cross-building fails with generating manpages

[umlaeute]

The build-system builds manpages on the fly by calling binaries with the -help-man flag.

https://github.com/bplaum/gmerlin/blob/68cddb0791c90bd32bcdd7155cb67e3e59bf185e/apps/transcoder/Makefile.am#L29-L30

This only works if the generated binaries can be executed by the current CPU...an assumption that does not hold true when cross-compiling.

Personally I would say that manpages are "minor artifacts", so if they should be omitted if cross-compiling.

[umlaeute]

random (and totally untested) ideas for detecting whether we are cross-compiling:

detecting at configure time

add this to configure.ac:

AM_CONDITIONAL(cross_compiling, [test "x${cross_compiling}" = "xyes"])

and then use something like this in the Makefile.am:

man_MANS = 
if cross_compiling
 man_MANS += gmerlin-transcoder.1
endif

detecting at build time

use something like this in the Makefile:

gmerlin-transcoder.1: gmerlin-transcoder
ifeq ($(host), $(build))
    $(builddir)/gmerlin-transcoder -help-man > $(builddir)/gmerlin-transcoder.1 
else
       touch $(builddir)/gmerlin-transcoder.1
endif

detecting at configure time seems to be preferable, as it doesn't build empty dummy manpages.

[bplaum]

I agree, disabling manpages for cross-compiling would be a good idea. Go ahead if you have a good idea.