OpenMP: Handle descriptors in target's firstprivate [PR104949]

For allocatable/pointer arrays, a firstprivate to a device
not only needs to privatize the descriptor but also the actual
data. This is implemented as:
  firstprivate(x) firstprivate(x.data) attach(x [bias: &x.data-&x)
where the address of x in device memory is saved in hostaddrs[i]
by libgomp and the middle end actually passes hostaddrs[i]' to
attach.

OG11 version of the GCC 13/mainline patch submitted at
  https://gcc.gnu.org/pipermail/gcc-patches/2022-May/594582.html
Note: Contrary to GCC 12+, OG11 does not support has_device_addr,
which is the main difference to the posted patch.

gcc/fortran/ChangeLog:

	PR fortran/104949
	* f95-lang.c (LANG_HOOKS_OMP_ARRAY_SIZE): Redefine.
	* trans-openmp.c (gfc_omp_array_size): New.
	* trans.h (gfc_omp_array_size): New.

gcc/ChangeLog:

	PR fortran/104949
	* langhooks-def.h (lhd_omp_array_size): New.
	(LANG_HOOKS_OMP_ARRAY_SIZE): Define
	(LANG_HOOKS_DECLS): Add it.
	* langhooks.c (lhd_omp_array_size): New.
	* langhooks.h (struct lang_hooks_for_decls): Add hook.
	* omp-low.c (scan_sharing_clauses, lower_omp_target):
	Handle GOMP_MAP_FIRSTPRIVATE for array descriptors.

libgomp/ChangeLog:

	PR fortran/104949
	* target.c (gomp_map_vars_internal, copy_firstprivate_data):
	Support attach for GOMP_MAP_FIRSTPRIVATE.
	* testsuite/libgomp.fortran/target-firstprivate-1.f90: New test.
	* testsuite/libgomp.fortran/target-firstprivate-2.f90: New test.
	* testsuite/libgomp.fortran/target-firstprivate-3.f90: New test.

11 files changed, 341 insertions, 1 deletions

diff --git a/gcc/fortran/f95-lang.c b/gcc/fortran/f95-lang.c
index d23ad3a7520..d4dd9b7e127 100644
--- a/gcc/fortran/f95-lang.c
+++ b/gcc/fortran/f95-lang.c
@@ -114,6 +114,7 @@ static const struct attribute_spec gfc_attribute_table[] =
 #undef LANG_HOOKS_TYPE_FOR_SIZE
 #undef LANG_HOOKS_INIT_TS
 #undef LANG_HOOKS_OMP_ARRAY_DATA
+#undef LANG_HOOKS_OMP_ARRAY_SIZE
 #undef LANG_HOOKS_OMP_IS_ALLOCATABLE_OR_PTR
 #undef LANG_HOOKS_OMP_CHECK_OPTIONAL_ARGUMENT
 #undef LANG_HOOKS_OMP_PRIVATIZE_BY_REFERENCE
@@ -155,6 +156,7 @@ static const struct attribute_spec gfc_attribute_table[] =
 #define LANG_HOOKS_TYPE_FOR_SIZE	gfc_type_for_size
 #define LANG_HOOKS_INIT_TS		gfc_init_ts
 #define LANG_HOOKS_OMP_ARRAY_DATA		gfc_omp_array_data
+#define LANG_HOOKS_OMP_ARRAY_SIZE		gfc_omp_array_size
 #define LANG_HOOKS_OMP_IS_ALLOCATABLE_OR_PTR	gfc_omp_is_allocatable_or_ptr
 #define LANG_HOOKS_OMP_CHECK_OPTIONAL_ARGUMENT	gfc_omp_check_optional_argument
 #define LANG_HOOKS_OMP_PRIVATIZE_BY_REFERENCE	gfc_omp_privatize_by_reference
diff --git a/gcc/fortran/trans-openmp.c b/gcc/fortran/trans-openmp.c
index 146aa748611..a51d8227c76 100644
--- a/gcc/fortran/trans-openmp.c
+++ b/gcc/fortran/trans-openmp.c
@@ -182,6 +182,48 @@ gfc_omp_array_data (tree decl, bool type_only)
   return decl;
 }
 
+/* Return the byte-size of the passed array descriptor. */
+
+tree
+gfc_omp_array_size (tree decl, gimple_seq *pre_p)
+{
+  stmtblock_t block;
+  if (POINTER_TYPE_P (TREE_TYPE (decl)))
+    decl = build_fold_indirect_ref (decl);
+  tree type = TREE_TYPE (decl);
+  gcc_assert (GFC_DESCRIPTOR_TYPE_P (type));
+  bool allocatable = (GFC_TYPE_ARRAY_AKIND (type) == GFC_ARRAY_ALLOCATABLE
+		      || GFC_TYPE_ARRAY_AKIND (type) == GFC_ARRAY_POINTER
+		      || GFC_TYPE_ARRAY_AKIND (type) == GFC_ARRAY_POINTER_CONT);
+  gfc_init_block (&block);
+  tree size = gfc_full_array_size (&block, decl,
+				   GFC_TYPE_ARRAY_RANK (TREE_TYPE (decl)));
+  size = fold_convert (size_type_node, size);
+  tree elemsz = gfc_get_element_type (TREE_TYPE (decl));
+  if (TREE_CODE (elemsz) == ARRAY_TYPE && TYPE_STRING_FLAG (elemsz))
+    elemsz = gfc_conv_descriptor_elem_len (decl);
+  else
+    elemsz = TYPE_SIZE_UNIT (elemsz);
+  size = fold_build2 (MULT_EXPR, size_type_node, size, elemsz);
+  if (!allocatable)
+    gimplify_and_add (gfc_finish_block (&block), pre_p);
+  else
+    {
+      tree var = create_tmp_var (size_type_node);
+      gfc_add_expr_to_block (&block, build2 (MODIFY_EXPR, sizetype, var, size));
+      tree tmp = fold_build2_loc (input_location, NE_EXPR, boolean_type_node,
+				  gfc_conv_descriptor_data_get (decl),
+				  null_pointer_node);
+      tmp = build3_loc (input_location, COND_EXPR, void_type_node, tmp,
+			gfc_finish_block (&block),
+			build2 (MODIFY_EXPR, sizetype, var, size_zero_node));
+      gimplify_and_add (tmp, pre_p);
+      size = var;
+    }
+  return size;
+}
+
+
 /* True if OpenMP should privatize what this DECL points to rather
    than the DECL itself.  */
 
diff --git a/gcc/fortran/trans.h b/gcc/fortran/trans.h
index a4398821ccd..d1888ae5c3d 100644
--- a/gcc/fortran/trans.h
+++ b/gcc/fortran/trans.h
@@ -816,6 +816,7 @@ bool gfc_get_array_descr_info (const_tree, struct array_descr_info *);
 bool gfc_omp_is_allocatable_or_ptr (const_tree);
 tree gfc_omp_check_optional_argument (tree, bool);
 tree gfc_omp_array_data (tree, bool);
+tree gfc_omp_array_size (tree, gimple_seq *);
 bool gfc_omp_privatize_by_reference (const_tree);
 enum omp_clause_default_kind gfc_omp_predetermined_sharing (tree);
 enum omp_clause_defaultmap_kind gfc_omp_predetermined_mapping (tree);
diff --git a/gcc/langhooks-def.h b/gcc/langhooks-def.h
index fc90018e08e..0f37dc1805d 100644
--- a/gcc/langhooks-def.h
+++ b/gcc/langhooks-def.h
@@ -86,6 +86,7 @@ extern bool lhd_omp_deep_mapping_p (const gimple *, tree);
 extern tree lhd_omp_deep_mapping_cnt (const gimple *, tree, gimple_seq *);
 extern void lhd_omp_deep_mapping (const gimple *, tree, unsigned HOST_WIDE_INT,
 				  tree, tree, tree, tree, tree, gimple_seq *);
+extern tree lhd_omp_array_size (tree, gimple_seq *);
 struct gimplify_omp_ctx;
 extern void lhd_omp_firstprivatize_type_sizes (struct gimplify_omp_ctx *,
 					       tree);
@@ -255,6 +256,7 @@ extern tree lhd_unit_size_without_reusable_padding (tree);
 #define LANG_HOOKS_POST_COMPILATION_PARSING_CLEANUPS NULL
 #define LANG_HOOKS_DECL_OK_FOR_SIBCALL	lhd_decl_ok_for_sibcall
 #define LANG_HOOKS_OMP_ARRAY_DATA	hook_tree_tree_bool_null
+#define LANG_HOOKS_OMP_ARRAY_SIZE	lhd_omp_array_size
 #define LANG_HOOKS_OMP_IS_ALLOCATABLE_OR_PTR hook_bool_const_tree_false
 #define LANG_HOOKS_OMP_CHECK_OPTIONAL_ARGUMENT hook_tree_tree_bool_null
 #define LANG_HOOKS_OMP_PRIVATIZE_BY_REFERENCE hook_bool_const_tree_false
@@ -291,6 +293,7 @@ extern tree lhd_unit_size_without_reusable_padding (tree);
   LANG_HOOKS_POST_COMPILATION_PARSING_CLEANUPS, \
   LANG_HOOKS_DECL_OK_FOR_SIBCALL, \
   LANG_HOOKS_OMP_ARRAY_DATA, \
+  LANG_HOOKS_OMP_ARRAY_SIZE, \
   LANG_HOOKS_OMP_IS_ALLOCATABLE_OR_PTR, \
   LANG_HOOKS_OMP_CHECK_OPTIONAL_ARGUMENT, \
   LANG_HOOKS_OMP_PRIVATIZE_BY_REFERENCE, \
diff --git a/gcc/langhooks.c b/gcc/langhooks.c
index 2f7295ce3ec..afdd7ae35c7 100644
--- a/gcc/langhooks.c
+++ b/gcc/langhooks.c
@@ -638,6 +638,14 @@ lhd_omp_deep_mapping (const gimple *, tree, unsigned HOST_WIDE_INT, tree, tree,
 {
 }
 
+/* Return array size; cf. omp_array_data.  */
+
+tree
+lhd_omp_array_size (tree, gimple_seq *)
+{
+  return NULL_TREE;
+}
+
 /* Return true if DECL is a scalar variable (for the purpose of
    implicit firstprivatization & mapping). Only if alloc_ptr_ok
    are allocatables and pointers accepted. */
diff --git a/gcc/langhooks.h b/gcc/langhooks.h
index 302425e0bf9..5920903d9ae 100644
--- a/gcc/langhooks.h
+++ b/gcc/langhooks.h
@@ -231,6 +231,11 @@ struct lang_hooks_for_decls
      is true, only the TREE_TYPE is returned without generating a new tree.  */
   tree (*omp_array_data) (tree, bool);
 
+  /* Return a tree for the actual data of an array descriptor - or NULL_TREE
+     if original tree is not an array descriptor.  If the second argument
+     is true, only the TREE_TYPE is returned without generating a new tree.  */
+  tree (*omp_array_size) (tree, gimple_seq *pre_p);
+
   /* True if OpenMP should regard this DECL as being a scalar which has Fortran's
      allocatable or pointer attribute.  */
   bool (*omp_is_allocatable_or_ptr) (const_tree);
diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index ee6b4271447..68794c01c43 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -1685,6 +1685,15 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
 		install_var_field (decl, by_ref, 3, ctx);
 	    }
 	  install_var_local (decl, ctx);
+	  /* For descr arrays on target: firstprivatize data + attach ptr.  */
+	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
+	      && is_gimple_omp_offloaded (ctx->stmt)
+	      && !is_gimple_omp_oacc (ctx->stmt)
+	      && lang_hooks.decls.omp_array_data (decl, true))
+	    {
+	      install_var_field (decl, false, 16 | 3, ctx);
+	      install_var_field (decl, true, 8 | 3, ctx);
+	    }
 	  break;
 
 	case OMP_CLAUSE_USE_DEVICE_PTR:
@@ -13578,6 +13587,9 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 	    SET_DECL_VALUE_EXPR (new_var, x);
 	    DECL_HAS_VALUE_EXPR_P (new_var) = 1;
 	  }
+	  /* Fortran array descriptors: firstprivate of data + attach.  */
+	  if (lang_hooks.decls.omp_array_data (var, true))
+	    map_cnt += 2;
 	break;
 
       case OMP_CLAUSE_PRIVATE:
@@ -14226,6 +14238,81 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 				 <= tree_to_uhwi (TYPE_MAX_VALUE (tkind_type)));
 	    CONSTRUCTOR_APPEND_ELT (vkind, purpose,
 				    build_int_cstu (tkind_type, tkind));
+	    /* Fortran array descriptors: firstprivate of data + attach.  */
+	    if (lang_hooks.decls.omp_array_data (ovar, true))
+	      {
+		tree not_null_lb, null_lb, after_lb;
+		tree var1, var2, size1, size2;
+		tree present = omp_check_optional_argument (ovar, true);
+		if (present)
+		  {
+		    location_t clause_loc = OMP_CLAUSE_LOCATION (c);
+		    not_null_lb = create_artificial_label (clause_loc);
+		    null_lb = create_artificial_label (clause_loc);
+		    after_lb = create_artificial_label (clause_loc);
+		    gimple_seq seq = NULL;
+		    present = force_gimple_operand (present, &seq, true,
+						    NULL_TREE);
+		    gimple_seq_add_seq (&ilist, seq);
+		    gimple_seq_add_stmt (&ilist,
+		      gimple_build_cond_from_tree (present,
+						   not_null_lb, null_lb));
+		    gimple_seq_add_stmt (&ilist,
+					 gimple_build_label (not_null_lb));
+		  }
+		var1 = lang_hooks.decls.omp_array_data (var, false);
+		size1 = lang_hooks.decls.omp_array_size (var, &ilist);
+		var2 = build_fold_addr_expr (x);
+		if (!POINTER_TYPE_P (TREE_TYPE (var)))
+		  var = build_fold_addr_expr (var);
+		size2 = fold_build2 (POINTER_DIFF_EXPR, ssizetype,
+				   build_fold_addr_expr (var1), var);
+		size2 = fold_convert (sizetype, size2);
+		if (present)
+		  {
+		    tree tmp = create_tmp_var (TREE_TYPE (var1));
+		    gimplify_assign (tmp, var1, &ilist);
+		    var1 = tmp;
+		    tmp = create_tmp_var (TREE_TYPE (var2));
+		    gimplify_assign (tmp, var2, &ilist);
+		    var2 = tmp;
+		    tmp = create_tmp_var (TREE_TYPE (size1));
+		    gimplify_assign (tmp, size1, &ilist);
+		    size1 = tmp;
+		    tmp = create_tmp_var (TREE_TYPE (size2));
+		    gimplify_assign (tmp, size2, &ilist);
+		    size2 = tmp;
+		    gimple_seq_add_stmt (&ilist, gimple_build_goto (after_lb));
+		    gimple_seq_add_stmt (&ilist, gimple_build_label (null_lb));
+		    gimplify_assign (var1, null_pointer_node, &ilist);
+		    gimplify_assign (var2, null_pointer_node, &ilist);
+		    gimplify_assign (size1, size_zero_node, &ilist);
+		    gimplify_assign (size2, size_zero_node, &ilist);
+		    gimple_seq_add_stmt (&ilist, gimple_build_label (after_lb));
+		  }
+		x = build_sender_ref ((splay_tree_key) &DECL_NAME (ovar), ctx);
+		gimplify_assign (x, var1, &ilist);
+		tkind = GOMP_MAP_FIRSTPRIVATE;
+		talign = DECL_ALIGN_UNIT (ovar);
+		talign = ceil_log2 (talign);
+		tkind |= talign << talign_shift;
+		gcc_checking_assert (tkind
+				     <= tree_to_uhwi (
+					  TYPE_MAX_VALUE (tkind_type)));
+		purpose = size_int (map_idx++);
+		CONSTRUCTOR_APPEND_ELT (vsize, purpose, size1);
+		if (TREE_CODE (size1) != INTEGER_CST)
+		  TREE_STATIC (TREE_VEC_ELT (t, 1)) = 0;
+		CONSTRUCTOR_APPEND_ELT (vkind, purpose,
+					build_int_cstu (tkind_type, tkind));
+		x = build_sender_ref ((splay_tree_key) &DECL_UID (ovar), ctx);
+		gimplify_assign (x, var2, &ilist);
+		tkind = GOMP_MAP_ATTACH;
+		purpose = size_int (map_idx++);
+		CONSTRUCTOR_APPEND_ELT (vsize, purpose, size2);
+		CONSTRUCTOR_APPEND_ELT (vkind, purpose,
+					build_int_cstu (tkind_type, tkind));
+	      }
 	    break;
 
 	  case OMP_CLAUSE_USE_DEVICE_PTR:
diff --git a/libgomp/target.c b/libgomp/target.c
index 77adb300ccd..182ae5769f3 100644
--- a/libgomp/target.c
+++ b/libgomp/target.c
@@ -1394,7 +1394,24 @@ gomp_map_vars_internal (struct gomp_device_descr *devicep,
 		gomp_copy_host2dev (devicep, aq,
 				    (void *) (tgt->tgt_start + tgt_size),
 				    (void *) hostaddrs[i], len, false, cbufp);
+		/* Save device address in hostaddr to permit latter availablity
+		   when doing a deep-firstprivate with pointer attach.  */
+		hostaddrs[i] = (void *) (tgt->tgt_start + tgt_size);
 		tgt_size += len;
+
+		/* If followed by GOMP_MAP_ATTACH, pointer assign this
+		   firstprivate to hostaddrs[i+1], which is assumed to contain a
+		   device address.  */
+		if (i + 1 < mapnum
+		    && (GOMP_MAP_ATTACH
+			== (typemask & get_kind (short_mapkind, kinds, i+1))))
+		  {
+		    uintptr_t target = (uintptr_t) hostaddrs[i];
+		    void *devptr = *(void**) hostaddrs[i+1] + sizes[i+1];
+		    gomp_copy_host2dev (devicep, aq, devptr, &target,
+					sizeof (void *), false, cbufp);
+		    ++i;
+		  }
 		continue;
 	      case GOMP_MAP_FIRSTPRIVATE_INT:
 	      case GOMP_MAP_ZERO_LEN_ARRAY_SECTION:
@@ -2674,13 +2691,18 @@ copy_firstprivate_data (char *tgt, size_t mapnum, void **hostaddrs,
   tgt_size = 0;
   size_t i;
   for (i = 0; i < mapnum; i++)
-    if ((kinds[i] & 0xff) == GOMP_MAP_FIRSTPRIVATE)
+    if ((kinds[i] & 0xff) == GOMP_MAP_FIRSTPRIVATE && hostaddrs[i] != NULL)
       {
 	size_t align = (size_t) 1 << (kinds[i] >> 8);
 	tgt_size = (tgt_size + align - 1) & ~(align - 1);
 	memcpy (tgt + tgt_size, hostaddrs[i], sizes[i]);
 	hostaddrs[i] = tgt + tgt_size;
 	tgt_size = tgt_size + sizes[i];
+	if (i + 1 < mapnum && (kinds[i+1] & 0xff) == GOMP_MAP_ATTACH)
+	  {
+	    *(*(uintptr_t**) hostaddrs[i+1] + sizes[i+1]) = (uintptr_t) hostaddrs[i];
+	    ++i;
+	  }
       }
 }
 
diff --git a/libgomp/testsuite/libgomp.fortran/target-firstprivate-1.f90 b/libgomp/testsuite/libgomp.fortran/target-firstprivate-1.f90
new file mode 100644
index 00000000000..7b77992a21d
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/target-firstprivate-1.f90
@@ -0,0 +1,33 @@
+! PR fortran/104949
+
+implicit none (type,external)
+integer, allocatable :: A(:)
+A = [1,2,3,4,5,6]
+
+!$omp parallel firstprivate(A)
+!$omp master
+  if (any (A /= [1,2,3,4,5])) error stop
+  A(:) = [99,88,77,66,55]
+!$omp end master
+!$omp end parallel
+
+!$omp target firstprivate(A)
+  if (any (A /= [1,2,3,4,5])) error stop
+  A(:) = [99,88,77,66,55]
+!$omp end target
+if (any (A /= [1,2,3,4,5])) error stop
+
+!$omp parallel default(firstprivate)
+!$omp master
+  if (any (A /= [1,2,3,4,5])) error stop
+  A(:) = [99,88,77,66,55]
+!$omp end master
+!$omp end parallel
+if (any (A /= [1,2,3,4,5])) error stop
+
+!$omp target defaultmap(firstprivate)
+  if (any (A /= [1,2,3,4,5])) error stop
+  A(:) = [99,88,77,66,55]
+!$omp end target
+if (any (A /= [1,2,3,4,5])) error stop
+end
diff --git a/libgomp/testsuite/libgomp.fortran/target-firstprivate-2.f90 b/libgomp/testsuite/libgomp.fortran/target-firstprivate-2.f90
new file mode 100644
index 00000000000..d00b4070c11
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/target-firstprivate-2.f90
@@ -0,0 +1,113 @@
+! PR fortran/104949
+
+module m
+use omp_lib
+implicit none (type, external)
+
+contains
+subroutine one
+  integer, allocatable :: x(:)
+  integer :: i
+
+  do i = 1, omp_get_num_devices() + 1
+    !$omp target firstprivate(x)
+      if (allocated(x)) error stop
+    !$omp end target
+    if (allocated(x)) error stop
+  end do
+
+  do i = 1, omp_get_num_devices() + 1
+    !$omp target firstprivate(x, i)
+      if (allocated(x)) error stop
+      x = [10,20,30,40] + i
+      if (any (x /= [10,20,30,40] + i)) error stop
+      ! This leaks memory!
+      ! deallocate(x)
+    !$omp end target
+    if (allocated(x)) error stop
+  end do
+
+  x = [1,2,3,4]
+
+  do i = 1, omp_get_num_devices() + 1
+    !$omp target firstprivate(x, i)
+      if (i <= 0) error stop
+      if (.not.allocated(x)) error stop
+      if (size(x) /= 4) error stop
+      if (lbound(x,1) /= 1) error stop
+      if (any (x /= [1,2,3,4])) error stop
+      ! no reallocation, just malloced + assignment
+      x = [10,20,30,40] + i
+      if (any (x /= [10,20,30,40] + i)) error stop
+      ! This leaks memory!
+      ! deallocate(x)
+    !$omp end target
+    if (.not.allocated(x)) error stop
+    if (size(x) /= 4) error stop
+    if (lbound(x,1) /= 1) error stop
+    if (any (x /= [1,2,3,4])) error stop
+  end do
+  deallocate(x)
+end
+
+subroutine two
+  character(len=:), allocatable :: x(:)
+  character(len=5)  :: str
+  integer :: i
+
+  str = "abcde" ! work around for PR fortran/91544
+  do i = 1, omp_get_num_devices() + 1
+    !$omp target firstprivate(x)
+      if (allocated(x)) error stop
+    !$omp end target
+    if (allocated(x)) error stop
+  end do
+
+  do i = 1, omp_get_num_devices() + 1
+    !$omp target firstprivate(x, i)
+      if (allocated(x)) error stop
+      ! no reallocation, just malloced + assignment
+      x = [character(len=2+i) :: str,"fhji","klmno"]
+      if (len(x) /= 2+i) error stop
+      if (any (x /= [character(len=2+i) :: str,"fhji","klmno"])) error stop
+      ! This leaks memory!
+      ! deallocate(x)
+    !$omp end target
+    if (allocated(x)) error stop
+  end do
+
+  x = [character(len=4) :: "ABCDE","FHJI","KLMNO"]
+
+  do i = 1, omp_get_num_devices() + 1
+    !$omp target firstprivate(x, i)
+      if (i <= 0) error stop
+      if (.not.allocated(x)) error stop
+      if (size(x) /= 3) error stop
+      if (lbound(x,1) /= 1) error stop
+      if (len(x) /= 4) error stop
+      if (any (x /= [character(len=4) :: "ABCDE","FHJI","KLMNO"])) error stop
+      !! Reallocation runs into the issue PR fortran/105538
+      !!
+      !!x = [character(len=2+i) :: str,"fhji","klmno"]
+      !!if (len(x) /= 2+i) error stop
+      !!if (any (x /= [character(len=2+i) :: str,"fhji","klmno"])) error stop
+      !! This leaks memory!
+      !! deallocate(x)
+      ! Just assign:
+      x = [character(len=4) :: "abcde","fhji","klmno"]
+      if (any (x /= [character(len=4) :: "abcde","fhji","klmno"])) error stop
+    !$omp end target
+    if (.not.allocated(x)) error stop
+    if (lbound(x,1) /= 1) error stop
+    if (size(x) /= 3) error stop
+    if (len(x) /= 4) error stop
+    if (any (x /= [character(len=4) :: "ABCDE","FHJI","KLMNO"])) error stop
+  end do
+  deallocate(x)
+end
+end module m
+
+use m
+call one
+call two
+end
diff --git a/libgomp/testsuite/libgomp.fortran/target-firstprivate-3.f90 b/libgomp/testsuite/libgomp.fortran/target-firstprivate-3.f90
new file mode 100644
index 00000000000..7406cdc4e41
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/target-firstprivate-3.f90
@@ -0,0 +1,24 @@
+implicit none
+  integer, allocatable :: x(:)
+  x = [1,2,3,4]
+  call foo(x)
+  if (any (x /= [1,2,3,4])) error stop
+  call foo()
+contains
+subroutine foo(c)
+  integer, allocatable, optional :: c(:)
+  logical :: is_present
+  is_present = present (c)
+  !$omp target firstprivate(c)
+    if (is_present) then
+      if (.not. allocated(c)) error stop
+      if (any (c /= [1,2,3,4])) error stop
+      c = [99,88,77,66]
+      if (any (c /= [99,88,77,66])) error stop
+    end if
+  !$omp end target
+  if (is_present) then
+    if (any (c /= [1,2,3,4])) error stop
+  end if
+end
+end