The `make` manual documents that a rule of the form target1 target2: prereq recipe
is equivilent to target1: prereq recipe target2: prereq recipe This is correct if only target1 or target2 is wanted, but is not the case if both target1 and target2 are wanted to be rebuilt in the same pass. In such a case, executing the recipe to generate target1 causes the entire rule to be considered complete, short circuiting the search to regenerate target2. This bug can be demonstrated with the generation of documentation from pandoc source. ./xen.git$ touch docs/features/templace.pandoc ./xen.git$ make -C docs/ # Regenerates html/features/template.html ./xen.git$ make -C docs/ # Regenerates txt/features/template.txt ./xen.git$ make -C docs/ # Regenerates pdf/features/template.pdf To work around this, there need to be three distinct rules, so the execution of one recipe doesn't short ciruit the others. To avoid copy&paste duplication, introduce a metarule, and evalute it for each document target. As $(PANDOC) is used to generate documentation from different source types, the metarule can be extended to also encompas the rule to create pdfs from markdown. Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com> --- CC: Ian Jackson <ian.jack...@eu.citrix.com> CC: Wei Liu <wei.l...@citrix.com> --- docs/Makefile | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/docs/Makefile b/docs/Makefile index b9da605..e2537e8 100644 --- a/docs/Makefile +++ b/docs/Makefile @@ -180,22 +180,24 @@ txt/%.txt: %.markdown @$(INSTALL_DIR) $(@D) $(INSTALL_DATA) $< $@ -pdf/%.pdf: %.markdown -ifneq ($(PANDOC),) - @$(INSTALL_DIR) $(@D) - $(PANDOC) --number-sections --toc --standalone $< --output $@ -else - @echo "pandoc not installed; skipping $@" -endif +# Metarule for generating pandoc rules. +define GENERATE_PANDOC_RULE +# $(1) is the target documentation format. $(2) is the source format. -pdf/%.pdf txt/%.txt html/%.html: %.pandoc +$(1)/%.$(1): %.$(2) ifneq ($(PANDOC),) - @$(INSTALL_DIR) $(@D) - $(PANDOC) --number-sections --toc --standalone $< --output $@ + @$(INSTALL_DIR) $$(@D) + $(PANDOC) --number-sections --toc --standalone $$< --output $$@ else - @echo "pandoc not installed; skipping $@" + @echo "pandoc not installed; skipping $$@" endif +endef +$(eval $(call GENERATE_PANDOC_RULE,pdf,pandoc)) # pdf/%.pdf: %.pandoc +$(eval $(call GENERATE_PANDOC_RULE,txt,pandoc)) # txt/%.txt: %.pandoc +$(eval $(call GENERATE_PANDOC_RULE,html,pandoc)) # html/%.html: %.pandoc +$(eval $(call GENERATE_PANDOC_RULE,pdf,markdown)) # pdf/%.pdf: %.markdown + ifeq (,$(findstring clean,$(MAKECMDGOALS))) $(XEN_ROOT)/config/Docs.mk: $(error You have to run ./configure before building docs) -- 2.1.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel