#include "../lib/lua-$(LUA_VERSION)/src/lualib.h"' >> $@
-	@echo '#include "../lib/lua-$(LUA_VERSION)/src/lauxlib.h"' >> $@
+		< $(LUAHEADERS)/lua.h >> $@
+	@echo '#include "../$(LUAHEADERS)/lualib.h"' >> $@
+	@echo '#include "../$(LUAHEADERS)/lauxlib.h"' >> $@
 	@echo '/*nhlua.h*/' >> $@
+# LUATESTTARGET is this by default
 lib/lua-$(LUA_VERSION)/src/lua.h:
 	@echo "Please do 'make fetch-lua' to obtain lua-$(LUA_VERSION)"
 	@false
+# hints file could set LUATESTTARGET to this if GITSUBMODULES is defined
+submodules/lua/lua.h:
+	git submodule init submodules/lua
+	git submodule update --remote submodules/lua
 
 # Note: many of the dependencies below are here to allow parallel make
 # to generate valid output
@@ -339,7 +350,7 @@ clean: clean-lib clean-keep-lib
 	@true
 
 clean-lib:
-	-( cd lib/lua-$(LUA_VERSION)/src && $(MAKE) clean )
+	-( cd $(LUATOP) && $(MAKE) clean )
 
 clean-keep-lib:
 	( cd src ; $(MAKE) clean )