[PING] Re: [PATCH 1/2] C++: more location wrapper nodes (PR c++/43064, PR c++/43486)

Jeff Law law@redhat.com
Mon Dec 3 22:10:00 GMT 2018


On 11/19/18 9:51 AM, David Malcolm wrote:
> Ping, for these patches:
> 
> [PATCH 1/2] C++: more location wrapper nodes (PR c++/43064, PR c++/43486)
>   https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00304.html
> 
> [PATCH 2/2] C++: improvements to binary operator diagnostics (PR c++/87504)
>   https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00303.html
> 
> 
> Thanks
> Dave
> 

>>
>> [1] I've split them up for ease of review; they could be reworked to
>> be
>> fully independent, but there's some churn in the results for
>> -Wtautological-compare introduced by the 1st patch which the 2nd
>> patch addresses.
>>
>> gcc/ChangeLog:
>> 	PR c++/43064
>> 	PR c++/43486
>> 	* convert.c: Include "selftest.h".
>> 	(preserve_any_location_wrapper): New function.
>> 	(convert_to_pointer_maybe_fold): Update to handle location
>> 	wrappers.
>> 	(convert_to_real_maybe_fold): Likewise.
>> 	(convert_to_integer_1): Handle location wrappers when checking
>> for
>> 	INTEGER_CST.
>> 	(convert_to_integer_maybe_fold): Update to handle location
>> 	wrappers.
>> 	(convert_to_complex_maybe_fold): Likewise.
>> 	(selftest::test_convert_to_integer_maybe_fold): New functions.
>> 	(selftest::convert_c_tests): New function.
>> 	* fold-const.c (operand_equal_p): Strip any location wrappers.
>> 	* selftest-run-tests.c (selftest::run_tests): Call
>> 	selftest::convert_c_tests.
>> 	* selftest.h (selftest::convert_c_tests): New decl.
>> 	* tree.c (tree_int_cst_equal): Strip any location wrappers.
>> 	(maybe_wrap_with_location): Don't create wrappers if any
>> 	auto_suppress_location_wrappers are active.
>> 	(suppress_location_wrappers): New variable.
>> 	* tree.h (CONSTANT_CLASS_OR_WRAPPER_P): New macro.
>> 	(suppress_location_wrappers): New decl.
>> 	(class auto_suppress_location_wrappers): New class.
>>
>> gcc/c-family/ChangeLog:
>> 	PR c++/43064
>> 	PR c++/43486
>> 	* c-common.c (unsafe_conversion_p): Strip any location wrapper.
>> 	(verify_tree): Handle location wrappers.
>> 	(c_common_truthvalue_conversion): Strip any location wrapper.
>> 	Handle CONST_DECL.
>> 	(fold_offsetof): Strip any location wrapper.
>> 	(complete_array_type): Likewise for initial_value.
>> 	(convert_vector_to_array_for_subscript): Call fold_for_warn on
>> the
>> 	index before checking for INTEGER_CST.
>> 	* c-pretty-print.c (c_pretty_printer::primary_expression):
>> Don't
>> 	print parentheses around location wrappers.
>> 	* c-warn.c (warn_logical_operator): Call fold_for_warn on
>> op_right
>> 	before checking for INTEGER_CST.
>> 	(warn_tautological_bitwise_comparison): Call
>> 	tree_strip_any_location_wrapper on lhs, rhs, and bitop's
>> operand
>> 	before checking for INTEGER_CST.
>> 	(readonly_error): Strip any location wrapper.
>> 	(warn_array_subscript_with_type_char): Strip location wrappers
>> 	before checking for INTEGER_CST.  Use the location of the index
>> if
>> 	available.
>>
>> gcc/cp/ChangeLog:
>> 	PR c++/43064
>> 	PR c++/43486
>> 	* call.c (build_conditional_expr_1): Strip location wrappers
>> when
>> 	checking for CONST_DECL.
>> 	(conversion_null_warnings): Use location of "expr" if
>> available.
>> 	* class.c (fixed_type_or_null): Handle location wrappers.
>> 	* constexpr.c (potential_constant_expression_1): Likewise.
>> 	* cvt.c (ignore_overflows): Strip location wrappers when
>> 	checking for INTEGER_CST, and re-wrap the result if present.
>> 	(ocp_convert): Call fold_for_warn before checking for
>> INTEGER_CST.
>> 	* decl.c (reshape_init_r): Strip any location wrapper.
>> 	(undeduced_auto_decl): Likewise.
>> 	* decl2.c (grokbitfield): Likewise for width.
>> 	* expr.c (mark_discarded_use): Likewise for expr.
>> 	* init.c (build_aggr_init): Likewise before checking init for
>> 	DECL_P.
>> 	(warn_placement_new_too_small): Call fold_for_warn on adj
>> before
>> 	checking for CONSTANT_CLASS_P, and on nelts.  Strip any
>> location
>> 	wrapper from op0 and on oper before checking for VAR_P.
>> 	* lambda.c (add_capture): Strip any location from initializer.
>> 	* name-lookup.c (handle_namespace_attrs): Strip any location
>> from
>> 	x before checking for STRING_CST.
>> 	* parser.c (cp_parser_primary_expression): Call
>> 	maybe_add_location_wrapper on numeric and string literals.
>> 	(cp_parser_postfix_expression): Strip any location wrapper when
>> 	checking for DECL_IS_BUILTIN_CONSTANT_P.
>> 	(cp_parser_binary_expression): Strip any location wrapper when
>> 	checking for DECL_P on the lhs.
>> 	(cp_parser_decltype_expr): Suppress location wrappers in the
>> 	id-expression.
>> 	(cp_parser_mem_initializer): Add location wrappers to the
>> 	parenthesized expression list.
>> 	(cp_parser_template_parameter_list): Don't create wrapper nodes
>> 	within a template-parameter-list.
>> 	(cp_parser_template_argument_list): Don't create wrapper nodes
>> 	within a template-argument-list.
>> 	(cp_parser_parameter_declaration): Strip location wrappers from
>> 	default arguments.
>> 	(cp_parser_gnu_attribute_list): Don't create wrapper nodes
>> within
>> 	an attribute.
>> 	(cp_parser_late_parsing_default_args): Strip location wrappers
>> 	from default arguments.
>> 	(cp_parser_omp_all_clauses): Don't create wrapper nodes within
>> 	OpenMP clauses.
>> 	(cp_parser_omp_for_loop): Likewise.
>> 	(cp_parser_omp_declare_reduction_exprs): Likewise.
>> 	* pt.c (convert_nontype_argument_function): Strip location
>> 	wrappers from fn_no_ptr before checking for FUNCTION_DECL.
>> 	(do_auto_deduction): Likewise from init before checking for
>> 	DECL_P.
>> 	* semantics.c (force_paren_expr): Likewise from expr before
>> 	checking for DECL_P.
>> 	(finish_parenthesized_expr): Likewise from expr before
>> 	checking for STRING_CST.
>> 	(perform_koenig_lookup): Likewise from fn.
>> 	(finish_call_expr): Likewise.
>> 	(finish_id_expression): Rename to...
>> 	(finish_id_expression_1): ...this, calling
>> 	maybe_add_location_wrapper on the result.
>> 	* tree.c (cp_stabilize_reference): Strip any location wrapper.
>> 	(builtin_valid_in_constant_expr_p): Likewise.
>> 	(is_overloaded_fn): Likewise.
>> 	(maybe_get_fns): Likewise.
>> 	(selftest::test_lvalue_kind): Verify lvalue_p.
>> 	* typeck.c (cxx_sizeof_expr): Strip any location wrapper.
>> 	(cxx_alignof_expr): Likewise.
>> 	(is_bitfield_expr_with_lowered_type): Handle location wrappers.
>> 	(cp_build_array_ref): Strip location wrappers from idx before
>> 	checking for INTEGER_CST.
>> 	(cp_build_binary_op): Strip location wrapper from first_arg
>> before
>> 	checking for PARM_DECL.  Likewise for op1 before checking for
>> 	INTEGER_CST in two places.  Likewise for orig_op0 and orig_op1
>> 	when checking for STRING_CST.
>> 	(cp_build_addr_expr_1): Likewise for arg when checking for
>> 	FUNCTION_DECL.
>> 	(cp_build_modify_expr): Likewise for newrhs when checking for
>> 	STRING_CST.
>> 	(convert_for_assignment): Don't strip location wrappers when
>> 	stripping NON_LVALUE_EXPR.
>> 	(maybe_warn_about_returning_address_of_local): Strip location
>> 	wrapper from whats_returned before checking for DECL_P.
>> 	(can_do_nrvo_p): Strip location wrapper from retval.
>> 	(treat_lvalue_as_rvalue_p): Likewise.
>> 	(check_return_expr): Likewise.
>> 	* typeck2.c (cxx_incomplete_type_diagnostic): Strip location
>> 	wrapper from value before checking for VAR_P or PARM_DECL.
>> 	(digest_init_r): Strip location wrapper from init.  When
>> 	copying "init", also copy the wrapped node.
>>
>> gcc/objc/ChangeLog:
>> 	PR c++/43064
>> 	PR c++/43486
>> 	* objc-act.c (objc_maybe_build_component_ref): Strip any
>> location
>> 	wrapper before checking for UOBJC_SUPER_decl and self_decl.
>> 	(objc_finish_message_expr): Strip any location wrapper.
>>
>> gcc/testsuite/ChangeLog:
>> 	PR c++/43064
>> 	PR c++/43486
>> 	* c-c++-common/pr51712.c (valid2): Mark xfail as passing on
>> C++.
>> 	* g++.dg/cpp1z/decomp48.C: Update expected location of warning
>> 	for named local variables to use that of the local variable.
>> 	* g++.dg/init/array43.C: Update expected column to be that of
>> the
>> 	initializer.
>> 	* g++.dg/init/initializer-string-too-long.C: New test.
>> 	* g++.dg/init/pr43064-1.C: New test.
>> 	* g++.dg/init/pr43064-2.C: New test.
>> 	* g++.dg/init/pr43064-3.C: New test.
>> 	* g++.dg/wrappers/Wparentheses.C: New test.
Well, you probably know my biggest worry with this -- the unwrappign
wack-a-mole problem.  It looks like additional memory usage is
measurable, but tiny.

Have you received any feedback from Jason on the C++ side?  That's the
bulk of this patch AFAICT.

I don't see anything objectionable in the c-family/ or generic bits.
But again I worry more about the need to sprinkle unwrapping all over
the place.



Jeff



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