Cactus shouldn't mess with some flags after they have been setup.

Issue #1345 closed
Frank Löffler created an issue

Currently Cactus sets up flags like CPPFLAGS or CFLAGS by adding e.g. CPP_OPENMP_FLAGS. However, later it overwrites these again by their original value in sbin/ProcessConfiguration.pl (search for FIXME).

The attached patch implements what the 'FIXME' suggests - accepting the drawbacks that are mentioned there: that configuration settings not originating from a thorn might not be forwarded from e.g., a .cactus/config file. MPI was one of these, but this is now handled differently anyway. With this patch, we would need to be aware of these and might need to add them to @allowed_opts in the future.

Without the patch however, compilation might fail for perfectly valid setups. One of these is when using openmp, setting all the corresponding _OPENMP_FLAGS, but not setting CPPFLAGS (only CPP_OPENMP_FLAGS). In this case ProcessConfiguration.pl will set CFLAGS to the version in the config file (without the -openmp), but it will leave CPPFLAGS to the version with* -openmp. This later leads to a linker error in external libraries, since compilation there uses CPPFLAGS (with openmp), but the linker doesn't (It correctly uses CFLAGS, but this doesn't have openmp flags here).

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Comments (13)

  1. Erik Schnetter
    • removed comment

    Curl is building fine for me, as do all other thorns in ExternalLibraries. What are your setting and symptoms?

  2. Frank Löffler reporter
    • removed comment

    Same as above. A build fails when using openmp, set using C_OPENMP_FLAGS (and corresponding), but not defining CPPFLAGS. For the release we can use a workaround to define CPPFLAGS (as empty), but this should be cleaned up later.

  3. Roland Haas
    • removed comment

    I never used a global .config file. So if that is the only thing that possibly breaks. Fine with me.

  4. Frank Löffler reporter
    • removed comment

    It's the only thing I am aware of. Now (just after a release) is probably the best time to get it into the development version I would think. Ok to apply?

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