[flang] Check for calling a type parameter as a function

[PeteSteinfeld]

Summary

It's possible to refer to type type parameter of a derived type as a function.
We were not detecting this situation and emitting an error message. I added
the necessary check along with a test.

[klausler]

flang/lib/Semantics/expression.cpp

2743

This may not be the right place to fix. Want me to take a look at this?

[PeteSteinfeld]

flang/lib/Semantics/expression.cpp

2743

Go for it.

[klausler]

Can this review now be closed?

[PeteSteinfeld]

Fixed elsewhere.

flang/lib/Semantics/expression.cpp

if (Symbol *
                            [&](parser::Name &name) { return name.symbol; },
                            [&](parser::ProcComponentRef &pcr) {
                              return pcr.v.thing.component.symbol;
                            },
                        },
                 proc.u)}) {
       Symbol &symbol{origSymbol->GetUltimate()};
       if (symbol.has<semantics::ObjectEntityDetails>() ||
-          symbol.has<semantics::AssocEntityDetails>()) {
+          symbol.has<semantics::AssocEntityDetails>() ||
+          symbol.has<semantics::TypeParamDetails>()) {
         // Note that expression in AssocEntityDetails cannot be a procedure
         // pointer as per C1105 so this cannot be a function reference.
         if constexpr (common::HasMember<common::Indirection<parser::Designator>,
                           uType>) {
           CheckFuncRefToArrayElementRefHasSubscripts(context, funcRef);
           u = common::Indirection{funcRef.ConvertToArrayElementRef()};
         } else {
           DIE("can't fix misparsed function as array reference");

flang/test/Semantics/resolve59.f90

 
 subroutine array_rank_test()
   real :: x(10, 10), y
   !ERROR: Reference to rank-2 object 'x' has 1 subscripts
   y = x(1)
   !ERROR: Reference to rank-2 object 'x' has 3 subscripts
   y = x(1, 2, 3)
 end
+
+subroutine with_type_param
+  type derived(typeParam)
+    integer,kind :: typeParam
+    integer :: field(typeParam)
+  end type
+  type(derived(3)) x
+  x = derived(3)([11,22,33])
+  !ERROR: 'typeparam' is not a function
+  print *,x%typeParam()
+  !ERROR: Reference to array 'field' with empty subscript list
+  print *,x%field()
+end