Re: [dpdk-dev] [PATCH] examples: warn about broken pkg-config

[Thomas Monjalon <thomas@monjalon.net>]

29/01/2021 17:05, Bruce Richardson:
> On Fri, Jan 29, 2021 at 04:04:18PM +0000, Burakov, Anatoly wrote:
> > On 29-Jan-21 3:55 PM, Bruce Richardson wrote:
> > > On Fri, Jan 29, 2021 at 04:47:35PM +0100, Thomas Monjalon wrote:
> > > > 19/01/2021 14:03, Bruce Richardson:
> > > > > Since the examples are designed to be built by end-users using Make, we
> > > > > can detect and warn about broken pkg-config on the user's system as part
> > > > > of the build process.
> > > > > 
> > > > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
[...]
> > > > >   56 files changed, 455 insertions(+), 3 deletions(-)
> > > > 
> > > > That's a lot of duplicated code that may need some extension in future.
> > > > What about having a file examples/common.mk to include?
> > > > With the special syntax -include there will be no error in case
> > > > ../common.mk does not exist. Deal?
> > > > 
> > > > ref: https://www.gnu.org/software/make/manual/html_node/Include.html
> > > > 
> > > 
> > > Yes, and no. There is far more boilerplate already in these files which
> > > needs to be consolidated, so I see little point in just trying to extract
> > > this part out alone. Therefore, what I'd like to see done (if ever someone
> > > has the time) is to extract all the boilerplate out to a common makefile,
> > > but also add a postinstall script to flatten out the makefile on install,
> > > so that each example is once again self-contained.
> > > 
> > > I've been thinking about this for a while, just haven't got time for it.
> > > 
> > > /Bruce
> > > 
> > 
> > These makefiles are supposed to be examples. Meaning, it should be possible
> > to just take the example app and compile it as is. That means we can't rely
> > on external makefiles, they're supposed to be self-contained.
> > 
> Exactly. Hence the need to "flatten" out the makefiles, by changing the
> include to be the actual contents.

My proposal is just for pkg-config check, which doesn't serve as an example.
If this check is not there, it still works.
That's what -include is for: include optional stuff which can be missing.