svn commit: r263778 - in head: bin lib lib/clang sbin share/mk usr.bin usr.sbin

[Justin T. Gibbs]

Why wouldn’t we fix these with explicit subdir dependencies (e.g: subdira: subdirb)?  I’m pretty sure I had this working with a hacked up bsd.subdir.mk at a previous job, but my memory is hazy.

—
Justin
  
On Apr 21, 2014, at 7:35 AM, Warner Losh <imp at bsdimp.com> wrote:

> (sorry for the top post)
> 
> This looks good to my eye. I’d be tempted to toss in a comment about the
> __wait=.WAIT construct is due to the primitive nature of bmake’s parser
> so it runs afoul of the .for/.if construction rules and this is needed to expand
> the for variable. It tripped me up when I looked at it, until I recalled a comment
> from similar code in NetBSD.
> 
> Warner
> 
> On Apr 21, 2014, at 7:15 AM, Ian Lepore <ian at FreeBSD.org> wrote:
> 
>> On Thu, 2014-03-27 at 20:44 +0100, Dimitry Andric wrote:
>>> On 27 Mar 2014, at 19:12, Jilles Tjoelker <jilles at stack.nl> wrote:
>>>> On Thu, Mar 27, 2014 at 11:05:00AM -0600, Warner Losh wrote:
>>>>> On Mar 26, 2014, at 4:30 PM, Dimitry Andric <dim at freebsd.org> wrote:
>>>>>> Author: dim
>>>>>> Date: Wed Mar 26 22:30:38 2014
>>>>>> New Revision: 263778
>>>>>> URL: http://svnweb.freebsd.org/changeset/base/263778
>>>> 
>>>>>> Log:
>>>>>> Add a SUBDIR_PARALLEL option to bsd.subdir.mk, to allow make to process
>>>>>> all the SUBDIR entries in parallel, instead of serially.  Apply this
>>>>>> option to a selected number of Makefiles, which can greatly speed up the
>>>>>> build on multi-core machines, when using make -j.
>>>> 
>>>>>> This can be extended to more Makefiles later on, whenever they are
>>>>>> verified to work correctly with parallel building.
>>>> 
>>>>> Why not have this ‘opt out’ rather than ‘opt in’ like it is now? Are
>>>>> there any known bad dependencies this introduces?
>>>> 
>>>> I'm paranoid about build systems ;) It is easy to add dependencies
>>>> across directories and as long as directories are built in sequence,
>>>> nothing goes wrong.
>>>> 
>>>> In fact, I had enabled SUBDIR_PARALLEL in sys/modules/Makefile as well,
>>>> but this caused mysterious failures with some kernels such as mips
>>>> ADM5120.
>>> 
>>> There are a bunch of other parts that don't really like parallel builds
>>> at the moment.  For example, gnu/usr.bin/binutils needs its libraries
>>> (libbfd.a, etc) built first, before it can link the programs.  Similar
>>> for gnu/usr.bin/cc, which needs libiberty, libcpp, etc before being able
>>> to build the rest of gcc.
>>> 
>>> Most of these cases can hopefully be solved by adding .WAIT targets at
>>> strategic points in the SUBDIR lists, but this also needs a bit of extra
>>> logic in bsd.subdir.mk.
>>> 
>>> -Dimitry
>>> 
>> 
>> It turns out I needed the .WAIT functionality to use SUBDIR_PARALLEL for
>> $work, so I came up with the attached, does this look okay to commit?
>> 
>> -- Ian
>> 
>> diff -r 67802e319fc6 share/mk/bsd.subdir.mk
>> --- a/share/mk/bsd.subdir.mk	Sun Apr 20 21:01:07 2014 -0600
>> +++ b/share/mk/bsd.subdir.mk	Mon Apr 21 06:59:37 2014 -0600
>> @@ -4,10 +4,10 @@
>> # The include file <bsd.subdir.mk> contains the default targets
>> # for building subdirectories.
>> #
>> -# For all of the directories listed in the variable SUBDIRS, the
>> +# For all of the directories listed in the variable SUBDIR, the
>> # specified directory will be visited and the target made. There is
>> # also a default target which allows the command "make subdir" where
>> -# subdir is any directory listed in the variable SUBDIRS.
>> +# subdir is any directory listed in the variable SUBDIR.
>> #
>> #
>> # +++ variables +++
>> @@ -42,7 +42,7 @@ distribute:
>> 
>> _SUBDIR: .USE
>> .if defined(SUBDIR) && !empty(SUBDIR) && !defined(NO_SUBDIR)
>> -	@${_+_}for entry in ${SUBDIR}; do \
>> +	@${_+_}for entry in ${SUBDIR:N.WAIT}; do \
>> 		if test -d ${.CURDIR}/$${entry}.${MACHINE_ARCH}; then \
>> 			${ECHODIR} "===> ${DIRPRFX}$${entry}.${MACHINE_ARCH} (${.TARGET:realinstall=install})"; \
>> 			edir=$${entry}.${MACHINE_ARCH}; \
>> @@ -57,7 +57,7 @@ distribute:
>> 	done
>> .endif
>> 
>> -${SUBDIR}: .PHONY
>> +${SUBDIR:N.WAIT}: .PHONY
>> 	${_+_}@if test -d ${.TARGET}.${MACHINE_ARCH}; then \
>> 		cd ${.CURDIR}/${.TARGET}.${MACHINE_ARCH}; \
>> 	else \
>> @@ -65,13 +65,18 @@ distribute:
>> 	fi; \
>> 	${MAKE} all
>> 
>> +__wait=.WAIT
>> .for __target in all all-man checkdpadd clean cleandepend cleandir \
>>    depend distribute lint maninstall manlint \
>>    obj objlink realinstall regress tags \
>>    ${SUBDIR_TARGETS}
>> .ifdef SUBDIR_PARALLEL
>> +__subdir_targets=
>> .for __dir in ${SUBDIR}
>> -${__target}: ${__target}_subdir_${__dir}
>> +.if ${__wait} == ${__dir}
>> +__subdir_targets+= .WAIT
>> +.else
>> +__subdir_targets+= ${__target}_subdir_${__dir}
>> ${__target}_subdir_${__dir}: .MAKE
>> 	@${_+_}set -e; \
>> 		if test -d ${.CURDIR}/${__dir}.${MACHINE_ARCH}; then \
>> @@ -85,7 +90,9 @@ distribute:
>> 		fi; \
>> 		${MAKE} ${__target:realinstall=install} \
>> 		    DIRPRFX=${DIRPRFX}$$edir/
>> +.endif
>> .endfor
>> +${__target}: ${__subdir_targets}
>> .else
>> ${__target}: _SUBDIR
>> .endif
> 
> 
>