Check for VOLATILE and ASYNCHRONOUS.

Author: vzakhari

flang/lib/Lower/ConvertVariable.cpp

@@ -1016,6 +1016,10 @@ static void deallocateIntentOut(Fortran::lower::AbstractConverter &converter,
   }
 }
 
+/// Return true iff the given symbol represents a dummy array
+/// that needs to be repacked when -frepack-arrays is set.
+/// In general, the repacking is done for assumed-shape
+/// dummy arguments, but there are limitations.
 static bool needsRepack(Fortran::lower::AbstractConverter &converter,
                         const Fortran::semantics::Symbol &sym) {
   const auto &attrs = sym.attrs();
@@ -1027,7 +1031,10 @@ static bool needsRepack(Fortran::lower::AbstractConverter &converter,
       // TARGET dummy may be accessed indirectly, so it is unsafe
       // to repack it. Some compilers provide options to override
       // this.
-      attrs.test(Fortran::semantics::Attr::TARGET))
+      // Repacking of VOLATILE and ASYNCHRONOUS is also unsafe.
+      attrs.HasAny({Fortran::semantics::Attr::ASYNCHRONOUS,
+                    Fortran::semantics::Attr::TARGET,
+                    Fortran::semantics::Attr::VOLATILE}))
     return false;
 
   return true;

flang/test/Lower/repack-arrays-asynchronous.f90

@@ -0,0 +1,10 @@
+! RUN: bbc -emit-hlfir -frepack-arrays %s -o - | FileCheck --check-prefixes=CHECK %s
+
+! Check that there is no repacking for ASYNCHRONOUS dummy argument.
+
+! CHECK-LABEL:   func.func @_QPtest(
+! CHECK-NOT: fir.pack_array
+! CHECK-NOT: fir.unpack_array
+subroutine test(x)
+  integer, asynchronous :: x(:)
+end subroutine test

flang/test/Lower/repack-arrays-target.f90

@@ -1,4 +1,4 @@
-! RUN: bbc -emit-hlfir -frepack-arrays %s -o - -I nowhere | FileCheck --check-prefixes=CHECK %s
+! RUN: bbc -emit-hlfir -frepack-arrays %s -o - | FileCheck --check-prefixes=CHECK %s
 
 ! Check that there is no repacking for TARGET dummy argument.