[Bug fortran/100917] Bind(c): errors handling long double real

[sandra at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100917

sandra at gcc dot gnu.org changed:

           What    |Removed                     |Added
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                 CC|                            |sandra at gcc dot gnu.org

--- Comment #4 from sandra at gcc dot gnu.org ---
I've observed this bug in my own testing as well, and traced it to the same
cause:  the GFC descriptor structure doesn't encode the kind, only the
elem_len, so the runtime can't convert it to a valid C descriptor.

IIUC the GFC descriptor needs to encode the kind to support assumed-type
arguments in functions that are not declared bind(c) (for example, a subroutine
with Fortran binding that acts as a wrapper around a C function).  I imagine
any proper fix for this would involve an ABI change affecting programs that
don't even use bind(c).