Execute ocamlbuild only once per make invocation

This fixes in particular parallel make execution (even
if it does not lead to any speed-up).

Makefile.in

@@ -6,6 +6,7 @@
 # authors: George Necula, Gabriel Kerneis
 
 CILLY			  = cilly
+CIL_VERSION = @CIL_VERSION@
 
 .PHONY: all
 all: cillib $(CILLY)
@@ -52,53 +53,67 @@ OBJDIR      = _build
 BINDIR		  = bin
 CILLYDIR	  = lib
 
-OCAMLBEST = @OCAMLBEST@
-CILLIB_FILES = $(OBJDIR)/src/cil.cma
-ifeq ($(OCAMLBEST),opt)
- CILLIB_FILES  += $(OBJDIR)/src/cil.cmxa $(OBJDIR)/src/cil.a
- EXEMODE        = .native
-else
- EXEMODE        = .byte
+# Ocaml tools
+OCAMLC = @OCAMLC@
+OCAMLOPT = @OCAMLOPT@
+OCAMLFIND = @OCAMLFIND@
+OCAMLBUILD = @OCAMLBUILD@
+
+PERL = @PERL@
+
+# Build the list of files for cillib
+CILLIB_TARGETS=
+CILLY_EXE_FILES=
+
+ifneq ($(OCAMLC),"no")
+  CILLIB_TARGETS  += $(OBJDIR)/src/cil.cma
+  CILLY_EXE_FILES += $(OBJDIR)/src/cilly.byte
+endif
+ifneq ($(OCAMLOPT),"no")
+  CILLIB_TARGETS  += $(OBJDIR)/src/cil.cmxa $(OBJDIR)/src/cil.a
+  CILLY_EXE_FILES += $(OBJDIR)/src/cilly.native
 endif
 
-EXE = $(EXEMODE)$(EXEEXT)
+CILLIB_FILES = $(OBJDIR)/src/cil.libfiles
+CILDOC_INDEX = $(OBJDIR)/cil.docdir/index.html
 
-OCAMLBUILD = @OCAMLBUILD@
-OCAMLBUILD += -build-dir $(OBJDIR) -no-links -classic-display
 
-OCAMLFIND = @OCAMLFIND@
+# Force a single invocation of ocamlbuild per make execution
 
-PERL = @PERL@
+OCAMLBUILD += -build-dir $(OBJDIR) -no-links -classic-display
 
-# Force to always rebuild a target (for ocamlbuild targets)
-.PHONY: .FORCE
-.FORCE:
+OCAMLBUILD_TARGETS = \
+	$(CILLIB_TARGETS) \
+	$(CILLIB_FILES)		\
+  $(CILLY_EXE_FILES) \
+	$(CILDOC_INDEX)
 
-$(OBJDIR)/src/%: .FORCE
-	$(OCAMLBUILD) src/$*
+# Trick: this no-op rule is executed for each target, but
+# its PHONY dependency is built exactly once.
+$(OCAMLBUILD_TARGETS): ocamlbuild
+	@:
 
-$(OBJDIR)/doc/%: .FORCE
-	CIL_VERSION=@CIL_VERSION@ $(OCAMLBUILD) doc/$*
+.PHONY: ocamlbuild
+ocamlbuild:
+	export CIL_VERSION
+	$(OCAMLBUILD) $(patsubst $(OBJDIR)/%,%,$(OCAMLBUILD_TARGETS))
 
 # OCaml CIL library
 .PHONY: cillib
-cillib: $(CILLIB_FILES) $(OBJDIR)/src/cil.libfiles
-
-# cilly main executable
-$(BINDIR)/$(CILLY)$(EXE): $(OBJDIR)/src/main$(EXEMODE)
-	cp $< $@
+cillib: $(CILLIB_TARGETS)
 
 # cilly perl wrapper
 prefix = @prefix@
 INSTALL_BASE = $(prefix)
 
 CILLYMOD := Cilly
 
-$(CILLYDIR)/Makefile: Makefile $(CILLYDIR)/Makefile.PL $(CILLYDIR)/App/$(CILLYMOD).pm
+$(CILLYDIR)/Makefile: $(CILLYDIR)/Makefile.PL $(CILLYDIR)/App/$(CILLYMOD).pm
 	cd $(CILLYDIR); $(PERL) Makefile.PL INSTALL_BASE="$(INSTALL_BASE)"
 
 .PHONY: $(CILLY)
-$(CILLY): $(BINDIR)/$(CILLY)$(EXE) $(CILLYDIR)/Makefile
+$(CILLY): $(CILLY_EXE_FILES) $(CILLYDIR)/Makefile
+	cp $(CILLY_EXE_FILES) bin/
 	$(MAKE) -C $(CILLYDIR)
 
 # Create the machine dependency module
@@ -167,7 +182,7 @@ $(OBJDIR)/machdep.ml : src/machdep-ml.c configure.ac Makefile.in
 
 $(CILLYDIR)/App/$(CILLYMOD).pm: $(CILLYDIR)/App/$(CILLYMOD).pm.in src/machdep-ml.c configure.ac Makefile.in
 	cp $(CILLYDIR)/App/$(CILLYMOD).pm.in $(CILLYDIR)/App/$(CILLYMOD).pm
-	sed -e "s|CIL_VERSION|@CIL_VERSION@|" $(CILLYDIR)/App/$(CILLYMOD).pm > $(CILLYDIR)/App/$(CILLYMOD).pm.tmp; \
+	sed -e "s|CIL_VERSION|$(CIL_VERSION)|" $(CILLYDIR)/App/$(CILLYMOD).pm > $(CILLYDIR)/App/$(CILLYMOD).pm.tmp; \
 	mv $(CILLYDIR)/App/$(CILLYMOD).pm.tmp $(CILLYDIR)/App/$(CILLYMOD).pm; \
 	if $(MACHDEPCC) -m32 src/machdep-ml.c -o $(OBJDIR)/machdep-ml32.exe ;then \
 	  sed -e "s|nogcc32model|`$(EMUL) $(OBJDIR)/machdep-ml32.exe --env`|" $(CILLYDIR)/App/$(CILLYMOD).pm > $(CILLYDIR)/App/$(CILLYMOD).pm.tmp; \
@@ -223,7 +238,7 @@ doc: texdoc pdfdoc odoc
 .PHONY: odoc texdoc pdfdoc
 
 # Documentation generated by "ocamldoc"
-odoc: $(OBJDIR)/doc/cil.docdir/index.html
+odoc: $(CILDOC_INDEX)
 	-rm -rf doc/html/cil/api
 	-mkdir -p doc/html/cil/
 	-cp -r $(dir $<) doc/html/cil/api
@@ -237,7 +252,7 @@ doc/cilpp.tex: doc/cilcode.pl doc/cil.tex $(CILLY)
 
 # Documentation generated from latex files using "hevea"
 texdoc: doc/cilpp.tex
-	cd doc/html/cil; printf '\\def\\cilversion{@CIL_VERSION@}\n' >cil.version.tex
+	cd doc/html/cil; printf '\\def\\cilversion{$(CIL_VERSION)}\n' >cil.version.tex
 	cd doc/html/cil; hevea -exec xxdate.exe ../../cilpp
 	cd doc/html/cil; hevea -exec xxdate.exe ../../cilpp
 	cd doc/html/cil; mv cilpp.html cil.html
@@ -246,7 +261,7 @@ texdoc: doc/cilpp.tex
 	cp -f doc/header.html doc/html/cil
 
 pdfdoc: doc/cilpp.tex
-	cd doc; printf '\\def\\cilversion{@CIL_VERSION@}\n' >cil.version.tex
+	cd doc; printf '\\def\\cilversion{$(CIL_VERSION)}\n' >cil.version.tex
 	cd doc; pdflatex cilpp.tex; pdflatex cilpp.tex
 	cd doc; mv cilpp.pdf html/cil/CIL.pdf
 
@@ -311,11 +326,12 @@ ifneq ($(DESTDIR),)
 endif
 export OCAMLFIND_DESTDIR
 
-install-findlib: cillib
+install-findlib: $(CILLIB_FILES) $(CILLIB_TARGETS)
 ifneq ($(OCAMLFIND_DESTDIR),)
 	mkdir -p $(OCAMLFIND_DESTDIR)
 endif
-	$(OCAMLFIND) install -patch-version @CIL_VERSION@ cil META $(CILLIB_FILES) `cat $(OBJDIR)/src/cil.libfiles`
+	$(OCAMLFIND) install -patch-version $(CIL_VERSION) cil META \
+		$(CILLIB_TARGETS) `cat $(CILLIB_FILES)`
 
 uninstall-findlib:
 	$(OCAMLFIND) remove cil

doc/_tags

@@ -1 +1,2 @@
 <cilcode.tmp>: not_hygienic
+<..>: include

src/_tags

@@ -2,4 +2,4 @@
 "ext": include
 "frontc": include
 
-<main.{byte,native}>: use_unix, use_str, use_nums, use_cil
+<cilly.{byte,native}>: use_unix, use_str, use_nums, use_cil