Add gimple_range_type for statements.

The existing mechanisms for picking up the type of a statement are
inconsistent with the needs of ranger. Encapsulate all the bits
required to pick up the return type of a statement in one place, and check
whether the type is supported.

	* gimple-range-fold.cc (adjust_pointer_diff_expr): Use
	gimple_range_type.
	(fold_using_range::fold_stmt): Ditto.
	(fold_using_range::range_of_range_op): Ditto.
	(fold_using_range::range_of_phi): Ditto.
	(fold_using_range::range_of_call): Ditto.
	(fold_using_range::range_of_builtin_ubsan_call): Ditto.
	(fold_using_range::range_of_builtin_call): Ditto.
	(fold_using_range::range_of_cond_expr): Ditto.
	* gimple-range-fold.h (gimple_range_type): New.

1 files changed, 30 insertions, 0 deletions

diff --git a/gcc/gimple-range-fold.h b/gcc/gimple-range-fold.h
index dc1b28f..ceed7ba 100644
--- a/gcc/gimple-range-fold.h
+++ b/gcc/gimple-range-fold.h
@@ -56,6 +56,36 @@ gimple_range_handler (const gimple *s)
   return NULL;
 }
 
+// Return the type of range which statement S calculates.  If the type is
+// unsupported or no type can be determined, return NULL_TREE.
+
+static inline tree
+gimple_range_type (const gimple *s)
+{
+  tree lhs = gimple_get_lhs (s);
+  tree type = NULL_TREE;
+  if (lhs)
+    type = TREE_TYPE (lhs);
+  else
+    {
+      enum gimple_code code = gimple_code (s);
+      if (code == GIMPLE_COND)
+	type = boolean_type_node;
+      else if (code == GIMPLE_PHI)
+	type = TREE_TYPE (gimple_phi_result (s));
+      else if (code == GIMPLE_CALL)
+	{
+	  type = gimple_call_fntype (s);
+	  // If it has a type, get the return type.
+	  if (type)
+	    type = TREE_TYPE (type);
+	}
+    }
+  if (irange::supports_type_p (type))
+    return type;
+  return NULL_TREE;
+}
+
 // Return EXP if it is an SSA_NAME with a type supported by gimple ranges.
 
 static inline tree