https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110825
--- Comment #3 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- On Wed, Jul 26, 2023 at 08:54:01PM +0000, anlauf at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110825 > > --- Comment #1 from anlauf at gcc dot gnu.org --- > (In reply to kargl from comment #0) > > Thus, when compiled and executed the program hits 'STOP 1'. Likely, > > gfortran needs to add a possibly unused hidden argument to the argument list > > for a TYPE(*) dummy argument. > > I guess it should be the other way around: if the dummy argument is TPYE(*), > we only pass a reference to the actual argument, but no hidden argument, > as is the case for bind(c). This is also what the called procedure expects. I had not thought about how gfortran handles bind(c). In my codes that use bind(c), I use an array with character(len=1) with the last element set to c_null_char. On the C side, it looks like a C null-terminated string. I don't use type(*) in my codes, so I'm unsure how, or even if, the length type parameter would/(need to) be passed along. > What if the caller passed a type other than character? That's why I wrote '***possibly unused*** hidden argument' > So we just need to update the caller (the "monster" gfc_conv_procedure_call). > > Do you have an idea what would be the use of the hidden argument here anyway? Hmmm, a scan of F2018 suggest that type(*) has rather limited uses C710 An assumed-type variable name shall not appear in a designator or expression except as an actual argument corresponding to a dummy argument that is assumed-type, or as the first argument to the intrinsic function IS_CONTIGUOUS, LBOUND, PRESENT, RANK, SHAPE, SIZE, or UBOUND, or the function C_LOC from the intrinsic module ISO_C_BINDING. I suspect that a hidden argument isn't needed. This means that gfc_conv_procedure_call will need to suppress a hidden argument for a type(*) dummy argument when the actual argument is of character type. > As TYPE(*) is rather new, and I did not find any mentioning of it in the > ABI specification, we should clarify what we want and also document it at > > https://gcc.gnu.org/onlinedocs/gfortran/Argument-passing-conventions.html Sorry, I cannot be of much help. type(*) is well off my radar for my owns codes.
