Re: [Discuss-gnuradio] Recent Commit Issue

[Tim Newman]

I think this is a sort of different beast.  You could check for gslcblas and even pass -lgslcblas as a compile flag, in fact that is what is going on.  The problem is GSL needs BLAS but does not call it directly from the object file, and the --as-needed doesnt check for symbols recursively, so doesnt link it, even if you specifically pass -lgslcblas as a parameter.  I suppose one option is to directly link the gr-wavelet library to CBLAS,  which honestly I thought was already happening.

Tim

On Wed, Jun 26, 2013 at 2:55 PM, Michael Dickens <address@hidden> wrote:

Regarding commit c0b3ce38db0eaaca05fe2f45827fcf6c9184b72b "wavelet: fix for -lgslcblas getting stripped out of the link flags due to -Wl,--as-needed default on newer gcc toolchains, results in missing blas symbols at runtime", as well as other assumptions being made about GCC:

<soapbox>

Just because the compiler is GCC does not mean it will accept the flag being passed to it, nor that it is guaranteed to provide specific functionality if >= a specific version.  Maybe this works on Linux, but it does not on Mac OS X using either Apple's or MacPorts' GCC (4.2, 4.6, 4.7).  So, the above "-Wl,--no-as-needed" does not work, nor does the "xgetbv" instruction, because all versions of GCC use Apple's assembler (which does not support these features).

Clang as provided by Xcode or MacPorts does -not- use Apple's assembler, which means it should be multi-OS compatible for flags and instructions -- but:

The best way to check for a feature (compiler flag, or specific instruction) is to actually test for it, just like we do for most other compiler flags, headers, and many functions (both OS-provided and other dependencies).

</soapbox>

Thanks for listening.  I'm patching the MacPorts install of GNU Radio to remove this commit until a better solution is found. - MLD


_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio