openmp: Add support for omp::directive and omp::sequence attributes in C2X

The following patch adds support for attribute syntax which we have in C++11
and above since GCC 12 also for C, where OpenMP standard is going to add it
in OpenMP 6.0.

2023-11-04  Jakub Jelinek  <jakub@redhat.com>

gcc/c/
	* c-tree.def: New file.
	* c-tree.h (struct c_tree_token_vec): Forward declare.
	(c_tree_size): Declare.
	* c-lang.h (struct c_omp_declare_target_attr): Add attr_syntax member.
	(struct c_omp_begin_assumes_data): New type.
	(current_omp_begin_assumes): Change type from int to
	vec<c_omp_begin_assumes_data, va_gc> *.
	* c-lang.cc: Include c-family/c-pragma.h and c-parser.h.
	* c-parser.h (struct c_tree_token_vec_struct): New type.
	(C_TOKEN_VEC_TOKENS): New macro.
	* c-parser.cc (struct c_parser): Add omp_attrs_forbidden_p and
	in_omp_attribute_pragma members.
	(c_parser_skip_until_found): Handle CPP_PRAGMA_EOL when
	parser->in_omp_attribute_pragma.
	(c_parser_skip_to_pragma_eol): Likewise.
	(c_parser_translation_unit): Adjust for current_omp_begin_assumes
	being a vector rather than counter.
	(c_parser_declaration_or_fndef): Handle omp::directive and
	omp::sequence attributes on attribute declaration and declare simd
	or declare variant directives in those on function declarations.
	(c_parser_check_balanced_raw_token_sequence): Forward declare.
	(c_parser_omp_directive_args, c_parser_omp_sequence_args): New
	functions.
	(c_parser_std_attribute): Handle omp::directive and omp::sequence
	attributes.
	(struct c_omp_attribute_data): New type.
	(c_parser_handle_statement_omp_attributes,
	c_parser_handle_directive_omp_attributes): New functions.
	(c_parser_compound_statement_nostart): Handle omp::directive and
	omp::sequence attributes on statements.  Formatting fix.
	(c_parser_all_labels): Handle omp::directive and omp::sequence
	attributes on statements.
	(c_parser_statement): Clear parser->omp_attrs_forbidden_p.
	(c_parser_omp_variable_list): Handle parser->tokens
	!= &parser->tokens_buf[0] by saving/restoring it.
	(c_parser_omp_structured_block): Set parser->omp_attrs_forbidden_p.
	(c_parser_omp_section_scan): New function.
	(c_parser_omp_structured_block_sequence, c_parser_omp_sections_scope):
	Use it.
	(c_parser_omp_parallel): Set parser->omp_attrs_forbidden_p.
	(c_parser_omp_task): Likewise.
	(c_parser_omp_declare_simd): Handle function declaration after
	std attributes.
	(c_finish_omp_declare_simd): Don't assert all kinds are the same.
	(c_parser_omp_declare_target): Also push attr_syntax flag.
	(c_parser_omp_begin): Likewise.  Adjust for current_omp_begin_assumes
	type change.
	(c_parser_omp_end): Adjust for current_omp_begin_assumes type
	change.  Diagnose mixing of attribute vs. pragma syntax on end assumes
	or end declare target.
	(c_parser_omp_declare_reduction): Handle parser->tokens
	!= &parser->tokens_buf[0] by saving/restoring it.
	* c-decl.cc: Include c-parser.h.
	(current_omp_begin_assumes): Change type from int to
	vec<c_omp_begin_assumes_data, va_gc> *.
	(struct c_tree_token_vec): New type.  Add static assertions
	for sizeof and offsetof.
	(union lang_tree_node): Add c_token_vec member and adjust GTY
	desc for it.
	(c_tree_size): New function.
	(c_decl_attributes): Diagnose invalid omp::directive attribute
	uses.
	* c-objc-common.h (LANG_HOOKS_TREE_SIZE): Redefine.
gcc/cp/
	* parser.h (struct cp_parser): Adjust comment on omp_attrs_forbidden_p
	member.
	* parser.cc (cp_parser_omp_section_scan): Allow __directive__ spelling.
gcc/objc/
	* objc-act.h (objc_common_tree_size): Remove.
	* objc-act.cc (objc_common_tree_size): Remove.
	* objc-lang.cc (LANG_HOOKS_TREE_SIZE): Remove.
gcc/testsuite/
	* gcc.dg/gomp/attrs-1.c: New test.
	* gcc.dg/gomp/attrs-2.c: New test.
	* gcc.dg/gomp/attrs-3.c: New test.
	* gcc.dg/gomp/attrs-4.c: New test.
	* gcc.dg/gomp/attrs-5.c: New test.
	* gcc.dg/gomp/attrs-6.c: New test.
	* gcc.dg/gomp/attrs-7.c: New test.
	* gcc.dg/gomp/attrs-8.c: New test.
	* gcc.dg/gomp/attrs-9.c: New test.
	* gcc.dg/gomp/attrs-10.c: New test.
	* gcc.dg/gomp/attrs-11.c: New test.
	* gcc.dg/gomp/attrs-12.c: New test.
	* gcc.dg/gomp/attrs-13.c: New test.
	* gcc.dg/gomp/attrs-14.c: New test.
	* gcc.dg/gomp/attrs-15.c: New test.
	* gcc.dg/gomp/attrs-16.c: New test.
	* gcc.dg/gomp/attrs-17.c: New test.
	* gcc.dg/gomp/attrs-18.c: New test.
	* g++.dg/gomp/attrs-2.C: Enable for c++11 rather than just
	c++17.  Avoid using omp : syntax for c++11, c++14 and c.

1 files changed, 2 insertions, 1 deletions

diff --git a/gcc/cp/parser.h b/gcc/cp/parser.h
index 9ba8021..ee3afba 100644
--- a/gcc/cp/parser.h
+++ b/gcc/cp/parser.h
@@ -408,7 +408,8 @@ struct GTY(()) cp_parser {
      identifiers) rather than an explicit template parameter list.  */
   bool fully_implicit_function_template_p;
 
-  /* TRUE if omp::directive or omp::sequence attributes may not appear.  */
+  /* TRUE if omp::directive, omp::decl or omp::sequence attributes may not
+     appear.  */
   bool omp_attrs_forbidden_p;
 
   /* Tracks the function's template parameter list when declaring a function