PR fortran/93308/93963/94327/94331/97046 problems raised by descriptor handling

Fortran: Fix attributes and bounds in ISO_Fortran_binding.

2021-07-26  José Rui Faustino de Sousa  <jrfsousa@gmail.com>
	    Tobias Burnus  <tobias@codesourcery.com>

	PR fortran/93308
	PR fortran/93963
	PR fortran/94327
	PR fortran/94331
	PR fortran/97046

gcc/fortran/ChangeLog:

	* trans-decl.c (convert_CFI_desc): Only copy out the descriptor
	if necessary.
	* trans-expr.c (gfc_conv_gfc_desc_to_cfi_desc): Updated attribute
	handling which reflect a previous intermediate version of the
	standard. Only copy out the descriptor if necessary.

libgfortran/ChangeLog:

	* runtime/ISO_Fortran_binding.c (cfi_desc_to_gfc_desc): Add code
	to verify the descriptor. Correct bounds calculation.
	(gfc_desc_to_cfi_desc): Add code to verify the descriptor.

gcc/testsuite/ChangeLog:

	* gfortran.dg/ISO_Fortran_binding_1.f90: Add pointer attribute,
	this test is still erroneous but now it compiles.
	* gfortran.dg/bind_c_array_params_2.f90: Update regex to match
	code changes.
	* gfortran.dg/PR93308.f90: New test.
	* gfortran.dg/PR93963.f90: New test.
	* gfortran.dg/PR94327.c: New test.
	* gfortran.dg/PR94327.f90: New test.
	* gfortran.dg/PR94331.c: New test.
	* gfortran.dg/PR94331.f90: New test.
	* gfortran.dg/PR97046.f90: New test.

2 files changed, 33 insertions, 23 deletions

diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index bf8783a..784f7b6 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -4539,22 +4539,28 @@ convert_CFI_desc (gfc_wrapped_block * block, gfc_symbol *sym)
       gfc_add_expr_to_block (&outer_block, incoming);
       incoming = gfc_finish_block (&outer_block);
 
-
       /* Convert the gfc descriptor back to the CFI type before going
 	 out of scope, if the CFI type was present at entry.  */
-      gfc_init_block (&outer_block);
-      gfc_init_block (&tmpblock);
-
-      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 = NULL_TREE;
+      if ((sym->attr.pointer || sym->attr.allocatable)
+	  && !sym->attr.value
+	  && sym->attr.intent != INTENT_IN)
+	{
+	  gfc_init_block (&outer_block);
+	  gfc_init_block (&tmpblock);
 
-      outgoing = build3_v (COND_EXPR, present,
-			   gfc_finish_block (&tmpblock),
-			   build_empty_stmt (input_location));
-      gfc_add_expr_to_block (&outer_block, outgoing);
-      outgoing = gfc_finish_block (&outer_block);
+	  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 = build3_v (COND_EXPR, present,
+			       gfc_finish_block (&tmpblock),
+			       build_empty_stmt (input_location));
+	  gfc_add_expr_to_block (&outer_block, outgoing);
+	  outgoing = gfc_finish_block (&outer_block);
+	}
 
       /* Add the lot to the procedure init and finally blocks.  */
       gfc_add_init_cleanup (block, incoming, outgoing);
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index b18a9ec..c4291cc 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -5502,13 +5502,12 @@ gfc_conv_gfc_desc_to_cfi_desc (gfc_se *parmse, gfc_expr *e, gfc_symbol *fsym)
 	attribute = 1;
     }
 
-  /* If the formal argument is assumed shape and neither a pointer nor
-     allocatable, it is unconditionally CFI_attribute_other.  */
-  if (fsym->as->type == AS_ASSUMED_SHAPE
-      && !fsym->attr.pointer && !fsym->attr.allocatable)
-   cfi_attribute = 2;
+  if (fsym->attr.pointer)
+    cfi_attribute = 0;
+  else if (fsym->attr.allocatable)
+    cfi_attribute = 1;
   else
-   cfi_attribute = attribute;
+    cfi_attribute = 2;
 
   if (e->rank != 0)
     {
@@ -5616,10 +5615,15 @@ gfc_conv_gfc_desc_to_cfi_desc (gfc_se *parmse, gfc_expr *e, gfc_symbol *fsym)
   gfc_prepend_expr_to_block (&parmse->post, tmp);
 
   /* Transfer values back to gfc descriptor.  */
-  tmp = gfc_build_addr_expr (NULL_TREE, parmse->expr);
-  tmp = build_call_expr_loc (input_location,
-			     gfor_fndecl_cfi_to_gfc, 2, gfc_desc_ptr, tmp);
-  gfc_prepend_expr_to_block (&parmse->post, tmp);
+  if (cfi_attribute != 2  /* CFI_attribute_other.  */
+      && !fsym->attr.value
+      && fsym->attr.intent != INTENT_IN)
+    {
+      tmp = gfc_build_addr_expr (NULL_TREE, parmse->expr);
+      tmp = build_call_expr_loc (input_location,
+				 gfor_fndecl_cfi_to_gfc, 2, gfc_desc_ptr, tmp);
+      gfc_prepend_expr_to_block (&parmse->post, tmp);
+    }
 
   /* Deal with an optional dummy being passed to an optional formal arg
      by finishing the pre and post blocks and making their execution