[flang][lowering] Do not instantiate component symbols used in spec expr

Lowering analyse specification expressions in order to create order the
symbol instantiations in the IR (If symbol B is used in the
specification expression of A, symbol B must be instantiated first).

This analysis was mistakenly collecting component symbols used in
component references inside specification expressions, which led
lowering to instantiate component symbols as if they were local
objects.

This patch prevents collecting component symbols during this analysis.

Differential Revision: https://reviews.llvm.org/D149328

flang/lib/Lower/PFTBuilder.cpp

@@ -1451,6 +1451,14 @@ struct SymbolDependenceAnalysis {
     // in some cases. Non-dummy procedures don't.
     if (semantics::IsProcedure(sym) && !isProcedurePointerOrDummy)
       return 0;
+    // Derived type component symbols may be collected by "CollectSymbols"
+    // below when processing something like "real :: x(derived%component)". The
+    // symbol "component" has "ObjectEntityDetails", but it should not be
+    // instantiated: it is is part of "derived" that should be the only one to
+    // be instantiated.
+    if (sym.owner().IsDerivedType())
+      return 0;
+
     semantics::Symbol ultimate = sym.GetUltimate();
     if (const auto *details =
             ultimate.detailsIf<semantics::NamelistDetails>()) {

flang/test/Lower/HLFIR/convert-variable.f90

@@ -95,3 +95,16 @@ subroutine scalar_numeric_parameter()
 ! CHECK-LABEL: func.func @_QPscalar_numeric_parameter() {
 ! CHECK:  %[[VAL_0:.*]] = fir.address_of(@_QFscalar_numeric_parameterECp) : !fir.ref<i32>
 ! CHECK:  %[[VAL_1:.*]] = hlfir.declare %[[VAL_0]] {fortran_attrs = #fir.var_attrs<parameter>, uniq_name = "_QFscalar_numeric_parameterECp"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+
+subroutine test_component_in_spec_expr(x, derived)
+  type t
+    integer :: component
+  end type
+  type(t) :: derived
+  ! Test that we do not try to instantiate "component" just because
+  ! its symbol appears in a specification expression.
+  real :: x(derived%component)
+end subroutine
+! CHECK-LABEL: func.func @_QPtest_component_in_spec_expr(
+! CHECK-NOT: alloca
+! CHECK: return