Re: [PATCH 06/13] build: Generate man pages after compiling guile objects.

[Eric Bavier <ericbavier@openmailbox.org>]

On 2016-01-28 09:44, Mathieu Lirzin wrote:
> Hi Eric,
> 
> Eric Bavier <ericbavier@openmailbox.org> writes:
> 
>> Here's my rough first take at this.  It uses the status 77 convention
>> to update a sentinel file and selectively run help2man.
>> 
>> I realize the silent rule output isn't yet polished.
> 
> I have pushed the reviewed patches.  So now it is polished. :)
> 
>> From 038645a3d14cd10fdb37f94703e463d8f7a3241a Mon Sep 17 00:00:00 2001
>> From: Eric Bavier <bavier@member.fsf.org>
>> Date: Wed, 27 Jan 2016 20:31:04 -0600
>> Subject: [PATCH] doc: Generate manpages after .go are compiled.
>> 
>> * build-aux/compile-all.scm: Exit 77 if no files to compile.
>> * Makefile.am (make-go): Rename target to make-go.stamp.  Update if 
>> any
>>   files were successfully compiled.
>> * doc.am (subcommand-manual-target): Add dependency on make-go.stamp.
>>   Run help2man only if script input is changed.
>> ---
>>  Makefile.am               | 12 +++++++++---
>>  build-aux/compile-all.scm |  1 +
>>  doc.am                    | 15 ++++++++++++---
>>  3 files changed, 22 insertions(+), 6 deletions(-)
>> 
> [...]
>> diff --git a/doc.am b/doc.am
>> index f15efcc..b3996d1 100644
>> --- a/doc.am
>> +++ b/doc.am
>> @@ -106,9 +106,18 @@ doc/guix-daemon.1: nix/nix-daemon/guix-daemon.cc
>> 
>>  define subcommand-manual-target
>> 
>> -doc/guix-$(1).1: guix/scripts/$(1).scm
>> -	-LANGUAGE= $(top_builddir)/pre-inst-env		\
>> -	  $(HELP2MAN) --output="$$@" "guix $(1)"
>> +# Note: The dependency on make-go.stamp is to force these docs to be 
>> made only
>> +# after all guile modules have been compiled, so that they are not 
>> compiled
>> +# during this rule.  But we only want to actually generate the 
>> manpages if the
>> +# corresponding script source has been changed.
>> +doc/guix-$(1).1: guix/scripts/$(1).scm make-go.stamp
>> +	-$(AM_V_at)case '$$?' in \
>> +	  *$$<*) \
>> +	    echo "  GEN     $$@"; \
>> +	    LANGUAGE= $(top_builddir)/pre-inst-env \
>> +	    $(HELP2MAN) --output="$$@" "guix $(1)" ;; \
>> +	  *) : ;; \
>> +	esac
> 
> IIUC, there is a problem with adding ‘make-go.stamp’ as a prerequisite
> here.  Since building ‘.go’ files from the tarball will trigger the
> rebuild of man pages.

That's what the case statement is for, it skips the invocation of 
help2man if the script source was not among the dependents updated.  A 
'touch' could be run on $@ in that case, rather than just exiting, so 
that the rule in not run repeatedly.

-- 
`~Eric