From 8433baadec88e5f31fa141b6d78094e91256079d Mon Sep 17 00:00:00 2001 From: Iain Sandoe Date: Sun, 8 Nov 2020 09:04:07 +0000 Subject: C-family: Add attribute 'unavailable'. If an interface is marked 'deprecated' then, presumably, at some point it will be withdrawn and no longer available. The 'unavailable' attribute makes it possible to mark up interfaces to indicate this status. It is used quite extensively in some codebases where a single set of headers can be used to permit code generation for multiple system versions. From a configuration perspective, it also allows a compile test to determine that an interface is missing - rather than requiring a link test. The implementation follows the pattern of attribute deprecated, but produces an error (where deprecation produces a warning). This attribute has been implemented in clang for some years. Signed-off-by: Iain Sandoe gcc/c-family/ChangeLog: * c-attribs.c (handle_unavailable_attribute): New. gcc/c/ChangeLog: * c-decl.c (enum deprecated_states): Add unavailable state. (merge_decls): Copy unavailability. (quals_from_declspecs): Handle unavailable case. (start_decl): Amend the logic handling suppression of nested deprecation states to include unavailability. (smallest_type_quals_location): Amend comment. (grokdeclarator): Handle the unavailable deprecation state. (declspecs_add_type): Set TREE_UNAVAILABLE from the decl specs. * c-tree.h (struct c_declspecs): Add unavailable_p. * c-typeck.c (build_component_ref): Handle unavailability. (build_external_ref): Likewise. gcc/cp/ChangeLog: * call.c (build_over_call): Handle unavailable state in addition to deprecation. * class.c (type_build_ctor_call): Likewise. (type_build_dtor_call): Likewise. * cp-tree.h: Rename cp_warn_deprecated_use to cp_handle_deprecated_or_unavailable. * decl.c (duplicate_decls): Merge unavailability. (grokdeclarator): Handle unavailability in addition to deprecation. (type_is_unavailable): New. (grokparms): Handle unavailability in addition to deprecation. * decl.h (enum deprecated_states): Add UNAVAILABLE_DEPRECATED_SUPPRESS. * decl2.c (cplus_decl_attributes): Propagate unavailability to templates. (cp_warn_deprecated_use): Rename to ... (cp_handle_deprecated_or_unavailable): ... this and amend to handle the unavailable case. It remains a warning in the case of deprecation but becomes an error in the case of unavailability. (cp_warn_deprecated_use_scopes): Handle unavailability. (mark_used): Likewise. * parser.c (cp_parser_template_name): Likewise. (cp_parser_template_argument): Likewise. (cp_parser_parameter_declaration_list): Likewise. * typeck.c (build_class_member_access_expr): Likewise. (finish_class_member_access_expr): Likewise. * typeck2.c (build_functional_cast_1): Likewise. gcc/ChangeLog: * doc/extend.texi: Document unavailable attribute. * print-tree.c (print_node): Handle unavailable attribute. * tree-core.h (struct tree_base): Add a bit to carry unavailability. * tree.c (error_unavailable_use): New. * tree.h (TREE_UNAVAILABLE): New. (error_unavailable_use): New. gcc/objc/ChangeLog: * objc-act.c (objc_add_property_declaration): Register unavailable attribute. (maybe_make_artificial_property_decl): Set available. (objc_maybe_build_component_ref): Generalise to the method prototype to count availability. (objc_build_class_component_ref): Likewise. (build_private_template): Likewise. (objc_decl_method_attributes): Handle unavailable attribute. (lookup_method_in_hash_lists): Amend comments. (objc_finish_message_expr): Handle unavailability in addition to deprecation. (start_class): Likewise. (finish_class): Likewise. (lookup_protocol): Likewise. (objc_declare_protocol): Likewise. (start_protocol): Register unavailable attribute. (really_start_method): Likewise. (objc_gimplify_property_ref): Emit error on encountering an unavailable entity (and a warning for a deprecated one). gcc/testsuite/ChangeLog: * g++.dg/ext/attr-unavailable-1.C: New test. * g++.dg/ext/attr-unavailable-2.C: New test. * g++.dg/ext/attr-unavailable-3.C: New test. * g++.dg/ext/attr-unavailable-4.C: New test. * g++.dg/ext/attr-unavailable-5.C: New test. * g++.dg/ext/attr-unavailable-6.C: New test. * g++.dg/ext/attr-unavailable-7.C: New test. * g++.dg/ext/attr-unavailable-8.C: New test. * g++.dg/ext/attr-unavailable-9.C: New test. * gcc.dg/attr-unavailable-1.c: New test. * gcc.dg/attr-unavailable-2.c: New test. * gcc.dg/attr-unavailable-3.c: New test. * gcc.dg/attr-unavailable-4.c: New test. * gcc.dg/attr-unavailable-5.c: New test. * gcc.dg/attr-unavailable-6.c: New test. * obj-c++.dg/attributes/method-unavailable-1.mm: New test. * obj-c++.dg/attributes/method-unavailable-2.mm: New test. * obj-c++.dg/attributes/method-unavailable-3.mm: New test. * obj-c++.dg/property/at-property-unavailable-1.mm: New test. * obj-c++.dg/property/at-property-unavailable-2.mm: New test. * obj-c++.dg/property/dotsyntax-unavailable-1.mm: New test. * objc.dg/attributes/method-unavailable-1.m: New test. * objc.dg/attributes/method-unavailable-2.m: New test. * objc.dg/attributes/method-unavailable-3.m: New test. * objc.dg/property/at-property-unavailable-1.m: New test. * objc.dg/property/at-property-unavailable-2.m: New test. * objc.dg/property/dotsyntax-unavailable-1.m: New test. --- gcc/print-tree.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'gcc/print-tree.c') diff --git a/gcc/print-tree.c b/gcc/print-tree.c index 8ad0dcf..d1fbd04 100644 --- a/gcc/print-tree.c +++ b/gcc/print-tree.c @@ -364,6 +364,8 @@ print_node (FILE *file, const char *prefix, tree node, int indent, fputs (code == CALL_EXPR ? " must-tail-call" : " static", file); if (TREE_DEPRECATED (node)) fputs (" deprecated", file); + if (TREE_UNAVAILABLE (node)) + fputs (" unavailable", file); if (TREE_VISITED (node)) fputs (" visited", file); -- cgit v1.1