[flang] Catch error: base of DATA statement object can't be a pointer

A pointer with subscripts, substring indices, or components cannot
be initialized by a DATA statement (although of course a whole pointer
can be so).  Catch the missing cases.

Differential Revision: https://reviews.llvm.org/D109931

flang/lib/Semantics/check-data.cpp

@@ -70,7 +70,9 @@ public:
                 : IsHostAssociated(symbol, scope)  ? "Host-associated object"
                 : IsUseAssociated(symbol, scope)   ? "USE-associated object"
                 : symbol.has<AssocEntityDetails>() ? "Construct association"
-                                                   : nullptr}) {
+                : IsPointer(symbol) && (hasComponent_ || hasSubscript_)
+                ? "Target of pointer"
+                : nullptr}) {
       context_.Say(source_,
           "%s '%s' must not be initialized in a DATA statement"_err_en_US,
           whyNot, symbol.name());

flang/test/Semantics/data04.f90

@@ -65,6 +65,10 @@ module m
       type(large) :: largeNumberArray(i)
       type(large) :: largeArray(5)
       character :: name(i)
+      type small
+        real :: x
+      end type
+      type(small), pointer :: sp
       !C877
       !ERROR: Default-initialized 'largenumber' must not be initialized in a DATA statement
       DATA(largeNumber % numsArray(j) % headOfTheList, j = 1, 10) / 10 * NULL() /
@@ -92,6 +96,8 @@ module m
       !C876
       !ERROR: Automatic variable 'name' must not be initialized in a DATA statement
       DATA name( : 2) / 'Ancd' /
+      !ERROR: Target of pointer 'sp' must not be initialized in a DATA statement
+      DATA sp%x / 1.0 /
     end
   end