llvm-gcc42 does not accept -march

[naromero@…]

The llvm-gcc42 port does not accept -march 64.

This is the error message I get,

cc1: error: unrecognized command line option "-march"

but this option should just be passed to the GNU compiler.

[naromero@…]

This looks like this bug which is supposed to be fixed: #20660

[naromero@…]

This current bug is for the flag -march, while the older ticket is for -arch

[ryandesign (Ryan Carsten Schmidt)]

Is this a bug in the MacPorts portfile for llvm-gcc42, or a bug in the llvm-gcc42 software? If the latter, submit it to the developers of the software.

[naromero@…]

Not really sure. Will need to do some digging around to figure this out.

[naromero@…]

I asked on the llvm-dev list and they say that the problem is not in llvm but in MacPorts. Note that the problem was with -arch and not -march as I heard stated earlier.

One developer stated:

The -arch option is handled by Apple's "driver-driver", and the MacPorts build is probably not using that. See the driverdriver.c source file in llvm-gcc for details.

My follow-up

Since presumably Macports is just fetching an llvm tar ball from some repository, is the issue that llvm has been misconfigure in some obvious way? Yes, I can take a look at the driverdriver.c source file as well.

Reply by another developer: Just plain configure/make/make install won't build the driver driver. You need an apple style buildit for that. Check out the build_llvm or build_gcc scripts in the source directory for a guideline.

Should this also be working in LLVM 2.9 or is the latest SVN also needed?

2.9 should be fine.

Could someone please take look into this?

[jmroot (Joshua Root)]

Please remember to cc the maintainers. The message in the description shows a problem with -march, but in the comments you're now saying the problem is with -arch. Which is it?

[naromero@…]

Cc Me!

[naromero@…]

The problem is with -arch, sorry about the confusion.

[mfeiri]

Thanks for your report. We prefer the standard "configure/make/make install" build process. Note that llvm-gcc is deprecated. Please consider clang if you need a (obj)c(++) compiler with support for the -arch flag.