[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 John David Anglin changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #14 from John David Anglin --- Yes.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #13 from Jonathan Wakely --- Maybe this time!
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #12 from CVS Commits --- The master branch has been updated by Jonathan Wakely : https://gcc.gnu.org/g:61da01772a3dff61cf23ba2ffba33bccb68d1063 commit r13-5052-g61da01772a3dff61cf23ba2ffba33bccb68d1063 Author: Jonathan Wakely Date: Fri Jan 6 18:39:14 2023 + libstdc++: Refactor time_zone::_Impl::rules_counter [PR108235] Abstract the atomic counter used to synchronize access to time_zone infos behind a Lockable class API, and use atomic_signed_lock_free instead of atomic, as that should be the most efficient type. (For futex-supporting targets it makes no difference, but might benefit other targets in future.) The new API allows the calling code to be simpler, without needing to repeat the same error prone preprocessor conditions in multiple places. It also allows using template metaprogramming to decide whether to use the atomic or a mutex, which gives us more flexibility than only using preprocessor conditions. That allows us to choose the mutex implementation for targets such as hppa-hp-hpux11.11 where 32-bit atomics are not lock-free and so would introduce an unwanted dependency on libatomic. libstdc++-v3/ChangeLog: PR libstdc++/108235 * src/c++20/tzdb.cc (time_zone::_Impl::RulesCounter): New class template and partial specialization for synchronizing access to time_zone::_Impl::infos. (time_zone::_M_get_sys_info, reload_tzdb): Adjust uses of rules_counter.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235
--- Comment #11 from Jonathan Wakely ---
(In reply to John David Anglin from comment #10)
> No. We still have the following symbols in tzdb.o:
> U __atomic_compare_exchange_4
> U __atomic_fetch_add_4
Oh the time_zone::_Impl::rules_counter atomic counter is still used even if not
lock-free. I can fix that.
> U __atomic_fetch_add_8
> U __atomic_fetch_sub_8
Ah, these are caused by __detail::__platform_wait_t being uint64_t, which will
be changed soon by
https://gcc.gnu.org/pipermail/gcc-patches/2023-January/609479.html
That would mean we only need 4-byte atomics, but if I stop using
time_zone::_Impl::rules_counter for this target, we won't need that either.
>
> There was this warning compiling tzdb.o:
> ../../../../../gcc/libstdc++-v3/src/c++20/tzdb.cc: In function 'std::string
> std::chrono::{anonymous}::zoneinfo_dir()':
> ../../../../../gcc/libstdc++-v3/src/c++20/tzdb.cc:983:44: warning: the
> address of 'const char* __gnu_cxx::zoneinfo_dir_override()' will never be
> NULL [-Waddress]
> 983 | static const string dir = __gnu_cxx::zoneinfo_dir_override
> | ~~~^
> ../../../../../gcc/libstdc++-v3/src/c++20/tzdb.cc:77:29: note: 'const char*
> __gnu_cxx::zoneinfo_dir_override()' declared here
>77 | [[gnu::weak]] const char* zoneinfo_dir_override()
> | ^
Harmless, it's just because we added the definition of that weak symbol, so now
it's never null.
I'll add a #pragma to ignore -Waddress there.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235
--- Comment #10 from John David Anglin ---
No. We still have the following symbols in tzdb.o:
U __atomic_compare_exchange_4
U __atomic_fetch_add_4
U __atomic_fetch_add_8
U __atomic_fetch_sub_8
There was this warning compiling tzdb.o:
../../../../../gcc/libstdc++-v3/src/c++20/tzdb.cc: In function 'std::string
std::chrono::{anonymous}::zoneinfo_dir()':
../../../../../gcc/libstdc++-v3/src/c++20/tzdb.cc:983:44: warning: the address
of 'const char* __gnu_cxx::zoneinfo_dir_override()' will never be NULL
[-Waddress]
983 | static const string dir = __gnu_cxx::zoneinfo_dir_override
| ~~~^
../../../../../gcc/libstdc++-v3/src/c++20/tzdb.cc:77:29: note: 'const char*
__gnu_cxx::zoneinfo_dir_override()' declared here
77 | [[gnu::weak]] const char* zoneinfo_dir_override()
| ^
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #9 from John David Anglin --- Created attachment 54206 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54206=edit Updated preprocessed source
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #8 from dave.anglin at bell dot net --- On 2023-01-04 7:54 p.m., redi at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 > > --- Comment #7 from Jonathan Wakely --- > Does that fix it? I just started a new build and check.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #7 from Jonathan Wakely --- Does that fix it?
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #6 from CVS Commits --- The master branch has been updated by Jonathan Wakely : https://gcc.gnu.org/g:b1ad748754401613b5cf8e5d46b38ad1ee49d07a commit r13-5003-gb1ad748754401613b5cf8e5d46b38ad1ee49d07a Author: Jonathan Wakely Date: Wed Jan 4 16:45:14 2023 + libstdc++: Only use std::atomic if lock free [PR108228] This fixes linker errors for hppa-hp-hpux11.11 due to an undefined weak symbol and the use of atomic operations that require libatomic. The weak symbol can simply be defined, which we already do for darwin. The std::atomic<_Node*> is only an optimization, so can be avoided for targets where the underlying atomic ops aren't available without help from libatomic. The accesses to the std::atomic<_Node*> can be abstracted behind a new API for getting and setting the cached value, and then the atomics can be used conditionally. libstdc++-v3/ChangeLog: PR libstdc++/108228 PR libstdc++/108235 * config/abi/pre/gnu.ver: Move zoneinfo_dir_override export to the latest symbol version. * src/c++20/tzdb.cc (USE_ATOMIC_SHARED_PTR): Define to 0 if atomic<_Node*> is not always lock free. (USE_ATOMIC_LIST_HEAD): New macro. [__hpux__] (__gnu_cxx::zoneinfo_dir_override()): Provide definition of weak symbol. (tzdb_list::_Node::_S_head): Rename to _S_head_cache. (tzdb_list::_Node::_S_list_head): New function for accessing list head efficiently. (tzdb_list::_Node::_S_cache_list_head): New function for updating _S_list_head.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #5 from Jonathan Wakely --- tzdb.cc doesn't need atomics, it can just work with a mutex. I'm still on holiday until tomorrow though.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #4 from John David Anglin --- Working on a patch to add support for sync libfuncs. Downside is one needs to add -fno-sync-libcalls to generate calls for libatomic. I think the HP implementations of pthread_mutex_lock and pthread_mutex_unlock in libpthread are better than what I will do for the sync routines. That's why I haven't implemented the sync routines before. Is there an alternative?
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 Jonathan Wakely changed: What|Removed |Added Ever confirmed|0 |1 Last reconfirmed||2022-12-30 Status|UNCONFIRMED |ASSIGNED
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 Jonathan Wakely changed: What|Removed |Added Target Milestone|--- |13.0 Assignee|unassigned at gcc dot gnu.org |redi at gcc dot gnu.org
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #3 from John David Anglin --- Created attachment 54168 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54168=edit Preprocessed source for tzdb.cc See atomic routines needed by tzdb.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235 --- Comment #2 from John David Anglin --- Looks like ./libstdc++-v3/config/cpu/hppa/atomicity.h needs updating to provide undefined routines.
[Bug libstdc++/108235] FAIL: g++.dg/compat/abi/bitfield1 cp_compat_x_tst.o-cp_compat_y_tst.o link
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108235
John David Anglin changed:
What|Removed |Added
CC||jwakely.gcc at gmail dot com
--- Comment #1 from John David Anglin ---
bash-5.1$ find . -name '*.o'|xargs /opt/gnu64/bin/nm -AC|grep atomic
./src/c++98/pool_allocator.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++98/mt_allocator.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++98/ios_failure.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++98/ios_init.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++98/locale_init.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++98/locale.o: U __gnu_cxx::__atomic_add(int volatile*,
int)
./src/c++98/localename.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++98/stdexcept.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++98/messages_members_cow.o: U
__gnu_cxx::__atomic_add(int volatile*, int)
./src/c++11/cow-stdexcept.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++11/ios-inst.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++11/cow-locale_init.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++11/cow-shim_facets.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++11/cxx11-shim_facets.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++11/cow-string-inst.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++11/cow-wstring-inst.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++17/fs_dir.o: U __gnu_cxx::__atomic_add(int volatile*,
int)
./src/c++17/fs_ops.o: U __gnu_cxx::__atomic_add(int volatile*,
int)
./src/c++17/cow-fs_dir.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++17/cow-fs_ops.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++17/cow-fs_path.o: U __gnu_cxx::__atomic_add(int
volatile*, int)
./src/c++20/tzdb.o: U __gnu_cxx::__atomic_add(int volatile*,
int)
./src/c++20/tzdb.o: t void
std::__atomic_notify_address(int const*, bool) [clone .isra.0]
./src/c++20/tzdb.o: W void std::__atomic_wait_address_v::wait(int, std::memory_order) const::{lambda()#1}>(int
const*, int, std::__atomic_base::wait(int, std::memory_order)
const::{lambda()#1})
./src/c++20/tzdb.o: U __atomic_compare_exchange_4
./src/c++20/tzdb.o: U __atomic_compare_exchange_8
./src/c++20/tzdb.o: U __atomic_exchange_8
./src/c++20/tzdb.o: U __atomic_fetch_add_4
./src/c++20/tzdb.o: U __atomic_fetch_add_8
./src/c++20/tzdb.o: U __atomic_fetch_sub_8
[...]
I believe the direct use of the above atomic symbols was introduced in the
following change:
commit 9fc61d45fa15fdd3b084d30998ecda164af33e95
Author: Jonathan Wakely
Date: Thu Dec 22 00:37:54 2022 +
libstdc++: Implement C++20 time zone support in
I have the following patch to work around PR 108228:
diff --git a/libstdc++-v3/src/c++20/tzdb.cc b/libstdc++-v3/src/c++20/tzdb.cc
index 2a4e213d3d9..92752242096 100644
--- a/libstdc++-v3/src/c++20/tzdb.cc
+++ b/libstdc++-v3/src/c++20/tzdb.cc
@@ -64,8 +64,8 @@ namespace __gnu_cxx
#else
[[gnu::weak]] const char* zoneinfo_dir_override();
-#ifdef __APPLE__
- // Need a weak definition for Mach-O.
+#if defined(__APPLE__) || defined(__hpux__)
+ // Need a weak definition for Mach-O and HP-UX.
[[gnu::weak]] const char* zoneinfo_dir_override()
{ return _GLIBCXX_ZONEINFO_DIR; }
#endif
