Re: [dpdk-dev] [PATCH v2] examples/ip_pipeline: fix freebsd build error

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Apr 10, 2018 at 02:19:38PM +0200, Thomas Monjalon wrote:
> 10/04/2018 12:25, Singh, Jasvinder:
> > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > 10/04/2018 11:51, Jasvinder Singh:
> > > > IP_Pipeline app is not supported in FreeBSD environment. Therefore,
> > > > skip it while building the sample apps on FreeBSD.
> > > [...]
> > > > --- a/examples/ip_pipeline/Makefile +++
> > > > b/examples/ip_pipeline/Makefile @@ -67,6 +67,13 @@ RTE_TARGET ?=
> > > > x86_64-native-linuxapp-gcc
> > > >
> > > >  include $(RTE_SDK)/mk/rte.vars.mk
> > > >
> > > > +ifneq ($(CONFIG_RTE_EXEC_ENV),"linuxapp")
> > > 
> > > You can use CONFIG_RTE_EXEC_ENV_LINUXAPP
> > > 
> > > > +$(info This application can only operate in a linuxapp
> > > > environment, \ +please change the definition of the RTE_TARGET
> > > > environment variable) +all: +clean: +else
> > > 
> > > 
> > > Copy of my previous comment: " It is not skipping the example, just
> > > throwing an error (which is needed).
> > > 
> > > You should add a test in examples/Makefile to really skip it.  "
> > 
> > In V2, we follow the same pattern as followed in other examples such as
> > l3fwd-power, ethtool, etc.
> 
> A kind of counter example is: ifeq ($(CONFIG_RTE_ARCH_X86_64),y) DIRS-y
> += performance-thread endif
> 
> But I get your point that it is done this way in several examples.
> 
> > If we put check in examples/Makefile, than how the situation is handled
> > if someone tries to build ip_pipeline straight instead of building all
> > examples.
> 
> My thought is that if you try to build explicitly this example on
> FreeBSD, you should get an error.
> 
> > > In this v2, you replaced the error by an info message.  Error was
> > > better in my opinion.
> 
> I will get this v2 and not bother you more about that.  All examples
> could be fixed at once. Not sure it is worth though, given this is the
> legacy build system.
> 

Well, we still need a make-based solution for the example apps, because if
we using meson & ninja for the main DPDK build, we still need to provide a
makefile for each sample app. That makefile should build each app
standalone using the pkg-config info to find DPDK libs. It also needs to
signal to the user when they are trying to compile the app on an
unsupported platform.

The alternative, I suppose, is not to have unsupported examples shipped for
different platforms, but I think that is not as good a solution.

/Bruce