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Now that we support NRV from an inner block, we can also support non-NRV
returns from other blocks, since once the NRV is out of scope a later return
expression can't possibly alias it.
This fixes 58487 and half-fixes 53637: now one of the returns is elided, but
not the other.
Fixing the remaining xfails in these testcases will require a very different
approach, probably involving a full tree/block walk from finalize_nrv, and
check_return_expr only adding to a list of potential return variables.
PR c++/58487
PR c++/53637
gcc/cp/ChangeLog:
* cp-tree.h (INIT_EXPR_NRV_P): New.
* semantics.cc (finalize_nrv_r): Check it.
* name-lookup.h (decl_in_scope_p): Declare.
* name-lookup.cc (decl_in_scope_p): New.
* typeck.cc (check_return_expr): Allow non-NRV
returns if the NRV is no longer in scope.
gcc/testsuite/ChangeLog:
* g++.dg/opt/nrv26.C: New test.
* g++.dg/opt/nrv26a.C: New test.
* g++.dg/opt/nrv27.C: New test.
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Our implementation of the named return value optimization has been limited
to variables declared in the outermost block of the function, to avoid
needing to handle the case where the variable needs to be destroyed due to
going out of scope. PR92407 pointed out a case we were missing, where the
variable goes out of scope due to a goto and we were failing to destroy it.
It occurred to me that this problem is the flip side of PR33799, where we
need to be sure to destroy the return value if a cleanup throws on return;
here we want to avoid destroying the return value when exiting the
variable's scope on return. We can use the same flag to indicate to both
cleanups that we're returning.
This implements the guaranteed copy elision specified by P2025 (which is not
yet part of the draft standard).
PR c++/51571
PR c++/92407
gcc/cp/ChangeLog:
* decl.cc (finish_function): Simplify NRV handling.
* except.cc (maybe_set_retval_sentinel): Also set if NRV.
(maybe_splice_retval_cleanup): Don't add the cleanup region
if we don't need it.
* semantics.cc (nrv_data): Add simple field.
(finalize_nrv): Set it.
(finalize_nrv_r): Check it and retval sentinel.
* cp-tree.h (finalize_nrv): Adjust declaration.
* typeck.cc (check_return_expr): Remove named_labels check.
gcc/testsuite/ChangeLog:
* g++.dg/opt/nrv23.C: New test.
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While looking at PR92407 I noticed that the expectations of
maybe_splice_retval_cleanup weren't being met; an sk_cleanup level was
confusing its attempt to recognize the outer block of the function. And
even if I fixed the detection, it failed to actually wrap the body of the
function because the STATEMENT_LIST it got only had the label, not anything
after it. So I moved the call after poplevel does pop_stmt_list on all the
sk_cleanup levels.
PR c++/33799
gcc/cp/ChangeLog:
* except.cc (maybe_splice_retval_cleanup): Change
recognition of function body and try scopes.
* semantics.cc (do_poplevel): Call it after poplevel.
(at_try_scope): New.
* cp-tree.h (maybe_splice_retval_cleanup): Adjust.
gcc/testsuite/ChangeLog:
* g++.dg/eh/return1.C: Add label cases.
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[except.handle]/7 says that when we enter std::terminate due to a throw,
that is considered an active handler. We already implemented that properly
for the case of not finding a handler (__cxa_throw calls __cxa_begin_catch
before std::terminate) and the case of finding a callsite with no landing
pad (the personality function calls __cxa_call_terminate which calls
__cxa_begin_catch), but for the case of a throw in a try/catch in a noexcept
function, we were emitting a cleanup that calls std::terminate directly
without ever calling __cxa_begin_catch to handle the exception.
A straightforward way to fix this seems to be calling __cxa_call_terminate
instead. However, that requires exporting it from libstdc++, which we have
not previously done. Despite the name, it isn't actually part of the ABI
standard. Nor is __cxa_call_unexpected, as far as I can tell, but that one
is also used by clang. For this case they use __clang_call_terminate; it
seems reasonable to me for us to stick with __cxa_call_terminate.
I also change __cxa_call_terminate to take void* for simplicity in the front
end (and consistency with __cxa_call_unexpected) but that isn't necessary if
it's undesirable for some reason.
This patch does not fix the issue that representing the noexcept as a
cleanup is wrong, and confuses the handler search; since it looks like a
cleanup in the EH tables, the unwinder keeps looking until it finds the
catch in main(), which it should never have gotten to. Without the
try/catch in main, the unwinder would reach the end of the stack and say no
handler was found. The noexcept is a handler, and should be treated as one,
as it is when the landing pad is omitted.
The best fix for that issue seems to me to be to represent an
ERT_MUST_NOT_THROW after an ERT_TRY in an action list as though it were an
ERT_ALLOWED_EXCEPTIONS (since indeed it is an exception-specification). The
actual code generation shouldn't need to change (apart from the change made
by this patch), only the action table entry.
PR c++/97720
gcc/cp/ChangeLog:
* cp-tree.h (enum cp_tree_index): Add CPTI_CALL_TERMINATE_FN.
(call_terminate_fn): New macro.
* cp-gimplify.cc (gimplify_must_not_throw_expr): Use it.
* except.cc (init_exception_processing): Set it.
(cp_protect_cleanup_actions): Return it.
gcc/ChangeLog:
* tree-eh.cc (lower_resx): Pass the exception pointer to the
failure_decl.
* except.h: Tweak comment.
libstdc++-v3/ChangeLog:
* libsupc++/eh_call.cc (__cxa_call_terminate): Take void*.
* config/abi/pre/gnu.ver: Add it.
gcc/testsuite/ChangeLog:
* g++.dg/eh/terminate2.C: New test.
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All uses of in_template_function except for the one in cp_make_fname_decl
seem like they could be generalized to consider any template context.
To that end this patch replaces the predicate with a generalized
in_template_context predicate that returns true if we're inside any
template context. If we legitimately need to consider only function
contexts, as in cp_make_fname_decl, we can just additionally check e.g.
current_function_decl.
One concrete benefit of this, which the adjusted testcase below
demonstrates, is that we no longer instantiate/odr-use entities based on
uses within a non-function template.
gcc/cp/ChangeLog:
* class.cc (build_base_path): Check in_template_context instead
of in_template_function.
(resolves_to_fixed_type_p): Likewise.
* cp-tree.h (in_template_context): Define.
(in_template_function): Remove.
* decl.cc (cp_make_fname_decl): Check current_function_decl
and in_template_context instead of in_template_function.
* decl2.cc (mark_used): Check in_template_context instead of
in_template_function.
* pt.cc (in_template_function): Remove.
* semantics.cc (enforce_access): Check in_template_context
instead of current_template_parms directly.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Waddress-of-packed-member2.C: No longer expect a()
to be marked as odr-used.
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gcc/cp/ChangeLog:
* call.cc (promoted_arithmetic_type_p): Use _P defines from tree.h.
(build_conditional_expr): Ditto.
(convert_like_internal): Ditto.
(convert_arg_to_ellipsis): Ditto.
(build_over_call): Ditto.
(compare_ics): Ditto.
* class.cc (is_empty_base_ref): Ditto.
* coroutines.cc (rewrite_param_uses): Ditto.
* cp-tree.h (DECL_DISCRIMINATOR_P): Ditto.
(ARITHMETIC_TYPE_P): Ditto.
* cvt.cc (ocp_convert): Ditto.
* cxx-pretty-print.cc (pp_cxx_template_argument_list): Ditto.
* decl.cc (layout_var_decl): Ditto.
(get_tuple_size): Ditto.
* error.cc (dump_simple_decl): Ditto.
* lambda.cc (start_lambda_scope): Ditto.
* mangle.cc (write_template_arg): Ditto.
* method.cc (spaceship_comp_cat): Ditto.
* module.cc (node_template_info): Ditto.
(trees_out::start): Ditto.
(trees_out::decl_node): Ditto.
(trees_in::read_var_def): Ditto.
(set_instantiating_module): Ditto.
* name-lookup.cc (maybe_record_mergeable_decl): Ditto.
(consider_decl): Ditto.
(maybe_add_fuzzy_decl): Ditto.
* pt.cc (convert_nontype_argument): Ditto.
* semantics.cc (handle_omp_array_sections_1): Ditto.
(finish_omp_clauses): Ditto.
(finish_omp_target_clauses_r): Ditto.
(is_this_parameter): Ditto.
* tree.cc (build_cplus_array_type): Ditto.
(is_this_expression): Ditto.
* typeck.cc (do_warn_enum_conversions): Ditto.
* typeck2.cc (store_init_value): Ditto.
(check_narrowing): Ditto.
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* Harden some tree accessor macros and fix a couple of bad
PLACEHOLDER_TYPE_CONSTRAINTS accesses uncovered by this.
* Use strip_innermost_template_args in outer_template_args.
* Add !processing_template_decl early exit tests to some dependence
predicates.
gcc/cp/ChangeLog:
* cp-tree.h (PLACEHOLDER_TYPE_CONSTRAINTS_INFO): Harden via
TEMPLATE_TYPE_PARM_CHECK.
(TPARMS_PRIMARY_TEMPLATE): Harden via TREE_VEC_CHECK.
(TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL): Harden via
TEMPLATE_TEMPLATE_PARM_CHECK.
* cxx-pretty-print.cc (cxx_pretty_printer::simple_type_specifier):
Guard PLACEHOLDER_TYPE_CONSTRAINTS access.
* error.cc (dump_type) <case TEMPLATE_TYPE_PARM>: Use separate
variable to store CLASS_PLACEHOLDER_TEMPLATE result.
* pt.cc (outer_template_args): Use strip_innermost_template_args.
(any_type_dependent_arguments_p): Exit early if
!processing_template_decl. Use range-based for.
(any_dependent_template_arguments_p): Likewise.
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While looking at the empty base handling for 109678, it occurred to me that
we ought to be able to look for an empty base at a specific offset, not just
in general.
PR c++/109678
gcc/cp/ChangeLog:
* cp-tree.h (lookup_base): Add offset parm.
* constexpr.cc (cxx_fold_indirect_ref_1): Pass it.
* search.cc (struct lookup_base_data_s): Add offset.
(dfs_lookup_base): Handle it.
(lookup_base): Pass it.
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The functions strip_array_types, is_typedef_decl, typedef_variant_p
and cp_expr_location are used throughout the C++ front end including in
some fairly hot parts (e.g. in the tsubst routines and cp_walk_subtree)
and they're small enough that the overhead of calling them out-of-line
is relatively significant.
So this patch moves their definitions into the appropriate headers to
enable inlining them.
gcc/cp/ChangeLog:
* cp-tree.h (cp_expr_location): Define here.
* tree.cc (cp_expr_location): Don't define here.
gcc/ChangeLog:
* tree.cc (strip_array_types): Don't define here.
(is_typedef_decl): Don't define here.
(typedef_variant_p): Don't define here.
* tree.h (strip_array_types): Define here.
(is_typedef_decl): Define here.
(typedef_variant_p): Define here.
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This adds a new built-in to replace the recursive class template
instantiations done by traits such as std::tuple_element and
std::variant_alternative. The purpose is to select the Nth type from a
list of types, e.g. __type_pack_element<1, char, int, float> is int.
We implement it as a special kind of TRAIT_TYPE.
For a pathological example tuple_element_t<1000, tuple<2000 types...>>
the compilation time is reduced by more than 90% and the memory used by
the compiler is reduced by 97%. In realistic examples the gains will be
much smaller, but still relevant.
Unlike the other built-in traits, __type_pack_element uses template-id
syntax instead of call syntax and is SFINAE-enabled, matching Clang's
implementation. And like the other built-in traits, it's not mangleable
so we can't use it directly in function signatures.
N.B. Clang seems to implement __type_pack_element as a first-class
template that can e.g. be used as a template-template argument. For
simplicity we implement it in a more ad-hoc way.
Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
PR c++/100157
gcc/cp/ChangeLog:
* cp-trait.def (TYPE_PACK_ELEMENT): Define.
* cp-tree.h (finish_trait_type): Add complain parameter.
* cxx-pretty-print.cc (pp_cxx_trait): Handle
CPTK_TYPE_PACK_ELEMENT.
* parser.cc (cp_parser_constant_expression): Document default
arguments.
(cp_parser_trait): Handle CPTK_TYPE_PACK_ELEMENT. Pass
tf_warning_or_error to finish_trait_type.
* pt.cc (tsubst) <case TRAIT_TYPE>: Handle non-type first
argument. Pass complain to finish_trait_type.
* semantics.cc (finish_type_pack_element): Define.
(finish_trait_type): Add complain parameter. Handle
CPTK_TYPE_PACK_ELEMENT.
* tree.cc (strip_typedefs): Handle non-type first argument.
Pass tf_warning_or_error to finish_trait_type.
* typeck.cc (structural_comptypes) <case TRAIT_TYPE>: Use
cp_tree_equal instead of same_type_p for the first argument.
libstdc++-v3/ChangeLog:
* include/bits/utility.h (_Nth_type): Conditionally define in
terms of __type_pack_element if available.
* testsuite/20_util/tuple/element_access/get_neg.cc: Prune
additional errors from the new built-in.
gcc/testsuite/ChangeLog:
* g++.dg/ext/type_pack_element1.C: New test.
* g++.dg/ext/type_pack_element2.C: New test.
* g++.dg/ext/type_pack_element3.C: New test.
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Like other diagnostic functions that might be silenced by options, it should
return whether or not it actually emitted a diagnostic.
gcc/cp/ChangeLog:
* typeck2.cc (cxx_incomplete_type_diagnostic): Return bool.
* cp-tree.h (cxx_incomplete_type_diagnostic): Adjust.
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Here we're crashing during satisfaction for the NTTP 'C<B> auto V'
ultimately because convert_template_argument / unify don't pass all
outer template arguments to do_auto_deduction, and during satisfaction
we need to know all arguments. While these callers do pass some outer
arguments, they are only sufficient to properly substitute the
(level-lowered) 'auto' and are not necessarily the entire set.
Fortunately it seems these callers have access to the full set of outer
arguments via convert_template_argument's 'in_decl' parameter and
unify's 'tparms' parameter. So this patch adds a new parameter to
do_auto_deduction, used only during adc_unify deduction, through which
these callers can pass the enclosing (partially instantiated) template
and from which do_auto_deduction can obtain _all_ outer template
arguments for sake of satisfaction.
This patch also ensures that the 'in_decl' argument passed to
coerce_template_parms is always a TEMPLATE_DECL, which in turn allows us
to pass it as-is to do_auto_deduction; the only coerce_template_parms
caller that needed adjustment was tsubst_decl it seems.
PR c++/109160
gcc/cp/ChangeLog:
* cp-tree.h (do_auto_deduction): Add defaulted tmpl parameter.
* pt.cc (convert_template_argument): Pass 'in_decl' as 'tmpl' to
do_auto_deduction.
(tsubst_decl) <case VAR_/TYPE_DECL>: Pass 'tmpl' instead of 't' as
'in_decl' to coerce_template_parms.
(unify) <case TEMPLATE_PARM_INDEX>: Pass TPARMS_PRIMARY_TEMPLATE
as 'tmpl' to do_auto_deduction.
(do_auto_deduction): Document default arguments. Rename local
variable 'tmpl' to 'ctmpl'. Use 'tmpl' to obtain a full set of
template arguments for satisfaction in the adc_unify case.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-placeholder12.C: New test.
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While parsing the anonymous union, we don't yet know that it's an anonymous
union, so we build the reference to 'v' in the static_assert relative to the
union type. But at instantiation time we know it's an anonymous union, so
we need to avoid trying to check access for 'v' in the union again; the
simplest approach seemed to be to make accessible_p step out to the
containing class.
While looking at this I also noticed that we were having trouble with DMI in
an anonymous union referring to members of the containing class; there
we just need to give current_class_ptr the right type.
PR c++/105452
gcc/cp/ChangeLog:
* search.cc (type_context_for_name_lookup): New.
(accessible_p): Handle anonymous union.
* init.cc (maybe_instantiate_nsdmi_init): Use
type_context_for_name_lookup.
* parser.cc (cp_parser_class_specifier): Likewise.
* cp-tree.h (type_context_for_name_lookup): Declare.
gcc/testsuite/ChangeLog:
* g++.dg/lookup/anon8.C: New test.
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The following two testcases are miscompiled, because we keep TREE_READONLY
on the vars even when they are (possibly) dynamically initialized by a TLS
wrapper function. Normally cp_finish_decl drops TREE_READONLY from vars
which need dynamic initialization, but for TLS we do this kind of
initialization upon every access to those variables. Keeping them
TREE_READONLY means e.g. PRE can hoist loads from those before loops
which contain the TLS wrapper calls, so we can access the TLS variables
before they are initialized.
2023-03-20 Jakub Jelinek <jakub@redhat.com>
PR c++/109164
* cp-tree.h (var_needs_tls_wrapper): Declare.
* decl2.cc (var_needs_tls_wrapper): No longer static.
* decl.cc (cp_finish_decl): Clear TREE_READONLY on TLS variables
for which a TLS wrapper will be needed.
* g++.dg/tls/thread_local13.C: New test.
* g++.dg/tls/thread_local13-aux.cc: New file.
* g++.dg/tls/thread_local14.C: New test.
* g++.dg/tls/thread_local14-aux.cc: New file.
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As in 108242, we need to instantiate in the context of the enclosing
function, not after it's gone.
PR c++/105809
gcc/cp/ChangeLog:
* init.cc (get_nsdmi): Split out...
(maybe_instantiate_nsdmi_init): ...this function.
* cp-tree.h: Declare it.
* pt.cc (tsubst_expr): Use it.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-__func__3.C: New test.
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C++20 class template argument deduction for an alias template involves
adding a constraint that the template arguments for the alias template can
be deduced from the return type of the deduction guide for the underlying
class template. In the standard, this is modeled as defining a class
template with a partial specialization, but it's much more efficient to
implement with a trait that directly tries to perform the deduction.
The first argument to the trait is a template rather than a type, so various
places needed to be adjusted to accommodate that.
PR c++/105841
gcc/ChangeLog:
* doc/extend.texi (Type Traits):: Document __is_deducible.
gcc/cp/ChangeLog:
* cp-trait.def (IS_DEDUCIBLE): New.
* cxx-pretty-print.cc (pp_cxx_trait): Handle non-type.
* parser.cc (cp_parser_trait): Likewise.
* tree.cc (cp_tree_equal): Likewise.
* pt.cc (tsubst_copy_and_build): Likewise.
(type_targs_deducible_from): New.
(alias_ctad_tweaks): Use it.
* semantics.cc (trait_expr_value): Handle CPTK_IS_DEDUCIBLE.
(finish_trait_expr): Likewise.
* constraint.cc (diagnose_trait_expr): Likewise.
* cp-tree.h (type_targs_deducible_from): Declare.
gcc/testsuite/ChangeLog:
* g++.dg/ext/is_deducible1.C: New test.
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ia32 with -mno-sse2 [PR108883]
_Float16 and decltype(0.0bf16) types are on x86 supported only with
-msse2. On x86_64 that is the default, but on ia32 it is not.
We should still emit fundamental type tinfo for those types in
libsupc++.a/libstdc++.*, regardless of whether libsupc++/libstdc++
is compiled with -msse2 or not, as user programs can be compiled
with different ISA flags from libsupc++/libstdc++ and if they
are compiled with -msse2 and use std::float16_t or std::bfloat16_t
and need RTTI for it, it should work out of the box. Furthermore,
libstdc++ ABI on ia32 shouldn't depend on whether the library
is compiled with -mno-sse or -msse2.
Unfortunately, just hacking up libsupc++ Makefile/configure so that
a single source is compiled with -msse2 isn't appropriate, because
that TU emits also code and the code should be able to run on CPUs
which libstdc++ supports. We could add [[gnu::attribute ("no-sse2")]]
there perhaps conditionally, but it all gets quite ugly.
The following patch instead adds a target hook which allows the backend
to temporarily tweak registered types such that emit_support_tinfos
emits whatever is needed.
Additionally, it makes emit_support_tinfos_1 call emit_tinfo_decl
immediately, so that temporarily created dummy types for emit_support_tinfo
purposes only can be nullified again afterwards. And removes the
previous fallback_* types used for dfloat*_type_node tinfos even when
decimal types aren't supported.
2023-03-03 Jakub Jelinek <jakub@redhat.com>
PR target/108883
gcc/
* target.h (emit_support_tinfos_callback): New typedef.
* targhooks.h (default_emit_support_tinfos): Declare.
* targhooks.cc (default_emit_support_tinfos): New function.
* target.def (emit_support_tinfos): New target hook.
* doc/tm.texi.in (emit_support_tinfos): Document it.
* doc/tm.texi: Regenerated.
* config/i386/i386.cc (ix86_emit_support_tinfos): New function.
(TARGET_EMIT_SUPPORT_TINFOS): Redefine.
gcc/cp/
* cp-tree.h (enum cp_tree_index): Remove CPTI_FALLBACK_DFLOAT*_TYPE
enumerators.
(fallback_dfloat32_type, fallback_dfloat64_type,
fallback_dfloat128_type): Remove.
* rtti.cc (emit_support_tinfo_1): If not emitted already, call
emit_tinfo_decl and remove from unemitted_tinfo_decls right away.
(emit_support_tinfos): Move &dfloat*_type_node from fundamentals array
into new fundamentals_with_fallback array. Call emit_support_tinfo_1
on elements of that array too, with the difference that if
the type is NULL, use a fallback REAL_TYPE for it temporarily.
Drop the !targetm.decimal_float_supported_p () handling. Call
targetm.emit_support_tinfos at the end.
* mangle.cc (write_builtin_type): Remove references to
fallback_dfloat*_type. Handle bfloat16_type_node mangling.
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Here we're mishandling the unevaluated array new-expressions due to a
supposed non-constant array size ever since r12-5253-g4df7f8c79835d569
made us no longer perform constant evaluation of non-manifestly-constant
expressions within unevaluated contexts. This shouldn't make a difference
here since the array sizes are constant literals, except they're expressed
as NON_LVALUE_EXPR location wrappers around INTEGER_CST, wrappers which
used to get stripped as part of constant evaluation and now no longer do.
Moreover it means build_vec_init can't constant fold the MINUS_EXPR
'maxindex' passed from build_new_1 when in an unevaluated context (since
it tries reducing it via maybe_constant_value called with mce_unknown).
This patch fixes these issues by making maybe_constant_value (and
fold_non_dependent_expr) try folding an unevaluated non-manifestly-constant
operand via fold(), as long as it simplifies to a simple constant, rather
than doing no simplification at all. This covers e.g. simple arithmetic
and casts including stripping of location wrappers around INTEGER_CST.
In passing, this patch also fixes maybe_constant_value to avoid constant
evaluating an unevaluated operand when called with mce_false, by adjusting
the early exit test appropriately.
Co-authored-by: Jason Merrill <jason@redhat.com>
PR c++/108219
PR c++/108218
gcc/cp/ChangeLog:
* constexpr.cc (fold_to_constant): Define.
(maybe_constant_value): Move up early exit test for unevaluated
operands. Try reducing an unevaluated operand to a constant via
fold_to_constant.
(fold_non_dependent_expr_template): Add early exit test for
CONSTANT_CLASS_P nodes. Try reducing an unevaluated operand
to a constant via fold_to_constant.
* cp-tree.h (fold_to_constant): Declare.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/new6.C: New test.
* g++.dg/cpp2a/concepts-new1.C: New test.
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This patch converts the constexpr machinery's manifestly_const_eval flag
into a tri-state enum to allow us to express wanting to fold
__builtin_is_constant_evaluated to false via speculative constexpr
evaluation. For now, only the maybe_constant_value entry point is
changed to take this enum; the others continue to take bool. The
subsequent patch will teach cp_fold (which uses maybe_constant_value) to
fold the builtin to false when called from cp_fold_function and
cp_fully_fold_init.
gcc/cp/ChangeLog:
* constexpr.cc (constexpr_call::manifestly_const_eval): Give
it type int instead of bool.
(constexpr_ctx::manifestly_const_eval): Give it type mce_value
instead of bool.
(cxx_eval_builtin_function_call): Adjust after making
manifestly_const_eval tri-state.
(cxx_eval_call_expression): Likewise.
(cxx_eval_binary_expression): Likewise.
(cxx_eval_conditional_expression): Likewise.
(cxx_eval_constant_expression): Likewise.
(cxx_eval_outermost_constant_expr): Likewise.
(cxx_constant_value): Likewise.
(cxx_constant_dtor): Likewise.
(maybe_constant_value): Give manifestly_const_eval parameter
type mce_value instead of bool and adjust accordingly.
(fold_non_dependent_expr_template): Adjust call
to cxx_eval_outermost_constant_expr.
(fold_non_dependent_expr): Likewise.
(maybe_constant_init_1): Likewise.
* constraint.cc (satisfy_atom): Adjust call to
maybe_constant_value.
* cp-tree.h (enum class mce_value): Define.
(maybe_constant_value): Adjust manifestly_const_eval parameter
type and default argument.
* decl.cc (compute_array_index_type_loc): Adjust call to
maybe_constant_value.
* pt.cc (convert_nontype_argument): Likewise.
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Currently when resolving a TYPENAME_TYPE for 'typename T::m' via
make_typename_type, we consider only type bindings of 'm' and ignore
non-type ones. But [temp.res.general]/3 says, in a note, "the usual
qualified name lookup ([basic.lookup.qual]) applies even in the presence
of 'typename'", and qualified name lookup doesn't discriminate between
type and non-type bindings. So when resolving such a TYPENAME_TYPE
we want the lookup to consider all bindings.
An exception is when we have a TYPENAME_TYPE corresponding to the
qualifying scope of the :: scope resolution operator, such as 'T::type'
in 'T::type::m'. In that case, [basic.lookup.qual]/1 applies, and
lookup for such a TYPENAME_TYPE must ignore non-type bindings. So in
order to correctly handle all cases, make_typename_type needs an
additional flag controlling whether to restrict the lookup.
To that end this patch adds a new tsubst flag tf_qualifying_scope
denoting whether we're substituting the LHS of the :: operator,
which make_typename_type will look for to conditionally restrict the
lookup to type bindings (by default we want to consider all bindings).
So in contexts such as substituting into the scope of TYPENAME_TYPE,
SCOPE_REF or USING_DECL we simply pass tf_qualifying_scope to the
relevant tsubst / tsubst_copy call, and if that scope is a TYPENAME_TYPE
then make_typename_type will restrict the lookup accordingly. This flag
is intended to apply only to overall scope (TYPENAME_TYPE or not) so we
must be careful to clear the flag to avoid propagating it when recursing
into sub-trees of the scope.
PR c++/107773
gcc/cp/ChangeLog:
* cp-tree.h (enum tsubst_flags): New flag tf_qualifying_scope.
* decl.cc (make_typename_type): Use lookup_member instead of
lookup_field. If tf_qualifying_scope is set, pass want_type=true
instead of =false to lookup_member. Generalize format specifier
in diagnostic to handle both type and non-type bindings.
* pt.cc (tsubst_aggr_type_1): Clear tf_qualifying_scope. Tidy
the function.
(tsubst_decl) <case USING_DECL>: Set tf_qualifying_scope when
substituting USING_DECL_SCOPE.
(tsubst): Clear tf_qualifying_scope right away and remember if
it was set. Do the same for tf_tst_ok sooner.
<case TYPENAME_TYPE>: Set tf_qualifying_scope when substituting
TYPE_CONTEXT. Pass tf_qualifying_scope to make_typename_type
if it was set.
(tsubst_qualified_id): Set tf_qualifying_scope when substituting
the scope.
(tsubst_copy): Clear tf_qualifying_scope and remember if it was
set.
<case SCOPE_REF>: Set tf_qualifying_scope when substituting the
scope.
<case *_TYPE>: Pass tf_qualifying_scope to tsubst if it was set.
* search.cc (lookup_member): Document default argument.
gcc/testsuite/ChangeLog:
* g++.dg/template/typename24.C: New test.
* g++.dg/template/typename25.C: New test.
* g++.dg/template/typename25a.C: New test.
* g++.dg/template/typename26.C: New test.
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Many functions defined in our headers are declared 'static inline' which
is a C idiom whose use predates our move to C++ as the implementation
language. But in C++ the inline keyword is more than just a compiler
hint, and is sufficient to give the function the intended semantics.
In fact declaring a function both static and inline is a pessimization
since static effectively disables the desired definition merging
behavior enabled by inline, and is also a source of (harmless) ODR
violations when a static inline function gets called from a non-static
inline one (such as tree_operand_check calling tree_operand_length).
This patch mechanically fixes the vast majority of occurrences of this
anti-pattern throughout the compiler's headers via the command line
sed -i 's/^static inline/inline/g' gcc/*.h gcc/*/*.h
There's also a manual change to remove the redundant declarations
of is_ivar and lookup_category in gcc/objc/objc-act.cc which would
otherwise conflict with their modified definitions in objc-act.h
(due to the difference in staticness).
Besides fixing some ODR violations, this speeds up stage1 cc1plus by
about 2% and reduces the size of its text segment by 1.5MB.
gcc/ChangeLog:
* addresses.h: Mechanically drop 'static' from 'static inline'
functions via s/^static inline/inline/g.
* asan.h: Likewise.
* attribs.h: Likewise.
* basic-block.h: Likewise.
* bitmap.h: Likewise.
* cfghooks.h: Likewise.
* cfgloop.h: Likewise.
* cgraph.h: Likewise.
* cselib.h: Likewise.
* data-streamer.h: Likewise.
* debug.h: Likewise.
* df.h: Likewise.
* diagnostic.h: Likewise.
* dominance.h: Likewise.
* dumpfile.h: Likewise.
* emit-rtl.h: Likewise.
* except.h: Likewise.
* expmed.h: Likewise.
* expr.h: Likewise.
* fixed-value.h: Likewise.
* gengtype.h: Likewise.
* gimple-expr.h: Likewise.
* gimple-iterator.h: Likewise.
* gimple-predict.h: Likewise.
* gimple-range-fold.h: Likewise.
* gimple-ssa.h: Likewise.
* gimple.h: Likewise.
* graphite.h: Likewise.
* hard-reg-set.h: Likewise.
* hash-map.h: Likewise.
* hash-set.h: Likewise.
* hash-table.h: Likewise.
* hwint.h: Likewise.
* input.h: Likewise.
* insn-addr.h: Likewise.
* internal-fn.h: Likewise.
* ipa-fnsummary.h: Likewise.
* ipa-icf-gimple.h: Likewise.
* ipa-inline.h: Likewise.
* ipa-modref.h: Likewise.
* ipa-prop.h: Likewise.
* ira-int.h: Likewise.
* ira.h: Likewise.
* lra-int.h: Likewise.
* lra.h: Likewise.
* lto-streamer.h: Likewise.
* memmodel.h: Likewise.
* omp-general.h: Likewise.
* optabs-query.h: Likewise.
* optabs.h: Likewise.
* plugin.h: Likewise.
* pretty-print.h: Likewise.
* range.h: Likewise.
* read-md.h: Likewise.
* recog.h: Likewise.
* regs.h: Likewise.
* rtl-iter.h: Likewise.
* rtl.h: Likewise.
* sbitmap.h: Likewise.
* sched-int.h: Likewise.
* sel-sched-ir.h: Likewise.
* sese.h: Likewise.
* sparseset.h: Likewise.
* ssa-iterators.h: Likewise.
* system.h: Likewise.
* target-globals.h: Likewise.
* target.h: Likewise.
* timevar.h: Likewise.
* tree-chrec.h: Likewise.
* tree-data-ref.h: Likewise.
* tree-iterator.h: Likewise.
* tree-outof-ssa.h: Likewise.
* tree-phinodes.h: Likewise.
* tree-scalar-evolution.h: Likewise.
* tree-sra.h: Likewise.
* tree-ssa-alias.h: Likewise.
* tree-ssa-live.h: Likewise.
* tree-ssa-loop-manip.h: Likewise.
* tree-ssa-loop.h: Likewise.
* tree-ssa-operands.h: Likewise.
* tree-ssa-propagate.h: Likewise.
* tree-ssa-sccvn.h: Likewise.
* tree-ssa.h: Likewise.
* tree-ssanames.h: Likewise.
* tree-streamer.h: Likewise.
* tree-switch-conversion.h: Likewise.
* tree-vectorizer.h: Likewise.
* tree.h: Likewise.
* wide-int.h: Likewise.
gcc/c-family/ChangeLog:
* c-common.h: Mechanically drop static from static inline
functions via s/^static inline/inline/g.
gcc/c/ChangeLog:
* c-parser.h: Mechanically drop static from static inline
functions via s/^static inline/inline/g.
gcc/cp/ChangeLog:
* cp-tree.h: Mechanically drop static from static inline
functions via s/^static inline/inline/g.
gcc/fortran/ChangeLog:
* gfortran.h: Mechanically drop static from static inline
functions via s/^static inline/inline/g.
gcc/jit/ChangeLog:
* jit-dejagnu.h: Mechanically drop static from static inline
functions via s/^static inline/inline/g.
* jit-recording.h: Likewise.
gcc/objc/ChangeLog:
* objc-act.h: Mechanically drop static from static inline
functions via s/^static inline/inline/g.
* objc-map.h: Likewise.
* objc-act.cc: Remove the redundant redeclarations of is_ivar
and lookup_category.
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After r13-5684-g59e0376f607805 the (pruned) callee of a non-dependent
CALL_EXPR is a bare FUNCTION_DECL rather than ADDR_EXPR of FUNCTION_DECL.
This innocent change revealed that cp_tree_equal doesn't first check
dependence of a CALL_EXPR before treating a FUNCTION_DECL callee as a
dependent name, which leads to us incorrectly accepting the first two
testcases below and rejecting the third:
* In the first testcase, cp_tree_equal incorrectly returns true for
the two non-dependent CALL_EXPRs f(0) and f(0) (whose CALL_EXPR_FN
are different FUNCTION_DECLs) which causes us to treat #2 as a
redeclaration of #1.
* Same issue in the second testcase, for f<int*>() and f<char>().
* In the third testcase, cp_tree_equal incorrectly returns true for
f<int>() and f<void(*)(int)>() which causes us to conflate the two
dependent specializations A<decltype(f<int>()(U()))> and
A<decltype(f<void(*)(int)>()(U()))>.
This patch fixes this by making called_fns_equal treat two callees as
dependent names only if the overall CALL_EXPRs are dependent, via a new
convenience function call_expr_dependent_name that is like dependent_name
but also checks dependence of the overall CALL_EXPR.
PR c++/107461
gcc/cp/ChangeLog:
* cp-tree.h (call_expr_dependent_name): Declare.
* pt.cc (iterative_hash_template_arg) <case CALL_EXPR>: Use
call_expr_dependent_name instead of dependent_name.
* tree.cc (call_expr_dependent_name): Define.
(called_fns_equal): Adjust to take two CALL_EXPRs instead of
CALL_EXPR_FNs thereof. Use call_expr_dependent_name instead
of dependent_name.
(cp_tree_equal) <case CALL_EXPR>: Adjust call to called_fns_equal.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/overload5.C: New test.
* g++.dg/cpp0x/overload5a.C: New test.
* g++.dg/cpp0x/overload6.C: New test.
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Here we crash because a CAST_EXPR, representing T(), doesn't have
its operand, and operand_equal_p's STRIP_ANY_LOCATION_WRAPPER doesn't
expect that. (o_e_p is called from warn_duplicated_cond_add_or_warn.)
In the past we've adjusted o_e_p to better cope with template codes,
but in this case I think we just want to avoid attempting to warn
about inst-dependent expressions; I don't think I've ever envisioned
-Wduplicated-cond to warn about them. Also destroy the chain when
an inst-dependent expression is encountered to not warn in
Wduplicated-cond4.C.
The ICE started with r12-6022, two-stage name lookup for overloaded
operators, which gave dependent operators a TREE_TYPE (in particular,
DEPENDENT_OPERATOR_TYPE), so we no longer bail out here in o_e_p:
/* Similar, if either does not have a type (like a template id),
they aren't equal. */
if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1))
return false;
PR c++/107593
PR c++/108597
gcc/c-family/ChangeLog:
* c-common.h (instantiation_dependent_expression_p): Declare.
* c-warn.cc (warn_duplicated_cond_add_or_warn): If the condition
is dependent, invalidate the chain.
gcc/c/ChangeLog:
* c-objc-common.cc (instantiation_dependent_expression_p): New.
gcc/cp/ChangeLog:
* cp-tree.h (instantiation_dependent_expression_p): Don't
declare here.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Wduplicated-cond3.C: New test.
* g++.dg/warn/Wduplicated-cond4.C: New test.
* g++.dg/warn/Wduplicated-cond5.C: New test.
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[PR108437]
As the following testcases shows, when adding static operator[]
support I've missed that the 2 build_min_non_dep_op_overload functions
need to be adjusted. The first one we only use for the single index
case, but as cp_tree_code_length (ARRAY_REF) is 2, we were running
into an assertion there which compared nargs and expected_nargs.
For ARRAY_REF, the operator[] is either a non-static member or newly
static member, never out of class and for the static member case
if user uses single index the operator[] needs to have a single
argument as well, but the function is called with 2 - the object
it is invoked on and the index. We need to evaluate side-effects
of the object and use just a single argument in the call - the index.
The other build_min_non_dep_op_overload overload has been added
solely for ARRAY_REF - CALL_EXPR is the other operator that accepts
variable number of operands but that one goes through different
routines. There we asserted it is a METHOD_TYPE, so again
we shouldn't assert that but handle the case when it is not one
by making sure object's side-effects are evaluated if needed and
passing all the index arguments to the static operator[].
2023-01-19 Jakub Jelinek <jakub@redhat.com>
PR c++/108437
* cp-tree.h (keep_unused_object_arg): Declare.
* call.cc (keep_unused_object_arg): No longer static.
* tree.cc (build_min_non_dep_op_overload): Handle ARRAY_REF
with overload being static member function.
* g++.dg/cpp23/subscript12.C: New test.
* g++.dg/cpp23/subscript13.C: New test.
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|
When instantiating a constrained hidden template friend, we substitute
into its template-head requirements in tsubst_friend_function. For this
substitution we use the template's full argument vector whose outer
levels correspond to the instantiated class's arguments and innermost
level corresponds to the template's own level-lowered generic arguments.
But for A<int>::f here, for which the relevant argument vector is
{{int}, {Us...}}, the substitution into (C<Ts, Us> && ...) triggers the
assert in use_pack_expansion_extra_args_p since one argument is a pack
expansion and the other isn't.
And for A<int, int>::f, for which the relevant argument vector is
{{int, int}, {Us...}}, the use_pack_expansion_extra_args_p assert would
also trigger but we first get a bogus "mismatched argument pack lengths"
error from tsubst_pack_expansion.
Sidestepping the question of whether tsubst_pack_expansion should be
able to handle such substitutions, it seems we can work around this by
using only the instantiated class's arguments and not also the template
friend's own generic arguments, which is consistent with how we normally
substitute into the signature of a member template.
PR c++/107853
gcc/cp/ChangeLog:
* constraint.cc (maybe_substitute_reqs_for): Substitute into
the template-head requirements of a template friend using only
its outer arguments via outer_template_args.
* cp-tree.h (outer_template_args): Declare.
* pt.cc (outer_template_args): Define, factored out and
generalized from ...
(ctor_deduction_guides_for): ... here.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-friend12.C: New test.
* g++.dg/cpp2a/concepts-friend13.C: New test.
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We currently declare __builtin_source_location with a const void* return
type instead of the actual type const std::source_location::__impl*, and
later when folding this builtin we obtain the actual type via name lookup.
But the below testcase demonstrates this approach seems to interact
poorly with modules, since we may import an entity that uses
std::source_location::current() in its default argument (or DMI) without
necessarily importing <source_location>, and thus the name lookup for
std::source_location will fail at the call site (when using the default
argument) unless we also import <source_location>.
This patch fixes this by instead initially declaring the builtin with an
auto return type and updating it appropriately upon its first use (in
standard code the first/only use would be in the definition of
std::source_location). Thus when folding calls to this builtin we can
get at its return type through the type of the CALL_EXPR and avoid
needing to do a name lookup.
PR c++/100881
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_builtin_function_call): Adjust calls
to fold_builtin_source_location.
* cp-gimplify.cc (cp_gimplify_expr): Likewise.
(cp_fold): Likewise.
(get_source_location_impl_type): Remove location_t parameter and
adjust accordingly. No longer static.
(fold_builtin_source_location): Take a CALL_EXPR tree instead of a
location and obtain the impl type from its return type.
* cp-tree.h (enum cp_tree_index): Remove CPTI_SOURCE_LOCATION_IMPL
enumerator.
(source_location_impl): Remove.
(fold_builtin_source_location): Adjust parameter type.
(get_source_location_impl_type): Declare.
* decl.cc (cxx_init_decl_processing): Declare
__builtin_source_location with auto return type instead of
const void*.
(require_deduced_type): Update the return type of
__builtin_source_location.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/srcloc3.C: Adjust expected note s/evaluating/using.
* g++.dg/cpp2a/srcloc4.C: Likewise.
* g++.dg/cpp2a/srcloc5.C: Likewise.
* g++.dg/cpp2a/srcloc6.C: Likewise.
* g++.dg/cpp2a/srcloc7.C: Likewise.
* g++.dg/cpp2a/srcloc8.C: Likewise.
* g++.dg/cpp2a/srcloc9.C: Likewise.
* g++.dg/cpp2a/srcloc10.C: Likewise.
* g++.dg/cpp2a/srcloc11.C: Likewise.
* g++.dg/cpp2a/srcloc12.C: Likewise.
* g++.dg/cpp2a/srcloc13.C: Likewise.
* g++.dg/modules/pr100881_a.C: New test.
* g++.dg/modules/pr100881_b.C: New test.
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When constructing a vector<string> from { "strings" }, first is built an
initializer_list<string>, which is then copied into the strings in the
vector. But this is inefficient: better would be treat the { "strings" }
as a range and construct the strings in the vector directly from the
string-literals. We can do this transformation for standard library
classes because we know the design patterns they follow.
PR c++/105838
gcc/cp/ChangeLog:
* call.cc (list_ctor_element_type): New.
(braced_init_element_type): New.
(has_non_trivial_temporaries): New.
(maybe_init_list_as_array): New.
(maybe_init_list_as_range): New.
(build_user_type_conversion_1): Use maybe_init_list_as_range.
* parser.cc (cp_parser_braced_list): Call
recompute_constructor_flags.
* cp-tree.h (find_temps_r): Declare.
gcc/testsuite/ChangeLog:
* g++.dg/tree-ssa/initlist-opt1.C: New test.
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In this PR, initializing the array of std::string to pass to the vector
initializer_list constructor gets very confusing to the optimizers as the
number of elements increases, primarily because of all the std::allocator
temporaries passed to all the string constructors. Instead of creating one
for each string, let's share an allocator between all the strings; we can do
this safely because we know that std::allocator is stateless and that string
doesn't care about the object identity of its allocator parameter.
PR c++/105838
gcc/cp/ChangeLog:
* cp-tree.h (is_std_allocator): Declare.
* constexpr.cc (is_std_allocator): Split out from...
(is_std_allocator_allocate): ...here.
* init.cc (find_temps_r): New.
(find_allocator_temp): New.
(build_vec_init): Use it.
gcc/testsuite/ChangeLog:
* g++.dg/tree-ssa/allocator-opt1.C: New test.
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Here we end up giving the two BOUND_TEMPLATE_TEMPLATE_PARMs
C<decltype(f::t)> and C<decltype(g::t)> the same TYPE_CANONICAL because
the hash table that interns TYPE_CANONICAL for template type parameters
doesn't set the comparing_specializations flag which controls how
PARM_DECLs from different contexts compare equal.
Later, from spec_hasher::equal for the corresponding two specializations
A<C<decltype(f::t)>> and A<C<decltype(g::t)>>, we compare the two bound
ttps with comparing_specializations set hence they now (structurally)
compare different despite having the same TYPE_CANONICAL, and so we get
the error:
internal compiler error: same canonical type node for different types
'C<decltype (t)>' and 'C<decltype (t)>'
This suggests that we should be setting comparing_specializations from
ctp_hasher::equal to match spec_hasher::equal. But doing so introduces
a separate ICE in cpp2a/concepts-placeholder3.C:
internal compiler error: canonical types differ for identical types
'auto [requires ::same_as<<placeholder>, decltype(f::x)>]' and
'auto [requires ::same_as<<placeholder>, decltype(g::x)>]'
because norm_hasher::equal doesn't set comparing_specializations either.
I'm not sure when exactly we need to set comparing_specializations given
what it controls (TYPENAME_TYPE equality/hashing and PARM_DECL equality)
but it seems to be the conservative choice to set the flag wherever we
have a global hash table that relies on type equality. To that end this
patch sets comparing_specializations in ctp_hasher and norm_hasher, as
well as in atom_hasher and sat_hasher for good measure. This turns out
to be a compile time win of about 2% in some concepts tests, probably
because of the improved TYPENAME_TYPE hashing enabled by the flag.
PR c++/107539
gcc/cp/ChangeLog:
* constraint.cc (norm_hasher::hash, norm_hasher::equal): Set
comparing_specializations.
(sat_hasher::hash, sat_hasher::equal): Likewise.
* cp-tree.h (atom_hasher::hash, atom_hasher::equal): Likewise.
* pt.cc (ctp_hasher::hash, ctp_hasher::equal): Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/template/canon-type-19.C: New test.
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Implement the P1492 versions of contracts, along with extensions that
support the emulation of N4820 and other proposals. This implementation
assigns a concrete semantic (one of: ignore, assume, enforce, or
observe) to each contract attribute depending on its labels and
configuration options.
Co-authored-by: Andrew Sutton <asutton@lock3software.com>
Co-authored-by: Andrew Marmaduke <amarmaduke@lock3software.com>
Co-authored-by: Michael Lopez <mlopez@lock3software.com>
Co-authored-by: Jason Merrill <jason@redhat.com>
gcc/ChangeLog:
* doc/invoke.texi: Document contracts flags.
gcc/c-family/ChangeLog:
* c.opt: Add contracts flags.
* c-cppbuiltin.cc (c_cpp_builtins): Add contracts feature-test
macros.
gcc/cp/ChangeLog:
* cp-tree.h (enum cp_tree_index): Add
CPTI_PSEUDO_CONTRACT_VIOLATION.
(pseudo_contract_violation_type): New macro.
(struct saved_scope): Add x_processing_contract_condition.
(processing_contract_condition): New macro.
(comparing_override_contracts): New variable decl.
(find_contract): New inline.
(set_decl_contracts): New inline.
(get_contract_semantic): New inline.
(set_contract_semantic): New inline.
* constexpr.cc (cxx_eval_assert): Split out from...
(cxx_eval_internal_function): ...here.
(cxx_eval_constant_expression): Use it for contracts.
(potential_constant_expression_1): Handle contracts.
* cp-gimplify.cc (cp_genericize_r): Handle contracts.
* cp-objcp-common.cc (cp_tree_size): Handle contracts.
(cp_common_init_ts): Handle contracts.
(cp_handle_option): Handle contracts.
* decl.cc (duplicate_decls): Handle contracts.
(check_tag_decl): Check for bogus contracts.
(start_decl): Check flag_contracts.
(grokfndecl): Call rebuild_postconditions.
(grokdeclarator): Handle contract attributes.
(start_preparsed_function): Call start_function_contracts.
(finish_function): Call finish_function_contracts.
* decl2.cc (cp_check_const_attributes): Skip contracts.
(comdat_linkage): Handle outlined contracts.
* error.cc (dump_type): Handle null TYPE_IDENTIFIER.
* g++spec.cc (EXPERIMENTAL): New macro.
(lang_specific_driver): Add -lstdc++exp if -fcontracts.
* mangle.cc (write_encoding): Handle outlined contracts.
* module.cc (trees_out::fn_parms_init): Handle outlined contracts.
(trees_in::fn_parms_init): Likewise.
(check_mergeable_decl): Likewise.
(module_state_config::get_dialect): Record -fcontracts.
* parser.h (struct cp_unparsed_functions_entry): Add contracts.
* parser.cc (unparsed_contracts): New macro.
(push_unparsed_function_queues): Adjust.
(contract_attribute_p): New.
(cp_parser_statement): Check contracts.
(cp_parser_decl_specifier_seq): Handle contracts.
(cp_parser_skip_to_closing_square_bracket): Split out...
(cp_parser_skip_up_to_closing_square_bracket): ...this fn.
(cp_parser_class_specifier): Do contract late parsing.
(cp_parser_class_head): Check contracts.
(cp_parser_contract_role): New.
(cp_parser_contract_mode_opt): New.
(find_error, contains_error_p): New.
(cp_parser_contract_attribute_spec): New.
(cp_parser_late_contract_condition): New.
(cp_parser_std_attribute_spec): Handle contracts.
(cp_parser_save_default_args): Also save contracts.
* pt.cc (register_parameter_specializations): No longer static.
(register_local_identity): New.
(check_explicit_specialization): Call remove_contract_attributes.
(tsubst_contract, tsubst_contract_attribute): New.
(tsubst_contract_attributes): New.
(tsubst_attribute): Add comment.
(tsubst_copy): Also allow parm when processing_contract_condition.
(tsubst_expr): Handle contracts.
(regenerate_decl_from_template): Handle contracts.
* search.cc (check_final_overrider): Compare contracts.
* semantics.cc (set_cleanup_locs): Skip POSTCONDITION_STMT.
(finish_non_static_data_member): Check contracts.
(finish_this_expr): Check contracts.
(process_outer_var_ref): Handle contracts.
(finish_id_expression_1): Handle contracts.
(apply_deduced_return_type): Adjust contracts.
* tree.cc (handle_contract_attribute): New.
(get_innermost_component, is_this_expression): New.
(comparing_this_references): New.
(equivalent_member_references): New.
(cp_tree_equal): Check it.
* typeck.cc (check_return_expr): Apply contracts.
* Make-lang.in: Add contracts.o.
* config-lang.in: Add contracts.cc.
* cp-tree.def (ASSERTION_STMT, PRECONDITION_STMT)
(POSTCONDITION_STMT): New.
* contracts.h: New file.
* contracts.cc: New file.
gcc/testsuite/ChangeLog:
* g++.dg/modules/modules.exp: Pass dg-options to link command.
* lib/g++.exp: Add -L for libstdc++exp.a.
* g++.dg/contracts/backtrace_handler/assert_fail.cpp: New test.
* g++.dg/contracts/backtrace_handler/handle_contract_violation.cpp: New test.
* g++.dg/contracts/contracts-access1.C: New test.
* g++.dg/contracts/contracts-assume1.C: New test.
* g++.dg/contracts/contracts-assume2.C: New test.
* g++.dg/contracts/contracts-assume3.C: New test.
* g++.dg/contracts/contracts-assume4.C: New test.
* g++.dg/contracts/contracts-assume5.C: New test.
* g++.dg/contracts/contracts-assume6.C: New test.
* g++.dg/contracts/contracts-comdat1.C: New test.
* g++.dg/contracts/contracts-config1.C: New test.
* g++.dg/contracts/contracts-constexpr1.C: New test.
* g++.dg/contracts/contracts-constexpr2.C: New test.
* g++.dg/contracts/contracts-constexpr3.C: New test.
* g++.dg/contracts/contracts-conversion1.C: New test.
* g++.dg/contracts/contracts-ctor-dtor1.C: New test.
* g++.dg/contracts/contracts-ctor-dtor2.C: New test.
* g++.dg/contracts/contracts-cv1.C: New test.
* g++.dg/contracts/contracts-deduced1.C: New test.
* g++.dg/contracts/contracts-deduced2.C: New test.
* g++.dg/contracts/contracts-friend1.C: New test.
* g++.dg/contracts/contracts-ft1.C: New test.
* g++.dg/contracts/contracts-ignore1.C: New test.
* g++.dg/contracts/contracts-ignore2.C: New test.
* g++.dg/contracts/contracts-large-return.C: New test.
* g++.dg/contracts/contracts-multiline1.C: New test.
* g++.dg/contracts/contracts-multiple-inheritance1.C: New test.
* g++.dg/contracts/contracts-multiple-inheritance2.C: New test.
* g++.dg/contracts/contracts-nested-class1.C: New test.
* g++.dg/contracts/contracts-nested-class2.C: New test.
* g++.dg/contracts/contracts-nocopy1.C: New test.
* g++.dg/contracts/contracts-override.C: New test.
* g++.dg/contracts/contracts-post1.C: New test.
* g++.dg/contracts/contracts-post2.C: New test.
* g++.dg/contracts/contracts-post3.C: New test.
* g++.dg/contracts/contracts-post4.C: New test.
* g++.dg/contracts/contracts-post5.C: New test.
* g++.dg/contracts/contracts-post6.C: New test.
* g++.dg/contracts/contracts-pre1.C: New test.
* g++.dg/contracts/contracts-pre10.C: New test.
* g++.dg/contracts/contracts-pre2.C: New test.
* g++.dg/contracts/contracts-pre2a1.C: New test.
* g++.dg/contracts/contracts-pre2a2.C: New test.
* g++.dg/contracts/contracts-pre3.C: New test.
* g++.dg/contracts/contracts-pre4.C: New test.
* g++.dg/contracts/contracts-pre5.C: New test.
* g++.dg/contracts/contracts-pre6.C: New test.
* g++.dg/contracts/contracts-pre7.C: New test.
* g++.dg/contracts/contracts-pre9.C: New test.
* g++.dg/contracts/contracts-redecl1.C: New test.
* g++.dg/contracts/contracts-redecl2.C: New test.
* g++.dg/contracts/contracts-redecl3.C: New test.
* g++.dg/contracts/contracts-redecl4.C: New test.
* g++.dg/contracts/contracts-redecl5.C: New test.
* g++.dg/contracts/contracts-redecl6.C: New test.
* g++.dg/contracts/contracts-redecl7.C: New test.
* g++.dg/contracts/contracts-redecl8.C: New test.
* g++.dg/contracts/contracts-tmpl-attr1.C: New test.
* g++.dg/contracts/contracts-tmpl-spec1.C: New test.
* g++.dg/contracts/contracts-tmpl-spec2.C: New test.
* g++.dg/contracts/contracts-tmpl-spec3.C: New test.
* g++.dg/contracts/contracts1.C: New test.
* g++.dg/contracts/contracts10.C: New test.
* g++.dg/contracts/contracts11.C: New test.
* g++.dg/contracts/contracts12.C: New test.
* g++.dg/contracts/contracts13.C: New test.
* g++.dg/contracts/contracts14.C: New test.
* g++.dg/contracts/contracts15.C: New test.
* g++.dg/contracts/contracts16.C: New test.
* g++.dg/contracts/contracts17.C: New test.
* g++.dg/contracts/contracts18.C: New test.
* g++.dg/contracts/contracts19.C: New test.
* g++.dg/contracts/contracts2.C: New test.
* g++.dg/contracts/contracts20.C: New test.
* g++.dg/contracts/contracts22.C: New test.
* g++.dg/contracts/contracts24.C: New test.
* g++.dg/contracts/contracts25.C: New test.
* g++.dg/contracts/contracts3.C: New test.
* g++.dg/contracts/contracts35.C: New test.
* g++.dg/contracts/contracts4.C: New test.
* g++.dg/contracts/contracts5.C: New test.
* g++.dg/contracts/contracts6.C: New test.
* g++.dg/contracts/contracts7.C: New test.
* g++.dg/contracts/contracts8.C: New test.
* g++.dg/contracts/contracts9.C: New test.
* g++.dg/modules/contracts-1_a.C: New test.
* g++.dg/modules/contracts-1_b.C: New test.
* g++.dg/modules/contracts-2_a.C: New test.
* g++.dg/modules/contracts-2_b.C: New test.
* g++.dg/modules/contracts-2_c.C: New test.
* g++.dg/modules/contracts-3_a.C: New test.
* g++.dg/modules/contracts-3_b.C: New test.
* g++.dg/modules/contracts-4_a.C: New test.
* g++.dg/modules/contracts-4_b.C: New test.
* g++.dg/modules/contracts-4_c.C: New test.
* g++.dg/modules/contracts-4_d.C: New test.
* g++.dg/modules/contracts-tpl-friend-1_a.C: New test.
* g++.dg/modules/contracts-tpl-friend-1_b.C: New test.
* g++.dg/contracts/backtrace_handler/Makefile: New test.
* g++.dg/contracts/backtrace_handler/README: New test.
* g++.dg/contracts/backtrace_handler/example_out.txt: New test.
* g++.dg/contracts/backtrace_handler/example_pretty.txt: New test.
* g++.dg/contracts/backtrace_handler/prettytrace.sh: New test.
* g++.dg/contracts/except_preload_handler/Makefile: New test.
* g++.dg/contracts/except_preload_handler/README: New test.
* g++.dg/contracts/except_preload_handler/assert_fail.cpp: New test.
* g++.dg/contracts/except_preload_handler/handle_contract_violation.cpp: New test.
* g++.dg/contracts/noexcept_preload_handler/Makefile: New test.
* g++.dg/contracts/noexcept_preload_handler/README: New test.
* g++.dg/contracts/noexcept_preload_handler/assert_fail.cpp: New test.
* g++.dg/contracts/noexcept_preload_handler/handle_contract_violation.cpp: New test.
* g++.dg/contracts/preload_handler/Makefile: New test.
* g++.dg/contracts/preload_handler/README: New test.
* g++.dg/contracts/preload_handler/assert_fail.cpp: New test.
* g++.dg/contracts/preload_handler/handle_contract_violation.cpp: New test.
* g++.dg/contracts/preload_nocontinue_handler/Makefile: New test.
* g++.dg/contracts/preload_nocontinue_handler/README: New test.
* g++.dg/contracts/preload_nocontinue_handler/assert_fail.cpp: New test.
* g++.dg/contracts/preload_nocontinue_handler/handle_contract_violation.cpp: New test.
* g++.dg/contracts/preload_nocontinue_handler/nocontinue.cpp: New test.
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This patch implements C++23 P2448, which lifts more restrictions on the
constexpr keyword. It's effectively going the way of being just a hint
(hello, inline!).
This gist is relatively simple: in C++23, a constexpr function's return
type/parameter type doesn't have to be a literal type; and you can have
a constexpr function for which no invocation satisfies the requirements
of a core constant expression. For example,
void f(int& i); // not constexpr
constexpr void g(int& i) {
f(i); // unconditionally calls a non-constexpr function
}
is now OK, even though there isn't an invocation of 'g' that would be
a constant expression. Maybe 'f' will be made constexpr soon, or maybe
this depends on the version of C++ used, and similar. The patch is
unfortunately not that trivial. The important bit is to use the new
require_potential_rvalue_constant_expression_fncheck in
maybe_save_constexpr_fundef (and where appropriate). It has a new flag
that says that we're checking the body of a constexpr function, and in
that case it's OK to find constructs that aren't a constant expression.
Since it's useful to be able to check for problematic constructs even
in C++23, this patch implements a new warning, -Winvalid-constexpr,
which is a pedwarn turned on by default in C++20 and earlier, and which
can be turned on in C++23 as well, in which case it's an ordinary warning.
This I implemented by using the new function constexpr_error, used in
p_c_e_1 and friends. (In some cases I believe fundef_p will be always
false (= hard error), but it made sense to me to be consistent and use
constexpr_error throughout p_c_e_1.)
While working on this I think I found a bug, see constexpr-nonlit15.C
and <https://gcc.gnu.org/PR107598>. This patch doesn't address that.
This patch includes changes to diagnose the problem if the user doesn't
use -Winvalid-constexpr and calls a constexpr function that in fact isn't
constexpr-ready yet: maybe_save_constexpr_fundef registers the function
if warn_invalid_constexpr is 0 and explain_invalid_constexpr_fn then
gives the diagnostic.
PR c++/106649
gcc/c-family/ChangeLog:
* c-cppbuiltin.cc (c_cpp_builtins): Update value of __cpp_constexpr for
C++23.
* c-opts.cc (c_common_post_options): Set warn_invalid_constexpr
depending on cxx_dialect.
* c.opt (Winvalid-constexpr): New option.
gcc/cp/ChangeLog:
* constexpr.cc (constexpr_error): New function.
(is_valid_constexpr_fn): Use constexpr_error.
(maybe_save_constexpr_fundef): Call
require_potential_rvalue_constant_expression_fncheck rather than
require_potential_rvalue_constant_expression. Register the
function if -Wno-invalid-constexpr was specified.
(explain_invalid_constexpr_fn): Don't return early if a function marked
'constexpr' that isn't actually a constant expression was called.
(non_const_var_error): Add a bool parameter. Use constexpr_error.
(inline_asm_in_constexpr_error): Likewise.
(cxx_eval_constant_expression): Adjust calls to non_const_var_error
and inline_asm_in_constexpr_error.
(potential_constant_expression_1): Add a bool parameter. Use
constexpr_error.
(require_potential_rvalue_constant_expression_fncheck): New function.
* cp-tree.h (require_potential_rvalue_constant_expression_fncheck):
Declare.
* method.cc (struct comp_info): Call
require_potential_rvalue_constant_expression_fncheck rather than
require_potential_rvalue_constant_expression.
gcc/ChangeLog:
* doc/invoke.texi: Document -Winvalid-constexpr.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-ctor2.C: Expect an error in c++20_down only.
* g++.dg/cpp0x/constexpr-default-ctor.C: Likewise.
* g++.dg/cpp0x/constexpr-diag3.C: Likewise.
* g++.dg/cpp0x/constexpr-ex1.C: Likewise.
* g++.dg/cpp0x/constexpr-friend.C: Likewise.
* g++.dg/cpp0x/constexpr-generated1.C: Likewise.
* g++.dg/cpp0x/constexpr-ice5.C: Likewise.
* g++.dg/cpp0x/constexpr-ice6.C: Likewise.
* g++.dg/cpp0x/constexpr-memfn1.C: Likewise.
* g++.dg/cpp0x/constexpr-neg2.C: Likewise.
* g++.dg/cpp0x/constexpr-non-const-arg.C: Likewise.
* g++.dg/cpp0x/constexpr-reinterpret1.C: Likewise.
* g++.dg/cpp0x/pr65327.C: Likewise.
* g++.dg/cpp1y/constexpr-105050.C: Likewise.
* g++.dg/cpp1y/constexpr-89285-2.C: Likewise.
* g++.dg/cpp1y/constexpr-89285.C: Likewise.
* g++.dg/cpp1y/constexpr-89785-2.C: Likewise.
* g++.dg/cpp1y/constexpr-neg1.C: Likewise.
* g++.dg/cpp1y/constexpr-nsdmi7b.C: Likewise.
* g++.dg/cpp1y/constexpr-throw.C: Likewise.
* g++.dg/cpp23/constexpr-nonlit3.C: Remove dg-error.
* g++.dg/cpp23/constexpr-nonlit6.C: Call the test functions.
* g++.dg/cpp23/feat-cxx2b.C: Adjust the expected value of
__cpp_constexpr.
* g++.dg/cpp2a/consteval3.C: Remove dg-error.
* g++.dg/cpp2a/constexpr-new7.C: Expect an error in c++20_down only.
* g++.dg/cpp2a/constexpr-try5.C: Remove dg-error.
* g++.dg/cpp2a/spaceship-constexpr1.C: Expect an error in c++20_down
only.
* g++.dg/cpp2a/spaceship-eq3.C: Likewise.
* g++.dg/diagnostic/constexpr1.C: Remove dg-error.
* g++.dg/gomp/pr79664.C: Use -Winvalid-constexpr -pedantic-errors.
* g++.dg/ubsan/vptr-4.C: Likewise.
* g++.dg/cpp23/constexpr-nonlit10.C: New test.
* g++.dg/cpp23/constexpr-nonlit11.C: New test.
* g++.dg/cpp23/constexpr-nonlit12.C: New test.
* g++.dg/cpp23/constexpr-nonlit13.C: New test.
* g++.dg/cpp23/constexpr-nonlit14.C: New test.
* g++.dg/cpp23/constexpr-nonlit15.C: New test.
* g++.dg/cpp23/constexpr-nonlit16.C: New test.
* g++.dg/cpp23/constexpr-nonlit8.C: New test.
* g++.dg/cpp23/constexpr-nonlit9.C: New test.
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The following patch adds parsing of attributes to concept definition,
allows deprecated attribute to be specified (as CONCEPT_DECL now needs
to be checked in c-family/c-attribs.cc, I had to move its declaration
from cp/*.def to c-family/*.def) and checks TREE_DEPRECATED in
build_standard_check (not sure if that is the right spot, or whether
it shouldn't be checked also for variable and function concepts and
how to write testcase coverage for that).
2022-11-16 Jakub Jelinek <jakub@redhat.com>
gcc/c-family/
* c-common.def (CONCEPT_DECL): New tree, moved here from
cp-tree.def.
* c-common.cc (c_common_init_ts): Handle CONCEPT_DECL.
* c-attribs.cc (handle_deprecated_attribute): Allow deprecated
attribute on CONCEPT_DECL.
gcc/cp/
* cp-tree.def (CONCEPT_DECL): Move to c-common.def.
* cp-objcp-common.cc (cp_common_init_ts): Don't handle CONCEPT_DECL
here.
* cp-tree.h (finish_concept_definition): Add ATTRS parameter.
* parser.cc (cp_parser_concept_definition): Parse attributes in
between identifier and =. Adjust finish_concept_definition
caller.
* pt.cc (finish_concept_definition): Add ATTRS parameter. Call
cplus_decl_attributes.
* constraint.cc (build_standard_check): If CONCEPT_DECL is
TREE_DEPRECATED, emit -Wdeprecated-declaration warnings.
gcc/testsuite/
* g++.dg/cpp2a/concepts-dr2428.C: New test.
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It seems the only and original purpose of tsubst_copy_and_build's
integral_constant_expression_p boolean parameter (added in r116276, which
predates the constexpr machinery) is to diagnose certain constructs that
aren't allowed to appear in a C++98 integral constant expression
context, specifically casts to a non-integral type (diagnosed from the
*_CAST_EXPR case of tsubst_copy_and_build) or dependent names that
resolve to a non-constant decl (diagnosed from the IDENTIFIER_NODE case
of tsubst_copy_and_build). The parameter has no effect outside of C++98
AFAICT.
But diagnosing such constructs should arguably be the job of the constexpr
machinery (e.g. is_constant_expression) after substitution, and doing it
during substitution by way of an additional parameter complicates the
API of this workhorse function for what amounts to a couple of archaic
C++98 restrictions. And it seems is_constant_expression already does a
good job of diagnosing the aforementioned two constructs in C++98 mode,
at least as far as our testsuite is concerned.
So this patch removes this parameter from tsubst_copy_and_build,
tsubst_expr and tsubst_copy_and_build_call_args. The only interesting
changes are to potential_constant_expression_1 and the IDENTIFIER_NODE
and *_CAST_EXPR cases of tsubst_copy_and_build; the rest are mechanical
adjustments to the functions' signatures and their call sites.
gcc/cp/ChangeLog:
* constexpr.cc (potential_constant_expression_1)
<case *_CAST_EXPR>: Use
cast_valid_in_integral_constant_expression_p instead of
open coding it.
* constraint.cc (tsubst_valid_expression_requirement): Adjust
calls to tsubst_copy_and_build and tsubst_expr.
(tsubst_constraint): Likewise.
(satisfy_atom): Likewise.
(diagnose_trait_expr): Likewise.
* cp-tree.h (tsubst_copy_and_build): Remove i_c_e_p parameter.
(tsubst_expr): Likewise.
* init.cc (get_nsdmi): Adjust calls to tsubst_copy_and_build
and tsubst_expr.
* pt.cc (expand_integer_pack): Likewise.
(instantiate_non_dependent_expr_internal): Likewise.
(tsubst_friend_function): Likewise.
(tsubst_attribute): Likewise.
(instantiate_class_template): Likewise.
(tsubst_template_arg): Likewise.
(gen_elem_of_pack_expansion_instantiation): Likewise.
(tsubst_fold_expr_init): Likewise.
(tsubst_pack_expansion): Likewise.
(tsubst_default_argument): Likewise.
(tsubst_function_decl): Likewise.
(tsubst_decl): Likewise.
(tsubst_arg_types): Likewise.
(tsubst_exception_specification): Likewise.
(tsubst): Likewise.
(tsubst_init): Likewise.
(tsubst_copy): Likewise.
(tsubst_omp_clause_decl): Likewise.
(tsubst_omp_clauses): Likewise.
(tsubst_copy_asm_operands): Likewise.
(tsubst_omp_for_iterator): Likewise.
(tsubst_expr): Likewise. Remove i_c_e_p parameter.
(tsubst_omp_udr): Likewise.
(tsubst_non_call_postfix_expression): Likewise. Remove i_c_e_p parameter.
(tsubst_lambda_expr): Likewise.
(tsubst_copy_and_build_call_args): Likewise.
(tsubst_copy_and_build): Likewise. Remove i_c_e_p parameter.
<case IDENTIFIER_NODE>: Adjust call to finish_id_expression
following removal of i_c_e_p.
<case *_CAST_EXPR>: Remove C++98-specific cast validity check
guarded by i_c_e_p.
(maybe_instantiate_noexcept): Adjust calls to
tsubst_copy_and_build and tsubst_expr.
(instantiate_body): Likewise.
(instantiate_decl): Likewise.
(tsubst_initializer_list): Likewise.
(tsubst_enum): Likewise.
gcc/objcp/ChangeLog:
* objcp-lang.cc (objcp_tsubst_copy_and_build): Adjust calls to
tsubst_copy_and_build and tsubst_expr.
gcc/testsuite/ChangeLog:
* g++.dg/template/crash55.C: Don't expect additional
C++98-specific diagnostics.
* g++.dg/template/ref3.C: Remove C++98-specific xfail.
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The function_p parameter of tsubst_copy_and_build (added in r69316) is
inspected only in its IDENTIFIER_NODE case, where it controls whether we
diagnose unqualified name lookup failure for the given identifier. But
I think ever since r173965, we never substitute an IDENTIFIER_NODE with
function_p=true for which the lookup can possibly fail, and therefore
the flag is effectively unneeded.
Before that commit, we would incorrectly repeat unqualified lookup for
an ADL-enabled CALL_EXPR at instantiation time, which naturally could
fail and thus motivated the flag. Afterwards, we no longer substitute
an IDENTIFIER_NODE callee when koenig_p is true, so the flag isn't needed
for its original purpose. What about when koenig_p=false? Apparently
we still may have an IDENTIFIER_NODE callee in this case, namely when
unqualified name lookup found a dependent local function declaration,
but repeating that lookup can't fail (ditto for USING_DECL callees).
So this patch removes this effectively unneeded parameter from
tsubst_copy_and_build. It also updates an outdated comment in the
CALL_EXPR case about when we may see an IDENTIFIER_NODE callee with
koenig_p=false.
gcc/cp/ChangeLog:
* cp-lang.cc (objcp_tsubst_copy_and_build): Remove
function_p parameter.
* cp-objcp-common.h (objcp_tsubst_copy_and_build):
Likewise.
* cp-tree.h (tsubst_copy_and_build): Likewise.
* init.cc (get_nsdmi): Adjust calls to tsubst_copy_and_build.
* pt.cc (expand_integer_pack): Likewise.
(instantiate_non_dependent_expr_internal): Likewise.
(tsubst_function_decl): Likewise.
(tsubst_arg_types): Likewise.
(tsubst_exception_specification): Likewise.
(tsubst): Likewise.
(tsubst_copy_asm_operands): Likewise.
(tsubst_expr): Likewise.
(tsubst_non_call_postfix_expression): Likewise.
(tsubst_lambda_expr): Likewise.
(tsubst_copy_and_build_call_args): Likewise.
(tsubst_copy_and_build): Remove function_p parameter
and adjust function comment. Adjust recursive calls.
<case CALL_EXPR>: Update outdated comment about when
we can see an IDENTIFIER_NODE callee with koenig_p=false.
(maybe_instantiate_noexcept): Adjust calls to
tsubst_copy_and_build.
gcc/objcp/ChangeLog:
* objcp-lang.cc (objcp_tsubst_copy_and_build): Remove
function_p parameter.
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I've noticed I've made a typo in the name of the function.
Fixed thusly.
2022-11-15 Jakub Jelinek <jakub@redhat.com>
* cp-tree.h (next_common_initial_seqence): Rename to ...
(next_common_initial_sequence): ... this.
* typeck.cc (next_common_initial_seqence): Rename to ...
(next_common_initial_sequence): ... this.
(layout_compatible_type_p): Call next_common_initial_sequence
rather than next_common_initial_seqence.
* semantics.cc (is_corresponding_member_aggr): Likewise.
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This paper is resolving the problem of well-formed C++17 code becoming
ambiguous in C++20 due to asymmetrical operator== being compared with itself
in reverse. I had previously implemented a tiebreaker such that if the two
candidates were functions with the same parameter types, we would prefer the
non-reversed candidate. But the committee went with a different approach:
if there's an operator!= with the same parameter types as the operator==,
don't consider the reversed form of the ==.
So this patch implements that, and changes my old tiebreaker to give a
pedwarn if it is used. I also noticed that we were giving duplicate errors
for some testcases, and fixed the tourney logic to avoid that.
As a result, a lot of tests of the form
struct A { bool operator==(const A&); };
need to be fixed to add a const function-cv-qualifier, e.g.
struct A { bool operator==(const A&) const; };
The committee thought such code ought to be fixed, so breaking it was fine.
18_support/comparisons/algorithms/fallback.cc also breaks with this patch,
because of the similarly asymmetrical
bool operator==(const S&, S&) { return true; }
As a result, some of the asserts need to be reversed.
The H test in spaceship-eq15.C is specified in the standard to be
well-formed because the op!= in the inline namespace is not found by the
search, but that seems wrong to me. I've implemented that behavior, but
disabled it for now; if we decide that is the way we want to go, we can just
remove the "0 &&" in add_candidates to enable it.
Co-authored-by: Jakub Jelinek <jakub@redhat.com>
gcc/cp/ChangeLog:
* cp-tree.h (fns_correspond): Declare.
* decl.cc (fns_correspond): New.
* call.cc (add_candidates): Look for op!= matching op==.
(joust): Complain about non-standard reversed tiebreaker.
(tourney): Fix champ_compared_to_predecessor logic.
(build_new_op): Don't complain about error_mark_node not having
'bool' type.
* pt.cc (tsubst_copy_and_build): Don't try to be permissive
when seen_error().
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/spaceship-eq15.C: New test.
* g++.dg/cpp0x/defaulted3.C: Add const.
* g++.dg/cpp2a/bit-cast7.C: Add const.
* g++.dg/cpp2a/spaceship-rewrite1.C: Expect error.
* g++.dg/cpp2a/spaceship-rewrite5.C: Expect error.
* g++.old-deja/g++.jason/byval2.C: Expect error.
* g++.old-deja/g++.other/overload13.C: Add const.
libstdc++-v3/ChangeLog:
* testsuite/18_support/comparisons/algorithms/fallback.cc: Adjust
asserts.
|
|
This implements ABI-compliant lambda discriminators. Not only do we
have per-scope counters, but we also distinguish by lambda signature.
Only lambdas with the same signature will need non-zero
discriminators. As the discriminator is signature-dependent, we have
to process the lambda function's declaration before we can determine
it. For templated and generic lambdas the signature is that of the
uninstantiated lambda -- not separate for each instantiation.
With this change, gcc and clang now produce the same lambda manglings
for all these testcases.
gcc/cp/
* cp-tree.h (LAMBDA_EXPR_SCOPE_SIG_DISCRIMINATOR): New.
(struct tree_lambda_expr): Add discriminator_sig bitfield.
(recrd_lambda_scope_sig_discriminator): Declare.
* lambda.cc (struct lambda_sig_count): New.
(lambda_discriminator): Add signature vector.
(start_lambda_scope): Adjust.
(compare_lambda_template_head, compare_lambda_sig): New.
(record_lambda_scope_sig_discriminator): New.
* mangle.cc (write_closure_type): Use the scope-sig discriminator for
ABI >= 18. Emit abi mangling warning if needed.
* module.cc (trees_out::core_vals): Stream the new discriminator.
(trees_in::core_vals): Likewise.
* parser.cc (cp_parser_lambda_declarator_opt): Call
record_lambda_scope_sig_discriminator.
* pt.cc (tsubst_lambda_expr): Likewise.
libcc1/
* libcp1plugin.cc (plugin_start_lambda_closure_class_type):
Initialize the per-scope, per-signature discriminator.
gcc/testsuite/
* g++.dg/abi/lambda-sig1-18.C: New.
* g++.dg/abi/lambda-sig1-18vs17.C: New.
* g++.dg/cpp1y/lambda-mangle-1-18.C: New.
|
|
We currently use a per-extra-scope counter to discriminate multiple
lambdas in a particular such scope. This is not ABI compliant. This
patch merely refactors the existing code to make it easier to drop in
a conformant mangling -- there's no functional change here. I rename
the LAMBDA_EXPR_DISCIMINATOR to LAMBDA_EXPR_SCOPE_ONLY_DISCRIMINATOR,
foreshadowing that there'll be a new discriminator. To provide ABI
warnings we'll need to calculate both, and that requires some
repacking of the lambda_expr's fields. Finally, although we end up
calling the discriminator setter and the scope recorder (nearly)
always consecutively, it's clearer to handle it as two separate
operations. That also allows us to remove the instantiation
special-case for a null extra-scope.
gcc/cp/
* cp-tree.h (LAMBDA_EXPR_DISCRIMINATOR): Rename to ...
(LAMBDA_EXPR_SCOPE_ONLY_DISCRIMINATOR): ... here.
(struct tree_lambda_expr): Make default_capture_mode &
discriminator_scope bitfields.
(record_null_lambda_scope) Delete.
(record_lambda_scope_discriminator): Declare.
* lambda.cc (struct lambda_discriminator): New struct.
(lambda_scope, lambda_scope_stack): Adjust types.
(lambda_count): Delete.
(struct tree_int): Delete.
(start_lambda_scope, finish_lambda_scope): Adjust.
(record_lambda_scope): Only record the scope.
(record_lambda_scope_discriminator): New.
* mangle.cc (write_closure_type_name): Adjust.
* module.cc (trees_out::core_vals): Likewise,
(trees_in::core_vals): Likewise.
* parser.cc (cp_parser_lambda_expression): Call
record_lambda_scope_discriminator.
* pt.cc (tsubst_lambda_expr): Adjust record_lambda_scope caling. Call
record_lambda_scope_discriminator. Commonize control flow on tsubsting
the operator function.
libcc1/
* libcp1plugin.cc (plugin_start_closure): Adjust.
gcc/testsuite/
* g++.dg/abi/lambda-sig1-17.C: New.
* g++.dg/abi/lambda-sig1.h: New.
* g++.dg/cpp1y/lambda-mangle-1.C: Extracted to ...
* g++.dg/cpp1y/lambda-mangle-1.h: ... here.
* g++.dg/cpp1y/lambda-mangle-1-11.C: New
* g++.dg/cpp1y/lambda-mangle-1-17.C
|
|
C2x adds support for enums with a fixed underlying type specified
("enum e : long long;" and similar). Implement this in the C front
end. The same representation is used for these types as in C++, with
two macros moved from cp-tree.h to c-common.h.
Such enums can have bool as the underlying type, and various C
front-end code checking for boolean types is adjusted to use a new
C_BOOLEAN_TYPE_P to handle such enums the same way as bool. (Note
that for C++ we have bug 96496 that enums with underlying type bool
don't work correctly there.)
There are various issues with the wording for such enums in the
current C2x working draft (including but not limited to wording in the
accepted paper that failed to make it into the working draft), which I
intend to raise in NB comments. I think what I've implemented and
added tests for matches the intent.
Bootstrapped with no regressions for x86_64-pc-linux-gnu.
PR c/61469
gcc/c-family/
* c-common.h (ENUM_UNDERLYING_TYPE, ENUM_FIXED_UNDERLYING_TYPE_P):
New. Moved from cp/cp-tree.h.
* c-warn.cc (warnings_for_convert_and_check): Do not consider
conversions to enum with underlying type bool to overflow.
gcc/c/
* c-convert.cc (c_convert): Handle enums with underlying boolean
type like bool.
* c-decl.cc (shadow_tag_warned): Allow shadowing declarations for
enums with enum type specifier, but give errors for storage class
specifiers, qualifiers or alignment specifiers in non-definition
declarations of such enums.
(grokdeclarator): Give error for non-definition use of type
specifier with an enum type specifier.
(parser_xref_tag): Add argument has_enum_type_specifier. Pass it
to lookup_tag and use it to set ENUM_FIXED_UNDERLYING_TYPE_P.
(xref_tag): Update call to parser_xref_tag.
(start_enum): Add argument fixed_underlying_type. Complete enum
type with a fixed underlying type given in the definition. Give
error for defining without a fixed underlying type in the
definition if one was given in a prior declaration. Do not mark
enums with fixed underlying type as packed for -fshort-enums.
Store the enum type in the_enum.
(finish_enum): Do not adjust types of values or check their range
for an enum with a fixed underlying type. Set underlying type of
enum and variants.
(build_enumerator): Check enumeration constants for enum with
fixed underlying type against that type and convert to that type.
Increment in the underlying integer type, with handling for bool.
(c_simulate_enum_decl): Update call to start_enum.
(declspecs_add_type): Set specs->enum_type_specifier_ref_p.
* c-objc-common.cc (c_get_alias_set): Use ENUM_UNDERLYING_TYPE
rather than recomputing an underlying type based on size.
* c-parser.cc (c_parser_declspecs)
(c_parser_struct_or_union_specifier, c_parser_typeof_specifier):
Set has_enum_type_specifier for type specifiers.
(c_parser_enum_specifier): Handle enum type specifiers.
(c_parser_struct_or_union_specifier): Update call to
parser_xref_tag.
(c_parser_omp_atomic): Check for boolean increment or decrement
using C_BOOLEAN_TYPE_P.
* c-tree.h (C_BOOLEAN_TYPE_P): New.
(struct c_typespec): Add has_enum_type_specifier.
(struct c_declspecs): Add enum_type_specifier_ref_p.
(struct c_enum_contents): Add enum_type.
(start_enum, parser_xref_tag): Update prototypes.
* c-typeck.cc (composite_type): Allow for enumerated types
compatible with bool.
(common_type, comptypes_internal, perform_integral_promotions):
Use ENUM_UNDERLYING_TYPE.
(parser_build_binary_op, build_unary_op, convert_for_assignment)
(c_finish_return, c_start_switch, build_binary_op): Check for
boolean types using C_BOOLEAN_TYPE_P.
gcc/cp/
* cp-tree.h (ENUM_FIXED_UNDERLYING_TYPE_P, ENUM_UNDERLYING_TYPE):
Remove. Moved to c-common.h.
gcc/testsuite/
* gcc.dg/c11-enum-4.c, gcc.dg/c11-enum-5.c, gcc.dg/c11-enum-6.c,
gcc.dg/c2x-enum-6.c, gcc.dg/c2x-enum-7.c, gcc.dg/c2x-enum-8.c,
gcc.dg/gnu2x-enum-1.c: New tests.
|
|
This patch implements a new experimental warning (enabled by -Wall) to
detect references bound to temporaries whose lifetime has ended. The
primary motivation is the Note in
<https://en.cppreference.com/w/cpp/algorithm/max>:
Capturing the result of std::max by reference produces a dangling reference
if one of the parameters is a temporary and that parameter is returned:
int n = 1;
const int& r = std::max(n-1, n+1); // r is dangling
That's because both temporaries for n-1 and n+1 are destroyed at the end
of the full expression. With this warning enabled, you'll get:
g.C:3:12: warning: possibly dangling reference to a temporary [-Wdangling-reference]
3 | const int& r = std::max(n-1, n+1);
| ^
g.C:3:24: note: the temporary was destroyed at the end of the full expression 'std::max<int>((n - 1), (n + 1))'
3 | const int& r = std::max(n-1, n+1);
| ~~~~~~~~^~~~~~~~~~
The warning works by checking if a reference is initialized with a function
that returns a reference, and at least one parameter of the function is
a reference that is bound to a temporary. It assumes that such a function
actually returns one of its arguments! (I added code to check_return_expr
to suppress the warning when we've seen the definition of the function
and we can say that it can return a variable with static storage
duration.)
It warns when the function in question is a member function, but only if
the function is invoked on a temporary object, otherwise the warning
would emit loads of warnings for valid code like obj.emplace<T>({0}, 0).
It does detect the dangling reference in:
struct S {
const S& self () { return *this; }
};
const S& s = S().self();
It warns in member initializer lists as well:
const int& f(const int& i) { return i; }
struct S {
const int &r;
S() : r(f(10)) { }
};
I've run the testsuite/bootstrap with the warning enabled by default.
There were just a few FAILs, all of which look like genuine bugs.
A bootstrap with the warning enabled by default passed as well.
When testing a previous version of the patch, there were many FAILs in
libstdc++'s 22_locale/; all of them because the warning triggered on
const test_type& obj = std::use_facet<test_type>(std::locale());
but this code looks valid -- std::use_facet doesn't return a reference
to its parameter. Therefore I added a #pragma and code to suppress the
warning.
PR c++/106393
gcc/c-family/ChangeLog:
* c.opt (Wdangling-reference): New.
gcc/cp/ChangeLog:
* call.cc (expr_represents_temporary_p): New, factored out of...
(conv_binds_ref_to_temporary): ...here. Don't return false just
because a ck_base is missing. Use expr_represents_temporary_p.
(do_warn_dangling_reference): New.
(maybe_warn_dangling_reference): New.
(extend_ref_init_temps): Call maybe_warn_dangling_reference.
* cp-tree.h: Adjust comment.
* typeck.cc (check_return_expr): Suppress -Wdangling-reference
warnings.
gcc/ChangeLog:
* doc/invoke.texi: Document -Wdangling-reference.
libstdc++-v3/ChangeLog:
* include/bits/locale_classes.tcc: Add #pragma to disable
-Wdangling-reference with std::use_facet.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/elision4.C: Use -Wdangling-reference, add dg-warning.
* g++.dg/cpp23/elision7.C: Likewise.
* g++.dg/warn/Wdangling-pointer-2.C: Use -Wno-dangling-reference.
* g++.dg/warn/Wdangling-reference1.C: New test.
* g++.dg/warn/Wdangling-reference2.C: New test.
* g++.dg/warn/Wdangling-reference3.C: New test.
|
|
The parameter use_default_args of coerce_template_parms, introduced way
back in r110693, is effectively unused ever since r7-5536-g3c75aaa3d884ef
removed the last 'coerce_template_parms (..., true, false)' call. So
this patch aims to simplify this function's API by getting rid of this
parameter.
In passing, I noticed we currently define wrapper overloads of
coerce_template_parms that act as defacto default arguments for complain
and require_all_args. It seems cleaner however to just specify real
default arguments for the main overload instead. And I suppose we
should also give c_innermost_t_p the same defaults.
But I'm not sure about defaulting complain to tf_none, which is
inconsistent with how we default it in other places to either tf_error
or tf_warning_or_error (as a convenience for non-SFINAE callers). And
since in general it's probably better to not default complain as that's
a source of SFINAE bugs, and only a handful of callers use this defacto
complain=tf_none default, this patch gets rid of this complain default
(but keeps the require_all_args default).
gcc/cp/ChangeLog:
* constraint.cc (resolve_function_concept_overload): Explicitly
pass complain=tf_none to coerce_template_parms.
(resolve_concept_check): Likewise.
(normalize_concept_check): Likewise.
* cp-tree.h (coerce_template_parms): Declare the main overload
and default its last parameter to true. Remove wrapper overloads.
* pt.cc (determine_specialization): Adjust calls to
coerce_template_parms and coerce_innermost_template_parms after
removing their last parameter.
(coerce_template_args_for_ttp): Likewise.
(coerce_ttp_args_for_tta): Likewise.
(coerce_template_template_parms): Likewise.
(coerce_template_parms): Remove use_default_args parameter and
adjust function comment. Document default argument. Remove
wrapper overloads. No longer static.
(coerce_innermost_template_parms): Remove use_default_args
parameter. Default require_all_args to true.
(lookup_template_class): As with determine_specialization.
(finish_template_variable): Likewise.
(tsubst_decl): Likewise.
(instantiate_alias_template): Likewise.
(fn_type_unification): Likewise.
(resolve_overloaded_unification): Likewise.
(resolve_nondeduced_context): Likewise.
(get_partial_spec_bindings): Likewise.
|
|
I noticed that we were printing "the comparison reduces to (x == 42)" when
we should be able to give the value of x. Fixed by doing the same
evaluation in diagnose_failing_condition that we already do in
find_failing_clause.
gcc/cp/ChangeLog:
* constexpr.cc (fold_operand): New function.
(find_failing_clause_r): Add const.
(find_failing_clause): Add const.
(diagnose_failing_condition): Add ctx parameter.
(cxx_eval_internal_function): Pass it.
* semantics.cc (diagnose_failing_condition): Move to constexpr.cc.
* cp-tree.h: Adjust.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/attr-assume2.C: Expect constant values.
|
|
... unless marked noreturn.
This should not get in anyone's way, but should permit the use of main()
in freestanding more easily, especially for writing test cases that
should work both in freestanding and hosted modes.
gcc/c/ChangeLog:
* c-decl.cc (finish_function): Ignore hosted when deciding
whether to implicitly return zero, but check noreturn.
* c-objc-common.cc (c_missing_noreturn_ok_p): Loosen the
requirements to just MAIN_NAME_P when hosted, or `int main'
otherwise.
gcc/cp/ChangeLog:
* cp-tree.h (DECL_MAIN_P): Move most logic, besides the hosted
check, from here...
(DECL_MAIN_ANY_P): ... to here, so that it can be reused ...
(DECL_MAIN_FREESTANDING_P): ... here, with an additional
constraint on (hosted OR return type == int)
* decl.cc (finish_function): Use DECL_MAIN_FREESTANDING_P
instead of DECL_MAIN_P, to loosen the hosted requirement, but
check noreturn, before adding implicit returns.
gcc/testsuite/ChangeLog:
* gcc.dg/noreturn-4.c: Removed.
* g++.dg/freestanding-main.C: New test.
* g++.dg/freestanding-nonint-main.C: New test.
* gcc.dg/freestanding-main.c: New test.
* gcc.dg/freestanding-nonint-main.c: New test.
|
|
My earlier patches gimplify the simplest non-side-effects assumptions
into if (cond) ; else __builtin_unreachable (); and throw the rest
on the floor.
The following patch attempts to do something with the rest too.
For -O0, it throws the more complex assumptions on the floor,
we don't expect optimizations and the assumptions are there to allow
optimizations. Otherwise arranges for the assumptions to be
visible in the IL as
.ASSUME (_Z2f4i._assume.0, i_1(D));
call where there is an artificial function like:
bool _Z2f4i._assume.0 (int i)
{
bool _2;
<bb 2> [local count: 1073741824]:
_2 = i_1(D) == 43;
return _2;
}
with the semantics that there is UB unless the assumption function
would return true.
Aldy, could ranger handle this? If it sees .ASSUME call,
walk the body of such function from the edge(s) to exit with the
assumption that the function returns true, so above set _2 [true, true]
and from there derive that i_1(D) [43, 43] and then map the argument
in the assumption function to argument passed to IFN_ASSUME (note,
args there are shifted by 1)?
During gimplification it actually gimplifies it into
[[assume (D.2591)]]
{
{
i = i + 1;
D.2591 = i == 44;
}
}
which is a new GIMPLE_ASSUME statement wrapping a GIMPLE_BIND and
specifying a boolean_type_node variable which contains the result.
The GIMPLE_ASSUME then survives just a couple of passes and is lowered
during gimple lowering into an outlined separate function and
IFN_ASSUME call. Variables declared inside of the
condition (both static and automatic) just change context, automatic
variables from the caller are turned into parameters (note, as the code
is never executed, I handle this way even non-POD types, we don't need to
bother pretending there would be user copy constructors etc. involved).
The assume_function artificial functions are then optimized until the
new assumptions pass which doesn't do much right now but I'd like to see
there the backwards ranger walk and filling up of SSA_NAME_RANGE_INFO
for the parameters.
There are a few further changes I'd like to do, like ignoring the
.ASSUME calls in inlining size estimations (but haven't figured out where
it is done), or for LTO arrange for the assume functions to be emitted
in all partitions that reference those (usually there will be just one,
unless code with the assumption got inlined, versioned etc.).
2022-10-18 Jakub Jelinek <jakub@redhat.com>
PR c++/106654
gcc/
* gimple.def (GIMPLE_ASSUME): New statement kind.
* gimple.h (struct gimple_statement_assume): New type.
(is_a_helper <gimple_statement_assume *>::test,
is_a_helper <const gimple_statement_assume *>::test): New.
(gimple_build_assume): Declare.
(gimple_has_substatements): Return true for GIMPLE_ASSUME.
(gimple_assume_guard, gimple_assume_set_guard,
gimple_assume_guard_ptr, gimple_assume_body_ptr, gimple_assume_body):
New inline functions.
* gsstruct.def (GSS_ASSUME): New.
* gimple.cc (gimple_build_assume): New function.
(gimple_copy): Handle GIMPLE_ASSUME.
* gimple-pretty-print.cc (dump_gimple_assume): New function.
(pp_gimple_stmt_1): Handle GIMPLE_ASSUME.
* gimple-walk.cc (walk_gimple_op): Handle GIMPLE_ASSUME.
* omp-low.cc (WALK_SUBSTMTS): Likewise.
(lower_omp_1): Likewise.
* omp-oacc-kernels-decompose.cc (adjust_region_code_walk_stmt_fn):
Likewise.
* tree-cfg.cc (verify_gimple_stmt, verify_gimple_in_seq_2): Likewise.
* function.h (struct function): Add assume_function bitfield.
* gimplify.cc (gimplify_call_expr): If the assumption isn't
simple enough, expand it into GIMPLE_ASSUME wrapped block or
for -O0 drop it.
* gimple-low.cc: Include attribs.h.
(create_assumption_fn): New function.
(struct lower_assumption_data): New type.
(find_assumption_locals_r, assumption_copy_decl,
adjust_assumption_stmt_r, adjust_assumption_stmt_op,
lower_assumption): New functions.
(lower_stmt): Handle GIMPLE_ASSUME.
* tree-ssa-ccp.cc (pass_fold_builtins::execute): Remove
IFN_ASSUME calls.
* lto-streamer-out.cc (output_struct_function_base): Pack
assume_function bit.
* lto-streamer-in.cc (input_struct_function_base): And unpack it.
* cgraphunit.cc (cgraph_node::expand): Don't verify assume_function
has TREE_ASM_WRITTEN set and don't release its body.
(symbol_table::compile): Allow assume functions not to have released
body.
* internal-fn.cc (expand_ASSUME): Remove gcc_unreachable.
* passes.cc (execute_one_pass): For TODO_discard_function don't
release body of assume functions.
* cgraph.cc (cgraph_node::verify_node): Don't verify cgraph nodes
of PROP_assumptions_done functions.
* tree-pass.h (PROP_assumptions_done): Define.
(TODO_discard_function): Adjust comment.
(make_pass_assumptions): Declare.
* passes.def (pass_assumptions): Add.
* timevar.def (TV_TREE_ASSUMPTIONS): New.
* tree-inline.cc (remap_gimple_stmt): Handle GIMPLE_ASSUME.
* tree-vrp.cc (pass_data_assumptions): New variable.
(pass_assumptions): New class.
(make_pass_assumptions): New function.
gcc/cp/
* cp-tree.h (build_assume_call): Declare.
* parser.cc (cp_parser_omp_assumption_clauses): Use build_assume_call.
* cp-gimplify.cc (build_assume_call): New function.
(process_stmt_assume_attribute): Use build_assume_call.
* pt.cc (tsubst_copy_and_build): Likewise.
gcc/testsuite/
* g++.dg/cpp23/attr-assume5.C: New test.
* g++.dg/cpp23/attr-assume6.C: New test.
* g++.dg/cpp23/attr-assume7.C: New test.
|
|
Here is a complete patch to add std::bfloat16_t support on
x86 (AArch64 and ARM left for later). Almost no BFmode optabs
are added by the patch, so for binops/unops it extends to SFmode
first and then truncates back to BFmode.
For {HF,SF,DF,XF,TF}mode -> BFmode conversions libgcc has implementations
of all those conversions so that we avoid double rounding, for
BFmode -> {DF,XF,TF}mode conversions to avoid growing libgcc too much
it emits BFmode -> SFmode conversion first and then converts to the even
wider mode, neither step should be imprecise.
For BFmode -> HFmode, it first emits a precise BFmode -> SFmode conversion
and then SFmode -> HFmode, because neither format is subset or superset
of the other, while SFmode is superset of both.
expr.cc then contains a -ffast-math optimization of the BF -> SF and
SF -> BF conversions if we don't optimize for space (and for the latter
if -frounding-math isn't enabled either).
For x86, perhaps truncsfbf2 optab could be defined for TARGET_AVX512BF16
but IMNSHO should FAIL if !flag_finite_math || flag_rounding_math
|| !flag_unsafe_math_optimizations, because I think the insn doesn't
raise on sNaNs, hardcodes round to nearest and flushes denormals to zero.
By default (unless x86 -fexcess-precision=16) we use float excess
precision for BFmode, so truncate only on explicit casts and assignments.
The patch introduces a single __bf16 builtin - __builtin_nansf16b,
because (__bf16) __builtin_nansf ("") will drop the sNaN into qNaN,
and uses f16b suffix instead of bf16 because there would be ambiguity on
log vs. logb - __builtin_logbf16 could be either log with bf16 suffix
or logb with f16 suffix. In other cases libstdc++ should mostly use
__builtin_*f for std::bfloat16_t overloads (we have a problem with
std::nextafter though but that one we have also for std::float16_t).
2022-10-14 Jakub Jelinek <jakub@redhat.com>
gcc/
* tree-core.h (enum tree_index): Add TI_BFLOAT16_TYPE.
* tree.h (bfloat16_type_node): Define.
* tree.cc (excess_precision_type): Promote bfloat16_type_mode
like float16_type_mode.
(build_common_tree_nodes): Initialize bfloat16_type_node if
BFmode is supported.
* expmed.h (maybe_expand_shift): Declare.
* expmed.cc (maybe_expand_shift): No longer static.
* expr.cc (convert_mode_scalar): Don't ICE on BF -> HF or HF -> BF
conversions. If there is no optab, handle BF -> {DF,XF,TF,HF}
conversions as separate BF -> SF -> {DF,XF,TF,HF} conversions, add
-ffast-math generic implementation for BF -> SF and SF -> BF
conversions.
* builtin-types.def (BT_BFLOAT16, BT_FN_BFLOAT16_CONST_STRING): New.
* builtins.def (BUILT_IN_NANSF16B): New builtin.
* fold-const-call.cc (fold_const_call): Handle CFN_BUILT_IN_NANSF16B.
* config/i386/i386.cc (classify_argument): Handle E_BCmode.
(ix86_libgcc_floating_mode_supported_p): Also return true for BFmode
for -msse2.
(ix86_mangle_type): Mangle BFmode as DF16b.
(ix86_invalid_conversion, ix86_invalid_unary_op,
ix86_invalid_binary_op): Remove.
(TARGET_INVALID_CONVERSION, TARGET_INVALID_UNARY_OP,
TARGET_INVALID_BINARY_OP): Don't redefine.
* config/i386/i386-builtins.cc (ix86_bf16_type_node): Remove.
(ix86_register_bf16_builtin_type): Use bfloat16_type_node rather than
ix86_bf16_type_node, only create it if still NULL.
* config/i386/i386-builtin-types.def (BFLOAT16): Likewise.
* config/i386/i386.md (cbranchbf4, cstorebf4): New expanders.
gcc/c-family/
* c-cppbuiltin.cc (c_cpp_builtins): If bfloat16_type_node,
predefine __BFLT16_*__ macros and for C++23 also
__STDCPP_BFLOAT16_T__. Predefine bfloat16_type_node related
macros for -fbuilding-libgcc.
* c-lex.cc (interpret_float): Handle CPP_N_BFLOAT16.
gcc/c/
* c-typeck.cc (convert_arguments): Don't promote __bf16 to
double.
gcc/cp/
* cp-tree.h (extended_float_type_p): Return true for
bfloat16_type_node.
* typeck.cc (cp_compare_floating_point_conversion_ranks): Set
extended{1,2} if mv{1,2} is bfloat16_type_node. Adjust comment.
gcc/testsuite/
* lib/target-supports.exp (check_effective_target_bfloat16,
check_effective_target_bfloat16_runtime, add_options_for_bfloat16):
New.
* gcc.dg/torture/bfloat16-basic.c: New test.
* gcc.dg/torture/bfloat16-builtin.c: New test.
* gcc.dg/torture/bfloat16-builtin-issignaling-1.c: New test.
* gcc.dg/torture/bfloat16-complex.c: New test.
* gcc.dg/torture/builtin-issignaling-1.c: Allow to be includable
from bfloat16-builtin-issignaling-1.c.
* gcc.dg/torture/floatn-basic.h: Allow to be includable from
bfloat16-basic.c.
* gcc.target/i386/vect-bfloat16-typecheck_2.c: Adjust expected
diagnostics.
* gcc.target/i386/sse2-bfloat16-scalar-typecheck.c: Likewise.
* gcc.target/i386/vect-bfloat16-typecheck_1.c: Likewise.
* g++.target/i386/bfloat_cpp_typecheck.C: Likewise.
libcpp/
* include/cpplib.h (CPP_N_BFLOAT16): Define.
* expr.cc (interpret_float_suffix): Handle bf16 and BF16 suffixes for
C++.
libgcc/
* config/i386/t-softfp (softfp_extensions): Add bfsf.
(softfp_truncations): Add tfbf xfbf dfbf sfbf hfbf.
(CFLAGS-extendbfsf2.c, CFLAGS-truncsfbf2.c, CFLAGS-truncdfbf2.c,
CFLAGS-truncxfbf2.c, CFLAGS-trunctfbf2.c, CFLAGS-trunchfbf2.c): Add
-msse2.
* config/i386/libgcc-glibc.ver (GCC_13.0.0): Export
__extendbfsf2 and __trunc{s,d,x,t,h}fbf2.
* config/i386/sfp-machine.h (_FP_NANSIGN_B): Define.
* config/i386/64/sfp-machine.h (_FP_NANFRAC_B): Define.
* config/i386/32/sfp-machine.h (_FP_NANFRAC_B): Define.
* soft-fp/brain.h: New file.
* soft-fp/truncsfbf2.c: New file.
* soft-fp/truncdfbf2.c: New file.
* soft-fp/truncxfbf2.c: New file.
* soft-fp/trunctfbf2.c: New file.
* soft-fp/trunchfbf2.c: New file.
* soft-fp/truncbfhf2.c: New file.
* soft-fp/extendbfsf2.c: New file.
libiberty/
* cp-demangle.h (D_BUILTIN_TYPE_COUNT): Increment.
* cp-demangle.c (cplus_demangle_builtin_types): Add std::bfloat16_t
entry.
(cplus_demangle_type): Demangle DF16b.
* testsuite/demangle-expected (_Z3xxxDF16b): New test.
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PR87390]
The following incremental patch implements the C11 behavior (for all C++
versions) for
cond ? int : float
cond ? float : int
int cmp float
float cmp int
where int is any integral type, float any floating point type with
excess precision and cmp ==, !=, >, <, >=, <= and <=>.
2022-10-14 Jakub Jelinek <jakub@redhat.com>
PR c/82071
PR c/87390
PR c++/107097
gcc/cp/
* cp-tree.h (cp_ep_convert_and_check): Remove.
* cvt.cc (cp_ep_convert_and_check): Remove.
* call.cc (build_conditional_expr): Use excess precision for ?: with
one arm floating and another integral. Don't convert first to
semantic result type from integral types.
(convert_like_internal): Don't call cp_ep_convert_and_check, instead
just strip EXCESS_PRECISION_EXPR before calling cp_convert_and_check
or cp_convert.
* typeck.cc (cp_build_binary_op): Set may_need_excess_precision
for comparisons or SPACESHIP_EXPR with at least one operand integral.
Don't compute semantic_result_type if build_type is non-NULL. Call
cp_convert_and_check instead of cp_ep_convert_and_check.
gcc/testsuite/
* gcc.target/i386/excess-precision-8.c: For C++ wrap abort and
exit declarations into extern "C" block.
* gcc.target/i386/excess-precision-10.c: Likewise.
* g++.target/i386/excess-precision-7.C: Remove.
* g++.target/i386/excess-precision-8.C: New test.
* g++.target/i386/excess-precision-9.C: Remove.
* g++.target/i386/excess-precision-10.C: New test.
* g++.target/i386/excess-precision-12.C: New test.
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The following patch implements excess precision support for C++.
Like for C, it uses EXCESS_PRECISION_EXPR tree to say that its operand
is evaluated in excess precision and what the semantic type of the
expression is.
In most places I've followed what the C FE does in similar spots, so
e.g. for binary ops if one or both operands are already
EXCESS_PRECISION_EXPR, strip those away or for operations that might need
excess precision (+, -, *, /) check if the operands should use excess
precision and convert to that type and at the end wrap into
EXCESS_PRECISION_EXPR with the common semantic type.
This patch follows the C99 handling where it differs from C11 handling.
There are some cases which needed to be handled differently, the C FE can
just strip EXCESS_PRECISION_EXPR (replace it with its operand) when handling
explicit cast, but that IMHO isn't right for C++ - the discovery what exact
conversion should be used (e.g. if user conversion or standard or their
sequence) should be decided based on the semantic type (i.e. type of
EXCESS_PRECISION_EXPR), and that decision continues in convert_like* where
we pick the right user conversion, again, if say some class has ctor
from double and long double and we are on ia32 with standard excess
precision promoting float/double to long double, then we should pick the
ctor from double. Or when some other class has ctor from just double,
and EXCESS_PRECISION_EXPR semantic type is float, we should choose the
user ctor from double, but actually just convert the long double excess
precision to double and not to float first. We need to make sure
even identity conversion converts from excess precision to the semantic one
though, but if identity is chained with other conversions, we don't want
the identity next_conversion to drop to semantic precision only to widen
afterwards.
The existing testcases tweaks were for cases on i686-linux where excess
precision breaks those tests, e.g. if we have
double d = 4.2;
if (d == 4.2)
then it does the expected thing only with -fexcess-precision=fast,
because with -fexcess-precision=standard it is actually
double d = 4.2;
if ((long double) d == 4.2L)
where 4.2L is different from 4.2. I've added -fexcess-precision=fast
to some tests and changed other tests to use constants that are exactly
representable and don't suffer from these excess precision issues.
There is one exception, pr68180.C looks like a bug in the patch which is
also present in the C FE (so I'd like to get it resolved incrementally
in both). Reduced testcase:
typedef float __attribute__((vector_size (16))) float32x4_t;
float32x4_t foo(float32x4_t x, float y) { return x + y; }
with -m32 -std=c11 -Wno-psabi or -m32 -std=c++17 -Wno-psabi
it is rejected with:
pr68180.c:2:52: error: conversion of scalar ‘long double’ to vector ‘float32x4_t’ {aka ‘__vector(4) float’} involves truncation
but without excess precision (say just -std=c11 -Wno-psabi or -std=c++17 -Wno-psabi)
it is accepted. Perhaps we should pass down the semantic type to
scalar_to_vector and use the semantic type rather than excess precision type
in the diagnostics.
2022-10-14 Jakub Jelinek <jakub@redhat.com>
PR middle-end/323
PR c++/107097
gcc/
* doc/invoke.texi (-fexcess-precision=standard): Mention that the
option now also works in C++.
gcc/c-family/
* c-common.def (EXCESS_PRECISION_EXPR): Remove comment part about
the tree being specific to C/ObjC.
* c-opts.cc (c_common_post_options): Handle flag_excess_precision
in C++ the same as in C.
* c-lex.cc (interpret_float): Set const_type to excess_precision ()
even for C++.
gcc/cp/
* parser.cc (cp_parser_primary_expression): Handle
EXCESS_PRECISION_EXPR with REAL_CST operand the same as REAL_CST.
* cvt.cc (cp_ep_convert_and_check): New function.
* call.cc (build_conditional_expr): Add excess precision support.
When type_after_usual_arithmetic_conversions returns error_mark_node,
use gcc_checking_assert that it is because of uncomparable floating
point ranks instead of checking all those conditions and make it
work also with complex types.
(convert_like_internal): Likewise. Add NESTED_P argument, pass true
to recursive calls to convert_like.
(convert_like): Add NESTED_P argument, pass it through to
convert_like_internal. For other overload pass false to it.
(convert_like_with_context): Pass false to NESTED_P.
(convert_arg_to_ellipsis): Add excess precision support.
(magic_varargs_p): For __builtin_is{finite,inf,inf_sign,nan,normal}
and __builtin_fpclassify return 2 instead of 1, document what it
means.
(build_over_call): Don't handle former magic 2 which is no longer
used, instead for magic 1 remove EXCESS_PRECISION_EXPR.
(perform_direct_initialization_if_possible): Pass false to NESTED_P
convert_like argument.
* constexpr.cc (cxx_eval_constant_expression): Handle
EXCESS_PRECISION_EXPR.
(potential_constant_expression_1): Likewise.
* pt.cc (tsubst_copy, tsubst_copy_and_build): Likewise.
* cp-tree.h (cp_ep_convert_and_check): Declare.
* cp-gimplify.cc (cp_fold): Handle EXCESS_PRECISION_EXPR.
* typeck.cc (cp_common_type): For COMPLEX_TYPEs, return error_mark_node
if recursive call returned it.
(convert_arguments): For magic 1 remove EXCESS_PRECISION_EXPR.
(cp_build_binary_op): Add excess precision support. When
cp_common_type returns error_mark_node, use gcc_checking_assert that
it is because of uncomparable floating point ranks instead of checking
all those conditions and make it work also with complex types.
(cp_build_unary_op): Likewise.
(cp_build_compound_expr): Likewise.
(build_static_cast_1): Remove EXCESS_PRECISION_EXPR.
gcc/testsuite/
* gcc.target/i386/excess-precision-1.c: For C++ wrap abort and
exit declarations into extern "C" block.
* gcc.target/i386/excess-precision-2.c: Likewise.
* gcc.target/i386/excess-precision-3.c: Likewise. Remove
check_float_nonproto and check_double_nonproto tests for C++.
* gcc.target/i386/excess-precision-7.c: For C++ wrap abort and
exit declarations into extern "C" block.
* gcc.target/i386/excess-precision-9.c: Likewise.
* g++.target/i386/excess-precision-1.C: New test.
* g++.target/i386/excess-precision-2.C: New test.
* g++.target/i386/excess-precision-3.C: New test.
* g++.target/i386/excess-precision-4.C: New test.
* g++.target/i386/excess-precision-5.C: New test.
* g++.target/i386/excess-precision-6.C: New test.
* g++.target/i386/excess-precision-7.C: New test.
* g++.target/i386/excess-precision-9.C: New test.
* g++.target/i386/excess-precision-11.C: New test.
* c-c++-common/dfp/convert-bfp-10.c: Add -fexcess-precision=fast
as dg-additional-options.
* c-c++-common/dfp/compare-eq-const.c: Likewise.
* g++.dg/cpp1z/constexpr-96862.C: Likewise.
* g++.dg/cpp1z/decomp12.C (main): Use 2.25 instead of 2.3 to
avoid excess precision differences.
* g++.dg/other/thunk1.C: Add -fexcess-precision=fast
as dg-additional-options.
* g++.dg/vect/pr64410.cc: Likewise.
* g++.dg/cpp1y/pr68180.C: Likewise.
* g++.dg/vect/pr89653.cc: Likewise.
* g++.dg/cpp0x/variadic-tuple.C: Likewise.
* g++.dg/cpp0x/nsdmi-union1.C: Use 4.25 instead of 4.2 to
avoid excess precision differences.
* g++.old-deja/g++.brendan/copy9.C: Add -fexcess-precision=fast
as dg-additional-options.
* g++.old-deja/g++.brendan/overload7.C: Likewise.
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Split out from the C++ contracts patch.
gcc/cp/ChangeLog:
* cp-tree.h: Fix whitespace.
* parser.h: Fix whitespace.
* decl.cc: Fix whitespace.
* parser.cc: Fix whitespace.
* pt.cc: Fix whitespace.
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This patch removes the two-stage overload resolution when performing
implicit move, whereby the compiler does two separate overload resolutions:
one treating the operand as an rvalue, and then (if that resolution fails)
another one treating the operand as an lvalue. In the standard this was
introduced via CWG 1579 and implemented in gcc in r251035. In r11-2412,
we disabled the fallback OR in C++20 (but not in C++17). Then C++23 P2266
removed the fallback overload resolution, and changed the implicit move rules
once again. So we wound up with three different behaviors.
The two overload resolutions approach was complicated and quirky, so
users should transition to the newer model. Removing the maybe-rvalue
OR also allows us to simplify our code, for instance, now we can get
rid of LOOKUP_PREFER_RVALUE altogether.
This change means that code that previously didn't compile in C++17 will
now compile, for example:
struct S1 { S1(S1 &&); };
struct S2 : S1 {};
S1
f (S2 s)
{
return s; // OK, derived-to-base, use S1::S1(S1&&)
}
And conversely, code that used to work in C++17 may not compile anymore:
struct W {
W();
};
struct F {
F(W&);
F(W&&) = delete;
};
F fn ()
{
W w;
return w; // use w as rvalue -> use of deleted function F::F(W&&)
}
I plan to add a note to porting_to.html.
gcc/cp/ChangeLog:
* call.cc (standard_conversion): Remove LOOKUP_PREFER_RVALUE code.
(reference_binding): Honor clk_implicit_rval even pre-C++20.
(implicit_conversion_1): Remove LOOKUP_PREFER_RVALUE code.
(build_user_type_conversion_1): Likewise.
(convert_like_internal): Likewise.
(build_over_call): Likewise.
* cp-tree.h (LOOKUP_PREFER_RVALUE): Remove.
(LOOKUP_NO_NARROWING): Adjust definition.
* except.cc (build_throw): Don't perform two overload resolutions.
* typeck.cc (maybe_warn_pessimizing_move): Don't use
LOOKUP_PREFER_RVALUE.
(check_return_expr): Don't perform two overload resolutions.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/Wredundant-move10.C: Adjust dg-warning.
* g++.dg/cpp0x/Wredundant-move7.C: Likewise.
* g++.dg/cpp0x/move-return2.C: Remove dg-error.
* g++.dg/cpp0x/move-return4.C: Likewise.
* g++.dg/cpp0x/ref-qual20.C: Adjust expected return value.
* g++.dg/cpp0x/move-return5.C: New test.
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