ICE on this test was fixed by r15-2131.  This just adds test for it.

2025-03-06  Jakub Jelinek  <jakub@redhat.com>

	PR fortran/104826
	* gfortran.dg/gomp/pr104826.f90: New test.

The recently-approved Standard Library Hardening proposal (P3471R4)
gives pop_front and pop_back member functions hardened preconditions,
but std::list was missing assertions on them. Our other sequence
containers do have assertions on those members.

libstdc++-v3/ChangeLog:

	* include/bits/stl_list.h (list::pop_front, list::pop_back):
	Add non-empty assertions.

Reviewed-by: Patrick Palka <ppalka@redhat.com>

We need to include <bits/stl_pair.h> in C++23 and later, so that
__pair_like_convertible_from can use __pair_like, and so that
__is_tuple_like_v is declared before we define a partial specialization.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_util.h: Include <bits/stl_pair.h>.

Reviewed-by: Patrick Palka <ppalka@redhat.com>

This destructor declaration serves no purpose, as pointed out by LWG
3903 which was approved at Varna, June 2023.

libstdc++-v3/ChangeLog:

	* include/std/span (span::~span): Remove, as per LWG 3903.

Reviewed-by: Patrick Palka <ppalka@redhat.com>

This test fails due to duplicate explicit instantiations on targets
where size_t and unsigned int are the same type. It also fails with
-D_GLIBCXX_USE_CXX11_ABI=0 due to using std::string in constexpr
functions, and with --disable-libstdcxx-pch due to not including
<algorithm> for ranges::fold_left.

libstdc++-v3/ChangeLog:

	PR libstdc++/119144
	* testsuite/26_numerics/complex/tuple_like.cc: Include
	<algorithm>, replace std::string with std::string_view,
	instantiate tests for long instead of size_t.

This reverts commit e836d803.

The following makes sure to also walk CONSTRUCTOR element indexes
which can be FIELD_DECLs, referencing otherwise unused types we
need to clean.  walk_tree only walks CONSTRUCTOR element data.

	PR lto/114501
	* ipa-free-lang-data.cc (find_decls_types_r): Explicitly
	handle CONSTRUCTORs as walk_tree handling of those is
	incomplete.

	* g++.dg/pr114501_0.C: New testcase.

	libstdc++-v3/
	* src/c++20/tzdb.cc [__GTHREADS && !__GTHREADS_CXX0X]: Use
	'__gnu_cxx::__mutex'.

Co-authored-by: Thomas Schwinge <tschwinge@baylibre.com>

libstdc++: Avoid '-Wunused-parameter' for 'out' in member function 'std::codecvt_base::result std::__format::{anonymous}::__encoding::conv(std::string_view, std::string&) const'

In a newlib configuration:

    ../../../../../source-gcc/libstdc++-v3/src/c++20/format.cc: In member function ‘std::codecvt_base::result std::__format::{anonymous}::__encoding::conv(std::string_view, std::string&) const’:
    ../../../../../source-gcc/libstdc++-v3/src/c++20/format.cc:100:35: error: unused parameter ‘out’ [-Werror=unused-parameter]
      100 |   conv(string_view input, string& out) const
          |                           ~~~~~~~~^~~

	libstdc++-v3/
	* src/c++20/format.cc (conv): Tag 'out' as '[[maybe_unused]]'.

libstdc++: Avoid '-Wunused-parameter' for 'is_directory' in member function 'bool std::filesystem::__cxx11::_Dir::do_unlink(bool, std::error_code&) const'

In a newlib configuration:

    ../../../../../source-gcc/libstdc++-v3/src/c++17/fs_dir.cc: In member function ‘bool std::filesystem::__cxx11::_Dir::do_unlink(bool, std::error_code&) const’:
    ../../../../../source-gcc/libstdc++-v3/src/c++17/fs_dir.cc:147:18: error: unused parameter ‘is_directory’ [-Werror=unused-parameter]
      147 |   do_unlink(bool is_directory, error_code& ec) const noexcept
          |             ~~~~~^~~~~~~~~~~~

	libstdc++-v3/
	* src/c++17/fs_dir.cc (do_unlink): Tag 'is_directory' as
	'[[maybe_unused]]'.

libstdc++: Avoid '-Wunused-parameter' for 'nofollow' in static member function 'static std::filesystem::__gnu_posix::DIR* std::filesystem::_Dir_base::openat(const _At_path&, bool)'

In a newlib configuration:

    In file included from ../../../../../source-gcc/libstdc++-v3/src/c++17/fs_dir.cc:37,
                     from ../../../../../source-gcc/libstdc++-v3/src/c++17/cow-fs_dir.cc:26:
    ../../../../../source-gcc/libstdc++-v3/src/c++17/../filesystem/dir-common.h: In static member function ‘static std::filesystem::__gnu_posix::DIR* std::filesystem::_Dir_base::openat(const _At_path&, bool)’:
    ../../../../../source-gcc/libstdc++-v3/src/c++17/../filesystem/dir-common.h:210:36: error: unused parameter ‘nofollow’ [-Werror=unused-parameter]
      210 |   openat(const _At_path& atp, bool nofollow)
          |                               ~~~~~^~~~~~~~

	libstdc++-v3/
	* src/filesystem/dir-common.h (openat): Tag 'nofollow' as
	'[[maybe_unused]]'.

libstdc++: Avoid '-Wunused-parameter' for '__what' in function 'void std::__throw_format_error(const char*)'

In a '-fno-exceptions' configuration:

    In file included from ../../../../../source-gcc/libstdc++-v3/src/c++20/format.cc:29:
    [...]/build-gcc/[...]/libstdc++-v3/include/format: In function ‘void std::__throw_format_error(const char*)’:
    [...]/build-gcc/[...]/libstdc++-v3/include/format:200:36: error: unused parameter ‘__what’ [-Werror=unused-parameter]
      200 |   __throw_format_error(const char* __what)
          |                        ~~~~~~~~~~~~^~~~~~

	libstdc++-v3/
	* include/bits/c++config [!__cpp_exceptions]
	(_GLIBCXX_THROW_OR_ABORT): Reference '_EXC'.

Co-authored-by: Jonathan Wakely <jwakely@redhat.com>

The old COW std::string is not usable in constant expressions, so these
new tests fail with -D_GLIBCXX_USE_CXX11_ABI=0.

The parts of the tests using std::string can be conditionally skipped.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/specialized_algorithms/uninitialized_copy/constexpr.cc:
	Do not test COW std::string in constexpr contexts.
	* testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constexpr.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill/constexpr.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_move/constexpr.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constexpr.cc:
	Likewise.

Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

The PR claims that pair-fusion has invalid uses of gcc_assert (such that
the pass will misbehave with --disable-checking).  As noted in the
comments, in the case of the calls to restrict_movement, the only way we
can possibly depend on the side effects is if we call it with a
non-singleton move range.  However, the intent is that we always have a
singleton move range here, and thus we do not rely on the side effects.

This patch therefore adds asserts to check for a singleton move range
before calling restrict_movement, thus clarifying the intent and
hopefully dispelling any concerns that having the calls wrapped in
asserts is problematic here.

gcc/ChangeLog:

	PR rtl-optimization/114492
	* pair-fusion.cc (pair_fusion_bb_info::fuse_pair): Check for singleton
	move range before calling restrict_movement.
	(pair_fusion::try_promote_writeback): Likewise.

This commit implements P2819R2 for C++26, making std::complex
destructurable and tuple-like (see [complex.tuple]).

std::get needs to get forward declared in stl_pair.h (following the
existing precedent for the implementation of P2165R4, cf.
r14-8710-g65b4cba9d6a9ff), and implemented in <complex>.

Also, std::get(complex<T>) needs to return *references* to the real and
imaginary parts of a std::complex object, honoring the value category
and constness of the argument. In principle a straightforward task, it
gets a bit convoluted by the fact that:

1) std::complex does not have existing getters that one can use for this
(real() and imag() return values, not references);

2) there are specializations for language/extended floating-point types,
which requires some duplication -- need to amend the primary and all
the specializations;

3) these specializations use a `__complex__ T`, but the primary template
uses two non-static data members, making generic code harder to write.

The implementation choice used here is to add the overloads of std::get
for complex as declared in [complex.tuple]. In turn they dispatch to a
newly added getter that extracts references to the real/imaginary parts
of a complex<T>. This getter is private API, and the implementation
depends on whether it's the primary (bind the data member) or a
specialization (use the GCC language extensions for __complex__).
To avoid duplication and minimize template instantiations, the getter
uses C++23's deducing this (this avoids const overloads). The value
category is dealt with by the std::get overloads.

Add a test that covers the aspects of the tuple protocol, as well as the
tuple-like interface. While at it, add a test for the existing
tuple-like feature-testing macro.

	PR libstdc++/113310

libstdc++-v3/ChangeLog:

	* include/bits/stl_pair.h (get): Forward-declare std::get for
	std::complex.
	* include/bits/version.def (tuple_like): Bump the value of
	the feature-testing macro in C++26.
	* include/bits/version.h: Regenerate.
	* include/std/complex: Implement the tuple protocol for
	std::complex.
	(tuple_size): Specialize for std::complex.
	(tuple_element): Ditto.
	(__is_tuple_like_v): Ditto.
	(complex): Add a private getter to obtain references to the real
	and the imaginary part, on the primary class template and on its
	specializations.
	(get): Add overloads of std::get for std::complex.
	* testsuite/20_util/tuple/tuple_like_ftm.cc: New test.
	* testsuite/26_numerics/complex/tuple_like.cc: New test.

Following on from the discussion in:

  https://gcc.gnu.org/pipermail/gcc-patches/2025-February/675256.html



this patch removes TARGET_IRA_CALLEE_SAVED_REGISTER_COST_SCALE and
replaces it with two hooks: one that controls the cost of using an
extra callee-saved register and one that controls the cost of allocating
a frame for the first spill.

(The patch does not attempt to address the shrink-wrapping part of
the thread above.)

On AArch64, this is enough to fix PR117477, as verified by the new tests.
The patch does not change the SPEC2017 scores significantly.  (I saw a
slight improvement in fotonik3d and roms, but I'm not convinced that
the improvements are real.)

The patch makes IRA use caller saves for gcc.target/aarch64/pr103350-1.c,
which is a scan-dump correctness test that relies on not using
caller saves.  The decision to use caller saves looks appropriate,
and saves an instruction, so I've just added -fno-caller-saves
to the test options.

The x86 parts were written by Honza.

gcc/
	PR rtl-optimization/117477
	* config/aarch64/aarch64.cc (aarch64_count_saves): New function.
	(aarch64_count_above_hard_fp_saves, aarch64_callee_save_cost)
	(aarch64_frame_allocation_cost): Likewise.
	(TARGET_CALLEE_SAVE_COST): Define.
	(TARGET_FRAME_ALLOCATION_COST): Likewise.
	* config/i386/i386.cc (ix86_ira_callee_saved_register_cost_scale):
	Replace with...
	(ix86_callee_save_cost): ...this new hook.
	(TARGET_IRA_CALLEE_SAVED_REGISTER_COST_SCALE): Delete.
	(TARGET_CALLEE_SAVE_COST): Define.
	* target.h (spill_cost_type, frame_cost_type): New enums.
	* target.def (callee_save_cost, frame_allocation_cost): New hooks.
	(ira_callee_saved_register_cost_scale): Delete.
	* doc/tm.texi.in (TARGET_IRA_CALLEE_SAVED_REGISTER_COST_SCALE): Delete.
	(TARGET_CALLEE_SAVE_COST, TARGET_FRAME_ALLOCATION_COST): New hooks.
	* doc/tm.texi: Regenerate.
	* hard-reg-set.h (hard_reg_set_popcount): New function.
	* ira-color.cc (allocated_memory_p): New variable.
	(allocated_callee_save_regs): Likewise.
	(record_allocation): New function.
	(assign_hard_reg): Use targetm.frame_allocation_cost to model
	the cost of the first spill or first caller save.  Use
	targetm.callee_save_cost to model the cost of using new callee-saved
	registers.  Apply the exit rather than entry frequency to the cost
	of restoring a register or deallocating the frame.  Update the
	new variables above.
	(improve_allocation): Use record_allocation.
	(color): Initialize allocated_callee_save_regs.
	(ira_color): Initialize allocated_memory_p.
	* targhooks.h (default_callee_save_cost): Declare.
	(default_frame_allocation_cost): Likewise.
	* targhooks.cc (default_callee_save_cost): New function.
	(default_frame_allocation_cost): Likewise.

gcc/testsuite/
	PR rtl-optimization/117477
	* gcc.target/aarch64/callee_save_1.c: New test.
	* gcc.target/aarch64/callee_save_2.c: Likewise.
	* gcc.target/aarch64/callee_save_3.c: Likewise.
	* gcc.target/aarch64/pr103350-1.c: Add -fno-caller-saves.

Co-authored-by: Jan Hubicka <hubicka@ucw.cz>

Incremental LTO disabled cleanup of output_files since they have to
persist in ltrans cache.
This unintetionally also kept temporary early debug "*.debug.temp.o"
files.

Bootstrapped/regtested on x86_64-linux.
Ok for trunk?

lto-plugin/ChangeLog:

	* lto-plugin.c (cleanup_handler): Keep only files in ltrans
	cache.

The following testcase runs into a re-gimplification issue during
inlining when processing

  MEM[(struct e *)this_2(D)].a = {};

where re-gimplification does not handle assignments in the same
way than the gimplifier but instead relies on rhs_predicate_for
and gimplifying the RHS standalone.  This fails to handle
special-casing of CTORs.  The is_gimple_mem_rhs_or_call predicate
already handles clobbers but not empty CTORs so we end up in
the fallback code trying to force the CTOR into a separate stmt
using a temporary - but as we have a non-copyable type here that ICEs.

The following generalizes empty CTORs in is_gimple_mem_rhs_or_call
since those need no additional re-gimplification.

	PR middle-end/119119
	* gimplify.cc (is_gimple_mem_rhs_or_call): All empty CTORs
	are OK when not a register type.

	* g++.dg/torture/pr11911.C: New testcase.

We have been miscompiling the following valid code since GCC8, and
r8-3497-g281e6c1d8f1b4c

=== cut here ===
struct span {
  span (const int (&__first)[1]) : _M_ptr (__first) {}
  int operator[] (long __i) { return _M_ptr[__i]; }
  const int *_M_ptr;
};
void foo () {
  constexpr int a_vec[]{1};
  auto vec{[&a_vec]() -> span { return a_vec; }()};
}
=== cut here ===

The problem is that perform_implicit_conversion_flags (via
mark_rvalue_use) replaces "a_vec" in the return statement by a
CONSTRUCTOR representing a_vec's constant value, and then takes its
address when invoking span's constructor. So we end up with an instance
that points to garbage instead of a_vec's storage.

As per Jason's suggestion, this patch simply removes the calls to
mark_*_use from perform_implicit_conversion_flags, which fixes the PR.

	PR c++/117504

gcc/cp/ChangeLog:

	* call.cc (perform_implicit_conversion_flags): Don't call
	mark_{l,r}value_use.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/constexpr-117504.C: New test.
	* g++.dg/cpp2a/constexpr-117504a.C: New test.

The changes to vsetvl pass since 14 result in the asm check failure,
update the asm check to meet the newest behavior.

The below test suites are passed for this patch.
* The rv64gcv fully regression test.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/partial/multiple_rgroup_zbb.c: Tweak
	the asm check for vsetvl.

Signed-off-by: Pan Li <pan2.li@intel.com>

Inspired by Liao Shihua, this adjusts two tests in the RISC-V testsuite
to get more coverage.  Drop the -O1 argument and replace it with -fext-dce.
That way the test gets run across the full set of flags.  We just need to
make sure to skip -O0.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/core_list_init.c: Use -fext-dce rather than
	-O1.  Skip for -O0.
	* gcc.target/riscv/pr111384.c: Ditto.

When creating contained program-ids, I simply couldn't figure out how to stop the
middle end from the name of the contained program through the name mangler twice.

So, instead of using an uppercase 'X' as the substitute for a hyphen, I switched
to a '$', which is not part of the allowed COBOL character set for identifier
names.

This patch allow a packedset to be rotated by the system module intrinsic
procedure function.  It ensures that both operands to the tree rotate are
of the same type.  In turn the result will be the same type and the
assignment into the designator (of the same set type) will succeed.

gcc/m2/ChangeLog:

	PR modula2/118998
	* gm2-gcc/m2expr.cc (m2expr_BuildLRotate): Convert nBits
	to the return type.
	(m2expr_BuildRRotate): Ditto.
	(m2expr_BuildLogicalRotate): Convert op3 to an integer type.
	Replace op3 aith rotateCount.
	Negate rotateCount if it is negative and call rotate right.
	* gm2-gcc/m2pp.cc (m2pp_bit_and_expr): New function.
	(m2pp_binary_function): Ditto.
	(m2pp_simple_expression): BIT_AND_EXPR new case clause.
	LROTATE_EXPR ditto.
	RROTATE_EXPR ditto.

gcc/testsuite/ChangeLog:

	PR modula2/118998
	* gm2/iso/pass/testrotate.mod: New test.
	* gm2/pim/fail/tinyconst.mod: New test.
	* gm2/sets/run/pass/simplepacked.mod: New test.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>

Implement LWG 3912, approved in Varna, June 2023.

libstdc++-v3/ChangeLog:

	* include/std/ranges (enumerate_view::_Iterator::operator-):
	Add noexcept, as per LWG 3912.
	* testsuite/std/ranges/adaptors/enumerate/1.cc: Check iterator
	difference is noexcept.

I notice std::timespec and std::timespec_get are used in preprocessor
condition _GLIBCXX_HAVE_TIMESPEC_GET. So in module std, it should be
the same.

libstdc++-v3:

	* src/c++23/std-clib.cc.in (timespec): Move within preprocessor
	group guarded by _GLIBCXX_HAVE_TIMESPEC_GET.

The new test functions I added in r15-7765-g3866ca796d5281 are causing
those tests to FAIL on Solaris and arm-thumb due to the linker
complaining about undefined functions.  The new test functions are not
called, so it shouldn't matter that they call undefined member
functions, but it does.

Move those functions to separate { dg-do compile } files so the linker
isn't used and won't complain.

libstdc++-v3/ChangeLog:

	PR libstdc++/119110
	* testsuite/25_algorithms/move/constrained.cc: Move test06
	function to ...
	* testsuite/25_algorithms/move/105609.cc: New test.
	* testsuite/25_algorithms/move_backward/constrained.cc: Move
	test04 function to ...
	* testsuite/25_algorithms/move_backward/105609.cc: New test.

fortran added a new -Wexternal-argument-mismatch option, but the
lang.opt.urls file wasn't regenerated.

Fixes: 21ca9153 ("C prototypes for external arguments; add warning for mismatch.")

gcc/fortran/ChangeLog:

	* lang.opt.urls: Regenerated.

libstdc++-v3/ChangeLog:

	* include/bits/version.def (ranges_cache_latest): Define.
	* include/bits/version.h: Regenerate.
	* include/std/ranges (__detail::__non_propagating_cache::_M_reset):
	Export from base class _Optional_base.
	(cache_latest_view): Define for C++26.
	(cache_latest_view::_Iterator): Likewise.
	(cache_latest_view::_Sentinel): Likewise.
	(views::__detail::__can_cache_latest): Likewise.
	(views::_CacheLatest, views::cache_latest): Likewise.
	* testsuite/std/ranges/adaptors/cache_latest/1.cc: New test.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

This PR complains that we issue a -Wnonnull even in a decltype.
This fix disables even -Wformat and -Wrestrict.  I think that's fine.

	PR c++/115580

gcc/c-family/ChangeLog:

	* c-common.cc (check_function_arguments): Return early if
	c_inhibit_evaluation_warnings.

gcc/testsuite/ChangeLog:

	* g++.dg/warn/Wnonnull16.C: New test.

Reviewed-by: Jason Merrill <jason@redhat.com>

This is a C++ >= 26 codepath for supporting constexpr stable_sort, so we
know that we have if consteval available; it just needs protection with
the feature-testing macro. Also merge the return in the same statement.
Amends r15-7708-gff43f9853d3b10.

libstdc++-v3/ChangeLog:

	* include/bits/stl_algo.h (__stable_sort): Use if consteval
	instead of is_constant_evaluated.

Reviewed-by: Jonathan Wakely <jwakely@redhat.com>

Because coroutines insert a call to the resumer between the initialization
of the return value and the actual return to the caller, we need to
duplicate the work of gimplify_return_expr for the !aggregate_value_p case.

	PR c++/117364
	PR c++/118874

gcc/cp/ChangeLog:

	* coroutines.cc (cp_coroutine_transform::build_ramp_function): For
	!aggregate_value_p return force return value into a local temp.

gcc/testsuite/ChangeLog:

	* g++.dg/coroutines/torture/pr118874.C: New test.

Co-authored-by: Jakub Jelinek <jakub@redhat.com>