generate the post index

Makefile

@@ -8,11 +8,12 @@ post_compiler := src/webcc.ml
 builddir := _build/default
 
 POSTCC := $(builddir)/$(patsubst %.ml,%.exe,$(post_compiler))
+INDEXCC := $(POSTCC) -i
 
 post-sources := $(shell find $(src)/ -type f)
 post-htmls   := $(patsubst $(src)/%.md,$(www)/%.html,$(post-sources))
 
-.PHONY: all serve clean $(post_index)
+.PHONY: all serve clean $(POSTCC)
 
 all: $(POSTCC) $(post-htmls) $(post_index) $(www_root)/static
 	cp -R ~/www/* $(www_root)
@@ -23,10 +24,8 @@ $(www):
 $(www)/%.html: $(src)/%.md $(www)
 	$(POSTCC) $< -o $@
 
-# make sure that this target is .PHONY!
-$(post_index):
-	echo hm > $@
-
+$(post_index): $(post-sources)
+	$(INDEXCC) $^ -o $@
 
 $(www_root)/static:
 	cp -R static $@
@@ -35,7 +34,6 @@ $(POSTCC): $(post_compiler)
 	dune build
 
 clean:
-	rm $(POSTCC)
 	rm -fr $(www_root)
 
 serve: