Ensure that changing a Makefile rebuilds everything on the next run.

Also change the default target for protocol/Makefile to not build unconditionally.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

Makefile

@@ -3,15 +3,19 @@
 # sudo pip install rst2html5
 
 .PHONY: all all-zips protocol
-all-zips:
+all-zips: Makefile.uptodate
 	$(MAKE) README.rst
 	$(MAKE) index.html $(addsuffix .html,$(filter-out README,$(basename $(wildcard *.rst))))
 
 all: all-zips protocol
 
-protocol:
+protocol: Makefile.uptodate
 	$(MAKE) -C protocol
 
+Makefile.uptodate: Makefile
+	$(MAKE) clean
+	touch Makefile.uptodate
+
 define PROCESSRST
 $(eval TITLE := $(shell echo '$(basename $<)' | sed -E 's|zip-0{0,3}|ZIP |'): $(shell grep -E '^(\.\.)?\s*Title:' $< |sed -E 's|.*Title:\s*||'))
 rst2html5 -v --title="$(TITLE)" $< >$@

protocol/Makefile

@@ -14,8 +14,16 @@ LATEX=$(ENGINE) --halt-on-error --file-line-error
 #NOCRUFT=
 NOCRUFT=|awk '{gsub(/[({<][/][^ ]* ?/,"")}1'
 
-.PHONY: all
-all: heartwood blossom sapling sprout
+.PHONY: all-specs all
+all-specs: Makefile.uptodate
+	$(MAKE) heartwood.pdf blossom.pdf sapling.pdf sprout.pdf
+
+all: Makefile.uptodate
+	$(MAKE) heartwood blossom sapling sprout
+
+Makefile.uptodate: Makefile
+	$(MAKE) clean
+	touch Makefile.uptodate
 
 sprout.pdf: protocol.tex zcash.bib incremental_merkle.png key_components.png
 	$(MAKE) sprout