[flang] Do not finalize main program variables. (#66326)

Author: vzakhari

flang/lib/Lower/ConvertVariable.cpp

@@ -660,6 +660,11 @@ static bool needEndFinalization(const Fortran::lower::pft::Variable &var) {
   if (!var.hasSymbol())
     return false;
   const Fortran::semantics::Symbol &sym = var.getSymbol();
+  const Fortran::semantics::Scope &owner = sym.owner();
+  if (owner.kind() == Fortran::semantics::Scope::Kind::MainProgram) {
+    // The standard does not require finalizing main program variables.
+    return false;
+  }
   if (!Fortran::semantics::IsPointer(sym) &&
       !Fortran::semantics::IsAllocatable(sym) &&
       !Fortran::semantics::IsDummy(sym) &&

flang/test/Lower/derived-type-finalization.f90

@@ -248,20 +248,7 @@ subroutine local_t4()
 program p
   use derived_type_finalization
   type(t1) :: t
-  if (t%a == 10) return
-  print *, 'end of program'
 end program
 
 ! CHECK-LABEL: func.func @_QQmain() attributes {fir.bindc_name = "p"} {
-! CHECK: %[[T:.*]] = fir.alloca !fir.type<_QMderived_type_finalizationTt1{a:i32}> {bindc_name = "t", uniq_name = "_QFEt"}
-! CHECK: cf.cond_br %{{.*}}, ^bb1, ^bb2
-! CHECK: ^bb1:
-! CHECK:  %[[EMBOX:.*]] = fir.embox %[[T]] : (!fir.ref<!fir.type<_QMderived_type_finalizationTt1{a:i32}>>) -> !fir.box<!fir.type<_QMderived_type_finalizationTt1{a:i32}>>
-! CHECK:  %[[BOX_NONE:.*]] = fir.convert %[[EMBOX]] : (!fir.box<!fir.type<_QMderived_type_finalizationTt1{a:i32}>>) -> !fir.box<none>
-! CHECK:  %{{.*}} = fir.call @_FortranADestroy(%[[BOX_NONE]]) {{.*}} : (!fir.box<none>) -> none
-! CHECK:  return
-! CHECK: ^bb2:
-! CHECK:  %[[EMBOX:.*]] = fir.embox %[[T]] : (!fir.ref<!fir.type<_QMderived_type_finalizationTt1{a:i32}>>) -> !fir.box<!fir.type<_QMderived_type_finalizationTt1{a:i32}>>
-! CHECK:  %[[BOX_NONE:.*]] = fir.convert %[[EMBOX]] : (!fir.box<!fir.type<_QMderived_type_finalizationTt1{a:i32}>>) -> !fir.box<none>
-! CHECK:  %{{.*}} = fir.call @_FortranADestroy(%[[BOX_NONE]]) {{.*}} : (!fir.box<none>) -> none
-! CHECK:  return
+! CHECK-NOT: fir.call @_FortranADestroy