Thanks Joshua.
I have never seen "-Xarch" before in a Makefile. That looks like very simple
and elegant way to address the issue. I will give it a shot. I will be able
to easily verify that it works because Intel builds will fail with following
error if CFLAGS contains the -faltivec flag:
clang: error: invalid argument '-faltivec' only allowed with 'ppc/ppc64'
I am glad to hear that I can use conditional expressions in my Portfiles, if
need be. It looks like I will need to brush up on my Tcl.
Thanks again,
Rob
________________________________
From: Joshua Root <j...@macports.org>
Sent: July 31, 2022 9:38 PM
To: Robert Kennedy <am...@hotmail.com>
Cc: MacPorts Development <macports-dev@lists.macports.org>
Subject: Re: Help with New Port - M2VDownsizer
On 2022-8-1 10:11 , Robert Kennedy wrote:
> Hello everyone!
>
> I am working on a new port, M2VDownzsizer, which is a sister port to the
> recent existing port, M2VRequantiser. Both ports are command line
> programs that shrink MPEG-2 video and are commonly used when shrinking
> a DVD-9 video disc to fit onto a much more affordable DVD-5 writable disc.
>
> M2VDownsizer was released as an open source project many years ago and
> was developed as an old XCode project for Macs running PowerPC and Intel
> 32 bit. The code is quite old.
>
> I have converted the project from an XCode project to a much simpler
> project using a Makefile. I have also hacked and updated the code so it
> will run on modern compilers. I also eliminated the need to compile the
> very old libraries in the source code by linking to much more up to date
> libraries available in Macports. I have even written a man page!
> M2VDownsizer appears to run just fine on more modern Macs!
>
> Now my challenge is creating a Portfile! I have a couple of questions:
>
> 1. How do I tell Macports to copy my Makefile (which I will place in
> the Files directory along with my source code patches) into my
> working directory before building? (The original source never had a
> Makefile so there is nothing to patch). P.S. I could always create
> my own GitHub project and download the source (with the Makefile)
> from there.
post-extract {
copy ${filespath}/Makefile ${worksrcpath}
}
> 2. How do I tell Macports to include the -faltivec flag in CFLAGS but
> only when a ppc build is being done? I have the following in my
> Makefile but I suspect it would be much better to address this issue
> in the Portfile in case an Intel Mac is trying to build a ppc/x86
> FAT binary:
>
> ifeq ($(findstring ppc, $(UNAME_P)), ppc)
> CFLAGS += -faltivec
> CXXFLAGS += -flativec
> endif
You could instead do:
CFLAGS += -Xarch_ppc -faltivec
CXXFLAGS += -Xarch_ppc -faltivec
That will apply -faltivec only when building for ppc.
> 3. Is there anything like an "if-then-else" statement in Portfiles?
Yes, Portfiles are written in Tcl and can use all Tcl's control flow
mechanisms.
- Josh
