c: add support for per-location warning groups.

gcc/ChangeLog:
	* tree.h (warning_suppressed_at, copy_warning,
	warning_suppressed_p, suppress_warning): New functions.

gcc/c/ChangeLog:

	* c-decl.c (pop_scope): Replace direct uses of TREE_NO_WARNING with
	warning_suppressed_p, suppress_warning, and copy_no_warning.
	(diagnose_mismatched_decls): Same.
	(duplicate_decls): Same.
	(grokdeclarator): Same.
	(finish_function): Same.
	(c_write_global_declarations_1): Same.
	* c-fold.c (c_fully_fold_internal): Same.
	* c-parser.c (c_parser_expr_no_commas): Same.
	(c_parser_postfix_expression): Same.
	* c-typeck.c (array_to_pointer_conversion): Same.
	(function_to_pointer_conversion): Same.
	(default_function_array_conversion): Same.
	(convert_lvalue_to_rvalue): Same.
	(default_conversion): Same.
	(build_indirect_ref): Same.
	(build_function_call_vec): Same.
	(build_atomic_assign): Same.
	(build_unary_op): Same.
	(c_finish_return): Same.
	(emit_side_effect_warnings): Same.
	(c_finish_stmt_expr): Same.
	(c_omp_clause_copy_ctor): Same.

1 files changed, 15 insertions, 0 deletions

diff --git a/gcc/tree.h b/gcc/tree.h
index e5d1718..8bdf16d 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -6448,9 +6448,24 @@ constexpr opt_code no_warning = opt_code ();
 /* Wildcard code that refers to all warnings.  */
 constexpr opt_code all_warnings = N_OPTS;
 
+/* Return the disposition for a warning (or all warnings by default)
+   at a location.  */
+extern bool warning_suppressed_at (location_t, opt_code = all_warnings);
 /* Set the disposition for a warning (or all warnings by default)
    at a location to disabled by default.  */
 extern bool suppress_warning_at (location_t, opt_code = all_warnings,
 				 bool = true);
+/* Copy warning disposition from one location to another.  */
+extern void copy_warning (location_t, location_t);
+
+/* Return the disposition for a warning (or all warnings by default)
+   for an expression.  */
+extern bool warning_suppressed_p (const_tree, opt_code = all_warnings);
+/* Set the disposition for a warning (or all warnings by default)
+   at a location to disabled by default.  */
+extern void suppress_warning (tree, opt_code = all_warnings, bool = true)
+  ATTRIBUTE_NONNULL (1);
+/* Copy warning disposition from one expression to another.  */
+extern void copy_warning (tree, const_tree);
 
 #endif  /* GCC_TREE_H  */