Generally, I have no objection to this change. But instead of setting it to NO_SUCH_PATH, I would not set it at all, and avoid the $(shell) to see if it exists completely. Just don't set CUSTOM_MAKE_DIR if it does not exist. Then you don't need the HAS_CUSTOM_MAKE, it can just be ifdef CUSTOM_MAKE_DIR
Not sure I like the word CUSTOM, but that's just a name debate. Maybe ADDON or MODDING or MODS or oo oo PIGGYBACK? ;^) http://3.bp.blogspot.com/-cHeD4qJSB44/TbMtSsAiY4I/AAAAAAAAA1c/gctQfVffu_o/s1600/PiggyBack.jpg -kto On Jan 15, 2012, at 9:01 PM, David Holmes wrote: > Presently the build system contains some files, and directives involving > those files, that supports the building of the Java SE Embedded product. What > I would like to do is remove direct support for this and replace it with a > more general mechanism that allows for custom make files to be included from > an arbitrary location - which then allows for the removal of the embedded > specific files. > > Initially I've modeled this on some other conditional mechanisms by defining > the default location for non-OpenJDK builds, checking its existence and then > using that as a guard for the individual files. > > http://cr.openjdk.java.net/~dholmes/custom-make/webrev/ > > ! ifneq ($(OPENJDK),true) > ! CUSTOM_MAKE_DIR_REL=closed > ! else > ! CUSTOM_MAKE_DIR_REL=NO_SUCH_PATH > ! endif > ! CUSTOM_MAKE_DIR=$(BUILDDIR)/$(CUSTOM_MAKE_DIR_REL) > > + # Use this variable to guard inclusion of the custom files > + HAS_CUSTOM_MAKE := $(shell if [ -d $(CUSTOM_MAKE_DIR) ]; then echo 1; else > echo 0; fi) > > ... > > + ifeq ($(HAS_CUSTOM_MAKE),1) > + include $(CUSTOM_MAKE_DIR)/Defs.gmk > + endif > > Initially there are only two hooks for these custom files: > > 1. At the end common/Defs.gmk (as it gets included by all the Makefiles) > 2. In the top-level JDK Makefile, including a custom Release.gmk > > Naturally these map to the existing uses of the *-embedded.gmk files. > > It then occurred to me that if someone wanted to add an additional hook > somewhere else, that it might be best to check for the existence of the > actual file rather than a root directory for all such files. That led me to > consider a function custom_include(<filename>) to hide the existence logic. > But I wasn't sure if a function could contain an include directive and upon > checking on that I discovered a much simpler approach: the -include > directive. This is like the include directive but does not trigger an error > if the file does not exist. So we would simply have this in Defs.gmk: > > ifneq ($(OPENJDK),true) > CUSTOM_MAKE_DIR_REL=closed > else > CUSTOM_MAKE_DIR_REL=NO_SUCH_PATH > endif > CUSTOM_MAKE_DIR=$(BUILDDIR)/$(CUSTOM_MAKE_DIR_REL) > > and then > > -include $(CUSTOM_MAKE_DIR)/<path-to-file.gmk> > > wherever we needed it (again initially only the two locations I mentioned). > > I'd like to hear people's opinions on this. > > Thanks, > David
