Customized make file inclusion

[David Holmes]

FYI here is proposed webrev:

http://cr.openjdk.java.net/~dholmes/7130909/webrev/

CR 7130909 was filed.

David

On 19/01/2012 1:30 PM, David Holmes wrote:
> Hi Kelly,
>
> On 19/01/2012 2:22 AM, Kelly O'Hair wrote:
>>
>> On Jan 17, 2012, at 7:17 PM, David Holmes wrote:
>>
>>> On 18/01/2012 7:07 AM, Kelly O'Hair wrote:
>>>> 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 $(shell) to see if it
>>>> exists completely. Just don't set CUSTOM_MAKE_DIR if it does not exist.
>>>> Then you don't need the HAS_CUSTOM_MAKE, it can just be ifdef
>>>> CUSTOM_MAKE_DIR
>>>
>>> But I/we want the default setting to occur in the build files and not
>>> require that it be set externally. My final suggestion gets rid of
>>> the HAS_CUSTOM_MAKE and the shell usage. Incorporating your
>>> suggestion it simplifies to:
>>>
>>> ifneq ($(OPENJDK),true)
>>> CUSTOM_MAKE_DIR = $(BUILDDIR)/closed
>>> endif
>>
>> Or something like:
>>
>> # Custom makefile additions
>> ifneq ($(OPENJDK),true)
>> CUSTOM_MAKE_DIR = $(BUILDDIR)/closed
>> # This directory should exist if OPENJDK is not "true"
>> ifeq ($(shell if [ ! -d $(CUSTOM_MAKE_DIR) ]; then echo "missing";
>> fi),missing)
>> x:=$(error "ERROR: Not OPENJDK, and missing $(CUSTOM_MAKE_DIR)")
>> endif
>> endif
>
> Not sure we need to force it to be available. Seems this kind of thing
> belongs in a sanity test if anywhere, but personally I don't think it
> has to be enforced.
>
>>>
>>> in Defs.gmk and then:
>>>
>>> -include $(CUSTOM_MAKE_DIR)/<path-to-file.gmk>
>>
>> And:
>>
>> # Custom makefile additions
>> ifdef CUSTOM_MAKE_DIR
>> include $(CUSTOM_MAKE_DIR)/<path-to-file.gmk>
>> endif
>
> The -include is accounting not only for the directory not being present
> but also the actual file. Over time we may add these include hooks to
> support a number of different use-cases but that doesn't mean that
> anybody involved in any single use-case needs to provide every single
> custom file that might exist.
>
>>>
>>> as needed. Though I may get an error with CUSTOM_MAKE_DIR being
>>> undefined in which case I'll need to declare it for OpenJDK builds.
>>
>> Undefined is the same as being defined as empty in terms of expansion
>> $(var)
>
> Was unsure as I see examples where people ensure a variable is always
> defined in both an if and else clause - even if one is empty.
>
> Thanks,
> David
> -----
>
>>>
>>>> Not sure I like the word CUSTOM, but that's just a name debate.
>>>
>>> It customizes the build logic. I preferred it to the "alt" name we
>>> use for hotspot as here it isn't an alternative but an addition.
>>> Anyway just a name game.
>>
>> Not a big deal, but kind of liked the piggyback idea. ;^)
>>
>> -kto
>>
>>>
>>> Thanks,
>>> David
>>>
>>>> Maybe ADDON or MODDING or MODS or oo oo PIGGYBACK? ;^)
>>>> http://3.bp.blogspot.com/-cHeD4qJSB44/TbMtSsAiY4I/AAAAAAAAA1c/gctQfVffu_o/s1600/PiggyBack.jpg
>>>>
>>>>
>>>> -kto
>>>>
>>>> On Jan 15, 2012, at 9:01 PM, David Holmes wrote:
>>>>
>>>>> Presently the build system contains some files, and directives
>>>>> involving those files, that supports the building of the Java SE
>>>>> Embedded product. What I would like to do is remove direct support
>>>>> for this and replace it with a more general mechanism that allows
>>>>> for custom make files to be included from an arbitrary location -
>>>>> which then allows for the removal of the embedded specific files.
>>>>>
>>>>> Initially I've modeled this on some other conditional mechanisms by
>>>>> defining the default location for non-OpenJDK builds, checking its
>>>>> existence and then using that as a guard for the individual files.
>>>>>
>>>>> http://cr.openjdk.java.net/~dholmes/custom-make/webrev/
>>>>>
>>>>> ! ifneq ($(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
>>>>
>>