C/C++: show pertinent open token when missing a close token

C/C++: show pertinent open token when missing a close token

gcc/c/ChangeLog:
	* c-parser.c (c_parser_error): Rename to...
	(c_parser_error_richloc): ...this, making static, and adding
	"richloc" parameter, passing it to the c_parse_error call,
	rather than calling c_parser_set_source_position_from_token.
	(c_parser_error): Reintroduce, reimplementing in terms of the
	above, converting return type from void to bool.
	(class token_pair): New class.
	(struct matching_paren_traits): New struct.
	(matching_parens): New typedef.
	(struct matching_brace_traits): New struct.
	(matching_braces): New typedef.
	(get_matching_symbol): New function.
	(c_parser_require): Add param MATCHING_LOCATION, using it to
	highlight matching "opening" tokens for missing "closing" tokens.
	(c_parser_skip_until_found): Likewise.
	(c_parser_static_assert_declaration_no_semi): Convert explicit
	parsing of CPP_OPEN_PAREN and CPP_CLOSE_PAREN to use of
	class matching_parens, so that the pertinent open parenthesis is
	highlighted when there are problems locating the close
	parenthesis.
	(c_parser_struct_or_union_specifier): Likewise.
	(c_parser_typeof_specifier): Likewise.
	(c_parser_alignas_specifier): Likewise.
	(c_parser_simple_asm_expr): Likewise.
	(c_parser_braced_init): Likewise, for matching_braces.
	(c_parser_paren_condition): Likewise, for matching_parens.
	(c_parser_switch_statement): Likewise.
	(c_parser_for_statement): Likewise.
	(c_parser_asm_statement): Likewise.
	(c_parser_asm_operands): Likewise.
	(c_parser_cast_expression): Likewise.
	(c_parser_sizeof_expression): Likewise.
	(c_parser_alignof_expression): Likewise.
	(c_parser_generic_selection): Likewise.
	(c_parser_postfix_expression): Likewise for cases RID_VA_ARG,
	RID_OFFSETOF, RID_TYPES_COMPATIBLE_P, RID_AT_SELECTOR,
	RID_AT_PROTOCOL, RID_AT_ENCODE, reindenting as necessary.
	In case CPP_OPEN_PAREN, pass loc_open_paren to the
	c_parser_skip_until_found call.
	(c_parser_objc_class_definition): Use class matching_parens as
	above.
	(c_parser_objc_method_decl): Likewise.
	(c_parser_objc_try_catch_finally_statement): Likewise.
	(c_parser_objc_synchronized_statement): Likewise.
	(c_parser_objc_at_property_declaration): Likewise.
	(c_parser_oacc_wait_list): Likewise.
	(c_parser_omp_var_list_parens): Likewise.
	(c_parser_omp_clause_collapse): Likewise.
	(c_parser_omp_clause_default): Likewise.
	(c_parser_omp_clause_if): Likewise.
	(c_parser_omp_clause_num_threads): Likewise.
	(c_parser_omp_clause_num_tasks): Likewise.
	(c_parser_omp_clause_grainsize): Likewise.
	(c_parser_omp_clause_priority): Likewise.
	(c_parser_omp_clause_hint): Likewise.
	(c_parser_omp_clause_defaultmap): Likewise.
	(c_parser_oacc_single_int_clause): Likewise.
	(c_parser_omp_clause_ordered): Likewise.
	(c_parser_omp_clause_reduction): Likewise.
	(c_parser_omp_clause_schedule): Likewise.
	(c_parser_omp_clause_num_teams): Likewise.
	(c_parser_omp_clause_thread_limit): Likewise.
	(c_parser_omp_clause_aligned): Likewise.
	(c_parser_omp_clause_linear): Likewise.
	(c_parser_omp_clause_safelen): Likewise.
	(c_parser_omp_clause_simdlen): Likewise.
	(c_parser_omp_clause_depend): Likewise.
	(c_parser_omp_clause_map): Likewise.
	(c_parser_omp_clause_device): Likewise.
	(c_parser_omp_clause_dist_schedule): Likewise.
	(c_parser_omp_clause_proc_bind): Likewise.
	(c_parser_omp_clause_uniform): Likewise.
	(c_parser_omp_for_loop): Likewise.
	(c_parser_cilk_clause_vectorlength): Likewise.
	(c_parser_cilk_clause_linear): Likewise.
	(c_parser_transaction_expression): Likewise.
	* c-parser.h (c_parser_require): Add param matching_location with
	default UNKNOWN_LOCATION.
	(c_parser_error): Convert return type from void to bool.
	(c_parser_skip_until_found): Add param matching_location with
	default UNKNOWN_LOCATION.

gcc/c-family/ChangeLog:
	* c-common.c (c_parse_error): Add rich_location * param, using it
	rather implicitly using input_location.
	* c-common.h (c_parse_error): Add rich_location * param.

gcc/cp/ChangeLog:
	* parser.c (cp_parser_error): Update for new param to
	c_parse_error.
	(class token_pair): New class.
	(struct matching_paren_traits): New struct.
	(matching_parens): New typedef.
	(struct matching_brace_traits): New struct.
	(matching_braces): New typedef.
	(cp_parser_statement_expr): Convert explicit parsing of
	CPP_OPEN_PAREN and CPP_CLOSE_PAREN to use of
	class matching_parens, so that the pertinent open parenthesis is
	highlighted when there are problems locating the close
	parenthesis.
	(cp_parser_primary_expression): Likewise.
	(cp_parser_compound_literal_p): Remove consumption of opening
	paren.
	(cp_parser_postfix_expression): Convert explicit parsing of
	CPP_OPEN_PAREN and CPP_CLOSE_PAREN to use matching parens, as
	above.  Use it to consume the opening paren previously consumed by
	cp_parser_compound_literal_p.
	(cp_parser_parenthesized_expression_list): Likewise.
	(cp_parser_unary_expression): Likewise.
	(cp_parser_new_expression): Likewise.
	(cp_parser_cast_expression): Likewise.
	(cp_parser_builtin_offsetof): Likewise.
	(cp_parser_trait_expr): Likewise.
	(cp_parser_lambda_declarator_opt): Likewise.
	(cp_parser_lambda_body): Likewise, for matching_braces.
	(cp_parser_compound_statement): Likewise.
	(cp_parser_selection_statement): Likewise, for matching_parens.
	(cp_parser_iteration_statement): Likewise.
	(cp_parser_already_scoped_statement): Likewise, for
	matching_braces.
	(cp_parser_linkage_specification): Likewise.
	(cp_parser_static_assert): Likewise, for matching_parens.
	(cp_parser_decltype): Likewise.
	(cp_parser_operator): Likewise.
	(cp_parser_enum_specifier): Likewise.
	(cp_parser_namespace_definition): Likewise.
	(cp_parser_direct_declarator): Likewise.
	(cp_parser_braced_list): Likewise.
	(cp_parser_class_specifier_1): Likewise, for matching_braces.
	(cp_parser_constant_initializer): Likewise.
	(cp_parser_noexcept_specification_opt): Likewise, for
	matching_parens.
	(cp_parser_exception_specification_opt): Likewise.
	(cp_parser_handler): Likewise.
	(cp_parser_asm_specification_opt): Likewise.
	(cp_parser_asm_operand_list): Likewise.
	(cp_parser_gnu_attributes_opt): Likewise.
	(cp_parser_std_attribute_spec): Likewise.
	(cp_parser_requirement_parameter_list): Likewise.
	(cp_parser_requirement_body): Likewise, for matching_braces.
	(cp_parser_compound_requirement): Likewise.
	(cp_parser_template_introduction): Likewise.
	(cp_parser_sizeof_pack): Likewise, for matching_parens.
	(cp_parser_sizeof_operand): Likewise; use it to consume the
	opening paren previously consumed by cp_parser_compound_literal_p.
	(get_matching_symbol): New function.
	(cp_parser_required_error): Add param "matching_location".  Remove
	calls to cp_parser_error, instead setting a non-NULL gmsgid, and
	handling it if set by calling c_parse_error, potentially with a
	secondary location if matching_location was set.
	(cp_parser_require): Add param "matching_location", with a default
	value of UNKNOWN_LOCATION.
	(cp_parser_require_keyword): Update for new param of
	cp_parser_required_error.
	(cp_parser_objc_encode_expression): Update to class matching_parens
	as above.
	(cp_parser_objc_defs_expression): Likewise.
	(cp_parser_objc_protocol_expression): Likewise.
	(cp_parser_objc_selector_expression): Likewise.
	(cp_parser_objc_typename): Likewise.
	(cp_parser_objc_superclass_or_category): Likewise.
	(cp_parser_objc_try_catch_finally_statement): Likewise.
	(cp_parser_objc_synchronized_statement): Likewise.
	(cp_parser_objc_at_property_declaration): Likewise.
	(cp_parser_oacc_single_int_clause): Likewise.
	(cp_parser_oacc_shape_clause): Likewise.
	(cp_parser_omp_clause_collapse): Likewise.
	(cp_parser_omp_clause_default): Likewise.
	(cp_parser_omp_clause_final): Likewise.
	(cp_parser_omp_clause_if): Likewise.
	(cp_parser_omp_clause_num_threads): Likewise.
	(cp_parser_omp_clause_num_tasks): Likewise.
	(cp_parser_omp_clause_grainsize): Likewise.
	(cp_parser_omp_clause_priority): Likewise.
	(cp_parser_omp_clause_hint): Likewise.
	(cp_parser_omp_clause_defaultmap): Likewise.
	(cp_parser_omp_clause_ordered): Likewise.
	(cp_parser_omp_clause_schedule): Likewise.
	(cp_parser_omp_clause_num_teams): Likewise.
	(cp_parser_omp_clause_thread_limit): Likewise.
	(cp_parser_omp_clause_aligned): Likewise.
	(cp_parser_omp_clause_linear): Likewise.
	(cp_parser_omp_clause_safelen): Likewise.
	(cp_parser_omp_clause_simdlen): Likewise.
	(cp_parser_omp_clause_depend): Likewise.
	(cp_parser_omp_clause_device): Likewise.
	(cp_parser_omp_clause_dist_schedule): Likewise.
	(cp_parser_oacc_clause_async): Likewise.
	(cp_parser_omp_critical): Likewise.
	(cp_parser_omp_for_loop): Likewise.
	(cp_parser_omp_sections_scope): Likewise.
	(cp_parser_omp_declare_reduction_exprs): Likewise.
	Update for new param to cp_parser_required_error.
	(cp_parser_oacc_routine): Likewise.
	(cp_parser_transaction_expression): Likewise.
	(cp_parser_cilk_simd_vectorlength): Likewise.

gcc/testsuite/ChangeLog:
	* c-c++-common/missing-close-symbol.c: New test case.
	* c-c++-common/missing-symbol.c: New test case.
	* gcc.dg/unclosed-init.c: New test case.
	* g++.dg/diagnostic/unclosed-extern-c.C: New test case.
	* g++.dg/diagnostic/unclosed-function.C: New test case.
	* g++.dg/diagnostic/unclosed-namespace.C: New test case.
	* g++.dg/diagnostic/unclosed-struct.C: New test case.
	* g++.dg/parse/pragma2.C: Update to reflect movement of the
	"expected identifier" error.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@251026 138bc75d-0d04-0410-961f-82ee72b054a4