re PR debug/54828 (ICE in based_loc_descr at dwarf2out.c:10560 with -g -O0)

	PR debug/54828
	* gimple.h (is_gimple_sizepos): New inline function.
	* gimplify.c (gimplify_one_sizepos): Use it.  Remove useless
	final assignment to expr variable.
	* tree.c (RETURN_TRUE_IF_VAR): Return true also if
	!TYPE_SIZES_GIMPLIFIED (type) and _t is going to be gimplified
	into a local temporary.

	* g++.dg/debug/pr54828.C: New test.

From-SVN: r192759

1 files changed, 18 insertions, 0 deletions

diff --git a/gcc/gimple.h b/gcc/gimple.h
index bca1e14..b34016a 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -957,6 +957,24 @@ struct gimplify_ctx
   bool in_cleanup_point_expr;
 };
 
+/* Return true if gimplify_one_sizepos doesn't need to gimplify
+   expr (when in TYPE_SIZE{,_UNIT} and similar type/decl size/bitsize
+   fields).  */
+static inline bool
+is_gimple_sizepos (tree expr)
+{
+  /* gimplify_one_sizepos doesn't need to do anything if the value isn't there,
+     is constant, or contains A PLACEHOLDER_EXPR.  We also don't want to do
+     anything if it's already a VAR_DECL.  If it's a VAR_DECL from another
+     function, the gimplifier will want to replace it with a new variable,
+     but that will cause problems if this type is from outside the function.
+     It's OK to have that here.  */
+  return (expr == NULL_TREE
+	  || TREE_CONSTANT (expr)
+	  || TREE_CODE (expr) == VAR_DECL
+	  || CONTAINS_PLACEHOLDER_P (expr));
+}                                        
+
 extern enum gimplify_status gimplify_expr (tree *, gimple_seq *, gimple_seq *,
 					   bool (*) (tree), fallback_t);
 extern void gimplify_type_sizes (tree, gimple_seq *);