re PR c++/60336 (empty struct value is passed differently in C and C++)

	PR c++/60336
	PR middle-end/67239
	PR target/68355
	* c-decl.c (grokdeclarator): Set DECL_PADDING_P on unnamed bit-fields.

	* class.c (layout_class_type): Set DECL_PADDING_P on padding.
	* decl.c (cxx_init_decl_processing): Set TRANSLATION_UNIT_WARN_EMPTY_P.
	(grokdeclarator): Set DECL_PADDING_P on unnamed bit-fields.

	* lto.c (compare_tree_sccs_1): Compare TYPE_EMPTY_P and DECL_PADDING_P.

	* calls.c (initialize_argument_information): Call
	warn_parameter_passing_abi target hook.
	(store_one_arg): Use 0 for empty record size.  Don't push 0 size
	argument onto stack.
	(must_pass_in_stack_var_size_or_pad): Return false for empty types.
	* common.opt: Update -fabi-version description.
	* config/i386/i386.c (init_cumulative_args): Set cum->warn_empty.
	(ix86_gimplify_va_arg): Call arg_int_size_in_bytes instead of
	int_size_in_bytes.
	(ix86_is_empty_record): New function.
	(ix86_warn_parameter_passing_abi): New function.
	(TARGET_EMPTY_RECORD_P): Redefine.
	(TARGET_WARN_PARAMETER_PASSING_ABI): Redefine.
	* config/i386/i386.h (CUMULATIVE_ARGS): Add warn_empty.
	* doc/tm.texi: Regenerated.
	* doc/tm.texi.in (TARGET_EMPTY_RECORD_P,
	TARGET_WARN_PARAMETER_PASSING_ABI): Add.
	* dwarf2out.c (get_ultimate_context): Move to tree.c.
	* explow.c (hard_function_value): Call arg_int_size_in_bytes
	instead of int_size_in_bytes.
	* expr.c (copy_blkmode_to_reg): Likewise.
	* function.c (aggregate_value_p): Return 0 for empty types.
	(assign_parm_find_entry_rtl): Call warn_parameter_passing_abi target hook.
	(locate_and_pad_parm): Call arg size_in_bytes instead
	size_in_bytes.
	* lto-streamer-out.c (hash_tree): Hash TYPE_EMPTY_P and DECL_PADDING_P.
	* stor-layout.c (finalize_type_size): Set TYPE_EMPTY_P.
	* target.def (empty_record_p, warn_parameter_passing_abi): New target
	hooks.
	* targhooks.c (hook_void_CUMULATIVE_ARGS_tree): New hook.
	(std_gimplify_va_arg_expr): Skip empty records.  Call
	arg_size_in_bytes instead size_in_bytes.
	* targhooks.h (hook_void_CUMULATIVE_ARGS_tree): Declare.
	* tree-core.h (tree_type_common): Add empty_flag.
	(tree_decl_common): Update comments.
	* tree-streamer-in.c (unpack_ts_decl_common_value_fields): Stream
	DECL_PADDING_P.
	(unpack_ts_type_common_value_fields): Stream TYPE_EMPTY_P.
	* tree-streamer-out.c (pack_ts_decl_common_value_fields): Stream
	DECL_PADDING_P.
	(pack_ts_type_common_value_fields): Stream TYPE_EMPTY_P.
	* tree.c (default_is_empty_type): New function.
	(default_is_empty_record): New function.
	(arg_int_size_in_bytes): New function.
	(arg_size_in_bytes): New function.
	(get_ultimate_context): New function.
	* tree.h: Define TYPE_EMPTY_P, DECL_PADDING_P and
	TRANSLATION_UNIT_WARN_EMPTY_P.
	(default_is_empty_record, arg_int_size_in_bytes,
	arg_size_in_bytes, get_ultimate_context): Declare.

	* g++.dg/abi/empty12.C: New test.
	* g++.dg/abi/empty12.h: New test.
	* g++.dg/abi/empty12a.c: New test.
	* g++.dg/abi/empty13.C: New test.
	* g++.dg/abi/empty13.h: New test.
	* g++.dg/abi/empty13a.c: New test.
	* g++.dg/abi/empty14.C: New test.
	* g++.dg/abi/empty14.h: New test.
	* g++.dg/abi/empty14a.c: New test.
	* g++.dg/abi/empty15.C: New test.
	* g++.dg/abi/empty15.h: New test.
	* g++.dg/abi/empty15a.c: New test.
	* g++.dg/abi/empty16.C: New test.
	* g++.dg/abi/empty16.h: New test.
	* g++.dg/abi/empty16a.c: New test.
	* g++.dg/abi/empty17.C: New test.
	* g++.dg/abi/empty17.h: New test.
	* g++.dg/abi/empty17a.c: New test.
	* g++.dg/abi/empty18.C: New test.
	* g++.dg/abi/empty18.h: New test.
	* g++.dg/abi/empty18a.c: New test.
	* g++.dg/abi/empty19.C: New test.
	* g++.dg/abi/empty19.h: New test.
	* g++.dg/abi/empty19a.c: New test.
	* g++.dg/abi/empty20.C: New test.
	* g++.dg/abi/empty21.C: New test.
	* g++.dg/abi/empty22.C: New test.
	* g++.dg/abi/empty22.h: New test.
	* g++.dg/abi/empty22a.c: New test.
	* g++.dg/abi/empty23.C: New test.
	* g++.dg/abi/empty24.C: New test.
	* g++.dg/abi/empty25.C: New test.
	* g++.dg/abi/empty25.h: New test.
	* g++.dg/abi/empty25a.c: New test.
	* g++.dg/abi/empty26.C: New test.
	* g++.dg/abi/empty26.h: New test.
	* g++.dg/abi/empty26a.c: New test.
	* g++.dg/abi/empty27.C: New test.
	* g++.dg/abi/empty28.C: New test.
	* g++.dg/abi/pr60336-1.C: New test.
	* g++.dg/abi/pr60336-10.C: New test.
	* g++.dg/abi/pr60336-11.C: New test.
	* g++.dg/abi/pr60336-12.C: New test.
	* g++.dg/abi/pr60336-2.C: New test.
	* g++.dg/abi/pr60336-3.C: New test.
	* g++.dg/abi/pr60336-4.C: New test.
	* g++.dg/abi/pr60336-5.C: New test.
	* g++.dg/abi/pr60336-6.C: New test.
	* g++.dg/abi/pr60336-7.C: New test.
	* g++.dg/abi/pr60336-8.C: New test.
	* g++.dg/abi/pr60336-9.C: New test.
	* g++.dg/abi/pr68355.C: New test.
	* g++.dg/lto/pr60336_0.C: New test.

Co-Authored-By: H.J. Lu <hongjiu.lu@intel.com>
Co-Authored-By: Jason Merrill <jason@redhat.com>

From-SVN: r255066

1 files changed, 19 insertions, 0 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index 0ec092a..c2cabfc 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -696,6 +696,14 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
    emitted.  */
 #define TREE_NO_WARNING(NODE) ((NODE)->base.nowarning_flag)
 
+/* Nonzero if we should warn about the change in empty class parameter
+   passing ABI in this TU.  */
+#define TRANSLATION_UNIT_WARN_EMPTY_P(NODE) \
+  (TRANSLATION_UNIT_DECL_CHECK (NODE)->decl_common.decl_flag_0)
+
+/* Nonzero if this type is "empty" according to the particular psABI.  */
+#define TYPE_EMPTY_P(NODE) (TYPE_CHECK (NODE)->type_common.empty_flag)
+
 /* Used to indicate that this TYPE represents a compiler-generated entity.  */
 #define TYPE_ARTIFICIAL(NODE) (TYPE_CHECK (NODE)->base.nowarning_flag)
 
@@ -2619,6 +2627,10 @@ extern void decl_value_expr_insert (tree, tree);
 #define DECL_NONADDRESSABLE_P(NODE) \
   (FIELD_DECL_CHECK (NODE)->decl_common.decl_flag_2)
 
+/* Used in a FIELD_DECL to indicate that this field is padding.  */
+#define DECL_PADDING_P(NODE) \
+  (FIELD_DECL_CHECK (NODE)->decl_common.decl_flag_3)
+
 /* A numeric unique identifier for a LABEL_DECL.  The UID allocation is
    dense, unique within any one function, and may be used to index arrays.
    If the value is -1, then no UID has been assigned.  */
@@ -4515,6 +4527,10 @@ storage_order_barrier_p (const_tree t)
 
 extern tree get_containing_scope (const_tree);
 
+/* Returns the ultimate TRANSLATION_UNIT_DECL context of DECL or NULL.  */
+
+extern const_tree get_ultimate_context (const_tree);
+
 /* Return the FUNCTION_DECL which provides this _DECL with its context,
    or zero if none.  */
 extern tree decl_function_context (const_tree);
@@ -5438,6 +5454,9 @@ extern void gt_pch_nx (tree &, gt_pointer_operator, void *);
 
 extern bool nonnull_arg_p (const_tree);
 extern bool is_redundant_typedef (const_tree);
+extern bool default_is_empty_record (const_tree);
+extern HOST_WIDE_INT arg_int_size_in_bytes (const_tree);
+extern tree arg_size_in_bytes (const_tree);
 
 extern location_t
 set_source_range (tree expr, location_t start, location_t finish);