[PATCH] D120483: [flang] Handle allocatable dummy arguments

[Jean Perier via Phabricator via llvm-commits]

jeanPerier added inline comments.


================
Comment at: flang/lib/Lower/CallInterface.cpp:658
+      // Need to pass type parameters in fir.box if any.
+      return derived->parameters().empty();
+    return false;
----------------
rogfer01 wrote:
> I am curious about this. Does this mean that a type like
> 
> ```lang=fortran
> type foo
>    integer :: x  
> end type foo
> ```
> 
> is boxed (its number of parameters is empty) while
> 
> 
> ```lang=fortran
> type foo2(l)
>   integer, len :: l 
>   integer :: x  
> end type foo2
> ```
> 
> is not boxed (its number of parameters is not empty).
> 
> Maybe the intent of the code is the opposite?
> I am curious about this. Does this mean that a type like
> 
> ```lang=fortran
> type foo
>    integer :: x  
> end type foo
> ```
> 
> is boxed (its number of parameters is empty) while
> 
> 
> ```lang=fortran
> type foo2(l)
>   integer, len :: l 
>   integer :: x  
> end type foo2
> ```
> 
> is not boxed (its number of parameters is not empty).
> 
> Maybe the intent of the code is the opposite?

Absolutely, thanks for catching this. This was not very exposed because this code is only visited when `dummy.CanBePassedViaImplicitInterface()` is false, but it means flang is currently using descriptors to pass explicit shape non parametrized derived type dummies with the OPTIONAL attribute , or TARGET attribute (or other attributes that require an explicit interface), and that is a waste of time.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D120483/new/

https://reviews.llvm.org/D120483