re PR fortran/89843 (CFI_section delivers incorrect result descriptor)

2019-04-14  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/89843
	* trans-decl.c (gfc_get_symbol_decl): Assumed shape and assumed
	rank dummies of bind C procs require deferred initialization.
	(convert_CFI_desc): New procedure to convert incoming CFI
	descriptors to gfc types and back again.
	(gfc_trans_deferred_vars): Call it.
	* trans-expr.c (gfc_conv_gfc_desc_to_cfi_desc): Null the CFI
	descriptor pointer. Free the descriptor in all cases.

	PR fortran/89846
	* expr.c (is_CFI_desc): New function.
	(is_subref_array): Tidy up by referencing the symbol directly.
	* gfortran.h : Prototype for is_CFI_desc.
	* trans_array.c (get_CFI_desc): New function.
	(gfc_get_array_span, gfc_conv_scalarized_array_ref,
	gfc_conv_array_ref): Use it.
	* trans.c (get_array_span): Extract the span from descriptors
	that are indirect references.

	PR fortran/90022
	* trans-decl.c (gfc_get_symbol_decl): Make sure that the se
	expression is a pointer type before converting it to the symbol
	backend_decl type.
	* trans-expr.c (gfc_conv_gfc_desc_to_cfi_desc): Eliminate
	temporary creation for intent(in).

2019-04-14  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/89843
	* gfortran.dg/ISO_Fortran_binding_4.f90: Modify the value of x
	in ctg. Test the conversion of the descriptor types in the main
	program.
	* gfortran.dg/ISO_Fortran_binding_10.f90: New test.
	* gfortran.dg/ISO_Fortran_binding_10.c: Called by it.

	PR fortran/89846
	* gfortran.dg/ISO_Fortran_binding_11.f90: New test.
	* gfortran.dg/ISO_Fortran_binding_11.c: Called by it.

	PR fortran/90022
	* gfortran.dg/ISO_Fortran_binding_1.c: Correct the indexing for
	the computation of 'ans'. Also, change the expected results for
	CFI_is_contiguous to comply with standard.
	* gfortran.dg/ISO_Fortran_binding_1.f90: Correct the expected
	results for CFI_is_contiguous to comply with standard.
	* gfortran.dg/ISO_Fortran_binding_9.f90: New test.
	* gfortran.dg/ISO_Fortran_binding_9.c: Called by it.

2019-04-14  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/89843
	* runtime/ISO_Fortran_binding.c (cfi_desc_to_gfc_desc): Only
	return immediately if the source pointer is null. Bring
	forward the extraction of the gfc type. Extract the kind so
	that the element size can be correctly computed for sections
	and components of derived type arrays. Remove the free of the
	CFI descriptor since this is now done in trans-expr.c.
	(gfc_desc_to_cfi_desc): Only allocate the CFI descriptor if it
	is not null.
	(CFI_section): Normalise the difference between the upper and
	lower bounds by the stride to correctly calculate the extents
	of the section.

	PR fortran/89846
	* runtime/ISO_Fortran_binding.c (cfi_desc_to_gfc_desc): Use
	the stride measure for the gfc span if it is not a multiple
	of the element length. Otherwise use the element length.

	PR fortran/90022
	* runtime/ISO_Fortran_binding.c (CFI_is_contiguous) : Return
	1 for true and 0 otherwise to comply with the standard. Correct
	the contiguity check for rank 3 and greater by using the stride
	measure of the lower dimension rather than the element length.

From-SVN: r270353

1 files changed, 73 insertions, 0 deletions

diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index ada6370..a0e1f6a 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -4268,6 +4268,72 @@ gfc_null_and_pass_deferred_len (gfc_symbol *sym, stmtblock_t *init,
 }
 
 
+/* Convert CFI descriptor dummies into gfc types and back again.  */
+static void
+convert_CFI_desc (gfc_wrapped_block * block, gfc_symbol *sym)
+{
+  tree gfc_desc;
+  tree gfc_desc_ptr;
+  tree CFI_desc;
+  tree CFI_desc_ptr;
+  tree dummy_ptr;
+  tree tmp;
+  tree incoming;
+  tree outgoing;
+  stmtblock_t tmpblock;
+
+  /* dummy_ptr will be the pointer to the passed array descriptor,
+     while CFI_desc is the descriptor itself.  */
+  if (DECL_LANG_SPECIFIC (sym->backend_decl))
+    CFI_desc = GFC_DECL_SAVED_DESCRIPTOR (sym->backend_decl);
+  else
+    CFI_desc = NULL;
+
+  dummy_ptr = CFI_desc;
+
+  if (CFI_desc)
+    {
+      CFI_desc = build_fold_indirect_ref_loc (input_location, CFI_desc);
+
+      /* The compiler will have given CFI_desc the correct gfortran
+	 type. Use this new variable to store the converted
+	 descriptor.  */
+      gfc_desc = gfc_create_var (TREE_TYPE (CFI_desc), "gfc_desc");
+      tmp = build_pointer_type (TREE_TYPE (gfc_desc));
+      gfc_desc_ptr = gfc_create_var (tmp, "gfc_desc_ptr");
+      CFI_desc_ptr = gfc_create_var (pvoid_type_node, "CFI_desc_ptr");
+
+      gfc_init_block (&tmpblock);
+      /* Pointer to the gfc descriptor.  */
+      gfc_add_modify (&tmpblock, gfc_desc_ptr,
+		      gfc_build_addr_expr (NULL, gfc_desc));
+      /* Store the pointer to the CFI descriptor.  */
+      gfc_add_modify (&tmpblock, CFI_desc_ptr,
+		      fold_convert (pvoid_type_node, dummy_ptr));
+      tmp = gfc_build_addr_expr (ppvoid_type_node, CFI_desc_ptr);
+      /* Convert the CFI descriptor.  */
+      incoming = build_call_expr_loc (input_location,
+			gfor_fndecl_cfi_to_gfc, 2, gfc_desc_ptr, tmp);
+      gfc_add_expr_to_block (&tmpblock, incoming);
+      /* Set the dummy pointer to point to the gfc_descriptor.  */
+      gfc_add_modify (&tmpblock, dummy_ptr,
+		      fold_convert (TREE_TYPE (dummy_ptr), gfc_desc_ptr));
+      incoming = gfc_finish_block (&tmpblock);
+
+      gfc_init_block (&tmpblock);
+      /* Convert the gfc descriptor back to the CFI type before going
+	 out of scope.  */
+      tmp = gfc_build_addr_expr (ppvoid_type_node, CFI_desc_ptr);
+      outgoing = build_call_expr_loc (input_location,
+			gfor_fndecl_gfc_to_cfi, 2, tmp, gfc_desc_ptr);
+      gfc_add_expr_to_block (&tmpblock, outgoing);
+      outgoing = gfc_finish_block (&tmpblock);
+
+      /* Add the lot to the procedure init and finally blocks.  */
+      gfc_add_init_cleanup (block, incoming, outgoing);
+    }
+}
+
 /* Get the result expression for a procedure.  */
 
 static tree
@@ -4844,6 +4910,13 @@ gfc_trans_deferred_vars (gfc_symbol * proc_sym, gfc_wrapped_block * block)
 	}
       else if (!(UNLIMITED_POLY(sym)) && !is_pdt_type)
 	gcc_unreachable ();
+
+      /* Assumed shape and assumed rank arrays are passed to BIND(C) procedures
+	 as ISO Fortran Interop descriptors. These have to be converted to
+	 gfortran descriptors and back again.  This has to be done here so that
+	 the conversion occurs at the start of the init block.  */
+      if (is_CFI_desc (sym, NULL))
+	convert_CFI_desc (block, sym);
     }
 
   gfc_init_block (&tmpblock);