gzip would run as 'gzip -f' when no uncompressed man pages were found,
making it compress the (empty) stdin to stdout.
A few alternative solutions:
- 'find' with {} + might be speedier, but maybe that's not portable
enough (though it's in POSIX 2001 at least AFAICS)
- xargs --no-run-if-empty, but that's a GNU extension
- Always discarding stdout, if it's unlikely to ever be helpful
- More fancy stuff like the following, though maybe some of them could
run into shell limits too, re. d56fcf299fb4 (DocBook: Do not exceed
argument list limit)
* A plain shell 'for' loop
* mandocs: $(MAN)
if [ `find $(obj)/man -name '*.9' | wc -l` -gt 0 ]; then \
find $(obj)/man -name '*.9' | xargs gzip -f; \
fi
* mandocs: $(MAN)
man_pages=`find $(obj)/man -name '*.9'`; \
if [ -n "$$man_pages" ]; then \
echo "$$man_pages" | xargs gzip -f; \
fi
Signed-off-by: Ulf Magnusson <[email protected]>
---
Documentation/DocBook/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index b6a6a2e..73bddf7 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -56,7 +56,7 @@ htmldocs: $(HTML)
MAN := $(patsubst %.xml, %.9, $(BOOKS))
mandocs: $(MAN)
- find $(obj)/man -name '*.9' | xargs gzip -f
+ find $(obj)/man -name '*.9' -exec gzip -f {} \;
installmandocs: mandocs
mkdir -p /usr/local/man/man9/
--
2.1.4
On Sun, Jul 12, 2015 at 2:59 PM, Ulf Magnusson <[email protected]> wrote:
> gzip would run as 'gzip -f' when no uncompressed man pages were found,
> making it compress the (empty) stdin to stdout.
> --- a/Documentation/DocBook/Makefile
> +++ b/Documentation/DocBook/Makefile
> @@ -56,7 +56,7 @@ htmldocs: $(HTML)
>
> MAN := $(patsubst %.xml, %.9, $(BOOKS))
> mandocs: $(MAN)
> - find $(obj)/man -name '*.9' | xargs gzip -f
> + find $(obj)/man -name '*.9' -exec gzip -f {} \;
>
> installmandocs: mandocs
> mkdir -p /usr/local/man/man9/
That does get rid of the binary burp, but 'xargs gzip -f' has been in
the Makefile since January, and gzipping '\n' just started recently.
So what's changed?
It looks like, for whatever reason, make installmandocs always ends up
rerunning mandocs -- there's now a 'GEN Documentation
Docbook//v4l2.xml' printed, and that extra mandocs invocation is where
the problematic second invocation of find is coming from. I won't
pretend to understand the Makefile flow to guess at why that's
happening, but obviously 'make mandocs; make installmandocs' shouldn't
need to regenerate things already generated.
In any event,
Tested-by: Jim Davis <[email protected]>
Jim
On Sun, Jul 12, 2015 at 04:36:53PM -0700, Jim Davis wrote:
> On Sun, Jul 12, 2015 at 2:59 PM, Ulf Magnusson <[email protected]> wrote:
> > gzip would run as 'gzip -f' when no uncompressed man pages were found,
> > making it compress the (empty) stdin to stdout.
>
> > --- a/Documentation/DocBook/Makefile
> > +++ b/Documentation/DocBook/Makefile
> > @@ -56,7 +56,7 @@ htmldocs: $(HTML)
> >
> > MAN := $(patsubst %.xml, %.9, $(BOOKS))
> > mandocs: $(MAN)
> > - find $(obj)/man -name '*.9' | xargs gzip -f
> > + find $(obj)/man -name '*.9' -exec gzip -f {} \;
> >
> > installmandocs: mandocs
> > mkdir -p /usr/local/man/man9/
>
> That does get rid of the binary burp, but 'xargs gzip -f' has been in
> the Makefile since January, and gzipping '\n' just started recently.
> So what's changed?
>
No idea. I just assumed it had been broken since then, since the version
before d56fcf299fb4 (DocBook: Do not exceed argument list limit) looked
for *.9 files before running gzip:
mandocs: $(MAN)
$(if $(wildcard $(obj)/man/*.9),gzip -f $(obj)/man/*.9)
> It looks like, for whatever reason, make installmandocs always ends up
> rerunning mandocs -- there's now a 'GEN Documentation
> Docbook//v4l2.xml' printed, and that extra mandocs invocation is where
> the problematic second invocation of find is coming from. I won't
> pretend to understand the Makefile flow to guess at why that's
> happening, but obviously 'make mandocs; make installmandocs' shouldn't
> need to regenerate things already generated.
I won't pretend to understand the Makefile flow either. Guess it might
be worth looking into v4l2.xml as well then. Could be some directory
shenanigans going on judging from the '//'.
>
> In any event,
>
> Tested-by: Jim Davis <[email protected]>
>
> Jim
I just noticed the commit message only mentions the alternative
solutions and not the implemented solution. Could send a v2 that fixes
that, but I'll wait for more comments first.
Cheers,
Ulf
On Mon, Jul 13, 2015 at 2:46 AM, Ulf Magnusson <[email protected]> wrote:
> On Sun, Jul 12, 2015 at 04:36:53PM -0700, Jim Davis wrote:
>> On Sun, Jul 12, 2015 at 2:59 PM, Ulf Magnusson <[email protected]> wrote:
>> > gzip would run as 'gzip -f' when no uncompressed man pages were found,
>> > making it compress the (empty) stdin to stdout.
>>
>> > --- a/Documentation/DocBook/Makefile
>> > +++ b/Documentation/DocBook/Makefile
>> > @@ -56,7 +56,7 @@ htmldocs: $(HTML)
>> >
>> > MAN := $(patsubst %.xml, %.9, $(BOOKS))
>> > mandocs: $(MAN)
>> > - find $(obj)/man -name '*.9' | xargs gzip -f
>> > + find $(obj)/man -name '*.9' -exec gzip -f {} \;
>> >
>> > installmandocs: mandocs
>> > mkdir -p /usr/local/man/man9/
>>
>> That does get rid of the binary burp, but 'xargs gzip -f' has been in
>> the Makefile since January, and gzipping '\n' just started recently.
>> So what's changed?
>>
>
> No idea. I just assumed it had been broken since then, since the version
> before d56fcf299fb4 (DocBook: Do not exceed argument list limit) looked
> for *.9 files before running gzip:
>
> mandocs: $(MAN)
> $(if $(wildcard $(obj)/man/*.9),gzip -f $(obj)/man/*.9)
>
>> It looks like, for whatever reason, make installmandocs always ends up
>> rerunning mandocs -- there's now a 'GEN Documentation
>> Docbook//v4l2.xml' printed, and that extra mandocs invocation is where
>> the problematic second invocation of find is coming from. I won't
>> pretend to understand the Makefile flow to guess at why that's
>> happening, but obviously 'make mandocs; make installmandocs' shouldn't
>> need to regenerate things already generated.
>
> I won't pretend to understand the Makefile flow either. Guess it might
> be worth looking into v4l2.xml as well then. Could be some directory
> shenanigans going on judging from the '//'.
>
I looked into it some more, and I'm now fairly certain that 'mandocs' always
runs its recipe regardless of the status of the prerequisites. Changing the
top-level Makefile to do
$(Q)$(MAKE) --debug=v $(build)=Documentation/DocBook $@
and running 'make mandocs', you see some FORCEs in the output, which -- unless
my make fu is weak -- causes all the targets above that to always be considered
out of date:
File 'mandocs' does not exist.
Considering target file 'Documentation/DocBook/z8530book.9'.
Considering target file 'Documentation/DocBook/z8530book.xml'.
...
Considering target file 'FORCE'.
File 'FORCE' does not exist.
Finished prerequisites of target file 'FORCE'.
Must remake target 'FORCE'.
Successfully remade target file 'FORCE'.
...
Must remake target 'Documentation/DocBook/z8530book.xml'.
...
Must remake target 'mandocs'.
Re. the 'GEN Documentation Docbook//v4l2.xml', I think the problem is the
following rule in Documentation/DocBook/media/Makefile:
$(MEDIA_OBJ_DIR)/v4l2.xml: $(OBJIMGFILES)
@$($(quiet)gen_xml)
@(ln -sf `cd $(MEDIA_SRC_DIR) && /bin/pwd`/v4l/*xml $(MEDIA_OBJ_DIR)/)
@(ln -sf `cd $(MEDIA_SRC_DIR) && /bin/pwd`/dvb/*xml $(MEDIA_OBJ_DIR)/)
./Documentation/DocBook/v4l2.xml is a symlink, so make compares the
modification time of the symlink *target* (which is never updated) against the
image (*.png, *.gif, etc.) files in $(OBJIMGFILES). Updating the symlink itself
won't change that modification time, so that's why it always runs.
Passing --check-symlink-times to make so that it also looks at the modification
time of the symlink seems to change a bunch of other stuff in the output too.
Maybe there's other problems lurking here as well.
>>
>> In any event,
>>
>> Tested-by: Jim Davis <[email protected]>
>>
>> Jim
>
> I just noticed the commit message only mentions the alternative
> solutions and not the implemented solution. Could send a v2 that fixes
> that, but I'll wait for more comments first.
>
> Cheers,
> Ulf
Cheers,
Ulf
On Tue, Jul 14, 2015 at 6:27 AM, Ulf Magnusson <[email protected]> wrote:
> On Mon, Jul 13, 2015 at 2:46 AM, Ulf Magnusson <[email protected]> wrote:
>> On Sun, Jul 12, 2015 at 04:36:53PM -0700, Jim Davis wrote:
>>> On Sun, Jul 12, 2015 at 2:59 PM, Ulf Magnusson <[email protected]> wrote:
>>> > gzip would run as 'gzip -f' when no uncompressed man pages were found,
>>> > making it compress the (empty) stdin to stdout.
>>>
>>> > --- a/Documentation/DocBook/Makefile
>>> > +++ b/Documentation/DocBook/Makefile
>>> > @@ -56,7 +56,7 @@ htmldocs: $(HTML)
>>> >
>>> > MAN := $(patsubst %.xml, %.9, $(BOOKS))
>>> > mandocs: $(MAN)
>>> > - find $(obj)/man -name '*.9' | xargs gzip -f
>>> > + find $(obj)/man -name '*.9' -exec gzip -f {} \;
>>> >
>>> > installmandocs: mandocs
>>> > mkdir -p /usr/local/man/man9/
>>>
>>> That does get rid of the binary burp, but 'xargs gzip -f' has been in
>>> the Makefile since January, and gzipping '\n' just started recently.
>>> So what's changed?
>>>
>>
>> No idea. I just assumed it had been broken since then, since the version
>> before d56fcf299fb4 (DocBook: Do not exceed argument list limit) looked
>> for *.9 files before running gzip:
>>
>> mandocs: $(MAN)
>> $(if $(wildcard $(obj)/man/*.9),gzip -f $(obj)/man/*.9)
>>
>>> It looks like, for whatever reason, make installmandocs always ends up
>>> rerunning mandocs -- there's now a 'GEN Documentation
>>> Docbook//v4l2.xml' printed, and that extra mandocs invocation is where
>>> the problematic second invocation of find is coming from. I won't
>>> pretend to understand the Makefile flow to guess at why that's
>>> happening, but obviously 'make mandocs; make installmandocs' shouldn't
>>> need to regenerate things already generated.
>>
>> I won't pretend to understand the Makefile flow either. Guess it might
>> be worth looking into v4l2.xml as well then. Could be some directory
>> shenanigans going on judging from the '//'.
>>
>
> I looked into it some more, and I'm now fairly certain that 'mandocs' always
> runs its recipe regardless of the status of the prerequisites. Changing the
> top-level Makefile to do
>
> $(Q)$(MAKE) --debug=v $(build)=Documentation/DocBook $@
>
> and running 'make mandocs', you see some FORCEs in the output, which -- unless
> my make fu is weak -- causes all the targets above that to always be considered
> out of date:
>
> File 'mandocs' does not exist.
> Considering target file 'Documentation/DocBook/z8530book.9'.
> Considering target file 'Documentation/DocBook/z8530book.xml'.
> ...
> Considering target file 'FORCE'.
> File 'FORCE' does not exist.
> Finished prerequisites of target file 'FORCE'.
> Must remake target 'FORCE'.
> Successfully remade target file 'FORCE'.
> ...
> Must remake target 'Documentation/DocBook/z8530book.xml'.
> ...
> Must remake target 'mandocs'.
Had forgotten that 'mandocs' is a phony target too. That alone makes it always
run its recipe when it's a prerequisite of some target that's run.
>
>
> Re. the 'GEN Documentation Docbook//v4l2.xml', I think the problem is the
> following rule in Documentation/DocBook/media/Makefile:
>
> $(MEDIA_OBJ_DIR)/v4l2.xml: $(OBJIMGFILES)
> @$($(quiet)gen_xml)
> @(ln -sf `cd $(MEDIA_SRC_DIR) && /bin/pwd`/v4l/*xml $(MEDIA_OBJ_DIR)/)
> @(ln -sf `cd $(MEDIA_SRC_DIR) && /bin/pwd`/dvb/*xml $(MEDIA_OBJ_DIR)/)
>
> ./Documentation/DocBook/v4l2.xml is a symlink, so make compares the
> modification time of the symlink *target* (which is never updated) against the
> image (*.png, *.gif, etc.) files in $(OBJIMGFILES). Updating the symlink itself
> won't change that modification time, so that's why it always runs.
>
> Passing --check-symlink-times to make so that it also looks at the modification
> time of the symlink seems to change a bunch of other stuff in the output too.
> Maybe there's other problems lurking here as well.
>
>>>
>>> In any event,
>>>
>>> Tested-by: Jim Davis <[email protected]>
>>>
>>> Jim
>>
>> I just noticed the commit message only mentions the alternative
>> solutions and not the implemented solution. Could send a v2 that fixes
>> that, but I'll wait for more comments first.
>>
>> Cheers,
>> Ulf
>
> Cheers,
> Ulf
Cheers,
Ulf