diff mbox series

[Ada] Small fix for records with boolean discriminants

Message ID 20065154.R3ZBKFATig@polaris
State New
Headers show
Series [Ada] Small fix for records with boolean discriminants | expand

Commit Message

Eric Botcazou Dec. 14, 2018, 10:54 a.m. UTC 
The point is to avoid building comparisons of the form "D == true" in this 
case for the qualifiers of the union describing the variant part because 1) 
it's useless and 2) it's output as "D = 1" by -gnatR, which is not valid Ada.

The dwarf2out.c change only affects the Ada compiler.

Tested on x86_64-suse-linux, applied on the mainline as obvious.


2018-12-14  Eric Botcazou  <ebotcazou@adacore.com>

	* dwarf2out.c (analyze_discr_in_predicate): Simplify.
	(analyze_variants_discr): Deal with naked boolean discriminants.
ada/
	* gcc-interface/decl.c (choices_to_gnu): Directly use a naked boolean
	discriminant if the value is the boolean true.
diff mbox series

Patch

Index: dwarf2out.c
===================================================================
--- dwarf2out.c	(revision 267062)
+++ dwarf2out.c	(working copy)
@@ -24537,6 +24537,7 @@  gen_inheritance_die (tree binfo, tree ac
 
 /* Return whether DECL is a FIELD_DECL that represents the variant part of a
    structure.  */
+
 static bool
 is_variant_part (tree decl)
 {
@@ -24550,17 +24551,8 @@  is_variant_part (tree decl)
 static tree
 analyze_discr_in_predicate (tree operand, tree struct_type)
 {
-  bool continue_stripping = true;
-  while (continue_stripping)
-    switch (TREE_CODE (operand))
-      {
-      CASE_CONVERT:
-	operand = TREE_OPERAND (operand, 0);
-	break;
-      default:
-	continue_stripping = false;
-	break;
-      }
+  while (CONVERT_EXPR_P (operand))
+    operand = TREE_OPERAND (operand, 0);
 
   /* Match field access to members of struct_type only.  */
   if (TREE_CODE (operand) == COMPONENT_REF
@@ -24780,6 +24772,19 @@  analyze_variants_discr (tree variant_par
 	      new_node->dw_discr_range = true;
 	    }
 
+	  else if ((candidate_discr
+		      = analyze_discr_in_predicate (match_expr, struct_type))
+		   && TREE_TYPE (candidate_discr) == boolean_type_node)
+	    {
+	      /* We are matching:  <discr_field> for a boolean discriminant.
+		 This sub-expression matches boolean_true_node.  */
+	      new_node = ggc_cleared_alloc<dw_discr_list_node> ();
+	      if (!get_discr_value (boolean_true_node,
+				    &new_node->dw_discr_lower_bound))
+		goto abort;
+	      new_node->dw_discr_range = false;
+	    }
+
 	  else
 	    /* Unsupported sub-expression: we cannot determine the set of
 	       matching discriminant values.  Abort everything.  */
Index: ada/gcc-interface/decl.c
===================================================================
--- ada/gcc-interface/decl.c	(revision 267062)
+++ ada/gcc-interface/decl.c	(working copy)
@@ -6848,6 +6848,9 @@  choices_to_gnu (tree gnu_operand, Node_I
 			     build_binary_op (LE_EXPR, boolean_type_node,
 					      gnu_operand, gnu_high, true),
 			     true);
+      else if (gnu_low == boolean_true_node
+	       && TREE_TYPE (gnu_operand) == boolean_type_node)
+	gnu_test = gnu_operand;
       else if (gnu_low)
 	gnu_test
 	  = build_binary_op (EQ_EXPR, boolean_type_node, gnu_operand, gnu_low,