tree.h (categorize_ctor_elements): Adjust prototype and add descriptive comment...

	* tree.h (categorize_ctor_elements): Adjust prototype and add
	descriptive comment, both in accordance with the interface change
	described below.
	* varasm.c (constructor_static_from_elts_p): New function.
	Whether a constructor node is a valid static constant initializer
	if all its elements are.
	(initializer_constant_valid_p) <CONSTRUCTOR value>: Use it.
	* output.h: Declare it.	
	* expr.c (categorize_ctor_elements_1): Return whether the constructor
	is a valid constant initializer instead of computing the number of
	non-constant elements.  Use constructor_static_from_elts_p for this
	purpose.  Replace the head comment with an indication that this is a
	helper for categorize_ctor_elements.
	(categorize_ctor_elements): Same interface change as for the _1
	helper.  Former head comment from this helper moved here, adjusted to
	account for the interface changes.
	(mostly_zeros_p): Adjust call to categorize_ctor_elements.
	(all_zeros_p): Likewise.	
	* gimplify.c (gimplify_init_constructor): Decide whether we can make
	static versions of the constructor from the categorize_ctor_elements
	return value instead of the formerly computed number of non-constant
	elements.

	* gnat.dg/outer_agg_bitfield_constructor.adb: New test.
	* gnat.dg/nested_agg_bitfield_constructor.adb: New test.

From-SVN: r115553

1 files changed, 14 insertions, 2 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index 12e2f59..dfea92a 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3924,8 +3924,20 @@ extern int fields_length (tree);
 
 extern bool initializer_zerop (tree);
 
-extern void categorize_ctor_elements (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
-				      HOST_WIDE_INT *, bool *);
+/* Examine CTOR to discover:
+   * how many scalar fields are set to nonzero values,
+     and place it in *P_NZ_ELTS;
+   * how many scalar fields in total are in CTOR,
+     and place it in *P_ELT_COUNT.
+   * if a type is a union, and the initializer from the constructor
+     is not the largest element in the union, then set *p_must_clear.
+
+   Return whether or not CTOR is a valid static constant initializer, the same
+   as "initializer_constant_valid_p (CTOR, TREE_TYPE (CTOR)) != 0".  */
+
+extern bool categorize_ctor_elements (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
+				      bool *);
+
 extern HOST_WIDE_INT count_type_elements (tree, bool);
 
 /* integer_zerop (tree x) is nonzero if X is an integer constant of value 0.  */